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81.
Mechanisms of cold sensitivity of paramyotonia congenita mutation R1448H and overlap syndrome mutation M1360V 总被引:1,自引:2,他引:1
Bahram Mohammadi Nenad Mitrovic Frank Lehmann-Horn Reinhard Dengler Johannes Bufler 《The Journal of physiology》2003,547(3):691-698
Missense mutations of the human skeletal muscle voltage-gated Na+ channel (hSkM1) cause a variety of neuromuscular disorders. The mutation R1448H results in paramyotonia congenita and causes cold-induced myotonia with subsequent paralysis. The mutation M1360V causes an overlapping syndrome with both K+ -induced muscle weakness and cold-induced myotonia. The molecular mechanisms of the temperature dependence of these disorders are not well understood. Therefore we investigated physiological parameters of these Na+ channel mutations at different temperatures. Channel proteins were recombinantly expressed in human embryonic kidney cells and studied electrophysiologically, using the whole-cell patch-clamp technique. We compared the wild-type (WT) channel with both mutants at different temperatures. Both mutations had slower inactivation and faster recovery from inactivation compared to WT channels. This effect was more pronounced at the R1448H mutation, leading to a larger depolarization of the cell membrane causing myotonia and paralysis. The voltage dependence of activation of R1448H was shifted to more negative membrane potentials at lower temperature but not at the M1360V mutation or in the WT. The window current by mutation R1448H was increased at lower temperatures. The results of this study may explain the stronger cold-induced clinical symptoms resulting from the R1448H mutation in contrast to the M1360V mutation. 相似文献
82.
A brief introduction to the Danish Cytogenetic Central Register (DCCR) is given, and possibilities, principles and problems concerning the establishment and maintenance of a national cytogenetic register are presented.
Various data carrier media for registers in general are discussed, of which the magnetic disc is considered most appropriate. General principles for programs capable of performing insertions, deletions and other modifications in the data base are outlined as well as the principles for the programs in the DCCR.
The individual records should preferably be identified by aid of a central person registration number (CPR) rather than by name. The data should be stored and sorted by this identification in order to facilitate retrieval of a desired record. The structure of the records is discussed with regard to prevention of the occurrence of certain errors as well as the optimization of processing.
Flexibility and economy of space are achieved by using programs able to handle records of unequal length, and problems occurring in connection with this are discussed. The question of how to protect sensitive data is dealt with, and two different methods used in the DCCR are outlined. Programs capable of analyzing karyotypes with the purpose of recognizing various cytogenetic syndromes have been developed for use in the DCCR. Various examples of computing times of typical program runs are presented. 相似文献
Various data carrier media for registers in general are discussed, of which the magnetic disc is considered most appropriate. General principles for programs capable of performing insertions, deletions and other modifications in the data base are outlined as well as the principles for the programs in the DCCR.
The individual records should preferably be identified by aid of a central person registration number (CPR) rather than by name. The data should be stored and sorted by this identification in order to facilitate retrieval of a desired record. The structure of the records is discussed with regard to prevention of the occurrence of certain errors as well as the optimization of processing.
Flexibility and economy of space are achieved by using programs able to handle records of unequal length, and problems occurring in connection with this are discussed. The question of how to protect sensitive data is dealt with, and two different methods used in the DCCR are outlined. Programs capable of analyzing karyotypes with the purpose of recognizing various cytogenetic syndromes have been developed for use in the DCCR. Various examples of computing times of typical program runs are presented. 相似文献
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85.
SSCP analysis of paraffin wax embedded tissues in a family with an atypical form of Fabry disease 下载免费PDF全文
Kirsten Marie Madsen Lis Hasholt Johannes Berger Sven Asger S?rensen 《Journal of clinical pathology》1996,49(5):M310-M312
To investigate the distribution of a single base pair mutation within a family with one known case of Fabry disease, DNA from paraffin wax embedded necropsy material was studied using single-strand conformation polymorphism (SSCP) analysis. The proband, who presented with an atypical form of Fabry disease, had a G to A transition in exon 6 of the α-galactosidase A gene. This patient had mainly cardiac symptoms and late onset disease. Further cases of coronary disorders occurred in this family, including the proband's brother who died at 42 years of age of a cardiac disorder. Formalin fixed, paraffin wax embedded material from the brother and two more distant relatives was available for analysis. SSCP analysis showed that the proband's brother also carried the G to A transition. Thus, the atypical form of Fabry disease and unrelated cardiac diseases with similar clinical symptoms occurred within a single family. The variant form is rare but may account for a few of the numerous cases of cardiac disease in men and should be considered when clusters of cases of cardiac disease occur within a single family. 相似文献
86.
Zusammenfassung Die natürliche intramolluskäre Entwicklung des Darmegels Isthmiophora melis verläuft über zwei morphologisch distinkte Redienformen: Auf zwei Generationen makropharyngeater Redien (Mutterredien) folgen nur noch Generationen mikropharyngeater Redien (Tochterredien) sowie Cercarien. Die Bildung von Mutterredien unterbleibt in Schnecken, die nur durch Implantation von Tochterredien experimentell infiziert wurden. Werden Schnecken nacheinander beiden Infektionsmodi unterworfen, der Tochterredienimplantation und der Miracidienexposition, so läßt sich aus dem Vorhandensein oder Fehlen von Mutterredien ablesen, welche der Infektionen von Erfolg war.Mittels dieser Methode wurde geprüft, ob Isthmiophora-parasitierte Lymnaea-Individuen gegen homologen Miracidienbefall resistent sind. Sie erwiesen sich als nicht resistent gegen Reinfektion, und zwar auch dann, wenn sie bereits in die Phase des Cercarienausstoßes eingetreten waren.
