渐进式教学模式在实验课程思政教学中的实践与探讨——以有机化学实验“阿司匹林的合成”为例

以有机化学实验“阿司匹林的合成”为例,通过确定思政教学目标、挖掘思政元素、选择思政载体、开展思政实践活动、进行思政评价五个步骤,采取渐进式教学模式,探讨了有机化学实验课程融合思政教学的具体实施措施,并对实验课程思政的有效实施提出了几点建议与措施。

Enhancing the crystallinity and stability of perovskite solar cells with 4-tert-butylpyridine induction for efficiency exceeding 24%

Perovskite solar cells(PSCs)have emerged as a promising photovoltaic technology because of their high light absorption coefficient,long carrier diffusion distance,and tunable bandgap.However,PSCs face challenges such as hysteresis effects and stability issues.In this study,we introduced a novel approach to improve film crystallization by leveraging 4-tert-butylpyridine(TBP)molecules,thereby enhancing the performance and stability of PSCs.Our findings demonstrate the effective removal of PbI_(2)from the perovskite surface through strong coordination with TBP molecules.Additionally,by carefully adjusting the concentration of the TBP solution,we achieved enhanced film crystallinity without disrupting the perovskite structure.The TBP-treated perovskite films exhibit a low defect density,improved crystallinity,and improved carrier lifetime.As a result,the PSCs manufactured with TBP treatment achieve power conversion efficiency(PCE)exceeding 24%.Moreover,we obtained the PCE of 21.39%for the 12.25 cm^(2)module.

Sedimentary elements,evolutions and controlling factors of the Miocene channel system:a case study of the deep-water Taranaki Basin in New Zealand

Deep-water channel systems are important petroleum reservoirs,and many have been discovered worldwide.Understanding deep-water channel sedimentary elements and evolution is helpful for deep-sea petroleum exploration and development.Based on high-resolution 3D seismic data,the Miocene channel system in the deep-water Taranaki Basin,New Zealand,was analyzed by using seismic interpretation techniques such as interlayer attribute extraction and strata slicing.The channel system was divided into five composite channels(CC-I to CC-V)according to four secondary level channel boundaries,and sedimentary elements such as channels,slump deposits,inner levees,mass transport deposits,and hemipelagic drape deposits were identified in the channel system.The morphological characteristics of several composite channels exhibited stark variances,and the overall morphology of the composite channels changed from relatively straight to highly sinuous to relatively straight.The evolution of the composite channels involved a gradual and repeated process of erosion and filling,and the composite channels could be divided into three evolutionary stages:initial erosion-filling,later erosion-filling(multistage),and channel abandonment.The middle Miocene channel system may have formed as a consequence of combined regional tectonic activity and global climatic change,and its intricate morphological alterations may have been influenced by the channel's ability to self-regulate and gravity flow properties.When studying the sedimentary evolution of a large-scale deep-water channel system in the Taranaki Basin during the Oligocene-Miocene,which transitioned from a passive margin to plate convergence,it can be understood how tectonic activity affected the channel and can also provide a theoretical reference for the evolution of the deepwater channels in areas with similar tectonic conversion environments around the world.

Role of dendritic cells in MYD88-mediated immune recognition and osteoinduction initiated by the implantation of biomaterials

Bone substitute material implantation has become an important treatment strategy for the repair of oral and maxillofacial bone defects.Recent studies have shown that appropriate inflammatory and immune cells are essential factors in the process of osteoinduction of bone substitute materials.Previous studies have mainly focused on innate immune cells such as macrophages.In our previous work,we found that T lymphocytes,as adaptive immune cells,are also essential in the osteoinduction procedure.As the most important antigen-presenting cell,whether dendritic cells(DCs)can recognize non-antigen biomaterials and participate in osteoinduction was still unclear.In this study,we found that surgical trauma associated with materials implantation induces necrocytosis,and this causes the release of high mobility group protein-1(HMGB1),which is adsorbed on the surface of bone substitute materials.Subsequently,HMGB1-adsorbed materials were recognized by the TLR4-MYD88-NFκB signal axis of dendritic cells,and the inflammatory response was activated.Finally,activated DCs release regeneration-related chemokines,recruit mesenchymal stem cells,and initiate the osteoinduction process.This study sheds light on the immune-regeneration process after bone substitute materials implantation,points out a potential direction for the development of bone substitute materials,and provides guidance for the development of clinical surgical methods.

