全文获取类型
收费全文 | 6819篇 |
免费 | 272篇 |
国内免费 | 183篇 |
专业分类
耳鼻咽喉 | 55篇 |
儿科学 | 145篇 |
妇产科学 | 87篇 |
基础医学 | 907篇 |
口腔科学 | 70篇 |
临床医学 | 708篇 |
内科学 | 1043篇 |
皮肤病学 | 63篇 |
神经病学 | 394篇 |
特种医学 | 99篇 |
外科学 | 530篇 |
综合类 | 894篇 |
预防医学 | 380篇 |
眼科学 | 15篇 |
药学 | 1473篇 |
3篇 | |
中国医学 | 162篇 |
肿瘤学 | 246篇 |
出版年
2023年 | 47篇 |
2022年 | 99篇 |
2021年 | 186篇 |
2020年 | 158篇 |
2019年 | 118篇 |
2018年 | 131篇 |
2017年 | 134篇 |
2016年 | 163篇 |
2015年 | 181篇 |
2014年 | 379篇 |
2013年 | 384篇 |
2012年 | 375篇 |
2011年 | 404篇 |
2010年 | 318篇 |
2009年 | 330篇 |
2008年 | 357篇 |
2007年 | 316篇 |
2006年 | 272篇 |
2005年 | 229篇 |
2004年 | 191篇 |
2003年 | 168篇 |
2002年 | 130篇 |
2001年 | 119篇 |
2000年 | 115篇 |
1999年 | 119篇 |
1998年 | 91篇 |
1997年 | 110篇 |
1996年 | 93篇 |
1995年 | 94篇 |
1994年 | 82篇 |
1993年 | 53篇 |
1992年 | 77篇 |
1991年 | 57篇 |
1990年 | 68篇 |
1989年 | 72篇 |
1988年 | 75篇 |
1987年 | 75篇 |
1986年 | 68篇 |
1985年 | 104篇 |
1984年 | 94篇 |
1983年 | 55篇 |
1982年 | 99篇 |
1981年 | 73篇 |
1980年 | 56篇 |
1979年 | 54篇 |
1978年 | 41篇 |
1977年 | 44篇 |
1976年 | 52篇 |
1975年 | 33篇 |
1973年 | 39篇 |
排序方式: 共有7274条查询结果,搜索用时 31 毫秒
81.
Seiji Shibuya Yoshihiro Wakayama Masahiko Inoue Makoto Murahasi Hiroaki Oniki 《Medical Electron Microscopy》1998,31(3):135-141
To examine the influence of thyroid hormone on the skeletal muscle plasma membrane, we analyzed the changes in ultrastructural architecture and membrane area complexed with digitonin of muscle plasma membrane in myopathic patients with hypo-and hyperthyroidism by the conventional freeze-fracture (F-F) technique and F-F cytochemistry using the sterol-specific ligand digitonin. The densities of flask-shaped invaginations, which are mainly thought to correspond to caveolae, intramembranous particles, and orthogonal arrays, and the changes of digitoninreacted membrane areas in the muscle plasma membranes in three patients with hypothyroid myopathy and one patient with both myasthenia gravis and hyperthyroidism were compared with those in age-matched controls. In the conventional F-F study, the muscle plasma membrane of hypothyroid patients showed increased invagination density, whereas that of the hyperthyroid patient was normal ultrastructurally. In the F-F cytochemistry study, however, the ratio of digitonin-reacted membrane areas versus fractured membrane areas was not different between hypothyroid patients and controls, whereas that of the hyperthyroid patient was lowered in comparison with that of control. These results suggest that thyroid hormone may alter the biochemical properties and ultrastructural architecture of muscle plasma membrane.This study was presented at the 29th annual meeting of the Clinical Electron Microscopy Society of Japan, Sapporo, October 2–3, 1997 相似文献
82.
