Dynamics of a two-layer immiscible fluid system exposed to ultrasound.

The relocation dynamics of a two-layer immiscible fluid system exposed to bulk acoustic waves using simulations and experiments are reported. A theoretical formulation of the acoustic radiation pressure (ARP) acting on the interface reveals that ARP is a nonlinear function of the impedance contrast. It has been shown that the force acting on the interface is the simple sum of the ARP and the interfacial tension, which is dependent on the angle of the interface. It was discovered that although the acoustic radiation force is directed from high-impedance fluid (HIF) to low-impedance fluid (LIF), the final steady-state configuration depends on the wall-fluid contact angle (CA). Our study reveals that the HIF and LIF would relocate to the channel center for CA>110°, and CA<70°, respectively, while complete flipping of the fluids is observed for intermediate angles. The forces relocate the fluids in the channel, generally, by a clockwise or anticlockwise rotation. Here, it is demonstrated that the direction of this twist can be determined by the relative densities and wettabilities of the two fluids.

High-consequence infectious diseases: the conception and development of a multi-disciplinary, interprofessional simulation training programme.

BACKGROUND: High-consequence infectious diseases (HCIDs) represent a group of acute infectious diseases with the potential to impact healthcare systems and public health profoundly. Effective management requires a system-based strategy focused on early detection, initiation of infection prevention and control measures, and appropriate use of personal protective equipment (PPE). Inadequate training in the safe use of HCID PPE, and lack of familiarity with key processes such as HCID waste and spills management, exacerbates the risk posed to healthcare workers (HCWs). Enhanced training opportunities are required to ensure that staff are equipped with the necessary knowledge and capabilities to protect themselves from pathogen exposure and infection. AIM: To create a bespoke interprofessional HCID simulation training programme. METHODS: A detailed learning needs analysis was undertaken, which identified multiple areas amenable to educational intervention. A full-day HCID simulation programme was developed, providing HCWs the opportunity to practice and gain proficiency in various domains. FINDINGS: Six interprofessional participants took part in the HCID simulation programme pilot. All six (100%) participants felt that the stated learning objectives had been achieved, and five and one participants found the programme to be extremely useful (83%) or very useful (17%), respectively. Following refinement based on pilot feedback, a further six courses have been run for 38 participants, of whom 97% found the programme to be extremely useful or very useful. CONCLUSION: The development of a training intervention in the low-frequency, high-risk field of HCIDs had a positive impact. Given the disproportionate impact on HCWs at times of HCID outbreaks, more investment is needed to keep the workforce upskilled.

Seroepidemological investigation of Toxoplasma gondii and Trichinella spp. in pigs reared by tribal communities and small-holder livestock farmers in Northeastern India.

Toxoplasma gondii and Trichinella spp. are critical tissue-dwelling foodborne zoonotic parasites associated with pork consumption and pig rearing. Despite being a major pig-rearing region in the country, Northeastern India has not undergone any investigation regarding the presence of T. gondii and Trichinella spp. in pigs. Therefore, this study aims to determine the seroprevalence of T. gondii and Trichinella spp. and identify associated risk factors in pigs reared by tribal communities and small-holder livestock farmers in the northeastern region of India. In a cross-sectional serological survey, 400 pigs from 400 households across five northeastern states of India underwent testing for the seroprevalence of porcine toxoplasmosis and trichinellosis. Serum samples (80 from each state) were analyzed using commercially available ELISA assays. Data on backyard farm characteristics and various management aspects were collected, and risk factors linked with prevalence were analyzed through univariate and multivariate logistic regression analysis. The findings revealed that the apparent and true prevalence of anti-T. gondii antibodies were 45% (40.12-49.88, 95% CI) and 45.7% (40.7-50.69, 95% CI), respectively. As for anti- Trichinella antibodies, both the apparent and true prevalence were 0.75% (-0.1-1.6, 95% CI). The univariate and multivariate analyses indicated that age above 24 months (OR 7.20, 95% CI 2.45-23.71), exposure to cats (OR = 5.87, 95% CI 2.55-14.05), and farms operating for breeding purposes (OR = 5.60, 95% CI 3.01-11.04) were significant risk factors associated with the seroprevalence of T. gondii. This study marks the initial documentation of the seroprevalence of T. gondii and Trichinella spp. in pigs reared by tribal communities in Northeastern India. The results emphasize the significance of these parasites as foodborne zoonotic threats in the region, potentially posing substantial public health risks, especially within tribal and rural communities. The insights derived from this research could be valuable in formulating targeted preventive and control strategies against T. gondii and Trichinella spp. in pigs, not only in this region but also in areas with similar rearing practices.

