全文获取类型
收费全文 | 1801篇 |
免费 | 113篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 58篇 |
妇产科学 | 3篇 |
基础医学 | 234篇 |
口腔科学 | 7篇 |
临床医学 | 166篇 |
内科学 | 425篇 |
皮肤病学 | 4篇 |
神经病学 | 151篇 |
特种医学 | 19篇 |
外科学 | 525篇 |
综合类 | 10篇 |
预防医学 | 178篇 |
眼科学 | 1篇 |
药学 | 54篇 |
肿瘤学 | 77篇 |
出版年
2021年 | 24篇 |
2020年 | 13篇 |
2019年 | 14篇 |
2018年 | 14篇 |
2017年 | 18篇 |
2016年 | 27篇 |
2015年 | 25篇 |
2014年 | 25篇 |
2013年 | 41篇 |
2012年 | 70篇 |
2011年 | 98篇 |
2010年 | 53篇 |
2009年 | 56篇 |
2008年 | 88篇 |
2007年 | 77篇 |
2006年 | 88篇 |
2005年 | 90篇 |
2004年 | 57篇 |
2003年 | 67篇 |
2002年 | 66篇 |
2001年 | 73篇 |
2000年 | 99篇 |
1999年 | 88篇 |
1998年 | 38篇 |
1997年 | 27篇 |
1996年 | 19篇 |
1995年 | 26篇 |
1994年 | 19篇 |
1993年 | 16篇 |
1992年 | 43篇 |
1991年 | 52篇 |
1990年 | 35篇 |
1989年 | 38篇 |
1988年 | 26篇 |
1987年 | 26篇 |
1986年 | 35篇 |
1985年 | 31篇 |
1984年 | 14篇 |
1983年 | 19篇 |
1982年 | 11篇 |
1981年 | 22篇 |
1980年 | 14篇 |
1979年 | 13篇 |
1978年 | 14篇 |
1977年 | 12篇 |
1976年 | 10篇 |
1975年 | 13篇 |
1973年 | 11篇 |
1972年 | 8篇 |
1967年 | 8篇 |
排序方式: 共有1916条查询结果,搜索用时 15 毫秒
1.
Philippe Topart Guillaume Becouarn Patrick Ritz 《Surgery for obesity and related diseases》2007,3(5):521-525
BACKGROUND: Of patients who have undergone gastric banding, 11-25% will require a major reoperation with band removal and conversion to another bariatric procedure after they have failed to lose sufficient weight or have developed dysphagia or reflux. The aim of this study was to evaluate the respective benefits of Roux-en-Y gastric band (RYGB) or biliopancreatic diversion with duodenal switch (BPD-DS) after failed gastric banding and whether 1 of the 2 procedures might be a better procedure for such cases. METHODS: RYGB or BPD-DS was performed according to the institutional protocols with synchronous band removal, irrespective of the reason for failure. RESULTS: Of the 53 patients, 32 underwent laparoscopic RYGB for a body mass index (BMI) of 43.1 +/- 6.4 kg/m(2) (BMI 45.8 +/- 6.4 kg/m(2) before laparoscopic adjustable gastric banding) and 21 underwent BPD-DS for a BMI of 46.0 +/- 5.5 kg/m(2) (BMI 49.6 +/- 5.2 kg/m(2) before laparoscopic adjustable gastric banding). BPD-DS required significantly longer operative times (239.7 +/- 55.8 versus 135 +/- 26.7 minutes) and resulted in more complications (62% versus 12.5%; P <.002). No patients died postoperatively. The 2 groups of patients had a similar BMI at 12 and 18 months after revision (BMI 33.4 +/- 5.6 kg/m(2) and 31.4 +/- 3.5 kg/m(2)). The weight loss was greater after BPD-DS than after RYGB compared with the prerevision weight loss (66.2% versus 58.8% excess weight loss) or initial weight (73% versus 61.8%), although this was not significant. CONCLUSION: Despite an excessive rate of complications that were, in part, related to the learning curve in this series, BPD-DS resulted in greater weight loss compared with RYGB. However, both procedures were successful after failed gastric banding. A more accurate definition of failure could help to determine the respective indications for revisional surgery. 相似文献
2.
3.
