全文获取类型
收费全文 | 8723篇 |
免费 | 306篇 |
国内免费 | 98篇 |
专业分类
耳鼻咽喉 | 131篇 |
儿科学 | 151篇 |
妇产科学 | 81篇 |
基础医学 | 1410篇 |
口腔科学 | 141篇 |
临床医学 | 702篇 |
内科学 | 1795篇 |
皮肤病学 | 487篇 |
神经病学 | 636篇 |
特种医学 | 518篇 |
外科学 | 1029篇 |
综合类 | 20篇 |
现状与发展 | 1篇 |
一般理论 | 1篇 |
预防医学 | 313篇 |
眼科学 | 194篇 |
药学 | 835篇 |
4篇 | |
中国医学 | 143篇 |
肿瘤学 | 535篇 |
出版年
2024年 | 38篇 |
2023年 | 91篇 |
2022年 | 244篇 |
2021年 | 341篇 |
2020年 | 188篇 |
2019年 | 248篇 |
2018年 | 284篇 |
2017年 | 233篇 |
2016年 | 322篇 |
2015年 | 400篇 |
2014年 | 511篇 |
2013年 | 483篇 |
2012年 | 786篇 |
2011年 | 773篇 |
2010年 | 403篇 |
2009年 | 370篇 |
2008年 | 499篇 |
2007年 | 428篇 |
2006年 | 345篇 |
2005年 | 380篇 |
2004年 | 266篇 |
2003年 | 224篇 |
2002年 | 225篇 |
2001年 | 175篇 |
2000年 | 184篇 |
1999年 | 130篇 |
1998年 | 48篇 |
1997年 | 27篇 |
1996年 | 35篇 |
1995年 | 15篇 |
1994年 | 32篇 |
1993年 | 16篇 |
1992年 | 41篇 |
1991年 | 44篇 |
1990年 | 37篇 |
1989年 | 49篇 |
1988年 | 28篇 |
1987年 | 30篇 |
1986年 | 25篇 |
1985年 | 22篇 |
1984年 | 10篇 |
1983年 | 6篇 |
1981年 | 9篇 |
1980年 | 14篇 |
1979年 | 15篇 |
1978年 | 7篇 |
1977年 | 9篇 |
1971年 | 4篇 |
1970年 | 4篇 |
1967年 | 4篇 |
排序方式: 共有9127条查询结果,搜索用时 109 毫秒
991.
Jeong Ill Suh Jeong Kyu Sakong Kwan Lee Yong Kook Lee Jeong Bae Park Dong Joon Kim Yeon Seok Seo 《World journal of gastroenterology : WJG》2013,19(47):9069-9076
AIM:To investigate anxiety and depression propensities in patients with toxic liver injury.METHODS:The subjects were divided into three groups:a healthy control group(Group 1,n=125),an acute non-toxic liver injury group(Group 2,n=124),and a group with acute toxic liver injury group caused by noncommercial herbal preparations(Group 3,n=126).These three groups were compared and evaluated through questionnaire surveys and using the Hospital Anxiety-Depression Scale(HADS),Beck Anxiety Inventory(BAI),Beck Depression Inventory(BDI),and the hypochondriasis scale.RESULTS:The HADS anxiety subscale was 4.9±2.7,5.0±3.0 and 5.6±3.4,in Groups 1,2,and 3,respectively.The HADS depression subscale in Group 3 showed the most significant score(5.2±3.2,6.4±3.4 and 7.2±3.4in Groups 1,2,and 3,respectively)(P<0.01 vs Group 1,P<0.05 vs Group 2).The BAI and BDI in Group 3showed the most significant score(7.0±6.3 and 6.9±6.9,9.5±8.6 and 8.8±7.3,10.7±7.2 and 11.6±8.5in Groups 1,2,and 3,respectively)(BAI:P<0.01 vs Group 1,P<0.05 vs Group 2)(BDI:P<0.01 vs Group1 and 2).Group 3 showed a significantly higher hypochondriasis score(8.2±6.0,11.6±7.5 and 13.1±6.5in Groups 1,2,and 3,respectively)(P<0.01 vs Group 1,P<0.05 vs Group 2).CONCLUSION:Psychological factors that present vulnerability to the temptation to use alternative medicines,such as herbs and plant preparations,are important for understanding toxic liver injury. 相似文献
992.
