全文获取类型
收费全文 | 1255篇 |
免费 | 68篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 40篇 |
妇产科学 | 34篇 |
基础医学 | 116篇 |
口腔科学 | 72篇 |
临床医学 | 98篇 |
内科学 | 276篇 |
皮肤病学 | 13篇 |
神经病学 | 67篇 |
特种医学 | 127篇 |
外科学 | 225篇 |
综合类 | 10篇 |
一般理论 | 2篇 |
预防医学 | 23篇 |
眼科学 | 102篇 |
药学 | 56篇 |
中国医学 | 1篇 |
肿瘤学 | 45篇 |
出版年
2024年 | 1篇 |
2023年 | 17篇 |
2022年 | 18篇 |
2021年 | 17篇 |
2020年 | 15篇 |
2019年 | 21篇 |
2018年 | 36篇 |
2017年 | 25篇 |
2016年 | 38篇 |
2015年 | 51篇 |
2014年 | 41篇 |
2013年 | 60篇 |
2012年 | 72篇 |
2011年 | 57篇 |
2010年 | 40篇 |
2009年 | 47篇 |
2008年 | 83篇 |
2007年 | 92篇 |
2006年 | 95篇 |
2005年 | 91篇 |
2004年 | 83篇 |
2003年 | 53篇 |
2002年 | 56篇 |
2001年 | 46篇 |
2000年 | 45篇 |
1999年 | 51篇 |
1998年 | 5篇 |
1997年 | 8篇 |
1996年 | 11篇 |
1995年 | 4篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 6篇 |
1991年 | 12篇 |
1990年 | 6篇 |
1989年 | 9篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有1330条查询结果,搜索用时 15 毫秒
41.
Zeynep Cakar Burcu Cetinkaya Duru Aras Betül Koca Sinan Ozkavukcu İskender Kaplanoglu Alp Can Ozgur Cinar 《Journal of assisted reproduction and genetics》2016,33(8):1059-1065
Purpose
The present study aimed to evaluate whether combining the magnetic-activated cell sorting (MACS) with density-gradient (DG) or swim-up (SU) sperm separation techniques can improve sperm selection to obtain higher quality spermatozoa.Methods
Two commonly used sperm selection techniques, SU and DG, were compared to MACS combined with either SU or DG. Spermatozoa obtained from normozoospermic (n?=?10) and oligozoospermic (n?=?10) cases were grouped as SU, DG, SU+MACS, and DG+MACS followed by the analysis of sperm morphology, motility, DNA integrity, and the levels of Izumo-1 and PLCZ proteins.Results
Although spermatozoa obtained by SU or DG when combined with MACS have improved aspects when compared to SU or DG alone, results did not reach a statistically significant level. Moreover, separation with MACS caused a significant loss in the numbers of total and rapid progressive spermatozoa.Conclusions
Considering the cost/benefit ratio, MACS application together with traditional techniques may only be preferred in certain cases having higher concentrations of spermatozoa, but it does not seem to be an ideal and practical sperm selection technique for routine use.42.
43.
Yildiz O Gokce C Alp E Durak AC Aygen B Kelestimur F Doganay M 《Endocrine journal》2005,52(2):183-188
The aim of the study was to investigate the hypothalamo-pituitary-adrenal (HPA) axis by ACTH stimulation test and the changes in adrenal size in acute brucellosis before and after therapy in a prospective study. Sixteen patients with acute brucellosis and 15 healthy subjects were included in the study during the last two years. Cortisol levels were assessed before, 30 and 60 minutes after ACTH (250 microg i.v.) injection and the size of the adrenals was measured in both groups. Mean basal cortisol levels in the patients before the therapy and after the therapy were 22.1 +/- 6.9 microg/dL and 11.3 +/- 6.0 microg/dL, respectively. The difference was statistically significant (p<0.001). There was also statistically significant difference for basal cortisol levels between the healthy subjects (12.2 +/- 4.6 microg/dL) and the patients before the therapy (p<0.001). Peak cortisol responses to ACTH were higher before the therapy in the patients with acute brucellosis (39.3 +/- 10.7 microg/dL) than in the healthy subjects (30.4 +/- 4.8 microg/dL, p = 0.014). However, there was no significant difference for peak cortisol levels in the patients before and after the therapy (32.7 +/- 8.0 microg/dL). Mean basal cortisol levels and peak cortisol responses to ACTH between the patients after the therapy and the healthy controls were similar. Both the maximum width of the adrenal glands and the width of the adrenal limbs were significantly greater before the therapy compared to healthy subjects and post-treatment period. We concluded that the HPA axis is activated and the adrenal glands are enlarged in acute brucellosis, which is reduced after appropriate therapy. 相似文献
44.
