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91.
Invasive infections by Scedosporium prolificans have increased alarmingly in recent years, mainly in immunosuppressed patients. The epidemiology, pathogenesis and the natural habitat of this pathogen are practically unknown. Isolates of S. prolificans were distinguished from one another by inter-simple-sequence-repeat (ISSR) fingerprinting, a technique based on the high degree of polymorphism of the multisatellite genetic markers used. This technique was found useful for typing 84 isolates of S. prolificans from different countries and sources. The assemblage of S. prolificans isolates tested was extremely diverse, with 35 genotypes present. Several patients were found to have been infected or colonized by more than one strain. Overall, this technique facilitates the epidemiological study of S. prolificans infection.  相似文献   
92.
Group A Streptococcus (GAS), the most frequent bacterial cause of suppurative infections in humans, expresses on the cell surface M proteins with capacity to bind factor H, FHL-1 and C4b binding protein (C4BP). This has been interpreted as a mechanism developed by this pathogen to decrease phagocytosis by macrophages and polymorphonuclear cells. We report the analysis of the capacity to bind factor H, FHL-1 and C4BP of 69 clinical isolates from 19 different serotypes. We show that strains binding complement regulators (30/69) belong to specific M serotypes. Of these, M18 strains are relatively frequent and interact with all three complement regulators simultaneously. However, the most virulent M1 and M3 strains did not bind complement regulators in our assays. The relevance of the interaction between complement regulators and S. pyogenes was analyzed using different approaches with the conclusion that under physiological conditions only FHL-1 and C4BP bind to streptococci. We show that FHL-1 presents a higher binding affinity for S. pyogenes than factor H because it carries a hydrophobic, high-affinity, GAS binding site in addition to the heparin binding site in SCR7. Using synthetic peptides we provide evidence that the high-affinity GAS binding site in FHL-1 involves the hydrophobic tail (Ser-Phe-Thr-Leu) that distinguishes FHL-1 from factor H.  相似文献   
93.
Event-related potentials (ERPs) were recorded in male and female participants in response to 32 male and 32 female faces. Participants were instructed to simply look carefully at each face; after ERP collection they were asked to rate each face on a 5-point attractiveness scale. A positive correlation between average rating and average P300 scores to opposite sex faces was observed in male (r = .40) and in preovulatory (r = .41) and postovulatory (r = .44) female subjects. Correlations to same sex faces were only found in postovulatory females (r = .61). Male participants showed a much larger average P300 than did female participants, and the P300 evoked in female participants was unexpectedly larger to female than to male faces. Neither task relevance nor stimulus probability is a plausible explanations for these findings because they were experimentally controlled. These results support the emotional value hypothesis, according to which classical P300 processes reflect an affective evaluation of the stimulus, which in turn produces context updating.  相似文献   
94.
Bordetella bronchiseptica is closely related to Bordetella pertussis, which produces respiratory disease primarily in mammals other than humans. However, its importance as a human pathogen is being increasingly recognized. Although a large amount of research on Bordetella has been generated regarding protein virulence factors, the participation of the surface lipopolysaccharide (LPS) during B. bronchiseptica infection is less understood. To get a better insight into this matter, we constructed and characterized the behavior of an LPS mutant with the deepest possible rough phenotype. We generated the defective mutant B. bronchiseptica LP39 on the waaC gene, which codes for a heptosyl transferase involved in the biosynthesis of the core region of the LPS molecule. Although in B. bronchiseptica LP39 the production of the principal virulence determinants adenylate cyclase-hemolysin, filamentous hemagglutinin, and pertactin persisted, the quantity of the two latter factors was diminished, with the levels of pertactin being the most greatly affected. Furthermore, the LPS of B. bronchiseptica LP39 did not react with sera obtained from mice that had been infected with the parental strain, indicating that this defective LPS is immunologically different from the wild-type LPS. In vivo experiments demonstrated that the ability to colonize the respiratory tract is reduced in the mutant, being effectively cleared from lungs within 5 days, whereas the parental strain survived at least for 30 days. In vitro experiments have demonstrated that, although B. bronchiseptica LP39 was impaired for adhesion to human epithelial cells, it is still able to survive within the host cells as efficiently as the parental strain. These results seem to indicate that the deep rough form of B. bronchiseptica LPS cannot represent a dominant phenotype at the first stage of colonization. Since isolates with deep rough LPS phenotype have already been obtained from human B. bronchiseptica chronic infections, the possibility that this phenotype arises as a consequence of selection pressure within the host at a late stage of the infection process is discussed.  相似文献   
95.
