Temperature dependence of single-event transients in SiGe heterojunction bipolar transistors for cryogenic applications

We experimentally demonstrate that the dominant mechanism of single-event transients in silicon-germanium heterojunction bipolar transistors(SiGe HBTs)can change with decreasing temperature from+20℃to-180℃.This is accomplished by using a new well-designed cryogenic experimental system suitable for a pulsed-laser platform.Firstly,when the temperature drops from+20℃to-140℃,the increased carrier mobility drives a slight increase in transient amplitude.However,as the temperature decreases further below-140℃,the carrier freeze-out brings about an inflection point,which means the transient amplitude will decrease at cryogenic temperatures.To better understand this result,we analytically calculate the ionization rates of various dopants at different temperatures based on Altermatt's new incomplete ionization model.The parasitic resistivities with temperature on the charge-collection pathway are extracted by a two-dimensional(2D)TCAD process simulation.In addition,we investigate the impact of temperature on the novel electron-injection process from emitter to base under different bias conditions.The increase of the emitter-base junction's barrier height at low temperatures could suppress this electron-injection phenomenon.We have also optimized the built-in voltage equations of a high current compact model(HICUM)by introducing the impact of incomplete ionization.The present results and methods could provide a new reference for effective evaluation of single-event effects in bipolar transistors and circuits at cryogenic temperatures,and could provide a new evidence of the potential of SiGe technology in applications in extreme cryogenic environments.

Exploring reservoir computing:Implementation via double stochastic nanowire networks

Neuromorphic computing,inspired by the human brain,uses memristor devices for complex tasks.Recent studies show that self-organizing random nanowires can implement neuromorphic information processing,enabling data analysis.This paper presents a model based on these nanowire networks,with an improved conductance variation profile.We suggest using these networks for temporal information processing via a reservoir computing scheme and propose an efficient data encoding method using voltage pulses.The nanowire network layer generates dynamic behaviors for pulse voltages,allowing time series prediction analysis.Our experiment uses a double stochastic nanowire network architecture for processing multiple input signals,outperforming traditional reservoir computing in terms of fewer nodes,enriched dynamics and improved prediction accuracy.Experimental results confirm the high accuracy of this architecture on multiple real-time series datasets,making neuromorphic nanowire networks promising for physical implementation of reservoir computing.

Identification of M2 macrophage-related genes for establishing a prognostic model in pancreatic cancer: FCGR3A as key gene

Background:Pancreatic ductal adenocarcinoma(PDAC)has a rich and complex tumor immune microenvironment(TIME).M2 macrophages are among the most extensively infiltrated immune cells in the TIME and are necessary for the growth and migration of cancers.However,the mechanisms and targets mediating M2 macrophage infiltration in pancreatic cancer remain elusive.Methods:The M2 macrophage infiltration score of patients was assessed using the xCell algorithm.Using weighted gene co-expression network analysis(WGCNA),module genes associated with M2 macrophages were identified,and a predictive model was designed.The variations in immunological cell patterns,cancer mutations,and enrichment pathways between the cohorts with the high-and low-risk were examined.Additionally,the expression of FCGR3A and RNASE2,as well as their association with M2 macrophages were evaluated using the HPA,TNMplot,and GEPIA2 databases and verified by tissue immunofluorescence staining.Moreover,in vitro cell experiments were conducted,where FCGR3A was knocked down in pancreatic cancer cells using siRNA to analyze its effects on M2 macrophage infiltration,tumor proliferation,and metastasis.Results:The prognosis of patients in high-risk and low-risk groups was successfully distinguished using a prognostic risk score model of M2 macrophage-related genes(p=0.024).Between the high-and low-risk cohorts,there have been notable variations in immune cell infiltration patterns,tumor mutations,and biological functions.The risk score was linked to the manifestation of prevalent immunological checkpoints,immunological scores,and stroma values(all p<0.05).In vitro experiments and tissue immunofluorescence staining revealed that FCGR3A can promote the infiltration or polarization of M2 macrophages and enhance tumor proliferation and migration.Conclusions:In this study,an M2 macrophage-related pancreatic cancer risk score model was established,and found that FCGR3A was correlated with tumor formation,metastasis,and M2 macrophage infiltration.

