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   539篇
  免费   21篇
耳鼻咽喉   10篇
儿科学   6篇
基础医学   39篇
口腔科学   2篇
临床医学   18篇
内科学   125篇
皮肤病学   1篇
神经病学   57篇
特种医学   43篇
外科学   173篇
综合类   1篇
预防医学   8篇
眼科学   1篇
药学   13篇
肿瘤学   63篇
  2022年   4篇
  2020年   3篇
  2019年   4篇
  2018年   7篇
  2017年   3篇
  2015年   7篇
  2013年   5篇
  2012年   9篇
  2011年   10篇
  2010年   9篇
  2009年   6篇
  2008年   14篇
  2007年   24篇
  2006年   19篇
  2005年   11篇
  2004年   9篇
  2003年   16篇
  2002年   12篇
  2001年   16篇
  2000年   16篇
  1999年   14篇
  1998年   10篇
  1997年   10篇
  1996年   12篇
  1995年   12篇
  1994年   15篇
  1993年   5篇
  1992年   39篇
  1991年   29篇
  1990年   18篇
  1989年   17篇
  1988年   16篇
  1987年   20篇
  1986年   9篇
  1985年   22篇
  1984年   14篇
  1983年   11篇
  1982年   5篇
  1981年   3篇
  1980年   4篇
  1979年   15篇
  1977年   5篇
  1976年   5篇
  1974年   3篇
  1972年   5篇
  1970年   5篇
  1969年   4篇
  1968年   7篇
  1966年   7篇
  1965年   2篇
排序方式: 共有560条查询结果,搜索用时 218 毫秒
551.

Objective

The ability of the ImmuKnow (Cylex) assay to predict the risk of infection in rheumatoid arthritis (RA) patients receiving synthetic or biological disease-modifying antirheumatic drugs (DMARDs) was examined.

Methods

The amount of adenosine triphosphate (ATP) produced by CD4+ cells in response to phytohemagglutinin was measured in whole blood from 117 RA patients without infection versus 17 RA patients with infection, and compared with results in 75 healthy controls.

Results

The mean ATP level was significantly lower in patients with infection compared to both healthy controls (P < 0.0005) and patients without infection (P = 0.040). Also, the mean ATP level in patients without infection was significantly lower than that in healthy controls (P = 0.012). There was no correlation between the ATP level and the Disease Activity Score in 28 joints.

