بررسی حیطه‌های موجود در فرم‌های ارزشیابی از دیدگاه دانشجویان در دانشگاه علوم پزشکی زنجان در سال تحصیلی 86- 87

زمینه و هدف: ارزشیابی استادان متداول‌ترین روش جهت سنجش کیفیت آموزش می‌باشد. دانشجویان بیش از دست‌اندرکاران در جریان روند آموزش قرار‌دارند بنابراین با نظرخواهی از آنان دیدگاه کاملی برای مسئولین در مورد نقاط قوت و ضعف استادان به‌دست می‌آید. هدف از این پژوهش بررسی حیطه‌های موجود در فرم‌های ارزشیابی از دیدگاه دانشجویان در دانشکده‌های پزشکی، پیراپزشکی و پرستاری و مامایی می‌باشد. روش بررسی: این تحقیق به صورت توصیفی انجام گرفت. 1683 برگ ارزشیابی دانشجویان از استادان هیأت علمی (73 نفر) مربوط به دانشکده‌های پزشکی، پیراپزشکی و پرستاری- مامایی بررسی شد. پرسش‌نامه‌ی دانشجویان پزشکی حاوی 15 سؤوال و دانشجویان پیراپزشکی و پرستاری مامایی 21 سؤوال بود که بر اساس مقیاس لیکرات از حیطه‌های مختلف مقرراتی، علمی و آموزشی، نظارتی و نگرشی تشکیل شده بود. نمرات سؤوالات از نمره‌ی 100 محاسبه شد، نمرات بالاتر بیانگر عملکرد مطلوب‌تراستادان می‌باشد. تجزیه و تحلیل داده‌ها به‌صورت آمار توصیفی با نرم‌افزار SPSS انجام شد. یافته‌ها: نتایج نشان داد مقایسه در سطوح کلی بین دانشکده‌ها، دانشکده‌ی پیراپزشکی با میانگین کل و انحراف معیار 61/3 ±50/85 نسبت به سایر دانشکده‌ها برتری دارد. دانشکده‌ی پیراپزشکی در حیطه‌ی مقرراتی با میانگین و انحراف معیار 89/3±01/91، دانشکده‌ی پزشکی در حیطه‌ی نگرشی با میانگین و انحراف معیار 45/5±48/90 و دانشکده‌ی پرستاری مامایی در حیطه‌ی مقرراتی با میانگین و انحراف معیار 25/4±34/88 بیشترین امتیاز را داشتند. نتیجه‌نهایی نشان می‌دهد، حیطه‌ی علمی و آموزشی نسبت به سایر حیطه‌ها در سطح پایین‌تر می‌باشد. نتایج حیطه‌ها (علمی و آموزشی، نظارتی و نگرشی) بین دانشکده‌ها معنی‌دار می‌باشد (0001/0=P). نتیجه‌گیری: به نظر می‌رسد با برنامه‌ریزی جهت برگزاری کارگاه‌های آموزشی، روش تدریس و تحقیق جهت ارتقای آموزش استادان، اعطا‌ی فرصت مطالعاتی و تشویق انجام کارهای تحقیقاتی و پژوهشی گام مؤثری جهت ارتقای سطح علمی و بالاخره عملکرد بالای استادان خواهد بود

Effective identification of terrain positions from gridded DEM data using multimodal classification integration

Terrain positions are widely used to describe the Earth’s topographic features and play an important role in the studies of landform evolution, soil erosion and hydrological modeling. This work develops a new multimodal classification system with enhanced classification performance by integrating different approaches for terrain position identification. The adopted classification approaches include local terrain attribute (LA)-based and regional terrain attribute (RA)-based, rule-based and supervised, and pixel-based and object-oriented methods. Firstly, a double-level definition scheme is presented for terrain positions. Then, utilizing a hierarchical framework, a multimodal approach is developed by integrating different classification techniques. Finally, an assessment method is established to evaluate the new classification system from different aspects. The experimental results, obtained at a Loess Plateau region in northern China on a 5 m digital elevation model (DEM), show reasonably positional relationship, and larger inter-class and smaller intra-class variances. This indicates that identified terrain positions are consistent with the actual topography from both overall and local perspectives, and have relatively good integrity and rationality. This study demonstrates that the current multimodal classification system, developed by taking advantage of various classification methods, can reflect the geographic meanings and topographic features of terrain positions from different levels

Electrophile-Induced Ether Transfer and Application in Natural Product Total Synthesis

Numerous polyketide natural products contain methyl ether functionality generated by either methoxymalonyl extender units or a selective O-methyl transferase associated with the polyketide synthase (PKS) gene cluster. In laboratory syntheses of such natural products, discrete steps for generating a hydroxyl stereogenic center and subsequent methylation are typically bracketed by additional protecting group manipulation steps. A fundamentally new tactic has been designed and developed. This methodology is capable of significantly simplifying the creation of functionality common to polyketide natural products by controlling the generation of a stereogenic center simultaneous with ether incorporation. In this thesis it is demonstrated that alkoxymethyl-protected homoallylic alcohols, under the treatment of iodine monochloride (ICl), undergo efficient alkyl ether (for example, methyl and benzyl) transfer to afford syn-1,3-diol monoalkyl ethers in good yields and with excellent diastereocontrol. The proposed reactive intermediate, bearing a chloromethyl functionality, was proven by NMR analysis. It was also observed that this intermediate has decent stability so that it's reactivity can be fully explored, allowing formation of a variety of synthetically useful fragments that can potentially be used in syntheses of complex molecules. The mechanism of the ether transfer reaction initiated by N-iodosuccinimide (NIS) has also been studied. By incorporating isotopic labels in the products followed by product analyses with NMR spectroscopy and comparison with the results from non-labeled experiments, relative rates of different pathways as well as the stereoselectivity preference within each has been investigated and identified. This stereoselective ether transfer methodology has also been successfully applied to the total synthesis of the family of all-syn isotactic polymethoxy natural products. Two syntheses examples of this product family are shown in this thesis. In addition, a generalized, convergent synthetic strategy aiming toward synthesis of any member of these polymer-like compounds is also proposed

