全文获取类型
收费全文 | 80736篇 |
免费 | 7486篇 |
国内免费 | 5290篇 |
专业分类
耳鼻咽喉 | 575篇 |
儿科学 | 989篇 |
妇产科学 | 1236篇 |
基础医学 | 9764篇 |
口腔科学 | 1575篇 |
临床医学 | 10232篇 |
内科学 | 12639篇 |
皮肤病学 | 836篇 |
神经病学 | 4402篇 |
特种医学 | 2818篇 |
外国民族医学 | 32篇 |
外科学 | 7759篇 |
综合类 | 12976篇 |
现状与发展 | 14篇 |
一般理论 | 12篇 |
预防医学 | 5527篇 |
眼科学 | 2117篇 |
药学 | 8713篇 |
80篇 | |
中国医学 | 4343篇 |
肿瘤学 | 6873篇 |
出版年
2024年 | 330篇 |
2023年 | 1295篇 |
2022年 | 3199篇 |
2021年 | 4075篇 |
2020年 | 3099篇 |
2019年 | 2647篇 |
2018年 | 2809篇 |
2017年 | 2516篇 |
2016年 | 2363篇 |
2015年 | 3595篇 |
2014年 | 4364篇 |
2013年 | 4104篇 |
2012年 | 6184篇 |
2011年 | 6516篇 |
2010年 | 4191篇 |
2009年 | 3295篇 |
2008年 | 4452篇 |
2007年 | 4276篇 |
2006年 | 3882篇 |
2005年 | 3811篇 |
2004年 | 2754篇 |
2003年 | 2497篇 |
2002年 | 2237篇 |
2001年 | 1822篇 |
2000年 | 1903篇 |
1999年 | 1997篇 |
1998年 | 1276篇 |
1997年 | 1259篇 |
1996年 | 983篇 |
1995年 | 954篇 |
1994年 | 780篇 |
1993年 | 490篇 |
1992年 | 564篇 |
1991年 | 515篇 |
1990年 | 440篇 |
1989年 | 390篇 |
1988年 | 304篇 |
1987年 | 306篇 |
1986年 | 235篇 |
1985年 | 186篇 |
1984年 | 124篇 |
1983年 | 85篇 |
1982年 | 62篇 |
1981年 | 47篇 |
1980年 | 33篇 |
1979年 | 44篇 |
1978年 | 18篇 |
1974年 | 17篇 |
1973年 | 17篇 |
1966年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
The intraocular pressure (IOP) course during the first postoperative month was measured with Goldmann applanation tonometry in 93 eyes. The patients include 30 eyes of intracapsular cataract extraction (ICCE), 32 eyes of extracapsular cataract extraction (ECCE) and 31 eyes of ECCE combined with posterior chamber intraocular lens (PC-IOL) implantation. The preoperative average IOP was 13.30 +/- 3.24 mmHg in 93 eyes. The first day after cataract extraction was 25.33 +/- 8.18 mmHg and 59 eyes (63.44%) had an IOP higher than 23 mmHg. On the second day it was 16.03 +/- 7.54 mmHg. On the third day it was 14.69 +/- 5.45 mmHg. On the seventh day it was 13.32 +/- 3.44 mmHg and only 2 eyes (2.14%) IOP was higher than 23 mmHg. The first postoperative month average IOP was 12.93 +/- 1.31 mmHg and it was above 23 mmHg in only one eye. When compared with preoperation a significant increase in IOP was found postoperatively. But on the seventh day and after the first month there was no significant difference (P greater than 0.05). The IOP rise among ICCE group, ECCE group and PC-IOL group did not differ significantly. 相似文献
102.
This paper deals with the anti-injurious effect of Qigong Waiqi on ozone toxicity. NIH male mice were randomly divided into three groups, O3 group, mice kept in 0.9 ppm O3 in a special room 12 hours/day for 12 days; Qigong group received Waiqi from a Qigong master for 30 minutes every morning in addition to what O3 group was treated; and a normal group for control. After 12 successive days, all the animals were decapitated and autopsy performed. Tissues taken from lung, liver, spleen and thymus were prepared for biochemical assay and microscopic examination. It was found that MDA content of lung and liver of O3 group was much higher than those of the control group and Qigong group. On the contrary, GSH-Px activity was significantly (P less than 0.001) lower than those of the control and Qigong groups. Both the MDA content and GSH-Px activity between the latter two groups were not significantly different. Microscopic examination revealed severe interstitial pneumonia with marked edema of lung and prominent leucocytic infiltration in liver of O3 group mice, but only slight changes were seen in Qigong group, so the differences were significant. The two immune organs of mice in O3 group were reduced in size and weight. Microscopic examination of immune organs of O3 group revealed thinner T lymphocyte population in cortex of thymus and periarterial sheath of spleen than those of Qigong group.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
103.
FOREWORDPeritonealdialysisrepresentssoluteandfluidexchangemainlybetweenperitonealcapillarybloodanddialysissolutionintheperitonealcavity'CombinedwithhemodialySisandrenaltransplantation,peritonealdialysisisusedmainlyforthetreatmentofrenalfailure,particularlyforchronicfailure'In1976,Prof'Popovichdevelopedcontinuousambulatoryperitonealdialysis(CAPD)basingontheconceptofcontinuousequilibrationdialysis('1'Fromthenon,peritonealdialysisfounditsclinicaluse'Continuouscyclicperitonealdialysis(CCPD… 相似文献
104.
采用微波炉中的谐振场和外辐射天线的平面波对冻存在-196℃的活细胞进行复温试验。结果表明:谐振场加温迅速但极不均匀,造成细胞大量死亡。平面电磁波微波泄漏大,效率低,加温时间过长,不能应用。本文阐述了微波对超低温细胞复温的可能性和现有微波仪不宜进行细胞复温的原因,并提出改进设计的建议。 相似文献
105.
