全文获取类型
收费全文 | 33052篇 |
免费 | 3443篇 |
国内免费 | 1900篇 |
专业分类
耳鼻咽喉 | 227篇 |
儿科学 | 715篇 |
妇产科学 | 347篇 |
基础医学 | 2868篇 |
口腔科学 | 565篇 |
临床医学 | 3888篇 |
内科学 | 4421篇 |
皮肤病学 | 615篇 |
神经病学 | 1403篇 |
特种医学 | 1358篇 |
外国民族医学 | 5篇 |
外科学 | 3530篇 |
综合类 | 6690篇 |
现状与发展 | 9篇 |
一般理论 | 4篇 |
预防医学 | 3130篇 |
眼科学 | 439篇 |
药学 | 3734篇 |
31篇 | |
中国医学 | 2410篇 |
肿瘤学 | 2006篇 |
出版年
2024年 | 115篇 |
2023年 | 370篇 |
2022年 | 872篇 |
2021年 | 1194篇 |
2020年 | 1051篇 |
2019年 | 877篇 |
2018年 | 954篇 |
2017年 | 936篇 |
2016年 | 987篇 |
2015年 | 1403篇 |
2014年 | 1740篇 |
2013年 | 2132篇 |
2012年 | 2720篇 |
2011年 | 2906篇 |
2010年 | 2373篇 |
2009年 | 2121篇 |
2008年 | 2114篇 |
2007年 | 2148篇 |
2006年 | 1899篇 |
2005年 | 1572篇 |
2004年 | 1427篇 |
2003年 | 1467篇 |
2002年 | 1245篇 |
2001年 | 959篇 |
2000年 | 628篇 |
1999年 | 368篇 |
1998年 | 198篇 |
1997年 | 209篇 |
1996年 | 148篇 |
1995年 | 109篇 |
1994年 | 102篇 |
1993年 | 60篇 |
1992年 | 67篇 |
1991年 | 68篇 |
1990年 | 51篇 |
1989年 | 48篇 |
1988年 | 39篇 |
1987年 | 47篇 |
1986年 | 29篇 |
1984年 | 23篇 |
1965年 | 39篇 |
1964年 | 36篇 |
1963年 | 27篇 |
1962年 | 27篇 |
1959年 | 47篇 |
1958年 | 51篇 |
1957年 | 67篇 |
1956年 | 28篇 |
1955年 | 19篇 |
1954年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Binding of sulfaethidole to bovine serum albumin was studied by equilibrium dialysis, fluorescence probe technique, uv difference
spectrophotometry and circular dichroism. Equilibrium dialysis method enabled us to estimate the total number of drug binding
sites of albumin molecule. For sulfaethidole, albumin had 6 primary and 40 secondary binding sites. The primary and secondary
binding constants were 0.9×105 M−1 and 0.2×106 M−1, respectively. 1-Anilino-8-naphthalenesulfonate (ANS) and 2-(4′-hydroxylbenzeneazo)-benzoic acid (HBAB) were used as the
fluorescence probe and the uv spectrophotometric probe, respectively. In fluorescence probe technique, results indicated that
the number of higher affinity drug binding site of albumin was 1 and the number of lower affinity drug binding sites of albumin
was 3, and the primary and secondary drug binding constants for bovine serum albumin were 2.15×105 M−1 and 1.04×105 M−1, respectively. In uv difference spectrophotometry, binding sites were 3 and binding constant was 1.88×105 M−1. The above results suggest that several different methods should be used in ompensation for insufficient information about
drug binding to albumin molecule given by only one method. 相似文献
82.
Chun Yuan Jay S. Tsuruda Kirk N. Beach Cecil E. Hayes Marina S. Ferguson Charles E. Alpers Thomas K. Foo D. Eugene Strandness 《Journal of magnetic resonance imaging : JMRI》1994,4(1):43-49
Atherosclerotic cardiovascular disease is the most common cause of death in the United States. Investigation of atherosclerotic plaque morphology and composition is important because the findings may be useful in predicting prognosis or response to therapy. This study presents high-resolution magnetic resonance (MR) imaging techniques developed on a 1.5-T whole-body imager with a custom-built surface coil, for characterizing the composition and morphology of plaque removed at carotid endarterectomy. The initial comparison of MR imaging and histologic results showed good correlation. In conjunction with MR angiography, these techniques could be used in in vivo imaging to define the size, location, and contents of atherosclerotic plaque at the carotid bifurcation. 相似文献
83.
目的:探讨用氨甲喋呤(Methotraxate,MTX)配伍中药治疗条件适宜的输卵管妊娠的可行性及疗效。方法:对MTX配伍中治疗的输卵管妊娠86例临床资料进行分析。结果:82例治疗成功,成功率为95.35%,其中,治疗1个疗程69例,2个疗程13例,随访16例妊娠,1例2年后对侧输卵管妊娠,4例治疗失败者改手术治疗,病理见不同程度的滋养细胞溶解,绒毛坏死,出血,结论:使用MTX配伍中药治疗输卵管异位妊娠,方法简便易行,安全有效,副作用少,特别适合于基层医院。 相似文献
84.
