全文获取类型
收费全文 | 1005篇 |
免费 | 48篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 98篇 |
妇产科学 | 11篇 |
基础医学 | 108篇 |
口腔科学 | 21篇 |
临床医学 | 57篇 |
内科学 | 217篇 |
皮肤病学 | 12篇 |
神经病学 | 60篇 |
特种医学 | 103篇 |
外科学 | 115篇 |
综合类 | 69篇 |
预防医学 | 47篇 |
眼科学 | 52篇 |
药学 | 62篇 |
肿瘤学 | 27篇 |
出版年
2022年 | 7篇 |
2021年 | 12篇 |
2020年 | 10篇 |
2019年 | 6篇 |
2018年 | 14篇 |
2017年 | 6篇 |
2016年 | 15篇 |
2015年 | 23篇 |
2014年 | 14篇 |
2013年 | 29篇 |
2012年 | 23篇 |
2011年 | 27篇 |
2010年 | 33篇 |
2009年 | 42篇 |
2008年 | 29篇 |
2007年 | 34篇 |
2006年 | 44篇 |
2005年 | 29篇 |
2004年 | 27篇 |
2003年 | 14篇 |
2002年 | 17篇 |
2001年 | 25篇 |
2000年 | 24篇 |
1999年 | 38篇 |
1998年 | 46篇 |
1997年 | 38篇 |
1996年 | 42篇 |
1995年 | 21篇 |
1994年 | 25篇 |
1993年 | 24篇 |
1992年 | 24篇 |
1991年 | 17篇 |
1990年 | 16篇 |
1989年 | 21篇 |
1988年 | 32篇 |
1987年 | 23篇 |
1986年 | 19篇 |
1985年 | 30篇 |
1984年 | 11篇 |
1983年 | 6篇 |
1980年 | 9篇 |
1977年 | 8篇 |
1976年 | 9篇 |
1974年 | 8篇 |
1973年 | 6篇 |
1971年 | 6篇 |
1970年 | 5篇 |
1968年 | 5篇 |
1967年 | 7篇 |
1966年 | 5篇 |
排序方式: 共有1062条查询结果,搜索用时 46 毫秒
21.
Comparison of total alkaline phosphatase and three assays for bone-specific alkaline phosphatase in childhood and adolescence 总被引:2,自引:0,他引:2
F Rauch B Middelmann M Cagnoli KM Keller E Schönau 《Acta paediatrica (Oslo, Norway : 1992)》1997,86(6):583-587
We compared serum levels of total alkaline phosphatase (TAP) and bone-specific alkaline phosphatase (BAP) as determined by three different assays (lectin affinity electrophoresis, immunoradiometric assay, enzyme-linked immunosorbent assay) in subjects aged 5–20 years suffering from X-linked hypophosphatemic rickets ( n = 14), chronic renal failure ( n = 10) and chronic cholestatic liver disease ( n = 16). Results were compared to controls of the same age and were expressed as standard deviation scores (SDS). TAP correlated significantly with BAP ( r > 0.9 for each assay; p <0.001) in controls. In children with cholestatic diseases, TAP (median SDS + 2.0) was elevated, but BAP, as measured by the electrophoretic assay, was within the reference range for most patients (median SDS: -0.4; p = 0.003 for the difference between the median SDS of TAP and BAP). In contrast, results for BAP as determined by the two immunoassays were not significantly different from TAP in any of the three patient groups ( p > 0.05 in each group for both assays). In this study, the two immunoassays did not have a detectable advantage over lectin affinity electrophoresis in the determination of BAP. 相似文献
22.
