Speed and surface steepness affect internal tibial loading during running

Background:Internal tibial loading is influenced by modifiable factors with implications for the risk of stress injury.Runners encounter varied surface steepness(gradients)when running outdoors and may adapt their speed according to the gradient.This study aimed to quantify tibial bending moments and stress at the anterior and posterior peripheries when running at different speeds on surfaces of different gradients.Methods:Twenty recreational runners ran on a treadmill at 3 different speeds(2.5 m/s,3.0 m/s,and 3.5 m/s)and gradients(level:0%;uphill:+5%,+10%,and+15%;downhill:-5%,-10%,and-15%).Force and marker data were collected synchronously throughout.Bending moments were estimated at the distal third centroid of the tibia about the medial-lateral axis by ensuring static equilibrium at each 1%of stance.Stress was derived from bending moments at the anterior and posterior peripheries by modeling the tibia as a hollow ellipse.Two-way repeated-measures analysis of variance were conducted using both functional and discrete statistical analyses.Results:There were significant main effects for running speed and gradient on peak bending moments and peak anterior and posterior stress.Higher running speeds resulted in greater tibial loading.Running uphill at+10%and+15%resulted in greater tibial loading than level running.Running downhill at-10%and-15%resulted in reduced tibial loading compared to level running.There was no difference between+5%or-5%and level running.Conclusion:Running at faster speeds and uphill on gradients≥+10%increased internal tibial loading,whereas slower running and downhill running on gradients≥-10%reduced internal loading.Adapting running speed according to the gradient could be a protective mechanism,providing runners with a strategy to minimize the risk of tibial stress injuries.

How discrimination and participation are associated with psychosomatic problems among boys and girls in northern Sweden

Background: Negative impact on health from school disturbance due to asymmetric power relations such as discrimination and offensive treatment are frequent problems among students. This study sought to analyze associations between occurrence of discrimination at schools, participation and psychosomatic problems. Methods: Pupils in grades 6 - 9 in ten schools in a northern Swedish municipality participated in the study. The frequency of discrimination at school was measured by six items: sex;culture or ethnicity;disability;religion beliefs;sexual preferences;and any other form of discrimination. The Social and Civic Objectives Scale (SCOS) was used for an estimation of the level of participation. The pupils’ health was measured by the PsychoSomatic Problem (PSP) scale. Multivariate logistic regression models were used for estimation of increased risk of PSP. The formula Z = d/s(d) was used to test mediation. Results: Two thirds of the boys and three fourths of the girls reported occurrences of discrimination at schools (p = 0.001). Discrimination was a mediating factor between participation and PSP among boys and girls as the mediating formula Z = d/s (d) was > ± 2 SD, -2.59 for boys and -39.27 for girls. Independent of each other, low participation and discrimination were associated with increased risk of PSP. Conclusion: Discrimination was a mediating factor between participation and PSP. The mediating effect was stronger in girls than in boys. There is a need for school health promotion programs focusing on participation in terms of democratic processes, communication and cooperation in the classroom.

Workplace Health Interventions and Physical Fitness Status among Managers of Small-Scale Enterprises in Norway and Sweden

Background: The ability of managers of small-scale enterprises (SSEs) to prioritize health, working conditions, and their own physical fitness is an important issue for workplace health promotion in Norway and Sweden, where most owner-manager positions are in SSEs. Aim: To assess the physical fitness status of SSE managers compared to a norm population and to study changes in physical fitness status, self-reported physical activity, and sickness outcomes after workplace health interventions. Methods: The study allocated SSE managers to either an intervention or a reference group. The intervention, over twelve months, consisted of motivational input related to lifestyle and physical activity through tests and feedback, individual support, and courses on health and psychosocial working conditions. The participants (N = 28) completed health screening checks, questionnaires and testing before and after the intervention. Results: SSE managers in the study had positive outcomes for BMI levels and strength compared to the norm population, while percentage of fat for both men and women indicated poor results. There were no further improvements in the intervention group after comparison with the reference group. Separately, both groups seemed to improve strength and body composition. Conclusion: Workplace health interventions with essentially motivational components may increase SSE managers’ attention to physical fitness, but appear to have limited effects on objective and subjective physical fitness outcomes.

