聚碳酸酯低聚物改性碳纤维及其增强聚碳酸酯复合材料的性能

以双酚A(BPA)和碳酸二苯酯(DPC)为原料进行酯交换制备了低聚合度聚碳酸酯(PC),通过红外光谱(IR)、凝胶渗透色谱(GPC)等确认产物相对分子质量为5516,且具有较高的端羟基含量。采用溶液浸渍法以LPC为上浆剂对碳纤维(CF)进行表面修饰,并制备了碳纤维增强聚碳酸酯复合材料(CFRPC),考察了LPC和CF含量对复合材料拉伸强度和热导率的影响。结果表明,经过脱浆及氧化处理后的CF(OCF)在LPC的修饰作用下与PC基材的界面附着力更高,使复合材料的性能得到明显提高,拉伸强度和热导率最高可分别达到136.3 MPa和0.739 W/(m·k),同条件下比采用DCF(仅经过脱浆处理的CF)增强PC的拉伸强度和热导率分别提高了26.0%和8.8%。经扫描电镜图观察到了拉伸样条断面上的OCF表面包裹着均匀的树脂层,显示了PC与OCF之间较强的附着力。

Combination of Shengmai San and Radix puerariae ameliorates depression-like symptoms in diabetic rats at the nexus of PI3K/BDNF/SYN protein expression

Background:Hyperglycemia is a characteristic feature of diabetes that often results in neuropsychological complications such as depression.Diabetic individuals are more vulnerable to experience depression compared to the normal population.Thus,novel treatment approaches are required to reduce depressive symptoms among diabetic individuals.Traditional Chinese medicines(TCMs)such as Shengmai San(SMS)and Radix puerariae(R)are usually widely used to treat ailments such as neurological com-plications since ancient time.Methods:In this study,SMS was combined with R to prepare an R-SMS formulation and screened for their antidepressant activity in diabetic rats.The antidepressant po-tential of the prepared combination was evaluated behaviorally using open field test,novelty-induced hypophagia,and forced swim test in diabetic rats with biochemical and protein expression(PI3K,BDNF[brain-derived neurotrophic factor],and SYN[pr-esynaptic vesicle protein])analysis.Results:Diabetic rats(streptozotocin,45 mg/kg)showed elevated fasting blood glu-cose(FBG)>12 mM with depressive symptoms throughout the study.Treatment with R-SMS(0.5,1.5,and 4.5 g/kg)significantly reverted depressive symptoms in diabetic rats as evinced by significantly(p<0.05)reduced immobility time with an increased tendency to eat food in a novel environment.Treatment with R-SMS also significantly increased the protein expression of PI3K,BDNF,and SYN protein,which play a crucial role in depression.Conclusion:This study showed that R-SMS formulation antagonized depressive symptoms in diabetic rats;thus,this formulation might be studied further to develop as an antidepressant.

聚醚酰亚胺修饰碳纤维及其对聚碳酸酯基复合材料界面和性能的影响

以聚醚酰亚胺(PEI)为修饰剂,对氧化后的碳纤维(CF)进行表面修饰,并通过红外光谱、X射线光电子能谱和扫描电镜(SEM)表征了表面修饰效果。结果表明,氧化处理使CF表面PEI修饰层更加均匀。考察了PEI和CF含量对CF增强聚碳酸酯(PC/CF)复合材料力学性能、导热性能及耐热性能的影响,发现PEI修饰层使PC/CF复合材料的拉伸强度比未经修饰的PC/CF提高了35.2%,维卡软化温度(VST)进一步上升了约2℃,热导率最大提高了13.1%。拉伸样条断面的SEM图确认了PEI修饰层改善了复合材料的界面附着效果。结合复合材料中CF的长度分布统计及样品断面的SEM图对PC/CF复合材料的性能表现进行了分析。

Photosynthetic acclimation to long-term high temperature and soil drought stress in two spruce species (Picea crassifolia and P. wilsonii) used for afforestation

