Comprehensive Comparison of MOCVD- and LPCVD-SiNx Surface Passivation for AlGaN/GaN HEMTs for 5G RF Applications

Passivation is commonly used to suppress current collapse in AlGaN/GaN HEMTs. However, the conventional PECV-fabricated SiNx passivation layer is incompatible with the latest process, like the "passivation-prior-to-ohmic" method. Research attention has therefore turned to high-temperature passivation schemes. In this paper, we systematically investigated the differences between the SiNx/GaN interface of two high-temperature passivation schemes, MOCVD-SiNx and LPCVD-SiNx, and investigated their effects on the ohmic contact mechanism. By characterizing the device interface using TEM, we reveal that during the process of MOCVD-SiNx, etching damage and Si diffuses into the semiconductor to form a leakage path and reduce the breakdown voltage of the AlGaN/GaN HEMTs. Moreover, N enrichment at the edge of the ohmic region of the LPCVD-SiNx device indicates that the device is more favorable for TiN formation, thus reducing the ohmic contact resistance, which is beneficial to improving the PAE of the device. Through the CW load-pull test with drain voltage VDS = 20V, LPCVD-SiNx devices obtain a high PAE of 66.35%, which is about 6% higher than MOCVD-SiNx devices. This excellent result indicates that the prospect of LPCVD-SiNx passivation devices used in 5G small terminals will be attractive.

Live-cell three-dimensional single-molecule tracking reveals modulation of enhancer dynamics by NuRD

To understand how the nucleosome remodeling and deacetylase (NuRD) complex regulates enhancers and enhancer-promoter interactions, we have developed an approach to segment and extract key biophysical parameters from live-cell three-dimensional single-molecule trajectories. Unexpectedly, this has revealed that NuRD binds to chromatin for minutes, decompacts chromatin structure and increases enhancer dynamics. We also uncovered a rare fast-diffusing state of enhancers and found that NuRD restricts the time spent in this state. Hi-C and Cut&Run experiments revealed that NuRD modulates enhancer-promoter interactions in active chromatin, allowing them to contact each other over longer distances. Furthermore, NuRD leads to a marked redistribution of CTCF and, in particular, cohesin. We propose that NuRD promotes a decondensed chromatin environment, where enhancers and promoters can contact each other over longer distances, and where the resetting of enhancer-promoter interactions brought about by the fast decondensed chromatin motions is reduced, leading to more stable, long-lived enhancer-promoter relationships.

Comparison of the Time and Accuracy of Intraoral Scans Performed by Dentists, Nurses, Postgraduates, and Undergraduates

OBJECTIVE

This study aimed to assess the scanning time (ST) and accuracy of 10 repeated upper and lower dentition scans by four groups of operators with different professional backgrounds.

METHODS

There were a total of 32 participants, including dentists, nurses, postgraduates, and undergraduates (n=8). They received the same training about intraoral scanning and then performed 10 repeat scans on the plaster maxillary and mandibular dentition models in a manikin head, with the first five scans being the T1 phase and the last five scans being the T2 phase. Each ST was recorded. Trueness and precision were evaluated by root mean square (RMS) value gained from alignments of corresponding virtual models. For statistical analysis, the paired-sample t-tests, one-way ANOVA, and Pearson correlation tests were employed (α=0.05).

RESULTS

Limiting the comparison in scan phase and scan target the sequence of STs for the four groups was the same (p<0.05), by which undergraduates, postgraduates, nurses, and dentists were in descending order. Undergraduates gained the best precision, followed by postgraduates, dentists, and nurses, in both maxillary and mandibular scanning (p<0.05). Compared with corresponding items of the T1 phase, the trueness of the T2 phase was much higher (p<0.05), while the ST of the T2 phase was much shorter (p<0.05).

CONCLUSIONS

The operator's professional background affects the precision and scanning time but not the trueness. Most dental personnel have good access to the intraoral scanner. As the number of scans increased, the accuracy and scanning efficiency also improved.

