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   377篇
  免费   26篇
  2023年   2篇
  2022年   2篇
  2021年   4篇
  2020年   5篇
  2019年   7篇
  2018年   9篇
  2017年   8篇
  2016年   13篇
  2015年   21篇
  2014年   20篇
  2013年   20篇
  2012年   28篇
  2011年   36篇
  2010年   18篇
  2009年   22篇
  2008年   19篇
  2007年   26篇
  2006年   28篇
  2005年   19篇
  2004年   22篇
  2003年   14篇
  2002年   10篇
  2001年   1篇
  2000年   3篇
  1999年   6篇
  1998年   2篇
  1997年   3篇
  1996年   3篇
  1995年   2篇
  1994年   3篇
  1993年   1篇
  1992年   4篇
  1991年   4篇
  1988年   1篇
  1987年   3篇
  1985年   3篇
  1984年   1篇
  1983年   1篇
  1981年   2篇
  1980年   1篇
  1978年   1篇
  1975年   2篇
  1974年   2篇
  1973年   1篇
排序方式: 共有403条查询结果,搜索用时 146 毫秒
91.
The paper discusses areas of behavioral functioning of children with intellectual disability, such as behavior with or without hyperactivity. The study covered 124 children with intellectual disability attending elementary schools in Belgrade. The Conners Rating Scale was used, and the areas of behavior in the classroom, participation in the group and attitude towards authority were covered. The results of our study suggest the presence of disorders in behavior and social-emotional functioning ranging from 11.2 to 40.4%. We have highlighted the importance of the use of multimodal approach and method of reeducation of psychomotor activity in rehabilitation of the studied children.  相似文献   
92.
Background: The study compares the eradication success of standard first-line triple therapies of different durations (7, 10, and 14 days).
Materials and Methods: A total of 592 naive Helicobacter pylori -positive patients were randomized to receive pantoprazole, amoxicillin, and clarithromycin or metronidazole for 14 days (PACl14 or PAM14), 10 days (PACl10 or PAM10), or 7 days (PACl7 or PAM7). H. pylori eradication was assessed by histological, microbiological, and rapid urease examination.
Results: The intention-to-treat (ITT) and per-protocol (PP) analyses have shown no overall statistically significant differences between the eradication success of PACl and PAM treatment groups (ITT p  = .308, PP p  = .167). Longer treatment duration has yielded statistically significant increase in eradication success for clarithromycin (ITT p  = .004; PP p  = .004) and metronidazole (ITT p  = .010; PP p  = .034) based regimens. Namely, PACl10, PACl14, and PAM14 protocols resulted in eradication success exceeding 80% in ITT and 90% in PP analysis. Primary resistance to clarithromycin and metronidazole equals 8.2% and 32.9%, respectively. Prolonging the metronidazole-based treatment duration in patients with resistant strains resulted in statistically significant higher eradication success.
Conclusions: For all antimicrobial combinations, 14 days protocols have led to a significant increase of H. pylori eradication success when compared to 10 and 7 days, respectively. Prolonging the treatment duration can overcome the negative effect of metronidazole resistance. Only PAM14, PACl10 protocols achieved ITT success > 80% and should be recommended as the first line eradication treatment in Croatia.  相似文献   
93.
94.
