全文获取类型
收费全文 | 14882篇 |
免费 | 698篇 |
国内免费 | 104篇 |
专业分类
耳鼻咽喉 | 94篇 |
儿科学 | 350篇 |
妇产科学 | 190篇 |
基础医学 | 1914篇 |
口腔科学 | 351篇 |
临床医学 | 757篇 |
内科学 | 3736篇 |
皮肤病学 | 484篇 |
神经病学 | 1129篇 |
特种医学 | 923篇 |
外科学 | 2773篇 |
综合类 | 61篇 |
一般理论 | 2篇 |
预防医学 | 378篇 |
眼科学 | 237篇 |
药学 | 714篇 |
中国医学 | 26篇 |
肿瘤学 | 1565篇 |
出版年
2023年 | 82篇 |
2022年 | 154篇 |
2021年 | 300篇 |
2020年 | 192篇 |
2019年 | 218篇 |
2018年 | 289篇 |
2017年 | 260篇 |
2016年 | 346篇 |
2015年 | 356篇 |
2014年 | 476篇 |
2013年 | 569篇 |
2012年 | 797篇 |
2011年 | 918篇 |
2010年 | 584篇 |
2009年 | 506篇 |
2008年 | 888篇 |
2007年 | 909篇 |
2006年 | 918篇 |
2005年 | 932篇 |
2004年 | 876篇 |
2003年 | 831篇 |
2002年 | 912篇 |
2001年 | 258篇 |
2000年 | 217篇 |
1999年 | 246篇 |
1998年 | 254篇 |
1997年 | 193篇 |
1996年 | 225篇 |
1995年 | 176篇 |
1994年 | 139篇 |
1993年 | 129篇 |
1992年 | 179篇 |
1991年 | 142篇 |
1990年 | 139篇 |
1989年 | 128篇 |
1988年 | 116篇 |
1987年 | 91篇 |
1986年 | 107篇 |
1985年 | 83篇 |
1984年 | 77篇 |
1983年 | 61篇 |
1982年 | 42篇 |
1981年 | 50篇 |
1980年 | 50篇 |
1979年 | 37篇 |
1978年 | 30篇 |
1977年 | 31篇 |
1976年 | 29篇 |
1975年 | 19篇 |
1971年 | 16篇 |
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
1.
Takao Itoi Atsushi Sofuni Fumihide Itokawa Yasushi Shinohara Kazuya Takeda Kazuto Nakamura Toshio Kurihara Takayoshi Tsuchiya Fuminori Moriyasu 《Digestive endoscopy》2006,18(3):232-238
We describe our methods and outcomes of multidisciplinary treatments in patients with unresectable hilar cholangiocarcinoma. Fifty‐seven patients with a known outcome were enrolled. Thirty‐four of 57 patients were treated and evaluated by salvage therapy. For salvage therapy, we used internal and external radiotherapy, photodynamic therapy, YAG laser therapy and microwave coagulation therapy. The median survival time was 548 days for the group receiving salvage therapy and 198 days for the group not receiving this treatment. In conclusion, although no randomization of the patients was performed in this retrospective study, our present data provide convincing evidence that salvage therapy is a useful therapeutic approach for unresectable hilar cholangiocarcinomas. 相似文献
2.
Kazunori Aizawa Takeshi Hanaoka Hiroki Kasai Kaoru Kogashi Setsuo Kumazaki Jun Koyama Hiroshi Tsutsui Yoshikazu Yazaki Noboru Watanabe Osamu Kinoshita Uichi Ikeda 《Hypertension research》2006,29(2):123-128
The phosphodiesterase-5 (PDE-5) inhibitor, sildenafil, has been reported to produce sustained pulmonary vasodilatation in patients with pulmonary hypertension (PH). Recently, vardenafil, a more potent and selective PDE-5 inhibitor than sildenafil, has been approved for the treatment of erectile dysfunction. However, the long-term effects of oral vardenafil in patients with PH are unknown. We studied five consecutive patients with PH; one with primary pulmonary hypertension, two with chronic pulmonary thromboembolism, one with Eisenmenger syndrome (ventricular septal defect) and one with secondary pulmonary hypertension after a ventricular septal defect closure operation. In an acute hemodynamic trial, vardenafil (5 mg) significantly decreased both the pulmonary vascular resistance (PVR) and systemic vascular resistance (SVR) with an increase in cardiac output. In a chronic hemodynamic trial, the maintenance dose of vardenafil (10 to 15 mg) for 3 months significantly decreased the PVR, but not the SVR, with a 20.7% reduction of the PVR/ SVR ratio. Plasma brain natriuretic peptide (BNP) levels were also significantly decreased after 3 months. This pilot study demonstrates that long-term oral vardenafil therapy may be a safe and effective treatment for patients with PH. 相似文献
3.
