全文获取类型
收费全文 | 628篇 |
免费 | 109篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 22篇 |
妇产科学 | 8篇 |
基础医学 | 89篇 |
口腔科学 | 17篇 |
临床医学 | 86篇 |
内科学 | 80篇 |
皮肤病学 | 14篇 |
神经病学 | 22篇 |
特种医学 | 123篇 |
外科学 | 25篇 |
综合类 | 36篇 |
预防医学 | 35篇 |
眼科学 | 3篇 |
药学 | 41篇 |
中国医学 | 9篇 |
肿瘤学 | 133篇 |
出版年
2022年 | 5篇 |
2021年 | 12篇 |
2020年 | 10篇 |
2019年 | 20篇 |
2018年 | 30篇 |
2017年 | 20篇 |
2016年 | 25篇 |
2015年 | 17篇 |
2014年 | 27篇 |
2013年 | 36篇 |
2012年 | 21篇 |
2011年 | 31篇 |
2010年 | 28篇 |
2009年 | 28篇 |
2008年 | 33篇 |
2007年 | 27篇 |
2006年 | 16篇 |
2005年 | 16篇 |
2004年 | 32篇 |
2003年 | 27篇 |
2002年 | 36篇 |
2001年 | 24篇 |
2000年 | 12篇 |
1999年 | 17篇 |
1998年 | 32篇 |
1997年 | 14篇 |
1996年 | 13篇 |
1995年 | 12篇 |
1994年 | 15篇 |
1993年 | 17篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1989年 | 8篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 7篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 6篇 |
1982年 | 6篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 5篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1970年 | 3篇 |
1969年 | 2篇 |
1967年 | 2篇 |
排序方式: 共有744条查询结果,搜索用时 11 毫秒
51.
A double-blind, randomized study was performed to compare discomfort and pain associated with the use of iopamidol and Hypaque (diatrizoate sodium and diatrizoate meglumine) during iliofemoral runoff arteriography in 33 patients. Iopamidol caused substantially less discomfort and pain. The evaluation was helped by audiotaping the study and comparing patients' vocal responses to injections of these materials. 相似文献
52.
53.
CT Thompson 《Journal of cutaneous pathology》2005,32(1):118-118
Large cell transformation of mycosis fungoides (MF) is an uncommon phenomenon. We present a case of CD30‐positive large cell transformation and discuss its possible pathophysiology. A 74 year‐old male with a 36‐year history of patch stage MF presented with a 3‐month history of right chest cellulitis that was refractory to IV antibiotic treatment. Skin biopsies from his thigh demonstrated a patchy dermal infiltrate of irregular and hyperchromatic lymphocytes and epidermotropism. The majority of the infiltrate was positive for CD4, CD3, CD2, and negative for CD7. Only 10% were positive for CD25 and CD8. Biopsies obtained from the ulcerated chest nodules showed a dermal infiltrate of large and pleomorphic lymphoid cells with prominent nucleoli. These large lymphoid cells were strongly positive for CD3, CD30, CD25, CD2 and UCHL‐1. Occasional cells were positive for CD4 and CD20. They were negative for ALK‐1, TIA‐1, CD7, CD8, and CD15. T‐gamma receptor gene rearrangement analyses by polymerase chain reaction demonstrated a clonal process with similar rearrangement patterns identified in the patch stage MF as well as in large cell transformation areas. Examinations of his peripheral blood and bone marrow were negative. The patient had tolerated one cycle of CHOP chemotherapy. 相似文献
54.
Fadi Brimo MD Andrew A. Renshaw MD Majorie Deschenes MD Michele Charbonneau CT Manon Auger MD 《Cancer cytopathology》2009,117(5):311-317
BACKGROUND:
Documenting the performance of gynecologic screening in actual practice settings is difficult to achieve. In the current study, the screening performance of 11 individual cytotechnologists as well as that of the overall laboratory over 2 consecutive time periods was examined using the rapid prescreening (RPS) method.METHODS:
RPS was performed by all cytotechnologists in a single laboratory over 2 separate 8‐month periods. The sensitivity of screening for individual and groups of cytotechnologists was examined. For purposes of comparison, cytotechnologists were divided into 2 groups: screeners with an overall routine sensitivity ≥95% and screeners with an overall sensitivity <95%.RESULTS:
Atypical squamous cells (ASC) were used as a threshold, and routine screening sensitivity was found to vary from 68.3% to 96.8%. The overall sensitivity of the laboratory for RPS and routine screening was 43.6% and 88.4%, respectively. Over time, the overall laboratory sensitivity of routine screening improved from 85.3% to 91.3% (P = .01). During this same time frame, the sensitivity of the screeners with an overall sensitivity <95% improved from 79.3% to 91.2% (P < .001), whereas the sensitivity of screeners with an overall routine sensitivity ≥95% remained the same (96.1% to 96.4%; P = .6).CONCLUSIONS:
In addition to improved overall performance of the laboratory by detecting and correcting errors, the results of the current study indicate that using RPS consistently over time might play a role leading to improved performance of cytotechnologists with an overall routine sensitivity <95% but not of cytotechnologists with an overall routine sensitivity ≥95%. Cancer (Cancer Cytopathol) 2009. © 2009 American Cancer Society. 相似文献55.
