全文获取类型
收费全文 | 2645篇 |
免费 | 230篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 22篇 |
儿科学 | 64篇 |
妇产科学 | 62篇 |
基础医学 | 478篇 |
口腔科学 | 75篇 |
临床医学 | 271篇 |
内科学 | 541篇 |
皮肤病学 | 38篇 |
神经病学 | 211篇 |
特种医学 | 58篇 |
外科学 | 425篇 |
综合类 | 15篇 |
一般理论 | 1篇 |
预防医学 | 204篇 |
眼科学 | 20篇 |
药学 | 169篇 |
中国医学 | 1篇 |
肿瘤学 | 235篇 |
出版年
2023年 | 14篇 |
2022年 | 25篇 |
2021年 | 47篇 |
2020年 | 59篇 |
2019年 | 69篇 |
2018年 | 67篇 |
2017年 | 55篇 |
2016年 | 61篇 |
2015年 | 64篇 |
2014年 | 85篇 |
2013年 | 121篇 |
2012年 | 169篇 |
2011年 | 160篇 |
2010年 | 94篇 |
2009年 | 99篇 |
2008年 | 148篇 |
2007年 | 128篇 |
2006年 | 152篇 |
2005年 | 122篇 |
2004年 | 136篇 |
2003年 | 119篇 |
2002年 | 117篇 |
2001年 | 48篇 |
2000年 | 48篇 |
1999年 | 59篇 |
1998年 | 25篇 |
1997年 | 30篇 |
1996年 | 15篇 |
1995年 | 20篇 |
1994年 | 27篇 |
1993年 | 13篇 |
1992年 | 31篇 |
1991年 | 37篇 |
1990年 | 30篇 |
1989年 | 28篇 |
1988年 | 25篇 |
1987年 | 36篇 |
1986年 | 34篇 |
1985年 | 25篇 |
1984年 | 19篇 |
1983年 | 16篇 |
1982年 | 15篇 |
1979年 | 14篇 |
1977年 | 14篇 |
1976年 | 12篇 |
1974年 | 12篇 |
1970年 | 15篇 |
1969年 | 11篇 |
1967年 | 12篇 |
1966年 | 18篇 |
排序方式: 共有2890条查询结果,搜索用时 15 毫秒
31.
Tanja Neupert Gabriele Ihorst Wilfried Karmaus Thomas Frischer Matthias Kopp Christel Ulmer Brigitte Schwöbel Johannes Forster Joachim Kühr 《Zeitschrift fur Gesundheitswissenschaften》1997,5(1):63-75
Conclusion
Geographical differences in morbidity of asthma and asthmalike complaints were ascertained and remained stable after adjustment for potential confounders. However, the choice of the way of presentation (relative risk versus deviation from the weighted mean of the prevalences) can provoke different suggestive effects. 相似文献32.
Efficiency of automotive cabin air filters to reduce acute health effects of diesel exhaust in human subjects 总被引:1,自引:1,他引:0 下载免费PDF全文
B. Rudell U. Wass P. Horstedt J. O. Levin R. Lindahl U. Rannug A. L. Sunesson Y. Ostberg T. Sandstrom 《Occupational and environmental medicine》1999,56(4):222-231
OBJECTIVES: To evaluate the efficiency of different automotive cabin air filters to prevent penetration of components of diesel exhaust and thereby reduce biomedical effects in human subjects. Filtered air and unfiltered diluted diesel exhaust (DDE) were used as negative and positive controls, respectively, and were compared with exposure to DDE filtered with four different filter systems. METHODS: 32 Healthy non- smoking subjects (age 21-53) participated in the study. Each subject was exposed six times for 1 hour in a specially designed exposure chamber: once to air, once to unfiltered DDE, and once to DDE filtered with the four different cabin air filters. Particle concentrations during exposure to unfiltered DDE were kept at 300 micrograms/m3. Two of the filters were particle filters. The other two were particle filters combined with active charcoal filters that might reduce certain gaseous components. Subjective symptoms were recorded and nasal airway lavage (NAL), acoustic rhinometry, and lung function measurements were performed. RESULTS: The two particle filters decreased the concentrations of diesel exhaust particles by about half, but did not reduce the intensity of symptoms induced by exhaust. The combination of active charcoal filters and a particle filter significantly reduced the symptoms and discomfort caused by the diesel exhaust. The most noticable differences in efficacy between the filters were found in the reduction of detection of an unpleasant smell from the diesel exhaust. In this respect even the two charcoal filter combinations differed significantly. The efficacy to reduce symptoms may depend on the abilities of the filters investigated to reduce certain hydrocarbons. No acute effects on NAL, rhinometry, and lung function variables were found. CONCLUSIONS: This study has shown that the use of active charcoal filters, and a particle filter, clearly reduced the intensity of symptoms induced by diesel exhaust. Complementary studies on vehicle cabin air filters may result in further diminishing the biomedical effects of diesel exhaust in subjects exposed in traffic and workplaces.
相似文献
33.
