微通道反应器内α-烯烃连续磺化工艺的实验研究

α-烯烃磺酸钠(AOS)是具有良好生物降解性、润湿性、低刺激性的阴离子表面活性剂。利用微通道反应器,分别以1-十四烯(AO)和混合烯烃为原料,SO_(3)为磺化剂,考察了磺化温度、SO_(3)/AO摩尔比、磺化剂质量分数、停留时间等工艺条件对活性物AOS含量的影响规律。结果表明:1-十四烯磺化最佳工艺条件为磺化温度40℃、SO_(3)/AO摩尔比为1.2、SO_(3)质量分数为10%;混合烯烃磺化最佳工艺条件为磺化温度50℃、SO_(3)/AO摩尔比为1.1、SO_(3)质量分数为10%。增大流速有利于强化传质过程、提高产物中活性物AOS含量;延长停留时间会加剧副反应发生、降低产物中活性物含量。微通道反应器内α-烯烃磺化是以传质为主的强放热反应,热量移除及时,反应过程易于控制,可有效提高产品质量,大大增强生产工艺的本质安全性,对于开发煤基α-烯烃下游产品具有实际意义。

Numerical study of plasmas start-up by electron cyclotron waves in NCST spherical tokamak and CN-H1 stellarator

According to the physics of tokamak start-up,this study constructs a zero-dimensional(0D)model applicable to electron cyclotron(EC)wave assisted start-up in NCST spherical torus(spherical tokamak)and CN-H1 stellarators.Using the constructed 0D model,the results obtained in this study under the same conditions are compared and validated against reference results for pure hydrogen plasma start-up in tokamak.The results are in good agreement,especially regarding electron temperature,ion temperature and plasma current.In the presence of finite Ohmic electric field in the spherical tokamak,a study on the EC wave assisted start-up of the NCST plasma at frequency of 28 GHz is conducted.The impact of the vertical magnetic field B_(v)on EC wave assisted start-up,the relationship between EC wave injection power P_(inj),Ohmic electric field E,and initial hydrogen atom density n_(H0)are explored separately.It is found that under conditions of Ohmic electric field lower than ITER(~0.3 V m^(-1)),EC wave can expand the operational space to achieve better plasma parameters.Simulating the process of28 GHz EC wave start-up in the CN-H1 stellarator plasma,the plasma current in the zerodimensional model is replaced with the current in the poloidal coil of the stellarator.Plasma startup can be successfully achieved at injection powers in the hundreds of kilowatts range,resulting in electron densities on the order of 10^(17)-10^(18)m^(-3).

Effect of amnion membrane transplantation on corneal neovascularization in 10 patients with alkali burn

By observing clinical cases, we studied the curative effect of amnion membrane transplantation on decreasing corneal neovascularization (CNV). It was a non-randomized retrospective case-control study. Among 17 cases (21 eyes) of third-degree alkali burns from 2007 to 2010, 10 cases (12 eyes) were performed with amnion membrane transplantation operation, and others were not. Amnion membrane transplantation was performed at the 3rd day after burn in the treatment group. Areas of CNV in double groups were measured at the 14th day and 60th day after burn. Area of CNV in the treatment group was (66.207±7.251)mm2 at the 14th day after burn, and was 18.27% lower than that in the control group. Area of CNV in the treatment group was (120.046±13.812)mm2 at the 60th day after burn, and was 11.35% lower than that in the control group. There was both statistical significance (P<0.05). Amnion membrane transplantation operation can inhibit the growth of corneal neovascularization induced by alkali burn.

鞋印花纹裂缝特征自动检测方法

本文提出了基于复杂花纹切分与配对的鞋印上裂缝特征的自动检测方法。对于鞋印花纹局部图像,首先进行连通域分析,计算每个连通成分的复杂度,并基于边界到边界的方向距离算法进行复杂花纹的切分,然后根据简单花纹段的方向、宽度和空间关系进行裂缝花纹配对,根据配对花纹的间隙,确定裂缝特征的位置和范围,完成裂缝特征检测,并在实验室采集的直线型、网格型、波折型等鞋印花纹上进行验证。结果表明,在实验数据集上裂缝特征的检出率为87.5%。裂缝特征自动检测算法能够应用于鞋印检验鉴定中,可有效降低对人员经验的依赖,消除人为因素影响。

Towards Kinetic Modeling of Global Metabolic Networks： Methylobacterium extorquens AM1 Growth as Validation

