Search

Numerous efforts have been undertaken to mitigate the Debye screening effect of FET biosensors for achieving higher sensitivity. There are few reports that show sub-femtomolar detection of biomolecules by FET mechanisms but they either suffer from significant background noise or lack robust control. In this aspect, deformed/crumpled graphene has been recently deployed by other researchers for various biomolecule detection like DNA, COVID-19 spike proteins and immunity markers like IL-6 at sub-femtomolar levels. However, the chemical vapor deposition (CVD) approach for graphene fabrication suffers from various surface contamination while the transfer process induces structural defects. In this paper, an alternative fabrication methodology has been proposed where glass substrate has been initially texturized by wet chemical etching through the sacrificial layer of synthesized silver nanoparticles, obtained by annealing of thin silver films leading to solid state dewetting. Graphene has been subsequently deposited by thermal reduction technique from graphene oxide solution. The resulting deformed graphene structure exhibits higher sensor response towards glial fibrillary acidic protein (GFAP) detection with respect to flat graphene owing to the combined effect of reduced Debye screening and higher surface area for receptor immobilization. Additionally, another interesting aspect of the reported work lies in the biomolecule capture by dielectrophoretic (DEP) transport on the crests of the convex surfaces of graphene in a coplanar gated topology structure which has resulted in 10 aM and 28 aM detection limits of GFAP in buffer and undiluted plasma respectively, within 15 min of application of analyte. The detection limit in buffer is almost four decades lower than that documented for GFAP using biosensors which is is expected to pave way for advancing graphene FET based sensors towards ultrasensitive point-of-care diagnosis of GFAP, a biomarker for traumatic brain injury. [ABSTRACT FROM AUTHOR]

The study investigates the effect of emissions of particulate matter arising out of different construction activities from five construction sites in Kanpur city, India. Limited research studies on exposure assessments related to particulate matter (PM) emissions from construction activities in the Indian context contribute to the uniqueness of this study. It was observed that for all study areas the concentrations of particulate matter (PM2.5 and PM10) exceeded the National Ambient Air Quality Standard (NAAQS) by a factor of 18–20. The highest concentration of PM10 (1308; 1267 µg/m3) and PM2.5 (1056; 1123 µg/m3) was associated with construction activity related to cutting and laying of tiles observed over the two monitoring campaigns conducted during November–December 2019 and January–February 2020. The human health risk exposure assessment assessed on relative risk (RR) determined on WHO methodology showed that the highest RR values of 2.669 and 4.13 were obtained for emissions of PM10 and PM2.5, respectively, from laying and cutting of tiles. The attributable factor (AF) from both PM10 (AF = 0.6253) and PM2.5 (AF = 0.757) also showed higher possibility of respiratory diseases for workers associated with laying and cutting of tiles. Health impact assessment conducted using the International Council for Radiological Protection (ICRP) model also confirmed that maximum and minimum deposition rates of particulates occurred for construction activities associated with cutting and laying of tiles and painting and washing, respectively. This suggests potential occupational health hazards for workers involved in construction activities being exposed to high levels of PM concentrations. [ABSTRACT FROM AUTHOR]

Diverse efforts undertaken to mitigate the Debye screening effect of field-effect transistor (FET) biosensors have achieved higher sensitivity. However, the charge transfer or induction mechanism between the captured biomolecules and the sensing surface, resulting in shift of surface potential and, hence, the drain current magnitude, shows poor selectivity for real time detection of ultra-low biomolecule concentration in unamplified samples. Herein, enabling direct interaction of the target molecule with edge passivated thermally reduced graphene oxide, through the template of molecularly imprinted polymer (MIP), specific trap induced characteristic bulges in the noise spectrum has been observed only in the presence of target molecule. Such a phenomenon has not been observed either with antibodies or aptamers as receptors. Hence, the direct interface of MIP with a graphene FET (GFET) results in the generation of an additional electronic label in FET transduction. As a proof of concept, this principle has been validated for serotonin detection in serum in the presence of other neurotransmitters, resulting in detection limit of 0.05 fM in real time, which is more than two orders of magnitude lower than existing reports and, hence, is expected to pave the way for advancing GFET based sensors toward ultrasensitive point-of-care applications without requiring complex machine learning algorithms. [ABSTRACT FROM AUTHOR]