Failure of reduction with an external fixator in the management of injuries of the pelvic ring. Long-term evaluation of 110 patients 总被引:10,自引:0,他引:10
Lindahl J Hirvensalo E Böstman O Santavirta S 《The Journal of bone and joint surgery. British volume》1999,81(6):955-962
We reviewed 110 patients with an unstable fracture of the pelvic ring who had been treated with a trapezoidal external fixator after a mean follow-up of 4.1 years. There were eight open-book (type B1, B3-1) injuries, 62 lateral compression (type B2, B3-2) and 40 rotationally and vertically unstable (type C1-C3) injuries. The rate of complications was high with loss of reduction in 57%, malunion in 58%, nonunion in 5%, infection at the pin site in 24%, loosening of the pins in 2%, injury to the lateral femoral cutaneous nerve in 2%, and pressure sores in 3%. The external fixator failed to give and maintain a proper reduction in six of the eight open-book injuries, in 20 of the 62 lateral compression injuries, and in 38 of the 40 type-C injuries. Poor functional results were usually associated with failure of reduction and an unsatisfactory radiological appearance. In type-C injuries more than 10 mm of residual vertical displacement of the injury to the posterior pelvic ring was significantly related to poor outcome. In 14 patients in this unsatisfactory group poor functional results were also affected by associated nerve injuries. In lateral compression injuries the degree of displacement of fractures of the pubic rami caused by internal rotation of the hemipelvis was an important prognostic factor. External fixation may be useful in the acute phase of resuscitation but it is of limited value in the definitive treatment of an unstable type-C injury and in type-B open-book injuries. It is usually unnecessary in minimally displaced lateral compression injuries. 相似文献
34.
35.
The influence of quercetin, chlorpromazine, aristolochic acid, and indomethacin on group I phospholipase A2 (PLA2) from porcine pancreas and on group II PLA2 fromVipera russelli was compared. Quercetin and chlorpromazine were found to inhibit PLA2 activity in lower concentrations (< 100M), while aristolochic acid and indomethacin were inhibitory only in higher concentrations (> 100M). The order of potency againstVipera PLA2 was: quercetin >chlorpromazin aristolochic acid > indomethacin, while the order of potency against pancreatic PLA2 was: chlorpromazine > aristolochic acid > indomethacin> quercetin. Thus, quercetin was a potent inhibitor towards group II PLA2 (IC50=2M), but a very weak inhibitor against group I PLA2, with maximum 30% inhibition. Aristolochic acid and indomethacin were three to four times more potent towards group II PLA2 than towards group I PLA2, while chlorpromazine was equally potent towards the two PLA2 types. Quercetin and chlorpromazine were also tested against two PLA2 fractions purified from the plasma of septic shock patients; chlorpromazine was then equally potent towards the two PLA2 fractions, whereas quercetin was a potent inhibitor of only one of the two PLA2 fractions (IC50=4M). Together, these results indicate that (1) different PLA2 inhibitors have different potency depending on which type of PLA2 they are used against, (2) quercetin selectively inhibits group II PLA2 and may therefore be used to discriminate between different PLA2 forms in biological materials, and (3) both PLA2 of group I and group II are present in septic shock plasma. 相似文献
36.
37.
38.
Christel M. Olsen Elise T. M. Meussen‐Elholm Mari Samuelsen Jrn A. Holme Jan K. Hongslo 《Basic & clinical pharmacology & toxicology》2003,92(4):180-188
Abstract: Bisphenol A is extensively used in the manufacturing of epoxy resins and polycarbonate plastics, whereas several brominated and chlorinated analogues are used as flame retardants and intermediates in the plastic industry. Due to the structural relationship between these chemicals and the high production volumes, we wanted to characterize and compare their potential oestrogen‐like potency using several end‐points in MCF‐7 cells: induction of pS2 protein and progesterone receptor, reduction of oestrogen receptor level, and stimulation of cell growth. Bisphenol A, tetrachloro‐ and tetrabromo‐bisphenol A, 4‐hydroxybiphenyl and 4,4′‐dihydroxybiphenyl all showed oestrogen‐like properties in MCF‐7 cells. The chemicals tested had affinity to the oestrogen receptor isolated from MCF‐7 cells, although their EC50s were 1,000 to 80,000 times higher than the EC50 of 17β‐oestradiol. Bisphenol A and 4‐hydroxybiphenyl induced cell growth in MCF‐7 cells, and the highest test concentrations induced responses, apparently exceeding the cell growth induced by 17β‐oestradiol. The other chemicals tested induced less than 50% of the maximum 17β‐oestradiol‐stimulated cell growth. Bisphenol A, 4‐hydroxybiphenyl, tetrabromobisphenol A and tetrachlorobisphenol A all increased the level of the oestrogen‐regulated proteins, progesterone receptor and pS2, whereas 4,4′‐dihydroxybiphenyl showed no such effect. Bisphenol A was the only chemical tested that clearly mimicked 17β‐oestradiol in its ability to reduce the level of cytosolic oestrogen receptors in MCF‐7 cells. By measuring several oestrogen‐dependent endpoints it seems that some xeno‐oestrogens cause an imbalanced oestrogen‐response. Their ability and potency in mimicking 17β‐oestrogen in one parameter is not necessarily accompanied by a similar effect in another oestrogen‐linked parameter. 相似文献
39.
