Erratum: Measurement of the 2νββ Decay Half-Life of ^{130}Te with CUORE [Phys. Rev. Lett. 126, 171801 (2021)]

This corrects the article DOI: 10.1103/PhysRevLett.126.171801.

[Comparison of two child growth standards in assessing the nutritional status of children under 6 years of age]

Objective: To compare the application of China growth standard for children under 7 years of age (China standards) and World Health Organization child growth standards (WHO standards) in evaluating the prevalence of malnutrition in children aged 0-<6 years in China. Methods: The research data came from the national special program for science & technology basic resources investigation of China, named "2019-2021 survey and application of China's nutrition and health system for children aged 0-18 years". Multi-stage stratified random sampling was used to recruit 28 districts (regions) in 14 provinces, autonomous regions or municipalities across the country. Children (n=38 848) were physically measured and questionnaires were conducted in the guardians of the children. The indicators of stunting, underweight, wasting, overweight and obesity were evaluated by China standards and WHO standards respectively. Chi-square test was used to comparing the prevalence of each nutritional status between the two standards, as well as the comparison between the two standards by gender and age. Results: Among the 38 848 children, 19 650 were boys (50.6%) and 19 198 were girls (49.4%), 19 480 urban children (50.1%) and 19 368 rural children (49.9%). The stunting, underweight and wasting cases in the study population were 2 090 children (5.4%), 1 354 children (3.5%) and 1 276 children (3.3%) according to the China standards, and 1 474 children (3.8%), 701 children (1.8%) and 824 children (2.1%) according to the WHO standards, respectively; the above rates according to the China standards were slightly higher than those to the WHO standards (χ²=111.59, 213.14, and 99.99, all P<0.001). The overweight and obesity cases in the study population were 2 186 children (5.6%) and 1 153 children (3.0%) according to the China standards, and 2 210 children (5.7%) and 1 186 children (3.1%) according to the WHO standards, with no statistically significant differences (χ²=0.14 and 0.48, P=0.709 and 0.488, respectively). Compared to the results based on WHO standards, the China standards showed a lower prevalence of overweight and obesity in boys (χ²=14.95 and 5.85, P<0.001 and =0.016, respectively), and higher prevalence of overweight in girls (χ²=12.60, P<0.001); but there was no statistically significant differences in girls' obesity prevalence between the two standards (χ²=2.62, P=0.106). Conclusions: In general, the prevalence of malnutrition among children aged 0-<6 years based on China standards is slightly higher than that on WHO standards. To evaluate the nutritional status of children, it is advisable to select appropriate child growth standards based on work requirements, norms or research objectives.

Disrupted resting-state brain functional network properties in non-neuropsychiatric systemic lupus erythematosus patients

INTRODUCTION

Previous fMRI studies revealed that the abnormal functional connectivity (FC) was related to cognitive impairment in patients with SLE. However, it remains unclear how the disease severity affects the functional topological organization of the whole-brain network in SLE patients without neuropsychiatric symptoms (non-NPSLE).

OBJECTIVE

We aim to examine the impairment of the whole-brain functional network in SLE patients without neuropsychiatric symptoms (non-NPSLE), which may improve the understanding of neural mechanism in SLE.

METHODS

We acquired resting-state fMRI data from 32 non-NPSLE patients and 32 healthy controls (HC), constructed their whole-brain functional network, and then estimated the topological properties including global and nodal parameters by using graph theory. Meanwhile, we also investigated the differences in intra- and inter-network FC between the non-NPSLE patients and the HC.

RESULTS

The non-NPSLE patients showed significantly lower clustering coefficient, global and local efficiency, but higher characteristic path length than the HC. The non-NPSLE patients had significantly lower nodal strength in two regions, ventromedial prefrontal cortex (vmPFC) and anterior PFC (aPFC) than the HC. We found the non-NPSLE patients had significantly lower intra-network FC within frontal-parietal network (FPN) and within default mode network (DMN), and significantly lower inter-network FC between DMN and FPN than the HC. The intra-network FC within DMN was negatively correlated with systemic lupus erythematosus disease activity index (SLEDAI).

CONCLUSION

Abnormal whole-brain functional network properties and abnormal intra- and inter-network FC may be related to cognitive impairment and disease degree in the non-NPSLE patients. Our findings provide a network perspective to understand the neural mechanisms of SLE.

Parametric MRI Detects Aristolochic Acid Induced Acute Kidney Injury

Exposure to aristolochic acid (AA) is of increased concern due to carcinogenic and nephrotoxic effects, and incidence of aristolochic acid nephropathy (AAN) is increasing. This study characterizes renal alterations during the acute phase of AAN using parametric magnetic resonance imaging (MRI). An AAN and a control group of male Wistar rats received administration of aristolochic acid I (AAI) and polyethylene glycol (PEG), respectively, for six days. Both groups underwent MRI before and 2, 4 and 6 days after AAI or PEG administration. T₂ relaxation times and apparent diffusion coefficients (ADCs) were determined for four renal layers. Serum creatinine levels (sCr) and blood urea nitrogen (BUN) were measured. Tubular injury scores (TIS) were evaluated based on histologic findings. Increased T₂ values were detected since day 2 in the AAN group, but decreased ADCs and increased sCr levels and BUN were not detected until day 4. Significant linear correlations were observed between T₂ of the cortex and the outer stripe of outer medulla and TIS. Our results demonstrate that parametric MRI facilitates early detection of renal injury induced by AAI in a rat model. T₂ mapping may be a valuable tool for assessing kidney injury during the acute phase of AAN.

New Direct Limit on Neutrinoless Double Beta Decay Half-Life of ^{128}Te with CUORE

The Cryogenic Underground Observatory for Rare Events (CUORE) at Laboratori Nazionali del Gran Sasso of INFN in Italy is an experiment searching for neutrinoless double beta (0νββ) decay. Its main goal is to investigate this decay in ^{130}Te, but its ton-scale mass and low background make CUORE sensitive to other rare processes as well. In this Letter, we present our first results on the search for 0νββ decay of ^{128}Te, the Te isotope with the second highest natural isotopic abundance. We find no evidence for this decay, and using a Bayesian analysis we set a lower limit on the ^{128}Te 0νββ decay half-life of T_{1/2}>3.6×10^{24}  yr (90% CI). This represents the most stringent limit on the half-life of this isotope, improving by over a factor of 30 the previous direct search results, and exceeding those from geochemical experiments for the first time.

Kartogenin (KGN)/synthetic melanin nanoparticles (SMNP) loaded theranostic hydrogel scaffold system for multiparametric magnetic resonance imaging guided cartilage regeneration

Cartilage regeneration after injury is still a great challenge in clinics, which suffers from its avascularity and poor proliferative ability. Herein we designed a novel biocompatible cellulose nanocrystal/GelMA (gelatin-methacrylate anhydride)/HAMA (hyaluronic acid-methacrylate anhydride)-blended hydrogel scaffold system, loaded with synthetic melanin nanoparticles (SMNP) and a bioactive drug kartogenin (KGN) for theranostic purpose. We found that the SMNP-KGN/Gel showed favorable mechanical property, thermal stability, and distinct magnetic resonance imaging (MRI) contrast enhancement. Meanwhile, the sustained release of KGN could recruit bone-derived mesenchymal stem cells to proliferate and differentiate into chondrocytes, which promoted cartilage regeneration in vitro and in vivo. The hydrogel degradation and cartilage restoration were simultaneously monitored by multiparametric MRI for 12 weeks, and further confirmed by histological analysis. Together, these results validated the multifunctional hydrogel as a promising tissue engineering platform for noninvasive imaging-guided precision therapy in cartilage regenerative medicine.

