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1.
Preterm birth (PTB) is commonest cause of perinatal mortality and morbidity in multiple pregnancies with significant long-term sequelae. The etiology of PTB is multifactorial. Universal screening by a transvaginal assessment of cervical length (CL) at midtrimester scan is recommended for all women with twin pregnancies. Women with CL ≤ 25 mm should be offered prophylactic vaginal progesterone to mitigate the risk of PTB. Other modalities like home uterine activity monitoring, digital cervical examination, fetal fibronectin (FFN) assessment, and screening for infections are not recommended. History-indicated cerclage is not advised in unselected twin pregnancies, but a combination of physical examination-indicated cerclage, tocolytics, and antibiotics may be considered in twin pregnancies with a dilated cervix prior to 24 weeks’ gestation. Routine use of cervical pessary is not advised and should be limited to research settings. Neither transvaginal CL nor FFN assessment is supported by evidence to predict the risk of PTB in symptomatic women with multiple pregnancies. More research is warranted to develop and validate algorithms to predict PTB to provide individualized care to these high-risk pregnancies.  相似文献   
2.
The detection of low doses of recombinant growth hormone is a challenge in antidoping testing. Future testing may lead toward the longitudinal monitoring of IGF‐I and P‐III‐NP in an endocrine module. Additional biomarkers, for example vitamin D binding protein, alpha‐HS‐glycoprotein, fibronectin 1, and decorin have been identified in different omics studies. This was a longitudinal study of the usefulness of these putative biomarkers in relation to 2 weeks administration of low doses of recombinant growth hormone in healthy male volunteers. Moreover, the hematological parameters included in the athlete biological passport were studied as well as the serum concentration of testosterone and dihydrotestosterone. Fibronectin 1 increased by 20% during the treatment period (P ? 0.05), confirming the previous finding. Alpha‐HS‐glycoprotein decreased by 25% up to 3 weeks after treatment (P ? 0.05), contradicting previous results. The addition of fibronectin 1 increased the likelihood of detecting recombinant growth hormone intake based on individual calculated thresholds in some of the participants compared with the GH2000, IGF‐I, and P‐III‐NP. The multiplication of fibronectin 1 concentration by IGF‐I resulted in the most profound (up to 4‐fold) changes. A minor 15% increase (P = 0.003) in the reticulocyte percentage was observed, but the changes did not lead to any atypical profile based on individual passport thresholds. Vitamin D binding protein, decorin, testosterone, and dihydrotestosterone were not affected by growth hormone. Dihydrotestosterone sulfate was negatively correlated with IGF‐I at baseline (R = –0.50, P = 0.003) and post dose (R = –0.59, P = 0.01). In conclusion, fibronectin 1 was verified as a promising future biomarker for detecting low doses of recombinant growth hormone.  相似文献   
3.

目的:探讨不同浓度白细胞介素-6(IL-6)刺激下体外培养的牛眼小梁细胞中纤维连接蛋白的表达变化。

方法:采用组织块培养法取新鲜牛眼的小梁网组织,提取并培养第3代牛眼小梁细胞,采用细胞形态学对细胞进行鉴定。经终浓度为0、0.1、0.5、1ng/mL的IL-6药物刺激24h后,采用荧光定量PCR和蛋白质免疫印迹法检测各浓度IL-6刺激下牛眼小梁细胞中FN mRNA和蛋白的表达。

结果:培养出的牛眼小梁细胞符合第3代牛眼小梁细胞形态特征。实时荧光定量PCR和蛋白质免疫印迹法显示,不同浓度IL-6刺激下的牛眼小梁细胞所产生的FN mRNA量分别为1.000±0.000、0.213±0.004、0.056±0.001、0.019±0.002,FN蛋白表达量分别为1.167±0.012、0.662±0.009、0.238±0.011、0.061±0.011,均呈下调趋势(rs=-0.713、-0.901,均P<0.05),4组间FN mRNA和蛋白表达均有差异(P<0.05)。

结论:体外培养的牛眼小梁细胞在外源性IL-6刺激下影响FN mRNA和蛋白的表达,且IL-6浓度与蛋白表达呈负相关性,推测IL-6可能通过影响FN基因与蛋白的表达,进而改变小梁网组织结构。  相似文献   

