以人为本理念下基础化学实验室安全建设模式探究——以分析化学实验室为例

实验室安全建设是实验室高效有序运行的保障。大学生作为基础教学实验室运行的主力,他们的安全素养直接影响着实验室的安全状况。在实验教学过程中构建注重安全素养培养的“实验室管理人员、教师、学生——全员、全时三位一体实验教学模式”,并在分析化学实验教学中进行了具体实践。新的实验教学模式加强了实验室管理员、教师与学生之间的沟通,通过COOP与7S实验教学方案,使学生在学习的同时沉浸式参与实验环境维护及建设、根植安全理念。利用Partial Eta Squared(η2)检验和多元Logistic回归模型分析发现,实验过程操作规范性和操作区有序度对学生安全素养影响明显。实践证明,该模式有助于培养学生良好的实验习惯和安全素养,增加学生在实验室中的责任感和获得感,实现管教增质、教学相长、安全铸魂的教学目标,使实验室人员可以把安全时刻掌握在自己手中,实验室安全运行水平有效提升。

Immune checkpoint inhibitors:breakthroughs in cancer treatment

Over the past two decades,immunotherapies have increasingly been considered as first-line treatments for most cancers.One such treatment is immune checkpoint blockade(ICB),which has demonstrated promising results against various solid tumors in clinical trials.Monoclonal antibodies(mAbs)are currently available as immune checkpoint inhibitors(ICIs).These ICIs target specific immune checkpoints,including cytotoxic T-lymphocyte-associated antigen-4(CTLA-4)and programmed cell death protein 1(PD-1).Clinical trial results strongly support the feasibility of this immunotherapeutic approach.However,a substantial proportion of patients with cancer develop resistance or tolerance to treatment,owing to tumor immune evasion mechanisms that counteract the host immune response.Consequently,substantial research focus has been aimed at identifying additional ICIs or synergistic inhibitory receptors to enhance the effectiveness of anti-PD-1,anti-programmed cell death ligand 1(anti-PD-L1),and anti-CTLA-4 treatments.Recently,several immune checkpoint molecular targets have been identified,such as T cell immunoreceptor with Ig and ITIM domains(TIGIT),mucin domain containing-3(TIM-3),lymphocyte activation gene-3(LAG-3),V-domain immunoglobulin suppressor of T cell activation(VISTA),B and T lymphocyte attenuator(BTLA),and signal-regulatory proteinα(SIRPα).Functional m Abs targeting these molecules are under development.CTLA-4,PD-1/PD-L1,and other recently discovered immune checkpoint proteins with distinct structures are at the forefront of research.This review discusses these structures,as well as clinical progress in m Abs targeting these immune checkpoint molecules and their potential applications.

Investigation of a facile plasma-driven method for in situ cleaning of metal-based contamination

Self-cleaning of tin contaminants was realized utilizing a self-driven hydrogen plasma.Cleaning rates of 0.7-6 nm min-1were achieved for removal of discontinuous tin particles at different powers.The analysis of topography and cross-sectional morphology revealed that the removal of tin particles was achieved through top-down cleaning with hydrogen plasma,where the upper part of spherical tin particles was always more intensely cleaned under the synergistic effect of hydrogen atoms and ions due to the vertical incidence of ions to the substrate during the whole cleaning process.Redeposition of tin atoms caused by physical sputtering and its promotion of the chemical cleaning effect was observed for the first time.Reflectance recovery measurements during cleaning and surface analysis of the substrate after cleaning indicated that nondestructive cleaning with a reflectance loss of less than 1%can be achieved at a relatively low power of120 W.Plasma-induced substrate damage,such as holes and valleys,reduced the reflectance of the substrate when cleaning was performed at a high power greater than 120 W,so this method should only be considered for application under conditions without substrate exposure.This study provides a comprehensive understanding of the removal of discontinuous tin particles using the in situ self-driven plasma cleaning method,and also provides meaningful guidance for the extension of this method in other potential fields of application.