Diffusion-weighted magnetic resonance imaging in rat kidney using two-dimensional navigated, interleaved echo-planar imaging at 7.0 T

The purpose of this study was to investigate the feasibility of two-dimensional (2D) navigated, interleaved multishot echo-planar imaging (EPI) to enhance kidney diffusion-weighted imaging (DWI) in rats at 7.0 T. Fully sampled interleaved four-shot EPI with 2D navigators was tailored for kidney DWI (Sprague-Dawley rats, n = 7) on a 7.0-T small bore preclinical scanner. The image quality of four-shot EPI was compared with T₂ -weighted rapid acquisition with relaxation enhancement (RARE) (reference) and single-shot EPI (ss-EPI) without and with parallel imaging (PI). The contrast-to-noise ratio (CNR) was examined to assess the image quality for the EPI approaches. The Dice similarity coefficient and the Hausdorff distance were used for evaluation of image distortion. Mean diffusivity (MD) and fractional anisotropy (FA) were calculated for renal cortex and medulla for all DWI approaches. The corticomedullary difference of MD and FA were assessed by Wilcoxon signed-rank test. Four-shot EPI showed the highest CNR among the three EPI variants and lowest geometric distortion versus T₂ -weighted RARE (mean Dice: 0.77 for ss-EPI without PI, 0.88 for ss-EPI with twofold undersampling, and 0.92 for four-shot EPI). The FA map derived from four-shot EPI clearly identified a highly anisotropic region corresponding to the inner stripe of the outer medulla. Four-shot EPI successfully discerned differences in both MD and FA between renal cortex and medulla. In conclusion, 2D navigated, interleaved multishot EPI facilitates high-quality rat kidney DWI with clearly depicted intralayer and interlayer structure and substantially reduced image distortion. This approach enables the anatomic integrity of DWI-MRI in small rodents and has the potential to benefit the characterization of renal microstructure in preclinical studies.

[Application of three risk assessment methods to noise risk assessment in an automobile foundry enterprise]

Objective: To explore the applicability of three different kinds of noise occupational health risk assessment methods to the occupational health risk assessment of noise exposed positions in an automobile foundry enterprise. Methods: In July 2020, the occupational-health risk assessment of noise-exposed positions was conducted by using the Guidelines for risk management of occupational noise hazard (guideline method) , the International Commission on Mining and Metals Guidelines for Occupational Health Risk Assessment (ICMM) method and the Occupational-health risk index method (index method) respectively, and the results were analyzed and compared. Results: Through the occupational health field investigation, the noise exposure level of the enterprise's main workstations was between 80.3 and 94.8 dB (A) , among which the noise of the posts of shaking-sand, cleaning and modeling was greater than 85 dB (A) ; The noise risk of each position was evaluated by the three methods, and the adjustment risk level was between 2 and 5 assessed using the guideline method, between 2 and 3 assessed using the index method, and 5 evaluated using the ICMM model. Conclusion: Each of the three risk assessment methods has its own advantages and disadvantages. The ICMM model has a large difference in value assignment, and values in the results are larger than expected. The evaluation results of the guideline method and the index method are consistent in some positions, there is certain subjectivity in the evaluation using the index method, and the guideline method is more objective.

Trapped Alkali-Metal Rydberg Qubit

Rydberg interactions of trapped alkali-metal atoms are used widely to facilitate quantum gate operations in quantum processors and repeaters. In most laboratory realizations using this protocol, the Rydberg states are repelled by the trapping laser fields, requiring that the fields be turned off during gate operations. Here we create a quasi-two-level system in a regime of Rydberg excitation blockade for a mesoscopic Rb ensemble of several hundred atoms confined in a magic-wavelength optical lattice. We observe many-body Rabi oscillations between the ground and collective Rydberg state. In addition we use Ramsey interference techniques to obtain the light shifts of both the lower and upper states of the collective qubit. Whereas the coupling producing the Rabi oscillations is enhanced by a factor of sqrt[N], there is no corresponding enhancement for the light shifts. We derive an effective two-level model which is in good agreement with our observations. Trapped Rydberg qubits and an effective two-level description are expected to have broad applicability for studies of quantum simulation and networking using collective encoding in ensembles of neutral atoms.

[Neck musculoskeletal disorders and their influence factors among welders in an automobile factory]

Objective: To explore the prevalence and risk factors of neck musculoskeletal diseases (MSDs) of welders among an automobile factory. Methods: In June 2019, a cluster random sampling method was used to select 677 electric welders from an automobile manufacturing plant in Shiyan City as the survey objects, and a questionnaire survey was conducted using the "Musculoskeletal Disorders Questionnaire" to analyze the prevalence and influencing factors of neck MSDs, and used logistic regression to analyze the relationship between the influencing factors and the prevalence of cervical MSDs. Results: The prevalence rate of MSDs in neck of welders was 54.8% (371/677) . The exposure rate of occupational factors, from high to low, were neckin a bent formord porsure was 71.6% (486/677) , repetitive head movements was 55.1% (373/677) , working in uncomfortable postures was 48.7% (330/677) and neck twisted was 46.8% (317/677) respectively. Sex, age, educational level, length of service, smoking, neck tilt, neck twist, working in uncomfortable posture and head repetitive movements were the risk factors of neck MSDs (P<0.05) . Multiple logistic regression analysis showed that, the main influencing factors of neck MSDs were sex, education level, age, length of service, smoking, neck tilt, working in uncomfortable posture (OR = 2.11, 2.03, 1.83, 1.21, 1.78, 1.90, 1.58, 95%CI: 1.28~3.48、1.47~2.81、1.33~2.52、1.03~1.41、1.22~2.60、1.28~2.83、1.11~2.27, P<0.05) , rest had protective effect on neck MSDs (OR= 0.38, 95%CI: 0.17~0.88, P<0.05) . Conclusion: Welders in automobile factory was highly exposed to occupational risk factors for neck MSDs. Occupational risk factors such as neck in a bent forward posture, working in an uncomfortable posture, prolonged siting, repetitive head movement should be the focus of intervention.

Application of amide proton transfer imaging for the diagnosis of neonatal hypoxic-ischemic encephalopathy

OBJECTIVE

This study aimed to evaluate cerebral amide proton transfer signal intensity (SI) among controls, hypoxic-ischemic encephalopathy (HIE) neonates with normal conventional magnetic resonance imaging (HIE/MRI-) findings, and HIE neonates with abnormal conventional MRI (HIE/MRI+) findings.

METHODS

Forty neonates diagnosed with neonatal HIE and sixteen normal neonates were evaluated. All neonates underwent conventional MRI scans and APT imaging. Cerebral APT SIs were compared to identify cerebral regions with significant APT changes among sixteen controls, thirteen HIE/MRI- patients, and twenty-seven HIE/MRI+ patients.

RESULTS

Significantly increased APT SIs were observed in the HIE/MRI- group compared with controls, in the left insula, right occipital lobe, left cingulate gyrus (posterior part), and corpus callosum. Significantly increased APT SIs were found in the HIE/MRI+ group compared with controls, in the right anterior temporal lobe (medial part), anterior parts of the right parahippocampal and ambient gyri, left superior temporal gyrus (middle part), left insula, left cingulate gyrus (posterior part), and right lentiform nucleus. No significant APT SI differences were observed in the cerebellum and brainstem among the three groups.

CONCLUSION

Amide proton transfer imaging plays an important role in detecting hypoxic-ischemic encephalopathy regardless of conventional MRI findings. Changes in APT signal intensity may provide important insights into the characterization of the cerebral internal environment. This study suggests that APT imaging could be used as a complement to conventional MRI in the detection of hypoxic-ischemic encephalopathy in clinical practice.

