全文获取类型
收费全文 | 8665篇 |
免费 | 515篇 |
国内免费 | 546篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 127篇 |
妇产科学 | 143篇 |
基础医学 | 359篇 |
口腔科学 | 21篇 |
临床医学 | 1490篇 |
内科学 | 1108篇 |
皮肤病学 | 39篇 |
神经病学 | 101篇 |
特种医学 | 173篇 |
外科学 | 3343篇 |
综合类 | 1093篇 |
预防医学 | 411篇 |
眼科学 | 29篇 |
药学 | 639篇 |
8篇 | |
中国医学 | 196篇 |
肿瘤学 | 444篇 |
出版年
2024年 | 7篇 |
2023年 | 159篇 |
2022年 | 264篇 |
2021年 | 413篇 |
2020年 | 329篇 |
2019年 | 277篇 |
2018年 | 278篇 |
2017年 | 281篇 |
2016年 | 327篇 |
2015年 | 414篇 |
2014年 | 642篇 |
2013年 | 665篇 |
2012年 | 509篇 |
2011年 | 472篇 |
2010年 | 420篇 |
2009年 | 397篇 |
2008年 | 427篇 |
2007年 | 436篇 |
2006年 | 375篇 |
2005年 | 383篇 |
2004年 | 321篇 |
2003年 | 248篇 |
2002年 | 200篇 |
2001年 | 208篇 |
2000年 | 153篇 |
1999年 | 118篇 |
1998年 | 76篇 |
1997年 | 76篇 |
1996年 | 80篇 |
1995年 | 106篇 |
1994年 | 77篇 |
1993年 | 72篇 |
1992年 | 65篇 |
1991年 | 44篇 |
1990年 | 39篇 |
1989年 | 44篇 |
1988年 | 51篇 |
1987年 | 26篇 |
1986年 | 44篇 |
1985年 | 44篇 |
1984年 | 32篇 |
1983年 | 19篇 |
1982年 | 22篇 |
1981年 | 15篇 |
1980年 | 18篇 |
1979年 | 15篇 |
1978年 | 11篇 |
1976年 | 7篇 |
1975年 | 7篇 |
1973年 | 4篇 |
排序方式: 共有9726条查询结果,搜索用时 31 毫秒
91.
92.
Tarek Alhamad Michelle Lubetzky Krista L. Lentine Emmanuel Edusei Ronald Parsons Martha Pavlakis Kenneth J. Woodside Deborah Adey Christopher D. Blosser Beatrice P. Concepcion John Friedewald Alexander Wiseman Neeraj Singh Su-Hsin Chang Gaurav Gupta Miklos Z. Molnar Arpita Basu Edward Kraus Song Ong Arman Faravardeh Ekamol Tantisattamo Leonardo Riella Jim Rice Darshana M. Dadhania 《American journal of transplantation》2021,21(9):3034-3042
Kidney allograft failure and return to dialysis carry a high risk of morbidity. A practice survey was developed by the AST Kidney Pancreas Community of Practice workgroup and distributed electronically to the AST members. There were 104 respondents who represented 92 kidney transplant centers. Most survey respondents were transplant nephrologists at academic centers. The most common approach to immunosuppression management was to withdraw the antimetabolite first (73%), while only 12% responded they would withdraw calcineurin inhibitor (CNI) first. More than 60% reported that the availability of a living donor is the most important factor in their decision to taper immunosuppression, followed by risk of infection, risk of sensitization, frailty, and side effects of medications. More than half of respondents reported that embolization was either not available or offered to less than 10% as an option for surgical intervention. Majority reported that ≤50% of failed allograft patients were re-listed before dialysis, and less than a quarter of transplant nephrologists performed frequent visits with their patients with failed kidney allograft after they return to dialysis. This survey demonstrates heterogeneity in the care of patients with a failing allograft and the need for more evidence to guide improvements in clinical practice related to transition of care. 相似文献
93.
94.
95.
腹膜透析治疗小儿先天性心脏病术后急性肾功能衰竭 总被引:5,自引:1,他引:4
目的:探讨腹膜透析(PD)对小儿先天性心脏病(先心病)术后急性肾功能衰竭(ARF)的治疗效果。方法:对36例先心病术后ARF行PD治疗患儿的临床资料作回顾性调查。结果:全组经PD治疗后的病死率为30.6%,其中单纯ARF的病死率12.5%,显著低于合并其他系统器官衰竭组的45%(P〈0.05)。PD3~30d内肾功能恢复,其中1~2d内血K^+恢复正常,2~5d内血碳酸氢根(HCO3^-)恢复正常,4~6d内血尿素氮下降49.2%,血肌酐下降42.6%。结论:对小儿先心病术后ARF及早进行PD具有较好的治疗效果。 相似文献
96.
