全文获取类型
收费全文 | 17042篇 |
免费 | 875篇 |
国内免费 | 100篇 |
专业分类
耳鼻咽喉 | 108篇 |
儿科学 | 226篇 |
妇产科学 | 146篇 |
基础医学 | 2104篇 |
口腔科学 | 497篇 |
临床医学 | 1318篇 |
内科学 | 4358篇 |
皮肤病学 | 262篇 |
神经病学 | 1234篇 |
特种医学 | 627篇 |
外科学 | 3256篇 |
综合类 | 46篇 |
预防医学 | 398篇 |
眼科学 | 259篇 |
药学 | 1156篇 |
中国医学 | 22篇 |
肿瘤学 | 2000篇 |
出版年
2023年 | 100篇 |
2022年 | 162篇 |
2021年 | 357篇 |
2020年 | 196篇 |
2019年 | 276篇 |
2018年 | 294篇 |
2017年 | 276篇 |
2016年 | 295篇 |
2015年 | 327篇 |
2014年 | 382篇 |
2013年 | 480篇 |
2012年 | 740篇 |
2011年 | 736篇 |
2010年 | 445篇 |
2009年 | 375篇 |
2008年 | 697篇 |
2007年 | 725篇 |
2006年 | 730篇 |
2005年 | 754篇 |
2004年 | 736篇 |
2003年 | 700篇 |
2002年 | 728篇 |
2001年 | 639篇 |
2000年 | 662篇 |
1999年 | 584篇 |
1998年 | 253篇 |
1997年 | 178篇 |
1996年 | 156篇 |
1995年 | 142篇 |
1994年 | 133篇 |
1993年 | 142篇 |
1992年 | 522篇 |
1991年 | 485篇 |
1990年 | 444篇 |
1989年 | 426篇 |
1988年 | 344篇 |
1987年 | 319篇 |
1986年 | 302篇 |
1985年 | 258篇 |
1984年 | 170篇 |
1983年 | 158篇 |
1979年 | 140篇 |
1978年 | 94篇 |
1977年 | 79篇 |
1975年 | 64篇 |
1974年 | 85篇 |
1973年 | 72篇 |
1972年 | 79篇 |
1971年 | 72篇 |
1969年 | 64篇 |
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
1.
Dalton Luiz Schiessel Ricardo K. Yamazaki Marcelo Kryczyk Isabela Coelho de Castro Adriana A. Yamaguchi Danielle C. T. Pequito 《Nutrition and cancer》2016,68(8):1369-1380
Objective: Polyunsaturated fatty acids n-3 (PUFA n-3) have shown effects in reducing tumor growth, in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) abundantly present in fish oil (FO). When these fatty acids are provided in the diet, they alter the functions of the cells, particularly in tumor and immune cells. However, the effects of α-linolenic fatty acid (ALA), which is the precursor of EPA and DHA, are controversial. Thus, our objective was to test the effect of this parental fatty acid. Methods: Non-tumor-bearing and tumor-bearing Wistar rats (70 days) were supplemented with 1 g/kg body weight of FO or Oro Inca® (OI) oil (rich in ALA). Immune cells function, proliferation, cytokine production, and subpopulation profile were evaluated. Results: We have shown that innate immune cells enhanced phagocytosis capacity, and increased processing and elimination of antigens. Moreover, there was a decrease in production of pro-inflammatory cytokines (tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6)) by macrophages. Lymphocytes showed decreased proliferation capacity, increased cluster of differentiation 8 (CD8+) subpopulation, and increased TNF-α production. Conclusions: Oil rich in ALA caused similar immune modulation in cancer when compared with FO. 相似文献
2.
3.
