全文获取类型
收费全文 | 779篇 |
免费 | 115篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 23篇 |
妇产科学 | 49篇 |
基础医学 | 92篇 |
口腔科学 | 7篇 |
临床医学 | 110篇 |
内科学 | 121篇 |
皮肤病学 | 26篇 |
神经病学 | 36篇 |
特种医学 | 129篇 |
外科学 | 64篇 |
综合类 | 42篇 |
预防医学 | 31篇 |
眼科学 | 5篇 |
药学 | 21篇 |
中国医学 | 3篇 |
肿瘤学 | 140篇 |
出版年
2024年 | 2篇 |
2023年 | 3篇 |
2022年 | 10篇 |
2021年 | 16篇 |
2020年 | 15篇 |
2019年 | 21篇 |
2018年 | 42篇 |
2017年 | 25篇 |
2016年 | 33篇 |
2015年 | 18篇 |
2014年 | 35篇 |
2013年 | 44篇 |
2012年 | 26篇 |
2011年 | 45篇 |
2010年 | 30篇 |
2009年 | 34篇 |
2008年 | 52篇 |
2007年 | 43篇 |
2006年 | 26篇 |
2005年 | 27篇 |
2004年 | 28篇 |
2003年 | 35篇 |
2002年 | 41篇 |
2001年 | 34篇 |
2000年 | 18篇 |
1999年 | 19篇 |
1998年 | 32篇 |
1997年 | 15篇 |
1996年 | 14篇 |
1995年 | 15篇 |
1994年 | 15篇 |
1993年 | 16篇 |
1992年 | 6篇 |
1991年 | 5篇 |
1989年 | 8篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 7篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 5篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1974年 | 1篇 |
排序方式: 共有905条查询结果,搜索用时 0 毫秒
1.
2.
骨巨细胞瘤的MRI诊断价值 总被引:10,自引:0,他引:10
目的探讨骨巨细胞瘤的MRI表现特点及其病理基础。资料与方法搜集经手术病理证实的12例骨巨细胞瘤患者资料,分析其MRI征象并与病理结果对照。结果T1WI上肿瘤实体表现为低、等信号,T2WI上为不均匀高信号,Gd-DTPA增强扫描呈中度到明显强化。此外,MRI还可显示肿瘤内坏死、出血、含铁血黄素沉着等。结论MRI能够提供比较全面的影像学信息,可提高对骨巨细胞瘤诊断的准确性。 相似文献
3.
4.
Novel proteins with binding specificity for DNA CTG repeats and RNA CUG repeats: implications for myotonic dystrophy 总被引:7,自引:6,他引:7
While an unstable CTG triplet repeat expansion is responsible for myotonic
dystrophy, the mechanism whereby this genetic defect induces the disease
remains unknown. To detect proteins binding to CTG triplet repeats, we
performed bandshift analysis using as probes double- stranded DNA fragments
having CTG repeats [ds(CTG)6-10] and single- stranded oligonucleotides
having CTG repeats ss(CTG)8 or RNA CUG triplet repeats (CUG)8. The source
of protein was nuclear and cytoplasmic extracts of HeLa cells, fibroblasts
and myotubes. Proteins binding to the double-stranded DNA repeat
[ds(CTG)6-10], were inhibited by nonlabeled ds(CTG)6-10, but not by a
non-specific DNA fragment (USF/AD-ML). Another protein binding to ssCTG
probe and RNA CUG probe was inhibited by nonlabeled (CTG)8 and (CUG)8.
Nonlabeled oligos with different triplet repeat sequences, ss(CAG)8 or
ss(CGG)8, did not inhibit binding to the ss(CTG)8 probe. However, when
labeled as probes, the (CAG)8 and (CGG)8 bound to proteins distinct from
the CTG proteins and binding was inhibited by nonlabeled (CAG)8 or (CGG)8
respectively. The protein binding only to the RNA repeat (CUG)8 was
inhibited by nonlabeled (CUG)8 but not by nonlabeled single- or
double-stranded CTG repeats. Furthermore, the CUG-BP exhibited no binding
to an RNA oligonucleotide of triplet repeats of the same length but having
a different sequence, CGG. The CUG binding protein was localized to the
cytoplasm, whereas dsDNA binding proteins were localized to the nuclear
extract. Thus, several trinucleotide binding proteins exist and their
specificity is determined by the triplet sequence. The novel protein,
CUG-BP, is particularly interesting since it binds to triplet repeats known
to be present in myotonin protein kinase mRNA which is responsible for
myotonic dystrophy.
