222 research outputs found
Renal blood flow in critically ill cardiac patients: effect of dobutamine on total flow and selective redistribution of the cardiac index
Structure, function, and application of self-healing adhesives from mistletoe viscin
Berries from the European Mistletoe (Viscum album) possess a sticky tissue called viscin that facilitates adhesion and germination onto host trees. Recent studies of viscin have demonstrated its adhesive capacity on a range of natural and synthetic surfaces including wood, skin, metals, and plastic. Yet, the underlying mechanisms remain poorly understood. Here, an investigation of the adhesive performance of mistletoe viscin is performed, demonstrating its hygroscopic nature and ability to self-heal following adhesive failure. It is identified that adhesion originates from a water-soluble adhesive component that can be extracted, isolated, and characterized independently. Lap shear mechanical testing indicates that the mistletoe adhesive extract (MAE) outperforms native viscin tissue, as well as gum arabic and arabinogalactan—common plant-based adhesives. Furthermore, humidity uptake experiments reveal that MAE can reversibly absorb nearly 100% of its mass in water from the atmosphere. In-depth spectroscopic and mass spectrometry investigations reveal a composition consisting primarily of an atypical arabinogalactan, with additional sugar alcohols. Finally, several proof-of-concept applications are demonstrated using MAE for hygro-responsive reversible adhesion between various surfaces including skin, plastic, PDMS, and paper, revealing that MAE holds potential as a biorenewable and reusable adhesive for applications in cosmetics, packaging, and potentially, tissue engineering
Characterization of the thermal and photoinduced reactions of photochromic spiropyrans in aqueous solution
Six water-soluble spiropyran derivatives have been characterized with respect to the thermal and photoinduced reactions over a broad pH-interval. A comprehensive kinetic model was formulated including the spiro- and the merocyanine isomers, the respective protonated forms, and the hydrolysis products. The experimental studies on the hydrolysis reaction mechanism were supplemented by calculations using quantum mechanical (QM) models employing density functional theory. The results show that (1) the substitution pattern dramatically influences the pKa-values of the protonated forms as well as the rates of the thermal isomerization reactions, (2) water is the nucleophile in the hydrolysis reaction around neutral pH, (3) the phenolate oxygen of the merocyanine form plays a key role in the hydrolysis reaction. Hence, the nonprotonated merocyanine isomer is susceptible to hydrolysis, whereas the corresponding protonated form is stable toward hydrolytic degradation
School refusal behavior. role of personality styles, social functioning, and psychiatric symptoms in a sample of adolescent help-seekers
Objective: School refusal (SR) in adolescence represents an important risk factor associated with adverse consequences. Although many clinical features of adolescents presenting with SR have been studied, the relationship between SR and personality styles-specifically in the help-seeking population-remains unclear. The present study aimed at investigating differences in personality style, adaptive functioning, and symptomology between Italian help-seeking adolescents who refused (SRa) and did not refuse (non-SRa) to attend school, to provide preliminary evidence of personality patterns in adolescent help-seekers presenting with SR.Method: The study sample was comprised of 103 help-seeking adolescents (54 female, 49 male) aged 14-18 years. Participants were recruited during their first clinical visit and evaluated using the Shedler and Westen Assessment Procedure - Adolescent version (SWAP-A), the Hamilton Rating Scale for Depression (HAM-D), the Hamilton Rating Scale for Anxiety (HAM-A), the Maniac Rating Scale (MRS), the Global Assessment of Functioning (GAF), the Global Functioning Social Scale (GFSS), and the Global Functioning Role Scale (GFRS). Differences in the studied variables between SRa and non-SRa were measured and a multivariable logistic regression analysis was performed to identify possible predictive factors of SR.Results: SRa presented with more anxious and depressive symptomatology and worse social functioning compared to non-SRa. With respect to personality, SRa displayed more schizoid and schizotypal characteristics and fewer adaptive and healthy personality features. Irrespective of any differences between groups, SRa were largely characterized by inhibited-self-constricted and emotionally dysregulated personality styles.Conclusions: The results suggest that personality styles arc clinical features that may contribute to broadening our knowledge of SR behavior and aid in the detection of SRa, also in the help-seeking population. The findings have clinical, social, and political implications for prevention, diagnosis, and treatment, in both clinical and non-clinical settings. However, more data are needed on personality features to clarify their contribution to the more complex phenomenon of school absenteeism
