Dynamics of Droplet Pinch-Off at Emulsified Oil-Water Interfaces: Interplay between Interfacial Viscoelasticity and Capillary Forces.

The presence of submicrometer structures at liquid-fluid interfaces modifies the properties of many science and technological systems by lowering the interfacial tension, creating tangential Marangoni stresses, and/or inducing surface viscoelasticity. Here we experimentally study the break-up of a liquid filament of a silica nanoparticle dispersion in a background oil phase that contains surfactant assemblies. Although self-similar power-law pinch-off is well documented for threads of Newtonian fluids, we report that when a viscoelastic layer is formed in situ at the interface, the pinch-off dynamics follows an exponential decay. Recently, such exponential neck thinning was found theoretically when surface viscous effects were taken into account. We introduce a simple approach to calculate the effective relaxation time of viscoelastic interfaces and estimate the thickness of the interfacial layer and the viscoelastic properties of liquid-fluid interfaces, where the direct measurement of interfacial rheology is not possible.

The Structural Relationship Between Teacher Support and Willingness to Communicate: The Mediation of L2 Anxiety and the Moderation of Growth Language Mindset.

The important role of willingness to communicate (WTC) in facilitating second language (L2) learning and use has been widely endorsed. However, few studies have examined how teacher support in an L2 class may predict students' L2 WTC. Such a relationship may also be mediated by learners' L2 anxiety, a typical predictor of L2 WTC, and moderated by learners' beliefs about the malleability of their language learning ability, a construct known as growth language mindset. Framed from the Control-Value Theory (Pekrun, in Educ Psychol Rev 18(4):315-341, 2006) and the Language-Mindset Meaning System (Lou and Noels, in: Lamb, Csizér, Henry, Ryan (eds) The Palgrave handbook of motivation for language learning, Palgrave Macmillan, 2019a, System 86:102126, 2019b), this study aimed to investigate the relationships between teacher support, L2 anxiety, growth language mindset, and L2 WTC. The data were collected from 551 English-as-a-Foreign-Language (EFL) learners in Iran and analyzed using structural equation modeling (SEM). The results showed that teacher support was directly and positively associated with L2 WTC, and this relationship was significantly mediated by L2 anxiety. The relationship between teacher support and L2 WTC, however, was only significant among learners with medium and high levels of growth language mindset. In addition, growth language mindset also moderated the negative relationship between L2 anxiety and L2 WTC, with this relationship being weaker among learners with higher levels of growth language mindset. Finally, theoretical and pedagogical implications and directions for future research are presented.

Evaluation of a novel lentiviral vaccine expressing KMP11-HASPB fusion protein against Leishmania infantum in BALB/c mice.

Hydrophilic acylated surface protein B (HASPB) is an immunogenic Leishmania protein against which antibodies are produced in the sera of cutaneous and visceral Leishmaniasis (VL) patients. Kinetoplastid membrane protein 11 (KMP11) is another protein antigen of Leishmania which is reported as a promising candidate for vaccination of VL. It is a highly conserved surface protein present in all members of kinetoplastid family and is expressed in both promastigotes and amastigotes. In this study, the coding sequence of KMP11 and HASPB was cloned into a pCDH-cGFP lentiviral vector as a fusion protein. The gene expression was confirmed using RT-PCR and Western blot methods. After injection of the recombinant KMP11-HASPB-expressing lentiviruses to BALB/c mice, using ELISA technique, a significant increase in IFN-γ and IL-4 as well as IgG1 and IgG2a was observed compared to the control group. Furthermore, the number of parasites in the liver and spleen of vaccinated mice decreased significantly compared with the control group.

Lie symmetry, chaos optimal control in non-linear fractional-order diabetes mellitus, human immunodeficiency virus, migraine Parkinson's diseases models: using evolutionary algorithms.