[Cumulative noise exposure and the risk of high-frequency hearing loss relationships]

Objective: To explore the dose-response relationship between cumulative noise exposure and high-frequency hearing loss, and further to provide a basis for the control of occupational hazards of noise. Methods: A Meta-analysis of dose-response relationships was performed on the data of eligible literatures published in China from January 2000.1 to December 2019.12. Results: The initial combined Odds Ratio (OR) and its 95%CI in the Meta-analysis were 1.10 (1.08-1.12) . As the Begg's funnel plot and Egger's test indicated publication bias (t=5.97, P<0.01) , the Trim-and-Fill Method was used for OR value adjustment. The adjusted-OR was 1.09 (1.07-1.12) ; sensitivity analysis showed that the results of this Meta-analysis have high stability; subgroup analysis indicated that the ORs of the steady-state noise group and the non-steady-state noise group were 1.10 (1.08-1.12) and 1.14 (1.07-1.21) , the ORs of the old standard group and the new standard group were 1.10 (1.08-1.12) and 1.11 (1.00-1.24) , respectively. The nonlinear dose-response relationship curve demonstrated that the risk of high-frequency hearing loss increases rapidly after CNE reaches 95 dB (A) ·years. Conclusion: There is a definite dose-response relationship between CNE and high-frequency hearing loss, which can be used to predict the risk of high-frequency hearing loss in noisy workers.

Carotid arterial wall MRI of apolipoprotein e-deficient mouse at 7 T using DANTE-prepared variable-flip-angle rapid acquisition with relaxation enhancement

PURPOSE

To optimize a sequence combining the delay alternating with nutation for tailored excitation (DANTE) preparative module with the variable-flip-angle rapid acquisition with relaxation enhancement (VF-RARE) sequence (DANTE-VF-RARE) and to investigate its feasibility for vessel wall imaging in Apolipoprotein E-Deficient (ApoE^-/-) mouse at 7 Tesla (T).

MATERIALS AND METHODS

Specific T1/T2 values were used for producing a sharper vessel wall in the variable-flip-angle optimization scheme. The DANTE RF pulse flip angle and pulse train length were optimized for maximizing the wall-lumen contrast. ApoE^-/- (fed high fat diet for 20/40/ 60 weeks, n = 9/4/4) and wild-type mice (controls, n = 3) were imaged at 7 T using VF-RARE, DANTE-VF-RARE, time-of-flight (TOF) angiography, and multi-slice T1-weighted 2D RARE coupled with inflow outflow saturation bands (IOSB-RARE). Wall-lumen contrast-to-noise-ratio efficiency (CNR_eff), lumen area (LA), and wall area (WA) were compared between DANTE-VF-RARE and 2D IOSB-RARE sequences. Additionally, linear regression analysis was conducted between MR measurements and histomorphometric planimetry results.

RESULTS

Residual blood signal was observed in the four out of eighteen carotids on VF-RARE images, whereas it was significantly suppressed on DANTE-VF-RARE images. Compared with IOSB-RARE, DANTE-VF-RARE offered significantly improved CNR_eff (P < 0.001). The LA and WA were both comparable (P = 0.085 and 0.112, respectively) and showed excellent agreement between DANTE-VF-RARE and IOSB-RARE (ICC = 0.96 and 0.95, respectively). The luminal stenosis identified by DANTE-VF-RARE was in consistent with the results of TOF. Strong correlations were found between MR measurements and histopathological analysis for both WA (DANTE-VF-RARE: r = 0.92, slope = 0.94, P < 0.001; IOSB-RARE: r = 0.93, slope = 0.94, P < 0.001) and LA (DANTE-VF-RARE: r = 0.82, slope = 0.54, P < 0.001; IOSB-RARE: r = 0.78, slope = 0.50, P < 0.001).

CONCLUSION

DANTE-VF-RARE achieves effective blood signal suppression and is a feasible approach for the 3D carotid arterial wall imaging of ApoE^-/- mouse at 7 T.

Quantitative evaluation of bone marrow fat content and unsaturated fatty index in young male soccer players using proton magnetic resonance spectroscopy (1H-MRS): a preliminary study

Background

Marrow fat exists as a distinct adipose tissue and plays a critical role in affecting both the quantity and quality of bone. However, the effect of soccer training on marrow fat has been rarely reported. This study aims to evaluate and characterize the marrow fat content and composition in different bone areas of soccer players and age-matched healthy subjects using proton magnetic resonance spectroscopy (¹H-MRS).

Methods

Between May 2020 and June 2020, 20 professional soccer players (20.7±0.9 years) and 20 age-matched healthy subjects (21.2±0.8 years) were enrolled in this cross-sectional study. The ¹H-MRS were acquired from the 3^rd lumbar vertebrae, bilateral femoral necks, and distal tibias of all subjects using a single-voxel point-resolved spatially localized spectroscopy (PRESS) sequence. Four soccer players underwent a second magnetic resonance (MR) examination within a 30-minute interval after the initial scan to evaluate test-retest reproducibility. Inter- and intra-observer measurement reliabilities were assessed using 10 randomly selected spectra from the soccer players group. All spectra were processed using the jMRUI software package (http://www.jmrui.eu/). Quantified water and lipid signals were used to calculate fat content (FC) and the unsaturated fatty index (UI).

Results

Compared with healthy subjects, we found that soccer players had a lower FC in L3 and bilateral femoral necks and higher UI in the left femoral neck (P<0.05). All FC and UI values of the bilateral distal tibias showed no significant differences between the two groups (P>0.05). The UI values of the right femoral neck or distal tibia were markedly higher than the left side in both inactive subjects and soccer players (P<0.05, except for the femoral neck in players), and there were notable ΔUI differences in the lower limbs between the soccer players and the healthy subjects (P<0.05).

Conclusions

Soccer practice can be considered a positive sport that contributes to decreasing FC in lumbar vertebrae and femoral necks and increasing the UI in femoral necks. Quantitative MRS provides an ideal modality to predict marrow fat metabolism caused by mechanical stimulation.

[1-deoxynojirimycin alleviates liver fibrosis induced by type 2 diabetes in mice]

OBJECTIVE

To investigate the effect of 1-deoxynojirimycin (DNJ) for improving diabetic liver fibrosis and explore the underlying mechanism.

METHODS

Mouse models of type 2 diabetes were established in 10 Kunming mice by high-fat diet feeding for 8 weeks and intraperitoneal injection of STZ, with 5 mice receiving intraperitoneal injection of citrate buffer solution with normal feeding as the control group. The mouse models were randomized into two groups (n=5) for further highfat feeding (model group) and additional treatment with 10% DNJ in drinking water (200 mg · kg^-1 per day; DNJ group) for 8 weeks. The mice were monitored for changes in body weight (BW), blood glucose, serum total cholesterol (TC), triglyceride (TG) and superoxide dismutase (SOD) levels. The pathological changes in the liver tissue were observed using HE and Sirius Red staining, and the solubility of collagens in the liver tissues was determined. The expression levels of MCP-1, TNF-α, IL-1β and TGF-β1 mRNA were detected with real-time PCR, and the protein expressions of α-SMA and collagen2 (ColA2) were determined with Western blotting. In the in vitro experiment, mouse fibroblasts L929 cells were pretreated with DNJ (10 μg/ mL) or PBS for 30 min followed by culture in high-glucose medium for 24 h, and the level of ROS production was measured using dihydroethidium (DHE) staining.

