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1.
《Molecular therapy》2022,30(1):209-222
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目的探讨CRISPR/CAS9靶向敲除Oct3/4基因后化疗药物索拉菲尼(Sorafenib)对肝癌细胞的作用影响。方法通过实时荧光定量PCR和免疫印迹检测人肝癌细胞Li-7、HepG2、Huh7、BEL-7405和人肝正常细胞LX-2中Oct3/4的表达水平。通过CRISPR设计工具(http://crispr.mit.edu/)设计靶向Oct3/4的gRNA,并通过CRISPR/CAS9技术敲除肝癌细胞HepG2的Oct3/4,评估Oct3/4缺失情况下,化疗药物Sorafenib对肝癌细胞HepG2的凋亡水平和DNA损伤水平的影响。结果Oct3/4在人肝癌细胞Li-7、HepG2、Huh7、BEL-7405中的mRNA表达水平显著高于人肝正常细胞LX-2(P<0.05);同时,Oct3/4在人肝癌细胞Li-7、HepG2、Huh7、BEL-7405中的蛋白表达水平也显著高于人肝正常细胞LX-2。使用CRISPR/CAS9对HepG2细胞进行基因编辑后,挑取嘌呤霉素筛选出的2个单克隆细胞株进行Oct3/4表达水平的检测,1#号单克隆细胞株Oct3/4表达水平低于野生型WT,2#号单克隆细胞株没有表达Oct3/4。测序后发现1#号基因组上的Oct3/4第1个外显子只有1条染色体缺失了2个碱基,另一条染色体并未缺失;2#号基因组上的Oct3/4第1个外显子2条染色体均存在不同程度的缺失,一条缺失2个碱基,另一条缺失4个碱基。使用Sorafenib处理野生型HepG2细胞和2#Oct3/4 KO HepG2细胞后,Oct3/4 KO细胞株的凋亡水平显著上升(P<0.05),DNA损伤水平显著上升(P<0.05)。结论Oct3/4基因的敲除能够显著提高化疗药物Sorafenib促肝癌细胞凋亡和DNA损伤的作用。  相似文献   
3.
目的建立一种基于规律成簇的间隔短回文重复序列及其相关蛋白(CRISPR/Cas13a)的乙型肝炎病毒(HBV)共价闭合环状DNA(HBV cccDNA)检测方法。方法提取2017年6月至2020年10月于首都医科大学附属北京佑安医院就诊的4例乙型肝炎患者肝脏总DNA后,使用HindⅢ内切酶和质粒安全性ATP依赖DNA酶(PSAD)分别进行酶切;根据松弛环状DNA(rcDNA)和cccDNA的结构差异,设计特异性扩增HBV cccDNA的引物,对酶切后的产物进行滚环扩增(RCA)和PCR扩增;并筛选crRNA,建立基于CRISPR/Cas13a技术的HBV cccDNA检测新方法。结果利用α-1-抗胰蛋白酶(A1AT)和HBV表面抗原(HBsAg)引物对双重酶切后的产物进行扩增,验证产物中HBV基因组的存在;利用HBV cccDNA和HBV rcDNA引物对PSDA酶切后的产物扩增,验证了产物中只存在HBV cccDNA;利用RCA后的阳性样本作为模板梯度稀释,然后进行PCR扩增转录后使用CRISPR/Cas13a检测,计算出检测下限为10拷贝/μl。结论本研究建立了RCA-PCR-CRISPR-Cas13a的新型检测方法,可对HBV cccDNA进行高灵敏度和高特异性检测,为乙型肝炎患者抗病毒治疗评估、治疗终点的确定以及调整治疗方案提供了有效的监测手段。  相似文献   
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Objective To determine if ARHGEF10 has a haploinsufficient effect and provide evidence to evaluate the severity,if any,during prenatal consultation.Methods Zebrafish was used as a model for generating mutant.The pattern of arhgef10 expression in the early stages of zebrafish development was observed using whole-mount in situ hybridization(WISH).CRISPR/Cas9 was applied to generate a zebrafish model with a single-copy or homozygous arhgef10 deletion.Activity and light/dark tests were performed in arhgef10?/?,arhgef10+/?,and wild-type zebrafish larvae.ARHGEF10 was knocked down using small interferon RNA(siRNA)in the SH-SY5Y cell line,and cell proliferation and apoptosis were determined using the CCK-8 assay and Annexin V/PI staining,respectively.Results WISH showed that during zebrafish embryonic development arhgef10 was expressed in the midbrain and hindbrain at 36-72 h post-fertilization(hpf)and in the hemopoietic system at 36-48 hpf.The zebrafish larvae with single-copy and homozygous arhgef10 deletions had lower exercise capacity and poorer responses to environmental changes compared to wild-type zebrafish larvae.Moreover,arhgef10?/? zebrafish had more severe symptoms than arhgef10+/- zebrafish.Knockdown of ARHGEF10 in human neuroblastoma cells led to decreased cell proliferation and increased cell apoptosis.Conclusion Based on our findings,ARHGEF10 appeared to have a haploinsufficiency effect.  相似文献   
7.