Measurement of energy and directional distribution of neutron ambient dose equivalent for the 7Li(p,n)7Be reaction.

Double differential neutron fluence distributions were measured in the 7Li(p,n)7Be reaction for proton beam energies 7, 9 and 12 MeV. Seven liquid scintillator based detectors were employed to measure neutron fluence distributions using the Time of Flight technique. Neutron ambient dose equivalents were determined from the measured fluence distribution using ICRP (International Commission on Radiological Protection) recommended fluence to dose equivalent conversion coefficients. Neutron dose equivalents were also measured using a conventional BF3 detector based REM counter. Ambient dose equivalent measured by the REM counter is found to be in agreement with that determined from the neutron fluence spectra within their uncertainties. Angular distributions of the ambient dose equivalents were also determined from the measured fluence distributions at different angles.

First Seroepidemiological Investigation of Hepatitis E Virus Infection in Backyard Pigs from Northeastern India: Prevalence and Associated Risk Factors.

Hepatitis E virus (HEV) is the leading cause of acute viral hepatitis globally, with zoonotic potential, and pigs are considered the major reservoir. To determine the seroprevalence of HEV infection in pigs reared in backyard conditions in the northeastern region of India, blood samples were collected from 400 pigs from five northeastern states (80 samples from each state) and tested for IgG antibodies against HEV using an ELISA assay. Questionnaires on farm characteristics and management practices were completed, and risk factors associated with HEV were studied using univariate and multivariate analysis. The apparent seroprevalence of HEV infection was 51% (46.1-55.9, 95% CI), with a true prevalence of 52.98% (47.22-58.75, 95% CI). The risk factors significantly associated with higher HEV seropositivity were as follows: lack of disinfection (OR 4.65), feeding swill (restaurant and bakery waste) (OR 2.55), failure to follow the all-in-all-out production system (OR 3.47), and medium holding size (OR 9.83), which refers to mixed rearing of younger and older age groups. This study demonstrates that HEV is widespread among pigs reared in northeastern India. The risk factor analysis conducted in this study provides valuable insights into the prevalence of HEV in the region.

Current debates and emerging trends in the history of science in premodern Islamicate societies.

This roundtable brings together contributions from nine senior, mid-career and junior scholars who work on the history of science in pre-1800 Islamicate societies. The contributions reflect upon some of the challenges that have historically constrained the subfield, how they have sought to overcome them, and what they see as some of the more productive and fruitful turns the field has taken and/or should take in the future. A central trend in all contributions is how they seek to confront the combined weight of colonialism, Orientalism, and the teleological history of science that continues to haunt contemporary discussions in both academia and the general public with regards to science in pre-1800 Islamicate societies. Without diminishing the pioneering achievements of the generations of historians who have preceded us, and upon whose work we continue to rely, this combined weight has tended a) to marginalize the study of occult sciences in Islamicate societies; b) to emphasize investigations of content from an etic perspective of how we got to the present, which is primarily seen as how the scientific content is connected to the rise of modern science in Europe; and c) to concomitantly marginalize the study of science in post-1200 Islamicate societies, particularly those with little to no connection to the rise of "Western" science. The contributions build upon conversations that took place among participants in December 2019 at a workshop at New York University (NYU), Abu Dhabi Institute in New York City, funded by a grant from NYU Abu Dhabi.

Ultrasound resonance in coflowing immiscible liquids in a microchannel.