RESULTS

In the mouse model of type 2 diabetes, DNJ treatment significantly lowered serum level of glucose, TC, and TG (P < 0.05) and increased serum SOD activity (P < 0.05). DNJ obviously attenuated liver fibrosis in the diabetic mice, as shown by alleviated cross-linking of collagens and reduced contents of pepsin-solubilized collagen (PSC) and total collagen (P < 0.05). DNJ treatment also significantly reduced the overexpression of the proinflammatory cytokines and fibrosis-related cytokines induced by diabetes (P < 0.05). In L929 cells exposed to high glucose, pretreatment with DNJ significantly lowered the intensity of red fluorescence in DHE staining.

CONCLUSION

DNJ can attenuate type 2 diabetes-induced liver fibrosis in mice through its hypoglycemic, anti-inflammatory and anti-oxidative effects.

[Determination of Methoxyacetic acid in urine by pre-column derivatization-liquid-liquid microextraction coupled with gas chromatography]

Objective: To establish a method for determining methoxyacetic acid in urine by pre-column derivatization-liquid-liquid microextraction coupled with gas chromatography (GC) . Methods: Phosphate buffer solution, tert-butoxyacetic acid (internal standard) and pentafluorobenzyl bromide (derivative) were added to the urine sample. After derived in a water bath at 90 ℃ for 40 min, the mixture was cooled and filtered, then the dichloromethane was used as an extractant. After being shaken and centrifuged, the lower organic phase was sucked and injected into a gas chromatograph, separated by a DB-5 capillary column, and detected by an ECD detector. Results: The linear range of the method was 0.6~60.0 mg/L with the correlation coefficients (r) above 0.999. The average recovery was76.6%~110.7%, the inter-day precision was 8.00%~8.82%, and the detection limit was 0.13 mg/L. Conclusion: The method was founded to be high sensitivity, low organic reagent usage and green. So it is suitable for the detection of methoxyacetic acid in urine of occupational exposure to ethylene glycol monomethyl ether.

Value of Magnetic Resonance Cholangiopancreatography in Santorinicele and Wirsungocele

BACKGROUND

Former studies showed that magnetic resonance cholangiopancreatography (MRCP) is useful in diagnosing the presence of santorinicele; however, few studies have evaluated MRCP in diagnosing wirsungocele and the association between pancreatitis and santorinicele or wirsungocele. The purpose of the study was to explore the performance of MRCP in diagnosing santorinicele and wirsungocele and investigate the potential association among pancreatitis, pancreas divisum, and santorinicele or wirsungocele. <P> Method: Seventy-five patients (mean age, 54.6 years; range, 11-82 years) with santorinicele or wirsungocele were included and sorted into two groups: the santorinicele group (n = 57) and the wirsungocele group (n = 18). All patients underwent MRCP. The images were evaluated for the appearance and size of santorinicele or wirsungocele. The diagnostic sensitivity of MRCP was assessed. Additionally, whether two groups are correlated with pancreas divisum or pancreatitis were investigated. <P> Result: The sensitivity of MRCP in detecting santorinicele and wirsungocele showed no difference (70.2% and 77.8%, respectively). The proportion of patients who developed pancreatitis in santorinicele and wirsungocele groups were 59.6% and 11.1%, respectively (p < 0.05). Pancreas divisum accounted for 78.9% and 11.1% of the patients in the santorinicele and wirsungocele groups, respectively (p < 0.05). Patients with santorinicele and pancreas divisum tended to be older when they acquired pancreatitis. <P> Conclusion: MRCP could be an alternative imaging method to detect cystic dilation of the pancreatic duct. Pancreatitis is more common in patients with santorinicele than in those with wirsungocele. Moreover, santorinicele is more closely associated with pancreatitis than with pancreas divisum.

Measurement of the 2νββ Decay Half-Life of ^{130}Te with CUORE

We measured two-neutrino double beta decay of ^{130}Te using an exposure of 300.7 kg yr accumulated with the CUORE detector. Using a Bayesian analysis to fit simulated spectra to experimental data, it was possible to disentangle all the major background sources and precisely measure the two-neutrino contribution. The half-life is in agreement with past measurements with a strongly reduced uncertainty: T_{1/2}^{2ν}=7.71_{-0.06}^{+0.08}(stat)_{-0.15}^{+0.12}(syst)×10^{20}  yr. This measurement is the most precise determination of the ^{130}Te 2νββ decay half-life to date.

Inflow-based vascular-space-occupancy (iVASO) might potentially predict IDH mutation status and tumor grade in diffuse cerebral gliomas

PURPOSE

The aim of the study is to assess the diagnostic performance of inflow-based vascular-space-occupancy (iVASO) MR imaging for differentiating glioblastomas (grade IV, GBM) and lower-grade diffuse gliomas (grade II and III, LGG) and its potential to predict IDH mutation status.

METHODS

One hundred and two patients with diffuse cerebral glioma (56 males; median age, 43.5 years) underwent iVASO and dynamic susceptibility contrast (DSC) MR imaging. The iVASO-derived arteriolar cerebral blood volume (CBVa), relative CBVa (rCBVa), and the DSC-derived relative cerebral blood volume (rCBV) were obtained, and these measurements were compared between the GBM group (n = 43) and the LGG group (n = 59) and between the IDH-mutation group (n = 54) and the IDH-wild group (n = 48).

RESULTS

Significant correlation was observed between rCBV and CBVa (P < 0.001) or rCBVa (P < 0.001). Both CBVa (P < 0.001) and rCBVa (P < 0.001) were higher in the GBM group. Both CBVa (P < 0.001) and rCBVa (P < 0.001) were lower in the IDH-mutation group compared to the IDH-wild group. Receiver operating characteristic analyses showed the area under curve (AUC) of 0.95 with CBVa and 0.97 with rCBVa in differentiating GBM from LGG. The AUCs were 0.82 and 0.85 for CBVa and rCBVa in predicting IDH gene status, respectively, which were lower than that of rCBV (AUC = 0.90). Combined rCBV and rCBVa significantly improved the diagnostic performance (AUC = 0.95).

CONCLUSIONS

iVASO MR imaging has the potential to predict IDH mutation and grade in glioma.

[Determination of n-butyl alcohol in urine by headspace solid-phase microextraction coupled with gas chromatography]

Objective: To establish a headspace solid phase microextraction-gas chromatography method for determination of n-Butyl alcohol in urine. Methods: In October 2019, the n-butyl alcohol in urine was extracted with a polydimethylsiloxane/divinylbenzene (PDMS/DVB) solid-phase microextraction head. The conditions of salt amount, extraction temperature, extraction time and desorption time were optimized. The separation was performed on HP-5 (30 m×0.32 mm×0.25 μm) capillary column and detected with flame ionization detector. The quantification was based on the external standard curve. Results: The linear relationship of n-butyl alcohol in urine was good in the range of 0.04-3.00 mg/L, the correlation coefficient was 0.999, the detection limit of the method was 0.04 mg/L, the recovery was 77.4%-102.8%, the intra-run precision was 3.67%-8.11%, and the inter-assay precision was 4.94%-6.90%. Conclusion: The method has simple operation, high concentration efficiency and high sensitivity, and it is suitable for the determination of n-butyl alcohol in urine of occupational exposure to n-butyl alcohol.

T1 mapping and feature tracking imaging of left ventricular extracellular remodeling in severe aortic stenosis

Background

Left ventricular (LV) extracellular remodeling is a critical process in aortic stenosis (AS), which is related to functional abnormalities. Data regarding the use of combined T1 mapping and feature tracking (FT) to assess LV extracellular remodeling in severe AS are scarce. This study aimed to investigate the ability of T1-derived and FT-derived parameters to identify and assess the changes in process of LV extracellular remodeling in patients with severe AS.

