全文获取类型
收费全文 | 837篇 |
免费 | 37篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 32篇 |
妇产科学 | 17篇 |
基础医学 | 75篇 |
口腔科学 | 21篇 |
临床医学 | 111篇 |
内科学 | 207篇 |
皮肤病学 | 41篇 |
神经病学 | 59篇 |
特种医学 | 105篇 |
外科学 | 37篇 |
综合类 | 71篇 |
预防医学 | 38篇 |
眼科学 | 20篇 |
药学 | 33篇 |
中国医学 | 1篇 |
肿瘤学 | 29篇 |
出版年
2017年 | 5篇 |
2016年 | 12篇 |
2015年 | 10篇 |
2014年 | 18篇 |
2013年 | 60篇 |
2012年 | 8篇 |
2011年 | 17篇 |
2010年 | 36篇 |
2009年 | 31篇 |
2008年 | 11篇 |
2007年 | 40篇 |
2006年 | 14篇 |
2005年 | 14篇 |
2004年 | 13篇 |
2003年 | 15篇 |
2002年 | 10篇 |
2001年 | 12篇 |
2000年 | 10篇 |
1999年 | 14篇 |
1998年 | 50篇 |
1997年 | 47篇 |
1996年 | 36篇 |
1995年 | 26篇 |
1994年 | 31篇 |
1993年 | 35篇 |
1992年 | 6篇 |
1991年 | 8篇 |
1990年 | 14篇 |
1989年 | 35篇 |
1988年 | 22篇 |
1987年 | 23篇 |
1986年 | 15篇 |
1985年 | 8篇 |
1984年 | 9篇 |
1983年 | 7篇 |
1982年 | 9篇 |
1981年 | 10篇 |
1980年 | 10篇 |
1977年 | 5篇 |
1976年 | 7篇 |
1975年 | 6篇 |
1972年 | 4篇 |
1969年 | 4篇 |
1966年 | 4篇 |
1965年 | 4篇 |
1963年 | 6篇 |
1962年 | 5篇 |
1960年 | 5篇 |
1955年 | 4篇 |
1941年 | 11篇 |
排序方式: 共有898条查询结果,搜索用时 31 毫秒
1.
HUGH F. MOLLOY F.A.C.D. ERIC LAMONT-GREGORY M.SC. CHRIS IDZIKOWSKI PH.D. F.B.PS.S. TERENCE J. RYAN D.M. F.R.C.P. 《International journal of dermatology》1993,32(9):668-672
Background. Extensive questioning of patients with a wide variety of skin disorders led to the impression that nocturnal overheating was probably an important factor in the initiation and the perpetuation of many skin disorders. Methods. In order to test the hypothesis, 12 “clean-skinned” subjects (6M/6F) aged 18 to 45 years were monitored electronically every 30 seconds during an 8 hour sleep period (2300 to 0700 hours), sleeping under a standard 10 tog duvet. Results. All the subjects were too hot by 3 to 4°C. All showed changes in their EEG patterns with reduced REM sleep, increased awakenings, and all showed changes in their sleep stage patterns. In addition, they all showed evidence of increased sweating in the “heat-sink” area. Conclusions. The mechanisms where by such changes could be implicated in the precipitation and perpetuation of skin disease are discussed. “Lifestyle” modification as a very effective, noninvasive, therapeutic regime is recommended. Further research along these lines would probably be very valuable and instructive. 相似文献
2.
3.
Ten thrombocytopenic patients (platelets < 10–24 × 10(9)/L) who were refractory to platelet transfusion were investigated for their responsiveness to staphylococcal protein A column therapy. Nine patients had previously been treated with steroids, intravenous immune globulin, and/or other forms of immunosuppressive therapy without improvement in their transfusion response. All patients were receiving multiple platelet transfusions without achieving 1-hour corrected count increments (CCIs) > or = 7500. Eight patients had antibodies that reacted with platelets and were directed against HLA class I antigens, ABO antigens, and/or platelet-specific alloantigens. Plasma (500-2000 mL) from each patient was passed over a protein A silica gel column and then returned to the patient. Patients received from 1 to 14 treatments. A positive response to protein A therapy was defined as at least a doubling of the pretreatment platelet count and/or two successive 10- to 120-minute posttransfusion CCIs > or = 7500. Following plasma treatments, 6 of 10 patients responded with daily platelet counts that averaged 48 +/− 11 × 10(9) per L as compared with counts of 16 +/− 7 × 10(9) per L (p < 0.0005) before treatment. Posttransfusion CCI values determined in four of these patients averaged 2480 +/− 810 and 10,010 +/− 3540 (p < 0.005) before and after treatment, respectively. In contrast, among the four unresponsive patients, platelet counts averaged 10 +/− 9 and 13 +/− 10 × 10(9) per L (p = NS), respectively, while posttransfusion CCIs were 700 +/− 1410 and 1520 +/− 2460 (p = NS), respectively.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
4.