The purpose of this article is to investigate the optimal control of nonlinear fractional order chaotic models of diabetes mellitus, human immunodeficiency virus, migraine and Parkinson's diseases using genetic algorithms and particle swarm optimization. Mathematical chaotic models of nonlinear fractional order type of the above diseases were presented. Then optimal control for each of the models and numerical simulation was done using genetic algorithm and particle swarm optimization algorithm. The results of the genetic algorithm method are excellent. All the results obtained for the particle swarm optimization method show that this method is also very successful and the results are very close to the genetic algorithm method. Very low values of MSE and RMSE errors indicate that the simulation is effective and efficient. Also, Lie symmetry was calculated for the proposed models and the results were presented.

Growth language mindset and willingness to communicate: Contributions of linguistic risk taking and learning experience.

As various contextual and individual difference factors determine how and when mindsets may influence learning outcomes, burgeoning L2 research has recently addressed the role of growth language mindset (GLM) in different learning outcomes such as L2 Willingness to Communicate (WTC). Since little is known about the underlying mechanism through which GLM may contribute to WTC, a highly desirable goal of L2 education and an important criterion for assessing its efficiency and success, the present study addresses this gap by investigating the possible mediating and moderating roles of linguistic risk taking and L2 learning experience, respectively. The participants were 392 Iranian L2 students chosen by multi-stage cluster sampling. Findings showed that GLM predicted WTC directly and positively, and their association was mediated and moderated by linguistic risk taking (an important affective factor) and L2 learning experience (an essential motivational factor), respectively. Suggestions for future studies and implications for promoting learners' GLM, linguistic risk taking, and L2 learning experience are presented.

Are teachers with better quality of work life more innovative? The mediating roles of psychological empowerment and teaching mindsets.

Are teachers with better quality of work life (QWL) more innovative, and why? This study examined the relationship between teachers' QWL and their innovative behaviours, alongside the potential underlying mechanisms through psychological empowerment and teaching mindsets. A total of 321 elementary teachers completed a questionnaire. Path analysis demonstrated a significant positive association between QWL and innovative teaching behaviours. Moreover, both psychological empowerment and teaching mindsets significantly mediated this relationship. Specifically, teachers with higher QWL showed greater psychological empowerment and embraced stronger growth mindsets about their teaching abilities, which enables them to become more innovative in their teaching approaches. These findings suggest that quality of work life is not just a matter of teachers' well-being, but it also plays an important role in their teaching quality, which can ultimately benefit the institutions and the students.

Charge carrier recombination processes, intragap defect states, and photoluminescence mechanisms in stoichiometric and reduced TiO2 brookite nanorods: an interpretation scheme through in situ photoluminescence excitation spectroscopy in controlled environment.

The study of titanium dioxide (TiO2) in the brookite phase is gaining popularity as evidence has shown the efficient photocatalytic performance of this less investigated polymorph. It has been recently reported that defective anisotropic brookite TiO2 nanorods display remarkable substrate-specific reactivity towards alcohol photoreforming, with rates of hydrogen production significantly (18-fold) higher than those exhibited by anatase TiO2 nanoparticles. To elucidate the basic photo-physical mechanisms and peculiarities leading to such an improvement in the photoactive efficiency, we investigated the recombination processes of photoexcited charge carriers in both stoichiometric and reduced brookite nanorods via photoluminescence excitation spectroscopy in controlled environment. Through an investigation procedure employing both supragap and subgap excitation during successive exposure to oxidizing and reducing gaseous agents, we firstly obtained an interpretation scheme describing the main photoluminescence and charge recombination pathways in stoichiometric and reduced brookite, which includes information about the spatial and energetic position of the intragap states involved in photoluminescence mechanisms, and secondly identified a specific photoluminescence enhancement process occurring in only reduced brookite nanorods, which indicates the injection of a conduction band electron during ethanol photo-oxidation. The latter finding may shed light on the empirical evidence about the exceptional reactivity of reduced brookite nanorods toward the photo-oxidation of alcohols and the concomitant efficiency of photocatalytic hydrogen generation.

TLR2 and TLR4 in cutaneous leishmaniasis caused by Leishmania major.

