Microglial response to aging and neuroinflammation in the development of neurodegenerative diseases

Cellular senescence and chronic inflammation in response to aging are considered to be indicators of brain aging;they have a great impact on the aging process and are the main risk factors for neurodegeneration.Reviewing the microglial response to aging and neuroinflammation in neurodegenerative diseases will help understand the importance of microglia in neurodegenerative diseases.This review describes the origin and function of microglia and focuses on the role of different states of the microglial response to aging and chronic inflammation on the occurrence and development of neurodegenerative diseases,including Alzheimer's disease,Huntington's chorea,and Parkinson's disease.This review also describes the potential benefits of treating neurodegenerative diseases by modulating changes in microglial states.Therefore,inducing a shift from the neurotoxic to neuroprotective microglial state in neurodegenerative diseases induced by aging and chronic inflammation holds promise for the treatment of neurodegenerative diseases in the future.

11.2 W/mm power density AlGaN/GaN high electron-mobility transistors on a GaN substrate

In this letter,high power density AlGaN/GaN high electron-mobility transistors(HEMTs)on a freestanding GaN substrate are reported.An asymmetricΓ-shaped 500-nm gate with a field plate of 650 nm is introduced to improve microwave power performance.The breakdown voltage(BV)is increased to more than 200 V for the fabricated device with gate-to-source and gate-to-drain distances of 1.08 and 2.92μm.A record continuous-wave power density of 11.2 W/mm@10 GHz is realized with a drain bias of 70 V.The maximum oscillation frequency(f_(max))and unity current gain cut-off frequency(f_(t))of the AlGaN/GaN HEMTs exceed 30 and 20 GHz,respectively.The results demonstrate the potential of AlGaN/GaN HEMTs on freestanding GaN substrates for microwave power applications.

Westward extension of summer atmospheric circulation over the North Pacific after the 1990s

本文研究了20世纪90年代前后夏季北太平洋大气环流(NPcirculation)向西扩展,并探讨了其可能的原因.结果表明,在1961-1983年期间NP中心主要位于东北太平洋,而在1994-2016年期间NP中心发生西移,至北太平洋中部进一步分析指出,90年代以后NP活动中心的西移和春季中纬度北太平洋海温(SST_NP)与NP关系的加强有关.春季SST_NP异常通过引起后期夏季北太平洋中部地表热通量(即感热通量和潜热通量)和垂直运动异常,有利于NP活动中心向西移动,此外,20世纪90年代以后,北太平洋中部海平面气压的年际变率增加,这可能是NP向西扩展的另一原因。

王浆酸及其护肤功效的研究进展

王浆酸简称10-HDA(10-Hydroxy-2-Decenoic acid,10-HDA),是蜂王浆中的一种不饱和脂肪酸。在自然界,目前只存在于蜂王浆中,且难以分离获取,生物合成法将有望解决王浆酸原料获取困难、价格昂贵的现状。王浆酸具有很强的生物活性,在抑菌、抗炎、抗癌、抗氧化等功效,在食品、医药、保健品、化妆品方面有广泛的应用前景。目前随着时代的发展与市场的变化,化妆品原料的不断研发将会是提升化妆品品质的关键。文章综述了王浆酸在抗衰、抗炎、美白、抗氧化、抑菌方面的功效,以期为王浆酸在护肤品中的应用提供理论依据,为化妆品公司在开发新型、高效、多种用途的护肤原料上提供新的选择。

