全文获取类型
收费全文 | 247篇 |
免费 | 8篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 7篇 |
妇产科学 | 3篇 |
基础医学 | 25篇 |
口腔科学 | 2篇 |
临床医学 | 39篇 |
内科学 | 64篇 |
皮肤病学 | 2篇 |
神经病学 | 8篇 |
特种医学 | 83篇 |
外科学 | 5篇 |
综合类 | 11篇 |
预防医学 | 7篇 |
眼科学 | 3篇 |
药学 | 14篇 |
肿瘤学 | 6篇 |
出版年
2021年 | 3篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2015年 | 3篇 |
2014年 | 2篇 |
2013年 | 5篇 |
2012年 | 2篇 |
2011年 | 1篇 |
2010年 | 4篇 |
2009年 | 7篇 |
2008年 | 1篇 |
2007年 | 21篇 |
2006年 | 3篇 |
2005年 | 8篇 |
2004年 | 2篇 |
2003年 | 4篇 |
2002年 | 1篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 1篇 |
1998年 | 13篇 |
1997年 | 12篇 |
1996年 | 7篇 |
1995年 | 7篇 |
1994年 | 12篇 |
1993年 | 12篇 |
1992年 | 5篇 |
1991年 | 5篇 |
1990年 | 9篇 |
1989年 | 11篇 |
1988年 | 14篇 |
1987年 | 6篇 |
1986年 | 11篇 |
1985年 | 8篇 |
1984年 | 12篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 8篇 |
1979年 | 1篇 |
1978年 | 6篇 |
1977年 | 9篇 |
1976年 | 5篇 |
1975年 | 4篇 |
1974年 | 1篇 |
1970年 | 1篇 |
1939年 | 1篇 |
排序方式: 共有284条查询结果,搜索用时 0 毫秒
71.
LR Petersen ; E Lackritz ; WF Lewis ; DS Smith ; G Herrera ; V Raimondi ; J Aberle- Grasse ; RY Dodd 《Transfusion》1994,34(10):865-869
BACKGROUND: The confidential unit exclusion (CUE) option is intended to reduce human immunodeficiency virus (HIV) transmission by excluding donors newly infected with HIV who have not yet developed HIV antibody (window-period donors); however, its efficacy in excluding window- period donors has not been evaluated. STUDY DESIGN AND METHODS: The use of the CUE option was studied among the donors of 3.7 million units at 18 American Red Cross blood services regions during 1991 and 1992 and among 322 previously HIV-1-seronegative donors who subsequently donated a seropositive unit between 1987 and 1990 at 40 United States blood centers. These seroconverting donors had previously been shown to be highly likely to donate during their window period. RESULTS: On the basis of data from these two populations, it was estimated that only 3 to 5 percent of units donated by window-period donors were not transfused because of the CUE option, that 0.4 percent of all donations were from donors who confidentially excluded their blood from transfusion, and that donors who confidentially excluded their blood were 21 times more likely to be HIV antibody-positive than donors who did not use the CUE option. It is estimated that, if all US blood centers used the CUE option, a total of 2 to 17 otherwise acceptable units donated by window-period donors would not be transfused annually. CONCLUSION: Although donors who confidentially exclude their blood from transfusion are 21 times more likely to have HIV antibody, the rarity of window-period donors and the infrequency of confidential exclusion by window-period donors cause the CUE option to have minimal impact on transfusion safety. 相似文献
72.
SUMMARY A patient with polycythaemia rubra vera is described, presenting primarily with symptoms attributed to depression. While in the ward she developed a stroke, confirmed on CT scan of the head. Venesection alone produced marked improvement in her neurological and psychiatric symptoms. The clinical picture corresponds most accurately to the neurological syndrome of abulia, which is an important differential diagnosis of depression with psychomotor retardation. The pathophysiology of impaired cerebral blood flow causing neuropsychiatrie symptoms in polycythaemia is discussed. 相似文献
73.
74.
75.
