Prevention of hepatocellular carcinoma in chronic viral hepatitis B and C infection

Hepatocellular carcinoma(HCC)is a leading cause of cancer-related mortality worldwide,with the majority of cases associated with persistent infection from hepatitis B virus(HBV)or hepatitis C virus(HCV).Natural history studies have identified risk factors associated with HCC development among chronic HBV and HCV infection.High-risk infected individuals can now be identified by the usage of risk predictive scores.Vaccination plays a central role in the prevention of HBV-related HCC.Treatment of chronic HBV infection,especially by nucleoside analogue therapy,could also reduce the risk of HBV-related HCC.Concerning HCV infection,besides the advocation of universal precautions to reduce the rate of infection,pegylated interferon and ribavirin could also reduce the risk of HCV-related HCC among those achieving a sustained virologic response.Recently there has been mounting evidence on the role of chemopreventive agents in reducing HBV-and HCV-related HCC.The continued advances in the understanding of the molecular pathogenesis of HCC would hold promise in preventing this highly lethal cancer.

Efficient decolorization of dye-containing wastewater using mycelial pellets formed of marine-derived Aspergillus niger

In order to improve the efficient decolorization of dye-containing water by biosorbent and understand the biosorption mechanism, the self-immobilization mycelial pellets were prepared using a marine-derived fungus Aspergillus niger ZJUBE-1, and an azo dye, Congo red was chosen as a model dye to investigate batch decolorization efficiency by pellets. The pellets as biosorbent showed strong salt and acid tolerance in biosorption process. The results for dye adsorption showed that the biosorption process fitted well with models of pseudo-second-order kinetic and Langmuir isotherm, with a maximum adsorption capacity of 263.2 mg·g^(-1) mycelium. During 6 batches of continuous decolorization operation, the mycelial pellets could possess efficient decolorization abilities(>98.5%).The appearance of new peak in the UV–Vis spectral result indicated that the decolorization process may also contain biodegradation. The mechanism studies showed that efficient biosorption ability of pellets only relies on the active zone on the surface of the pellet, which can be enhanced by nutrition supplement or be shifted outward by a reculture process.

Nucleation potency prediction of LaB_6 with E2EM model and its influence on microstructure and tensile properties of Al-7Si-0.3Mg alloy

The edge-to-edge matching(E2EM)crystallographic model was used to predict the orientation relationships(ORs)between LaB6 and Al.Three different possible ORs can be predicted between LaB6 and Al,which are(100)Al||(100)LaB6,[001]Al||[001]LaB6;(110)Al||(110)LaB6,[001]Al||[001]LaB6;and(111)Al||(111)LaB6,[011]Al||[011]LaB6.The prediction results are perfectly confirmed through TEM analysis and prove the nucleation potency of LaB6.The refining efficacy of Al-2La-1B refiner and its influence on the tensile properties were investigated in the as-cast Al-7Si-0.3Mg alloy.According to the results,LaB6 has higher nucleation potency than TiB2,leading to better grain refining efficacy of Al-2La-1B refiner in the as-cast Al-7Si-0.3Mg alloy.Regarding the mechanical performances,tensile properties of the as-cast Al-7Si-0.3Mg casting alloy are prominently improved after addition of Al-2La-1B refiner,due to the refined microstructures.

Neuroprotection of phenolic alkaloids from Menispermum dauricum versus melatonin against oxygen-glucose-serum-deprivation-mediated injury