Sadahiro Hijikata Igen Hongo Shu-ichi Nakayama Tetsuo Yamaguchi Yoshiyuki Sekikawa Toshihiro Nozato Takashi Ashikaga 《The Canadian journal of cardiology》2019,35(1):104.e9-104.e11
Syphilis is a sexually transmitted disease caused by Treponema pallidum. Syphilitic aortitis might coexist in a dysfunctional aortic valve, but the etiology remains unclear, because microbiological diagnosis is difficult. A 62-year-old man with low-grade fever was diagnosed with aortitis and infective endocarditis, due to Treponema pallidum infection, using polymerase chain reaction analysis. This case suggests that syphilis might cause infective endocarditis. 相似文献
4.
5.
Kota Sahara Rin Yamada Takashi Fujiwara Koichi Koizumi Shin‐ichiro Horiguchi Tsunekazu Hishima Tatsuro Yamaguchi 《Digestive endoscopy》2015,27(7):768-771
Idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) is a rare and poorly understood ischemic colitis that occurs in the rectosigmoid colon of predominantly young, previously healthy, male patients. A 76‐year‐old Japanese man presented to our hospital with a 1‐year history of worsening diarrhea, lower abdominal pain, and weight loss (−6 kg). Laboratory evaluation revealed white blood cell count of 13 200/μL, C‐reactive protein level of 2.0 mg/dL (normal range, 0.0–0.3), and negative results for stool culture (including Clostridium difficile). Colonoscopy showed circumferential and edematous narrowing of the sigmoid colon with deep longitude ulceration. Biopsy was done and examination of the specimen demonstrated no specific ischemia. The patient was treated with bowel rest, antibiotics, and i.v. fluids; however, his symptoms worsened. Finally, sigmoidectomy was carried out. Histological examination demonstrated significant myointimal hyperplasia of mesenteric veins leading to thickening and stenosis of the venous lumen. Therefore, the final diagnosis was IMHMV. Three months following sigmoidectomy, he was asymptomatic. 相似文献
6.
Regional fractional ventilation mapping in spontaneously breathing mice using hyperpolarized 129Xe MRI 下载免费PDF全文
Hirohiko Imai Hironobu Matsumoto Erika Miyakoshi Shintaro Okumura Hideaki Fujiwara Atsuomi Kimura 《NMR in biomedicine》2015,28(1):24-29
The feasibility of ventilation imaging with hyperpolarized (HP) 129Xe MRI has been investigated for quantitative and regional assessment of ventilation in spontaneously breathing mice. The multiple breath ventilation imaging technique was modified to the protocol of spontaneous inhalation of HP 129Xe delivered continuously from a 129Xe polarizer. A series of 129Xe ventilation images was obtained by varying the number of breaths before the 129Xe lung imaging. The fractional ventilation, r, was successfully evaluated for spontaneously breathing mice. An attempt was made to detect ventilation dysfunction in the emphysematous mouse lung induced by intratracheal administration of porcine pancreatic elastase (PPE). As a result, the distribution of fractional ventilation could be visualized by the r map. Significant dysfunction of ventilation was quantitatively identified in the PPE‐treated group. The whole‐lung r value of 0.34 ± 0.01 for control mice (N = 4) was significantly reduced, to 0.25 ± 0.07, in PPE‐treated mice (N = 4) (p = 0.038). This study is the first application of multiple breath ventilation imaging to spontaneously breathing mice, and shows that this methodology is sensitive to differences in the pulmonary ventilation. This methodology is expected to improve simplicity as well as noninvasiveness when assessing regional ventilation in small rodents. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
7.
