High-performance deep spiking neural networks via at-most-two-spike exponential coding.

Spiking neural networks (SNNs) provide necessary models and algorithms for neuromorphic computing. A popular way of building high-performance deep SNNs is to convert ANNs to SNNs, taking advantage of advanced and well-trained ANNs. Here we propose an ANN to SNN conversion methodology that uses a time-based coding scheme, named At-most-two-spike Exponential Coding (AEC), and a corresponding AEC spiking neuron model for ANN-SNN conversion. AEC neurons employ quantization-compensating spikes to improve coding accuracy and capacity, with each neuron generating up to two spikes within the time window. Two exponential decay functions with tunable parameters are proposed to represent the dynamic encoding thresholds, based on which pixel intensities are encoded into spike times and spike times are decoded into pixel intensities. The hyper-parameters of AEC neurons are fine-tuned based on the loss function of SNN-decoded values and ANN-activation values. In addition, we design two regularization terms for the number of spikes, providing the possibility to achieve the best trade-off between accuracy, latency and power consumption. The experimental results show that, compared to other similar methods, the proposed scheme not only obtains deep SNNs with higher accuracy, but also has more significant advantages in terms of energy efficiency and inference latency. More details can be found at https://github.com/RPDS2020/AEC.git.

Anomalous Hall effect and magnetic transition in the kagome material YbMn6Sn6.

We investigate the magnetic and transport properties of a kagome magnet YbMn6Sn6. We have grown YbMn6Sn6single crystals having a HfFe6Ge6type structure with ordered Yb and Sn atoms, which is different from the distorted structure previously reported. The single crystal undergoes a ferromagnetic phase transition around 300 K and a ferrimagnetic transition at approximately 30 K, and the magnetic transition at low temperature may be correlated to the ordered Yb sublattice. Negative magnetoresistance has been observed at high temperatures, while the positive magnetoresistance appears at 5 K when the current is oriented out of kagome plane. We observe a large anisotropic anomalous Hall effect with the intrinsic Hall contribution of 141 Ω-1cm-1forσzxintand 32 Ω-1cm-1forσxyint, respectively. These values are similar to those in YMn6Sn6with the same anisotropy. The magnetic transition and anomalous Hall behavior in YbMn6Sn6highlights the influence of the ordered Yb atoms and rare earth elements on its magnetic and transport properties.

Predictive Value of Nutritional Risk for All-Cause Death and Functional Outcomes in Chinese Elderly Patients with Acute Stroke: A 3-Year Follow-Up Study.

Purpose: To explore the predictive value of nutritional risk for all-cause death and functional outcomes among elderly acute stroke patients. Patients and Methods: A total of 479 elderly acute stroke patients were enrolled in this study. The nutritional risk of patients was screened by the GNRI and NRS-2002. The primary outcome was all-cause death, and the secondary outcome was poor prognosis defined as a modified Rankin Scale (mRS) score ≥3. Results: Based on the NRS-2002, patients with nutritional risk had a higher risk of all-cause death at 3 months (adjusted OR: 3.642, 95% CI 1.046~12.689) and at 3 years (adjusted OR: 2.266, 95% CI 1.259~4.076) and a higher risk of adverse functional outcomes at 3 months (adjusted OR: 2.748, 95% CI 1.518~4.972. Based on the GNRI, compared to those without nutritional risk, patients with mild malnutrition also had a higher risk of all-cause death at 3 months (adjusted OR: 7.186, 95% CI 1.550~33.315) and at 3 years (adjusted OR: 2.255, 95% CI 1.211~4.199) and a higher risk of adverse functional outcomes at 3 months (adjusted OR: 1.947, 95% CI 1.030~3.680), so patients with moderate and severe malnutrition had a higher risk of all-cause death at 3 months (adjusted OR: 6.535, 95% CI 1.380~30.945) and at 3 years (adjusted OR: 2.498, 95% CI 1.301~4.799) and a higher risk of adverse functional outcomes at 3 months (adjusted OR: 2.213, 95% CI 1.144~4.279). Conclusion: Nutritional risk increases the risk of poor short-term and long-term outcomes in elderly patients with acute stroke. For elderly stroke patients, we should pay attention to early nutritional risk screening, and effective intervention should be provided to improve the prognosis of such patients.

Exosomes combined with biosynthesized cellulose conduits improve peripheral nerve regeneration.

