Cooperative catalysis by silica-supported organic functional groups

Hybrid inorganic–organic materials comprising organic functional groups tethered from silica surfaces are versatile, heterogeneous catalysts. Recent advances have led to the preparation of silica materials containing multiple, different functional groups that can show cooperative catalysis; that is, these functional groups can act together to provide catalytic activity and selectivity superior to what can be obtained from either monofunctional materials or homogeneous catalysts. This tutorial review discusses cooperative catalysis of silica-based catalytic materials, focusing on the cooperative action of acid–base, acid–thiol, amine–urea, and imidazole–alcohol–carboxylate groups. Particular attention is given to the effect of the spatial arrangement of these organic groups and recent developments in the spatial organization of multiple groups on the silica surface

Promoting healthy eating and physical activity among school children: findings from Health-E-PALS, the first pilot intervention from Lebanon

Background: In Lebanon, childhood obesity doubled during the past decade. Preventive measures should start early in life and Schools are considered an important environment to promote energy balance health behaviours. School-based programmes promoting healthy lifestyles are lacking. The purpose of this study was to evaluate the feasibility and effectiveness of a multicomponent school-based intervention to promote healthy eating and physical activity (and prevent obesity) with school children aged 9–11 years in Lebanon. Methods: The intervention was developed based on the constructs of the Social Cognitive Theory and adapted to the culture of Lebanese and Arab populations. It consisted of three components: class curriculum, family involvement and food service. Eight schools were purposively selected from two communities of different socioeconomic status (SES) in Beirut and, within each school type, were matched on SES, religious sect profile, and then randomly assigned to either the intervention or control group. Anthropometric measurements and questionnaires on determinants of behavioural change, eating and physical activity habits were completed by the students in both groups at baseline and post intervention. Focus group interviews were conducted in intervention schools at the end of the study. Challenges encountered during the programme implementation were also identified, since Lebanon is considered a country with political unrest and no similar research projects were conducted in the area. Results: Students in the intervention group reported purchasing and consuming less chips and sweetened drinks post-intervention compared with controls (86% & 88% less respectively p < 0.001). Knowledge and self-efficacy scores increased for the intervention (+2.8 & +1.7 points respectively p < 0.001) but not for the control group. There was no difference in physical activity and screen time habits and no changes in BMI between groups at post intervention. Interview data from focus groups showed that the programme was generally well accepted. Limitations for better outcomes include the length of the programme and the school environment. Conclusion: “Health-E-PALS” intervention is a promising innovative, theory-based, culturally sensitive intervention to promote healthy eating habits and physical activity in Lebanese school children with a potential to be scaled up, replicated and sustained

Organized Surface Functional Groups: Cooperative Catalysis via Thiol/Sulfonic Acid Pairing

The synthesis and characterization of heterogeneous catalysts containing surfaces functionalized with discrete pairs of sulfonic acid and thiol groups are reported. A catalyst having acid and thiol groups separated by three carbon atoms is ca. 3 times more active than a material containing randomly distributed acid and thiol groups in the condensation of acetone and phenol to bisphenol A and 14 times more active in the condensation of cyclohexanone and phenol to bisphenol Z. Increasing the acid/thiol distance in the paired materials decreases both the activity and selectivity. This work clearly reveals the importance of nanoscale organization of two disparate functional groups on the surface of heterogeneous catalysts

RADIATION RISKS EVALUATION FROM PHOSPHATE ROCKS, SIBAIYA REGION, CENTRAL EASTERN DESERT, EGYPT

Radioactivity in the environment is caused by natural radiation (terrestrial and cosmic) and anthropogenic activities. The present work used the integrated carbone γ-ray Spectrome-ter data to the prospect of radioactive zones at Sibaiya area, Central Eastern Desert, Egypt

The downward spiral of chronic pain, prescription opioid misuse, and addiction: Cognitive, affective, and neuropsychopharmacologic pathways

Prescription opioid misuse and addiction among chronic pain patients are emerging public health concerns of considerable significance. Estimates suggest that more than 10% of chronic pain patients misuse opioid analgesics, and the number of fatalities related to nonmedical or inappropriate use of prescription opioids is climbing. Because the prevalence and adverse consequences of this threat are increasing, there is a pressing need for research that identifies the biobehavioral risk chain linking chronic pain, opioid analgesia, and addictive behaviors. To that end, the current manuscript draws upon current neuropsychopharmacologic research to provide a conceptual framework of the downward spiral leading to prescription opioid misuse and addiction among chronic pain patients receiving opioid analgesic pharmacotherapy. Addictive use of opioids is described as the outcome of a cycle initiated by chronic pain and negative affect and reinforced by opioidergic-dopamingeric interactions, leading to attentional hypervigilance for pain and drug cues, dysfunctional connectivity between self-referential and cognitive control networks in the brain, and allostatic dysregulation of stress and reward circuitry. Implications for clinical practice are discussed; multimodal, mindfulness-oriented treatment is introduced as a potentially effective approach to disrupting the downward spiral and facilitating recovery from chronic pain and opioid addiction

Views on a brief mindfulness intervention among patients with long-term illness.

