全文获取类型
收费全文 | 11706篇 |
免费 | 578篇 |
国内免费 | 87篇 |
专业分类
耳鼻咽喉 | 63篇 |
儿科学 | 165篇 |
妇产科学 | 77篇 |
基础医学 | 1427篇 |
口腔科学 | 222篇 |
临床医学 | 708篇 |
内科学 | 2920篇 |
皮肤病学 | 232篇 |
神经病学 | 929篇 |
特种医学 | 696篇 |
外科学 | 2053篇 |
综合类 | 43篇 |
预防医学 | 385篇 |
眼科学 | 183篇 |
药学 | 759篇 |
中国医学 | 46篇 |
肿瘤学 | 1463篇 |
出版年
2024年 | 13篇 |
2023年 | 90篇 |
2022年 | 169篇 |
2021年 | 332篇 |
2020年 | 164篇 |
2019年 | 232篇 |
2018年 | 261篇 |
2017年 | 249篇 |
2016年 | 296篇 |
2015年 | 311篇 |
2014年 | 419篇 |
2013年 | 482篇 |
2012年 | 731篇 |
2011年 | 841篇 |
2010年 | 488篇 |
2009年 | 405篇 |
2008年 | 682篇 |
2007年 | 743篇 |
2006年 | 741篇 |
2005年 | 805篇 |
2004年 | 740篇 |
2003年 | 711篇 |
2002年 | 750篇 |
2001年 | 120篇 |
2000年 | 93篇 |
1999年 | 128篇 |
1998年 | 199篇 |
1997年 | 142篇 |
1996年 | 159篇 |
1995年 | 131篇 |
1994年 | 115篇 |
1993年 | 108篇 |
1992年 | 83篇 |
1991年 | 58篇 |
1990年 | 51篇 |
1989年 | 45篇 |
1988年 | 30篇 |
1987年 | 27篇 |
1986年 | 25篇 |
1985年 | 23篇 |
1984年 | 23篇 |
1983年 | 16篇 |
1982年 | 27篇 |
1981年 | 18篇 |
1980年 | 18篇 |
1979年 | 8篇 |
1977年 | 7篇 |
1975年 | 9篇 |
1974年 | 11篇 |
1973年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Isao Katayama Masaki Shimizu Myota Miura Masanobu Maruyama Masayuki Kobayashi Yuuichi Iino Masaru Izuo Susumu Wakatsuki 《Virchows Archiv : an international journal of pathology》1984,402(4):353-359
Summary In a study of 277 patients with breast carcinomas, the PAP immunoperoxidase method for demonstrating endogenous estrogen was correlated with the sucrose density gradient (SDG) assay and with histologic and clinical features. The results from the PAP method and SDG assay agreed in 59 of 84 patients (82.1%) on whom both methods were performed. Histologically, the PAP method was positive in 7 of 7 patients with non-invasive carcinomas, in 164 of 233 patients (70.4%) with common invasive ductal carcinoma, and in 21 of 22 of those with special histological types of invasive carcinomas not including Paget's disease, medullary or apocrine carcinoma, where only 5 of 14 were positive. Clinically, 15 of 18 patients with positive endogenous estrogen showed a response to endocrine therapy as opposed to 1 of 9 patients with a negative endogenous estrogen. The mean survival was 31.2 and 15.6 months, respectively for patients with positive and negative endogenous estrogen. Remission for longer than 2 years was seen more often in patients with positive endogenous estrogen. These results suggest a clinical utility of the present PAP method which, therefore, deserves a further trial as an alternative to histochemical methods aiming at the estrogen receptors.This work was supported by Grants-in Aid for Scientific Research from the Ministry of Education, Science, and Culture of Japan (No. 56480119).This paper was presented at the 72nd Annual Meeding of International Academy of Pathology (United States-Canadian Division), Atlanta, Georgia, March 1, 1983. 相似文献
92.
93.
