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   7897篇
  免费   529篇
  国内免费   50篇
耳鼻咽喉   99篇
儿科学   209篇
妇产科学   211篇
基础医学   1114篇
口腔科学   730篇
临床医学   687篇
内科学   1768篇
皮肤病学   247篇
神经病学   808篇
特种医学   119篇
外科学   668篇
综合类   50篇
一般理论   2篇
预防医学   724篇
眼科学   111篇
药学   463篇
中国医学   49篇
肿瘤学   417篇
  2024年   14篇
  2023年   135篇
  2022年   250篇
  2021年   449篇
  2020年   264篇
  2019年   367篇
  2018年   401篇
  2017年   262篇
  2016年   293篇
  2015年   362篇
  2014年   450篇
  2013年   521篇
  2012年   748篇
  2011年   750篇
  2010年   395篇
  2009年   288篇
  2008年   538篇
  2007年   445篇
  2006年   325篇
  2005年   325篇
  2004年   248篇
  2003年   238篇
  2002年   169篇
  2001年   19篇
  2000年   13篇
  1999年   34篇
  1998年   32篇
  1997年   12篇
  1996年   10篇
  1995年   9篇
  1994年   9篇
  1993年   3篇
  1992年   11篇
  1991年   15篇
  1990年   5篇
  1989年   10篇
  1988年   4篇
  1987年   10篇
  1986年   4篇
  1984年   6篇
  1983年   3篇
  1979年   3篇
  1976年   3篇
  1975年   2篇
  1974年   2篇
  1972年   5篇
  1971年   2篇
  1969年   2篇
  1964年   2篇
  1962年   2篇
排序方式: 共有8476条查询结果,搜索用时 15 毫秒
991.
The aim of this study was to characterize the health-related quality of life (HR-QOL) and functioning in 90 bipolar I remitted outpatients. According to Diagnostic and Statistical Manual of Mental Disorders IV remission specifiers, patients were categorized into 4 groups: group 1, fully remitted; group 2, less than 2 months remitted; group 3, with persisting manic symptoms; group 4, with persisting depressive symptoms. The severity of psychopathology was evaluated by using the Bech-Rafaelsen Mania-Melancholia Scale. The HR-QOL, functioning, and insight were assessed via the medical outcomes study 36-item short form, the global assessment of functioning scale, and the scale to assess unawareness of mental disorder, respectively. Fully remitted patients reported the highest scores in almost all domains of medical outcomes study 36-item short form, and had significantly higher scores on physical functioning, general health, social functioning, and mental health compared to patients with persisting depressive symptoms. Furthermore, patients with persisting manic symptoms reported significantly higher scores on general health, vitality and mental health than the group with persisting depressive symptoms. In contrast, the global assessment of functioning scale score differed among the 4 groups, with fully remitted patients reporting higher, although not statistically significant, scores than the other groups. Our data suggest that the persistence of depressive or manic symptoms seem to affect self-report measures of HR-QOL. An affectively biased cognition may explain the gap between patient's perception of functioning and estimated functional adjustment, as assessed by clinicians.  相似文献   
992.
MLVI has been used to assess adherence. To determine the MLVI in children <12 years of age at transplantation and to identify demographic correlates and consequences for the graft. This is a retrospective study of 50 outpatients (4.0 ± 3.5 years), at least 13‐month post‐liver transplantation. The outcomes evaluated were MLVI, ALT > 60 IU/L, ACR, death, and graft loss. We analyzed demographic and socioeconomic characteristics, indication for transplantation, and type of donor. Student's t test and the chi‐square test were used. Statistical significance was set at P ≤ .05. Seventy‐two percent were infants or preschoolers, 62% biliary atresia. Seventy‐four percent of the mothers had middle‐school education, and 54% of the families had an income ≤3632.4 US$/y. Twenty‐two (44%) patients had a MLVI ≥ 2 SD; this was more prevalent in families with higher incomes (P = .045). ALT levels > 60 IU/L were more common in MLVI ≥ 2 SD group (P = .035). ACR episodes were similar between groups (P = 1.000). No patient died or lost the graft. MLVI ≥ 2 SD may be an indicator of the risk of medication non‐adherence.  相似文献   
993.
