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1.
J Acoust Soc Am ; 155(3): 1655-1666, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38426837

RESUMEN

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.

2.
J Food Sci Technol ; 60(1): 243-251, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36618040

RESUMEN

This study is aimed to determine and compare the antioxidant activity of Orange Peel Powder (OPP) in ghee at different temperatures (4 °C, 25 °C and 60 °C) for divergent storage periods (0, 7, 14 and 21 days). To compare the antioxidant potentiality, synthetic antioxidant BHA (Butylated Hydroxy Anisole) is used. Twelve ghee samples were prepared where one was control, another one was BHA treated and the rest ten were admixing OPP in ghee at different ratios. After sensory evaluation three highest scored ghee samples (0.5%. 1.0% and 1.5%) were selected. Samples were analyzed for peroxide (PV), thiobarbituric acid (TBA), free fatty acids (FFA) value and radical scavenging activity. Though storage temperature and storage period were increased OPP treated ghee samples peroxide, TBA and FFA values were lowered significantly compared to control samples. Moreover, 1.0% and 1.5% OPP treated ghee samples such values were lowered than BHA treated ghee samples and all these are on the favor of ghee quality. OPP treated ghee samples' DPPH quench potentiality is also stronger than BHA treated ghee samples. Therefore, OPP is a great source of antioxidants and this can be used in ghee as a natural source of antioxidants.

3.
Phys Rev Lett ; 127(13): 134501, 2021 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-34623851

RESUMEN

Transition between stream and droplet regimes in a coflow is typically achieved by adjusting the capillary numbers (Ca) of the phases. Remarkably, we experimentally evidence a reversible transition between the two regimes by controlling exposure of the system to acoustic standing waves, with Ca fixed. By satisfying the ratio of acoustic radiation force to the interfacial tension force, Ca_{ac}>1, experiments reveal a reversible stream drop transition for Ca<1, and stream relocation for Ca≥1. We explain the phenomenon in terms of the pinching, advection, and relocation timescales and a transition between convective and absolute instability from a linear stability analysis [P. Guillot et al., Phys. Rev. Lett. 99, 104502 (2007)PRLTAO0031-900710.1103/PhysRevLett.99.104502].

4.
J Acoust Soc Am ; 150(1): 307, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34340505

RESUMEN

The dynamical motion of a pair of microparticles exposed to acoustic standing waves and located at the pressure nodal plane is studied using numerical simulations and experiments. The insight into their dynamical behavior along the pressure nodal plane due to the competition between the axial primary radiation and interparticle forces is elucidated. An expression for axial primary radiation force acting on a particle is derived, and the particle dynamics is simulated using fluid-structure interaction model based on the arbitrary Lagrangian-Eulerian method. Considering the total radiation force acting on a particle is the sum of the axial primary radiation force and the interparticle force, three distinct dynamical regimes are observed depending upon the relative magnitudes of the acoustic forces which in turn depend on the gradient of the acoustic energy density. Acceleration, deceleration, and constant velocity motion of the pair of approaching particles are observed, which are explained by the interplay of the acoustic and non-acoustic forces. The dynamical motion of the pair of particles predicted using the model is in very good agreement with the experimental observations.

5.
Nanotechnology ; 27(28): 285702, 2016 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-27251385

RESUMEN

The paper reports the thermo-therapeutic applications of chitosan- and PEG-coated nickel ferrite (NiFe2O4) nanoparticles. In this study NiFe2O4 nanoparticles were synthesized by the co-precipitation method, tuning the particle size through heat treatment in the temperature range from 200-800 °C for 3 h. XRD and TEM analysis revealed that the the ultrafine nanoparticles were of size 2-58 nm. Crystallinity of the NiFe2O4 nanoparticles in the as-dried condition with the particle size ∼2-3 nm was confirmed from the presence of a lattice fringe in the HRTEM image. VSM measurements showed that a superparamagnetic/ferromagnetic transition occurs with increasing particle size, which was further confirmed by Mössbauer spectroscopy. The nickel ferrite nanoparticles with optimum particle size of 10 nm were then coated with materials commonly used for biomedical applications, i.e. chitosan and PEG, to form homogeneous suspensions. The hydrodynamic diameter and the polydispersity index (PDI) were analyzed by dynamic light scattering at the physiological temperature of 37 °C and found to be 187 nm and 0.21 for chitosan-coated nanoparticles and 285 nm and 0.32 for PEG-coated ones. The specific loss power of rf induction heating by the set-up for hyperthermia and r 2 relaxivity by the nuclear magnetic resonance were determined. The results of induction heating measurements showed that the temperature attained by the nanoparticles of size 10 nm and concentration of about 20 mg ml(-1) was >70 °C (for chitosan) and >64 °C (for PEG). It has been demonstrated that the required temperature for hyperthermia heating could be tuned by tuning the particle size, shape and magnetization and the concentration of solution. For other potential biomedical applications of the NiFe2O4 nanoparticle solution, e.g. magnetic resonance imaging, the NMR studies yielded the T 1 and T 2 relaxivities as 0.348 and 89 mM(-1) s(-1) respectively. The fact that the T 2 relaxivity is orders of magnitude higher than T 1 indicates that this is suitable as a T 2 contrast agent for magnetic resonance imaging.