Simulation of Single-Event Transient Effect for GaN High-Electron-Mobility Transistor

A GaN high-electron-mobility transistor (HEMT) was simulated using the semiconductor simulation software Silvaco TCAD in this paper. By constructing a two-dimensional structure of GaN HEMT, combined with key models such as carrier mobility, the effects of a different state, different incidence position, different drain voltage, different LET values, and a different incidence angle on the single-event transient effect of GaN HEMT are simulated. LET stands for the linear energy transfer capacity of a particle, which refers to the amount of energy transferred by the particle to the irradiated substance on the unit path. The simulation results show that for GaN HEMTs, the single-event transient effect is more obvious when the device is in off-state than in on-state. The most sensitive location of GaN HEMTs to the single-event effect is in the region near the drain. The peak transient current increases with the increase in the drain bias and incident ion LET values. The drain charge collection time increases with the angle of incidence of heavy ion.

Unusual 3,4-Oxidative Coupling Polymerization on 1,2,5-Trisubstituted Pyrroles for Novel Porous Organic Polymers

Porous organic polymers (POPs) have demonstrated promising task-specific applications due to their structure designability and thus functionality. Herein, an unusual 3,4-polymerization on 1,2,5-trisubstituted pyrroles has been developed to give linear polypyrrole-3,4 in high efficiency, with Mn of 20000 and PDI of 1.7. This novel polymerization technique was applied to prepare a series of polypyrrole-based POPs (PY-POP-1-4), which exhibited high BET surface areas (up to 762 m2 g-1) with a meso-micro-supermicro hierarchically porous structure. Furthermore, PY-POPs were doped in the mixed matrix membranes based on the polysulfone matrix to enhance the gas permeability and gas pair selectivity, with H2/N2 selectivity up to 84.6 and CO2/CH4 and CO2/N2 selectivity up to 46.8 and 39.6.

Exhaled volatile fatty acids, ruminal methane emission, and their diurnal patterns in lactating dairy cows

To date, the commonly used methods to assess rumen fermentation are invasive. Exhaled breath contains hundreds of volatile organic compounds (VOC) that can reflect animal physiological processes. In the present study, for the first time, we aimed to use a noninvasive metabolomics approach based on high-resolution mass spectrometry to identify rumen fermentation parameters in dairy cows. Enteric methane (CH4) production from 7 lactating cows was measured 8 times over 3 consecutive days using the GreenFeed system (C-Lock Technology Inc.). Simultaneously, exhalome samples were collected in Tedlar gas sampling bags and analyzed offline using a secondary electrospray ionization high-resolution mass spectrometry system. In total, 1,298 features were detected, among them targeted exhaled volatile fatty acids (eVFA; i.e., acetate, propionate, butyrate), which were putatively annotated using their exact mass-to-charge ratio. The intensity of eVFA, in particular acetate, increased immediately after feeding and followed a similar pattern to that observed for ruminal CH4 production. The average total eVFA concentration was 35.5 count per second (CPS), and among the individual eVFA, acetate had the greatest concentration, averaging 21.3 CPS, followed by propionate at 11.5 CPS, and butyrate at 2.67 CPS. Further, exhaled acetate was on average the most abundant of the individual eVFA at around 59.3%, followed by 32.5 and 7.9% of the total eVFA for propionate and butyrate, respectively. This corresponds well with the previously reported proportions of these VFA in the rumen. The diurnal patterns of ruminal CH4 emission and individual eVFA were characterized using a linear mixed model with cosine function fit. The model characterized similar diurnal patterns for eVFA and ruminal CH4 and H2 production. Regarding the diurnal patterns of eVFA, the phase (time of peak) of butyrate occurred first, followed by that of acetate and propionate. Importantly, the phase of total eVFA occurred around 1 h before that of ruminal CH4. This corresponds well with existing data on the relationship between rumen VFA production and CH4 formation. Results from the present study revealed a great potential to assess the rumen fermentation of dairy cows using exhaled metabolites as a noninvasive proxy for rumen VFA. Further validation, with comparisons to rumen fluid, and establishment of the proposed method are required.

Inter-fraction Dynamics during Adaptive Hypofractionated Radiotherapy for Brain Metastases with a MR LINAC

PURPOSE/OBJECTIVE(S)

This study examined the displacement and deformation in brain metastases (BMs) during adaptive hypofractionated radiotherapy (HFRT) on a magnetic resonance imaging linear accelerator (MR LINAC). In addition, the contouring variability between enhanced T1 (T1+c) and T2/FLAIR (T2f) sequence to define gross tumor volume (GTV) was compared.

