Computational fluid dynamic simulations for dispersion of nanoparticles in a magnetohydrodynamic liquid: a Galerkin finite element method

This investigation studies the effects of the thermo-physical properties of four types of nano-metallic particles on the thermo-physical properties of radiative fluid in the presence of buoyant forces and Joule heating (ohmic dissipation). The Galerkin finite element algorithm is used to perform computations and simulated results are displayed in order to analyze the behavior of velocity and temperature of copper, silver, titanium dioxide and aluminum oxide-nanofluids. All the simulations are performed with η_max = 6 computational tolerance 10⁻⁶ for 200 elemental discretizations. Due to the dispersion of nano-sized particles in the base fluid, an increase in the thermal conduction is noticed. This study also predicts future improvements in the thermal systems. Due to magnetic field and fluid flow interaction, the electrical energy converts into heat. This is undesirable in many thermal systems. Therefore, control of Joule heating in the design of thermos systems is necessary. However, this dissipation of heat may be desirable in some biological fluid flows. An increase in energy losses is noted as magnetic intensity is increased.

This investigation studies the effects of the thermo-physical properties of four types of nano-metallic particles on the thermo-physical properties of radiative fluid in the presence of buoyant forces and Joule heating (ohmic dissipation).

Genetic Defects in DNAH2 Underlie Male Infertility With Multiple Morphological Abnormalities of the Sperm Flagella in Humans and Mice

Asthenozoospermia accounts for over 80% of primary male infertility cases. Reduced sperm motility in asthenozoospermic patients are often accompanied by teratozoospermia, or defective sperm morphology, with varying severity. Multiple morphological abnormalities of the flagella (MMAF) is one of the most severe forms of asthenoteratozoospermia, characterized by heterogeneous flagellar abnormalities. Among various genetic factors known to cause MMAF, multiple variants in the DNAH2 gene are reported to underlie MMAF in humans. However, the pathogenicity by DNAH2 mutations remains largely unknown. In this study, we identified a novel recessive variant (NM_020877:c.12720G > T;p.W4240C) in DNAH2 by whole-exome sequencing, which fully co-segregated with the infertile male members in a consanguineous Pakistani family diagnosed with asthenozoospermia. 80-90% of the sperm from the patients are morphologically abnormal, and in silico analysis models reveal that the non-synonymous variant substitutes a residue in dynein heavy chain domain and destabilizes DNAH2. To better understand the pathogenicity of various DNAH2 variants underlying MMAF in general, we functionally characterized Dnah2-mutant mice generated by CRISPR/Cas9 genome editing. Dnah2-null males, but not females, are infertile. Dnah2-null sperm cells display absent, short, bent, coiled, and/or irregular flagella consistent with the MMAF phenotype. We found misexpression of centriolar proteins and delocalization of annulus proteins in Dnah2-null spermatids and sperm, suggesting dysregulated flagella development in spermiogenesis. Scanning and transmission electron microscopy analyses revealed that flagella ultrastructure is severely disorganized in Dnah2-null sperm. Absence of DNAH2 compromises the expression of other axonemal components such as DNAH1 and RSPH3. Our results demonstrate that DNAH2 is essential for multiple steps in sperm flagella formation and provide insights into molecular and cellular mechanisms of MMAF pathogenesis.

Cold storage induces time-dependent F2-isoprostane formation in renal tubular cells and rat kidneys

BACKGROUND

Previous findings suggest a possible role for free radicals in cold-storage-associated tissue injury. Because free radical-induced lipid peroxidation catalyzes the cyclooxygenase-independent formation of vasoconstrictive F2-isoprostanes, the hypothesis that isoprostanes are produced during cold storage was tested in this study.

METHODS

Total isoprostanes (free and esterified) in renal tubular epithelial (LLC-PK1) cells or whole kidneys, subjected to cold storage, were quantitated employing the gas chromatographic-mass spectroscopic method. LLC-PK1 cells were stored at 4 degrees C in a University of Wisconsin (UW) solution for 0, 24, 48, and 72 hours or 48 hours with desferrioxamine (DFO) or the lazaroid compound 2-methyl aminochroman (2-MAC). In the rat model, kidneys were perfused and stored for 48 hours in the UW solution with or without added DFO or 2-MAC.