Here we report a systematic method for constructing a large scale kinetic metabolic model and its initial application to the modeling of central metabolism of Methylobacterium extorquens AM1, a methylotrophic and environmental important bacterium. Its central metabolic network includes formaldehyde metabolism, serine cycle, citric acid cycle, pentose phosphate pathway, gluconeogensis, PHB synthesis and acetyl-CoA conversion pathway, respiration and energy metabolism. Through a systematic and consistent procedure of finding a set of parameters in the physiological range we overcome an outstanding difficulty in large scale kinetic modeling: the requirement for a massive number of enzymatic reaction parameters. We are able to construct the kinetic model based on general biological considerations and incomplete experimental kinetic parameters. Our method consists of the following major steps: 1) using a generic enzymatic rate equation to reduce the number of enzymatic parameters to a minimum set while still preserving their characteristics; 2) using a set of steady state fluxes and metabolite concentrations in the physiological range as the expected output steady state fluxes and metabolite concentrations for the kinetic model to restrict the parametric space of enzymatic reactions; 3) choosing enzyme constants K's and K'eqs optimized for reactions under physiological concentrations, if their experimental values are unknown; 4) for models which do not cover the entire metabolic network of the organisms, designing a dynamical exchange for the coupling between the metabolism represented in the model and the rest not included.

Comparison of outcomes of idiopathic macular holes treated by vitrectomy with air or silicone oil tamponade based on the hole size

AIM:To compare the efficacy of vitrectomy combined with air or silicone oil in the treatment of idiopathic macular hole(IMH).METHODS:According to the results of high-definition optical coherence tomography(HD-OCT),75 cases(75 eyes)of IMH in stage II-IV(Gass stage)in the General Hospital of Chinese PLA from January 2017 to December 2019 were collected for this retrospective study.The best corrected visual acuity(BCVA)and minimum diameter of IMH(MMHD)were measured.Eyes underwent vitrectomy combined with internal limiting membrane peeling operation,and were divided into disinfection air group(30 eyes)and silicone oil group(45 eyes)according to the intraocular tamponade.For MMHD≤400μm(MMHD1),there were 23 eyes in air group and 16 eyes in silicone oil group.For MMHD2>400μm(MMHD2),there were 7 eyes in air group and 29 eyes in silicone oil group.One month after surgery,the closure rates of IMH and BCVA were compared and analyzed.According to HD-OCT,the closure shape was graded with A(bridge closure)and B(good closure).RESULTS:The closure rates of air group and silicone oil group were 86.67%and 95.56%respectively with no significant difference(P>0.05);For MMHD1,those of air group and silicone oil group were 95.65%and 100%respectively with no significant difference(P>0.05);For MMHD2,those of air group and silicone oil group were 57.14%and 93.10%respectively,and those of the silicone oil group were higher than the air group(P<0.05).There was no significant difference in the closure shape grade between MMHD1 air group and silicone oil group(P>0.05).The proportion of Grade B in MMHD2 silicone oil group was higher than that in the air group(P<0.05).BCVA of each group after operation was better than that before operation,and there was no significant difference between air group and silicone oil group.While among them,MMHD1 air group was better than silicone oil group(P<0.05),and there was no significant difference between MMHD2 air group and silicone oil group(P>0.05).CONCLUSION:For smaller IMH(≤400μm),the efficacy of vitrectomy combined with air should be considered better than silicone oil;for larger IMH(>400μm),the efficacy of silicone oil may be better than air.

磁吸式角钢冲孔模具自动更换设备

自动化换模是多品种小批量生产企业实现均衡化生产的前提,当一种产品生产完成后,需要暂停生产线更换工具、原料、模具等操作,为提高生产线效率和保证模具安全,设计一种依附于移动式冲孔平台[1]的磁吸式角钢冲孔模具自动更换设备。该设备主要包括辅助冲孔机构、模具更换机构和模具架机构,实现了模具的自动化更换,达到有效缩短产品切换时间、提高设备利用率与人员作业效率的目的,对生产竞争力有重要意义,解决了冲压模具更换人工化,模具更换摩擦损坏的问题。

文化传播视角下广州城中村村口空间改造策略探究——以广州海珠区石基村为例

在众多城中村改造中,村口空间往往是被忽略的,城中村村口集中呈现了当地的文化内涵与文明进程,在社会不断发展进步、国家对传统文化保护越来越重视的形势下,村口的功能不仅是人车过往的起止点,还代表了城中村的形象,也代表了城市的形象,可以作为村内文化传播的途径之一。本文尝试从文化传播的视角,以广州海珠区石基村为例,结合实地调研分析现状,对城中村村口空间改造设计策略进行探究。

