线上线下混合式实验教学模式的改革与探索

大学化学实验课程是培养材料、化学、化工等专业人才应用基本操作和理论解决实际问题的综合性实践训练环节。文章探讨了当前大学化学实验发展由于受到仪器设备大型化、专业化、成本大、更新快等因素限制出现瓶颈,设计了线上线下混合实验教学模式,进行相应的软硬件建设,并开展线上线下混合式实验教学模式的改革与探索。该教学模式具有良好的教学效果,并且可复制可推广,为创新人才的培养和实验教学的创新提供了有益的借鉴。

大学化学课程思政的现状与应对策略——基于学生视角的探讨

教育发展新形势下,高校思政教育面临新的需求和挑战。本文围绕化学学科特点,以学生视角为出发点,探讨大学化学中的课程思政问题,并提出若干应对策略。要深入推进课程思政,应在教学内容中,考虑学生的价值诉求,提升价值导向的针对性;在教学评价中,搭建师生沟通的渠道,提升评价活动的精准性,增强学生对课程思政的认同度;在学生层面,转换学生的学习动机,有效传递教学内容。

聚醋酸乙烯酯的光引发可控合成——介绍一个高分子化学综合实验

本实验开展了醋酸乙烯酯的可逆加成-断裂链转移自由基聚合(RAFT),分别运用偶氮二异丁腈(AIBN)引发和可见光引发两种方式进行了聚合反应,运用核磁共振和凝胶色谱等多种手段对所得聚合物结构进行了表征与分析。通过比较AIBN引发与光引发所获得聚合物端基结构的异同,加深了学生对RAFT聚合方法原理的理解。同时,运用该方法实现了聚合物两端端基结构的高度功能化,深入体会聚合物合成设计概念。本综合实验教学不仅通过对比法加深了学生对实验原理和专业知识的理解,提升了学生创新研究能力,而且训练了学生的实验操作技能、大型仪器使用能力和结果分析能力,提升了综合素质。

苯甲醇的绿色选择性氧化

醇的氧化是制备醛和酮的重要反应之一,也是有机化学理论教学和实验教学的一个重点内容。目前,大多数本科生实验教材安排了环己醇氧化合成环己酮的实验。虽然现有实验教材提供了一例将伯醇氧化为醛的方案,即采用Na_(2)WO_(4)×2H_(2)O/(C_(4)H_(9))_(4)NHSO_(4)催化体系,在90℃用H_(2)O_(2)将苯甲醇选择性氧化为苯甲醛,但是存在着产率低、安全性不高和重金属污染等问题。本文采用Fe(NO_(3))_(3)×9H_(2)O、4-羟基-2,2,6,6-四甲基哌啶氧化物(4-OH-TEMPO)和乙酸(HOAc)为催化剂、O_(2)为氧化剂,以H_(2)O为溶剂,在温和的反应条件下高选择性地将苯甲醇氧化为苯甲醛,分离产率可达91%,这为伯醇的选择性氧化提供了一个低成本且高效绿色的实验教学新方案。同时,在实验过程中引入薄层色谱、气相色谱、快速制备液相色谱和核磁共振氢谱等手段对产物进行分离、提纯和表征,有效提升了本科生的综合实验技能和科研素养。

Cilostazol inhibits plasmacytoid dendritic cell activation and antigen presentation

Background Cilostazol, an anti-platelet drug for treating coronary heart disease, has been reported to modulate immune cell functions Plasmacytoid dendritic cells （pDCs） have been found to participate in the progression of atherosclerosis mainly through interferon ct （IFN-ct） production. Whether cilostazol influences pDCs activation is still not clear. In this study, we aimed to investigate the effects of cilostazol on cell activation and antigen presentation ofpDCs in vitro in this study. Methods Peripheral blood mononuclear cells isolated by Ficoll cen- trifugation and pDCs sorted by flow cytometry were used in this study. After pretreated with cilostazol for 2 h, cells were stimulated with CpG-A, R848 or virus for 6 h or 20 h, or stimulated with CpG-B for 48 h and then co-cultured with naive T cell for five days. Cytokines in supernatant and intracellular cytokines were analyzed by ELISA or flow cytometry respectively. Results Our data indicated that cilostazol could inhibit IFN-α and tumor necrosis factor α （TNF-α） production from pDCs in a dose-dependent manner. In addition, the ability of priming na ve T cells of pDCs was also impaired by cilostazol. The inhibitory effect was not due to cell killing since the viability of pDCs did not change upon cilostazol treatment. Conclusion Cilostazol inhibits pDCs cell activation and antigen presentation in vitro, which may explain how cilostazol protects against atherosclerosis.

