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941.
Linkage analysis of candidate regions for coeliac disease genes   总被引:5,自引:0,他引:5  
A strong HLA association is seen in coeliac disease [specifically to the DQ(alpha1*0501,beta1*0201 heterodimer], but this cannot entirely account for the increased risk seen in relatives of affected cases. One or more genes at HLA-unlinked loci also predispose to coeliac disease and are probably stronger determinants of disease susceptibility than HLA. A recent study has proposed a number of candidate regions on chromosomes 6p23 (distinct from HLA), 6p12, 3q27, 5q33.3, 7q31.3, 11p11, 15q26, 19p13.3, 19q13.1, 19q13.4 and 22cen for the location of a non-HLA linked susceptibility gene. We have examined these regions in 28 coeliac disease families by linkage analysis. There was excess sharing of chromosome 6p markers, but no support for a predisposition locus telomeric to HLA. No significant evidence in favour of linkage to coeliac disease was obtained for chromosomes 3q27, 5q33.3, 7q31.3, 11p11, 19p13.3, 19q13.1, 19q13.4 or 22cen. There was, however, excess sharing close to D15S642. The maximum non-parametric linkage score was 1.99 (P = 0.03). Although the evidence for linkage of coeliac disease to chromosome 15q26 is not strong, the well established association between coeliac disease and insulin dependent diabetes mellitus, together with the mapping of an IDDM susceptibility locus (IDDM3) to chromosome 15q26, provide indirect support for this as a candidate locus conferring susceptibility to coeliac disease in some families.   相似文献   
942.
分子生物学,特别是重组DNA技术的出现,使我们对人类遗传病有了更深入的认识。这一领域的进展是极其迅速的,其中最明显的例子就是对X-连锁遗传病Duchenne肌营养不良症(DMD)的研究。用基因组探针检测携带者和产前诊断已经证明XJ1.1和pERT基因组探针,及侧翼探针如C7、754和99.6对于发现DMD携带者和产前诊断具有不可估量的价值。受累患儿血清CK水平是正常儿童的100~200倍,但用于检测携带者却不可靠,因为有1/3的肯定携带者的CK水平在正常范围。而应用RFLP进行的连锁分析具有很高的可信  相似文献   
943.
Vitamin D is an important factor in bone metabolism. Animal studies have shown a positive effect of vitamin D3 supplementation on fracture healing, but evidence from clinical trials is inconclusive. A randomized controlled trial was performed to assess the effects of vitamin D3 supplementation on fracture healing using HR-pQCT–based outcome parameters. Thirty-two postmenopausal women with a conservatively treated distal radius fracture were included within 2 weeks postfracture and randomized to a low-dose (N = 10) and a high-dose (N = 11) vitamin D intervention group receiving a 6-week bolus dose, equivalent to 700 and 1800 IU vitamin D3 supplementation per day, respectively, in addition to a control group (N = 11) receiving no supplementation. After the baseline visit 1–2 weeks postfracture, follow-up visits were scheduled at 3–4, 6–8, and 12 weeks postfracture. At each visit, HR-pQCT scans of the fractured radius were performed. Cortical and trabecular bone density and microarchitectural parameters and microfinite element analysis–derived torsion, compression, and bending stiffness were assessed. Additionally, serum markers of bone resorption (CTX) and bone formation (PINP) were measured. Baseline serum levels of 25OHD3 were <50 nmol/L in 33% of all participants and <75 nmol/L in 70%. Compared with the control group, high-dose vitamin D3 supplementation resulted in a decreased trabecular number (regression coefficient β: −0.22; p < 0.01) and lower compression stiffness (B: −3.63; p < 0.05, together with an increase in the bone resorption marker CTX (B: 0.062; p < 0.05). No statistically significant differences were observed between the control and low-dose intervention group. In conclusion, the bolus equivalent of 700 U/day vitamin D3 supplementation in a Western postmenopausal population does not improve distal radius fracture healing and an equivalent dose of 1800 IU/day may be detrimental in restoring bone stiffness during the first 12 weeks of fracture healing. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).  相似文献   
944.