56.
Marcelo de Sousa VieiraValéria de Oliveira Eliana Martins LimaMassuo Jorge Kato Marize C. Valadares 《Experimental and toxicologic pathology》2011,63(5):505-510
Preclinical investigations can start with preliminary in vitro studies before using animal models. Following this approach, the number of animals used in preclinical acute toxicity testing can be reduced. In this study, we employed an in-house validated in vitro cytotoxicity test based on the Spielmann approach for toxicity evaluation of the lignan grandisin, a candidate anticancer agent, and its major metabolite, the 4-O-demethylgrandisin, by neutral red uptake (NRU) assay, on mouse fibroblasts Balb/c 3T3 cell line. Using different concentrations of grandisin and its major metabolite (2.31; 1.16; 0.58; 0.29; 0.14; 0.07; 0.04; 0.002 μM) in Balb/c 3T3-A31 NRU cytotoxicity assay, after incubation for 48 h, we obtained IC50 values for grandisin and its metabolite of 0.078 and 0.043 μM, respectively. The computed LD50 of grandisin and 4-O-demethylgrandisin were 617.72 and 429.95 mg/kg, respectively. Both were classified under the Globally Harmonized System as category 4. Since pharmacological and toxicological data are crucial in the developmental stages of drug discovery, using an in vitro assay we demonstrated that grandisin and its metabolite exhibit distinct toxicity profiles. Furthermore, results presented in this work can contribute to reduce the number of animals required in subsequent pharmacological/toxicological studies. 相似文献
57.
58.
59.
Y. Nejaim A. Farias Gomes C.V. Valadares E.D. Costa L.V. Peroni F.C. Groppo F. Haiter-Neto 《The British journal of oral & maxillofacial surgery》2019,57(4):336-340
We have used cone-beam computed tomographic (CT) images to retrospectivelyevaluate the influence of sex, skeletal class, facial type, and the presence of septa on the volume of the sphenoid sinus in 172 images from 85 men (mean (SD) age 28 (2) years) and 87 women (mean (SD) age 30 (1) years). Skeletal class and facial type were calculated for each patient from multiplanar reconstructions using NemoCeph® software. Volumetric analysis of the sphenoid sinus was made with the help of the ITK-SNAP® 3.4.0 segmentation software, while the presence or absence of septa in the sphenoid sinus was evaluated with the Carestream 3D Imaging® software 3.4.3. We analysed the results using two-way ANOVA, Student’s independent sample t test, and Fisher’s exact test, as appropriate, and probabilities of <0.05 were accepted as significant. Sex (p = 0.0946), facial type (p = 0.790), and skeletal class (p = 0.120) had no significant influence on the volume of the sphenoid sinus, and nor did the volumes of the right and left sphenoid sinuses (p = 0.0923), or the presence of a septum within the sinus (p = 0.330) in its volume. 相似文献
60.
Hans Heemskerk Christa de Winter Petra van Kuik Niki Heuvelmans Patrizia Sabatelli Paola Rimessi Paola Braghetta Gert-Jan B van Ommen Sjef de Kimpe Alessandra Ferlini Annemieke Aartsma-Rus Judith CT van Deutekom 《Molecular therapy》2010,18(6):1210-1217
Antisense oligonucleotides (AONs) are being developed as RNA therapeutic molecules for Duchenne muscular dystrophy. For oligonucleotides with the 2′-O-methyl-phosphorothioate (2OMePS) RNA chemistry, proof of concept has been obtained in patient-specific muscle cell cultures, the mouse and dog disease models, and recently by local administration in Duchenne patients. To further explore the pharmacokinetic (PK)/pharmacodynamic (PD) properties of this chemical class of oligonucleotides, we performed a series of preclinical studies in mice. The results demonstrate that the levels of oligonucleotides in dystrophin-deficient muscle fibers are much higher than in healthy fibers, leading to higher exon-skipping levels. Oligonucleotide levels and half-life differed for specific muscle groups, with heart muscle showing the lowest levels but longest half-life (~46 days). Intravenous (i.v.), subcutaneous (s.c.), and intraperitoneal (i.p.) delivery methods were directly compared. For each method, exon-skipping and novel dystrophin expression were observed in all muscles, including arrector pili smooth muscle in skin biopsies. After i.v. administration, the oligonucleotide peak levels in plasma, liver, and kidney were higher than after s.c. or i.p. injections. However, as the bioavailability was similar, and the levels of oligonucleotide, exon-skipping, and dystrophin steadily accumulated overtime after s.c. administration, we selected this patient-convenient delivery method for future clinical study protocols. 相似文献