Asunto(s)
Nanopartículas del Metal , Quitosano , Compuestos Férricos , Níquel
6.
Mater Lett ; 162: 60-63, 2016 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-26549918

RESUMEN

Biomedical applications of ZnFe2O4 nanoparticle are preferable among all kinds of ferrites due to the compatibility of Zn2+ ions for human bodies. We have followed the soft chemical route to synthesize chitosan and PEG coated ZnFe2O4 nanoparticles and also the chitosan-coated-nanoparticles encapsulated with liposome. X-ray diffraction studies by the Mo Kα target, showed the formation of single phase spinel structure. The lattice parameter turned out to be 8.48Å and grain size ~ 4.8 nm (± 0.1 nm). Similar particle size was observed by transmission electron microscope analysis. HRTEM studies showed the distinct lattice fringes thus confirming the good crystallinity of the synthesized nanoparticles. M-H curve at room temperature showed the prepared sample was superparamagnetic in nature, which is also confirmed by the doublets of Mössbauer spectroscopy. Relaxivity values (r2) of Chitosan and PEG coated ZnFe2O4 nanoparticles are 68 and 76 mM-1s-1 respectively. In order to achieve further biocompatibility the chitosan-coated-nanoparticles were encapsulated with liposome. The r2 relaxivity was found as 54mM-1s-1. MR images obtained from the in vitro experiments based on phantoms demonstrated good contrast enhancement. Induction heating of bare and coated particles was investigated to reveal the self heating temperature rising properties of ZnFe2O4 nanoparticles.

7.
Mymensingh Med J ; 23(2): 208-12, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24858144

RESUMEN

Childhood diarrhea represents a major public health problem in developing countries, where campylobacteriosis is widespread and causes significant morbidity and mortality in infants and children. Despite the increasing importance of campylobacteriosis, most developing countries and even many developed countries do not have surveillance systems to measure the health and economic burden of human campylobacteriosis, nor detect trends in outbreaks. The present study was carried out to diagnose etiology of diarrhea caused by Campylobacter species. A total of 150 clinically diagnosed diarrheal pediatric patients were included in this study, of which 98(65.3%) were male and 52(34.6%) female from the Department of Pediatrics, Mymensingh Medical College Hospital, Mymensingh, Bangladesh from July 2011 to April 2012. Stool specimens were collected from each of the cases. The specimens were cultured in appropriate media and Campylobacters were isolated and identified by recommended tests. Among 150 cases, 17(11.3%) were culture positive for Campylobacter species, of which 15(88.2%) were C. jejuni and 02(11.7%) were C. coli. Of the cases, below 1 year of age group were 106(70.6%) cases showing 12(70.5%) positive for Campylobacters and 44(29.33%) cases were above 1 year of age group showing 05(29.41%) positive. The prevalence of Campylobacter infection found in the present study was higher below 1 year age group and was very much close to other countries of this subcontinent.