Maintaining the cholesterol homeostasis is essential for normal CNS functioning. The enzyme responsible for elimination of cholesterol excess from the brain is cholesterol 24-hydroxylase (Cyp46). Since cholesterol homeostasis is disrupted following brain injury, in this study we examined the effect of right sensorimotor cortex suction ablation on cellular and temporal pattern of Cyp46 expression in the rat brain. Increased expression of Cyp46 at the lesion site at all post injury time points (2, 7, 14, 28 and 45 days post injury, dpi) was detected. Double immunofluorescence staining revealed colocalization of Cyp46 expression with different types of glial cells in time-dependent manner. In ED1+ microglia/macrophages Cyp46 expression was most prominent at 2 and 7 dpi, whereas Cyp46 immunoreactivity persisted in reactive astrocytes throughout all time points post-injury. However, during the first 2 weeks Cyp46 expression was enhanced in both GFAP+ and Vim+ astrocytes, while at 28 and 45 dpi its expression was mostly associated with GFAP+ cells. Pattern of neuronal Cyp46 expression remained unchanged after the lesion, i.e. Cyp46 immunostaining was detected in dendrites and cell body, but not in axons. The results of this study clearly demonstrate that in pathological conditions, like brain injury, Cyp46 displayed atypical expression, being expressed not only in neuronal cells, but also in microglia and astrocytes. Therefore, injury-induced expression of Cyp46 in microglial and astroglial cells may be involved in the post-injury removal of damaged cell membranes contributing to re-establishment of the brain cholesterol homeostasis.  相似文献   
95.
Biochemical properties of nucleotide pyrophosphatase/phosphodiesterase (NPP) in rat serum have been described by assessing its nucleotide phosphodiesterase activity, using p-nitrophenyl-5′-thymidine monophosphate (p-Nph-5′-TMP) as a substrate. It was demonstrated that NPP activity shares some typical characteristics described for other soluble NPP, such as divalent cation dependence, strong alkaline pH optimum (pH 10.5), inhibition by glycosaminoglycans, and K m for p-Nph-5′-TMP hydrolysis of 61.8 ± 5.2 μM. In order to characterize the relation between phosphodiesterase and pyrophosphatase activities of NPP, we have analyzed the effects of different natural nucleotides and nucleotide analogs. ATP, ADP, and AMP competitively inhibited p-Nph-5′-TMP hydrolysis with K i values ranging 13–43 μM. Nucleotide analogs, α,β-metATP, BzATP, 2-MeSATP, and dialATP behaved as competitive inhibitors, whereas α,β-metADP induced mixed inhibition, with K i ranging from 2 to 20 μM. Chromatographic analysis revealed that α,β-metATP, BzATP, and 2-MeSATP were catalytically degraded in the serum, whereas dialATP and α,β-metADP resisted hydrolysis, implying that the former act as substrates and the latter as true competitive inhibitors of serum NPP activity. Since NPP activity is involved in generation, breakdown, and recycling of extracellular adenine nucleotides in the vascular compartment, the results suggest that both hydrolyzable and non-hydrolyzable nucleotide analogs could alter the amplitude and direction of ATP actions and could have potential therapeutic application.  相似文献   
96.
Our aim was to explore and compare the job satisfaction between family physicians and hospital specialists in Split, Croatia. The survey was carried out in 2005 and 2006. A validated questionnaire was composed of two parts: 92 statements and questions about job satisfaction in the form of a Lickert scale (range 1-5) and eight questions concerning demographic issues. The questionnaire was completed and returned by 165 hospital specialists from the University Hospital and by 131 family physicians from the Split County. Response rate for family physicians was 39.81% and 41.46% for hospital specialists. Hospital doctors were divided in two groups: internal and surgical. There were no significant differences between family physicians and hospital specialists in total job satisfaction (F = 1.02; p = 0.41). Family physicians were more satisfied with their workplace conditions than internal medicine specialists (19.37 +/- 4.23 vs. 17.37 +/- 4.59; F = 5.93; p = 0.003), and less satisfied with the possibilities for postgraduate training than surgeons (5.27 +/- 1.90 vs. 6.59 +/- 2.07; F = 9.26; p < 0.001). Global job satisfaction was rather low but does not differ between the three medical groups. Disparities were observed in some segments (opportunity for further training and academic advancement, vacation, and salary). The reason for the family physician's relative satisfaction may be due to stable working conditions, independence in organizing work schedules and personal responsibility.  相似文献   
97.
