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•A numerical method for multiphase flows to study COVID-19 aerosol transmission.•The effectiveness of partitions on dining tables assessed.•Spread of respiratory droplets revealed.
...With the prevalence of COVID-19, the phenomenon of viruses spreading through aerosols has become a focus of attention. Diners in university dining halls have a high risk of exposure to respiratory droplets from others without the protection of face masks, which greatly increases the risk of COVID-19 transmission. Therefore, the transmission mechanism of respiratory droplets in extremely crowded dining environments should be investigated. In this study, a numerical simulation of coughing at dining tables under two conditions was performed, namely the presence and absence of protective partitions, and the evaporation and condensation of aerosol droplets in the air were examined. By using the numerical method, we analyzed and verified the isolation effect of dining table partitions in the propagation of aerosol droplets. The effect of changes in room temperature on the diffusion of coughed aerosols when partitions were present was analyzed. We demonstrated how respiratory droplets spread through coughing and how these droplets affect others. Finally, we proposed a design for a dining table partition that minimizes the transmission of COVID-19.
Empyema is a rare but important complication among patients with end-stage renal disease (ESRD). However, a nationwide, propensity-matched cohort study has never been performed.
We conducted a ...retrospective cohort study using data from the National Health Insurance Research Database of Taiwan. The ESRD group consisted of 82 765 patients diagnosed between 2000 and 2008. The comparison group consisted of individuals without kidney disease selected at a 1:1 ratio matched by propensity score estimated with age, gender, year of diagnosis and comorbidities. The occurrence of empyema was monitored until the end of 2011. The hazard ratios (HRs) of empyema were estimated using the Cox proportional hazards model.
The incidence of empyema was 2.76-fold higher in the ESRD group than in the comparison group (23.7 vs. 8.19/10 000 person-years, P <0.001), with an adjusted HR of 3.01 95% confidence interval (CI) = 2.67-3.39. There was no difference of the incidence of empyema between hemodialysis (HD) and peritoneal dialysis (PD) (adjusted HR = 0.96, 95% CI = 0.75-1.23). In addition, 30-day mortality rate since empyema diagnosis was significantly higher in ESRD group than the comparison group (15.9% vs. 10.9%), with an adjusted OR of 1.69 (95% CI = 1.17-2.44).
The risk of empyema was significantly higher in patients with ESRD than in those without kidney disease. The occurrence of empyema was without difference in patients undergoing HD compared to those undergoing PD. The 30-day mortality rate since empyema diagnosis was also significantly higher in patients with ESRD.
Zinc oxide nanoparticles have found wide application due to their unique optoelectronic and photocatalytic characteristics. However, their safety aspects remain of critical concern, prompting the use ...of physicochemical modifications of pristine ZnO to reduce any potential toxicity. However, the relationships between these modifications and their effects on biology are complex and still relatively unexplored. To address this knowledge gap, a library of 45 types of ZnO nanoparticles with varying particle size, aspect ratio, doping type, doping concentration, and surface coating is synthesized, and their biological effects measured. Three biological assays measuring cell damage or stress are used to study the responses of human umbilical vein endothelial cells (HUVECs) or human hepatocellular liver carcinoma cells (HepG2) to the nanoparticles. These experimental data are used to develop quantitative and predictive computational models linking nanoparticle properties to cell viability, membrane integrity, and oxidative stress. It is found that the concentration of nanoparticles the cells are exposed to, the type of surface coating, the nature and extent of doping, and the aspect ratio of the particles make significant contributions to the cell toxicity of the nanoparticles tested. Our study shows that it is feasible to generate models that could be used to design or optimize nanoparticles with commercially useful properties that are also safe to humans and the environment.
Modifying the surfaces of ZnO nanoparticles can reduce potential cell toxicity of these widely used particles. The relationship is elucidated between surface chemistry and toxicity by screening 45 modified ZnO nanoparticles for cell toxicity and generating quantitative, predictive computational models. The models can be used to design functional nanomaterials with lower adverse impacts than unmodified nanoparticles.
Abstract
Introduction
Although the relationships amongst sleep, pain and anxiety have been evidenced, the underlying neurological mechanisms remain elusive. Primary dysmenorrhea is a good model of ...spontaneous pain with clear painful (menstruation, state) and pain free (e.g., peri-ovulatory phase, trait) conditions. We sought to investigate the state- and trait-related neural signatures that link sleep and anxiety in primary dysmenorrhea.
Methods
Thirty female subjects with primary dysmenorrhea and 30 healthy female controls completed resting-state functional magnetic resonance imaging, the State-Trait Anxiety Inventory and sleep quality assessments during menstruation and peri-ovulatory phases. As we have reported that there was altered default mode network in the primary dysmenorrhea, posterior parietal cortex (PPC) was therefore chosen as the seed to elucidate the functional connectivity that may correlate with sleep and anxiety.
