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961.
Neurons and glial cells in the fly's visual system exhibit circadian rhythms through changes in shape and size. Moreover, the number of synaptic contacts between these cells changes during the day and night and in the case of one type of synapses, feedback synapses, is maintained under constant conditions indicating an endogenous origin of this rhythm. The structural changes described above, involving the oscillations in the number of synapses and the size of interneurons and glial cells, are examples of plasticity in the central nervous system driven by internal inputs from a circadian clock and by external stimuli such as light. They are also modulated by visual and other sensory stimuli and by motor activity.  相似文献   
962.
Infectious hematopoietic necrosis virus (IHNV) is one of the most important pathogens of salmonid fish. In this study a comprehensive phylogenetic analysis of the genetic evolution and variety of Austrian IHNV strains, as well as selected strains ensuring worldwide coverage, is presented. The phylogenetic investigation is based on sequences comprising the “mid-G” region of the G gene, and it includes all currently available IHNV sequences of the G gene with a length of at least 615 bp. Austrian IHNVs are located—together with other European IHNV isolates—in two clusters of genogroup M (M-Eur1 and M-Eur2) and are clearly separated from American and Asian lineages. The genetic clustering, however, could not be linked to certain clinical symptoms or significant differences in the mortality rates.  相似文献   
963.
Prompted by reports challenging the validity of the low-positive Neisseria gonorrhoeae and Chlamydia trachomatis results generated by the APTIMA Combo 2 assay (Gen-Probe, Incorporated) and by a Centers for Disease Control and Prevention recommendation to confirm N. gonorrhoeae- or C. trachomatis-positive screens by using an alternative amplification target, we report on a comparison of this means of confirmation with an in-house algorithm of repeat testing. Primary clinical specimens yielding N. gonorrhoeae- or C. trachomatis-specific luminescent values between 100,000 and 1,000,000 were repeat tested in duplicate. A subset of specimens was forwarded for confirmatory assays (Gen-Probe) individualized for alternative N. gonorrhoeae or C. trachomatis targets. An 18-month audit revealed that 230 of 29,977 C. trachomatis screens (0.8%) and 41 of 29,064 N. gonorrhoeae assays (0.1%) yielded low-positive data. When a subset of 40 low-positive N. gonorrhoeae screens was repeat tested, 20 (50.0%) remained positive; 22 (55.0%) of the screens remained positive following performance of the confirmatory assay. In contrast, repeat testing of 153 low-positive C. trachomatis screens yielded a positive result for fewer specimens (n = 97; 63.4%) than when commercial confirmatory testing was used (n = 124; 81.0%). However, confirmation of the results for additional C. trachomatis screens by use of an alternative target did not translate into significant differences in the calculated overall C. trachomatis-positive screen rates (7.39% by repeat testing versus 7.52% by the confirmatory assay; P = 0.53). Furthermore, use of the confirmatory assay raised the positive predictive value only 1.8% over that of repeat testing. Molecular confirmatory testing did not significantly enhance the reliability of C. trachomatis- or N. gonorrhoeae-specific nucleic acid amplification testing in this metropolitan setting compared to the reliability of repeat testing.  相似文献   
964.
We report on a 17-year-old female with numerous developmental abnormalities associated with 46,XX,dup(9)(q33.3q34.1), where the duplication occurred de novo. The patient presented with dysmorphic features and notable psychomotor delays, manifestations similar to those described in other reported cases of duplication of 9q34-qter. Due to late presentation and diagnosis, our patient was not evaluated and characterized until adolescence, when particular attention was paid to the development of secondary sexual characteristics, secondary amenorrhea and obesity.  相似文献   
965.
Prenatal development is currently recognized as a critical period in the etiology of human diseases. This is particularly so when an unfavorable environment interacts with a genetic predisposition. The fetal programming concept suggests that maternal nutritional imbalance and metabolic disturbances may have a persistent and intergenerational effect on the health of offspring and on the risk of diseases such as obesity, diabetes, and cardiovascular diseases.  相似文献   
966.
PURPOSE OF REVIEW: This article reviews recent findings concerning occupational upper airway diseases, which, although very frequent, are usually not considered serious. However, the concept of the 'united airway', evoked during recent years, should change our attitude regarding these diseases. Moreover, new agents in the occupational environment must be characterized. Furthermore, exposure to carcinogens has changed over the years, and in most cases risk should be reassessed. RECENT FINDINGS: Recent findings concerning work-related upper airway diseases caused by allergens and irritants, and their relationship to lower airway diseases, are reviewed. Findings of studies aimed at characterizing occupational allergens of plant and animal origin are presented. Recognition of work-related upper airway diseases both in clinic and in epidemiological studies is discussed. Current evidence on occupational cancer of the upper airways, its risk factors and changes in them over the years resulting from preventative measures are also described. SUMMARY: There is significant evidence that occupational allergic diseases of the upper airways can pose important health problems because they represent an early stage of allergy throughout the respiratory system. However, how to detect those rhinitic patients who will develop asthma remains unresolved. New occupational health problems due to irritants were recently reported, and both follow-up studies and evaluations of their implications for the lower airways are warranted. Although preventative measures have been effective to some extent, risk for occupational cancer of the upper airways persists and more targeted epidemiological studies in this area are needed.  相似文献   
967.