Lysine-specific demethylase 1 inhibitor rescues the osteogenic ability of mesenchymal stem cells under osteoporotic conditions by modulating H3K4 methylation

Bone tissue engineering may be hindered by underlying osteoporosis because of a decreased osteogenic ability of autologous seed cells and an unfavorably changed microenvironment in these patients. Epigenetic regulation plays an important role in the developmental origins of osteoporosis; however, few studies have investigated the potential of epigenetic therapy to improve or rescue the osteogenic ability of bone marrow mesenchymal stem cells(BMMSCs) under osteoporotic conditions. Here, we investigated pargyline, an inhibitor of lysine-specific demethylase 1(LSD1), which mainly catalyzes the demethylation of the di- and mono-methylation of H3K4. We demonstrated that 1.5 mmol·Lpargyline was the optimal concentration for the osteogenic differentiation of human BMMSCs. Pargyline rescued the osteogenic differentiation ability of mouse BMMSCs under osteoporotic conditions by enhancing the dimethylation level of H3K4 at the promoter regions of osteogenesis-related genes. Moreover, pargyline partially rescued or prevented the osteoporotic conditions in aged or ovariectomized mouse models, respectively. By introducing the concept of epigenetic therapy into the field of osteoporosis, this study demonstrated that LSD1 inhibitors could improve the clinical practice of MSC-based bone tissue engineering and proposes their novel use to treat osteoporosis.

Cobalt Sulfide Confined in N-Doped Porous Branched Carbon Nanotubes for Lithium-Ion Batteries

Lithium-ion batteries(LIBs) are considered new generation of large-scale energy-storage devices.However,LIBs suffer from a lack of desirable anode materials with excellent specific capacity and cycling stability.In this work,we design a novel hierarchical structure constructed by encapsulating cobalt sulfide nanowires within nitrogen-doped porous branched carbon nanotubes(NBNTs)for LIBs.The unique hierarchical Co9S8@NBNT electrode displayed a reversible specific capacity of 1310 mAhg-1 at a current density of 0.1 Ag-1,and was able to maintain a stable reversible discharge capacity of 1109 mAhg-1 at a current density of 0.5 Ag-1 with coulombic efficiency reaching almost 100% for 200 cycles.The excellent rate and cycling capabilities can be ascribed to the hierarchical porosity of the one-dimensional Co9S8@NBNT internetworks,the incorporation of nitrogen doping,and the carbon nanotube confinement of the active cobalt sulfide nanowires offering a proximate electron pathway for the isolated nanoparticles and shielding of the cobalt sulfide nanowires from pulverization over long cycling periods.

P2RY6在非小细胞肺癌中的表达和临床意义分析

目的:探讨P2RY6在非小细胞肺癌(non-small cell lung cancer,NSCLC)患者中的表达及临床意义。方法:在基因表达集(Gene Expression Omnibus,GEO)和癌症基因组图谱计划(The Cancer Genome Atlas Program,TCGA)数据库中获取多个NSCLC、肺腺癌和肺鳞癌的基因表达以及临床信息数据集。使用非参数检验分析癌组织与邻近正常组织的P2RY6表达水平差异,并且通过免疫组织化学研究肺鳞癌及肺腺癌组织和正常组织的P2RY6蛋白表达情况。使用χ2检验分析P2RY6表达与肺腺癌、肺鳞癌患者临床特征之间的相关性。使用Kaplan-Meier方法和Log-rank检验评估肺腺癌和肺鳞癌P2RY6表达水平与总生存期和无进展生存期之间的关系。使用Cox比例风险回归模型进一步评估P2RY6表达量对肺鳞癌患者总生存期和无进展生存期的预测效能。结果:P2RY6在NSCLC、肺腺癌和肺鳞癌中均高表达。在肺腺癌患者中,P2RY6表达与生存无关,而与性别有关。在P2RY6高表达的肺鳞癌患者中,总生存期和无进展生存期较短,P2RY6高表达是独立危险因素。结论:P2RY6与肺鳞癌患者的生存相关,P2RY6高表达预示着肺鳞癌患者总生存期与无进展生存期较短,是预后不良的独立危险因素。

