全文获取类型
收费全文 | 2473835篇 |
免费 | 178248篇 |
国内免费 | 3718篇 |
专业分类
耳鼻咽喉 | 33897篇 |
儿科学 | 80025篇 |
妇产科学 | 65453篇 |
基础医学 | 364017篇 |
口腔科学 | 69788篇 |
临床医学 | 221662篇 |
内科学 | 483275篇 |
皮肤病学 | 54834篇 |
神经病学 | 195919篇 |
特种医学 | 91483篇 |
外国民族医学 | 508篇 |
外科学 | 368647篇 |
综合类 | 48651篇 |
现状与发展 | 12篇 |
一般理论 | 908篇 |
预防医学 | 197022篇 |
眼科学 | 56821篇 |
药学 | 182316篇 |
11篇 | |
中国医学 | 5068篇 |
肿瘤学 | 135484篇 |
出版年
2021年 | 22064篇 |
2019年 | 22386篇 |
2018年 | 30968篇 |
2017年 | 23304篇 |
2016年 | 25409篇 |
2015年 | 28786篇 |
2014年 | 40483篇 |
2013年 | 59487篇 |
2012年 | 83141篇 |
2011年 | 88370篇 |
2010年 | 51610篇 |
2009年 | 48457篇 |
2008年 | 81276篇 |
2007年 | 86659篇 |
2006年 | 86813篇 |
2005年 | 84484篇 |
2004年 | 80659篇 |
2003年 | 77339篇 |
2002年 | 73527篇 |
2001年 | 111139篇 |
2000年 | 113668篇 |
1999年 | 95571篇 |
1998年 | 27958篇 |
1997年 | 24482篇 |
1996年 | 24825篇 |
1995年 | 23420篇 |
1994年 | 21547篇 |
1993年 | 20344篇 |
1992年 | 73355篇 |
1991年 | 71432篇 |
1990年 | 69654篇 |
1989年 | 66913篇 |
1988年 | 61469篇 |
1987年 | 60213篇 |
1986年 | 56259篇 |
1985年 | 53999篇 |
1984年 | 40057篇 |
1983年 | 34013篇 |
1982年 | 20228篇 |
1979年 | 36414篇 |
1978年 | 26003篇 |
1977年 | 21522篇 |
1976年 | 20614篇 |
1975年 | 22165篇 |
1974年 | 26506篇 |
1973年 | 25160篇 |
1972年 | 23495篇 |
1971年 | 22314篇 |
1970年 | 20540篇 |
1969年 | 19593篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
31.
Gabriela Perdomo Coral Angelo Alves de Mattos 《Journal canadien de gastroenterologie》2003,17(3):187-190
BACKGROUND/AIMS: Spontaneous bacterial peritonitis (SBP) is an important complication in cirrhotic patients. The aim of the present study was to assess the incidence, predictive factors and prognosis for renal impairment (RI) after SBP in cirrhotic patients from southern Brazil. METHODS: Of the 1030 hospitalizations evaluated, 114 episodes of SBP were diagnosed in 94 patients (mean age 49 years; 76.59% men). SBP diagnosis was established when the ascitic fluid polymorphonuclear cell count was equal to or greater than 250 cells/mm3. Five cases were excluded. The variables assessed as possible predictors of steady or progressive RI were blood urea nitrogen and creatinine levels before the diagnosis of SBP; type of infection, antibiotic prophylaxis, first episode or recurrent SBP, presence of gastrointestinal bleeding and hepatic encephalopathy during hospitalization, SBP resolution, Child-Pugh classification, levels of blood pressure, ascitic fluid and blood polymorphonuclear cell count, bacteriological data (positive and negative ascitic fluid culture), albumin, bilirubin, sodium and prothrombin time at the moment of diagnosis. RESULTS: The incidence of SBP was 11.07%. In 61 (55.96%) episodes, SBP was associated with RI (transient in 57.37%; steady in 19.67%; and progressive in 22.95%). The mortality rate associated with progressive RI was 100%; 58.33% with steady RI; and 2.85% with transient RI. The mortality rate in patients with or without RI was 36.07% and 6.25%, respectively (P<0.001). The level of creatinine (greater than or equal to 1.3mg/dL) before the diagnosis of SBP and the rate of infection resolution were the only predictors of RI in the multivariate analysis. CONCLUSIONS: RI after SBP is a common complication, and indicates a poor prognosis for this infection. High levels of creatinine before infection and the rate of infection resolution are independent predictors of RI. 相似文献
32.
33.
34.
Effects of poor glucose handling on arterial stiffness and left ventricular mass in normal children.