4.
目的:探讨血清S100钙结合蛋白(S100b)、TIMP金属钛酶抑制剂(TIMP1)、纤连蛋白1(FN1)联合检验在子痫前期诊断中的价值。方法:选取2020年1月~2020年12月间某院收治的妊娠期子痫前期患者80例为试验组,选取同期健康孕中期妊娠妇女80例为对照组,检测两组血清S100b、TIMP1、FN1水平。采用受试者工作特征曲线(ROC)的曲线下面积(AUC)分析S100b、TIMP1、FN1在子痫前期诊断中的价值。结果:试验组血清S100b、TIMP1、FN1水平均显著高于对照组,差异均具有统计学意义(P<0.05)。S100b的AUC为(0.86±0.08),以93.27ng/L为阳性临界值,其灵敏度为89%、特异度为88%;TIMP1的AUC为(0.88±0.07),以80.95ng/L为阳性临界值,其灵敏度为91%、特异度为89%;FN1的AUC为(0.82±0.05),以35.93ng/L为临界值,其灵敏度为96%、特异度为63%。血清S100b、TIMP1、FN1联合检测在子痫前期诊断中,其灵敏度为93.75%(75/80)、特异度为88.75%(71/80)、准确度为91.25%(146/160)。结论:血清S100b、TIMP1、FN1联合检验在子痫前期诊断中具有良好效能。  相似文献   
5.
目的探讨秦皮甲素对高糖诱导的大鼠肾小球系膜细胞(HBZY-1)增殖及纤维连接蛋白(FN)表达的影响。方法采用CCK-8法检测不同浓度秦皮甲素(10、30、90μmol·L-1)对正常培养条件(含糖5.6 mmol·L-1)和高糖培养条件(含糖25 mmol·L-1)下的HBZY-1细胞增殖的影响;以PI3K抑制剂Wortmannin(1μmol·L-1)干预为对照,采用Western Blot法检测秦皮甲素对高糖培养条件下HBZY-1细胞FN蛋白表达及PI3K/Akt蛋白磷酸化水平变化的影响。结果在正常培养条件下,与正常组比较,秦皮甲素给药组(10、30、90μmol·L-1)的HBZY-1细胞增殖均无明显变化(P>0.05)。在高糖培养条件下,与正常组比较,高糖组的细胞活力明显增加(P<0.05),HBZY-1细胞FN蛋白表达和PI3K/Akt磷酸化水平明显升高(P<0.05);与高糖组比较,90μmol·L-1秦皮甲素给药组的HBZY-1细胞活力明显降低(P<0.05),FN蛋白表达和PI3K/Akt磷酸化水平亦显著下调(P<0.05)。结论秦皮甲素能够抑制高糖诱导的HBZY-1细胞增殖,下调FN蛋白表达,可能与其抑制PI3K/Akt信号通路激活密切相关。  相似文献   
6.
Accumulation of extracellular matrix derived from glomerular mesangial cells is an early feature of diabetic nephropathy. Ca2+ signals mediated by store–operated Ca2+ channels regulate protein production in a variety of cell types. The aim of this study was to determine the effect of store–operated Ca2+ channels in mesangial cells on extracellular matrix protein expression. In cultured human mesangial cells, activation of store–operated Ca2+ channels by thapsigargin significantly decreased fibronectin protein expression and collagen IV mRNA expression in a dose-dependent manner. Conversely, inhibition of the channels by 2-aminoethyl diphenylborinate significantly increased the expression of fibronectin and collagen IV. Similarly, overexpression of stromal interacting molecule 1 reduced, but knockdown of calcium release–activated calcium channel protein 1 (Orai1) increased fibronectin protein expression. Furthermore, 2-aminoethyl diphenylborinate significantly augmented angiotensin II–induced fibronectin protein expression, whereas thapsigargin abrogated high glucose– and TGF-β1–stimulated matrix protein expression. In vivo knockdown of Orai1 in mesangial cells of mice using a targeted nanoparticle siRNA delivery system resulted in increased expression of glomerular fibronectin and collagen IV, and mice showed significant mesangial expansion compared with controls. Similarly, in vivo knockdown of stromal interacting molecule 1 in mesangial cells by recombinant adeno–associated virus–encoded shRNA markedly increased collagen IV protein expression in renal cortex and caused mesangial expansion in rats. These results suggest that store–operated Ca2+ channels in mesangial cells negatively regulate extracellular matrix protein expression in the kidney, which may serve as an endogenous renoprotective mechanism in diabetes.  相似文献   
7.
For more than a century there has been debate concerning the mechanism of accommodation—whether the lens capsule or lens material itself determines the functional relationship between ciliary muscle contractility and lens deformation during refractive adaptation. This morphological study in monkey eyes investigates the composition and distribution of several connective tissue components in the accommodative apparatus relaying muscle force to lens organization. Elastin distributes on the marginal surface of the ciliary process. A zonule is composed of fibrillin produced by epithelial cells of the process. In the progress of extension over the posterior chamber, fibrils unite into strands and possess longitudinal plasticity. By induction of the elastin