BACKGROUND： Recent studies have demonstrated that phenolic alkaloids from Menispermum dauricum （PAMD） can protect the heart and brain from ischemia/reperfusion injury, and promote neuron survival by inhibiting neuronal Bax and upregulating Bcl-2 expression following ischemia/reperfusion. OBJECTIVE： To investigate the neuroprotective effects of PAMD versus exogenous melatonin against ischemia/reperfusion injury. DESIGN, TIME AND SETTING： Observation and comparison experiments at a cellular level were performed at the Department of Biochemistry and Molecular Biology, Tongji Medical College of Huazhong University of Science and Technology between February 2007 and February 2008. MATERIALS： PAMD （95% purity） was provided by Kunming Institute of Botany, Chinese Academy of Sciences; melatonin was provided by Sigma, USA. METHODS： N2a mouse neuroblastoma cells were cultured in vitro deprived of glucose, serum and oxygen for 90 minutes, then cultured in normal medium containing different concentrations of PAMD （0.1, 1.0, 10 mg/L） or melatonin （1, 10, and 100 μmol/L）. Cells cultured in normal conditions served as a control. MAIN OUTCOME MEASURES： The culture solution was collected to determine the content of ex- citatory neurotransmitters such as glutamic acid and aspartic acid; cell viability was detected by MTT methods; reactive oxygen species production was determined by fluorescence spectroscopy; mito- chondrial transmembrane potential （？Ψm） was detected by laser confocal scanning; cytochrome C was measured by western blotting; and caspase-3 activity was determined by visible spectropho- tometry. RESULTS： Melatonin and PAMD both promoted oxygen-glucose-serum deprivation-mediated N2a cell survival （P 〈 0.01） and inhibited glutamic acid release （P 〈 0.01）, but melatonin did not inhibit aspartic acid production. The protective effects were the strongest using melatonin 100 μmol/L and PAMD 10 mg/L, so subsequent experiments were the performed at those doses. Although PAMD could no longer maintain mitochondrial transmembrane potential 6 hours after reperfusion, its in- hibitory effects on cytochrome C release from mitochondria and scavengers of reactive oxygen species were stronger than those of melatonin （P 〈 0.01）. However, its inhibitory effect on caspase-3 activity was weaker than that of melatonin： PAMD could inhibit caspase-3 activity 12 hours after reperfusion （P 〈 0.01）, but melatonin inhibited caspase-3 activity 28 hours after reperfusion （P 〈 0.01）. CONCLUSION： The results show that melatonin and PAMD have neuroprotective effects, but that the mechanisms are varied. Melatonin can maintain mitochondrial transmembrane potential, but its inhibitory effects on cytochrome C release, caspase-3 activity, and reactive oxygen species scav-enging are different from those of PAMD.

Salt-tolerant mechanism of marine Aspergillus niger cellulase cocktail and improvement of its activity

The cellulase cocktail produced by marine Aspergillus niger exhibits a property of salt-tolerance,which is of great potential in cellulose degradation in high salt environment.In order to explain the mechanism on the salttolerance of the cellulase cocktail produced by marine A.niger,six cellulase components(AnCel6,AnCel7A,AnCel7B,AnEGL,AnBGL1 and AnBGL2)were obtained by directed expression.Studies on their enzymatic properties revealed that oneβ-glucosidase(AnBGL2)and one endoglucanase(AnEGL)exhibited an outstanding salttolerant property,and one cellobiohydrolase(AnCel7B)exhibited a certain salt-tolerant property.Subsequent study revealed that the salt-tolerant An EGL and AnCel7B endowed the cellulase cocktail with stronger salttolerant property,while the salt-tolerant An BGL2 had no positive effect.Moreover,after overexpression of AnCel6,AnCel7A,AnCel7B and AnEGL,the activity of cellulase cocktail increased by 80%,70%,63%and 68%,respectively.However,the activity of cellulase cocktail was not improved after overexpression of AnBGL1 and AnBGL2.After mixed-strain fermentation with cellobiohydrolase recombinants(cel6 a,cel7a and cel7b recombinants)and endoglucanase recombinant(egl recombinant),the the activity of cellulase cocktail increased by 114%,102%and91%,respectively.

Removal process and mechanism of hexavalent chromium by adsorption-coupled reduction with marine-derived Aspergillus niger mycelial pellets

In order to remove hexavalent chromium(Cr(Ⅵ))from solutions efficiently,the mycelial pellets with a marine-derived fungus Aspergillus niger as a biosorbent were prepared.The effects of removal process parameters such as solution pH,initial Cr(Ⅵ)concentration and biomass concentration on Cr(Ⅵ)removal process were investigated.The results showed that Cr(Ⅵ)removal rate up to 100%could be achieved under optimized conditions,which indicated the excellent Cr(Ⅵ)removal performance of the Aspergillus niger pellets.As a more important point,the Cr(Ⅵ)removal mechanism was studied,and the results revealed that Cr(Ⅵ)removal was achieved in the adsorption-coupled reduction process.A little of Cr(Ⅵ)was reduced to less toxic trivalent chromium(Cr(Ⅲ))in solution,while some was absorbed on the surface of mycelial pellets.Then they may be reduced on the surface or transferred into cells and then be reduced.The marine-derived A.niger mycelial pellets show properties of easy preparation and separation and cost effectiveness,which are potential biosorbent and reductant in the treatment of trace chromate containing wastewater.