John P. Aris Ashley L. Alvers Roy A. Ferraiuolo Laura K. Fishwick Amanda Hanvivatpong Doreen Hu Christine Kirlew Michael T. Leonard Kyle J. Losin Michelle Marraffini Arnold Y. Seo Veronica Swanberg Jennifer L. Westcott Michael S. Wood Christiaan Leeuwenburgh William A. Dunn Jr. 《Experimental gerontology》2013
We have previously shown that autophagy is required for chronological longevity in the budding yeast Saccharomyces cerevisiae. Here we examine the requirements for autophagy during extension of chronological life span (CLS) by calorie restriction (CR). We find that autophagy is upregulated by two CR interventions that extend CLS: water wash CR and low glucose CR. Autophagy is required for full extension of CLS during water wash CR under all growth conditions tested. In contrast, autophagy was not uniformly required for full extension of CLS during low glucose CR, depending on the atg allele and strain genetic background. Leucine status influenced CLS during CR. Eliminating the leucine requirement in yeast strains or adding supplemental leucine to growth media extended CLS during CR. In addition, we observed that both water wash and low glucose CR promote mitochondrial respiration proficiency during aging of autophagy-deficient yeast. In general, the extension of CLS by water wash or low glucose CR was inversely related to respiration deficiency in autophagy-deficient cells. Also, autophagy is required for full extension of CLS under non-CR conditions in buffered media, suggesting that extension of CLS during CR is not solely due to reduced medium acidity. Thus, our findings show that autophagy is: (1) induced by CR, (2) required for full extension of CLS by CR in most cases (depending on atg allele, strain, and leucine availability) and, (3) promotes mitochondrial respiration proficiency during aging under CR conditions. 相似文献
993.
Ho Cheol Hong Ji-Sung Lee Hae Yoon Choi Sae Jeong Yang Hye Jin Yoo Ji A Seo Sin Gon Kim Nan Hee Kim Sei Hyun Baik Dong Seop Choi Kyung Mook Choi 《Metabolism: clinical and experimental》2013
Objective
Increased liver enzymes and decreased vitamin D levels are associated with insulin resistance and type 2 diabetes. We examined liver enzymes and vitamin D levels in metabolically healthy but obese (MHO) individuals and compared the values with those of other body size phenotypes in the Korean population.Materials/Methods
A total of 16,190 people over the age of 18 years were analyzed using data from the Fourth Korean National Health and Nutrition Examination Survey, which is a nationally representative survey. Body size phenotypes were classified into four groups by body mass index (BMI) and number of metabolic syndrome components.Results
The prevalence of MHO was 14.9% in the entire population and 47.7% in the obese population. In a correlation analysis adjusted for age, sex, and BMI, AST and ALT levels were positively correlated with insulin resistance and cardiometabolic risk factors of the metabolic syndrome, whereas vitamin D level was negatively correlated with these variables. MHO individuals had significantly lower concentrations of AST and ALT compared to metabolically abnormal obese (MAO) subjects, although vitamin D levels were not significantly different. Furthermore, a multiple logistic regression analysis revealed that MHO individuals had lower risk of liver enzyme abnormality compared to MAO after adjusting for potential confounding factors. However, the risk of vitamin D deficiency was not significantly different among groups with different body size phenotypes.Conclusions
Although both liver enzymes and vitamin D levels are related to insulin resistance and metabolic syndrome, only liver enzymes were independently associated with MHO phenotype. 相似文献994.