Insulin-like growth factor 2 targets IGF1R signaling transduction to facilitate metastasis and imatinib resistance in gastrointestinal stromal tumors

BACKGROUND Gastrointestinal stromal tumors(GISTs)are typical gastrointestinal tract neoplasms.Imatinib is the first-line therapy for GIST patients.Drug resistance limits the long-term effectiveness of imatinib.The regulatory effect of insulin-like growth factor 2(IGF2)has been confirmed in various cancers and is related to resistance to chemotherapy and a worse prognosis.AIM To further investigate the mechanism of IGF2 specific to GISTs.METHODS IGF2 was screened and analyzed using Gene Expression Omnibus(GEO:GSE225819)data.After IGF2 knockdown or overexpression by transfection,the phenotypes(proliferation,migration,invasion,apoptosis)of GIST cells were characterized by cell counting kit 8,Transwell,and flow cytometry assays.We used western blotting to evaluate pathway-associated and epithelial-mesenchymal transition(EMT)-associated proteins.We injected transfected cells into nude mice to establish a tumor xenograft model and observed the occurrence and metastasis of GIST.RESULTS Data from the GEO indicated that IGF2 expression is high in GISTs,associated with liver metastasis,and closely related to drug resistance.GIST cells with high expression of IGF2 had increased proliferation and migration,invasiveness and EMT.Knockdown of IGF2 significantly inhibited those activities.In addition,OEIGF2 promoted GIST metastasis in vivo in nude mice.IGF2 activated IGF1R signaling in GIST cells,and IGF2/IGF1R-mediated glycolysis was required for GIST with liver metastasis.GIST cells with IGF2 knockdown were sensitive to imatinib treatment when IGF2 overexpression significantly raised imatinib resistance.Moreover,2-deoxy-D-glucose(a glycolysis inhibitor)treatment reversed IGF2 overexpressionmediated imatinib resistance in GISTs.CONCLUSION IGF2 targeting of IGF1R signaling inhibited metastasis and decreased imatinib resistance by driving glycolysis in GISTs.

Factors influencing willingness to participate in ophthalmic clinical trials and strategies for effective recruitment

AIM:To explore the factors influencing individuals’willingness to participate in ophthalmic clinical trials.METHODS:A questionnaire survey was conducted from January to April 2021 among patients and their family members at Zhongshan Ophthalmic Center,Sun Yat-sen University,in Guangzhou,China.The survey gathered data on respondents’willingness,demographic and socioeconomic profiles,as well as their reasons and concerns regarding engagement in clinical trials.RESULTS:Of the 1078 residents surveyed(mean age 31.2±13.1y;65.8%females)in Guangzhou,749(69.5%)expressed a willingness to participate in future ophthalmic clinical trials.Specific characteristics associated with greater willingness included a younger age,lower annual income,higher education,prior participation experience,previous ophthalmic treatment,and a better understanding of clinical trials.With the exception of age,these characteristics were significantly linked to a higher willingness.The primary barrier to participation,expressed by 64.8%of those willing and 54.4%of those unwilling,was“Uncertain efficacy”.In terms of motivations,the willing group ranked“Better therapeutic benefits”(35.0%),“Professional monitoring”(34.3%),and“Trust in healthcare professionals”(33.1%)as their top three reasons,whereas the unwilling participants indicated“Full comprehension of the protocol”(46.2%)as the key facilitator.CONCLUSION:This study reveals a substantial willingness to participate in ophthalmic clinical trials and demonstrates the predictive role of demographic and socioeconomic factors.Variations in motivators and concerns between willing and unwilling participants highlight the significance of tailored recruitment strategies.Importantly,the need for and trust in healthcare professionals stand out as powerful motivations,underscoring the importance of enhancing physician-patient relationships,adopting patient-centered communication approaches,and addressing individualized needs to improve accrual rates.

浅谈阿育吠陀医学中的人体生理节律

该文介绍印度阿育吠陀医学中关于人体生理节律方面的相关学说思想,包括年龄节律、季节节律、星象节律、昼夜节律、营养转化为身体组织的节律、进餐后的食物消化过程节律等,可供中医及藏医、蒙医等民族医学研究者参考。

Apparent diffusion coefficient evaluation for secondary changes in the cerebellum of rats after middle cerebral artery occlusion

Supratentorial cerebral infarction can cause functional inhibition of remote regions such as the cerebellum, which may be relevant to diaschisis. This phenomenon is often analyzed using positron emission tomography and single photon emission CT. However, these methods are expensive and radioactive. Thus, the present study quantified the changes of infarction core and remote regions after unilateral middle cerebral artery occlusion using apparent diffusion coefficient values. Diffu- sion-weighted imaging showed that the area of infarction core gradually increased to involve the cerebral cortex with increasing infarction time. Diffusion weighted imaging signals were initially in- creased and then stabilized by 24 hours. With increasing infarction time, the apparent diffusion co- efficient value in the infarction core and remote bilateral cerebellum both gradually decreased, and then slightly increased 3-24 hours after infarction. Apparent diffusion coefficient values at remote regions （cerebellum） varied along with the change of supratentorial infarction core, suggesting that the phenomenon of diaschisis existed at the remote regions. Thus, apparent diffusion coefficient values and diffusion weighted imaging can be used to detect early diaschisis.