Solution combustion synthesis of high-entropy metal spinel oxide as oxygen evolution reaction catalyst

High-entropy metal spinel oxide(HEO)is proved to be a promising oxygen evolution reaction(OER)catalyst with high catalytic performance and stability.A short routine synthesis process based on solution combustion synthesis was proposed to prepare(Co_(0.25)Ni_(0.25)Mn_(0.25)Zn_(0.25))Fe_(2)O_(4)spinel HEO in this work.During the process,the products were rapidly synthesized and melted due to the high-temperature reaction,and then quickly crystallized on the surface of nickel foam to form a nano-structure coating.With the aid of nano-scale spinel structure,the overpotential of non-activation HEO electrode reaches 276 mV at the current density of 10 mA·cm^(-2),and after 100 h i-t test,it can be further reduced to 230 mV,which proves the high activity of OER catalysis.The promotion of OER catalytic performance can be attributed to the surface reconstruction caused by the selective element leaching and the boost of oxygen vacancy,leading to the formation of nano-scale flocculation around spinel core after the long-term OER process.This work indicates a special casting process for functional materials and explores the application of rapid crystallization.

氮氧同位素示踪湿沉降NO_(3)^(-)来源及氧化途径

为探明焦作市大气湿沉降中硝态氮的污染水平,识别其来源及其形成过程,于2020年1月-2021年12月采集了焦作市大气湿沉降样品41个,测定并分析了TN、NH_(4)^(+)-N、NO_(3)^(-)-N浓度以及δ^(15)N-NO_(3)^(-)、δ^(18)O-NO_(3)^(-)值.结果表明:①TN、NH_(4)^(+)-N、NO_(3)^(-)-N浓度范围分别为2.52~13.27、0.11~1.70、1.64~8.31 mg/L,焦作市湿沉降中氮的主要存在形态为NO_(3)^(-)-N,占比为52.11%~83.92%.②δ^(18)O-NO_(3)^(-)、δ^(15)N-NO_(3)^(-)值的范围分别为54.9‰~93.9‰、-9.8‰~3.0‰,非雨季δ^(18)O-NO_(3)^(-)值(62.5‰~93.3‰)更接近于N2O5氧化途径生成的δ^(18)O-HNO_(3)值(100.9‰~103.1‰),雨季δ^(18)O-NO_(3)^(-)值(53.2‰~73.0‰)更接近于OH氧化途径生成的δ^(18)O-HNO_(3)值(50.9‰~60.9‰),说明非雨季大气湿沉降NO_(3)^(-)主要来自N2O5的氧化,而雨季主要来自OH的氧化.③雨季,OH和N2O5氧化途径对湿沉降NO_(3)^(-)的贡献率分别为80.32%和19.67%,非雨季,两种氧化途径的贡献率分别为65.37%和34.62%;在考虑了同位素分馏情况下,基于贝叶斯模型识别了湿沉降NO_(3)^(-)的主要来源,即土壤排放、生物质燃烧、机动车尾气排放和煤炭燃烧,其贡献率平均值分别为31.70%±4.90%、28.30%±14.00%、22.80%±12.10%、17.20%±0.08%.该研究结果将为降雨中硝酸盐的来源及形成途径提供证据.