Cutaneous leishmaniasis (CL) is a self-healing skin disease which rarely for unknown reason(s) the lesion develops to a non-healing form. It seems that the initial contact of Leishmania parasites with the host innate immune system is an important step in the outcome of the disease. Recent studies suggested that toll-like receptors (TLRs) play a role in Leishmania recognition. In this study, the level of TLR2 and TLR4 was checked in patients with healing form of lesion and compared with that of patients with non-healing form of lesion caused by Leishmania major. Gene expression of TLR2 and TLR4 in peripheral blood-derived macrophages, before and after stimulation with live L. major promastigotes, was evaluated using quantitative real-time reverse transcription PCR and flow cytometry. The results showed that the mean relative gene expression and difference membrane expression of TLR2 in macrophages of patients with healing form of lesion were significantly higher than patients with non-healing form of lesion (P < 0.0001 and P = 0.0034), respectively, and the mean relative gene expression and difference in protein expression of TLR4 in macrophages of patients with healing form of lesion were significantly higher than that of patients with non-healing form of lesion (P = 0.021 and P = 0.002), respectively. The data suggested a possible role for TLR2 and TLR4 in the outcome of CL lesion. Further studies are needed to understand more about the detail role of the immune factors in leishmaniasis.

Comparison of therapeutic effect of topical Nigella with Betamethasone and Eucerin in hand eczema.

BACKGROUND: Nigella sativa has been used in traditional medicine. Although it was investigated in different studies, its effect on hand eczema has not been studied yet. OBJECTIVE: To compare the effects of Nigella, Betamethasone and Eucerin on severity of hand eczema and patients' life quality. METHODS: In this randomized, controlled, double-blinded clinical trial, we allocated new cases of hand eczema with 18-60 years of age in three therapeutic groups (Nigella, Betamethasone and Eucerin) by using permuted blocks for randomization. Patients applied medications twice a day and followed in a 4-week period. The primary outcome of the study was changes in severity and life quality, which were assessed at the beginning, 14th and 28th days of the study by Hand Eczema Severity index (HECSI) and Dermatology Life Quality Index (DLQI) respectively. RESULTS: Sixty patients recruited in the study with 20 patients allocated in each study arm. Eighteen, 19 and 15 patients in Eucerin, Nigella and Betamethasone groups, respectively, attended at least one of the therapy sessions. Nigella and Betamethasone showed significantly more rapid improvement in hand eczema compared with Eucerin (P = 0.003 and P = 0.012 respectively); Nigella and Betamethasone ointments caused significant decreases in DLQI scores compared with Eucerin (P < 0.0001 and P = 0.007 respectively). No significant difference was detected in mean DLQI and HECSI of the Nigella and Betamethasone groups over time (P = 0.38 and P = 0.99 respectively). CONCLUSION: It seems that Nigella might have the same efficacy as Betamethasone in improvement of life quality and decreasing severity of hand eczema.

Birth weight and risk of childhood acute leukaemia.

Studies of risk factors for acute leukaemia are inconclusive. This case-control study was done in West Azerbaijan province, Islamic Republic of Iran, to determine the relationship between birth weight and acute leukaemia in children aged under 15 years. For every patient 2 age- and sex-matched controls were selected from hospital and community populations. Of 130 cases diagnosed over the period 2003-2009,108 (83.1%) had lymphoblastic and 22 (16.9%) myloblastic type. Significantly more of them were male than female (55.4% versus 44.6%). In a multivariate logistic regression model variables significantly associated with acute leukaemia were: birth weight (OR = 2.25), birth order (OR = 2.25), birth place (OR = 7.93), history of chickenpox (OR = 0.46) and mothers' education (OR = 3.23). The risk of acute leukaemia increased significantly with increasing birth weight in the total group and among girls, but not among boys.

Presentation of the model and optimal control of non-linear fractional-order chaotic system of glucose-insulin.

Recent advances in optimal diabetes control have made it possible for diabetic patients to live longer, healthier, and happier lives. In this research, particle swarm optimization and genetic algorithm are applied in order to control the non-linear fractional order chaotic system of glucose-insulin optimally. A fractional system of differential equations discussed the chaotic behavior of the growth of the blood glucose system. Particle swarm optimization and genetic algorithm were used to solve the presented optimal control problem. The results showed that when the controller is applied from the beginning, the results of the genetic algorithm method are excellent. All the results obtained for the particle swarm optimization method show that this method is also very successful and the results are very close to the genetic algorithm method.