Background

The response to first-line, platinum-based treatment of muscle-invasive bladder cancer has not improved in 3 decades.

Objective

To identify genes that influence cisplatin resistance in bladder cancer.

Design, setting, and participants

We performed a whole-genome CRISPR screen in a bladder cancer cell line to identify genes that mediate resistance to cisplatin.

Outcome measurements and statistical analysis

Targeted validation was performed in two bladder cancer cell lines. The top gene candidate was validated in a publicly available bladder cancer dataset.

Results and limitations

From the CRISPR screen, we identified MSH2 as the most significantly enriched gene and mismatch repair as the most significantly enriched pathway that promoted resistance to cisplatin. Bladder cancer cells with knockdown of MSH2 showed a reduction in cisplatin-mediated apoptosis. MSH2 loss did not impact the sensitivity to other chemotherapies, including the cisplatin analog oxaliplatin. Bladder tumors with low MSH2 protein levels, quantified using reverse-phase protein array, showed poorer survival when treated with cisplatin- or carboplatin-based therapy; these results require future validation using immunohistochemistry. Additionally, results are retrospective from patients with primarily high-grade tumors; thus, validation in a controlled clinical trial is needed.

Conclusions

We generated in vitro evidence that bladder cancer cell lines depleted of MSH2 are more resistant to cisplatin. We additionally found an association between low MSH2 in bladder tumors and poorer patient survival when treated with platinum-based chemotherapy. If successfully validated prospectively, MSH2 protein level could assist in the selection of patients for chemotherapy.

Patient summary

We report the first evidence that MSH2 protein level may contribute to chemotherapy resistance observed in muscle-invasive bladder cancer. MSH2 has potential as a biomarker predictive of response to platinum-based therapy.  相似文献   
8.
《Molecular therapy》2020,28(1):19-28
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9.
目的了解贵州省鼠伤寒沙门菌单相变异株规律的成簇间隔短回文重复序列(CRISPR)的基因型及遗传多样性,为贵州省沙门菌病的预防控制提供依据。方法对分离自2013—2018年贵州省7个市(州)的71株疑似鼠伤寒沙门菌单相变异株进行系统生化鉴定及血清分型,结合双重PCR法确定疑似菌株为鼠伤寒沙门菌单相变异株。提取鼠伤寒沙门菌单相变异株的DNA作为模板,进行CRISPR1和CRISPR2的PCR扩增,将阳性扩增产物进一步测序,获得菌株的CRISPR1和CRISPR2间隔序列,根据间隔序列的组成,确定CRISPR基因型,并使用Bionumerics软件对菌株进行遗传多样性分析。结果71株疑似鼠伤寒沙门菌单相变异菌株经系统生化鉴定、血清分型及双重PCR法鉴定为鼠伤寒沙门菌单相变异株,经CRISPR1和CRISPR2两个位点的PCR扩增和产物测序,71株菌共检测到163个间隔序列,其中CRISPR1有102个,CRISPR2有61个。联合CRISPR1和CRISPR2两个位点的间隔序列进行分析,发现71株菌被分为33个CRISPR基因型(TSTs),其中TST11和TST1为贵州省的优势基因型,分别占总菌株数的25.35%和12.68%。71株菌经Bionumerics软件聚类分析后被分为A、B、C、D 4个簇,A簇包含的菌株最多,B簇包含的基因型最多,不同来源的3株参考株独立成簇,D簇包含7个TSTs基因型。结论贵州省鼠伤寒沙门菌单相变异株具有优势的CRISPR基因型和遗传多样性的特点,可能有其他的感染来源。  相似文献   
10.
《Cancer cell》2020,37(1):71-84.e7
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