目的:探讨腹膜透析对可溶性细胞间粘附分子-1(sICAM-1)水平的影响及其在长期透析患者免疫功能下降中的作用。方法:采用夹心ELISA方法分别检测感染期、非感染期连续不卧床腹膜透析(CAPD)患者血清及腹膜透析液中sICAM-1水平的变化。结果:与非感染期CAPD患者相比,感染期CAPD患者血清sICAM-1水平显著降低,腹透液sICAM-1水平明显升高(P〈0.01);治疗后血清及腹透液sICAM-1水平,均较治疗前显著升高或降低(P〈0.01)。结论:sICAM-1在感染期CAPD患者血清及腹透液中的变化,可能损害了巨噬细胞的正常粘附能力,从而降低机体的免疫能力。 相似文献
97.
The absorption profile of phenytoin Na emulsion were examined compared to that of phenytoin suspension after oral administration
in the rat. The corn oil-in-water emulsion, particle size of 184±57.8 nm, was prepared using a microfludizer, and phenytoin
Na added by shaft homogenizer. The phenytoin emulsion or suspension, 100 mg/kg, were intubated intragastrically using oral
dosing needle and blood samples were withdrawn via an indwelling cannula from the conscious rat. Plasma concentrations of
phenytoin were measured with HPLC using phenacetin as an internal standard. The plasma concentration versus time data were
fitted to a one compartment open model and the pharmacokinetic parameters were calculated using the computer program, Boomer.
The phenytoin plasma concentrations from the emulsion at each observed time were about 1.5–2 times higher than those from
the suspension, significantly at time of 5, 6 and 7 hr after administration. The absorption (ka) and elimination rate constant (ke) were not altered significantly, however the AUC increased from 65.6 to 106.7 μg·hr/ml after phenytoin suspension or emulsion
oral administration, respectively. From an equilibrium dialysis study, the diffusion rate constant (kIE) was considerably higher from the phenytoin Na emulsion (0.0439 hr−1) than phenytoin suspension (0.0014 hr−1). 相似文献
98.
Thieler H.; Achenbach H.; Bischoff J.; Koall W.; Kraatz G.; Osten B.; Smit H. 《Nephrology, dialysis, transplantation》1994,9(3):238-241
Diminished availability of facilities for renal replacementtherapy is known to cause spuriously low acceptance and treatmentrates. In this context the evolution of renal replacement therapyin the former German Democratic Republic is a useful model tostudy and to quantify some of the relevant factors. We performed a survey in all dialysis units for adults in EastGermany (excluding East Berlin) by questionnaire, achievinga response rate of 97%. From December 1989 to December 1992the number of dialysis centres increased from 53 to 96 (+81%),reaching 6.7 centres p.m.p. Of these facilities, 45% were hospitalunits, 29% private units, and 26% dialysis units run by non-profithealth care organizations. The number of dialysis stations forregular dialysis treatment increased from 602 to 1276 (+112%),i.e. 89 stations p.m.p. In parallel, the number of chronic dialysispatients increased from 2127 to 3848 (+81%), i.e. 267 patientsp.m.p. A more detailed survey was carried out in Thüringen andpart of Sachsen, in a region covering 5 million inhabitants.The acceptance rate for chronic dialysis treatment has increasedfrom 49 to 107 patients p.m.p. (+115%). The average age of newpatients increased from 49 to 59 years, the proportion of patientsaged 65 years increased from 16 to 42% and the proportion ofdiabetics from 13 to 35%. Introduction of alternative treatmentmodalities became possible, with 2.3% of the patients receivinghaemofiltrations and 3% CAPD. The proportion of HBs-antigen-positivepatients decreased from 14.2% to 5%. At the end of 1989 in the former GDR (excluding East Berlin),773 patients and, at the end of 1992, 1153 patients were alivewith functioning renal transplants (+49%). The annual rate oftransplantations was 254 in 1989, and 283 in 1992 (+11%), i.e.18 transplantations p.m.p. (including East Berlin). At the end of 1989 2900 patients (193 p.m.p.), and at the endof 1992 5001 patients (347 p.m.p.), werealive on renal replacementtherapy (dialysis or functioning renal transplant) in East Germany,excluding East Berlin; this represents a 72% increase. The figures in East Germany are now almost equivalent to thosein West Germany regarding the number of admissions (incidence),whereas the number of patients on renal replacement therapyis still lower (prevalence). 相似文献
99.