Yoshida E Hashimoto M Hori M Kaga M Sano H Oguchi H 《Journal of biomedical materials research. Part B, Applied biomaterials》2004,68(1):29-35
This study investigated the effects of NaOCl on resin-tooth bonds to simulate the situations of long-term durability and caries invasion. Resin-tooth bonded specimens were produced with the use of two resin adhesives (Excite and One-Bond). Resin-tooth bonded beams (adhesive area; 0.9 mm2) were serially sectioned and the specimens were immersed in 10% NaOCl medium for 0 (control), 2, 4, and 6 h after being stored in water for 24 h. After immersion, microtensile bond tests were performed. SEM fractography was conducted to calculate each failure mode by image analysis. In addition, the adhesive interface was examined with the use of TEM. In the control specimens, enamel bond strengths had no difference between Excite (45.6 +/- 15.0) and One-Bond (56.9 +/- 12.9). On the other hand, dentin bond strengths had significant difference between Excite (80.6 +/- 21.2) and One-Bond (50.7 +/- 11.2). The bond strengths decreased with increased storage time for both systems with enamel and dentin bonds. The deteriorated mineralized dentin of beams resulted in bond-strength reduction for resin-enamel bonds. For dentin bonding, the adhesive interface was gradually dissolved from the outer to the center portion of the beam. The depletion of collagen fibrils within the demineralized dentin or hybrid layer deformation was found under SEM and TEM examinations. These morphological changes are responsible for bond strength reduction of resin-dentin bonds. 相似文献
94.
Kasahara K Taguchi T Yamasaki I Kamada M Yuri K Shuin T 《Cancer Genetics and Cytogenetics》2002,137(1):59-63
In this study, we examined nine cases of advanced Japanese prostate cancer by comparative genomic hybridization (CGH) to detect chromosomal imbalances across the entire genome and to identify several new regions likely to contain genes important to the development and progression of this disease. These cases had been previously examined for numerical chromosomal aberrations by fluorescence in situ hybridization (FISH). By CGH, the following regions were found to be over-represented (gains), with fluorescence ratio values higher than the threshold: 4p, 6p, 8q, 11q, 12q, 15q, 16p, 17q, 20, and 21 (>4 cases); underrepresentation (losses) involved: 1q, 4q, 5q, 6q, 13q, 14q, and 22 (>4 cases). The shortest regions of overlap (SRO) of gains were noted at 8q24.1 through q24.3, 12q23, and 17q23 through q24 (>5 cases). The SRO of losses were seen at 5q14 through q21, 6q16.1 through q21, 13q21.3 through q22, and 14q21 (>5 cases). Notably, the gain of chromosomes 8 and 12 by CGH was in agreement with the FISH data, suggesting that the gain of chromosomes 8 and 12 may play an important role in prostate carcinogenesis. The genes on the SRO regions were also discussed in relation to oncogenes and bone metastases. 相似文献
95.
Motonobu Nishimura MD Takashi Nishimura MD Masayuki Ishikawa MD Ayumu Masuoka MD Nobuyuki Okamura MD Keiko Abe MD Takahiro Matsuoka MD Mika Iwazaki MD Kazuhito Imanaka MD Haruhiko Asano MD Shunei Kyo MD 《Journal of artificial organs》2006,9(4):209-213
The presence of a significant organ dysfunction does not immediately exclude patients from consideration for treatment with
a left ventricular assist system (LVAS). However, in treating morbid circulatory shock patients with multiple organ failure,
it is important to know the preoperative and postoperative factor or factors related to the recovery of the damaged organ
function. In this study, we retrospectively analyzed patients receiving a LVAS at our institution and tried to determine the
important factors related to the survival of patients with multisystem failure. Twenty-seven patients who underwent LVAS placement
at Saitama Medical School Hospital between 1993 and 2003 were included in this study. The preoperative risk factors analyzed
were renal dysfunction, respiratory dysfunction, hepatic dysfunction, the existence of active infection, and the combination
of all four factors. As a postoperative factor, the pump flow index (mean LVAS pump flow during the first 2 weeks after LVAS
surgery divided by the body surface area) was analyzed. None of the analyzed preoperative factors could predict survival after
LVAS surgery, but a pump flow index of less than 2.5 l/min/m2 had a significant relationship with death after LVAS surgery. Further analysis revealed that all the patients with a pump
flow index of 3.0 l/min/m2 or more could overcome preoperative organ dysfunction. Congestive heart failure patients with multisystem failure need luxury
pump flow for successful LVAS surgery; this factor could be especially important in device selection and postoperative management. 相似文献
96.
