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。

天下冷暖,知于化学——化学能与热能的转化

冷热现象是人类最早观察和认识的自然现象之一。在自然界的能量转化现象中,化学能与热能的转化是常见形式之一。现代社会中,有很多相关应用给大众生活带来了极大的便利。本科普实验秉承着“应用化学,安全至上,造福社会”的理念,旨在通过简单的实验,激发普通大众对化学的兴趣,帮助他们正确认识化学,了解化学反应可能存在的安全风险,并培养其正确的安全意识。实验围绕化学反应中两个特征鲜明的反应:吸热反应(氯化铵与氢氧化钡反应)和放热反应(发热包与水反应),针对不同知识背景的受众,设计了不同的呈现形式(如趣味实验——气球捏捏冰、情景剧——碘-淀抱抱乐),在幼儿园、中学和社区开展了多场主题科普教育活动。实验通过这些活动向大众展示了化学能与热能之间相互转化的奇妙现象,普及了相关安全常识,使不同的受众真切地感受到了化学的无穷魅力,同时也提高了他们的安全意识。

汉语阅读中的语义相似度效应:语义预测的证据

采用眼动追踪技术,探讨汉语阅读中预测加工普遍发生在词汇水平还是语义水平。操纵句子中的目标词为高预测词和三种水平的低预测词,高预测词和低预测词之间的语义相似度逐渐降低(L1>L2>L3)。结果发现,在早期眼动指标上,低预测词和高预测词之间的语义相似度越低,读者对低预测词的加工时间越长,即语义相似度效应显著,体现了渐进性的语义预测特征;此外,语境限制性调节预测加工。研究结果支持“语义预测”观点。

Recent advances in stretchable triboelectric nanogenerators for use in wearable bioelectronic devices

Wearable bioelectronic devices have the capacity for real-time human health monitoring,the provision of tailored services,and natural interaction with smart devices.However,these wearable bioelectronic devices rely on conventional rigid batteries that are frequently charged or replaced and are incompatible with the skin,leading to a discontinuity in complex therapeutic tasks related to human health monitoring and human-machine interaction.Stretchable triboelectric nanogenerator(TENG)is a high-efficiency energy harvesting technology that converts mechanical into electrical energy,effectively powering wearable bioelectronic devices.This study comprehensively overviews recent advances in stretchable TENG for use in wearable bioelectronic devices.The working mechanism of stretchable TENG is initially explained.A comprehensive discussion presents the approaches for fabricating stretchable TENG,including the design of stretchable structures and the selection of stretchable materials.Furthermore,applications of wearable bioelectronic devices based on stretchable TENG in human health monitoring(body movements,pulse,and respiration)and human-machine interaction(touch panels,machine control,and virtual reality)are introduced.Ultimately,the challenges and developmental trends regarding wearable bioelectronic devices based on stretchable TENG are elaborated.

Coupling of Adhesion and Anti‑Freezing Properties in Hydrogel Electrolytes for Low‑Temperature Aqueous‑Based Hybrid Capacitors

Solid-state zinc-ion capacitors are emerging as promising candidates for large-scale energy storage owing to improved safety,mechanical and thermal stability and easy-to-direct stacking.Hydrogel electrolytes are appealing solid-state electrolytes because of eco-friendliness,high conductivity and intrinsic flexibility.However,the electrolyte/electrode interfacial contact and anti-freezing properties of current hydrogel electrolytes are still challenging for practical applications of zinc-ion capacitors.Here,we report a class of hydrogel electrolytes that couple high interfacial adhesion and anti-freezing performance.The synergy of tough hydrogel matrix and chemical anchorage enables a well-adhered interface between hydrogel electrolyte and electrode.Meanwhile,the cooperative solvation of ZnCl2 and LiCl hybrid salts renders the hydrogel electrolyte high ionic conductivity and mechanical elasticity simultaneously at low temperatures.More significantly,the Zn||carbon nanotubes hybrid capacitor based on this hydrogel electrolyte exhibits low-temperature capacitive performance,delivering high-energy density of 39 Wh kg^(-1)at-60°C with capacity retention of 98.7%over 10,000 cycles.With the benefits of the well-adhered electrolyte/electrode interface and the anti-freezing hydrogel electrolyte,the Zn/Li hybrid capacitor is able to accommodate dynamic deformations and function well under 1000 tension cycles even at-60°C.This work provides a powerful strategy for enabling stable operation of low-temperature zinc-ion capacitors.

