全文获取类型
收费全文 | 39767篇 |
免费 | 2126篇 |
国内免费 | 138篇 |
专业分类
耳鼻咽喉 | 522篇 |
儿科学 | 2572篇 |
妇产科学 | 697篇 |
基础医学 | 4752篇 |
口腔科学 | 1116篇 |
临床医学 | 2873篇 |
内科学 | 7146篇 |
皮肤病学 | 1116篇 |
神经病学 | 2349篇 |
特种医学 | 1182篇 |
外科学 | 5973篇 |
综合类 | 1274篇 |
一般理论 | 17篇 |
预防医学 | 2016篇 |
眼科学 | 1455篇 |
药学 | 3989篇 |
1篇 | |
中国医学 | 351篇 |
肿瘤学 | 2630篇 |
出版年
2023年 | 327篇 |
2022年 | 964篇 |
2021年 | 1609篇 |
2020年 | 884篇 |
2019年 | 978篇 |
2018年 | 1394篇 |
2017年 | 1012篇 |
2016年 | 1331篇 |
2015年 | 1330篇 |
2014年 | 1960篇 |
2013年 | 2217篇 |
2012年 | 3125篇 |
2011年 | 3045篇 |
2010年 | 1824篇 |
2009年 | 1439篇 |
2008年 | 2039篇 |
2007年 | 2062篇 |
2006年 | 1879篇 |
2005年 | 1665篇 |
2004年 | 1550篇 |
2003年 | 1314篇 |
2002年 | 1128篇 |
2001年 | 773篇 |
2000年 | 706篇 |
1999年 | 588篇 |
1998年 | 263篇 |
1997年 | 212篇 |
1996年 | 218篇 |
1995年 | 184篇 |
1994年 | 154篇 |
1993年 | 130篇 |
1992年 | 350篇 |
1991年 | 335篇 |
1990年 | 357篇 |
1989年 | 329篇 |
1988年 | 285篇 |
1987年 | 241篇 |
1986年 | 234篇 |
1985年 | 228篇 |
1984年 | 174篇 |
1983年 | 122篇 |
1982年 | 68篇 |
1981年 | 75篇 |
1980年 | 69篇 |
1979年 | 109篇 |
1978年 | 71篇 |
1977年 | 87篇 |
1976年 | 66篇 |
1973年 | 62篇 |
1971年 | 60篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
981.
982.
983.
Tushar Sharma Kevin Aroom Sahil Naik Brijesh Gill John X. J. Zhang 《Annals of biomedical engineering》2013,41(4):744-751
We demonstrate the design of thin flexible pressure sensors based on piezoelectric PVDF-TrFE (polyvinyledenedifluoride-tetrafluoroethylene) co-polymer film, which can be integrated onto a catheter, where the compact inner lumen space limit the dimensions of the pressure sensors. Previously, we demonstrated that the thin-film sensors of one micrometer thickness were shown to have better performance compared to the thicker film with no additional electrical poling or mechanical stretching due to higher crystallinity. The pressure sensors can be mass producible using standard lithography process, with excellent control of film uniformity and thickness down to one micrometer. The fabricated pressure sensors were easily mountable on external surface of commercial catheters. Elaborate experiments were performed to demonstrate the applicability of PVDF sensors towards catheter based biomedical application. The resonant frequency of the PVDF sensor was found to be 6.34 MHz. The PVDF sensors can operate over a broad pressure range of 0–300 mmHg. The average sensitivity of the PVDF sensor was found to be four times higher (99 μV/mmHg) than commercial pressure sensor while the PVDF sensor (0.26 s) had fivefold shorter response time than commercial pressure sensor (1.30 s), making the PVDF sensors highly suitable for real-time pressure measurements using catheters. 相似文献
984.
Neena Verma Dharmendra Singh Krishna Pandey Vidya Nand Rabi Das Chandra Shekhar Lal Rakesh Bihari Verma Prabhat Kumar Sinha Pradeep Das 《Journal of clinical microbiology》2013,51(12):4217-4219
Diagnosis of post-kala-azar dermal leishmaniasis (PKDL), particularly the macular form, is difficult when based on microscopy. This study compared the results of nested PCR (91.9% positive samples) with imprint smear microscopy (70.9% positive samples) for 62 PKDL samples. We found that nested PCR, which indicated 87.5% positivity for the macular lesions, compared to 41.6% positivity by imprint smear microscopy, is an efficient method for early diagnosis of PKDL. 相似文献
985.
Paul S. Foster Maximilian Plank Adam Collison Hock L. Tay Gerard E. Kaiko JingJing Li Sebastian L. Johnston Philip M. Hansbro Rakesh K. Kumar Ming Yang Joerg Mattes 《Immunological reviews》2013,253(1):198-215
Chronic inflammatory diseases of the lung are leading causes of morbidity and mortality worldwide. Many of these disorders can be attributed to abnormal immune responses to environmental stimuli and infections. As such, understanding the innate host defense pathways and their regulatory systems will be critical to developing new approaches to treatment. In this regard, there is increasing interest in the role of microRNAs (miRNAs) in the regulation of pulmonary innate host defense responses and the inflammatory sequelae in respiratory disease. In this review, we discuss recent findings that indicate an important role for miRNAs in the regulation in mouse models of various respiratory diseases and in host defense against bacterial and viral infection. We also discuss the potential utility and limitations of targeting these molecules as anti-inflammatory strategies and also as a means to improve pathogen clearance from the lung. 相似文献
986.
