全文获取类型
收费全文 | 914篇 |
免费 | 73篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 17篇 |
妇产科学 | 8篇 |
基础医学 | 144篇 |
口腔科学 | 6篇 |
临床医学 | 41篇 |
内科学 | 164篇 |
皮肤病学 | 36篇 |
神经病学 | 38篇 |
特种医学 | 22篇 |
外科学 | 157篇 |
综合类 | 46篇 |
预防医学 | 57篇 |
眼科学 | 25篇 |
药学 | 100篇 |
中国医学 | 12篇 |
肿瘤学 | 114篇 |
出版年
2023年 | 6篇 |
2021年 | 22篇 |
2020年 | 8篇 |
2019年 | 15篇 |
2018年 | 30篇 |
2017年 | 17篇 |
2016年 | 20篇 |
2015年 | 25篇 |
2014年 | 41篇 |
2013年 | 43篇 |
2012年 | 84篇 |
2011年 | 82篇 |
2010年 | 56篇 |
2009年 | 23篇 |
2008年 | 35篇 |
2007年 | 53篇 |
2006年 | 50篇 |
2005年 | 43篇 |
2004年 | 37篇 |
2003年 | 34篇 |
2002年 | 25篇 |
2001年 | 28篇 |
2000年 | 19篇 |
1999年 | 19篇 |
1998年 | 6篇 |
1997年 | 8篇 |
1996年 | 5篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 7篇 |
1991年 | 11篇 |
1990年 | 8篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1986年 | 10篇 |
1985年 | 9篇 |
1983年 | 9篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1979年 | 6篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 6篇 |
1975年 | 7篇 |
1974年 | 5篇 |
1972年 | 6篇 |
1971年 | 5篇 |
1970年 | 3篇 |
1967年 | 3篇 |
排序方式: 共有990条查询结果,搜索用时 93 毫秒
1.
Md. Golzar Hossain Aneela Javed Sharmin Akter Sukumar Saha 《Journal of microbiology, immunology, and infection》2021,54(2):175-181
Coronavirus disease-19 (COVID-19) caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is now a pandemic threat. This virus is supposed to be spread by human to human transmission. Cellular angiotensin-converting enzyme 2 (ACE2) is the receptor of SARS-CoV-2 which is identical or similar in different species of animals such as pigs, ferrets, cats, orangutans, monkeys, and humans. Moreover, a recent study predicted that dogs might be secondary hosts during the evolution of SARS-CoV-2 from bat to human. Therefore, there is a possibility of spreading SARS-CoV-2 through domestic pets. There are now many reports of SARS-CoV-2 positive cases in dogs, cats, tigers, lion, and minks. Experimental data showed ferrets and cats are highly susceptible to SARS-CoV-2 as infected by virus inoculation and can transmit the virus directly or indirectly by droplets or airborne routes. Based on these natural infection reports and experimental data, whether the pets are responsible for SARS-CoV-2 spread to humans; needs to be deeply investigated. Humans showing clinical symptoms of respiratory infections have been undergoing for the COVID-19 diagnostic test but many infected people and few pets confirmed with SARS-CoV-2 remained asymptomatic. In this review, we summarize the natural cases of SARS-CoV-2 in animals with the latest researches conducted in this field. This review will be helpful to think insights of SARS-CoV-2 transmissions, spread, and demand for seroprevalence studies, especially in companion animals. 相似文献
2.
The aim of the present investigation was to study the pineal activity during the seasonal gonadal cycle in both sexes of the Indian tree pie (Dendrocitta vagabunda). The findings revealed that the nuclear diameter of the pineal parenchymal cells moderately decreased and was followed by a moderate increase in the cell population density (per microscopic field of the pineal sections) and serotonin content of the gland during the progressive phase. The values of these parameters were further altered (decreased nuclear diameter with increased cell population density and serotonin level) during breeding but were reversibly altered to some extent during the regression phase, and further altered during the nonbreeding phase in both sexes of the birds. It is suggested that the pineal activity distinctly varies with the seasonal gonadal cycle, being minimum during breeding and maximum during nonbreeding in both sexes of the tree pie. 相似文献
3.
The present study was undertaken to isolate a novel antidiabetic molecule from Swietenia macrophylla seeds. The hydroalcohol extract of Swietenia macrophylla seeds was subjected for bioassay guided isolation employing glucose utilization assay by the isolated rat hemi‐diaphragm method in vitro. One tetranortriterpenoid, swietenine, isolated from the chloroform fraction exhibited significant (p < 0.01) activity and the effect was comparable to that of human insulin (p < 0.01). Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
4.
5.
6.
7.