We study ultrasonic resonance in a coflow system comprising a pair of immiscible liquids in a microchannel exposed to bulk acoustic waves. We show using an analytical model that there are two resonating frequencies corresponding to each of the coflowing liquids, which depend on the speed of sound and stream width of the liquid. We perform a frequency domain analysis using numerical simulations to reveal that resonance can be achieved by actuating both liquids at a single resonating frequency that depends on the speeds of sound, densities, and widths of the liquids. In a coflow system with equal speeds of sound and densities of the pair of fluids, the resonating frequency is found to be independent of the relative width of the two streams. In coflow systems with unequal speeds of sound or densities, even with matching characteristic acoustic impedances, the resonating frequency depends on the stream width ratio, and the value increases with an increase in the stream width of the liquid with a higher speed of sound. We show that a pressure nodal plane can be realized at the channel center by operating at a half-wave resonating frequency when the speeds of sound and densities are equal. However, the pressure nodal plane is found to shift away from the center of the microchannel when the speeds of sound and densities of the two liquids are unequal. The results of the model and simulations are verified experimentally via acoustic focusing of microparticles suggesting the formation of a pressure nodal plane and hence a resonance condition. Our study will find relevance in acoustomicrofluidics involving immiscible coflow systems.

Phase switching phenomenon in a system of three coupled DC glow discharge plasmas.

We report the first experimental observations of phase switching in a system of three coupled plasma sources. Two of the plasma sources are inductively coupled to each other while the third one is directly coupled to one of them. The coupled system acquires a frequency pulling synchronized state following which a transition occurs to a frequency entrainment state with an increase in the frequency of the directly coupled system. We also observe a sudden jump from a lower to a higher frequency entrainment state and a concomitant phase switching between the oscillations of the two directly coupled sources while the phase difference between the inductively coupled sources remains constant. These experimental findings are established using various diagnostic tools, such as the Fourier spectra, frequency bifurcation plots, Lissajous plots, and Hilbert transforms of the data. The experimental results are qualitatively modeled using three coupled van der Pol equations, in which two of them are environmentally coupled while the third one is directly coupled with one of them.

Effects of surface acoustic waves on droplet impact dynamics.

HYPOTHESIS: Surface acoustic waves (SAW) propagating along a solid surface can significantly affect the dynamics of droplet impact. Although droplet impact in presence of SAW has been attempted recently, here, we investigate the effects of surface wettability, droplet size, impact velocity, and SAW power on the impact and spreading dynamics along with post-impact oscillation dynamics of a drop. EXPERIMENTS: Here, we study droplet impact on a surface exposed to traveling SAW produced using an interdigitated electrode patterned on a piezoelectric substrate. The effects of Weber number (We), surface wettability, and SAW power on the impact and spreading dynamics and post-impact oscillation dynamics are studied. FINDINGS: Our study unravels that the interplay between capillary and viscous forces, and inertia forces arising due to pre-impact kinetic energy and SAW-induced bulk acoustic streaming underpins the phenomena. Remarkably, we find that the effect of SAW on droplet impact dynamics is predominant in the case of a hydrophilic (HPL) substrate at a higher SAW power and smaller We and hydrophobic (HPB) substrate irrespective of SAW power. Our study reveals that the maximum droplet spreading diameter increases with SAW power at smaller We for an HPL surface whereas it is independent of SAW power at higher We. Post-impact oscillation of a droplet over an HPL surface is found to be overdamped with a smaller amplitude compared to an HPB substrate, and a faster decay in oscillation amplitude is observed in the case of an HPB surface and higher We. Our study provides an improved understanding of droplet impact on a surface exposed to SAW that may find relevance in various practical applications.

Kelvin-Helmholtz instability in a compressible dust fluid flow.