Peripheral nerve injury is one of the more common forms of peripheral nerve disorders, and the most severe type of peripheral nerve injury is a defect with a gap. Biosynthetic cellulose membrane (BCM) is a commonly used material for repair and ligation of nerve defects with gaps. Meanwhile, exosomes from mesenchymal stem cells can promote cell growth and proliferation. We envision combining exosomes with BCMs to leverage the advantages of both to promote repair of peripheral nerve injury. Prepared exosomes were added to BCMs to form exosome-loaded BCMs (EXO-BCM) that were used for nerve repair in a rat model of sciatic nerve defects with gaps. We evaluated the repair activity using a pawprint experiment, measurement and statistical analyses of sciatica function index and thermal latency of paw withdrawal, and quantitation of the number and diameter of regenerated nerve fibers. Results indicated that EXO-BCM produced comprehensive and durable repair of peripheral nerve defects that were similar to those for autologous nerve transplantation, the gold standard for nerve defect repair. EXO-BCM is not predicted to cause donor site morbidity to the patient, in contrast to autologous nerve transplantation. Together these results indicate that an approach using EXO-BCM represents a promising alternative to autologous nerve transplantation, and could have broad applications for repair of nerve defects.

Programming correlated magnetic states with gate-controlled moiré geometry.

The ability to control the underlying lattice geometry of a system may enable transitions between emergent quantum ground states. We report in situ gate switching between honeycomb and triangular lattice geometries of an electron many-body Hamiltonian in rhombohedral (R)-stacked molybdenum ditelluride (MoTe2) moiré bilayers, resulting in switchable magnetic exchange interactions. At zero electric field, we observed a correlated ferromagnetic insulator near one hole per moiré unit cell with a widely tunable Curie temperature up to 14 K. Applying an electric field switched the system into a half-filled triangular lattice with antiferromagnetic interactions; further doping this layer-polarized superlattice tuned the antiferromagnetic exchange interaction back to ferromagnetic. Our work demonstrates R-stacked MoTe2 moirés to be a laboratory for engineering correlated states with nontrivial topology.

Phase Transition Engineering of Host Perovskite toward Optimal Exsolution-facilitated Catalysts for Carbon Dioxide Electrolysis.

The in situ exsolution technique of nanoparticles has brought new opportunities for the utilization of perovskite-based catalysts in solid oxide cells. However, the lack of control over the structural evolution of host perovskites during the promotion of exsolution has restricted the architectural exploitation of exsolution-facilitated perovskites. In this study, we strategically broke the long-standing trade-off phenomenon between promoted exsolution and suppressed phase transition via B-site supplement, thus broadening the scope of exsolution-facilitated perovskite materials. Using carbon dioxide electrolysis as an illustrative case study, we demonstrate that the catalytic activity and stability of perovskites with exsolved nanoparticles (P-eNs) can be selectively enhanced by regulating the explicit phase of host perovskites, accentuating the critical role of the architectures of perovskite scaffold in catalytic reactions occurring on P-eNs. The concept demonstrated could potentially pave the way for designing the advanced exsolution-facilitated P-eNs materials and unveiling a wide range of catalytic chemistry taking place on P-eNs.

Magneto-optical Kerr Effect in Ferroelectric Antiferromagnetic Two-Dimensional Heterostructures.

We studied the magneto-optical Kerr effect (MOKE) of two-dimensional (2D) heterostructure CrI3/In2Se3/CrI3 using density functional theory calculations and symmetry analysis. The spontaneous polarization in the In2Se3 ferroelectric layer and the antiferromagnetic ordering in CrI3 layers break the mirror and the time-reversal symmetry, thus activating MOKE. We show that the Kerr angle can be reversed by either the polarization or the antiferromagnetic order parameter. Our results suggest that ferroelectric and antiferromagnetic 2D heterostructures could be exploited for ultracompact information storage devices, where the information is encoded by the two ferroelectric or the two time-reversed antiferromagnetic states and the read-out is performed optically by MOKE.

Serum Anti-Fumarate Hydratase Autoantibody as a Biomarker for Predicting Prognosis of Acute-on-Chronic Liver Failure