Methods

A total of 49 patients with severe AS and 20 healthy volunteers were prospectively recruited. Modified look-locker inversion-recovery T1 mapping and FT imaging were performed in all participants using 3.0-T cardiac magnetic resonance imaging. The degree of myocardial fibrosis was quantified using Masson trichrome stain in biopsy specimens obtained intraoperatively from 13 patients and expressed as collagen volume fraction (CVF). Patients were divided into subgroups according to preserved LV ejection fraction (LVEF) (LVEF ≥50%) or reduced LVEF (LVEF <50%).

Results

Regarding the diffuse fibrosis burden, extracellular volume (ECV) was statistically insignificant between patients with preserved LVEF) and controls (28.0%±3.3% vs. 26.5%±2.3%, P>0.05). ECV in the reduced LVEF group (n=20) was significantly higher than that in the preserved LVEF group (n=29) (30.4%±3.9% vs. 28.0%±3.3%, P<0.05). Regarding the myocardial strain, global longitudinal strain (GLS) showed increasing impairment from the control group to the preserved LVEF AS group to the reduced LVEF AS group (-23.4%±3.3% vs. -18.6%±3.8% vs. -11.2%±4.8%, P<0.05). A significant correlation was found between ECV and CVF (r=0.64, P=0.020), whereas the correlation between GLS and CVF was insignificant. Significant correlations were observed between GLS and LV mass index (r=0.72, P=0.006) and LVEF (r=0.82, P<0.001). However, no correlations were found between ECV and LV mass index (P=0.172) and between ECV and LVEF (P=0.339). Discrimination of patients with preserved LVEF from controls, GLS yielded the best diagnostic performance as defined by the area of under the curve (-0.83), and GLS, ECV, and post-T1 were significant discriminators after regression analysis.

Conclusions

In the process of LV extracellular remodeling in severe AS, ECV is the structural marker of extracellular fibrosis burden, and GLS is the functional marker before the fibrosis burden intensifies.

[Determination of metabolites of styrene in urine by dispersive liquid-liquid microextraction coupled with high performance liquid chromatography]

Objective: To establish a method for the determination of mandelic acid and phenylglyoxylic acid in the urine of styrene by dispersive liquid-liquid microextraction-high coupled with high performance liquid chromatography. Methods: N-octanol was used as an extractant and ethanol was used as a dispersing agent. The phenylglycolic acid and phenylglyoxylic acid in the urine were extracted, and the upper liquid was taken after vortexing and centrifuged, and then was injected into HPLC for analysis. Results: The linear correlation coefficient of the concentration of phenylglycolic acid in the range of 0~10.0 mg/L was greater than 0.999. The detection limit of the method was 9.9 μg/L, the recovery rates were 86.1%~101.6%. The intraday RSDs of the method were 1.07%~3.76%, and the interday RSDs were 1.24%~3.33%. The linear correlation coefficient of phenylglyoxylic acid in the range of 0.0~2.0 mg/L is greater than 0.999. The detection limit of the method was 2.6 μg/L, the recovery rates were 88.8%~100.3%. The intraday RSDs of the method were 1.02%~ 3.17%, and the interday RSDs were 1.59%~2.41%. Conclusion: The method has low detection limit, high enrichment ratio and good sensitivity, and is suitable for determination of phenylglycolic acid and phenylglyoxylic acid in urine of occupational exposure to styrene.

[Determination of nickel in urine by ultrasonic-assisted ionic liquid microextraction-graphite furnace atomic absorption spectrometry]

Objective: To set up a new method to determine the nickel of urine in urine using dispersive liquid-liquid microextraction (DLLME) coupled with graphite furnace atomic absorption spectrometry (GFAAS) . Methods: From September 2018 to September 2019, the methanol, pyrrolidine dithiocarbamate and ionic liquid 1-hexyl-3-methyl-imidazolium hexafluorophosphate were used as dispersive solvent, the chelating agent and extraction solvent for the preconcentration of nickel, respectively. After adding into buffer solution of pH 9, ultrasonic dissolving for 10 minutes, centrifugal separation and then discarding the supernatant, the precipitate was saved. Dissolving the precipitate by methanol, mixing thoroughly on a vortex mixer, the 15 μl of the mixed solution was used for determination by graphite furnace atomic absorption spectrometry. Results: The linear correlation coefficient of urine nickel concentration in the range of 2.0-10.0 μg/L, r=0.999, with the detection limitation of 0.43 μg/L. The recovery rate and the relative standard deviations were 95.6%-103.7% and 2.53%-4.82%, respectively. Conclusion: The method, which has low detection limit, high recovery rate and good precision, is suitable for the determination of nickel in urine for the occupational populations exposure to nickel and non-occupational exposure.

[Determination of manganese in human urine by dispersive ionic liquid-liquid microextraction-graphite furnace atomic absorption spectrometry]

Objective: To establish a method for the determination of manganese in urine with graphite furnace atomic absorption spectrometry (GFAAS) by using ionic liquid microextraction. Methods: The ethanol, 8-hydroxyquinoline and ionic liquid 1-octyl-3-methyl-imidazolium hexafluorophosphate were used as dispersive solvent, chelating agent and extraction solvent respectively, for the preconcentration of manganese. After the optimal extraction conditions were optimized by single factor rotations, evaluate the performance indicators such as methodological precision, accuracy, and detection limit. Results: The linear range of urine manganese was 0.0-1.6 μg/L, and the correlation coefficient of standard curve line was 0.992, the detection limit was 0.03 μg/L, the recovery of sample spiked was 84.90%-96.50%, and the relative standard deviation was 0.36%-1.84%. Conclusion: The method has the advantages of low detection limit, high recovery rate and high sensitivity. It is suitable for the determination of manganese in urine samples from occupational exposure populations and the general population.

Physiological system analysis of the kidney by high-temporal-resolution T 2 ∗ monitoring of an oxygenation step response

PURPOSE

Examine the feasibility of characterizing the regulation of renal oxygenation using high-temporal-resolution monitoring of the T 2 ∗ response to a step-like oxygenation stimulus.

METHODS

For T 2 ∗ mapping, multi-echo gradient-echo imaging was used (temporal resolution = 9 seconds). A step-like renal oxygenation challenge was applied involving sequential exposure to hyperoxia (100% O₂ ), hypoxia (10% O₂ + 90% N₂ ), and hyperoxia (100% O₂ ). In vivo experiments were performed in healthy rats (N = 10) and in rats with bilateral ischemia-reperfusion injury (N = 4). To assess the step response of renal oxygenation, a second-order exponential model was used (model parameters: amplitude [A], time delay [Δt], damping constant [D], and period of the oscillation [T]) for renal cortex, outer stripe of the outer medulla, inner stripe of the outer medulla, and inner medulla.

RESULTS

The second-order exponential model permitted us to model the exponential T 2 ∗ recovery and the superimposed T 2 ∗ oscillation following renal oxygenation stimulus. The in vivo experiments revealed a difference in D_{outer medulla} between healthy controls (D < 1, indicating oscillatory recovery) and ischemia-reperfusion injury (D > 1, reflecting aperiodic recovery). The increase in D_{outer medulla} by a factor of 3.7 (outer stripe of the outer medulla) and 10.0 (inner stripe of the outer medulla) suggests that this parameter might be rather sensitive to (patho)physiological oxygenation changes.