Picea crassifolia and P.wilsonii,commonly used for afforestation in northern China,are increasingly likely to be subjected to high temperatures and soil drought stress as a result of global warming.However,little is known about the effects of these stresses on foliar photosynthesis in the two species.To investigate how photosynthetic characteristics and sensitivity respond to prolonged high temperatures and soil drought,foliar gas exchange and other closely related parameters were recorded from four-year-old seedlings of both species.Seedlings were grown under two temperature treatments(25/15 and 35/25 °C) and four soil water regimes [80,60,40 and 20% of maximum field capacity(FC)] for 4 months.Although all treatments significantly reduced photosynthetic rates(Pn) of both species,P.crassifolia exhibited greater photosynthetic acclimation than P.wilsonii.Differences in photosynthetic acclimation were mainly related to variations in stomatal conductance(Cond) and the maximum quantum yield of PSII(Fv/Fm) between treatments.Indeed,higher Cond and Fv/Fmin all treatments were shown for P.crassifolia than for P.wilsonii.Moreover,photosynthesis in P.crassifolia exhibited inherently lower temperature sensitivities(broader span for the temperature response curves; lower b) and higher thermostability(invariable b between treatments).Further,severe drought stress(20% FC) limited the survival of P.wilsonii.Our results indicate that P.wilsonii is more susceptible to high temperatures and soil drought stress.Planting P.crassifolia would be more expected to survive these conditions and hence be of greater benefit to forest stability if predicted increases in drought and temperature in northern China occur.

Commercial Credit and Corporate Productivity

As an important form of informal finance,commercial credit is widely used among enterprises.Does commercial credit promote the total factor productivity of enterprises?According to the theoretical literature and the reality,using the large sample data of Chinese industrial enterprises,the paper empirically tests the impact of commercial credit on the productivity of enterprises from three aspects:the provision and acquisition of commercial credit and the net commercial credit.The study finds that the provision of commercial credit reduces the productivity level of enterprises;the acquisition of commercial credit fails to promote productivity;while the net commercial credit as a short-term financial buffer for enterprises can alleviate the financing constraints,faced by enterprises,especially private enterprises,which help to increase their productivity levels.In addition,the study found that the higher the marketization process in the region,the more favorable the commercial credit is to the improvement of the production efficiency of private enterprises.

Learning Effect and Productivity Convergence of Chinese Industrial Enterprises

The main purpose of this paper is to test the production efficiency of different Chinese property industrial enterprises.Based on the large sample panel data of industrial enterprises of the National Bureau of Statistics,we found that although the production efficiency of China-funded enterprises is generally weaker than foreign-funded enterprises,some China-funded enterprises have better learning ability.On the one hand,dynamic analysis found that private enterprises have significant learning ability.On the other hand,the results of convergence analysis show that China’s private enterprises have the potential to gradually catch up with the frontier level of world production efficiency and have better learning ability to catch up potential.And state-owned enterprises tend to be more efficient at the beginning of their establishment,but their productivity is fairly slow to improve,especially for state-owned enterprises with high efficiency sub-samples,so that it’s hard for them to continue improving their efficiency.Institutional analysis found that the marketization process helped the China enterprises to improve their learning ability and China should continue to strengthen the reform of property rights and promote the marketization process.

Changes of dynamical balance of free radicals induced by levodopa in rat glia-containing mesencephalic culture fluid