A wireless, implantable optoelectrochemical probe for optogenetic stimulation and dopamine detection

Physical and chemical technologies have been continuously progressing advances in neuroscience research.The development of research tools for closed-loop control and monitoring neural activities in behaving animals is highly desirable.In this paper,we introduce a wirelessly operated,miniaturized microprobe system for optical interrogation and neurochemical sensing in the deep brain.Via epitaxial liftoff and transfer printing,microscale light-emitting diodes(micro-LEDs)as light sources and poly(3,4-ethylenedioxythiophene)polystyrene sulfonate(PEDOT:PSS)-coated diamond films as electrochemical sensors are vertically assembled to form implantable optoelectrochemical probes for real-time optogenetic stimulation and dopamine detection capabilities.A customized,lightweight circuit module is employed for untethered,remote signal control,and data acquisition.After the probe is injected into the ventral tegmental area(VTA)of freely behaving mice,in vivo experiments clearly demonstrate the utilities of the multifunctional optoelectrochemical microprobe system for optogenetic interference of place preferences and detection of dopamine release.The presented options for material and device integrations provide a practical route to simultaneous optical control and electrochemical sensing of complex nervous systems.

Novel implantable devices delivering electrical cues for tissue regeneration and functional restoration

Millions of people suffer from tissue diseases and organ dysfunction,such as bone or nerve defects,spinal cord injuries and arrhythmia,which often leads to morbidity and disability.Electrical stimulation as a promising nonpharmacological technique has been proven to be effective in promoting tissue regeneration and functional restoration.Nevertheless,existing clinical electrical therapies are often limited to intraoperative window or percutaneous stimulation that suffer from insufficient time frame and potential infection risks.To overcome these challenges,innovative electrical stimulation implants with miniaturized,self-powered,flexible or biodegradable features have been proposed.This review summarizes recent advances of novel materials strategies and device schemes for tissue regeneration and/or functional restoration of bones,nerves,gastrointestinal tracts,cardiac systems,etc.Insights on future directions of electrical stimulation devices are given at the end.

新时代体育科普高质量发展研究

体育科普是我国科技创新战略的重要组成部分,高质量发展是全面建设社会主义现代化国家的首要任务,新时代体育科普高质量发展是落实全民健身计划,实现体育强国建设伟大目标的重要方式与途径。通过文献资料法和逻辑分析法,明确新时代体育科普高质量发展内涵特征和动力机制,进一步探究体育科普高质量发展的实践桎梏和推进策略。经研究发现,新时代体育科普高质量发展内容要素包含体育科普政策、人才、环境、技术、文化、项目五个方面,同时新时代体育科普面临体育科普观念初步形成,体育科普专业人才单一,体育科普政策法规粗化,体育科普技术尚待完善,体育科普产业融合不足,体育科普体系仍未构建等实践桎梏。为进一步推动新时代体育科普高质量发展,要深科普观念、育科普人才、细科普政策,融现代科技、推科普产业、构科普体系、弘优秀文化。

直接抗病毒药物治疗HIV/HCV合并感染患者长期疗效及肝纤维化改变

目的探讨人类免疫缺陷病毒(HIV)/丙型肝炎病毒(HCV)合并感染患者接受直接抗病毒药物(DAAs)治疗后病毒学、免疫学及肝纤维化指标长期变化特征。方法以2014年5月至2019年12月广州医科大学附属市八医院HIV/HCV合并感染患者为研究对象,观察DAAS结束治疗后144周随访期间病毒学应答率、外周血CD4^(+)T淋巴细胞水平及肝纤维化血清学指标(APRI评分及FIB-4指数)变化。统计学方法采用Kruskal-Wallis检验。结果共103例患者纳入本研究,男性87例(87.5%),年龄中位数44岁,DAAS治疗结束后12周持续病毒学应答(SVR12)率达97.6%,整个随访过程SVR至少95.9%。与基线相比,CD4^(+)T淋巴细胞计数治疗结束后12周(Z=-2.283,P=0.022)、24周(Z=-3.538,P<0.001)、48周(Z=-3.297,P=0.001)、96周(Z=-3.562,P<0.001)以及144周(Z=-2.842,P=0.004)均显著升高。DAAS治疗第4周时,APRI评分(Z=-6.394,P<0.001)和FIB-4指数(Z=-2.528,P=0.011)即较基线显著下降,之后它们一直维持在较低水平,但未进步下降。结论HIV/HCV合并感染者经DAAS治疗后可长期保持较高SVR,获得良好免疫重建,并明显改善肝纤维化。

