全文获取类型
收费全文 | 14726篇 |
免费 | 929篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 171篇 |
儿科学 | 492篇 |
妇产科学 | 293篇 |
基础医学 | 2302篇 |
口腔科学 | 357篇 |
临床医学 | 1462篇 |
内科学 | 3071篇 |
皮肤病学 | 250篇 |
神经病学 | 1086篇 |
特种医学 | 466篇 |
外国民族医学 | 1篇 |
外科学 | 1995篇 |
综合类 | 95篇 |
一般理论 | 8篇 |
预防医学 | 1144篇 |
眼科学 | 349篇 |
药学 | 1156篇 |
2篇 | |
中国医学 | 14篇 |
肿瘤学 | 964篇 |
出版年
2022年 | 120篇 |
2021年 | 229篇 |
2020年 | 208篇 |
2019年 | 263篇 |
2018年 | 271篇 |
2017年 | 264篇 |
2016年 | 310篇 |
2015年 | 277篇 |
2014年 | 400篇 |
2013年 | 534篇 |
2012年 | 700篇 |
2011年 | 658篇 |
2010年 | 390篇 |
2009年 | 370篇 |
2008年 | 570篇 |
2007年 | 607篇 |
2006年 | 550篇 |
2005年 | 533篇 |
2004年 | 606篇 |
2003年 | 499篇 |
2002年 | 483篇 |
2001年 | 420篇 |
2000年 | 462篇 |
1999年 | 405篇 |
1998年 | 181篇 |
1997年 | 140篇 |
1996年 | 158篇 |
1995年 | 141篇 |
1994年 | 138篇 |
1993年 | 134篇 |
1992年 | 304篇 |
1991年 | 334篇 |
1990年 | 329篇 |
1989年 | 339篇 |
1988年 | 261篇 |
1987年 | 275篇 |
1986年 | 236篇 |
1985年 | 288篇 |
1984年 | 191篇 |
1983年 | 163篇 |
1982年 | 127篇 |
1981年 | 101篇 |
1980年 | 89篇 |
1979年 | 165篇 |
1978年 | 123篇 |
1977年 | 107篇 |
1975年 | 97篇 |
1974年 | 117篇 |
1973年 | 105篇 |
1972年 | 86篇 |
排序方式: 共有10000条查询结果,搜索用时 750 毫秒
101.
Physiological and cognitive performance of soldiers conducting routine patrol and reconnaissance operations in the tropics 总被引:1,自引:0,他引:1
The physiological and cognitive performance of acclimatized soldiers undertaking routine patrol and reconnaissance activities in the tropics was investigated. Data were obtained during a patrol and a reconnaissance exercise followed by a short assault. Ambient conditions were characterized by temperatures of 30 to 33 degrees C, low humidity (52-59%), and moderate to high solar radiation. Maximum metabolic rates during patrol were high, although the equipment carried was modest and the terrain was not severe. Rectal temperatures peaked at 38.2 and 38.4 degrees C for patrol and assault activities, respectively; peak heart rates were 160 beats min-1 for each activity. Sweat rates of approximately 9 and 14 g kg-1 body weight h-1 were recorded for patrol and assault activities, respectively. The soldiers maintained adequate hydration levels and displayed no evidence of deterioration in cognitive performance. The data show that routine operational activities in tropical conditions induced physiological strain in acclimatized soldiers. However, this strain was not maintained at hazardous levels for lengthy periods. 相似文献
102.
