Boosted output performance of triboelectric nanogenerator via electric double layer effect

For existing triboelectric nanogenerators ( TENGs), it is important to explore unique methods to further enhance the output power under realistic environments to speed up their commercialization. We report here a practical TENG composed of three layers, in which the key layer, an electric double layer, is inserted between a top layer, made of Al/polydimethylsiloxane, and a bottom layer, made of Al. The efficient charge separation in the middle layer, based on Volta's electrophorus, results from sequential contact configuration of the TENG and direct electrical connection of the middle layer to the earth. A sustainable and enhanced output performance of 1.22mA and 46.8 mW cm(-2) under low frequency of 3 Hz is produced, giving over 16-fold enhancement in output power and corresponding to energy conversion efficiency of 22.4%. Finally, a portable power-supplying system, which provides enough d.c. power for charging a smart watch or phone battery, is also successfully developed.ope

Cell motility: the integrating role of the plasma membrane

The plasma membrane is of central importance in the motility process. It defines the boundary separating the intracellular and extracellular environments, and mediates the interactions between a motile cell and its environment. Furthermore, the membrane serves as a dynamic platform for localization of various components which actively participate in all aspects of the motility process, including force generation, adhesion, signaling, and regulation. Membrane transport between internal membranes and the plasma membrane, and in particular polarized membrane transport, facilitates continuous reorganization of the plasma membrane and is thought to be involved in maintaining polarity and recycling of essential components in some motile cell types. Beyond its biochemical composition, the mechanical characteristics of the plasma membrane and, in particular, membrane tension are of central importance in cell motility; membrane tension affects the rates of all the processes which involve membrane deformation including edge extension, endocytosis, and exocytosis. Most importantly, the mechanical characteristics of the membrane and its biochemical composition are tightly intertwined; membrane tension and local curvature are largely determined by the biochemical composition of the membrane and the biochemical reactions taking place; at the same time, curvature and tension affect the localization of components and reaction rates. This review focuses on this dynamic interplay and the feedbacks between the biochemical and biophysical characteristics of the membrane and their effects on cell movement. New insight on these will be crucial for understanding the motility process

Tailored Print Communication and Telephone Motivational Interviewing Are Equally Successful in Improving Multiple Lifestyle Behaviors in a Randomized Controlled Trial

Background: Computer tailoring and motivational interviewing show promise in promoting lifestyle change, despite few head-to-head comparative studies. Purpose: Vitalum is a randomized controlled trial in which the efficacy of these methods was compared in changing physical activity and fruit and vegetable consumption in middle-aged Dutch adults. Methods: Participants (n?=?1,629) were recruited via 23 general practices and randomly received either four tailored print letters, four motivational telephone calls, two of each type of intervention, or no information. The primary outcomes were absolute change in self-reported physical activity and fruit and vegetable consumption. Results: All three intervention groups (i.e., the tailored letters, the motivational calls, and the combined version) were equally and significantly more effective than the control group in increasing physical activity (hours/day), intake of fruit (servings/day), and consumption of vegetables (grams/day) from baseline to the intermediate measurement (week 25), follow-up 1 (week 47) and 2 (week 73). Effect sizes (Cohen's d) ranged from 0.15 to 0.18. Participants rated the interventions positively; interviews were more positively evaluated than letters. Conclusions: Tailored print communication and telephone motivational interviewing or their combination are equally successful in changing multiple behaviors. © 2010 The Author(s)

Perceived need to increase physical activity levels among adults at high risk of type 2 diabetes. A cross-sectional analysis within a community-based diabetes prevention project FIN-D2D

Background. Increased physical activity is a cornerstone of type 2 diabetes prevention. The perception of a need to change is considered essential in behaviour change processes. However, the existing literature on individuals' perceived need to change health behaviour is limited. In order to improve understanding of diabetes prevention through increased physical activity levels (PAL), we assessed factors associated with perceiving a need to increase PAL among adults at high risk of diabetes. Methods. Opportunistic screening was used within a primary-care based lifestyle intervention covering 10 149 men and women at high risk of type 2 diabetes. Data were obtained at baseline visits. The explored determinants were demographic, anthropometric/clinical, behavioural and psychosocial characteristics, along with four categories of PAL awareness. Logistic regression was used in the analysis. Results. 74% of men (n=2 577) and 76% of women (n=4 551) perceived a need to increase their PAL. The participants most likely to perceive this need were inactive, had a larger waist circumference, rated their PAL as insufficient, and were at the contemplation stage of change. Smoking, elevated blood pressure, dyslipidaemia, and a family history of diabetes were not associated with this perception. The likelihood was also greater among women with less perceived fitness and less education. Demographic factors other than education did not determine participants' perceived need to increase PAL. PAL overestimators were less likely to perceive the need to increase their PAL than realistic inactive participants. Conclusions. Subjective rather than objective health factors appear to determine the perception of a need to increase PAL among adults at high risk of diabetes. Client perceptions need to be evaluated in health counselling in order to facilitate a change in PAL. Practical descriptions of the associations between metabolic risk factors, PAL, and diabetes are needed in order to make the risk factors concrete for at-risk individuals.peerReviewe