Summary We have characterized the in vitro secondary antibody response to FMDV of peripheral blood mononuclear cells (PBMC) from immunized pigs. The results obtained indicated that primed swine leukocytes can support an in vitro T-B cell cooperation which is functional and leads to the production of viral specific antibodies. The response was shown to be independent of viral replication, being induced by both infective and inactivated virus as well as by recombinant polypeptides VP1 and VP3. In all cases, concentration of PBMC supernatants allowed the detection of viral-specific IgG antibodies by ELISA. Significant titers of foot-and-mouth disease virus (FMDV) specific neutralizing antibodies were detected in concentrated supernatants after stimulation with either infective or inactivated whole virus, whereas no neutralizing activity was found in supernatants from PBMC responding to individual capsid polypeptides. The titers of IgG1 and IgG2 were similar for PBMC incubated with viruses, while IgG2 predominated when VP1 or VP3 were used as stimulators. In addition, significant titers of IFN- were detected in supernatants of PBMC stimulated with infectious or chemically inactivated FMDV.  相似文献   
96.
The complex pathogenesis of bile duct stones, the anatomical properties of the biliary tree, the patient's age, associated diseases, as well as the technical devices available, may explain the great variety of procedures and preferences of different groups in the treatment of choledocholithiasis. Since no technique is infallible or free of complications, it seems unfair to argue that procedures whose efficacy has been proven by many authors are obsolete. This is the case of choledochoduodenostomy (CDS) in the treatment of common bile duct (CBD) stones. The complications associated with CDS, (ascending cholangitis, and sump syndrome) have been overemphasized and have led CDS to be rejected by many surgeons. Our experience with this technique is good and concurs with that of Madden and others.Data on 125 patients with CBD stones treated with CDS between 1968 and 1982 are analyzed. Sixty-eight of them were female and the mean age was 61.4 years; 73.6% were more than 50 years old. There were frequent accompanying diseases, especially cardiovascular ones. More than half of the patients had a previous operation on the biliary tree. The duct diameter was always greater than 20 mm and it was frequently associated with stenosis of the distal choledochus. Floercken's technique of CDS was the most frequently used, after Kocher's maneuver had been performed. There was no intraoperative mortality. Postoperative mortality was 3.2% and is analyzed in detail. The incidence of postoperative complications was 42.4%. Most were septic complications or those ascribed to accompanying diseases. Late operative cholangitis was present in 1.6% of patients, comparable with reports of other authors. We encourage the use of CDS in the treatment of CBD stones provided that: (a) careful attention is paid to its clinical indications, considering that the patient may benefit from alternative techniques, for example, duodenoscopic papillotomy; and (b) choledochal dilatation is greater than 20 mm in diameter and the choledochal and duodenal walls are normal. We specifically recommend CDS as the primary operation for patients with choledochal funnel syndrome. The operation is simple, restores normal digestive function, and almost always resolves the problems of CBD stones in high-risk patients.
Resumen La compleja patogenia de los cálculos del colédoco, las propiedades anatómicas del árbol biliar, la edad del paciente, las patologías asociadas y otros factores, junto con la disponibilidad de diversos elementos técnicos, explican la gran variedad de procedimientos y de preferencias por parte de los cirujanos en el tratamiento y de preferencias por parte de los cirujanos en el tratamiento de la litiasis biliar. Puesto que ninguna técnica operatoria es infalible ni totalmente libre de complicaciones, parece injusto argumentar que procedimientos cuya eficacia ha sido comprobada por muchos autores sean calificados como obsoletos. Tal es el caso de la coledocoduodenostomía (CDS) en el tratamiento de los cálculos del colédoco. Las complicaciones asociadas con la CDS (colangitis ascendente y el sindrome del segmento distal ciego) han sido exageradas, lo cual ha llevado a muchos cirujanos a rechazar la CDS. Nuestra experiencia con esta técnica es buena y está de acuerdo con la