MATERIALS/METHODS

Patients with 1-3 BMs and treated with MR LINAC were enrolled. T1+c sequence was acquired at initial planning, while T2/T2f was acquired during each fraction. GTV at initial planning (GTVi) and fraction 1-n (GTV1-n) were contoured in all images. Dice similarity coefficient (DSC) was used to quantify the contouring variability between different sequences at initial planning. The three-dimensional coordinate values of geometric centers of GTVi and GTV1-n were recorded and the distance was calculated. Statistical analysis was performed using two-sided paired t-test.

RESULTS

Between December 2019 and October 2022, 19 patients with 22 BMs were analyzed. The median age was 64 y (37-84 y) and the major primary tumor was lung cancer (89.5%). The median dose was 52 Gy in 13 fractions (30 Gy/5f- 60 Gy/20 f). The median GTVi on T1c, T2f and T2 sequences were 6.70cc (0.41-84.85 cc), 6.70 cc (0.35-84.14 cc, p = 0.924) and 6.16 cc (0.32-79.44 cc, p = 0.117), respectively. The mean DSC was 0.95 (0.76-1.00) and 0.86 (0.64-0.97) when comparing GTVi on T1c/T2f and T1c/T2, respectively. All of the lesions achieved volume reduction during HFRT and the mean reduction rate was 28.8% (4.8%-71.0%) at the end of HFRT. 54.5% of the BMs were reduced by more than 20%. The median treatment course and BED to get 20% reduction was 2/3 (40%-93%) and 40.8 Gy (24.5-67.5 Gy), respectively. The median shift of center of GTV1-n was 0.8 mm (0-2.5mm). The center of 7 lesions (31.8%) deviated more than 1mm from GTVi.

CONCLUSION

GTV contouring variability was seen between T1c, T2f and T2 sequences. The coincidence of T1+c and T2f was better than T1+c and T2 in BMs. Since reductions in volume and changes of lesion center was observed during HFRT, the use of MR-guided radiation therapy (RT) and treatment adaptation is needed. The optimal timing for treatment plan modification might be when the course of treatment reaches 2/3 for most large BMs. Further research to find out patients who may benefit form MR-guided adaptive RT is ongoing.

Self-reported sleep disorders and the risk of all cancer types: evidence from the Kailuan Cohort study

OBJECTIVES

Previous studies that focussed on sleep disturbance have primarily examined specific aspects of sleep disorders rather than considering overall sleep quality. We aimed to investigate different sleep disorders and their combination as risk factors for different types of cancer.

STUDY DESIGN

Prospective cohort study.

METHODS

In this prospective cohort study, we included 78,232 participants. A self-reported questionnaire was used to address insomnia, daytime sleepiness, snoring, and sleep duration. Overall sleep quality was evaluated by summarising these four sleep parameters. Cox proportional hazards analysis was used to estimate the hazard ratios and their 95% confidence intervals for determining the effect of the overall sleep-quality score and its components on the risk of incident cancer.

RESULTS

During a median follow-up of 5.67 years, 1266 participants were diagnosed with incident cancer. Compared to participants in the best sleep-quality score group, participants in the worst sleep-quality score group had a higher subsequent risk of overall cancer, and colorectal, breast, uterine or uterine cervical, prostatic, kidney, and bladder cancer. Participants with insomnia and snoring status had an elevated risk of head and neck, breast, uterine or uterine cervical, prostatic, kidney, bladder cancer, and lymphoma.

CONCLUSIONS

Poor overall sleep-quality scores as well as poor scores for the scale's components, including insomnia and snoring status, elevated the risk of overall and several specific-site cancers.

TRIAL REGISTRATION

Kailuan Study, ChiCTR2000029767. Registered 12 February, 2020-Retrospectively registered, https://www.chictr.org.cn/showprojEN.html?proj=48316.

[Surveillance on dengue vector Aedes albopictus in Ningbo City in 2021]

OBJECTIVE

To analyze the density, distribution and insecticide resistance of Aedes albopictus in Ningbo City in 2021, so as to provide insights into formulation of dengue fever control strategies.