Can digital technology promote sustainable agriculture? Empirical evidence from urban China

In the face of increasing global unsustainable risks such as poverty, hunger, and pollution. Building sustainable agriculture (SA) in the digital age is a fundamental task for human survival. Based on the coupled coordination perspective, this paper constructs an SA system that takes into account more stakeholders by considering poverty alleviation and income increase (PI), food security (FS), and green agriculture (GA) as subsystems. The impact of digital technology on SA is systematically analyzed through data from 276 prefecture-level and above cities in China from 2005 to 2020. The study shows that digital technology has a significant upgrading effect on SA and its subsystems. And digital technology is more likely to promote SA in the developed eastern region and peripheral cities. Moreover, agricultural productivity and labor productivity play a mediating mechanism in the process of digital technology for SA. Digital financial inclusion fuels the high input process of digital technology for incentivizing SA, PI, and GA, but it cannot affect the highly technical process of digital farming. Further research found that the incentives of digital technology for SA and GA are characterized by the nonlinear characteristic of increasing marginal effects. Due to the second digital divide, there is a U-shaped incentive process of digital technology for PI to fall and then rise. Finally, the spillover nature of digital technology leads to spatial spillovers in its contribution to SA development.</p

Efficient Method for the Synthesis of 2,3-Unsubstituted Nitro Containing Indoles from <i>o</i>-Fluoronitrobenzenes

A methodology was developed for the efficient synthesis of 2,3-unsubstituted nitro containing indoles via acid catalyzed intramolecular electrophilic cyclization. Subsequent reduction of nitro groups allows the construction of some indole fused heterocycles and indole quinone diimines. This strategy provides an efficient method for the preparation of biologically and medicinally interesting molecules

DataSheet1_The r1 relaxivity and T1 imaging properties of dendrimer-based manganese and gadolinium chelators in magnetic resonance imaging.doc

We report the preparation and characterization of gadolinium (Gd)- or manganese (Mn)-loaded dendrimers and Gd-loaded dendrimer-entrapped gold nanoparticles (Gd-Au DENPs) to examine the relationship between the number of metal ion chelators and r1 relaxivity. In this study, amine-terminated fifth-generation poly(amidoamine) dendrimers (G5.NH2) modified with different numbers of DOTA-NHS chelators were used to chelate Gd and Mn ions. The remaining amine groups were then acetylated completely, followed by the use of materials with better r1 relaxivities and T1-weighted imaging performances as templates to synthesize Gd-Au DENPs. The Gd and Mn chelators as well as Gd-Au DENPs were characterized via different techniques. We show that the r1 relaxivity and T1 imaging performance increase with loading of greater numbers of Gd and Mn ions on the G5.NH2 and that the acetylation process affects the relaxivity and imaging properties to a certain extent. After entrapment with Au NPs, the r1 relaxivity and T1-weighted imaging performance of Gd-Au DENPs decrease with greater loading of Au NPs. This systematic study of the relaxivities and T1-weighted imaging performances of Gd, Mn, and Gd-Au DENP chelators are expected to be a theoretical basis for developing multifunctional dual-mode contrast agents.</p

Additional file 1: of Decomposing health inequality with population-based surveys: a case study in Rwanda

Box S1. Sampling and implementation process of the Integrated Living Conditions Survey (EICV). Box S2. Measurement of covariates used in the models on analyzing medical care utilization and catastrophic health spending. Box S3. Measurement of household catastrophic health spending (HCHS). Box S4. Multivariate logistic regression models in the analysis of adjusted mean of medical care utilization and HCHS. Table S1. Summary statistics for variables used in regression models on medical care utilization. Table S2. Summary statistics for variables used in regression models on HCHS. Table S3. T-tests about the mean differences of covariates by poverty status. Table S4. Odds ratios for covariates from the logistic model: Medical care utilization. Table S5. Odds ratios for covariates from the logistic model: HCHS. Table S6. Estimated absolute contribution of covariates to inequalities in medical care utilization by poverty status using BO decomposition method (EICV 2005, 2010). Table S7. Estimated contribution of covariates to inequalities in HCHS with different thresholds by poverty status using BO decomposition method (EICV 2005, 2010). Figure S1. Absolute inequalities in HCHS using different thresholds in 2005 and 2010. Figure S2. Decomposing absolute inequality in HCHS using different thresholds by poverty status in 2005 and 2010. (DOCX 89 kb

Highly Efficient Synthesis of 1,3-Dihydroxy-2-carboxycarbazole and Its Neuroprotective Effects

Carbazoles represent a family of tricyclic compounds that widely appeared in nature. Numerous studies have revealed a diverse array of bioactivity associated with this scaffold. In the present study, a novel and highly efficient methodology for preparing 1,3-dihydroxy-2-carboxycarbazole from indole-3-acetic acid and Meldrum’s acid was developed. Furthermore, biological characterization demonstrated that this multisubstituted carbazole analogue exhibited inhibitory activity on Aβ aggregation, antioxidative properties, and promising neuroprotective activities in a cellular model of Alzheimer’s disease, thus further supporting the valuable application of this synthetic methodology in search for effective neuroprotectants

Variables definitions.

Variables definitions.</p