脉敏(Marma):阿育吠陀中的“腧穴”

脉敏在印度传统医学阿育吠陀中指人体上用于对疾病诊断治疗的许多脆弱或敏感部位。关于脉敏的知识是阿育吠陀理论和实践的重要基础,就像腧穴对于中医一样意义重大,但是目前国内对此研究很少。在学习和整理国外关于脉敏文献的基础上,介绍脉敏的含义、起源、发展和临床治疗方法等。阿育吠陀中重要脉敏的总数为107个,包括一系列的解剖结构如皮肤、骨骼、关节、神经和内脏。在阿育吠陀中通过对特定脉敏部位进行按摩、指压、元气疗愈、涂抹草药膏、刺脉放血、针刺、热疗或烧灼等操作以达到治疗目的。这些知识可为传统医学尤其是中医针灸按摩研究提供参考。

High-temperature mechanical properties of near-eutectoid steel

The high-temperature mechanical properties of near-eutectoid steel were studied with a Cleeble-1500 simu- lation machine. Zero strength temperature （ZST）, zero ductility temperature （ZDT）, hot ductility curves, and strength curves were measured. Two brittle zones and one plastic zone were found in the temperature range from the melting point to 600℃. Embrittlement in zone I is caused by the existence of liquid film along dendritic interfaces. Ductility loss in zone Ⅲ mainly results from precipitates and inclusions as well as S segregation along grain boundaries. Pearlite transformation also accounts for ductility deterioration in the temperature range of 700-600℃. Moreover, the straightening temperature of the test steel should be higher than 925℃ for avoiding the initiation and propagation of surface cracks in billets.

A new adaptive backstepping method for nonlinear control of turbine main steam valve

A new approach for nonlinear adaptive control of turbine main steam valve is developed. In comparison with the existing controller based on ＂classical＂ adaptive backstepping, this method does not follow the classical certaintyequivalence principle in the design of adaptive control law. We introduce this approach, for the first time, to power systems and present a novel parameter estimator and dynamic feedback controller for a single machine infinite bus （SMIB） system with steam valve control. This system contains unknown parameters such as reactance of transmission lines. Besides preserving useful nonlinearities and the real-time estimation of uncertain parameters, the proposed approach possesses better performances with respect to the response of the system and the speed of adaptation. The simulation results demonstrate that the proposed approach is better than the design based on ＂classical＂ adaptive backstepping in terms of properties of stability and parameter estimation, and recovers the performance of the ＂full-information＂ controller. Hence, the proposed method provides an alternative for engineers in applications.

Catalytic conversion of ethyl lactate to 1,2-propanediol over CuO

An efficient conversion of biomass-derived ethyl lactate to 1,2-propanediol(1,2-PDO) over CuO was investigated.Among the catalysts we tested, CuO, Cu2 O and Co showed excellent catalytic activity for the conversion of ethyl lactate to 1,2-PDO in water, and CuO was more active and gave the best result. The 1,2-PDO yield of 93.6% was achieved when Zn acted as a reductant. The results indicated that in situ formed hydrogen by the oxidation of Zn in water is more effective than gaseous hydrogen, which failed to produce the 1,2-PDO from ethyl lactate.From a practical point of view, the present method may provide a useful route for the production of 1,2-PDO from ethyl lactate.

Involvement of X-chromosome Reactivation in Augmenting Cancer Testis Antigens Expression:A Hypothesis

Cancer testis antigens(CTAs)are attractive targets for tumor immunotherapy because of their tumor-specific expression.Since more than half of confirmed CTAs are located on the X-chromosome,we asked whether there is a link between CTA expression and X-chromosomes.Recent reports have shown that reactivation of the inactive X-chromosome,known as X-chromosome reactivation(XCR),a unique phenomenon that exists in many high-risk tumors in women,can transform the expression of many X-linked genes from monoallelic to biallelic.In this review,we discuss the link between CTA and XCR with the hopes of providing some novel insights into tumor biology.