Ermöglicht durch Beihilfen der Deutschen Forschungsgemeinschaft. 相似文献
Experimental re-infection of Lymnaea stagnalis with Isthmiophora melis (trematoda, echinostomatidae) by exposition to miracidia after implantation of rediae
Summary The natural intramolluscular development of the intestinal fluke Isthmiophora melis takes place in two morphologically distinct forms of rediae: Two generations of macropharyngeate rediae (mother rediae) are followed only by generations of micropharyngeate rediae (daughter rediae) and cercariae. Mother rediae are not produced in snails infected by implantation of daughter rediae only. If snails are subjected to the implantation of daughter rediae and exposed to miracidiae successsively, the presence, or absence, of mother rediae indicates which of the infections has been successful.This method of investigation was used in order to ascertain whether Lymnaea individuals parasitized by Isthmiophora are resistant against invading miracidia of homologous species. They proved not resistant against re-infection, even if they had already entered the stage of shedding cercariae.
Ermöglicht durch Beihilfen der Deutschen Forschungsgemeinschaft. 相似文献
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Wollmer MA Papassotiropoulos A Streffer JR Grimaldi LM Kapaki E Salani G Paraskevas GP Maddalena A de Quervain D Bieber C Umbricht D Lemke U Bosshardt S Degonda N Henke K Hegi T Jung HH Pasch T Hock C Nitsch RM 《Psychiatric genetics》2002,12(3):155-160
Tissue inhibitor of metalloproteinases 1 (TIMP-1) inhibits several proteinases including a disintegrin and metalloproteinase 10 (ADAM10), a major alpha-secretase that cleaves the beta-amyloid precursor protein within its amyloidogenic Abeta domain. The gene encoding TIMP-1 (TIMP 1) maps to the short arm of the X chromosome, in a region previously suggested as conferring genetic susceptibility for Alzheimer's disease (AD). To determine whether genetic variability of TIMP 1 contributes to the pathogenesis of AD, we analysed one single nucleotide polymorphism within TIMP 1 and one single nucleotide polymorphism in the 5'-untranslated region of TIMP 1 in patients with AD and control subjects from two independent and ethnically different populations. We did not observe any association between TIMP 1 genotypes and the diagnosis of AD in men or women. We also measured TIMP-1 protein levels in the cerebrospinal fluid of patients with AD, healthy control subjects, and patients with other neurological disorders. TIMP-1 levels were similar in all groups. In addition, no significant differences were observed after stratification for TIMP 1 genotypes. Our data show that neither genetic variability nor protein levels of TIMP-1 are associated with AD. 相似文献
89.
Marc Fischer Gabriele Wiest Ismail Tekesin Kerstin Amann Johannes Mann Christian Hasslacher Harald Derks Gerhard Mall 《Virchows Archiv : an international journal of pathology》1992,420(6):499-506
Summary The effects of combined renovascular hypertension and diabetes mellitus on the rat heart were investigated in order to detect possible synergistic effects of the two conditions. Hypertensive diabetic and hypertensive non-diabetic animals were compared to diabetic and non-diabetic controls. Hypertension was established for 12 weeks by a surgical stenosis of the left renal artery; diabetes mellitus was maintained for 8 weeks by a single intraperitoneal injection of 60 mg/kg streptozotocin. Light microscopic stereology did not reveal significant divergences between diabetic hypertensives and non-diabetic hypertensives. Hypertension induced a focal perivascular and interstitial fibrosis with increased volume densities of non-vascular interstitium and fibrosis (P<0.001). Capillary density (QA) was decreased in transverse sections (P<0.01) and increased in longitudinal sections (P<0.01). This indicates a three-dimensional remodelling of the capillary bed with an increased number of obliquely running capillaries. At least the length density (LV) of capillaries (mm/mm3) tends to be normalized in long-term renovascular hypertension. At the ultrastructural level, a synergism of hypertension and diabetes mellitus was observed: the volume ratio of mitochondria to myofibrils was significantly decreased in hypertensive diabetics, but not in non-diabetic hypertensives or in diabetics. This may enhance the risk of cardiac deterioration. We conclude that the primary target of the synergistic damage in hypertensive diabetic heart muscle disease is the myocardial cell and not the cardiac interstitium.Preliminary results of this study have been published in: Mall G (1991) Morphometric study on the rat heart in combined renovascular hypertension and diabetes mellitus. In: Nagano N, Dhalla NS (eds) The diabetic heart. Raven Press, New York, pp 115–124Dedicated to Prof. Dr. med. G. Seifert on the occasion of his 70th birthday 相似文献
90.
Mouse models of atopic eczema critically evaluated 总被引:2,自引:0,他引:2
Gutermuth J Ollert M Ring J Behrendt H Jakob T 《International archives of allergy and immunology》2004,135(3):262-276
Atopic eczema (AE) is a chronic relapsing inflammatory skin disorder with increasing prevalence in Western societies. Even though we have made considerable progress in understanding the cellular and molecular nature of cutaneous inflammation, the precise pathomechanisms of AE still remain elusive. Experimental animal models are indispensable tools to study the pathogenic mechanisms and to test novel therapeutic approaches in vivo. For AE a considerable number of mouse models have been proposed and have been used to study specific aspects of the disease, such as genetics, skin barrier defects, immune deviations, bacteria-host interactions or the role of cytokines or chemokines in the inflammatory process. While some models closely resemble human AE, others appear to reflect only specific aspects of the disease. Here we review the currently available mouse models of AE in light of the novel World Allergy Organization classification of eczematous skin diseases and evaluate them according to their clinical, histopathological and immunological findings. The pathogenetic analogies between mice and men will be discussed. 相似文献