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31.
Preeti G. Lal Roopa S. Ghirnikar Lawrence F. Eng 《Journal of molecular neuroscience : MN》1996,29(1):93-104
Glial fibrillary acidic protein (GFAP) is the principal intermediate filament protein found in mature astrocytes. Although
the exact function of GFAP is poorly understood, it is presumed to stabilize the astrocyte’s cytoskeleton and help in maintaining
cell shape. Previous studies from our laboratory have shown that when astrocytes were cocultured with primary Schwann cells
(pSCs), astrocytes became hypertrophied and fibrous with intensely positive GFAP staining and segregated Schwann cells (SCs)
into pockets. In order to understand the functional role of GFAP in this already established astrocyte-SC coculture model,
we generated GFAP-negative cell lines from a GFAP-positive astrocytoma cell line and cocultured both the cell lines with pSCs.
Our studies demonstrate that the GFAP-positive cell line put out processes toward the SCs, whereas the GFAP-negative cells
did not form processes and the majority of the cells remained round. The most significant and interesting finding of this
study, however, is the formation of elaborate processes by SCs when grown in coculture with the astrocytoma cells, unlike
SCs cultured alone, which showed their typical bipolar spindle-shaped morphology. The extent of processes did not seem to
be dependent on GFAP, since SCs cultured with both the cell lines formed similar processes. This coculture model may be useful
in elucidating the factor(s) responsible for the formation of processes by SCs and can be further help in our understanding
of the mechanism of morphological transformation of SCs. 相似文献
32.
商陆多糖Ⅰ(PEP Ⅰ)10,20mg·kg~1 ip能显著抑制S180生长,最大抑瘤率可达51.7%,Cy 10mg·kg~1 ip.抑瘤率为55.1%,两者合用抑瘤率为68.6%,PEP-Ⅰ治疗能显著促进脾脏增生,但不影响体重,PEP-Ⅰ治疗后,小鼠的T淋巴细胞转化及白介素2(IL-2)产生能力显著高于对照组,计数外周白细胞,骨髓有核细胞并用[~3H]TdR参入法观察rmGM-CSF刺激骨髓细胞增殖.结果表明PEP-Ⅰ与Cy合用治疗至d 11的外周白细胞数,骨髓有核细胞数和骨髓细胞的增殖能力显著高于单用Cy组,以上实验结果说明EPP-Ⅰ可能通过增强T淋巴细胞功能来抑制移植性肿瘤生长,并具有保护造血功能的作用。 相似文献
33.
目的:观察过量运动对健康大鼠肾脏结构与功能的影响并探讨其可能机制。方法:将30只健康Sprauge-Dawley(SD)大鼠按照随机数字表随机分为安静对照组和过量运动组,每组15只。安静对照组在鼠笼内安静饲养,过量运动组进行16周高强度跑台力竭运动。实验后,测定24 h尿蛋白(UP)、血尿素氮(BUN)和血清肌酐(SCr)含量评价肾功能;分别行HE、Masson染色观察肾脏组织病理学改变,同时获取肾小球和肾小管损伤评分以及纤维化指数(FI);免疫印迹测定转化生长因子-β1(TGF-β1)、基质金属蛋白酶-9(MMP-9)、α-平滑肌肌动蛋白(α-SMA)和E-钙黏蛋白(E-CA)蛋白表达量。结果:与安静对照组比较,过量运动组肾脏结构异常,肾小球损伤评分、肾小管损伤评分、FI、UP、BUN和SCr增加(t分别为-6.895、-7.365、-9.234、-4.964、-7.753、-16.444,均P<0.05),MMP-9蛋白表达下调(t=5.077,P<0.05),而TGF-β1、α-SMA和E-CA蛋白表达差异无统计学意义(t分别为-1.801、-1.129、1.585,... 相似文献
34.