Hansen KJ Cherr GS Craven TE Motew SJ Travis JA Wong JM Levy PJ Freedman BI Ligush J Dean RH 《Journal of vascular surgery》2000,32(3):472-81; discussion 481-2
PURPOSE: This retrospective review describes the surgical management of consecutive patients with severe hypertension and ischemic nephropathy due to atherosclerotic renovascular disease. METHODS: From January 1987 through December 1998, a total of 590 patients underwent operative renal artery repair at our center. A subgroup of 232 hypertensive patients (97 women, 135 men; mean age, 66 +/- 8 years) with atherosclerotic renovascular disease and preoperative serum creatinine levels of 1.8 mg/dL or more forms the basis of this report. Change in renal function was determined from glomerular filtration rates estimated from preoperative and postoperative serum creatinine. The influence of selected preoperative parameters and renal function response on time to dialysis and dialysis-free survival was determined by a proportional hazards regression model. RESULTS: In all, 83 patients underwent unilateral renal artery repair and 149 patients underwent bilateral repair, including repair to a solitary kidney in 17 cases. A total of 332 renal arteries were reconstructed, and 32 nephrectomies were performed in these patients. After surgery, there were 17 deaths (7.3%) in the hospital or within 30 days of surgery. Advanced patient age (P =.001; hazard ratio, 1.1; 95% CI [1.1, 1.2]) and congestive heart failure (P =.04; hazard ratio, 2.9 CI [1.0, 8.6]) demonstrated significant and independent associations with perioperative mortality. With a change of 20% or more in EGFR being considered significant, 58% of patients had improved renal function, including 27 patients removed from dialysis dependence; function was unchanged in 35% and worsened in 7%. Follow-up death from all causes or progression to dialysis dependence demonstrated a significant and independent association with early renal function response. Both patients whose function was unchanged (P =.005; hazard ratio, 6.0; CI [2.2, 16.6]) and patients whose function was worsened (P =.03; hazard ratio, 2.2; CI [1.1, 4. 5]) remained at increased risk of death or dialysis dependence. For patients with unchanged renal function after operation, risk of death or dialysis demonstrated a significant interaction with preoperative renal function. In addition to severe preoperative renal dysfunction, diabetes mellitus demonstrated a significant and independent association with follow-up death or dialysis. CONCLUSION: Surgical correction of atherosclerotic renovascular disease can retrieve excretory renal function in selected hypertensive patients with ischemic nephropathy. Patients with improved renal function had a significant and independent increase in dialysis-free survival in comparison with patients whose function was unchanged and patients whose function was worsened after operation. These results add further evidence in support of a prospective, randomized trial designed to define the value of renal artery intervention in patients with ischemic nephropathy. 相似文献
103.
Peter Marker Viggo Svane-Knudsen Karsten E. J rgensen Arnoff Nielsen Olfred Hansen 《Acta oncologica (Stockholm, Sweden)》1997,36(1):41-44
Closure of the surgical defect immediately after partial maxillectomy is the treatment of choice. The advantages are: maintaining facial contour, rapid re-establishment of speech, swallowing and mastication. A number of methods for the fixation of the immediate obturator in patients without teeth have been described. A new technique is reported where a transnasal wire holds the existing denture in position after partial maxillectomy. The method has been carried out on 7 patients with sino-nasal cancer during the period 1978-1994. The advantages of the technique are that the wire acts as an axis of rotation which together with the sponge in the cavity provide good stability of the denture. There is minimal preoperative laboratory work and simplification in replacing the surgical dressing. 相似文献
104.
105.