CONCLUSION

This study demonstrates the feasibility of monitoring the dynamic oxygenation response of renal tissues to a step-like oxygenation challenge using high-temporal-resolution T 2 ∗ mapping. Our results suggest that the implemented system analysis approach may help to unlock questions regarding regulation of renal oxygenation, with the ultimate goal of providing imaging means for diagnostics and therapy of renal diseases.

Applying Amide Proton Transfer-Weighted Imaging (APTWI) to Distinguish Papillary Thyroid Carcinomas and Predominantly Solid Adenomatous Nodules: Comparison With Diffusion-Weighted Imaging

Background: Amide proton transfer-weighted (ATPw) imaging is a novel MRI technique that has been used to identify benign and malignant tumors. The present study evaluated the role of APTw imaging in differentiating papillary thyroid carcinoma from predominantly solid adenomatous nodule.

Methods: This study included 24 cases of solitary papillary thyroid carcinoma, and 20 cases of solid adenomatous nodules. Normal thyroid tissues were examined in 12 healthy subjects. The healthy subjects, eight cases of adenomatous nodule with cystic degeneration, and 12 cases of thyroid goiter, were only considered in the descriptive analysis, not included in our statistical analysis. The mean APTw value and the apparent diffusion coefficients (ADCs) of papillary thyroid carcinoma and solid adenomatous nodule were compared via a Mann-Whitney U test and receiver operating characteristic (ROC)-curve analyses.

Results: The adenomatous nodule (3.3 ± 1.3%) exhibited significantly higher APTw value (p < 0.05) than that of the papillary thyroid carcinoma (1.8 ± 0.7%). The optimal cut-off value of the mean APTw value in differentiating papillary thyroid carcinoma from adenomatous nodule was 3.15%, with a sensitivity of 60% and a specificity of 100%. The mean ADC of papillary thyroid carcinoma (1.2 ± 0.2 × 10⁻³ mm²/s) was significantly lower than that of adenomatous nodule (2.0 ± 0.4 × 10⁻³ mm²/s). The optimal cut-off value of the mean ADC was 1.35 × 10⁻³ mm²/s, with a sensitivity of 100% and a specificity of 75%. Based on the ROC-curve analysis of APT and ADC, the ADC showed a higher area under the curve (AUC) than that of APT (AUC_APT = 0.84, AUC_ADC = 0.95).

Conclusion: APTw imaging may be as useful as DWI for the differentiation of papillary thyroid carcinoma from predominantly solid adenomatous nodule. Although the sensitivity of ADC was greater than that of APT, APT had greater specificity.

Non-Gaussian Diffusion Models and T1 rho Quantification in the Assessment of Hepatic Sinusoidal Obstruction Syndrome in Rats

BACKGROUND

Non-Gaussian diffusion models and T₁ rho quantification may reflect the changes in tissue heterogeneity in hepatic sinusoidal obstruction syndrome (SOS).

PURPOSE

To investigate the feasibility of diffusion kurtosis imaging (DKI), stretched exponential model (SEM), and T₁ rho quantification in detecting and staging SOS in a monocrotaline (MCT)-induced rat model.

STUDY TYPE

Animal study.

POPULATION

Thirty male Sprague-Dawley rats gavaged with MCT to induce hepatic SOS and six male rats without any intervention.

FIELD STRENGTH/SEQUENCE

3.0T, DWI with five b-values (0-2000 s/mm² ) and T₁ rho with five spin lock times (1-60 msec).

ASSESSMENT

MRI was performed 1 day before and 1, 3, 5, 7, and 10 days after MCT administration. The corrected apparent diffusion coefficient (D_app ), kurtosis coefficient (K_app ), distributed diffusion coefficient (DDC), and intravoxel water molecular diffusion heterogeneity (α) were calculated from the corresponding non-Gaussian diffusion model. The T₁ rho value was calculated using a monoexponential model. Specimens obtained from the six timepoints were categorized into normal liver (n = 6), early-stage (n = 16), and late-stage (n = 14) SOS in accordance with the pathological score.

STATISTICAL TESTS

Parametric statistical methods and receiver operating characteristic (ROC) curves were employed to determine diagnostic accuracy.

RESULTS

The D_app , K_app , DDC, α, and T₁ rho values were correlated with pathological score with r values of -0.821, 0.726, -0.828, -0.739, and 0.714 (all P < 0.001), respectively. DKI (combined D_app and K_app ) and SEM (combined DDC and α) were better than T₁ rho for staging SOS. The areas under the ROC curve of DKI, SEM, and T₁ rho for differentiating normal liver and early-stage SOS were 0.97, 1.00, and 0.79, whereas those of DKI, SEM, and T₁ rho for differentiating early-stage and late-stage SOS were 1.00, 0.97, and 0.92, respectively.

DATA CONCLUSION

DKI, SEM, and T₁ rho may be helpful in staging SOS.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY STAGE: 2 J. Magn. Reson. Imaging 2020;52:1110-1121.

Improved Limit on Neutrinoless Double-Beta Decay in ^{130} Te with CUORE

We report new results from the search for neutrinoless double-beta decay in ^{130} Te with the CUORE detector. This search benefits from a fourfold increase in exposure, lower trigger thresholds, and analysis improvements relative to our previous results. We observe a background of (1.38±0.07)×10^{-2}  counts/(keV kg yr)) in the 0νββ decay region of interest and, with a total exposure of 372.5 kg yr, we attain a median exclusion sensitivity of 1.7×10^{25}  yr. We find no evidence for 0νββ decay and set a 90% credibility interval Bayesian lower limit of 3.2×10^{25}  yr on the ^{130} Te half-life for this process. In the hypothesis that 0νββ decay is mediated by light Majorana neutrinos, this results in an upper limit on the effective Majorana mass of 75-350 meV, depending on the nuclear matrix elements used.

A robust electrical conductivity imaging method with total variation and wavelet regularization

PURPOSE

This study aims to develop and evaluate a robust conductivity imaging method that combines total variation and wavelet regularization to enhance the accuracy of conductivity maps.

THEORY AND METHODS

The proposed approach is based on a gradient-based method. The central equation is derived from Maxwell's equation and describes the relationship between conductivity and the transceive phase. A linear system equation is obtained via a finite-difference method and solved using a least-squares method. Total variation and wavelet transform regularization terms are added to the minimization problem and solved using the Split Bregman method to improve reconstruction stability. The proposed approach is compared with conventional and gradient-based methods. Numerical simulations are performed to validate the accuracy of the developed method, and the effects of noise are determined. Phantom and in vivo experiments are conducted at 3 T to verify the clinical applicability of the proposed method.

RESULTS

Numerical simulations show that the proposed method is more robust than other methods and can suppress the effects of noise. The quantitative conductivity value of the phantom experiment agrees with the measured value. The in vivo experiment results present a clear structure, and the conductivity value of the tumor region is significantly higher than that around healthy tissues.

CONCLUSION

The proposed electrical conductivity imaging method can improve the quality of conductivity reconstruction, and thus, has future clinical applications.