RESULTS

Isoprostanes in LLC-PK1 cells increased by fivefold following 24 hours of cold storage (36 +/- 2 pg/well to 185 +/- 6, mean +/- SE, following 24 hours of cold storage, P < 0.0001), and the levels continued to increase significantly at 48 and 72 hours. DFO and 2-MAC caused significant suppression of isoprostane formation. Cold storage of the kidneys in UW solution for 48 hours was accompanied by an eightfold increase in isoprostanes compared with control kidneys not subjected to cold storage (25.0 +/- 3.0 vs. 2.9 +/- 0.1 ng/g, P < 0.0001). The addition of 2-MAC or DFO to the UW solution was associated with a near complete suppression of 48-hour cold-induced isoprostane formation.

CONCLUSION

Our findings provide evidence for the formation of large quantities of antioxidant-suppressible isoprostanes in kidney cells and whole kidney during cold-preservation. Based on this, it is hypothesized that (a) isoprostanes, which are potent renal vasoconstrictors, may contribute to immediate post-transplant vasoconstriction and dysfunction in kidneys subjected to extended cold storage, and that (b) the addition of 2-MAC or DFO to a UW solution in such circumstances may attenuate these alterations partly by suppressing isoprostane formation.

Evaluation of hematological parameters as an indicator of disease severity in Covid-19 patients: Pakistan's experience

BACKGROUND

The severity of COVID-19 could be evaluated by examining several blood parameters mainly white blood cell (WBC) count, granulocytes, platelet, and novel hemocytometric markers neutrophils to lymphocyte ratio (NLR), platelet-to-lymphocyte (PLR), and lymphocyte to monocyte ratio (LMR). The current study was conducted to investigate alteration in blood parameters and their association with the severity and mortality of COVID-19 patients.

METHODOLOGY

An observational cross-sectional study was conducted retrospectively, a total of 101 COVID-19 positive patients were examined: 52 were mild, 24 were moderate, 09 were severe, and 16 were critically diseased patients. We also recorded 16 deaths associated with the critical group. The overall mean age observed in our study was 48.94 years, where the mean age for critical individuals was 62.12 ± 14.35 years.

RESULTS

A significant association between the disease severity and elevation in blood parameters were observed. The WBC's and granulocyte count were significantly increased (p value <0.001) while the mean platelet count (165.0 × 109 /L) and red blood cell volume distribution width (RDW) were decreased in the critical group (57.86%) compared to mild group's patients (177.3%) (p = 0.83). The lymphocytes count was decreased in critical patients (1.40 × 109 /L) compared to mild patients (1.92 × 109 /L) (p = 0.28). A significant association was observed in platelet-lymphocyte ratio (p < 0.001), Neutrophil-Lymphocyte ratio (p = <0.001), and Lymphocyte-Monocyte ratio (0.011).

CONCLUSION

These blood parameters could be used as a suitable biomarker for the prognosis and severity of COVID-19. Evaluating novel hemograms NLR, PLR, and LMR can aid clinicians to identify potentially severe cases at early stages, initiate effective management in time, and conduct early triage which may reduce the overall mortality of COVID-19 patients.

Silver disinfection of Pseudomonas aeruginosa and E. coli in rooftop harvested rainwater for potable purposes

