Hydrogen evolution reaction (HER) is one of the most important reactions in electrochemistry. This is not only because it is the simplest way to produce high purity hydrogen and the fact that it is the side reaction in many other technologies. HER actually shaped current electrochemistry because it was in focus of active research for so many years (and it still is). The number of catalysts investigated for HER is immense, and it is not possible to overview them all. In fact, it seems that the complexity of the field overcomes the complexity of HER. The aim of this review is to point out some of the latest developments in HER catalysis, current directions and some of the missing links between a single crystal, nanosized supported catalysts and recently emerging, single-atom catalysts for HER.
Abstract The short-lived 182Hf-182W isotope system (t1/2 = 9 Ma) left evidence in both ancient and modern terrestrial rock record of processes that took place during the earliest stages of Earth’s accretionary and differentiation history. We report µ182W values (the deviation of 182W/184W of a sample from that of laboratory standards, in parts per million) and corresponding 3He/4He ratios for rocks from 15 different hotspots. These rocks are characterized by µ182W values that range from ∼0 to as low as −23 ± 4.5. For each volcanic system that includes rocks with negative µ182W values, the values tend to be negatively correlated with 3He/4He. The W-He isotopic characteristics of all samples can be successfully modeled via mixing involving at least three mantle source reservoirs with distinct µ182W-3He/4He characteristics. One reservoir has 3He/4He ≈ 8 R/RA and μ182W ≈ 0, which is indistinguishable from the convecting upper mantle. Based on high 3He/4He, the other two reservoirs are presumed to be relatively un-degassed and likely primordial. One reservoir is characterized by µ182W ≈ 0, while the other is characterized by µ182W ≤ −23. The former reservoir likely formed from a silicate differentiation process more than 60 Myr after the origin of the solar system, but has remained partially or wholly isolated from the rest of the mantle for most of Earth history. The latter reservoir most likely includes a component that formed while 182Hf was extant. Mass balance constraints on the isotopic composition of the core suggest it has a strongly negative µ182W value of ∼−220. Thus, it is a candidate for the origin of the negative µ182W in the plume sources. Mixing models show that the direct addition of outer core metal into a plume rising from the core-mantle boundary would result in collateral geochemical effects, particularly in the abundances of highly siderophile elements, which are not observed in OIB. Instead, the reservoir characterized by negative µ182W most likely formed in the lowermost mantle as a result of core-mantle isotopic equilibration. The envisioned equilibration process would raise the W concentration and lower the µ182W of the resulting silicate reservoir, relative to the rest of the mantle. The small proportion (
BACKGROUND/AIMS With the growing popularity of water polo across the world, there has been rising awareness of the risks for orofacial injures in water polo. The aim of this study was to evaluate knowledge and attitudes of water polo coaches regarding dental trauma, dental emergency procedures and awareness about prevention of such injuries. MATERIALS AND METHODS A specific questionnaire comprising 25 questions regarding knowledge, experiences and behaviors following dental trauma was distributed to 62 water polo coaches during the license renewal seminar held by the Croatian Water Polo Federation, in February 2018 in Split, Croatia. Chi-square with Yates correction when necessary, and Fisher's exact tests were used in statistical analysis, and the results were considered statistically significant when P < 0.05. RESULTS There were 51 water polo coaches who participated in this study. Their ages ranged from 19 to 60 years. Most of the coaches (90.2%) have seen a dental injury in their players during their coaching careers. Concerning the procedure with handling an avulsed tooth, there were 68.6% coaches who would maintain the avulsed tooth in a handkerchief or gauze along with four coaches (7.8%) who would rinse the avulsed tooth under water and wrap it in a handkerchief or gauze afterwards. Only one participant (2%) would maintain the avulsed tooth in saline solution before its replantation. None of the coaches would use milk for maintaining the avulsed tooth. Only seven coaches (13.7%) have previously had education about sports-related dental injuries, dental emergency procedures and prevention of such injuries. CONCLUSIONS The results of this study demonstrated poor level of knowledge of water polo coaches about dental injuries and dental emergency procedures. Their knowledge and attitudes could be improved by educational programs on dental injuries and dental emergency procedures, as well as sports-related dental injuries management.
Background: The aim of the study was to address the working population with an occupational stress prevention program using mHealth solution and encourage healthy lifestyle choices.Methods: 16 participants were randomized from the corporate setting. A 24alife app with a good compliance program was selected. Test battery has been designed to test the physical readiness, psychological state of stress and to assess biological blood markers for stress. Participants were followed up after 30, 60 and 90 days, respectively, within the intervention period. Blood pressure and weight were tracked 3 times per month. At least once a week, but on average 6 times per month, participants also led the food diary. Univariate analysis compared the continuous variables by Student's t-test for the data that were normally distributed, or Wilcoxon rank sum test for abnormal distribution of variables.Results: Participants used the app with a compliance rate of 100%. The psychological evaluation revealed higher motivation for work, lower burnout scores and participants gave subjective responses of better general wellbeing. Some of the participants lost up to 4 kg of body mass. Physical readiness has significantly improved.Conclusions: Results of mHealth projects on corporate could include primary health care institutions and health ministry to extend the existing system to patients’ pockets where they can monitor their disease and increase the ability of self-care.