Experimental model of severe acute pancreatitis in rabbits Modelo experimental de pancreatite aguda grave em coelhos

PURPOSE: To develop an experimental model of severe acute pancreatitis in rabbits through a pancreatic ductal injection of sodium taurocholate. METHODS: Twenty-four albino rabbits of the New Zealand lineage were distributed into four groups of six animals (A, B, C and S). The rabbits of three experimental groups (A, B and C) were submitted to a laparatomy and received a pancreatic ductal injection of 1ml/kg sodium taurocholate 5%. Also, they were submitted to further laparatomies after 4h, 8h and 12h, respectively. The control group (S) was subdivided into two groups of three animals: in subgroup S1 only the pancreatic duct catheterization was performed whereas in subgroup S2 the pancreatic duct catheterization as well as an injection of 1ml/kg physiologic solution 0.9% were carried out. After 12 hours, the rabbits were evaluated. In the re-intervention, blood was collected to determine the amylasemia and a pancreatectomy was carried out to investigate interstitial infiltration, steatonecrosis and necrosis of the organ, using an optical microscope. RESULTS: There was an elevation of amylase in all groups thus proving the existence of acute pancreatitis. The size of the interlobular septum increased progressively with a greater variation between group S1 (0.13) and group C (0. 53) (p=0.035). While all the animals in group A exhibited focal cellular necrosis, it was more intense in the rabbits of group B and culminated with a high proportion of severe pancreatic necrosis in group C animals. The difference in the intensity of cellular necrosis showed statistic significance (p=0.001). CONCLUSION: The proposed experimental model demonstrated its reproducibility and effectiveness in producing severe acute pancreatitis in rabbits.<br>OBJETIVO: Desenvolver modelo experimental de pancreatite aguda grave em coelhos por meio da injeção de taurocolato de sódio no ducto pancreático. MÉTODOS: Vinte e quatro coelhos albinos da linhagem Nova Zelândia foram distribuídos em quatro grupos de seis animais (A, B, C e S). Os coelhos dos três grupos experimentais (A, B e C) foram submetidos a laparotomia e injetou-se taurocolato de sódio a 5%, 1ml/Kg no ducto pancreático. Realizou-se nova laparotomia, respectivamente, após 4h, 8h e 12h. No grupo controle (S), subdividido em dois grupos de três animais, foi realizada no subgrupo S1 apenas cateterização do ducto pancreático e no subgrupo S2 cateterização do ducto pancreático e injeção de solução fisiológica 0,9%, 1ml/Kg. Estes animais foram reavaliados após 12 horas. Na reintervenção coletou-se sangue para determinação da amilasemia e realizou-se pancreatectomia para análise histológica do infiltrado intersticial, da esteatonecrose e da necrose do órgão. RESULTADOS: Houve elevação da amilase em todos os grupos, demonstrando a presença da pancreatite aguda. O tamanho do septo interlobular aumentou progressivamente, observando-se maior diferença entre os grupos S1 (0,13) e C (0,53) (p=0,035). Todos os animais do grupo A apresentaram necrose celular focal que se tornou mais intensa nos coelhos do grupo B, culminando com o predomínio de necrose pancreática acentuada nos animais do grupo C. A diferença na intensidade da necrose celular apresentou significância estatística (p=0,001). CONCLUSÃO: O modelo experimental proposto se mostrou reprodutível e efetivo em provocar pancreatite aguda grave em coelhos

Readiness to change is a predictor of reduced substance use involvement: Findings from a randomized controlled trial of patients attending South African emergency departments

Background: This study examines whether readiness to change is a predictor of substance use outcomes and explores factors associated with RTC substance use among patients at South African emergency departments. Methods: We use data from participants enrolled into a randomized controlled trial of a brief substance use intervention conducted in three emergency departments in Cape Town, South Africa. Results: In adjusted analyses, the SOCRATES "Recognition" (B = 11.6; 95 % CI = 6.2-17.0) and "Taking Steps" score (B = -9.5; 95 % CI = -15.5- -3.5) as well as alcohol problems (B = 4.4; 95 % CI = 0.9-7.9) predicted change in substance use involvement at 3 month follow-up. Severity of depression (B = 0.2; 95 % CI = 0.1-0.3), methamphetamine use (B = 3.4; 95 % CI = 0.5- 6.3) and substance-related injury (B = 1.9; 95 % CI = 0.6-3.2) were associated with greater recognition of the need for change. Depression (B = 0.1; 95 % CI = 0.04 -0.1) and methamphetamine use (B = 2.3; 95 % CI = 0.1 -4.2) were also associated with more ambivalence about whether to change. Participants who presented with an injury that was preceded by substance use were less likely to be taking steps to reduce their substance use compared to individuals who did not (B = -1.7; 95 % CI = -5.0- -0.6). Conclusion: Findings suggest that brief interventions for this population should include a strong focus on building readiness to change substance use through motivational enhancement strategies. Findings also suggest that providing additional support to individuals with depression may enhance intervention outcomes. Trial registration: This trial registered with the Pan African Clinical Trial Registry ( PACTR201308000591418 ) on 14/07/2013