Coherent Spin Transport Through a Six-Coordinate FeN6 Spin-Crossover Complex with Two Di erent Spin Configurations

Due to the magnetic bistability, single-molecule spin-crossover (SCO) complexes have been considered to be the most promising building blocks for molecular spintronic devices. Here, we explore the SCO behavior and coherent spin transport properties of a six-coordinate FeN6 complex with the low-spin (LS) and high-spin (HS) states by performing extensive first-principles calculations combined with non-equilibrium Green’s function technique. Theoretical results show that the LS$HS spin transition via changing the metal-ligand bond lengths can be realized by external stimuli, such as under light radiation in experiments. According to the calculated zero-bias transmission coefficients and density of states as well as the I-V curves under small bias voltages of FeN6 SCO complex with the LS and HS states sandwiched between two Au electrodes, we find that the examined molecular junction can act as a molecular switch, tuning from the OFF (LS) state to the ON (HS) state. Moreover, the spin-down electrons govern the current of the HS molecular junction, and this observed perfect spin-filtering effect is not sensitive to the detailed anchoring structure. These theoretical findings highlight this examined six-coordinate FeN6 SCO complex for potential applications in molecular spintronics.

高校化学实验室危化品管理探索与实践

随着高校化学实验室综合设计类实验项目的增加,使得危化品种类及数量逐渐增多。近年来高校化学实验室安全事故频发,危化品的安全管理已经成为高校化学实验室工作内容中的重要关注点。针对现阶段高校化学实验室危化品管理现状及存在问题,提出实施三级联动责任及安全检查体系、加强实验室管理梯队建设,细化危化品购买、储存及使用流程,以及加强管理平台信息化建设等措施,有效提升了教师团队和学生的安全责任意识,并逐步减少了安全隐患,为化学实验室危化品的安全管理模式提供了一定的借鉴。

新媒体时代下化学实验教学与实验室管理探索

当今新媒体时代下,二维码和公众号技术虽然已经普遍成熟,但是其在化学实验教学和实验室管理方面的深层次应用尚处于探索阶段。本文结合目前高校实验教学特点,分析探索了二维码和公众号技术在化学实验教学和管理中的应用以及存在的问题。从学生和教师两方面出发,在同为辅助工具的基础上两者联用不仅促进了实验教学平台整体的运行效率和管理水平,而且在充分发挥教师主导作用的同时调动了学生的主观能动性,学习效果及实际教学效果亦日渐显著,为国内化学实验教学改革提供了帮助。

Mitogen-activated protein kinase phosphatase 1 protects PC12 cells from amyloid beta-induced neurotoxicity

The mitogen-activated protein kinase（MAPK） signaling pathway plays an important role in the regulation of cell growth, proliferation, differentiation, transformation and death. Mitogen-activated protein kinase phosphatase 1（MKP1） has an inhibitory effect on the p38 MAPK and JNK pathways, but it is unknown whether it plays a role in Aβ-induced oxidative stress and neuronal inflammation. In this study, PC12 cells were infected with MKP1 sh RNA, MKP1 lentivirus or control lentivirus for 12 hours, and then treated with 0.1, 1, 10 or 100 μM amyloid beta 42（Aβ42）. The cell survival rate was measured using the cell counting kit-8 assay. MKP1, tumor necrosis factor-alpha（TNF-α） and interleukin-1β（IL-1β） m RNA expression levels were analyzed using quantitative real time-polymerase chain reaction. MKP1 and phospho-c-Jun N-terminal kinase（JNK） expression levels were assessed using western blot assay. Reactive oxygen species（ROS） levels were detected using 2′,7′-dichlorofluorescein diacetate. Mitochondrial membrane potential was measured using flow cytometry. Superoxide dismutase activity and malondialdehyde levels were evaluated using the colorimetric method. Lactate dehydrogenase activity was measured using a microplate reader. Caspase-3 expression levels were assessed by enzyme-linked immunosorbent assay. Apoptosis was evaluated using the terminal deoxynucleotidyl transferase d UTP nick end labeling method. MKP1 overexpression inhibited Aβ-induced JNK phosphorylation and the increase in ROS levels. It also suppressed the Aβ-induced increase in TNF-α and IL-1β levels as well as apoptosis in PC12 cells. In contrast, MKP1 knockdown by RNA interference aggravated Aβ-induced oxidative stress, inflammation and cell damage in PC12 cells. Furthermore, the JNK-specific inhibitor SP600125 abolished this effect of MKP1 knockdown on Aβ-induced neurotoxicity. Collectively, these results show that MKP1 mitigates Aβ-induced apoptosis, oxidative stress and neuroinflammation by inhibiting the JNK signaling pathway, thereby playing a neuroprotective role.