天然微藻水热炭理化特性及热解动力学研究

为探索天然微藻资源化的利用途径,该文以天然栅藻为原料,采用傅立叶转换红外线光谱分析,X射线衍射分析,X射线荧光光谱分析,环境扫描电子显微镜与热重分析仪对水热炭进行测试分析。研究结果表明,随着水热温度的升高,水热炭产率从47.29%(180℃)降低至43.01%(240%);水热炭的O/C摩尔比从1.45减小至0.28,碳化程度加强,水热炭具有应用于固体燃料的潜力。鉴于水热炭含有大量灰分,其热值为8.43~9.67MJ/kg,因此脱灰预处理是必要的过程。经过水热碳化处理,天然栅藻的比表面积从4.36m^2/g增加到35.26m^2/g。热解动力学结果表明随着水热温度的提高,水热炭的热稳定性增强。研究结果对天然微藻的资源化利用提供了一定的理论参考。

微藻水热液化制取生物油的研究进展

微藻生产成本低,酯类和甘油含量较高,是制备液体燃料的理想原料。水热液化由于可直接处理湿藻并在适当的温度和压力下将其转化为高品质的石油替代产品而引起了广泛关注。本文探讨了微藻三组分,即蛋白质、脂质和碳水化合物的水热降解途径,并总结了目前微藻水热液化过程的主要影响因素,包括温度、停留时间、溶剂以及催化剂等反应条件或参数对生物油的影响。指出为提高微藻生物油的经济性,应进一步优化反应条件,降低催化剂成本,加强微藻水热定向液化技术的研究,富集液体产品中高附加值成分,实现高附加值化学品的综合利用,尽快实现微藻生物油的应用。

The influence of physiobiomechanical parameters,technical aspects of shooting,and psychophysiological factors on biathlon performance:A review

The biathlon, an Olympic sporting discipline that combines cross-country skiing with rifle marksmanship, entails considerable physiological demands, as well as fine motor control while shooting after intense exercise and under mental pressure. Although much of our knowledge about cross-country skiing is probably also applicable to the biathlon, carrying the rifle and shooting under stress make this discipline somewhat unique. The present review summarizes and examines the scientific literature related to biathlon performance, with a focus on physiological and biomechanical factors and shooting technique, as well as psychophysiological aspects of shooting performance. We conclude with suggestions for future research designed to extend our knowledge about the biathlon, which is presently quite limited.

Pacing and predictors of performance during cross-country skiing races:A systematic review

Background: Cross-country skiing(XCS) racing, a popular international winter sport, is complex and challenging from physical, technical, and tactical perspectives. Despite the vast amount of research focusing on this sport, no review has yet addressed the pacing strategies of elite XCS racers or the factors that influence their performance. The aim was to review the scientific literature in an attempt to determine the effects of pacing strategy on the performance of elite XCS racers.Methods: Four electronic databases were searched using relevant subject headings and keywords. Only original research articles published in peerreviewed journals and the English language and addressing performance, biomechanics, physiology, and anthropometry of XCS racers were reviewed.Results: All 27 included articles applied correlative designs to study the effectiveness of different pacing strategies. None of the articles involved the use of an experimental design. Furthermore, potential changes in external conditions(e.g., weather, ski properties) were not taken into consideration. A comparable number of studies focused on the skating or classical technique. In most cases, positive pacing was observed, with certain indications that higher-level athletes and those with more endurance and strength utilized a more even pacing strategy. The ability to achieve and maintain a long cycle length on all types of terrain was an important determinant of performance in all of the included studies, which was not the case for cycle rate. In general, uphill performance was closely related to overall race performance, with uphill performance being most closely correlated to the success of female skiers and performance on flat terrain being more important for male skiers. Moreover, pacing was coupled to the selection and distribution of technique during a race, with faster skiers employing more double poling and kick double poling,less diagonal stride, and more V2(double dance) than V1(single dance) skating across a race.Conclusion: We propose that skiers at all levels can improve their performance with more specific training in techniques(i.e., maintaining long cycles without compromising cycle rate and selecting appropriate techniques) in combination with training for endurance and more strength. Furthermore, we would advise less experienced skiers and/or those with lower levels of performance to apply a more even pacing strategy rather than a positive one(i.e., starting the race too fast).