J Bommer T Weinreich D H Lovett R Bouillon E Ritz D Gemsa 《Nephrology, dialysis, transplantation》1990,5(3):208-213
Loading of tissue macrophages with dialysis-tubing-derived particles may occur during chronic haemodialysis. Previous studies have demonstrated that these particle-laden macrophages release significant quantities of prostaglandins. In these experiments, the effects of dialysis-tubing-particle loading on the release of the central inflammatory mediator, interleukin 1 (IL 1), was examined. Rats received daily injections of silicone or polyvinylchloride (PVC) particles, and were compared to animals given saline alone. The silicone and PVC groups received a total of 3 x 10(9) particles over a 4-week period. Non-stimulated peritoneal macrophages from control animals released a median of 4.1 (range 1.2-10.3) U IL 1 per 10(6) cells. In contrast, macrophages from silicone- and PVC-loaded animals spontaneously released high levels of IL 1 (median 21.8; range 10-36.7) and 94 (range 36-336) U per 10(6) cells respectively). Following in vitro stimulation with bacterial lipopolysaccharide (LPS), peritoneal macrophages from silicone- and PVC-treated animals released large amounts of IL 1 (median 538 (range 359-2017) U and median 653 (range 326-1134) U per 10(6) cells, respectively) as compared to LPS-stimulated macrophages from control animals (median 332 (range 130-306) U per 10(6) cells]. Zymosan or LPS stimulation of splenic cells from silicone- and PVC-loaded animals also secreted increased quantities of IL 1 as compared to controls. The chronic loading of tissue macrophages in dialysis patients with tubing-derived particles may result in augmented release of IL 1, with subsequent activation of inflammatory processes. 相似文献
4.
Stefanie Sarantopoulos Kristen E Stevenson Haesook T Kim Nazmim S Bhuiya Corey S Cutler Robert J Soiffer Joseph H Antin Jerome Ritz 《Clinical cancer research》2007,13(20):6107-6114
PURPOSE: Recent studies suggest that donor B cells as well as T cells contribute to immune pathology in patients with chronic graft-versus-host disease (GVHD). B-cell activating factor (BAFF) promotes survival and differentiation of activated B cells. Thus, we tested whether BAFF correlated with chronic GVHD disease activity and time of onset after allogeneic hematopoietic stem cell transplantation (HSCT). EXPERIMENTAL DESIGN: Patients who had undergone allogeneic HSCT between 1994 and 2005 for hematologic malignancies were studied. ELISA was used to measure plasma BAFF levels and flow cytometry was used to assess BAFF receptor expression on B cells in patients with or without chronic GVHD. RESULTS: In 104 patients, BAFF levels were significantly higher in patients with active chronic GVHD compared with those without disease (P = 0.02 and 0.0004, respectively). Treatment with high-dose prednisone (>or=30 mg/d) was associated with reduced BAFF levels in patients with active chronic GVHD (P = 0.0005). Serial studies in 24 patients showed that BAFF levels were high in the first 3 months after HSCT but subsequently decreased in 13 patients who never developed chronic GVHD. In contrast, BAFF levels remained elevated in 11 patients who developed chronic GVHD. Six-month BAFF levels >or=10 ng/mL were strongly associated with subsequent development of chronic GVHD (P < 0.0001). Following transplant, plasma BAFF levels correlated inversely with BAFF receptor expression on B cells (P = 0.01), suggesting that soluble BAFF affected B cells through this receptor. CONCLUSION: These results suggest that elevated BAFF levels contribute to B-cell activation in patients with active chronic GVHD. 相似文献
5.
Background: diabetic patients with end-stage renal
failure (ESRD) have a high cardiovascular morbidity and mortality. The
underlying mechanisms are not completely elucidated. The aim of our study
was to define predictors of death in diabetic patients with end-stage renal
disease. Patients and methods: We preformed a
prospective study in 35 dialysis centres in Germany between 1985 and 1994.