The K121Q variant of the human PC-1 gene is not associated with insulin resistance or type 2 diabetes among Danish Caucasians 总被引:12,自引:0,他引:12
Rasmussen SK Urhammer SA Pizzuti A Echwald SM Ekstrøm CT Hansen L Hansen T Borch-Johnsen K Frittitta L Trischitta V Pedersen O 《Diabetes》2000,49(9):1608-1611
The human plasma-cell membrane differentiation antigen-1 (PC-1) has been shown to inhibit insulin receptor tyrosine kinase activity. Recently, a K121Q polymorphism in the human PC-1 gene was found in a Sicilian population and was shown to be strongly associated with insulin resistance. The objectives of the present investigation were to examine in the Danish Caucasian population whether the K121Q variant was associated with type 2 diabetes or, in glucose-tolerant subjects, with impaired whole-body insulin sensitivity. We genotyped 404 Danish type 2 diabetic patients and found that the allele frequency of the variant was 0.14 (95% CI 0.12-0.16), whereas the allele frequency was 0.16 (95% CI 0.13-0.19) among 237 matched glucose-tolerant control subjects (P = 0.6). In the control subjects, there were no significant differences among wild-type, heterozygous, or homozygous subjects in regard to 1) serum insulin and plasma glucose levels at fasting, 60 min, or 120 min during an oral glucose tolerance test (OGTT) or 2) the estimates of insulin resistance obtained from the homeostasis model assessment (HOMA). Furthermore, we investigated the impact of the variant in 2 other Danish population samples that comprised 356 young healthy subjects and 226 glucose-tolerant offspring of type 2 diabetic probands, respectively. In all of the study populations, the polymorphism was not associated with an altered insulin sensitivity index as estimated from an intravenous glucose tolerance test in combination with an intravenous injection of tolbutamide. In addition, among the 226 offspring, the variations in serum insulin and serum C-peptide responses measured during an OGTT were not related to the PC-1 genotype. In conclusion, the K121Q polymorphism of the human PC-1 gene is not associated with type 2 diabetes or insulin resistance among Danish Caucasians. 相似文献
106.
Roland Schnell Markus Dietlein Jan Oliver Staak Peter Borchmann Klaus Schomaecker Thomas Fischer Wolfgang Eschner Hinrich Hansen Franck Morschhauser Harald Schicha Volker Diehl Andrew Raubitschek Andreas Engert 《Journal of clinical oncology》2005,23(21):4669-4678
PURPOSE: Hodgkin's lymphoma (HL) has been demonstrated to be a good target for immunotherapy since lymphocyte activation markers such as CD30 are expressed in high numbers on the malignant cells. Thus, we developed a new radioimmunoconjugate consisting of the murine anti-CD30 monoclonal antibody (MAb) Ki-4 labeled with iodine-131 ((131)I). PATIENTS AND METHODS: The biodistribution of (131)I-Ki-4 was assessed via dosimetry after preinfusion of 5 mg native Ki-4 followed by 250 to 300 MBq (131)I-labeled Ki-4. Whole-body scintigraphy was performed 1 hour, 24 hours, 48 hours, 72 hours, and 6 days after the infusion. Dosimetry was calculated using the programs NucliDose ICON-IDL (version 5.0.2; Siemens, Erlanger, Germany) and MIRDOSE (version 3.1; Oak Ridge National Laboratories; Oak Ridge, TN). The therapeutic dose was given on day 8 after preinfusion of unlabeled Ki-4. RESULTS: We treated 22 patients with relapsed or refractory CD30-positive HL. Preinfusion of 5 mg native Ki-4 was sufficient to bind the soluble CD30. Imaging demonstrated localization of involved areas measuring 5 cm in diameter or more in four patients and 2.5 cm in one patient. Patients received total body doses of 0.035 Gy to 0.99 Gy. Acute toxicity was mild with grade 1 fatigue in 19 of 22 assessable patients. Seven patients experienced grade 4 degrees hematotoxicity 4 to 8 weeks after treatment. Response included one complete remission, five partial remissions, and three minor responses. CONCLUSION: Treatment with (131)I-Ki-4 is effective but can be associated with severe hematotoxicity. 相似文献
107.
