Gradient three-dimensional current collector with lithiophilic nanolayer regulation for efficient lithium metal anode construction

Metallic lithium (Li) is highly desirable for Li battery anodes due to its unique advantages. However, the growth of Li dendrites poses challenges for commercialization. To address this issue, researchers have proposed various three-dimensional (3D) current collectors. In this study, the selective modification of a 3D Cu foam scaffold with lithiophilic elements was explored to induce controlled Li deposition. The Cu foam was selectively modified with Ag and Sn to create uniform Cu foam (U-Cu) and gradient lithiophilic Cu foam (G-Cu) structures. Density Functional Theory (DFT) calculations revealed that Ag exhibited a stronger binding energy with Li compared to Sn, indicating superior Li induction capabilities. Electrochemical testing demonstrated that the half cell with the G-Cu@Ag electrode exhibited excellent cycling stability, maintaining 550 cycles with an average Coulombic efficiency (CE) of 97.35%. This performance surpassed that of both Cu foam and G-Cu@Sn. The gradient modification of the current collectors improved the utilization of the 3D scaffold and prevented Li accumulation at the top of the scaffold. Overall, the selective modification of the 3D Cu foam scaffold with lithiophilic elements, particularly Ag, offers promising prospects for mitigating Li dendrite growth and enhancing the performance of Li batteries.

[Association of sleep duration and physical exercise with dyslipidemia in older adults aged 80 years and over in China]

Objective: To explore the impact of sleep duration, physical exercise, and their interactions on the risk of dyslipidemia in older adults aged ≥80 (the oldest old) in China. Methods: The study subjects were the oldest old from four rounds of Healthy Aging and Biomarkers Cohort Study (2008-2009, 2011-2012, 2014 and 2017-2018). The information about their demographic characteristics, lifestyles, physical examination results and others were collected, and fasting venous blood samples were collected from them for blood lipid testing. Competing risk model was used to analyze the causal associations of sleep duration and physical exercise with the risk for dyslipidemia. Restricted cubic spline (RCS) function was used to explore the dose-response relationship between sleep duration and the risk for dyslipidemia. Additive and multiplicative interaction model were used to explore the interaction of sleep duration and physical exercise on the risk for dyslipidemia. Results: The average age of 1 809 subjects was (93.1±7.7) years, 65.1% of them were women. The average sleep duration of the subjects was (8.0±2.5) hours/day, 28.1% of them had sleep duration for less than 7 hours/day, and 27.2% had sleep for duration more than 9 hours/day at baseline survey. During the 9-year cumulative follow-up of 6 150.6 person years (follow-up of average 3.4 years for one person), there were 304 new cases of dyslipidemia, with an incidence density of 4 942.6/100 000 person years. The results of competitive risk model analysis showed that compared with those who slept for 7-9 hours/day, the risk for dyslipidemia in oldest old with sleep duration >9 hours/day increased by 22% (HR=1.22, 95%CI: 1.07-1.39). Compared with the oldest old having no physical exercise, the risk for dyslipidemia in the oldest old having physical exercise decreased by 33% (HR=0.67, 95%CI: 0.57-0.78). The RCS function showed a linear positive dose-response relationship between sleep duration and the risk for hyperlipidemia. The interaction analysis showed that physical exercise and sleep duration had an antagonistic effect on the risk for hyperlipidemia. Conclusion: Physical exercise could reduce the adverse effects of prolonged sleep on blood lipids in the oldest old.

Highly lithiophilic and structurally stable Cu-Zn alloy skeleton for high-performance Li-rich ternary anodes

Lithium (Li)-rich ternary alloy, comprising a multi-alloy phase as the built-in three-dimensional (3D) framework and a Li metal phase as a reversible Li reservoir, is a promising high-energy-density anode for rechargeable Li metal batteries. The introduction of metal/metalloid components to the alloy can effectively regulate Li deposition and maintain the dimensional integrity of the Li anode. Herein, the lithium-copper-zinc (Li-Cu-Zn) ternary alloy, as a new type of alloy anode, is synthesized via a facile thermal melting method. The fully delithiated 3D scaffold comprised two Cu-Zn alloy phases named CuZn and CuZn5. These alloy phases exhibit higher lithiophilicity and structural stability than Li-Zn and Li-Cu alloys. Moreover, the CuZn phase is electrochemically inert, ensuring the geometric stability of the anode, while the CuZn5 phase can readily undergo alloying reaction with Li to form the LiZn phase, thereby facilitating uniform Li nucleation and deposition. The hybridized multiphase alloy structure and specific energy storage mechanism of the Cu-Zn based alloy scaffold in the ternary alloy anode facilitate dendrite-free Li deposition and prolonged cycle lifetime. The Li metal full battery based on lithium iron phosphate (LiFePO4) cathode exhibits high cycling stability with high-capacity retention of 95.4% after 1000 cycles at 1C.

[Accurate localization and successful treatment of 23 cases of migrating pharynx and cervical esophageal foreign bodies]

Objective: To explore clinical features, diagnosis, localization, and therapeutic strategy of migratory pharyngeal and cervical esophageal foreign bodies. Methods: A total 23 cases of pharyngeal and cervical esophageal migratory foreign bodies were admitted between January 2015 and December 2021. There were 14 females and 9 males with the age ranged from 35 to 82 (55.0±12.7)years. In all the cases, esophageal CT was taken to confirm the esophageal foreign body. Multiplanar reconstruction (MPR) was performed to locate the foreign body from the horizontal, coronal and sagittal dimensions as well as the corrected reconstructed MPR. According to the location of the foreign body, appropriate surgical method was selected.The symptoms, complications, types of foreign body, positioning, surgical methods, and relevant information were recorded.Data were analyzed using the descriptive method and SPSS 25.0 software. Results: The clinical symptoms of 23 migrating esophageal foreign bodies included pharyngodynia (20/23), foreign body sensation (6/23), hoarsenss (1/23), difficulty in turning neck(1/23), difficulty in opening mouth (1/23), fever (7/23), poor appetite (1/23), and abdominal pain (1/23). The foreign bodies included 19 fish bones, 2 wires, 1 embroidery needle and 1 chicken bone. There were 9 cases (39.1%) of foreign bodies located in extraluminal cervical esophagus, 2 cases (8.7%) of foreign bodies located in the muscular layer of the cervical esophagus and 12 cases (52.2%) of foreign bodies located in pharynx. Twenty-one cases of foreign bodies were removed by cervical lateral incision, in which 11 were removed by cervical lateral incision directly, 10 by the second lateral cervical incision after the foreign bodies were accurately located by MPR and/or corrected MPR, 1 foreign body was removed by incision of the pharyngeal mucosa under suspension laryngoscope, 1 foreign body was removed by tracheoscopy. Compared with patients with intraluminal foreign bodies (n=308) treated in the same period, intake of fishbone [19 (19/23) vs. 133 (82.6% (43.2%, 133/308), OR=7.31] and first visit was more than 24 hours [20(87.0%, 20/23) vs. 77(25.0%, 77/308),OR=17.2] were the significant risk factors of migratory esophageal foreign bodies. Conclusions: MPR and the corrected MPR can accurately locate the migrating pharyngeal and cervical esophageal foreign bodies, by providing more intuitive imaging evidence for doctors, which provide imaging basis for formulation of surgical programs. Foreign bodies in pharyngeal and cervical esophagus need to be treated as soon as possible, otherwise they are easy to migrate, leading lead to serious complications.

Identification of CXCL16 as a diagnostic biomarker for obesity and intervertebral disc degeneration based on machine learning

Intervertebral disc degeneration (IDD) is the primary cause of neck and back pain. Obesity has been established as a significant risk factor for IDD. The objective of this study was to explore the molecular mechanisms affecting obesity and IDD by identifying the overlapping crosstalk genes associated with both conditions. The identification of specific diagnostic biomarkers for obesity and IDD would have crucial clinical implications. We obtained gene expression profiles of GSE70362 and GSE152991 from the Gene Expression Omnibus, followed by their analysis using two machine learning algorithms, least absolute shrinkage and selection operator and support vector machine-recursive feature elimination, which enabled the identification of C-X-C motif chemokine ligand 16 (CXCL16) as a shared diagnostic biomarker for obesity and IDD. Additionally, gene set variant analysis was used to explore the potential mechanism of CXCL16 in these diseases, and CXCL16 was found to affect IDD through its effect on fatty acid metabolism. Furthermore, correlation analysis between CXCL16 and immune cells demonstrated that CXCL16 negatively regulated T helper 17 cells to promote IDD. Finally, independent external datasets (GSE124272 and GSE59034) were used to verify the diagnostic efficacy of CXCL16. In conclusion, a common diagnostic biomarker for obesity and IDD, CXCL16, was identified using a machine learning algorithm. This study provides a new perspective for exploring the possible mechanisms by which obesity impacts the development of IDD.

Proposals for the Delineation of Neck Clinical Target Volume Specific to Oral Squamous Cell Cancer Based on Lymph Node Distribution

PURPOSE/OBJECTIVE(S)

To establish the regional lymph node (LN) distribution probability map and draw the neck clinical target volume specific to oral squamous cell cancer (OSCC).

MATERIALS/METHODS

A total of 293 patients with pathologically proven OSCC were enrolled from Jan 2014 to Jun 2022. The patients were divided into two groups according to the ≤1 cm or>1 cm of minimal distance from the lesion's edge to the midline of body. The center point of the LNs with a minimal axial diameter of ≥10 mm was marked on a single treatment planning computed tomography scan. The neck LN levels I to X were based on 2013 updated international consensus guidelines. LN distribution probability maps were established. The relationships between the LN distribution and consensus guidelines were analyzed to propose modifications for clinical target volume boundaries specific to OSCC.

