全文获取类型
收费全文 | 15200篇 |
免费 | 638篇 |
国内免费 | 91篇 |
专业分类
耳鼻咽喉 | 263篇 |
儿科学 | 252篇 |
妇产科学 | 158篇 |
基础医学 | 1760篇 |
口腔科学 | 415篇 |
临床医学 | 873篇 |
内科学 | 3716篇 |
皮肤病学 | 356篇 |
神经病学 | 1455篇 |
特种医学 | 586篇 |
外科学 | 2153篇 |
综合类 | 61篇 |
一般理论 | 1篇 |
预防医学 | 384篇 |
眼科学 | 438篇 |
药学 | 1146篇 |
中国医学 | 27篇 |
肿瘤学 | 1885篇 |
出版年
2023年 | 52篇 |
2022年 | 102篇 |
2021年 | 216篇 |
2020年 | 109篇 |
2019年 | 159篇 |
2018年 | 265篇 |
2017年 | 203篇 |
2016年 | 270篇 |
2015年 | 255篇 |
2014年 | 351篇 |
2013年 | 469篇 |
2012年 | 705篇 |
2011年 | 761篇 |
2010年 | 454篇 |
2009年 | 386篇 |
2008年 | 802篇 |
2007年 | 914篇 |
2006年 | 942篇 |
2005年 | 984篇 |
2004年 | 930篇 |
2003年 | 864篇 |
2002年 | 892篇 |
2001年 | 387篇 |
2000年 | 335篇 |
1999年 | 345篇 |
1998年 | 247篇 |
1997年 | 218篇 |
1996年 | 184篇 |
1995年 | 175篇 |
1994年 | 164篇 |
1993年 | 155篇 |
1992年 | 240篇 |
1991年 | 202篇 |
1990年 | 224篇 |
1989年 | 181篇 |
1988年 | 179篇 |
1987年 | 186篇 |
1986年 | 159篇 |
1985年 | 171篇 |
1984年 | 135篇 |
1983年 | 111篇 |
1982年 | 73篇 |
1981年 | 60篇 |
1980年 | 66篇 |
1979年 | 88篇 |
1978年 | 53篇 |
1977年 | 67篇 |
1976年 | 43篇 |
1975年 | 45篇 |
1974年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
Aim: The purpose of the present study was to investigate the differences in nutritive sucking patterns between very low, extremely low birth‐weight infants (LBWI) and full‐term infants (FTI) and to examine the change in those sucking patterns within 5 months after birth. Methods: Sucking patterns of eight LBWI and seven FTI were compared. In addition, sucking patterns were measured in four of the LBWI and seven of the FTI until 5 months of age to determine change in sucking wave patterns over time. Results: During the first month after birth, there was a significant difference in the sucking wave between the LBWI and FTI. The sucking cycle time was significantly shorter and the intensity of the sucking pressure was significantly smaller in the LBWI than that in the FTI. By 5 months, significant correlations were noted between the actual age or the modified age and the sucking pressure in both LBWI and FTI. Conclusions: The findings suggest that the weakness of oral muscular function and less sucking skill can bring about the weakness of intensity of sucking pressure, decreased time of the sucking stage in a sucking cycle, and unstable intensity of sucking pressure and time of the sucking stage in LBWI infants, causing low efficiency of milk intake and smaller amounts of milk swallowing during each sucking period as they obstructs the development of oral muscular function itself. These problems last for a longer period of time in LBWI than in FTI, leading to a deficit in the development of masticatory function in LBWI. The results of the current pilot study will serve as a foundation to investigate the development of masticatory function in LBWI as they grow into early childhood. 相似文献
82.
Chiaki Isobe Takahiko Murata Chigumi Sato Yasuo Terayama 《Journal of clinical neuroscience》2007,14(4):340-343
The concentrations of oxidized coenzyme Q-10 (CoQ-10) and reduced CoQ-10 in the cerebrospinal fluid (CSF) of patients with Parkinson's disease (PD) was examined in order to determine whether the balance in oxidized and reduced CoQ-10 is related to the pathogenesis of PD. The percentage of oxidized/total CoQ-10 (%CoQ-10) in the CSF was significantly higher in the untreated PD group (80.3+/-17.9%) compared to the normal control group (68.2+/-20.4%) (p<0.05). The %CoQ-10 in the CSF of PD patients showed significant negative correlation with the duration of illness. These findings in living patients provide in vivo evidence for a possible role for %CoQ-10 in the pathogenesis in the early stages of PD development. 相似文献
83.
