全文获取类型
收费全文 | 3508篇 |
免费 | 238篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 132篇 |
妇产科学 | 32篇 |
基础医学 | 516篇 |
口腔科学 | 152篇 |
临床医学 | 322篇 |
内科学 | 879篇 |
皮肤病学 | 85篇 |
神经病学 | 272篇 |
特种医学 | 306篇 |
外科学 | 325篇 |
综合类 | 52篇 |
一般理论 | 1篇 |
预防医学 | 237篇 |
眼科学 | 37篇 |
药学 | 184篇 |
1篇 | |
中国医学 | 4篇 |
肿瘤学 | 212篇 |
出版年
2023年 | 14篇 |
2022年 | 22篇 |
2021年 | 55篇 |
2020年 | 31篇 |
2019年 | 43篇 |
2018年 | 46篇 |
2017年 | 38篇 |
2016年 | 46篇 |
2015年 | 95篇 |
2014年 | 72篇 |
2013年 | 116篇 |
2012年 | 158篇 |
2011年 | 158篇 |
2010年 | 121篇 |
2009年 | 122篇 |
2008年 | 161篇 |
2007年 | 175篇 |
2006年 | 173篇 |
2005年 | 175篇 |
2004年 | 184篇 |
2003年 | 180篇 |
2002年 | 121篇 |
2001年 | 98篇 |
2000年 | 61篇 |
1999年 | 48篇 |
1998年 | 114篇 |
1997年 | 99篇 |
1996年 | 70篇 |
1995年 | 70篇 |
1994年 | 52篇 |
1993年 | 54篇 |
1992年 | 52篇 |
1991年 | 52篇 |
1990年 | 42篇 |
1989年 | 71篇 |
1988年 | 62篇 |
1987年 | 56篇 |
1986年 | 46篇 |
1985年 | 50篇 |
1984年 | 36篇 |
1983年 | 34篇 |
1982年 | 22篇 |
1981年 | 28篇 |
1980年 | 29篇 |
1979年 | 28篇 |
1978年 | 27篇 |
1977年 | 22篇 |
1976年 | 23篇 |
1975年 | 18篇 |
1969年 | 13篇 |
排序方式: 共有3769条查询结果,搜索用时 31 毫秒
71.
72.
M Reincke E Fischer S Gerum K Merkle S Schulz A Pallauf M Quinkler G Hanslik K Lang S Hahner B Allolio C Meisinger R Holle F Beuschlein M Bidlingmaier S Endres;Participants of the German Conn's Registry-Else Kröner-Fresenius-Hyperaldosteronism Registry 《Hypertension》2012,60(3):618-624
In comparison with essential hypertension, primary aldosteronism (PA) is associated with an increased risk of cardiovascular morbidity. To date, no data on mortality have been published. We assessed mortality of patients treated for PA within the German Conn's registry and identified risk factors for adverse outcome in a case-control study. Patients with confirmed PA treated in 3 university centers in Germany since 1994 were included in the analysis. All of the patients were contacted in 2009 and 2010 to verify life status. Subjects from the population-based F3 survey of the Cooperative Health Research in the Region of Augsburg served as controls. Final analyses were based on 600 normotensive controls, 600 hypertensive controls, and 300 patients with PA. Kaplan-Meyer survival curves were calculated for both cohorts. Ten-year overall survival was 95% in normotensive controls, 90% in hypertensive controls, and 90% in patients with PA (P value not significant). In multivariate analysis, age (hazard ratio, 1.09 per year [95% CI, 1.03-1.14]), angina pectoris (hazard ratio, 3.6 [95% CI, 1.04-12.04]), and diabetes mellitus (hazard ratio, 2.55 [95% CI, 1.07-6.09]) were associated with an increase in all-cause mortality, whereas hypokalemia (hazard ratio, 0.41 per mmol/L [95% CI, 0.17-0.99]) was associated with reduced mortality. Cardiovascular mortality was the main cause of death in PA (50% versus 34% in hypertensive controls; P<0.05). These data indicate that cardiovascular mortality is increased in patients treated for PA, whereas all-cause mortality is not different from matched hypertensive controls. 相似文献
73.