Background/Aims@#To investigate the autoantibody against fumarate hydratase (FH), which is a specific liver failure-associated antigen (LFAA) and determine whether it can be used as a biomarker to evaluate the prognosis of acute-on-chronic liver failure (ACLF). @*Methods@#An immunoproteomic approach was applied to screen specific LFAAs related to differential prognosis of ACLF (n=60). Enzyme-linked immunosorbent assay (ELISA) technology was employed for the validation of the frequency and titer of autoantibodies against FH in ACLF patients with different prognoses (n=82). Moreover, we clarified the expression of autoantibodies against FH in patients with chronic hepatitis B (n=60) and hepatitis B virus-related liver cirrhosis (n=60). The dynamic changes in the titers of autoantibodies against FH were analyzed by sample collection at multiple time points during the clinical course of eight ACLF patients with different prognoses. @*Results@#Ultimately, 15 LFAAs were screened and identified by the immunoproteomic approach.Based on ELISA-based verification, anti-FH/Fumarate hydratase protein autoantibody was chosen to verify its expression in ACLF patients. ACLF patients had a much higher anti-FH autoantibody frequency (76.8%) than patients with liver cirrhosis (10%, p=0.000), patients with chronic hepatitis B (6.7%, p=0.022), and normal humans (0%, p=0.000). More importantly, the frequency and titer of anti-FH protein autoantibodies in the serum of ACLF patients with a good prognosis were much higher than that of patients with a poor prognosis (83.9% vs 61.5%, p=0.019; 1.41±0.85 vs 0.94±0.56, p=0.017, respectively). The titer of anti-FH autoantibodies showed dynamic changes in the clinical course of ACLF. @*Conclusions@#The anti-FH autoantibody in serum may be a potential biomarker for predicting the prognosis of ACLF.

Analysis on Characteristics of Plantar Pressure and Balance in Patients with Chronic Nonspecific Low Back Pain / 医用生物力学

Objective To explore the difference of balance ability between patients with chronic nonspecific low back pain ( CNLBP) and healthy individuals, and the correlation between patients’ pain symptoms, lumbar flexibility, abdominal muscle endurance, overall function, quality of life and fear of avoidance with balance ability, so as to guide clinical rehabilitation evaluation. Methods A total of 34 patients with CNLBP were selected as the experimental group, and 34 healthy volunteers without history of low back pain were selected as control group. The plantar pressure measurement system was used to collect the ratio of forefoot to hindfoot pressure, pathlength ( L) of plantar center of pressure ( COP), displacement length in anteroposterior direction ( LAP ), displacement length in mediolateral direction (LML ), mean velocity (v), displacement velocity in anteroposterior direction (vAP ), displacement velocity in mediolateral direction (V-ML) and elliptical swing area (S). In addition,the experimental group was assessed by the visual analogue scale (VAS), the finger floor distance (FFD), the number of sit-ups in 1 minute, the Oswestry disability index (ODI), the 36-item short form survey (SF-36) and the fear avoidance beliefs questionnaire (FABQ), and correlated with plantar pressure parameters. Results All plantar pressure parameters were significantly different between the two groups ( P < 0. 05). The the ratio of forefoot to hindfoot pressure in experimental group was significantly lower than that in control group (P<0. 05), and the parameters L, LAP , LML , v, vAP , vML and S were significantly higher than those of control group (P<0. 05). With eyes open or closed, the VAS score of experimental group was positively correlated with L, LAP , LML(P<0. 05), and FFD and FABQ scores were positively correlated with L and LML , respectively (P< 0. 05). With eyes open, ODI was positively correlated with L, LAP and LML (P< 0. 05), and SF-36 score was negatively correlated with L and LML(P<0. 05). With eyes closed, the number of 1-min sit-ups was negatively correlated with LAP and S (P<0. 05), ODI was positively correlated with L and LML(P<0. 05), and the SF-36 score was negatively correlated with L (P<0. 05). Conclusions The static balance ability of patients with CNLBP is decreased, and it is correlated with pain symptoms, lumbar function, quality of life and psychological status. The result can provide references for the assessment of functional activities.

Application progress of artificial intelligence in the screening and identification of drug targets / 中国药科大学学报

@#In recent years, artificial intelligence (AI) has developed rapidly, with improved computing power and algorithms, which has greatly facilitated the collection and processing of biological, chemical information and clinical data, injecting new vitality into the research and development of new drugs.In this review, we began with a brief overview of the development and the main algorithms of AI in drug discovery.Then we elaborated through several specific cases on the various scenarios of AI application, including target identification, protein structure prediction, hit generation and optimization etc.Finally, we focused on a recent example to discuss the high efficiency of "end-to-end" application of AI.