目的 探讨急性脑梗死患者血清补体C1q/肿瘤坏死因子相关蛋白3(CTRP-3)、D-二聚体、可溶性髓样细胞触发受体2(sTREM2)水平及相关临床特征与溶栓后出血性转化(HT)的关系。方法 回顾性分析2018年9月—2022年9月在青海省人民医院接受溶栓治疗的120例急性脑梗死患者的临床资料,根据患者溶栓后是否发生HT分为HT组(30例)、非HT组(90例)。比较两组患者的临床资料及血清CTRP-3、D-二聚体、sTREM2水平。采用多因素逐步Logistic回归分析急性脑梗死患者溶栓后发生HT的危险因素;绘制受试者工作特征(ROC)曲线,分析急性脑梗死患者溶栓后HT预测模型预测HT发生的价值。结果 HT组心房颤动(以下简称房颤)、大面积脑梗死、入院NIHSS评分≥ 15分占比高于非HT组(P <0.05),血清CTRP-3水平低于非HT组(P <0.05),D-二聚体、sTREM2水平高于非HT组(P <0.05)。血清CTRP-3、D-二聚体、sTREM2水平预测急性脑梗死患者溶栓后发生HT的敏感性分别为66.7%(95% CI:0.598,0.756)、70.0%(95% CI:0.607,0.812)、80.0%(95% CI:0.714,0.889),特异性分别为73.3%(95% CI:0.636,0.821)、86.7%(95% CI:0.778,0.923)、86.7%(95% CI:0.747,0.942)。多因素Logistic逐步回归分析结果显示,房颤[O^R=1.237(95% CI:1.103,1.387)]、大面积脑梗死[O^R=2.338(95% CI:1.292,4.231)]、入院NIHSS评分≥ 15分[O^R=2.087(95% CI:1.231,3.538)]、CTRP-3 ≤ 269.265 μg/L [O^R=3.006(95% CI:1.508,5.992)]、D-二聚体≥ 2.625 mg/L [O^R=2.649(95% CI:1.374,5.107)]、sTREM2 ≥ 314.675 ng/L [O^R=2.328(95% CI:1.411,3.841)]是急性脑梗死患者溶栓后发生HT的危险因素(P <0.05)。根据多因素Logistic逐步回归分析结果建立急性脑梗死患者溶栓后HT预测模型,Logit(P) = -33.887 + 0.213×房颤+ 0.849×大面积脑梗死+0.736×入院NIHSS评分+ 1.101×CTRP-3 + 0.974×D-二聚体+ 0.845×sTREM2;ROC曲线分析结果表明,预测模型预测HT发生的敏感性为93.3%(95% CI:0.841,0.991),特异性为87.8%(95% CI:0.808,0.976)。结论 血清CTRP-3、D-二聚体、sTREM2水平与急性脑梗死患者溶栓后HT有关,预测价值较高,且急性脑梗死患者溶栓后HT预测模型预测HT优于各项指标单独预测。 相似文献
35.
目的: 通过对小鼠派氏集合淋巴结(PPs)、肠系膜淋巴结(MLNs)和腹股沟淋巴结(ILNs)的比较性研究,以分析PPs T细胞活化和调节性T细胞的功能特点。 方法: 无菌分离小鼠PPs、MLNs和ILNs,分别制备单个淋巴细胞悬液,运用流式细胞术结合荧光抗体染色技术来检测CD3+T细胞、CD3+CD4+辅助性T细胞和CD4+CD25+调节性T细胞的比例;用多克隆刺激剂刀豆蛋白A(Con A)、佛波醇酯(PDB)和离子霉素(Ion) 刺激活化淋巴细胞,随后运用流式细胞术结合双色荧光抗体染色技术来检测T细胞早期活化标志CD69的表达水平。 结果: PPs内CD3+T细胞所占比例明显低于MLNs和ILNs,然而CD4+CD25+调节性T细胞的比例明显高于MLNs和ILNs;在没有加入刺激剂的培养条件下,PPs来源的T细胞CD69的表达水平明显高于MLNs和ILNs来源的T细胞,MLNs来源的T细胞CD69的表达水平明显高于ILNs来源的T细胞;而在加入Con A或者单纯PDB的培养条件下,PPs来源的T细胞却表现出低反应性;在加入PDB+Ion的培养条件下,3者来源的T细胞CD69的表达水平没有明显差别。 结论: PPs内CD3+T细胞所占比例较低,CD4+CD25+调节性T细胞的比例较高,这可能是PPs整体T细胞低反应性的原因之一;PPs来源T细胞的高基础活化率可能与其不断接触小肠来源的食物和共生菌抗原有关;PPs来源T细胞选择性地对某些刺激剂表现出低反应性,提示这群细胞处于某种程度的无能状态。上述特征的生物学意义在于避免因为不断接受小肠来源的食物和共生菌抗原的刺激而发生病理性炎症的同时还保留对病原微生物抗原的应答。 相似文献
36.
