全文获取类型
收费全文 | 902篇 |
免费 | 67篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 25篇 |
妇产科学 | 45篇 |
基础医学 | 127篇 |
口腔科学 | 43篇 |
临床医学 | 99篇 |
内科学 | 175篇 |
皮肤病学 | 5篇 |
神经病学 | 40篇 |
特种医学 | 21篇 |
外科学 | 108篇 |
综合类 | 2篇 |
预防医学 | 77篇 |
眼科学 | 21篇 |
药学 | 34篇 |
肿瘤学 | 142篇 |
出版年
2023年 | 10篇 |
2022年 | 5篇 |
2021年 | 16篇 |
2020年 | 10篇 |
2019年 | 31篇 |
2018年 | 22篇 |
2017年 | 9篇 |
2016年 | 12篇 |
2015年 | 12篇 |
2014年 | 29篇 |
2013年 | 31篇 |
2012年 | 54篇 |
2011年 | 49篇 |
2010年 | 20篇 |
2009年 | 16篇 |
2008年 | 57篇 |
2007年 | 53篇 |
2006年 | 49篇 |
2005年 | 44篇 |
2004年 | 50篇 |
2003年 | 34篇 |
2002年 | 31篇 |
2001年 | 27篇 |
2000年 | 35篇 |
1999年 | 24篇 |
1998年 | 10篇 |
1997年 | 14篇 |
1996年 | 10篇 |
1995年 | 13篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 19篇 |
1991年 | 13篇 |
1990年 | 12篇 |
1989年 | 11篇 |
1987年 | 11篇 |
1986年 | 10篇 |
1985年 | 8篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1979年 | 14篇 |
1978年 | 9篇 |
1977年 | 8篇 |
1975年 | 6篇 |
1974年 | 8篇 |
1973年 | 7篇 |
1972年 | 4篇 |
1970年 | 5篇 |
1969年 | 4篇 |
1968年 | 4篇 |
排序方式: 共有971条查询结果,搜索用时 15 毫秒
101.
Oddbjorn Haugen Marit Farstad Venny Lise Kvalheim Stein-Erik Rynning Stig Hammersborg Arve Mongstad 《Scandinavian cardiovascular journal : SCJ》2013,47(1):54-61
Objective. To investigate if a mean arterial pressure below 50 mmHg during CPB may lead to cerebral ischemia. Material and methods. Piglets with low mean arterial pressure by nitroprusside (LP-group) (n?=?6) were compared with piglets given norepinephrine to obtain high pressure (HP-group) (n?=?6) during normothermic and hypothermic CPB. Intracranial pressure, flow and markers of cerebral energy metabolism (microdialysis) were recorded. Results. Mean arterial pressure differed significantly between the groups and stabilized about 40–45 mmHg in the LP-group. Cerebral perfusion pressure decreased to 21.3 (7.7) mmHg in the LP-group and increased to 51.8 (11.2) mmHg in the HP-group at 150 min of CPB (P?<?0.001, between groups). During bypass the intracerebral glucose concentration decreased significantly in the LP-group. In this group the lactate/pyruvate ratio increased from 15.5 (5.3) to 64.5 (87.6) at 90 min and 45.0 (36.5) at 150 min (P?<?0.05) with no such changes in the HP-group. Similarly the cerebral glycerol concentration increased significantly in the LP-group, whereas glycerol remained stable in the HP-group. Conclusion. Mean arterial pressure about 40 mmHg during CPB is associated with cerebral ischemia. 相似文献
102.
Takenoshita S; Hagiwara K; Gemma A; Nagashima M; Ryberg D; Lindstedt BA; Bennett WP; Haugen A; Harris CC 《Carcinogenesis》1997,18(7):1427-1429
The transforming growth factor-beta type II receptor (RII) is commonly
mutated in colon and gastric cancers with microsatellite instability (MI).
We utilized our series of lung cancers with MI and rare alleles of the
H-ras1 gene to determine the association between MI and RII mutations and
searched the entire RII coding region in 33 lung cancers with MI by
polymerase chain reaction-single-strand conformation polymorphism analysis.
We found no mutations, and these data support other recent evidence that
RII mutations rarely occur except in colon and gastric tumors with MI.
相似文献
103.