J. A. R. Smith J. Watkins W. Lorenz 《Journal of molecular medicine (Berlin, Germany)》1985,63(19):1005-1008
Summary The past decades have seen considerable shifts of emphasis in surgical care. The recognition that pus was not laudable, was followed by a realisation that not all complications were inevitable and that prophylaxis could effectively reduce the incidence of most common problems in the post-operative period. As anaesthesia has become safer, it has been possible to embark on more intricate and prolonged procedures and for sufficient time to be available to ensure adequate intraoperative care.These two phenomena have firstly increased the complexity of management in the post-operative period, and have brought this aspect of surgical care more obviously to the limelight. However, many separate disciplines are involved in the care of the patient post-operatively, and the Symposium was organised1 to bring the different groups together to identify the areas of recent development in the different specialities and to integrate the overall care of the individual patient.Abbreviations ARDS
adult respiratory distress syndrome
- DIC
disseminated intravascular clotting 相似文献
83.
Benjamin H. Natelson Walter N. Tapp Jean E. Adamus James C. Mittler Barry E. Levin 《Physiology & behavior》1981,26(6):1049-1054
Rats, bearing chronic venous cannulas, were subjected to 30 sec of constant current grid shock at 1 of 6 intensities (0, 0.25, 0.5, 1, 2, 4 mA), after being allowed to acclimate to the test chamber overnight. Blood, sampled before and after shock, was assayed for epinephrine, norepinephrine and corticosterone. Peak levels of both catecholamines increased in a stepwise fashion (i.e., monotonically) with increasing magnitude of stress, as reflected by current intensity of foot shock. Plasma corticosterone did not increase monotonically but instead showed similar increases in the 5 groups of rats that actually received shock. These data support earlier work which indicate that plasma corticosterone is not a sensitive index of stress; this is probably the case because of the relatively narrow range of responsiveness of the adrenal cortex to ACTH. In contrast, both plasma catecholamines appear to satisfy some of the requisites for a sensitive visceral index of stress. 相似文献
84.
V. Candas J. P. Libert G. Brandenberger J. C. Sagot C. Amoros J. M. Kahn 《European journal of applied physiology》1986,55(2):113-122
Summary Five young unacclimatised subjects were exposed for 4 h at 34 C (10 C dew-point temperature and 0.6 m · s–1 air velocity), while exercising on a bicycle ergometer: 25 min work — 5 min rest cycles for 2 hours followed by 20 min work — 10 min rest cycles for two further hours. 5 experimental sessions were carried out: one without rehydration (NO FLUID) resulting in 3.1% mean loss of body weight ( Mb), and four sessions with 20 C fluid ingestion of spring water (WATER), hypotonic (HYPO), isotonic (ISO) and hypertonic (HYPER) solutions to study the effects of fluid osmolarity on rehydration. Mean final rehydration (±SE) after fluid intake was 82.2% (±1.2). Heart rate was higher in NO FLUID while no difference among conditions was found in either Mb or hourly sweat rates. Sweating sensitivity was lowest in the dehydration condition, and highest in the WATER one. Modifications in plasma volume and osmolarity demonstrated that NO FLUID induced hyperosmotic hypovolemia, ISO rehydration rapidly led to plasma isoosmotic hypervolemia, while WATER led to slightly hypoosmotic normovolemia.It is concluded that adequate rehydration through ingestion of isotonic electrolyte-sucrose solution, although in quantities much smaller than evaporative heat loss, rapidly restored and expanded plasma volume. While osmolarity influenced sweating sensitivity, the plasma volume changes ( PV) within the range –6% PV+4% had little effect on temperature adjustments in our conditions. 相似文献
85.
Physiological and behavioral effects of prior aversive stimulation (preshock) in the rat 总被引:2,自引:0,他引:2
Physiological and behavioral measures were assessed in rats that had been previously exposed to unsignaled inescapable intense shock (preshock). Animals subjected to such prior aversive stimulation exhibited greater adrenocortical steroid response compared to nonpreshocked controls when subsequently tested in the open field. An increment in defecation was also observed, with ambulation and rearing behavior being markedly inhibited in the preshocked rat during these sessions. 相似文献
86.
The most important application of blood group genotyping by molecular genetics is the prediction of fetal RhD phenotype in pregnant women with anti-D, in order to assess the risk of haemolytic disease of the fetus and newborn. This diagnostic test performed on cell-free fetal DNA in the maternal plasma, is now a routine procedure in some countries. High-throughput modifications of this form of fetal D-typing would be valuable for testing fetuses of all D-negative pregnant women to avoid unnecessary antenatal treatment with anti-D immunoglobulin in the 40% of D-negative pregnant women with a D-negative fetus. The results of trials in Bristol and Amsterdam suggest that such routine testing is feasible and accurate. 相似文献
87.
