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71.
PURPOSE: To quantify the changes in brain water diffusivity in hepatic encephalopathy (HE) associated with cirrhosis using diffusion tensor imaging (DTI) and to correlate with neuropsychological (NP) scores. MATERIALS AND METHODS: DTI was performed in 14 patients with low-grade HE and age/gender-comparable 16 healthy controls. Whole brain mean diffusivity (MD) and fractional anisotropy (FA) maps were calculated, normalized to common space, smoothed, and compared voxel-by-voxel between groups using analysis of covariance with age included as a covariate. The average MD and FA values were also calculated from individual subjects for selected brain regions and correlated with the neuropsychological scores. RESULTS: Patients with HE showed increased MD in the cortical gray and white matter and the internal capsule. Less extensive brain regions with decreased FA were observed in the bilateral frontal and occipital white matter. MD values from the corpus callosum correlated inversely with several NP scores among HE patients and controls. Positive correlations were observed with FA values and cognitive scores. CONCLUSION: Voxel-based DTI analysis showed widespread brain regions with increased MD values, indicating enhanced water content and decreased FA in cirrhotic patients with HE. The MD and FA values from selected regions correlated with the NP scores.  相似文献   
72.
Anaplastic thyroid cancer is a rare but nearly universally fatal tumor. Epidemiologic data suggest that many anaplastic thyroid carcinomas arise from transformation of preexisting or coexisting well-differentiated thyroid carcinomas. At the molecular level, the mutations responsible for the anaplastic transformation are incompletely understood, although the mutational events are thought to involve tumor suppressor genes. To examine transformation from a well-differentiated thyroid carcinoma to anaplastic carcinoma, we studied coexisting well-differentiated (Hürthle cell and papillary carcinoma) and anaplastic tumors with a molecular genotyping panel of tumor suppressor genes associated with thyroid neoplasia. The patterns of allelic loss in our results showed that the majority of cases have a core of conserved mutations in the two morphologically distinct areas and substantial increases in mutation rates in the anaplastic components.  相似文献   
73.
Bone development and age-related bone loss in male C57BL/6J mice   总被引:3,自引:0,他引:3  
Ferguson VL  Ayers RA  Bateman TA  Simske SJ 《BONE》2003,33(3):387-398
The objective of this study was to examine changes in the long bones of male C57BL/6J mice with growth and aging, and to consider the applicability of this animal for use in studying Type II osteoporosis. Male C57BL/6J mice were aged in our colony between 4 and 104 weeks (n=9-15/group). The right femur and humeri were measured for length and subjected to mechanical testing (3-point flexure) and compositional analysis. The left femurs were embedded and thick slices at the mid-diaphysis were assessed for morphology, formation indices, and bone structure. In young mice, rapid growth was marked by substantial increases in bone size, mineral mass, and mechanical properties. Maturity occurred between 12 and 42 weeks of age with the maintenance of bone mass and mechanical properties. From peak levels, mice aged for 104 weeks experienced decreased whole femur mass (12.1 and 18.6% for dry and ash mass, respectively), percentage mineralization (7.4%), diminished whole bone stiffness (29.2%), energy to fracture (51.8%), and decreased cortical thickness (20.1%). Indices of surface-based formation decreased rapidly from the onset of the study. However, the periosteal perimeter and, consequently, the cross-sectional moments of inertia continued to increase through 104 weeks, thus maintaining structural properties. This compensated for cortical thinning and increased brittleness due to decreased mineralization and stiffness. The shape of the mid-diaphysis became increasingly less elliptical in aged mice, and endocortical resorption and evidence of subsequent formation were present in 20-50% of femurs aged > or =78 weeks. This, combined with the appearance of excessive endocortical resorption after 52 weeks, indicated a shift in normal mechanisms regulating bone shape and location, and was suggestive of remodeling. The pattern of bone loss at the femoral mid-diaphysis in this study is markedly similar to that seen in cortical bone in the human femoral neck in Type II osteoporosis. This study has thus demonstrated that the male C57BL/6J mouse is a novel and appropriate model for use in studying endogenous, aging-related osteopenia and may be a useful model for the study of Type II osteoporosis.  相似文献   
74.