RESULTS

A total of 1033 LNs were marked. Compared with the >1 cm group, The ≤1 cm group has following feature tendencies: strong addiction to smoking and drinking, predilection for tongue and oral floor cancer, larger primary lesion with mainly infiltrative growth pattern, more frequent extra-nodal extension with mainly contralateral LNs. For the ≤1cm group, the distribution probability of LNs was: ipsilateral II (42.67%), ipsilateral Ib (17.35%), contralateral II (11.18%), ipsilateral III (8.74%), contralateral Ib (7.46%), Ia (6.43%). The other group was: ipsilateral Ib (43.14%), ipsilateral II (37.64%), contralateral Ib (4.31%), ipsilateral III (3.92%), contralateral II (3.53%), Ia (0.78%). Accordingly, the proposals for the delineation of neck clinical target volume were: 1. the inferior boundary of level Ia extends until the level of the thyroid cartilage plate; 2. the upper boundary of level Ib descends to the level of the mandibular angle, and the inner posterior boundary only includes the lateral and posterior margin of the submandibular gland within 5mm; 3. the upper boundary of level II changes to the transverse process of the second cervical vertebra, and the posterior boundary retracts to the posterior edge of the levator scapula. 4. the anterior inner border of level IVa contains only the internal jugular arteriovenous sheath.

CONCLUSION

This is the first description of LN topographic spread patterns for OSCC. Optimization of CTV delineation is helpful to improve the treatment outcome and reduce adverse events.

Do Physician Patient Sharing Networks Impact Disparities in Access to Multidisciplinary Cancer Consultation for Early-Stage Lung Cancer? A SEER-Medicare Network Analysis

PURPOSE/OBJECTIVE(S)

To examine early-stage non-small cell lung cancer (NSCLC) patient and physician network characteristics associated with receipt of multidisciplinary cancer consultations (MDCCs), defined as an encounter with both a surgeon and a radiation oncologist after diagnosis. We tested the hypothesis that physician roles in patient-sharing networks can modify disparities in access to surgical and radiotherapy care. Specifically, we investigated the role of "linchpin physicians" using a novel network measure that assesses the extent to which a physician is the sole type of specialist in their physician patient sharing network, and the association of these physicians on patterns of care.

MATERIALS/METHODS

The study cohort included patients diagnosed with stage I/IIA NSCLC in 2016-17 using Surveillance, Epidemiology and End Results (SEER)-Medicare data. We assembled a physician patient-sharing network using all NSCLC patient encounters between 3 months prior to and 12 months following diagnosis. We weighted physicians' patient-sharing ties by the number of shared patients and calculated physician's linchpin scores as a continuous variable measuring the extent to which a physicians' peers in the network lack ties to others of the same specialty as the focal physician. Physicians in the top 15%ile were considered a linchpin specialist. We then derived the proportion of linchpin surgeons or radiation oncologists per hospital referral region (HRR). We assessed patient characteristics including age, sex, race, ethnicity, cancer stage, comorbidity index, rurality, and socioeconomic status (SES). The study outcome was a surgical, radiation oncology, or MDCC in the 2 months following diagnosis. We then performed multivariable logistic regressions (MLR) to assess whether linchpins modified disparities in MDCC.

RESULTS

Of 6,148 patients in the study, 12% received a MDCC, 28% only saw a radiation oncologist, 33% only saw a surgeon, and 27% saw neither for 2 months after diagnosis. On MLR, Hispanic patients were significantly less likely than White patients to receive consultations with a radiation oncologist, while patients in lowest SES quintile were significantly less likely to receive a surgical consultation than those in the highest SES. The proportion of linchpin surgeons and radiation oncologists per HRR was negatively associated with receipt of MDCC (OR low vs high [95% CI] = 0.75 [0.66 to 0.86]; 0.70 [0.61 to 0.80, respectively), but our regressions did not show that any demographic or SES disparities were modified by linchpin specialists.

CONCLUSION

Linchpin specialists do not impact known disparities in access to cancer consultations. Identifying additional system-level factors that contribute to disparities in cancer consultations may lead to policy insights aimed at reducing unwarranted variation in care.

Eosinophil Dynamics during Chemo-Radiation Correlate to Clinical Outcome in Stage II-IVA Nasopharyngeal Carcinoma Patients: Results from a Large Cohort Study

PURPOSE/OBJECTIVE(S)

We investigated the dynamics of eosinophil depletion and recovery during definitive concurrent chemo-radiotherapy (CCRT) and how they affect the prognosis of stage II-IVA nasopharyngeal carcinoma (NPC) patients.

MATERIALS/METHODS

A total of 1225 patients with pathologically proven NPC from 2013 to 2019 were enrolled. Fuzzy C-Means Clustering (FCM) was used to assess trends in eosinophil during CCRT longitudinally and to grade eosinophil decline during treatment in combination with absolute eosinophil counts (AECs) at the end of CCRT. Grade G0 refers to patients with no decreasing trend in eosinophils and AECs >0.05×109 cells/L, grade G1 refers to patients with a decreasing trend in eosinophils or AECs between 0-0.05×109 cells/L, grade G2 refers to patients with a decreasing trend in eosinophils and AECs between 0-0.05×109 cells/L. Progression-free survival (PFS) is the primary outcome measure, with overall survival (OS), distant metastasis-free survival (DMFS), and local recurrence-free survival (LRFS) as secondary outcome measures. A Cox proportional risk model was used to determine the hazard ratio for adverse prognostic effects in declining grades of eosinophil.

RESULTS

During a median follow-up of 4.1 years, 376 (30.69%) patients experienced disease progression events. The grade of eosinophil reduction after CCRT was significantly associated with PFS, OS, and DMFS but not with LRFS. After adjusting for demographics, clinical baseline indicators, tumor characteristics, and treatment characteristics, a 1.57-fold (p = 0.001), 1.69-fold (p = 0.007), and 1.51-fold (p = 0.019) increase in the risk of developing PFS, OS, and DMFS was observed for G1 compared with G0, whereas a 2.4-fold (p < 0.001), 2.76-fold (p < 0.001), and 2.31-fold (p < 0.001) increase in the risk of developing PFS, OS, and DMFS was observed for G2. Moreover, among patients with G0, treatment with CCRT with a cumulative dose of platinum-based chemotherapy < 200 mg/m2 resulted in PFS, OS, and DMFS that were not inferior to CCRT with cumulative doses ≥ 200 mg/m2.

CONCLUSION

Eosinophil is an easily detectable and inexpensive biomarker that may be useful in the clinical setting to aid in assessing the prognosis for standard treatment of NPC.

The Influence of Alumina Bubbles on the Properties of Lightweight Corundum-Spinel Refractory

The use of a lightweight corundum-spinel refractory in working lining could reduce the thermal conductivity of industrial furnaces. In this study, bubble alumina was introduced to realize a lightweight Al2O3-MgAl2O4 refractory assisted by the reactive sintering of Al2O3 and MgO. The effects of alumina bubble content and sintering temperature on the phase compositions, microstructure and properties of the lightweight refractory were investigated. The results indicated that the overall performance of the lightweight Al2O3-MgAl2O4 refractory was mainly dominated by the content of alumina bubbles. The bulk density, compressive strength and thermal conductivity all decreased when the alumina bubble content increased from 10 to 30 wt%. Meanwhile, the sintering temperature also significantly affected the properties of the obtained refractory. It is worth noting that specimens fired at 1650 °C achieved a high refractoriness under load (RUL) of more than 1700 °C when alumina bubble content was less than 30 wt%, which was comparable to that of the dense Al2O3-MgAl2O4 refractory. The thermal conductivity of the obtained samples was remarkably decreased to no more than 2.13 W/(m·K). In order to overcome the trade-off between the light weight of the refractory and overall performance, it is feasible to adjust the content of alumina bubbles and raise the sintering temperature appropriately.

Assessment of MRF for simultaneous T1 and T2 quantification and water-fat separation in the liver at 0.55 T

OBJECTIVE

The goal of this work was to assess the feasibility of performing MRF in the liver on a 0.55 T scanner and to examine the feasibility of water-fat separation using rosette MRF at 0.55 T.

MATERIALS AND METHODS

Spiral and rosette MRF sequences were implemented on a commercial 0.55 T scanner. The accuracy of both sequences in T1 and T2 quantification was validated in the ISMRM/NIST system phantom. The efficacy of rosette MRF in water-fat separation was evaluated in simulations and water/oil phantoms. Both spiral and rosette MRF were performed in the liver of healthy subjects.

RESULTS

In the ISMRM/NIST phantom, both spiral and rosette MRF achieved good agreement with reference values in T1 and T2 measurements. In addition, rosette MRF enables water-fat separation and can generate water- and fat- specific T1 maps, T2 maps, and proton density images from the same dataset for a spatial resolution of 1.56 × 1.56 × 5mm3 within the acquisition time of 15 s.

CONCLUSION

It is feasible to measure T1 and T2 simultaneously in the liver using MRF on a 0.55 T system with lower performance gradients compared to state-of-the-art 1.5 T and 3 T systems within an acquisition time of 15 s. In addition, rosette MRF enables water-fat separation along with T1 and T2 quantification with no time penalty.

Case report: Traumatic lumbosacral spondyloptosis with locked L5 inferior articular process

Background

Traumatic lumbosacral spondyloptosis is a very rare spinal disease caused by high-energy trauma. We report a case of traumatic lumbosacral spondyloptosis with locked L5 inferior articular process.

Case presentation

A 33-year-old man presented with multisite pain for 6 h following waist trauma and was admitted to the hospital. He suffered multiple injuries from severe impact on the waist after driving an out of control forklift truck. Preoperative imaging examinations revealed that the patient was diagnosed with traumatic lumbosacral spondyloptosis and the L5 inferior articular process was locked into the anterior margin of the S1 vertebra. A posterior instrumentation, decompression of the cauda equina, and interbody fusion procedure was performed. The patient received hyperbaric oxygen and rehabilitation treatment 10 days after the surgery. At the 6-month postoperative follow-up, the muscle strength of the lower limbs was improved, the patient had no numbness of both lower limbs, and the urinary retention symptom was significantly improved. The American Spinal Injury Association grade improved from grade C preoperatively to grade D postoperatively. As far as we know, there have been no relevant reports on traumatic lumbosacral spondyloptosis with locked L5 inferior articular process yet.