An initial study on left ventricular diastolic function in patients with hypertrophy cardiomyopathy using single-beat, real-time, three-dimensional echocardiography

Objectives To assess the regional diastolic function in patients with hypertrophic cardiomyopathy （HCM） by using single-beat, real-time, three-dimensional echocardiography （RT-3DE）. Methods Sixty-five patients with HCM in sinus rhythm together with fifty age- and gender-matched normal controls were studied by two dimensional echocardiography （2DE） and RT-3DE. The parameters analyzed by RT-3DE included： left ventrieular （LV） volumes, left ventricular ejection fraction （LVEF）, end diastolic sphericity index （EDSI）, diastolic dyssynchrony index （DDI）, dispersion end diastole （DISPED）, and normalized 17 segmental volume-time curves. Results Evaluated by RT-3DE, LVEF was slightly lower compared with 2DE （63.2 ± 6.8% vs. 59.1 ± 6.4%, P 〈 0.0001）. Normal subjects had relatively uniform volumetric curves for all LV segments. In HCM patients, the segmental volumetric curves were dyssynchronous. Increased DDI and DISPED in end diastole were observed in patients with HCM （9.95 ± 3.75, 41.76 ± 17.19, P 〈 0.0001）, and not all abnormal volumetric segments occurred in the hypertrophic regions. Conclusions Patients with HCM have presented regional diastolic dyssynchrony in the diastole phase, and this preclinical lesion can be recognized by single-beat RT-3DE.

Recent Advances in Spin-coating Precursor Mediated Chemical Vapor Deposition of Two-Dimensional Transition Metal Dichalcogenides

Two-dimensional(2D)transition metal dichalcogenides(TMDs)have garnered widespread interest in the scientific community and industry for their exceptional physical and chemistry properties,and great potential for applications in diverse fields including(opto)electronics,electrocatalysis,and energy storage.Chemical vapor deposition(CVD)is one of the most compelling growth methods for the scalable growth of high-quality 2D TMDs.However,the conventional CVD process for synthesis of 2D TMDs still encounters significant challenges,primarily attributed to the high melting point of precursor powders,and achieving a uniform distribution of precursor atmosphere on the substrate to obtain controllable smaple domains is difficult.The spin-coating precursor mediated chemical vapor deposition(SCVD)strategy provides refinement over traditional methods by eliminating the use of solid precursors and ensuring a more clean and uniform distribution of the growth material on the substrate.Additionally,the SCVD process allows fine-tuning of material thickness and purity by manipulating solution composition,concentration,and the spin coating process.This Review presents a comprehensive summary of recent advances in controllable growth of 2D TMDs with a SCVD strategy.First,a series of various liquid precursors,additives,source supply methods,and substrate engineering strategies for preparing atomically thin TMDs by SCVD are introduced.Then,2D TMDs heterostructures and novel doped TMDs fabricated through the SCVD method are discussed.Finally,the current challenges and perspectives to synthesize 2D TMDs using SCVD are discussed.

Chalcone derivatives as novel,potent and selective inhibitors against human Notum:Structure–activity relationships and biological evaluations

Human Notum(hNotum)inhibitors could be used for treating Wnt signalling-associated diseases including colorectal cancer.Herein,two series of chalcone derivatives were designed and synthesized aiming to find selective and potent hNotum inhibitors.Structure–activity relationship(SAR)studies showed that 2-methoxyl and 5-bromine substitutions on A-ring significantly enhanced anti-hNotum effect,while 4’-ethoxyl and 3’-alkyl substitutions on B-ring were beneficial for hNotum inhibition.Among all tested chalcones,B11 displayed the most potent anti-Notum effect(IC_(50)=3.6 nmol/L),good selectivity,excellent chemical stability and suitable metabolic stability.Further investigations showed that B11 acted as a competitive inhibitor of hNotum,while this agent(5μmol/L)significantly weaken the migration abilities of colorectal cancer cells.Collectively,this study deciphers the SARs of chalcones as hNotum inhibitors and reports a novel and potent hNotum inhibitor with the anti-migration effect on colorectal cancer cells,which offers a promising lead compound to develop novel anti-cancer agents.