We report the first experimental observations of a single-mode Kelvin-Helmholtz instability in a flowing dusty plasma in which the flow is compressible in nature. The experiments are performed in an inverted [Formula: see text]-shaped dusty plasma experimental device in a DC glow discharge Argon plasma environment. A gas pulse valve is installed in the experimental chamber to initiate directional motion to a particular dust layer. The shear generated at the interface of the moving and stationary layers leads to the excitation of the Kelvin-Helmholtz instability giving rise to a vortex structure at the interface. The growth rate of the instability is seen to decrease with an increase in the gas flow velocity in the valve and the concomitant increase in the compressibility of the dust flow. The shear velocity is further increased by making the stationary layer to flow in an opposite direction. The magnitude of the vorticity is seen to become stronger while the vortex becomes smaller with such an increase of the shear velocity. A molecular dynamics simulation provides good theoretical support to the experimental findings.

Deicing of Sessile Droplets Using Surface Acoustic Waves.

Deicing has significant relevance in various applications such as transportation, energy production, and telecommunication. The use of surface acoustic waves (SAWs) is an attractive option for deicing as it offers several advantages such as localized heating, in situ control, low power, and system integration for highly efficient deicing. Here, we report an understanding of the dynamics of deicing of microlitre volume water droplets (1 to 30 µL) exposed to low power (0.3 W) SAW actuation using an interdigitated electrode on a piezoelectric (LiNbO3) substrate. We study the time variation of the volume of liquid water from the onset of SAW actuation to complete deicing, which takes 2.5 to 35 s depending on the droplet volume. The deicing phenomenon is attributed to acoustothermal heating which is found to be greatly influenced by the loss of ice adhesion with the substrate and the acoustic streaming within the liquid water. Acoustothermal heating inside the droplet is characterized by the temperature distribution inside the droplet using infrared thermography, and acoustic streaming is observed using dye-based optical microscopy. A rapid enhancement in deicing is observed upon the detachment of ice from the substrate and the onset of acoustic streaming, marked by a sudden increase in the liquid water volume, droplet temperature, and heat transfer coefficient. The deicing time is found to increase linearly with droplet volume as observed from experiments and further verified using a theoretical model. Our study provides an improved understanding of the recently introduced SAW-based deicing technique that may open up the avenue for a suitable alternative to standard deicing protocols.

Magnetic resonance imaging (MRI) findings after knee, foot, and ankle traumas.

OBJECTIVE: The aim of this study is to investigate the demographic and clinical characteristics of knee and ankle traumas that could not be detected in the first post-traumatic evaluation and diagnosed within 15 days after the follow-up examination and to discuss the results we obtained with current data. PATIENTS AND METHODS: Patients admitted to the emergency department trauma department between January 1, 2017, and December 31, 2018, were retrospectively analyzed. Applications due to traffic accidents and all traumas except knee and ankle trauma were excluded from the study. Medical records were used to reveal the demographic characteristics of the cases, clinical findings, mechanisms of injury, additional injuries, and interventions in the emergency room. RESULTS: The mean age of 2,039 patients included in the study due to knee, foot, and ankle trauma was 35.69±12.01, and the median value was 36 (age range 11-71). The patients were divided into 2 groups knee trauma and ankle trauma and statistical evaluations were made. Of the patients evaluated for knee trauma (n=1,157), 463 (40%) were female and 694 (60%) were male. Of the patients evaluated for ankle trauma (n=882), 397 (45%) were female and 485 (55%) were male. CONCLUSIONS: It is evident that knee, foot, and ankle traumas after simple falls and sports injuries are frequently encountered by emergency physicians. It is known that post-traumatic ligament injury, bone contusion, intraarticular fluid/hematoma formation, and fractures that cannot be detected by radiographs can be overlooked in emergency departments where patient density is high.

Auto-correlations of microscopic density fluctuations for Yukawa fluids in the generalized hydrodynamics framework with viscoelastic effects.

The present work develops a theoretical procedure for obtaining transport coefficients of Yukawa systems from density fluctuations. The dynamics of Yukawa systems are described in the framework of the generalized hydrodynamic (GH) model that incorporates strong coupling and visco-elastic memory effects by using an exponentially decaying memory function in time. A hydrodynamic matrix for such a system is exactly derived and then used to obtain an analytic expression for the density autocorrelation function (DAF)-a marker of the time dynamics of density fluctuations. The present approach is validated against a DAF obtained from numerical data of Molecular Dynamics (MD) simulations of a dusty plasma system that is a practical example of a Yukawa system. The MD results and analytic expressions derived from the model equations are then used to obtain various transport coefficients and the latter are compared with values available in the literature from other models. The influence of strong coupling and visco-elastic effects on the transport parameters are discussed. Finally, the utility of our calculations for obtaining reliable estimates of transport coefficients from experimentally determined DAF is pointed out.

