全文获取类型
收费全文 | 6041篇 |
免费 | 445篇 |
国内免费 | 43篇 |
专业分类
耳鼻咽喉 | 109篇 |
儿科学 | 256篇 |
妇产科学 | 69篇 |
基础医学 | 885篇 |
口腔科学 | 153篇 |
临床医学 | 610篇 |
内科学 | 1183篇 |
皮肤病学 | 153篇 |
神经病学 | 439篇 |
特种医学 | 471篇 |
外国民族医学 | 1篇 |
外科学 | 913篇 |
综合类 | 89篇 |
一般理论 | 2篇 |
预防医学 | 394篇 |
眼科学 | 72篇 |
药学 | 415篇 |
中国医学 | 3篇 |
肿瘤学 | 312篇 |
出版年
2023年 | 36篇 |
2022年 | 33篇 |
2021年 | 57篇 |
2020年 | 58篇 |
2019年 | 66篇 |
2018年 | 110篇 |
2017年 | 115篇 |
2016年 | 122篇 |
2015年 | 137篇 |
2014年 | 176篇 |
2013年 | 246篇 |
2012年 | 249篇 |
2011年 | 257篇 |
2010年 | 214篇 |
2009年 | 194篇 |
2008年 | 230篇 |
2007年 | 250篇 |
2006年 | 294篇 |
2005年 | 229篇 |
2004年 | 246篇 |
2003年 | 171篇 |
2002年 | 215篇 |
2001年 | 187篇 |
2000年 | 189篇 |
1999年 | 146篇 |
1998年 | 137篇 |
1997年 | 112篇 |
1996年 | 129篇 |
1995年 | 96篇 |
1994年 | 98篇 |
1993年 | 63篇 |
1992年 | 104篇 |
1991年 | 109篇 |
1990年 | 99篇 |
1989年 | 120篇 |
1988年 | 106篇 |
1987年 | 88篇 |
1986年 | 80篇 |
1985年 | 89篇 |
1984年 | 56篇 |
1983年 | 40篇 |
1982年 | 36篇 |
1981年 | 48篇 |
1980年 | 38篇 |
1979年 | 39篇 |
1978年 | 37篇 |
1976年 | 31篇 |
1975年 | 42篇 |
1973年 | 30篇 |
1970年 | 32篇 |
排序方式: 共有6529条查询结果,搜索用时 15 毫秒
71.
McNamara JR Seman LJ Schaefer EJ 《MLO: medical laboratory observer》1999,31(10):24-8, 30-6, 51; quiz 38-9
72.
In an open trial with 18 healthy male volunteers (21-45 years old) the effect of processed (test) and non-processed (reference) coffee samples of same origin on the gastric potential difference (GPD) was studied. Test coffee samples were processed with the patented "Darboven improvement procedure" before roasting. All treatment groups were subdivided according to the Helicobacter pylori status of the volunteers. The evaluation of the target parameters Reizindex (RI), area under the baseline (AUB), maximum potential difference (Pdmax) and total time (ttot) revealed a significant lower RI (p = 0.0282) and AUB (p = 0.0136), and a significant shorter ttot (p = 0.0286) for the processed coffee. Total cholesterol, high-density lipoprotein (HDL) cholesterol, and pancreatic peptides showed a comparable marked increase of the arithmetic mean with both coffee samples, however, being more intense in the Helicobacter pylori-positive subgroup than in the Helicobacter pylori-negative subgroup. No negative findings concerning tolerability and safety could be seen. In conclusion, the test coffee samples processed with a new method to improve the stomach mucosal irritation-potential of coffee charges revealed a remarkably lower stomach mucosal irritation. 相似文献
73.
L M McDowell M A McCarrick D R Studelska W J Guilford D Arnaiz J L Dallas D R Light M Whitlow J Schaefer 《Journal of medicinal chemistry》1999,42(19):3910-3918
Double rotational-echo double resonance (double REDOR) has been used to investigate the bound conformations of (13)C,(15)N,(19)F-labeled factor Xa inhibitors to bovine trypsin. Carbon-fluorine dipolar couplings were measured by (13)C{(19)F} REDOR with natural-abundance background interferences removed by (13)C{(15)N} REDOR. The conformations of the bound inhibitors were characterized by molecular dynamics (MD) simulations of binding restrained by double REDOR-determined intramolecular C-F distances. A symmetrical bisamidine inhibitor and an asymmetrical monoamidine-monoamine inhibitor of the same general shape had distinctly different conformations in the bound state. According to the MD models, these differences arise from specific interactions of the amidine and amine groups with the active-site residues of trypsin and nearby water molecules. 相似文献
74.
SCHOLZ J.; ROEWER N.; RUM U.; SCHMITZ W.; SCHOLZ H.; SCHULTE AM ESCH J. 《British journal of anaesthesia》1991,66(6):692-696
-Adrenoceptor stimulation may induce malignant hyperthermia(MH) in vivo. Consequently, we have investigated the effectsof the -adrenoceptor agonist phenylephrine and, for comparison,the effects of the ß-adrenoceptor agonist isoproterenolon inositol-lipid metabolism of malignant hyperthermia susceptible(MHS) and healthy control (MHN) swine. The experiments wereperformed on electrically stimulated (frequency 0.2 Hz) trabeculaeisolated from the right ventricles of the hearts of MHS andMHN animals. After labelling with [3H] inositol for 6 h, differentinositol phosphates were measured by high pressure liquid chromatography,including inositol 1 - phosphate, inositol 1,4-bisphosphate,inositol 1,3,4-trisphosphate, inositol 1,4,5-trisphosphate (1,4,5-IP3)and inositol 1,3,4,5 - tetrakisphosphate. After stimulationwith isoproterenol, the inositol phosphate content did not increaseor vary between muscle from MHS and MHN animals. In contrast,all inositol phosphates increased after stimulation with phenylephrinein both muscle types, the effects being greater in MHS thanin MHN, especially as regards 1,4,5-IP3 content. As 1,4,5-IP3,a presumed second messenger, has been shown to mobilize intracellularcalcium, it is concluded that an enhanced -adrenergic responseis involved in the development of MH.