The Spatiotemporal Distribution Characteristics of Cloud Types and Phases in the Arctic Based on CloudSat and CALIPSO Cloud Classification Products

The cloud type product 2B-CLDCLASS-LIDAR based on CloudSat and CALIPSO from June 2006 to May 2017 is used to examine the temporal and spatial distribution characteristics and interannual variability of eight cloud types(high cloud, altostratus, altocumulus, stratus, stratocumulus, cumulus, nimbostratus, and deep convection) and three phases(ice,mixed, and water) in the Arctic. Possible reasons for the observed interannual variability are also discussed. The main conclusions are as follows:(1) More water clouds occur on the Atlantic side, and more ice clouds occur over continents.(2)The average spatial and seasonal distributions of cloud types show three patterns: high clouds and most cumuliform clouds are concentrated in low-latitude locations and peak in summer;altostratus and nimbostratus are concentrated over and around continents and are less abundant in summer;stratocumulus and stratus are concentrated near the inner Arctic and peak during spring and autumn.(3) Regional averaged interannual frequencies of ice clouds and altostratus clouds significantly decrease, while those of water clouds, altocumulus, and cumulus clouds increase significantly.(4) Significant features of the linear trends of cloud frequencies are mainly located over ocean areas.(5) The monthly water cloud frequency anomalies are positively correlated with air temperature in most of the troposphere, while those for ice clouds are negatively correlated.(6) The decrease in altostratus clouds is associated with the weakening of the Arctic front due to Arctic warming, while increased water vapor transport into the Arctic and higher atmospheric instability lead to more cumulus and altocumulus clouds.

LIN28A/B在肿瘤发生发展中的作用研究进展

LIN28A及其同源蛋白LIN28B是高度保守的RNA结合蛋白,在胚胎早期发育、体细胞重编程、葡萄糖代谢以及肿瘤发生发展中具有重要作用。LIN28A/B在乳腺癌等恶性肿瘤中高表达,在肿瘤的起始、维持和转移中均发挥重要作用,并与预后不良相关。研究表明,LIN28A/B主要通过抑制let-7s等microRNA和直接靶向mRNA的方式发挥调控作用。本文主要综述了LIN28A/B在肝癌、乳腺癌、结直肠癌等恶性肿瘤中的功能及其分子调控机制,以期为进一步研究LIN28A/B的作用机制及其在临床治疗中的可能应用提供理论参考。

Association between Exposure of Rare Earth Elements and Outcomes of In Vitro Fertilization-Embryo Transfer in Beijing

Objective The study aimed to investigate the impact of rare earth elements(REEs)exposure on pregnancy outcomes of in vitro fertilization-embryo transfer(IVF-ET)by analyzing samples from spouses.Methods A total of 141 couples were included.Blood and follicular fluid from the wives and semen plasma from the husbands,were analyzed for REEs using inductively coupled plasma mass spectrometry(ICP-MS).Spearman's correlation coefficients and the Mann–Whitney U test were used to assess correlations and compare REE concentrations among three types of samples,respectively.Logistic models were utilized to estimate the individual REE effect on IVF-ET outcomes,while BKMR and WQS models explored the mixture of REE interaction effects on IVF-ET outcomes.Results Higher La concentration in semen(median 0.089 ng/mL,P=0.03)was associated with a lower fertilization rate.However,this effect was not observed after artificial selection intervention through intracytoplasmic sperm injection(ICSI)(P=0.27).In semen,the REEs mixture did not exhibit any significant association with clinical pregnancy.Conclusion Our study revealed a potential association between high La exposure in semen and a decline in fertilization rate,but not clinical pregnancy rate.This is the first to report REEs concentrations in follicular fluid with La,Ce,Pr,and Nd found at significantly lower concentrations than in serum,suggesting that these four REEs may not accumulate in the female reproductive system.However,at the current exposure levels,mixed REEs exposure did not exhibit reproductive toxicity.

