全文获取类型
收费全文 | 543篇 |
免费 | 10篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 19篇 |
妇产科学 | 8篇 |
基础医学 | 79篇 |
口腔科学 | 43篇 |
临床医学 | 62篇 |
内科学 | 46篇 |
皮肤病学 | 19篇 |
神经病学 | 15篇 |
特种医学 | 15篇 |
外科学 | 143篇 |
综合类 | 15篇 |
预防医学 | 39篇 |
眼科学 | 11篇 |
药学 | 21篇 |
中国医学 | 1篇 |
肿瘤学 | 14篇 |
出版年
2022年 | 4篇 |
2018年 | 4篇 |
2015年 | 11篇 |
2014年 | 11篇 |
2013年 | 27篇 |
2012年 | 14篇 |
2011年 | 10篇 |
2010年 | 13篇 |
2009年 | 4篇 |
2008年 | 15篇 |
2007年 | 9篇 |
2006年 | 6篇 |
2005年 | 4篇 |
2004年 | 7篇 |
2003年 | 10篇 |
2002年 | 13篇 |
2001年 | 6篇 |
2000年 | 6篇 |
1999年 | 11篇 |
1998年 | 6篇 |
1997年 | 12篇 |
1996年 | 6篇 |
1995年 | 8篇 |
1993年 | 5篇 |
1992年 | 12篇 |
1991年 | 10篇 |
1990年 | 20篇 |
1989年 | 17篇 |
1988年 | 6篇 |
1987年 | 7篇 |
1986年 | 11篇 |
1985年 | 12篇 |
1984年 | 14篇 |
1983年 | 5篇 |
1981年 | 5篇 |
1979年 | 7篇 |
1978年 | 10篇 |
1977年 | 23篇 |
1976年 | 19篇 |
1975年 | 18篇 |
1974年 | 18篇 |
1973年 | 19篇 |
1972年 | 18篇 |
1971年 | 11篇 |
1970年 | 15篇 |
1969年 | 12篇 |
1967年 | 7篇 |
1966年 | 4篇 |
1965年 | 5篇 |
1964年 | 3篇 |
排序方式: 共有553条查询结果,搜索用时 0 毫秒
91.
O. V. Podobed L. M. Fedorova O. Yu. Abakumova I. V. Yakusheva T. A. Tsvetkova A. V. Gavril'chak A. B. Shekhter A. V. Karyakin 《Bulletin of experimental biology and medicine》1997,124(3):897-899
Hepatoprotective effect of Phospholiv, a phospholipid preparation containing phosphatidylcholine from sunflower seeds and
glycyrrhizic acid trisodium salt, is studied using a model of CCl4-induced cirrhosis of the liver. Phospholiv protects hepatic tissues from necrotic and dystrophic changes and prevents the
development of cirrhosis. Phospholiv restores impaired RNA and protein synthes is under conditions of chronic intoxication.
Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 9, pp. 311–314, September, 1997 相似文献
92.
Alexander Zlatkov Plamen Peikov Nikolai Danchev Dimiter Ivanov Boika Tsvetkova 《Archiv der Pharmazie》1998,331(10):313-318
The synthesis of four ester derivatives of 7-theophylline-acetic acid and glycols by DCC/DMAP-mediated esterification under mild conditions was studied. The structures of the synthesized compounds were proved by microanalyses, UV-, IR-, and 1H-NMR data. Acute toxicity assessment of the compounds in mice showed that compounds 2a–d are less toxic than aminophylline. It was shown by in vivo experiments that 2a–d had depressive action on CNS (increasing of hexobarbital sleeping time and decreasing of spontaneous locomotor activity), and they did not influence to a statistically significant extent the normal 24 hour diuresis of rats (except 2c ). The results of cardiovascular screening in rats show that compounds 2a and 2c decreased the heart rate of rats. A pharmacological study of the in vitro broncholytic effect (IC50 and pD2 values) of the derivatives and aminophylline showed that 2c exhibited good broncholytic effect in vitro especially in acetyl-choline and serotonin induced guinea pig tracheal contraction. It was demonstrated that compounds 2b,c exerted a stronger inhibitory effect on the enzymic activity of phosphodiesterase in concentration 2 × 10–3 M than aminophylline. 相似文献
93.
94.
N. Bouganim E. Tsvetkova M. Clemons E. Amir 《Breast cancer research and treatment》2013,139(2):603-606
Improvements in adjuvant therapy have led to a sustained fall in recurrences after early breast cancer. The differential reduction in local and systemic recurrences is poorly understood. This study aimed to explore changes in the distribution of loco-regional and distant recurrences in clinical trials reported over the last 20 years. We also aimed to determine the relative impact of adjuvant chemotherapy and endocrine therapy. MEDLINE search for adjuvant, phase III randomized breast cancer clinical studies between January 1990 and March 2011 was performed. Neoadjuvant, single agent biologics and studies that did not report the proportion of loco-regional and distant recurrences were excluded. The change in the frequency of recurrences was assessed as the nonparametric correlation between the number of loco-regional recurrences as a proportion of all recurrences and time. Studies were weighted by sample size. The differential effect of chemotherapy and endocrine therapy was also assessed. Fifty-three randomized clinical trials with a total of 86,598 patients were included in the analysis. Between 1990 and 2011, the proportion of loco-regional recurrences has decreased from approximately 30 to 15 % (Spearman’s ρ = ?0.40, p < 0.001). There was no interaction between type of surgery (mastectomy vs. lumpectomy), administration of adjuvant radiation therapy and menopausal status and the correlation of loco-regional recurrences and time. Chemotherapy regimen showed a larger negative correlation compared with endocrine therapy ( ρ = 0.49 vs. ρ = 0.24). Advances in treatment of early breast cancer have differentially reduced the proportion of loco-regional recurrences compared with distant recurrences. In recent trials, loco-regional recurrences account for less than 10–15 % of all recurrences. These falling event rates may affect patient care, especially when deciding on treatments influencing loco-regional control. This change may also impact on the design of clinical trials assessing loco-regional therapy such as surgery and/or local radiation therapy. 相似文献
95.