Square Lattice Formation in a Monodisperse Complex Plasma.

We present the first observations of a square lattice formation in a monodisperse complex plasma system, a configurational transition phenomenon that has long been an experimental challenge in the field. The experiments are conducted in a tabletop L-shaped dusty plasma experimental device in a dc glow discharge Argon plasma environment. By a careful control of the vertical potential confining the charged particles as well as the strength of the ion wake charge interactions with the dust particles, we are able to steer the system toward a crystalline phase that exhibits a square lattice configuration. The transition occurs when the vertical confinement strength is slightly reduced below a critical value leading to a buckling of the monodisperse hexagonal 2D dust crystal to form a narrowly separated bilayer state (a quasi-2D state). Some theoretical insights into the transition process are provided through molecular dynamics simulations carried out for the parameters relevant to our experiment.

Self-sustained non-equilibrium co-existence of fluid and solid states in a strongly coupled complex plasma system.

A complex (dusty) plasma system is well known as a paradigmatic model for studying the kinetics of solid-liquid phase transitions in inactive condensed matter. At the same time, under certain conditions a complex plasma system can also display characteristics of an active medium with the micron-sized particles converting energy of the ambient environment into motility and thereby becoming active. We present a detailed analysis of the experimental complex plasmas system that shows evidence of a non-equilibrium stationary coexistence between a cold crystalline and a hot fluid state in the structure due to the conversion of plasma energy into the motion energy of microparticles in the central region of the system. The plasma mediated non-reciprocal interaction between the dust particles is the underlying mechanism for the enormous heating of the central subsystem, and it acts as a micro-scale energy source that keeps the central subsystem in the molten state. Accurate multiscale simulations of the system based on combined molecular dynamics and particle-in-cell approaches show that strong structural nonuniformity of the system under the action of electostatic trap makes development of instabilities a local process. We present both experimental tests conducted with a complex plasmas system in a DC glow discharge plasma and a detailed theoretical analysis.

Microfluidics-based rapid measurement of nitrite in human blood plasma.

Nitric oxide (NO) is one of the vital gasotransmitters that takes part in many biological pathways such as infection, inflammation and ischemia, immune response, neurotransmission, and cardiovascular systems. Nitrite is one of the primary metabolites of NO and is considered to be a circulating storage pool for NO. Here, we report direct and rapid measurement of nitrite in human blood plasma using a fluorescence-based microfluidic method. The study revealed the factors that affect the endogenous concentration of nitrite in blood plasma, mainly the presence of blood cells, hemoglobin, and soluble proteins. We find that separation of blood plasma immediately after sample collection and subsequent dilution of plasma with buffer at a ratio of 1 : 4 eliminates the interference from cells and proteins, providing reliable measurements. The proposed method can measure plasma nitrite in the concentration range of 0-20 µM with a limit of detection of 60 nM and a sensitivity of 5.64 µM-1 within 10 min of sample collection. By spiking nitrite into plasma, a linear correlation between the nitrite concentration and FL intensity is obtained, which is utilized further to measure the endogenous concentration of nitrite present in the plasma of healthy volunteers and patients. The study revealed that the endogenous nitrite concentration in the blood plasma of healthy humans falls in the range of 0.4-1.2 µM. Furthermore, the study with blood samples obtained from patients showed that nitrite levels are inversely correlated with the total cholesterol and low-density lipoproteins levels, which is in good agreement with the literature.

The effectiveness and tolerability of clobazam in the pediatric population: Adjunctive therapy and monotherapy in a large-cohort multicenter study.

