Solvent Influence on Cellulose 1,4-β-Glycosidic Bond Cleavage: A Molecular Dynamics and Metadynamics Study

We explore the influence of two solvents, namely water and the ionic liquid 1-ethyl-3-methylimidazolium acetate (EmimAc), on the conformations of two cellulose models (cellobiose and a chain of 40 glucose units) and the solvent impact on glycosidic bond cleavage by acid hydrolysis by using molecular dynamics and metadynamics simulations. We investigate the rotation around the glycosidic bond and ring puckering, as well as the anomeric effect and hydrogen bonds, in order to gauge the effect on the hydrolysis mechanism. We find that EmimAc eases hydrolysis through stronger solvent–cellulose interactions, which break structural and electronic barriers to hydrolysis. Our results indicate that hydrolysis in cellulose chains should start from the ends and not in the centre of the chain, which is less accessible to solvent

The Electronic Nature of the 1,4-β-Glycosidic Bond and Its Chemical Environment: DFT Insights into Cellulose Chemistry

The molecular understanding of the chemistry of 1,4-β-glucans is essential for designing new approaches to the conversion of cellulose into platform chemicals and biofuels. In this endeavor, much attention has been paid to the role of hydrogen bonding occurring in the cellulose structure. So far, however, there has been little discussion about the implications of the electronic nature of the 1,4-β-glycosidic bond and its chemical environment for the activation of 1,4-β-glucans toward acid-catalyzed hydrolysis. This report sheds light on these central issues and addresses their influence on the acid hydrolysis of cellobiose and, by analogy, cellulose. The electronic structure of cellobiose was explored by DFT at the BB1 K/6-31++G(d,p) level. Natural bond orbital (NBO) analysis was performed to grasp the key bonding concepts. Conformations, protonation sites, and hydrolysis mechanisms were examined. The results for cellobiose indicate that cellulose is protected against hydrolysis not only by its supramolecular structure, as currently accepted, but also by its electronic structure, in which the anomeric effect plays a key role

Implementing the Patient Needs in Asthma Treatment (NEAT) questionnaire in routine care:a qualitative study among patients and health professionals

Abstract Background Many patients with asthma report unmet health care needs. The Patient Needs in Asthma Treatment (NEAT) questionnaire is a validated instrument to quantify these unmet needs. We explored how health professionals evaluated the instrument’s utility as well as patients’ and professionals’ perspectives of how NEAT could be incorporated into routine clinical practice. Methods Qualitative interviews were conducted by telephone between February and September 2021 with 19 patients with asthma and 21 health professionals (i.e., general practitioners, pneumologists, health professionals in pulmonary rehabilitation, and medical assistants). Interview recordings were transcribed verbatim and content-analyzed using both deductive and inductive approaches using MAXQDA. Results Health professionals could see the potential value of using NEAT to inform clinical decisions. However, health professionals tended to be skeptical towards the routine use of NEAT in outpatient settings, mainly due to a lack of time. Implementation of NEAT was seen as more valuable in the context of patient education (i.e., in Disease Management Programs [DMPs] or pulmonary rehabilitation) by patients and health professionals alike, because it offered greater opportunities to address any unmet needs identified. Both patients and health professionals considered it more useful to use the questionnaire for the first time some time after the initial diagnosis has been made (e.g., when the treatment regime is found rather than at time of initial diagnosis). In the context of DMPs and pulmonary rehabilitation, NEAT could be used twice, i.e., before and after patient education to support patient-centered planning and evaluation. Conclusion Both patients and health professionals consider the use of the NEAT, in particular in educational programs (i.e., during DMPs or pulmonary rehabilitation), as feasible and useful. There is now a need to undertake a feasibility trial in routine care