Laser-Etched Stretchable Graphene-Polymer Composite Array for Sensitive Strain and Viscosity Sensors

The ability to control surface wettability and liquid spreading on textured surfaces is of interest for extensive applications.Soft materials have prominent advantages for producing the smart coatings with multiple functions for strain sensing.Here,we report a simple method to prepare flexible hydrophobic smart coatings using graphene-polymer films.Arrays of individual patterns in the films were created by laser engraving and controlled the contact angle of small drops by pinning the contact lines in a horizontal tensile range of 0-200%.By means of experiments and model,we demonstrate that the ductility of drops is relied on the height-to-spacing ratio of the individual pattern and the intrinsic contact angle.Moreover,the change of drop size was utilized to measure the applied strain and liquid viscosity,enabling a strain sensitivity as high as 1068μm2/%.The proposed laser-etched stretchable graphene-polymer composite has potential applications in DNA microarrays,biological assays,soft robots,and so on.

Maximizing recovery time between knock-out races improves sprint cross-country skiing performance

Background:In a sprint cross-country(XC)ski competition,the difference in recovery times separating the first and the second semi-final(SF)heats from the final(F)may affect performance.The aim of the current study was to compare the effects of longer vs.shorter recovery periods prescribed between the 3 knock-out races of a simulated sprint XC ski competition involving a prologue(P),quarter-final(QF),SF,and F.Methods:Eleven well-trained XC ski athletes completed 2 simulated sprint XC ski competitions on a treadmill involving 4×883-m roller-ski bouts at a 4°incline using the gear 3 ski-skating sub-technique.The first 3 bouts were completed at a fixed speed(PFIX,QFFIX,and SFFIX)corresponding to~96%of each individual’s previously determined maximal effort.The final bout was performed as a self-paced sprint time trial(FSTT).Test conditions differed by the time durations prescribed between the QFFIX,SFFIX,and FSTT,which simulated real-world XC ski competition conditions using maximum(MAX-REC)or minimum(MIN-REC)recovery periods.Results:The FSTT was completed 5.4±5.5 s faster(p=0.009)during MAX-REC(179.2±18.1 s)compared to MIN-REC(184.6±20.0 s),and this was linked to a significantly higher power output(p=0.010)and total metabolic rate(p=0.009).The pre FSTT blood lactate(BLa)concentration was significantly lower during MAX-REC compared to MIN-REC(2.5±0.8 mmol/L vs.3.6±1.6 mmol/L,respectively;p=0.027),and the pre-to-post FSTT increase in BLa was greater(8.8±2.1 mmol/L vs.7.1±2.3 mmol/L,respectively;p=0.024).No other differences for MAX-REC vs.MIN-REC reached significance(p>0.05).Conclusion:Performance in a group of well-trained XC skiers is negatively affected when recovery times between sprint heats are minimized which,in competition conditions,would occur when selecting the last QF heat.This result is combined with a higher pre-race BLa concentration and a reduced rise in BLa concentration under shorter recovery conditions.These findings may help inform decision making when XC skiers are faced with selecting a QF heat within a sprint competition.