METHODS

Four administrative villages were randomly selected from each county (district) in Ningbo City from April to November, 2021, to investigate the indoor population density of Aedes larvae, and the Breteau index (BI) was calculated. The population density of adult mosquitoes was investigated in residential areas, parks/bamboo forests, waste tire stacking sites/waste stations/construction sites in each county (district). On June 2021, larvae of the natural strain A. albopictus were collected from epidemic sites of dengue fever in Ningbo City in 2018, and raised in laboratory. Then, larvae and female mosquitoes without blood feeding were selected for insecticide resistance bioassays, while insecticide-sensitive strains of A. albopictus served as controls. The resistance of A. albopictus larvae to deltamethrin, beta-cypermethrin, propoxur, temephos and dichlorvos using the impregnation method, and the medium lethal concentration (LC50) and resistance ratio (RR) were calculated. The resistance of adult A. albopictus to beta-cypermethrin, permethrin, deltamethrin, propoxur and malathion was determined using the tube bioassay, and the mosquito mortality was calculated.

RESULTS

A total of 10 072 small water containers from 9 935 households were investigated in Ningbo City in 2021, and there were 1 276 containers with Aedes larvae detected, with an average BI of 12.89. Totally 1 422 mosquito nets were allocated and 954 female A. albopictus were captured, with an average net trapping index of 1.34 mosquitoes/(net·hour). Both larval and adult A. albopictus mosquitoes were found from April to November, and the density of larval A. albopictus peaked in September (BI = 21.21), while the density of adult A. albopictus peaked in August, with a net trapping index of 2.38 mosquitoes/(net·hour). The LC50 values of delta-methrin, beta-cypermethrin, propoxur, temephos and dichlorvos were 0.017 4, 0.000 9, 0.364 1, 0.038 1 mg/L and 0.001 6 mg/L against larvae of natural strains of A. albopicchus, with RRs of 49.66, 25.53, 9.65, 2.24 and 6.06, and the mortality rates of adult mosquitoes were 66.00% (66/100), 69.39% (68/98), 25.00% (25/100), 98.97% (96/97) and 100.00% (98/98) 24 hours post-treatment with 0.08% beta-cypermethrin, 0.03% deltamethrin, 0.4% permethrin, 0.05% propoxur, and 0.5% malathion for 24 h, respectively.

CONCLUSIONS

A. albopictus is widely distributed in Ningbo City, with a high population density and presents high-level resistance to common pyrethroid insecticides. The population density and insecticide resistance of A. albopictus requires to be reinforced.

[Clinical effects of pedicled omental flap transplantation in repairing secondary rejection wounds after brain pacemaker implantation]

Objective: To explore the clinical effects of pedicled omental flap transplantation in repairing secondary rejection wounds after brain pacemaker implantation. Methods: A retrospective observational study was conducted. From January to August 2021, 5 patients with secondary rejection wounds after brain pacemaker implantation who met the inclusion criteria were admitted to the Wound Repair Center of Ruijin Hospital of Shanghai Jiao Tong University School of Medicine, including 3 males and 2 females, aged 56-69 years, with the wound developed at the pulse generator implantation site in the chest in 2 cases, at the connection site of the wire and electrode behind the ear in 2 cases, and at both the chest and the back of the ear in 1 case. All the wounds were repaired by pedicled omental flap transplantation. The wound area after debridement was 2-15 cm2. After operation, the wound healing and related complications (pain, infection, incisional hernia, omental flap necrosis, etc.) were observed. During follow-up, the recurrence of the wound was observed. Results: The wounds of all 5 patients healed within 2 weeks after operation, without related complications. During follow up of 12-18 months, 1 patient got a recurrence of rejection wound behind the left ear 4 months after surgery and eventually had the brain pacemaker removed; the other 4 patients had no recurrence of wounds. Conclusions: Pedicled omental flap transplantation can repair the secondary rejection wounds after brain pacemaker implantation safely and effectively, with few postoperative complications.