Antitumor vaccination of patients with glioblastoma multiforme: a pilot study to assess feasibility, safety, and clinical benefit. 总被引:5,自引:0,他引:5
Hans Herbert Steiner Matteo Mario Bonsanto Philipp Beckhove Michael Brysch Karsten Geletneky Rezvan Ahmadi Rebecca Schuele-Freyer Paul Kremer Golamreza Ranaie Dejana Matejic Harald Bauer Marika Kiessling Stefan Kunze Volker Schirrmacher Christel Herold-Mende 《Journal of clinical oncology》2004,22(21):4272-4281
PURPOSE: Prognosis of patients with glioblastoma is poor. Therefore, in glioblastoma patients, we analyzed whether antitumor vaccination with a virus-modified autologous tumor cell vaccine is feasible and safe. Also, we determined the influence on progression-free survival and overall survival and on vaccination-induced antitumor reactivity. PATIENTS AND METHODS: In a nonrandomized study, 23 patients were vaccinated and compared with nonvaccinated controls (n = 87). Vaccine was prepared from patient's tumor cell cultures by infection of the cells with Newcastle Disease Virus, followed by gamma-irradiation, and applied up to eight times. Antitumor immune reactivity was determined in skin, blood, and relapsed tumor by delayed-type hypersensitivity skin reaction, ELISPOT assay, and immunohistochemistry, respectively. RESULTS: Establishment of tumor cell cultures was successful in approximately 90% of patients. After vaccination, we observed no severe side effects. The median progression-free survival of vaccinated patients was 40 weeks (v 26 weeks in controls; log-rank test, P = .024), and the median overall survival of vaccinated patients was 100 weeks (v 49 weeks in controls; log-rank test, P < .001). Forty-five percent of the controls survived 1 year, 11% survived 2 years, and there were no long-term survivors (> or = 3 years). Ninety-one percent of vaccinated patients survived 1 year, 39% survived 2 years, and 4% were long-term survivors. In the vaccinated group, immune monitoring revealed significant increases of delayed-type hypersensitivity reactivity, numbers of tumor-reactive memory T cells, and numbers of CD8(+) tumor-infiltrating T-lymphocytes in secondary tumors. CONCLUSION: Postoperative vaccination with virus-modified autologous tumor cells seems to be feasible and safe and to improve the prognosis of patients with glioblastomas. This could be substantiated by the observed antitumor immune response. 相似文献
40.
Hans Gelderblom Ramon Salazar Jaap Verweij George Pentheroudakis Maja J A de Jonge Martin Devlin Christel van Hooije Francis Seguy Rosendo Obach Joan Pru?onosa Paola Principe Chris Twelves 《Clinical cancer research》2003,9(11):4101-4107
PURPOSE: Diflomotecan (BN80915) is an E-ring modified camptothecin analogue that possesses greater lactone stability in plasma compared with other topoisomerase I inhibitors, a potential advantage for antitumor activity. As with other camptothecins, oral administration has pharmacological and clinical advantages. This Phase I study was performed to assess the feasibility of the administration of oral diflomotecan, to determine the maximum-tolerated, dose its bioavailability, and to explore the pharmacokinetics. EXPERIMENTAL DESIGN: An initial i.v. bolus was administered to assess the bioavailability of diflomotecan. Fourteen days later, diflomotecan was administered p.o. once daily for 5 days to adult patients with solid malignant tumors and repeated every 3 weeks. BN80915 and its open lactone form BN80942 were measured. RESULTS: Twenty-two patients entered the study and received a total of 57 cycles of oral diflomotecan at flat dose levels of 0.10, 0.20, 0.27, and 0.35 mg. The main toxicity was hematological, but some patients experienced alopecia, mild gastrointestinal toxicity, and fatigue. At the 0.35-mg dose level, 2 of 4 patients experienced dose-limiting toxicity comprising grade 3 thrombocytopenia with epistaxis and febrile neutropenia in 1 patient and uncomplicated grade 4 neutropenia lasting for >7 days in another. Toxicity was acceptable at the 0.27-mg dose level at which dose-limiting toxicities were observed in 3 of 12 patients (grade 4 neutropenia > 7 days, complicated by fever in 1 patient but without other signs of infection). After two cycles of diflomotecan, 6 patients had disease stabilization, which was maintained in 2 patients for 9 months and >1 year, respectively. Diflomotecan pharmacokinetics were linear over the dose range studied. Systemic exposure correlated with the fall in WBC counts. The mean oral bioavailability (+/-SD) was 72.24 +/- 59.2% across all dose levels. Urinary excretion of BN80915 was very low. CONCLUSIONS: The recommended oral diflomotecan dose for Phase II studies is 0.27 mg/day x 5 every 3 weeks. This regimen is convenient and generally well tolerated with a favorable pharmacokinetic profile and high but variable bioavailability. 相似文献