Evaluation of facial temperature distribution changes during meditation using infrared thermal imaging:An experimental,cross-over study

Objective:To investigate the differences between meditation and resting states using infrared thermal imaging(IRTI)to determine facial temperature distribution features during meditation and annotate the patterns of facial temperature changes during meditation from the perspective of traditional Chinese medicine facial diagnosis.Methods:Each participant performed 10 min meditation and 10 min resting but in different sequences.A concentration test was set as the task load,followed by a meditation/resting or resting/meditation session,during which the participants'facial temperatures were observed using IRTI.Participants were scored on the Big Five Inventory(BFI)and Mindful Attention Awareness Scale(MAAS).Results:Forehead temperatures decreased more during meditation than during the resting state.The chin temperature increased only during meditation(P<.0001).For the subjects with meditation experience,there were significant differences in the temperatures of the left forehead(P<.01),right forehead(P<.01)and chin(P<.05)between the meditation and resting state at the 10~(th)min.In the nontask state,the BFI-Extraversion showed a negative correlation with the temperature of the left forehead(R=-0.41,P=.03).In the post-task state,the temperature of the left forehead was negatively correlated with scores on the MAAS(R=-0.42,P=.02).Conclusion:Using IRTI to study meditation offers a practical solution to the challenges in meditation research.The results indicate that an increase in chin temperature may be a representative feature of a meditation state,and forehead temperature is also a potential indicator.

Preparation, properties, and cell attachment/growth behavior of chitosan/acellular derm matrix composite materials

Composite membranes and sponge scaffolds consisting chitosan (CS) and acellular derm matrix (ADM) in six ratios were prepared by solvent evaporation technique and freeze-drying method, respectively. The composite materials were characterized by water contact angle measurement, scanning electron microscopy (SEM), water absorption and HaCat cells compatibility. The SEM result showed that CS/ADM three-dimensional (3D) micro-porous structures were successfully produced. The water absorption value of all scaffolds was over 18 times of its initial weight, which is high enough for skin regeneration scaffold, but there were no significant differences of water absorption ratio between deionized water and PBS solution for same scaffold (P > 0.05). HaCat cells were distributed uniformly on the surfaces of membrane 4-6, and an almost confluent monolayer was formed on membrane 6 on the fifth day, whereas cells maintained round and spherical in shape on the surface of membrane 1. The results showed that the cell compatibility of pure CS membrane needed to be improved, and addition of ADM realized this purpose. The results of compatibility of HaCat cells on scaffolds showed that the cell proliferated well on the scaffolds 3 and 4. In our study, the cell’s attachment and growth on the composite membranes was mainly determined by the content of the membrane, whereas the cell’s attachment and growth in the scaffolds was determined by both the content and structure of the scaffolds.

老年人跌倒风险感知研究现状及其对老年人主动跌倒预防的启示

跌倒是老年人致病致死的重要原因。临床医护人员虽已重视对跌倒的管理,但跌倒干预依从性尚不理想,跌倒发生率仍然维持在较高水平,从老年人角度探讨其对跌倒风险的理解可能是跌倒干预,尤其是主动跌倒预防的关键。本文从“健康第一责任人”的角度,对老年人跌倒风险感知的概念、行为后果及影响因素进行总结,发现目前国内外跌倒风险感知研究较少,概念内涵仍需进一步挖掘。老年人对跌倒风险的主观认知能够导致不同的跌倒风险应对行为模式,从而影响跌倒风险。跌倒风险感知影响因素主要聚焦于情绪心理、生理状况、社会文化和物理环境方面,影响过程均通过主观认知发挥作用。未来可结合风险感知形成过程,使用实证研究进一步验证跌倒风险感知的心理认知机制,为主动跌倒预防提供实证依据。

泛素特异性蛋白酶21对胆管癌细胞增殖及迁移的影响及机制

目的:探究泛素特异性蛋白酶21(USP21)在胆管癌(CCA)中的表达及其对CCA细胞增殖与迁移的作用及其机制。方法:通过生物信息学方法和免疫组化及WB法检测CCA组织及细胞中USP21的表达情况。利用体外克隆形成、EdU及Transwell实验检测敲低USP21对CCA细胞QBC939和RBE增殖及迁移的影响。通过RNA测序、质谱、免疫共沉淀(Co-IP)及WB法探究USP21的促癌机制。结果:TCGA等数据库分析结果显示,USP21 mRNA在CCA组织中呈高表达(均P<0.05)。USP21蛋白在CCA组织和细胞中呈高表达(P<0.05或P<0.001或P<0.0001)。敲低USP21后,QBC939和RBE细胞的增殖和迁移能力均显著降低(P<0.01或P<0.001)。RNA测序结果表明,敲低USP21可以通过抑制PI3K/AKT信号通路抑制CCA细胞的增殖和迁移能力(P<0.05)。质谱鉴定发现,USP21与胰岛素样生长因子2 mRNA结合蛋白1(IGF2BP1)相结合。Co-IP和WB实验结果表明,USP21与IGF2BP1结合并通过泛素化途径调控IGF2BP1的蛋白表达(P<0.001或P<0.0001)。结论:USP21在CCA组织和细胞中均呈高表达,其通过IGF2BP1/PI3K/AKT信号通路增强CCA细胞的增殖及迁移能力。