女性油性敏感皮肤面部生理参数与菌群特征分析

通过自我敏感评价问卷和皮脂分泌量的测定将人群分为健康皮肤非敏感型人群和油性皮肤敏感型人群,采用无创伤性皮肤测量和扩增子测序的方法对健康皮肤人群和油性敏感皮肤人群的皮肤生理特点和菌群组成进行研究。研究发现,与健康皮肤人群相比,油性敏感皮肤人群的皮肤含水量和b值显著降低(P<0.05),经皮水分流失率、皮脂、血红素和皮肤粗糙度显著升高(P<0.05),毛孔面积显著增大(P<0.05);皮肤菌群多样性分析表明Sobs指数(P<0.05)和Shannon指数显著降低(P<0.001),菌群多样性降低;物种组成分析表明,丙酸杆菌属和葡萄球菌属丰度明显上升,红球菌属和假单胞菌属丰度显著下降(P<0.001);斯皮尔曼相关性分析表明,皮脂与丙酸杆菌属和葡萄球菌属呈正相关,与其他菌属呈负相关性;且在皮肤生理参数和物种组成部分加入油性不敏感数据对比发现,这种皮肤也处于不健康的皮肤状态,其生理参数和皮肤菌群组成变化与油性敏感皮肤呈相同的变化趋势,但整体均好于油性敏感皮肤。通过以上结果分析得到,油性敏感皮肤的产生与皮肤菌群的变化密切相关,且丙酸杆菌属是影响皮肤菌群组成整体稳定性的重要菌属,以上研究结果将为油性敏感皮肤人群护肤品的开发提供科学依据。

毛囊与头皮问题及其对策

毛囊是头皮上的微小上皮器官,其结构复杂并且具有周期性。毛囊在头皮中占有重要地位,每个毛囊都是一个独立的毛发生产工厂,健康的毛囊对于头皮和头发的良好维持起到关键作用,而且毛囊是不可再生的。当毛囊受到遗传、雄激素、压力等因素的影响出现萎缩或者堵塞就会引发一系列的头皮问题。目前国内外与毛囊生物学相关的研究较广泛,然而将各种头皮问题与毛囊相联系的报道却很少。文章主要综述了各类头皮问题如头皮屑、雄激素脱发、毛囊炎等的发生与毛囊的相关性,从毛囊的角度总结各种头皮问题的发生机制并提供相应的解决思路。

Detection and Attribution of Changes in Thermal Discomfort over China during 1961-2014 and Future Projections

In this study, variation in the frequency of thermal discomfort days over China during the period of 1961-2014,including heat discomfort days(HDDs) and cold discomfort days(CDDs), and the influence of external forcings on it are discussed. HDDs are the conditions of overheating and overhumidity(represented by humidity index), and CDDs reflect the dangers from cold temperatures and winds(represented by wind chill index). Observations show significant increases(decreases) in the frequency of HDDs(CDDs) over China from 1961 to 2014, with clear regional distinctions. The historical ALL and greenhouse gas(GHG) simulations can sufficiently reproduce the spatial patterns of the observational trend in the frequency of both HDDs and CDDs over China. Further, the impacts of GHG and anthropogenic forcings on the HDDs(CDDs) are detectable over China, except for central and eastern China, based on the optimal fingerprinting method. GHG forcing is identified as a dominant factor for the observational changes in the frequency of HDDs over southern China;GHG and anthropogenic forcings have dominant effects on the variation in the frequency of CDDs over southwestern China. Although trends in the frequency of HDDs and CDDs in historical aerosol forcing simulations seems to be opposite to observations, an aerosol signal fails to be detected. Natural forcing contributes to the observational variation in the frequency of HDDs over northwestern China. In addition, the future projections of thermal discomfort days indicate that Chinese residents will face more threats of heat discomfort and fewer threats of cold discomfort in the future under global warming.

2.83-kV double-layered NiO/β-Ga_(2)O_(3) vertical p-n heterojunction diode with a power figure-of-merit of 5.98 GW/cm^(2)

This work demonstrates high-performance NiO/β-Ga_(2)O_(3) vertical heterojunction diodes(HJDs)with double-layer junc-tion termination extension(DL-JTE)consisting of two p-typed NiO layers with varied lengths.The bottom 60-nm p-NiO layer fully covers theβ-Ga_(2)O_(3) wafer,while the geometry of the upper 60-nm p-NiO layer is 10μm larger than the square anode elec-trode.Compared with a single-layer JTE,the electric field concentration is inhibited by double-layer JTE structure effectively,resulting in the breakdown voltage being improved from 2020 to 2830 V.Moreover,double p-typed NiO layers allow more holes into the Ga_(2)O_(3) drift layer to reduce drift resistance.The specific on-resistance is reduced from 1.93 to 1.34 mΩ·cm^(2).The device with DL-JTE shows a power figure-of-merit(PFOM)of 5.98 GW/cm^(2),which is 2.8 times larger than that of the conven-tional single-layer JTE structure.These results indicate that the double-layer JTE structure provides a viable way of fabricating high-performance Ga_(2)O_(3) HJDs.