Conclusion

ImmuKnow assay results may be effective in identifying RA patients at increased risk of infection, but the results showed no correlation with RA activity. Larger studies are required to establish the clinical advantages of this assay in RA treatment.  相似文献   
552.
[Purpose] We tested the reliability and validity of the Japanese version of the Short Questionnaire to Assess Health-enhancing Physical Activity scale in asymptomatic older adults and sought to confirm discriminator validity in women with osteoarthritis. [Subjects] The participants included an asymptomatic comparison group (men and women) and women with knee or hip osteoarthritis. [Methods] The test-retest method was used to assess reliability. The International Physical Activity Questionnaire was chosen to assess criterion-related validity. Discriminator validity was assessed by comparing the asymptomatic and osteoarthritis groups. [Results] Mean age for the asymptomatic groups was 63 ± 6 years for men (n = 23) and 61 ± 7 years for women (n = 51), and it was 63 ± 9 years for the osteoarthritis group (n = 32). The total score and scores for all items, except for heavy housework items, were significantly correlated with the retest. Criterion-related validity showed significantly weak to moderate correlations between the respective scale categories. For discriminator validity, the total scores and scores for bicycle commuting, light housework, and three leisure items differed significantly between the asymptomatic and osteoarthritis groups. [Conclusion] The Short Questionnaire to Assess Health-enhancing Physical Activity scale is a reliable and valid measure in asymptomatic older adults, and can discriminate between osteoarthritic and asymptomatic women.Key words: Physical activity scale, Older adults, Osteoarthritis  相似文献   
553.
Congenital nephrogenic diabetes insipidus (NDI) is a chronic disorder involving polyuria and polydipsia that results from unresponsiveness of the renal collecting ducts to the antidiuretic hormone vasopressin. Either of the genetic defects in vasopressin V2 receptor or the water channel aquaporin 2 (AQP2) cause the disease, which interfere the water reabsorption at the epithelium of the collecting duct. An unconscious state including a perioperative situation can be life threatening because of the difficulty to regulate their water balance. The Sendai virus (SeV) vector system deleting fusion protein (F) gene (SeV/DeltaF) is considered most suitable because of the short replication cycle and nontransmissible character. An animal model for NDI with reduced AQP2 by lithium chloride was used to develop the therapy. When the SeV/DeltaF vector carrying a human AQP2 gene (AQP2-SeV/DeltaF) was administered retrogradely via ureter to renal pelvis, AQP2 was expressed in the renal collecting duct to reduce urine output and water intake by up to 40%. In combination with the retorograde administration to pelvis, this system could be the cornerstone for the applicable therapies on not only NDI patients but also other diseases associate with the medullary collecting duct.  相似文献   
554.
The Arabidopsis thaliana AtHKT1 protein, a Na(+)/K(+) transporter, is capable of mediating inward Na(+) currents in Xenopus laevis oocytes and K(+) uptake in Escherichia coli. HKT1 proteins are members of a superfamily of K(+) transporters. These proteins have been proposed to contain eight transmembrane segments and four pore-forming regions arranged in a mode similar to that of a K(+) channel tetramer. However, computer analysis of the AtHKT1 sequence identified eleven potential transmembrane segments. We have investigated the membrane topology of AtHKT1 with three different techniques. First, a gene fusion alkaline phosphatase study in E. coli clearly defined the topology of the N-terminal and middle region of AtHKT1, but the model for membrane folding of the C-terminal region had to be refined. Second, with a reticulocyte-lysate supplemented with dog-pancreas microsomes, we demonstrated that N-glycosylation occurs at position 429 of AtHKT1. An engineered unglycosylated protein variant, N429Q, mediated Na(+) currents in X. laevis oocytes with the same characteristics as the wild-type protein, indicating that N-glycosylation is not essential for the functional expression and membrane targeting of AtHKT1. Five potential glycosylation sites were introduced into the N429Q. Their pattern of glycosylation supported the model based on the E. coli-alkaline phosphatase data. Third, immunocytochemical experiments with FLAG-tagged AtHKT1 in HEK293 cells revealed that the N and C termini of AtHKT1, and the regions containing residues 135-142 and 377-384, face the cytosol, whereas the region of residues 55-62 is exposed to the outside. Taken together, our results show that AtHKT1 contains eight transmembrane-spanning segments.  相似文献   
555.
This study evaluated the clinical features of 276 patients with aggressive adult T‐cell leukaemia‐lymphoma (ATL) in 3 Japan Clinical Oncology Group (JCOG) trials. We assessed the long‐term survivors who survived >5 years and constructed a prognostic index (PI), named the JCOG‐PI, based on covariates obtained by Cox regression analysis. The median survival time (MST) of the entire cohort was 11 months. In 37 patients who survived >5 years, no disease‐related deaths in 10 patients with lymphoma‐type were observed in contrast to the 10 ATL‐related deaths in other types. In multivariate analysis of 193 patients, the JCOG‐PI based on corrected calcium levels and performance status identified moderate and high risk groups with an MST of 14 and 8 months respectively (hazard ratio, 1·926). The JCOG‐PI was reproducible in an external validation. Patients with lymphoma‐type who survived >5 years might have been cured. The JCOG‐PI is valuable for identifying patients with extremely poor prognosis and will be useful for the design of future trials combining new drugs or investigational treatment strategies.  相似文献   