Rainwater harvesting being an alternate source in water scarce areas is becoming a common practice. Catchment contact, however, deteriorates the quality of rainwater making it unfit for potable purposes. To improve the quality of harvested rainwater, silver was used as antimicrobial agent in this study. Rainwater samples were taken from underground storage tank of a rooftop rainwater harvesting system installed in one of the buildings at Seoul National University, Seoul, South Korea. The target microorganisms (MOs) were Pseudomonas aeruginosa and Escherichia coli which were measured by using plate count method and standard MPN method, respectively. The efficiency of silver disinfection was evaluated at concentrations, ranging from 0.01 to 0.1 mg/l; the safe limit approved by WHO. The experiments were performed for 168 h with different time intervals to evaluate the parameters including inactivation rate, residual effect of silver and re-growth in both MOs at lower (i.e. 0.01-0.04 mg/l) as well as the higher concentrations of silver (i.e. 0.08-0.1 mg/l). Results showed the re-growth in both MOs was only in the case of lower concentrations of silver. The possible reason of re-growth at these concentrations of silver may be the halting of bacterial cell replication process for some time without permanent damage. The kinetics of this study suggest that higher inactivation and long term residual effect towards both MOs can be achieved with the application of silver at 0.08 mg/l or higher under safe limit.

Mothers' fear of child death due to acute diarrhoea: a study in urban and rural communities in northern Punjab, Pakistan

The investigation of cultural models of diarrhoeal illness which are employed by mothers and their emotional responses to children's illnesses is presented in a study of 595 households in urban and rural communities in Punjab, Pakistan. The household survey of mothers of children 0-36 months was complemented with in-depth interviews of a subsample of 70 mothers. Findings indicate that diarrhoea must be regarded not only as a disease but as a symptom belonging to several popular illness categories. Mothers' emotional responses to symptoms are in part shaped by the illness categories to which they assign a child's diarrhoea episode, and maternal fears that symptoms of diarrhoea may be life threatening are associated with previous experiences with death of children, with treatment choices and help-seeking. A significantly higher proportion of mothers who fear diarrhoea to be life threatening to their children than mothers with other concerns choose to use NIMKOL, the Pakistan ORS. The necessity of recognizing the complexity of interpretive and emotional processes which shape the care of children and the home treatment of childhood disease is emphasized.

Pharmacokinetics and urinary excretion of sulphadimidine in sheep during summer and winter

Pharmacokinetics and urinary excretion of sulphadimidine were investigated in sheep during summer and winter seasons. Average minimum and maximum environmental temperature in the summer ranged from 22.6 to 40.2 degrees C and in winter from 4.5 to 21.1 degrees C. The determination of plasma volume, plasma protein and packed cell volume during summer and winter revealed a significant decrease in plasma volume and a significant increase in plasma protein in the summer indicative of haemoconcentration. Packed cell volume did not differ significantly between the seasons. The pharmacokinetics of sulphadimidine were determined following a single intravenous injection (100 mg/kg) in summer and winter. Zero time plasma concentration of the drug was higher during summer than in winter. The elimination half-life of the drug was similar in summer and winter, but the apparent volume of distribution was lower in summer. Likewise, total body clearance was significantly lower in summer. Based on these studies a satisfactory intravenous dosage regimen might consist of 86 and 100 mg/kg for priming and 78 and 88 mg/kg as maintenance doses during summer and winter, respectively, the doses being repeated at 12 hour intervals. Twenty four hours after sulphadimidine administration 90 and 73 per cent of the dose was excreted in urine during summer and winter, respectively. The drug was excreted mainly as free amine.

Pharmacokinetics of sulphadimidine in normal and febrile dogs

Pharmacokinetic parameters which describe the distribution and elimination of sulphadimidine were determined in normal dogs and dogs in which fewer was produced by an intravenous injection of escherichia and staphylococcal species of bacteria. Sulphadimidine was injected as a single intravenous bolus at the dose of 100 mg/kg and the kinetics of the drug were described in terms of the biexponential expression: Cp = Ae-alpha t + Be-beta t. The distribution half-times of the drug were 1.52 h in the normal and 0.81 h in the febrile dogs. The drug distribution was significantly more rapid (P less than 0.05) in febrile than in normal dogs. Average +/- SD values for the half-lives of the drug were 16.2 +/- 5.7 h in normal and 16.7 +/- 4.7 h in the febrile dogs. The apparent volume of distribution (V'd(area)) was 628 +/- 251 ml/kg in the normal dogs, and was not statistically different from 495 +/- 144 ml/kg in the febrile dogs. The volume of the central compartment (V'c) was 445 +/- 55 ml/kg in normal dogs and this was significantly higher (P less than 0.01) than the V'c of 246 +/- 72 ml/kg in the febrile dogs. The body clearance was 22.4 +/- 4.8 and 20.2 +/- 3.6 ml/hour . kg in the normal and febrile dogs, respectively. The investigation revealed that the dosage regimen of sulphadimidine did not differ significantly between normal and febrile dogs.