M. Namik Oztanir Osman Ciftci Aslı Cetin M. Akif Durak Nese Basak Yener Akyuva 《Neurological sciences》2014,35(8):1221-1228
This study investigated the effects of 18β-glycyrrhetinic acid (GA) on neuronal damage in brain tissue caused by global cerebral ischemia/reperfusion (I/R) in C57BL/J6 mice. All subjects (n = 40) were equally divided into four groups: (1) sham-operated (SH), (2) I/R, (3) GA, and (4) GA+I/R. The SH group was used as a control. In the I/R group, the bilateral carotid arteries were clipped for 15 min, and the mice were treated with the vehicle for 10 days. In the GA group, mice were given GA (100 mg/kg) for 10 days following a median incision without carotid occlusion. In the GA+I/R group, the I/R model was applied to the mice exactly as in the I/R group, and they were then treated with the same dose of GA for 10 days. Cerebral I/R significantly induced oxidative stress via an increase in lipid peroxidaitons and a decrease in elements of the antioxidant defense systems. However, GA treatment was protective against the oxidative effects of I/R by inducing significant increases in antioxidant defense systems and a significant decrease of lipid peroxidations. Additionally, cerebral I/R increased the incidence of histopathological damage and apoptosis in brain tissue, but these neurodegenerative effects were eliminated by GA treatment. Therefore, the current study demonstrated that GA treatment effectively prevents oxidative and histological damage in the brain caused by global I/R. In this context, GA may be useful for the attenuation of the negative effects of global cerebral I/R and, in the future, it may be a viable and safe alternative treatment for ischemic stroke in humans. 相似文献
45.
46.
Aras Jamal Talabani Stian Lydersen Birger H. Endreseth Tom-Harald Edna 《International journal of colorectal disease》2014,29(8):937-945
Purpose
Hospitalization for acute colonic diverticulitis has become more and more frequent. We studied the changes in the rate of admission and incidence of the disease during the last 25 years.Methods
We performed a retrospective analysis of all cases treated for acute diverticulitis during 1988–2012 at one hospital serving a defined population in Mid-Norway. The study made a distinction between admission rates and incidence rates. The admission rates defined the total number of cases admitted, while the incidence rates defined the number of new patients hospitalized for acute diverticulitis (first admission). Poisson regression was used to analyse factors associated with diverticulitis incidence rates.Results
A total of 851 admissions in 650 different patients were identified, with an overall admission rate of 38.5 (CI 35.9 to 41.1) per 100,000 person-years. The admission rate increased from 17.9 (CI 14.1 to 22.3)/100,000 during 1988–1992 to 51.1 (CI 44.8 to 58.0)/100,000 during 2008–2012. Poisson regression analysis showed a significant increase in admission rates with a factor of 2.8 (C.I. 2.2 to 3.5) during 25 years. The overall incidence rate (IRR) of new patients was 29.4 (CI 27.1 to 31.7)/100,000 person-years. IRR increased significantly with a factor of 2.6 (CI 1.96 to 3.34) during 25 years, while IRR for perforations increased even more, by a factor of 3.3 (CI 1.24 to 8.58).Conclusion
The hospital admission rates as well as incidence rates for acute colonic diverticulitis increased significantly during the 25-year time span. 相似文献47.
Murat Altaş M. Aras S. Meydan E. Nacar K. T. Ulutaş Y. Serarslan N. Yılmaz 《Acta neurologica Belgica》2014,114(1):33-40
Cerebral ischemia–reperfusion (I/R) injury is caused by lack of blood supply to the brain. The accumulation of toxic products such as reactive oxygen species (ROS) occurs on reperfusion, when the occlusion is removed. The resulting oxidative stress results in the initiation of pathways leading to necrotic and apoptotic cell death. Tadalafil (TAD) prevents the accumulation of ROS and increases antioxidant cellular protective mechanisms. The aim of this study was to investigate the effect of TAD treatment against short-term global brain I/R injury in rats. The study was carried out on 30 Wistar-albino rats, which were divided into three groups including a control group (n = 10), an I/R group (n = 10) and an I/R + TAD group (n = 10) (2 mg/kg/day for 4 days before ischemia). At the end of the experiment, tissue samples were collected for both biochemical and histopathological analyses. Malondialdehyde was significantly lower in the TAD-administered group (9.06 ± 0.15) than in the I/R group (p < 0.05). However, no significant difference was observed in nitric oxide levels in the TAD-administered group compared to the I/R group. The mean superoxide dismutase level was significantly higher in the I/R–TAD group than the I/R group. There was no statistically significant difference in glutathione peroxidase levels in I/R + TAD group compared to I/R group. Histopathologically, TAD-administered group provided significant morphological improvement compared to the I/R group. We concluded that TAD prevented I/R-induced neurotoxicity as shown by obtained biochemical and histopathological findings. 相似文献
48.