Conclusion

We believe that the hyperflexion and shear forces were the potential causes of this injury. In addition, the preoperative imaging examinations should be evaluated carefully. If the inferior articular process of L5 were locked, we suggest removing the bilateral inferior articular processes first and then perform reduction.

[Analysis of recurrent factors and therapeutic effect after laparoscopic inguinal hernia repair]

Objective: To analyze the recurrence factors and reoperation effect of laparoscopic inguinal hernia repair. Methods: A total of 41 patients with recurrence after laparoscopic repair of the inguinal hernia admitted to the Department of Hernia and Abdominal Wall Surgery, Beijing Chaoyang Hospital Affiliated to Capital Medical University from January 2017 to December 2021 were retrospectively analyzed. All patients were males, aging (62±7) years (range: 51 to 75 years). The recurrence intervals were 3 days to 7 years postoperatively. The surgical methods, causes of recurrence, and treatment outcomes of the patients were analyzed. Fisher exact probability method is used to compare the rates. Results: Among all cases, the primary surgical procedures included transabdominal preperitoneal herniorrhaphy (TAPP) in 31 cases and total extraperitoneal herniorrhaphy in 10 cases. The reoperative procedures included the TAPP of 11 cases and the Lichtenstein procedure of 30 cases. The factors of recurrent cases in all patients could be divided into 4 categories, including insufficient mesh coverage in 23 cases, mesh curling in 9 cases, mesh contractuture in 7 cases, and improper mesh fixation in 2 cases. Recurrence, infection, chronic pain, foreign body sensation didn't occur in the followed period of(M(IQR)) 18(24) months(range: 12 to 50 months). There was no statistical difference in the incidence of postoperative seroma between the TAPP and Lichtenstein procedure (3/11 vs. 20.0% (6/30), P=0.68). Conclusions: Postoperative recurrence of laparoscopic inguinal hernia is mostly caused by the lack of mesh coverage. Due to the emphasis on standardized surgical operation, a good outcome could be achieved through reoperation by the TAPP or Lichtenstein procedure.

[Morphological study on the transverse branch of lateral femoral circumflex artery based on digital subtraction angiography]

Objective: To summarize the morphological characteristics of the transverse branch of lateral femoral circumflex artery (LFCA) using digital subtraction angiography (DSA) and explore its clinical significance. Methods: A retrospective observational study was conducted. From October 2020 to May 2021, 62 patients with soft tissue injuries in the extremities were hospitalized in Suzhou Ruihua Orthopedic Hospital, including 40 males and 22 females, aged from 20 to 72 years. DSA was performed in the lateral femoral region of patients before the anterolateral thigh flap transplantation, and in combination with imaging scale to observe and measure the general condition of the blood vessels and the occurrence (with the occurrence rate being calculated), source artery, location of the origin point, direction of course, and the location of the perforating point of the cutaneous perforator of the transverse branch of LFCA, and in addition to classify the morphological characteristics of the transverse branch. Results: DSA detection showed that the femoral artery, the deep femoral artery, and the branches of LFCA were clearly distinguishable in 62 patients. Transverse branches of LFCA were observed in 59 patients, including 52 cases with a single transverse branch, and 7 cases with double transverse branches. The occurrence rate of transverse branches was 95.2% (59/62). A total of 66 transverse branches of LFCA were observed, of which 3 originated from the deep femoral artery, and 63 originated from the LFCA. The origin point of the transverse branch was 6.5-12.7 cm away from the anterior superior iliac spine. The transverse branch which was approximately perpendicular to the long axis of the body, originated outwards, ran between the ascending branch of LFCA and the oblique branch of LFCA, and branched along the way, with the trunk running under the greater trochanter. The perforating point of the cutaneous perforator of the transverse branch was 8.0-18.0 cm away from the anterior superior iliac spine. In the classification of morphological characteristics of the transverse branch of LFCA, the most common type was the one that originated from the same trunk with other branches of LFCA, accounting for 50.0% (31/62), followed by the one that originated from the singular trunk of LFCA (12 cases) or deep femoral artery (3 cases), accounting for 24.2% (15/62); the special type accounted for 21.0% (13/62), including 7 cases of double transverse branches and 6 cases of the transverse branch originated from the same trunk with multiple other branches of LFCA; those with small/absent transverse branch only accounted for 4.8% (3/62). Among the above-mentioned common trunk relationship of two branches, those with shared trunk of ascending and transverse branches were most frequently observed, accounting for 77.4% (24/31); those with shared trunks of the transverse and oblique branches (5 cases) and the transverse and descending branches (2 cases) accounted for 22.6% (7/31) altogether. Conclusions: A high incidence rate of the transverse branch of LFCA is observed through DSA. The transverse branch originates from the lateral femoral artery approximately perpendicular to the long axis of the body, mainly from the same trunk with another main branch of LFCA, especially the ascending branch. This positioning analysis can provide an important reference for the design and resection of anterolateral femoral flaps.

Ultrathin Li-rich Li-Cu alloy anode capped with lithiophilic LiC6 headspace enabling stable cyclic performance

Li-rich dual-phase Li-Cu alloy is a promising candidate toward practical application of Li metal anode due to its in situ formed unique three-dimensional (3D) skeleton of electrochemical inert LiCu_x solid-solution phase. Since a thin layer of metallic Li phase appears on the surface of as-prepared Li-Cu alloy, the LiCu_x framework cannot regulate Li deposition efficiently in the first Li plating process. Herein, a lithiophilic LiC₆ headspace is capped on the upper surface of the Li-Cu alloy, which can not only offer free space to accommodate Li deposition and maintain dimensional stability of the anode, but also provide abundant lithiophilic sites and guide Li deposition effectively. This unique bilayer architecture is fabricated via a facile thermal infiltration method, where the Li-Cu alloy layer with an ultrathin thickness around 40 μm occupies the bottom of a carbon paper (CP) sheet, and the upper part of this 3D porous framework is reserved as the headspace for Li storage. Notably, the molten Li can quickly convert these carbon fibers of the CP into lithiophilic LiC₆ fibers while the CP is touched with the liquid Li. The synergetic effect between the LiC₆ fibers framework and LiCu_x nanowires scaffold can ensure a uniform local electric field and stable Li metal deposition during cycling. As a consequence, the CP capped ultrathin Li-Cu alloy anode demonstrates excellent cycling stability and rate capability.

Self-calibrated through-time spiral GRAPPA for real-time, free-breathing evaluation of left ventricular function

PURPOSE

Through-time spiral GRAPPA is a real-time imaging technique that enables ungated, free-breathing evaluation of the left ventricle. However, it requires a separate fully-sampled calibration scan to calculate GRAPPA weights. A self-calibrated through-time spiral GRAPPA method is proposed that uses a specially designed spiral trajectory with interleaved arm ordering such that consecutive undersampled frames can be merged to form calibration data, eliminating the separate fully-sampled acquisition.

THEORY AND METHODS

The proposed method considers the time needed to acquire data at all points in a GRAPPA calibration kernel when using interleaved arm ordering. Using this metric, simulations were performed to design a spiral trajectory for self-calibrated GRAPPA. Data were acquired in healthy volunteers using the proposed method and a comparison electrocardiogram-gated and breath-held cine scan. Left ventricular functional values and image quality are compared.

RESULTS

A 12-arm spiral trajectory was designed with a temporal resolution of 32.72 ms/cardiac phase with an acceleration factor of 3. Functional values calculated using the proposed method and the gold-standard method were not statistically significantly different (paired t-test, p < 0.05). Image quality ratings were lower for the proposed method, with statistically significantly different ratings (Wilcoxon signed rank test, p < 0.05) for two of five image quality aspects rated (level of artifact, blood-myocardium contrast).

CONCLUSIONS

A self-calibrated through-time spiral GRAPPA reconstruction can enable ungated, free-breathing evaluation of the left ventricle in 71 s. Functional values are equivalent to a gold-standard cine technique, although some aspects of image quality may be inferior due to the real-time nature of the data collection.

Dynamic Cardiac Magnetic Resonance Fingerprinting During Vasoactive Breathing Maneuvers: First Results

BACKGROUND

Cardiac magnetic resonance fingerprinting (cMRF) enables simultaneous mapping of myocardial T1 and T2 with very short acquisition times. Breathing maneuvers have been utilized as a vasoactive stress test to dynamically characterize myocardial tissue in vivo. We tested the feasibility of sequential, rapid cMRF acquisitions during breathing maneuvers to quantify myocardial T1 and T2 changes.

METHODS

We measured T1 and T2 values using conventional T1 and T2-mapping techniques (modified look locker inversion [MOLLI] and T2-prepared balanced-steady state free precession), and a 15 heartbeat (15-hb) and rapid 5-hb cMRF sequence in a phantom and in 9 healthy volunteers. The cMRF_5-hb sequence was also used to dynamically assess T1 and T2 changes over the course of a vasoactive combined breathing maneuver.

RESULTS

In healthy volunteers, the mean myocardial T1 of the different mapping methodologies were: MOLLI 1,224 ± 81 ms, cMRF_15-hb 1,359 ± 97 ms, and cMRF_5-hb 1,357 ± 76 ms. The mean myocardial T2 measured with the conventional mapping technique was 41.7 ± 6.7 ms, while for cMRF_15-hb 29.6 ± 5.8 ms and cMRF_5-hb 30.5 ± 5.8 ms. T2 was reduced with vasoconstriction (post-hyperventilation compared to a baseline resting state) (30.15 ± 1.53 ms vs. 27.99 ± 2.07 ms, p = 0.02), while T1 did not change with hyperventilation. During the vasodilatory breath-hold, no significant change of myocardial T1 and T2 was observed.