To evaluate predictors and risk factors in this population we examined 412
diabetic patients at the time of admission to dialysis treatment
(peritoneal dialysis (PD) or haemodialysis (HD)). Classification of the
type of diabetes was done according the criteria of the National Diabetes
Data Group [1,2]. Items assessed at the time of admission were coronary
artery disease (CAD), peripheral occlusive disease (POD), and stroke. CAD
was defined as a history of myocardial infarction with the corresponding
changes in the ECG or luminal narrowing by more than 50% in at least one
coronary artery upon coronarangiography; POD was defined as claudication
and/or brachial-tibial ratio (BTR) less than 0.9 or a history of
amputation. Assessment of the nutritional state comprised body mass index,
skinfold thickness of the upper arm and lateral thorax area, and urea
concentration. Cholesterol, HDL, LDL, apolipoprotein A (ApoA-I) and B
(ApoB), triglycerides, lipoprotein (a) (Lp(a)), and fibrinogen were
measured. As an index of disturbed cardiac innervation beat-to-beat
variation was measured. Outcome measurements were causes of death (i.e.
cardiac and non-cardiac) and time of survival.
Results: One hundred and eighty of 412 (44%) patients
died during the observation period Patients who died were older
(61±12 versus 53±15 years P
lt;0.0001), had lower skin fold thickness (13.1±6.0
versus 15.1±7.2 mm P <0.04), lower
ApoA-I (100±35 versus 111±32
mg/dl P <0.005) and higher fibrinogen (515±156
versus 451±155 mg/dl P <0.02). Type
II diabetic patients had a lower mean survival time than type I (34
versus 66 months P <0.0006). The mode of renal
replacement therapy (PD or HD) had no adverse effect on survival time.
Survivors less frequently had a history of CAD, POD and stroke than
non-survivors. In multivariate analysis ApoA-I, fibrinogen ,age and stroke
were independent predictors of cardiac and non-cardiac death in diabetic
patients with end-stage renal failure. Lipid values and nutritional state
did not independently predict the overall and cardiovascular mortality.
Conclusion: This study in dialysed diabetic patients
identified several predictors of death, some of which are susceptible to
intervention. 相似文献
6.
Kerstin Amann Christina Ritz Marcin Adamczak Eberhard Ritz 《Nephrology, dialysis, transplantation》2003,18(4):631-640
On September 6, 2001, Professor Fernando Valderrabano (Hospital Gregorio Mara?on, Madrid) died at the age of 59 years. He was a leading figure in Spanish nephrology, a full professor of Medicine/Nephrology at the University Complutense of Madrid, and an outstanding scientist who published more than 300 articles in medical journals. He was a very intelligent and cultured person, and a man of great style who enjoyed a wide range of hobbies and interests in addition to his medical work. All his colleagues and friends mourn his passing. 相似文献
7.
Marked increase of asymmetric dimethylarginine in patients with incipient primary chronic renal disease. 总被引:13,自引:0,他引:13
Jan T Kielstein Rainer H B?ger Stefanie M Bode-B?ger Jürgen C Fr?lich Hermann Haller Eberhard Ritz Danilo Fliser 《Journal of the American Society of Nephrology : JASN》2002,13(1):170-176
In patients with uremia, increased blood concentrations of the endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA) have been linked to the severity of atherosclerosis and to excess cardiovascular mortality. The ADMA levels and several traditional cardiovascular risk factors were assessed in 44 untreated nonsmoking patients with confirmed primary chronic renal disease at different stages of renal disease. True GFR was assessed by means of the inulin-clearance technique. For comparison, nonsmoking subjects matched with respect to age, gender, and body-mass index were examined. Mean plasma ADMA concentration was markedly higher (P < 0.0001) in all patients combined (4.2 +/- 0.9 micromol/L) than in control subjects (n = 16; age 45 +/- 10 yr; serum creatinine 1.0 +/- 0.1 mg/dl; ADMA 1.4 +/- 0.7 micromol/L). However, mean ADMA levels were similar in patients with normal renal function (n = 16; age 41 +/- 9 yr; serum creatinine 1.1 +/- 0.1 mg/dl; GFR 120 +/- 14 ml x min(-1) x 1.73 m2; ADMA 4.0 +/- 0.7 micromol/L), in patients with moderate renal failure (n = 15; 47 +/- 7 yr; 1.8 +/- 0.3 mg/dl; 65 +/- 10 ml x min(-1) x 1.73 m2; 3.8 +/- 0.6 micromol/L) and in patients with advanced renal failure (n = 13; 46 +/- 9 yr; 4.2 +/- 0.9 mg/dl; 25 +/- 4 ml x min(-1) x 1.73 m2; 4.7 +/- 1.2 micromol/L). Furthermore, ADMA levels were increased to the same extent in normotensive (n = 17; 4.0 +/- 0.8 micromol/L) and in hypertensive (n = 27; 4.2 +/- 0.9 micromol/L) patients. In contrast to ADMA, mean total plasma homocysteine concentration were similar in control subjects (10.6 +/- 2.9 micromol/L) and in patients with normal GFR (11.0 +/- 2.9 micromol/L), but were significantly higher in patients with moderate renal failure (17.7 +/- 4.1 micromol/L) and particularly in patients with advanced renal failure (28.2 +/- 10.6 micromol/L). Finally, mean total serum cholesterol concentrations were comparable in the control group and in the three groups of patients with renal disease. In contrast to several traditional cardiovascular risk factors, markedly increased blood concentrations of ADMA, a putative biochemical marker of atherosclerosis, are present even in nonsmoking patients without diabetes with incipient primary renal disease. Thus, the early increase of ADMA levels may be of relevance for the excess cardiovascular morbidity and mortality due to arterio- and atherosclerotic complications in patients with renal disease. 相似文献
8.