相似文献
5.
Ricardo Pietrobon Anand Shah Paul Kuo Matthew Harker Mariana McCready Christeen Butler Henrique Martins CT Moorman Danny O Jacobs 《BMC medical informatics and decision making》2006,6(1):32-11
Background
Although regulatory compliance in academic research is enforced by law to ensure high quality and safety to participants, its implementation is frequently hindered by cost and logistical barriers. In order to decrease these barriers, we have developed a Web-based application, Duke Surgery Research Central (DSRC), to monitor and streamline the regulatory research process. 相似文献6.
Dr. Linda K. Green MD Susan Zachariah MS CT David Y. Graham MD 《Digestive diseases and sciences》1990,35(11):1421-1425
Summary Secondary neoplasms of the stomach are rare and are often clinical and diagnostic problems. Three patients with bleeding volcano-like ulcers were diagnosed by combined endoscopic salvage cytology and surgical biopsy as having metastatic submucosal lesions from hematologic spread. The combination of endoscopic appearance, clinical findings, and tissue and cytologic examination can lead to the correct diagnosis. The results from these cases support the utility of this cytologic technique in combination with biopsy in this clinical setting. 相似文献
7.
Is serum leptin level regulated by thyroid functions, lipid metabolism and insulin resistance in polycystic ovary syndrome? 总被引:1,自引:0,他引:1
C T Erel L M Senturk S Kaleli A Gezer B Baysal E Tasan 《Gynecological endocrinology》2003,17(3):223-229
Our aim was to determine whether serum leptin level is regulated by thyroid hormones, lipid metabolic products and insulin resistance status in women with polycystic ovary syndrome (PCOS). A prospective case-controlled study was carried out in Istanbul University, Cerrahpasa School of Medicine in 25 lean PCOS (L-PCOS) women, 19 obese PCOS (O-PCOS) women and 28 normal women. The diagnosis of PCOS was established according to the clinical, hormonal (elevated luteinizing hormone and serum androgens) and ultrasonographic findings. Fasting serum levels of thyroid stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), fasting glucose, insulin, total cholesterol (TC), triglyceride (TG), high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), very low-density lipoprotein-cholesterol (VLDL-C) and leptin were measured and compared in the three groups and the correlations between serum levels of leptin and other parameters were evaluated. Serum leptin levels were higher in the O-PCOS group, while its level was comparable between the L-PCOS and control groups. Serum levels of FT4 were significantly lower in both L-PCOS and O-PCOS groups than the control group. Women in both L-PCOS and O-PCOS groups were found to be significantly hyperinsulinemic and insulin resistant. Serum levels of TC, VLDL-C and TG were significantly higher in the O-PCOS group, while serum HDL-C level was lower. There was a poor correlation between serum leptin, and FT4, TC, TG, HDL-C and VLDL-C levels. A significant correlation was observed between serum leptin levels and both BMI and insulin resistance status in PCOS. We believe that, although thyroid hormones and lipid metabolic products do not seem to participate in the regulation of serum leptin levels, BMI and insulin resistance status may have a key role in women with PCOS. 相似文献
8.
Early stage nasopharyngeal carcinoma: radiotherapy dose and time factors in tumor control 总被引:1,自引:0,他引:1
Chang JT; See LC; Liao CT; Chen LH; Leung WM; Chen SW; Chen WC 《Japanese journal of clinical oncology》1998,28(3):207-213
OBJECTIVE: To evaluate radiotherapy dose and length of treatment in the
control of early stage nasopharyngeal carcinoma (NPC) treated with a
combination of external radiotherapy and brachytherapy, MATERIALS &
METHODS: We reviewed the records of 133 patients with early stage
nasopharyngeal carcinoma (stage I or II, AJC/UICC staging system) who
received definitive radiotherapy in Chang Gung Memorial Hospital from 1979
to 1991. The median follow-up time was 7.1 years with a minimum of 2 years.
