全文获取类型
收费全文 | 246639篇 |
免费 | 55827篇 |
国内免费 | 9712篇 |
专业分类
耳鼻咽喉 | 2738篇 |
儿科学 | 6469篇 |
妇产科学 | 3049篇 |
基础医学 | 39371篇 |
口腔科学 | 7973篇 |
临床医学 | 32724篇 |
内科学 | 46307篇 |
皮肤病学 | 9292篇 |
神经病学 | 21000篇 |
特种医学 | 7844篇 |
外国民族医学 | 68篇 |
外科学 | 29765篇 |
综合类 | 27762篇 |
现状与发展 | 38篇 |
一般理论 | 44篇 |
预防医学 | 16608篇 |
眼科学 | 5551篇 |
药学 | 24969篇 |
155篇 | |
中国医学 | 10712篇 |
肿瘤学 | 19739篇 |
出版年
2024年 | 719篇 |
2023年 | 2803篇 |
2022年 | 7121篇 |
2021年 | 10198篇 |
2020年 | 11259篇 |
2019年 | 15853篇 |
2018年 | 15593篇 |
2017年 | 16434篇 |
2016年 | 16660篇 |
2015年 | 18920篇 |
2014年 | 20535篇 |
2013年 | 20994篇 |
2012年 | 16992篇 |
2011年 | 17678篇 |
2010年 | 18190篇 |
2009年 | 12793篇 |
2008年 | 11398篇 |
2007年 | 10132篇 |
2006年 | 9304篇 |
2005年 | 8254篇 |
2004年 | 6606篇 |
2003年 | 6348篇 |
2002年 | 5678篇 |
2001年 | 4940篇 |
2000年 | 4289篇 |
1999年 | 3337篇 |
1998年 | 1826篇 |
1997年 | 1926篇 |
1996年 | 1378篇 |
1995年 | 1309篇 |
1994年 | 1177篇 |
1993年 | 840篇 |
1992年 | 1201篇 |
1991年 | 1065篇 |
1990年 | 933篇 |
1989年 | 866篇 |
1988年 | 772篇 |
1987年 | 658篇 |
1986年 | 618篇 |
1985年 | 507篇 |
1984年 | 439篇 |
1983年 | 354篇 |
1982年 | 305篇 |
1981年 | 260篇 |
1980年 | 221篇 |
1979年 | 250篇 |
1978年 | 226篇 |
1977年 | 244篇 |
1976年 | 219篇 |
1974年 | 185篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
991.
Genetic alterations of HOXA10 and their effect on the severity of endometriosis in a Taiwanese population 总被引:1,自引:0,他引:1
Endometriosis is one of the most common gynaecological diseases and evidence has suggested that it may be inherited as a complex genetic trait. HOXA10, a homeobox gene, is expressed in the developing uterus and participates in endometrium development and may contribute to endometriosis. In this study, the HOXA10 gene was analysed in 112 patients with endometriosis and in 54 women without endometriosis, as diagnosed laparoscopically. The entire HOXA10 gene was amplified using polymerase chain reaction followed by single-strand conformation polymorphism analysis and sequencing. Association between the polymorphism and the clinical parameters of endometriosis were examined. There were 7.23% patients with HOXA10 genetic alterations; however, there was no significant increase in the endometriosis patients compared with the controls. Most of these DNA variants were found to be novel mutations that reside within the HOXA10 homeobox domain. Six variants generate amino acid changes in the protein and one harbours a premature stop codon. It was found that patients with HOXA10 polymorphism were associated with a lower serum cancer antigen-125, a lower American Fertility Society score and less severe obliterated cul-de-sac. It is postulated that genetic alterations in the homeobox domain might lead to less specificity for HOXA10 protein binding to a DNA molecule. 相似文献
992.
There is substantial heterogeneity of symptoms and signs among women with polycystic ovary syndrome (PCOS). In addition to different diagnostic criteria used, the ethnic background of women with PCOS may affect the clinical, hormonal, and metabolic characteristics of this condition. We present here studies related to the clinical, hormonal, and metabolic characteristics and response to the treatment of PCOS in Asia, which may be different from those in Western countries. It is important to take into consideration the ethnic background of patients in future studies related to PCOS. 相似文献
993.
994.
