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1.

Background

Although recent studies report on the benefits of blended learning in improving medical student education, there is still no empirical evidence on the relative effectiveness of blended over traditional learning approaches in medical statistics. We implemented blended along with on-site (i.e. face-to-face) learning to further assess the potential value of web-based learning in medical statistics.

Methods

This was a prospective study conducted with third year medical undergraduate students attending the Faculty of Medicine, University of Belgrade, who passed (440 of 545) the final exam of the obligatory introductory statistics course during 2013–14. Student statistics achievements were stratified based on the two methods of education delivery: blended learning and on-site learning. Blended learning included a combination of face-to-face and distance learning methodologies integrated into a single course.

Results

Mean exam scores for the blended learning student group were higher than for the on-site student group for both final statistics score (89.36±6.60 vs. 86.06±8.48; p = 0.001) and knowledge test score (7.88±1.30 vs. 7.51±1.36; p = 0.023) with a medium effect size. There were no differences in sex or study duration between the groups. Current grade point average (GPA) was higher in the blended group. In a multivariable regression model, current GPA and knowledge test scores were associated with the final statistics score after adjusting for study duration and learning modality (p<0.001).

Conclusion

This study provides empirical evidence to support educator decisions to implement different learning environments for teaching medical statistics to undergraduate medical students. Blended and on-site training formats led to similar knowledge acquisition; however, students with higher GPA preferred the technology assisted learning format. Implementation of blended learning approaches can be considered an attractive, cost-effective, and efficient alternative to traditional classroom training in medical statistics.  相似文献   
2.
Figures in scientific publications are critically important because they often show the data supporting key findings. Our systematic review of research articles published in top physiology journals (n = 703) suggests that, as scientists, we urgently need to change our practices for presenting continuous data in small sample size studies. Papers rarely included scatterplots, box plots, and histograms that allow readers to critically evaluate continuous data. Most papers presented continuous data in bar and line graphs. This is problematic, as many different data distributions can lead to the same bar or line graph. The full data may suggest different conclusions from the summary statistics. We recommend training investigators in data presentation, encouraging a more complete presentation of data, and changing journal editorial policies. Investigators can quickly make univariate scatterplots for small sample size studies using our Excel templates.  相似文献   
3.
A simple approach to a stable steroidal estrone derived A,B-spiro system is reported. Treatment of estrone derived A-ring diepoxyalcohol with the Ac2O–TMSOTf system at the ambient temperature led to acetylation, while at the reflux temperature the acid-catalysed rearrangement took place affording the spiro-compound. Results of extensive in vitro and in vivo anticancer tests on the diepoxide, as well as preliminary data on the antiproliferative activity of the spiro-product against three cancer cell lines, are also presented.  相似文献   
4.
Data presentation for scientific publications in small sample size studies has not changed substantially in decades. It relies on static figures and tables that may not provide sufficient information for critical evaluation, particularly of the results from small sample size studies. Interactive graphics have the potential to transform scientific publications from static reports of experiments into interactive datasets. We designed an interactive line graph that demonstrates how dynamic alternatives to static graphics for small sample size studies allow for additional exploration of empirical datasets. This simple, free, web-based tool (http://statistika.mfub.bg.ac.rs/interactive-graph/) demonstrates the overall concept and may promote widespread use of interactive graphics.  相似文献   
5.
p27(Kip1) is an important effector of G(1) arrest by transforming growth factor beta (TGF-beta). Investigations in a human mammary epithelial cell (HMEC) model, including cells that are sensitive (184(S)) and resistant (184A1L5(R)) to G(1) arrest by TGF-beta, revealed aberrant p27 regulation in the resistant cells. Cyclin E1-cyclin-dependent kinase 2 (cdk2) and cyclin A-cdk2 activities were increased, and p27-associated kinase activity was detected in 184A1L5(R) cells. p27 from 184A1L5(R) cells was localized to both nucleus and cytoplasm, showed an altered profile of phosphoisoforms, and had a reduced ability to bind and inhibit cyclin E1-cdk2 in vitro when compared to p27 from the sensitive 184(S) cells. In proliferating 184A1L5(R) cells, more p27 was associated with cyclin D1-cdk4 complexes than in 184(S). While TGF-beta inhibited the formation of cyclin D1-cdk4-p27 complexes in 184(S) cells, it did not inhibit the assembly of cyclin D1-cdk4-p27 complexes in the resistant 184A1L5(R) cells. p27 phosphorylation changed during cell cycle progression, with cyclin E1-bound p27 in G(0) showing a different phosphorylation pattern from that of cyclin D1-bound p27 in mid-G(1). These data suggest a model in which TGF-beta modulates p27 phosphorylation from its cyclin D1-bound assembly phosphoform to an alternate form that binds tightly to inhibit cyclin E1-cdk2. Altered phosphorylation of p27 in the resistant 184A1L5(R) cells may favor the binding of p27 to cyclin D1-cdk4 and prevent its accumulation in cyclin E1-cdk2 in response to TGF-beta.  相似文献   
6.
This article analyzes a set of five postcards, purchased from a street stand in Belgrade, the capital of Yugoslavia, shortly after the NATO bombing of the country took place in the spring of 1999. While the postcards obviously serve as protests against the bombing, as well as testimonies of the nation-wide trauma caused by it, they also reveal a careful negotiation between representations of trauma — keeping it displaced enough to avoid vicarious traumatization for individual survivors, but focused enough to translate it into a part of the national Serb identity and relying on the symbolism available in historical public narratives. However, since all the postcards analyzed here use English language in one form or another, they can also be read as peculiar interpretations of globalization on a local level. The article is an examination of the function of English, both in the negotiation of private/public trauma as described above, and its role in the complex reconfiguration of the phenomenon of globalization as embedded with local meaning given the context of the narrative within the Serbian popular culture. While these pop culture artifacts offer an assurance to the Serb national spirit, they also express a multifaceted national take on globalization visible in the use of English as the language of the Western ‘enemy’. Overall,the postcards can be read as a curious traumatic figuration of postmodernism which seems to be battling modernism in Belgrade's streets, while the Serb nationalism faces off with the global world in the realm of the imaginary.  相似文献   
7.