Results
The primary dysmenorrheic subjects exhibited sleep disturbances throughout the menstrual cycle with increased state anxiety. The primary dysmenorrheic subjects demonstrated significantly higher correlations between the sleep quality and the PPC-insula and -putamen functional connectivity during the peri-ovulatory phase. During menstruation, the primary dysmenorrheic subjects demonstrated significantly lower correlations between their state-anxiety scores and the PPC-occipital cortex functional connectivity.
Conclusion
After regressing out the effects of trait anxiety, the correlation between sleep quality and the PPC-putamen functional connectivity was not significant, indicating anxiety-mediated sleep-pain relationship. The PPC-insula functional connectivity, by contrast, was remained significant. Furthermore, state anxiety was associated with the PPC-occipital cortex functional connectivity that was significantly impaired in primary dysmenorrheic subjects. These findings hinted pain and anxiety mediating sleep quality in different neurological circuits.
Support
Taipei City Goverment(10401-62-046 and 10501-62-046)
This study investigates how the construction of a sports stadium affects residential housing values. Hedonic analyses are conducted to assess the price differentials between housing units in close ...proximity to FedEx Field (home of the Washington Redskins) and comparable units away from it. Using a difference-in-difference approach, the study finds that properties near FedEx Field sold at a discount; however, this price differential was narrowed after the completion of the stadium. Contrary to neighborhood activists concern that sports venues adversely affect property values, the findings of this study indicate that a new stadium improves housing values in the surrounding area. (JEL R53, R31)
Inorganic lead‐free halide perovskites, devoid of toxic or rare elements, have garnered considerable attention as photocatalysts for pollution control, CO2 reduction and hydrogen production. In the ...extensive perovskite design space, factors like substitution or doping level profoundly impact their performance. To address this complexity, a synergistic combination of machine learning models and theoretical calculations were used to efficiently screen substitution elements that enhanced the photoactivity of substituted Cs2AgBiBr6 perovskites. Machine learning models determined the importance of d10 orbitals, highlighting how substituent electron configuration affects electronic structure of Cs2AgBiBr6. Conspicuously, d10‐configured Zn2+ boosted the photoactivity of Cs2AgBiBr6. Experimental verification validated these model results, revealing a 13‐fold increase in photocatalytic toluene conversion compared to the unsubstituted counterpart. This enhancement resulted from the small charge carrier effective mass, as well as the creation of shallow trap states, shifting the conduction band minimum, introducing electron‐deficient Br, and altering the distance between the B‐site cations d band centre and the halide anions p band centre, a parameter tuneable through d10 configuration substituents. This study exemplifies the application of computational modelling in photocatalyst design and elucidating structure–property relationships. It underscores the potential of synergistic integration of calculations, modelling, and experimental analysis across various applications.
A simple machine learning model combined with theoretical calculations was employed to streamline optimisation and accurately identify substituents, highlighting the importance of d10 configuration in modulating Cs2AgBiBr6 perovskite electronic structure. This approach seamlessly integrates with experimental validation, affirming d10‐configured Zn2+ enhances Cs2AgBiBr6 photoactivity for toluene oxidation.
Xyloglucan endotransglucosylase/hydrolase (XTH) proteins that possess xyloglucan endotransglucosylase (XET) activity contribute to cell-wall assembly and remodelling, orchestrating plant growth and ...development. Little is known about in-vivo XET regulation, other than at the XTH transcriptional level. Plants contain 'cold-water-extractable, heat-stable polymers' (CHPs) which are XTH-activating factors (XAFs) that desorb and thereby activate wall-bound XTHs. Because XAFs may control cell-wall modification in vivo, we have further explored their nature.
Material was cold-water-extracted from 25 plant species; proteins were precipitated by heat-denaturation, then CHP was ethanol-precipitated. For XAF assays, CHP (or sub-fractions thereof) was applied to washed Arabidopsis thaliana cell walls, and the enzymes thus solubilized were assayed radiochemically for XET activity. In some experiments, the CHP was pre-treated with trifluoroacetic acid (TFA), alkali (NaOH) or glycanases.
CHP specifically desorbed wall-bound XTHs, but not β-glucosidases, phosphatases or peroxidases. CHP preparations from 25 angiosperms all possessed XAF activity but had no consistent monosaccharide composition. Of 11 individual plant polymers tested, only gum arabic and tamarind xyloglucan were XAF-active, albeit less so than CHP. On gel-permeation chromatography, XAF-active cauliflower CHP eluted with a molecular weight of ~7000-140 000, although no specific sugar residue(s) co-eluted exactly with XAF activity. Cauliflower XAF activity survived cold alkali and warm dilute TFA (which break ester and glycofuranosyl linkages, respectively), but was inactivated by hot 2 m TFA (which breaks glycopyranosyl linkages). Cauliflower XAF activity was remarkably stable to diverse glycanases and glycosidases.