Asunto(s)
Infecciones por Campylobacter/epidemiología , Infecciones por Campylobacter/microbiología , Campylobacter/aislamiento & purificación , Diarrea/microbiología , Técnicas Bacteriológicas , Bangladesh , Niño , Preescolar , Estudios de Cohortes , Femenino , Humanos , Lactante , Masculino , Prevalencia
8.
Heliyon ; 10(14): e34413, 2024 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-39082019

RESUMEN

Nanoscaled magnetic cobalt ferrite (CoFe2O4) of approximately size 17 nm was synthesized via the co-precipitation method and then annealed at 600 °C. The resultant materials were taken for various magnetic characterizations. The X-ray diffraction pattern confirms the formation of the fcc type of cubic crystal structure. The ferrimagnetic phenomenon of the specimen was confirmed by the hysteresis loop, which is comparable to the slow relaxation sextet pattern of the MÓ§ssbauer study. Isomer shift, quadrupole splitting, hyperfine field, and Fe3+ occupancy of various sites are also investigated from mÓ§ssbauer spectroscopy. The frequency-dependent initial permeability has a comparatively high value up to a certain frequency range and then decreases drastically, whereas the imaginary part of complex permeability decreases sharply with the increase of frequency. The temperature-dependent magnetization ensures the presence of a superparamagnetic blocking temperature of 433 K. In the study of the magnetocaloric effect, isothermal magnetization measurements were carried out around the superparamagnetic blocking temperature, revealing a maximum entropy change of ΔSmax = 1.32 J/kg K and a relative cooling power (RCP) of 52.22 J/kg (H = 1.5 T) through the Maxwell approach. These outcomes emphasize the potential of CoFe2O4 NPs for magnetic refrigeration at reduced temperatures with lower applied magnetic fields.

9.
Front Chem ; 12: 1347423, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38524916

RESUMEN

In this study, Mg1-xCoxFe2O4 (0≤x ≤ 1 with ∆x = 0.1) or MCFO nanoparticles were synthesized using a chemical co-precipitation method and annealed at 200, 400, 600, and 800°C respectively to investigate the structural properties of the materials by X-ray diffractometer (XRD), transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FTIR). Controlled annealing increased particle size for each value of x. The aim was to investigate how specific loss power (SLP) and maximum temperature (Tmax) during local magnetic hyperthermia were affected by structural alterations associated with particle size and composition. The lattice parameter, X-ray density, ionic radius, hopping length, bond length, cation-cation distance, and cation-anion distance increase with an increase in Co2+ content. Raman and FTIR spectroscopy reveal changes in cation distribution with Co2+ content and particle size. Magnetic properties measured by the physical property measurement system (PPMS) showed saturation magnetization (Ms), coercivity (Hc), remanent magnetization (Mr/Ms), and anisotropy constant (K1) of the Mg1-xCoxFe2O4 nanoparticles increase with Co2+ content and particle size. When exposed to an rf magnetic field, the nanohybrids experienced an increase in both the SLP (specific loss power) and Tmax (maximum temperature) as the particle size initially increased. However, these values reached their peak at critical particle size and subsequently decreased. This occurs since a modest increase in anisotropy, resulting from the presence of Co2+ and larger particle size, facilitates Néel and Brownian relaxation. However, for high anisotropy values and particle size, the Néel and Brownian relaxations are hindered, leading to the emergence of a critical size. The critical size increases as the Co2+ content decreases, but it decreases as the Co2+ content increases, a consequence of higher anisotropy with the increase in Co2+. Additionally, it is noteworthy that the maximum temperature (Tmax) rises as the concentration of nanohybrids grows, but the specific loss power (SLP) decreases. An increased concentration of chitosan-MCFO nanohybrids inhibits both the Néel and Brownian relaxation processes, reducing specific loss power.

10.
Heliyon ; 10(10): e31135, 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38774320

RESUMEN

This study was conducted to observe the storage conditions, such as solvent and temperature, of lycopene content and degradation kinetics from red amaranth (Amaranthus gangeticus). Jelly was prepared using the extracted lycopene, the physicochemical properties and lycopene content. The extract with the maximum amount of lycopene was obtained by extraction with hexane, acetone and ethanol (2:1:1),50 ± 9 mg/kg. Higher lycopene degradation was observed at refrigerated temperature as compared to ambient temperature in hexane acetone (6:4) solvent throughout the storage periods. In this period, the initial lycopene concentration was measured to be 17 ± 8 mg/kg, whereas at the end of the storage time, it was found to be 3.0 ± 0.8 mg/kg. Hence, the results indicate that the hexane, acetone, and ethanol (in a ratio of 2:1:1) solvent method is viable for extracting and purifying lycopene from red amaranth at refrigerated temperature. This lycopene can serve as both a natural colorant and a value-added product. However, it is worth noting that lycopene can also be extracted and purified using recrystallization, column chromatography, and thin-layer chromatography (TLC) methods. The Winter melon jelly using lycopene from red amaranth contained moisture 29.6 %, ash 0.67 %, acidity 0.35 %, reducing sugar 26.8 %, non-reducing sugar 35.4 %, total soluble solid 66°brix and lycopene content 26.04 mg/kg. Proper utilization of lycopene extracted from red amaranth during the preparation of bakery, confectionary, baby food etc., may help and encourage the development of small-scale industries in the country.

