Noninvasive evaluation of nonalcoholic fatty liver disease: Current evidence and practice

With the increasing number of individuals with diabetes and obesity,nonalcoholic fatty liver disease(NAFLD) is becoming increasingly prevalent,affecting one-quarter of adults worldwide. The spectrum of NAFLD ranges from simple steatosis or nonalcoholic fatty liver(NAFL) to nonalcoholic steatohepatitis(NASH). NAFLD, especially NASH, may progress to fibrosis, leading to cirrhosis and hepatocellular carcinoma. NAFLD can impose a severe economic burden,and patients with NAFLD-related terminal or deteriorative liver diseases have become one of the main groups receiving liver transplantation. The increasing prevalence of NAFLD and the severe outcomes of NASH make it necessary to use effective methods to identify NAFLD. Although recognized as the gold standard, biopsy is limited by its sampling bias, poor acceptability, and severe complications, such as mortality, bleeding, and pain. Therefore, noninvasive methods are urgently needed to avoid biopsy for diagnosing NAFLD. This review discusses the current noninvasive methods for assessing NAFLD,including steatosis, NASH, and NAFLD-related fibrosis, and explores the advantages and disadvantages of measurement tools. In addition, we analyze potential noninvasive biomarkers for tracking disease processes and monitoring treatment effects, and explore effective algorithms consisting of imaging and nonimaging biomarkers for diagnosing advanced fibrosis and reducing unnecessary biopsies in clinical practice.

Stable Li storage in micron-sized SiO_(x) particles with rigid-flexible coating

Micrometre-sized electrode materials have distinct advantages for battery applications in terms of energy density,processability,safety and cost.For the silicon monoxide anode that undergoes electrochemical alloying reaction with Li,the Li(de)intercalation by micron-sized active particles usually accompanies with a large volume variation,which pulverizes the particle structure and leads to rapidly faded storage performance.In this work,we proposed to stabilize the electrochemistry vs.Li of the micron-SiO_(x) anode by forming a rigid-flexible bi-layer coati ng on the particle surface.The coati ng consists of pyrolysis carbon as the inner layer and polydopamine as the outer layer.While the inner layer guarantees high structural rigidity at particle surface and provides efficient pathway for electron conduction,the outer layer shows high flexibility for maintaining the integrity of micrometre-sized particles against drastic volume variation,and together they facilitate formation of stable solid electrolyte interface on the SiO_(x) particles.A composite an ode prepared by mixing the coated micron-SiOx with graphite delivered improved Li storage performance,and promised a high-capacity,long-life LiFePO_(4)/SiO_(x)-graphite pouch cell.Our strategy provides a general and feasible solution for building high-energy rechargeable batteries from micrometre-sized electrode materials with significant volume variation.

质子泵抑制剂降低预防性内镜静脉曲张套扎术后早期出血风险的临床研究

目的探讨预防性内镜静脉曲张套扎术(EVL)后出血的相关危险因素,并评估质子泵抑制剂(PPI)的治疗效果。方法该研究为回顾性队列研究,共纳入505例首次接受预防性EVL的肝硬化并发食管静脉曲张高危患者。EVL后出血是指预防性EVL术后8周内出血,出血症状包括:黑便或呕血,血红蛋白降低>2.0 g/dl。如内镜确诊为溃疡EVL手术部位出血,则定义为EVL后溃疡出血。结果该组患者中14例患者预防性EVL术后出血。单因素分析显示,EVL术后出血的危险因素包括:饮酒、低白蛋白、高总胆红素、高Child-Pugh评分、高终末期肝病模型(MELD)评分、伴随胃底静脉曲张以及不使用PPI药物治疗。多因素Logistic分析显示,伴随胃底静脉曲张(OR=5.680,P=0.005)和不使用PPI(OR=8.217,P=0.002)与预防性EVL后出血有关。进一步排除接受胃底静脉曲张治疗的患者,发现未使用PPI药物(OR=8.827,P=0.008)是EVL术后出血相关的唯一危险因素。结论行预防性EVL术患者应考虑采用PPI治疗,能降低预防性EVL后出血风险。

New insights into the flotation responses of brucite and serpentine for different conditioning times: Surface dissolution behavior

The inadvertent dissolution of gangue minerals is frequently detrimental to the flotation of valuable minerals.We investigated the effect of conditioning time on the separation of brucite and serpentine by flotation.By analyzing the Mg2+concentration,relative element content,and pulp viscosity,we studied the effect of mineral dissolution on brucite flotation.The results of artificially mixed mineral flotation tests(with-10μm serpentine)showed that by extending the conditioning time from 60 to 360 s,a large amount of Mg2+on the mineral surface gradually dissolved into the pulp,resulting in a decreased brucite recovery(from 83.83%to 76.79%)and an increased recovery of serpentine from 52.12%to 64.03%.To analyze the agglomeration behavior of brucite and serpentine,we used scanning electron microscopy,which clearly showed the different adhesion behaviors of different conditioning times.Lastly,the total interaction energy,as determined based on the extended DLVO(Derjaguin-Landau-Verwey-Overbeek)theory,also supports the conclusion that the gravitational force between brucite and serpentine increases significantly with increased conditioning time.