Thermophysical properties of aqueous pluronic solutions of P85 and P85–P123 systems with concentrations varying between 0.1 and 11 mass% for P85 and equimolar solution of 11 mass% P85-10 mass% P123 were measured in the absence and presence of solubilized lavender oil at temperatures below and above their critical micellization temperature in the temperature range of 288.15 K to 323.15 K. Maximum oil solubility was 3% (v/v) in the case of 11 mass% P85 and 2% (v/v) for mixed P85–P123 system. From density and sound speed measurements thermodynamic parameters like apparent molar volume, isentropic compressibility and expansibility were derived to evaluate the interactions of these block copolymers below and above the micellar region in pure and mixed micellar states. Apparent molar isentropic compressibility exhibited unusual variation with concentration which could be explained in light of pre-micellar aggregate formation. Isothermal titration calorimetry (ITC) was used to evaluate the energy changes involved in the aggregation processes for these systems. Critical micelle concentration (cmc) for P85 was found to be 0.74 mass% and pre-micellar aggregation was observed at 0.276 mass% from ITC study. Enthalpy of pre-micellar aggregation and micellization for oil-solubilized P85 solution were found to be 60 kJ mol−1 and 15 kJ mol−1 in the absence of oil. Micellization enthalpy for P85–P123 system was obtained as 72 kJ mol−1 and 142 kJ mol−1, respectively, in the absence and presence of solubilized oil. No pre-micellar aggregation was observed in mixed micelle system. DLS study was carried out to corroborate the findings obtained from densimetry and calorimetry. [ABSTRACT FROM AUTHOR]

Aims: To assess the effects of 'clinical' and 'intensification inertia' by evaluating the impact of different intensification interventions on the probability of HbA1c goal attainment using real‐world data. Methods: Electronic health records (Cleveland Clinic, 2005–2016) were used to identify 7389 people with Type 2 diabetes mellitus and HbA1c ≥53 mmol/mol (≥7.0%), despite a stable regimen of two oral antihyperglycaemic drugs for ≥6 months. The participants were stratified by index HbA1c and analysed over a 6‐month period for pharmacological intensification, and then for 12 additional months for HbA1c goal attainment (<53 mmol/mol). Results: The probability of HbA1c goal attainment (Kaplan–Meier analysis) in the group with index HbA1c 53–63 mmol/mol (7.0–7.9%) was highest with the addition of oral antidiabetic drugs [57.3% (95% CI 52.1, 62.0)] or glucagon‐like peptide‐1 receptor agonists [56.7% (95% CI 40.4, 68.6)], in the 64–74 mmol/mol (8.0–8.9%) group with the addition of oral antidiabetic drugs [31.9% (95% CI 25.1, 38.1)] or insulin [30.6% (95% CI 18.3, 41.0)], and in the ≥75 mmol/mol (≥9.0%) group with the addition of glucagon‐like peptide‐1 receptor agonists [53.0% (95% CI 31.8, 67.6)] or insulin [43.5% (95% CI 36.4, 49.8)]. Conclusions: Numerical, but not statistically significant, differences in HbA1c goal attainment probability by type of intensification were most marked in people with the highest index HbA1c [≥75 mmol/mol (≥9.0%)]; in this group, injectable therapy showed trends toward greater glycaemic control benefits. Additional research into the phenomenon of intensification inertia is warranted. What's new?: 'Clinical inertia', lack of timely treatment intensification when indicated, is a common barrier to achieving Type 2 diabetes mellitus glycaemic goals.Another type of inertia that warrants investigation is 'intensification inertia', the implementation of intensification measures that result in little‐to‐no impact on attainment of target HbA1c.This study found that the real‐world probability of HbA1c goal attainment in people with uncontrolled Type 2 diabetes may vary by type of pharmacological intervention and baseline HbA1c.Awareness of intensification inertia should help reduce the frequency with which clinicians choose forms of intensification that may have a very low probability of success (HbA1c goal attainment). [ABSTRACT FROM AUTHOR]

