全文获取类型
收费全文 | 2381篇 |
免费 | 111篇 |
国内免费 | 6篇 |
学科分类
医药卫生 | 2498篇 |
出版年
2023年 | 13篇 |
2022年 | 39篇 |
2021年 | 81篇 |
2020年 | 30篇 |
2019年 | 42篇 |
2018年 | 58篇 |
2017年 | 47篇 |
2016年 | 49篇 |
2015年 | 46篇 |
2014年 | 71篇 |
2013年 | 89篇 |
2012年 | 176篇 |
2011年 | 166篇 |
2010年 | 100篇 |
2009年 | 83篇 |
2008年 | 152篇 |
2007年 | 169篇 |
2006年 | 112篇 |
2005年 | 94篇 |
2004年 | 115篇 |
2003年 | 94篇 |
2002年 | 73篇 |
2001年 | 55篇 |
2000年 | 43篇 |
1999年 | 51篇 |
1998年 | 21篇 |
1997年 | 14篇 |
1996年 | 10篇 |
1995年 | 9篇 |
1994年 | 11篇 |
1993年 | 10篇 |
1992年 | 18篇 |
1991年 | 21篇 |
1990年 | 25篇 |
1989年 | 22篇 |
1988年 | 18篇 |
1987年 | 22篇 |
1986年 | 33篇 |
1985年 | 17篇 |
1984年 | 15篇 |
1983年 | 15篇 |
1982年 | 9篇 |
1976年 | 10篇 |
1975年 | 9篇 |
1974年 | 11篇 |
1973年 | 17篇 |
1972年 | 14篇 |
1971年 | 19篇 |
1968年 | 12篇 |
1966年 | 9篇 |
排序方式: 共有2498条查询结果,搜索用时 0 毫秒
101.
Vilvapathy Senguttuvan Karthikeyan Sarath Chandra Sistla Ramachandran Srinivasan Debdatta Basu Lakshmi C. Panicker Sheik Manwar Ali Nagarajan Rajkumar 《International surgery》2014,99(1):52-55
Multiple primary malignant neoplasm is the occurrence of a second primary malignancy in the same patient within 6 months of the detection of first primary (synchronous), or 6 months or more after primary detection (metachronous). Multiple primary malignant neoplasms are not very frequently encountered in clinical practice. The relative risk for a second primary malignancy increases by 1.111-fold every month from the detection of the first primary malignancy in any individual. We present 2 patients treated for carcinoma of the breast who developed a metachronous primary malignancy in the stomach to highlight the rare occurrence of multiple primary malignant neoplasms. These tumors were histologically dissimilar, with distinct immunohistochemical parameters. The importance lies in carefully identifying the second primary malignancies, not dismissing them as metastases, and treating them accordingly.Key words: Breast neoplasms, Stomach neoplasms, Neoplasms, Second primaryBreast cancer is the most common malignancy among women worldwide. With proper screening, earlier detection, and improved treatment, survival has greatly increased, with the result that there is now a large population of women with a present or past history of breast cancer. This has led to an increased detection of second primary malignancies among these women. The relative risk for a second primary malignancy increases by 1.111-fold every month from the detection of the first primary malignancy in any individual.1 Several authors have reported on a lesion in the stomach being labeled as a second primary malignancy and subsequently found to be metastasis. When the primary breast tumor is positive for estrogen and progesterone receptors (ER/PRs) and the stomach tumor is ER/PR negative, the diagnosis is established easily.2 However, studies have shown that some primary gastric cancers can have ER/PR positivity. Further, if the primary breast lesion is ER/PR negative, the same cannot be used as a marker. Here, we present 2 breast cancer patients who developed second primary malignancies in the stomach and the final diagnosis was established based on histopathology and immunohistochemistry. 相似文献
102.
Senthil K. Vasan Parthasarathy Ramachandran Mary Mathew Natraj C.V. Belavendra Antonisamy Nihal Thomas 《Diabetes research and clinical practice》2014
Post-absorptive glucose lowering (PALG) is observed in individuals with glucose intolerance and in healthy individuals. We report a prevalence of about 23% among healthy Asian Indians. Individuals with PALG are characterized by leaner phenotype, low body fat percentage, increased insulin sensitivity and higher fasting glucose levels. 相似文献
103.
104.