XAFs are naturally occurring heat-stable polymers that specifically desorb (thereby activating) wall-bound XTHs. Their XAF activity considerably exceeds that of gum arabic and tamarind xyloglucan, and they were not identifiable as any major plant polysaccharide. We propose that XAF is a specific, minor, plant polymer that regulates xyloglucan transglycosylation in vivo, and thus wall assembly and restructuring.
Ionic liquid containing solvent systems are candidates for very large compositional space exploration due to the immensity of the possible combination of ions and molecular species. The prediction of ...key properties of such multicomponent solvent systems plays a vital role in the design and optimization of their structures for specific applications. In this study, we have explored two machine learning algorithms for predicting the surface tension and liquid nanostructure of solvents containing a protic ionic liquid (PIL) with water and excess acid or base present. Machine learning algorithms of multiple linear regression (MLR) and Bayesian regularized artificial neural networks (ANNs) were used to develop semiempirical structure–property models for the data set, which was comprised of 207 surface tension and 80 liquid nanostructure data elements which we previously reported (Phys. Chem. Chem. Phys. 2019, 21, 6810–6827). On the basis of the models, the significance levels for the impact of the alkyl chain length and the presence of hydroxyl groups on cation, type of anion, nonstoichiometry, and presence of water were elucidated. Both models are statistically applicable for designing new PIL containing solvent systems. Furthermore, the generated models were used to create response-surface plots, for both surface tension and liquid nanostructure, interpolated across the compositional space. An additional surface tension data set with 18 new data points within the same compositional space was used to test the prediction ability of models, and the results showed all of the models were successful for prediction. These machine learning approaches are highly suited to the development of structure–property relationships for ionic liquids and particularly for the increasing use of ionic liquid–molecular solvent mixtures.
Background
Hyperthermia upregulates DNAJA4, a member of heat shock proteins (HSPs) 40 family, in human keratinocytes and HPV‐infected tissue. DNAJA4 deficiency enhances growth arrest induced by ...hyperthermia. Clusterin (CLU) and phosphorylated ERK (p‐ERK) play a role in regulating cell proliferation and apoptosis, under environmental stress.
Objectives
To examine the downstream molecules and signalling pathways of DNAJA4 and assess their roles in cell cycle and apoptosis of keratinocytes in response to hyperthermia.
Methods
Wild‐type and DNAJA4‐knockout (KO) HaCaT cells were exposed to either 44 °C (hyperthermia) or 37 °C (control) for 30 min. The expression levels of CLU and p‐ERK were determined by RT‐PCR and Western blotting. RNAi and PD98059 were used to inhibit the expression of CLU and p‐ERK, respectively. Cell viability, cell cycle and apoptosis were analysed by MTS assay and flow cytometry. Fresh biopsy samples of human normal foreskin or condyloma acuminatum (CA) were utilized to examine the expression of CLU and p‐ERK after ex vivo culture at 44 °C.
Results
The expression of CLU and p‐ERK was significantly increased by hyperthermia treatment at 44 °C in HaCaT cells, foreskin and HPV‐infected tissues. In HaCaT cells subjected to hyperthermia, DNAJA4 deficiency further augmented the expression of CLU and p‐ERK. CLU deficiency enhanced the p‐ERK expression. Hyperthermia‐induced CLU and p‐ERK exerted protective roles mainly through inhibiting apoptosis and maintaining cell cycle, respectively.
Conclusions
In keratinocytes, CLU and p‐ERK are induced by hyperthermia, an effect which can be further enhanced by DNAJA4 deficiency. CLU deficiency also increases p‐ERK expression. Both CLU and p‐ERK are critical protective factors of human keratinocytes from hyperthermia‐induced injury.
Although mice lacking rod and cone photoreceptors are blind, they retain many eye-mediated responses to light, possibly through photosensitive retinal ganglion cells. These cells express melanopsin, ...a photopigment that confers this photosensitivity. Mice lacking melanopsin still retain nonvisual photoreception, suggesting that rods and cones could operate in this capacity. We observed that mice with both outer-retinal degeneration and a deficiency in melanopsin exhibited complete loss of photoentrainment of the circadian oscillator, pupillary light responses, photic suppression of arylalkylamine-N-acetyltransferase transcript, and acute suppression of locomotor activity by light. This indicates the importance of both nonvisual and classical visual photoreceptor systems for nonvisual photic responses in mammals.
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