中药双向发酵液制备及其抗衰老、保湿、美白功效研究

通过对中国灵芝、铁皮石斛、黄精、晚香玉进行双向发酵工艺优化,筛选制备出最优发酵液,利用不同质量分数中药双向发酵液对体外抑制蛋白质非酶糖基化、酪氨酸酶活性抑制、水通道蛋白Aquaporin3(AQP3)含量、2,2’-联氮-双-3-乙基苯并噻唑啉-6-磺酸(ABTS)自由基清除率、1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除率、小鼠黑素B16-F10细胞黑色素含量进行测定。研究结果发现,中药双向发酵液能够显著抑制蛋白质非酶糖基化、酪氨酸酶活性、小鼠B16-F10细胞黑色素含量(P<0.05),并且能够显著清除DPPH和ABTS自由基,促进角质形成细胞AQP3蛋白表达(P<0.01),这为化妆品原料的开发提供了新的方向和数据依据。

Rubidium-induced phase transitions among metallic,band-insulating,Mott-insulating phases in 1T-TaS_(2)

Realizing phase transitions via non-thermal sample manipulations is important not only for applications,but also for uncovering the underlying physics.Here,we report on the discovery of two distinct metal–insulator transitions in 1T-TaS_(2) via angle-resolved photoemission spectroscopy and in-situ rubidium deposition.At 205 K,the rubidium deposition drives a normal metal–insulator transition via filling electrons into the conduction band.While at 225 K,however,the rubidium deposition drives a bandwidth-controlled Mott transition as characterized by a rapid collapsing of Mott gap and a loss of spectral weight of the lower Hubbard band.Our result,from a doping-controlled perspective,succeeds in distinguishing the metallic,band-insulating,and Mott-insulating phases of 1T-TaS_(2),manifesting a delicate balance among the electronitineracy,interlayer-coupling and Coulomb repulsion.We also establish an effective method to tune the balance between these interactions,which is useful in seeking exotic electronic phases and designing functional phase-changing devices.

皮脂腺在护肤领域的研究进展

近年来,寻常痤疮、特应性皮炎等损容性皮肤病的发病率明显增加,其发病机理与皮脂腺功能异常密切相关。皮脂腺存在于真皮层,是皮肤的重要附属器官之一,其上存在着大量受体,受多种机制调控,其功能异常会造成多种皮肤问题。但目前国内对皮肤脂质的研究多针对于细胞间脂质,对皮脂腺分泌的脂质的作用机制研究还不够深入,临床应用与护肤品开发仍需大量基础研究支撑。文章从护肤角度对皮脂腺维持皮肤屏障功能、参与炎症反应、调控衰老进程以及调控肤色方面的作用机制进行了总结,并对皮脂腺相关皮肤问题、皮脂腺功能相关检测方法以及与皮脂腺调控相关的护肤品成分等进行了系统的概述,旨在为皮脂腺功能相关的皮肤护理和皮肤问题解决提供参考依据。

Variation in Principal Modes of Midsummer Precipitation over Northeast China and Its Associated Atmospheric Circulation

This study documents the first two principal modes of interannual variability of midsummer precipitation over Northeast China （NEC） and their associated atmospheric circulation anomalies. It is shown that the first principal mode exhibits the largest amount of variability in precipitation over the south of NEC （referred to as the south mode）, whereas the second principal mode behaves with the greatest precipitation anomaly over the north of NEC （referred to as the north mode）. Further findings reveal that, through modulating moisture transportation and upper- and lower-troposphere divergence circulation as well as vertical movement over NEC, the anomalous northwestern Pacific anticyclone and the anticyclone centered over northern NEC exert the dominant influence on the south and north modes, respectively. Additionally, it is quantitatively estimated that water vapor across the southern boundary of NEC dominates the moisture budget for the south mode, while the north mode has a close connection with moisture through NEC＇s northern and western boundal＇ies. Furthermore, the north （south） mode is strongly related to the intensity （meridional shift） of the East Asian westerly jet.

