全文获取类型
收费全文 | 3198篇 |
免费 | 224篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 115篇 |
妇产科学 | 101篇 |
基础医学 | 384篇 |
口腔科学 | 67篇 |
临床医学 | 323篇 |
内科学 | 771篇 |
皮肤病学 | 79篇 |
神经病学 | 189篇 |
特种医学 | 70篇 |
外科学 | 400篇 |
综合类 | 79篇 |
一般理论 | 5篇 |
预防医学 | 230篇 |
眼科学 | 85篇 |
药学 | 277篇 |
中国医学 | 14篇 |
肿瘤学 | 223篇 |
出版年
2024年 | 5篇 |
2023年 | 41篇 |
2022年 | 110篇 |
2021年 | 161篇 |
2020年 | 87篇 |
2019年 | 135篇 |
2018年 | 175篇 |
2017年 | 84篇 |
2016年 | 105篇 |
2015年 | 96篇 |
2014年 | 139篇 |
2013年 | 204篇 |
2012年 | 270篇 |
2011年 | 210篇 |
2010年 | 141篇 |
2009年 | 116篇 |
2008年 | 169篇 |
2007年 | 191篇 |
2006年 | 185篇 |
2005年 | 149篇 |
2004年 | 133篇 |
2003年 | 103篇 |
2002年 | 82篇 |
2001年 | 32篇 |
2000年 | 34篇 |
1999年 | 26篇 |
1998年 | 14篇 |
1997年 | 15篇 |
1996年 | 12篇 |
1995年 | 4篇 |
1994年 | 8篇 |
1993年 | 8篇 |
1992年 | 20篇 |
1991年 | 15篇 |
1990年 | 16篇 |
1989年 | 8篇 |
1988年 | 13篇 |
1987年 | 13篇 |
1986年 | 15篇 |
1985年 | 15篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1981年 | 10篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1976年 | 3篇 |
1973年 | 8篇 |
1972年 | 3篇 |
1971年 | 5篇 |
排序方式: 共有3432条查询结果,搜索用时 31 毫秒
21.
Sawsan Ibrahim Kreydiyyeh Rana Al-Sadi 《Journal of interferon & cytokine research》2002,22(10):1041-1048
The effect of interleukin-1beta (IL-1beta) on urine flow rates and Na(+)/K(+)-ATPase activity and expression was studied in rat intestinal and renal epithelia. The cytokine produced a significant diuretic effect and increased urine flow rate by around 10-fold compared with the control. This effect was considered to be secondary to the well-documented natriuretic effect of the cytokine described in the literature. On the other hand, we have shown previously that IL-1beta inhibits glucose absorption from the jejunum. As sodium excretion and glucose absorption are both dependent on Na(+)/K(+)-ATPase activity, the effect of the cytokine on the renal and intestinal pump was investigated. IL-1beta inhibited, in a dose-dependent manner, the activity of Na(+)/K(+)-ATPase in villus and crypt jejunal cells and in medullary and cortical kidney cells. Western blot analysis revealed a decrease in the protein expression of the enzyme, which was confirmed by the radiolabeled ouabain binding assay. The results suggest that the diuretic and natriuretic effect of IL-1beta and its inhibitory effect on glucose absorption are all due to downregulation of the Na(+)/K(+) pump in the kidney and jejunum. 相似文献
22.
Donnadieu E Jouvin MH Rana S Moffatt MF Mockford EH Cookson WO Kinet JP 《Immunity》2003,18(5):665-674
Allergic reactions are triggered via crosslinking of the high-affinity receptor for immunoglobulin E, F(c)epsilonRI. In humans, F(c)epsilonRI is expressed as a tetramer (alphabetagamma(2)) and a trimer (alphagamma(2)). The beta subunit is an amplifier of F(c)epsilonRI surface expression and signaling. Here, we show that as a consequence of alternative splicing, the F(c)epsilonRIbeta gene encodes two proteins with opposing and competing functions. One isoform is the full-length classical beta, the other a novel truncated form, beta(T). In contrast to beta, beta(T) prevents F(c)epsilonRI surface expression by inhibiting alpha chain maturation. Moreover, beta(T) competes with beta to control F(c)epsilonRI surface expression in vitro. We propose that the relative abundance of the products of the beta gene may control the level of F(c)epsilonRI surface expression and thereby influence susceptibility to allergic diseases. 相似文献
23.
