全文获取类型
收费全文 | 19585篇 |
免费 | 969篇 |
国内免费 | 99篇 |
专业分类
耳鼻咽喉 | 229篇 |
儿科学 | 454篇 |
妇产科学 | 287篇 |
基础医学 | 2416篇 |
口腔科学 | 552篇 |
临床医学 | 1389篇 |
内科学 | 5370篇 |
皮肤病学 | 404篇 |
神经病学 | 1643篇 |
特种医学 | 363篇 |
外科学 | 2981篇 |
综合类 | 128篇 |
一般理论 | 6篇 |
预防医学 | 1543篇 |
眼科学 | 497篇 |
药学 | 1074篇 |
1篇 | |
中国医学 | 53篇 |
肿瘤学 | 1263篇 |
出版年
2024年 | 14篇 |
2023年 | 147篇 |
2022年 | 385篇 |
2021年 | 723篇 |
2020年 | 334篇 |
2019年 | 625篇 |
2018年 | 735篇 |
2017年 | 413篇 |
2016年 | 448篇 |
2015年 | 559篇 |
2014年 | 718篇 |
2013年 | 934篇 |
2012年 | 1557篇 |
2011年 | 1645篇 |
2010年 | 884篇 |
2009年 | 849篇 |
2008年 | 1333篇 |
2007年 | 1322篇 |
2006年 | 1256篇 |
2005年 | 1190篇 |
2004年 | 1041篇 |
2003年 | 916篇 |
2002年 | 807篇 |
2001年 | 194篇 |
2000年 | 170篇 |
1999年 | 186篇 |
1998年 | 151篇 |
1997年 | 135篇 |
1996年 | 102篇 |
1995年 | 83篇 |
1994年 | 83篇 |
1993年 | 63篇 |
1992年 | 82篇 |
1991年 | 81篇 |
1990年 | 65篇 |
1989年 | 34篇 |
1988年 | 31篇 |
1987年 | 35篇 |
1986年 | 35篇 |
1985年 | 30篇 |
1984年 | 32篇 |
1983年 | 20篇 |
1982年 | 34篇 |
1981年 | 27篇 |
1980年 | 17篇 |
1978年 | 10篇 |
1977年 | 11篇 |
1975年 | 10篇 |
1974年 | 24篇 |
1973年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
Maria Hortal Miguel Estevan Ines Iraola Bremen De Mucio 《International journal of infectious diseases》2007,11(3):273-277
BACKGROUND: Population-based studies on childhood community-acquired pneumonia are scarce in Latin America. Pneumococcal epidemiology is poorly defined, hence the World Health Organization recommended standardized chest radiograph interpretation to improve the approach to bacterial pneumonia. Therefore, our study aimed to estimate the burden of pneumonia in hospitalized children. METHODS: A three-year surveillance study was carried out in four hospitals covering a population of 229,128 inhabitants of whom 10.2% were under five years of age. Clinical records and digitization of their chest radiographs were obtained. A pediatrician and a pediatric radiologist blinded to the clinical diagnosis interpreted the digital images. RESULTS: Of 2034 patients, 826 (40.6%) had consolidated pneumonia, 941 (46.3%) had non-consolidated pneumonia, and 267 (13.1%) had no pneumonia. Children under two years of age predominated (66.9%). The average annual incidence rate for consolidated pneumonia over the three-year study period was 1175/10(5). Eighteen invasive Streptococcus pneumoniae were isolated from patients with consolidated pneumonia and two from those with non-consolidated pneumonia. Respiratory syncytial virus was evenly distributed between both X-ray groups. CONCLUSIONS: Patients younger than two years of age predominated, being the main targets for anti-pneumococcal conjugated vaccines. Incidence rates provided evidence of the burden of consolidated pneumonia for childhood, estimating the potential benefits of vaccination. 相似文献
12.
13.
14.