Strengthened Relationship between the Antarctic Oscillation and ENSO After the Mid-1990s during Austral Spring

This paper documents a decadal strengthened co-variability of the Antarctic Oscillation （AAO） and ENSO in austral spring after the mid-1990s. During the period 1979-93, the ENSO （AAO） spatial signatures are restricted to the tropicsmidlatitudes （Antarctic-midlatitudes） of the Southern Hemisphere （SH）, with a weak connection between the two oscillations. Comparatively, after the mid-1990s, the E1 Nifio-related atmospheric anomalies project on a negative AAO pattern with a barotropic structure in the mid-high latitudes of the SH. The expansion of E1 Nifio-related air temperature anomalies have a heightened impact on the meridional thermal structure of the SH, contributing to a weakened circumpolar westerly and strengthened subtropical jet. Meanwhile, the ENSO-related southern three-cell circulations expand poleward and then strongly couple the Antarctic and the tropics. Numerical simulation results suggest that the intensified connection between ENSO and SST in the South Pacific since the mid-1990s is responsible for the strengthened AAO-ENSO relationship.

Impact of Global OceanicWarming on Winter Eurasian Climate

In the 20 th century, Eurasian warming was observed and was closely related to global oceanic warming(the first leading rotated empirical orthogonal function of annual mean sea surface temperature over the period 1901–2004). Here, large-scale patterns of covariability between global oceanic warming and circulation anomalies are investigated based on NCEP–NCAR reanalysis data. In winter, certain dominant features are found, such as a positive pattern of the North Atlantic Oscillation(NAO), low-pressure anomalies over northern Eurasia, and a weakened East Asian trough. Numerical experiments with the CAM3.5, CCM3 and GFDL models are used to explore the contribution of global oceanic warming to the winter Eurasian climate. Results show that a positive NAO anomaly, low-pressure anomalies in northern Eurasia, and a weaker-than-normal East Asian trough are induced by global oceanic warming. Consequently, there are warmer winters in Europe and the northern part of East Asia. However, the Eurasian climate changes differ slightly among the three models. Eddy forcing and convective heating from those models may be the reason for the different responses of Eurasian climate.

Seasonal prediction of extreme high-temperature days over the Yangtze River basin

Extreme high temperatures occur frequently over the densely populated Yangtze River basin(YRB)in China during summer,significantly impacting the local economic development and ecological system.However,accurate prediction of extreme high-temperature days in this region remains a challenge.Unfortunately,the Climate Forecast System Version 2(CFSv2)exhibits poor performance in this regard.Thus,based on the interannual increment approach,we develop a hybrid seasonal prediction model over the YRB(HM_(YRB))to improve the prediction of extreme high-temperature days in summer.The HM_(YRB)relies on the following four predictors:the observed preceding April-May snowmelt in north western Europe;the snow depth in March over the central Siberian Plateau;the CFSv2-forecasted concurrent summer sea surface temperatures around the Maritime Continent;and the 200-hPa geopotential height over the Tibetan Plateau.The HM_(YRB)indicates good capabilities in predicting the interannual variability and trend of extreme high-temperature days,with a markable correlation coefficient of 0.58 and a percentage of the same sign(PSS)of 76% during 1983-2015 in the one-year-out cross-validation.Additionally,the HM_(YRB) maintains high PSS skill(86%)and robustness in the independent prediction period(2016-2022).Furthermore,the HM_(YRB) shows a good performance for years with high occurrence of extreme high-temperature days,with a hit ratio of 40%.These predictors used in HM_(YRB)are beneficial in terms of the prediction skill for the average daily maximum temperature in summer over the YRB,albeit with biases existing in the magnitude.Our study provides promising insights into the prediction of 2022-like hot extremes over the YRB in China.

