首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   550篇
  免费   35篇
  国内免费   3篇
耳鼻咽喉   3篇
儿科学   12篇
妇产科学   4篇
基础医学   106篇
口腔科学   7篇
临床医学   30篇
内科学   151篇
皮肤病学   7篇
神经病学   22篇
特种医学   4篇
外科学   42篇
综合类   17篇
一般理论   1篇
预防医学   29篇
眼科学   42篇
药学   32篇
中国医学   3篇
肿瘤学   76篇
  2023年   5篇
  2022年   13篇
  2021年   30篇
  2020年   15篇
  2019年   16篇
  2018年   22篇
  2017年   12篇
  2016年   13篇
  2015年   24篇
  2014年   27篇
  2013年   26篇
  2012年   46篇
  2011年   41篇
  2010年   17篇
  2009年   14篇
  2008年   24篇
  2007年   21篇
  2006年   23篇
  2005年   20篇
  2004年   19篇
  2003年   23篇
  2002年   12篇
  2001年   6篇
  2000年   11篇
  1999年   6篇
  1998年   3篇
  1996年   5篇
  1995年   3篇
  1994年   3篇
  1993年   3篇
  1992年   16篇
  1991年   12篇
  1990年   11篇
  1989年   7篇
  1988年   4篇
  1987年   8篇
  1986年   2篇
  1985年   5篇
  1984年   3篇
  1983年   2篇
  1982年   3篇
  1981年   1篇
  1976年   1篇
  1975年   1篇
  1974年   1篇
  1973年   2篇
  1972年   1篇
  1971年   1篇
  1967年   1篇
  1944年   1篇
排序方式: 共有588条查询结果,搜索用时 31 毫秒
81.
Juvenile hyaline fibromatosis (JHF) is a rare, autosomal recessively inherited disorder characterized histologically by deposition of hyaline, collagen like substance aberrantly synthesized by the cells of the connective tissue and deposited within many organs, typically within the skin, gingiva, joints and bones. We report this rare case of Juvenile hyaline fibromatosis in a young boy who presented clinically with multiple papulonodular skin lesions, non tender soft tissue masses over the scalp, face, anterior chest wall, back, periarticular regions of the extremities with restricted mobility of joints and gingival hypertrophy. Calcifications were seen within the tumor shadows in the skull X-Rays. Histopathological study revealed characteristic features consistent with Juvenile hyaline fibromatosis. We report this case in view of its rarity.  相似文献   
82.
In 2000, Teebi reported on a 4-year-old boy with a distinctive pattern of malformation, which he termed the "Nablus mask-like facial syndrome" (OMIM# 608156). Characterization of this syndrome has been difficult because of the paucity of patients described in the medical literature and its unknown etiology and pathogenesis. We present two patients with Nablus mask-like facial syndrome who both display a microdeletion in the 8q21-8q22 region detected by array-based comparative genomic hybridization. Patient 1, a boy, has a distinct facial appearance characterized by severe blepharophimosis, tight-appearing glistening facial skin, sparse and unruly hair, a flat and broad nose, and distinctive ears that are triangular in shape with prominent antihelices. He also demonstrates camptodactyly, contractures, unusual dentition, cryptorchidism, mild developmental delay, and a happy demeanor. Patient 2, a girl with a strikingly similar phenotype, was previously described in a report by Salpietro et al. 2003. She has distinctive ears, dental anomalies, and developmental delay. The etiology of her pattern of malformation was not identified at that time. Although high-resolution chromosome and subtelomeric FISH analyses were normal, array-based comparative genomic hybridization revealed an approximately 4 Mb deletion involving the 8q21.3-8q22.1 region in both patients. This region encompasses a number of genes that may contribute to this unique phenotype. These results demonstrate a chromosomal microdeletion as the etiology of Nablus mask-like facial syndrome and emphasize the diagnostic utility of array-based comparative genomic hybridization in the evaluation of multiple malformation syndromes of previously unrecognized causation.  相似文献   
83.
Head injuries account for significant proportion of neurosurgical admissions and bed occupancy. Patients with head injuries also consume significant proportions of neurosurgical resources. A prospective 6-month study has been carried out to evaluate the expenditure incurred on head injury patients in a modern neurosurgical center equipped with state of the art infrastructure. Costing areas included wages / salaries of health care personnel, cost of medicines / surgical items / crystalloids, general store items, stationary, all investigation charges, equipment cost, overhead building cost, maintenance cost, electricity and water charges and cost of medical gases, air conditioning and operation theatre expenses. Expenditure in each area was calculated and apportioned to each bed. The statistical analysis was done using X2 test. The cost of stay in ward was found to be Rs. 1062 / bed / day and in neurosurgical ICU Rs. 3082 / bed / day. The operation theatre cost for each surgery was Rs. 11948. The cost of hospital stay per day for minor, moderate and severe head injury group was found to be Rs. 1921, Rs. 2569 and Rs. 2713 respectively. The patients who developed complications, the cost of stay per day in the hospital were Rs. 2867. In the operative group, the cost of hospital stay per day was Rs. 3804. The total expenditure in minor head injury was Rs. 7800 per patient, in moderate head injury was Rs. 22172 per patient, whereas in severe head injury, it was found to be Rs. 32852 per patient. Patients who underwent surgery, the total cost incurred was Rs. 33100 per operated patient.  相似文献   
84.