Haugen HJ Brunner M Pellkofer F Aigner J Will J Wintermantel E 《Journal of biomedical materials research. Part B, Applied biomaterials》2007,80(2):415-423
Biomaterials respond to sterilization methods differently. Steam sterilization might decrease the performance of thermoplastic polyether-urethane (TPU); however, the effect of different gamma-radiation doses on this polymer is contradictory in present literature. The purpose of this study was to investigate the differences between irradiative doses in comparison with steam sterilization on a porous TPU scaffold produced by a new processing method. No significant differences in the surface chemical structure were found with attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) analysis when comparing with the sterilization methods. The molecular weight (M(w)) had a net increase from 11.5 +/- 0.039 to 13.2 +/- 0.072 kDa by gamma-sterilization from 10 to 60 kGy. The samples that were irradiated (>60 kGy) had also an increase in polydispersity index (PDI; 1.45 +/- 0.007) in comparison with the nonsterile ones (1.31 +/- 0.017), which indicate branching. Liquid chromatography/mass spectroscopy (LC/MS) analysis showed that there was a correlation between the concentration of the breakdown product, methyl dianiline, and cytotoxicity. The concentration of this compound was found to be four times higher in steam-sterilized sample (1.3 +/- 0.01 ppb) compared with that of the polymer sample gamma-sterilized at 10 kGy (0.3 +/- 0.01 ppb). The cytotoxicity of TPU was found to decrease with higher radiation doses, and was significantly higher for the steam-sterilized samples. It is recommended that TPU produced with the described foaming method should be sterilized by gamma-irradiation at 25 kGy or higher doses. 相似文献
104.
105.
Dagny Faksvåg Haugen Karl Ove Hufthammer Christina Gerlach Katrin Sigurdardottir Marit Irene Tuen Hansen Grace Ting Vilma Adriana Tripodoro Gabriel Goldraij Eduardo Garcia Yanneo Wojciech Leppert Katarzyna Wolszczak Lair Zambon Juliana Nalin Passarini Ivete Alonso Bredda Saad Martin Weber John Ellershaw Catriona Rachel Mayland the ERANet-LAC CODE Project Group 《The oncologist》2021,26(7):e1273-e1284
106.
The neutrophil-attracting chemokine interleukin 8 (IL-8) is stored in the Weibel-Palade body (WPB) of endothelial cells (ECs) from which it can be rapidly released after exposure to the secretagogues histamine or thrombin. In this manner, IL-8 may enable rapid recruitment of leukocytes to inflammatory sites. To explore the possible storage of EC-derived chemokines that may attract other subsets of leukocytes, we examined the intracellular localization and secretagogue responsiveness of growth-related oncogene alpha (GROalpha), monocyte chemoattractant protein-1 (MCP-1), eotaxin-3, interferon-gamma-inducible protein 10 (IP-10), and regulated on activation, normal T-cell expressed and secreted (RANTES). While eotaxin-3, GROalpha, and MCP-1 were rapidly released from ECs, the release of the T-cell attractors RANTES and IP-10 was not sensitive to the secretagogues. Moreover, of the 3 former chemokines, only eotaxin-3 was stored in WPBs. GROalpha and MCP-1 resided mainly in smaller vesicles compatible with sorting to a different, histamine-responsive compartment, which has been described in ECs although not reported to contain chemokines. In conclusion, we propose that rapid release of chemokines is restricted to those primarily recruiting leukocytes of the innate immune system, and that their storage in ECs is not restricted to the WPB compartment. 相似文献
107.
108.
109.
Lien G Selvaag AM Flatø B Haugen M Vinje O Sørskaar D Dale K Egeland T Førre Ø 《Arthritis and rheumatism》2005,52(3):833-840
OBJECTIVE: To explore early changes and predictors of bone mass in children with juvenile idiopathic arthritis (JIA) in order to identify patients who will develop bone mass reductions. METHODS: We conducted a prospective cohort study of 108 children with early JIA (ages 6-18 years; mean disease duration 19.3 months) who were individually matched with 108 healthy children for age, sex, race, and county of residence. Bone mass and changes in total body, spine, femur, and forearm bone mineral density and bone mineral content (BMC), body composition, growth, and biochemical parameters of bone turnover were examined at baseline and at followup a mean of 24 months later. Low bone mass was defined as a Z score >1 SD below the reference population. RESULTS: Of the 200 children evaluated at followup, the 100 healthy children had greater gains in total body BMC (P = 0.035), distal radius BMC (P < 0.001), and total body lean mass (P < 0.001) than did the 100 JIA patients. Low or very low total body BMC was observed in 24% of the patients and 12% of the healthy children. Bone formation, bone resorption, and weight-bearing activities were reduced in the patients compared with the healthy children. Multiple regression analysis showed that in patients with JIA, serum bone-specific alkaline phosphatase, serum C-telopeptide of type I collagen, and weight-bearing activities were independent predictors of changes in total body BMC. Total body BMC was lower in patients with polyarticular onset than in those with oligoarticular disease onset. CONCLUSION: Patients with JIA have moderate reductions in bone mass gains, bone turnover, and total body lean mass early in the disease course. 相似文献
110.