Burnout among postgraduate medical trainees in Lebanon: Potential strategies to promote wellbeing
ObjectiveBurnout is a widespread issue in healthcare for many years. Lebanon combatted political and economic crises before the coronavirus disease 2019 (COVID-19) pandemic, in addition to the port explosion in August 2020. The study aimed to identify the determinants of personal burnout, patient-related burnout, and work-related burnout among postgraduate medical trainees (PGMT) and evaluate its relationship with sociodemographic characteristics.DesignA cross-sectional study utilized the Copenhagen Burnout Inventory (CBI) involving electronic, voluntary, and anonymous survey. The survey was completed by 188 PGMT including residents and fellows from all specialties and all levels of training.ResultsThe prevalence rates are 68.6% for personal burnout, 63.3% for work-related burnout, and 35.1% for patient-related burnout.ConclusionResults improve our understanding of the phenomenon of burnout, and the role of program leadership in shaping the impact of burnout on training and promoting wellbeing of PGMT. Discussion focuses on providing potential wellbeing strategies for program directors to follow for mitigating burnout
A Comparative Environmental Assessment for the Synthesis of 1,3-Oxazin-2-one by Metrics: Greenness Evaluation and Blind Spots
Alternative syntheses for the production of 3-benzyl-1,3-oxazinan-2-one are compared and evaluated employing
green metrics. An environmental assessment has been performed using the algorithm recently developed by Andraos that takes
into account the mass flows and the software EATOS that considers mass flows, environmental impacts of the substances
involved, and waste produced. Strengths and critical spots of the environmental tools employed are also discussed. Data collected
showed that the synthesis employing diethyl carbonate is the most promising one, having the lowest environmental impact
Inter-individual responses to sprint interval training, a pilot study investigating interactions with the sirtuin system
Adjusting the duration of androgen deprivation therapy (ADT) based on nadir PSA for high risk localized prostate cancer patients treated with definitive external beam radiation therapy and ADT
Background: A nadir Prostate-Specific Antigen (nPSA) of 0.06 ng/mL has been shown to be a strong independent predictor of biochemical recurrence-free survival (bRFS) in patients with intermediate or high-risk (HR) prostate cancer treated with definitive external beam radiation therapy (RT) and androgen deprivation therapy (ADT). We aimed to examine the association between the duration of ADT and bRFS in HR localized prostate cancer, based on nPSA. Methods: Between 1998 and 2015, 204 patients with HR localized prostate cancer were identified. Of them, 157 patients (77.0%) reached the desired nPSA of 6 months); (P = 0.043). The presenting T stage was borderline significant (HR 3.074; 95% CI 0.972–9.719; P = 0.056), while PSA at presentation, Gleason Score and age were not. On multivariate analysis, the use of ADT for 12 months (P = 0.012) and tnPSA (P = 0.037) remained significant. In the unfavorable group, receiving ADT beyond 9 and 12 months was associated with improved bRFS (P = 0.044 and 0.019, respectively). However, beyond 18 months, there was no significant difference. Conclusion: In HR localized prostate cancer patients treated with definitive RT and ADT, the total duration of ADT may be adjusted according to treatment response using nPSA. In patients reaching a nPSA below 0.06 ng/mL, a total of 12 months of ADT may be sufficient, while in those not reaching a nPSA below 0.06 ng/mL, a total duration of 18 months is required. © 2022, The Author(s)
C-Terminal Extension of the Yeast Mitochondrial DNA Polymerase Determines the Balance between Synthesis and Degradation
Saccharomyces cerevisiae mitochondrial DNA polymerase (Mip1) contains a C-terminal extension (CTE) of 279 amino acid residues. The CTE is required for mitochondrial DNA maintenance in yeast but is absent in higher eukaryotes. Here we use recombinant Mip1 C-terminal deletion mutants to investigate functional importance of the CTE. We show that partial removal of the CTE in Mip1Δ216 results in strong preference for exonucleolytic degradation rather than DNA polymerization. This disbalance in exonuclease and polymerase activities is prominent at suboptimal dNTP concentrations and in the absence of correctly pairing nucleotide. Mip1Δ216 also displays reduced ability to synthesize DNA through double-stranded regions. Full removal of the CTE in Mip1Δ279 results in complete loss of Mip1 polymerase activity, however the mutant retains its exonuclease activity. These results allow us to propose that CTE functions as a part of Mip1 polymerase domain that stabilizes the substrate primer end at the polymerase active site, and is therefore required for efficient mitochondrial DNA replication in vivo
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