Automatic detection of breast lesions in automated 3D breast ultrasound with cross-organ transfer learning

Background Deep convolutional neural networks have garnered considerable attention in numerous machine learning applications,particularly in visual recognition tasks such as image and video analyses.There is a growing interest in applying this technology to diverse applications in medical image analysis.Automated three dimensional Breast Ultrasound is a vital tool for detecting breast cancer,and computer-assisted diagnosis software,developed based on deep learning,can effectively assist radiologists in diagnosis.However,the network model is prone to overfitting during training,owing to challenges such as insufficient training data.This study attempts to solve the problem caused by small datasets and improve model detection performance.Methods We propose a breast cancer detection framework based on deep learning(a transfer learning method based on cross-organ cancer detection)and a contrastive learning method based on breast imaging reporting and data systems(BI-RADS).Results When using cross organ transfer learning and BIRADS based contrastive learning,the average sensitivity of the model increased by a maximum of 16.05%.Conclusion Our experiments have demonstrated that the parameters and experiences of cross-organ cancer detection can be mutually referenced,and contrastive learning method based on BI-RADS can improve the detection performance of the model.

Aggressive fluid management may be associated with disease progression in suspected sepsis patients admitted to the intensive care unit: a retrospective cohort study

Sepsis is a lethal condition characterized by multiple organ dysfunction due to disrupted host responses to severe infections.[1]Aff ected patients often have a Sequential Organ Failure Assessment(SOFA)score≥2.[2]Patients with a SOFA score<2 and at least one of the following were considered as“suspected sepsis”:(1)quick SOFA(qSOFA)score≥2;(2)SOFA score=1;or(3)National Early Warning Score(NEWS)4-6.[3]Compared with studies on fluid resuscitation in sepsis patients,there are few studies on fluid management in patients with suspected sepsis.Therefore,we conducted a retrospective cohort study to evaluate the relationship between fluid management and disease progression in suspected sepsis patients.

End-to-end computational design for an EUV solar corona multispectral imager with stray light suppression

An extreme ultraviolet solar corona multispectral imager can allow direct observation of high temperature coronal plasma,which is related to solar flares,coronal mass ejections and other significant coronal activities.This manuscript proposes a novel end-to-end computational design method for an extreme ultraviolet(EUV)solar corona multispectral imager operating at wavelengths near 100 nm,including a stray light suppression design and computational image recovery.To suppress the strong stray light from the solar disk,an outer opto-mechanical structure is designed to protect the imaging component of the system.Considering the low reflectivity(less than 70%)and strong-scattering(roughness)of existing extreme ultraviolet optical elements,the imaging component comprises only a primary mirror and a curved grating.A Lyot aperture is used to further suppress any residual stray light.Finally,a deep learning computational imaging method is used to correct the individual multi-wavelength images from the original recorded multi-slit data.In results and data,this can achieve a far-field angular resolution below 7",and spectral resolution below 0.05 nm.The field of view is±3 R_(☉)along the multi-slit moving direction,where R☉represents the radius of the solar disk.The ratio of the corona's stray light intensity to the solar center's irradiation intensity is less than 10-6 at the circle of 1.3 R_(☉).

情感教学提升思想政治课育人价值的逻辑理路与实践指向——深度学习的视角

在“主知主义”传统教学模式的束缚下,思想政治课较难实现情感与认知的深度融合。情感教学摒弃了唯工具性的教学观,改善了思政教学中理论认同和情感认同的分离态势,增强了理论亲和力。实践中,需明确情感教学发生的“情感认知基础”“师生知情互动”“情感教学环境”“教学实践转化”等前提条件,发挥情感教学的调节、感染、驱动和迁移功能,通过“问题驱动”“情境诱发”“深度对话”和“实践体验”等中介操作,打造深度学习的思政课,提升思政课育人的温度与深度。