Structure, Performance, and Application of BiFeO_(3) Nanomaterials

Multiferroic nanomaterials have attracted great interest due to simultaneous two or more properties such as ferroelectricity,ferromagnetism,and ferroelasticity,which can promise a broad application in multifunctional,lowpower consumption,environmentally friendly devices.Bismuth ferrite(BiFeO3,BFO)exhibits both(anti)ferromagnetic and ferroelectric properties at room temperature.Thus,it has played an increasingly important role in multiferroic system.In this review,we systematically discussed the developments of BFO nanomaterials including morphology,structures,properties,and potential applications in multiferroic devices with novel functions.Even the opportunities and challenges were all analyzed and summarized.We hope this review can act as an updating and encourage more researchers to push on the development of BFO nanomaterials in the future.

Estimation of a basal area growth model for individual trees in uneven-aged Caspian mixed species forests

The aim of this study was to estimate a basal area growth model for individual trees in uneven-aged Caspian forests.A survey was conducted in order to find a natural forest without any harvesting activities,a so called ＇untouched forest＇ and an area was selected from the Iranian Caspian forest.Three sample plots in the same aspect and of the same forest type were selected.In each plot,total tree height,diameter at breast height,distance of neighbor trees and azimuth were measured.Thirty trees were selected and drilled with increment borer to determine the increment model.Regression analysis was used to estimate the growth model.Results show that,for individual trees,there is a significant nonlinear relationship between the annual basal area increment,as the dependent variable,and the basal area.The results also show that the basal area of competing trees has a positive influence on growth.That the increment is higher with more competing neighboring trees is possibly because plots with higher volume per hectare and more competition,most likely also have higher site index or better soil or better site productivity than the plot with lower volume per hectare.

柔性版印刷中瓦楞纸板的印刷均匀性--瓦楞纸板对网目调网点变形的影响

印刷不均匀性是柔性版印刷的一个常见问题。多数印刷的不均匀性都被认为是由瓦楞纸板的结构本身引起的。虽然其他印刷质量问题也可能与结构有关,但条杠是最明显的一种。本文致力于研究纸板变形导致印刷不均匀性的原因,以及网目调柔性版印刷中条杠产生的机理。本文用有限的因子模型,分析在一定印刷压力下,瓦楞纸板的变形对网目调网点变形的影响。结果表明,由湿压压力不均匀引起的纸板变形被认为是引起印刷不均匀的一个潜在原因。瓦楞结构中楞峰和楞谷处不同的网点增大值造成了网目调印刷品的条杠。

Resistance Training in People at Risk of Developing Type 2 Diabetes and Their Experience of Health-Related Quality of Life

Background: Research indicates an association between impaired glucose metabolism and overweight, a serious public health problem involving an increased risk of Type 2 diabetes, related hypertension, and a reduced quality of life. Aim: The first aim is to assess different dimensions of Health-Related Quality of Life (HRQoL) in overweight individuals at risk of developing Type 2 diabetes compared to a normal population. The second aim is to examine the impact of resistance training on the pre-post HRQoL dimension scores of the intervention group. Methods: Eighteen participants were randomly assigned to one of the two resistance training groups. Group 1 engaged in supervised maximal resistance training (Bernstein inverted pyramid system: 5× 3 - 4, 60% - 85% of 1 Repetition Maximum (RM)), three days/week over four months, and Group 2 performed endurance resistance training (including lower weight loads and more repetitions over four months). The intervention consisted of eight exercises involving the entire body. The subjects completed the Short-Form Health Survey (SF-36) on HRQoL. The HRQoL scores of the norm population were higher than those of people at risk of developing Type 2 diabetes, and resistance training seemed to have a limited significant positive effect on the different HRQoL dimensions.