CONCLUSIONS

cMRF_5-hb enables simultaneous mapping of myocardial T1 and T2, and may be used to track dynamic changes of myocardial T1 and T2 during vasoactive combined breathing maneuvers.

Stabilization of the Li metal anode through constructing a LiZn alloy/polymer hybrid protective layer towards uniform Li deposition

Constructing an artificial solid electrolyte interphase (SEI) layer is an effective strategy for solving uncontrolled Li dendrite growth resulting from an unstable and heterogeneous Li/electrolyte interface. Herein, we develop a hybrid layer of a LiZn alloy and a polyethylene oxide (PEO) polymer to protect the Li metal anode for achieving a Li dendrite-free Li metal anode surface. The LiZn alloy is advantageous for fast Li⁺ transport, and is uniformly dispersed in the PEO matrix to regulate electronic and Li⁺ ion flux distributions homogeneously. Furthermore, the flexible PEO network can alleviate the volume change during cycling. The synergistic effect enables Li deposition underneath the hybrid film. Hence, the hybrid protection film results in significantly improved cycling stability with respect to the pristine Li metal anode. A symmetric Li/Li cell with a composite protective layer can be cycled for over 1000 h at a current density of 1 mA cm^-2 with a fixed capacity of 1 mA h cm^-2, and a full cell with a high areal capacity of the LiFePO₄ (2.45 mA h cm^-2) cathode exhibits an outstanding cycling performance.

[Application of initial anti-infectives and trends in children with septic shock]

Objective: To investigate the pathogen composition, initial anti-infectives and pathogen coverage, and trends over the last 5 years in children with septic shock in pediatric intensive care unit (PICU). Methods: The single-center retrospective study included 257 children with septic shock who were admitted to PICU of Beijing Children's Hospital, Capital Medical University from 2017 to 2021. The causitive pathogen composition, initial use of anti-infective drugs, pathogen coverage, and changes in recent years were analyzed. The children were divided into sufficient and insufficient coverage groups according to whether the pathogen were sufficiently covered by initial anti-infectives; community-and hospital-acquired groups; and with and without underlying disease groups. T test, rank-sum test and Chi-square test were used for comparison between the groups to investigate the differences in pathogen, treatment and prognosis. Results: A total of 257 septic shock children were included, with 162 males and 95 females, aged 36 (12, 117) months. The pathogen positive rate was 64.6% (166/257) and the in-hospital mortality was 27.6% (71/257). In the 208 pathogen-positive samples, bacteria was the most common (57.7%, 120/208) with G-negative bacteria predominating (55.8%, 67/120), followed by viruses (26.0%, 54/208). Nearly 99.2% (255/257) of the children were treated with antibacterial at the beginning, of whom 47.1% (121/257) were treated with carbapenems combined with vancomycin or linezolid. The proportion of 3 or more antibacterial combinations was higher in children with underlying diseases and hospital-acquired septic shock than in those without underlying disease or community-acquired septic shock (27.4% (49/179) vs. 14.1% (11/78), 29.4% (52/177) vs. 10.0% (8/80), χ²=5.35,11.56,all P<0.05). The proportion of initial combination of carbapenem and vancomycin or linezolid reduced from 52.5% (21/40) to 41.3% (19/46), and of adequate pathogen coverage increased from 40.0% (16/40) to 58.7% (27/46) in the last five years. Conclusions: The initial use of antibacterial drugs is common in children with septic shock in PICU, especially in those with hospital-acquired septic shock and underlying diseases. In recent years, antimicrobial combinations have decreased, but the pathogen coverage has improved, indicating that drug selection is more reasonable and accurate.

[Association of lead exposure with stunting and underweight among children aged 3-5 years in China]

Objective: To evaluate the association of lead exposure with stunting and underweight among children aged 3-5 years in China. Methods: Data was collected from China National Human Biomonitoring (CNHBM) between January 2017 and December 2018. A total of 3 554 children aged 3-5 years were included. Demographic characteristic, lifestyle and nutritional status were collected through questionnaires. Height and weight were measured by standardized method. Stunting and underweight status were determined by calculating height for age Z-score and weight for age Z-score. Blood and urine samples were collected to detect the concentrations of blood lead, urinary lead and urinary creatinine. Children were stratified into 4 groups (Q₁ to Q₄) by quartiles of blood lead level and corrected urinary lead level, respectively. Complex sampling logistic regression models were applied to evaluate the association of the blood lead level, urinary lead level with stunting and underweight. Results: Among 3 554 children, the age was (4.09±1.06) years, of which 1 779 (80.64%) were female and 1 948 (55.84%) were urban residents. The prevalence of stunting and wasting was 7.34% and 2.96%, respectively. The M (Q₁, Q₃) for blood lead levels and urinary lead levels in children was 17.49 (12.80, 24.71) μg/L, 1.20 (0.61, 2.14) μg/g Cr, respectively. After adjusting for confounding factors, compared with the lowest blood lead concentration group Q₁, the risk of stunting gradually increased in the Q₃ and Q₄ group (P_trend=0.010), with OR (95%CI) values of 1.40 (0.80-2.46) and 1.80 (1.07-3.04), respectively. Compared with the lowest urinary lead concentration group Q₁, the risk of stunting still increased in the Q₃ and Q₄ group (P_trend=0.012), with OR (95%CI) values of 1.69 (1.01-2.84) and 1.79 (1.05-3.06), respectively. The correlation between the lead exposure and underweight was not statistically significant (P>0.05). Conclusion: Lead exposure is positively associated with the risk of stunting among children aged 3-5 years in China.

Cardiac MRF using rosette trajectories for simultaneous myocardial T1, T2, and proton density fat fraction mapping

The goal of this work is to extend prior work on cardiac MR Fingerprinting (cMRF) using rosette k-space trajectories to enable simultaneous T₁, T₂, and proton density fat fraction (PDFF) mapping in the heart. A rosette trajectory designed for water-fat separation at 1.5T was used in a 2D ECG-triggered 15-heartbeat cMRF sequence. Water and fat specific T₁ and T₂ maps were generated from the cMRF data. A PDFF map was also retrieved using Hierarchical IDEAL by segmenting the rosette cMRF data into multiple echoes. The accuracy of rosette cMRF in T₁, T₂, and PDFF quantification was validated in the ISMRM/NIST phantom and an in-house built fat fraction phantom, respectively. The proposed method was also applied for myocardial tissue mapping of healthy subjects and cardiac patients at 1.5T. T₁, T₂, and PDFF values measured using rosette cMRF in the ISMRM/NIST phantom and the fat fraction phantom agreed well with the reference values. In 16 healthy subjects, rosette cMRF yielded T₁ values which were 80~90 ms higher than spiral cMRF and MOLLI. T₂ values obtained using rosette cMRF were ~3 ms higher than spiral cMRF and ~5 ms lower than conventional T₂-prep bSSFP method. Rosette cMRF was also able to detect abnormal T₁ and T₂ values in cardiomyopathy patients and may provide more accurate maps due to effective fat suppression. In conclusion, this study shows that rosette cMRF has the potential for efficient cardiac tissue characterization through simultaneous quantification of myocardial T₁, T₂, and PDFF.

Comment on "Distinct spin-lattice and spin-phonon interactions in monolayer magnetic CrI" by L. Webster, L. Liang and J.-A. Yan, Phys. Chem. Chem. Phys., 2018, , 23546

We point out four mistakes in the symmetry classification of vibrational modes of the CrI3 monolayer at the Γ point in Webster et al.'s paper [PCCP, 2018, 20, 23546]. The discrepancy of Raman activity of A2g mode as well as the misidentification of two optical modes A1u and A2u have been clarified.

[Evaluation of the impact of the Japanese encephalitis vaccine included in an expanded immunization program on the reported incidence rate of Japanese encephalitis in Gansu province-based on interrupted time series]

Objective: To evaluate the impact of the Japanese encephalitis vaccine included in an expanded immunization program on the reported incidence rate of Japanese encephalitis in Gansu province. Methods: Information on the reported incidence rate of Japanese encephalitis in Gansu province from 1987 to 2019 was collected through the National Population Health Science Data Center and the China Disease Prevention and Control Information System. In addition, the trend of Japanese encephalitis reported incidence rate in Gansu province before and after the inclusion of the Japanese encephalitis vaccine in the expanded immunization program was analyzed using an interrupted time-series design. Results: The annual reported incidence rate of Japanese encephalitis in Gansu province from 1987 to 2019 was 0.448/per 100 000. However, after the inclusion of the Japanese encephalitis vaccine in the expanded immunization program in Gansu province in 2008, the amount of change in the level of Japanese encephalitis reported incidence rate was -2.223/per 100 000 (t=-2.90, P=0.007), the amount of change in the slope of Japanese encephalitis reported incidence rate was 0.082 (t=2.87, P=0.008) with the slope of Japanese encephalitis reported incidence rate as 0.071 (β₁+β₃=0.071). Conclusions: The Japanese encephalitis vaccine has achieved good prevention and control effects in Gansu province in the short term after its inclusion in the expanded immunization program, but outbreaks of Japanese encephalitis have still occurred. Therefore, in the future, Gansu province should promptly adjust the immunization strategy of the Japanese encephalitis vaccine, and strengthen the vaccination of the adult population, especially the rural adult population in the southeastern region of Gansu province, based on the continued focus on the works on Japanese encephalitis vaccination for children and adolescents.