不同绝经年限及血脂代谢对绝经女性跟骨骨密度影响

目的探讨不同绝经年限及血脂代谢对绝经女性跟骨骨密度的关系。方法选取2014年11月-2016年5月在该院内分泌科进行体检的自然绝经后女性288例。按绝经的不同年限随机分为绝经年限≤5年组、6~10年组、11~15年组、16~20年组、21~25年组及26~30年组,分别收集6组患者的三酰甘油、总胆固醇、高密度脂蛋白、低密度脂蛋白及跟骨超声骨密度,分析不同绝经年限及血脂代谢与T值及骨硬度指数的关系。结果不同绝经年限各组的骨密度T值及骨硬度指数均随着绝经年限的延长而逐渐减小,差异有统计学意义(P<0.05);但不同绝经年限组组间的三酰甘油、总胆固醇、高密度脂蛋白、低密度脂蛋白的水平无明显变化,差异无统计学意义(P>0.05);总胆固醇、低密度脂蛋白与骨密度存在相关性(P<0.05)。结论不同绝经年限与女性跟骨骨密度下降密切相关,是骨质疏松发生的高危因素,与血脂代谢相关。

甘肃省和政县年龄相关性白内障患者术后生活质量分析

目的:评价甘肃省和政县年龄相关性白内障患者术后生活质量水平,并分析其影响因素。方法:于2015-10/2016-02采取整群随机抽样的方法,将确诊为年龄相关性白内障并自愿接受小切口白内障摘除联合人工晶状体植入术的患者195例纳入本研究,分别于术前和术后6mo采用参考美国国立研究所开发的QOL问卷修订后制成的眼健康相关生活质量量表调查患者的生活质量情况。结果:本研究最终回收有效问卷193份(99.0%)。将量表各维度总分的1/2作为此维度的正常生活质量水平,本组患者在身体运动功能、独立性/生活自理功能、社会角色和社会功能、精神心理健康维度得分均低于正常水平,且生活质量各维度得分均低于术前(均P<0.001)。视力损伤时间和双眼术后最佳矫正视力提高值对年龄相关性白内障患者术后生活质量影响显著。结论:手术干预能够显著提高年龄相关性白内障患者的生活质量水平,视力损伤时间和双眼术后最佳矫正视力提高值是年龄相关性白内障患者术后生活质量的主要影响因素。

新时代背景下物理化学实验的课程思政教学初探

以辽宁师范大学为例,介绍其化学化工学院在新时代背景下,深挖实验哲学思想,提升学生的政治素养;关注实验教学内容,培育学生的社会责任感;立足实验教学环节,培养学生严谨求实的科学态度;聆听实验背后科学家的故事,学习科学家的精神,以及重视研究设计型实验,强化创新精神、团队意识等,在物理化学实验教学中实施课程思政的初步探索,以期为高校实验教学中实施课程思政教学改革提供参考借鉴。

自动化电动车自行车停车装置的设计

目前,对电动车、自行车、摩托车停放的缺乏管理和布局设计.我们设计的新型自动化小型车立体停车装置,采用单片机和步进电机驱动,自动化控制实现车辆的存取和管理.智能化的车辆管理可以有效解决不规整的停放,减少占地面积,空间利用率大的优势,适合布置于小区这种寸土寸金的地方,实际地面使用面积不足3m^2,却能实现至少24辆小型车的存放.

肺腺癌胸水标本中PD-L1的蛋白表达与临床病理特征及分子改变的相关性研究

背景与目的非小细胞肺癌的免疫治疗药物pembrolizumab需要基于包括免疫组织化学(immunohistochemistry,IHC)在内的检测结果,即通过检测程序性死亡配体1(programmed cell death protein 1,PD-L1)的表达等手段来预测治疗反应。评估肺腺癌细胞学标本免疫细胞化学(immunocytochemistry,ICC)方法检测PD-L1的可行性,并探讨PD-L1表达与临床病理及分子特征的相关性。方法收集60例肺腺癌胸水细胞学标本应用PD-L1 sp263试剂按照生产说明书进行免疫细胞化学染色,同时对胸水细胞学标本做高通量二代测序(next-generation sequencing,NGS),探讨PD-L1与驱动基因突变的相关性。结果60例肺腺癌胸水细胞块标本ICC检测中,有35例PD-L1表达阳性,阳性表达率为58.3%。本院57例组织学标本PD-L1 IHC表达的阳性率为33.3%,细胞学标本与组织学标本差异无统计学意义(P>0.05)。60例细胞学标本中26例接受NGS检测,15例(57.7%)发现表皮生长因子受体(epidermal growth factorreceptor,EGFR)突变,经统计PD-L1表达与EGFR突变未发现相关性。PD-L1的阳性表达率与研究人群的年龄、性别、是否淋巴结或远处转移及是否进行放化疗或靶向治疗均未发现相关性(P>0.05)。结论在无手术标本可取时,胸水细胞学细胞块标本可以对PD-L1进行免疫细胞化学检测,其结果具有可行性。