In the study we evaluated the effects of infusion of exogenous leptin to the third ventricle of the brain on the expression of immunoreactive (ir) neuropeptide Y (NPY) neurons in the hypothalamus and ir gonadotrophin releasing hormone (GnRH) nerve terminals in the median eminence of prepubertal lambs in the conditions of short fasting. Merino female sheep (n=16) were randomly divided into four groups, two fed with standard feeds and two fasted for 72 h. One standard and one fasted groups were infused with Ringer saline (controls), remaining standard and fasted groups with leptin (25 microg/120 microl/h), for 4 h during three consecutive days, and then slaughtered. Ir NPY and ir GnRH were localized by immunohistochemistry using specific polyclonal antibodies. Detection of both hormones was followed by the image analysis and expressed as the percent area stained and integral density of immunostaining. In the hypothalami from all groups the ir NPY perikarya and varicose nerve fibers were localized in three distinct sub-areas, in the arcuate (ARC), paraventricular and periventricular nuclei. In fasted sheep the percent area and integral density for immunoreactivity of NPY increased significantly (P<0.001) in three sub-areas compared to the standard-fed animals. Leptin infusion lowered the both parameters (P<0.001) but solely in the ARC NPY population of fasted sheep. The percent area and integral density of immunostaining for ir GnRH in fasted sheep revealed the augmentation (P<0.001) compared to standard-fed sheep. Leptin infusions diminished (P<0.001) both parameters in fasted, without effects in standard-fed lambs. In conclusion, the enhanced by fasting immunoreactivity of the ARC NPY perikarya and varicose nerve fibers and restrained immunoreaction of GnRH terminals in the median eminence were reversed by exogenous leptin. It is suggested that leptin can affect GnRH release via ARC NPY neurons in conditions of deficit of nutrients in prepubertal, female lambs.  相似文献   
968.
Awareness of the age related situation as to the malocclusion prevalence in population and orthodontic treatment need is very important and useful for planning an orthodontic care, especially taking into account the interdisciplinary aspect of the problem. The aim of this study was to investigate the degree of severity of malocclusion and the need of orthodontic treatment in three different age groups of population in Latvia. The study group comprised samples of 12-13-yr-olds (n=46), 18-yr-olds (n=32) and 35-44-yr-olds (n=278). The Index of Complexity, Outcome and Need (ICON) was used for the assessment of the results. In order to provide the accuracy use of ICON, more than 4 missing teeth and prosthetic restorations were chosen as an exclusion factor for the age group 35-44 years. A statistically significant difference was determined between the mean ICON values in 12-13 and 18 year-old age groups. Professionally defined orthodontic treatment need according to ICON score >43 was determined to be higher in the age group 18 year-olds. Overall, the tendency for orthodontic treatment complexity grade was observed to increase with the age.  相似文献   
969.
Pemphigus is a severe autoimmune disease characterized by circulating and bound in vivo pemphigus autoantibodies. It was revealed that the autoantibodies occur in healthy first-degree relatives of pemphigus patients; however, their significance is not fully elucidated. Thus, the aim of the study was to assess the frequency of circulating IgG pemphigus autoantibodies in the healthy relatives of pemphigus patients and of their ability to bind in vivo in the epidermis. We also analyzed IgG subclasses distribution, both in the serum-positive relatives and in the patients. Our study included 67 healthy relatives, 50 healthy normal controls and 33 patients (25 at an active stage of the disease, 8 in clinical remission). To detect circulating pemphigus antibodies we applied indirect immunofluorescence and anti-desmoglein ELISA. Monoclonal anti-human IgG1, IgG2, IgG3, IgG4 antibodies were used to assess subclass distribution. The frequency of circulating pemphigus autoantibodies in the relatives, detected by IIF (30/67) was statistically higher (P < 0.001) than in the control group (0/50). ELISA revealed anti-desmoglein 1 and/or 3 antibodies in 13 out of 67 relatives. Direct immunofluorescence performed in 25 out of 32 seropositive relatives did not show intercellular bound in vivo IgG and/or C3 in the epidermis in any cases. Circulating IgG2 subclass was observed in 60% of the examined relatives and IgG4 was detected in 23.3% of them. In the patients at an active stage of pemphigus IgG4 and IgG1 were the dominant subclasses (96 and 76% relatively) while in clinical remission antibodies predominantly belonged to the IgG2 (75%) and IgG4 (37.5%) subclass. The obtained results confirmed polyclonal production of pemphigus autoantibodies and their different distributions dependent on the disease activity. Statistical analysis showed that the frequency of IgG1 and IgG4 subclasses was significantly higher in the patients at an active stage of the disease when compared to the patients in clinical remission (P < 0.001) or with seropositive healthy relatives (P < 0.001). The relevance of the presence of IgG4 autoantibodies in the healthy relatives' sera requires further studies that focus on their potential pathogenicity.  相似文献   
970.
Significant changes in the frequency of candidaemia and the distribution of causative species have been noted worldwide in the last two decades. In this study, we present the results of the first multicentre survey of fungaemia in Polish hospitals. A total of 302 candidaemia episodes in 294 patients were identified in 20 hospitals during a 2‐year period. The highest number of infections was found in intensive care (30.8%) and surgical (29.5%) units, followed by haematological (15.9%), ‘others’ (19.2%) and neonatological (4.6%) units. Candida albicans was isolated from 50.96% of episodes; its prevalence was higher in intensive care unit and neonatology (61.22% and 73.33%, respectively), and significantly lower in haematology (22%; P < 0.001). The frequency of C. krusei and C. tropicalis was significantly higher (24% and 18%) in haematology (P < 0.02); whereas, the distribution of C. glabrata (14.1%) and C. parapsilosis (13.1%) did not possess statistically significant differences between compared departments. Obtained data indicates that species distribution of Candida blood isolates in Polish hospitals reflects worldwide trends, particularly a decrease in the prevalence of infections due to C. albicans.  相似文献   
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