[Humanized anti-CD25 monoclonal antibody as a salvage therapy for steroid-refractory acute graft-versus-host disease after hematopoietic stem cell transplantation]

Objective: To investigate the efficacy of humanized anti-CD25 monoclonal antibody for steroid-refractory acute graft-versus-host disease (SR-aGVHD) in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. Methods: A total of 64 patients with SR-aGVHD between June 2019 and October 2020 in Suchow Hopes Hematology Hospital were enrolled in this study. Humanized anti-CD25 monoclonal antibodies 1 mg·kg(-1)·d(-1) were administered on days 1, 3, and 8, and then once per week according to the disease progression. Efficacy was assessed at days 7, 14, and 28 after humanized anti-CD 25 treatment. Results: Of the 64 patients with a median age of 31 (15-63) years, 38 (59.4%) were male and 26 (40.6%) were female. The overall response (OR) rate of the humanized CD25 monoclonal antibody in 64 patients with SR-aGVHD on days 7, 14, and 28 were 48.4% (31/64), 53.1% (34/64), and 79.7% (51/64), respectively. Liver involvement is an independent risk factor for poor efficacy of humanized CD25 monoclonal antibody for SR-aGVHD at day 28 (OR=9.588, 95% CI 0.004-0.291, P=0.002). The median follow-up time for all patients was 17.1 (0.2-50.8) months from the start of humanized CD25 monoclonal antibody therapy. The 1- and 2-year OS rates were 63.2% (95% CI 57.1% -69.3%) and 52.6% (95% CI 46.1% -59.1%), respectively. The 1- and 2-year DFS rates were 58.4% (95% CI 52.1% -64.7%) and 49.8% (95% CI 43.4% -56.2%), respectively. The 1- and 2-year NRM rates were 28.8% (95% CI 23.1% -34.5%) and 32.9% (95% CI 26.8% -39.0%), respectively. The results of the multifactorial analysis showed that liver involvement (OR=0.308, 95% CI 0.108-0.876, P=0.027) and GVHD grade Ⅲ/Ⅳ (OR=9.438, 95% CI 1.211-73.577, P=0.032) were independent risk factors for OS. Conclusion: Humanized CD25 monoclonal antibody has good efficacy and safety for SR-aGVHD. This study shows that SR-aGVHD with pretreatment grade Ⅲ/Ⅳ GVHD and GVHD involving the liver has poor efficacy and prognosis and requires early intervention.

Flow-Through Electrochemical Membrane Reactor with a Self-Supported Carbon Membrane Electrode for Highly Efficient Synthesis of Hydrogen Peroxide

In situ electroreduction of O2 to H2O2 by using electrons as reagents is known as a green process, which is highly desirable for environmental remediation and chemical industries. However, the development of a cost-effective electrode with superior H2O2 synthesis rate and stability is challenging. A self-supported carbon membrane (CM) was prepared in this study from activated carbon and phenolic resin by carbonization under a H2 atmosphere. It was employed as the cathode to build a flow-through electrochemical membrane reactor (FT-ECMR) for electrosynthesis of H2O2. The results showed that the CM had a small pore size (34 nm), a high porosity (42.3%), and a high surface area (450.7 m2 g-1). In contrast to most of the state-of-the-art self-supported carbon electrode reported in the previous works, the FT-ECMR exhibited a high concentration of continuous and stable H2O2 electrosynthesis (1042 mg L-1) as well as a H2O2 synthesis rate of 5.21 mg h-1 cm-2. It had also demonstrated a high oxygen conversion (0.37%) and current efficiency (88%). The outstanding performance of the FT-ECMR for H2O2 synthesis was attributed to the enhanced mass transfer of the reactor, the existence of a relatively high surface area of CM, and the abundant disordered carbon structures (sp3-C, defects, and edges). In conclusion, our work highlighted using the FT-ECMR with the CM to synthesize H2O2 efficiently and cost-effectively.

Biosensors with Boronic Acid-Based Materials as the Recognition Elements and Signal Labels

It is of great importance to have sensitive and accurate detection of cis-diol-containing biologically related substances because of their important functions in the research fields of metabolomics, glycomics, and proteomics. Boronic acids can specifically and reversibly interact with 1,2- or 1,3-diols to form five or six cyclic esters. Based on this unique property, boronic acid-based materials have been used as synthetic receptors for the specific recognition and detection of cis-diol-containing species. This review critically summarizes the recent advances with boronic acid-based materials as recognition elements and signal labels for the detection of cis-diol-containing biological species, including ribonucleic acids, glycans, glycoproteins, bacteria, exosomes, and tumor cells. We also address the challenges and future perspectives for developing versatile boronic acid-based materials with various promising applications.