Takaaki Ohmori Ryo Tabei Keiji Fukui Kazuhiko Sadamoto Saburo Sakaki 《Pathology international》1989,39(3):190-194
Two cases of meningioma revealing conspicuous plasmo lymphocytic tissue and hyalinized fibrous tissue components are reported. Histopathological examination of the plasmo lymphocytic infiltration was performed. Both lesions showed polyclonality of plasma cells as revealed by positive reactions for 1gG and paraimmunoglobulin χ- and λ light chains, and amyloid infiltration into the fibrous stroma and blood vessel walls. The histochemical and immunohistochemical characteristics of the lesion in relation to its etiology are briefly discussed. Acta Pathol. Jpn. 32: 190∼194, 1989. 相似文献
88.
To protect plasma supplies, donors are screened for infectiousdiseases. As an added measure of protection, donations are identifiedand stored for a period of time to allow future discard in theevent that an identified donor subsequently tests positive forsome screened disease. Previous models for evaluating such plasmaholds have only addressed the case of a single infectious disease.This paper extends the analysis to the case of multiple infections.Given knowledge of the marginal incidence rates for those infectionschecked, upper and lower bounds for important quantities suchas the probability of interdicting an infectious but undetecteddonation, the expected number of infections interdicted perdonation, and the net economic benefits of the holding policyare developed. Several examples are developed, illustratinghow the models can be used to evaluate the consequences of aplasma hold. 相似文献
89.
Isaac M. Libermann Héctor Brazzuna Jorge Rodríguez Aníbal Capano Juanita Neumark 《Pflügers Archiv : European journal of physiology》1976,365(2-3):191-196
Summary Plasma volume, hematocrit, protein and electrolyte concentrations in plasma were measured in control and water-deprived rats every three days after starting the experiment until the 15th day. Plasma volume variations, as related to body weight, suggest that water loss from plasma was proportional to total body water at three days and after 9 days of water deprivation. Greater plasma water than body water loss was found during the period between 3 and 9 days. Plasma protein and electrolyte variations suggest that during water deprivation there is a loss of protein, sodium and potassium from plasma, which is proportionally less than that of plasma water. Potassium, calcium and inorganic phosphorus were lost proportionally to plasma water. The variations in plasma volume changes were partially explained as due to variations in plasma protein and electrolyte concentrations. 相似文献
90.
H. Sinzinger J. Flores F. Rauscha 《Journal of molecular medicine (Berlin, Germany)》1988,66(17):779-783
Summary A screening investigation for the presence of risk factors for the development of atherosclerosis demonstrates a plasma factor deficiency in 0,8% in the Viennese population. These findings are in agreement with the data of a newborn screening performed earlier. All the persons were clinically healthy. In 4 of them at least 1 family member suffered from the same defect. The pathogenetic relevance of the plasma factor defect for thrombophilia at young age is discussed.
Abkürzungsverzeichnis VIP Viennese Initiative for Prostaglandin - PGI2 Prostazyklin - PG Prostaglandin - PF Plasmafaktor - PRP pättchenreiches Plasma - HUS hämolytischurämisches Syndrom - PF4 Plättchenfaktor 4 - TG Thromboglobulin - TXB2 Thromboxan B2 Diese Untersuchung im Rahmen des VIP(VienneseInitiative forProstaglandin)-Screenings wurde vom Medizinisch-Wissenschaftlichen Fonds des Bürgermeisters der Bundeshauptstadt Wien unterstützt 相似文献
Abkürzungsverzeichnis VIP Viennese Initiative for Prostaglandin - PGI2 Prostazyklin - PG Prostaglandin - PF Plasmafaktor - PRP pättchenreiches Plasma - HUS hämolytischurämisches Syndrom - PF4 Plättchenfaktor 4 - TG Thromboglobulin - TXB2 Thromboxan B2 Diese Untersuchung im Rahmen des VIP(VienneseInitiative forProstaglandin)-Screenings wurde vom Medizinisch-Wissenschaftlichen Fonds des Bürgermeisters der Bundeshauptstadt Wien unterstützt 相似文献