Heterogeneous expectations,IPO Underpricing and issuing mechanism

Background:Compared with the fixed-price mechanism,the bookbuilding mechanism has not changed the Chinese IPO high underpricing.How to develop scientific and reasonable IPO pricing,and reduce the high IPO underpricing has become a major challenge for China's securities market.Methods:In this paper,using behavioral finance theory and game theory,we build the Initial public offering(IPO)pricing and underpricing models with investors’heterogeneity based on different issuing mechanisms and provide a comparative analysis.Results:Firstly,our models show that IPO underpricing will not be eliminated by using either fixed-price or bookbuilding mechanisms,but when the investors’heterogeneity expectation is the same,lower IPO underpricing can be obtained by the issuing of bookbuilding compared with that of fixed price.Secondly,the IPO underpricing may be larger than that under fixed price if the heterogeneity of investors under bookbuilding is larger than that under fixed price.Thirdly,the numerical analysis results provide strong support for our model.Conclusions:These findings further explains the cause of the high IPO underpricing long-standing in China.

Microstructures and deformation mechanisms of experimentally deformed gabbro

The natural gabbro samples were deformed at temperature ranging from 700 to 1150 ℃ with strain rate steps of 1 ×10^-4, 2.5 ×10^-5, 6.3 ×10^-6 s^-1. The mechanical data show that sample experiences gradual transition from semi-brittle flow to plastic flow, corresponding to a systematically decreasing stress exponent n with the increasing temperature ranging from 16.5 to 4.1 （He et al. Sci China （D） 46（7）：730-742, 2003）. We investigate microstructures and deformation mechanisms of experimentally deformed gabbro under transmission electron microscope in this study. For low temperature of 700 ℃ to 950℃, the deformation is mainly accommodated with dislocation glide and mechanical twinning, corresponding to stress exponent lager than 5, which means semi-brittle deformation. Whereas with higher temperature up to 1000 ℃-1150 ℃, the deformation is accommodated mainly with dislocation glide and climb corresponding to stress exponent of 4.1, which means plastic deformation. Evidence of dislocation climb has been found as dislocation walls in plagioclase. The observed slip system in plagioclase is （001）1/21110] and that in clinopyroxene are （100）[001] and （010）[001]. The （010）[001] slip system in clinopyroxene is newly found in this work. Melt was found at temperature of 950 ℃-1050 ℃. The melt glass distributed both in melt thin film between two grain boundaries and melt tubules of triangular along three grain boundaries at temperature of 950℃-1000℃. The melt triangular interconnected to the melt film at temperature of 1050 ℃-1150℃, where the melt chemical compositiondifferentiated into iron-rich dark dots and silicate-rich matrix.

Metformin can mitigate skeletal dysplasia caused by Pck2 deficiency

As an important enzyme for gluconeogenesis, mitochondrial phosphoenolpyruvate carboxykinase(PCK2) has further complex functions beyond regulation of glucose metabolism. Here, we report that conditional knockout of Pck2 in osteoblasts results in a pathological phenotype manifested as craniofacial malformation, long bone loss, and marrow adipocyte accumulation. Ablation of Pck2 alters the metabolic pathways of developing bone, particularly fatty acid metabolism. However, metformin treatment can mitigate skeletal dysplasia of embryonic and postnatal heterozygous knockout mice, at least partly via the AMPK signaling pathway.Collectively, these data illustrate that PCK2 is pivotal for bone development and metabolic homeostasis, and suggest that regulation of metformin-mediated signaling could provide a novel and practical strategy for treating metabolic skeletal dysfunction.