556.
OBJECTIVES: To evaluate the focal nature of the early and late inhibition of corticospinal neurons demonstrated by a paired-pulse stimulation paradigm.METHODS: We performed paired-electric pulse stimulation studies using subdural electrodes implanted in 4 patients with intractable partial epilepsy.RESULTS: Inhibition of motor evoked potentials in the first dorsal interosseous muscle was obtained by paired-pulse stimulation of the hand motor cortex (M1) with a subthreshold conditioning stimulus at conditioning-test intervals between 1 and 6ms. This early inhibition was abolished when the conditioning stimulus was moved to the sensory cortex (S1) or the arm M1. The inhibition was also produced by paired-pulse stimulation of the hand M1 with a suprathreshold conditioning stimulus between 50 and 300ms in all 3 patients. This late inhibition was still recognized when moving the conditioning stimulus to the hand S1 only in one of 3 patients.CONCLUSIONS: The early inhibition arises from very small areas in the M1 and is little mediated by neuronal circuits in the S1. On the other hand, the focal nature of the late inhibition is complicated and it arises mainly from the M1 but the S1 may be related to the generation of the late inhibition in some cases.  相似文献   
557.
OBJECTIVES: The therapeutic effects of adult and embryonic neural precursor cells (NPCs) were evaluated and their therapeutic potential compared in a rat model of Parkinson disease. METHODS: Adult NPCs were obtained from the subventricular zone and embryonic NPCs were taken from the ganglionic eminence of 14-day-old embryos. Each NPC type was cultured with epidermal growth factor. The in vitro neuronal differentiation rate of adult NPCs was approximately equivalent to that of embryonic NPCs after two passages. Next, the NPCs were transfected with either green fluorescent protein or glial cell line-derived neurotrophic factor (GDNF) by adenoviral infection and transplanted into the striata in a rat model of Parkinson disease (PD) induced by unilateral intrastriatal injection of 6-hydroxydopamine. An amphetamine-induced rotation test was used to evaluate rat behavioral improvement, and immunohistochemical analysis was performed to compare grafted cell survival, differentiation, and host tissue changes. RESULTS: The rats with GDNF-transfected NPCs had significantly fewer amphetamine-induced rotations and less histological damage. Except for the proportion of surviving grafted cells, there were no significant differences between adult and embryonic NPCs. CONCLUSIONS: Adult and embryonic NPCs have a comparable therapeutic potential in a rat model of PD.  相似文献   
558.
We report a series of FDG PET findings of a 69-year-old male patient with autoimmune pancreatitis (AIP) associated with extrapancreatic disease. The first FDG PET revealed diffuse uptake of FDG in AIP and retroperitoneal fibrosis (RF). The second FDG PET after cessation of steroid treatment indicated subsiding of disease activity in AIP, continuous disease activity in RF, and new extrapancreatic lesions, including enlargement of a right salivary gland, nephritis, and lymphadenopathy. The last FDG PET under steroid treatment revealed reduced FDG uptake in the above abnormal FDG uptake lesions. A series of these FDG PET findings suggest the usefulness of FDG PET for the diagnosis and monitoring of AIP associated with extrapancreatic autoimmune diseases.  相似文献   
559.
Nonviral, site-specific gene delivery to deep tissue is required for gene therapy of a spinal cord injury. However, an efficient method satisfying these requirements has not been established. This study demonstrates efficient and targeted gene transfer into the spinal cord by using photomechanical waves (PMWs), which were generated by irradiating a black laser absorbing rubber with 532-nm nanosecond Nd:YAG laser pulses. After a solution of plasmid DNA coding for enhanced green fluorescent protein (EGFP) or luciferase was intraparenchymally injected into the spinal cord, PMWs were applied to the target site. In the PMW application group, we observed significant EGFP gene expression in the white matter and remarkably high luciferase activity only in the spinal cord segment exposed to the PMWs. We also assessed hind limb movements 24 h after the application of PMWs based on the Basso-Beattie-Bresnahan (BBB) score to evaluate the noninvasiveness of this method. Locomotor evaluation showed no significant decrease in BBB score under optimum laser irradiation conditions. These findings demonstrated that exogenous genes can be efficiently and site-selectively delivered into the spinal cord by applying PMWs without significant locomotive damage.  相似文献   
560.
Between 1984 and 1986, 7 patients with spontaneous carotid-cavernous fistulas (CCF) were treated by radiotherapy delivering 3,000 cGy (200 cGy, 5 times per week) to the sellar region. Improvements of clinical signs and symptoms were seen in all patients within 6 months of treatment. During a follow-up period of 7 to 35 months, 6 patients remained in good clinical condition and only one patient developed a recurrence. As an adverse effect, one patient developed early menopause, but no other side-effects or complications were seen. Radiotherapy should be considered in patients with spontaneous CCF, when CCF are seen in middle-high aged patients and progressive without relief of symptoms.  相似文献   
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