11.
RSC Adv ; 14(32): 23560-23573, 2024 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-39071478

RESUMEN

pH-responsive polymer microspheres undergoing reversible changes in their surface properties have been proved useful for drug delivery to targeted sites. This paper is aimed at preparing pH-responsive polymer-modified magnetic mesoporous SiO2 particles. First, mesoporous magnetic (Fe3O4) core-particles are prepared using a one-pot solvothermal method. Then, magnetic Fe3O4 particles are covered with a C[double bond, length as m-dash]C functional mesoporous SiO2 layer before seeded emulsion polymerization of 2-carboxyethyl acrylate (2-CEA). The composite polymer particles are named Fe3O4/SiO2/P(2-CEA). The average diameters of the Fe3O4 core and Fe3O4/SiO2/P(2-CEA) composite polymer particles are 414 and 595 nm, respectively. The mesoporous (pore diameter = 3.41 nm) structure of Fe3O4/SiO2/P(2-CEA) composite polymer particles is confirmed from Brunauer-Emmett-Teller (BET) surface analysis. The synthesized Fe3O4/SiO2/P(2-CEA) composite polymer exhibited pH-dependent changes in volume and surface charge density due to deprotonation of the carboxyl group under alkaline pH conditions. The change in the surface properties of Fe3O4/SiO2/P(2-CEA) composite polymer particles following pH change is confirmed from the pH-dependent sorption of cationic methylene blue (MB) and anionic methyl orange (MO) dye molecules. The opening of the pH-responsive P(2-CEA) gate valve at pH 10.0 allowed the release of loaded vancomycin up to 99% after 165 min and p-acetamido phenol (p-AP) up to 46% after 225 min. Comparatively, the amount of release is lower at pH 8.0 but still suitable for drug delivery applications. These results suggested that the mesoporous Fe3O4/SiO2 composite seed acted as a microcapsule, while P(2-CEA) functioned as a gate valve across the porous channel. The prepared composite polymer can therefore be useful for treating intestine/colon cancer, where the pH is comparatively alkaline.

12.
Biology (Basel) ; 13(6)2024 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-38927250

RESUMEN

Artificial insemination (AI) with liquid-preserved semen has recently become common in pig breeding. The semen doses are produced in a centralized manner at the boar stud and then subsequently distributed and transported to sow farms. However, vibration emissions during transportation by logistic vehicles may adversely affect the quality of boar sperm. Therefore, this study aimed to explore the impact of vibration-induced emissions on sperm quality and function under simulated transportation conditions. Each time, ejaculates from all 15 boars were collected and then pooled together to minimize individual variations, and the sample was split using an extender for dilution. Different rotational speeds (0 rpm, 80 rpm, 140 rpm, 200 rpm) were utilized to simulate varying intensities of vibration exposure using an orbital shaker, considering different transportation times (0 h, 3 h, and 6 h). Subsequently, evaluations were conducted regarding sperm motility, plasma membrane integrity, acrosome integrity, mitochondrial function, adenosine triphosphate (ATP) levels, mitochondrial reactive oxygen species (ROS) levels, pH, glycolytic pathway enzyme activities, and capacitation following exposure to vibration emissions. Both vibration time and intensity impact sperm motility, plasma membrane integrity, and acrosomal integrity. Vibration exposure significantly reduced sperm ATP levels, mitochondrial membrane potential, and the levels of mitochondria-encoded proteins (MT-ND1, MT-ND6) (p < 0.05). After vibration emission treatment, the pH value and mitochondrial ROS levels significantly increased (p < 0.05). Inhibition of sperm glycolysis was observed, with reduced activities of hexokinase (HK), pyruvate kinase (PK), and lactate dehydrogenase (LDH), along with decreased lactate levels (p < 0.05). Additionally, sperm tyrosine phosphorylation levels were significantly reduced by vibration emissions compared to the control group (p < 0.05). After the vibration emission treatment, the number of sperm bound to each square millimeter of oviduct explants decreased significantly compared to the control group (p < 0.05). Similarly, compared to the control group, using semen subjected to vibration stress for AI results in significantly reduced pregnancy rates, total born litter size, live-born litter size, and healthy born litter size (p < 0.05).