Atsushi SAITO Takashi INOUE Shinsuke SUZUKI Masayuki EZURA Hiroshi UENOHARA Teiji TOMINAGA 《Neurologia medico-chirurgica》2021,61(3):228
Few studies have reviewed the roles of perfusion magnetic resonance (MR) imaging in the histopathological examination of meningiomas. We analyzed the relationships between radiological findings on perfusion MR imaging and pathological characteristics such as origin of the tumor, mitotic activity, pathological subtype, and perifocal edema formation. The subjects were 21 surgical cases of meningioma preoperatively evaluated by perfusion MR imaging. A region of interest (ROI) was set inside of the tumor, and perifocal edema of the same size, cerebral blood volume (CBV), and cerebral blood flow (CBF) on perfusion MR and diffusion-weighted (DW) imaging were analyzed. These radiological data were evaluated in comparison with histopathological characteristics. On perfusion MR imaging, the average ratio of CBV against the contralateral side was 6.43 (1.13–20.0) and that of CBF was 7.73 (1.34–11.3). There was no significant relationship with perfusion MR imaging data, tumor volume, or perifocal edema volume. However, the large peritumoral edema group often had a higher CBV and CBF than the non-large peritumoral edema group. The skull base group had a significantly higher CBV and lower signal intensity on DW images than the non-skull base group. Signal intensity on DW images was higher in grade II or III than in grade I. Perfusion MR imaging data revealed that the higher ratio of peritumoral edema against tumor size was associated with higher blood flow and blood volume under intratumoral circulatory conditions, and that skull base meningioma had a higher blood volume than non-skull base meningioma. 相似文献
97.
98.
99.
Masayuki Takeda Yasushi Katayama Toshiki Tsutsui Hitoshi Takahashi Kazuhide Saito Shotaro Sato Tatsuhiko Yuasa Takeo Kuwabara 《Urological research》1993,21(3):193-197
Summary
31P nuclear magnetic resonance (NMR) spectroscopy of the in situ rat kidney was performed by a surface coil method, and the effects of ischemia and furosemide infusion were assessed.31P NMR spectra of the kidney subjected to 30 min of ischemia returned completely to the pre-ischemic level after 60 min of reperfusion. But the31P NMR spectra after 60 min of ischemia did not recover, even after 120 min of reperfusion. Levels of -ATP and inorganic phosphate (Pi) decreased and the chemical shift of Pi increased after intravenous infusion of furosemide. This increase in chemical shift might signal an alkalotic change in intracellular pH. Furosemide infusion prior to ischemia is thought to protect the kidney from injury induced by 60 min of warm ischemia. The chemical shift of Pi returned to the pre-ischemic level earlier than -ATP and Pi. In conclusion, according to the findings of31P NMR spectroscopy, furosemide infusion prior to ischemia may be effective in protecting the kidney against ischemic injury. But the change in Pi peak and the causes of the dissociation of Pi and -ATP should be examined further. 相似文献
100.
Takao Watanabe Okujou Iwani Shinichiro Shimbo Masayuki Ikeda 《International archives of occupational and environmental health》1993,65(Z1):S205-S208
Blood samples and 24-h duplicates of food were collected in the years around 1980 and then in 1990's from inhabitants of nonpolluted regions in Japan. The 1990 study is still in progress with 286 blood samples and 125 food duplicates already collected from 7 regions. A preliminary analysis is made in the present study with the data obtained from the 7 study regions where the survey was conducted in 1980 and then in 1990, to examine possible changes in dietary cadmium intake (Cd-D) and consequently cadmium levels in blood (Cd-B) during this 10 year period. The food duplicate analysis showed that Cd-D in 1980 was 47.1 g/day (1.74):65 [GM (GSD):N] for men and 27.7 g/day (1.75):65 for women. The counterpart values in 1990 were 29.5 g/day (1.66):40 for men and 23.8 g/day (1.73):85 for women; the difference between the two values for the same sex is significant (P<0.05) both=" in=" men=" and=" in=" women,=" suggesting=" that=" there=" occurred=" about=" 37%=" and=" 14%=" reduction=" in=" dietary=" cadmium=" intake=" during=" this=" 10=" year=" period=" in=" men=" and=" in=" women,=" respectively.=" comparison=" in=" cd-b=" showed=" that=" cd-b=" for=" men=" and=" women=" in=" 1990=" were=" 1.79=">0.05)>g/l (2.01):121 and 1.84 g/l; (1.67):165, respectively, whereas the counterpart values in 1980 were 3.84 g/l (1.64):123 and 3.57 g/l (1.42):141, respectively, indicating significant (P<0.01) reduction=" in=" cd-b=" in=" both=" sexes=" in=" parallel=" to=" the=" reduction=" in=" cd-d.=" the=" role=" of=" rice=" as=" a=" major=" source=" of=" cadmium=" among=" japanese=" population=" together=" with=" recent=" reduction=" in=" the=" importance=" is=" discussed;=" cd=" in=" rice=" accounted=" for=" 72%=" in=" late=" 1970's,=" whereas=" it=" is=" about=" 35%=" in=" the=" present=">0.01)> 相似文献