Dab2 attenuates brain injury in APP/PS1 mice via targeting transforming growth factor-beta/SMAD signaling

Transforming growth factor-beta （TGF-β） type II receptor （TβRⅡ） levels are extremely low in the brain tissue of patients with Alzheimer＇s disease. This receptor inhibits TGF-β1/SMAD signaling and thereby aggravates amyolid-beta deposition and neuronal injury. Dab2, a specific adapter protein, protects T RII from degradation and ensures the effective conduction of TGF-β 1/SMAD signaling. In this study, we used an adenoviral vector to overexpress the Dab2 gene in the mouse hippocampus and investigated the regulatory effect of Dab2 protein on TGF-β1/SMAD signaling in a mouse model of Alzheimer＇s disease, and the potential neuroprotective effect. The results showed that the TβRⅡ level was lower.in APP/PS1 mouse hippocampus than in normal mouse hippocampus. After Dab2 expression, hippocampal TβRⅡ and p-SMAD2/3 levels were signifi- cantly increased, while amyloid-beta deposition, microglia activation, tumor necrosis factor- and interleulin-6 levels and neuronal loss were significantly attenuated in APP/PS1 mouse brain tissue. These results suggest that Dab2 can exhibit neuroprotective effects in Alzheimer＇s disease by regulating TGF-β1/SMAD signaling.

Preparation and photoelectric properties of cadmium sulfide quantum dots

Cadmium sulfide quantum dots(CdS QDs) are widely used in solar cells, light emitting diodes, photocatalysis, and biological imaging because of their unique optical and electrical properties. However, there are some drawbacks in existing preparation techniques for CdS QDs, such as protection of inert gas, lengthy reaction time, high reaction temperature, poor crystallinity, and non-uniform particle size distribution. In this study, we prepared CdS QDs by liquid phase synthesis under ambient room temperature and atmospheric pressure using sodium alkyl sulfonate, CdCl_2, and Na_2S as capping agent, cadmium, and sulfur sources respectively. This technique offers facile preparation, efficient reaction, low-cost, and controllable particle size. The as-prepared CdS QDs exhibited good crystallinity, excellent monodispersity, and uniform particle size. The responsivity of CdS QDs-based photodetector is greater than 0.3 μA/W, which makes them suitable for use as ultra-violet(UV) detectors.

Generation of Hepatitis B virus PreS2-S antigen in Hansenula polymorpha

Despite the long availability of a traditional prophylactic vaccine containing the HBV surface antigen(HBsA g) and aluminum adjuvant, nearly 10% of the population remains unable to generate an effective immune response. Previous studies have indicated that hepatitis B virus(HBV) PreS 2-S is abundant in T/B cell epitopes, which induces a stronger immune response than HBsA g, particularly in terms of cytotoxic T lymphocyte(CTL) reaction. In the current study, the HBV PreS 2-S gene encoding an extra26 amino acids(PreS 2 C-terminus) located at the N-terminus of HBsA g was cloned into the pV CH1300 expression vector. Pre S2-S expressed in the methylotrophic yeast, Hansenula polymorpha, was produced at a yield of up to 250 mg/L. Subsequent purification steps involved hydrophobic adsorption to colloidal silica, ion-exchange chromatography and density ultracentrifugation. The final product was obtained with a total yield of ~15% and purity of ~99%. In keeping with previous studies, ~22 nm viruslike particles were detected using electron microscopy. The generated PreS 2-S antigen will be further studied for efficacy and safty in animals.

Line Segment Optimization Algorithm for High Resolution Optical Remote Sensing Image Based on Geometric and Texture Constraints

Aiming at the problem that high-resolution optical remote sensing image,lines are prone to fracture,and a line segment optimization algorithm is proposed in this paper.Firstly,the line segment is regarded as a way to express the contour of the ground object,and the laws of line segment fracture from two aspects of geometric features and texture features are analyzed;Secondly,the line segment optimization algorithm is proposed.It takes the results of detecting line segments as the processing primitives,determines the initial optimized line segment according to the length of the line segment,establishes the tracking rectangular region and geometric constraint model for the fractured line segments,builds a dynamic optimization model,and gives a complete line optimization process.Through the analysis of experimental results of multiple actual scenes and different types of remote sensing images,it is shown that this algorithm can not only solve the problem of line segment fracture caused by terrain occlusion,edge blurring,and edge serration,but also comparing with other methods,the proposed algorithm has great advantages in optimizing line length and restraining over extraction problem.