Jeyamani Ramachandran Ashrafali Mohamed Ismail Gaurav Chawla Gnanadurai John Fletcher Ashish Goel C. E. Eapen Priya Abraham 《Indian journal of gastroenterology》2014,33(2):131-135
Background and Aims
There is paucity of Indian data regarding serum HBsAg levels (qHBsAg) in treatment-naïve chronic hepatitis B (CHB). This study was done to determine correlation of qHBsAg with hepatitis B e antigen (HBeAg) and hepatitis B virus (HBV) DNA levels and its ability to independently categorize subgroups of CHB.Methods
We studied 131 treatment-naive CHB patients and initially classified them based on HBeAg status. The HBeAg-positive group was further classified into immune tolerance (IT) and immune clearance (IC) phases based on serum alanine aminotransferase. HBeAg-negative patients were classified into low replicators (LR) and HBeAg-negative chronic hepatitis (ENH) based on DNA levels. HBsAg quantification was performed using the Architect chemiluminescence system.Results
HBeAg-positive patients had higher DNA (7.89 vs. 2.69 log10?IU/mL) and higher qHBsAg (4.60 vs. 3.85 log10?IU/mL) compared to the HBeAg-negative group. Good correlation between qHBsAg and DNA was seen in HBeAg-positive (ρ?=?0.6, p?<?0.001) but not in HBeAg-negative CHB (ρ?=?0.2). A qHBsAg level greater than 4.39 log10?IU/mL predicted HBeAg-positive state with 81 % sensitivity and 85 % specificity. However, among HBeAg-negative CHB, qHBsAg failed to discriminate between LR and ENH.Conclusions
A single point estimation of qHBsAg in treatment-naïve patients could predict replicative HBeAg-positive CHB, but was not helpful in defining replicative status in the HBeAg-negative CHB. 相似文献105.
Audrey E Kaufman Sonum Naidu Sarayu Ramachandran Dalia S Kaufman Zahi A Fayad Venkatesh Mani 《World journal of radiology》2020,12(8):142-155
The purpose of this study is to review the published literature for the range of radiographic findings present in patients suffering from coronavirus disease 2019 infection. This novel corona virus is currently the cause of a worldwide pandemic. Pulmonary symptoms and signs dominate the clinical picture and radiologists are called upon to evaluate chest radiographs (CXR) and computed tomography (CT) images to assess for infiltrates and to define their extent, distribution and progression. Multiple studies attempt to characterize the disease course by looking at the timing of imaging relative to the onset of symptoms. In general, plain CXR show bilateral disease with a tendency toward the lung periphery and have an appearance most consistent with viral pneumonia. Chest CT images are most notable for showing bilateral and peripheral ground glass and consolidated opacities and are marked by an absence of concomitant pulmonary nodules, cavitation, adenopathy and pleural effusions. Published literature mentioning organ systems aside from pulmonary manifestations are relatively less common, yet present and are addressed in this review. Similarly, publications focusing on imaging modalities aside from CXR and chest CT are sparse in this evolving crisis and are likewise addressed in this review. The role of imaging is examined as it is currently being debated in the medical community, which is not at all surprising considering the highly infectious nature of Severe Acute Respiratory Syndrome coronavirus 2. 相似文献
106.
A Robust Method for Genome‐Wide Association Meta‐Analysis With the Application to Circulating Insulin‐Like Growth Factor I Concentrations 下载免费PDF全文
Tao Wang Baiyu Zhou Tingwei Guo Martin Bidlingmaier Henri Wallaschofski Alexander Teumer Ramachandran S. Vasan Robert C. Kaplan 《Genetic epidemiology》2014,38(2):162-171
Genome‐wide association studies (GWAS) offer an excellent opportunity to identify the genetic variants underlying complex human diseases. Successful utilization of this approach requires a large sample size to identify single nucleotide polymorphisms (SNPs) with subtle effects. Meta‐analysis is a cost‐efficient means to achieve large sample size by combining data from multiple independent GWAS; however, results from studies performed on different populations can be variable due to various reasons, including varied linkage equilibrium structures as well as gene‐gene and gene‐environment interactions. Nevertheless, one should expect effects of the SNP are more similar between similar populations than those between populations with quite different genetic and environmental backgrounds. Prior information on populations of GWAS is often not considered in current meta‐analysis methods, rendering such analyses less optimal for the detecting association. This article describes a test that improves meta‐analysis to incorporate variable heterogeneity among populations. The proposed method is remarkably simple in computation and hence can be performed in a rapid fashion in the setting of GWAS. Simulation results demonstrate the validity and higher power of the proposed method over conventional methods in the presence of heterogeneity. As a demonstration, we applied the test to real GWAS data to identify SNPs associated with circulating insulin‐like growth factor I concentrations. 相似文献
107.