Influence of Gate Geometry on the Characteristics of AlGaN/GaN Nanochannel HEMTs for High-Linearity Applications

In this study, AlGaN/GaN nanochannel high-electron-mobility transistors (HEMTs) with tri-gate (TGN-devices) and dual-gate (DGN-devices) structures were fabricated and investigated. It was found that the peak value of the transconductance (Gm), current gain cut-off frequency (fT) and power gain cut-off frequency (fmax) of the TGN-devices were larger than that of the DGN-devices because of the enhanced gate control from the top gate. Although the TGN-devices and DGN-devices demonstrated flattened transconductance, fT and fmax profiles, the first and second transconductance derivatives of the DGN-devices were lower than those of the TGN-devices, implying an improvement in linearity. With the nanochannel width decreased, the peak value of the transconductance and the first and second transconductance derivatives increased, implying the predominant influence of sidewall gate capacitance on the transconductance and linearity. The comparison of gate capacitance for the TGN-devices and DGN-devices revealed that the gate capacitance of the tri-gate structure was not simply a linear superposition of the top planar gate capacitance and sidewall gate capacitance of the dual-gate structure, which could be attributed to the difference in the depletion region shape for tri-gate and dual-gate structures.

Effect of P-Type GaN Buried Layer on the Temperature of AlGaN/GaN HEMTs

In this paper, a P-type GaN buried layer is introduced into the buffer layer of AlGaN/GaN HEMTs, and the effect of the P-type GaN buried layer on the device's temperature characteristics is studied using Silvaco TCAD software. The results show that, compared to the conventional device structure, the introduction of a P-type GaN buried layer greatly weakens the peak of the channel electric field between the gate and drain of the device. This leads to a more uniform electric field distribution, a substantial reduction in the lattice temperature of the device, and a more uniform temperature distribution. Therefore, the phenomenon of negative resistance caused by self-heating effect is significantly mitigated, while the breakdown performance of the device is also notably enhanced.

[The value of cardiac MRI in the risk stratification in patients with hypertrophic cardiomyopathy]

Objective: To explore the value of cardiac magnetic resonance imaging (CMR) in the risk stratification of hypertrophic cardiomyopathy (HCM). Methods: HCM patients who underwent CMR examination in Fuwai Hospital between March 2012 and May 2013 were retrospectively enrolled. Baseline clinical and CMR data were collected and patient follow-up was performed using telephone contact and medical record. The primary composite endpoint was sudden cardiac death (SCD) or and equivalent event. The secondary composite endpoint was all-cause death and heart transplant. Patients were divided into SCD and non-SCD groups. Cox regression was used to explore risk factors of adverse events. Receiver operating characteristic (ROC) curve analysis was used to assess the performance and the optimal cut-off of late gadolinium enhancement percentage (LGE%) for the prediction of endpoints. Kaplan-Meier and log-rank tests were used to compare survival differences between groups. Results: A total of 442 patients were enrolled. Mean age was (48.5±12.4) years and 143(32.4%) were female. At (7.6±2.5) years of follow-up, 30 (6.8%) patients met the primary endpoint including 23 SCD and 7 SCD equivalent events, and 36 (8.1%) patients met the secondary endpoint including 33 all-cause death and 3 heart transplant. In multivariate Cox regression, syncope(HR=4.531, 95%CI 2.033-10.099, P<0.001), LGE% (HR=1.075, 95%CI 1.032-1.120, P=0.001) and left ventricular ejection fraction (LVEF) (HR=0.956, 95%CI 0.923-0.991, P=0.013) were independent risk factors for primary endpoint; Age (HR=1.032, 95%CI 1.001-1.064, P=0.046), atrial fibrillation (HR=2.977, 95%CI 1.446-6.131, P=0.003),LGE% (HR=1.075, 95%CI 1.035-1.116, P<0.001) and LVEF (HR=0.968, 95%CI 0.937-1.000, P=0.047) were independent risk factors for secondary endpoint. ROC curve showed the optimal LGE% cut-offs were 5.1% and 5.8% for the prediction of primary and secondary endpoint, respectively. Patients were further divided into LGE%=0, 0<LGE%<5%, 5%≤LGE%<15% and LGE%≥15% groups. There were significant survival differences between these 4 groups whether for primary endpoint or secondary endpoint (all P<0.001) and the accumulated incidence of primary endpoint was 1.2% (2/161), 2.2% (2/89), 10.5% (16/152) and 25.0% (10/40), respectively. Conclusion: LGE is an independent risk factor for SCD events as well as all-cause death and heart transplant. LGE is of important value in the risk stratification in patients with HCM.

