全文获取类型
收费全文 | 8158篇 |
免费 | 705篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 58篇 |
儿科学 | 388篇 |
妇产科学 | 228篇 |
基础医学 | 933篇 |
口腔科学 | 145篇 |
临床医学 | 1030篇 |
内科学 | 1404篇 |
皮肤病学 | 57篇 |
神经病学 | 726篇 |
特种医学 | 472篇 |
外科学 | 1282篇 |
综合类 | 178篇 |
一般理论 | 2篇 |
预防医学 | 749篇 |
眼科学 | 172篇 |
药学 | 555篇 |
中国医学 | 9篇 |
肿瘤学 | 494篇 |
出版年
2021年 | 104篇 |
2020年 | 68篇 |
2019年 | 101篇 |
2018年 | 138篇 |
2017年 | 96篇 |
2016年 | 108篇 |
2015年 | 122篇 |
2014年 | 153篇 |
2013年 | 261篇 |
2012年 | 301篇 |
2011年 | 345篇 |
2010年 | 190篇 |
2009年 | 185篇 |
2008年 | 320篇 |
2007年 | 325篇 |
2006年 | 345篇 |
2005年 | 288篇 |
2004年 | 290篇 |
2003年 | 276篇 |
2002年 | 267篇 |
2001年 | 293篇 |
2000年 | 293篇 |
1999年 | 273篇 |
1998年 | 171篇 |
1997年 | 134篇 |
1996年 | 148篇 |
1995年 | 128篇 |
1994年 | 117篇 |
1993年 | 108篇 |
1992年 | 204篇 |
1991年 | 185篇 |
1990年 | 192篇 |
1989年 | 178篇 |
1988年 | 187篇 |
1987年 | 157篇 |
1986年 | 175篇 |
1985年 | 156篇 |
1984年 | 146篇 |
1983年 | 113篇 |
1982年 | 85篇 |
1981年 | 73篇 |
1980年 | 54篇 |
1979年 | 109篇 |
1978年 | 73篇 |
1977年 | 74篇 |
1976年 | 56篇 |
1975年 | 83篇 |
1974年 | 74篇 |
1973年 | 77篇 |
1972年 | 62篇 |
排序方式: 共有8882条查询结果,搜索用时 0 毫秒
91.
Serotypic and genotypic characterization of human serotype 10 rotaviruses from asymptomatic neonates. 总被引:2,自引:7,他引:2 下载免费PDF全文
S J Dunn H B Greenberg R L Ward O Nakagomi J W Burns P T Vo K A Pax M Das K Gowda C D Rao 《Journal of clinical microbiology》1993,31(1):165-169
Human rotaviruses were isolated from asymptomatic neonates at various hospitals and clinics in the city of Bangalore, India, and were found to be subgroup I specific and possess long RNA patterns (M. Sukumaran, K. Gowda, P. P. Maiya, T. P. Srinivas, M. S. Kumar, S. Aijaz, R. R. Reddy, L. Padilla, H. B. Greenberg, and C. D. Rao, Arch. Virol. 126:239-251, 1992). Three of these strains were adapted to tissue culture and found by serotype analysis and neutralization assays to be of serotype 10, a serotype commonly found in cattle but infrequently found in humans and not previously identified in neonates. By RNA-RNA hybridization, a high level of relatedness to a serotype 10 bovine rotavirus strain and a low-to-medium level of relatedness to a human rotavirus strain were observed. Since this human isolate shares a genogroup with bovine rotavirus, it is likely that it originated by interspecies transmission. A human rotavirus strain isolated from asymptomatic neonates and similar to bovine rotavirus might represent a good vaccine candidate. 相似文献
92.
Striated intramural gallbladder lucencies on US studies: predictors of acute cholecystitis 总被引:1,自引:0,他引:1
Ultrasound scans of 51 consecutive patients with gallbladder wall thickening were reviewed, and specific sonographic features were correlated with surgical and clinical follow-up. Two patterns of thickening were identified as specific indicators of the presence or absence of acute cholecystitis. "Striated" wall thickening, consisting of several alternating, irregular, discontinuous, lucent and echogenic bands, was seen in eight of 13 patients (62%) with acute cholecystitis. This pattern was not encountered in any of the patients who did not have acute cholecystitis. Conversely, "three-layer" thickening, consisting of a single circumferential lucent zone between two relatively uniform echogenic layers, was seen in only one of 13 patients (8%) with acute cholecystitis but in 11 of 38 patients (29%) with other diagnoses. Other abnormalities, including the presence of intramural echogenic foci and wall irregularities, were more frequently seen in patients with acute cholecystitis but were not as helpful. Use of these features may suggest or help exclude a diagnosis of acute cholecystitis in those patients in whom the cause of gallbladder wall thickening is otherwise not apparent. 相似文献
93.
