全文获取类型
收费全文 | 1656篇 |
免费 | 98篇 |
国内免费 | 79篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 91篇 |
妇产科学 | 31篇 |
基础医学 | 147篇 |
口腔科学 | 67篇 |
临床医学 | 139篇 |
内科学 | 343篇 |
皮肤病学 | 69篇 |
神经病学 | 34篇 |
特种医学 | 114篇 |
外科学 | 247篇 |
综合类 | 126篇 |
预防医学 | 68篇 |
眼科学 | 35篇 |
药学 | 218篇 |
中国医学 | 2篇 |
肿瘤学 | 91篇 |
出版年
2022年 | 27篇 |
2021年 | 54篇 |
2020年 | 16篇 |
2019年 | 30篇 |
2018年 | 42篇 |
2017年 | 26篇 |
2016年 | 32篇 |
2015年 | 22篇 |
2014年 | 34篇 |
2013年 | 59篇 |
2012年 | 91篇 |
2011年 | 85篇 |
2010年 | 60篇 |
2009年 | 51篇 |
2008年 | 69篇 |
2007年 | 113篇 |
2006年 | 94篇 |
2005年 | 73篇 |
2004年 | 65篇 |
2003年 | 61篇 |
2002年 | 40篇 |
2001年 | 33篇 |
2000年 | 42篇 |
1999年 | 40篇 |
1998年 | 41篇 |
1997年 | 33篇 |
1996年 | 32篇 |
1995年 | 22篇 |
1994年 | 24篇 |
1993年 | 26篇 |
1992年 | 26篇 |
1991年 | 25篇 |
1990年 | 18篇 |
1989年 | 36篇 |
1988年 | 25篇 |
1987年 | 24篇 |
1986年 | 25篇 |
1985年 | 24篇 |
1984年 | 9篇 |
1983年 | 11篇 |
1982年 | 17篇 |
1981年 | 16篇 |
1980年 | 15篇 |
1979年 | 14篇 |
1978年 | 10篇 |
1977年 | 13篇 |
1976年 | 11篇 |
1975年 | 13篇 |
1974年 | 9篇 |
1969年 | 9篇 |
排序方式: 共有1833条查询结果,搜索用时 0 毫秒
131.
Variation in restriction fragment length polymorphisms among serial isolates from patients with Trichophyton rubrum infection 总被引:5,自引:0,他引:5
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Molecular genotyping of strains of Trichophyton rubrum and T. mentagrophytes from patients with onychomycosis of the toes was performed to ascertain whether the fungal genotype changes over the course of time as sequential samples were obtained from patients receiving antifungal therapy and during follow-up. Sixty-six serial strains of T. rubrum and 11 strains of T. mentagrophytes were obtained from 20 patients (16 patients with T. rubrum, 4 with T. mentagrophytes) who were treated with oral antifungal therapy and observed over periods of up to 36 months. These strains were screened for genetic variation by hybridization of EcoRI-digested genomic DNAs with a probe amplified from the small-subunit (18S) ribosomal DNA and adjacent internal transcribed spacer regions. A total of five restriction fragment length polymorphism (RFLP) types were observed among 66 strains of T. rubrum. Two major RFLP types, differentiated by one band shift, represented 68% of the samples. None of the patients had a unique genotype. More than one RFLP type was often observed from a single patient (same nail) over a period of 1, 2, or 3 years, even in cases that did not appear cured at any time. Samples taken from different nails of the same patient had either the same or a different genotype. The genotypic variation did not correspond to any detectable phenotypic variation. Furthermore, no correlation was observed between the efficacy of the treatment administered and the genotype observed. While the DNA region studied distinguished among T. rubrum, T. mentagrophytes, and T. tonsurans, intraspecific RFLP variation was observed for T. rubrum and T. mentagrophytes strains. While independent multiple infection and coinhabitation of multiple strains may explain the presence of different genotypes in a nail, microevolutionary events such as rapid substrain shuffling, as seen in studies of repetitive regions in Candida species, may also produce the same result. The recovery of multiple strains during the course of sequential sampling of uncured patients further suggests that the typing system is not able to distinguish between relapse or reinfection, ongoing infection, and de novo infection. 相似文献
132.