Determinants of patients' needs in asthma treatment:a cross-sectional study

Patients’ needs in asthma remain insufficiently understood and met. We therefore aimed to investigate the potential determinants of patients’ needs in asthma treatment. Our study was based on survey data on 189 adults with asthma. Needs were measured using the 13-item Needs in Asthma Treatment questionnaire, which yields a total score and subscale-specific scores (‘exacerbations’, ‘patient expertise’, ‘handling drugs’ and ‘drug effects’). We considered age, sex, education, years since diagnosis and anxiety/depression (measured by the Patient Health Questionnaire-4) as potential determinants. Associations were estimated by multivariable linear regression. Overall, we observed that younger age, poor mental health and a more recently established asthma diagnosis were independently associated with increased needs. Information on drug effects was an exception to this pattern as the need in that domain was solely determined by sex (being greater in men). In conclusion, our study provides novel evidence on patient characteristics that are associated with needs in asthma treatment. If confirmed by future studies, our observations may assist healthcare professionals to identify asthma patients with potentially elevated information, support and training needs and could contribute to the development of tailored interventions

Neuroticism, extraversion, stressful life events and asthma: a cohort study of middle-aged adults

ABSTRACT Background: Stressful life events can trigger asthma exacerbations, but could also contribute to the development of incident asthma. However, only few studies have investigated the association between stressful life events and adult asthma prospectively. Likewise, stress-related personality traits (e.g. neuroticism and extraversion) may increase asthma risk, but this has been examined in only one prospective study. We therefore aimed to investigate the association between neuroticism, extraversion, stressful life events and incident asthma. Methods: A population-based sample of 5114 middle-aged adults completed questionnaires between 1992 and 1995. Among those alive in 2002/2003, 4010 (83%) were followed-up by questionnaires. Exposures of interest included neuroticism, extraversion and three stressful life events (unemployment, having broken off a life partnership and death of a close person). Associations with incident asthma were estimated by multivariable risk ratios (RR) and 95% confidence intervals (95% CI) using Poisson regression. Results: High vs low neuroticism predisposed to developing asthma (RR = 3.07, 95% CI = 1.71–5.48), but high extraversion did not (RR = 1.30, 95% CI = 0.79–2.15). Having broken off a life partnership significantly increased asthma risk (RR = 2.24, 95% CI = 1.20–4.21) in contrast to death of a close person (RR = 1.06, 95% CI = 0.64–1.75) or unemployment (RR = 1.65, 95% CI = 0.72–3.78). Conclusions: High levels of neuroticism may increase the risk of asthma in middle-aged adults. Having broken off a life partnership was the only stressful event, which was associated with incident asthma. Synthesized with evidence from earlier studies, this could reflect that interpersonal conflicts may increase asthma risk, possibly along an immunological pathway

Impact of pulmonary rehabilitation on patients’ health care needs and asthma control:a quasi-experimental study

Background!#!Pulmonary rehabilitation offers potential benefits to people with asthma. It is however unknown if rehabilitation favourably affects patients' health care needs. We therefore examined if rehabilitation reduced needs and, in addition, if it improved asthma control.!##!Methods!#!One hundred fifty patients with asthma were surveyed in three rehabilitation clinics at admission and at discharge. Additionally, we surveyed 78 participants with asthma twice 4 weeks apart. The latter sample (i.e. the control group) was recruited through other pathways than rehabilitation clinics. The Patient Needs in Asthma Treatment (NEAT) questionnaire and the Asthma Control Test (ACT) were completed at baseline and follow-up. Differences between baseline and follow-up and between rehabilitation and control group were examined by t-tests and chi-squared-tests. Univariate ANCOVAS were used to examine if NEAT and ACT follow-up scores differed significantly between groups. Within the rehabilitation group, linear regressions were used to examine if self-reported utilization of more interventions that addressed needs were associated with NEAT scores at follow-up.!##!Results!#!At baseline, there were no differences between the rehabilitation and the control group regarding needs and asthma control. At follow-up, the rehabilitation group showed reduced needs (t(149) = 10.33, p <  0.01) and increased asthma control (t(130) = -6.67, p <  0.01), whereas members of the control group exhibited no changes. Univariate ANCOVAS showed that unmet follow-up needs (F(1, 212) = 36.46, p <  0.001) and follow-up asthma control (F(1, 195) = 6.97, p = 0.009) differed significantly between groups. In the rehabilitation group, self-reported utilization of more interventions was associated with reduced needs (β = 0.21; p = 0.03).!##!Conclusions!#!This study provides preliminary evidence suggestion that pulmonary rehabilitation in adults with asthma may reduce asthma-related needs and confirms previous findings that rehabilitation may improve asthma control