Lingual mucosal graft urethroplasty for anterior urethral reconstruction   总被引:1,自引:0,他引:1  
OBJECTIVE: Evaluate the use of lingual mucosal graft (LMG) in anterior urethral strictures. METHODS: From January 2001 to December 2006, 29 men (mean age, 48.5 yr) with anterior urethral strictures underwent graft urethroplasty with LMG. The mean length of stricture was 3.6cm. Patients with bulbar, penile, or bulbopenile strictures received one-stage dorsal free graft urethroplasties. In patients with failed hypospadias repair we performed a two-stage urethroplasty. Criteria for successful reconstruction were spontaneous voiding with no postvoid residual urine and no postoperative instrumentation of any kind. Clinical assessment included the donor site morbidity. RESULTS: Mean follow-up was 17.7 mo. One-stage bulbar and penile urethroplasties without meatal involvement had an 81.8-100% success rate. Bulbopenile urethroplasties were successful in 60% of the cases, whereas one-stage urethral reconstructions in patients with meatal involvement were successful in 66.6%. The two cases of two-stage urethral reconstruction with LMG and buccal mucosal graft after failed multiple hypospadias repairs were unsuccessful. The overall early recurrence rate was 20.7%. Patients with the graft harvested from the tongue reported only slight oral discomfort at the donor site and difficulty in talking for 1 or 2 d. CONCLUSIONS: The mucosa of the tongue, which is identical to the mucosa of the rest of the oral cavity, is a safe and effective graft material in the armamentarium for urethral reconstruction with potential minor risks of donor site complications. LMG may be used alone for short strictures (<5cm) or in combination with buccal mucosa when longer grafts are needed.  相似文献   
75.
To determine whether the mouse loses bone with aging and whether the changes mimic those observed in human aging, we examined the changes in the tibial metaphysis and diaphysis in the male C57BL/6J mouse over its life span using microcomputed tomography (microCT). Cancellous bone volume fraction (BV/TV) decreased 60% between 6 weeks and 24 months of age. Loss was characterized by decreased trabecular number (Tb.N), increased trabecular spacing (Tb.Sp), and decreased connectivity. Anisotropy decreased while the structure model index increased with age. Cortical bone thickness increased between 6 weeks and 6 months of age and then decreased continuously to 24 months (-12%). Cortical bone area (Ct.Ar) remained constant between 6 and 24 months. Fat-free weight reached a peak at 12 months and gradually declined to 24 months. Total mass lost between 12 and 24 months reached 10%. Overall, the age-related changes in skeletal mass and architecture in the mouse were remarkably similar to those seen in human aging. Furthermore, the rapid early loss of cancellous bone suggests that bone loss is not just associated with old age in the mouse but rather occurs as a continuum from early growth. We conclude that the C57BL/6J male mouse maybe a useful model to study at least some aspects of age-related bone loss in humans.  相似文献   
76.
We report a successful replantation of a proximal-third avulsed left arm in a 26-year-old female with maintenance of good functional, clinical, Short Form 36, and the Disabilities of the Arm, Shoulder, and Hand outcomes results at 10 years. An organized approach combining staged surgical reconstruction and intense hand therapy allowed for both successful replantation and outcome. There exist no clear guidelines in making the decision between replantation and revision amputation. Controversy regarding the value of upper limb replantation seems to increase with ascending levels of amputation. A case report cannot provide guidelines, but several points can be made that may be of help to hand surgeons confronting this uncommon situation. In a highly motivated patient with realistic expectation, a preoperatively intact functioning shoulder should be considered an indication for attempt at replantation. With further staged reconstruction, a helper arm can still be achieved even in an avulsion-type amputation. Current operative and perioperative aspects of microsurgical replantation and subsequent reconstruction are discussed.  相似文献   
77.