Fatigue small crack growth threshold determination of a high-Nb TiAl alloy at different temperatures by in-situ observation

The purpose of this paper is to estimate the fatigue crack growth threshold of a high-Nb TiAl alloy at the different temperatures based on scanning electron microscopy （SEM） in-situ observation. The results indicated that the fatigue crack growth threshold △Kth of a nearly lamellar high-Nb TiAl alloy with 8% Nb content at room temperature and 750℃ was determined as 12.89 MPa.m^1/2 and 8.69 MPa.m^1/2, respectively. The effect of the elevated temperature on the fatigue crack growth threshold cannot be ignored. At the same time, the early stage of fatigue crack propagation exhibited multicrack initiation and bridge-link behavior.

Extracorporeal Membrane Oxygenation Therapy for Critically Ill Coronavirus Disease 2019 Patients in Wuhan,China:A Retrospective Multicenter Cohort Study

Currently,little in-depth evidence is known about the application of extracorporeal membrane oxygenation(ECMO)therapy in coronavirus disease 2019(COVID-19)patients.This retrospective multicenter cohort study included patients with COVID-19 at 7 designated hospitals in Wuhan,China.The patients were followed up until June 30,2020.Univariate and multivariate logistic regression analyses were performed to identify the risk factors associated with unsuccessful ECMO weaning.Propensity score matching was used to match patients who received veno-venous ECMO with those who received invasive mechanical ventilation(IMV)-only therapy.Of 88 patients receiving ECMO therapy,27 and 61 patients were and were not successfully weaned from ECMO,respectively.Additionally,15,15,and 65 patients were further weaned from IMV,discharged from hospital,or died during hospitalization,respectively.In the multivariate logistic regression analysis,a lymphocyte count≤0.5×10^(9)/L and D-dimer concentration>4×the upper limit of normal level at ICU admission,a peak PaCO_(2)>60 mmHg at 24 h before ECMO initiation,and no tracheotomy performed during the ICU stay were independently associated with lower odds of ECMO weaning.In the propensity scorematched analysis,a mixed-effect Cox model detected a lower hazard ratio for 120-day all-cause mortality after ICU admission during hospitalization in the ECMO group.The presence of lymphocytopenia,higher D-dimer concentrations at ICU admission and hypercapnia before ECMO initiation could help to identify patients with a poor prognosis.Tracheotomy could facilitate weaning from ECMO.ECMO relative to IMV-only therapy was associated with improved outcomes in critically ill COVID-19 patients.

Cardiac Electrophysiological Differences Between Kunming and C57BL6/J Mice

Objective To investigate the alterations of cardiac electrophysiological properties and substantial mechanism and find the stable arrhythmia mouse model in Kunming(KM) and C57BL6/J(C57) mice.Methods Electrocardiogram recordings were used to analyze the QT interval in vivo,and monophasic action potential of right and left ventricular epicardium was recorded to elicit changes of action potential duration(APD) in conventional and programmed electrical stimulation(PES).Transient outward potassium current(I to) was recorded via whole-cell patch-clamp technique in single right and left epicardial myocytes.Results QT interval was prolonged in KM mice relative to C57 mice(62.51±4.47 ms vs.52.59±4.85 ms,P<0.05).The APD at 50% repolarization of the left ventricular epicardium(18.60±0.91 ms vs.12.90±0.35 ms),and APDs at 50%(17.31±6.05 ms vs.12.00±3.24 ms) and 70% repolarization(36.13±5.32 ms vs.21.95±8.06 ms) of the right ventricular epicardium in KM mice were significantly prolonged compared with C57 mice,respectively(all P<0.05).KM mice were more sensitive to PES-induced ventricular tachycardia(25%,3 of 12 hearts),and especially to Burst-induced ventricular tachycardia(50%,6 of 12 hearts) compared with C57 mice,which were 20%(2 of 10 hearts) and 30%(3 of 10 hearts) respectively.I to densities both in the left and right ventricular epicardial myocytes from KM mice were significantly decreased compared with C57 mice,respectively(all P<0.01).Conclusion Our data showed that KM mice with the prolonged QT interval and APD are vulnerabilities to ventricular arrhythmia,which are attributed to lower I to densities in ventricular myocytes obtained from KM mice than that from C57 mice.