A Low Energy Consumption Clustering Routing Protocol Based on K-Means

A low energy consumption clustering algorism based on LEACH is researched. Firstly, A method for obtaining the number of clusters k is given, then using the K-Means algorism to divide all the sensor nodes in WSN to the k clusters, in the whole network life cycle the cluster will not changed, and when the energy of cluster head is lower than some threshold, it will be changed. The data transmission between cluster heads to sink node use mixed model, namely, the cluster near the sink node using the single hop and the one far from it using the multiple hops. The experiment shows our method has the longer life cycle and more received information. It is an effective clustering protocol.

A Load Balance Clustering Routing Algorism Based on SOM

In order to solve the uneven node load in the tradition clustering routing protocols, a new clustering algorism based on SOM is proposed. Firstly, the network radio model and the energy consumption model are defined. A new algorism using SOM to form the cluster and select the cluster head is defined. In the clustering node remain energy and the Euclidean distance from cluster head to the cluster member are considered. The experiment shows our method has the longer life cycle and less total energy consumption. It is an effective clustering protocol.

Knowledge,Attitude,and Practice Towards Mpox and Associated Factors Among HIV-Infected Individuals—Beijing Municipality,China,2023

Summary What is already known about this topic?Approximately 50%of patients with mpox are human immunodeficiency virus(HIV)-infected globally.Studies have shown that individuals with advanced HIV infection tend to have more severe clinical manifestations and higher mortality rates after mpox infection.What is added by this report?

Efficacy and safety of low-dose aspirin on preventing transplant renal artery stenosis: a prospective randomized controlled trial

Background:Transplant renal artery stenosis(TRAS)is a vascular complication after kidney transplantation associated with poor outcomes.This study aimed to analyze the efficacy and safety of low-dose aspirin for preventing TRAS.Methods:After kidney transplantation,patients were enrolled from January 2018 to December 2020 in Henan Provincial People’s Hospital.A total of 351 enrolled recipients were randomized to an aspirin group with low-dose intake of aspirin in addition to standard treatment(n=178),or a control group with only standard treatment(n=173).The patients was initially diagnosed as TRAS(id-TRAS)by Doppler ultrasound,and confirmed cases were diagnosed by DSA(c-TRAS).Results:In the aspirin and control groups,15.7%(28/178)and 22.0%(38/173)of the recipients developed id-TRAS,respectively,with no statistical difference.However,for c-TRAS,the difference of incidence and cumulative incidence was statistically significant.The incidence of c-TRAS was lower in the aspirin group compared with the control group(2.8%[5/178]vs.11.6%[20/173],P=0.001).Kaplan–Meier estimates and Cox regression model identified the cumulative incidence and hazard ratio(HR)of TRAS over time in two groups,showing that recipients treated with aspirin had a significantly lower risk of c-TRAS than those who were not treated(log-rank P=0.001,HR=0.23,95%confidence interval[CI]:0.09–0.62).The levels of platelet aggregation rate(P<0.001),cholesterol(P=0.028),and low-density lipoprotein cholesterol(P=0.003)in the aspirin group were decreased compared with the control group in the third-month post-transplantation.For the incidence of adverse events,there was no statistical difference.Conclusion:Clinical application of low-dose aspirin after renal transplant could prevent the development of TRAS with no significant increase in adverse effects.Trial Registration:Clinicaltrials.gov,NCT04260828.