Ultrasound-Driven Defect Engineering in TiO2-x Nanotubes─Toward Highly Efficient Platinum Single Atom-Enhanced Photocatalytic Water Splitting.

Single-atom catalysts (SACs) have demonstrated superior catalytic activity and selectivity compared to nanoparticle catalysts due to their high reactivity and atom efficiency. However, stabilizing SACs within hosting substrates and their controllable loading preventing single atom clustering remain the key challenges in this field. Moreover, the direct comparison of (co-) catalytic effect of single atoms vs nanoparticles is still highly challenging. Here, we present a novel ultrasound-driven strategy for stabilizing Pt single-atomic sites over highly ordered TiO2 nanotubes. This controllable low-temperature defect engineering enables entrapment of platinum single atoms and controlling their content through the reaction time of consequent chemical impregnation. The novel methodology enables achieving nearly 50 times higher normalized hydrogen evolution compared to pristine titania nanotubes. Moreover, the developed procedure allows the decoration of titania also with ultrasmall nanoparticles through a longer impregnation time of the substrate in a very dilute hexachloroplatinic acid solution. The comparison shows a 10 times higher normalized hydrogen production of platinum single atoms compared to nanoparticles. The mechanistic study shows that the novel approach creates homogeneously distributed defects, such as oxygen vacancies and Ti3+ species, which effectively trap and stabilize Pt2+ and Pt4+ single atoms. The optimized platinum single-atom photocatalyst shows excellent performance of photocatalytic water splitting and hydrogen evolution under one sun solar-simulated light, with TOF values being one order of magnitude higher compared to those of traditional thermal reduction-based methods. The single-atom engineering based on the creation of ultrasound-triggered chemical traps provides a pathway for controllable assembling stable and highly active single-atomic site catalysts on metal oxide support layers.

Nanoporous Titanium Oxynitride Nanotube Metamaterials with Deep Subwavelength Heat Dissipation for Perfect Solar Absorption.

We report a quasi-unitary broadband absorption over the ultraviolet-visible-near-infrared range in spaced high aspect ratio, nanoporous titanium oxynitride nanotubes, an ideal platform for several photothermal applications. We explain such an efficient light-heat conversion in terms of localized field distribution and heat dissipation within the nanopores, whose sparsity can be controlled during fabrication. The extremely large heat dissipation could not be explained in terms of effective medium theories, which are typically used to describe small geometrical features associated with relatively large optical structures. A fabrication-process-inspired numerical model was developed to describe a realistic space-dependent electric permittivity distribution within the nanotubes. The resulting abrupt optical discontinuities favor electromagnetic dissipation in the deep sub-wavelength domains generated and can explain the large broadband absorption measured in samples with different porosities. The potential application of porous titanium oxynitride nanotubes as solar absorbers was explored by photothermal experiments under moderately concentrated white light (1-12 Suns). These findings suggest potential interest in realizing solar-thermal devices based on such simple and scalable metamaterials.

In Vitro Study of the Leishmanicidal Activity of Perovskia Abrotanoides Terpenoid-Rich Fractions Against Leishmania Major (MRHO/IR/75/ER).