目的:建立高效液相色谱测定红药胶囊中6种成分三七皂苷R1、人参皂苷Rg1、人参皂苷Rb1、欧前胡素、异欧前胡素和羟基红花黄色素A的含量。方法:采用Waster XTerra C18色谱柱(250×4.6 mm,5μm),流动相为乙腈-0.1%磷酸水溶液,流速1.0 m L/min,检测波长为203 nm、300 nm和403 nm,柱温30℃。结果:三七皂苷R1、人参皂苷Rg1、人参皂苷Rb1、欧前胡素、异欧前胡素和羟基红花黄色素A的进样量分别在0.310~5.425μg(0.9997),0.404~7.070μg(0.9998),0.420~7.350μg(0.9997),0.008~0.140μg(0.9996),0.002~0.034μg(0.9996),0.012~0.217μg(0.9997)范围内与峰面积线性关系良好,平均加样回收率(n=6)分别为98.23%、99.15%、100.32%、99.91%,98.67%,99.27%。结论:含量测定方法可作为红药胶囊的质量控制的有效方法。  相似文献   
945.
前列腺癌中突变型p53蛋白的表达及意义   总被引:2,自引:2,他引:0  
殷金安  刘凡  刘荣福 《医学争鸣》1999,20(8):706-706
0 引言 p53蛋白是一个细胞周期相关蛋白,分为野生型(Wtp53)及突变型(Mtp53)两种. 虽然Mtp53蛋白已经丧失抑制细胞增殖的能力,但可能参与调节某些与细胞分化和增殖有关的基因表达. 我们采用组织抗原微波修复技术和免疫组织化学SABC法对前列腺癌(PC)标本中Mtp53蛋白进行检测,探讨PC的病因学、病理学分级、临床分期及其与预后的关系.  相似文献   
946.
Tissue engineering of autologous aorta using a new biodegradable polymer   总被引:27,自引:0,他引:27  
Background. Ovine pulmonary valve leaflets and pulmonary arteries have been tissue-engineered (TE) from autologous cells and biodegradable polyglycolic acid (PGA)-polyglactin copolymers. Use of this cell-polymer construct in the systemic circulation resulted in aneurysm formation. This study evaluates a TE vascular graft in the systemic circulation which is based on a new copolymer of PGA and polyhydroxyalkanoate (PHA).

Methods. Ovine carotid arteries were harvested, expanded in vitro, and seeded onto 7-mm diameter PHA-PGA tubular scaffolds. The autologous cell-polymer vascular constructs were used to replace 3–4 cm abdominal aortic segments in lambs (group TE, n = 7). In a control group (n = 4), aortic segments were replaced with acellular polymer tubes. Vascular patency was evaluated with echography. All control animals were sacrificed when the grafts became occluded. Animals in TE group were sacrificed at 10 days (n = 1), 3 (n = 3), and 5 months (n = 3). Explanted TE conduits were evaluated for collagen content, deoxyribonucleic acid (DNA) content, structural and ultrastructural examination, mechanical strength, and matrix metalloproteinase (MMP) activity.

Results. The 4 control conduits became occluded at 1, 2, 55, and 101 days. All TE grafts remained patent, and no aneurysms developed by the time of sacrifice. There was one mild stenosis at the anastomotic site after 5 months postoperatively. The percent collagen and DNA contents approached the native aorta over time (% collagen = 25.7% ± 3.4 [3 months] vs 99.6% ± 11.7 [5 months], p < 0.05; and % DNA = 30.8% ± 6.0 [3 months] vs 150.5% ± 16.9 [5 months], p < 0.05). Histology demonstrated elastic fibers in the medial layer and endothelial specific von Willebrand factor on the luminal surface. The mechanical strain-stress curve of the TE aorta approached that of the native vessel. A 66 kDa MMP-2 was found in the TE and native aorta but not in control group.

Conclusions. Autologous aortic grafts with biological characteristics resembling the native aorta can be created using TE approach. This may allow the development of “live” vascular grafts.  相似文献   

947.