Effects of differential ewe condition at mating and early postmating nutrition on embryo survival

Ewes in two trials were given either a high (H) or a low (L) level of premating nutrition for 19 wk followed by 6 wk of either H or L postmating nutrition to examine effects on reproductive performance. Trial 1 ewes were 5- to 8-yr-old Polypays and Trial 2 ewes were 3-yr-old Polypay and Coopworth x Polypay crosses. Ewes given L nutrition premating were either immunized with androstenedione-7-carboxyethylthioether:human serum albumin (also known as ovandrotone or Fecundin) in (diethylamino)ethyl-dextran adjuvant (Trial 1) or flushed for 3 wk premating (Trials 1 and 2) to enhance ovulation rates. All ewes were synchronized for mating in both trials. Trial 1 premating treatments created a difference of 10 kg in BW and 1.1 in condition score units between H and L ewes preflushing; flushing halved the BW difference. Ovulation rates averaged 2.58 and were similar for H, L-flushed, and L-immunized (LI) ewes; however, both conception rate and litter size were lowest for immunized ewes. Among both twin and triple-ovulating ewes, highest mean litter size was produced by H ewes, followed in order by L and LI ewes. High postmating nutrition increased BW by 6 kg vs slight weight loss in L ewes, but postmating treatments did not affect litter size of either twin or triple ovulators. The H and L premating groups of Trial 2 differed by 18 kg and 2.2 condition score units preflushing. The H ewes exhibited higher ovulation rates (overall mean = 2.63) but lower conception than the L ewes to synchronized estrus. Litter size averaged 2.15 for H ewes vs 1.82 for L ewes. Among both twin and triple ovulators, L ewes produced fewer lambs than H ewes.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular genotyping of Mycobacterium tuberculosis in Xi'an, China, using MIRU-VNTR typing

SETTING

The molecular genotyping of Mycobacterium tuberculosis is expected to lead to a better understanding of M. tuberculosis transmission in Xi'an, one of the largest cities in Western China.

OBJECTIVE

To characterize the population of M. tuberculosis strains circulating in Xi'an and to evaluate the feasibility of the mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) typing method.

DESIGN

A total of 195 M. tuberculosis clinical isolates from Xi'an were genotyped using spoligotyping and MIRU-VNTR.

RESULTS

Thirty-two different genotypes were identified by spoligotyping, with the Beijing family identified as the largest lineage (84.6%), followed by the T1 (3.08%), T2 (1.54%), H3 (1.03%) and U (1.03%) families. The Hunter-Gaston discriminatory index (HGDI) of spoligotyping is low (HGDI = 0.392). In contrast, 15-locus MIRU-VNTR shows a higher discriminatory power (HGDI = 0.998) than 12-locus MIRU-VNTR (HGDI = 0.948). By replacing the ETR C locus with the MIRU39 locus, the discriminatory power of 15-locus MIRU-VNTR is increased to 0.999.

CONCLUSIONS

The Beijing family accounts for the vast majority of M. tuberculosis isolates in Xi'an, China. The modified 15-locus MIRU-VNTR showed high HGDI and can be used as a first-line genotyping method in combination with spoligotyping in routine epidemiological investigations in Xi'an, China.

Clinical manifestations and outcomes of COVID-19 in the paediatric population: a systematic review

OBJECTIVE

Coronavirus disease 2019 (COVID-19), the respiratory illness caused by severe acute respiratory syndrome coronavirus 2, has affected hundreds of thousands of people. We aim to report the distribution of cases, prevalence, and clinical, radiological, and laboratory signs and outcomes of COVID-19 in paediatric patients. Moreover, we intend to evaluate neonatal clinical outcomes. Hence, our age range of interest is 0 to 19 years.