Background: Cutaneous leishmaniasis (CL) is an ulcerative skin disease caused by some species of the genus Leishmania. Evidence shows that Perovskia abrotanoides is an important herbal medicine against Leishmania. This study was conducted to investigate the killing effect of terpenoid-rich fractions on promastigotes of L. major (MRHO/IR/75/ER). Material and Method: The eluates of reverse phased medium pressure liquid chromatography (RP-MPLC) of the extract were subjected to thin-layer chromatography (TLC) and categorized into six final fractions. Primary proton nuclear magnetic resonance (H-NMR) spectroscopy confirmed fractions' nature. Fractions 4, 5, and 6 (F4, F5, F6) were identified as terpenoid-rich content. Two concentrations of 50 and 100 µg/ml were prepared to test leishmanicidal activity. Followed by treating promastigotes of L. major by the fractions in incubation times of 12, 24, and 48 hours, their viability was determined using a cell proliferation MTS ((3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay. Result: F4, F5, and F6 showed significant killing activity on promastigotes of L. major in a concentration-dependent manner. The viability of promastigotes was significantly reduced at a concentration of 100 µg/ml compared to 50 µg/ml (P-value <0.05). Also, over time a significant decreasing trend in the viability of promastigotes confirmed the time-dependent manner of the fractions (P-value <0.01). Furthermore, F5 had the highest leishmanicidal activity at the first incubation time compared with other fractions. Conclusion: Terpenoid-rich fractions of the P. abrotanoides have a leishmanicidal activity that depends on time and concentration. Among them, F5 has the highest potency that may contain potent terpenoid constituents.

Self-assembly of highly ordered micro- and nanoparticle deposits.

The evaporation of particle-laden sessile droplets is associated with capillary-driven outward flow and leaves nonuniform coffee-ring-like particle patterns due to far-from-equilibrium effects. Traditionally, the surface energies of the drop and solid phases are tuned, or external forces are applied to suppress the coffee-ring; however, achieving a uniform and repeatable particle deposition is extremely challenging. Here, we report a simple, scalable, and noninvasive technique that yields uniform and exceptionally ordered particle deposits on a microscale surface area by placing the droplet on a near neutral-wet shadow mold attached to a hydrophilic substrate. The simplicity of the method, no external forces, and no tuning materials' physiochemical properties make the present generic approach an excellent candidate for a wide range of sensitive applications. We demonstrate the utility of this method for fabricating ordered mono- and multilayer patternable coatings, producing nanofilters with controlled pore size, and creating reproducible functionalized nanosensors.

Spongy all-in-liquid materials by in-situ formation of emulsions at oil-water interfaces.

Printing a structured network of functionalized droplets in a liquid medium enables engineering collectives of living cells for functional purposes and promises enormous applications in processes ranging from energy storage to tissue engineering. Current approaches are limited to drop-by-drop printing or face limitations in reproducing the sophisticated internal features of a structured material and its interactions with the surrounding media. Here, we report a simple approach for creating stable liquid filaments of silica nanoparticle dispersions and use them as inks to print all-in-liquid materials that consist of a network of droplets. Silica nanoparticles stabilize liquid filaments at Weber numbers two orders of magnitude smaller than previously reported in liquid-liquid systems by rapidly producing a concentrated emulsion zone at the oil-water interface. We experimentally demonstrate the printed aqueous phase is emulsified in-situ; consequently, a 3D structure is achieved with flexible walls consisting of layered emulsions. The tube-like printed features have a spongy texture resembling miniaturized versions of "tube sponges" found in the oceans. A scaling analysis based on the interplay between hydrodynamics and emulsification kinetics reveals that filaments are formed when emulsions are generated and remain at the interface during the printing period. Stabilized filaments are utilized for printing liquid-based fluidic channels.

Health services utilization, satisfaction, and attachment to a regular source of care among participants in an urban health provider alliance.

This study examines the effect of a provider alliance on service utilization, satisfaction , self efficacy, and attachment to a regular source of care for participating low income urban children and their families. The use of Physician Assistants and community health workers to expand community outreach, primary care services, pediatric sub-specialty care, and service coordination within and between care settings improved health services utilization, satisfaction with health services, parental self efficacy in navigating the health care system for their children, and service convenience for an at-risk population. Also, the use of Physician Assistants to provide pediatric sub-specialty services did not have a negative effect on parental satisfaction with a child's care. Parents were slightly more satisfied with services received from a Physician Assistant in comparison with the physician sub- specialists in cardiology and nephrology clinics.

Spontaneous Formation of Double Emulsions at Particle-Laden Interfaces.