Immunomagnetic separation (IMS) is a method to isolate biomaterials from a host fluid in which specifically selected antibodies attached to magnetic particles bind with their corresponding antigens on the surface of the target biological entities. A magnet separates these entities from the fluid through magnetophoresis. The method has promising applications in microscale biosensors. We develop a comprehensive model to characterize the interaction between target species and magnetic particles in microfluidic channels. The mechanics of the separation of target nonmagnetic N particles by magnetic M particles are investigated using a particle dynamics simulation. We consider both interparticle magnetic interactions and the binding of the functionalizing strands of complementary particles. The temporal growth of a particle aggregate and the relative concentrations of M and N particles are investigated under different operating conditions. A particle aggregate first grows and then exhibits periodic washaway about a quasisteady mean size. The washaway frequency and amplitude depend on the initial fractional concentration of N particles while the aggregate size scales linearly with the dipole strength and inversely with the fluid flow rate. [ABSTRACT FROM AUTHOR]

Rotational dynamics of two structurally similar hydrophobic solutes, 2,5-dimethyl-1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DMDPP) and 1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DPP), has been investigated in 30% w/v aqueous solution of triblock copolymer, poly(ethylene oxide)20-poly(propylene oxide)70-poly(ethylene oxide)20 as a function of temperature. This study has been undertaken in an attempt to explore how the dynamics of a solute molecule solubilized in a copolymer solution is influenced when it undergoes sol-to-gel transition. It has been observed that the anisotropy decays of both DMDPP and DPP can be described by biexponential functions in the sol as well as in the gel phase. This observation has been rationalized on the basis of the probe molecule undergoing two different kinds of motion rather than being located in two different regions of the micelle. Even in the gel phase, which results as a consequence of micelle-micelle entanglement due to an increase in their volume fraction, the rotational relaxation of the solutes is similar to that observed in the micellar solution. The outcome of this work indicates that even though these gels have very high macroscopic viscosities and hence do not flow, the microenvironments experienced by the solutes are akin to that of a micellar solution. [ABSTRACT FROM AUTHOR]

Studies are conducted on an Al-6061 alloy reinforced with in situ ceramic mixture (AlO-SiC-C). The mixture is prepared by carbothermal reduction of flyash in a plasma reactor, where SiO is converted to SiC. The strength values for Al-6061-flyash (FA) and Al-6061-plasma synthesized flyash (PSFA) composites are 35% and 63% higher than that of the Al-6061 alloy. Wear resistance of the developed alloy composite prepared with treated flyash (Al-6061-PSFA) has increased two-fold in comparison to virgin alloy (Al-6061) and 1.5 fold higher in comparison to a similar alloy composites prepared with untreated flyash (Al-6061-FA). The unique property of the developed alloy composite is due to harder SiC particle reinforcement. Excess carbon in the form of graphite and the unique morphological feature of microstructure have enhanced the properties such as strength and wear resistance of the developed alloy composite. [ABSTRACT FROM AUTHOR]

The present investigation develops a next-generation hybrid Al metal matrix composite using coconut shell ash (CSA) and graphite (Gr) reinforcement. Stir-casting is adapted to prepare an Al-1100-based composite. Three other composites of Al-AlO, Al-AlO-Gr, and Al-CSA are prepared that contain equivalent volume fractions of AlO, CSA, and Gr. These assist in comparisons among the three composites and the developed hybrid Al-CSA-Gr composite. The study reveals that the addition of 3 pct Gr improves the specific strength, toughness, and tribological properties. The Al-CSA composite shows better mechanical properties, such as tensile strength and hardness, than the other three composites. Gr addition helps the hybrid Al-CSA-Gr composite to attain better tribological properties with a slightly lower specific strength. Scanning electron microscopy studies of the worn material surfaces corroborate the findings of the abrasion testing. Elemental analyses by energy-dispersive X-ray spectroscopy of the debris from the counter-face of the tribo surface confirm the presence of Al, O, Si, Fe, Mn, and C. [ABSTRACT FROM AUTHOR]

Details a study which analyzed the magnetization behavior of the organic ferromagnet (Nbu[sub4])[sub2]Mn[sub2][Cu(opba)][sub3]. Examination of zero field-cooled magnetization; Experimental procedures; Results and discussion.