Isolation and characterization of propagable cell lines (HUNC) from the androgen-sensitive Dunning R3327H rat prostatic adenocarcinoma 总被引:1,自引:0,他引:1
Presnell SC; Borchert KM; Glover WJ; Gregory CW; Mohler JL; Smith GJ 《Carcinogenesis》1998,19(4):585-590
The Dunning H rat prostate tumor (R3327H) is a widely used experimental
model of human prostatic adenocarcinoma (CaP). The Dunning H tumor has been
characterized as androgen-sensitive, androgen-receptor (AR) positive,
prostate-specific antigen and prostatic acid phosphatase (PAP) positive. To
date, the tumor has been maintained by serial passage in vivo because of
the lack of an in vitro cell line that retains the characteristics of the
in vivo tumor. The objective of the present study was to establish a
propagable cell line from R3327H adenocarcinoma that maintained androgen
sensitivity and expression of AR, PSA and PAP. Tissue harvested from an in
vivo R3327H tumor was dissociated with collagenase and placed into
Richter's improved media (with supplements). A cytokeratin-positive
epithelial cell line (HUNC- E) and a vimentin-positive stromal cell line
(HUNC-S) were generated from the primary culture, subcultured continuously
for >300 days, and passaged >50 times. Survival of the HUNC-E cell
line in vitro depended on several media supplements, including
nicotinamide, insulin, transferrin, selenium and epidermal growth factor
(EGF). HUNC-E cells expressed AR and produced PSA and PAP throughout the
culture period, as confirmed by immunocytochemistry and Western blot
analyses. Addition of 14 nM testosterone (T) or dihydrotestosterone (DHT)
to HUNC-E cells, stimulated DNA synthesis as well as anchorage-independent
growth and PSA production, which demonstrated the androgen-sensitive nature
of the cells in vitro. When HUNC-E and HUNC-S cells were combined in a 3:1
ratio and introduced subcutaneously into syngeneic male hosts, tumors
formed in 2/3 animals with an average latency of 7 months. RT-PCR and
immunocytochemical characterization of the HUNC cell lines revealed that
the cells expressed several growth factors and their cognate receptors,
including HGF, TGF-alpha and the TGF-betas, indicating the establishment of
potential autocrine loops in the neoplastic cells. The HUNC-E and HUNC-S
CaP cell lines, which retain the characteristics of the epithelial and
stromal components of the in vivo R3327H tumor, will allow a more thorough
and informative molecular and biological analysis of prostatic
adenocarcinoma.
相似文献
23.
24.
25.
M. Baumann S. Appold P. Geyer A. Knorr L. Voigtmann Th. Herrmann 《International journal of radiation biology》2013,89(4):477-485
Purpose : Multi-field radiation therapy for intrathoracic tumours results in a heterogeneous dose distribution in lung tissue. This study investigated whether irradiation of small lung volumes with high fibrogenic doses affects the dose–response relationship for development of fibrosis in distant parts of the ipsilateral lung of mini-pigs. Materials and methods : The whole right lung of 26 ’Mini-Lewe? pigs was irradiated with homogeneous doses of between 25 Gy and 40 Gy given in five equal fractions using opposing anterior–posterior portals and a linear accelerator. Another 32 animals were irradiated with a constant dose of 35 Gy to a small house-shaped high-dose field (base 3.0 cm, height 4 cm) located 3 cm caudolateral to the right hilus, while the surrounding right lung received either no irradiation or homogeneous doses of between 20 Gy and 30 Gy. The radiation fields were simulated and port films were obtained for each of the 10 fields in all pigs. Fibrosis was quantified 9 months after irradiation by determination of the hydroxyproline (HP) content of the 32 high-dose volumes and in the lung apex and the basolateral lung of all 58 pigs. Based on the reference value for the HP-ratio, i.e. the HP-concentration of the right lung over the left lung, obtained in 12 unirradiated control animals, the experimental results were converted into quantal data for probit analysis, a responder being an animal with an HP-ratio > 1.33. Results : A dose–response relationship for the HP-ratio was obtained in the different lung sites and irradiation groups. For a given dose level the mean HP-ratios and response rates did not differ systematically between the lung apex and the basolateral lung. Probit analysis of the pooled data produced ED 50 values of 21.8 Gy (95% CI 12–37) for irradiation without a high-dose volume and 25.9 Gy (24–28) for irradiation with a high-dose volume. These values are not significantly different. The results from both irradiation groups could be well fitted by a common dose–response curve with an ED 50 value of 26.1 Gy. Unexpectedly, the response rates in the high-dose volume increased with increasing dose to the surrounding right lung. Analysis of the port films provided an explanation for this finding: inaccuracies in daily field positioning. When this error was corrected for by use of the mean dose to the high-dose volume, a dose–response curve with an ED 50 of 25.2 Gy (22–29) was determined for the high-dose volume. Conclusions : The results of the study indicate that the irradiation of a small lung volume with high fibrogenic doses does not affect the dose–response relationship for development of fibrosis in distant parts of the ipsilateral lung. 相似文献
26.
