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81.
82.
Four behavioural states are recognised in the human fetus and are comparable to those of the neonate: 1F (quiet sleep), 2F (active state), 3F (quiet awake), and 4F (active awake). State 5, or crying, is not considered to have a fetal correlate. In a study assessing the effects of exposure to tobacco and cocaine during pregnancy on fetal response and habituation to vibroacoustic stimulation, what appears to be the fetal homologue of crying was observed. These behaviours were seen on ultrasound, and have been captured on video recordings and include: an initial exhalation movement associated with mouth opening and tongue depression, followed by a series of three augmented breaths, the last breath ending in an inspiratory pause followed by an expiration and settling. This is the first report/video documenting these behaviours and suggests the possibility of a state 5F.  相似文献   
83.
Using immunohistochemistry in light microscopy, the myelin basic protein and proteolipid protein were localized on sections of the spinal cord enlargements of opossums, Monodelphis domestica, to determine the timecourse of myelinogenesis therein and compare it with other events of motor systems development. Additional tissue not processed for immunohistochemistry was prepared for transmission electron microscopy. No immunolabeling for either protein occurred on spinal sections from the newborn opossum, but in electron microscopy occasional fibers surrounded by loose, irregular membranous rings were seen on the outskirts of the ventral horn. Immunolabeling was detected first in the brachial enlargement during the second week, presumably on motoneuronal, vestibular and reticular axons. The areas of the dorsal columns, other spino-encephalic, reticulospinal and propriospinal projections became labeled in the third week, and the area of rubrospinal axons at 4 weeks. In the brachial gray matter, immunolabeling appeared along ventrodorsal and lateromedial gradients from the fourth to seventh weeks. Labeling developed similarly in the white and gray matter of the lumbosacral enlargement, but 3-5 days later than at brachial levels. Labeling intensity in the white and gray matter increased until at least 4 months, but remained light in laminae I-III. Thus, myelinogenesis in the spinal cord enlargements of the opossum is protracted and follows general rostrocaudal, ventrodorsal and lateromedial sequences. It occurs later than synaptogenesis at comparable levels of the cord, but earlier than myelinogenesis in the corresponding ventral and dorsal roots. Spinal myelinogenesis correlates with the development of sensorimotor reflexes, weight support and quadrupedal locomotion.  相似文献   
84.
BACKGROUND: Through the 1990s, governments across Canada shifted health care funding allocation and organizational foci toward a community-based population health model. Major concerns of reform based on this model include ensuring equitable access to health and health care, and enhancing preventive and community-based resources for care. Reforms may act differentially relative to specific conditions and services, including those geared to chronic versus acute conditions. The present study therefore focuses on health service utilization, specifically cancer hospitalizations, in British Columbia during a decade of health system reform. METHODS: Data were drawn from the British Columbia Linked Health Data resource; income measures were derived from Statistics Canada 1996 Census public use enumeration area income files. Records with a discharge (separation) date between 1 January 1991 and 31 December 1998 were selected. All hospitalizations with ICD-9 codes 140 through 208 (except skin cancer, code 173) as principal diagnosis were included. Specific cancers analyzed include lung; colorectal; female breast; and prostate. Hospitalizations were examined in total (all separations), and as divided into first and all other hospitalizations attributed to any given individual. Annual trends in age-sex adjusted rates were analyzed by joinpoint regression; longitudinal multivariate analyses assessing association of residence and income with hospitalizations utilized generalised estimating equations. Results are evaluated in relation to cancer incidence trends, health policy reform and access to care. RESULTS: Age-sex adjusted hospitalization rates for all separations for all cancers, and lung, breast and prostate cancers, decreased significantly over the study period; colorectal cancer separations did not change significantly. Rates for first and other hospitalizations remained stationary or gradually declined over the study period. Area of residence and income were not significantly associated with first hospitalizations; effects were less consistent for all and other hospitalizations. No interactions were observed for any category of separations. CONCLUSIONS: No discontinuities were observed with respect to total hospitalizations that could be associated temporally with health policy reform; observed changes were primarily gradual. These results do not indicate whether equity was present prior to health care reform. However, findings concur with previous reports indicating no change in access to health care across income or residence consequent on health care reform.  相似文献   
85.
The authors investigated the effect of residues from copper- and gold-mining on the Cree population of Oujé-Bougoumou, located 560 km north of Quebec City, Canada. Subjects (225) from Oujé-Bougoumou and a control population (100) completed a questionnaire on lifestyle and dietary habits and provided blood and urine samples for analysis. Geometric means of arsenic, lead, cadmium, and copper concentrations were not significantly different for subjects or controls 15 yr and older or children (8-14 yr old). However, blood zinc was higher and selenium was lower in Oujé-Bougoumou samples. Mean blood lead level was higher in children from Oujé-Bougoumou, but lower in adults aged 40 yr and older. For adults (15 yr and older) blood lead level increased with age and was higher in men, those who hunted, and consumed wild meat (R2 = 0.43). Blood cadmium increased with age and smoking (R2 = 0.61). No influence of mine residues was observed among residents of Oujé-Bougoumou, but lifestyle exposure associations were noted for both communities.  相似文献   
86.