Chakraborty S Garg P Ramamurthy T Thungapathra M Gautam JK Kumar C Maiti S Yamasaki S Shimada T Takeda Y Ghosh A Nair GB 《Journal of medical microbiology》2001,50(10):879-888
This study identified 17 matching serogroups of Vibrio cholerae belonging to serogroups other than O1 and O139 isolated from human cases and from the environment during a concurrent clinical and environmental study conducted in Calcutta, a cholera endemic area. Isolates within these matching serogroups were compared by various phenotypic and genotypic traits to determine if the environment was the source of the organisms associated with the disease. Clinical strains of V. cholerae were resistant to a greater number of drugs and exhibited multi-drug resistance compared with their environmental counterparts. Except for the presence of the genes for the El Tor haemolysin and the regulatory element ToxR in most of the strains of V. cholerae examined, non-O1, non-O139 V. cholerae strains lacked most of the other known virulence traits associated with toxigenic V. cholerae O1 or O139. Restriction fragment-length polymorphism of virulence-associated genes, ribotypes and DNA fingerprints of strains of matched serogroups showed considerable diversity, although some gene polymorphisms and ribotypes of a few strains of different serogroups were similar. It is concluded that despite sharing the same serogroup, environmental and clinical isolates were genetically heterogeneous and were of different lineages. 相似文献
8.
Maiti PK Bose R Bandyopadhyay S Bhattacharya S Dey JB Ray A 《Indian journal of pathology & microbiology》2004,47(2):295-297
Subcutaneous mycoses caused by the family Entomophthoraceae is very rare type of disease and is being reported sporadically from various Tropical countries including India. Here we report 8 cases of rhinoentomophthoromycosis caused by Conidiobolous coronatus and 7 cases of chronic subcutaneous phycomycosis caused by Basidiobolus ranarum. Cases were detected during a span of 9 years between 1991 to 1999, from 9 districts in and around Kolkata (Eastern India). Former type of lesions were detected among 20 to 65 age group of healthy individuals, predominantly males (7:1). In the latter type, male-female ratio was 2:5, and except for one all cases belonged to below 20 years age group of healthy individuals. Several cases were detected only after examination of repeat biopsy samples. With high degree of clinical suspicion, right approach is needed for laboratory confirmation of diagnosis. 相似文献
9.
Methylation profiling of benign and malignant breast lesions and its application to cytopathology. 总被引:9,自引:0,他引:9
Robert T Pu Lauren E Laitala Patricia M Alli Mary Jo Fackler Saraswati Sukumar Douglas P Clark 《Modern pathology》2003,16(11):1095-1101
Methylation of tumor suppressor genes has been implicated in breast cancer development. However, methylation profiles of different breast lesions, subtypes of carcinoma in particular, have not been examined in detail. In this study, we use methylation-specific PCR (MSP) to generate gene methylation profiles of different breast lesions and to test the clinical utility of such profiles. We examined the methylation status of three genes, RARbeta2, RASSF1A, and cyclin D2, on 102 samples of breast tissue, from benign (n = 36), to in situ carcinoma (n = 21), to invasive carcinoma (n = 45). We found that almost all cases of invasive carcinoma (96%) contained at least one methylated gene from our panel, whereas gene methylation was less common among benign lesions (42%) and in situ carcinoma (76%). Of the three genes, cyclin D2 methylation was most specific for malignancy because only 1 of 35 benign cases was methylated at this gene (1 case was not informative). The major histologic subtypes of invasive carcinoma show similar methylation profiles in the genes examined. We next performed MSP analysis on archival breast fine-needle aspiration (FNA) biopsy samples and corresponding surgical biopsy specimens and found a high concordance between the two types of specimens. We then analyzed 17 breast FNA biopsy samples with an indeterminate diagnosis. In this setting, MSP had a high specificity (100%) and modest sensitivity (67%) for identifying malignancy. 相似文献
10.
Isolation and preliminary characterization of Escherichia coli mutants resistant to lethal action of the bacteriophage lambda P gene. 总被引:1,自引:0,他引:1
Both spontaneous and NTG-induced mutants of Escherichia coli 594 insensitive to the lethal action of lambda P gene were isolated and called rpl (resistant to P lethality). These mutants were of two types, showing different phenotypes. On type I rpl mutants, lambda cl- and lambda v1v3 did not plate, while lambda vir, lambda cl- c17, lambda imm434, and lambda imm21 did; plasmid pMR45 carrying the lambda P gene could not complement lambda imm21P- phage in type I mutants. On the other hand, the type II rpl mutants support the growth of all the above phages including lambda cl-. Neither type of rpl mutation affects growth of the bacteria. 相似文献