Steven P Treon Mark Hansen Andrew R Branagan Sigitas Verselis Christos Emmanouilides Eva Kimby Stanley R Frankel Nikolaos Touroutoglou Barry Turnbull Kenneth C Anderson David G Maloney Edward A Fox 《Journal of clinical oncology》2005,23(3):474-481
PURPOSE: Rituximab is an important therapeutic for Waldenstrom's macroglobulinemia (WM). Polymorphisms in FcgammaRIIIA (CD16) receptor expression modulate human immunoglobulin G1 binding and antibody-dependent cell-mediated cytotoxicity, and may therefore influence responses to rituximab. PATIENTS AND METHODS: Sequence analysis of the entire coding region of FcgammaRIIIA was undertaken in 58 patients with WM whose outcomes after rituximab were known. RESULTS: Variations in five codons of FcgammaRIIIA were identified. Two were commonly observed (FcgammaRIIIA-48 and FcgammaRIIIA-158) and predicted for amino acid polymorphisms at FcgammaRIIIA-48: leucine/leucine (L/L), leucine/arginine (L/R), and leucine/histidine (L/H). Polymorphisms at FcgammaRIIIA-158 were phenylalanine/phenylalanine (F/F), phenylalanine/valine (F/V), and valine/valine (V/V). A clear linkage between these polymorphisms was detected and all patients with FcgammaRIIIA-158F/F were always FcgammaRIIIA-48L/L, and patients with either FcgammaRIIIA-L/R or -L/H always expressed at least one valine at FcgammaRIIIA-158 (P < or = .001). The response trend was higher for patients with FcgammaRIIIA-48L/H (38.5%) versus -48L/R (25.0%) and LL (22.0%), and was significantly higher for patients with FcgammaRIIIA-158V/V (40.0%) and -V/F (35%) versus -158F/F (9.0%; P = .030). Responses for patients with FcgammaRIIIA-48L/L were higher when at least one valine was present at FcgammaRIIIA-158 (P = .057), thereby supporting a primary role for FcgammaRIIIA-158 polymorphisms in predicting rituximab responses. With a median follow-up of 13 months, no significant differences in the median time to progression and progression-free survival were observed when patients were grouped according to their FcgammaRIIIA-48 and -158 polymorphisms. CONCLUSION: The results of these studies therefore support a predictive role for FcgammaRIIIA-158 polymorphisms and responses to rituximab in WM. 相似文献
108.
109.
Lykkeberg AK Sengeløv G Cornett C Tjørnelund J Hansen SH Halling-Sørensen B 《Journal of pharmaceutical and biomedical analysis》2004,34(3):559-567
2-Acetyl-2-decarboxamido-oxytetracycline (ADOTC) is a major impurity of oxytetracycline (OTC) produced as a side product during fermentation. ADOTC was isolated from OTC and other impurities using preparative HPLC. The preparative column was an Xterra MS, C18 chromatographic column (100 mm x 19 mm i.d., 5 microm), and the mobile phase contained methanol-water (27:73 (v/v)) with 0.08 M formic acid added. The flow rate was 9.0 ml/min. It was possible to isolate few milligram ADOTC in a day. The compound was unambiguously identified using NMR and MS-MS. The anti-microbial activity against activated sludge bacteria was determined giving a potency of only 3% of that of OTC. With tetracycline-resistant bacteria, no anti-microbial activity was observed, indicating a mode of action similar to that of OTC. 相似文献
110.
Decentration of flexible loop posterior chamber intraocular lenses in a series of 222 postmortem eyes 总被引:4,自引:0,他引:4
S O Hansen M R Tetz K D Solomon M D Borup R N Brems D J O'Morchoe O Bouhaddou D J Apple 《Ophthalmology》1988,95(3):344-349
Two hundred twenty-two postmortem eyes containing posterior chamber intraocular lenses (IOLs) were analyzed for optic decentration in relationship to lens style, implant duration, and loop fixation site. Decentration values were not affected significantly by either lens style or implant duration. In 33.3% of specimens, both loops were situated within the lens capsular sac, 18.0% had both loops fixated in the ciliary sulcus, and in 48.7% one loop was fixated in the lens capsular sac and the opposite loop in the ciliary sulcus or zonular region. There was a statistically significant difference in the amount of decentration in the three fixation groups studied. Capsular fixation provides the best and most consistent centration compared with fixation of both loops in the ciliary sulcus or asymmetrical fixation with only one loop in the capsular sac. 相似文献