全文获取类型
收费全文 | 97708篇 |
免费 | 6458篇 |
国内免费 | 1168篇 |
专业分类
耳鼻咽喉 | 869篇 |
儿科学 | 3018篇 |
妇产科学 | 2586篇 |
基础医学 | 12867篇 |
口腔科学 | 1576篇 |
临床医学 | 8971篇 |
内科学 | 22394篇 |
皮肤病学 | 1840篇 |
神经病学 | 9855篇 |
特种医学 | 2796篇 |
外国民族医学 | 2篇 |
外科学 | 10433篇 |
综合类 | 2378篇 |
现状与发展 | 2篇 |
一般理论 | 44篇 |
预防医学 | 7334篇 |
眼科学 | 1436篇 |
药学 | 7823篇 |
8篇 | |
中国医学 | 1091篇 |
肿瘤学 | 8011篇 |
出版年
2024年 | 168篇 |
2023年 | 1063篇 |
2022年 | 2445篇 |
2021年 | 3962篇 |
2020年 | 2382篇 |
2019年 | 2840篇 |
2018年 | 3147篇 |
2017年 | 2554篇 |
2016年 | 2761篇 |
2015年 | 3207篇 |
2014年 | 4157篇 |
2013年 | 5204篇 |
2012年 | 7239篇 |
2011年 | 7301篇 |
2010年 | 4071篇 |
2009年 | 3602篇 |
2008年 | 5759篇 |
2007年 | 5795篇 |
2006年 | 5275篇 |
2005年 | 4895篇 |
2004年 | 4484篇 |
2003年 | 3944篇 |
2002年 | 3573篇 |
2001年 | 1661篇 |
2000年 | 1527篇 |
1999年 | 1488篇 |
1998年 | 770篇 |
1997年 | 608篇 |
1996年 | 540篇 |
1995年 | 447篇 |
1994年 | 424篇 |
1993年 | 346篇 |
1992年 | 765篇 |
1991年 | 650篇 |
1990年 | 604篇 |
1989年 | 621篇 |
1988年 | 527篇 |
1987年 | 486篇 |
1986年 | 460篇 |
1985年 | 373篇 |
1984年 | 341篇 |
1983年 | 277篇 |
1982年 | 197篇 |
1981年 | 161篇 |
1980年 | 149篇 |
1979年 | 240篇 |
1978年 | 159篇 |
1977年 | 144篇 |
1974年 | 141篇 |
1973年 | 144篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Effects of androgen treatment in impotent men with normal and low levels of free testosterone 总被引:1,自引:0,他引:1
Cesare Carani M.D. Dante Zini M.D. Augusto Baldini M.D. Luciano Della Casa M.D. Anna Ghizzani M.D. Paolo Marrama M.D. 《Archives of sexual behavior》1990,19(3):223-234
The relation between sexual function and serum free testosterone (fT) levels, which represent the active fraction of circulating testosterone, was evaluated. Two groups of impotent male subjects with mild hypogonadism were treated with oral testosterone undecanoate (TU); these men presented with tT/luteinizing hormone (LH) ratio and tT levels at the lower limits of normal. The first group had serum fT below 6.6 ng/ml, considered the lower normal value, according to our laboratory method, whereas the second group had normal fT limits. Administration of TU improved sexual function only in impotent men with low fT levels, but not in subjects with normal fT levels, even though the tT levels and the tT/LH ratio of the two groups were not significantly different. The results of our study suggest the presence of a minimun serum fT threshold, lying near the lower normal range, which determines the male sexual function. Moreover, serum fT levels were a more sensitive index than tT for identifying impotent men who can be successfully treated with androgens. 相似文献
62.
Analysis of reflex activity in cardiac sympathetic nerve induced by myelinated phrenic nerve afferents 总被引:2,自引:0,他引:2
Electrical stimulation of the phrenic nerve afferents evoked excitatory responses in the right inferior cardiac sympathetic nerve in chloralose-anaesthetized cats. The reflex was recorded in intact and spinal cats. The latency and threshold of the volley recorded from the phrenic nerve as well as of the cord dorsum potentials evoked by electrical stimulation of the phrenic nerve indicated that group III afferents were responsible for this reflex. The phrenicocardiac sympathetic reflex recorded in intact cats was followed by a silent period. The maximum amplitude of the reflex discharges was 800 microV, the latency was 83 ms and the central transmission time 53 ms. Duration of the silent period lasted up to 0.83 s. In spinal cats the reflex was recorded 5.5-8 h after spinalization. The maximum amplitude of the spinal reflex discharges ranged from 22 to 91 microV and the latency from 36 to 66 ms. 相似文献
63.