Rationally engineered IR-783 octanoate as an enzyme-activatable fluorogenic tool for functional imaging of h Notum in living systems

As a vital negative regulator of Wnt signaling pathway,human Notum(hNotum)plays a crucial regulatory role in the progression of many human diseases.Deciphering the relevance of h Notum to human diseases requires practical and reliable tools for visualizing h Notum activity in living systems.Herein,an enzyme-activatable fluorogenic tool(IR-783 octanoate)was rationally engineered for sensing and imaging h Notum activity in living systems by integrating computer-aided molecular design and biochemical assays.IR-783 octanoate showed good optical properties,excellent specificity and high binding-affinity towards h Notum(K_(m)=0.98μmol/L).IR-783 octanoate could be well up-taken into the cancerous cells or tumors that over-expressed organic anion transporting polypeptides(OATPs),and then hydrolyzed by cellular h Notum to release free IR-783 ketone,which created brightly fluorescent signals around 646 nm.Further investigations showed that IR-783 octanoate achieved a good performance for in-situ functional imaging of h Notum in both living cells,cancerous tissues and organs.It was also found that some SW620cells with multipolar spindles could be stained by IR-783 octanoate to emit extremely bright signals,suggesting that this agent could be used as a novel visualizing tool for tracing the cells undergoing abnormal cell mitoses.Collectively,this study devises a highly specific fluorogenic tool for in-situ functional imaging of hNotum in living systems,which offers a practical and reliable tool to dynamically track the changes in h Notum activity under various conditions.

唐山乐亭菩提岛海上风电场对海洋生态空间的影响研究

海上风电场建设与运营对海洋生态空间影响的研究具有重要意义。本文以唐山乐亭菩提岛海上风电场为例,识别了海上风电场周边鸟类、海洋生物及其多样性、渔业资源等海洋生态空间受影响因子;根据影响海洋生态空间的主要要素及其受影响因子,开展了相关数据的现场调查与资料搜集;结合电磁环境、海洋生物等实测数据以及噪声、鸟类等搜集资料,评估了海上风电场对海洋生态空间的影响。研究结果表明,案例区海上风电场施工期噪声远大于运营期,海面以上及水下电磁干扰很小;海上风电场对海洋生态空间的影响多集中于施工期,运营期产生的影响相对较小。

机器学习在即时诊断中的应用进展

即时诊断凭借廉价、快速、方便和准确的特点已成为疾病诊断的一大趋势.机器学习方法的应用大大提高了即时诊断的数据处理能力,使即时诊断焕发新的生机.目前,随着智能手机等智能电子设备的普及,由即时诊断设备、智能电子产品和云端构成的物联网系统已经逐步成为现实.本文概述了机器学习算法的基本原理并阐述了其在即时诊断中的优势,着重介绍了机器学习在即时诊断中的应用现状,涵盖纸基即时检测、微流控检测和可穿戴设备等领域,并给出了根据即时诊断数据形式和检测目标选择机器学习算法的相关建议.未来以智能电子设备为平台并基于机器学习算法的即时诊断方法将成为新的趋势.

High-performance asymmetric electrodes photodiode based on Sb/WSe2 heterostructure

Two-dimensional (2D) van der Waals (vdWs) metal-semiconductor heterostructures with atomically sharp interface and matched work functions have recently attracted great attention due to their unique electronic and optoelectronic properties. Here we report the vapor phase epitaxial growth of large-scale vertical Sb/WSe2 metal-semiconductor vdWs heterostructures with uniform stacking orientation. Compared with the growth on S1O2/S1 substrate, the thick ness of Sb nan osheet on WSe2 can be reduced effectively to mono layer. We con struct Sb-WSe2-Au asymmetric electrodes photodiode based on the Sb/WSe2 heterostructures. Electrical transport measurements indicate that the photodiode show obvious rectifying effect. Optoelectronic characterizations show prominent photoresponse with a high photoresposivity of 364 mA/W, a fast response time of less than 8 ms, a large open-circuit voltage of 0.27 V and a maximum electrical power output of 0.11 nW. The direct growth of high-quality metal-semiconductor vdWs heterostructures may open up new realms in 2D functional electronics and optoelectronics.

van der Waals epitaxial growth of ultrathin metallic NiSe nanosheets on WSe2 as high performance contacts for WSe2 transistors