INTRODUCTION: Bone replacement is often necessary during reconstruction of craniofacial anomalies or trauma. Adipose-derived stem cells (ASCs) possess osteogenic potential and are a promising cell source for bone tissue engineering. The present study was designed to assess the osteogenic potential and utility of using ASCs to regenerate bone in a rabbit calvarial defect model. METHODS: Rabbit ASCs were seeded on gelatin foam (GF) scaffolds and induced in osteogenic medium containing bone morphogenetic protein (BMP)-2. Thirty-four 8-mm calvarial defects were randomly treated with autograft, no treatment, GF scaffold, GF + ASCs, or GF + osteoinduced ASCs. After 6 weeks, calvaria were harvested and underwent histologic and radiologic analyses to compare healing between the treatment groups. RESULTS: Defects treated with autograft underwent complete healing. Radiologically, there were no significant (P > 0.05) differences in healing among empty defects, and those treated with GF alone or GF plus osteoinduced ASCs. Osteoinduced ASCs exhibited significantly (P < 0.05) greater healing than noninduced ASCs. CONCLUSION: Preimplantation osteoinduction of ASCs enhances their osteogenic capacity. Lack of a significant osteogenic effect of ASCs on calvarial healing at 6 weeks may be secondary to use of noncritical-sized defects. Larger defects would likely demonstrate the osteogenic potential of ASCs more definitively.  相似文献   
78.
79.
Surgical risk factors, morbidity, and mortality in elderly patients   总被引:2,自引:0,他引:2  
BACKGROUND: The aging population of the United States results in increasing numbers of surgical operations on elderly patients. This study observed aging related to morbidity, mortality, and their risk factors in patients undergoing major operations. STUDY DESIGN: We reviewed our institution's American College of Surgeons National Surgical Quality Improvement Program database from February 24, 2002, through June 30, 2005, including standardized preoperative, intraoperative, and 30-day postoperative data points. This required review and analysis of the prospectively collected data. We examined patient demographics, preoperative risk factors, intraoperative risk factors, and 30-day outcomes with a focus on those aged 80 years and older. RESULTS: A total of 7,696 surgical procedures incurred a 28% morbidity rate and 2.3% mortality rate, although those older than 80 years of age had a morbidity of 51% and mortality of 7%. Hypertension and dyspnea were the most frequent risk factors in those aged 80 years and older. Preoperative transfusion, emergency operation, and weight loss best predicted morbidity for those 80 years of age and older. Operative duration predicted "other" postoperative occurrences and emergent case status predicted respiratory occurrences across all age groups. Preoperative impairment of activities of daily living, emergency operation, and increased American Society of Anesthesiology classification predicted mortality across all age groups. A 30-minute increment of operative duration increased the odds of mortality by 17% in patients older than 80 years. Postoperative morbidity and mortality increased progressively with increasing age. Age was statistically significantly associated with morbidity (wound, p = 0.021; renal, p = 0.001; cardiovascular, p = 0.0004; respiratory, p < 0.0001) and mortality (p = 0.001). CONCLUSIONS: Although several risk factors for postoperative morbidity and mortality increase with age, increasing age itself remains an important risk factor for postoperative morbidity and mortality.  相似文献   
80.
Pregnancy presents many problems without working through additional problems in coping with an ostomy. Yet many women with an ostomy do get pregnant and do deliver healthy babies. Evidence-based nursing is of the utmost importance, as there is little published information on this topic. Because of the scarcity of pregnant subjects within the ostomy category, most studies, by necessity, select a purposive subject base. Therefore, other information sources regarding nursing management of the pregnant woman with an ostomy take on considerably more importance. This article explores other forms of evidence that can be used in managing the care of pregnant ostomy patients and specifically how nurses can integrate various sources of information in designing an evidence-based nursing care plan. Nonpharmacologic forms of relaxation therapy, easily used by nurses, such as mindfulness-based stress reduction, guided imagery, and hypnosis, are also identified as some ways nurses can relieve anxiety and experiential stress associated with pregnancy in women who have an ostomy.  相似文献   
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