HYPOTHESIS: Traditionally, double emulsions are produced in the presence of both oil-soluble and water-soluble surfactants in sequential droplet formation settings or unique fluidic designs. Micelles, assemblies of surfactants in liquid mediums, can generate single emulsion droplets without requiring input energy. We hypothesize that the synergy between nanoparticles in one phase, and micelles in the other phase can spontaneously generate double emulsions. Nanoparticles can become surface-activated by adsorbing surfactants and form the second type of emulsions from the initially emulsified phase by micelles. EXPERIMENTS: We design a thermodynamically-driven emulsification platform where double emulsions are spontaneously formed as soon an aqueous nanoparticle dispersion is placed in contact with an oleic micellar solution. Confocal and cryogenic-scanning electron microscopies are utilized to characterize structure and intensity of emulsions at various concentrations of silica nanoparticle and Span micelles. The rate of particle surface activation and emulsification and the amount of water intake are quantified using dynamic light scattering, dynamic interfacial tension, and density measurements. FINDINGS: Nanoscale water droplets nucleate in the oil in form of swollen micelles. Over time, nanoparticles form a water-shell encapsulating the swollen-micelle rich oil phase. The gradual surfaceactivation of nanoparticles is key in self-double emulsification and controlling the emulsion intensity. We build on this new discovery and design a novel system for double emulsification. Incorporating nanoparticles into spontaneous emulsification systems opens novel routes for designing emulsion-based materials.

An ensemble learning approach to digital corona virus preliminary screening from cough sounds.

This work develops a robust classifier for a COVID-19 pre-screening model from crowdsourced cough sound data. The crowdsourced cough recordings contain a variable number of coughs, with some input sound files more informative than the others. Accurate detection of COVID-19 from the sound datasets requires overcoming two main challenges (i) the variable number of coughs in each recording and (ii) the low number of COVID-positive cases compared to healthy coughs in the data. We use two open datasets of crowdsourced cough recordings and segment each cough recording into non-overlapping coughs. The segmentation enriches the original data without oversampling by splitting the original cough sound files into non-overlapping segments. Splitting the sound files enables us to increase the samples of the minority class (COVID-19) without changing the feature distribution of the COVID-19 samples resulted from applying oversampling techniques. Each cough sound segment is transformed into six image representations for further analyses. We conduct extensive experiments with shallow machine learning, Convolutional Neural Network (CNN), and pre-trained CNN models. The results of our models were compared to other recently published papers that apply machine learning to cough sound data for COVID-19 detection. Our method demonstrated a high performance using an ensemble model on the testing dataset with area under receiver operating characteristics curve = 0.77, precision = 0.80, recall = 0.71, F1 measure = 0.75, and Kappa = 0.53. The results show an improvement in the prediction accuracy of our COVID-19 pre-screening model compared to the other models.

Saffron in the treatment of patients with mild to moderate Alzheimer's disease: a 16-week, randomized and placebo-controlled trial.

WHAT IS KNOWN: Herbal medicines have been used in the treatment of behavioural and psychological symptoms of dementia but with variable response. Crocus sativus (saffron) may inhibit the aggregation and deposition of amyloid ß in the human brain and may therefore be useful in Alzheimer's disease (AD). OBJECTIVE: The goal of this study was to assess the efficacy of saffron in the treatment of mild to moderate AD. METHODS: Forty-six patients with probable AD were screened for a 16-week, double-blind study of parallel groups of patients with mild to moderate AD. The psychometric measures, which included AD assessment scale-cognitive subscale (ADAS-cog), and clinical dementia rating scale-sums of boxes, were performed to monitor the global cognitive and clinical profiles of the patients. Patients were randomly assigned to receive capsule saffron 30 mg/day (15 mg twice per day) (Group A) or capsule placebo (two capsules per day) for a 16-week study. RESULTS: After 16 weeks, saffron produced a significantly better outcome on cognitive function than placebo (ADAS-cog: F=4·12, d.f.=1, P=0·04; CDR: F=4·12, d.f.=1, P=0·04). There were no significant differences in the two groups in terms of observed adverse events. WHAT IS NEW AND CONCLUSION: This double-blind, placebo-controlled study suggests that at least in the short-term, saffron is both safe and effective in mild to moderate AD. Larger confirmatory randomized controlled trials are called for.