METHODS

A systematic literature review was conducted using the Medline database to identify papers published between 1 December 2019 and 9 April 2020 on COVID-19.

RESULTS

The search identified 27 relevant scientific papers and letters. The review showed that the prevalence of COVID-19 in the paediatric population accounts for a small percentage of patients, whose clinical signs and symptoms are often milder than those of adults. Despite better prognosis and low mortality in children, the disease can progress to severe pneumonia in some cases, especially in the presence of co-morbidities. Children are likely to become a hidden source of infection because of their atypical presentation, and they may play a role in community transmission, leading to unfavourable outcomes. There is little evidence about intrauterine vertical transmission. As no vaccine or specific antiviral is currently available, management plans include supportive treatment.

CONCLUSION

As compared with that in adults, the presentation of COVID-19 in children is mild and has a better prognosis. Sufficient evidence regarding the probability of intrauterine vertical transmission could not be found, and further studies need to be conducted to establish this relationship.

Selection, characterisation and evaluation of potential probiotic Lactobacillus spp. isolated from poultry droppings

Aim of the present study was to characterise and evaluate probiotic potential of lactobacilli isolated from indigenous poultry. Lactobacilli were isolated from poultry droppings and identified by genus specific polymerase chain reaction and 16S rRNA gene sequencing. Isolates were characterised in vitro by their ability to tolerate low pH and bile salts, phytase activity, antimicrobial activity, antibiotic susceptibility profile, and autoaggregation and coaggregation with poultry gut pathogens. In vivo evaluation of selected isolates was done by their effect on the body weight gain and immune response of broiler chicks. Total of 90, one-day old chicks, were randomly divided in 9 groups and given selected lactobacilli alone and in combinations (10⁸ cfu/bird, daily) from day 7 to day 35. Body weight gain and humoral immune response to New Castle Disease Virus (NDV) vaccine were determined weekly. Three lactobacilli isolates (SMP52, SMP64 and SMP70) were selected as potentially probiotic bacteria on the basis of in vitro characterisation and identified as Lactobacillus crispatus, Lactobacillus casei and L. crispatus, respectively. Chicks supplemented with 'SMP52', 'SMP64', 'SMP70' and 'SMP64+SMP70' and a commercial probiotic product (Protexin) showed significantly higher mean weight gain per bird (1,584±35.2, 1,629±30.6, 1,668±34.7, 1,619±29.5 and 1,576±31.7 g/bird, respectively) as compared to negative control group (1,394±26.7 g/bird), on day 35. SMP 70 also showed significantly higher geometric mean titre against NDV vaccine at day 21 as compared to negative control. It is concluded that L. crispatus SMP52, L. casei SMP64 and L. crispatus SMP70 are potential probiotic candidates which alone or in different combinations may increase body weight of broilers.

Structural, magnetic, optical properties and cation distribution of nanosized Ni0.3Cu0.3Zn0.4TmxFe2-xO4 (0.0 ≤ x ≤ 0.10) spinel ferrites synthesized by ultrasound irradiation

In this study, Tm³⁺ ion substituted NiCuZn nanospinel ferrites, Ni_0.3Cu_0.3Zn_0.4Tm_xFe_2-xO₄ (0.0 ≤ x ≤ 0.10), have been synthesized sonochemically. The structural, spectroscopic, morphological, optic and magnetic investigation of the samples were done by X-ray powder diffractometry (XRD), Fourier transform infrared spectrophotometry (FT-IR), UV-Vis diffused reflectance (%DR) spectrophotometry, transmission and scanning electron microscopies (TEM and SEM) along with EDX, Vibrating sample magnetometry (VSM), respectively. The purity of prepared products were confirmed via XRD, FT-IR, EDX and elemental mapping analyses. The analyses of magnetization versus M(H) (applied magnetic field) were performed at 300 and 10 K. The following magnetic parameters like M_s (saturation magnetization), SQR = M_r/M_s (squareness ratio), n_B(magnetic moment), H_c (coercivity) and M_r (remanence) have been discussed. M(H) loops revealed superparamagnetic property at RT and soft ferromagnetic nature at 10 K. It is showed that the Tm³⁺ substitutions significantly affect the magnetizations data. A decreasing trend in the M_s, H_c, M_r, and n_B values was detected with Tm³⁺ substitution.