OBJECTIVE: To evaluate the effectiveness and tolerability of clobazam therapy in the pediatric population in terms of seizure semiology, epileptic syndromes, and etiological subgroups. METHODS: A retrospective cohort study was conducted consisting of 1710 epileptic children from eight centers in seven geographic regions of Turkey. The initial efficacy of clobazam therapy was evaluated after three months of treatment. The long-term effectiveness of the drug, overall seizure outcomes, and overall therapeutic outcomes were evaluated during 12 months of therapy. RESULTS: Analysis of initial efficacy after the first three months of clobazam therapy showed that 320 (18.7 %) patients were seizure-free, 683 (39.9 %) had > 50 % seizure reductions, and 297 (17.4 %) had < 50 % seizure reductions. A positive response (seizure-free and >50 % seizure reduction) was determined for focal-onset (62.3 %) seizures, epileptic spasms (61.5 %), and generalized onset seisures (57.4). The highest positive response rate among the epileptic syndromes was for self-limited epilepsy with centrotemporal spikes (SeLECTS). The highest negative response rate was for developmental and/or epileptic encephalopathies (DEEs). Magnetic resonance imaging (MRI) revealed a structural etiological diagnosis in 25.8 % of the cohort. A higher positive response rate was observed at MRI in patients with sequelae lesions than in those with congenital lesions. The seizure recurrence rate was higher in the patient group with epilepsy with genetic and metabolic causes, in individuals with more than one seizure type, and in those using three or more antiseizure drugs. CONCLUSIONS: This cohort study provides additional evidence that clobazam is an effective and well-tolerable drug with a high seizure-free rate (18.7 %), a significant seizure reduction rate (57.3 %), and with excellent overall therapeutic outcomes with a low seizure relapse rate and considerable reversible benefits in the pediatric population.

Inter-cluster competition and resource partitioning may govern the ecology of Frankia.

Microbes live in a complex communal ecosystem. The structural complexity of microbial community reflects diversity, functionality, as well as habitat type. Delineation of ecologically important microbial populations along with exploration of their roles in environmental adaptation or host-microbe interaction has a crucial role in modern microbiology. In this scenario, reverse ecology (the use of genomics to study ecology) plays a pivotal role. Since the co-existence of two different genera in one small niche should maintain a strict direct interaction, it will be interesting to utilize the concept of reverse ecology in this scenario. Here, we exploited an 'R' package, the RevEcoR, to resolve the issue of co-existing microbes which are proven to be a crucial tool for identifying the nature of their relationship (competition or complementation) persisting among them. Our target organism here is Frankia, a nitrogen-fixing actinobacterium popular for its genetic and host-specific nature. According to their plant host, Frankia has already been sub-divided into four clusters C-I, C-II, C-III, and C-IV. Our results revealed a strong competing nature of CI Frankia. Among the clusters of Frankia studied, the competition index between C-I and C-III was the largest. The other interesting result was the co-occurrence of C-II and C-IV groups. It was revealed that these two groups follow the theory of resource partitioning in their lifestyle. Metabolic analysis along with their differential transporter machinery validated our hypothesis of resource partitioning among C-II and C-IV groups.

Trapping of Aqueous Droplets under Surface Acoustic Wave-Driven Streaming in Oil-Filled Microwells.

Microwell arrays are ideal platforms for cell culturing, cell separation, and low-volume liquid handling. The ability to manipulate droplets in microwells could open up the opportunity for developing new biochemical assays. Here, we study the trapping of aqueous droplets in an oil-filled microwell driven by the application of nanometer amplitude vibrations called surface acoustic waves (SAW). We elucidate the dynamics of the droplet within the vortex toward the final trapping location and the physics of the trapping phenomenon using a theoretical model by considering the relevant forces. Our study revealed that the combined effect of acoustic radiation and hydrodynamic forces leads to droplet migration and trapping. We demarcate the trapping and nontrapping regimes in terms of the minimum critical input power required for the trapping of droplets of different sizes and densities. We find that the critical power varies as the square of the droplet size and is higher for a denser droplet. The effects of input power and droplet size on the trapping location and trapping time are also studied.