异基因造血干细胞移植后腺病毒感染的临床特征分析

目的分析异基因造血干细胞移植(allo-HSCT)后人腺病毒(HAdV)感染患者的临床特征及预后。方法回顾性病例系列研究。收集2015年8月至2019年10月在北京大学人民医院血液科接受allo-HSCT后出现疑似感染症状但感染病原不明的2728例患者标本,采用荧光定量PCR法检测HAdV DNA,HAdV DNA检测阳性视为HAdV感染。分析HAdV感染患者临床表现,并根据患者年龄、移植类型、移植年份、随访时间采用巢式病例配对按1∶3匹配了未发生HAdV感染的患者作为对照组,采用Kaplan-Meier法分析并进行Log-rank检验,比较HAdV感染组和对照组的临床预后。结果共检测7119份标本,其中36例患者99例次HAdV DNA阳性。36例HAdV感染患者中22例发生HAdV血症;24例除HAdV感染外合并1种或多种其他病毒感染;19例(53%)有发热,25例(69%)有消化道症状,11例(31%)有呼吸道症状,9例(25%)有肝功能异常,6例(17%)有神经系统症状;23例同时发生2度及以上急性移植物抗宿主病;9例患者接受西多福韦抗病毒治疗,其中7例HAdV转阴,2例治疗无效。所有患者随访时间[M(Q_(1),Q_(3))]为496(216,940)d,Kaplan-Meier分析显示HAdV感染组5年总体生存率低于对照组(48.4%±9.2%比91.3%±3.5%;χ^(2)=65.03,P<0.001),移植后5年的非复发死亡率高于对照组(40.8%±8.8%比4.0%±2.0%;χ^(2)=34.17,P<0.001)。结论allo-HSCT后HAdV感染者以消化道、呼吸道症状为主,合并2度以上急性移植物抗宿主病的风险增加,HAdV感染患者总体生存差,非复发死亡率高。

Chemical and optical properties of aerosols and their interrelationship in winter in the megacity Shanghai of China

A field campaign on air quality was carried out in Shanghai in winter of 2012. The concentrations of NO, NO2, NOx, SO2, CO, and PM2.5increased during haze formation. The average masses of SO4^2-, NO3^-and NH4^＋were 10.3, 11.7 and 6.7 μg/m^3 during the haze episodes, which exceeded the average（9.2, 7.9, and 3.4 μg/m3） of these components in the non-haze days. The mean values for the aerosol scattering coefficient（b sp）, aerosol absorption coefficient（b ap） and single scattering albedo（SSA） were 288.7, 27.7 and0.91 Mm-1, respectively. A bi-peak distribution was observed for the mass concentrations of CO, NO, NO2, and NOx. More sulfate was produced during daytime than that in the evening due to photochemical reactions. The mass concentration of NH4＋achieved a small peak at noontime. NO3-showed lower concentrations in the afternoon and higher concentrations in the early morning. There were obvious bi-peak diurnal patterns for b sp and b ap as well as SSA. b sp and b ap showed a positive correlation with PM2.5mass concentration.（NH4）2SO4, NH4NO3, organic mass, elemental carbon and coarse mass accounted for 21.7%, 19.3%, 31.0%, 9.3% and 12.3% of the total extinction coefficient during non-haze days, and 25.6%, 24.3%, 30.1%, 8.1% and 8.2% during hazy days. Organic matter was the largest contributor to light extinction. The contribution proportions of ammonium sulfate and ammonium nitrate to light extinction were significantly higher during the hazy time than during the non-haze days.