An in-situ ternary ceramic composite material is developed indigenously by carbo thermal reduction of fly ash in a plasma reactor. X-ray diffraction (XRD), Scanning electron microscopy (SEM)-Energy dispersive x-ray (EDX) analyses of the developed ternary mixture has revealed in-situ conversion of SiO2 to SiC in the vicinity of Al2O3, present in the fly ash material. Presence of carbon in the form of graphite is also confirmed by XRD and EDX analyses. The morphology of the fly ash powder particles is changed from irregular to rod shaped particles with the presence of whiskers (diameter ∼ 0.2 µm, length 8–20 µm). Metal matrix based (Al6061) ceramic composites are prepared with the plasma synthesized fly ash and untreated fly ash composites by stir casting method with different volume fractions of ceramic powders of both the category. Progressive reductions of grain size by increasing volume fractions with segregation of ceramic particles at the grain boundaries are salient features of microstructures. Remarkable improvement in strength and wear resistance is the two significant features of the novel Al6061alloy based composite developed with plasma treated fly ash. Results are presented on the ageing behaviour of the alloy composite for both the categories and mechanical properties of age hardened alloy based composites are compared with monolithic alloy. Accelerated ageing behaviour is observed for alloy based composites, which is found to depend on the morphology of the incoherent dispersed phases. Accelerated precipitation during ageing has been confirmed by hardness versus time as well as by differential scanning calorimetry analysis. Sequences of precipitation for all materials are shown in differential scanning calorimetry thermogram. [ABSTRACT FROM AUTHOR]

Background: Uncuffed endotracheal tubes are commonly used in children but due to several decade preferred in paediatric oral surgery. Due to lack of conclusive evidences in this regard, we have conducted this study to compare post-operative morbidity following use of cuffed and uncuffed endotracheal tubes in paediatric patients undergoing cleft lip-palate surgery. Methods: This randomised controlled trial was conducted on children aged 2 to 12 years.110 patients were allocated in two parallel groups using computer generated list of random numbers. Post operative extubation stridor, sore throat, time to first oral intake and regaining of normal voice were compared between two groups. Results: The incidence of sore throat was significantly more (P value > 0.005) in patients of uncuffed group compared to cuffed group. The time to first oral intake and time to regain normal voice were significantly earlier in cuffed group compared to the other. Conclusion: With standard care, preformed cuffed ET tube has shown reduced incidence of post operative sore throat. Cuffed group has earlier oral intake and normal voice regain compared to uncuffed group. [ABSTRACT FROM AUTHOR]

In the present investigation a new ternary ceramic matrix composite is developed from Indian fly ash by thermal treatment under reducing atmosphere. The ternary mixture, comprising of AlO-SiC-C, is formed by insitu conversion of SiO to SiC in the fly ash under reducing atmosphere. Analyses of the treated product by XRD, SEM, and EDAX have ensured formation of SiC from SiO. Converted SiC are rod shaped whiskers with the aspect ratio ranging between 40 to 50. The ternary mixture is added to aluminum melt in a bottom pouring pit type resistance furnace for the preparation of novel aluminum fly ash metal matrix composite (ALFMMC). Physical and mechanical properties of the novel ALFMMC (treated fly ash) composite are evaluated. For comparison purpose, aluminum fly ash composite is prepared with (untreated flyash) under identical condition of melting and casting. Wear resistance is found to be superior for the novel composite. [ABSTRACT FROM AUTHOR]