de Madden y de otros. Se analizaron los datos en 125 pacientes con cálculos del colédoco tratados con CDS entre 1968 y 1982. Sesenta y ocho eran mujeres y la edad promedio fué de 61.4 años; 73.6% eran mayores de cincuenta años. Otras enfermedades asociadas fueron halladas con frecuencia, especialmente las cardiovasculares. Más de la mitad de los pacientes tenían historia de una operación previa sobre el árbol biliar. El diámetro del colédoco fué superior a 20 mm en todos los casos y con frecuencia se encontró estenosis árbol de la porción distal. La técnica de Floercken fué la más frecuentemente utilizada, una vez realizada la maniobra de Kocher. No hubo mortalidad intraoperatoria. La mortalidad postoperatoria fué de 3.2% y se analiza en detalle. La tasa de complicaciones postoperatorias fué de 42.4%, incluyendo las sistematicas y las locales, leves y severas, habiéndose observado predominancia de las complicaciones sépticas y de aquellas relativas a patologiás asociadas. La colangitis operatoria tardía ocurrió en el 1.6% de los pacientes, tasa comparable a la informada por otros autores. Nosotros preconizamos el uso de la CDS en el tratamiento de los cálculos del colédoco siempre que: (a) se preste atención cuidadosa a sus indicaciones clínicas, considerando que el paciente puede beneficiarse con otras alternativas, por ejemplo la papilotomía duodenoscópica; y (b) la dilatación del colédoco sea de un diámetro superior a 20 mm y que las paredes tanto del colédoco como del duodeno sean normales. Específicamente recomendamos la CDS como la operación primaria para pacientes con el síndrome del embudo coledociano (estenosis distal con dilatación proximal). La operación es sencilla, restaura la función digestiva normal y en forma casi uniforme resuelve los problemas que producen los cálculos del colédoco en pacientes de alto riesgo.

Résumé La pathogénie complexe de la lithiase biliaire, les caractères anatomiques des voies biliaires ainsi que l'âge des malades, les affections associées et la grande variété des méthodes techniques expliquent la grande diversité des procédés de traitement de la lithiase choledocienne employés par les différentes équipes chirurgicales. Aucune technique n'étant infaillible ou exempte de complications, il paraît inconsidéré d'abandonner toute méthode qui a fait ses preuves. Il en est ainsi de la choledocoduodénostomie. Les complications attribuées à ce type d'intervention comme l'angiocholite ascendante, et le syndrome du moignon sous-anastomotique ont été exagérées conduisant de nombreux chirurgiens à l'écarter de leur pratique. Notre expérience de la choledocoduodénostomie est bonne et coincide avec celle de Madden et d'autres auteurs. Les données recueillies chez 125 malades qui présentaient des calculs de la V.B.P. et qui furent traités par la choledocoduodénostomile de 1968 à 1982 ont été étudiées. Soixante-huit étaient des femmes. La moyenne d'âge était de 61.4 ans, 73.6% étaient âgés de plus de 50 ans. Les affections associées étaient fréquentes en particulier les affections cardiovasculaires. Plus de la moitié de nos opérés avaient déjà subi une intervention sur la voie biliaire. Le diamètre de la voie biliaire a toujours été supérieur à 20 mm et la dilatation se trouvait souvent au dessus d'un rétrécissement du bas cholédoque. La technique de Floercken fut le plus souvent employée après le décollement du bloc duodénopancréatique. Il n'y eu aucun décès peropératoire. La mortalité postopératoire s'est élevée à 3.2% et a été étudiée avec précision. Le taux des complications postopératoires a atteint 42.4%, dont les infections et les désordres secondaires aux affections associées occupent la première place. Le taux de l'angiocholite postopératoire tardive s'est élevé à 1.6%, identique à celui rapporté par d'autres auteurs. Notre expérience nous permet de recommander la choledocoduodénostomie à condition (a) d'apporter une attention particulière aux indications après avoir pris en considération la possibilité de traiter la lithiase par une autre méthode, la sphinctérotomie endoscopique par exemple; et (b) de la réserver aux cas où le diamètre de la V.B.P. est supérieur à 20 et ou les parois de la voie biliaire et du duodénum sont normales. Nous considérons qu'elle est particulièrement indiquée en présence du syndrome du cholédoque en entonnoir. L'intervention est simple, restaure la fonction digestive normale et résoud le problème des calculs de la V.B.P. chez les malades de haut risque.
  相似文献   
97.