A prerequisite for widespread applications of atomically thin transition metal dichalcogenides in future electronics is to achieve reliable electrical contacts,which is of considerable challenge due to the difficulties in selectively doping and inevitable physical damages of these atomically thin materials during typical metal integration process.Here,we report the in situ growth of ultrathin metallic NiSe single crystals on WSe2 in which the metallic NiSe nanosheets function as the contact electrodes to WSe2,creating an interface that is essentially free from chemical disorder.The NiSe/WSe2 heterostructures also exhibit well-aligned lattice orientation between the two layers,forming a periodic Moire pattern.Electrical transport studies demonstrate that the NiSe nanosheets exhibit an excellent metallic feature,as evidenced by the extra-high electrical conductivity of up to 1.6×10^6 S-nf1.The WSe2 transistors with the NiSe contact show field-effect mobilities (/vFe) more than double that with Cr/Au electrodes.This study demonstrates an effective pathway to achieve reliable electrical contacts to the atomically thin 2D materials,and maybe readily extended for fabricating 2D/2D low-resistance contacts for a variety of transition metal dichalcogenides.

Controllable synthesis of NiS and NiS2 nanoplates by chemical vapor deposition

Mulitipe stoichiometric ratio of two-dimensional(2D)transition metal dichalcogenides(TMDCs)attracted considerable interest for their unique chemical and physical properties.Here we developed a chemical vapor deposition(CVD)method to controllably synthesize ultrathin NiS and NiS2 nanoplates.By tuning the growth temperature and the amounts of the sulfur powder,2D nonlayered NiS and NiS2 nanoplates can be selectively prepared with the thickness of 2.0 and 7.0 nm,respectively.X-ray diffraction(XRD)and transmission electron microscopy(TEM)characterization reveal that the 2D NiS and N1S2 nanoplates are high-quality single crystals in the hexagonal and cubic phase,respectively.Electrical transport studies show that electrical conductivities of the 2D NiS and N1S2 nanoplates are as high as 4.6 x 10^5 and 6.3 x 10^5 S·m^-1,respectively.The electrical results demonstrate that the synthesized metallic NiS and NiS2 could serve as good electrodes in 2D electronics.

Direct van der Waals epitaxial growth of 1D/2D Sb2Se3/WS2 mixed-dimensional p-n heterojunctions

The mixed-dimensional integration of two-dimensional (2D) materials with non-2D materials can give rise to prominent advances in performance or function.To date,the mixed-dimensional one-dimensional (1D)/2D heterostructures have been fabricated using various physical assembly approaches.However,direct epitaxial growth method which has notable advantages in preparing large-scale products and obtaining perfect interfaces is rarely investigated.Herein,we demonstrate for the first time the direct synthesis of the 1D/2D mixed-dimensional heterostructures by sequential vapor-phase growth of Sb2Se3 nanowires on WS2 monolayers.X-ray diffraction (XRD) pattern and Raman spectrum confirm the composition of the Sb2Se3/NS2 heterostructures.Transmission electron microscope (TEM) measurement demonstrates high quality of the heterostructures.Electrical transport characterization reveals that Sb2Se3 nanowire exhibits p-type characteristic and that WS2 monolayer exhibits n-type behavior,and that the p-n diode from 1D/2D mixed-dimensional Sb2Se3/WS2 heterostructure possesses obvious current rectification behavior.Optoelectronic measurements of the heterostructures show apparent photovoltaic response with an open-circuit voltage of 0.19 V,photoresponsivity of 1.51 A/W (Vds =5 V) and fast response time of less than 8 ms.The van der Waals epitaxial growth mode of Sb2Se3 nanowires on WS2 monolayers is verified by stripping the Sb2Se3 nanowire from the heterostructures using tape.Together,the direct van der Waals epitaxy opens a facile pathway to 1D/2D mixed-dimensional heterostructures for functional electronic and optoelectronic devices.

结直肠上皮细胞ROS及FH检测对结直肠癌筛查的应用价值

目的:探讨结直肠上皮细胞活性氧(ROS)及亚铁原卟啉(FH)物质检测对于结直肠癌筛查的应用价值。方法:选取南京大学医学院附属鼓楼医院消化内镜中心2021年9月至2022年1月进行结肠镜检查的患者220例,所有患者均行结肠镜组织学病理活检及ROS+FH试剂盒检测,分别计算其灵敏度、特异度、约登指数等各评价指标,并进行Kappa检验,以此探究ROS及FH对于结直肠癌筛查的价值。结果:在220例患者病理结果中,结直肠癌患者样本20例,非结直肠癌患者样本200例。在结直肠癌患者中,ROS及FH检测的灵敏度分别为95%和100%;特异度分别为99%和69%;Kappa系数分别为0.919和0.288(P均<0.001)。结论:结直肠上皮细胞ROS及FH对于诊断均有较高的灵敏度、特异度,其中ROS检测结果与结直肠癌病理结果有极高的一致性,可作为临床早期结直肠癌筛查的简便指标。