Pollen identification and enumeration is subject to human errors, and hence, it is crucial to evaluate the proficiency of pollen counters. Many networks still depend on manual pollen monitoring, and those adopting automation use manual counting data as a reference. A quality control exercise was undertaken across the AusPollen Aerobiology Collaboration Network to compare data analysis methods, gauge factors associated with accuracy, and improvements in counting proficiency. Counters were instructed to count grass and other pollen of the same two slides. Reported pollen concentrations were compared to an approximation of the true concentration values applying the published benchmark approach and alternative approach using bootstrapping technique. Participants were asked about their experience, training and usual practice via an online questionnaire. The majority (92% of 72) of reported values fell within acceptable ranges of variation from approximated true values. Outcomes were similar regardless of analysis approach, but bootstrapping did not require detection of outliers, and worked well with a small sample size with non-normal distribution. Counter reported pollen data were significantly shifted towards better outcomes compared to an initial exercise, and five of eight counters who were tested two times improved. Counting performance seemed not to be associated with amount of training received but was significantly related to counter experience. For future quality control exercises, particularly for small and skewed datasets, confidence limits of true pollen concentrations may be analysed by bootstrapping. Implementation of quality control exercises with harmonised analysis would enhance delivery of reliable pollen information to community, clinicians and government agencies for forecasting and environmental health management.

  相似文献   
8.
Cytochromes P450 (CYPs) are critically important in the oxidative metabolism of a diverse array of xenobiotics and endogenous substrates. We have previously reported the cloning and characterisation of the koala CYP4A15, the first reported member of the CYP4 family from marsupials, and have demonstrated important species differences in CYP4A activity and tissue expression. In the present study, the cloning of CYP4B1 in the wallaby (Macropus eugenii) and their expression across marsupials is described. Rabbit anti-mouse CYP4B1 antibody detected immunoreactive proteins in lung and liver microsomes from all test marsupials, with relative weak signal detected from the koala, suggesting a species-specific expression. Microsomal 2-aminofluorene bio-activation (a CYP4B1 marker) in wallaby lung was comparable to that of rabbit, with significant higher activities detected in wallaby liver and kidneys compared to rabbit. A 1548 bp wallaby lung CYP4B complete cDNA, designated CYP4B1, which encodes a protein of 510 amino acids and shares 72% nucleotide and 69% amino acid sequence identity to human CYP4B1, was cloned by polymerase chain reaction approaches. The results demonstrate the presence of wallaby CYP4B1 that shares several common features with other published CYP4Bs; however the wallaby CYP4B1 cDNA contains four extra amino acid residues at the NH2-terminal, a fundamentally conserved transmembrane anchor of all eukaryote CYPs.  相似文献   
9.

Background

Medical statistics has become important and relevant for future doctors, enabling them to practice evidence based medicine. Recent studies report that students’ attitudes towards statistics play an important role in their statistics achievements. The aim of the study was to test the psychometric properties of the Serbian version of the Survey of Attitudes Towards Statistics (SATS) in order to acquire a valid instrument to measure attitudes inside the Serbian educational context.

Methods

The validation study was performed on a cohort of 417 medical students who were enrolled in an obligatory introductory statistics course. The SATS adaptation was based on an internationally accepted methodology for translation and cultural adaptation. Psychometric properties of the Serbian version of the SATS were analyzed through the examination of factorial structure and internal consistency.

Results

Most medical students held positive attitudes towards statistics. The average total SATS score was above neutral (4.3±0.8), and varied from 1.9 to 6.2. Confirmatory factor analysis validated the six-factor structure of the questionnaire (Affect, Cognitive Competence, Value, Difficulty, Interest and Effort). Values for fit indices TLI (0.940) and CFI (0.961) were above the cut-off of ≥0.90. The RMSEA value of 0.064 (0.051–0.078) was below the suggested value of ≤0.08. Cronbach’s alpha of the entire scale was 0.90, indicating scale reliability. In a multivariate regression model, self-rating of ability in mathematics and current grade point average were significantly associated with the total SATS score after adjusting for age and gender.

Conclusion

Present study provided the evidence for the appropriate metric properties of the Serbian version of SATS. Confirmatory factor analysis validated the six-factor structure of the scale. The SATS might be reliable and a valid instrument for identifying medical students’ attitudes towards statistics in the Serbian educational context.  相似文献   
10.
Based on biological properties of epoxyquinols from natural sources, bromo and epoxyquinols derived from estrone were synthesized and screened against Fem-X, HeLa and K(562) cell lines. Evidence was found that the bromine atom and the epoxy moiety significantly increase the antiproliferative activity within the series.  相似文献   
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