Franco Rilke M. D. F. R. C. Umberto Veronesi M. D. Alberto Luini M. D. Cristina Brambilla M. D. Viviana Galimberti M. D. Stefano Zurrida M. D. Silvana Pilotti M. D. M. I. A. C. Silvana Di Palma M. D. Roberto Zucali M. D. Laura Lozza M. D. 《The breast journal》1996,2(3):176-180
Abstract: Breast conservation surgery is an effective and safe treatment for many breast carcinomas. It may be possible to further limit the extent of resection (or expand the indication for breast conservation) by the application of preoperative chemotherapy and radiotherapy. We explored the feasibility of this in a pilot study.
Seventy-three patients (mean age 48, 63% premenopausal) with confirmed breast cancer, less than 2.5 cm, received chemotherapy (Group A) or chemotherapy plus radiotherapy (Group B) prior to limited resection (tumorectomy). Axillary dissection was always performed. Results: In 6/31 (19%) Group A and 17/42 (40%) Group B patients the tumor was not palpable after preoperative treatment, with complete pathological remission in 1 and 3 cases respectively. Histologic grading, mitosis, cellular alteration, and cellularity evaluations indicated a consistently greater therapeutic effect with chemoradiotherapy than with chemotherapy alone.
In conclusion, radiotherapy appears useful in the preoperative treatment of breast cancer and its use in association with various drug combinations should be further explored. 相似文献
Seventy-three patients (mean age 48, 63% premenopausal) with confirmed breast cancer, less than 2.5 cm, received chemotherapy (Group A) or chemotherapy plus radiotherapy (Group B) prior to limited resection (tumorectomy). Axillary dissection was always performed. Results: In 6/31 (19%) Group A and 17/42 (40%) Group B patients the tumor was not palpable after preoperative treatment, with complete pathological remission in 1 and 3 cases respectively. Histologic grading, mitosis, cellular alteration, and cellularity evaluations indicated a consistently greater therapeutic effect with chemoradiotherapy than with chemotherapy alone.
In conclusion, radiotherapy appears useful in the preoperative treatment of breast cancer and its use in association with various drug combinations should be further explored. 相似文献
64.
This report is a retrospective clinical randomized study carried out on 114 cases of incidental prostatic carcinoma aged 55-87 years, 58 untreated and 56 treated with cyproterone acetate (CPA 200 mg/day) for 6 months, immediately after surgery. 78 cases were staged A1 and the remaining 36 A2. In stage A1, 75 cases were histologically graded G1, and 3 G2, whereas in stage A2, 7 cases were G1, 19 G2 and 10 G3. Moreover, flow cytometric DNA analysis showed in A1 20 G1 carcinomas with nuclear diploidy and 3 G2 with nuclear aneuploidy, in stage A2, 4 G3 tumors with nuclear aneuploidy. During the 4-year follow-up, 25/28 patients of the untreated group and 15/56 of the CPA-treated group were found in progression. In A1, progression was found in 6/37 untreated patients and 5/41 CPA-treated, whilst in A2 progression was observed in 19/21 untreated patients and in 10/15 treated with CPA. The critical period for progression was between the 2nd and 3rd year of follow-up. In A1, therefore, 6 months of therapy with CPA does not modify the progression rate, which is significantly improved in A2 (66% in the treated and 90% in the untreated group) during the first 30 months of follow-up. The prognosis may probably be further improved by continuing endocrine therapy. 相似文献
65.
Abstract Maxillary and mandibular anterior permanent teeth in 38 children aged 7–12 years were examined 2 × with an interval of 2 years to determine whether spontaneous facial/lingual tooth position changes were related to alterations of the widths of keratinized and attached gingiva and the clinical crown height. Measurements included dental plaque, gingival inflammation, probing depth, and width of keratinized and attached gingiva. In addition, study casts from the baseline and 2-year examinations were used to measure clinical crown height and tooth position. The results showed that significant alterations in the widths of the keratinized and attached gingiva took place when the teeth changed positions in facial or lingual directions. The changes in gingival widths could to some extent be coupled to changes in clinical crown height. In teeth moving lingually, the gingival widths increased and the clinical crown height decreased. In teeth moving facially, the gingival widths decreased, and the facial gingiva sometimes receded. These gingival alterations call for examination of the facial gingiva as part of the monitoring of the development of the permanent dentition. 相似文献
66.
E Cianchetti R Cotellese A Dell'Osa M Nardi A D'Aulerio L Puglielli P Di Sebastiano C Saragani A M Napolitano 《Minerva chirurgica》1990,45(17):1093-1096
A case series of 5 male patients afflicted with breast carcinoma is reported. The Authors describe symptomatology, diagnostic iter, principles of surgical treatment and results. Underlined is the wider surgical demolition in male breast cancer in comparison with females, even if natural history and biological conduct are comparable. This is because in male breast carcinoma the local and remote infiltration is more rapid than female for the less development of breast gland. Finally, indications for radiochemotherapy are comparable to female breast cancer. 相似文献
67.