OA Dr. H. P. Bantleon H. Droschl K. P. Pfeiffer 《Journal of orofacial orthopedics》1989,50(4):243-255
Zusammenfassung Nivellierungsbögen aus verseilten Stahldrähten wurden mit Nickel-Titanium-Drähten der neuen Generation, ausgezeichnet durch Formgedächtnis, Superelastizität und exzellentes Rückstellvermögen, verglichen. Die im Biegeversuch ermittelten Werte wurden statistisch aufbereitet und ergaben eine lineare Kraftweg-Kennlinie der verseilten Stahldrähte. Die Nickel-Titanium-Drähte zeigten aber eine deutliche Abweichung von der Linearität mit kurviger Verlaufsform. Neben der atypischen Kraftweg-Kennlinie mit einer konstanten Kraftabgabe im Mittel der Kurve gaben diese Drähte, unabhängig vom Aktivierungsgrad (das heißt unabhängig davon, ob die Stufe zwischen den Brackets 1 oder 4 mm betrug), dieselbe Kraft ab. Je größer die Aktivierung zwischen den Brackets war, desto länger stellte sich der Bereich der konstanten Kraftabgabe-die Superelastizität-im Diagramm dar. Daher eignen sich die Drähe für große Niveauunterschiede oder Deflektionen. Bei geringer Aktivierung verläuft die Kennlinie sehr steil und annähernd linear. In diesen Fällen ist verseilten Stahldrähten aufgrund ihrer kleineren Federrate und Flexibilität der Vorzug zu geben.
Summary Levelling arches made of stainless-steel wires were compared with nickel-titanium wires of the new generation which are distinguished by their shape memory, superelasticity and their excellent spring-back. The data received from a bending test have been analysed statistically and revealed a linear unloading curve of the twisted stainless-steel wires. The nickel-titanium wires, however, showed a clear deviation form the linearity with a curviform course. Besides the unusual unloading curve with a constant force mechanism in the middle range of deactivation the wires give off the same amount of force irrespective of the degree of activation (that is to say, regardless whether the level difference between the brackets amounts to 1 or to 4 mm). The diagram shows that the greater the activity between the brackets, the longer the period of superelasticity. Therefore the nickel-titanium wires are suited for large level differences or deflections. At a low activation rate the characteristic line takes a very steep and almost linear deactivation curve. In these cases twisted stainless steal wires should be preferred because of their lower load deflection rate and flexibility.
Résumé Les arcs de nivelage de fils d'acier tressés ont été comparés avec les fils nickel-titane de la nouvelle génération, se distinguant par leur mémoire de forme, superélasticité et capacité excellente de rappel. Les valeurs relevées au cours de l'essai de pliage ont été enregistrées statistiquement et ont montré une caractéristique linéaire du tracé de force des fils d'acier tressés. Les fils nickel-titane ont cependant montré une déviation significative en présentant non une linéarité mais un tracé curviligne. A côté de leur caractéristique atypique de leur tracé de force avec un dégagement constant de force au centre de la courbe, ces fils ont produit la même force, indépendamment, du degré d'activation (c.-à-d., indépendamment du fait que l'espace entre les brackets fut de 1 ou 4 mm). Plus l'activation était grande entre les brackets, plus la zone du dégagement de la force constante-la superélasticité, paraissait longue sur le diagramme. C'est pourquoi ces fils sont indiqués pour de fortes différences de niveau ou déflexions importantes. En cas d'activation peu considérable, le tracé est très raide et presque linéaire. Dans ces cas, la préférence doit être accordée aux fils d'acier tressés, en raison de leur force élastique et flexibilité inférieures.相似文献
96.
OA Univ.-Doz. Dr. Dr. A. Eskici H. Droschl H. Bantleon I. Permann 《Journal of orofacial orthopedics》1989,50(4):285-293
Zusammenfassung Durch Tierversuche an jungen Beagle-Hunden konnte die normale Entwicklung des Parodontiums nach Zahnkeimtransplantationen histologisch nachgewiesen werden. Die klinisch-röntgenologischen Untersuchungen zeigten keine pathologischen Befunde im Parodontiumbereich nach Zahnkeimtransplantationen beim Menschen. Die transplantierten Zähne können wie die anderen kieferorthopädisch bewegt werden. In diesem Beitrag wird auf die häufigsten Indikationen von Zahnkeimtransplantationen von Molaren, Prämolaren und Eckzähnen hingewiesen.
Summary The normal development of the periodontal structures was confirmed histologically on young Beagle-dogs following tooth-germ transplants. In humans, clinical and radiographic examinations revealed no pathology of the periodontium following transplantation of tooth germs. The grafted teeth could be moved orthodontically in the same way as any other teeth. No precautions need to be taken. This paper describes the most common indications for transplanting the tooth-germs of canines, bicuspids and molars.
Résumé Dans les expérimentations animales chez de jeunes chiens-Beagles, on a prouvé que les structures parodontales sont normalement développées après la transplantation de germes dentaires. Les examens cliniques et radiologiques chez de jeunes sujets d'espèce humaine n'ont pas montré de résultats pathologiques au niveau du parodonte après la greffe de germes dentaires. Les dents transplantées peuvent être déplacées orthodontiquement comme les autres dents sans mesures spéciales. Dans cet article, on a donné les indications concernant les greffes des germes de molaires, prémolaires et canines.相似文献
97.
98.
99.