The 2020/21 Extremely Cold Winter in China Influenced by the Synergistic Effect of La Niña and Warm Arctic

In the first half of winter 2020/21,China has experienced an extremely cold period across both northern and southern regions,with record-breaking low temperatures set in many stations of China.Meanwhile,a moderate La Niña event which exceeded both oceanic and atmospheric thresholds began in August 2020 and in a few months developed into its mature phase,just prior to the 2020/21 winter.In this report,the mid−high-latitude large-scale atmospheric circulation anomalies in the Northern Hemisphere,which were forced by the negative phase of Arctic Oscillation,a strengthened Siberian High,an intensified Ural High and a deepened East Asian Trough,are considered to be the direct reason for the frequent cold surges in winter 2020/21.At the same time,the synergistic effect of the warm Arctic and the cold tropical Pacific(La Niña)provided an indispensable background,at a hemispheric scale,to intensify the atmospheric circulation anomalies in middle-to-high latitudes.In the end,a most recent La Niña prediction is provided and the on-coming evolution of climate is discussed for the remaining part of the 2020/21 winter for the purpose of future decision-making and early warning.

Variations in microbial community during nitrogen removal by in situ oxygen-enhanced indigenous nitrogen-removal bacteria

In this study, the enclosure system exhibited perfect nitrogen removal performance with in situ oxygen-enhanced indigenous aerobic denitrifying bacteria in an enclosure experiment. We explored changes in the microbial community during the nitrogen removal process using the MiSeq high-throughput sequencing technology. The results revealed a total of 7974 and 33653 operational taxonomic units(OTUs) for water and sediment systems, respectively, with 97% similarity. The OTUs were found to be affiliated with eight main phyla(Proteobacteria, Actinobacteria, Cyanobacteria, Bacteroidetes, Planctomycetes, Chloroflexi, Firmicutes, and Actinobacteria). The diversity of the enhanced system was found to be higher than that of the control system. Principal component analysis(PCA) revealed that significant spatial and temporal differences were exhibited in the microbial community during nitrogen removal in the enclosure experiment. Redundancy analysis(RDA)indicated that physical parameters(temperature, dissolved oxygen, and pH), nitrogen(total nitrogen and nitrate), functional genes(nirK and nirS), and dissolved organic carbon(DOC) were the most important factors affecting bacterial community function and composition. Lastly, the results suggested that the variation in the microbial community could be analyzed through the MiSeq high-throughput sequencing technology,which may provide technical support for future field tests.

An Innovative Non-Pillar Coal-Mining Technology with Automatically Formed Entry: A Case Study

A non-pillar coal-mining technology with an automatically formed entry is proposed,which reduces the waste of coal resources and the underground entry drivage workload.Three key techniques in this technology cooperate to achieve automatic formation and retaining of the gob-side entry,and to realize nonpillar mining.Constant-resistance large deformation(CRLD)support ensures the stability of the entry roof;directional presplitting blasting(DPB)separates the entry roof and the gob roof;and a blockinggangue support system(BGSS)integrates the caved rock material as an effective entry rib.An industrial test was conducted to verify the engineering effects of these key techniques.The field application results showed that the retained entry was under the pressure-relief zone due to the broken-expansion nature of the caved rock mass within the DPB height.After going through a provisional dynamic pressure-bearing zone,the retained entry entered the stability zone.The final stable entry meets the requirements of safety and production.The research results demonstrate the good engineering applicability of this technology.By taking the framework of the technology design principles into consideration and adjusting the measures according to different site conditions,it is expected that the proposed non-pillar coal-mining technology can be popularized on a large scale.