OBJECTIVES: To evaluate the microtensile bond strength (MTBS) of self-etch (with or without H(3)PO(4)-etching) and total-etch bonding systems bonded to different regions of dentin. METHODS: Long flat dentin cavity preparations extending from top-crown to root-apex within the same tooth were performed and bonded: using two-step (Clearfil SE Bond/SEB, Resulcin Aqua Prime/RES) and one-step (Etch & Prime 3.0/EP, One-Up Bond F/OUB, Prompt L-Pop/PLP, Solist/SOL and Futurabond/FUT) self-etch adhesives; these same adhesives were also applied following H(3)PO(4)-etching of dentin and finally two more groups were bonded with total-etch adhesives (Single Bond/SB and Prime & Bond NT/PBNT). Build-ups of resin composite were constructed incrementally to ensure sufficient bulk for the MTBS test and the different regions of dentin were identified by painting with different colours on the top of the resin composite. Specimens were sliced into beams and tested in tension. ANOVA and multiple comparisons tests were used (p<0.05). RESULTS: Regardless of the tested dentin region, SEB attained the highest MTBS to smear layer-covered surfaces (i.e., coronal dentin: 42.7MPa), while H(3)PO(4)-etching of dentin hampered bonds (i.e., coronal dentin: 27.7MPa). When bonding with PBNT, SB, RES, EP, PLP, SOL and FUT, MTBS was similar for different dentin regions. H(3)PO(4)-etching of dentin did not alter the attained MTBS. SIGNIFICANCE: SEB yielded the highest MTBS to all regions of dentin. When bonding to parallel-cut dentin, previous H(3)PO(4)-etching of dentin did not increase MTBS and differences in bond strength among dentin regions were absent.  相似文献   
994.
PURPOSE: The aim of this study was to evaluate the effectiveness of previous dental substrate treatments on the bond strength of two self-etching adhesives. MATERIALS AND METHODS: One hundred bovine incisors were sectioned at the cementoenamel junction. The labial tooth surface was ground to obtain flat superficial dentin. Teeth were randomly divided into two groups (n = 50): Clearfil Protect Bond and One Up Bond F. The specimens of each group were subdivided into five groups, according the dental substrate treatment, and then the adhesive system was applied as follows (n = 10): C: control, without previous treatment; TA: 37% phosphoric acid etching on enamel and dentin for 15 s; PA: 37% phosphoric acid etching only on enamel for 15 s; SB: Al2O3 sandblasting on dental surface; EDTA: enamel and dentin conditioning with 24% EDTA gel, pH 7.0. Resin composite blocks were fixed to the dental surfaces with dual-polymerized resin cement. Samples were sectioned in the mesiodistal direction and were trimmed to reduce the cross-sectional area to approximately 1.2 mm2. They were tested at a crosshead speed of 0.5 mm/min on a testing machine. Microtensile bond strength values from enamel, superficial dentin, and deep dentin were compared. Mean microtensile bond strength values were expressed in MPa and were analyzed by two-way ANOVA (2 x 3 x 5) and Tukey's tests. RESULTS: A significant difference was observed for interaction (p = 0.00001) among the factors. The highest mean bond strength to enamel was found with previous phosphoric acid etching, and to dentin when EDTA was previously applied. CONCLUSION: The most indicated previous treatment for increasing the bond strength to enamel and dentin simultaneously is EDTA for both self-etching adhesive systems used.  相似文献   
995.
OBJECTIVE: Effective treatments for major depressive disorder exist, yet some patients fail to respond, or achieve only partial response. One approach to optimizing treatment success is to identify which patients are more likely to respond best to which treatments. The objective of this investigation was to determine if patient personality characteristics are predictive of response to either cognitive-behavioural therapy (CBT) or pharmacotherapy (PHT). METHOD: Depressed patients completed the Revised NEO Personality Inventory, which measures the higher-order domain and lower-order facet traits of the Five-Factor Model of Personality, and were randomized to receive either CBT or PHT. RESULT: Four personality traits--the higher-order domain neuroticism and 3 lower-order facet traits: trust, straightforwardness, and tendermindedness--were able to distinguish a differential response rate to CBT, compared with PHT. CONCLUSION: The assessment of patient dimensional personality traits can assist in the selection and optimization of treatment response for depressed patients.  相似文献   
996.