BACKGROUND ： Parkinson disease is neurodegenerative disorders, characterized by a progressive and selective degeneration of nigrostdatal dopaminergic pathway. Its main clinical symptoms include bradykinesia, dgidity, rest tremor and disturbances in balance. Levodopa （L-DOPA） is the ＂gold standard＂ for the symptomatic treatment of Parkinson disease, but L-DOPA is toxic to dopaminergic neurons and the chronic administration of L-DOPA often causes the side effects of motor such as ＂on-off ＂, etc., and its mechanism still has not been completely clarified. OBJECTIVE ： To observe the changes of the content of glutathione （GSH）, activities of glutathione peroxidase （GSH-Px） and superoxide dismutase （SOD） and content of malondialdehyde （MDA） in gila-containing mesencephalic culture fluid after L-DOPA of different concentrations were added. DESIGN： A comparative observation. SETTINGS ： Department of Neurology, Affiliated Hospital of Taishan Medical University; Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology. MATERIALS ： The experiment was carried out in the Basic Research Institute, Taishan Medical University from December 2003 to September 2004. Ten postnatal newborn SD rats （within 2 days） were selected, either male or female. Fetal bovine serum （DMEM/F12） was from Gibco Company; L-DOPA and glial fibrillary acidic protein （GFAP） from Sigma Company. Kits for determination of GSH, GSH-Px, SOD and MDA were purchased from Nanjing Jiancheng Bioengineering Research Institute. METHODS ： Gila-containing mesencephalic culture fluid were placed in 24-well culture plate, and L-DOPA of 50, 100 and 500 μmot/L was added to each group, the blank control group was also set. The glia-containing mesencephalic culture fluid selected at 4, 24, 48 and 72 hours respectively to determine the GSH content with colorimetdc quantitative technique, GSH-Px activity with colorimetdc method, SOD activity with xanthine oxidase method and MDA content with thiol-barbituric acid method. MAIN OUTCOME MEASURES ： GSH and MDA contents, GSH-Px and SOD activities in the glia-containing mesencephalic culture fluid at 4, 24, 48 and 72 hours after L-DOPA of different concentrations were added. RESULTS ： In the glia-containing mesencephalic culture fluid after 100 μmol/L L-DOPA was added for 24, 48 and 72 hours, the GSH contents were lower than those in the blank control group [（174.14±39.28）, （161.55± 40.79）, （144.97±57.59） mg/L; （220.66±32.61）, （221.10±32.98）, （220.43±31.98） mg/L, P 〈 0.05]; The GSH-Px activities were lower than those in the blank control group [（4.03±1.05）, （3.99±1.12）, （3.47±1.00） μmol/L; （5.45±1.14）, （5.69±1.21）, （5.49±1.28） μmol/L, P 〈 0.05]; The SOD activities were also lower than those in the blank control group [（42.02±5.08）, （39.38±5.34）, （38.87±5.75）kNU/L; （51.35±8.87）, （51.78±8.96）, （50.99± 9.09） kNU/L, P 〈 0.05]; Whereas the MDA contents were higher than those in the blank control group [（3.51 ± 1.05）, （3.99±1.03）, （4.45±1.58） μmol/L; （2.09±1.13）, （2.18±1.29）, （2.01±1.05） μmol/L, P〈 0.05]. In the gli- a-containing mesencephalic culture fluid after 100 μmol/L L-DOPA was added for 4, 24, 48 and 72 hours, the GSH contents were （172.27±26.07）, （140.15±61.44）, （137.30±50.87）, （121.09±66.07） mg/L, the GSH-Px activities were （3.89±1.20）, （3.56±1.23）, （3.38±1.18）, （3.01±1.09） μmol/L, the SOD activities were （38.18±6.75）, （35.23±7.85）, （4.59±1.24）, （31.42±7.01） kNU/L, which were all lower than those in the blank control group （P 〈 0.05-0.01 ）; The MDA contents were （3.65±0.86）, （3.87±1.14）, （4.59±1.24）, （4.79±1.32） μmol/L, which were higher than those in the blank control group （P 〈 0.05-0.01）. In the gila-containing mesencephalic culture fluid added by 50 μmol/L L-DOPA, the GSH and MDA contents, GSH-Px and SOD activities at each time point were all close to those in the blank control group （P〉 0.05）. CONCLUSION ： L-DOPA of certain concentration can destroy the dynamical balance of free radicals in glia-containing mesencephalic culture fluid, and accelerate the degeneration of neurons, which are in concentration- and time-dependent manners.

Overexpressed Cyclin D1 and CDK4 proteins are responsible for the resistance to CDK4/6 inhibitor in breast cancer that can be reversed by PI3K/mTOR inhibitors

CDK4/6 inhibitors are the standard treatment in advanced HR+/HER2-breast cancer patients.Nevertheless,the resistance to CDK4/6 inhibitors is inevitable and the strategies to overcome resistance are of great interest.Here,we show that the palbociclibresistant breast cancer cells expressed significantly higher levels of Cyclin D1 and CDK4 proteins because of upregulated protein synthesis.Silencing Cyclin D1 or CDK4 led to cell cycle arrest while silencing Cyclin E1 or CDK2 restored the sensitivity to palbociclib.Furthermore,PI3K/mTOR pathway was hyper-activated in palbociclib-resistant cells,leading to more phosphorylated 4E-BP1 and higher levels of Cyclin D1 and CDK4 translation.Targeting PI3K/mTOR pathway with a specific PI3Kαinhibitor(BYL719)or an mTOR inhibitor(everolimus)reduced the protein levels of Cyclin D1 and CDK4,and restored the sensitivity to palbociclib.The tumor samples expressed significantly higher levels of Cyclin D1,CDK4,p-AKT and p-4E-BP1 after progression on palbociclib treatment.In conclusion,our findings suggest that overexpressed Cyclin D1 and CDK4 proteins lead to the resistance to CDK4/6 inhibitor and PI3K/mTOR inhibitors are able to restore the sensitivity to CDK4/6 inhibitors,which provides the biomarker and rationale for the combinational use of CDK4/6 inhibitors and PI3K/mTOR inhibitors after CDK4/6 inhibitor resistance in breast cancer.