Nathan LM Nerlander LM Dixon JR Ripley RM Barnabas R Wholeben BE Musoke R Palakudy T D'Agostino A Chakraborty R 《Journal of acquired immune deficiency syndromes (1999)》2003,34(2):237-241
OBJECTIVE: As a result of the HIV epidemic in Africa, much debate exists on whether institutionalized compared with community-based care provides optimum management of infected children. Previous reports calculated 89% mortality by age 3 years among outpatients in Malawi. No similar data are available for infected children in institutionalized care. We characterized patterns of morbidity and mortality among HIV-1-infected children residing at an orphanage in Nairobi. METHODS: Medical records for 174 children followed over 5 years were reviewed. Mortality was analyzed by Kaplan-Meier methods with adjustment to account for survival in the community before admission. Anthropometric indices were calculated to include mean z scores for weight for length and length for age. Low indices reflected wasting and stunting. Opportunistic infections were documented. RESULTS: Of 174 children, 64 had died. Survival was 70% at age 3 years. Morbidity included recurrent respiratory tract infections, gastroenteritis, parotitis, and lymphoid interstitial pneumonitis. No new cases of tuberculosis disease were noted after admission. Mean z scores for length for age suggested overall stunting (z = -1.65). Wasting was not observed (z = -0.39). CONCLUSION: The optimal form of care for HIV-infected children in resource-poor settings may be the development of similar homes. Absence of tuberculosis disease in long-standing residents may have contributed to improved survival. Stunting in the absence of wasting implied that growth was compromised by opportunistic infections and other cofactors. 相似文献
24.
When administered to animals cadmium is known to accumulate in the liver and kidney causing indentifiable toxicity. However, its binding with cell sap and nucleus and effects on their constituents are poorly known. Since nuclear changes reflect some of the metabolic disturbances and are of value in diagnosis, an attempt has been made to analyse their morphology and chemistry in the liver and kidney of rat after individual and combined treatment with Cd and Zn. Present observations clearly show that cadmium inhibits DNA synthesis by blocking the formation of the enzyme thymidine triphosphate which is prerequisite for DNA synthesis. Zinc exerted a stimulatory effect on DNA and RNA both by increasing the activity of thymidine kinase. Their combined effects were found to be less injurious to the cell. Though these changes could be a secondary or generalized response of nuclei to altered physiological conditions, specific reasons for these changes have been discussed. 相似文献
25.
26.
Reverse micelle and chemical hydrolysis techniques have been successfully combined to synthesize composite nanoparticles consisting of a photocatalytic shell of titania and a magnetic core of nickel ferrite. The nature of titania shell, i.e. anatase or brookite, depends on the TiO2 and NiFe2O4 molar ratio. The work presented here describes the photocatalytic and anti-microbial activity of the composite nanoparticles together with the magnetic characteristics of the nickel ferrite core. The TiO2-coated NiFe2O4 nanoparticles retain the magnetic characteristics of uncoated nanocrystalline nickel ferrites (superparamagnetism; absence of hysteresis, remanence and coercivity at 300 K) encouraging their application as removable anti-microbial photocatalyst nanoparticles that can be extracted from the sprayed surface (human body or environment) after exposure. 相似文献
27.
Nagarkatti R Kumar R Sharma SK Ghosh B 《International archives of allergy and immunology》2004,134(3):206-212
BACKGROUND: Asthma is a complex airway disorder, and a number of genetic loci have been found to be associated with asthma. The 5q31-33 region is one of the most important loci linked to asthma and atopic disorders. However, association studies with candidate genes in this region, such as IL4, were inconclusive, as both positive and negative results were obtained in several populations studied. The aim of our case-control study was to determine the association between IL4 and asthma in North Indians. PATIENTS AND METHODS: Polymorphisms in the promoter and a dinucleotide repeat in the 2nd intron in IL4 were genotyped by sequencing and GeneScan analysis, respectively, in ethnically matched, unrelated patients (n = 171) and controls (n = 128), following the guidelines of the American Thoracic Society. RESULTS: The proximal promoter region of the IL4 gene was found to be invariant. Previously reported polymorphisms, -590 C/T and +33 C/T, were found to be absent in our population. The chi2 test using only large expected cell counts (more than 5% of the sample size) showed a significant association between allele size and disease status (chi2 = 38.08, d.f. = 6, p < 0.05). In addition, a significant difference was observed for the allele and genotype frequencies (p < 0.0005 and p = 0.0009, respectively) in the patient and the control groups using the Fisher-Freeman-Halton test. CONCLUSION: Our studies indicate that the promoter of the IL4 gene is invariant in our population. The case-control studies on the CA repeat polymorphism in the 2nd intron of the IL4 gene have shown interesting results and indicate the need for further family-based studies. 相似文献
28.