大鼠肝细胞Ⅰ,Ⅲ型前胶原基因表达及PDGF的影响 总被引:3,自引:1,他引:2
目的观察大鼠肝细胞Ⅰ,Ⅲ型前胶原基因的表达及PDGF对其表达的影响.方法应用原位杂交技术检测分离培养的SD大鼠肝细胞(n=30)内Ⅰ,Ⅲ型前胶原基因的表达.同时观察10μg/L(n=30)和30μg/L(n=30)PDGF促进前胶原基因表达的作用.测定基因表达颗粒总面积占细胞总面积的百分比,并作比较分析.结果无论正常肝细胞或是在两种浓度的PDGF存在时,肝细胞内均可见到Ⅰ,Ⅲ型前胶原基因的表达.正常肝细胞Ⅰ,Ⅲ型前胶原基因表达面积的百分比(%)为77±19和75±21;加10μg/LPDGF后为115±19和112±10,而加30μg/L后为152±34及181±28,且在后者中表达明显增强(P<005及P<001).结论PDGF在转录水平上促进肝细胞胶原的合成. 相似文献
68.
Enza-Maria Valente Anjum Misbahuddin Francesco Brancati Mark R Placzek Barbara Garavaglia Sergio Salvi Andrea Nemeth Charles Shaw-Smith Nardo Nardocci Anna-Rita Bentivoglio Alfredo Berardelli Roberto Eleopra Bruno Dallapiccola Thomas T Warner 《Movement disorders》2003,18(9):1047-1051
The epsilon-sarcoglycan gene (SGCE) on human chromosome 7q21 has been reported to be a major locus for inherited myoclonus-dystonia. Linkage to the SGCE locus has been detected in the majority of families tested, and mutations in the coding region have been found recently in families with autosomal dominant myoclonus-dystonia. To evaluate the relevance of SGCE in myoclonus-dystonia, we sequenced the entire coding region of the epsilon-sarcoglycan gene in 16 patients with either sporadic or familial myoclonus-dystonia. No mutations were found. This study suggests that epsilon-sarcoglycan does not play an important role in sporadic myoclonus-dystonia and supports genetic heterogeneity in familial cases. 相似文献
69.
Previous exposure to a dopaminergic agonist (priming) strongly potentiates contralateral turning behaviour in response to D1 and D2 agonists in unilaterally 6-hydroxydopamine-lesioned rats. In order to study the influence of priming on the behavioural interaction of D1 and D2 receptors, we examined the effect of selective D1 and D2 receptor blockade on the contralateral turning induced by the mixed D2/D2 agonist apomorphine in drug-naive and primed 6-hydroxydopamine-lesioned rats. In drug-naive rats, apomorphine induced a dose-related, apparently monophasic rotation curve. Administration of selective D1 (SCH 23390) or D2 (raclopride) antagonists abolished the contralateral turning induced by 0.1 mg/kg of apomorphine and partially inhibited that induced by 0.5 mg/kg. In primed rats low doses of apomorphine (0.05 mg/kg) induced an apparently monophasic contralateral turning which was reduced by D1 receptor blockade and completely abolished by D2 receptor blockade; a higher dose of apomorphine (0.1 mg/kg) instead elicited a biphasic (two-peak) pattern of rotation. After this dose of the agonist, blockade of D1 or D2 receptors abolished the second peak of rotation but, while D1 blockade reduced the total number of turns, D2 blockade failed to do so. Quantitative analysis of the interaction between D1 and D2 receptors in the overall turning effect, as well as in the time-course of turning behaviour, indicates that D1 and D2 receptors interact not only positively but also negatively. After higher doses of apomorphine, both negative and positive interactions take place sequentially during the time-course of apomorphine action and provide a clue for explaining the two-peak pattern of rotation observed after apomorphine in rats previously exposed to the drug. 相似文献
70.
P L Di Patre 《Medical hypotheses》1991,34(2):165-170
A theory is presented here in the attempt to explain why Alzheimer's disease (AD) primarily affects areas of the human brain that have been acquired recently in phylogenesis. Disturbances in cytoskeletal function are proposed to play a fundamental role in triggering the sequence of pathologic events leading to the occurrence of AD-related histopathological markers and to the degeneration and death of neurons. These deficits are supposed to occur more likely in neuronal populations that possess a high degree of plasticity, the substrate of memory functions, and that constitute, in fact, the phylogenetically new telencephalic regions of the human brain. 相似文献