Biomechanical analysis of the "running" vs. "conventional" diagonal stride uphill techniques as performed by elite cross-country skiers

Purpose:This study aimed to compare biomechanical aspects of a novel"running"diagonal stride(DSRUN)with"conventional"diagonal stride(DSCONV)skiing techniques performed at high speed.Methods:Ten elite Italian male junior cross-country skiers skied on a treadmill at 10 km/h and at a 10°incline utilizing both variants of the diagonal stride technique.The 3-dimensional kinematics of the body,poles,and roller skis;the force exerted through the poles and foot plantar surfaces;and the angular motion of the leg joints were determined.Results:Compared to DSCONV,DSRUN demonstrated shorter cycle times(1.05±0.05 s vs.0.75±0.03 s(mean±SD),p<0.001)due to a shorter rolling phase(0.40±0.04 s vs.0.09±0.04 s,p<0.001);greater force applied perpendicularly to the roller skis when they had stopped rolling forward(413±190 N vs.890±170 N,p<0.001),with peak force being attained earlier;prolonged knee extension,with a greater range of motion during the roller ski-stop phase(28°±40 vs.16°±3°,p=0.00014);and more pronounced hip and knee flexion during most of the forward leg swing.The mechanical work performed against friction during rolling was significantly less with DSRUN than with DSCONV(0.04±0.01 J/m/kg vs.0.10±0.02 J/m/kg,p<0.001).Conclusion:Our findings demonstrate that DSRUN is characterize by more rapid propulsion,earlier leg extension,and a greater range of motion of knee joint extension than DSCONV-Further investigations,preferably on snow,should reveal whether DSRUN results in higher acceleration and/or higher peak speed.

Psychometric Properties of the Swedish Version of the Fear of Complications Questionnaire

Objectives: To translate and evaluate the psychometric properties of the Swedish version of the Fear of Complications Questionnaire. Design: Cross-sectional study design and scale development. Settings: Totally, 469 adults (response rate 63.5%) with Type 1 diabetes completed the questionnaires. Participants were recruited from two university hospitals in Sweden. Participants: Eligible patients were those who met the following inclusion criteria: diagnosed with Type 1 diabetes, diabetes duration of at least 1 year and aged at least 18 years. Methods: The Fear of Complications Questionnaire was translated using the forward-backward translation method. Factor analyses of the questionnaire were performed in two steps using both exploratory and confirmatory factor analysis. Convergent validity was examined using the Hospital Anxiety and Depression Scale and the Fear of Hypoglycaemia Fear Survey. Internal consistency was estimated using Cronbach’s alpha. Results: Exploratory factor analysis supported a two-factor solution. One factor contained three items having to do with fear of kidney-related complications and one factor included the rest of items concerning fear of other diabetes-related complications, as well as fear of complications in general. Internal consistency was high Cronbach’s alpha 0.96. The findings also gave support for convergent validity, with significant positive correlations between measures (r = 0.51 to 0.54). Conclusion: The clinical relevance of the identified two-factor model with a structure of one dominant subdomain may be considered. We suggest, however a one-factor model covering all the items as a relevant basis to assess fear of complications among people with Type 1 diabetes.

Thai Psychiatric Nurses’ Experiences and Perceptions of the Professional Role When Caring for Older People Displaying Depressive Symptoms

Purpose:?The aim of this study was to describe Thai psychiatric nurses’ experiences and perceptions of their professional role when caring for older people whom displayed symptoms of clinical depression.?Methods:?A qualitative descriptive research design was used. Thirteen psychiatric nurses working in the field of mental health and psychiatric nursing at a rural district hospital were purposively included. The data were collected through in-depth,?face to face interviews and analyzed using qualitative latent content analysis.?Results:?All participants were female, and the mean age was 43 years, and the mean experience of caring for mentally ill patients was 8.3 years. The psychiatric nurses’ experiences and perceptions of their professional role were mirrored in the following themes:?1) managing a central role in the care of the patients;?2) conflicting interests between the professional needs of caregiving and other requests;and?3) being compassionate beyond the profession.?Conclusion: The psychiatric nurses were challenged by the complexity of the caregiving situations and the partners involved in the process of caring for older people with depression. Professionally, the psychiatric nurses played an important role in preventive care and managerial work. They underwent stress under the influence of stakeholders, but they also contributed to the holistic patient care.?Health service authorities may use these results to develop plans for psychiatric nurses in managing a central role and in advocating for holistic care to mitigate the influence of stakeholders to enhance quality of caring for older?individuals with depression.