力学性能可调的高氧钛原位电弧增材制造

通过电弧增材制造原位制备高氧钛,并对高氧钛的成分偏析、显微组织和力学性能进行研究。结果表明,高氧钛试样的显微组织主要呈现为针状α相集束。随着氧含量的增加,试样针状α相逐渐变宽,集束尺寸变大。受氧的强化作用以及晶粒尺寸效应共同影响,试样的强度先提高后下降,伸长率显著下降,断裂形式由塑性断裂向解理断裂过渡。当氧含量达到0.37%(质量分数)时,伸长率约为7%,试样抗拉强度超过730 MPa,约为商业纯钛的2倍。

Estimation of speed-related car body acceleration limits with quantile regression

Purpose–This study aimed to facilitate a rapid evaluation of track service status and vehicle ride comfort based on car body acceleration.Consequently,a low-cost,data-driven approach was proposed for analyzing speed-related acceleration limits in metro systems.Design/methodology/approach–A portable sensing terminal was developed to realize easy and efficient detection of car body acceleration.Further,field measurements were performed on a 51.95-km metro line.Data from 272 metro sections were tested as a case study,and a quantile regression method was proposed to fit the control limits of the car body acceleration at different speeds using the measured data.Findings–First,the frequency statistics of the measured data in the speed-acceleration dimension indicated that the car body acceleration was primarily concentrated within the constant speed stage,particularly at speeds of 15.4,18.3,and 20.9 m/s.Second,resampling was performed according to the probability density distribution of car body acceleration for different speed domains to achieve data balance.Finally,combined with the traditional linear relationship between speed and acceleration,the statistical relationships between the speed and car body acceleration under different quantiles were determined.We concluded the lateral/vertical quantiles of 0.8989/0.9895,0.9942/0.997,and 0.9998/0.993 as being excellent,good,and qualified control limits,respectively,for the lateral and vertical acceleration of the car body.In addition,regression lines for the speedrelated acceleration limits at other quantiles(0.5,0.75,2s,and 3s)were obtained.Originality/value–The proposed method is expected to serve as a reference for further studies on speedrelated acceleration limits in rail transit systems.

基于网络药理学和分子对接技术探讨白芍治疗系统性红斑狼疮脑病的有效成分及作用机制

目的:采用网络药理学和分子对接的研究方法,探究白芍治疗系统性红斑狼疮脑病(NPSLE)的有效成分及作用机制。方法:利用中药系统药理学数据库与分析平台(TCMSP)筛选白芍生物活性成分及潜在靶点;运用Genecards数据库收集NPSLE的疾病靶点;利用在线韦恩图绘制平台Venny2.1得到二者共同的靶点,将共同靶点导入STRING数据库构建蛋白质相互作用网络,并利用Cytoscape3.8.0进行可视化处理;通过Metascape在线软件对靶点进行基因本体(Gene Ontology,GO)分析、京都基因与基因组百科全书(Kyoto Encylopaedia of Genes and Genomes,KEGG)通路富集分析,探究相关的生物过程与信号通路;应用Cytoscape3.8.0构建“成分—靶点—通路”网络;最后通过AutoDock软件对药物的主要活性成分及核心作用靶点进行分子对接验证。结果:共获得白芍的13个化学成分、70个潜在作用靶点和740个NPSLE相关作用靶点,其中白芍与NPSLE共同作用靶点有31个;PPI网络显示处于核心地位的靶点为白细胞介素(IL)-6、肿瘤坏死因子(TNF)、CASP3等,KEGG通路富集分析筛选得到83条与白芍治疗NPSLE相关通路,主要作用于IL-17信号通路、TNF信号通路、流体剪切应力和动脉粥样硬化、细胞凋亡、雌激素信号通路等。分子对接结果显示,主要活性成分能够分别与代表性的靶点结合并展现出较好的亲和力。结论:白芍对通过“多成分—多靶点—多途径”的特点与优势作用于NPSLE,为中医药治疗NPSLE的临床应用奠定了基础。