In the small intestinal mucosa, four principal epithelial cell lineages are found - the Paneth, goblet, enterocytic, and endocrine cell lineages. These cell lineages are terminally differentiated, non-proliferative, and derive from multipotent stem cells near the bases of the crypts of Lieberkühn. Intestinal metaplasia of the stomach is considered to be a premalignant condition. Since proliferative populations in this condition are not well studied, this feature was examined using double-labelling immunohistochemical and histochemical methods; 20 paraffin blocks of small intestinal mucosa and 24 paraffin blocks of intestinal metaplasia of the human stomach were studied. Double-staining was carried out with MIB-1 as a proliferation marker, with Alcian blue for goblet cells, anti-chromogranin A for endocrine cells, and p-dimethylaminobenzaldehyde-nitrite for Paneth cells. Double-labelling showed that numerous Paneth cells and goblet cells in intestinal metaplasia were in the cell cycle, but endocrine cells appeared non-proliferative. Double-labelled Paneth or endocrine cells were not seen in the control small intestinal mucosa but scanty double-labelled goblet cells were observed in normal intestinal mucosa. In intestinal metaplasia of the stomach, there is evidence of cell-cycle deregulation in the goblet and Paneth cell lineages. These observations have considerable implications for the biology and histogenesis of Paneth cells, goblet cells, and endocrine cells, and the nature of intestinal metaplasia in the gastric mucosa.  相似文献   
948.
The present study is the first prospective randomized controlled trial of the effect of pentoxifylline on future fertility in infertile women with asymptomatic minimal or mild endometriosis. After completion of a basic infertility workup and laparoscopy, patients were entered into the study and randomly allocated to receive either a 12 month course of oral pentoxifylline (800 mg/day) (n = 30) or an oral placebo (n = 30). Those patients with other infertility factors were included in the study only if the factors were correctable and ultimately determined to be non-contributory. Life-table analysis was used to compare pregnancy rates between the two groups over a 12 month period that started immediately after laparoscopy. The 12 month actuarial overall pregnancy rates were 31 and 18.5% in the pentoxifylline and placebo groups respectively. However, this difference was not statistically significant by the chi(2)-test. Similarly, the Cox regression method showed no differences between the hazard of pregnancy in the two groups studied (odds ratio, 0.56; 95% confidence interval, 0.18-1.67). Therefore, there is no evidence from this study that immunomodulation with pentoxifylline aids fertility in those women with minimal or mild endometriosis. Further studies including more infertile patients with endometriosis are desirable in order to confirm our results.   相似文献   
949.
HECD-1 monoclonal antibody has been used to localize E-cadherin, a calcium-dependent cell–cell adhesion molecule, in microwave-treated, paraffin-embedded sections from 53 cases of cervical intraepithelial neoplasia (CIN) (11 CIN I, 22 CIN II, and 20 CIN III), 16 invasive cervical squamous cell carcinomas, and seven metastases. In normal cervix, E-cadherin was expressed on the cell membrane of basal and parabasal cells. Cytoplasmic staining was present in occasional basal cells only. In CIN, the presence and localization of cytoplasmic E-cadherin were found to be significantly correlated with the grade of the CIN lesion. In squamous cell carcinomas, reduced membranous and increased cytoplasmic staining was seen with worsening differentiation. Loss of membranous E-cadherin expression was also detected in 4/7 metastatic deposits. E-cadherin expression (120 kD form on Western blotting) was seen in human cervical carcinoma cell lines (HT3, ME180, C41, Caski) that maintained the ability to aggregate in a homotypic adhesion assay and showed a typical epithelial morphology. E-cadherin-negative cell lines (Hela, SiHa, C33A) did not show adhesion. HOG-1 was the only E-cadherin-negative cell line which showed a significant degree of cell–cell aggregation. These data indicate that loss of membranous E-cadherin expression may represent one of the abnormalities underlying loss of cell polarity and differentiation which characterize CIN and invasive cervical cancer.  相似文献   
950.
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