Toshihisa Inoue MD Shigeru Watanabe MD Yoshiaki Masuda MD Katsuya Yoshida MD Hitoshi Imai MD Yasuo Imazeki MD Yoshiaki Ishizuya MD Masashi Koga MD Hirotoshi Kato MD Hiroo Ikehira MD Yukio Tateno MD 《Clinical imaging》1996,20(4):262-268
The magnetic resonance phase-contrast technique for the measurement of flow velocity and volume in true and false lumens was studied in six patients with chronic dissecting aneurysms. Phase-contrast images were obtained at a level perpendicular to the dissecting aneurysms of the descending aorta. As the maximum diameter of aneurysms increased, the ratio of the cross-sectional area of the false to the true lumen increased and the peak average velocity in the true lumen during systole was decreased. This technique proved invaluable for determining prognosis and operability for this condition. 相似文献
84.
Yoshimi Otani Ichiro Yoshida Satoshi Ohki Motoi Kano Osamu Kawashima Masao Suzuki Yasushi Sato Toru Takahashi Akio Ohtaki Susumu Ishikawa Yasuo Morishita 《Surgery today》1997,27(9):812-815
Pulmonary aspergillosis associated with old tuberculosis is generally resistant to treatment. Thus, if patients are treated
only with conservative therapy, their condition continues to deteriorate due to repetitive hemoptysis, and may even become
critical. Surgical treatment is required for these patients; however, it is extremely difficult to resect the lesion due to
severe adhesions to the chest wall and vascular proliferation surrounding the lesion. We performed preoperative arterial embolization,
achieving good results in three patients with hemoptysis caused by pulmonary aspergillosis. The feeding arteries were embolized
using microcoils and/or gelatin sponges, and a lobectomy was safely carried out in all patients. We concluded that preoperative
arterial embolization is a safe and effective technique to prevent massive hemorrhage occurring at the time of surgery.
This work was presented at the 11th Annual Meeting of the Japanese Association for Chest Surgery, held in Kyoto, Japan, May
13–14, 1994 相似文献
85.
Yuichi Ando Kenji Kikuchi Naoya Ichikawa Kazuhiko Meigata Yuji Nomura Kenshi Watanabe Yoshifumi Beck Hisakazu Degawa Shinji Tomikawa Takeshi Nagao Hisanori Chida 《Surgery today》1997,27(4):353-356
We herein report the case of a 53-year-old man with a nonspecific acute colonic ulcer whose liver function deteriorated after he had undergone hepatectomy. He was referred to our hospital for a hepatoma caused by hepatitis B virus and a right hemihepatectomy was performed. His liver function was poor after the operation, and minor complications such as pleural effusion and biliary fistula developed. A large amount of melena was seen 29 days after the hepatectomy and he developed hemorrhagic shock. Superior mesenteric arteriography revealed pooling of blood in both the hepatic flexure of the ascending colon and the cecum. An emergency right hemicolectomy was performed. There was a 5 x 1-mm ulcer 18 cm distal to the ileocecal valve. Numerous erosions were observed to be scattered throughout the colonic mucosa. The patient recovered slowly and was discharged 6 months after the hepatectomy. This is the first report of an acute colonic ulcer that could have been caused by liver dysfunction. 相似文献
86.
Tomoyuki Kawada M.D. Yasuo Kiryu M.D. Shigenobu Aoki Ph.D. Shosuke Suzuki M.D. 《Psychiatry and clinical neurosciences》1992,46(4):937-940
Abstract: The possibility on placing electrodes at Fpz-A2 instead of C3 -A2 was investigated to obtain a more stable configuration avoiding obstruction by the hair. Our original system of alpha wave detection by a microcomputer was used, and a total of 22 all-night hypnograms of five healthy young students waa recorded. Pearson's moment correlation coefficients of alpha wave % between the two positions were 0.780–0.948. Except for one subject, alpha wave % taken at Fpz-A2 tended to be 3–5% lower than that at C3 -A2 . The above analysis indicates that using EEG electrode position of Fpz-A2 is valid and useful as a stable electrode configuration for a long-time monitoring. 相似文献
87.