In vivo therapeutic effects of albendazole in combination with IFN-on cystic echinococcosis in mice

Objective:This study was aimed to evaluate the in vivo therapeutic effects of the combination of ABZ with interferon(IFN)-αon cystic echinococcosis(CE)in mice.Methods:After 5-month secondary infection with protoscolices,Balb/c mice were randomly divided into four groups:ABZtreated group,IFN-α-treated group,ABZ+IFN-αgroup and untreated control group.Drugs in different treated groups were respectively administered for 2 months.Blood was respectively taken from caudal veins in mice at treatment time points of 0 d,7 d,14 d,28 d,36 d,48 d and 60 d,in order to detect the changes in the level of antibodies in the serum.Mice were then sacrificed after the end of treatment,and related indicators were detected to evaluate the therapeutic effects.Results:In comparison with untreated control group(p<.01)and ABZ-treated group(p<.05),ABZ+IFN-αgroup showed a more significant decrease in the number of cysts,cyst size and cyst weight.After transmission electron microscopy(TEM)of the cysts in different treated groups,it was found that,there was an obvious change in cyst ultrastructure in ABZ+IFN-αgroup.ELISA experimental results showed that,in ABZ+IFN-αgroup,there was a significant decrease in IL-10 in serums and splenocytes(p<.01);In comparison with untreated control group,ABZ+IFN-αgroup showed a more significant decrease in the levels of IgE,IgG and its subtypes(p<.01).Conclusions:In this study,the combination of ABZ with IFN-αwas proved to be an effective CE treatment option.

Composite Recommendation of Artworks in E-Commerce Based on User Keyword-Driven Correlation Graph Search

With the ever-increasing diversification of people’s interests and preferences,artwork has become one of the most popular commodities or investment goods in E-commerce,and it increasingly attracts the attention of the public.Currently,many real-world or virtual artworks can be found in E-commerce,and finding a means to recommend them to appropriate users has become a significant task to alleviate the heavy burden on artwork selection decisions by users.Existing research mainly studies the problem of single-artwork recommendation while neglecting the more practical but more complex composite recommendation of artworks in E-commerce,which considerably influences the quality of experience of potential users,especially when they need to select a set of artworks instead of a single artwork.Inspired by this limitation,we put forward a novel composite recommendation approach to artworks by a user keyword-driven correlation graph search named ART_(com-rec).Through ART_(com-rec),the recommender system can output a set of artworks(e.g.,an artwork composite solution)in E-commerce by considering the keywords typed by a user to indicate his or her personalized preferences.Finally,we validate the feasibility of the ART_(com-rec) approach by a set of simulated experiments on a real-world PW dataset.

Single-atom nanozymes:From bench to bedside

Single-atom nanozymes(SANs)are the new emerging catalytic nanomaterials with enzyme-mimetic activities,which have many extraordinary merits,such as low-cost preparation,maximum atom utilization,ideal catalytic activity,and optimized selectivity.With these advantages,SANs have received extensive research attention in the fields of chemistry,energy conversion,and environmental purification.Recently,a growing number of studies have shown the great promise of SANs in biological applications.In this article,we present the most recent developments of SANs in anti-infective treatment,cancer diagnosis and therapy,biosensing,and antioxidative therapy.This text is expected to better guide the readers to understand the current state and future clinical possibilities of SANs in medical applications.

Characterization of mesenchymal stem cells in human fetal bone marrow by single-cell transcriptomic and functional analysis

Bone marrow mesenchymal stromal/stem cells (MSCs) are a heterogeneous population that can self-renew and generate stroma,cartilage, fat, and bone. Although a significant progress has been made toward recognizing about the phenotypic characteristics ofMSCs, the true identity and properties of MSCs in bone marrow remain unclear. Here, we report the expression landscape of humanfetal BM nucleated cells (BMNCs) based on the single-cell transcriptomic analysis. Unexpectedly, while the common cell surfacemarkers such as CD146, CD271, and PDGFRa used for isolating MSCs were not detected, LIFR+PDGFRB+ were identified to bespecific markers of MSCs as the early progenitors. In vivo transplantation demonstrated that LIFR+PDGFRB+CD45-CD31-CD235a-MSCs could form bone tissues and reconstitute the hematopoietic microenvironment (HME) effectively in vivo. Interestingly, wealso identified a subpopulation of bone unipotent progenitor expressing TM4SF1+CD44+CD73+CD45-CD31-CD235a-, which hadosteogenic potentials, but could not reconstitute HME. MSCs expressed a set of different transcription factors at the different stagesof human fetal bone marrow, indicating that the stemness properties of MSCs might change during development. Moreover,transcriptional characteristics of cultured MSCs were significantly changed compared with freshly isolated primary MSCs. Ourcellular profiling provides a general landscape of heterogeneity, development, hierarchy, microenvironment of the human fetal BMderivedstem cells at single-cell resolution.