2-Phenylindole and Arylsulphonamide: Novel
Scaffolds Bactericidal against Mycobacterium tuberculosis
Maruti Naik Sandeep Ghorpade LalitKumar Jena Gopinath Gorai Ashwini Narayan Supreeth Guptha Sreevalli Sharma Neela Dinesh Parvinder Kaur Radha Nandishaiah Jyothi Bhat Gayathri Balakrishnan Vaishali Humnabadkar Vasanthi Ramachandran Lava Kumar Naviri Pallavi Khadtare Manoranjan Panda Pravin S. Iyer Monalisa Chatterji 《ACS medicinal chemistry letters》2014,5(9):1005-1009
108.
109.
Santhosh Kuriakose MBBS MS Sasidharanpillai Sabeena MBBS DGO PhD Binesh Damodaran MBBS MD N. Ravishankar MSc PhD Amrutha Ramachandran MBBS MS Nurul Ameen MBBS MS 《Journal of medical virology》2020,92(12):3884-3888
One major advantage of molecular assays for human papillomavirus (HPV) DNA detection is that these assays can be performed on self-collected samples unlike cytology or visual inspection with acetic acid (VIA). This cross-sectional study was carried out between March 2017 and April 2019 to compare the diagnostic performance in self-collected urine and vaginal samples for HPV DNA detection. Viral DNA was extracted from processed samples using a Qiagen viral DNA extraction Kit (QIAamp DNA Mini Kit). To detect four common high-risk HPV types (16, 18, 31, 45), multiplex real-time polymerase chain reaction (PCR) targeting the LCR/E6/E7 region of the HPV genome was performed in ABI 7500 cycler (Applied Biosystems). The negative samples were screened by conventional PCR targeting the L1 capsid region to exclude other HPV types. The overall agreement between the two self-collecting sampling methods was 64.04% with a κ value of 0.29 pointing towards a fair agreement (P < .01). The sensitivity of HPV DNA detection in urine samples was 57.95% (47.52%, 67.72), and specificity was 84.6% (66.47%, 93.85%) when compared with vaginal samples. The study concludes that self-collected vaginal HPV DNA testing is more sensitive than unpreserved-urine samples for HPV DNA detection in a hospital-based setting. 相似文献
110.
Mary Adetinuke Boyd Sharon M. Tennant Venant A. Saague Raphael Simon Khitam Muhsen Girish Ramachandran Alan S. Cross James E. Galen Marcela F. Pasetti Myron M. Levine 《Clinical and Vaccine Immunology : CVI》2014,21(5):712-721
Invasive Salmonella infections for which improved or new vaccines are being developed include enteric fever caused by Salmonella enterica serovars Typhi, Paratyphi A, and Paratyphi B and sepsis and meningitis in young children in sub-Saharan Africa caused by nontyphoidal Salmonella (NTS) serovars, particularly S. enterica serovars Typhimurium and Enteritidis. Assays are needed to measure functional antibodies elicited by the new vaccines to assess their immunogenicities and potential protective capacities. We developed in vitro assays to quantify serum bactericidal antibody (SBA) activity induced by S. Typhi, S. Paratyphi A, S. Typhimurium, and S. Enteritidis vaccines in preclinical studies. Complement from various sources was tested in assays designed to measure antibody-dependent complement-mediated killing. Serum from rabbits 3 to 4 weeks of age provided the best complement source compared to serum from pigs, goats, horses, bovine calves, or rabbits 8 to 12 weeks of age. For S. Enteritidis, S. Typhimurium, and S. Typhi SBA assays to be effective, bacteria had to be harvested at log phase. In contrast, S. Paratyphi A was equally susceptible to killing whether it was grown to the stationary or log phase. The typhoidal serovars were more susceptible to complement-mediated killing than were the nontyphoidal serovars. Lastly, the SBA endpoint titers correlated with serum IgG anti-lipopolysaccharide (LPS) titers in mice immunized with mucosally administered S. Typhimurium, S. Enteritidis, and S. Paratyphi A but not S. Typhi live attenuated vaccines. The SBA assay described here is a useful tool for measuring functional antibodies elicited by Salmonella vaccine candidates. 相似文献