Associations of ambivalent leadership with distress and cortisol secretion

Ambivalent social ties, i.e., whereby a relationship is evaluated simultaneously in positive and negative terms, are a potential source of distress and can perturb health-relevant biological functions. Social interactions at the workplace, in particular with supervisors, are often described in ambivalent terms, but the psychological and psychobiological impact of such interactions has received little scientific attention. The current study examined associations between ambivalent attitudes towards one's supervisor, perceived distress (general and work-related), and diurnal dynamics of the stress hormone cortisol. 613 employees evaluated their supervisor in terms of positive and negative behaviors, which was combined into an ambivalent index. Higher ambivalence was associated with higher perceived distress and work-related stress (p < .001), and with a larger cortisol awakening response and higher day-time secretion post-awakening (p < .01). The present study is the first to identify ambivalence towards supervisors as a predictor of employee distress and stress-related endocrine dysregulation. In consequence, focusing solely on positive or negative leader behavior may insufficiently capture the true complexity of workplace interactions and attempts to compensate negative behaviors with positive are unlikely to reduce distress-but quite the opposite-by increasing ambivalence

Work stress and hair cortisol levels among workers in a Bangladeshi ready-made garment factory - results from a cross-sectional study

SummaryEvidence on the association of work stress with cortisol levels is inconsistent and mostly stems from Western countries, with limited generalizability to other regions of the world. These inconsistencies may partly be due to methodological limitations associated with the measurement of cortisol secretion in saliva, serum or urine. The present study set out to explore associations of work stress with long-term integrated cortisol levels in hair among 175 workers of an export oriented ready-made garment (RMG) factory in Dhaka, Bangladesh.Work-related demands (WD), interpersonal resources (IR) and work-related values (WV) were assessed using a psychometrically evaluated interview. WD consisted of four items on physical demands, time pressure, worries about mistakes and exposure to abusive language. IR comprised five items addressing support, recognition, adequate payment, workers’ trust in the management, and the management's trust in workers, as perceived by the workers. WV captured job security, promotion prospects and job latitude by three items. Hair cortisol concentrations (HCC) were analyzed by liquid chromatography–mass spectrometry. Stepwise multivariable linear regression models (backward elimination of predictors) were used to estimate associations of HCC with the three work stress components. For significant work stress component(s), further multivariable linear regression analyses were conducted to explore whether, and if so, which individual item(s) contributed most.The mean HCC equaled 3.27 (SD 2.58) pg/mg. HCC were found to be significantly associated with WV (beta=0.209, p=0.021). Additional analyses of the three WV items revealed that this association was largely driven the item on “promotion prospects” (beta=0.230, p=0.007) implying that the perception of good promotion prospects was associated with higher HCC.The finding of elevated HCC with good promotion prospects may initially seem counter-intuitive, but is supported by research documenting that job promotion may result in poorer mental well-being. Moreover, being promoted in the Bangladeshi RMG industry may represent a stressful experience: job promotions are rare in this setting and are associated with the need to meet exceptional job-related demands. Further research from ethnic and culturally diverse occupational settings is needed to test this hypothesis, to shed light on the reproducibility of our findings and to improve our understanding of the psychobiological implications of psychosocial working conditions across cultures and contexts