Ziprasidone was the fifth atypical antipsychotic approved by Food and Drug Administration (FDA) for use in bipolar mania and mixed episodes. This atypical antipsychotic has a unique profile, as it acts primarily through serotonergic and dopaminergic receptor antagonism, but also exerts effects as an inhibitor of norepinephrine reuptake. Moreover, one of the advantages of ziprasidone is its safety profile as it is not associated with clinically significant metabolic side effects and little or no effect on prolactin level or anticholinergic side effects. Most of the studies evaluating ziprasidone's efficacy and safety are short‐term double‐blind, placebo‐controlled studies in acute mania and mixed episodes. In two of them, ziprasidone was associated to significant improvement in the primary measures assessed. However, an add‐on study, lithium plus ziprasidone showed similar results than lithium monotherapy, although there was a significant advantage for the combination within the first week. In a more recent trial, ziprasidone was compared with placebo and haloperidol as monotherapies, again beating placebo. In that trial, ziprasidone appeared to be safer and better tolerated, although less likely efficacious than haloperidol. Particularly, subjects treated with ziprasidone were less likely to switch to depression. Despite the well‐studied efficacy of ziprasidone in the first weeks of treatment, there are no controlled trials that evaluate the role and efficacy of ziprasidone in long‐term treatment of bipolar disorder (BD). Overall, in the open‐label extension studies, there was a global improvement at all visits compared with baseline scores. Furthermore, ziprasidone appears to offer some antidepressant effect in patients with major depressive episode and resistant to treatment, as demonstrated in add‐on open‐label studies with ziprasidone plus selective serotonin reuptake inhibitor (SSRI).  相似文献   
997.
The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) has been studied relatively extensively in normal samples, and its theoretically derived index scores have been demonstrated to be useful in the assessment of a variety of clinical conditions. However, examinations of the empirical relationships between individual subtests are limited. The intent of the present study was to explore the component structure of the instrument in a sample of 351 individuals with a diagnosed memory disorder, to examine the impact of demographic factors on these empirically derived components, and to explore differences in performance between diagnostic groups. Findings suggested a three-component solution (Memory, Visuomotor Processing, and Verbal Processing). Demographic variables had relatively small, but significant relationships with various component scores. Significant differences were observed between probable Alzheimer's disease and non-Alzheimer's type dementia groups on the memory component score, but not on other component scores or on RBANS index scores.  相似文献   
998.
999.
The calcium binding proteins parvalbumin and calbindin-D28k were localized immunocytochemically within the lateral geniculate nucleus of adult monkeys at 1–7 months after monocular enucleation. Within the deafferented magno- and parvocellular layers, parvalbumin and calbindin-D28k immunoreactive fibers were depleted at all post-enucleation times. The neuronal staining for parvalbumin was similar in numerical density and intensity between the deafferented and intact layers. In hemispheres examined at 5 and 7 months post-enucleation, parvalbumin-immunoreactive fibers were also lost within the deprived ocular dominance bands in layers IVA, IVC and VI of the visual cortex, suggesting that cellular expression or axonal transport of parvalbumin may be decreased in the deafferented geniculate laminae. While the intact magno- and parvocellular layers contained very few neurons that were immunoreactive for calbindin-D28k, the density of calbindin-D28k-positive neurons increased in these layers after deafferentation. The counts of calbindin-D28k and parvalbumin immunostained neurons were not statistically different at 4–7 months post-enucleation. Because virtually all magno- and parvocellular projection neurons express parvalbumin, many parvalbumin neurons that normally do not contain calbindin-D28k may co-express this in response to injury. The findings suggest that long-term deafferentation imposes additional calcium buffering requirements on lateral geniculate neurons.  相似文献   
1000.
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