全文获取类型
收费全文 | 20874篇 |
免费 | 1011篇 |
国内免费 | 139篇 |
专业分类
耳鼻咽喉 | 141篇 |
儿科学 | 254篇 |
妇产科学 | 152篇 |
基础医学 | 2543篇 |
口腔科学 | 381篇 |
临床医学 | 1526篇 |
内科学 | 5636篇 |
皮肤病学 | 349篇 |
神经病学 | 1611篇 |
特种医学 | 1177篇 |
外科学 | 3586篇 |
综合类 | 124篇 |
一般理论 | 1篇 |
预防医学 | 467篇 |
眼科学 | 396篇 |
药学 | 1248篇 |
中国医学 | 45篇 |
肿瘤学 | 2387篇 |
出版年
2023年 | 114篇 |
2022年 | 204篇 |
2021年 | 372篇 |
2020年 | 215篇 |
2019年 | 292篇 |
2018年 | 391篇 |
2017年 | 328篇 |
2016年 | 353篇 |
2015年 | 395篇 |
2014年 | 508篇 |
2013年 | 589篇 |
2012年 | 883篇 |
2011年 | 1062篇 |
2010年 | 623篇 |
2009年 | 512篇 |
2008年 | 888篇 |
2007年 | 943篇 |
2006年 | 913篇 |
2005年 | 950篇 |
2004年 | 914篇 |
2003年 | 981篇 |
2002年 | 980篇 |
2001年 | 687篇 |
2000年 | 693篇 |
1999年 | 634篇 |
1998年 | 310篇 |
1997年 | 241篇 |
1996年 | 199篇 |
1995年 | 202篇 |
1994年 | 196篇 |
1993年 | 150篇 |
1992年 | 509篇 |
1991年 | 381篇 |
1990年 | 421篇 |
1989年 | 424篇 |
1988年 | 402篇 |
1987年 | 353篇 |
1986年 | 339篇 |
1985年 | 370篇 |
1984年 | 219篇 |
1983年 | 208篇 |
1982年 | 99篇 |
1979年 | 175篇 |
1978年 | 108篇 |
1977年 | 112篇 |
1975年 | 95篇 |
1973年 | 100篇 |
1971年 | 91篇 |
1969年 | 98篇 |
1968年 | 105篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Hiroyuki Ishiyama MD Hyunjin Kim MD PhD Satoshi Saito MD PhD Soichi Takeda PhD Misa Takegami PhD Yumi Yamamoto PhD Soichiro Abe MD Shinsaku Nakazawa MD Tomotaka Tanaka MD PhD Kazuo Washida MD PhD Yoshiaki Morita MD Seung-Taek Oh MD Hee-Jae Jung MD Jay Chol Choi MD PhD Yuriko Nakaoku MD PhD Jin Nakahara MD PhD Masatoshi Koga MD PhD Kazunori Toyoda MD PhD Kisaki Amemiya MD PhD Yoshihiko Ikeda MD PhD Kinta Hatakeyama MD PhD Ikuko Mizuta MD PhD Toshiki Mizuno MD PhD Kwang-Kuk Kim MD PhD Masafumi Ihara MD PhD 《Annals of neurology》2024,95(6):1040-1054
992.