Timothy E. Bunchman 《Pediatric nephrology (Berlin, Germany)》1995,9(Z1):S18-S22
Dialysis in the infant carries a mortality rate of 16%. Institution of dialysis may be the result of adequate nutritional intake, but avoidance of nutritional intake should never be seen as a way to prevent dialysis. Increased caloric intake, usually via enteral feeding tubes, is needed for optimal growth in the infant with end-stage renal disease (ESRD) in order to attain adequate nutrition with resulting good growth. Renal formulae may be constituted as dilute (as in thepolyuric infant) or concentrated (as in theanuric infant) to fit the infants needs. Peritoneal dialysis (PD) is the usual mode of renal replacement therapy (97%), with access via a surgically placed cuffed catheter with attention to the placement of the exit site in order to avoid fecal or urinary contamination. PD volumes of 30–40 ml/kg per pass or 800–1,200 ml/m2 per pass usually result in dialysis adequacy. Additional dietary sodium (3–5 mEq/kg per day) and protein (3–4 g/kg per day) are needed, due to sodium and protein losses in the dialysate. Protein losses are associated with significant infectious morbidity and nonresponsiveness to routine immunizations. Hemodialysis (HD) can be performed either as single- or dual-needle access that have minimal dead space (less then 2 ml) and recirculation rate (less then 5%). Attnetion to extracorporeal blood volume (<10% of=" intravascular=" volume),=" blood=" flow=" rates=" (3–5=" ml/kg=" per=" min),=" heparinization=" (activated=" clotting=" times),=" ultrafiltration=" (ultrafiltration=" monitor),=" and=" temperature=" control=" is=" imperative=" during=" each=" treatment.=" because=" infants'=" nutrition=" is=" mostly=" fluid,=" hd=" may=" be=" needed=" 4–6=" days/week=" (especially=" in=" the=" oligoanuric=" infant)=" to=" avoid=" excessive=" volume=" overload=" between=" treatments.=" at=" the=" end=" of=" the=" treatment=" a=" slow=" blood=" return=" with=" minimal=" saline=" rinse=" is=" needed=" to=" avoid=" hemodynamic=" compromise.=" infant=" dialysis,=" although=" technically=" challenging=" with=" a=" significant=" morbidity=" and=" mortality=" rate,=" can=" be=" safely=" carried=" out=" in=" the=" infant=" with=" esrd=" but=" requires=" infant-specific=" equipment=" and=" trained=">10%> 相似文献
100.
The widely used Kt/V concept for quantitating haemodialysis(HD) and ensuring adequate dialysis is based on several assumptions.In order to simplify the urea kinetic modelling, the body isassumed to be a single well-mixed compartment. Previously, morephysiological two-compartment or blood flow distribution modelshave been used to explain the phenomenon of blood urea reboundafter dialysis. This study attempts to evaluate the effectsof a multi compartment model on the removal of urea, i.e. onthe adequacy of dialysis. Four different tissue compartmentsof similar size are used, with flow rates between 40 and 3600ml/min for a bodyweight around 70 kg, allowing for blood flowheterogeneity within and between skeletal muscles. Dialysisis simulated by removing blood containing urea and replacingit with blood free of urea, during isovolumetric conditionsand assuming no diffusion barriers for urea. Several importantconclusions can be drawn from the model. Firstly the removalof urea is dependent both on the time of dialysis and on thenumber of HD treatments per week despite constant Kt/V. Secondlythe blood urea concentration is increased after dialysisureareboundin accordance with clinical data. Thirdlythe concept of blood flow distribution can fully explain thedifference between haemodialysis and peritoneal dialysis interms of Kt/V needed for adequate dialysis. Thus a weekly Kt/Vof 3.6 for HD 4 h 3 times per week removes the same amount ofurea as CAPD and a Kt/V of 2.1. Also, nightly intermittent PDrequires similar Kt/Vs (0.1 higher) as CAPD to obtain equivalentremoval of urea. Finally the crucial point is that the Kt/Vrequired for adequate dialysis must be increased if the dialysistreatment time is reduced. If not, the patient with renal insufficiencysuffers the risk of being under-dialysed. 相似文献