Vapor phase growth of two-dimensional PdSe2 nanosheets for high-photoresponsivity near-infrared photodetectors

Palladium diselenide(PdSe2),a stable layered material with pentagonal structure,has attracted extensive interest due to its excellent electrical and optoelectronic performance.Here,we report a reliable process to synthesize PdSe2 via chemical vapor deposition(CVD)method.Through systematic regulation of temperature in the growth process,we can tune the thickness,size,nucleation density and morphology of PdSe2 nanosheets.Field-effect transistors based on PdSe2 nanosheets exhibit n-type behavior and present a high electron mobility of 105 cm^2·V^−1·s^−1.The electrical property of the devices after 6 months keeping in the air show little change,implying outstanding air-stability of PdSe2.In addition,PdSe2 near-infrared photodetector shows a photoresponsivity of 660 A·W^−1 under 914 nm laser.These performances are better than those of most CVD-grown 2D materials,making ultrathin PdSe2 a highly qualified candidate material for next-generation optoelectronic applications.

Synthesis of Heterometallic Rare Earth(Ⅲ)-Cobalt(Ⅱ)Complexes and Their Application in Alternating Copolymerization of Cyclohexene Oxide and Carbon Dioxide

Comprehensive Summary Four heterometallic rare earth(Ⅲ)-cobalt(Ⅱ)complexes(rare earth=Y(1),Sm(2),Nd(3),La(4))stabilized by an o-phenylenediamine-bridged tris(phenolato)ligand(L)have been synthesized and characterized.In these tetranuclear complexes,one polydentate L coordinates to one rare earth(Ⅲ)ion,and one cobalt(Ⅱ)ion,respectively,while two rare earth ions are bridged by four acetate groups.These complexes were applied in the copolymerization of cyclohexene oxide and CO_(2),which showed good activity(TON up to 440)and high poly(cyclohexene carbonate)selectivity(>99%).Kinetic studies determined the equation as rate=k[CHO]1[CO_(2)]0[initiator]1,which proves a first-order dependence on initiator concentrations and implies a synergistic mechanism with rare earth and cobalt ions cooperating in epoxide ring-opening and chain propagation.

Ultimate dielectric scaling of 2D transistors via van der Waals metal integration

The two-dimensional transition metal dichalcogenides(TMDs)have attracted intense interest as an atomically thin semiconductor channel for the continued transistor scaling.However,with a dangling bond free surface,it has been a key challenge to reliably integrate high-quality gate dielectrics on TMDs.In particular,the atomic layer deposition of dielectrics on TMDs typically features highly non-uniform nucleation and produces a highly rough or porous dielectric film with rich pinholes that are prone to further damage during the gate integration process.Herein we report a van der Waals(vdW)integration route towards highly reliable gate metal integration on porous dielectrics.The physical lamination process employed by the vdW integration avoids the direct deposition of metal electrodes into porous dielectrics to ensure reliable gate integration and produce low gate leakage devices.The electrical measurements demonstrate the vdW integrated MoS_(2) top gate devices exhibit substantially reduced gate leakage current that is about 3-5 orders of magnitude smaller than that with deposited metal electrodes.Furthermore,we show the vdW integration process can be used to create high performance top-gated MoS_(2) transistors with ultrathin Al_(2)O_(3) dielectrics down to 1 nm,representing the ultimate dielectric scaling for TMDs transistors.This study demonstrates that vdW integration can enable highly reliable gate integration on relatively low quality dielectrics on TMDs,and opens an interesting pathway to high-performance top-gate transistors using dangling bond free two-dimensional(2D)semiconductors.

Two-stage Correction Strategy-based Real-time Dispatch for Economic Operation of Microgrids

Given the different energy rates of multiple types of power generation units,different operation plans affect the economy of microgrids.Limited by load and power generation forecasting technologies,the economic superiority of day-ahead plans is unable to be fully utilized because of the fluctuation of loads and power sources.In this regard,a two-stage correction strategy-based real-time dispatch method for the economic operation of microgrids is proposed.Based on the optimal day-ahead economic operation plan,unbalanced power is validly allocated in two stages in terms of power increment and current power,which maintains the economy of the day-ahead plan.Further,for operating point offset during real-time correction,a rolling dispatch method is introduced to dynamically update the system operation plan.Finally,the results verify the effectiveness of the proposed method.