Tatyana Danyukova Nataniel F. Ludwig Renata V. Velho Frederike L. Harms Nilay Güne Henning Tidow Ida V. Schwartz Beyhan Tüysüz Sandra Pohl 《Human mutation》2020,41(1):133-139
Mucolipidosis (ML) II and III alpha/beta are inherited lysosomal storage disorders caused by mutations in GNPTAB encoding the α/β‐precursor of GlcNAc‐1‐phosphotransferase. This enzyme catalyzes the initial step in the modification of more than 70 lysosomal enzymes with mannose 6‐phosphate residues to ensure their intracellular targeting to lysosomes. The so‐called stealth domains in the α‐ and β‐subunit of GlcNAc‐1‐phosphotransferase were thought to be involved in substrate recognition and/or catalysis. Here, we performed in silico alignment analysis of stealth domain‐containing phosphotransferases and showed that the amino acid residues Glu389, Asp408, His956, and Arg986 are highly conserved between different phosphotransferases. Interestingly, mutations in these residues were identified in patients with MLII and MLIII alpha/beta. To further support the in silico findings, we also provide experimental data demonstrating that these four amino acid residues are strictly required for GlcNAc‐1‐phosphotransferase activity and thus may be directly involved in the enzymatic catalysis. 相似文献
49.
Batyraliev TA Pershukov IV Niyazova-Karben ZA Karaus A Calenici O Guler N Eryonucu B Temamogullari A Ozgul S Akgul F Sengul H Dogru O Demirbas O Timoshin IS Gaigukov AV Petrakova LN Peresypko MK Sidorenko BA;International Invasive Cardiology Research Group 《Angiology》2006,57(1):21-32
Treatment of in-stent restenosis (ISR) with conventional percutaneous transluminal coronary angioplasty (PTCA) causes significant recurrent neointimal tissue growth in 30-85%. Therefore, laser ablation of intrastent neointimal hyperplasia before balloon dilation can be an attractive alternative. However, the long-term outcomes of such treatment have not been studied thoroughly enough. This prospective case-control study evaluated angiographic and clinical outcomes of PTCA alone and a combination of excimer laser coronary angioplasty (ELCA) and adjunct PTCA in 125 patients with ISR. ELCA was performed before balloon dilation in 67 patients, PTCA alone was performed in 58 patients. Basic demographic and clinical data were comparable in both groups. Lesions included in ELCA group were longer (17.1+/-9.9 vs 13.6+/-9.1 mm; p = 0.034), more complex (36.5% type C stenoses vs 14.3%; p = 0.006), and more frequently had reduced distal blood flow (TIMI <3: 18.9% vs 4.8%; p = 0.025) compared to lesions in the PTCA group. Immediate angiographic results of PTCA and ELCA + PTCA appeared to be comparable. PTCA alone was successful in 57 patients (98.3%), ELCA + PTCA, in 66 patients (98.5%). The rates of hospital complications were comparable (3.0% in ELCA group vs 8.6% in PTCA group). The 1-year follow-up showed that the rates of major adverse cardiac events (MACE) were comparable in the 2 groups (37.3% in ELCA group vs 46.6% in PTCA group). The rates of target vessel revascularization (TVR) within 1 year after the intervention were also similar in the 2 groups (32.8% vs 34.5%). The data mean that ELCA in patients with complex ISR is efficient and safe. Despite a higher complexity of lesions in the ELCA group, no increase in the rate of complications was registered. 相似文献
50.
Objective The aim of this study was to determine the prevalence of joint hypermobility among high school students and to define the characteristics of patients with joint hypermobility.Methods The students underwent complete history and physical examination. In order to designate marfanoid habitus, body weight, height, and span/height and upper/lower segment ratios were recorded. The degree of joint hypermobility was scored by the Beighton scoring system. The following features were also examined: arthralgia, myalgia, low back pain, sciatica, spinal deformities, temporomandibular joint pain and crepitus, effusion, swan neck deformity, arachnodactyly, joint dislocation, joint sprain, Raynauds phenomenon, stria, varicose veins, abdominal and inguinal hernia, heart disease history, myopia, dropping eyelids, and antimongoloid slant.Results Eight hundred sixty-one students (433 females and 428 males) with a mean age of 15.4±1.1 years (range 13–19) were examined. Joint hypermobility was observed in 101 (11.7%) of the students. According to the Beighton scoring system, the majority of these (61.4%) were observed to score 4. Our results show that phenotype has no relation with joint mobility. Of the total number of students, there were 31 male (7.2%) and 70 female (16.2%) hypermobile subjects. The difference between sexes was highly significant (P=0.00005). Joint sprain was detected in 14 of hypermobile students (13.9%) and 50 of nonhypermobile students (6.6%). Its presence was the only significant parameter between hypermobile and nonhypermobile students (P=0.0094).Conclusions Joint hypermobility was found in 11.7% of the students in our study, and the results are in harmony with the previous studies on Western populations. Although hypermobility does not seem to be very problematic in young people, as in our focus group, we believe that it is important for physicians to recognize this problem to ensure correct diagnosis and treatment, since it may lead to mimic rheumatic diseases in the future. 相似文献