Objectives
Most in vitro studies investigate the erosive process using relatively simple roughness parameters such as roughness average (Ra). In isolation, Ra may misrepresent the surface features. Further, few studies report baseline surface characteristics after sample preparation. This study aimed to test the hypothesis that measuring the bearing area parameters in addition to Ra may be useful when qualifying the surface of enamel at baseline and after an erosive challenge. The null hypothesis for this study was that the bearing area parameters provide no more useful information than Ra alone, when qualifying the surface of enamel at baseline and after an erosive challenge.Methods
Enamel slabs (n = 20) were prepared from human (n = 2) and bovine (n = 4) incisor teeth and polished with 0.05 μm paste. Roughness average (Ra) and bearing parameters (MR1, MR2, Rpk, Rk, Rvk) were used to record baseline characteristics. Specimens were subjected to erosion with 1% citric acid solution for 1 min. Profilometric characteristics were recorded post-erosion, along with the maximum height changes within the profile. T-tests were carried out in order to compare baseline surface characteristics between tissue types. Post-erosion, analysis of variance (ANOVA) was used to test the effects of tissue type (bovine or human).Results
There was no significant difference in Ra between human and bovine incisor enamel at baseline (human 0.11 μm, bovine 0.12 μm P > 0.05), and no significant difference was observed post-erosion (human 0.23 μm, bovine 0.20 μm P > 0.05). There were significant differences in bearing parameters at baseline and post-erosion that were not identified by the Ra measurement alone.Conclusions
The results suggest that if Ra alone is measured, important differences in surface characteristics may be missed. The null hypothesis is rejected, and the recommendation is made that bearing parameters are included within profile measurements in order to further triangulate the results of surface analysis studies.Clinical relevance
In isolation, Ra may misrepresent the surface features of a profile. These results have shown that the bearing parameters are an important and informative set of measurements. The recommendation is made that bearing parameters are included within profile measurements at baseline and post-erosion, in order to further triangulate the results of surface analysis studies. 相似文献74.
75.
Britta Auel Hartmut Goldschmidt Thomas Geer Thomas M. Moehler Uwe Platzbecker Ralph Naumann Igor Blau Mathias H?nel Wolfgang Knauf Holger Nückel Hans-Jürgen Salwender Christof Scheid Katja Weisel Marcus Gorschlüter Axel Glasmacher Ingo G. H. Schmidt-Wolf The German Refractory Myeloma Study Group 《Indian journal of hematology & blood transfusion》2012,28(2):67-76
Treatment of relapsed or refractory multiple myeloma remains a challenge and novel treatment regimen are required. Here, a matched pair analysis was performed comparing TCID (thalidomide, cyclophosphamide, idarubicin, dexamethasone) treatment to the treatment of patients with VID (vincristine, idarubicin, dexamethasone) or with VRID (vinorelbine, idarubicin, dexamethasone) for relapsed or refractory multiple myeloma. In total, 197 patients were enrolled in multicenter trials. After matching for important prognostic variables 46 matched-pairs (total of 138 patients) could be analysed with regard to survival, toxicity and efficacy. Interestingly, a significant improvement of overall response rate (ORR) for TCID treatment compared to VID and VRID was found. In addition, TCID treatment also led to a significantly higher overall survival (OS) as well as progression-free survival (PFS) compared to VID and VRID. In conclusion, TCID treatment appears to be superior to VRID and VID treatment in patients with progressive or refractory myeloma. 相似文献
76.
77.
German V. Fuentes Eric N. Doucet Alyson Abraham Nikki K. Rodgers Felix Alonso Nelson Euceda Michael H. Quinones Penelope A. Riascos Kristelle Pierre Nuhash H. Sarker Manya Dhar-Mascareno Mircea Cotlet Kim Kisslinger Fernando Camino Mingxing Li Fang Lu Ruomei Gao 《RSC advances》2020,10(29):17094
It is both challenging and desirable to have drug sensitizers released at acidic tumor pH for photodynamic therapy in cancer treatment. A pH-responsive carrier was prepared, in which fumed silica-attached 5,10,15,20-tetrakis(4-trimethylammoniophenyl)porphyrin (TTMAPP) was encapsulated into 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) nanocomposite liposomes. The sizes of agglomerates were determined by dynamic light scattering to be 115 nm for silica and 295 nm for silica-TTMAPP-DOPC liposomes. Morphological changes were also found in TEM images, showing liposome formation at pH 8.5 but collapse upon silanol protonation. TTMAPP release is enhanced from 13% at pH 7.5 to 80% at pH 2.3, as determined spectrophotometrically through dialysis membranes. Fluorescence emission of TTMAPP encapsulated in the dry film of liposomes was reduced to half at pH 8.6 when compared to that at pH 5.4, while the production of singlet oxygen was quintupled at pH 5.0 compared to pH 7.6. Upon treatment of human prostate cancer cells with liposomes containing 6.7 μM, 13 μM, 17 μM and 20 μM TTMAPP, the cell viabilities were determined to be 60%, 18%, 20% and 5% at pH 5.4; 58%, 30%, 25% and 10% at pH 6.3; and 90%, 82%, 68% and 35% at pH 7.4, respectively. Light-induced apoptosis in cancerous cells was only observed in the presence of liposomes at pH 6.3 and pH 5.4 but not at pH 7.4, as indicated by chromatin condensation.Nanocomposite liposomes are relatively stable in weak basic solutions but effectively release porphyrins at acidic pH, as indicated by the difference in fluorescence. 相似文献
78.