A kindling-like convulsive activity model produced by subthreshold, iterative electrical stimulation of the isolated male guinea pig ileum is described. In this model, the mechanical activity of the longitudinal muscular fibers of the ileum was systematically quantified in terms of the basic frequency, tonus, amplitude, and transient amplitude increments (A, n spikes/20 min) of "normal" contractions and presence of high-amplitude, paroxysmal, "epileptiform" contractures (B, n spikes/20 min). Changes in these parameters were statistically compared through consecutive stages of the same stimulated male ileum (I = initial activation, II = initial inhibition. IIIA = late activation, and IV = late inhibition) and equivalent stages of stimulated female and nonstimulated male ilea where "kindling-like" activities were only occasionally observed. Basic tonus, amplitude, and number of A spikes showed significant changes through consecutive stimulated male ileum "kindling" stages: increased from baseline to stage I, decreased from I to II, increased from II to III and from III to IIIA, and decreased from IIIA to IV. The number of B spikes significantly increased from II to III, III to IIIA, and IIIA to IV. No significant changes in baseline frequency were found through all stages nor in tonus, amplitude, A and B spikes between stage IV and the self-sustained activity observed 120 min after stimulation. In addition, there were significant correlations between B spikes vs. basic tonus and amplitude and A spikes when the stimulated male ileum shifted from stage II to IIIA (positive correlations) and from IIIA to IV (negative correlations). Basic tonus during stage I, basic amplitude during IIIA, A spikes during self-sustained activity and B spikes during III, IIIA, IV, and self-sustained activity were in the stimulated male ileum larger than those in both the stimulated female and the nonstimulated male ilea. Tonus and A spikes during III and IIIA in the stimulated male ileum were larger than in the nonstimulated, whereas tonus during IV and self-sustaining activity and amplitude during II in the stimulated male ileum were smaller than in the female stimulated ileum.  相似文献   
98.
Nutritional status during gestation can influence mother and offspring metabolism. Undernutrition in pregnancy affects women in both western and developing countries, and it is associated with a high prevalence of chronic diseases in later life. The present work was conducted in the rabbit model, as a longitudinal study, to examine the effect of food restriction during early and mid-gestation, and re-feeding ad libitum until the end of pregnancy on metabolic status and body reserves of mother and, its association with development and metabolism of fetuses and female offspring to the juvenile stage. Little changes in live body weight (LBW), compensatory feed intake, similar body reserves, and metabolism were observed in dams. Placenta biometry and efficiency were slightly affected, but fetal BW and phenotype were not modified. However, hyperinsulinemia, insulin resistance, and hypertriglyceridemia were demonstrated in pre-term fetuses. In the juvenile period, these changes were not evidenced, and a similar pattern of growth and serum metabolic parameters in offspring of food-restricted mothers were found, except in serum aminotransferases levels, which increased. These were associated with higher liver fibrosis. Maternal food restriction in the early and mid-pregnancy followed by re-feeding in our rabbit model established a compensatory energy status in dams and alleviated potential long-term consequences in growth and metabolism in the offspring, even if fetal metabolism was altered.  相似文献   
99.
The gut is a pivotal organ in health and disease. The events that take place in the gut during early life contribute to the programming, shaping and tuning of distant organs, having lifelong consequences. In this context, the maternal gut plays a quintessence in programming the mammary gland to face the nutritional, microbiological, immunological, and neuroendocrine requirements of the growing infant. Subsequently, human colostrum and milk provides the infant with an impressive array of nutrients and bioactive components, including microbes, immune cells, and stem cells. Therefore, the axis linking the maternal gut, the breast, and the infant gut seems crucial for a correct infant growth and development. The aim of this article is not to perform a systematic review of the human milk components but to provide an insight of their extremely complex interactions, which render human milk a unique functional food and explain why this biological fluid still truly remains as a scientific enigma.  相似文献   
100.
The prevalence of hypovitaminosis D has risen in developed countries over the past few years in association with lifestyle changes and an increase in unhealthy habits. Vitamin D deficiency has been implicated in various diseases, including metabolic syndrome (MetS), which is clinically defined by a set of metabolic and vascular disorders. The objective of this study was to review scientific evidence on the relationship between MetS and vitamin D deficiency to support the development of prevention strategies and health education programs. An inverse relationship has been reported between plasma vitamin D concentrations and the features that define MetS, i.e., elevated serum concentrations of glucose, total cholesterol, low-density lipoproteins, triglycerides, glycosylated hemoglobin, and a high body mass index. Numerous studies have described the benefits of vitamin D supplementation to improve outcomes in individuals with MetS. Interventions to maintain optimal vitamin D concentrations are proposed as a preventive strategy against MetS.  相似文献   
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