Munaza Fatima Santosh Kumar Mudassar Hussain Naveed Masood Memon Anum Vighio Muhammad Asif Syed Ambreen Chaudhry Zakir Hussain Zeeshan Iqbal Baig Mirza Amir Baig Rana Jawad Asghar Aamer Ikram Yousef Khader 《JMIR Public Health and Surveillance》2021,7(5)
BackgroundHyderabad, Pakistan, was the first city to witness an outbreak of extensively drug resistant (XDR) typhoid fever. The outbreak strain is resistant to ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole, fluoroquinolones, and third-generation cephalosporin, thus greatly limiting treatment options. However, despite over 5000 documented cases, information on mortality and morbidity has been limited.ObjectiveTo address the existing knowledge gap, this study aimed to assess the morbidity and mortality associated with XDR and non-XDR Salmonella serovar Typhi infections in Pakistan.MethodsWe reviewed the medical records of culture-confirmed typhoid cases in 5 hospitals in Hyderabad from October 1, 2016, to September 30, 2018. We recorded data on age, gender, onset of fever, physical examination, serological and microbiological test results, treatment before and during hospitalization, duration of hospitalization, complications, and deaths.ResultsA total of 1452 culture-confirmed typhoid cases, including 947 (66%) XDR typhoid cases and 505 (34%) non-XDR typhoid cases, were identified. Overall, ≥1 complications were reported in 360 (38%) patients with XDR typhoid and 89 (18%) patients with non-XDR typhoid (P<.001). Ileal perforation was the most commonly reported complication in both patients with XDR typhoid (n=210, 23%) and patients with non-XDR typhoid (n=71, 14%) (P<.001). Overall, mortality was documented among 17 (1.8%) patients with XDR S Typhi infections and 3 (0.6%) patients with non-XDR S Typhi infections (P=.06).ConclusionsAs this first XDR typhoid outbreak continues to spread, the increased duration of illness before hospitalization and increased rate of complications have important implications for clinical care and medical costs and heighten the importance of prevention and control measures. 相似文献
29.
Rana Roshane-Shahid Nazim Syed M. Ather M. Hammad 《International urology and nephrology》2021,53(1):21-26
International Urology and Nephrology - To evaluate the acute renal colic score (ARC) in predicting the need of emergency intervention (EI) in patients with ureteric colic secondary to a ureteral... 相似文献
30.
Sarah Suh Emily Hetzel Katie Alter-Troilo Kathleen Lak Jon C. Gould Tammy L. Kindel Rana M. Higgins 《Surgery for obesity and related diseases》2021,17(8):1480-1488
BackgroundPreoperative carbohydrate loading is a component of Enhanced Recovery After Surgery (ERAS) protocols, but there is limited literature in bariatric surgery patients.ObjectivesThe objective of this study was to characterize the impact of preoperative carbohydrate loading on postoperative bariatric surgery outcomes.SettingUniversity Hospital.MethodsPatients undergoing a primary minimally invasive Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) between 2018 and 2020 were randomized to standard management or intervention. Standard management patients were nothing by mouth (NPO) after midnight prior to surgery. Intervention patients consumed 2 carbohydrate drinks: 1 the night before and another 3 hours prior to surgery. Primary outcomes analyzed included postoperative nausea and vomiting (PONV), length of stay, and overall complications.ResultsIn total, 134 patients were analyzed: 64 intervention (47.8%) and 70 (52.2%) standard. In the end, 7% and 15% of patients were lost to follow-up at 6-weeks and 3-months, respectively. There was no statistically significant difference in length of stay (2.0 ± 1.2 vs 2.1 ± .9 d; P = .65) or postoperative outcomes between the 2 groups. There were no episodes of aspiration among the intervention group. Among RYGB patients, intervention patients had a shorter duration of nausea compared with standard patients. There was no significant difference in glycemic control among patients with and without diabetes.ConclusionsPreoperative carbohydrate drinks can be administered to bariatric surgery patients without significant risks. Carbohydrate loading preoperatively can decrease the duration of PONV in RYGB patients. Carbohydrate drinks can be safely included in bariatric ERAS protocols for patients with and without diabetes, although the benefits remain unknown. 相似文献