Fadi Brimo MD Andrew A. Renshaw MD Majorie Deschenes MD Michele Charbonneau CT Manon Auger MD 《Cancer cytopathology》2009,117(5):311-317
BACKGROUND:
Documenting the performance of gynecologic screening in actual practice settings is difficult to achieve. In the current study, the screening performance of 11 individual cytotechnologists as well as that of the overall laboratory over 2 consecutive time periods was examined using the rapid prescreening (RPS) method.METHODS:
RPS was performed by all cytotechnologists in a single laboratory over 2 separate 8‐month periods. The sensitivity of screening for individual and groups of cytotechnologists was examined. For purposes of comparison, cytotechnologists were divided into 2 groups: screeners with an overall routine sensitivity ≥95% and screeners with an overall sensitivity <95%.RESULTS:
Atypical squamous cells (ASC) were used as a threshold, and routine screening sensitivity was found to vary from 68.3% to 96.8%. The overall sensitivity of the laboratory for RPS and routine screening was 43.6% and 88.4%, respectively. Over time, the overall laboratory sensitivity of routine screening improved from 85.3% to 91.3% (P = .01). During this same time frame, the sensitivity of the screeners with an overall sensitivity <95% improved from 79.3% to 91.2% (P < .001), whereas the sensitivity of screeners with an overall routine sensitivity ≥95% remained the same (96.1% to 96.4%; P = .6).CONCLUSIONS:
In addition to improved overall performance of the laboratory by detecting and correcting errors, the results of the current study indicate that using RPS consistently over time might play a role leading to improved performance of cytotechnologists with an overall routine sensitivity <95% but not of cytotechnologists with an overall routine sensitivity ≥95%. Cancer (Cancer Cytopathol) 2009. © 2009 American Cancer Society. 相似文献993.
目的 通过对深圳地区正常人群腰椎骨密度测量 ,获得本地区QCT骨密度正常参考值。方法 采用CT扫描机 ,羟磷灰石固体体模和QCT骨密度测量软件 ,选择了无骨质疏松疾病的正常人 1 0 2 8例 ,扫描第 3、第 4腰椎中层横断面 ,做QCT骨密度测量。对测量结果进行统计处理 ,得到男女人群骨峰值和年龄组均值。通过对年龄组数据进行不同标准的统计处理 ,探讨较为合理的诊断标准。通过不同的测量方法 (单纯松质和包括皮质 )的对比 ,探讨QCT与其他方法的差异。结果 根据 2 1~ 35岁年龄段统计出的骨峰值男性第 3腰椎为 1 65 85± 30 1 7,第 4腰椎为 1 70 95± 31 81。女性第 3腰椎为 1 75 33± 2 6 95 ,第 4腰椎为 1 81 97± 2 7 63。采用 4种不同的骨峰值降低标准统计骨质疏松症检出率 ,发现M 2 5 %组检出率偏高 ,M 30 %与M 2S较接近。包括皮质骨的测量降低敏感性。结论 进行深圳地区骨密度正常值调查 ,获得了男女人群骨峰值和年龄组均值 ,临床诊断建议采用骨峰值 30 %作为QCT测量诊断骨质疏松症的基本界限 相似文献
994.
995.
Syringocystadenoma papilliferum associated with apocrine poroma 总被引:2,自引:0,他引:2
A 65-year-old Japanese man presented with a gradually enlarging mass on the right side of the abdomen, which he had first noticed about 4 years previously. He was otherwise asymptomatic. Histopathological examination of the mass revealed an aggregation of neoplastic cells (tumor cell nests) with cellular proliferation extending from the epidermis to the dermis. The tumor consisted of two histologically distinct parts. One part was composed of uniformly small cells with a cuboidal appearance. Some ductal structures were visualized, and some of the cells lining the ductal lumina contained decapitation secretions. These histological changes were consistent with the diagnosis of apocrine poroma. The remaining part of the tumor was composed of cystic invaginations with numerous projections oriented toward the lumen. There were two rows of cells in the projections; the cells on the luminal side were columnar, and those at the apical aspect were small cuboidal cells. These histological changes were characteristic of syringocystadenoma papilliferum (SCAP). Based on these findings, a diagnosis of SCAP associated with apocrine poroma was made. To the best of our knowledge, there have been no previous reports of such a case in the published work. 相似文献
996.
The in vivo effects of convulsant drugs (penicillamine, semicarbazide and isonicotinic acid hydrazide) on the γ-aminobutyric acid (GABA) levels in subcellular fractions were studied in mice. All the drugs reduced the concentration of GABA in the synaptosomal fraction; it was unlikely that this decrease in the GABA concentration was due to redistribution or degradation during the separating procedures. When the convulsions were prevented by simultaneous pyridoxine injection, the GABA level in synaptosomes rose to normal. It is suggested that the decrease of GABA concentration in nerve endings may be an important factor in the onset of some kinds of convulsions. 相似文献
997.