Diana A. Lepore Kenneth R. Knight Surajit Bhattacharya Morris Ritz Sonia P. Robbins Peter Sieg Wayne A. Morrison Bernard McC. O'Brien 《Microsurgery》1994,15(10):685-692
The chief aim of this study was to maximize flap survival by counteracting the pathophysiological changes occurring during ischemia-reperfusion. Rabbit epigastric skin flaps given 21 hours of ischemia were infused intra-arterially with selected drugs at the start of reperfusion. Compared with control infused ischemic flaps, which had a 33% survival rate on day 7 post-ischemia, significant improvement was found with vasodilators nitrendipine (61%) and prostacyclin (65%) and the thrombolytic agent urokinase (65%); marginal improvement with the free radical scavenger desferrioxamine (53%); but no change with streptokinase (44%), heparin (21%), and ATP-MgCl2 (35%). A drug mixture comprising all of these agents except streptokinase and urokinase produced 87% survival, suggesting an additive effect. Biochemical assays on skin homogenates and blood implicated oxygen free radicals, neutrophil infiltration, and thromboxane in flap failure. These results imply that multiple factors are responsible for ischemic flap failure and that a mixture of drugs needs to be infused to counteract all of the detrimental changes. © 1994 Wiley-Liss, Inc. 相似文献
9.
L G Arlian D L Vyszenski-Moher A T Lawrence K R Schrotel H L Ritz 《The Journal of allergy and clinical immunology》1992,89(4):866-876
The outer portions (husk) of psyllium seeds are a concentrated source of natural fiber used in some bulk-fiber laxatives and cereals. They are known to elicit respiratory allergic reactions after inhalation or ingestion among sensitized individuals. Antigenic and allergenic characterization of three psyllium-seed fractions (husk, endosperm, and embryo) was conducted with crossed immunoelectrophoresis (CIE), crossed radioimmunoelectrophoresis, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis to determine the source of psyllium allergenicity. Homologous CIE demonstrated psyllium endosperm and embryo extracts contained seven and four antigens, respectively. Husk extracts were too gelatinous to react by CIE. However, heterologous CIE profiles of endosperm or embryo extracts, reacted with antihusk antibodies, resulted in antigen-antibody precipitin peaks that matched the heavy staining precipitin lines of homologous reactions for endosperm and embryo, respectively. These results indicated that commercial-grade husk, endosperm, and embryo contained similar antigens. Extracts of all three seed components contained antigens that bound IgE antibodies in the sera of 11 psyllium RAST-positive individuals, as determined by crossed radioimmunoelectrophoresis. The few prominent husk protein/peptide bands resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis were common in either embryo or endosperm. Immunoblots revealed common IgE reactive bands in all three seed fractions. Microscopic examination of the powdered commercial-grade psyllium (95% pure) revealed it contained endosperm and embryo particles. These immunologic, biochemical, and microscopic findings suggest that other contaminating seed components are primarily responsible for the allergenicity of commercial-grade psyllium-husk powder rather than the husk itself. 相似文献
10.
Diabetic nephropathy and anaemia 总被引:2,自引:0,他引:2