Biosensors with Metal Ion-Phosphate Chelation Interaction for Molecular Recognition

Biosensors show promising prospects in the assays of various targets due to their advantages of high sensitivity, good selectivity and rapid response. Molecular recognition is a key event of biosensors, which usually involves the interaction of antigen-antibody, aptamer-target, lectin-sugar, boronic acid-diol, metal chelation and DNA hybridization. Metal ions or complexes can specifically recognize phosphate groups in peptides or proteins, obviating the use of biorecognition elements. In this review, we summarized the design and applications of biosensors with metal ion-phosphate chelation interaction for molecular recognition. The sensing techniques include electrochemistry, fluorescence, colorimetry and so on.

Vertically molybdenum disulfide nanosheets on carbon cloth using CVD by controlling growth atmosphere for electrocatalysis

Molybdenum disulfide (MoS2) has been deemed as one of the promising noble-metal-free electrocatalysts for hydrogen evolution reaction (HER), but it suffers from the inert basal plane and low electronic conductivity. Regulating the morphology of MoS2 during the synthesis on conductive substrates is a synergistic strategy for enhancing the HER performance. In this work, vertical MoS2 nanosheets were fabricated on carbon cloth using an atmospheric pressure chemical vapor deposition method. The growth process could be effectively tuned through introducing hydrogen gas during vapor deposition process, resulting in nanosheets with increased edge density. The mechanism for edge-enriching through controlling the growth atmosphere is systematically studied. The as-prepared MoS2 exhibits excellent HER activity due to the combination of optimized microstructures and coupling with carbon cloth. Our findings provide new insights to design advanced MoS2-based electrocatalysts for HER. &#xD.

Multi-functional MXene quantum dots enhance the quality of perovskite polycrystalline films and charge transport for solar cells

Recently, two-dimensional (2D) transition metal carbides/nitrides (MXenes) find applications in perovskite solar cells (PSCs), due to their high conductivity, tunable electronic structures, and rich surface chemistry, etc. However, the integration of 2D MXenes into PSCs is limited by their large lateral sizes and relatively-small surface volume ratios, and the roles of MXenes in PSCs are still ambiguous. In this paper, zero-dimensional (0D) MXene quantum dots (MQDs) with an average size of 2.7 nm are obtained through clipping step by step combining a chemical etching and a hydrothermal reaction, which display rich terminals (i.e., -F, -OH, -O) and unique optical properties. The 0D MQDs incorporated into SnO₂ electron transport layers (ETLs) of PSCs exhibit multifunction: 1) increasing the electrical conductivity of SnO₂, 2) promoting better alignments of energy band positions at the perovskite/ETL interface, 3) improving the film quality of atop polycrystalline perovskite. Particularly, the MQDs not only tightly bond with the Sn atom for decreasing the defects of SnO₂, but also interact with the Pb²⁺ of perovskite. As a result, the defect density of PSCs is significantly decreased from 5.21 × 10²¹ to 6.4 × 10²⁰ cm^-3, leading to enhanced charge transport and reduced nonradiative recombination. Furthermore, the power conversion efficiency (PCE) of PSCs is substantially improved from 17.44% to 21.63% using the MQDs-SnO₂ hybrid ETL compared with the SnO₂ ETL. Besides, the stability of the MQDs-SnO₂-based PSC is greatly enhanced, with only ～4% degradation of the initial PCE after storage in ambient condition (25 °C, RH: 30-40%) for 1128 h, as compared to that of the reference device with a rapid degradation of ～60% of initial PCE after 460 h. And MQDs-SnO₂-based PSC also presents higher thermal stability than SnO₂-based device with continuous heating for 248 h at 85 °C. The unique MQDs exhibited in this work might also find other exciting applications such as light-emitting diodes, photodetectors, and fluorescent probes.