BACKGROUND: Chronic illness is the leading cause of death in the UK and worldwide. Psychological therapies to support self-management have been shown to play an important role in helping those with chronic illness cope; more recently, the therapeutic benefits of mindfulness approaches have become evident for managing depression and other distressing emotions. Brief guided mindfulness interventions, are more convenient than intensive traditional programmes requiring regular attendance but have been less explored. This study assessed views on a brief (i.e., 10 min) mindfulness intervention for those with specific long-term illnesses. METHODS: Semi-structured interviews and focus groups were conducted with chronic illness patient groups (i.e., chronic obstructive pulmonary disease, chronic pain and cardiovascular disease), designed to capture the acceptability and feasibility of the intervention. The interviews were conducted after use of a mindfulness based audio in clinic and, one week later, after use in the patient's own environment. Interviews were recorded, transcribed and analysed using thematic analysis. RESULTS: In total, a combination of 18 interviews and focus groups were conducted among 14 patients. Recruitment was most successful with chronic pain patients. All patients reported benefits such as feelings of relaxation and improved coping with symptoms. While the wording and content of the audio were generally well received, it was suggested that the length could be increased, as it felt rushed, and that more guidance about the purpose of mindfulness, and when to use it, was needed. CONCLUSIONS: A brief mindfulness intervention was well accepted among patients with long-term illness. The intervention may benefit by being lengthened and by offering further guidance on its use

Using A Damper Seal To Eliminate Subsynchronous Vibrations In Three Back-To-Back Compressors.

LecturePg. 59-72A new type of labyrinth seal that reduces cross coupled rotor forces and produces a remarkable amount of damping has been invented at Texas A&M University. Laboratory tests have shown complete elimination of critical speeds under some conditions and orders of magnitude more damping than conventional labyrinth seals. The new seal acts as a damper by dynamic variations of gas pressure in large pockets around the shaft that always oppose the rotor vibratory motion. The pocket walls also serve to block the gas swirl that produces the cross coupling in conventional seals. The background is described of the invention of the new seal along with two case histories of its design, installation, and use for solving subsynchronous vibration problems in back-to-hack centrifugal compressors. In Case 1, the seal construction is of conventional metallic materials, while in Case 2, the seal is made of an amorphous copolymer with engineered properties to produce a better tolerance of shaft rubs during surge events. The subsynchronous vibration problems were solved in both cases by retrofitting the new type of seal. In Case 2, a small number of seal blades was used in order to produce large pockets with a very large damping value, and the use of engineered plastic as a seal material allowed the machine to tolerate surge and remain stable, which had not been possible with conventional labyrinth seals

Effects of a brief mindfulness-based intervention on emotional regulation and levels of mindfulness in senior students

Mindfulness-based interventions have been applied in diverse populations and achieved mental health benefits. This study examined the effects of a brief mindfulness program for emotional regulation and levels of mindfulness on senior students in Brazil. The intervention consisted of six weekly meetings attended by 30 participants. It is a pre-experimental research, with pre- and post-test comparative and correlation measurements. The preliminary results, which relied on parametrical and non-parametrical tests, revealed a reduction in total emotional regulation difficulties (p = 0.0001; r = − 0.55). Also, there was an increase in the levels of mindfulness in the subtests for both dimensions under evaluation: “Awareness” (p = 0.0001; d = 0.77) and “Acceptance” (p = 0.048; d = 0.37). By associating the amount of meditative practices performed by students with the variables, a significant positive correlation was found with the mindfulness dimension “Awareness” (rP = 0.422; p = 0.020), and there was a significant negative correlation with Difficulties in emotion regulation (rS = − 0.478; p = 0.008) and with its respective subscales “Non-acceptance” (rS = − 0.654; p = 0.0001) and “Clarity” (rS = − 0.463; p = 0.010). In conclusion, the application of a brief mindfulness-based intervention is promising in Brazilian university contexts; moreover, it can bring benefits to students, e.g., an increase in emotion regulation as well as in levels of mindfulness. We suggest that further research should use an experimental design and follow-up.info:eu-repo/semantics/publishedVersio

Restructuring of colloidal aggregates in shear flow: Coupling interparticle contact models with Stokesian dynamics

A method to couple interparticle contact models with Stokesian dynamics (SD) is introduced to simulate colloidal aggregates under flow conditions. The contact model mimics both the elastic and plastic behavior of the cohesive connections between particles within clusters. Owing to this, clusters can maintain their structures under low stress while restructuring or even breakage may occur under sufficiently high stress conditions. SD is an efficient method to deal with the long-ranged and many-body nature of hydrodynamic interactions for low Reynolds number flows. By using such a coupled model, the restructuring of colloidal aggregates under stepwise increasing shear flows was studied. Irreversible compaction occurs due to the increase of hydrodynamic stress on clusters. Results show that the greater part of the fractal clusters are compacted to rod-shaped packed structures, while the others show isotropic compaction.Comment: A simulation movie be found at http://www-levich.engr.ccny.cuny.edu/~seto/sites/colloidal_aggregates_shearflow.htm

Triaxial Deformation and Nuclear Shape Transition in \u3csup\u3e192\u3c/sup\u3eAu

Background: Nuclei in the A≈190 mass region show gradual shape changes from prolate through nonaxial deformed shapes and ultimately towards spherical shapes as the Pb region is approached. Exploring how this shape evolution occurs will help us understand the evolution of collectivity in this region. Purpose: The level scheme of the 192Au nucleus in A ≈ 190 region was studied in order to deduce its deformations. Methods: High-spin states of 192Au have been populated in the 186W(11B, 5n) reaction at a beam energy of 68 MeV and their γ decay was studied using the YRAST Ball detector array at the Wright Nuclear Structure Laboratory (WNSL), Yale University. Results: Based on double and triple γ-ray coincidence data the level scheme of 192Au has been extended up to Iπ = 32+ at an excitation energy of ∼6 MeV. Conclusion: The results are discussed in the framework of pairing and deformation self-consistent total Routhian surface (TRS) and cranked shell model (CSM) calculations. The comparison of the experimental observations with the calculations indicates that this nucleus takes a nonaxial shape similar to other Au nuclei in this region