Li-Ca Alloy Composite Anode with Ant-Nest-Like Lithiophilic Channels in Carbon Cloth Enabling High-Performance Li Metal Batteries

Constructing a three-dimensional (3D) multifunctional hosting architecture and subsequent thermal infusion of molten Li to produce advanced Li composite is an effective strategy for stable Li metal anode. However, the pure liquid Li is difficult to spread across the surface of various substrates due to its large surface tension and poor wettability, hindering the production and application of Li composite anode. Herein, heteroatomic Ca is doped into molten Li to generate Li-Ca alloy, which greatly regulates the surface tension of the molten alloy and improves the wettability against carbon cloth (CC). Moreover, a secondary network composed of CaLi2 intermetallic compound with interconnected ant-nest-like lithiophilic channels is in situ formed and across the primary scaffold of CC matrix by infiltrating molten Li-Ca alloy into CC and then cooling treatment (LCAC), which has a larger and lithiophilic surface to enable uniform Li deposition into interior space of the hybrid scaffold without Li dendrites. Therefore, LCAC exhibits a long-term lifespan for 1100 h under a current density of 5 mA cm-2 with fixed areal capacity of 5 mAh cm-2. Remarkably, full cells paired with practical-level LiFePO4 cathode of 2.45 mAh cm-2 deliver superior performance.

[Disease spectrum analysis of children with inherited metabolic diseases detected by gas chromatography-mass spectrometry of urinary organic acids]

Objective: To investigate the spectrum of amino acid, organic acid, and fatty acid oxidative metabolic diseases in children diagnosed by detecting urinary organic acid levels using gas chromatography-mass spectrometry. Methods: From January 2005 to December 2021, clinical data of 2 461 children diagnosed with inherited metabolic diseases (IMD) by gas chromatography-mass spectrometry, in combination with tandem mass spectrometry and genetic testing in Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine were retrospectively analyzed. Results: Among 2 461 children, 1 446 were male and 1 051 were female. A total of 32 types of IMD were detected among 2 461 patients, which included 10 amino acid disorders in 662 cases (26.9%), 6 common diseases were hyperphenylalaninemia, citrin deficiency, ornithine carbamoyltransferase deficiency, maple syrup urine disease, alkaptonuria, and tyrosinemia-I, 17 types of organic acidemias in 1 683 cases (68.4%), 6 common diseases were methylmalonic acidemia, propionic acidemia, valeric acidemia-type Ⅰ, isovaleric acidemia, 3-methylcrotonyl-CoA carboxylase deficiency and multiple carboxylase deficiency and 5 fatty acid β oxidative defects in 116 cases (4.7%), 2 common diseases were multiple acyl-CoA dehydrogenase deficiency and short-chain acyl-CoA dehydrogenase deficiency). Conclusion: Among the diseases diagnosed by analyzing urinary organic acid profiling with gas chromatography-mass spectrometry, the most common are organic acidemias, followed by amino acid disorders and fatty acid oxidation defects.

[Association of blood lead and blood selenium with serum high-sensitivity C-reactive protein among Chinese adults aged 19 to 79 years]

Objective: To investigate the association of blood lead and blood selenium with serum high-sensitivity C-reactive protein (hs-CRP) among Chinese adults aged 19 to 79 years. Methods: The participants were enrolled from the first wave of China National Human Biomonitoring (CNHBM) conducted from 2017 to 2018. 10 153 participants aged 19 to 79 years were included in this study. Fasting blood samples were obtained from participants. Lead and selenium in whole blood and hs-CRP in serum were measured. Individuals with hs-CRP levels above 3.0 mg/L were defined as elevated hs-CRP. Generalized linear mixed models and restricted cubic spline models were used to analyze the association of blood lead and blood selenium with elevated hs-CRP. Logistic regression models were used to analyze the multiplicative scale and additive scale interaction between blood lead and blood selenium on elevated hs-CRP. Results: The age of participants was (48.91±15.38) years, of which 5 054 (61.47%) were male. 1 181 (11.29%) participants were defined as elevated hs-CRP. After multivariable adjustment, results from generalized linear models showed that compared with participants with the lowest quartile of blood lead, the OR (95%CI) of elevated hs-CRP for participants with the second, third, and highest quartiles were 1.14 (0.94-1.37), 1.25 (1.04-1.52) and 1.38 (1.13-1.68), respectively. When compared with participants with the lowest quartile of blood selenium, the OR (95%CI) of elevated hs-CRP for participants with the second, third and highest quartiles were 0.86 (0.72-1.04), 0.91 (0.76-1.11), and 0.75 (0.61-0.92), respectively. Results from the interaction analysis showed no significant interaction between lead and selenium on elevated hs-CRP. Conclusion: Blood concentration of lead was positively associated with elevated serum hs-CRP, and blood concentration of selenium was inversely related to elevated hs-CRP, while blood lead and selenium did not present interaction on elevated hs-CRP.

[Clinical analysis of 6 critically ill children with acute chlorine poisoning]

Objective: To analyze the clinical characteristics and treatment of critically ill children with acute chlorine poisoning and explore the risk factors and effective strategies. Methods: This retrospective study collected the clinical data, including general state, clinical characteristics, treatment and follow-up(till 1 year and 6 months after discharge), of 6 critically ill children who were hospitalized in the Pediatric Intensive Care Unit of Beijing Children's Hospital due to acute chlorine poisoning in August 2019. Results: There were 6 children characterized by severe dyspnea in this accident, among whom 4 were boys and two girls, aged 4-12 years. When the accident occurred, they were within 5 m of the chlorine source. These patients underwent tracheal intubation and mechanical ventilation in 3.5-7.0 h after poisoning. The child who was the closest to the chlorine source (1.5 m) and took the longest time (5 min) to evacuate was the most severe one. He suffered hypoxia which could not be corrected by conventional mechanical ventilation and severe shock, then had veno-arterial extracorporeal membrane oxygenation(ECMO) treatment started 10 h after the accident. All the 6 children in this study survived. Following-up found no growth and developmental abnormality. The pulmonary function tests were normal except for one case with increased small airway resistance due to previous suspected asthma, and the lung CT, electhoencephalogram, and brain magnetic resonance imaging were all normal. Conclusions: Severe chlorine poisoning is mainly characterized by respiratory failure. Mechanical ventilation is often required within a few hours after poisoning. When conventional mechanical ventilation is ineffective, ECMO could save live. Timely treatment could improve prognosis.

[Prediction of 6-year risk of activities of daily living disability in elderly aged 65 years and older in China]

Objective: To construct an easy-to-use risk prediction tool for 6-year risk of activities of daily living(ADL) disability among Chinese elderly aged 65 and above. Methods: A total of 34 349 elderly aged 65 and above were recruited from the Chinese Longitudinal Healthy Longevity Survey. Demographic characteristics, lifestyle and chronic diseases of the elderly were collected through face-to-face interviews. The functional status of the elderly was evaluated by the instrumental activities of daily living(IADL) scale. The mental health status of the elderly was evaluated by the Mini-Mental State Examination. The height, weight, blood pressure and other information of the subjects were obtained through physical examination and body mass index(BMI) was calculated. The ADL status was evaluated by Katz Scale at baseline and follow-up surveys. Taking ADL status as the dependent variable and the key predictors were selected from Lasso regression as the independent variables, a Cox proportional risk regression model was constructed and visualized by the nomogram tool. Area under the receiver operating characteristic curve(AUC) and calibration curve were used to evaluate the discrimination and calibration of the model. A total of 200 bootstrap resamples were used for internal validation of the model. Sensitivity analysis was used to evaluate the robustness of the model. Results: The M(Q₁, Q₃) of subjects' age as 86(75, 94) years old, of which 9 774(46.0%) were males. A total of 112 606 person-years were followed up, 4 578 cases of ADL disability occurred and the incidence density was 40.7/1 000 person-years. Cox proportional risk regression model analysis showed that older age, higher BMI, female, hypertension and history of cerebrovascular disease were associated with higher risk of ADL disability [HR(95%CI) were 1.06(1.05-1.06), 1.05(1.04-1.06), 1.17(1.10-1.25),1.07(1.01-1.13) and 1.41(1.23-1.62), respectively.]; Ethnic minorities, walking 1 km continuously, taking public transportation alone and doing housework almost every day were associated with lower risk of ADL disability [HR(95%CI): 0.71(0.62-0.80), 0.72(0.65-0.80), 0.74(0.68-0.82) and 0.69(0.64-0.74), respectively]. The AUC value of the model was 0.853, and the calibration curve showed that the predicted probability was highly consistent with the observed probability. After excluding non-intervening factors(age, sex and ethnicity), the AUC value of the model for predicting the risk of ADL disability was 0.779. The AUC values of 65-74 years old and 75 years old and above were 0.634 and 0.765, respectively. The AUC values of the model based on walking 1 km continuous and taking public transport alone in IADL and the model based on comprehensive score of IADL were 0.853 and 0.851, respectively. Conclusion: The risk prediction model of ADL disability established in this study has good performance and robustness.

[Clinical research progress on disappearing colorectal liver metastases]

Colorectal cancer is currently one of the most common digestive system tumors, and the liver is the most common metastatic site of colorectal cancer. In recent years, with the continuous development of the multidisciplinary treatment for colorectal cancer patients, there are quite a few cases of disappearing liver metastases (DLM) after receiving preoperative chemotherapy (or combined targeted drug therapy), and the diagnosis and treatment of DLM is currently still a very challenging and controversial topic. This article sorts out the related researches on DLM in recent years, mainly including the following 4 aspects: (1) The factors associated with DLM, including the size and number of liver metastases, chemotherapy regimens and cycles, targeted therapy drugs, and the pattern of liver metastases, Ras/Braf status and the location of the primary lesion. (2) The relationship between DLM and true complete response (pathological complete response and persistent clinical complete response), and the related predictive factors of pathological complete response. (3) Clinical evaluation of DLM: preoperative evaluation includes ultrasound, CT, MRI, and PET, while intraoperative evaluation includes intraoperative exploration, intraoperative ultrasound, and augmented reality. (4) DLM treatment strategies, including surgical treatment, local treatment, non-surgical treatment and individualized treatment.