Ho Dong Kim Do Hyun Kim Hyeuk Park Woo Jong Kim Yong Soo Ahn Young Jik Lee Sun Mi Park Eun Seon Seo Chul Park Yang Ho Kim Hyung Rag Kim Young Eun Joo Young Do Jung 《Gut and liver》2013,7(1):30-34
Background/Aims
The objective of this study was to evaluate a monoclonal antibody-based test to detect Helicobacter pylori-specific antigen in gastric aspirates from humans.Methods
Sixty-one volunteers were enrolled in the study. All of the subjects underwent a 13C-urea breath test (UBT) before esophagogastroduodenoscopy. Gastric aspirates were analyzed for pH and ammonia and used for polymerase chain reaction (PCR), culture, and monoclonal antibody-based detection of H. pylori. Multiple biopsies of the gastric antrum and body were obtained for a rapid urease test (RUT) and histological evaluation.Results
Thirty-six subjects were H. pylori-positive and 25 were H. pylori-negative according to the UBT results. Compared with the H. pylori-negative subjects, H. pylori-positive subjects had a higher pH (4.77±1.77 vs 3.49±1.30, p<0.05) and ammonia level (1,130.9±767.4 vs 184.2±126.3, p<0.0001). The sensitivities and specificities of the PCR test, RUT, culture test, and monoclonal antibody-based test were 100% and 72%, 89% and 100%, 47% and 100%, and 78% and 100%, respectively.Conclusions
The monoclonal antibody-based test for diagnosing H. pylori infection in gastric aspirates has increased sensitivity compared with the culture test and specificity as high as that of the RUT. The test may be useful as an additive test for examining gastric aspirates. 相似文献995.
Nark-Soon Park Yoon Tae Jeen Hyuk Soon Choi Eun Sun Kim Young Jin Kim Bora Keum Yeon Seok Seo Hoon Jai Chun Hong Sik Lee Soon Ho Um Chang Duck Kim Ho Sang Ryu 《Gut and liver》2013,7(4):443-449
Background/Aims
Acute complicated diverticulitis can be subdivided into moderate diverticulitis and severe diverticulitis. Although there have been numerous studies on the risk factors for complicated diverticulitis, little research has focused on severe diverticulitis. This study was designed to identify the risk factors for severe diverticulitis in an acute diverticulitis attack using the modified Hinchey classification.Methods
Patients were included if they had any evidence of acute diverticulitis detected by computed tomography. The patients were subdivided into severe diverticulitis (Hinchey class ≥Ib; abscesses or peritonitis) and moderate diverticulitis (Hinchey class Ia; pericolic inflammation) groups.Results
Of the 128 patients, 25 exhibited severe diverticulitis, and 103 exhibited moderate diverticulitis. In a multivariate analysis, age >50 years (odds ratio [OR], 5.27; p=0.017), smoking (OR, 3.61; p=0.044), comorbidity (OR, 4.98; p=0.045), leukocytosis (OR, 7.70; p=0.003), recurrence (OR, 4.95; p=0.032), and left-sided diverticulitis (OR, 6.92; p=0.006) were significantly associated with severe diverticulitis.Conclusions
This study suggests that the risk factors for severe diverticulitis are age >50 years, smoking, comorbidity, leukocytosis, recurrent episodes, and left-sided diverticulitis. 相似文献996.
997.
998.
Identification and characterization of a novel efflux-related multidrug resistance phenotype in Staphylococcus aureus 总被引:6,自引:0,他引:6
Moxifloxacin is a C8-methoxy (C8-OMe) fluoroquinolone that is highly active against Staphylococcus aureus, including many strains resistant to older fluoroquinolones such as ciprofloxacin. Available data indicate that it is a poor substrate for the NorA multidrug efflux pump. We produced a mutant of S. aureus in vitro (SA-K2068) with a novel non-NorA-mediated multidrug resistance phenotype characterized by raised MICs of several fluoroquinolones, including the C8-OMe fluoroquinolones, moxifloxacin and gatifloxacin, and the organic cations ethidium and tetraphenylphosphonium. Reserpine reduced MIC increases by two- to eight-fold. SA-K2068 also demonstrated reduced accumulation of moxifloxacin, gatifloxacin and enoxacin, and increased efflux of ethidium, activities that were completely blocked by carbonyl cyanide m-chlorophenyl hydrazone (CCCP); competition experiments indicated that a single pump was responsible for the phenotype. The effect of CCCP and ionophores identified the proton motive force as the source of energy for efflux. These data, combined with previous work from our laboratory and genome sequence data, indicate that S. aureus possesses several multidrug efflux pump proteins and it is apparent that C8-OMe fluoroquinolones can be substrates for such pumps. 相似文献
999.