*Address for correspondence: Abteilung für Anästhesiologie,Universitäts-Krankenhaus Eppendorf, Martinistrasse52, D-2000Hamburg 20, Germany.
Presented in part at the 1989 Meeting of the European Academyof Anaesthesiology in Bonn. 相似文献
75.
Charles E. Schaefer 《Child & youth care forum》1977,6(4):288-299
The literature on the socialization of children is reviewed. It is concluded that a major factor contributing to conduct problems in children is the lack of effective child caring at home. The special adult-child relationship which differentiates biological from psychological parenting is described. Implications for the residential treatment of children are discussed. 相似文献
76.
A gas chromatographic (GC) method is presented for the specific determination of acetic acid in air and total ionic acetate (as acetic acid) in industrial waste water. Atmospheric air samples are collected in fritted midget bubblers containing aqueous sodium carbonate solution; wastewater samples are treated directly with sodium carbonate. Both air and water samples are concentrated by evaporation of water, and the acetic acid is regenerated by the addition of hydrochloric acid. The amount of acetic acid is determined quantitatively on a porous polymer packed column by internal standardization with propionic acid. GC conditions are described for the suppression of "ghosting" and "tailing" caused by adsorption phenomena associated with the GC behavior of organic acids. 相似文献
77.
Kammerl MC Schaefer RM Schweda F Schreiber M Riegger GA Krämer BK 《Clinical nephrology》2000,53(6):486-488
The negatively charged membrane AN69 is known to evoke anaphylactoid reactions both without and with concomitant ACE inhibition. Underlying reasons are mainly the induction of bradykinin release due to the negatively charged membrane and the reduced degradation of bradykinin due to ACE inhibition. This complication has been reported repeatedly, but anaphylactoid reactions still occur in clinical practice. We recently had to treat two patients who suffered anaphylactoid reactions during extracorporal therapy with an AN69 membrane and simultaneous ACE inhibition. The first incident occurred in a patient on hemodialysis, the second was in a patient on continuous venovenous hemofiltration. An anaphylactoid reaction induced by an AN69 membrane during continuous, extracorporal treatment in combination with ACE inhibition has not been reported so far. Our report intends to serve as a reminder that the potentially lethal combination of AN69 membranes with ACE inhibitor treatment should be avoided. 相似文献
78.
79.
80.
Effects of bicarbonate- and lactate-buffered replacement fluids on cardiovascular outcome in CVVH patients 总被引:8,自引:0,他引:8
Barenbrock M Hausberg M Matzkies F de la Motte S Schaefer RM 《Kidney international》2000,58(4):1751-1757
BACKGROUND: Bicarbonate-buffered replacement fluid (RF-bic) in continuous venovenous hemofiltration (CVVH) may be superior to lactate-buffered replacement fluid (RF-lac) in acute renal failure. In an open, randomized, multicenter study, we investigated the effects of RF-bic and RF-lac on cardiovascular outcome in patients requiring CVVH following acute renal failure. METHODS: One hundred seventeen patients between the age of 18 and 80 years were randomized to CVVH either with RF-bic (N = 61) or RF-lac (N = 56). Patients were treated with CVVH for five days or until either renal function was restored or the patient was removed from the study. Data were analyzed on day 5 or according to the "last observation carried forward" (LOCF) option. Adverse events were classified according to the WHO-Adverse Reaction Terminology system. RESULTS: Blood lactate levels were significantly lower and blood bicarbonate levels were significantly higher in patients treated with RF-bic than in those treated with RF-lac (lactate, 17.4 +/- 8.5 vs. 28.7 +/- 10.4 mg/dL, P < 0.05; bicarbonate, 23.7 +/- 0.4 vs. 21.8 +/- 0.5 mmol/L, P < 0. 01). The number of hypotensive crises was lower in RF-bic-treated patients than in RF-lac-treated patients (RF-bic 14 out of 61 patients, RF-lac in 29 out of 56 patients; 0.26 +/- 0.09 vs. 0.60 +/- 0.31 episodes per 24 h, P < 0.05). Nine out of 61 patients (15%) treated with RF-bic and 21 out of 56 patients (38%) treated with RF-lac developed cardiovascular events during CVVH therapy (P < 0. 01). A multiple regression analysis showed that the occurrence of cardiovascular events was dependent on replacement fluid and previous cardiovascular disease and not on age or blood pressure. Patients with cardiac failure died less frequently in the group treated with RF-bic (7 out of 24, 29%) than in the group treated with RF-lac (12 out of 21, 57%, P = 0.058). In patients with septic shock, lethality was comparable in both groups (RF-bic, 10 out of 27, 37%; RF-lac, 7 out of 20, 35%, P = NS). CONCLUSIONS: The results show that the administration of RF-bic solution was superior in normalizing acidosis of patients without the risk of alkalosis. The data also suggest that the use of RF-bic during CVVH reduces cardiovascular events in critically ill patients with acute renal failure, particularly those with previous cardiovascular disease or heart failure. 相似文献