[Association between a novel regulatory genetic variants and lung cancer risk in Chinese: a two-stage case-control study]

Objective: Regulatory quantitative trait loci (regQTL) theory can help to evaluate the regulation function of single nucleotide polymorphisms (SNPs) on crucial biological signals from a three-dimensional perspective. The aim of this study was to investigate the effect of these regQTL-SNPs on the susceptibility of lung cancer. Methods: Based on the regQTL theory, using the database of identified lung cancer regQTL-SNPs, we screened the SNPs that may function as regQTL in the reported susceptible regions of lung cancer by genome-wide association study(GWAS), and a two-stage case-control study was conducted (screening stage: 2 331 lung cancer cases and 3 077 healthy controls; validation stage: 626 lung cancer cases and 667 healthy controls) to definite the association of related regQTL-SNPs with the susceptibility of lung cancer. Results: A total of 8 regQTL-SNPs were screened in the reported susceptible regions of lung cancer by GWAS. Among which, 3 SNPs were significantly associated with the risk of lung cancer (P<0.05) in the screening stage. Further validation results indicated that the variant T allele of rs6998591 in ADRA1A was significantly associated with increased risk of lung cancer (additive model: OR=1.33, 95%CI:1.01-1.74, P=0.040). In addition, the variant G allele of rs11202916 in ACTA2 was significantly associated with decreased risk of lung cancer (recessive model: OR=0.71, 95%CI:0.52-0.96, P=0.026). Stratified analysis indicated that the variant T allele of rs6998591 significantly increased lung squamous cell carcinoma risk (additive model: OR=1.53, 95%CI: 1.01-2.32, P=0.043), while the variant G allele of rs11202916 significantly decreased lung adenocarcinoma risk (additive model: OR=0.83, 95%CI: 0.69-0.98, P=0.031). Gene-environment interaction analysis indicated that the risk of developing lung cancer increased by 235% in smoking individuals carrying rs6998591 variant T allele compared with those non-smoking individuals carrying no rs6998591 variant T allele(OR=3.35,95%CI:2.10-5.34,P<0.001). Conclusion: There are two regQTL-SNPs that could significantly affect the susceptibility of lung cancer in the GWAS reported susceptible regions of lung cancer.

[A cohort study on plasma uric acid levels and the risk of type 2 diabetes mellitus among the oldest old in longevity areas of China]

Objective: To investigate the effect of plasma uric acid level on the incident risk of type 2 diabetes mellitus (T2DM) among the oldest old (those aged ≥80 years). Methods: Participants were recruited from the Healthy Aging and Biomarkers Cohort Study (HABCS), which conducted a baseline survey in 2008-2009 and follow-up of 3 times in 2011-2012, 2014, and 2017-2018, respectively. A total of 2 213 oldest old were enrolled in this study. The general demographic, socioeconomic, lifestyle and disease data of the oldest old were collected, and physical measurements were made for the oldest old. Fasting venous blood was collected for uric acid and blood glucose detection. Information on the incident and death of T2DM were collected through the follow-up. Cox proportional hazard regression model was used to explore the association of hyperuricemia and plasma uric acid level with the incidence of T2DM. Restricted cubic spline (RCS) function was used to explore the dose-response relationship of plasma uric acid levels with the risk of T2DM. Results: The age of participants was (93.2±7.6) years old, and 66.7% of the participants (1 475) were female. The plasma uric acid level at baseline was (289.1±88.0)μmol/L, and the prevalence of hyperuricemia was 13.3% (294 cases). During 9 years of cumulative follow-up of 7 471 person-years (average of 3.38 years for each), 122 new cases of T2DM occurred and the incidence density was 1 632.98/10⁵ person year. Cox proportional hazards regression analysis showed that per 10μmol/L increase in plasma uric acid level, the risk of T2DM increased by 1.1% [HR (95%CI): 1.011 (1.004, 1.017)]. Compared with the participants with the lowest quintile of plasma uric acid (Q₁), the risk of diabetes increased by 20.7 % among the oldest old with uric acid in the highest quintile (Q₅) [HR (95%CI):1.207 (1.029, 1.416)]. The risk of T2DM was 19.2% higher in the hyperuricemia group than that in the oldest old with normal plasma uric acid [HR (95%CI): 1.192 (1.033, 1.377)]. RCS function showed that the risk of T2DM increased with the increase in plasma uric acid levels in a nonlinear dose-response relationship (P=0.016). Conclusion: The incident risk of T2DM increases with the elevates of plasma uric acid levels in the oldest old.

[Study on the effectiveness of silicon dust prevention and control of small sandblasting cabinet type water curtain exhaust hood]

Objective: To explore the effect of cabinet type water curtain exhaust hood applied to small sandblasting machine to prevent and control silicon dust, and put forward a new idea of dust ventilation protection facilities to effectively protect the occupational health of workers. Methods: From August to October 2018, the cabinet type water curtain exhaust hood of sandblasting room in a research institute was selected as the research object, and the methods of occupational health survey, on-site detection and physical simulation of air distribution were used to conduct on-site detection and smoke emission test on the local exhaust facilities, silica dust concentration, control wind speed and air distribution before and after the transformation line analysis and evaluation. Results: The air distribution simulation experiment showed that the air distribution of the cabinet type water curtain exhaust hood was reasonable and could effectively control the whole range of silica dust emission during the cleaning process. After modification, the capture velocity was increased from 0.01 m/s to 0.53 m/s, and the capture velocity was increased by 98.1%. The time weighted average allowable concentration (C(TWA)) of silicon dust (total dust) during sand blasting, cabin opening and cleaning was reduced from 7.00 mg/m(3) to 0.50 mg/m(3). The C(TWA) of silica dust (exhalation dust) was decreased from 3.36 mg/m(3) to 0.27 mg/m(3), and the C(TWA) dust reduction rates of total dust and respirable dust were 92.9% and 92.0%, respectively. Conclusion: The combination of cabinet type exhaust hood and water curtain dedusting optimizes the combination mode of dust prevention and control. It has the advantages of high efficiency of dedusting and purification, energy saving and environmental protection, and can be popularized and used in enterprises of the same nature.

[Research progress of conversion therapy in colorectal cancer liver metastases]

The probability of developing liver metastases in patients with colorectal cancer is 40%-50%. Liver metastases remain an important adverse factor affecting long-term prognosis of colorectal cancer patients. Surgical resection of liver metastases is the only potentially curative treatment option. After comprehensive treatment, initially unresectable liver metastases might be converted to resectable tumors. This concept is known as conversion therapy. In this review, research status of conversion therapy in colorectal cancer liver metastases was summarized, providing updated concept of resectability, discussions on the assessment of tumor response and timing of operation, debates on the influence on tumor sidedness, and latest advancement in the treatment strategy of conversion therapy. Through analyzing existing problems, we hope to offer insights into possible progress in the future and provide references for the development of clinical practice.

[Association of sleep duration with cognitive impairment among older adults aged 65 years and older in China]

Objective: The study is to examine association of sleep duration and cognitive impairment in the older adults aged 65 years and older in China. Methods: We analyzed data from 2017-2018 wave of Chinese Longitudinal Healthy Longevity Survey (CLHLS). A total of 14 966 participants were included in the analysis. Data with respect to socioeconomic status, community involvement, behavior pattern, diet, life style, family structure, disease condition, mental health and cognitive function were collected. Cognitive function was measured with Mini-mental State Examination (MMSE). We conducted generalized linear mixed models to examine associations of sleep duration with cognitive impairment, and subgroup analyses of sex and age were conducted. Results: Among 14 966 participants, the percentage of participants aged 65 to 79 years, 80 to 89 years, 90 to 99 years and 100 years and older was 5 148 (4.40%), 3 777 (25.24%), 3 322 (22.20%) and 2 719 (18.16%), respectively. A total of 2 704 participants reported sleep duration of 5 h and less, and 3 883 reported 9 h and more, accounting for 18.94% and 27.19%, respectively. In total, 3 748 were defined with cognitive impairment, accounting for 25.04%. The results of generalized linear mixed models showed that both short (≤5 h) and long (≥ 9 h) sleep duration were associated with cognitive impairment compared with sleep duration of 7 h, with OR(95%CI) of 1.35(1.09-1.68) and 1.70(1.39-2.07), respectively. The association of sleep duration with cognitive impairment was more obvious in males and individuals aged 65 to 79 years old. Conclusion: Short or long sleep duration was responsible for increased risk of cognitive impairment in older Chinese.

[Effects of oxygen saturation on all-cause mortality among the elderly over 65 years old in 9 longevity areas of China]

Objective: To investigate the association between oxygen saturation (SpO₂) and risk of 3-year all-cause mortality among Chinese older adults aged 65 or over. Methods: The participants were enrolled from Healthy Aging and Biomarkers Cohort Study in year of 2012 to 2014 in 9 longevity areas in China. In this prospective cohort study, 2 287 participants aged 65 or over were enrolled. Data on SpO₂ and body measurements were collected at baseline in 2012, and data on survival outcome and time of mortality were collected at the follow-up in 2014. Participants were divided into two groups according to whether SpO₂ was abnormal (SpO₂<94% was defined as abnormal). Results: The 2 287 participants were (86.5±12.2) years old, 1 006 were males (44.0%), and 315 (13.8%) were abnormal in SpO₂. During follow-up in 2014, 452 were died, 1 434 were survived, and 401 were lost to follow-up. The all-cause mortality rate was 19.8%, and the follow-up rate was 82.5%. The mortality rate of SpO₂ in normal group was 21.1%, and that of abnormal group was 41.6% (P<0.001). After adjusting for confounding factors, compared to participants with normal SpO₂, participants with abnormal SpO₂ had increased risk of all-cause mortality with HR (95%CI) of 1.62 (1.31-2.02); HR (95 % CI) was 1.49 (0.98-2.26) for males and 1.71 (1.30-2.26) for females in abnormal SpO₂ group, respectively; HR (95%CI) was 2.70 (0.98-7.44) for aged 65-79 years old, 1.22 (0.63-2.38) for aged 80-89 years old, and 1.72 (1.35-2.19) for aged over 90 years old in abnormal SpO₂ group, respectively. Conclusion: Abnormal SpO₂ was responsible for increased risk of 3-year all-cause mortality among Chinese elderly adults.