用于光动力疗法的pH敏感性碳酸钙-二氢卟吩e6纳米粒的制备与表征

本研究将碳酸钙纳米粒与光敏剂二氢卟吩e6(Ce6)结合构建碳酸钙-二氢卟吩e6纳米粒(CaCO_(3)-Ce6 NPs),对其粒径、电位、光学性质、pH敏感性和ROS产生能力进行表征。结果表明,CaCO_(3)-Ce6 NPs为粒径均匀的纳米粒,具有优良的光学特性和pH敏感性。在4T1细胞中,660 nm激光照射下,CaCO_(3)-Ce6 NPs具有比Ce6更强的ROS产生能力。上述结果表明,CaCO_(3)-Ce6 NPs在660 nm激光照射下具有增强的光动力作用,有望获得更强的抗肿瘤药效。

氧化锌纳米粒的制备与表征

本研究采用溶胶-凝胶法制备氧化锌纳米粒(ZnO NPs),并对其粒径、形貌、晶型、光学特性和pH敏感性等理化性质进行表征,在PC-3M和4T1两株细胞系上对ZnO NPs的体外抗肿瘤药效进行评价。实验结果表明,ZnO NPs为粒径均匀的球形纳米颗粒,具有优良的光学性能及pH敏感性能,对PC-3M和4T1两株细胞系有明显的抗肿瘤细胞药效。上述结果表明, ZnO NPs可作为载体载带活性物质以产生抗肿瘤诊断和治疗作用。

Regulation of signaling pathways in hair follicle stem cells

Hair follicle stem cells(HFSCs)reside in the bulge region of the outer root sheath of the hair follicle.They are considered slow-cycling cells that are endowed with multilineage differentiation potential and superior proliferative capacity.The normal morphology and periodic growth of HFSCs play a significant role in normal skin functions,wound repair and skin regeneration.The HFSCs involved in these pathophysiological processes are regulated by a series of cell signal transduction pathways,such as lymphoid enhancer factor/T-cell factor,Wnt/β-catenin,transforming growth factor-β/bone morphogenetic protein,Notch and Hedgehog.The mechanisms of the interactions among these signaling pathways and their regulatory effects on HFSCs have been previously studied,but many mechanisms are still unclear.This article reviews the regulation of hair follicles,HFSCs and related signaling pathways,with the aims of summarizing previous research results,revealing the regulatory mechanisms of HFSC proliferation and differentiation and providing important references and new ideas for treating clinical diseases.

聚氨基胺-聚乙二醇-聚氨基胺共聚物的合成及其含阿霉素凝胶的制备与评价（英文）

本研究通过选择适宜反应温度,合成具有适宜pH/温度敏感性的聚氨基胺-聚乙二醇-聚氨基胺三嵌段共聚物(PAA-PEG-PAA),制备PAA-PEG-PAA凝胶并对其性质进行考察;选择阿霉素为模型药物,制备含阿霉素的PAA-PEG-PAA凝胶并对其释放进行研究;选择B16F10黑色素瘤细胞为模型,考察含阿霉素的PAA-PEG-PAA凝胶的细胞药效。实验结果表明,通过降低反应温度,可降低PAA的分子量,使PAA-PEG-PAA具有适宜的pH/温度敏感性。PAA-PEG-PAA凝胶的粘度具有浓度依赖和温度依赖的特征。在pH6.0到7.4的范围内,PAA-PEG-PAA凝胶(12%,w/w)的液体-凝固相转变温度为35到29oC。含阿霉素的PAA-PEG-PAA凝胶具有体外药物释放缓释的特征及体外抗肿瘤药效的作用。所制备的含阿霉素的PAA-PEG-PAA凝胶具有响应肿瘤酸性微环境及体温发生凝固、缓慢释放药物的特点,推测经肿瘤内或者肿瘤旁注射后,可发挥相应的抗肿瘤药效。