AIM: Cardiovascular risk factors can be present in children and young adults. We previously found abnormal microvascular function in children who had glucose intolerance and insulin resistance. The aim of the present study was to investigate whether they also have abnormalities in left ventricular mass (LVM) and arterial stiffness. METHODS: We measured heart dimensions and LVM using echocardiography, and arterial stiffness using pulse wave analysis in 23 children with good glucose handling (postfeeding glucose: 3.9 to 5 mmol/L) and 21 with poor glucose handling (7.7 to 11.4 mmol/L). RESULTS: The time to pulse reflection was slightly shorter in the poorer glucose handlers (mean+/-SD: 143+/-10 vs 153+/-20 ms, P=0.04), suggestive of increased arterial stiffness. Also in this group, there were significant relationships between intraventricular septal thickness, blood pressure and body mass index, but not in the normal glucose handlers. CONCLUSIONS: We have found that normal children who are in the lowest quintile of glucose tolerance in comparison with their peers are exhibiting the first signs of arterial stiffening. In addition, we have seen the beginnings of a relationship between blood pressure, body mass index and left ventricular enlargement in this group. While these changes may not yet be clinically significant, their emergence might be further evidence of early predisposition to cardiovascular disease. 相似文献
35.
R C Pattinson L C Snyman A P Macdonald 《Suid-Afrikaanse tydskrif vir geneeskunde》2006,96(11):1191-1194
AIM: To evaluate whether the introduction of a strict protocol approach based on the systemic evaluation of critically ill pregnant women with complications of abortion affected outcome. SETTING: Indigent South Africans managed in the regional and tertiary hospitals of the Pretoria Academic Complex. METHOD: Since 1997 a standard definition of severe acute maternal morbidity (SAMM) has been used in the Pretoria Academic Complex. All cases of SAMM and maternal deaths were entered on the Maternal Morbidity and Mortality Audit System programme. A comparison of outcome of severely ill women who had complications of abortion was made between 1997-1998 (original protocol) and 2002-2004 (strict protocol). OUTCOME MEASURES: The mortality index and prevalence of organ system failure or dysfunction. RESULTS: In 1997-1998 there were 43 women with SAMM who survived and a further 10 maternal deaths due to complications of abortion, compared with 107 women with SAMM and 7 maternal deaths during 2002-2004. The mortality index declined from 18.9% in 1997-1998 to 6.1% in 2002-2004 (p = 0.02, odds ratio 0.28, 95% confidence limits 0.10 - 0.79). Significantly more women had hypovolaemic shock in 2002-2004 compared with 1997-1998 (54.4% v. 35.8%, p = 0.04), but fewer women had immune system failure including septic shock (18.4% v. 47.2%, p = 0.0002) and metabolic dysfunction (0 v. 5.7%, p = 0.03) and there was a trend to less renal failure (10.5% v. 22.6%, p = 0.06) and cardiac failure (4.4% v. 13.2%, p = 0.08). CONCLUSION: The strict protocol approach based on systemic evaluation in managing critically ill pregnant women with complications of abortion, coupled with an intensive, regular feedback mechanism, has been associated with a reduction in the mortality index. 相似文献
36.
37.
38.
A M Carella 《Leukemia》2003,17(6):1199-1200
39.
Manuel Steiner Andishe Attarbaschi Margit K nig Helmut Gadner Oskar A. Haas Georg Mann 《Pediatric hematology and oncology》2004,22(1):11-16
Constitutional trisomy 21 is the most prominent predisposing factor to childhood leukemia, whereas the t(12;21)(p13;q22) with its molecular genetic counterpart, the TEL/AML1 fusion gene, is the most common acquired chromosomal rearrangement in childhood B-cell precursor (BCP) acute lymphoblastic leukemia (ALL). Thus, it was somewhat surprising that according to the currently available literature the incidence of TEL/AML1+ BCP ALL is extremely low in patients with Down syndrome (DS). To further investigate this issue in a population-based fashion, the authors retrospectively assessed the number of DS patients with a TEL/AML1+ ALL in two consecutive Austrian ALL multicenter trials. Accordingly, they were able to analyze 8 of 10 individuals with DS and a BCP ALL, including 2 who suffered from a TEL/AML1+ leukemia. Based on this observation we concluded that individuals with a constitutional trisomy 21 may have the similar likelihood to develop a TEL/AML1+ leukemia as BCP ALL patients without this specific predisposing factor. 相似文献
40.
S Dvorakova E Vaclavikova A Ryska J Cap P Vlcek J Duskova D Kodetova V Holub Z Novak B Bendlova 《Experimental and clinical endocrinology & diabetes》2006,114(4):192-196
Medullary thyroid carcinoma (MTC) is a rare form of thyroid cancer representing about 10% of all thyroid malignancies. It occurs mostly as a sporadic tumor or in association with autosomal dominant inherited cancer syndromes--multiple endocrine neoplasia (MEN) types 2A and 2B and familial MTC. Germline mutations in exons 8, 10, 11, 13, 14, 15 and 16 of the RET proto-oncogene are found in most of the familial cases. There are only a few published data reporting multiple germline mutations in the RET proto-oncogene. We have detected double germline mutations in 2 different exons on the same RET allele in two MEN 2 families. In the MEN 2A family, double germline mutation in exons 10 (Cys620Phe) and 13 (Tyr791Phe) was detected. In the MEN 2B family, beside the classical germline mutation in exon 16 (Met918Thr) a second germline mutation in exon 13 (Tyr791Phe) was found. This study revealed that MEN 2 syndromes can also be caused by double germline mutations in the RET proto-oncogene and these families can be added to small worldwide cohort of families with multiple germline mutations. 相似文献