Efficacy differences between electroacupuncture and moxibustion for neurogenic bladder after spinal cord injury: a randomized controlled trial / 中国针灸

OBJECTIVE@#To compare the clinical efficacy between electroacupuncture(EA) and moxibustion for neurogenic bladder (NB) after spinal cord injury (SCI).@*METHODS@#One hundred and twenty patients with NB after SCI were randomly divided into an EA group, a moxibustion group, and an intermittent catheterization group, with 40 patients in each group. The patients in the intermittent catheterization group were treated with routine treatment and intermittent catheterization, while the patients in the EA group and the moxibustion group were treated with additional treatments of EA (discontinuous wave, with a frequency of 1.3-1.6 Hz, and intensity based on patient tolerance) and moxibustion, respectively. The acupoints used in both groups were Zhongji (CV 3) and Guanyuan (CV 4), bilateral Zusanli (ST 36), Yinlingquan (SP 9), and Baliao points. Each session lasted for 30 min, once daily, six times a week, for a total of six weeks.The maximum bladder capacity (MBC), residual urine vdume (RUV), detrusor pressure (Pdet) during the filling phase, bladder compliance (BC), maximum renal pelvis separation width of both kidneys, urine white blood cell count, TCM syndrome score, and World Health Organization quality of life assessment-BREF (WHOQOL-BREF) score were compared before and after treatment in the 3 groups. The number of patients in each group who achieved bladder functional balance was recorded, and the clinical efficacy was assessed after treatment.@*RESULTS@#After treatment, the MBC, Pdet, BC, and WHOQOL-BREF scores in the EA group and the moxibustion group were increased (P<0.05), while the RUV, maximum renal pelvis separation width of both kidneys, urine white blood cell count, and TCM syndrome scores were decreased (P<0.05, P<0.01). In the intermittent catheterization group, MBC, RUV, maximum renal pelvis separation width of both kidneys, and urine white blood cell count were decreased (P<0.05), while BC and WHOQOL-BREF score were increased (P<0.05) after treatment. After treatment, the MBC, Pdet, BC, and WHOQOL-BREF scores in the EA group and the moxibustion group were higher than those in the intermittent catheterization group (P<0.05), while the RUV and TCM syndrome scores were lower than those in the intermittent catheterization group (P<0.05). Moreover, after treatment, the MBC and Pdet in the moxibustion group were higher than those in the EA group (P<0.05), while the RUV, maximum renal pelvis separation width of both kidneys, and TCM syndrome score in the EA group were lower than those in the moxibustion group (P<0.05). The number of patients who achieved bladder functional balance after treatment in the EA group and the moxibustion group was higher than that in the intermittent catheterization group (P<0.05). The cured and effective rate was 85.0% (34/40) in the EA group and 82.5% (33/40) in the moxibustion group, which were both higher than 65.0% (26/40) in the intermittent catheterization group (P<0.05), there was no significant difference between the EA group and the moxibustion group (P>0.05).@*CONCLUSION@#EA and moxibustion could effectively improve the functional state of bladder in patients with NB after SCI. EA is more effective in reducing residual urine volume and excessive activity of the urethral sphincter, and relieving TCM syndromes, while moxibustion is more effective in increasing the pressure of the detrusor during the filling period and establishing the detrusor reflex.

Research progress of the regulatory role of autophagy in metabolic liver diseases / 中华肝脏病杂志

Autophagy is one of several hepatic metabolic processes in which starved cells are supplied with glucose, free fatty acids, and amino acids to produce energy and synthesize new macromolecules. Moreover, it regulates the quantity and quality of mitochondria and other organelles. As the liver is a vital metabolic organ, specific forms of autophagy are necessary for maintaining liver homeostasis. Protein, fat, and sugar are the three primary nutrients that can be altered by different metabolic liver diseases. Drugs that have an effect on autophagy can either promote or inhibit autophagy, and as a result, it can either increase or inhibit the three major nutritional metabolisms that are affected by liver disease. Thus, this opens up a novel therapeutic option for liver disease.

Mechanism of Learning and Memory Impairment in Rats Exposed to Arsenic and/or Fluoride Based on Microbiome and Metabolome / 生物医学与环境科学（英文）

OBJECTIVE@#Arsenic (As) and fluoride (F) are two of the most common elements contaminating groundwater resources. A growing number of studies have found that As and F can cause neurotoxicity in infants and children, leading to cognitive, learning, and memory impairments. However, early biomarkers of learning and memory impairment induced by As and/or F remain unclear. In the present study, the mechanisms by which As and/or F cause learning memory impairment are explored at the multi-omics level (microbiome and metabolome).@*METHODS@#We stablished an SD rats model exposed to arsenic and/or fluoride from intrauterine to adult period.@*RESULTS@#Arsenic and/fluoride exposed groups showed reduced neurobehavioral performance and lesions in the hippocampal CA1 region. 16S rRNA gene sequencing revealed that As and/or F exposure significantly altered the composition and diversity of the gut microbiome，featuring the Lachnospiraceae_NK4A136_group, Ruminococcus_1, Prevotellaceae_NK3B31_group, [Eubacterium]_xylanophilum_group. Metabolome analysis showed that As and/or F-induced learning and memory impairment may be related to tryptophan, lipoic acid, glutamate, gamma-aminobutyric acidergic (GABAergic) synapse, and arachidonic acid (AA) metabolism. The gut microbiota, metabolites, and learning memory indicators were significantly correlated.@*CONCLUSION@#Learning memory impairment triggered by As and/or F exposure may be mediated by different gut microbes and their associated metabolites.