27.
Human burst-forming units-erythroid need direct interaction with stem cell factor for further development 总被引:6,自引:3,他引:6
To understand the factors that regulate the early growth and development of immature erythroid progenitor cells, the burst-forming units-erythroid (BFU-E), it is necessary to have both highly purified target cells and a medium free of serum. When highly purified human blood BFU-E were cultured in a serum-free medium adequate for the growth of later erythroid progenitors, BFU-E would not grow even with the addition of recombinant human interleukin-3 (rIL-3), known to be essential for these cells. However, the addition of recombinant human stem cell factor (rSCF), which supports germ cell and pluripotential stem cell growth, stimulated BFU-E to grow equally well in serum-free as in serum-containing medium. Limiting dilution studies showed that rSCF acts directly on the BFU-E that do not require accessory cells for growth. Furthermore, rSCF was necessary for BFU-E development during the initial 7 days of culture, until these cells reached the stage of the late progenitors, the colony-forming units-erythroid (CFU-E). These studies indicate that early erythropoiesis is dependent on the direct action of SCF that not only affects early stem cells but is continually necessary for the further development of committed erythroid progenitor cells until the CFU-E stage of maturation. 相似文献
28.
PD Dr. univ. B. Schuler-Thurner K.-U. Bartz-Schmidt N. Bornfeld C. Cursiefen B. Fuisting S. Grisanti L. M. Heindl L. Holbach M. Keserü H. Knorr K. Koch F. Kruse R. Meiller C. Metz T. Meyer-ter-Vehn M. Much M. Reinsberg S. Schliep B. Seitz G. Schuler D. Süsskind A. Viestenz L. Wagenfeld M. Zeschnigk 《Der Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft》2015,112(12):1017-1021
29.
30.
Johannes Schleusener Shuxia Guo Maxim E. Darvin Gisela Thiede Olga Chernavskaia Florian Knorr Jürgen Lademann Jürgen Popp Thomas W. Bocklitz 《Biomedical optics express》2021,12(2):1123
Psoriasis is considered a widespread dermatological disease that can strongly affect the quality of life. Currently, the treatment is continued until the skin surface appears clinically healed. However, lesions appearing normal may contain modifications in deeper layers. To terminate the treatment too early can highly increase the risk of relapses. Therefore, techniques are needed for a better knowledge of the treatment process, especially to detect the lesion modifications in deeper layers. In this study, we developed a fiber-based SORS-SERDS system in combination with machine learning algorithms to non-invasively determine the treatment efficiency of psoriasis. The system was designed to acquire Raman spectra from three different depths into the skin, which provide rich information about the skin modifications in deeper layers. This way, it is expected to prevent the occurrence of relapses in case of a too short treatment. The method was verified with a study of 24 patients upon their two visits: the data is acquired at the beginning of a standard treatment (visit 1) and four months afterwards (visit 2). A mean sensitivity of ≥85% was achieved to distinguish psoriasis from normal skin at visit 1. At visit 2, where the patients were healed according to the clinical appearance, the mean sensitivity was ≈65%. 相似文献