[Expression level of miR-199b in human colorectal cancer tissues and its correlation with clinicopathological features and prognosis of patients]

Objective: To investigate the relationship between miR-199b and clinicopathologic features and prognosis of patients with colorectal cancer. Methods: Cancer tissues and adjacent normal tissues of 202 patients with colorectal cancer treated in Cancer Hospital of Chinese Academy of Medical Sciences from March to December 2011 were collected. Reverse transcription-quantitative real-time polymerase chain reaction was used to detect the expression level of miR-199b in colorectal cancer tissues and corresponding adjacent normal tissues. Kaplan-Meier method and Log rank test were used for survival analysis, and receiver operating characteristic (ROC) curve was used to evaluate the prognostic value of miR-199b in colorectal cancer patients. Results: The relative expression level of miR-199b in colorectal cancer tissues (-7.88±0.11) was lower than that in adjacent normal tissues (-6.49±0.12, P<0.001). The expression level of miR-199b in colorectal cancer tissues with lymph node metastasis (-7.51±0.14) was higher than that in colorectal cancer tissues without lymph node metastasis (-8.23±0.17, P<0.001). The relative expression levels of miR-199b in stage Ⅰ/Ⅱ, Ⅲ and Ⅳ colorectal cancer tissues were gradually increased, which were -8.26±0.17, -7.70±0.16 and -6.57±0.27, respectively, and the difference was statistically significant (P<0.001). The 5-year survival rates of patients with high and low expressions of miR-199b were 75.6% and 84.6%(P=0.045) respectively. ROC curve showed that when miR-199b was -7.965, the area under the curve was 0.578 (95% CI: 0.468, 0.688). Conclusion: The high expression of miR-199b in colorectal cancer tissues is associated with late TNM stage, lymph node metastasis and poor prognosis in colorectal cancer patients, and miR-199b may be used as a potential marker for postoperative progress and prognosis in colorectal cancer patients.

Switch-on Fluorescence Analysis of Protease Activity with the Assistance of a Nickel Ion-Nitrilotriacetic Acid-Conjugated Magnetic Nanoparticle

Heterogeneous protease biosensors show high sensitivity and selectivity but usually require the immobilization of peptide substrates on a solid interface. Such methods exhibit the disadvantages of complex immobilization steps and low enzymatic efficiency induced by steric hindrance. In this work, we proposed an immobilization-free strategy for protease detection with high simplicity, sensitivity and selectivity. Specifically, a single-labeled peptide with oligohistidine-tag (His-tag) was designed as the protease substrate, which can be captured by a nickel ion-nitrilotriacetic acid (Ni-NTA)-conjugated magnetic nanoparticle (MNP) through the coordination interaction between His-tag and Ni-NTA. When the peptide was digested by protease in a homogeneous solution, the signal-labeled segment was released from the substrate. The unreacted peptide substrates could be removed by Ni-NTA-MNP, and the released segments remained in solution to emit strong fluorescence. The method was used to determine protease of caspase-3 with a low detection limit (4 pg/mL). By changing the peptide sequence and signal reporters, the proposal could be used to develop novel homogeneous biosensors for the detection of other proteases.

Memristor-Based Signal Processing for Compressed Sensing

With the rapid progress of artificial intelligence, various perception networks were constructed to enable Internet of Things (IoT) applications, thereby imposing formidable challenges to communication bandwidth and information security. Memristors, which exhibit powerful analog computing capabilities, emerged as a promising solution expected to address these challenges by enabling the development of the next-generation high-speed digital compressed sensing (CS) technologies for edge computing. However, the mechanisms and fundamental properties of memristors for achieving CS remain unclear, and the underlying principles for selecting different implementation methods based on various application scenarios have yet to be elucidated. A comprehensive overview of memristor-based CS techniques is currently lacking. In this article, we systematically presented CS requirements on device performance and hardware implementation. The relevant models were analyzed and discussed from the mechanism level to elaborate the memristor CS system scientifically. In addition, the method of deploying CS hardware using the powerful signal processing capabilities and unique performance of memristors was further reviewed. Subsequently, the potential of memristors in all-in-one compression and encryption was anticipated. Finally, existing challenges and future outlooks for memristor-based CS systems were discussed.