The paper deals with the wear behaviour of the newly developed composite reinforced with a novel ceramic composite. The wear study is made through pin-on-disc wear test under three loads, namely 20, 40 and 60 N for a sliding distance of 2·52 km. Al colliery shale (CS) composite has shown excellent wear resistance compared to the other two composites (taken as a reference for comparison) i.e. Al-Al2O3 and Al-Al2O3-SiC. The presence of carbon in the form of graphite in Al-CS composite has enhanced the resistance to wear and reduced coefficient of friction. Wear rate is higher for the three composites initially up to 2·16 km of sliding distance and has then declined at higher sliding distance. It is observed that up to a sliding distance of 2·16 km the primary mode of wear is due to delamination and decohesion of the particles. As the sliding distance increases to 2·52 km the work hardening phenomenon plays a major role and the resistance to wear has increased for all the three composites. SEM photographs from the worn out surfaces have corroborated the results. [ABSTRACT FROM AUTHOR]

A novel method is adapted to prepare an in situ ceramic composite from waste colliery shale (CS) material. Heat treatment of the shale material, in a plasma reactor and/or in a high temperature furnace at 1673 K (1400 °C) under high vacuum (10 Torr), has enabled in situ conversion of SiO to SiC in the vicinity of carbon and AlO present in the shale material. The composite has the chemical constituents, SiC-AlO-C, as established by XRD/EDX analysis. Particle sizes of the composite range between 50 nm and 200 μm. The shape of the particles vary, presumably rod to spherical shape, distributed preferably in the region of grain boundaries. The CS composite so produced is added to aluminum melt to produce Al-CS composite (12 vol. pct). For comparison of properties, the aluminum metal matrix composite (AMCs) is made with AlO particulates (15 vol. pct) with size <200 μm. The heat-treated Al-CS composite has shown better mechanical properties compared to the Al-AlO composite. The ductility and toughness of the Al-CS composite are greater than that of the Al-AlO composite. Fractographs revealed fine sheared dimples in the Al-CS composite, whereas the same of the Al-AlO composite showed an appearance of cleavage-type facets. Abrasion and frictional behavior of both the composites have been compared. The findings lead to the conclusion that the in situ composite developed from the colliery shale waste material has a good future for its use in AMCs. [ABSTRACT FROM AUTHOR]

A theoretical model for oscillatory motion of a non-wetting immiscible ferrofluid plug-driven micropump is developed. The plug drives an immiscible host fluid through a microchannel under the influence of an oscillating magnetic line dipole as it simultaneously experiences magnetic, pressure, viscous, and capillary forces. When a sinusoidal oscillation of the driving magnetic field is imposed, the plug exhibits different waveforms of oscillatory displacement depending upon the operating parameters. Dynamic response of the plug under varied magnetic susceptibility and the oscillation frequency of the dipole are reported. Results of the study will be useful in design and selection of operating ranges for ferrofluid-based micropump systems. [ABSTRACT FROM AUTHOR]

Analyses of magnetophoretic transport of magnetic microspheres in representative T-shaped microchannels and field flow fractionation (FFF) devices are performed to arrive at the design basis for MEMS-scale bio-separators. The trajectories of the particles in the flow through a two-dimensional microchannel under an external magnetic field produced by a line dipole are described. Capture efficiency and separation index for the particles are defined and computed at the two outlets. Variations of the capture indices under different geometric parameters are characterized. The capture efficiency is found to be a function of the widths of the outlet ports. The study helps to determine the optimum geometric and operating conditions to achieve the best performance of the T-shaped microchannel and FFF device for BioMEMS applications. [ABSTRACT FROM AUTHOR]

Al-AlO (18%) composite was prepared by stir-cast melt technique. The microstructures showed uniform distribution of particulates, dispersed in the matrix. There exists discontinuity (~0.25 μm) in the interface between particulates and matrix. The composite was hot forged. Hot working resulted in fine recrystallized microstructure with particulates dispersed along grain boundaries. Formation of pancake microstructure with some inhomogeneity in the microstructure along three faces of the forged composite was observed. The discontinuity across the interface between Al-AlO was reduced to 0.125 μm after forging. The as-cast and forged Al-AlO composites showed higher wear resistance than pure Al. In lubricant media, there was no significant wear observed for either the as-cast or forged composite, whereas Al had shown higher wear at 50 N load. [ABSTRACT FROM AUTHOR]