Kohli A Rao KS Nachiappan M Geelani MA Balachander J Bannerjee A Jayakumar TK Alam P 《Journal of the Indian Medical Association》2001,99(9):499-501
Sixty-seven patients who underwent pericardiectomy for constrictive pericarditis at JIPMER, Pondicherry between 1987 and 1998 were the subjects of the study. Pre-operatively 70% of cases were in the New York Heart Association classes III and IV categories with clinical signs suggestive of constriction ie, raised jugular venous pressure in 99%, pleural effusion in 77%, pedal oedema in 61% and ascites in 55% of the cases. Seventy-five per cent of the cases underwent pericardiectomy through a median sternotomy and the rest via left anterolateral thoracotomy. Low cardiac output was evidenced in 70% of cases postoperatively which was managed by early institution and prolonged use of inotropes. There was 9% mortality especially in the early part of the experience. Tuberculous pathology was confirmed histologically in 57% cases. Sixty-three per cent of cases are presenting in follow-up in New York Heart Association class I. Prolonged use of inotropes instituted early in postoperative period is recommended to prevent postoperative ventricular dysfunction with adrenaline being the preferred inotrope. It is concluded that postoperative New York Heart Association class and long term survival were not significantly influenced by pre-operative New York Heart Association class, operative approach or peri-operative low cardiac output syndrome requiring prolonged inotropic support. 相似文献
133.
Periurethral collagen injection for stress incontinence with and without urethral hypermobility 总被引:8,自引:0,他引:8
OBJECTIVE: To compare the use of periurethral collagen injection in the treatment of female stress urinary incontinence due to intrinsic sphincter deficiency in women with and without urethral hypermobility. METHODS: A retrospective review was performed of 60 periurethral collagen injections performed on 40 consecutive women from January 1996 to December 1997. A review of the office chart and operative notes was performed to obtain demographic, urodynamic, and procedural data. Outcome data were obtained by personal or telephone interview, using patients' subjective assessments including an analog satisfaction scale. RESULTS: Nine of 40 patients (23%) had urethral hypermobility. Compared with patients without hypermobility, patients with hypermobility required a similar number of procedures (a mean of 1.9 compared with 1.4, P = .13) and required similar amounts of collagen on the first injection (5.6 mL compared with 5.3 mL, P = .69). Preoperative urodynamic parameters were similar in both groups. Rates of subjective dryness were equivalent in patients with and without hypermobility at 1 month (76% and 46%, P = .24) and at 6 months (71% and 32%, P = .09) following initial injection. A post hoc power analysis was performed to evaluate the primary study measures of continence at 1 and 6 months, and number of collagen injections. This revealed that a sample size of 40 patients would be sufficient to detect a 2.5-fold difference in number of injections and a 3-fold difference in subjective dryness. CONCLUSION: Coexisting urethral hypermobility should not preclude the use of collagen injections in women with stress urinary incontinence. 相似文献
134.
Parvinderjit Singh Kohli Naresh Kumar Soni 《Indian journal of otolaryngology and head and neck surgery》2008,60(3):269-270
Anaplastic thyroid carcinoma (ATC) is the most aggressive and lethal form of thyroid malignancy which is difficult to treat.
At the time of diagnosis, majority of patients have distant metastases most commonly in lung, bone, and liver. However nasal
tip metastasis is not reported in literature. Implantation of malignant cells on nasal tip is also unknown. We hereby report
an interesting and unusual mechanism for nasal tip metastasis in a patient with ATC. 相似文献
135.
蛇胆汁中牛磺胆酸含量测定方法的比较研究 总被引:2,自引:0,他引:2
目的:比较分析了3种测定蛇胆汁中主要成分牛磺胆酸含量的方法,制定科学合理统一的质量标准。方法:用薄层层析-磷钼酸比色法、薄层扫描法及高效液相色谱法对蛇胆汁中主要成分牛磺胆酸进行测定,并将结果进行比较分析。结果:薄层层析-磷钼酸比色法、薄层扫描法及高效液相色谱法的含量测定结果有一定差异,平均回收率分别为97.48%,98.51%和100.34%,RSD分别为4.6%,4.3%和1.5%。结论:高效液 相似文献
136.
137.
138.
139.
Functional complementation between mutations in a yeast suppressor tRNA gene reveals potential for evolution of tRNA sequences. 总被引:7,自引:1,他引:6
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
140.
Lymphangiomas in children: MR imaging 总被引:9,自引:0,他引:9
Seventeen lymphangiomas in 15 patients were imaged with magnetic resonance (MR) to define the nature, extent, and anatomic relationships of these lesions. The MR and pathologic findings were then compared to determine the histologic basis for the signal-intensity characteristics of these lesions. The signal intensity of 13 lesions was similar to or slightly less than that of muscle on T1-weighted images and greater than that of fat on T2-weighted images. This appearance correlated with the presence of ectatic lymphatic channels containing clear fluid on histologic section. Four lymphangiomas had high signal intensity, approximately equal to that of fat, on T1-weighted images, reflecting the presence of clotted blood or small cystic spaces with a higher ratio of fat to fluid. Sixteen of 17 lesions had visible septations on MR images. The authors' experience suggests that most lymphangiomas have a characteristic appearance on MR images. The information obtained with MR imaging can help in providing a preoperative diagnosis, in planning surgical resection, and in defining recurrence. 相似文献