“三长制”视域下高校劳动教育实践路径研究——以贵州大学为例

高校学生社区是学生生活学习的重要场所,同时也是高校落实立德树人根本任务的重要组成部分。2021年,贵州大学在学生社区推行“三长制”(楼长、层长、寝室长),并将“三长制”作为“五育并举”的重要抓手和主要途径之一。在高校“三长制”学生社区建设背景下开展劳动教育,有助于增强学生的劳动意识,培养学生的劳动精神,提高学生的劳动能力。本文通过分析贵州大学“三长制”下劳动教育开展存在的问题,构建“三长制”劳动教育新模式,改变传统枯燥的劳动形式,从学生兴趣与特点出发,激发劳动热情,创新劳动形式,加强劳动教育学生社区文化建设。探讨新的学生社区劳动教育实践路径,有助于提升高校劳动教育的实效性,发挥和完善“三长制”视域下劳动教育的功能,充分体现高校育人功能。

治理界面的集中化及其建构逻辑——以河长制、街长制和路长制为中心的分析

在治理意义上,界面是组织和实施治理活动的平台,是行动者相互关系构成的互动网络。治理界面的集中化是问题驱动的治理变革,是破解"分工-协作"模式导致的"碎片化"弊端的重要策略,为应对公共治理碎片化问题提供了系统化的解决方案,已成为当前公共治理实践的重要趋向。河长制、街长制和路长制的应用场景虽有所不同,但都推动了治理问题、对象、权力、责任和信息的集中化,打造出了相对集中的治理界面,实现了对复杂性问题的一体化治理。其建构逻辑包括确定整体性治理目标、建构协同共治机制、推行系统化操作方案、应用现代技术手段和实现高度的信息化。

Synergistic effect of all-trans-ret inoic acid and arsenic trioxide on growth inhibition and apoptosis in human hepatoma, breast cancer, and lung cancer cells in vitro

AIM： To investigate the effect of all-trans-retinoic acid （ATRA） on arsenic trioxide （As2O3）-induced apoptosis of human hepatoma, breast cancer, and lung cancer cells in an attempt to find a better combination therapy for solid tumors. METHODS： Human hepatoma cell lines HepG2, Hep3B, human breast cancer cell line MCF-7, and human lung adenocarcinoma cell line AGZY-83-a were treated with As203 together with ATRA. Cell survival fraction was determined by MTT assay, cell viability and apoptosis were measured by annexin V-fluorescein isothiocyanate （FITC） and PI staining, and intracellular glutathione （GSH） and glutathione-S-transferase （GST） activities were determined using commercial kits. RESULTS： Cytotoxicity of ATRA was low. ATRA （0.1, 1, and 10 μmol/L） could synergistically potentiate As2O3 to exert a dose-dependent inhibition of growth and to induce apoptosis in each of the cell lines. HepG2 and Hep3B with low intracellular GSH or GST activities were remarkably sensitive to As2O3 or As2O3＋ATRA, while AGZY-83-a with higher GSH or GST activities was less sensitive to As2O3 or As2O3＋ATRA. Treatment with 2 μmol/L As2O3 for 72 h significantly decreased intracellular GSH and GST levels in each of the cell lines, and 1 μmol/L ATRA alone reduced minimal intracellular GSH and GST levels. ATRA potentiated the effect of As2O3 on intracellular GSH levels, but intracellular GST levels were not significantly affected by the combination of As2O3 and ATRA for 72 h as compared to As2O3 alone.CONCLUSION： ATRA can strongly potentiate As2O3- induced growth-inhibition and apoptosis in each of the cell lines, and two drugs can produce a significant synergic effect. The sensitivity to As2O3 or As2O3＋ATRA is inversely proportional to intracellular GSH or GST levels in each of the cell lines. The GSH redox system may be the possible mechanism by which ATRA synergistically potentiates As203 to exert a dose-dependent inhibition of growth and to induce apoptosis. 2005 The WJG Press and Elsevier Inc. All rights reserved.