Correlation between surface charge and hydration on mineral surfaces in aqueous solutions: A critical review

Surface charges and hydration are predominant properties of colloidal particles that govern colloidal stability in aqueous suspensions.These properties usually coexist and interact with each other.The correlation between the surface charge and hydration of minerals is summarized on the basis of innovative experimental,theoretical,and molecular dynamics simulation studies.The factors affecting the adsorption behavior of ions and water molecules,such as ion concentration,ion hydration radius and valence,and surface properties,are discussed.For example,the hydration and adsorption states completely differ between monovalent and divalent ions.For ions of the same valence,the effect of surface charge on the hydration force follows the Hofmeister adsorption series.Electrolyte concentration exerts a significant effect on the hydration force at high ion concentrations.Meanwhile,the ion correlations in high-concentration electrolyte systems become long range.The interfacial water structure largely depends on surface chemistry.The hydration layer between different surfaces shows large qualitative differences.

No significant association between dipeptidyl peptidase-4 inhibitors and adverse outcomes of COVID-19

BACKGROUND Dipeptidyl peptidase-4(DPP4)is commonly targeted to achieve glycemic control and has potent anti-inflammatory and immunoregulatory effects.Recent structural analyses indicated a potential tight interaction between DPP4 and severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),raising a promising hypothesis that DPP4 inhibitor(DPP4i)drugs might be an optimal strategy for treating coronavirus disease 2019(COVID-19)among patients with diabetes.However,there has been no direct clinical evidence illuminating the associations between DPP4i use and COVID-19 outcomes.AIM To illuminate the associations between DPP4i usage and the adverse outcomes of COVID-19.METHODS We conducted a multicenter,retrospective analysis including 2563 patients with type 2 diabetes who were hospitalized due to COVID-19 at 16 hospitals in Hubei Province,China.After excluding ineligible individuals,142 patients who received DPP4i drugs and 1115 patients who received non-DPP4i oral anti-diabetic drugs were included in the subsequent analysis.We performed a strict propensity score matching(PSM)analysis where age,sex,comorbidities,number of oral hypoglycemic agents,heart rate,blood pressure,pulse oxygen saturation(SpO2)<95%,CT diagnosed bilateral lung lesions,laboratory indicators,and proportion of insulin usage were matched.Finally,111 participants treated with DPP4i drugs were successfully matched to 333 non-DPP4i users.Then,a linear logistic model and mixed-effect Cox model were applied to analyze the associations between inhospital DPP4i use and adverse outcomes of COVID-19.RESULTS After rigorous matching and further adjustments for imbalanced variables in the linear logistic model and Cox adjusted model,we found that there was no significant association between in-hospital DPP4i use(DPP4i group)and 28-d allcause mortality(adjusted hazard ratio=0.44,95%CI:0.09-2.11,P=0.31).Likewise,the incidences and risks of secondary outcomes,including septic shock,acute respiratory distress syndrome,or acute organ(kidney,liver,and cardiac)injuries,were also comparable between the DPP4i and non-DPP4i groups.The performance of DPP4i agents in achieving glucose control(e.g.,the median level of fasting blood glucose and random blood glucose)and inflammatory regulation was approximately equivalent in the DPP4i and non-DPP4i groups.Furthermore,we did not observe substantial side effects such as uncontrolled glycemia or acidosis due to DPP4i application relative to the use of non-DPP4i agents in the study cohort.CONCLUSION Our findings demonstrated that DPP4i use is not significantly associated with poor outcomes of COVID-19 or other adverse effects of anti-diabetic treatment.The data support the continuation of DPP4i agents for diabetes management in the setting of COVID-19.

Botany,Traditional Uses,and Pharmacology of Polygonati Rhizoma

Huang Jing (黄精 Polygonati Rhizoma, PR) was first documented as a herbal medicine in Ming Yi Bie Lu (《名医别录》 Miscellaneous Records of Famous Physicians) in China. However, there was no comprehensive review on the botany, traditional uses, and pharmacological effects of PR till now. In this study, the botany, traditional uses including Taoist medicine, and pharmacological effects of PR were reviewed and summarized to provide insights on drug development of PR. In Taoist medicine, PR maintains agerasia and helps prolong human life-span, and is used for fasting (Bigu). In the Zhong Guo Yao Dian (《中国药典》Chinese Pharmacopeia) version 2020, PR exerts replenishing qi and nourishing yin, invigorating the spleen, moistening the lung, and strengthening the kidney. Pharmacological studies show that PR has effects of anti-oxidation, anti-diabetes, anti-osteoporosis, anti-cancer, anti-hyperlipidemia, cardiomyocyte protection, immunomodulatory, and thus can be used for treatment of infertility, anti-microorganisms, and improving sleep and memory. In conclusion, PR may play a potential role for chronic disease management and health preservation and this very role deserves a more in-depth research.