Study on Genetic Toxicity of Solidago decurrens

[Objectives]This study was conducted to analyze the genetic toxicity of Solidago decurrens,with a view to scientifically and safely using S.decurrens.[Methods]Using commercially available S.decurrens as an experimental material,according to Vicia faba root tip micronucleus technique,V.faba root tips were treated with different doses of aqueous extract from S.decurrens for different times,and the mitotic index,frequency of micronucleus and chromosomal aberration of root tips in V.faba were detected,so as to reveal the allelopathic potential and the potential ecological risks of S.decurrens at the cellular level.[Results]The decrease in the mitotic index caused by the aqueous extract of S.decurrens was positively related to the concentration of the aqueous extract and the treatment time.The aqueous extract of S.decurrens increased the frequency of micronucleus in root tip cells of V.faba,and the increase was positively related to the concentration of the aqueous extract and the treatment time.The aqueous extract of S.decurrens caused abnormal phenomena such as chromosome bridges,chromosome fragmentation,and chromosome lag in V.faba root tip cells,and the effect of the aqueous extract on V.faba root tips had significant effects dependent on time and concentration.Above results indicate that the aqueous extract of S.decurrens inhibited and damaged the mitosis of V.faba root tip cells to some degrees,had certain genetic toxicity and had the ability to rapidly spread.[Conclusions]This study provides a theoretical basis for scientifically and rationally using S.decurrens and preventing the spread of S.decurrens.

Three dimensional nonlinear shock waves in inhomogeneous plasmas with different size dust grains and external magnetized field

The evolution of three dimensional nonlinear shock waves is investigated in a dusty plasma with inhomogeneous particles’density,nonadiabatic dust charge variation,external magnetized field and power law dust size distribution.For this purpose,a modified nonlinear Korteweg-de Vries Burgers equation containing variable coefficients is obtained by reductive perturbation method.The effects of inhomogeneity,dust size distribution,external magnetized field,dust charge variation and obliqueness parameter on shock structures are numerically examined in great detail.Furthermore,research results show that oscillatory shock waves and monotone shock waves exist and transform each other in this system.

Optimal aeroassisted symmetric transfer between coplanar elliptical orbits

The problem of optimal aeroassisted symmetric transfer between elliptical orbits is concerned.The complete trajectory is assumed as consisting of two impulsive velocity changes at the beginning and the end of an interior atmospheric subarc,where the vehicle is controlled via the lift coefficient and thrust.The corresponding dynamic equations are built and bounded controls are considered.For the purpose of optimization computation,the equations are normalized.In order to minimize the total fuel consumption,the geocentric radius of initial elliptical transfer orbital perigee and controls during atmospheric flight should all be optimized.It is an optimal control problem which involves additional parameter optimization.To solve the problem,a two-level optimization method denoted by ＂genetic algorithm ＋ Gauss pseudospectral method＂ is adopted：the genetic algorithm is used for parameter optimization and the Gauss pseudospectral method is used for optimal control problems.The flow chart of simulation is given.On this basis,the issue of more realistic modeling with two finite-thrust subarcs in the nonatmospheric part of the trajectory is simultaneously addressed.The orbital transfer problem is transformed to three continuous optimal control problems,and the constraints at different times are given,which are respectively solved by using the Gauss pseudospectral method.The obtained numerical results indicate that the optimal thrust control is of bangbang type.The minimum-fuel trajectory in the atmosphere consists of aeroglide,aerocruise and aeroglide.They are compared with the results of pure impulsive model,and the conclusions that a significant fuel saving will be achieved by synergetic maneuver are drawn.

Heterogeneous Cu_2O-mediated ethylene glycol production from dimethyl oxalate

An efficient process for the conversion of dimethyl oxalateinto ethylene glycol with high selectivity and high yield over CuO was investigated. In situ formed Cu as a true catalytically active species showed a good catalytic performance for DMO conversion to produce EG in 95% yield.

Stage Ⅲ should be subclassified into Stage ⅢA and ⅢB in the American Joint Committee on Cancer(8^(th) Edition) staging system for pancreatic cancer

AIM To ascertain the prognostic role of the T4 and N2 category in stage Ⅲ pancreatic cancer according to the 8 th edition of the American Joint Committee on Cancer(AJCC) classification.METHODS Patients were collected from the Surveillance Epidemiology and End Results(SEER) database(2004-2013) and were divided into three groups: T(1-3)N2, T4 N(0-1), and T4 N2. Overall survival(OS) and disease-specific survival(DSS) of patients were evaluated by the Kaplan-Meier method. RESULTS For the first time, we found a significant difference in OS and DSS between T(1-3)N2/T4 N(0-1) and T4 N2 butnot between T(1-3)N2 and T4 N(0-1). A higher grading correlated with a worse prognosis in the T(1-3)N2 and T4 N2 groups.CONCLUSION Patients with stage T4 N2 had a worse prognosis than those with stage T(1-3)N2/T4 N(0-1) in the 8 th edition AJCC staging system for pancreatic cancer. We recommend that stage Ⅲ should be subclassified into stage ⅢA [T(1-3)N2/T4 N(0-1)] and stage ⅢB(T4 N2).