NiSe2/Ni(OH)2 Heterojunction Composite through Epitaxial-like Strategy as High-Rate Battery-Type Electrode Material

Constructing heterojunction is a promising way to improve the charge transfer efficiency and can thus promote the electrochemical properties. Herein, a facile and effective epitaxial-like growth strategy is applied to NiSe₂ nano-octahedra to fabricate the NiSe₂-(100)/Ni(OH)₂-(110) heterojunction. The heterojunction composite and Ni(OH)₂ (performing high electrochemical activity) is ideal high-rate battery-type supercapacitor electrode. The NiSe₂/Ni(OH)₂ electrode exhibits a high specific capacity of 909 C g^-1 at 1 A g^-1 and 597 C g^-1 at 20 A g^-1. The assembled asymmetric supercapacitor composed of the NiSe₂/Ni(OH)₂ cathode and p-phenylenediamine-functional reduced graphene oxide anode achieves an ultrahigh specific capacity of 303 C g^-1 at 1 A g^-1 and a superior energy density of 76.1 Wh kg^-1 at 906 W kg^-1, as well as an outstanding cycling stability of 82% retention for 8000 cycles at 10 A g^-1. To the best of our knowledge, this is the first example of NiSe₂/Ni(OH)₂ heterojunction exhibiting such remarkable supercapacitor performance. This work not only provides a promising candidate for next-generation energy storage device but also offers a possible universal strategy to fabricate metal selenides/metal hydroxides heterojunctions.

"HOT" Alkaline Hydrolysis of Amorphous MOF Microspheres to Produce Ultrastable Bimetal Hydroxide Electrode with Boosted Cycling Stability

Nickel/cobalt hydroxide is a promising battery-type electrode material for supercapacitors. However, its low cycle stability hinders further applications. Herein, Ni_0.7 Co_0.3 (OH)₂ core-shell microspheres exhibiting extreme-prolonged cycling life are successfully synthesized, employing Ni-Co-metal-organic framework (MOF) as the precursor/template and a specific hydrolysis strategy. The Ni-Co-MOF and KOH aqueous solution are separated and heated to 120 °C before mixing, rather than mixing before heating. Through this hydrolysis strategy, no MOF residual exists in the product, contributing to close stacking of the hydroxide nanoflakes to generate Ni_0.7 Co_0.3 (OH)₂ microspheres with a robust core-shell structure. The electrode material exhibits high specific capacity (945 C g^-1 at 0.5 A g^-1 ) and unprecedented cycling performance (100% after 10 000 cycles). The fabricated asymmetric supercapacitor delivers an energy density of 40.14 Wh kg^-1 at a power density of 400.56 W kg^-1 and excellent cycling stability (100% after 20 000 cycles). As far as is known, it is the best cycling performance for pure Ni/Co(OH)₂ .

Differential detection of metastatic and inflammatory lymph nodes using intravoxel incoherent motion diffusion-weighted imaging

PURPOSE

This study sought to monitor the dynamic process of lymph node (LN) metastasis with intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI), and to investigate the impact of disease course on the detection of metastatic LNs by IVIM-DWI.

METHODS

Twenty female New Zealand rabbits with 2.5-3.0 kg body weight were studied. VX2 cells and egg yolk emulsion were randomly inoculated into one thigh to induce metastatic and inflammatory popliteal LNs, respectively. Eight rabbits underwent IVIM-DWI (14 b values, 0-2000 s/mm²) 2 h prior to, and 14, 21, and 28 days after inoculation (D0, D14, D21, D28). The apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudodiffusion coefficient (D*), and perfusion fraction (f) were measured and compared between the metastatic and the inflammatory groups at each time point. Three rabbits randomly chosen from the remaining twelve rabbits were sacrificed at each time point to perform hematoxylin and eosin staining and histologic evaluation.

RESULTS

The patterns of dynamic change of D*, ADC, and D were different between the metastatic and the inflammatory LNs. The metastatic group had a lower D* value at D14 (p = .003), and greater ADC and D values at both D21 (p = .001, p = .001) and D28 (p = .021, p = .001), compared to the inflammatory group. The f value of the metastatic group was greater than that of the inflammatory only at D28 (p = .001).

CONCLUSIONS

IVIM-DWI can reflect the dynamic process of LN metastasis, and disease course has a significant influence on the ability of IVIM-DWI to detect metastatic nodes.

Intravoxel incoherent motion MR imaging for differentiating malignant lesions in spine: A pilot study

PURPOSE

To determine the diagnostic potential of Intravoxel Incoherent Motion (IVIM) MRI for differentiating malignant spinal tumours from acute vertebral compression fractures and tuberculous spondylitis, and to compare IVIM with diffusion-weighted imaging (DWI) and chemical shift imaging (CSI).

METHODS

The Institutional Review Board approved this prospective study, and informed consent was obtained. IVIM MRI, DWI, and CSI at 1.5 T were performed in 25 patients with 12 acute compression fractures, 14 tuberculous spondylitis, and 18 malignant spinal tumours. The parameters of these techniques were assessed using the Kruskal-Wallis test. The diagnostic performance of the parameters was evaluated using receiver operating characteristic (ROC) analysis.

RESULTS

ADC, SIR, D_slow, D_fast, and f values of malignant tumours were significantly different from those of acute compression fracture (for all, p < 0.05). The mean D_slow and D_fast values of malignant spinal tumours had significant differences compared with those of tuberculous spondylitis (for all, p < 0.05). However, no significant differences were observed in any quantitative parameters between the acute compression fracture and the tuberculous spondylitis (p > 0.05). D_slow•f showed the highest AUC value of 0.980 (95%CI: 0.942-1.000) in differentiating acute compression fracture and malignant spinal tumours. D_slow showed the highest AUC value of 0.877 (95%CI: 0.713-0.966) in differentiating tuberculous spondylitis and malignant spinal tumours.

CONCLUSIONS

IVIM MR imaging may be helpful for differentiating malignant spinal tumours from acute vertebral compression fractures and tuberculous spondylitis.

Early identification of neonatal mild hypoxic-ischemic encephalopathy by amide proton transfer magnetic resonance imaging: A pilot study

PURPOSE

This study aimed to evaluate the amide proton transfer (APT) values in neonates with mild hypoxic-ischemic encephalopathy (HIE) using APT imaging.

METHOD

A total of 30 full-term neonates with mild HIE (16 males and 14 females; mean postnatal age 4.2 days, age range 2-7 days) and 12 normal neonates (six males and six females; mean postnatal age 3.3 days, age range 2-5 days) underwent conventional magnetic resonance imaging and APT imaging. APT measurements were performed in multiple regions of interest (ROIs) in the brain. APT values were statistically analyzed to assess for significant differences between the mild HIE and normal neonates in different regions of the brain, and correlation with neonatal gestational age.

RESULTS

In 30 neonates with mild HIE, 10% (3/30) of the HIE patients had normal conventional MRI. There were significant differences in APT values of the HIE group in bilateral caudate, bilateral thalamus, bilateral centrum semiovale and left globus pallidus/putamen (p < 0.05), and no statistical difference was observed in right globus pallidus/putamen (p = 0.051) and brainstem (p = 0.073) between the two groups. Furthermore, APT values in bilateral caudate, bilateral globus pallidus/putamen, bilateral thalamus, and brainstem regions (p < 0.05) exhibited positive linear correlations with gestational age in the control group, except for bilateral centrum semiovale (right: Pearson's r = 0.554, p = 0.062; left: Pearson's r = 0.561, p = 0.058). In the mild HIE groups, no significant correlation with gestational age was found in all regions.

CONCLUSIONS

APT imaging is a feasible and useful technique with diagnostic capability for neonatal HIE.