Nagata H Numata T Konno A Mikata I Kurasawa K Hara S Nishimura M Yamamoto K Shimizu N 《Pathology international》2001,51(10):778-785
Chronic active Epstein-Barr virus infection (CAEBV) is a syndrome that takes diverse clinical courses and is often associated with lymphoproliferative disorders of T/natural killer (NK)-cell lineage. We describe a patient with CAEBV associated with persistent pharyngeal ulcer, and with subsequent nasal T/NK-cell lymphoma in her neck lymph nodes and nasopharynx. Immunophenotyping of lymphoid cells showed that the lineage of Epstein-Barr virus (EBV)-positive cells in the patient was of NK-cell origin. By means of high-dose recombinant interleukin-2, we established an EBV-positive cell line of NK-cell lineage from her peripheral blood. Southern blot analysis for the number of terminal repeat sequences of EBV detected three NK-cell clones in the patient's lymph node. One of these clones was identical to the established cell line but was not observed in the pharyngeal ulcer, while the other two clones were present in the pharyngeal ulcer. These results suggest that the patient had expansion of the three NK-cell clones, one of which had proliferative capacity in vitro and was involved in the formation of the lymphoma. Moreover, the results suggest that the proliferative capacity of EBV-positive cells can be variable even in a single patient, and this variability may explain the clinical diversity in CAEBV. 相似文献
37.
医学图像序列压缩是远程医疗系统中的重要技术,而运动估计在视频序列压缩中起着关键作用。我们提出了一种改进的正方形-菱形搜索算法来实现医学图像序列的运动估计。这种改进的正方形-菱形算法减少了搜索点数。我们将其应用于小波域的医学图像序列的运动估计,并对数字减影血管造影图像序列(DSA)进行实验。结果表明,改进后的小波域正方形-菱形算法较其他算法精度高。 相似文献
38.
NIH 3T3细胞转化前后细胞骨架及细胞表面纤维粘连蛋白的免疫荧光观察 总被引:1,自引:0,他引:1
本实验用抗纤维粘连蛋白(FN)亲和层析纯抗体和抗管蛋白抗体及鬼笔环肽,以免疫荧光组织化学方法,对NIH3T3细胞转染人肺腺癌细胞系AGZY基因组DNA前后细胞表面FN及细胞内骨架系统进行染色观察。结果表明,细胞在发生转化后,微丝及微管均表现出明显受损,细胞骨架结构不清,呈现为弥散样荧光;细胞表面FN大量减少,仅及正常NIH3T3细胞的1/9,其分布也由细丝形成的网状,变成斑点或斑块状。这一结果进一步证实,细胞恶变是涉及到细胞骨架系统及膜表面糖蛋白变化的复杂过程,并预示这些变化可能就是导致细胞形态发生变化、细胞失去正常生长调控的原因之一。 相似文献
39.
H. Heuer Jörg Sangals 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1998,119(2):224-236
In two experiments the involvement of relative and fixed coordinate systems in visuomotor transformations was examined. The
experimental task required the successive performance of two movements in each trial, which had to “correspond” to different
visual stimuli. One kind of visual display indicated target positions by way of different horizontal positions of a vertical
line on a monitor (position mode), while the other indicated movement amplitudes by way of different lengths of a horizontal
line (amplitude mode). Formal analysis of variances and covariances of successive individual movements led to the conclusion
that in the position mode visuomotor transformations were based on a mixture of relative and fixed coordinate systems, while
in the amplitude mode only a relative coordinate system was involved. Thus, visuomotor transformations can be characterized
as mixtures of different coordinate systems, and their respective weights in the mixtures are task-dependent.
Received: 18 March 1997 / Accepted: 25 September 1997 相似文献
40.
Summary The glyceraldehyde-3-phosphate dehydrogenase (gpd) gene of Podospora anserina has been isolated from a genomic library by heterologous hybridization with the corresponding gene of Curvularia lunata. The coding region consists of 1014 nucleotides and is interrupted by a single intron. The amino-acid sequence encoded by the gpd gene shows a high degree of sequence identity with the corresponding gene products of various fungi. Multiple alignments of all fungal GPD sequences so far available resulted in the construction of a phylogenetic tree. The evolutionary relationships of the various fungi belonging to different taxa will be discussed on the basis of these data. Sequence analysis of 1.9 kbp of the 5 non-coding region revealed the presence of typical fungal promoter elements. Utilizing different parts of the 5 regulatory sequence of the Podospora gpd gene, expression vectors containing a dominant selectable marker gene (hygromycin B phosphotransferase) have been constructed for the transformation of P. anserina protoplasts. The use of these homologous gpd regulatory sequences resulted in a significant increase in transformation efficiencies compared to those obtained with vectors in which the selectable marker gene is under the control of the corresponding heterologous promoter of Aspergillus nidulans. 相似文献