Recent progress on biodegradable materials and transient electronics

Transient electronics(or biodegradable electronics)is an emerging technology whose key characteristic is an ability to dissolve,resorb,or physically disappear in physiological environments in a controlled manner.Potential applications include eco-friendly sensors,temporary biomedical implants,and datasecure hardware.Biodegradable electronics built with water-soluble,biocompatible active and passive materials can provide multifunctional operations for diagnostic and therapeutic purposes,such as monitoring intracranial pressure,identifying neural networks,assisting wound healing process,etc.This review summarizes the up-to-date materials strategies,manufacturing schemes,and device layouts for biodegradable electronics,and the outlook is discussed at the end.It is expected that the translation of these materials and technologies into clinical settings could potentially provide vital tools that are beneficial for human healthcare.

特纳综合征并年轻女性急性心肌梗死1例

1病例资料患者,女,27岁,因"间断胸闷6d"入院。患者于2019-08-14在活动时出现胸闷,位于胸骨中段后方,呈压迫感,不向咽部、左肩及背部放射,持续约数分钟,休息后自行缓解,后上述症状反复发作。2019-08-17至当地医院就诊,查心肌肌钙蛋白0.73ng/ml,心电图(图1)提示V1~V5导联ST段下移,部分>0.1 mV,伴T波倒置或低平。

The Cooperative Activities of CSLD2, CSLD3, and CSLD5 Are Required for Normal Arabidopsis Development

Glycosyltransferases of the Cellulose Synthase Like D （CS/D） subfamily have been reported to be involved in tip growth and stem development in Arabidopsis. The csld2 and csld3 mutants are root hair defective and the csld5 mutant has reduced stem growth. In this study, we produced double and triple knockout mutants of CSLD2, CSLD3, and CSLD5. Unlike the single mutants and the csld2/csld3 double mutant, the csld2/csld5, csld3/csld5, and csld2/csld3/csld5 mutants were dwarfed and showed severely reduced viability. This demonstrates that the cooperative activities of CSLD2, CSLD3, and CSLD5 are required for normal Arabidopsis development, and that they are involved in important processes besides the specialized role in tip growth. The mutant phenotypes indicate that CSLD2 and CSLD3 have overlapping functions with CSLD5 in early plant development, whereas the CSLD2 and CSLD3 proteins are non-redundant. To determine the biochemical function of CSLD proteins, we used transient expression in tobacco leaves. Microsomes containing heterologously expressed CSLD5 transferred mannose from GDP-mannose onto endogenous acceptors. The same activity was detected when CSLD2 and CSLD3 were coexpressed but not when they were expressed separately. With monosaccharides as exogenous acceptors, microsomal preparations from CSLD5-expressing plants mediated the transfer of mannose from GDP-mannose onto mannose. These results were supported by immunodetection studies that showed reduced levels of a mannan epitope in the cell walls of stem interfascicular fibers and xylem vessels of the csld2/csld3/csld5 mutant.

Optoelectronic sensing of biophysical and biochemical signals based on photon recycling of a micro-LED

Conventional bioelectrical sensors and systems integrate multiple power harvesting,signal amplification and data transmission components for wireless biological signal detection.This paper reports the real-time biophysical and biochemical activities can be optically captured using a microscale light-emitting diode(micro-LED),eliminating the need for complicated sensing circuit.Such a thin-film diode based device simultaneously absorbs and emits photons,enabling wireless power harvesting and signal transmission.Additionally,owing to its strong photon-recycling effects,the micro-LED^photoluminescence(PL)emission exhibits a superlinear dependence on the external conductance.Taking advantage of these unique mechanisms,instantaneous biophysical signals including galvanic skin response,pressure and temperature,and biochemical signals like ascorbic acid concentration,can be optically monitored,and it demonstrates that such an optoelectronic sensing technique outperforms a traditional tethered,electrically based sensing circuit,in terms of its footprint,accuracy and sensitivity.This presented optoelectronic sensing approach could establish promising routes to advanced biological sensors.