Juan J. Muoz Cristina Roca Jos L. Santos Miguel Arroyo Rafael E. de Salamanca 《Basic & clinical pharmacology & toxicology》1993,73(4):189-191
Two alternatives for the treatment of lead intoxication, administration of zinc or a thiol donor, S-adenosyl-L-methionine (SAM), were analysed. Rats were exposed to lead (Pb)-acetate (60 mg/1) in drinking water during 90 days; one group also received SO4Zn in water (40 mg/l), while another received both Pb and SAM (5 mg/24 hr intraperitoneally. Erythrocytic δ-aminolaevulinic dehydratase (ALA-D) activity was significantly reduced (P<0.001) both in rats receiving Pb alone and in rats receiving Pb and each of the other two treatments. The high erythrocytic uroporphyrinogen synthetase (URO-S) activity noticed in Pb administered rats, was significantly (P< 0.001) reduced in animals treated either with zinc or with SAM. Hepatic ALA-D activity tended to decrease while renal enzyme activity was not modified by the low level Pb exposure used in this work. Interestingly, SAM treated rats in both tissues exhibited significantly (P<0.01) higher activities of the enzyme. It is argued that SAM treatment causes a surplus of thiols that allows the full expression of ALA-D catalytic activity. 相似文献
15.
Miguel A. Rodriguez-Bigas MD Remedios B. Penetrante MD Lemuel Herrera MD Nicholas J. Petrelli MD 《Gastrointestinal endoscopy》1995,42(6)
Background: In familial adenomatous polyposis and juvenile polyposis, polyps can occur throughout the gastrointestinal tract.Methods: We report seven patients with familial adenomatous polyposis and two patients with juvenile polyposis who underwent small bowel enteroscopy at the time of exploratory celiotomy either for colectomy or other pathology.Results: Polyps in the jejunum and/or ileum were noted in five of nine (56%) patients at enteroscopy. In three of nine (33%) patients these polyps were adenomatous. Two of these patients had polyps in the jejunum and in the ileum, whereas one patient had jejunal adenomas alone. These polyps were from 3 mm to 30 mm in size. The remaining two patients with polyps had lymphoid hyperplasia in the ileum. All three patients who had adenomas at intraoperative small bowel enteroscopy had duodenal adenomas at esophagogastroduodenoscopy. At the age of 14 years, one patient had an intramucosal carcinoma in a small bowel juvenile polyp.Conclusion: Baseline small bowel enteroscopy should be considered at the time of surgical exploration in patients with asymptomatic familial adenomatous polyposis and juvenile polyposis. In patients with duodenal polyps, enteroscopy should be performed at the time of surgery. Biopsy and/or excision of larger polyps should be performed because these polyps may harbor a carcinoma. (Gastrointest Endosc 1995;42:560-4.) 相似文献
16.
Dr. Joseph A. Paladino Pharm.D. Dr. Miguel A. Rainstein M.D. FACS Mrs. Deborah J. Serrianne R.N. Dr. John E. Przylucki M.D. FACS Dr. Lynda S. Welage Pharm.D. Dr. Mario L. Collura M.D. FACS Dr. Jerome J. Schentag Pharm.D. FCCP 《Pharmacotherapy》1994,14(6):734-739
This double-blind study compared ampicillin-sulbactam 3 g versus cefoxitin 2 g in 136 adult patients at risk for developing an infection after abdominal surgery. Separate randomization schedules were used for colorectal, upper gastrointestinal/biliary, and other abdominal procedures. Study antibiotics were administered within 30 minutes before incision and repeated 6 hours later. Patients having colorectal surgery received a third dose of antibiotic 6 hours after the second. Efficacy evaluations were made on 123 patients, 62 in the ampicillin-sulbactam group and 61 in the cefoxitin group. The overall postoperative infection rates were 12.9% for ampicillin-sulbactam and 9.8% for cefoxitin (p>0.05); one wound infection occurred in each group. Adverse events were experienced by 13.2% of the ampicillin-sulbactam and 19.1% of the cefoxitin recipients (p>0.05). Cost-minimization analysis revealed that ampicillin-sulbactam was a cost-effective alternative to cefoxitin for the prevention of infection after abdominal surgery. 相似文献
17.
18.
19.
20.