Brigitte Schiller Chun He David J. Salant Alice Lim Jessy J. Alexander Richard J. Quigg 《The Journal of experimental medicine》1998,188(7):1353-1358
Crry (complement receptor 1–related protein/gene y) is a key cellular complement regulator in rodents. It is also present in Fx1A, the renal tubular preparation used to immunize rats to induce active Heymann nephritis (HN), a model of membranous nephropathy. We hypothesized that rats immunized with anti-Fx1A develop autoantibodies (auto-Abs) to Crry as well as to the megalin-containing HN antigenic complex, and that anti-Crry Abs promote the development of injury in HN by neutralizing the complement regulatory activity of Crry. Rats immunized with Fx1A lacking Crry remained free of proteinuria and glomerular deposits of C3 during a 10-wk follow-up despite typical granular immunoglobulin (Ig)G deposits in glomeruli. Anti-Fx1A auto-Abs were present in their sera at levels that were not different from sera pooled from proteinuric rats with HN induced with nephritogenic Fx1A. Passive administration of sheep anti-Crry Abs to rats immunized with Crry-deficient Fx1A led to proteinuria and glomerular C3 deposition, which were not seen in such rats injected with preimmune IgG, nor in rats with collagen-induced arthritis injected with anti-Crry IgG. To directly examine the role of Crry in HN, rats were immunized with Crry-deficient Fx1A reconstituted with rCrry. This led to typical HN, with 8 out of 15 rats developing proteinuria within 14 wk. Moreover, the extent of glomerular C3 deposition correlated with proteinuria, and anti-Crry Abs were present in glomerular eluates. Thus, Crry is a key nephritogenic immunogen in Fx1A. Formation of neutralizing auto-Abs to Crry impairs its function, leading to unrestricted complement activation by Abs reactive with the HN antigenic complex on the epithelial cell surface. 相似文献
85.
86.
金黄色葡萄球菌儿童株耐药性分析 总被引:2,自引:0,他引:2
目的 了解儿童中金黄色葡萄球菌所致疾病的分布及其对常用抗生素的敏感情况。方法 收集连续12个月的临床致病株,根据菌落形态、革兰染色特点和乳胶凝集实验对金黄色葡萄球菌进行初步筛选,用细菌自动鉴定系统Vitek GPI卡和GPS-101卡进行菌株鉴定和药敏试验。结果 分离到金黄色葡萄球菌145株,其中来自呼吸道感染患儿痰或咽拭子培养109株,占75.17%,来自血培养16株,占11.03%,来自脓液、阴道分泌物培养分别占6.21%和5.51%。药敏试验显示92.4l%的菌株产生β-内酰胺酶,96.55%的菌株对青霉素耐药,但耐苯唑西林的仅占6.21%。99.31%和100%的菌株分别对利福平和万古霉素敏感,对环丙沙星、阿莫西林/棒酸、头孢唑林、复方新诺明、庆大霉素和林可霉素的敏感率分别为95.86%、93.10%、92.41%、86.21%、84.83%和80.69%,37.93%的菌株对红霉素耐药。结论金黄色葡萄球菌常引起儿童呼吸道感染,对苯唑西林的耐药率低.该药仍是治疗小儿会黄色葡萄球菌感染的有效药物。 相似文献
87.
88.
89.
Vasomotion in rat diaphragm microcirculation at rest and during stepwise arterial pressure reduction
C. W. CHEN C. H. LEE T. R. HSIUE H. Y. CHANG 《Acta physiologica (Oxford, England)》1997,161(3):281-288
The effect of haemorrhagic hypotension on the incidence, frequency and relative amplitude of vasomotion in rat diaphragm microcirculation was assessed by laser Doppler flowmetry (LDF). Graded bleeding to four hypotension levels (80, 60, 40 and 30% of the control state) were performed in 24 Sprague–Dawley rats. The incidence of vasomotion was 83% in the control state, 96% at the 80% level, 100% at the 60% level, 96% at the 40% level, and 46% at the 30% level. The median fundamental frequency of vasomotion determined manually during the control state and at the hypotension levels (in descending order) was 4.11 (range, 3.29–5.58) cycles min?1 (cpm), 4.48 (3.21–5.92) cpm, 4.20 (3.5–5.56) cpm, 4.01 (3.33–5.36) cpm, 3.71 (3.25–4.49) cpm (P < 0.01 from the fundamental frequency at 80 and 60% hypotension levels). The median relative amplitudes determined manually during the control state and descending hypotension levels were 44.5% (range, 24.9–135.9%), 69.4% (26.6–147.2%), 84.0% (40.3–177.1%) (P < 0.01 from resting and last stage of bleeding), 90.40% (26.2–189.6%) (P < 0.01 from resting and last stage of bleeding), 69.2% (35.6–93.2%). We concluded first that during the resting condition, vasomotion was frequently present in diaphragm microcirculation, which is distinct from other vascular beds of skeletal muscles. Second, the relative amplitude of vasomotion during haemorrhagic hypotension plotted against decreasing blood pressure exhibited a reverse U-shaped curve with a maximum at 40–60% of the control blood pressure, while the frequency of vasomotion remained relatively constant until the last stage of haemorrhage and centred around 3–5 cpm. 相似文献
90.
寒冷干燥地区平时火器伤的早期处理 总被引:3,自引:3,他引:0
目的 探讨寒冷干燥地区平时火器伤伤情特点与早期救治方法。方法 对 1991年 1月— 2 0 0 2年 12月间 40例火器伤病人的临床救治进行回顾分析。结果 2 4例枪伤中 ,2 0例一期缝合伤口 ,均一期愈合 ,另外 4例只清创未一期缝合的伤口 ,3例愈合 ,1例感染 ;4例骨折内固定均愈合良好 ,无骨髓炎发生。 16例炸伤病人局部软组织损伤及污染比枪弹伤重 ,14例一期缝合伤口中 ,10例一期愈合 ,4例感染 ,骨折内固定 2例 ,均愈合良好 ,无骨髓炎发生。结论 寒冷干燥地区火器伤早期伤道清创时限可适当延长 ,在平时火器伤的救治中 ,对软组织条件较好的创面 ,早期清创后可一期闭合伤口和骨折内固定 ,这样可减少感染和伤残 ,促进康复 相似文献