13.
Antioxidants (Basel) ; 13(1)2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38247528

RESUMEN

Sperm motility is an important factor in the migration of sperm from the uterus to the oviduct. During sperm preservation in vitro, sperm generates excessive ROS that damages its function. This study aims to investigate whether the addition of pyrroloquinoline quinone (PQQ) to the diluted medium could improve chilled ram sperm quality, and then elucidates the mechanism. Ram semen was diluted with Tris-citric acid-glucose (TCG) medium containing different doses of PQQ (0 nM, 10 nM, 100 nM, 1000 nM, 10,000 nM), and stored at 4 °C. Sperm motility patterns, plasma membrane integrity, acrosome integrity, mitochondrial membrane potential, reactive oxygen species (ROS) levels, malondialdehyde (MDA) levels, superoxide dismutase (SOD) activity, and ATP levels were measured after preservation. Furthermore, the expressions of NADH dehydrogenase 1 (MT-ND1) and NADH dehydrogenase 6 (MT-ND6) in sperm were also detected by western blotting. In addition, sperm capacitation and the ability of sperm to bind to the zona pellucina were also evaluated. It was observed that the addition of PQQ significantly (p < 0.05) improved ram sperm motility, membrane integrity, and acrosome integrity during preservation. The percentage of sperm with high mitochondrial membrane potential in the PQQ treatment group was much higher than that in the control. In addition, supplementation of PQQ also decreased the sperm MDA and ROS levels, while increasing ATP levels. Interestingly, the levels of MT-ND1 and MT-ND6 protein in sperm treated with PQQ were also higher than that of the control. Furthermore, the addition of 100 nM PQQ to the medium decreased ROS damage in MT-ND1 and MT-ND6 proteins. The addition of 100 nM PQQ significantly (p < 0.05) increased protein tyrosine phosphorylation in ram sperm after induced capacitation. Furthermore, the value of the sperm-zona pellucida binding capacity in the 100 nM PQQ treatment group was also much higher than that of the control. Overall, during chilled ram- sperm preservation, PQQ protected ram sperm quality by quenching the ROS levels to reduce ROS damage and maintain sperm mitochondrial function, and preserved the sperm's high ability of fertilization.

14.
Prev Med Rep ; 43: 102788, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38952431

RESUMEN

Objective: Low back pain (LBP) is a major global public health issue, prevalent among various occupational groups worldwide. However, existing studies have predominantly focused on sedentary workers in developed nations, leaving a gap in understanding LBP prevalence and associated factors among occupational cohorts in low- and middle-income countries like Bangladesh. This study aimed to determine the prevalence and occupational factors contributing to LBP among ride-sharing motorbike drivers (RSMD) in Bangladesh. Methods: A cross-sectional study was conducted in Dhaka city from May 20 to August 08, 2023. Data were collected from Bangladeshi adult RSMD using a paper-based questionnaire developed by Eriksen et al. Chi-square or Fisher's Exact tests compared categorical variables with and without LBP, and multiple logistic regression analyses were performed with LBP as the dependent variable and various predictors to compute adjusted odds ratios with a 95% confidence interval. Results: The one-month prevalence of LBP was 58.8%. Regression analysis revealed elevated adjusted odds of experiencing LBP among participants with hypertension, those using multiple ride-sharing operators, commuter and older bike users, and non-users of riding kits. Additionally, increased adjusted odds of LBP were observed among participants of higher age, higher body mass index, and those covering longer distances per week. Conclusion: This study underscores a significantly higher prevalence of LBP among RSMD in Bangladesh, with occupational factors strongly predicting LBP. Implementing strategies such as regular physical exercise, weight reduction, using sports and newer motorbikes, and reducing working hours per week may help mitigate the prevalence of LBP within this cohort.