[Association of blood lead level with cognition impairment among elderly aged 65 years and older in 9 longevity areas of China]

Objective: To investigate the association between blood lead concentrations and cognition impairment among Chinese older adults aged 65 or over. Method: Data was collected in 9 longevity areas from Heathy Aging and Biomarkers Cohort Study between 2017 and 2018. This study included 1 684 elderly aged 65 years and older. Information about demographic characteristics, socioeconomic factors, health status and cognitive function score of respondents were collected by questionnaire survey and physical examination. Venous blood of the subjects was collected to detect the blood lead concentration. Subjects were stratified into four groups (Q₁-Q₄) by quartile of blood lead concentration. Multivariate logistic regression model was used to analyze the association between blood lead concentration and cognitive impairment. The linear or non-linear association between blood lead concentration and cognitive impairment were described by restrictive cubic splines (RCS). Results: Among the 1 684 respondents, 843 (50.1%) were female and 191 (11.3%) suffered from cognition impairment. After adjusting for confounding factors, the OR value and 95%CI of cognition impairment was 1.05 (1.01-1.10) for every 10 μg/L increase in blood lead concentration in elderly; Compared with the elderly in Q₁, the elderly with higher blood lead concentration had an increased risk of cognitive impairment. The OR value and 95%CI of Q₂, Q₃ and Q₄ groups were 1.19 (0.69-2.05), 1.45 (0.84-2.51) and 1.92 (1.13-3.27), respectively. Conclusion: Higher blood lead concentration is associated with cognitive impairment among the elderly aged 65 years and older in 9 longevity areas in China.

[Association of blood oxidative stress level with hypertriglyceridemia in the elderly aged 65 years and older in 9 longevity areas of China]

Objective: To investigate the association of blood oxidative stress level with hypertriglyceridemia in the elderly aged 65 years and older in China. Methods: A total of 2 393 participants aged 65 years and older were recruited in 9 longevity areas from Heathy Aging and Biomarkers Cohort Study, during 2017 to 2018. Information on demographics characteristic, life style and health status were collected by questionnaire and physical examination, and venous blood was collected to detect the levels of blood oxidative stress and hypertriglyceridemia. The linear or non-linear association between oxidative stress and hypertriglyceridemia was described by restrictive cubic splines (RCS) fitting multiple linear regression model. The generalized linear mixed effect model was conducted to assess the association between oxidative stress and hypertriglyceridemia. Results: A total of 2 393 participants, mean age was 84.6 years, the youngest was 65 and the oldest was 112, the male was 47.9%(1 145/2 393), the triglyceride level was (1.4±0.8) mmol/L. The hypertriglyceridemia detection rate was 9.99%(239/2 393). The results of multiple linear regression model with restrictive cubic spline fitting showed that MDA level was linear association with triglyceride level; SOD level was nonlinear association with triglyceride level. MDA level had significantly association with hypertriglyceridemia, and the corresponding OR value was 1.063 (95%CI: 1.046,1.081) with 1 nmol/ml increment of blood MDA; SOD level had significantly association with hypertriglyceridemia, and the corresponding OR value was 0.986(95%CI: 0.983,0.989) with 1 U/ml increment of blood SOD. Conclusion: Among the elderly aged 65 and older in 9 longevity areas in China, MDA and SOD levels were associated with the risk of hypertriglyceridemia.

Dynamic oxygen-17 MRI with adaptive temporal resolution using golden-means-based 3D radial sampling

PURPOSE

The aim of this study was to develop a high-resolution 3D oxygen-17 (¹⁷ O) MRI method to delineate the kinetics of ¹⁷ O-enriched water (H₂ ¹⁷ O) across the entire mouse brain after a bolus injection via the tail vein.

METHODS

The dynamic ¹⁷ O signal was acquired with a golden-means-based 3D radial sampling scheme. To achieve adequate temporal resolution with preserved spatial resolution, a k-space-weighted view sharing strategy was used in image reconstruction with an adaptive window size tailored to the kinetics of the ¹⁷ O signal. Simulation studies were performed to determine the adequate image reconstruction parameters. The established method was applied to delineating the kinetics of intravenously injected H₂ ¹⁷ O in vivo in the post-stroke mouse brain.

RESULTS

The proposed dynamic ¹⁷ O-MRI method achieved an isotropic resolution of 1.21 mm (0.77 mm nominal) in mouse brain at 9.4T, with the temporal resolution increased gradually from 3 s at the initial phase of rapid signal increase to 15 s at the steady-state. The high spatial resolution enabled the delineation of the heterogeneous H₂ ¹⁷ O uptake and washout kinetics in stroke-affected mouse brain.

CONCLUSION

The current study demonstrated a 3D ¹⁷ O-MRI method for dynamic monitoring of ¹⁷ O signal changes with high spatial and temporal resolution. The method can be utilized to quantify physiological parameters such as cerebral blood flow and blood-brain barrier permeability by tracking injected H₂ ¹⁷ O. It can also be used to measure oxygen consumption rate in ¹⁷ O-oxygen inhalation studies.

[Bioinformatics analysis of key genes and prognosis-related genes during the onset of hepatocellular carcinoma]

Objective: To screen and analyze the differentially-expressed genes (DEGs) in primary hepatocellular carcinoma tissues and adjacent tissues using bioinformatics methods to explore the molecular mechanism of the occurrence and prognosis of primary hepatocellular carcinoma. Methods: GSE76427 data set was collected through GEO database, and DEGs were identified using GEO2R online analysis. Go and KEGG databases were used for enrichment and functional annotation of DEGs. Protein interaction network was built based on the STRING database and Cytoscape software to analyze the key genes of hepatocellular carcinoma, and the survival curve of these key genes were analyzed using the GEPIA database. Results: A total of 74 hepatocellular carcinoma DEGs were screened, of which 3 and 71 were up-and-down-regulated genes. The results of GO enrichment analysis showed that the down-regulated DEGs were mainly involved in cell response to cadmium and zinc ions, negative growth regulation, heterologous metabolic processes and hormone-mediated signaling pathways. KEGG pathway enrichment analysis results showed that the down-regulated DEGs pathway were mainly involved in retinol metabolism, chemical carcinogenesis, drug metabolism-cytochrome P450, cytochrome P450 metabolizing xenobiotics, tryptophan metabolism and caffeine metabolism. Protein interaction network had screened out 10 down-regulated core genes: MT1G, MT1F, MT1X, MT1E, MT1H, insulin-like growth factor 1, FOS, CXCL12, EGR1, and BGN. Among them, the insulin-like growth factor 1 was related to the prognosis of primary hepatocellular carcinoma. Conclusion: Bioinformatics analysis results of HCC chip data showed that 10 key genes may play a key role in the occurrence and development of HCC and the insulin like growth factor 1 is associated with the prognosis of primary hepatocellular carcinoma.

Spintronic Sensors Based on Magnetic Tunnel Junctions for Wireless Eye Movement Gesture Control

The tracking of eye gesture movements using wearable technologies can undoubtedly improve quality of life for people with mobility and physical impairments by using spintronic sensors based on the tunnel magnetoresistance (TMR) effect in a human-machine interface. Our design involves integrating three TMR sensors on an eyeglass frame for detecting relative movement between the sensor and tiny magnets embedded in an in-house fabricated contact lens. Using TMR sensors with the sensitivity of 11 mV/V/Oe and ten <1 mm³ embedded magnets within a lens, an eye gesture system was implemented with a sampling frequency of up to 28 Hz. Three discrete eye movements were successfully classified when a participant looked up, right or left using a threshold-based classifier. Moreover, our proof-of-concept real-time interaction system was tested on 13 participants, who played a simplified Tetris game using their eye movements. Our results show that all participants were successful in completing the game with an average accuracy of 90.8%.

Low-temperature fusion fabrication of Li-Cu alloy anode with in situ formed 3D framework of inert LiCux nanowires for excellent Li storage performance

The commercialization of rechargeable Li metal batteries is hindered by dendrite growth and volumetric variation. Herein, we report a Li-rich dual-phase Li-Cu alloy with built-in 3D conductive skeleton to replace conventional planar Li anode. The Li-Cu alloy is simply prepared by fusion of Li and Cu metals at a relatively low-temperature of 500 °C, followed by a cooling process where phase-segregation leads to metallic Li phase distributed in the network of LiCu_x solid solution phase. Different from the common Li alloy, the electrochemical alloying reaction between Li and Cu metals is not observed. Therefore, the lithiophilic LiCu_x nanowires guides conformal plating of Li and the porous framework provides superior dimensional stability for the anode. This unique ferroconcrete-like structure of Li-Cu alloy enables dendrite-free Li plating for an expanded cycling lifetime. Constructing a new type of Li alloy with in situ formed electrochemically inactive framework is a promising and easily scaled-up strategy toward practical application of Li metal anodes.