Antonino Germanò Stefano Priola Filippo Flavio Angileri Alfredo Conti Domenico La Torre Salvatore Cardali Giovanni Raffa Lucia Merlo Francesca Granata Marcello Longo Francesco Tomasello 《Neurosurgical review》2013,36(1):123-132
The purpose of this study is to describe our series of nine unclippable and uncoilable ruptured aneurysms in eight patients treated by microsurgical wrapping with autologous muscle. Records were retrospectively reviewed for rebleeding rate, morbidity and mortality, changes in size or the aneurysm’s configurations, and inflammatory reaction. We conducted a Medline search in the post-microsurgical era, excluding patients in whom wrapping was part of the aneurysm treatment in combination with clipping or coiling. The surgically related morbidity was 12.5 %. Global mortality rate was 25 % due to vasospasm (one case) and rebleeding (one case). Six patients are still alive. Rebleeding rate was 14.3 % within 6 months; then, it was zero. Glasgow outcome scale (GOS) score at discharge was 1 and 4 in one patient, respectively, and 5 in the remaining six. Mean clinical follow-up was 126 months. GOS at last follow-up was 4 and 5 in 50 % of patients, respectively. Mean mRS score was 0.8 at 2 months, and 2.4 at 12 months. Follow-up MR demonstrated persistence of the aneurysm’s sac, without changes in size and configuration. Patients did not describe or exhibit symptoms attributable to complications inherent to the use of muscle. Microsurgical muscle-wrapping of ruptured intracranial aneurysm is safe, is associated with a low rate of acute and delayed postoperative complications and rebleeding, and could be a valid alternative for unclippable and non-amenable to endovascular procedure ruptured aneurysms. 相似文献
79.
Dan Bieler Thomas Paffrath Annelie Schmidt Maximilian Vollmecke Rolf Lefering Martin Kull Erwin Kollig Axel Franke Sektion NIS of the German Trauma Society 《中华创伤杂志(英文版)》2020,23(4):224-232
Purpose: The mortality rate for severely injured patients with the injury severity score (ISS) 16 has decreased in Germany. There is robust evidence that mortality is influenced not only by the acute trauma itself but also by physical health, age and sex. The aim of this study was to identify other possible influences on the mortality of severely injured patients.
Methods: In a matched-pair analysis of data from Trauma Register DGU®, non-surviving patients from Germany between 2009 and 2014 with an ISS 16 were compared with surviving matching partners. Matching was performed on the basis of age, sex, physical health, injury pattern, trauma mechanism,
conscious state at the scene of the accident based on the Glasgow coma scale, and the presence of shock on arrival at the emergency room.
Results: We matched two homogeneous groups, each of which consisted of 657 patients (535 male, average age 37 years). There was no significant difference in the vital parameters at the scene of the accident, the length of the pre-hospital phase, the type of transport (ground or air), pre-hospital fluid management and amounts, ISS, initial care level, the length of the emergency room stay, the care received at night or from on-call personnel during the weekend, the use of abdominal sonographic imaging, the type of X-ray imaging used, and the percentage of patients who developed sepsis. We found a significant difference in the new injury severity score, the frequency of multi-organ failure, hemoglobine at admission, base excess and international normalized ratio in the emergency room, the type of accident (fall or road traffic accident), the pre-hospital intubation rate, reanimation, in-hospital fluid management, the frequency of transfusion, tomography (whole-body computed tomography), and the necessity of emergency intervention.
Conclusion: Previously postulated factors such as the level of care and the length of the emergency room stay did not appear to have a significant influence in this study. Further studies should be conducted to analyse the identified factors with a view to optimising the treatment of severely injured patients. Our study shows that there are significant factors that can predict or influence the mortality of severely
injured patients. 相似文献
80.