All patients were treated with megavoltage external radiotherapy to the
nasopharynx area (63-72 Gy) followed by high dose rate intracavitary
brachytherapy (5-16.5 Gy in one to three fractions, spaced 1-2 weeks
apart). The median total dose and time of irradiation was 75 Gy (69.8-81.4
Gy) and 11.6 weeks (7.8-20 weeks) respectively. Survival analysis was used
to examine the effect of several variables on prognosis. RESULTS: The
5-year rates were 86.4% for local control, 84.7% for disease free survival,
88.5% for actuarial survival and 84.2% for overall survival. The treatment
group (combination of time and dose of irradiation) was the most important
prognostic factor according to Cox's proportional hazard model. Patients
receiving radiation at a total dose of < or = 75 Gy completed in < 12
weeks showed the best prognosis. CONCLUSION: Treatment time and total
treatment dose are both important factors in treating early stage NPC.
Decreasing the total radiation time to < 12 weeks and not exceeding a
radiation dose of 75 Gy gave the best results.
相似文献
9.
Benjamin R. Kipp PhD CT MP Fabiola Medeiros MD Michael B. Campion BS Tammy J. Distad CT Lisa M. Peterson CLSp Gary L. Keeney MD Kevin C. Halling MD PhD Amy C. Clayton MD 《Cancer cytopathology》2008,114(4):228-235
BACKGROUND.
Endometrial cytology sampling devices for direct uterine sampling have been shown in previous studies to be a reliable and relatively painless method for detecting endometrial lesions. The purpose of the current study was to determine the performance characteristics of endometrial cytology for the detection of malignancy and atypical hyperplasia using liquid‐based cytology specimens collected with the Tao brush sampler.METHODS.
Brushings of the endometrial cavity were obtained from 139 hysterectomy specimens before routine histopathologic evaluation. Cytology specimens were fixed in PreservCyt and processed using ThinPrep technology. Cytology diagnoses were classified as nondiagnostic, negative, atypical, or positive for malignancy. Histopathologic findings were used as the gold standard for determining the performance characteristics of cytology.RESULTS.
Histopathologic results from the 139 patients included 81 (58%) endometrial cancers, 7 (5%) complex hyperplasias with atypia, 2 (1%) complex hyperplasias without atypia, and 49 (35%) patients with benign histology. The number of specimens diagnosed cytologically as positive, atypical, negative, or nondiagnostic was 60 (43%), 40 (29%), 37 (27%), and 2 (1%) specimens, respectively. The overall sensitivity and specificity of cytology for detecting endometrial cancer and atypical hyperplasia were 95% and 66% when atypical cytology specimens were considered positive.CONCLUSIONS.
The results of the current study indicate that direct endometrial sampling by liquid‐based endometrial cytology collected with the Tao brush sampler produces specimens that contain cellular material that may be identified as endometrial cancer or atypical hyperplasia. Both atypical and positive cytology diagnoses are indicators for triage to more specific methods of diagnosis. Cancer (Cancer Cytopathol) 2008. © 2008 American Cancer Society 相似文献10.
爆裂性骨折所致眼球内陷的CT研究 总被引:6,自引:0,他引:6
目的:研究眼眶爆裂性骨折后,眼球内陷与眼眶容积扩大的关系并对眼球内陷进行早期预报。方法:28例单侧眼眶爆裂性骨折后1~350 d患者,分别测量双侧眼球位置和骨性眼眶容积值,计算患侧眼球内陷值(E)和骨性眼眶容积扩大值(V),应用pearson积矩法研究E、V相关性并建立直线回归方程。结果:28例患侧E、V呈正相关(r=0.88,P<0.001);15例≤24 d的患者直线回归方程为E=0.85 V-1.74(r=0.86,P<0.001),13例>24 d的患者直线回归方程为E=0.86 V-0.60(r=0.9,P<0.001)。结论:眼球内陷值与眼眶容积扩大值高度相关;1 mL眼眶容积的扩大,可引起大约0.9mm(0.85~0.86 mm)的眼球内陷。与伤后>24 d的相比,≤24 d的眼球有明显的抗拒内陷的趋势,>24 d之后,这种趋势逐渐消失,随之发生眼球内陷。 相似文献