Male Eurasian jays were previously reported to alter their food-sharing response in line with the specific satiety of their female partner. Here, we tested the flexibility of the same males’ food-sharing behavior by testing whether they can process information from contextual cues that predict the opposite pattern of food shared to that observed in previous studies. In Experiment 1, we manipulated the amount of food eaten by the females in a choice context before males shared with them. In Experiment 2, we manipulated the identity of the non-chosen food that was available in a choice context before males shared with the females. In both experiments, males showed flexibility in their sharing pattern in a comparison between the experimental and control conditions. In Experiment 1, this observed pattern appears to be based on the males’ response to the amount of food eaten by the female, and in Experiment 2, it appears to be based on the males’ response to the choice context in which the female’s eating took place. Although the experimental conditions in Experiments 1 and 2 were conceptual replications, the predicted pattern of food shared by the males was detected only in the latter. While replications are needed to test the generalizability and robustness of these results, the current study provides a first set of data in line with the hypothesis that the Eurasian jay males may be able to flexibly adjust their food-sharing behavior to contextual cues. Raw data are available at 10.5281/zenodo.3633986, and code and meta-data are available at https://osf.io/n9rcd/.
OBJECTIVE A 15-year-experience of the personal modification of Misgav Ladach (ML) caesarean section in relation to the Dörffler method. STUDY DESIGN A retrospective clinical randomized observational study included 822 transperitoneal cesarean sections: 557 were performed via modified ML (without bladder catheterization, small transverse fascial incision with muscular stretching and non-preparation of vesicouterine plica) vs. 265 Dörffler (Pfannenstiel - Kerr) method. RESULTS Perioperative and postoperative complications were significantly more frequent in the Dörffler method (p < 0.0005) (perioperative hemorrhage, more frequent adhesions, plastic peritonitis in repeated caesarean sections, as well as two bladder lesions). Postoperative febrility, dehiscence and wound seroma were more frequent in the first study group (p < 0.0005). More frequent paralytic ileus, uroinfections and bladder atony, which we did not observe in our own technique (p < 0.0005). The use of antibiotics and analgesics was prolonged until the fifth postoperative day in the first group compared to the second group where it was reduced to only 10 % on the second day (p < 0.0005). Also, the incidence of anemia and the need for blood transfusions were higher in the first study group, as well as the need for revision behind caesarean section and two hysterectomies due to massive postoperative intraperitoneal and retroperitoneal bleeding (p < 0.0005). CONCLUSION Our fifteen-year study highlighted the importance of our own published modified ML caesarean section in minimizing technique of surgery and the reduction of perioperative morbidity and significantly faster recovery of operated patients in the current era of enormous caesarean section increase.
This paper explores ethno-villages in Bosnia and Herzegovina as an important element of rural and cultural tourism. The attractiveness of natural and cultural heritage is very important for sustainable rural tourism development. In order to improve the process of decision making to enable the sustainable development of ethno-villages, a multi-criteria assessment model has been developed. The methodology is based on qualitative modeling using a multi-criteria analysis via the DEXi software. The model is based on hierarchical relations consisting of three main criteria that are the basis of sustainable tourism development: economic, social, and environmental criteria. The ultimate goal of the model in this study was to evaluate ethno-villages, namely six ethno-villages in Bosnia and Herzegovina. The results of the study show how ethno-villages contribute to sustainable development.
The application of different evaluation approaches in logistics requires considering many factors with different significance for making the final decision. Multi-criteria decision-making (MCDM) methods are often applied in logistics to create different strategies and evaluations. In this paper, research has been carried out in a transport system of an international transport company. An MCDM model has been created for the purpose of human resource evaluation, on which the overall efficiency of the company depends. A total of 23 drivers were evaluated on the basis of five crucial criteria in order to increase employees’ motivation through their periodic remuneration. The Full Consistency Method (FUCOM) was applied to determine the significance of the criteria, while the evaluation of potential solutions was performed using Measurement Alternatives and Ranking according to COmpromise Solution (MARCOS). After the results had been obtained, the created model was validated throughout comparisons with seven other MCDM methods.
Purpose We examined ideas about how youth would mitigate non-medical use of prescription medications among their peers. Design/methodology/approach The National Monitoring of Adolescent Prescription Stimulants Study (N-MAPSS) interviewed 11,048 youth10-18 years of age between 2008 and 2011 from entertainment venues of 10 US urban, suburban, and rural areas. Using a mixed-methods approach, participants completed a survey culminating in open ended questions asking: 1) How should kids your age be told about prescription drugs and their effects?; 2) If you ran the world, how would you stop kids from taking other people's prescription medicines?; 3)Why do people use prescription stimulants without a prescription? Responses from a random sample of 900 children were analyzed using qualitative thematic analyses. Findings The random sample of 900 youth (52% female, 40% white, with a mean age was 15.1 years) believed they should be educated about prescription drugs and their negative effects at schools, at home by parents, through the media, and health professionals. Youth would stop kids from using other people's prescription drugs through more stringent laws that restricted use, and education about negative consequences of use. Peer pressure was the most common reason youth gave for using other's pills, though some reported using for curiosity. Originality/value This analysis shows the importance of considering youth's opinions on non-medical use of prescription medications, which are often overlooked. Studies should disseminate this data from youth to stop the illicit use of prescription drugs among teens and youth.
Instead of the commonly used chemical doping, it can be more favorable to consider transforming graphene through proximity effects by carefully choosing its adjacent regions. While gate-tunable room-temperature spin-dependent properties could be induced in graphene by magnetic proximity effects from common metallic ferromagnets, this approach is complicated by chemical bonding between a metal and graphene suggesting the need for an intervening buffer layer. However, even with a buffer layer there is still a large energy shift of the Dirac cone in graphene away from the Fermi level. Compared to such a large negative shift and its resulting $n$-doping when graphene is separated from cobalt by a monolayer h-BN or another layer of graphene, we show that it can be favorable to instead separate graphene by a monolayer of gold or platinum. The resulting proximity induced magnetization is larger, energy shift is somewhat reduced and changes its sign, offering a path for proximity-induced spin polarization in graphene which can be tuned at smaller gate-controlled electric field than for the h-BN buffer layer.
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