Exfoliated mucosal cells were collected from the oral cavityof three groups at high risk for oral cancer: Indian betel nutchewers, Filipino inverted smokers (burning end of cigar inmouth) and Indian Khaini tobacco chewers. DNA was extractedfrom these samples, as well as from samples of exfoliated cellsof Canadian non-smoking controls. DNA was analyzed for the presenceof aromatic DNA adducts using 32P-postlabel-ling analysis. Fivechromatographically distinct adducts were found in samples fromboth the high risk groups and the nonsmoking controls. Individualadducts were detectable in 3095% of samples, dependingon the adduct and population group. Estimated levels of specificadducts ranged from non-detectable (prevalence relative to normalnucleotides < 1 x 10-9) to occasionally > 1x 10-7. Noadducts were found in high risk groups which did not also appearin control subjects. 相似文献
94.
Dunn Jennifer A. Hackney Jonathan J. Martin Rachelle A. Tietjens Donna Young Timothy Bourke John A. Snell Deborah L. Nunnerley Joanne L. Hall Andrew Derrett Sarah 《Journal of occupational rehabilitation》2021,31(4):730-743
Journal of Occupational Rehabilitation - Purpose Little is currently known about how early intervention vocational rehabilitation (EIVR) works for people with newly acquired neurological conditions... 相似文献
95.
96.
Modupeola Diyaolu Anne-Laure Thomas Lauren SY Wood Jordan Taylor James CY Dunn 《Journal of pediatric surgery》2021,56(1):5-10
BackgroundShort gut syndrome, a condition characterized by inadequate absorption of nutrients owing to decreased bowel length, has minimal avenues for treatment. We have proposed spring-mediated distraction enterogenesis to lengthen bowel in porcine jejunum as a treatment for short gut. We aim to evaluate the extent of mesenteric neovascularization in segments of lengthened bowel via spring-mediated enterogenesis.MethodsFemale juvenile Yucatan pigs underwent laparotomy and insertion of gelatin-encapsulated compressed nitinol springs, held in place with plication sutures, into the jejunum. At surgery and sacrifice, macroscopic mesenteric blood vessels were counted between the plication sites. Histologic samples of the mesentery were obtained to evaluate microscopic vasculature.ResultsA statistically significant increase in macroscopic mesenteric blood vessels was seen after intestinal lengthening (before: 1.9 ± 0.7 vessels, after: 4.7 ± 1.2 vessels, p = 0.001). A statistical significance is also seen in the density of arterioles (control: 3.0 ± 3.0 vessels/mm, spring: 7.0 ± 9.0 vessels/mm, p = 0.01) and venules (control: 4.0 ± 3.0 vessels/mm, spring: 8.0 ± 8.0 vessels/mm, p = 0.003).ConclusionIntestinal segments lengthened by intraluminal springs demonstrated total greater number of macroscopic vessels and microscopic blood vessels per length of mesentery as compared to control. This suggests local changes within the mesentery to recruit blood supply to growing intestine.Level of evidenceN/AType of studyTreatment study. 相似文献
97.
98.
Xuejin Ma ME Xiaoxi Chen MD Guoyuan Jiang MBBS Lin Jiang MD Tingchao Li MBBS Ling Wei MBBS Shiguang Li MD 《The breast journal》2021,27(12):890-894
Rhabdomyosarcoma (RMS) is a common malignancy in children, but embryonal rhabdomyosarcoma (ERMS) deposits rarely occur in the breast in adults. Therefore, little is known about magnetic resonance imaging (MRI) features of breast metastases from RMS, especially the embryonal type. We reported a case of a 22-year-old woman who was diagnosed with ERMS at left foot 2 years ago and accepted operation and chemotherapy. She was confirmed to have breast metastases from the left foot. Successive imaging examinations were performed 3 months apart. Breast ultrasound indicated a benign lesion, and further examination did not reveal any bone metastases. However, predominant restricted diffusion and rim contrast enhancement on MRI combined with the patient's medical history suggested a malignancy of BI-RADS 5. After 3 months, breast ultrasound revealed masses detected last time became larger and lobulated. In addition, internal heterogeneous intensity and rim contrast enhancement with restricted diffusion were revealed on MRI. We speculated that typical MRI findings of breast metastases from RMS may include iso- to hypointensity on T1WI, heterogeneous hyperintensity on T2WI, and circular enhancement with restricted diffusion. Moreover, mild peritumoral edema, rapid expansion of necrosis, and ascending time-intensity curve detected on MRI may be features of the ERMS type. 相似文献
99.
100.
Viral hepatitis is the most common serious contagious disease caused by viruses that attack the liver. Approximately 70,000 cases are reported to the Centers for Disease Control each year, representing only a fraction of U.S. cases. There are five types of viral hepatitis currently known: Hepatitis A--formerly called infectious hepatitis; Hepatitis B--formerly called serum hepatitis, and the most serious form; Hepatitis C--formerly called non-A, non-B hepatitis; Hepatitis D--formerly called delta hepatitis; Hepatitis E--formerly called enteric or epidemic non-A, non-B hepatitis. The following Open Forum, prepared by leading EMS experts, explores the differences among the types of hepatitis, signs and symptoms, and EMS implications. 相似文献