Bioassay-guided fractionation of the root wood of Zanthoxylum wutaiense led to the isolation of 11 new compounds, wutaiensol methyl ether (1), demethoxywutaiensol methyl ether (2), methyl wutaiensate (3), methyl 7-hydroxyanodendroate (4), methyl 7-methoxyanodendroate (5), wutaifuranol (6), 7-methoxywutaifuranol (7), 7-methoxywutaifuranal (8), methyl wutaifuranate (9), methyl 7-methoxybenzofuran-5-carboxylate (10), and wutaipyranol (12), together with another 37 known compounds, of which one, 7-methoxybenzofuran-5-carboxaldehyde (11), was not previously known as a plant constituent. The structures of these isolates were identified by means of spectroscopic analysis. Five of these isolates were found to be antitubercular constituents, namely, methyl 7-methoxyanodendroate (5), 7-methoxywutaifuranal (8), wutaiensal (13), dictamnine (14), and gamma-fagarine (15), which exhibited antitubercular activity against Mycobacterium tuberculosis H37Rv, showing MIC values of 35, 35, 30, 30, and 30 microg/mL, respectively. 相似文献
995.
Huang KL Chen CS Hsu CW Li MH Chang H Tsai SH Chu SJ 《The American journal of Chinese medicine》2008,36(2):301-311
Baicalin is a flavonoid present in many traditional Chinese medicines. A number of studies show that baicalin has anti-inflammatory actions and protects against a variety of tissue and organ injuries. The effect of baicalin in lipopolysaccharide (LPS)-induced acute lung injury is not well studied. In this study, typically acute lung injury was induced in rat by intratracheal injection of LPS, which increased lactate dehydrogenase activity and protein content in bronchoalveolar lavage fluid, wet/dry lung weight ratio, Evan's blue dye leakage, and neutrophil infiltration. Baicalin (20 mg/kg) was administrated 1 hour before or 30 min after LPS injection. Both pre and post-treatment with baicalin attenuated the increase of these parameters and improved histological finding. Our results suggest that baicalin has a therapeutic effect on LPS-induced acute lung injury. 相似文献
996.
997.
Antiosteoporotic chemical constituents from Er-Xian Decoction, a traditional Chinese herbal formula 总被引:2,自引:0,他引:2
AIM OF THE STUDY: Er Xian Decoction (EXD), a traditional Chinese medicine formula, has long been used for the treatment of osteoporosis and menopausal syndrome in China. The present study was designed to investigate the antiosteoporotic constituents of EXD, and evaluate their antiosteoporotic effects in ovariectomized rats. MATERIALS AND METHODS: Osteoblasts in neonatal calvaria cultures and osteoclasts derived from rat marrow cells were used to bioactivity-guided screen the active constituents. The proliferation of osteoblast was assayed by MTT methods. The activity of ALP and TRAP was measured by p- nitrophenyl sodium phosphate assay. The antiosteoporotic effects of icariin (1), anemarsaponin B II (8) and berberine (6) were verified by using OVX rats model. The bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry using the small animal scan mode. The undecalcified longitudinal proximal tibial metaphysical (PTM) sections were cut and stained for the bone histomorphometric analysis. RESULTS: Bioactivity-guided fractionation has led to the successful isolation of antiosteoporotic constituents, i.e., icariin (1), icariside I (2), baohuoside I (3), mangiferin (4), neomangiferin (5), berberine (6), anemarsaponin B (7), anemarsaponin BII (8), anemarsaponin C (9), anemarrhenasaponin I (10), rubiadin-1-methyl ether (11) and obaculactone (12) from EXD. Further study showed that icariin (1), anemarsaponin BII (8) and berberine (6) increased the BMD in ovariectomized rats, and icariin (1) not only increased the bone formation, but also inhibited bone resorption; anemarsaponin BII (8) mainly increased bone formation and berberine (6) only inhibited the bone resorption in ovariectomized rats. CONCLUSION: Our findings demonstrate that multiple ingredients are responsible for antiosteoporotic activity in traditional Chinese medicine formula Er-Xian decoction. 相似文献
998.