Medial border of the perirenal space: CT and anatomic correlation 总被引:11,自引:0,他引:11
5.
6.
Ayce Unverdi Eldeniz Ali Erdemir Firuze Kurtoglu Timur Esener 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,103(3):e86-e91
OBJECTIVE: This is an in vitro assessment of pH level and calcium ion release exhibited by 3 calcium hydroxide-based root canal sealers-Sealapex, Apexit, and Acroseal. STUDY DESIGN: The materials were prepared according to the manufacturers' instructions and placed in 1 cm long and 4 mm diameter tubes. The tubes were then immersed in a glass flask containing 10 mL bidistilled water (n = 15), which was sealed and stored at 37 degrees C before the materials had set. The control group contained bidistilled water with empty tubes (n = 12). At predetermined time intervals (24 h, 96 h, and 7, 15, and 28 days) the pH of the bidistilled water was tested with a pH meter and for released calcium by using spectrophotometry. The data were statistically analyzed using 1-way analysis of variance for the comparison of the materials at each time point. If the difference was significant, individual comparisons were performed by Tukey multiple comparisons test (alpha = .05). RESULTS: Sealapex produced higher pH and released significantly higher calcium amounts than the other 2 sealers at all periods (P < .05). Apexit showed higher calcium release than Acroseal at the end of 15 days (P < .05). There was no significant difference in the pH between Apexit and Acroseal (P > .05). CONCLUSION: The new Acroseal sealer presented the least calcium ion release and pH than Sealapex and less calcium ion release than Apexit sealer. 相似文献
7.
Anderson RA; Evans LW; Irvine DS; McIntyre MA; Groome NP; Riley SC 《Human reproduction (Oxford, England)》1998,13(12):3319-3325
Follistatin is a binding protein for the activin and inhibin family of
hormones, regulating their biological activity. In the male reproductive
tract, the interaction of these factors is likely to be involved in the
regulation of the proliferation of several cell types. We have investigated
the presence of follistatin and activin A in seminal plasma using specific
immunoassays and have localized follistatin and activin/inhibin subunits in
the adult human testis, prostate and seminal vesicle to establish their
likely sources. High concentrations of immunoreactive follistatin were
present in seminal plasma in normal men (mean 97.9 ng/ml; 1.43 ng/ml in
peripheral plasma) and were similar in men with oligo/azoospermia and
following vasectomy. Follistatin immunoreactivity was localized to both
Leydig and Sertoli cells of the testis, and to epithelial cells of the
prostate gland and seminal vesicle, which are likely to be the predominant
sources of the hormone in seminal plasma. Activin A was also present in
seminal plasma in normal men but was undetectable following vasectomy, thus
deriving from the testis. Consistent with this finding, the betaA-subunit
was immunolocalized in Sertoli and Leydig cells but was not present in
seminal vesicle or prostate gland. The functional significance of the high
concentrations of follistatin secreted into seminal plasma by the prostate
gland and/or seminal vesicle is uncertain, but they may regulate the
biological activity of testis-derived activin A and inhibin B.
相似文献
8.
9.
10.
Mihrimah Ozkan Mark Wang Cengiz Ozkan Richard Flynn Sadik Esener 《Biomedical microdevices》2003,5(1):61-67
In this paper, we review optical techniques used for micro-manipulation of small particles and cells in microfluidic devices. These techniques are based on the object's interaction with focused laser light (consequential forces of scattering and gradient). Inorganic objects including polystyrene spheres and organic objects including biological cells were manipulated and switched in and between fluidic channels using these forces that can typically be generated by vertical cavity surface emitting laser (VCSEL) arrays, with only a few mW optical powers. T-, Y-, and multi-layered X fluidic channel devices were fabricated by polydimethylsiloxane (PDMS) elastomer molding of channel structures over photolithographically defined patterns using a thick negative photoresist. We have also shown that this optical manipulation technique can be extended to smaller multiple objects by using an optically trapped particle as a handle, or an optical handle. Ultimately, optical manipulation of small particles and biological cells could have applications in biomedical devices for drug discovery, cytometry and cell biology research. 相似文献