We have reported previously that simultaneous sterno-thoracic cardiopulmonary resuscitation (SST-CPR) using a device that compresses the sternum and constricts the thorax circumferentially during a compression systole that can be achieved using standard cardiopulmonary resuscitation (STD-CPR). This study was designed to assess whether SST-CPR improves the survival rate of dogs with cardiac arrest compared with STD-CPR. Twenty-nine mongrel dogs (19-31 kg) were enrolled in this study. After 4 min of ventricular fibrillation induced by an AC current, animals were randomized to be resuscitated by either STD-CPR (n=15) or SST-CPR (n=14). Defibrillation was attempted 10 min after the induction of cardiac arrest. Standard advanced cardiac life support was started if defibrillation was unsuccessful. Aortic blood pressure, coronary perfusion pressure, and end tidal CO(2) tension were measured during CPR and the post-resuscitation period. Survival was determined 12 h after the induction of cardiac arrest. SST-CPR resulted in a significantly (P<0.001) higher systolic arterial pressure (91+/-47 vs 47+/-24 mmHg), diastolic pressure (43+/-24 vs 17+/-10 mmHg), coronary perfusion pressure (35+/-25 vs 13+/-9 mmHg), and end tidal CO(2) tension (9+/-4 vs 3+/-2 mmHg). Two of 15 animals (13%) resuscitated by STD-CPR and seven of 14 animals (50%) resuscitated by SST-CPR survived for 12 h after cardiac arrest (P<0.05). In conclusion, SST-CPR improves the short-term survival rate in canine cardiac arrest compared with STD-CPR. 相似文献
1000.
Human malignant effusions were found to contain transforming growth factor (TGF) activity capable of stimulating anchorage independent growth of nontransformed rodent fibroblasts. Bio-Gel P-60 chromatography of acid-ethanol extracts demonstrated the presence of three populations of TGF activities in 57% of malignant effusions. Two activities were similar to those of TGF alpha and TGF beta as judged by their size (Mr approximately equal to 6,000 and approximately equal to 25,000, respectively), biological activity (ability to stimulate anchorage independent growth of NRK fibroblasts in the absence or presence of epidermal growth factor, respectively), and capacity to competitively inhibit binding of 125I-labeled epidermal growth factor to A-431 membranes and 125I-TGF beta to baby hamster kidney fibroblasts, respectively. In addition a third factor which stimulated anchorage independent growth of nontransformed rodent fibroblast and human colonic epithelial cells was also recovered following Bio-Gel P-60 chromatography of extracts from several cytology positive human malignant effusions of patients with colonic and breast carcinoma as well as other malignancies. The latter malignant effusion related transforming growth factor was not present in benign or cytology negative effusions. Malignant effusion related TGF factor was inactivated by sulfhydryl reducing agents, heat, and trypsin treatment but was stable in 1% acetic acid and ethanol. Partial purification was accomplished by chromatography of an acid-ethanol extract on Bio-Gel P-60 followed by high performance liquid chromatography with C18-mu Bondapak to yield a nearly pure protein with apparent molecular weights of 64,000 by sodium dodecyl sulfate-polacrylamide gel electrophoresis when run in nonreducing conditions and 32,000 when run in reducing conditions. Malignant effusion related TGF was able to stimulate anchorage independent growth of nontransformed fibroblasts in the absence of other growth factors. It did not competitively inhibit binding of 125I-labeled epidermal growth factor, 125I-TGF beta, or 125I-labeled platelet derived growth factor. Therefore, this factor isolated from human malignant effusions may be distinct from previously described transforming growth factors. Collectively these observations indicate that human malignant effusions contain a multiplicity of transforming growth factors. It is possible that the malignant effusion related transforming growth factors play a role or reflect the metastatic growth properties of various tumors. 相似文献