Shinichiro Uchiyama Takao Hoshino Leila Sissani Monteiro Tavares Linsay Kenji Kamiyama Taizen Nakase Kazuo Kitagawa Kazuo Minematsu Kenichi Todo Yasushi Okada Jyoji Nakagawara Ken Nagata Hiroshi Yamagami Takenori Yamaguchi Pierre Amarenco 《Journal of stroke and cerebrovascular diseases》2019,28(8):2232-2241
BackgroundTIAregistry.org is an international cohort of patients with transient ischemic attack (TIA) or minor stroke within 7 days before enrollment in the registry. Main analyses of 1-year follow-up data have been reported.5 We conducted subanalysis on the baseline and 1-year follow-up data of Japanese patients.MethodsThe patients were classified into 2 groups based on Japanese ethnicity, Japanese (345) and non-Japanese (3238), and their baseline data and 1-year event rates were compared. We also determined risk factors and predictors of 1-year stroke.ResultsCurrent smoking, regular alcohol drinking, intracranial arterial stenosis, and small vessel occlusion; and hypertension, dyslipidemia, coronary artery disease, and extracranial arterial stenosis were more and less common among Japanese patients, respectively. Stroke risk was higher and TIA risk was lower at 1-year follow-up among Japanese patients. The baseline risk factors for recurrent stroke were diabetes, alcohol drinking, and large artery atherosclerosis. Independent predictors of 1-year stroke risk were prior congestive heart failure and alcohol consumption.ConclusionsThe two populations of patients featured differences in risk factors, stroke subtypes, and outcome events. Predictors of recurrent stroke among Japanese patients included congestive heart failure and regular alcohol drinking. Strategies to attenuate residual risk of stroke aside from adherence to current guidelines should take our Japanese-patient specific findings into account. 相似文献
8.
Marie Ohata Susumu Fujiwara Ai Yoshioka Hiroshi Nagai Shintaro Sugita Nozomi Yamano Yusuke Inoue Chikako Nishigori 《Pediatric dermatology》2019,36(6):997-998
Fibroblastic connective tissue nevus (FCTN) is a benign cutaneous mesenchymal lesion characterized by proliferation of CD34‐positive fibroblastic/myofibroblastic spindle‐shaped cells. We report a case of agminated FCTN on the right lower abdomen of a 1‐year‐old boy. 相似文献
9.
Intraductal papillary mucinous tumor (IPMT) of the pancreas is characterized by slow growth and a relatively favorable prognosis, however, invasive cancer originating in an IPMT is associated with a poor prognosis. Although various parameters in imaging modalities have been advocated to differentiate between benign IPMN and malignant ones, it is not easy to obtain definite diagnosis based on these parameters. Peroral pancreatoscopy (POPS) allows a clear and direct visualization of the pancreatic duct, providing useful information regarding tumor nature in IPMT. The authors have studied the usefulness of POPS in the diagnosis of IPMT. Nevertheless, its usefulness is not necessarily widely accepted and the significance of POPS is still controversial. In this review, the authors intended to address the diagnostic value of POPS and to clarify its role in the diagnosis of IPMT. The authors think treatment of IPMT can be improved by introducing POPS because the determination of surgical procedure as well as the area of resection based on the preoperative diagnosis of the involvement of the main pancreatic duct and branch duct is inevitable. 相似文献
10.
Hitoshi Tajiri M.D Kosuke Kozaiwa M.D Tokuzo Harada M.D Yoshikazu Ozaki M.D Kazunori Miki M.D Kazuo Shimizu M.D Shintaro Okada M.D. 《Pediatrics international》1991,33(3):323-326
We assessed the efficacy of a government-sponsored mass protection program in Osaka, Japan, for perinatal HBV infection in infants born to HBeAg positive HBV carrier mothers. We also evaluated the impact of optional follow-up procedures in such infants, including an evaluation of anti-HBs response and a booster dose of HBV vaccine for poor responders. The results demonstrated that this mass protection program protected 94.4% of the infants from perinatal HBV infection in the Osaka area. However, the proportion of infants with an unprotective level of anti-HBs was higher in the standard group than in the follow-up group both at 1.0 and 1.5 years of age, which was also the case for HBV events. Furthermore, the present study showed that a booster dose of vaccine in poor responders was very effective in promoting an anti-HBs response. In conclusion, we recommend that a follow-up blood test to confirm a response of anti-HBs to HBV vaccine should be performed at 4–8 weeks after the third injection of HBV vaccine in infants born to HBeAg positive HBV carrier mothers. We also recommend that a booster injection of HBV vaccine should be immediately given to poor responding infants who otherwise are at a considerable risk of developing HBV infection in late infancy. 相似文献