Current research status of hepatitis D virus RNA detection / 临床肝胆病杂志

Hepatitis D caused by hepatitis D virus (HDV) infection is the most serious type of viral hepatitis. The prevalence rate of HDV has been seriously underestimated due to the lack of accurate HDV RNA detection methods. HDV RNA is the gold standard for the diagnosis of HDV infection and is of great significance in the diagnosis, screening, and treatment guidance of HDV. However, the multiple genotypes and strong secondary structure of HDV have led to great difficulties in HDV RNA detection. This article reviews the advances in HDV RNA detection methods and elaborates on the development from qualitative to quantitative detection methods, in order to provide new ideas for understanding the significance of HDV RNA detection and promoting the research and development of new HDV RNA detection methods.

Boosting the stability of perovskites with exsolved nanoparticles by B-site supplement mechanism.

Perovskites with exsolved nanoparticles (P-eNs) have immense potentials for carbon dioxide (CO2) reduction in solid oxide electrolysis cell. Despite the recent achievements in promoting the B-site cation exsolution for enhanced catalytic activities, the unsatisfactory stability of P-eNs at high voltages greatly impedes their practical applications and this issue has not been elucidated. In this study, we reveal that the formation of B-site vacancies in perovskite scaffold is the major contributor to the degradation of P-eNs; we then address this issue by fine-regulating the B-site supplement of the reduced Sr2Fe1.3Ni0.2Mo0.5O6-δ using foreign Fe sources, achieving a robust perovskite scaffold and prolonged stability performance. Furthermore, the degradation mechanism from the perspective of structure stability of perovskite has also been proposed to understand the origins of performance deterioration. The B-site supplement endows P-eNs with the capability to become appealing electrocatalysts for CO2 reduction and more broadly, for other energy storage and conversion systems.

Quasi-symmetry protected topology in a semi-metal.

The crystal symmetry of a material dictates the type of topological band structures it may host, and therefore symmetry is the guiding principle to find topological materials. Here we introduce an alternative guiding principle, which we call 'quasi-symmetry'. This is the situation where a Hamiltonian has an exact symmetry at lower-order that is broken by higher-order perturbation terms. This enforces finite but parametrically small gaps at some low-symmetry points in momentum space. Untethered from the restraints of symmetry, quasi-symmetries eliminate the need for fine-tuning as they enforce that sources of large Berry curvature will occur at arbitrary chemical potentials. We demonstrate that a quasi-symmetry in the semi-metal CoSi stabilizes gaps below 2 meV over a large near-degenerate plane that can be measured in the quantum oscillation spectrum. The application of in-plane strain breaks the crystal symmetry and gaps the degenerate point, observable by new magnetic breakdown orbits. The quasi-symmetry, however, does not depend on spatial symmetries and hence transmission remains fully coherent. These results demonstrate a class of topological materials with increased resilience to perturbations such as strain-induced crystalline symmetry breaking, which may lead to robust topological applications as well as unexpected topology beyond the usual space group classifications.

Construction of Exosomes that Overexpress CD47 and Evaluation of Their Immune Escape.

Our general purpose was to provide a theoretical and practical foundation for the use of exosomes (EXOs) that have high levels of CD47 as stable and efficient drug carriers. Thus, we prepared EXOs from adipose tissue-derived mesenchymal stromal cells (ADMSCs) that had high levels of CD47 (EXOsCD47) and control EXOs (without CD47), and then compared their immune escape in vivo and their resistance to phagocytosis in vitro. Nanoflow cytometry was used to determine the CD47 level in these EXOs, and the amount of EXOsCD47 that remained in rat plasma at 3 h after intraperitoneal injection. Phagocytosis of the EXOs was also determined using in vitro rat macrophage bone marrow (RMA-BM) experiments. Our in vitro results showed that macrophages ingested significantly more control EXOs than EXOsCD47 (p < 0.01), with confirmation by ultra-high-definition laser confocal microscopy. Consistently, our in vivo results showed that rats had 1.377-fold better retention of EXOsCD47 than control EXOs (p < 0.01). These results confirmed that these engineered EXOsCD47 had improved immune escape. Our results therefore verified that EXOsCD47 had increased immune evasion relative to control EXOs, and have potential for use as drug carriers.