Three Gorges Dam Controls Sediment Coarsening of the Mud Patch on the Inner East China Sea Shelf

The well-known Three Gorges Dam(TGD) within the Yangtze catchment launched its operation in 2003. The effect of the TGD operation on the sediment size on the East China Sea shelf is rarely known. High resolution(0.5 cm sampling) grain size analysis and 137 Cs and 210 Pb dating of the DH8-1 core were conducted with core collected from the distal part of a main sink for the modern Yangtze sediment entering the sea, the Min-Zhe Coastal Mud Deposits(MZCMD) on the inner East China Sea shelf. The 137 Cs dating results show that the core DH8-1 formed during 1946–2012 with a mean deposition rate of 0.65 cm yr^(-1), indicating that the 0.5 cm sampling for grain size analysis in this local area could reflect environmental changes generally on a one-year time scale. The mean grain size of DH8-1 core sediment that deposited after 2003 is significantly larger than that deposited during 1988–2002. After ruling out other possible factors, we infer that the sediment coarsening of DH8-1 core after 2003 is attributed to the TGD operation which causes the erosion of the Yangtze subaqueous delta. Specifically, the TGD operation significantly intensifies the declining trend of the Yangtze sediment loads to the sea despite no decreased water discharge, which results in extensive erosion of the Yangtze subaqueous delta. The relatively coarse sediment of the subaqueous delta is eroded and resuspended by ocean dynamics and then transported by coastal current, finally depositing on the MZCMD area. In addition, the general sediment fining of core DH8-1 that deposited during 1988–2002, comparing with 1946–1987, is mainly caused by dam construction and soil and water conservation within the Yangtze catchment. Our findings are helpful for better understanding the effects of such a huge dam as the TGD on a sediment sink like the MZCMD of such a large river as the Yangtze River.

Formation mechanism of freshwater zone around the Meimao Sandbank in the Changjiang estuary

This study focuses on dynamic mechanism behind the formation of the freshwater zone around the Meimao Sandbank by use of 3D numerical simulation.The Meimao Sandbank is located along the southern bank of the South Passage in the Changjiang(Yangtze River) estuary,which is considered as a freshwater resource for Shanghai City.Interaction between runoff and tide is the main mechanism of the freshwater zone formation.However,the freshwater zone often suffers from saltwater intrusion in dry season.Tidal oscillation is stronger during spring tides,able to carry freshwater farther seaward.Therefore,it is more likely to occur during the ebb of a spring tide in dry seasons.In addition,the water zone is sensitive to runoff:when runoff decreases,it disappears,and vice versa.The northerly winds favor the formation of the freshwater zone.

Investigation of the long-term stability and forced degradation of valtrate by high performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry

Valtrate is the main drug quality control for the qualitative and quantitative analysis of Valerian medicines in the Chinese Pharmacopoeia 2010. However, valtrate is unstable under some conditions. We, for the first time, systemically evaluated the stability of two bath reference standards （RS） by high performance liquid chromatography coupled with a triple quadrupole mass spectrometer （HPLC-MS/MS）. The forced degradations of valtrate were performed to evaluate its optimal storage, transportation and experiment conditions according to ICH guideline. The developed HPLC method was validated to determine the degradation products. Valtrate RS was sensitive to alkaline and thermal conditions, but it was relatively stable under acidic, oxidation and photolysis conditions. A total of nine degradation components were identified under alkaline hydrolysis （N1-N4） and thermal degradation （B1-B5）. The information obtained in this work would be valuable to minimize the decomposition of valtrate during the processes of preparation, storage, distribution and utilization. It was highly suggested to store valtrate with a single dose packing in brown closed ampoule at -20℃. Under the above-mentioned storage condition, valtrate could be stable for up to 3 years.

Application of facile solution-processed ternary sulfide Ag_8SnS_6 as light absorber in thin film solar cells

Light absorber is critical to the further applications of thin film solar cells. Here, we report a facile solution-processed method with an annealing temperature below250°C to fabricate Ag8 SnS6(ATS) light absorber for thin film solar cells. After optimization, the ATS-based thin film solar cells exhibited a reproducible power conversion efficiency(PCE) of about 0.25% and an outstanding long-term stability with 90% of the initial PCE retained after a more than 1,000 h degradation test. This research revealed the potential application of ATS as an earth-abundant, low toxic and chemically stable light absorber in thin film solar cells.