乳腺癌患者不同病理特征中H3K9ac、PD-L1、VISTA表达及其联合检测对乳腺癌不良预后的预测价值

目的探讨乳腺癌患者不同病理特征中组蛋白H3第9位赖氨酸残基乙酰化(H3K9ac)、程序性死亡因子配体1(PD-L1)、T细胞激活抑制物免疫球蛋白的可变区结构域(VISTA)及其联合检测对乳腺癌不良预后的预测价值。方法选取2018年5月至2020年7月平顶山市第一人民医院收治的130例乳腺癌患者,免疫组化检测乳腺癌组织及癌旁组织中H3K9ac、PD-L1及VISTA表达情况。比较乳腺癌组织、癌旁组织中H3K9ac、PD-L1及VISTA表达情况;比较乳腺癌不同病理特征中H3K9ac、PD-L1及VISTA表达情况;随访3 a,根据是否发生转移、复发、死亡分为预后不良和预后良好;比较预后不良和预后良好乳腺癌患者H3K9ac、PD-L1及VISTA表达情况;分析H3K9ac、PD-L1、VISTA表达联合检测对乳腺癌不良预后的预测价值。结果乳腺癌组织中H3K9ac、PD-L1、VISTA高表达率均高于癌旁组织(P<0.05);不同组织分化程度、T分期、N分期、阳性淋巴细胞数目中H3K9ac、PD-L1、VISTA高表达率比较,差异有统计学意义(P<0.05);随访3 a,130例乳腺癌患者失访7例(5.38%),预后不良22例,预后良好101例。预后不良患者H3K9ac、PD-L1、VISTA高表达率高于预后良好患者(P<0.05);H3K9ac、PD-L1、VISTA联合检测预测乳腺癌患者不良预后的AUC为0.902,大于各指标单独预测的0.714、0.866、0.781(P<0.05)。结论乳腺癌患者癌组织中H3K9ac、PD-L1及VISTA均呈高表达,其高表达与分化程度、分期、淋巴细胞数目等病理特征相关,H3K9ac、PD-L1、VISTA联合检测对乳腺癌患者不良预后具有较高的预测价值。

132例晚期非小细胞肺癌胸腔积液EGFR基因突变检测结果及其临床意义:一项来自单中心的回顾性研究

背景与目的恶性胸腔积液表皮生长因子受体(epidermal growth factor receptor,EGFR)基因突变检测缺乏病理质控,导致对检测结果解释及指导临床EGFR酪氨酸激酶抑制剂(tyrosine kinase inhibitor,TKI)使用造成困惑。因此,提出质控标准,并按此标准进行胸水EGFR突变检测尤为重要。本研究拟回顾性分析按照严格病理质控标准进行的胸水沉渣切片EGFR基因突变检测结果以及据此结果指导EGFR-TKIs治疗的疗效。方法回顾性分析中国医学科学院北京协和医院病理科2012年1月-2018年6月收到的胸腔积液标本的患者临床资料,其中具有临床资料相对完整,且按照制定的质控标准进行了胸水沉渣石蜡包埋切片EGFR基因突变检测的患者132例。根据EGFR基因突变检测结果,分为阳性组和阴性组,比较不同组别使用EGFR-TKIs的疗效。结果胸腔积液经离心后,沉渣石蜡包埋、切片,HE染色后镜下观察,若肿瘤细胞数目≥100个,即满足病理质控标准,可用于后续EGFR基因突变检测。132例患者中,72例(54.5%)患者胸水中检出EGFR基因突变。72例突变阳性患者中,69例患者使用了EGFR-TKIs。60例EGFR突变阴性患者中,仅15例使用EGFR-TKIs。EGFR突变阳性组的疾病控制率(disease control rate,DCR)为95.8%,中位无疾病进展生存时间(progression-free survival,PFS)为11个月;EGFR突变阴性组的DCR为0%,中位PFS为1个月,两组患者DCR和PFS均有显著差异(P<0.05)。结论经病理质控的胸水沉渣包埋切片可用于EGFR基因突变检测,其结果可指导临床EGFR-TKIs使用。