Utilization of Consultant Doctors’ Competence and Impact on Perceived Psychosocial Work Environment: A Pilot Study

Background: Work agencies that assign temporary jobs to doctors and nurses are becoming an increasing phenomenon. Aim: The purpose of this pilot study was to explore how consultant doctors (CDs) experience their competence as utilized in practice and what impact this has on their perceived psychosocial work environment. Methods: The findings are based on 11 interviews with CDs working on consultancy assignments in Norway. The CDs were all specialists in fields such as general practice, psychiatry, anesthesia, gynecology, orthopedics, and otolaryngology. Results: The competence that the CDs contributed to their hosting work organization was interpreted differently based on whether the consultant played an active role in the psychosocial work environment and also depended on the doctor’s specialty. Not being integrated into the hosting work organization enhanced the feeling of exclusion and the idea that little or no room was available to contribute one’s competence. Most of the CDs experienced their competence as being utilized to a certain extent, which strengthened their work satisfaction and feeling of playing an active role in the psychosocial work environment.

Impact of training specificity on exercise-induced cardiac troponin elevation in professional athletes: A pilot study

BACKGROUND Release of cardiac biomarkers is common after strenuous endurance exercise,but data on intermittent exercise are scarce.It has not been investigated whether cardiac troponin elevation is influenced depending on the type of exercise that an athlete is adapted to perform.We hypothesized that intermittent but not continuous exercise induces cardiac troponin elevation in professional athletes adapted to high-intensity intermittent exercise.AIM To examine how training specificity impacts high-sensitivity cardiac troponin T(hs-cTnT)release.METHODS Nine professional floorball players participated in the study,which comprised two different exercise tests:a continuous incremental cycle ergometer test and a Yo-Yo Intermittent Recovery 2(Yo-Yo IR2)test.Serial assessment of hs-cTnT was performed after the cycle ergometer test and the Yo-Yo IR2 test(baseline,0,2,6,and 24 h).RESULTS No hs-cTnT elevation above the myocardial damage cutoff(≥14 ng/L)was shown after the cycle ergometer test,whereas hs-cTnT levels rose over the cutoff in three of nine participants after the Yo-Yo IR2 test.The hs-cTnT levels peaked at 6 h after both tests,but were significantly higher after the Yo-Yo IR2 test compared to the cycle ergometer test(median hs-cTnT concentration 10.6 ng/L vs 7.8 ng/L,P=0.038).All levels returned to baseline within 24 h.CONCLUSION In professional athletes adapted to high-intensity intermittent exercise,hs-cTnT was significantly elevated after intermittent but not continuous exercise.This principle of specificity training should be considered when designing future studies to avoid misinterpretation of hs-cTnT elevation.

The Effects of a Recovery-Focused Program for Stress Management in Women<br/>—An Exploratory Study

Current research indicates that stress problems primarily could be conceptualized as deficiencies in recovery and recuperation between stress periods. Accordingly, interventions should put more emphasis on this aspect. A group based intervention program focusing exclusively on recovery behavior in everyday life was evaluated in this quasi-experimental, waiting-list control group study, where the control group was also treated in a second phase. Thirty-two self-referred female subjects, considering themselves in need of treatment for stress related health problems, were available for analyzes. Fifteen of these constituted the first phase treatment group (INT), while the remaining 17 subjects were placed on waiting list (WLC). Adding a few late applicants leaved 20 subjects later treated in the second intervention phase. Significant and clinically meaningful positive effects emerged in the INT—compared to the WLC-group on recovery behaviors, stress—and recovery experiences, as well as on burnout symptoms, worry, anxiety and depression. Secondary analyzes of all treated subjects indicated that the positive change the primary clinical endpoint was predicted by the increase in frequency of recovery behaviors and by the decrease in the worry level. Thus, the present intervention model merits further research with more rigorous experimental design as well as with follow-up assessments.