MC GRIMM WE PULLMAN GM BENNETT PJ SULLIVAN P. PAVLI WF DOE 《Journal of gastroenterology and hepatology》1995,10(4):387-395
Alterations in phenotype and function of intestinal macrophages occur in inflammatory bowel disease (IBD) but it is unclear whether these changes result from the recruitment of circulating monocytes to the intestine or from proliferation of resident intestinal macrophages. We sought to demonstrate the arrival of blood monocytes, the precursors of macrophages, in IBD mucosa. Peripheral blood mononuclear cells were isolated from 23 patients with clinically active intestinal inflammation (13 Crohn's disease, eight ulcerative colitis, two infective colitis), then radiolabelled with 99mtechnetium (Tc)-stannous colloid (n=13) or 111indium (In)-oxine (n=10) before re-injection and abdominal scanning. Four patients had demonstrable intestinal monocyte uptake using [99mTc]-stannous colloid, while six [111In]-oxine-labelled monocyte scans were positive. Uptake sites correlated with actively inflamed regions. Patients demonstrating monocyte uptake had been treated with corticosteroids for a significantly (P < 0.02) shorter duration (median 3 vs 20 days) than those with negative scans. There was no significant difference between positive and negative scans for disease category, clinical or histological disease activity, or radioisotope used. Biopsies of inflamed mucosa from two patients suffering ulcerative colitis who had positive scans showed a high proportion of CD14-positive macrophages, 4–9% of which contained autoradiographic grains. These results demonstrate that blood monocytes are recruited to the mucosa of actively inflamed bowel, and suggest that this process may be inhibited by corticosteroids. Moreover, the phenotype of the recently-arrived monocytes indicates their susceptibility to stimulation by lipopolysaccharide, and suggests a mechanism for the continuing inflammation in the bacterial product-rich milieu of IBD. 相似文献
76.
77.
78.
Mansoor JK Decile KC Giri SN Pinkerton KE Walby WF Bratt JM Grewal H Margolin SB Schelegle ES 《Pulmonary pharmacology & therapeutics》2007,20(6):660-668
Pirfenidone was administered to sensitized Brown Norway rats prior to a series of ovalbumin challenges. Airway hyperresponsiveness, inflammatory cell infiltration, mucin and collagen content, and the degree of epithelium and smooth muscle staining for TGF-beta were examined in control, sensitized, and sensitized/challenged rats fed a normal diet or pirfenidone diet. Pirfenidone had no effect on airway hyperresponsiveness, but reduced distal bronchiolar cell infiltration and proximal and distal mucin content. Statistical analysis showed that the control group and sensitized/challenged pirfenidone diet group TGF-beta staining intensity scores were not significantly different from isotype controls, but that the staining intensity scores for the sensitized/challenged normal diet group was significantly different from isotype controls. These results suggest that pirfenidone treatment is effective in reducing some of the components of acute inflammation induced by allergen challenge. 相似文献
79.
Ozone (O3) inhalation induces pulmonary function decrements and inflammation. The present study was designed to determine if a relationship exists between O3 induced pulmonary function changes and the presence of inflammatory markers as measured in exhaled breath condensates (EBCs) obtained from O3-sensitive and nonsensitive human subjects. Eight healthy adult volunteers (4 males/4 females, age 18 to 30 years) were studied, characterized as to their ozone sensitivity and placed into 2 groups (sensitive and nonsensitive) with each group having 2 males and 2 females. Subjects completed a 20-minute EBC collection and pulmonary function test (PFT) prior to a single 60-minute bout of cycle ergometer exercise (V(E) = 50-55 L/min) while breathing filtered air (FA) or 0.35 ppm O3. Subjective symptom scores (SSSs) were collected at 6, 20, 40, and 60 minutes during exposure. An immediate postexposure PFT was performed followed by an EBC collection. Subjective symptom scores, EBCs, and PFTs were collected at 1, 4 and 8 hours post exposure. EBCs were analyzed for prostaglandin E2 (PGE2), leukotriene B4 (LTB4), 8-isoprostane, and total nitric oxide (NO) metabolites (nitrate + nitrite content). Sensitive subjects, breathing O3, had significantly greater functional decrements in PFTs, increased SSSs, and increased rapid shallow breathing as well as elevated levels of 8-isoprostane and LTB4 in EBCs compared to those breathing FA. In addition, there were significant increases in nitrate + nitrite content in both sensitive and nonsensitive subjects breathing O3 compared to FA. These results indicate that sensitive subjects have elevated arachidonic acid metabolites in EBCs compared to nonsensitive subjects after O3 inhalation. 相似文献
80.
Fredriksen Kristin J. Schaufel Margrethe A. Johannessen Jan O. Walby Fredrik A. Davidson Larry Schoeyen Helle K. 《The Psychiatric quarterly》2020,91(1):223-236
Psychiatric Quarterly - To investigate which factors individuals with a psychotic depression experience as preventive of suicide while beeing hospitalized. Semi-structured qualitative interviews... 相似文献