Primary gastric non Hodgkin lymphoma (PGNHL) is a distinct group of extranodal lymphomas with interesting geographical distribution and variable prevalence in different countries. We analysed epidemiological data of our patients with PGNHL in Primorsko-goranska County. Clinical data of 30 patients with PGNHL diagnosed and treated in Clinical Hospital Center of Rijeka, Croatia between January 1995 and December 2005 were prospectively analyzed. We used statistical analysis (t-test, chi2-test) for small groups. Out of 30 pts with PGNHL, 19 were born in Primorsko-goranska County, part of Croatia situated by the Adriatic sea which consists of three regions: City of Rijeka, Islands and Gorski Kotar. 6 of 19 patients (31.6%) were originally from Gorski Kotar which made incidence rate of PGNHL in Gorski Kotar 7 times higher than in other two regions. Many authors emphasized that relative frequency of PGNHL is very variable in various countries and regions. Geographical distribution of our patients was very surprising because Gorski Kotar is the region with lowest number of citizens, rural area without any known pollutants, and ecologically one of the most preserved microsystem in this part of Croatia. Gorski Kotar is known to be an endemic region for multiple sclerosis and lyme borreliosis. Is it for PGNHL too?  相似文献   
98.
Symbiotic associations are of a wide significance in evolution and biodiversity. Green hydra is a typical example of endosymbiosis. In its gastrodermal myoepithelial cells, it harbors individuals of unicellular green algae. Morphological characteristics of isolated algae determined by light and electron microscopy are presented. Cytological morphometric parameters (cell area, cell radius, chloroplast area) of isolated algae from green hydra (Cx), as well as from reference species Chlorella kessleri (Ck) and Chlorella vulgaris (Cv), revealed similarity between the isolated endosymbiont and C. kessleri. Isoenzyme patterns of esterase (EST), peroxidase (POX), and catalase (CAT) were used for the investigation of genetic variability in endosymbiotic algae isolated from green hydra. Out of 14 EST isoenzymes observed in Cx species, 9 were expressed in the Cx sample. Results of the EST isoenzyme analysis indicated a higher degree of similarity between Cx and Cv than between Cx and Ck. Due to much higher heterogeneity, EST isoenzymes seem to be more suitable genetic markers for identification of different Chlorella species than CAT and POX isoenzymes. Results obtained suggest that symbiogenesis in green hydra has probably not been terminated yet.  相似文献   
99.
Volatile compounds of hedge mustard (Sysimbrium officinale) have been investigated for the first time. Forthy‐two compounds were identified after hydrodistillation (without or upon autolysis) after gas chromatography and gas chromatography/mass spectrometry analyses. In addition, after decoction and hydrolysis of O‐glycosides, 18 volatile O‐aglycones were identified. In general, the main volatiles found in hydrodistillates were: isopropyl isothiocyanate (27.6–48.9%), 2‐methylpropanenitrile (0.5–18.8%), (Z)‐hex‐3‐en‐1‐ol (0.5–18.0%), sec‐butyl isothiocyanate (4.9–9.4%), (E)‐hex‐2‐enal (3.5–8.6%), (Z)‐hex‐2‐en‐1‐ol (0.3–8.4%), octanoic (0.5–8.6%) and dodecanoic acid (0–5.0%), 2‐methylbutanenitrile (0–4.6%), dibutyl phthalate (0–4.5%), and ethyl linolenate (0–3.6%). The main volatile O‐aglycones were: 2‐phenylethyl alcohol (21.5%), 6,7‐dehydro‐7,8‐dihydro‐3‐oxo‐α‐ionol (9.3%), eugenol (8.3%), benzyl alcohol (7.0%), ethyl vanillate (5.2%), 6‐(tert‐butyl)‐5‐methylphenol (5.1%), vanillin acetone (4.7%), ethyl 4‐hydroxybenzoate (4.3%), and 2‐hydroxy‐β‐ionone (3.8%). All hydrodistillates exhibited great potential of antibacterial activity against five Gram‐positive bacteria, nine ampicillin‐resistant Gram‐negative bacteria, and four fungi at a concentration of 500 μg/ml using the disc diffusion method.  相似文献   
100.
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