祁连拉脊山中段中奥陶世石英二长斑岩成因及其动力学意义

花岗岩类广泛分布于地球地壳中,主要为壳源物质岩浆作用的产物,其地球化学组成、岩石组合特征及时空分布规律等信息记录了源区性质、岩浆演化过程及岩浆形成的动力学机制。以祁连拉脊山中段克前垭口石英二长斑岩为研究对象,通过对其开展岩相学、锆石U-Pb年代学、全岩地球化学及Sr-Nd同位素研究,并结合区域内已有的同时期岩浆作用的研究,探讨石英二长斑岩的岩石成因及其形成的深部动力学背景。研究结果显示,石英二长斑岩的年龄为(466±5)Ma。在地球化学组成上,其具有相对较高的SiO 2(63.57%~64.04%)和Na_(2)O(7.08%~7.36%)以及相对较低的CaO(1.19%~2.52%)和K_(2)O(1.53%~1.96%)含量;在微量元素蛛网图上,其表现为富集Ba、U及Pb,亏损Zr、Hf及Sr;此外,其具有轻微的Eu负异常(Eu*=0.80~0.91)以及较为明显轻重稀土元素分异((La/Yb)N=13.0~15.7);其Sr、Nd同位素组成较为均一,初始Sr同位素和εNd(t)分别介于0.7054~0.7062和0.87~1.03。综合研究表明,克前垭口石英二长斑岩形成于加厚新生玄武质地壳物质的部分熔融;其与研究区同时期岩浆岩具有向缝合带逐渐变年轻的趋势,指示了俯冲板片回转的深部动力学过程;拉脊山构造带内470~460 Ma的花岗岩类的(La/Yb)N值整体具有持续降低的趋势,记录了由板片回转引发的岩石圈持续拉张过程。

无创呼吸机治疗急性左心衰的临床效果观察

目的观察急性左心衰患者采用无创呼吸机治疗的临床价值及安全性。方法将120例急性左心衰患者随机分为观察组(予以无创呼吸机治疗,n=60)和对照组(予以常规治疗,n=60),对比两组患者的临床治疗效果、不同时间动脉血气水平变化情况、并发症发生情况及生活质量评分等。结果观察组患者的临床总疗效(96.67%)及动脉血气水平的变化情况明显优于对照组,组间差异均有统计学意义(P<0.05);观察组患者的各项并发症发生率及生活质量评分明显优于对照组,组间差异有统计学意义(P<0.05)。结论无创呼吸机治疗急性左心衰的临床效果显著,有效提高了治疗的安全性和可靠性,值得推广。

原花青素在深龋的治疗及修复中的应用进展

原花青素(proanthocyanidin,PA)是一种天然植物类多酚。由于PA具有促进再矿化、诱导胶原交联、抑制蛋白酶活性、抗菌等多种生物学作用,使其在治疗及修复深龋的临床应用中有着广阔的应用前景,例如促进牙本质再矿化、改善树脂-牙本质粘接效果、改善牙本质酸蚀效果等。首先,PA不仅能通过其自身或与其他再矿化剂联合促进牙本质再矿化,同时它还具有抗菌作用,在减少致龋病原菌及其生物膜形成的同时能够抑制其产酸,基于以上特性,PA能够减少龋病的发生,进而改善深龋治疗后的远期效果。此外,将PA加入到粘接剂或酸蚀剂中,利用其诱导胶原交联、抑制蛋白酶活性等生物学作用,能够改善对牙本质的酸蚀及粘接效果,继而达到改善深龋修复效果的最终目的。本文归纳总结了近年来PA在深龋的治疗及修复等方面的相关研究进展,从促进牙本质再矿化、抗菌和改善牙本质的粘接及酸蚀效果四个方面进行综述,以期能为临床深龋的治疗及修复提供更全面的参考。