Osamu Tochikubo Naoki Kura Hiroko Tokita Seiko Sakon Kiyoko Nishijima 《Hypertension research》2006,29(4):233-241
Direct measurement of intra-arterial blood pressure (BP) for 24-h provides approximately 100,000 values that vary enormously, but each (BPi) can be expressed by the equation BPi = BP0 + DeltaBPi (BP0, base BP; DeltaBPi, BP increment, i=1, 2, ..., 100 x 10(3)). About 20% of outpatients with hypertension exhibit white-coat hypertension (WCH). In such patients, DeltaBPc (i = c; c, time at the clinic) is surmised to be large. A method for explaining the physiological factors in DeltaBPc and the estimation of base BP in the outpatient clinic is important. This study addresses this issue. A total of 293 subjects were divided into four groups: 1) WCH group, 45 individuals (office BP > or = 140/90 mmHg and 24-h indirect BP < 125/80 mmHg); 2) normotensive (NT) group, 84 controls matched for age and sex; 3) WHO-I group, 95 hypertensive patients with WHO stage I (office BP > or = 140/90 mmHg and 24-h BP > or = 125/80 mmHg); and 4) WHO-II group, 69 hypertensive patients with WHO stage II. Their BPc and heart rate (HR; HRc, clinic HR) values were measured by a BP-ECG monitoring device in the outpatient clinic. Power-spectral analysis was used to obtain the ratio between the low-frequency component (LF) and high-frequency component (HF) of ECG-RR variability (LF/HF = LH). Twenty-four-hour indirect BP (and BP0) and base HR (HR0) were measured by a portable device (TM2425) at 30-min intervals. Then, DeltaBPc (= BPc - BP0) was estimated by performing linear multivariate analysis applying the model equation DeltaBPc = (BPc -alphaLH)(1-betaHR0/HRc) + epsilon to the above variables (alpha and beta, constant values; epsilon, error). This model equation made it possible to estimate BP0 (and DeltaBPc) with a high coefficient of correlation (r > or = 0.85, mean of error less than 0.82 +/- 5.9 mmHg). The predictive accuracy for discrimination between WCH and sustained hypertension (WHO-I and WHO-II groups) by this equation was 88%. The new DeltaBP-estimation device (BP-ECG monitor) enabled us to infer BP0 and is therefore useful in estimating WCH in the outpatient clinic. 相似文献
4.
5.
6.
7.
Yoshinobu Okabe Osamu Tsuruta Yoshiki Naito Hideya Suga Michio Sata 《Digestive endoscopy》2007,19(Z1):S121-S125
Regarding peroral cholangioscopy (POCS) for biliary disease, due to the recent appearance of a video cholangioscope that can obtain high‐quality images, it is possible to observe subtle changes of the biliary mucosa. In addition to the conventional observation method using POCS, the biliary mucosa with also observed with narrow band imaging (NBI) in one case of chronic cholangitis and four cases of extra hepatic bile duct tumor (three surgical cases). In the conventional observation method, the vessels in the surface layer of the biliary mucosa could be observed more clearly using NBI. In one case in which a tumor was observed, the irregularity of the biliary mucosa became clear on NBI, and the vessels inside a papillary tumor could also be easily observed. In another case of bile duct tumor, the conventional observation method showed a region in the proximity of the tumor where the vessels could not be seen clearly, but they could be seen clearly on NBI. In all of the cases, the bile juice was seen as red on NBI, which disturbed the observation. With POCS using NBI, it was possible to observe the vessels and irregularities in the surface layer of the biliary mucosa more clearly than with conventional observation methods. 相似文献
8.
Tsuneharu Miki Yoichi Mizutani Hideyuki Akaza Seiichiro Ozono Taiji Tsukamoto Toshiro Terachi Katsusuke Naito Norio Nonomura Isao Hara Osamu Yoshida The Japan Blood Cell Transplantation Study Group for Testicular Germ Cell Tumor 《International journal of urology》2007,14(1):54-59
OBJECTIVE: Standard chemotherapy shows relatively low long-term survival in patients with poor-risk testicular germ cell tumor (GCT). First-line high-dose chemotherapy (HD-CT) may improve the result. High-dose carboplatin, etoposide, ifosfamide chemotherapy followed by autologous peripheral blood stem cell transplantation (PBSCT) was investigated as first-line chemotherapy in patients with advanced testicular GCT. METHODS: Fifty-five previously untreated testicular GCT patients with Indiana 'advanced disease' criteria received three cycles of bleomycin, etoposide and cisplatin (BEP) followed by one cycle of HD-CT plus PBSCT, if elevated serum tumor markers were observed after three cycles of the BEP regimen. RESULTS: Thirty patients were treated with BEP alone, because the tumor marker(s) declined to normal range. Twenty-five patients received BEP and HD-CT. One patient died of rhabdomyolysis due to HD-CT. Three and six (13% and 25%) out of 24 patients treated with BEP and HD-CT achieved marker-negative and marker-positive partial responses, respectively. The other patients achieved no change. Fifteen (63%) are alive and 14 (58%) are free of disease at a median follow-up time of 54 months. Severe toxicity included treatment-related death (4%). CONCLUSIONS: HD-CT with peripheral stem cell support can be successfully applied in a multicenter setting. HD-CT demonstrated modest anticancer activity for Japanese patients with advanced testicular GCT and was well tolerated. This regimen might be examined for further investigation in randomized trials in first-line chemotherapy for patients with poor-risk testicular GCT. 相似文献
9.
Nobuhiro Kawatsuki Ken Takatani Tohei Yamamoto Osamu Sangen 《Macromolecular chemistry and physics.》1997,198(9):2853-2866
Photoreactive (meth)acrylate monomers having mesogenic groups based on 4-hexyloxy-4′-(3-methyl-2-butenyloxy)biphenyl and 4-hexyloxy-4′-(2-butenyloxy)biphenyl were synthesized. Methacrylate monomers ( 3c, d ) and acrylate monomer having 3-methyl-2-butenyloxy group ( 3b ) were polymerized by free radical mechanism; the acrylate monomer having 2-butenyloxy group ( 3a ) caused gelation during the polymerization. To obtain photoreactivity, 4-benzoylphenyl (meth)acrylates were radically copolymerized with monomers 3b and 3d . Thermal behavior of (co)polymers was determined by differential scanning calorimetry, polarized optical microscopy and temperature-controlled X-ray analysis. (Co)polymers showed liquid-crystalline behaviour with nematic and smectic phases. UV-irradiation was used to photochemically crosslink copolymer films, and the resultant films were insoluble in organic solvents. The uniaxially oriented copolymer thin film was photo-crosslinked and showed thermally stable orientation. 相似文献
10.