3D electronic and photonic structures as active biological interfaces

Biocompatible materials and structures with three-dimensional(3D)architectures establish an ideal platform for the integration of living cells and tissues,serving as desirable interfaces between biotic and abiotic systems.While conventional 3D bioscaffolds provide a mechanical support for biomatters,emerging developments of micro-,nano-,and mesoscale electronic and photonic devices offer new paradigms in analyzing and interrogating biosystems.In this review,we summarize recent advances in the development of 3D functional biointerfaces,with a particular focus on electrically and optically active materials,devices,and structures.We first give an overview of representative methods for manufacturing 3D biointegrated structures,such as chemical synthesis,microfabrication,mechanical assembly,and 3D printing.Subsequently,exemplary 3D nano-,micro-,and mesostructures based on various materials,including semiconductors,metals,and polymers are presented.Finally,we highlight the latest progress on versatile applications of such active 3D structures in the biomedical field,like cell culturing,biosignal sensing/modulation,and tissue regeneration.We believe future 3D micro-,nano-,and mesostructures that incorporate electrical and/or optical functionalities will not only profoundly advance the fundamental studies in biological sciences,but also create enormous opportunities for medical diagnostics and therapies.

Soft and transient magnesium plasmonics for environmental and biomedical sensing

Due to its controlled reaction with water and biofluids, Mg as a dissolvable conductor has enabled the development of many transient electronic devices. In addition, Mg is a novel plasmonic material with high extinction efficiency but its transient optical properties have not been explored thoroughly. In this study for the first time, we exploit the transient and tunable plasmonic properties of Mg in environmental and biomedical sensor applications. We used soft nanoimprint lithography to fabricate flexible and large-area Mg plasmonic structures that can be applied on the human skin. Their resonance （or color） can be tuned in the visible range by gradual Mg dissolution in a water fluid or vapor-rich environment; these structures can be easily implemented as passive optical sensors without the need for complex electronic circuits or a power supply. We demonstrate the applications of our optical sensors in the accurate monitoring of environmental humidity and physiological detection of sweat loss on the human skin during exercise. Our devices could be used as decomposable/resorbable optical sensors and can help minimize long-term health effects and environmental risks associated with consumer device waste, which will lead to many new possibilities in transient photonic device applications.

An Optoelectronic thermometer based on microscale infrared-to-visible conversion devices

Thermometric detectors are crucial in evaluating the condition of target objects spanning from environments to the human body.Optical-based thermal sensing tools have received extensive attention,in which the photon upconversion process with low autofluorescence and high tissue penetration depth is considered as a competent method for temperature monitoring,particularly in biomedical fields.Here,we present an optoelectronic thermometer via infrared-to-visible upconversion,accomplished by integrated light receiving and emission devices.Fully fabricated thin-film,microscale devices present temperature-dependent light emission with an intensity change of 1.5%℃^(-1) and a spectral shift of 0.18 nm℃^(-1).The sensing mechanism is systematically characterized and ascribed to temperature dependent optoelectronic properties of the semiconductor band structure and the circuit operation condition.Patterned device arrays showcase the capability for spatially resolved temperature mapping.Finally,in vitro and in vivo experiments implemented with integrated fiber-optic sensors demonstrate real-time thermal detection of dynamic human activity and in the deep brain of animals,respectively.

Emerging Applications of Optical Fiber‑Based Devices for Brain Research

Research in neuroscience and neuroengineering has attracted tremendous interest in the past decades.However,the complexity of the brain tissue,in terms of its structural,chemical,mechanical,and optical properties,makes the interrogation of biophysical and biochemical signals within the brain of living animals extremely challenging.As a viable and versatile tool for brain studies,optical fber based technologies have provided exceptional opportunities to unravel the mysteries of the brain and open the door for clinical applications in the treatment,diagnosis,and prevention of neurological diseases.Typically,optical fbers with diameters from 10 to 1000μm are capable of guiding and delivering light to deep levels of the living tissue.Moreover,small dimensions of such devices along with their fexibility and light weight paved the way for understanding the complex behaviours of living and freely moving mammals.This article provides a review of the emerging applications of optical fbers in neuroscience,specifcally in the mammalian brain.Representative utilities,including optogenetics,fuorescence sensing,drug administration and phototherapy,are highlighted.We also discuss other biological applications of such implantable fbers,which may provide insights into the future study of brain.It is envisioned that these and other optical fber based techniques ofer a powerful platform for multi-functional neural activity sensing and modulation.