network, strands extend in a concentric direction covering the equatorial region of the capsule. Upon tethering to the lens, the strand ramifies into fibrils, penetrating deeply close to the epithelial layer of the lens and binding with the collagen of the intercellular spaces. Tight linkage of the zonule with the capsule transmits precise contractility. Inside the lens, the cortical layer's elastic connective tissue network forms widely spaced lamellae of crystalline fibers. In contrast, the central nuclear lamellae are tightly opposed. The accumulation of lamellae is greater in the anterior cortex than in the posterior, yielding a more variable anterior chamber depth in the visual axis. The plasticity of the zonule and connective tissue distribution inside the lens produces an adjustable configuration. Thus, tight linkage between the dynamism of the capsule with interaction of the lenticular flexibility provides a novel understanding of accommodation. Anat Rec, 298:630–636, 2015. © 2014 The Authors The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology Published by Wiley Periodicals, Inc.  相似文献   
8.
目的本研究探讨整合素αvβ3抑制剂(Cyclo-RGDfK)对纤连蛋白(fibronectin,FN)诱导人乳腺上皮细胞MCF-10A上皮间质转化的影响。方法体外传代培养MCF-10A细胞,采用FN诱导建立上皮间质转化(EMT)模型。Western blot实验检测αv integrin、β3 integrin、上皮标志物E-cadherin和间充质标志物N-cadherin、Vimentin的蛋白表达;划痕修复实验和Transwell小室实验检测细胞的迁移和侵袭能力。结果 Western blot结果显示FN作用48 h后可明显增强αv integrin、β3 integrin、N-cadherin、Vimentin的蛋白表达,下调E-cadherin蛋白表达,在给予Cyclo-RGDfK作用后,FN诱导的N-cadherin和Vimentin表达上调和E-cadherin表达下调被明显逆转;划痕修复实验和Transwell小室实验结果表明,FN能显著增强MCF-10A细胞迁移和侵袭能力,Cyclo-RGDfK能显著抑制FN的诱导作用。结论 Cyclo-RGDfK能抑制FN诱导乳腺上皮细胞MCF-10A的EMT过程,降低细胞的侵袭和迁移能力,其可能是治疗乳腺癌转移的潜在药物。  相似文献   
9.
目的探讨最适合人毛囊干细胞体外培养及扩增的纤维连接蛋白(FN)铺层浓度。方法将新鲜FN稀释至所需要的4个浓度:5μg/mL、200ng/mL、10ng/mL、0ng/mL。使用酶消化法分离人毛囊细胞,将原代人毛囊干细胞在不同浓度铺层的培养皿中的细胞增值能力和克隆形成率进行统计分析,获得最适合人毛囊干细胞体外培养的铺层浓度。结果接种同一样本相同数量细胞,做克隆效率测定,在原代培养第8天做Giemsa染色,结果显示0ng/cm2铺层的培养皿中克隆团小,数量少;10ng/cm2铺层的克隆团大,数量多;200ng/cm2和5μg/cm2铺层的克隆团较小,数量不多。取10个样本,分别对4个FN铺层浓度的克隆效率进行统计分析,10ng/cm2铺层的克隆效率最高。在不同FN铺层浓度条件下,细胞扩增能力也不同,10ng/cm2铺层浓度细胞扩增能力最强,与其他3个浓度比较,差异均有统计学意义(P0.05),200ng/cm2与其余3个浓度差异均无统计学意义(P0.05)。结论10ng/cm2的FN铺层浓度效果最佳。  相似文献   
10.
Scar formation after injury of the brain or spinal cord is a common event. While glial scar formation by astrocytes has been extensively studied, much less is known about the fibrotic scar, in particular after stroke. Platelet-derived growth factor receptor ß-expressing (PDGFRß+) pericytes have been suggested as a source of the fibrotic scar depositing fibrous extracellular matrix (ECM) proteins after detaching from the vessel wall. However, to what extent these parenchymal PDGFRß+ cells contribute to the fibrotic scar and whether targeting these cells affects fibrotic scar formation in stroke is still unclear. Here, we utilize male transgenic mice that after a permanent middle cerebral artery occlusion stroke model have a shift from a parenchymal to a perivascular location of PDGFRß+ cells due to the loss of regulator of G-protein signaling 5 in pericytes. We find that only a small fraction of parenchymal PDGFRß+ cells co-label with type I collagen and fibronectin. Consequently, a reduction in parenchymal PDGFRß+ cells by ca. 50% did not affect the overall type I collagen or fibronectin deposition after stroke. The redistribution of PDGFRß+ cells to a perivascular location, however, resulted in a reduced thickening of the vascular basement membrane and changed the temporal dynamics of glial scar maturation after stroke. We demonstrate that parenchymal PDGFRß+ cells are not the main contributor to the fibrotic ECM, and therefore targeting these cells might not impact on fibrotic scar formation after stroke.  相似文献   
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