吡那地尔对高血压心脏结构和功能重构的影响 总被引:5,自引:0,他引:5
在等降压剂量下吡那地尔和赖诺普利可使4月龄自发性高血压大鼠的血压下降6.0 ̄8.0kPa,并接近同种属正常血压大刀瓣血压水平。 相似文献
106.
Region-specific growth properties and trophic requirements of brain- and spinal cord-derived rat embryonic neural precursor cells 总被引:2,自引:0,他引:2
To determine whether neural precursor cells have region-specific growth properties, we compared the proliferation, mitogenicity, and differentiation of these cells isolated from the embryonic day 16 rat forebrain and spinal cord. Neural precursor cells isolated from both regions were cultured in growth medium supplemented with epidermal growth factor, basic fibroblast growth factor, or epidermal growth factor+basic fibroblast growth factor. Under all three conditions, both neural precursor cell populations proliferated for multiple passages. While spinal cord-derived neural precursor cells proliferated moderately faster in epidermal growth factor-enriched growth medium, brain-derived cells proliferated much faster in basic fibroblast growth factor-enriched growth medium. When exposed to both epidermal growth factor and basic fibroblast growth factor, the two neural precursor cell populations expanded and proliferated more rapidly than when exposed to a single factor, with brain-derived neural precursor cells expanding significantly faster than spinal cord-derived ones (P<0.0001). Differentiation studies showed that both neural precursor cell populations were multi-potent giving rise to neurons, astrocytes, and oligodendrocytes. However, neuronal differentiation from brain-derived neural precursor cells was greater than spinal cord-derived ones (11.95+/-5.00% vs 1.92+/-1.13%; passage 2). Further, the two neural precursor cell populations differentiated into a similar percentage of oligodendrocytes (brain: 8.66+/-5.85%; spinal cord: 7.69+/-3.91%; passage 2). Immunofluorescence and Western blot studies showed that neural precursor cells derived from both regions expressed receptors for basic fibroblast growth factor and epidermal growth factor. However, brain-derived neural precursor cells expressed higher levels of the two receptors than spinal cord-derived ones in growth medium containing epidermal growth factor+basic fibroblast growth factor. Thus, our results showed that neural precursor cells isolated from the two regions of the CNS have distinct properties and growth requirements. Identifying phenotypic differences between these neural precursor cell populations and their growth requirements should provide new insights into the development of cell therapies for region-specific neurological degenerative diseases. 相似文献
107.
目的 探讨肝黏膜相关淋巴组织淋巴瘤的临床病理特征。方法 对1例罕见多脏器恶性肿瘤术后肝黏膜相关淋巴瘤病例结合文献进行临床、病理和免疫组化分析。结果 患者于8年和3年前先后发生胃恶性间质瘤、阴囊阴茎皮肤湿疹样癌,有长期化疗史。肿瘤组织学以单核样B细胞为主,并有淋巴滤泡和淋巴上皮病变形成。免疫表型示瘤细胞CD45、CD79α、CD20阳性,CD5、CD10、ALK、TdT阴性,bcl—2、Ki—67少数肿瘤细胞阳性。结论 肝黏膜相关淋巴瘤可以发生于多脏器恶性肿瘤术后,其发病可能与长期使用免疫抑制剂有关,诊断本病时需与肝继发性淋巴瘤及肝的炎性假瘤鉴别。 相似文献
108.
109.
OBJECTIVE: Raloxifene, a selective estrogen receptor modulator, is estrogen-like in the skeleton and cardiovascular system and antiestrogenic in reproductive tissues. In contrast to estrogens, raloxifene is not indicated for the treatment of hot flashes. This study was designed to examine the characteristics of hot flashes among healthy postmenopausal women participating in osteoporosis prevention trials who were receiving raloxifene or placebo. METHODS: Adverse event data from three randomized, double-blind trials (N = 876) comparing raloxifene 60 mg/day with placebo for 30 months were integrated and analyzed. Two of the three trials (one European, two North American) were identically designed and were open to healthy postmenopausal women ages 45 through 60 without regard to prior hysterectomy. The third trial was multinational, was open to women ages 40 through 60, and all enrollees had prior hysterectomy at baseline. Women were questioned in general terms about the occurrence of adverse events at 3-6-month intervals. Treatment-emergent adverse events pertaining to hot flashes were included in the current study. RESULTS: At baseline, 12% of women randomly assigned to placebo and 13% assigned to raloxifene reported prevalent hot flashes. After 30 months, the cumulative incidence of hot flashes was 21% for placebo and 28% for raloxifene (P = 0.022), with the difference in incidence rate confined to the first 6 months of therapy. There was no difference between placebo and raloxifene in reported maximum severity of or early discontinuations as a result of hot flashes (< or = 3% per group for both outcomes). Among women whose hot flashes had stopped completely during the 30-month study period, the median total duration of the event prior to becoming symptom-free was 246 days for placebo and 205 days for raloxifene. Among all women reporting a hot flash, the extrapolated total duration of hot flashes was the same for women treated with either raloxifene or placebo. No subgroup-by-therapy interactions were detected. Multivariable regression analysis revealed several factors that were independently weakly predictive of hot flashes. CONCLUSIONS: Raloxifene slightly affects the incidence but not the natural history of hot flashes in healthy postmenopausal women seeking prevention therapy. 相似文献
110.
作者对抗体包被的红为性进行研究,发现抗体包被改变了红细胞的变形性,在我们研究的抗体量范围内,抗体量越多,红细胞的变形性越小,作者从血液流变学的角度对上述结果作了讨论,并提出了通过测定其对红细胞变形性的影响来比较准确地标定抗体效价的可能性。 相似文献