Exploration of catalytic and cytotoxicity activities of CaxMgxNi1-2xFe2O4 nanoparticles

The Ca_xMg_xNi_1-2xFe₂O₄ (x ≤ 0.05) nanoparticles (NPs) have been synthesized hydrothermally. The XRD analyses confirmed the purity of all products and their spherical morphology and compositions were explained by SEM, TEM, EDX and Elemental mapping analyses. Results confirmed the composition of Ca_xMg_xNi_1-2xFe₂O₄. The surface area of them was determined by BET analysis. Results indicated that when x is increased surface area of Ca_xMg_xNi_1-2xFe₂O₄ is decreased as compare with x = 0.0, however, at high composition (x = 0.05), surface area is increased. Catalytic activity of Ca_xMg_xNi_1-2xFe₂O₄ (x ≤ 0.05) NPs was studied for the reduction of 4-nitrophenol as a model compound. Reaction was monitored by UV-spectrophotometer at room temperature and at different times. Among different compositions of Ca_xMg_xNi_1-2xFe₂O₄, it was noticed that x = 0.04 exhibited more activity for the reduction of 4-nitrophenol and x = 0.03 was observed least active. Results suggested that Ca_xMg_xNi_1-2xFe₂O₄ could be useful material for catalytic applications. Cytotoxicity activity of Ca_xMg_xNi_1-2xFe₂O₄ (x ≤ 0.05) NPs against HCT116 (Human colon cancer cell line) cell line and MCF-7 (breast cancer cell line) was evaluated by using MTT assay. It was observed that Ca_xMg_xNi_1-2xFe₂O₄ (x ≤ 0.05) NPs exhibited less cytotoxicity. Due to less cytotoxicity, Ca_xMg_xNi_1-2xFe₂O₄ may also be useful in the field of biomedical applications.

Amelioration of ovalbumin induced allergic symptoms in Balb/c mice by potentially probiotic strains of lactobacilli

To evaluate the antiallergic effect of newly characterised probiotic strains, Lactobacillus fermentum NWS29, Lactobacillus casei NWP08 and Lactobacillus rhamnosus NWP13, mice were divided into six experimental groups: control, ovalbumin (OVA), NWS29, NWP08, NWP13 and L. rhamnosus GG (LGG). Mice were immunised and probiotics were administered via oral gavage followed by challenge with OVA. After last challenge with OVA, inflammatory cells in bronchoalveolar lavage fluid (BALF), recruitment of inflammatory cells in airways and OVA-specific immunoglobulin E (IgE) in serum were determined by Giemsa, haematoxylin and eosin (HE) staining, and ELISA, respectively. Relative mRNA expression of interleukins (IL-4, IL-5, IL-10, IL-13 and IL-17), transforming growth factor-β (TGF-β) and interferon-γ (IFN-γ) in lung and spleen tissue was determined by real time RT-PCR. OVA-specific IgE levels, recruitment of eosinophils and mRNA expressions of inflammatory cytokines were remarkably increased in OVA-exposed mice compared with the control group. Administration of NWS29 and NWP13 suppressed inflammatory cell infiltration in airways and BALF, and level of OVA-specific IgE in serum of OVA-exposed mice. Furthermore, NWS29 and NWP13 also abrogated the mRNA expression of 1L-4, IL-5, IL-13 and TGF-β in mice immunised and exposed to OVA. Our findings suggest that NWS29 and NWP13 might be good candidates for the prevention of allergic airway inflammation.