Epilepsy is an important health problem due to its high prevalence and potential for causing long-term morbidity. It is commonly treated in children with phenytoin sodium. It has wide pharmacokinetic variability and a narrow therapeutic range that leads to toxicity. Here, we report a case of phenytoin-induced cerebellar atrophy in a 16-year-old epileptic boy who presented to the hospital with a viral infection.KEY WORDS: Adverse drug reaction, antiepileptic drugs, antiseizure drugs, cerebellar atrophy, phenytoin  相似文献   
85.
86.
Parosteal osteosarcoma is a well-differentiated, predominantly fibro-osseous variant of osteosarcoma, accounting for 5% of all osteosarcomas. We report a case of parosteal osteosarcoma in the metaphyseal area of right femur, of 2 years' duration in a male aged 35 years. It was mistaken for osteochondroma in the initial biopsy, and the possibility of bizarre parosteal osteochondromatous proliferation (BPOP) was also considered. Subsequent excision of the tumor showed it to be a parosteal osteosarcoma. The patient had recurrence of the lesion after 1 year, and he attended a cancer institute. Follow-up showed metastases of the tumor on bone scan.  相似文献   
87.
In a systematic sequencing screen of synaptic genes on the X chromosome, we have identified an autistic female without mental retardation (MR) who carries a de novo frameshift Ile367SerfsX6 mutation in Interleukin-1 Receptor Accessory Protein-Like 1 (IL1RAPL1), a gene implicated in calcium-regulated vesicle release and dendrite differentiation. We showed that the function of the resulting truncated IL1RAPL1 protein is severely altered in hippocampal neurons, by measuring its effect on neurite outgrowth activity. We also sequenced the coding region of the close related member IL1RAPL2 and of NCS-1/FREQ, which physically interacts with IL1RAPL1, in a cohort of subjects with autism. The screening failed to identify non-synonymous variant in IL1RAPL2, whereas a rare missense (R102Q) in NCS-1/FREQ was identified in one autistic patient. Furthermore, we identified by comparative genomic hybridization a large intragenic deletion of exons 3-7 of IL1RAPL1 in three brothers with autism and/or MR. This deletion causes a frameshift and the introduction of a premature stop codon, Ala28GlufsX15, at the very beginning of the protein. All together, our results indicate that mutations in IL1RAPL1 cause a spectrum of neurological impairments ranging from MR to high functioning autism.  相似文献   
88.
We report on two patients with developmental delay, hypotonia, and autistic features associated with duplications of chromosome region 2q23.1-2q23.2 detected by chromosome microarray analysis. The duplications include one OMIM Morbid Map gene, MBD5, as well as seven known RefSeq genes (ACVR2A, ORC4L, EPC2, KIF5C, MIR1978, LYPD6B, and LYPD6). MBD5 lies in the minimum area of overlap of the 2q23.1 microdeletion syndrome. This report provides the first detailed clinical examination of two individuals with a duplication of this region and suggests that brain development and cognitive function may be affected by an increased dosage of the genes involved.  相似文献   
89.
Variation in the apolipoprotein E gene (APOE) has been reported to be associated with longevity in humans. The authors assessed the allelic distribution of APOE isoforms ε2, ε3, and ε4 among 10,623 participants from 15 case-control and cohort studies of age-related macular degeneration (AMD) in populations of European ancestry (study dates ranged from 1990 to 2009). The authors included only the 10,623 control subjects from these studies who were classified as having no evidence of AMD, since variation within the APOE gene has previously been associated with AMD. In an analysis stratified by study center, gender, and smoking status, there was a decreasing frequency of the APOE ε4 isoform with increasing age (χ(2) for trend = 14.9 (1 df); P = 0.0001), with a concomitant increase in the ε3 isoform (χ(2) for trend = 11.3 (1 df); P = 0.001). The association with age was strongest in ε4 homozygotes; the frequency of ε4 homozygosity decreased from 2.7% for participants aged 60 years or less to 0.8% for those over age 85 years, while the proportion of participants with the ε3/ε4 genotype decreased from 26.8% to 17.5% across the same age range. Gender had no significant effect on the isoform frequencies. This study provides strong support for an association of the APOE gene with human longevity.  相似文献   
90.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号