全文获取类型
收费全文 | 277717篇 |
免费 | 9671篇 |
国内免费 | 6154篇 |
专业分类
耳鼻咽喉 | 2253篇 |
儿科学 | 8111篇 |
妇产科学 | 5282篇 |
基础医学 | 28540篇 |
口腔科学 | 3482篇 |
临床医学 | 26289篇 |
内科学 | 46840篇 |
皮肤病学 | 1548篇 |
神经病学 | 21873篇 |
特种医学 | 12374篇 |
外国民族医学 | 43篇 |
外科学 | 39710篇 |
综合类 | 17091篇 |
现状与发展 | 25篇 |
一般理论 | 20篇 |
预防医学 | 24034篇 |
眼科学 | 5579篇 |
药学 | 20051篇 |
59篇 | |
中国医学 | 5476篇 |
肿瘤学 | 24862篇 |
出版年
2024年 | 286篇 |
2023年 | 1530篇 |
2022年 | 3877篇 |
2021年 | 5072篇 |
2020年 | 3607篇 |
2019年 | 3299篇 |
2018年 | 25111篇 |
2017年 | 20132篇 |
2016年 | 22121篇 |
2015年 | 5332篇 |
2014年 | 6456篇 |
2013年 | 5762篇 |
2012年 | 14375篇 |
2011年 | 28975篇 |
2010年 | 23532篇 |
2009年 | 15181篇 |
2008年 | 24506篇 |
2007年 | 26939篇 |
2006年 | 5868篇 |
2005年 | 7773篇 |
2004年 | 7106篇 |
2003年 | 7629篇 |
2002年 | 5413篇 |
2001年 | 2700篇 |
2000年 | 3053篇 |
1999年 | 2857篇 |
1998年 | 1770篇 |
1997年 | 1680篇 |
1996年 | 1394篇 |
1995年 | 1259篇 |
1994年 | 1075篇 |
1993年 | 692篇 |
1992年 | 1034篇 |
1991年 | 890篇 |
1990年 | 805篇 |
1989年 | 674篇 |
1988年 | 644篇 |
1987年 | 566篇 |
1986年 | 441篇 |
1985年 | 360篇 |
1984年 | 226篇 |
1983年 | 181篇 |
1982年 | 109篇 |
1981年 | 98篇 |
1980年 | 122篇 |
1979年 | 118篇 |
1978年 | 63篇 |
1977年 | 59篇 |
1974年 | 64篇 |
1938年 | 60篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
Late-onset and Recurrent Neonatal Group B Streptococcal Disease Associated with Breast-milk Transmission 总被引:2,自引:0,他引:2
Michael Kotiw Gwang W. Zhang Grant Daggard Elizabeth Reiss-Levy John W. Tapsall Andrew Numa 《Pediatric and developmental pathology》2003,6(3):251-256
The purpose of the study was to determine the epidemiological relationships in three unrelated cases of neonatal late-onset Group B streptococcal (GBS) disease and maternal breast-milk infection with GBS. All deliveries were by cesarean section; case 1 was at term, and cases 2 and 3 were at 32- and 33-wk gestation, respectively. Case 1 relates to a mother with clinical mastitis and recurrent GBS infection in a 20-day-old male infant. Following antibiotic therapy and cessation of breast-feeding, the infant recovered without sequelae. Case 2 refers to a mother with clinical mastitis and the occurrence of late-onset GBS disease in 5-wk-old male twins. Despite intervention, one infant died and the second became ill. Following antibiotic therapy and cessation of breast-feeding, the surviving infant recovered without sequelae. Case 3 refers to a mother with sub-clinical mastitis and late-onset GBS infection occurring in a 6-day-old female twin. Following intervention, the infant recovered but suffered a bilateral thalamic infarction resulting in developmental delay and a severe seizure disorder. Following recovery of GBS from an inapparent mastitis and cessation of breast-feeding, the second infant remained well. Blood cultures from all affected infants and maternal breast milk were positive for GBS. Epidemiological relationships between neonatal- and maternal-derived GBS isolates were confirmed by a random amplified polymorphic DNA polymerase chain reaction assay (RAPD-PCR). This study is significant in that it has demonstrated that maternal milk (in cases of either clinical or sub-clinical mastitis) can be a potential source of infection resulting in either late-onset or recurrent neonatal GBS disease. 相似文献
103.
Ona Faye-Petersen 《Pediatric and developmental pathology》2003,6(6):599-600
104.