A reduction of renal arterial pressure in mongrel dogs to 70 mmHg resulted in marked increases in plasma renin activity and plasma levels of angiotensin I (AI) and angiotensin II (AII). Production of renin and AI but not AII in the kidney was observed. A reduction of renal arterial pressure also resulted in a redistribution of blood flow from the outer to inner cortex. An arterial infusion of AII (200 ng/min), however, failed to affect the intrarenal distribution of the blood flow. An intrarenal infusion of AII rather restored the normal pattern of the distribution of intrarenal blood flow altered by the pressure reduction. These results indicate that the renin-angiotensin system is probably not involved in the control of renal hemodynamics through the intrarenal formation of AII, and that the intrarenal hemodynamic changes caused by pressure reduction is due to the intrinsic differences in myogenic force in different cortical zones. 相似文献
998.
Metolazone, the sulfonamide diuretic was investigated to determine the sites of action. We used a radioactive microsphere, clearance and stop-flow method in anesthetized dogs. Urine flow and urinary excretion of sodium and potassium were increased at 5--60 min when metolazone was given intravenously at doses of 0.2--5.0 mg/kg, while total renal blood flow, distribution of cortical renal blood flow and GFR did not change. The urinary excretion rate of sodium to potassium (Na/K) increased from 5.69 +/- 0.82 to 8.07 +/- 0.76 in a dose of 1.0 mg/kg, i.v. Osmolar clearance and free water reabsorption increased almost proportionally, indicating that metolazone has little effect on the medullary portion of the ascending limb of Henle and may have a proximal site of action. In stop-flow experiments, a significantly raised U/PNa/U/Pcreatinine was observed at the dip situated distally to the ascending limb of Henle. These findings indicate that the diuretic action of metolazone may be due to the inhibition of sodium reabsorption in the distal nephron segments, in addition to the absence of modification of the cortical regional blood flow. 相似文献
999.
Hideyuki Mizuno Tatsuaki Kanai Yohsuke Kusano Susumu Ko Mari Ono Akifumi Fukumura Kyoko Abe Kanae Nishizawa Munefumi Shimbo Suoh Sakata Satoshi Ishikura Hiroshi Ikeda 《Radiotherapy and oncology》2008,86(2):258-263
INTRODUCTION: The characteristics of a glass dosimeter were investigated for its potential use as a tool for postal dose audits. Reproducibility, energy dependence, field size and depth dependence were compared to those of a thermoluminescence dosimeter (TLD), which has been the major tool for postal dose audits worldwide. MATERIALS AND METHODS: A glass dosimeter, GD-302M (Asahi Techno Glass Co.) and a TLD, TLD-100 chip (Harshaw Co.) were irradiated with gamma-rays from a (60)Co unit and X-rays from a medical linear accelerator (4, 6, 10 and 20 MV). RESULTS: The dosimetric characteristics of the glass dosimeter were almost equivalent to those of the TLD, in terms of utility for dosimetry under the reference condition, which is a 10 x 10 cm(2) field and 10 cm depth. Because of its reduced fading, compared to the TLD, and easy quality control with the ID number, the glass dosimeter proved to be a suitable tool for postal dose audits. Then, we conducted postal dose surveys of over 100 facilities and got good agreement, with a standard deviation of about 1.3%. CONCLUSIONS: Based on this study, postal dose audits throughout Japan will be carried out using a glass dosimeter. 相似文献
1000.
A 53-year-old woman diagnosed with chronic renal failure requiring homodialysis, and Beh?et's disease was found, during a regular examination, having a large protruding mobile atheroma in the ascending aorta by transthoracic echocardiography. We performed surgery to remove the atheroma and localized debridement using moderate hypothermic circulatory arrest to prevent future stroke and embolism. She had an uneventful postoperative course. 相似文献