Synergistic Reinforcement of Phenol-Formaldehyde Resin Composites by Poly(Hexanedithiol)/Graphene Oxide

In this paper, the preparation of graphene oxide was achieved by Hummers method and the surface modification was achieved by poly(hexaneditiol), which was a synthetic thermotropic liquid crystalline polymer. The c-PHDT/GO/PF composites were prepared by blending, rolling and compression molding techniques. Then, the as-prepared samples were characterized by FTIR, Raman, XRD, TGA and POM to obtain information on their structures and properties. After that, the effects of c-PHDT/GO content on the mechanical properties, friction performance and dynamic mechanical performance of c-PHDT/GO/PF composites were studied by Mechanical and Dynamic Mechanical Analysis (DMA) methods. Also, Scanning Electron Microscope (SEM) was used for the characterization of wear and fracture surface morphology. The results revealed that the reinforcing effect of c-PHDT/GO was significant as a considerable enhancement on the mechanical performance of c-PHDT/GO/PF composite as compared to pure phenol-formaldehyde composites was observed: the impact strength, bending modulus and bending strength increased from 1.63 kJ/m2, 8.61 GPa and 41.55 MPa to 2.31 kJ/m2, 10.16 GPa and 54.40 MPa respectively at the c-PHDT/GO content = 0.75%. Moreover, the initial storage modulus increased by 28.4%, while the wear mass loss decreased by 17.8%. More importantly, the reinforcement by c-PHDT/GO was further enhanced as compared to GO/PF and p-PHDT/GO/PF composites, the impact strength of c-PHDT/GO/PF composite increased by 27.6% and 11.1%, the bending strength increased by 11.8% and 7.6%, the initial storage modulus increased by 16.2% and 4.2% and the mass loss due to wear decreased by 12.7% and 8.8%, respectively. Based on these results, we can conclude that the surface modification of GO by poly(hexanedithiol), which includes synergistic effect by c-PHDT and GO, improves the interfacial adhesion between GO and the resin matrix, thus reinforcing the composites.

Changes in corneal curvature and aberrations after cataract surgery

Background:Surgically induced astigmatism(SIA)and corneal high-order aberrations(HOAs)are the two main causes of poor visual quality after cataract surgery.Changes in the parameters of corneal HOAs after cataract surgery and their effects on and relationships with changes in corneal curvature have not yet been reported.This study aimed to explore changes in anterior,posterior and total corneal curvature,astigmatism and HOAs after microincision cataract surgery.Methods:Sixty-one age-related cataract patients(61 eyes)were included in this prospective study.The total,anterior and posterior corneal astigmatism and corneal HOAs were analyzed by anterior segment optical coherence tomography(AS-OCT)and iTrace before,one day,one week and three months after 2.2 mm temporal microincision coaxial phacoemulsification to evaluate the changes in anterior,posterior and total corneal curvature,astigmatism and corneal HOAs.Results:The mean J0 and J45 values of anterior,posterior and total corneal curvature obtained by ASOCT showed no statistically significant difference between preoperatively and any postoperative followup.SIA occurred on the anterior,posterior and total corneal surfaces and showed no statistically significant difference at any postoperative follow-up.No significant changes in 3rd-order oblique trefoil,vertical coma or 4th-order spherical aberrations were observed after surgery except for a significant increase in horizontal coma at postoperative day 1(POD1).Conclusions:There were no significant changes in corneal curvature after 2.2 mm temporal microincision coaxial phacoemulsification,and the corneal HOAs were not changed significantly except for the increase in horizontal coma at POD1,which may be one of the main reasons of poor visual quality at POD1 in some cataract patients who have good uncorrected or corrected distance vision.

Causes of Vocational College Students'Reticence in EFL Classrooms of China's Mainland-based on Panxi Vocational College

This article reports on a study of students' reticence in English as a Foreign Language(EFL)classrooms in Panxi Vocational College in Sichuan Province of China's Mainland.Forty-one students answered a 28-item questionnaire.The students' reticence levels,general tendency of unwillingness-to-speak,and their learning behaviors were identified.Individual and social factors contributing to the reticence phenomenon in the vocational college's EFL classrooms were also determined.The results suggested that culture have strong influences on Chinese vocational college students'reticence.However,their habitual classroom behaviors that have been established for a long time should be taken into account in regard to their reticence.