层状V_(2)O_(5)薄膜中本征漂移和Mott纳米通道用于突触和痛觉感受器模拟

生物神经系统中痛觉感受器、神经元和突触的整合与协作,使人类能够有效感知和处理有害信息,从而规避危险.受生物神经系统的启发,目前人工神经电子器件包括电解液基晶体管、依赖外来离子的忆阻器和卤化物钙钛矿忆阻器.这些器件在一定程度上存在重复性、可控性、稳定性差和集成困难等问题.本文引入了一种CMOS兼容、简单、稳定的Pt/V_(2)O_(5)/Pt三明治结构器件,并通过在层状V_(2)O_(5)介质层中构建和调控缺氧V_(2)O_(5-x)和Mott VO2纳米通道分别模拟了类脑处理和神经痛觉感知功能.此外,在基于V_(2)O_(5-x)纳米通道突触器件卷积神经网络中,手写数字识别准确率在5个训练后高达80%,52个训练后达到89%.利用Mott VO2纳米通道器件的优异阈值转变完美地模拟了痛觉感受器的所有关键特征.特别是,器件展现了0.4 V的超低阈值电压和亚毫秒级孵化时间.这些结果表明,在Pt/V_(2)O_(5)/Pt单一器件中构建的漂移型和Mott纳米通道能够很好地模拟突触和伤害感受器功能.该工作为开发多功能、超灵敏和高集成人工智能系统提供了新思路.

Influence of circulation types on temporal and spatial variations of ozone in Beijing

This study analyzes the impact of circulation types(CTs)on ozone(O_(3))pollution in Beijing.The easterly high-pressure(SWW)circulation occurred most frequently(30%;276 day),followed by northwesterly high-pressure(AN)circulation(24.3%;224 day).The SWW type had the highest O_(3) anomaly of+17.28μg/m^(3),which was caused by excellent photochemical reactions,poor diffusion ability and regional transport.Due to the higher humidity and precipitation in the low-pressure type(C),the O_(3) increase(+8.02μg/m^(3))was less than that in the SWW type.Good diffusion/wet deposition and weak formation ability contributed to O_(3) decrease in AN(-12.54μg/m^(3))and northerly high-pressure(ESN)CTs(-12.26μg/m^(3)).The intra-area transport of O_(3) was significant in polluted circulations(SWW-and C-CTs).In addition,higher temperature,radiation and less rainfall also contributed to higher O_(3) in northern Beijing under the SWW type.For the clean CTs(AN and ESN CTs),precursor amount and intra-area transport played a dominant role in O_(3) distribution.Under the northeasterly low-pressure CT,better formation conditions and higher precursor amount combined with the intra-area southerly transport to cause higher O_(3) values in the south than in the north.The higher O_(3) in the northwestern area under the northeasterly high-pressure type was influenced by weaker titration loss and high O_(3) concentration in previous day.Annual variation in the CTs contributed up to 86.1%of the annual variation in O_(3).About 78%-83%of the diurnal variation in O_(3) resulted from local meteorological factors.

Coulometric Response of H-Selective Solid-Contact Ion-Selective Electrodes and Its Application in Flexible Sensors+

The analytical performance of H+-selective solid-contact ion-selective electrodes(SCISEs)based on solid contact polyaniline doped with chloride(PANI(Cl))and poly(3,4-ethylenedioxythiophene)doped with poly(styrene sulfonate)(PEDOT(PSS))was characterized by a developed coulometric signal transduction method.PEDOT(PSS)solid contact is covered by PVC based H+-selective membrane.The obtained coulometric signal demonstrates that the cumulated charge can be amplified by increasing the capacitance of solid contact.SCISEs covered with spin-coated membrane behave faster amperometric response than electrodes with drop-cast mem-brane.In contrast to earlier works,the amperometric response and impedance spectrum demonstrates H+transfer through SCISEs is independent from the thickness of membrane.The exceptional behavior of PANI(Cl)H+-SCISEs shows that the capacitance estimated from impedance spectrum at low frequency 10 mHz and coulometric signal of PANI(Cl)based SCISEs is influenced by the applied po-tentials,whereas PEDOT(PSS)solid contact is independent from the chosen applied potentials.Furthermore,preliminary investiga-tions of coulometric signal transduction on flexible pH sensor implies its potential applications in wearable sensors for sweat ion concentration detection.