15.
Mymensingh Med J ; 22(2): 229-31, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23715340

RESUMEN

The antimicrobial susceptibility of 80 coagulase-negative staphylococci (CoNS) isolates from surgical wound, pus from infected skin lesions, burn exudates and diabetic ulcer exudates of patients in Mymensingh Medical College Hospital, Bangladesh, was evaluated in order to see their pattern of antimicrobial resistance. The study was carried out in the department of Microbiology, Mymensingh Medical College during the period from July 2009 to May 2011. The 80 CoNS isolates were subjected to antimicrobial susceptibility to relevant antibiotics including oxacillin by disk diffusion method. Out of 80 CoNS isolates, the highest number were resistant to oxacillin 36(45%), followed by gentamicin 32(40%), cefuroxime 25(31%), ceftriaxone 24(30%) and ciprofloxacin 18(22%). All isolates of CoNS were sensitive to imipenem and vancomycin. As MRCoNS were found multidrug resistant, therefore, antibiotic sensitivity must be done prior to treatment in infections caused by these species.


Asunto(s)
Antibacterianos/farmacología , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Pruebas de Sensibilidad Microbiana/métodos , Infecciones Estafilocócicas/tratamiento farmacológico , Ceftriaxona/farmacología , Cefuroxima/farmacología , Ciprofloxacina/farmacología , Coagulasa/metabolismo , Farmacorresistencia Bacteriana Múltiple , Exudados y Transudados/microbiología , Gentamicinas/farmacología , Humanos , Imipenem/farmacología , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Oxacilina/farmacología , Supuración/microbiología , Infección de la Herida Quirúrgica/microbiología , Vancomicina/farmacología
16.
Phys Rev E ; 107(3-2): 035104, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37073059

RESUMEN

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.

17.
R Soc Open Sci ; 10(10): 230384, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37830020

RESUMEN

We used a hydrothermal technique to develop nano-scale α-Fe2O3 particles and functionalized them with chitosan. An X-ray diffraction study revealed α-Fe2O3 nanoparticles were of single-phase, lattice constants were a = 5.07 Å and c = 13.68 Å, and the grain size was 27 nm. The presence of lattice fringes in the HRTEM image confirmed the crystalline nature of the α-Fe2O3. The Mössbauer spectra reveal a mixed relaxation state, which supports the PPMS studies. Zero-field cooled studies revealed the existence of a Morin transition and blocking temperature. The z-average value of the coated particles by DLS was between 218 and 235 nm, PDI ranged from 0.048 to 0.119, and zeta potential was +46.8 mV. We incubated the Vero and HeLa cell lines for 24 h to study the viability of the nanohybrids at different concentrations. Hyperthermia studies revealed the maximum temperature and specific loss power attained by the hematite-chitosan nanohybrid solution of a concentration between 0.25-4 mg ml-1. The Tmax at the lowest and highest concentrations of 0.25 and 4 mg ml-1 were 42.9 and 48.3°C, while the SLP were 501.6 and 35.5 W g-1, which are remarkably high when the maximum magnetization of α-Fe2O3 nanoparticles was as small as 1.98 emu g-1 at 300 K.

18.
Int J Surg Case Rep ; 106: 108138, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37043897

RESUMEN

BACKGROUND: Genital myiasis in females is a parasitic infection of the vulval region with the larva of various files species. Only a few cases of urogenital myiasis have been reported in the literature. CASE PRESENTATION: We present a case of 55 years postmenopausal, farmer female otherwise healthy presenting to the outpatient department with complaints of maggots and severe itching in the vulval region. Examination revealed erythema in the labia major and groin without lymphadenopathy. In the vaginal examination; inflammation and a large number of maggots were observed in the urethral meatus, labia minora, and vaginal canal, progressing to the cervix. With this, she was diagnosed to be a case of urogenital myiasis. She was managed with the extraction of maggots using turpentine oil, along with broad-spectrum antibiotics and Foleys catheterization for a week. Later during follow up, she was asymptomatic and examination revealed no maggots, and the lesions were healed. CLINICAL DISCUSSION: Extraction of maggots along with symptomatic management is the mainstay of treatment of myiasis. A significant number of the adult population in the rural areas of developing countries are illiterate and are not familiarized with education regarding genital hygiene. So, along with physicians, policy makers should also be involved in public awareness for genital hygiene. CONCLUSION: Despite being rare, urogenital myiasis is preventable and treatable condition. Efforts at increasing genital hygiene awareness in a low resource country are utmost for its prevention.