Research status of biodegradable metals designed for oral and maxillofacial applications:A review

The oral and maxillofacial regions have complex anatomical structures and different tissue types,which have vital health and aesthetic functions.Biodegradable metals(BMs)is a promising bioactive materials to treat oral and maxillofacial diseases.This review summarizes the research status and future research directions of BMs for oral and maxillofacial applications.Mg-based BMs and Zn-based BMs for bone fracture fixation systems,and guided bone regeneration(GBR)membranes,are discussed in detail.Zn-based BMs with a moderate degradation rate and superior mechanical properties for GBR membranes show great potential for clinical translation.Fe-based BMs have a relatively low degradation rate and insoluble degradation products,which greatly limit their application and clinical translation.Furthermore,we proposed potential future research directions for BMs in the oral and maxillofacial regions,including 3D printed BM bone scaffolds,surface modification for BMs GBR membranes,and BMs containing hydrogels for cartilage regeneration,soft tissue regeneration,and nerve regeneration.Taken together,the progress made in the development of BMs in oral and maxillofacial regions has laid a foundation for further clinical translation.

镁锂钙合金作为骨植入材料的体内外研究（英文）

本文制备了三元Mg-(3.5,6.5 wt.%)Li-(0.2, 0.5, 1.0 wt.%)Ca合金,并研究了其力学性能、腐蚀性能与生物相容性.此合金的力学性能较纯镁显著提高,并具有良好的耐腐蚀性.然后,将体外性能最佳的Mg-3.5Li-0.5Ca合金植入小鼠股骨骨髓腔,体内实验结果显示, Mg-3.5Li-0.5Ca合金周围的骨厚度增加,未见不良反应. Western blot和免疫荧光染色结果显示, Mg-3.5Li-0.5Ca合金通过经典的Wnt/β-catenin信号通路促进了人骨髓间充质干细胞的成骨向分化.研究结果表明, Mg-3.5Li-0.5Ca合金具有作为骨植入材料的巨大潜力.

Experimental investigation of reactions between two-mica granite and boron-rich fluids: Implications for the formation of tourmaline granite

The genetic relationship between different types of granite is critical for understanding the formation and evolution of granitic magma. Fluid-rock interaction experiments between two-mica leucogranite and boron-rich fluids were carried out at 600–700°C and 200 MPa to investigate the effects of boron content in fluid and temperature on the reaction products. Our experimental results show that tourmaline granite can be produced by reactions between boron-rich fluid and two-mica granite.At 700°C, the addition of boron-rich fluid resulted in partial melting of two-mica granite and crystallization of tourmaline from the boron-rich partial melt. Increasing boron concentration in fluid promotes the melting of two-mica granite and the growth of tourmaline. No melt was produced in experiments at 600°C, in which Fe, Mg and Al released from biotite decomposition combined with boron from the fluid to form tourmaline under subsolidus conditions. The Na required for tourmaline crystallization derived from Na/K exchange between feldspar and the K released by biotite decomposition. The produced tourmaline generally has core-rim structures, indicating that the composition of melt or fluid evolved during tourmaline crystallization.Based on the experimental results, we propose that tourmaline granite veins or dikes can be formed by the reactions between boron-rich fluids, presumably produced by devolatilization of boron-bearing granitic magma, and incompletely crystallized granite at the top of the magma chamber. This 'self-metasomatism' involving boron-rich fluid in the late stage of magma crystallization could be an important mechanism for the formation of tourmaline granite.