Manasi Majumdar Mini P. Singh Sujit Kumar Pujhari Deepak Bhatia Y. Chawla R.K. Ratho 《Journal of medical virology》2013,85(5):823-827
Hepatitis E virus (HEV) is implicated in many outbreaks of viral hepatitis in the Indian subcontinent. The conventional diagnosis of such outbreaks rests on the detection of anti‐HEV IgM antibodies. However, IgM antibodies develop after 4–5 days of infection. An early‐diagnostic marker is imperative for timely diagnosis of the outbreak and also initiation of control measures. This study aimed to determine the use of hepatitis E virus antigen detection as an early diagnostic marker in an outbreak in comparison to anti‐HEV IgM and RT‐PCR analyses. Forty samples were collected during a suspected outbreak of viral hepatitis due to HEV. A total of 36 samples were positive for one or more HEV markers. The positivity for anti‐HEV IgM, HEV antigen, and RT‐PCR was 91.6%, 69.4%, and 47.2% respectively. RT‐PCR and HEV antigen detection gave the highest positive results (100%) in the first 3 days of illness. Positive HEV PCR declined to 54% by Days 4–7, whereas HEV antigen and IgM detection were 88% and 100%, respectively. Sequencing of representative HEV samples indicated that the strains responsible for this outbreak belonged to genotype I, subtype 1a. HEV antigen was found to be an early diagnostic marker of acute infection. HEV antigen was detected in three additional cases in the early phase (1–3 days), and they had no detectable anti‐HEV IgM antibodies. These three samples were also positive for HEV RNA. After Day 7, anti‐HEV IgM was the main diagnostic indicator of infection. J. Med. Virol. 85:823–827, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
987.
Sandeep Kumar Alok Kumar Verma Mukul Das Premendra D. Dwivedi 《Immunology letters》2013,149(1-2):101-109
Food allergy is an immune provocation induced by certain food in susceptible individuals. Most of the food allergic manifestations are evident in the individual having impaired oral tolerance. In spite of worldwide prevalence, there is no permanent cure of food allergy. Food allergic reactions are complex immunological events that comprises of several immune molecules like IgE, IL-4, IL-13 and T-cells, therefore, researchers are trying to pick the correct molecule to find out pivotal therapeutic solutions. Being a key regulatory molecule in suppressing T-cells functional activities, cytotoxic T-cell lymphocyte antigen-4 (CTLA-4) or cluster of differentiation-152 (CD-152) has contributed a novel and revolutionary dimension toward therapeutic research of several diseases. This review focuses on different immunological and mechanistic perspectives of CTLA-4 in correlation with food allergy. 相似文献
988.
Malathesh Barikar C. Ibrahim Ferose Aziz Nirisha P. Lakshmi Kumar Channaveerachari Naveen Chand Prabhat Kumar Manjunatha Narayana Math Suresh Bada Thirthalli Jagadisha Manjappa Adarsha Alur Parthasarathy Rajani Reddy Shanivaram Arora Sanjeev 《The Psychiatric quarterly》2021,92(3):843-850
Psychiatric Quarterly - Technology driven capacity building initiatives are the way to break the barrier of shortage of mental health human resources in India. This new path, while is a welcome... 相似文献
989.
Objective: To assess the relationship between the HLA-DRB1 genes with disease severity as assessed by radiological erosions in Malaysian patients with rheumatoid arthritis (RA).Methods: In this cross-sectional study, we studied 61 RA patients who fulfilled the ACR criteria for the diagnosis of RA. HLA-DRB1 genotyping was performed by sequence specific primer (SSP)—PCR. Radiological grading and erosive score of the hands and wrists was calculated according to the Larsen–Dale method. Demographic data and treatment given to the patients were obtained from their case records.Results: Fifty-six females and five males were studied from three ethnic groups. In 57 patients with erosions, rheumatoid factor was detected in 80%, HLA-DR4 in 40%, HLA-DRB1*0405 in 24% and shared epitope (SE) in 31%. The median delay in starting DMARDs was 24 months. The presence of rheumatoid factor, HLA-DR4 and HLA-DRB1*0405 were not significantly associated with a worse erosive score. Patients who possessed the SE had a higher erosive scores, compared to those who did not (p = 0.05). Concurrently, a delay in starting DMARD was associated with a high erosive score (p = 0.023, r = 0.348). However, after adjustment for the delay in starting DMARD, SE was no longer significantly associated with the erosive score.Conclusions: In these patients, the delay in starting DMARDs had a greater influence on the erosive score than SE alone. Whilst we cannot discount the contribution of the SE presence, we would advocate early usage of DMARDs in every RA patient to reduce joint erosions and future disability. 相似文献
990.
Alok Kumar Singh Vivek Singh Mahendra Pal Singh Pratima Shrivastava Nisha Singh Indrajeet Singh Gambhir 《Immunopharmacology and immunotoxicology》2013,35(2):411-423
It is well established that the immune potential declines with age. However, there is a great paucity of information regarding role of monocytes in elderly suffering from cerebrovascular accident. This present study was undertaken to investigate if the functions of peripheral blood mononuclear cells have any correlation to the manifestation of an age-associated cerebrovascular disorders: myocardial infraction, cerebrovascular (infract & hemorrhage). An age-associated inhibition in the production of interleukin-1 (IL-1) by monocytes was observed while the production of nitric oxide (NO) remained unaltered in the response of monocytes, obtained from normal elderly donors, to Lipopolysaccharide (LPS) treatment in vitro. Cerebrovascular pathologies were found to be associated with an augmentation of IL-1 production by monocyte, while NO production was augmented in case of CVA (hemorrhage) and MI. Trace element copper was found to be lower in the serum of patients suffering from CVA, while concentration of zinc was found to be elevated in serum compared to these trace elements in normal adults. Thus these factors are likely to play a role in the pathogenesis of age-related cerebrovascular disorders. 相似文献