The adjuvant effects of Antrodia Camphorata extracts combined with anti-tumor agents on multidrug resistant human hepatoma cells 总被引:1,自引:0,他引:1
Chang CY Huang ZN Yu HH Chang LH Li SL Chen YP Lee KY Chuu JJ 《Journal of ethnopharmacology》2008,118(3):387-395
AIM OF THE STUDY: The objectives of this study were to investigate the adjuvant anti-tumor effects of Antrodia camphorate in human hepatoma cells (C3A and PLC/PRF/5) which are resistance to most anti-tumor agents, elucidate the possible regulation pathways, and measure the tumor growth and survival rate in xenograft-nude mice after combined with anti-tumor agents. MATERIALS AND METHODS: The AC extracts were measured by using a phenol/sulfuric acid method as previously described. The in vitro cell proliferation assay of ACs and anti-tumor agents was tested on C3A and PLC/PRF/5 cell lines. The percentage of human hepatoma cells undergoing apoptosis and distributing in different phases of cell cycle were determined by Flow cytometric analysis. Western blot analysis for MDR-1 and apoptosis- related proteins. The measurements of tumor growth and survival analysis of hepatoma implanted nude mice treated with Antrodia camphorata extracts and anti-tumor agents alone or in combinations. RESULTS: We have found that Antrodia camphorata extracts, when combined with anti-tumor agents, showed adjuvant antiproliferative effects on hepatoma cells (in vitro) and on xenografted cells in tumor-implanted nude mice (in vivo), which then extended their median survival days. Furthermore, solid-state extracts of Antrodia camphorata (AC-SS) showed its adjuvant effects through the inhibition of MDR gene expressions and the pathway of COX-2- dependent inhibition of p-AKT, which ultimately resulted in the induction of apoptosis in hepatoma cells. CONCLUSIONS: In this study, we have found that Antrodia camphorata extract, when combined with anti-tumor agents, showed adjuvant antiproliferative effects on hepatoma cells (in vitro) and on xenografted cells in tumor-implanted nude mice (in vivo). 相似文献
999.
OBJECTIVE: To discover the effect of the total flavones from Semen cuscutae (TFSC) on the kidney-yang deficiency male mouse, especially on hormone levels and the androgen receptor (AR) mRNA and protein level in the kidney and testicle. METHODS: ICR male mouse were separated into six groups, and, except for the normal group, hydrocortisone was injected intraperitoneally to make the kidney-yang deficiency. The groups were then treated with TFSC, methyltestosterone and Jinkui Shenqi Wan, except for the normal group and control group. 14 days after administering, testosterone levels in the total serum were analysed by radioimmunoassay, AR mRNA levels measured by real time RT-PCR and protein levels by immunohistochemistry. RESULTS: The control group had the lowest testosterone level, AR mRNA level and protein level, and the TFSC can reverse the reduction of testosterone level, AR mRNA level and protein level induced by the hydrocortisone. CONCLUSIONS: This is the first study to demonstrate that TFSC treatment may reverse kidney-yang deficiency symptoms by restoring the levels of testosterone and AR mRNA and protein expression in the kidney and testicle. 相似文献
1000.
AIM: Cardiac infarction is one of the main causes of death in both developing and developed countries over past decades. Currently available approaches for treating patients with this disease are not satisfactory. Traditional Chinese medicines have been increasingly paid attention to. The aim of this study was to characterize the dynamic protective effects of Guanxin No. 2 decoction (GX II) on cardiac dysfunction combined with the blood viscosity and myocardial hypertrophy parameters in myocardial infarction (MI) rats. METHODS: Male Sprague-Dawley rats (180-200 g) were randomly divided into three groups: sham-operated, coronary artery ligation (CAL), and CAL plus GX II (GX II, 10.0 g raw materials/kg/d, bid, p.o.). The experiment was carried out at 4 time points as the 3rd, 7th, 14th, and 28th day after ligation. RESULT: It was found that on the one hand, GX II could significantly improve the heart function, and remarkably decrease infarct size and inhibit ventricular remodeling. On the other hand, GX II showed some unique effects such as angiogenesis which was induced in the left ventricular tissue. This result was consistent with the finding of an augmented vascular endothelial growth factor (VEGF) expression in this area. CONCLUSIONS: The studies demonstrated that GX II exerted extensively beneficial cardioprotective effect on CAL rats, it might stimulate angiogenesis of ischemic region to compensate blood supply to the heart via upregulated VEGF expression. 相似文献