BACKGROUND: About 35% of elders living at home fall each year. The objectives of this study were to evaluate the environmental hazards associated with falls in 58 low income housings for elders and to determine the contribution of environmental factors to these falls. METHODS: Participants were interviewed to document their health problems, their knowledge concerning the Issue of falls, and their history of falls during the last year. Environmental hazards were identified and evaluated with a standardised checklist. The levels of hazards (percentage of factors identified which represent a hazard) were measured for the different sectors and for the entire dwelling and communal spaces. The hazards were also evaluated according to four main variables (structure of the building, characteristics of the floor surface, environmental obstacles, risk-taking behaviour). RESULTS: A total of 172 participants were recruited for the study. For dwellings and communal spaces, the hazards were respectively higher in bathrooms (mean=27.0%; p<0.05) and interior stairs (mean=22.5%; p<0.05). For the communal spaces of buildings of less than 20 Years, the global hazard was higher in the smaller buildings (three stories, mean=12.6%; p<0.001). For dwellings of the larger buildings, the global hazard was higher for younger buildings (<20 years, mean=16.6%; >or=20 years, mean=13.5%; p<0.001). Among the variables documented, risk-taking behaviour was the more frequent factor for the dwellings (mean=32.0%; p<0.05) as for the communal spaces (mean=42.5%; p<0.05). Finally, only 34% of the participants mentioned receiving information concerning the falls among elders. Among the 27 falls documented, an environmental factor was identified in 55% of the cases. CONCLUSION: The study helped to document the presence of environmental factors which could be a hazard for falls in elders' housing and to suggest preventive and remedial actions.  相似文献   
87.
The AAP has alerted pediatricians to the importance of safe sleep environment for infants. The elements of a safe sleep environment include supine sleep position, safe crib, and avoidance of smoke exposure, soft bedding, and overheating. With the Back to Sleep campaign, prone sleeping among all U.S. infants has decreased to less than 20%, and the incidence of SIDS has decreased 40%. However, the decline in SIDS and prone sleeping has leveled off in recent years. Further declines may be possible with decreasing other modifiable risk factors, such as prenatal and postnatal exposure to cigarette smoking. Prior studies have demonstrated that health care professional advice is influential in determining infant care practices. It is important that physicians caring for infants be aware of the importance of a safe sleep environment and understand other modifiable risk factors for SIDS. We surveyed a random sample of 3,717 physicians in North Carolina and the metropolitan Washington, DC, area to determine knowledge, beliefs, and practices regarding SIDS and SIDS risk reduction among physicians caring for pregnant women and infants. Twenty-three percent (835) responded. Most physicians are aware of prone sleeping and cigarette smoke exposure as risk factors for SIDS. Almost all physicians agree that there are measures that can be taken to reduce the risk of SIDS, and they consider it important to discuss SIDS and SIDS risk reduction strategies with parents of young infants. In spite of this belief, only 56% of family/general practitioners, 18% of obstetrician-gynecologists, and 79% of pediatricians discuss SIDS routinely. Only 35% of pediatricians, 15% of family/general practitioners, and 16% of obstetrician-gynecologists provide written information. In addition, only 38% of physicians recommend supine, while 50% recommend side or back, 6% side, and 7% prone. Only two thirds of pediatricians and one third of family/general practitioners are aware that the AAP recommends supine as the preferred sleep position for infants. Pediatricians are more likely to be aware of the AAP recommendation (p<0.0001) and to discuss SIDS risk reduction strategies with parents (p=0.03). We conclude that many physicians who care for infants are unaware of the AAP's most current recommendation for sleep position and are incorrectly recommending the side position. Physicians may also be unaware of other sleep environment hazards. Further educational efforts must continue for physicians who provide care to pregnant women and children to ensure a continued decline in the incidence of SIDS.  相似文献   
88.
Deficiency of early components of the classical pathway of complement, particularly C1q, predisposes to the development of systemic lupus erythematosus. Several studies have suggested an association between the classical complement pathway and the clearance of apoptotic cells. Mice with a targeted deletion of the C1q gene develop a lupus-like renal disease, which is associated with the presence of multiple apoptotic bodies in the kidney. In the present study we demonstrate that highly purified C1q binds to apoptotic cells and isolated blebs derived from these apoptotic cells. Binding of C1q to apoptotic cells occurs via the globular heads of C1q and induces activation of the classical complement pathway, as shown by the deposition of C4 and C3 on the surface of these cells and on cell-derived blebs. In addition, for the first time, we demonstrate that surface-bound C1q is present on a subpopulation of microparticles isolated from human plasma. Taken together, these observations demonstrate that C1q binds directly to apoptotic cells and blebs derived therefrom and support a role for C1q, possibly in concert with C4 and C3, in the clearance of apoptotic cells and blebs by the phagocytic system.  相似文献   
89.
A comparison was made of the speed of visual recovery in the deprived eye of kittens after a 6-day period of monocular deprivation imposed at 5-9 weeks of age in two postdeprivation conditions. In one condition, binocular recovery (BR), both eyes were open, whereas in the other condition, reverse lid-suture (RLS), the formerly nondeprived eye was closed to force the animal to use the originally deprived eye. In littermate pairs, BR kittens began to recover form vision 12 to 30 h before those subjected to RLS. The vision of the deprived eye of the BR animals remained superior to that of their RLS littermates for 4-8 days. Although this finding is difficult to reconcile with competitive mechanisms of synaptic plasticity, it supports a prediction of an alternative model of synaptic plasticity [Bienenstock, E. L., Cooper, L. N. & Munro, P. W. (1982) J. Neurosci. 2, 32-48] for slower initial recovery with RLS because of the time required to reset the modification threshold.  相似文献   
90.
3.男性:高催乳素血症通常导致阳痿、不孕和性功能低下.男性患者通常为大腺瘤,有神经系统症状.其原因可能是对症状认识的延误或者肿瘤生物学行为的差异.  相似文献   
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