生命历程流行病学视角下的童年期不良经历和围孕期压力性生活事件对妊娠期糖尿病的影响

目的基于生命历程流行病学视角,探讨童年期不良经历(ACE)和围孕期压力性生活事件(SLE)对妊娠期糖尿病(GDM)发生风险的影响及作用方式。方法本研究为回顾性研究,选取2019年5至9月在马鞍山市妇幼保健院产检的孕早期孕妇作为研究对象。收集孕妇在过去1年是否经历过SLE、SLE的类型和SLE累积事件数,以及其否经历过ACE、ACE的类型和ACE的累计得分,在其妊娠24~28周时进行75 g口服葡萄糖耐量试验以诊断GDM。采用logistic回归模型分析ACE和SLE对GDM发生风险的独立影响;采用交互作用分析判断ACE和SLE对GDM的发生是否存在相加或相乘交互作用,进一步采用分层分析判断ACE对SLE是否存在调节作用。结果共纳入研究对象1001例,ACE检出率为19.1%(191/1001),SLE检出率为38.5%(385/1001)。logistic回归分析结果表明,是否经历过ACE、ACE的类型及ACE的累计得分,以及是否经历过SLE、SLE的类型及SLE累积事件数,对GDM发生风险的影响均无统计学意义(均P>0.05)。分层分析结果表明,在有ACE的孕妇中,与无SLE者相比,SLE数量≥2的孕妇GDM发生风险增加1.64倍(OR=2.64,95%CI 1.08~6.47,异质性检验P值=0.036)。结论ACE和SLE单独对GDM的发生均无影响,但ACE对SLE和GDM间的关系具有调节作用,只有在经历了ACE的孕妇中,围孕期SLE才会增加GDM的发生风险。

液态金属基柔性可穿戴热电冷却结构及冷却性能优化

为了提高柔性热电冷却器(TEC)的冷却能力,解决液态金属材料的泄漏问题,同时研究热电腿的尺寸、密度和形状对TEC冷却能力的影响.本文将具有液态核心氧化壳结构的Ni-GaIn(掺镍液态金属)和LMPs(液态金属纳米颗粒)引入柔性TEC中,并针对材料的特性,采用“较大的电极”和“三层PDMS”对传统的热电冷却结构进行了改进.采用“大电极”和“三层PDMS”解决了液态金属量大、易泄漏的问题,降低了成本和环境污染,提高了产品可靠性和制造效率.利用有限元分析软件对结构进行了进一步优化,提供了多物理场和多因素影响下的TEC设计方案.与已报道的采用EGaIn互连和传统热电冷却结构的柔性TEC相比,本文制备的两种新型柔性TEC分别具有冷却能力高(7.4℃)和性能稳定(受弯曲变形影响小)的特点.

装载自噬抑制剂的纳米银核介孔硅协同增强胶质瘤放疗

先前研究表明,银纳米颗粒可作为潜在的胶质瘤放疗的增敏剂,但这一作用受到自噬的限制.作为最有前途的药物递送载体之一,介孔二氧化硅纳米球由于其优异的药物负载性能、固有的生物相容性和可调节的孔径,对生物医学的发展做出了巨大贡献.在此,我们设计了一种负载自噬抑制剂3-甲基腺嘌呤的纳米银核介孔二氧化硅纳米球,其在体外和体内均表现出优异的协同抗癌作用.并且证实了抑制自噬可以进一步改善胶质瘤放疗的效果.此外,还从与氧化应激相关的核转录因子Nrf2的角度探讨了可能的机制,包括自噬抑制增强辐射诱导的氧化应激损伤以及Nrf2与自噬的相互作用.这项研究为将纳米银作为与自噬抑制剂结合用于胶质瘤放射增敏提供了一个愿景,并为其临床转化提供了一种可行的策略.

Study on the challenge and influence of the built thermal environment on elderly health in rural areas:Evidence from Shandong,China

Elderly health is increasingly recognized as a worldwide challenge with the continuous social aging trend.This study aimed to investigate the thermal conditions of the elderly in rural areas of Shandong,China.The thermal sensation and physiological response performances of elderly participants were examined in their own houses.Results show a clear seasonal pattern in cardiovascular disease mortality,cold stress increases the cardiovascular disease risk.The coal-based stoves serve as the main source of home heating and their limited coverage of the room area gave rise to poor quality of thermal comfort.The analysis of skin temperature for those under 65 and above did not reveal any significant difference in response to different indoor temperatures.The regression results confirm that a colder home leads to a rising value of the elderly’s systolic blood pressure,rising by more than 1 mmHg for every 1℃decrease in indoor temperature and thus posing a greater risk of cardiovascular diseases.The systolic blood pressure value of older subjects rise more when they are exposed to decreasing indoor temperatures,possibly due to an age-related decline in their ability to maintain stability of blood pressure.It is noteworthy that the average blood velocity of older subjects reduces less in response to decreasing indoor temperatures,indicating a weakened capacity to resist cold stress and its associated high risk of hypertension.This investigation provides evidence in favor of improving the thermal environment of the elderly and reducing their risk of cardiovascular diseases.