Controlled Hydrolysis of Metal-Organic Frameworks: Hierarchical Ni/Co-Layered Double Hydroxide Microspheres for High-Performance Supercapacitors

Pseudomorphic conversion of metal-organic frameworks (MOFs) enables the fabrication of nanomaterials with well-defined porosities and morphologies for enhanced performances. However, the commonly reported calcination strategy usually requires high temperature to pyrolyze MOF particles and often results in uncontrolled growth of nanomaterials. Herein, we report the controlled alkaline hydrolysis of MOFs to produce layered double hydroxide (LDH) while maintaining the porosity and morphology of MOF particles. The preformed trinuclear M₃(μ₃-OH) (M = Ni²⁺ and Co²⁺) clusters in MOFs were demonstrated to be critical for the pseudomorphic transformation process. An isotopic tracing experiment revealed that the ¹⁸O-labeled M₃(μ₃-¹⁸OH) participated in the structural assembly of LDH, which avoided the leaching of metal cations and the subsequent uncontrolled growth of hydroxides. The resulting LDHs maintain the spherical morphology of MOF templates and possess a hierarchical porous structure with high surface area (BET surface area up to 201 m²·g^-1), which is suitable for supercapacitor applications. As supercapacitor electrodes, the optimized LDH with the Ni:Co molar ratio of 7:3 shows a high specific capacitance (1652 F·g^-1 at 1 A·g^-1) and decent cycling performance, retaining almost 100% after 2000 cycles. Furthermore, the hydrolysis method allows the recycling of organic ligands and large-scale synthesis of LDH materials.

Reproducibility of quantitative susceptibility mapping in lumbar vertebra

Background

To evaluate the reliability and reproducibility of quantitative susceptibility mapping (QSM) in the lumbar vertebra.

Methods

From May 2017 to September 2017, 61 subjects who underwent QSM MRI and quantitative computed tomography (QCT) were consecutively enrolled in this prospective study. QSM examination was performed two times with an interval of less than 1 week for each subject. For each data set, the QSM and QCT values on L1-L4 vertebral bodies were measured independently by two radiologists. The correlation coefficient between QSM and QCT values was calculated on L1-L4 vertebral bodies. The intraclass correlation coefficient (ICC) and Bland-Altman plots were used to evaluate the inter-observer reliability and the inter-scan reproducibility on QSM.

Results

A total of 61 subjects (mean age, 55.5±13.7 years) with 244 vertebral bodies were analyzed. Overall, QSM and QCT showed good correlation in the L1-L4 vertebral body, especially in the L3 (R=-0.75). QSM value showed excellent inter-observer reliability (ICC, 0.992, 95% CI: 0.985-0.996) with a mean difference of 0.35 and 95% limits of agreements of within -22.74 to 23.45 ppb, and very good inter-scan reproducibility (ICC, 0.932, 95% CI: 0.886-0.959) with a mean difference of -7.60 ppb and 95% limits of agreements of within of -92.85 to 77.62 ppb.

Conclusions

QSM in the lumbar vertebra is a reliable and reproducible technique for evaluating bone mineral density.

Comparison of T1 Mapping and T1rho Values with Conventional Diffusion-weighted Imaging to Assess Fibrosis in a Rat Model of Unilateral Ureteral Obstruction

RATIONALE AND OBJECTIVES

The aim of this study was to investigate the potential of magnetic resonance imaging (MRI) T1 mapping and T1 relaxation time in the rotating frame (T1rho) for assessment of renal fibrosis in a rat model of unilateral ureteral obstruction (UUO).

MATERIALS AND METHODS

UUO was created in 36 rats. Six rats were scanned at each of the six time points (on days 0, 1, 3, 5, 10, and 15 after UUO). The contralateral kidneys were examined as controls. Hematoxylin-eosin, Masson's trichrome, and alpha-smooth muscle actin (α-SMA) antibody staining assays were performed. MRI data obtained with a 3.0T scanner were analyzed with α-SMA expression and Masson's staining.

RESULTS

The T1 relaxation times and T1rho values increased, and the mean apparent diffusion coefficient (ADC) values decreased with time after UUO. Simple regression analysis indicated that the mean ADCs, T1 relaxation times, and T1rho values had strong correlations with the α-SMA expression levels (R² = 0.34, R² = 0.66, R² = 0.71, respectively; P< .001) and positive Masson's staining (R² = 0.38, R² = 0.67, R² = 0.65, respectively; P< .001).

CONCLUSIONS

The T1 mapping and T1rho parameters had better correlations with α-SMA expression and Masson's staining than ADC values.

Unveiling the thermolysis natures of ZIF-8 and ZIF-67 by employing in situ structural characterization studies

ZIF-8 and ZIF-67 exhibit different thermolysis natures based on the in situ structural characterization techniques.

Technical Note: Clustering-based motion compensation scheme for multishot diffusion tensor imaging

PURPOSE

To extend image reconstruction using image-space sampling function (IRIS) to address large-scale motion in multishot diffusion-weighted imaging (DWI).

METHODS

A clustered IRIS (CIRIS) algorithm that would extend IRIS was proposed to correct for large-scale motion. For DWI, CIRIS initially groups the shots into clusters without intracluster large-scale motion and reconstructs each cluster by using IRIS. Then, CIRIS registers these cluster images and combines the registered images by using a weighted average to correct for voxel mismatch caused by intercluster large-scale motion. For diffusion tensor imaging (DTI), CIRIS further reduces the effect of motion on diffusion directions by treating motion-induced direction changes as additional diffusion directions. CIRIS also introduces the detection and rejection of motion-corrupted data to avoid corresponding image degradation. The proposed method was evaluated by simulation and in vivo diffusion datasets.

RESULTS

Experiments demonstrated that CIRIS can reduce motion-induced blurring and artifacts in DWI and provide more accurate DTI estimations in the presence of large-scale motion, compared with IRIS.

CONCLUSION

The proposed method presents a novel approach to correct for large-scale in-plane motion for multishot DWI and is expected to benefit the practical application of high-resolution diffusion imaging.

Intravoxel Incoherent Motion and Arterial Spin Labeling MRI Analysis of Reversible Unilateral Ureteral Obstruction in Rats

BACKGROUND

Renal fibrosis is a common consequence of chronic kidney disease (CKD) and is the mechanism by which various forms of CKD progress to endstage renal failure. Accurate assessment of renal fibrosis is important for treatment.

PURPOSE

To measure longitudinal changes of intravoxel incoherent motion (IVIM) and arterial spin labeling (ASL) before and after reversible unilateral ureteral obstruction in an animal model.

STUDY TYPE

Self-controlled animal study.

ANIMAL MODEL

Surgical obstruction of the ureters was performed and then removed after 5 days. Rats were scanned on Days 0, 1, 3, and 5 after creating the obstruction and on Days 4, 7, and 12 after releasing the obstruction.

FIELD STRENGTH/SEQUENCE

3.0T/IVIM/ASL.

ASSESSMENT

The apparent diffusion coefficient (ADC), pure molecular diffusion (D), perfusion fraction (f), pseudodiffusion (D*), and renal blood flow (RBF) obtained from the ASL were measured.

STATISTICAL TESTS

Using SPSS v. 20.0 software, P < 0.05 were considered statistically significant. The data from each timepoint were compared using one-way analysis of variance and correlation analysis was applied to various parameters.

RESULTS

The postobstruction kidneys showed renal tubule swelling and increased collagen fiber content. Renal tubule swelling was relieved after reversing the obstruction, but Masson staining and cell density analysis revealed progressive changes that were primarily localized to the medulla. In general, ADC, D, f, D*, and RBF decreased with time during the 5 days of obstruction, and increased after release of the obstruction. ADC positively correlated with D, f, D*, and RBF (r = 0.415, r = 0.634, r = 0.465 r = 0.586, P < 0.001, respectively) in the cortex in this study. Also, ADC showed a positive correlation with D, f, and D* (r = 0.724, r = 0.749, r = 0.151, P < 0.001, respectively) in the medulla.

DATA CONCLUSION

Kidney perfusion was the major factor affecting ADC. Functional imaging may be useful for following progression of CKD.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:288-296.