19.
Biology (Basel) ; 12(2)2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36829509

RESUMEN

Carboxylated ε-poly-l-lysine (CPLL), a novel cryoprotectant, can protect the sperm membranes by inhibiting ice crystal formation during the cryopreservation process. The present study was conducted to investigate the consequence of CPLL supplementation on the post-thaw quality of cryopreserved goat sperm. For this, different doses (0, 0.5%, 1%, 1.5%, and 2%; v/v) of CPLL were added to the cryopreservation medium, and the motility, membrane and acrosome integrity, mitochondrial membrane potential (MMP), ATP level, ROS production, anti-oxidant defense system, malondialdehyde (MDA) level, and apoptosis in post-thaw sperm were evaluated. It was observed that the addition of 1% CPLL significantly (p < 0.05) increased the total motility, membrane integrity, acrosome integrity, and catalase (CAT) activity of post-thaw sperm compared to those of control and other CPLL doses. The ATP content was observed significantly (p < 0.05) higher in 0.5% and 1% CPLL, however, the SOD activity and progressive motility were significantly (p < 0.05) increased by adding CPLL at 1% and 1.5% level. Moreover, the addition of CPLL at 1% dose not only showed a lower percentage of apoptosis, but also significantly (p < 0.05) increased the MMP while reducing ROS production and MDA levels compared to those of other CPLL doses and/or control. Therefore, it is clear that the supplementation of 1% CPLL can remarkably improve the post-thaw goat sperm motility, membrane and acrosome integrity, antioxidant abundance, mitochondrial potentials, and ATP supply by protecting the sperm from cryodamage and undergoing apoptosis. These findings will provide novel insights into sperm cryobiology.

20.
Cancers (Basel) ; 15(24)2023 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-38136281

RESUMEN

PURPOSE: When autocontouring based on artificial intelligence (AI) is used in the radiotherapy (RT) workflow, the contours are reviewed and eventually adjusted by a radiation oncologist before an RT treatment plan is generated, with the purpose of improving dosimetry and reducing both interobserver variability and time for contouring. The purpose of this study was to evaluate the results of application of a commercial AI-based autocontouring for RT, assessing both geometric accuracies and the influence on optimized dose from automatically generated contours after review by human operator. MATERIALS AND METHODS: A commercial autocontouring system was applied to a retrospective database of 40 patients, of which 20 were treated with radiotherapy for prostate cancer (PCa) and 20 for head and neck cancer (HNC). Contours resulting from AI were compared against AI contours reviewed by human operator and human-only contours using Dice similarity coefficient (DSC), Hausdorff distance (HD), and relative volume difference (RVD). Dosimetric indices such as Dmean, D0.03cc, and normalized plan quality metrics were used to compare dose distributions from RT plans generated from structure sets contoured by humans assisted by AI against plans from manual contours. The reduction in contouring time obtained by using automated tools was also assessed. A Wilcoxon rank sum test was computed to assess the significance of differences. Interobserver variability of the comparison of manual vs. AI-assisted contours was also assessed among two radiation oncologists for PCa. RESULTS: For PCa, AI-assisted segmentation showed good agreement with expert radiation oncologist structures with average DSC among patients ≥ 0.7 for all structures, and minimal radiation oncology adjustment of structures (DSC of adjusted versus AI structures ≥ 0.91). For HNC, results of comparison between manual and AI contouring varied considerably e.g., 0.77 for oral cavity and 0.11-0.13 for brachial plexus, but again, adjustment was generally minimal (DSC of adjusted against AI contours 0.97 for oral cavity, 0.92-0.93 for brachial plexus). The difference in dose for the target and organs at risk were not statistically significant between human and AI-assisted, with the only exceptions of D0.03cc to the anal canal and Dmean to the brachial plexus. The observed average differences in plan quality for PCa and HNC cases were 8% and 6.7%, respectively. The dose parameter changes due to interobserver variability in PCa were small, with the exception of the anal canal, where large dose variations were observed. The reduction in time required for contouring was 72% for PCa and 84% for HNC. CONCLUSIONS: When an autocontouring system is used in combination with human review, the time of the RT workflow is significantly reduced without affecting dose distribution and plan quality.

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