[Analysis on risk factors of the degree of radical resection and prognosis of patients with locally recurrent rectal cancer]

Objective: To evaluate the factors affecting the degree of radical resection and the prognosis of patients with locally recurrent rectal cancer (LRRC). Methods: A retrospective case-control study was performed. Clinical data of 111 patients with LRRC undergoing operation at the General Surgery Department of Peking University First Hospital from January 2009 to August 2019 were analyzed retrospectively. The "Peking University First Hospital F typing" was performed according to the preoperative images of the pelvic involvement. The pelvis was assigned into four directions: the front wall, lateral sides of the pelvic wall and the sacrum. According to the degree of pelvic wall involvement, F typing included F0 type (no involvement of the pelvic wall, the cancer only involved the adjacent organs or invaded conteriorly the urinary tract, genital organs or small intestine), F1 type (cancer involved the pelvic wall in one direction, such as the sacrum, or one side of the pelvic wall), F2 type (cancer involved the pelvic wall in two directions) and F3 type (cancer involved the pelvic wall in three directions). Case inclusion criteria: (1) LRRC was confirmed by imaging and pathological examination of samples (puncture or endoscopic biopsy); (2) complete clinical and follow-up data; (3) informed consent of patient. Those with dysfunction of heart, lung, etc., intolerance of operation, F3 type indicated by image, and distant metastasis were excluded. The degree of radical resection was evaluated according to the postoperative pathological results. Patients were followed up every 12 months and related examinations were arranged. The univariate analysis of radical resection was performed by χ(2) test, and the multivariate analysis was performed by logistic methods. The survival rate was calculated by Kaplan-Meier method and the survival curve was drawn. The survival rate was compared by log-rank test. Cox proportional hazards model was used to analyze the factors affecting the prognosis of patients with LRRC. Results: A total of 111 patients were included in this study. Of 111 patients, 59 were male and 52 were female; recurrent age of 36 cases was ≥ 65 years old; CEA level of 48 cases was ≥15 μg/L. According to the "Peking University First Hospital F typing", 70 cases were F0 type, 38 F1 type and 3 F2 type. Surgical procedures were abdominoperineal resection (n=28), posterior pelvic exenteration (n=32), and total pelvic exenteration (n=51, including 1 case of TPE combined with sacrectomy). According to the postoperative pathological results, R0, R1 and R2 resections were 83, 20 and 8 cases, respectively. Univariate analysis showed that the degree of radical resection was associated with the secondary surgical procedure, F typing and lymph node metastasis (all P<0.05). Multivariate analysis showed that F typing (F1-F2) was an independent risk factor for non- R0 resection (OR=37.256, 95%CI:8.572 to 161.912, P<0.001). The morbidity of operative complications was 22.5% (25/111); the perioperative mortality was 1.8% (2/111); the local recurrence rate after the second operation was 37.8% (42/111). The 3- and 5-year overall survival rates were 41.2% and 21.9% respectively. The 3-year survival rates of patients with and without postoperative chemotherapy were 52.7% and 32.4% respectively (P=0.005). The 3-year survival rates of patients with lower (<15 μg/L) and higher CEA level (≥15 μg/L) were 52.9% and 24.3% respectively (P<0.001). The 3-year survival rates of patients with R0, R1 and R2 resection were 49.8%, 21.3% and 8.5% respectively (P=0.002). The 3-year survival rates of patients with F0, F1 and F2 type were 52.7%, 22.0% and 0 respectively (P<0.001). Cox analysis confirmed that the degree of radical resection (HR=2.088, 95%CI:1.095 to 3.979, P=0.025), the CEA level before the secondary operation (HR=1.857, 95%CI:1.157 to 2.980, P=0.010) and postoperative chemotherapy (HR=1.826, 95%CI:1.137 to 2.934, P=0.013) were independent factors affecting the prognosis. Conclusions: The indication of LRRC surgical treatments must be strictly limited. Evaluation of the fixation site to the pelvic wall is helpful for improving the rate of R0 resection. Lower preoperative CEA level, radical resection and postoperative chemotherapy are protective factors of prolonged overall survival time of patients with LRRC.

Evaluation of dyspnea of unknown etiology in HIV patients with cardiopulmonary exercise testing and cardiovascular magnetic resonance imaging

AIM

Human Immunodeficiency Virus (HIV) patients commonly experience dyspnea for which an immediate cause may not be always apparent. In this prospective cohort study of HIV patients with exercise limitation, we use cardiopulmonary exercise testing (CPET) coupled with exercise cardiovascular magnetic resonance (CMR) to elucidate etiologies of dyspnea.

METHODS AND RESULTS

Thirty-four HIV patients on antiretroviral therapy with dyspnea and exercise limitation (49.7 years, 65% male, mean absolute CD4 count 700) underwent comprehensive evaluation with combined rest and maximal exercise treadmill CMR and CPET. The overall mean oxygen consumption (VO2) peak was reduced at 23.2 ± 6.9 ml/kg/min with 20 patients (58.8% of overall cohort) achieving a respiratory exchange ratio > 1. The ventilatory efficiency (VE)/VCO2 slope was elevated at 36 ± 7.92, while ventilatory reserve (VE: maximal voluntary ventilation (MVV)) was within normal limits. The mean absolute right ventricular (RV) and left ventricular (LV) contractile reserves were preserved at 9.0% ± 11.2 and 9.4% ± 9.4, respectively. The average resting and post-exercise mean average pulmonary artery velocities were 12.2 ± 3.9 cm/s and 18.9 ± 8.3 respectively, which suggested lack of exercise induced pulmonary artery hypertension (PAH). LV but not RV delayed enhancement were identified in five patients. Correlation analysis found no relationship between peak VO2 measures of contractile RV or LV reserve, but LV and RV stroke volume correlated with PET CO2 (p = 0.02, p = 0.03).

CONCLUSION

Well treated patients with HIV appear to have conserved RV and LV function, contractile reserve and no evidence of exercise induced PAH. However, we found evidence of impaired ventilation suggesting a non-cardiopulmonary etiology for dyspnea.

High-Resolution Dynamic 31P-MR Spectroscopic Imaging for Mapping Mitochondrial Function

OBJECTIVE

To enable non-invasive dynamic metabolic mapping in rodent model studies of mitochondrial function using 31P-MR spectroscopic imaging (MRSI).

METHODS

We developed a novel method for high-resolution dynamic 31P-MRSI. The method synergistically integrates physics-based models of spectral structures, biochemical modeling of molecular dynamics, and subspace learning to capture spatiospectral variations. Fast data acquisition was achieved using rapid spiral trajectories and sparse sampling of (k, t, T)-space; image reconstruction was accomplished using a low-rank tensor-based framework.

RESULTS

The proposed method provided high-resolution dynamic metabolic mapping in rat hindlimb at spatial and temporal resolutions of 4[Formula: see text]2 mm3 and 1.28 s, respectively. This allowed for in vivo mapping of the time-constant of phosphocreatine resynthesis, a well established index of mitochondrial oxidative capacity. Multiple rounds of in vivo experiments were performed to demonstrate reproducibility, and in vitro experiments were used to validate the accuracy of the estimated metabolite maps.

CONCLUSIONS

A new model-based method is proposed to achieve high-resolution dynamic 31P-MRSI. The proposed method's ability to delineate metabolic heterogeneity was demonstrated in rat hindlimb.

SIGNIFICANCE

Abnormal mitochondrial metabolism is a key cellular dysfunction in many prevalent diseases such as diabetes and heart disease; however, current understanding of mitochondrial function is mostly gained from studies on isolated mitochondria under nonphysiological conditions. The proposed method has the potential to open new avenues of research by allowing in vivo and longitudinal studies of mitochondrial dysfunction in disease development and progression.

Self-Powered Implantable Medical Devices: Photovoltaic Energy Harvesting Review

Implantable technologies are becoming more widespread for biomedical applications that include physical identification, health diagnosis, monitoring, recording, and treatment of human physiological traits. However, energy harvesting and power generation beneath the human tissue are still a major challenge. In this regard, self-powered implantable devices that scavenge energy from the human body are attractive for long-term monitoring of human physiological traits. Thanks to advancements in material science and nanotechnology, energy harvesting techniques that rely on piezoelectricity, thermoelectricity, biofuel, and radio frequency power transfer are emerging. However, all these techniques suffer from limitations that include low power output, bulky size, or low efficiency. Photovoltaic (PV) energy conversion is one of the most promising candidates for implantable applications due to their higher-power conversion efficiencies and small footprint. Herein, the latest implantable energy harvesting technologies are surveyed. A comparison between the different state-of-the-art power harvesting methods is also provided. Finally, recommendations are provided regarding the feasibility of PV cells as an in vivo energy harvester, with an emphasis on skin penetration, fabrication, encapsulation, durability, biocompatibility, and power management.

Myocardial T1 and T2 quantification and water-fat separation using cardiac MR fingerprinting with rosette trajectories at 3T and 1.5T

PURPOSE

This work aims to develop an approach for simultaneous water-fat separation and myocardial T₁ and T₂ quantification based on the cardiac MR fingerprinting (cMRF) framework with rosette trajectories at 3T and 1.5T.

METHODS

Two 15-heartbeat cMRF sequences with different rosette trajectories designed for water-fat separation at 3T and 1.5T were implemented. Water T₁ and T₂ maps, water image, and fat image were generated with B₀ inhomogeneity correction using a B₀ map derived from the cMRF data themselves. The proposed water-fat separation rosette cMRF approach was validated in the International Society for Magnetic Resonance in Medicine/National Institute of Standards and Technology MRI system phantom and water/oil phantoms. It was also applied for myocardial tissue mapping of healthy subjects at both 3T and 1.5T.

RESULTS

Water T₁ and T₂ values measured using rosette cMRF in the International Society for Magnetic Resonance in Medicine/National Institute of Standards and Technology phantom agreed well with the reference values. In the water/oil phantom, oil was well suppressed in the water images and vice versa. Rosette cMRF yielded comparable T₁ but 2~3 ms higher T₂ values in the myocardium of healthy subjects than the original spiral cMRF method. Epicardial fat deposition was also clearly shown in the fat images.

CONCLUSION

Rosette cMRF provides fat images along with myocardial T₁ and T₂ maps with significant fat suppression. This technique may improve visualization of the anatomical structure of the heart by separating water and fat and could provide value in diagnosing cardiac diseases associated with fibrofatty infiltration or epicardial fat accumulation. It also paves the way toward comprehensive myocardial tissue characterization in a single scan.