Corundum dissolution in concentrated sodium hydroxide solution

The corundum(α-alumina) core has been considered as a suitable candidate for investment casting of hollow, high pressure turbine engine airfoils due to its excellent properties. However, the efficiency of removing alumina cores in concentrated caustic solution cannot meet the needs of industrial production. In this paper, the effects of temperature and initial solution concentration on dissolution of α-alumina were studied by the classical weight-loss method. The fractal kinetic model was developed in order to describe α-alumina dissolution, assuming that the nonporous particles shrank during reaction process. The results show that the dissolution rate increases with increasing reaction temperature and initial solution concentration. Especially, the initial solution concentration has a significant influence on α-alumina dissolution rate at a higher reaction temperature. The activation energies decrease with increasing initial solution concentration, and the chemical reaction is the rate-controlling step.

Patients taking angiotensin-converting enzyme inhibitors/angiotensin II type I receptor blockers:higher risks of severe acute respiratory syndrome coronavirus 2 infection but milder clinical manifestations?

Recently,there has been an unprecedented interest in the topic of angiotensin converting enzyme 2(ACE2)-associated drugs administration,such as angiotensin-converting enzyme inhibitors(ACEIs)/angiotensin II type I receptor blockers(ARBs),in COVID-19 patients.A recent article put forward the concern that patients taking ACEIs/ARBs were under higher risk of COVID-19 infection.[1]They revealed that expression of ACE2,the receptor for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)to enter host cells,is up-regulated,thus facilitating the initial viral attachment step of SARS-CoV-2 in these patients.[2]

AI 2.0时代的类人与超人感知:研究综述与趋势展望（英文）

感知是智能系统与现实世界的交互界面。如果没有复杂而灵活的感知能力,就不可能创造出高级的人工智能(Artificial intelligence,AI)系统。最近,潘云鹤院士提出了AI 2.0的概念,其最重要的特征就是未来的AI系统应拥有类人甚至超人的智能感知能力。本文简要回顾了不同智能感知领域的研究现状,包括视觉感知、听觉感知、言语感知、感知信息处理与学习引擎等方面。在此基础上,论文对即将到来的AI 2.0时代智能感知领域需要大力研究发展的重点方向进行了展望,包括:(1)类人和超人的主动视觉;(2)自然声学场景的听知觉感知;(3)自然交互环境的言语感知及计算;(4)面向媒体感知的自主学习;(5)大规模感知信息处理与学习引擎;(6)城市全维度智能感知推理引擎。这些研究方向应在未来AI 2.0的研究规划中进行重点布局。

Feature Selection and Feature Learning for High-dimensional Batch Reinforcement Learning: A Survey

Tremendous amount of data are being generated and saved in many complex engineering and social systems every day.It is significant and feasible to utilize the big data to make better decisions by machine learning techniques. In this paper, we focus on batch reinforcement learning(RL) algorithms for discounted Markov decision processes(MDPs) with large discrete or continuous state spaces, aiming to learn the best possible policy given a fixed amount of training data. The batch RL algorithms with handcrafted feature representations work well for low-dimensional MDPs. However, for many real-world RL tasks which often involve high-dimensional state spaces, it is difficult and even infeasible to use feature engineering methods to design features for value function approximation. To cope with high-dimensional RL problems, the desire to obtain data-driven features has led to a lot of works in incorporating feature selection and feature learning into traditional batch RL algorithms. In this paper, we provide a comprehensive survey on automatic feature selection and unsupervised feature learning for high-dimensional batch RL. Moreover, we present recent theoretical developments on applying statistical learning to establish finite-sample error bounds for batch RL algorithms based on weighted Lpnorms. Finally, we derive some future directions in the research of RL algorithms, theories and applications.

A Task Allocation Method for Stream Processing with Recovery Latency Constraint

Stream processing applications continuously process large amounts of online streaming data in real time or nearreal time. They have strict latency constraints. However, the continuous processing makes them vulnerable to any failures,and the recoveries may slow down the entire processing pipeline and break latency constraints. The upstream backupscheme is one of the most widely applied fault-tolerant schemes for stream processing systems. It introduces complexbackup dependencies to tasks, which increases the difficulty of controlling recovery latencies. Moreover, when dependenttasks are located on the same processor, they fail at the same time in processor-level failures, bringing extra recovery latencies that increase the impacts of failures. This paper studies the relationship between the task allocation and therecovery latency of a stream processing application. We present a correlated failure effect model to describe the recoverylatency of a stream topology in processor-level failures under a task allocation plan. We introduce a recovery-latency awaretask allocation problem （RTAP） that seeks task allocation plans for stream topologies that will achieve guaranteed recoverylatencies. We discuss the difference between RTAP and classic task allocation problems and present a heuristic algorithmwith a computational complexity of O（n log2 n） to solve the problem. Extensive experiments were conducted to verify thecorrectness and effectiveness of our approach. It improves the resource usage by 15%-20% on average.