Gen Matsuo Yasuo Matsumura Kiyoshi Tadano Takashi Hashimoto Shiro Morimoto 《Clinical and experimental pharmacology & physiology》1997,24(7):487-491
1. The effects of sarafotoxin S6c (S6c), a selective endothelin ETB receptor agonist, on renal haemodynamics and urine formation were examined in anaesthetized dogs. 2. Intrarenal arterial infusion of S6c at a rate of 1 or 5 ng/kg per min produced a transient increase in renal blood flow (RBF), with no change in systemic blood pressure and heart rate; RBF then decreased gradually to below the basal value. There were significant and dose-dependent increases in urine flow and free water clearance and decreases in urine osmolality during S6c infusion, whereas urinary excretion of sodium and glomerular filtration rate (GFR) remained unchanged. Simultaneously, S6c administration elicited a marked increase in urinary excretion of nitric oxide (NO) metabolites, N02? and N03? (UNO*V). 3. In dogs simultaneously administered S6c (5 ng/kg per min) and iVG-nitro-L-arginine (NOARG; 40 (jig/kg per min), a NO synthase inhibitor, the renal vasodilator effect of S6c was abolished and marked reductions in RBF and GFR were observed. The S6c-induced diuretic action was not affected by NOARG. In the presence of NOARG, there was a small amount of UNOxV at the basal level and the administration of S6c did not increase UNOxV. 4. These results suggest that an intrarenal arterial infusion of S6c enhances the production of NO in the kidney and that this enhancement contributes to the peptide-induced renal vasodilation. In contrast, it is unlikely that S6c-induced water diuresis is related to NO production stimulated by this peptide. 相似文献
88.
Tatsuya Nomura Tokihiro Yoshikawa Hideo Kato Keiya Nikkuni Koichi Sasaki Yoshio Shirai Katsuyoshi Hatakeyama 《Surgery today》1997,27(4):334-336
A case of early gastric cancer, limited to submucosal layer, which was manifested as cerebral metastasis is presented herein. A 47-year-old man was admitted to Nagaoka Chuo General Hospital with convulsions and a disturbance in consciousness, where a computed tomography (CT) scan revealed a cerebral tumor in the left temporal lobe. The resected tumor was identified as a metastatic adenocarcinoma. Further investigation revealed gastric cancer involving the posterior wall of the cardia. At laparotomy, multiple and small metastases of the liver and a jejunal metastasis were found, and a palliative total gastrectomy was performed. The surgical specimen revealed a protruding, poorly differentiated medullary adenocarcinoma, with invasion of the submucosal layer. The patient died 4 months after undergoing the laparotomy. This case report is presented to make clinicians aware of the possibility that early gastric cancers may present as brain metastasis. 相似文献
89.
S Arai C Arai M Fujimaki Y Iwamoto M Kawarada Y Saito Y Nomura T Suzuki 《Journal of comparative pathology》1991,104(4):439-441
Cutaneous tumour-like growths were observed on the face and other areas of the body surface of young Chilean flamingos. In the cells of these lesions, avian pox-specific cytoplasmic inclusion bodies were observed by light microscopy and virus particles were detected under an electron-microscope. It was diagnosed as avian pox. 相似文献
90.
Extracellular single-unit activity was recorded from 21 median preoptic nucleus (MnPO) neurones, antidromically identified as projecting to the hypothalamic paraventricular nucleus (PVN), in urethane-anaesthetized male rats. Of these identified MnPO neurones, 14 displayed an excitatory response in neuronal excitability following electrical stimulation (5 Hz, 600 microA) of the A1 noradrenergic region of the ventrolateral medulla, while the remaining neurones were unresponsive. The excitatory response of MnPO neurones was blocked by microiontophoretically applied phentolamine, an alpha-adrenoceptor antagonist, but not by timolol, a beta-adrenoceptor antagonist. These results suggest that the A1 region acts to enhance the activity of MnPO neurones projecting to the PVN via an alpha-adrenoceptor mechanism. 相似文献