全基因组蛋白质的标签细胞和小鼠资源库建设

小鼠是最广泛使用的模式生物,构建基因改造的小鼠模型是研究基因功能和疾病发生机制的重要手段。从20世纪80年代发展至今,小鼠基因改造技术更新迭代,主要包括胚胎干细胞介导的同源重组策略、配子介导的转基因策略、以及最新基于CRISPR/Cas9技术的遗传改造策略等。由我国科学家自主研发的全新小鼠基因改造技术——“人造精子细胞”(或“类精子干细胞”)介导的半克隆技术与以往策略相比,具有小鼠构建周期短、效率高、成本低、应用场景兼容性强等特点。为了摆脱我国小鼠实验动物“卡脖子”风险,填补标签蛋白质小鼠资源库的国际空白,中国科学院分子细胞科学卓越创新中心进行了战略资源布局,于2017年启动了基因组标签计划(genome tagging project,GTP),并成立了GTP研发中心致力于建立全新的标签细胞和小鼠战略资源库。GTP研发中心通过对“人造精子细胞”基因组上编码蛋白质的基因原位系统性地添加标签序列,建立了可用液氮保存的标签细胞资源库,并作为生产标签小鼠的种子贮备。当需要标签小鼠时,利用半克隆技术将标签细胞注射到小鼠卵子中,一步法获得标签小鼠。标签小鼠可通过标准化的标签抗体监测特定蛋白质从而实现蛋白质的在体、实时、动态研究。目前,GTP研发中心已构建1532个标签细胞和277个标签小鼠,初步形成了具有特色标签产品战略资源库;已有242个标签小鼠品系被分发到3个囯家15个地区的32个研究机构,供66个研究团队使用。同时,GTP研发中心已建立完备的标签产品信息,定期在GTP官网上发布更新,供科研人员查询、订购和定制。后续标签小鼠的配繁规律、标签蛋白质组织图谱描绘、发表文献等也会陆续更新到GTP官网。GTP研发中心将对标行业尖端,打造全球独特性战略资源,为蛋白质功能研究提供标准化平台,推动生命科学的发展和临床转化。

Interaction of an unwetted liquid Li-based capillary porous system with high-density plasma

This study examined the effects of plasma irradiation on an unwetted liquid lithium-based capillary porous system(Li-CPS). The Li-CPS was irradiated with high-density Ar plasma using a linear plasma device at Sichuan University for Plasma Surface Interaction. The high-speed camera, Langmuir probe, and multi-channel spectrometer were used to characterize the effects of plasma irradiation. Upon Ar plasma irradiation, liquid Li drops were formed on the surface of the unwetted Li-CPS. Immediately after this irradiation, the drops fractured and were ejected into the plasma within ~20 ms scale, which is not observed before to the best of our knowledge. Related results showed that the ejection behavior of Li could effectively cool electron temperature and reduce incident heat flux by ~30% and correspondingly matrix temperature ~150 ℃, revealing an enhanced vapor shielding effect. The involved internal mechanism and physical processes deserve further investigations.

Cleaning of nitrogen-containing carbon contamination by atmospheric pressure plasma jet

Atmospheric pressure plasma jet(APPJ)was used to clean nitrogen-containing carbon films(C–N)fabricated by plasma-assisted chemical vapor deposition method employing the plasma surface interaction linear device at Sichuan University(SCU-PSI).The properties of the contaminated films on the surface of pristine and He-plasma pre-irradiated tungsten matrix,such as morphology,crystalline structure,element composition and chemical structure were characterized by scanning electron microscopy,grazing incidence x-ray diffraction and x-ray photoelectron spectroscopy.The experimental results revealed that the removal of C–N film with a thickness of tens of microns can be realized through APPJ cleaning regardless of the morphology of the substrates.Similar removal rates of 16.82 and 13.78μm min^(-1)were obtained for C–N films deposited on a smooth pristine W surface and rough fuzz-covered W surface,respectively.This is a remarkable improvement in comparison to the traditional cleaning method.However,slight surface oxidation was found after APPJ cleaning,but the degree of oxidation was acceptable with an oxidation depth increase of only 3.15 nm.Optical emission spectroscopy analysis and mass spectrometry analysis showed that C–N contamination was mainly removed through chemical reaction with reactive oxygen species during APPJ treatment using air as the working gas.These results make APPJ cleaning a potentially effective method for the rapid removal of C–N films from the wall surfaces of fusion devices.

Output regulation of nonlinear singularly perturbed systems based on T-S fuzzy model

Based on the T-S model, the output regulation of nonlinear singularly perturbed systems via state feedback is discussed. It is shown that, under standard assumptions, this problean is solvable if and only if certain linear matrix equations are solvable. Once these equations are solvable, the state feedback regulator can easily be constructed.