Murine studies and expressional analyses of human cardiac pericytes reveal novel trajectories of SARS-CoV-2 Spike protein-induced microvascular damage

Dear Editor,The Coronavirus disease 2019(COVID-19)pandemic has caused over 670 million cases and 6.7 million deaths worldwide,many of which are attributed to cardiovascular complications.Virus-induced endothelial damage,endothelial barrier dysfunction,thrombosis,and cytokine storm are implicated in heart and multi-organ failure.

Infrared avalanche photodiodes from bulk to 2D materials

Avalanche photodiodes (APDs) have drawn huge interest in recent years and have been extensively used in a range of fields including the most important one—optical communication systems due to their time responses and high sensitivities. This article shows the evolution and the recent development of A^(Ⅲ)B^(Ⅴ), A^(Ⅱ)B^(Ⅵ), and potential alternatives to formerly mentioned—“third wave” superlattices (SL) and two-dimensional (2D) materials infrared (IR) APDs. In the beginning, the APDs fundamental operating principle is demonstrated together with progress in architecture. It is shown that the APDs evolution has moved the device’s performance towards higher bandwidths, lower noise, and higher gain-bandwidth products. The material properties to reach both high gain and low excess noise for devices operating in different wavelength ranges were also considered showing the future progress and the research direction. More attention was paid to advances in A^(Ⅲ)B^(Ⅴ) APDs, such as AlInAsSb, which may be used in future optical communications, type-Ⅱ superlattice (T2SLs, “Ga-based” and “Ga-free”), and 2D materials-based IR APDs. The latter—atomically thin 2D materials exhibit huge potential in APDs and could be considered as an alternative material to the well-known, sophisticated, and developed A^(Ⅲ)B^(Ⅴ) APD technologies to include single-photon detection mode. That is related to the fact that conventional bulk materials APDs’ performance is restricted by reasonably high dark currents. One approach to resolve that problem seems to be implementing low-dimensional materials and structures as the APDs’ active regions. The Schottky barrier and atomic level thicknesses lead to the 2D APD dark current significant suppression. What is more, APDs can operate within visible (VIS), near-infrared (NIR)/mid-wavelength infrared range (MWIR), with a responsivity ~80 A/W, external quantum efficiency ~24.8%, gain ~10^(5) for MWIR [wavelength, λ = 4 μm, temperature, T = 10–180 K, Black Phosphorous (BP)/InSe APD]. It is believed that the 2D APD could prove themselves to be an alternative providing a viable method for device fabrication with simultaneous high-performance—sensitivity and low excess noise.

Digital light processing 3D printing of porous ceramics based on multi-materials additive manufacturing

1.Introduction Porous ceramics are widely used in many fields,including aerospace,electronics,medical materials,and biochemistry.They possess properties such as high-temperature resistance,corrosion resistance,good chemical stability,and large specific surface areas[1].Traditionally,porous ceramics are prepared using techniques such as partial sintering,pore-forming method,freeze-drying,tin plating,direct foaming,and recrystallization[2,3].However,it is challenging for these techniques to meet the requirements for complicated structures and rapid prototyping.

Van der Waals two-color infrared photodetector

With the increasing demand for multispectral information acquisition,infrared multispectral imaging technology that is inexpensive and can be miniaturized and integrated into other devices has received extensive attention.However,the widespread usage of such photodetectors is still limited by the high cost of epitaxial semiconductors and complex cryogenic cooling systems.Here,we demonstrate a noncooled two-color infrared photodetector that can provide temporal-spatial coexisting spectral blackbody detection at both near-infrared and mid-infrared wavelengths.This photodetector consists of vertically stacked back-to-back diode structures.The two-color signals can be effectively separated to achieve ultralow crosstalk of~0.05%by controlling the built-in electric field depending on the intermediate layer,which acts as an electron-collecting layer and hole-blocking barrier.The impressive performance of the two-color photodetector is verified by the specific detectivity(D^(*))of 6.4×10^(9)cm Hz^(1/2)W^(−1)at 3.5μm and room temperature,as well as the promising NIR/MWIR two-color infrared imaging and absolute temperature detection.