Recent reports of sexually transmitted infection-rate increases among men indicate the need for renewed study of male sexual risk behavior to aid development of updated and novel risk reduction interventions. Men who have childhood sexual abuse (CSA) histories consistently report frequent sexual risk behavior. The objective of this sturdy is to explore whether posttraumatic stress disorder (PTSD) and depression are moderators and/or mediators of the association between CSA and sexual risk in adult men. A cross-sectional survey study employing random digit dial recruitment was administered to men aged 18–49 years from Philadelphia County. Two bundred ninety eight men were recruited and screened for CSA history, administered items from the Posttraumatic Stress Diagnostic Scale (PDS) and Center for Epidemiologic Studies—Depression (CES-D), and asked to estimate their number of lifetime sexual partners (LSPs). Effects of sociodemographic characteristics, CSA, PTSD, and depression on the number of LSPs were modeled using Poisson regression. Results show that 197 (66%) men participated; 43 (22%) had CSA histories. CSA was significantly associated with PTSD/depression (P=.03). Four sociodemographic variables (age, race, sexual identity, and education), CSA (incidence rate ratio, IRR=1.47, P<.001), PTSD (IRR=1.19, P=.04), depression (IRR=1.29, P=.001), all 2-way interactions, and the 3-way CSA/PTSD/depression interaction (IRR=11.00, P<.001) were associated with the number of LSPs (R2=0.27). In conclusion, sexual partnership patterns unique to men with CSA histories and comorbid PTSD/depression appear to lead to substantially higher numbers of LSPs. Estimates of this relationship may have been biased toward the null by underreporting that can occur with phone surveys. Cross-sectional studies do not support causal inferences; however, the identification of a moderating and mediating influence of PTSD/depression on the relationship between CSA and sexual risk behavior is important and suggests the need for future studies with larger samples that examine trajectories for CSA, psychiatric illness, and sexual partnerships. 相似文献
105.
OBJECTIVES: To examine the effect of individual patient factors (age, parity, body mass index, menstrual cycle, menopause, hormone replacement therapy, bladder neck position and urethral mobility) on the appearance of Doppler flow in urethral vessels, to investigate the association between the Doppler flow parameters and intrinsic urethral function, storage and voiding, and to explore differences in the urethral vasculature between subjects with and without urodynamic stress incontinence (USI). METHODS: Over a 4-year period we prospectively performed imaging studies in 355 women, including 244 who denied any lower urinary tract symptoms within the previous 3 months (Group A) and 111 who had had lower urinary tract symptoms (Group B). Studies included morphologic assessment and Doppler flow investigation of the lower urinary tract. Vascular flow velocity and vessel density in the urethral vasculature were measured. For women in Group B, multichannel urodynamic studies were also performed. RESULTS: The urethral vasculature has five main branches of vessels. Their appearance was not affected by the menstrual cycle or menopause except for those of the anterior vaginal vessel and anterior branch of the middle urethral vessel. Other than that of the posterior urethral vessel, in which there was a correlation with parity, the resistance index (RI) was not affected by individual patient factors. However, there was a correlation between the vascular index (VI) and individual factors such as age (r = -0.336, P = 0.002), body mass index (r = -0.287, P = 0.028), menopause (r = -0.402, P < 0.001), and hormone replacement therapy (r = 0.392, P = 0.027). Only the VI and RI of the posterior urethral vessel correlated significantly with the urethral pressure profile. In subjects with lower urinary tract symptoms, the appearance of the urethral vasculature on power Doppler imaging and the corresponding RI and VI values were not correlated with objective evidence of USI. CONCLUSION: Patient factors may affect specific Doppler flow parameters of the urethral vasculature, which are related to intrinsic resting urethral closure. There is no difference in the appearance of the urethral vasculature in subjects with or without USI. 相似文献
106.
107.
108.
109.
Amyloidosis is a systemic disease that usually occurs in the gastrointestinal tract or in muscular or adipose tissue. Primary amyloidosis of the urinary bladder is a rare disease that can mimic bladder cancer on cystoscopic examination as well as in its clinical presentation of painless gross hematuria. This report describes a 49-year-old male with repeated painless gross hematuria, who underwent transurethral resection of a suspected bladder tumor. Pathologic examination revealed papillary urothelial hyperplasia with vascular ectasia and no signs of malignancy. Massive gross hematuria occurred 2.5 years later. Cystoscopy showed multiple papillary lesions with yellowish-brown submucosal plaques on the posterior bladder wall. A second transurethral tumor resection was performed and histologic examination revealed plasma cell infiltration and eosinophilic amorphous deposits in the subepithelial stroma and vascular wall. The deposits were positive for Congo red and apple-green birefringence under polarized light examination but negative for Masson's trichrome stain, indicating that they were not fibrotic in nature. Hence, the diagnosis of amyloidosis of the urinary bladder was confirmed. Screening for amyloidosis was negative in other organ systems and the patient has remained disease-free up to the last follow-up 4 years after the second transurethral resection. Amyloidosis should be considered in the differential diagnosis of patients with recurrent hematuria who have symptoms characteristic of bladder cancer but negative pathologic study for malignancy. Correct diagnosis relies on clinical alertness and the use of a special staining technique during pathologic examination. 相似文献
110.
目的了解初级护士资格考试通过情况。方法采用历史性研究方法,对我校近3年参加护士资格考试的188名学生考试情况进行调查。结果护士资格考试通过率低,其中基础知识通过率在4个科目中最低。结论有必要对参加考试的考生进一步强化基础知识的训练,从而提高护士资格考试的过线率。 相似文献