Thermal Diffusivity of Lherzolite at High Pressures and High Temperatures Using Pulse Method

Lherzolite is one of the most important components of the subcontinental mantle lithosphere, and the study of its heat transfer properties aids in understanding the thermal structure of the continental mantle lithosphere. Currently, few studies have examined the heat transfer properties of lherzolite, and the experimental results remain controversial. This experiment utilized a pulse method to measure the thermal diffusivity of lherzolite at pressures ranging from 1.0 to 4.0 GPa and temperatures from 300 to 1 073 K on a cubic press apparatus. We obtained a thermal diffusivity for lherzolite of approximately 2.10 mm^2s^(-1) at ambient condition. The experimental pressure derivative of the thermal conductivity of lherzolite decreased with temperature, reaching approximately 10% at high temperature, a value higher than the previously reported 4%, which indicates that the temperature gradient of the upper mantle lithosphere is smaller than previously thought. Therefore, concerning calculation of the lithosphere thickness using the thermal conductivity of the lherzolite, the previous calculation using pressure derivative of the thermal conductivity of 4% may cause an underestimation of the upper mantle lithosphere thickness by approximately 6% in a first approximation.

Exosomes derived from human adipose-derived stem cells ameliorate osteoporosis through miR-335-3p/Aplnr axis

Treatment of osteoporosis is still a challenge in clinic,which leads to an increasing social burden as the aging of population.Exosomes originated from human adipose-derived stem cells(hASCs)hold promise to promote osteogenic differentiation,thus may ameliorate osteoporosis.The main purpose of this study was to investigate the novel usage of hASC-derived exosomes in the treatment of osteoporosis and their underlying mechanism.Two types of exosomes,i.e.,exosomes derived from hASCs cultured in proliferation medium(P-Exos)and osteogenic induction medium(O-Exos),were obtained.As compared with P-Exos,O-Exos could promote the osteogenic differentiation of mouse bone marrow-derived stem cells(mBMSCs)from osteoporotic mice in vitro and ameliorated osteoporosis in vivo.Then,microRNA(miRNA)-335-3p was identified to be the key differentially expressed microRNA between the two exosomes by small RNA sequencing,gene overexpression and knock-down,qRT-PCR,and dual-luciferase reporter assay,and Aplnr was confirmed to be the potential target gene of miRNA-335-3p.In addition,miR335-3p inhibitor-optimized O-Exos were established by transfection of miR-335-3p inhibitor,which significantly enhanced the osteogenic differentiation of mBMSCs in vitro,and bone density and number of trabecular bones in vivo compared with unoptimized O-Exos.Our results indicated that the ASC-exosome-based therapy brings new possibilities for osteoporosis treatment.Besides,engineered exosomes based on transfection of miRNA are a promising strategy to optimize the therapeutic effect of exosomes on osteoporosis.

The PCK2-glycolysis axis assists three-dimensional-stiffness maintaining stem cell osteogenesis

Understanding mechanisms underlying the heterogeneity of multipotent stem cells offers invaluable insights into biogenesis and tissue development. Extracellular matrix (ECM) stiffness has been acknowledged as a crucial factor regulating stem cell fate. However, how cells sense stiffness cues and adapt their metabolism activity is still unknown. Here we report the novel role of mitochondrial phosphoenolpyruvate carboxykinase (PCK2) in enhancing osteogenesis in 3D ECM via glycolysis. We experimentally mimicked the physical characteristics of 3D trabeculae network of normal and osteoporotic bone with different microstructure and stiffness, observing that PCK2 promotes osteogenesis in 3D ECM with tunable stiffness in vitro and in vivo. Mechanistically, PCK2 enhances the rate-limiting metabolic enzyme pallet isoform phosphofructokinase (PFKP) in 3D ECM, and further activates AKT/extracellular signal-regulated kinase 1/2 (ERK1/2) cascades, which directly regulates osteogenic differentiation of MSCs. Collectively, our findings implicate an intricate crosstalk between cell mechanics and metabolism, and provide new perspectives for strategies of osteoporosis.