下泪小点烧灼治疗重度水液缺乏型干眼的临床疗效

目的: 评价高温烧灼封闭下泪小点治疗重度水液缺乏型干眼的临床疗效。方法: 前瞻性非随机对照研究。选择2019年6月至2020年10月在福建医科大学附属第二医院眼科就诊的使用人工泪液和局部抗炎保守治疗后疗效不佳的重度水液缺乏型干眼患者29例(58眼)。根据是否患有干燥综合征分为2组:干燥综合征干眼(SS)组17例(34眼)和非干燥综合征干眼(非SS)组12例(24眼)。采用高温热烧灼封闭双眼下泪点, 记录泪小点烧灼前2个月、1 d及烧灼后2周、2个月时患者的眼表疾病指数(OSDI)、泪膜破裂时间(TBUT)、角膜荧光素染色(FL)和泪液分泌试验(SⅠT)结果。数据分析采用独立样本t检验、配对样本t检验及单因素重复测量方差分析。结果: 2组烧灼前各项干眼相关指标差异无统计学意义。烧灼后2周和2个月与烧灼前1 d比较, SS组OSDI评分、TBUT及FL评分差异均有统计学意义(F=69.58, P<0.001;F=49.45, P<0.001;F=34.07, P<0.001);非SS组OSDI评分、BUT、FL评分及SⅠT值差异均有统计学意义(F=57.89, P<0.001;F=72.83, P<0.001;F=47.44, P<0.001;F=28.35;P<0.001), 但SS组SⅠT值差异无统计学意义。烧灼2个月后, 非SS组OSDI评分、TBUT、FL评分、SIT值均较SS组改善更明显(t=2.22, P=0.04;t=-3.32, P<0.001;t=2.90, P=0.01;t=-4.00, P<0.001)。SS组和非SS组均未发生明显眼部并发症, 最常见的并发症为泪道再通, 再通率为5.2%。结论: 下泪小点烧灼封闭治疗重度干眼可改善重度干眼的症状和体征, 是一种简单、经济且安全有效的方法, 对非干燥综合征干眼患者效果更佳。

PsyMuKB: An Integrative De Novo Variant Knowledge Base for Developmental Disorders

De novo variants(DNVs)are one of the most significant contributors to severe earlyonset genetic disorders such as autism spectrum disorder,intellectual disability,and other developmental and neuropsychiatric(DNP)disorders.Presently,a plethora of DNVs have been identified using next-generation sequencing,and many efforts have been made to understand their impact at the gene level.However,there has been little exploration of the effects at the isoform level.The brain contains a high level of alternative splicing and regulation,and exhibits a more divergent splicing program than other tissues.Therefore,it is crucial to explore variants at the transcriptional regulation level to better interpret the mechanisms underlying DNP disorders.To facilitate a better usage and improve the isoform-level interpretation of variants,we developed NeuroPsychiatric Mutation Knowledge Base(PsyMuKB).It contains a comprehensive,carefully curated list of DNVs with transcriptional and translational annotations to enable identification of isoformspecific mutations.PsyMuKB allows a flexible search of genes or variants and provides both table-based descriptions and associated visualizations,such as expression,transcript genomic structures,protein interactions,and the mutation sites mapped on the protein structures.It also provides an easy-to-use web interface,allowing users to rapidly visualize the locations and characteristics of mutations and the expression patterns of the impacted genes and isoforms.PsyMuKB thus constitutes a valuable resource for identifying tissue-specific DNVs for further functional studies of related disorders.PsyMuKB is freely accessible at http://psymukb.net.

Segmentation of the communication tower and its accessory equipment based on geometrical shape context from 3D point cloud

Communication tower(CT)and its accessory equipment(AE)such as radio frequency equipment(RFE)and antenna,are essential in providing highspeed and stable mobile network services.It is necessary to routinely monitor the security and stability of CT and AE for seamless communication.There is limited research on fine segmentation of communication base station objects.This paper proposes a method for accurately segmenting the point cloud of the CT and AE from Terrestrial Laser Scanning(TLS)data.At first,the CT point cloud is accurately segmented based on region growing and Random Sample Consensus(RANSAC).Then,the point cloud of pole-shaped apart is extended to a certain distance to obtain the buffer point cloud containing AE.Normal Differential(ND)clustering is employed to obtain several groups of clusters containing planes,and calculate each plane's filling rate and size.Finally,the cluster type(such as antenna,RFE,or other)is distinguished.The experimental results demonstrate that the point-based average F1-score of CTs is 98.70%,the point-based and object-based average F1-scores of antennas are 96.09%and 97.93%,and the corresponding values for the RFE are 89.89%and 90.00%,respectively,indicating the optimal performance of the proposed method.