We present images of 29 post-starburst quasars (PSQs) from a Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) Wide Field Channel Snapshot program. These broadlined active galactic nuclei (AGNs) possess the spectral signatures of massive (Mburst ~ 1010 M⊙), moderate-aged stellar populations (hundreds of Myr). Thus, their composite nature provides insight into the AGN-starburst connection. We measure quasar-to-host galaxy light contributions via semi-automated two-dimensional light profile fits of point-spread-function-subtracted images. We examine the host morphologies and model the separate bulge and disk components. The HST/ACS-FrO6W images reveal an equal number of spiral (13/29) and early-type (13/29) hosts, with the remaining three hosts having indeterminate classifications. AGNs hosted by early-type galaxies have on average greater luminosity than those hosted by spiral galaxies. Disturbances such as tidal tails, shells, star-forming knots, and asymmetries are seen as signposts of interaction/merger activity. Disturbances like these were found in 17 of the 29 objects and are evenly distributed among early-type and spiral galaxies. Two of these systems are clearly merging with their companions. Compared to other AGNs of similar luminosity and redshift, these PSQs have a higher fraction of early-type hosts and disturbances. Our most luminous objects with disturbed early-type host galaxies appear to be consistent with merger products. Thus, these luminous galaxies may represent a phase in an evolutionary scenario for merger-driven activity. Our less luminous objects appear to be consistent with Seyfert galaxies not requiring triggering by major mergers. Many of these Seyferts are barred spiral galaxies. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to determine the geometric accuracy of cone beam CT (CBCT)-based linear measurements of bone height obtained with the Galileos CBCT (Sirona Dental Systems Inc., Bensheim, Hessen, Germany) in the presence of soft tissues. Methods: Six embalmed cadaver heads were imaged with the Galileos CBCT unit subsequent to placement of radiopaque fiduciary markers over the buccal and lingual cortical plates. Electronic linear measurements of bone height were obtained using the Sirona software. Physical measurements were obtained with digital calipers at the same location. This distance was compared on all six specimens bilaterally to determine accuracy of the image measurements. Results: The findings showed no statistically significant difference between the imaging and physical measurements (P > 0.05) as determined by a paired sample t-test. The intraclass correlation was used to measure the intrarater reliability of repeated measures and there was no statistically significant difference between measurements performed at the same location (P > 0.05). Conclusions: The Galileos CBCT image-based linear measurement between anatomical structures within the mandible in the presence of soft tissues is sufficiently accurate for clinical use. [ABSTRACT FROM AUTHOR]

In a randomised control study, we evaluated the efficacy of intravenous low-dose magnesium sulphate for the management of eclampsia. A total of 144 women with eclampsia were divided into a study group and a control group of 72 women each. The study group received 0.75 g/h of magnesium sulphate intravenously after a loading intravenous dose of 4 g and the control group was given the standard intramuscular regimen as advocated by Pritchard. The primary outcome measure was recurrence rate of the seizures. The secondary outcome measures were development of magnesium toxicity if any, and maternal and perinatal outcomes. The difference in the incidence of fit recurrence was statistically insignificant when both groups were compared (7.46%% vs 8.57%%, p == 0.939). The total dose of magnesium sulphate was significantly lower in the intravenous group ( p < 0.0001), in which no patient developed magnesium toxicity. Low-dose intravenous magnesium sulphate was found to be as effective as the standard intramuscular regimen, while maintaining a high safety margin. [ABSTRACT FROM AUTHOR]

Many Drosophila cytochrome P450 or Cyp genes are induced by caffeine and phenobarbital (PB). To understand the induction mechanism, we created Drosophila S2 cell lines stably transformed with different luciferase reporter plasmids carrying upstream DNAs of Cyp6a8 allele of the resistant 91-R strain, and the 1.1-kb upstream DNAs of Cyp6g1 of the 91-R and the susceptible 91-C strains. Following 24 h treatment with dichlorodiphenyltrichloroethane (DDT), caffeine or PB, luciferase activity of all cell lines was determined. Results showed that the 0.1-kb DNA of Cyp6a8 and the upstream DNAs of Cyp6g1 from both strains are not induced by these chemicals in S2 cells. However, the 0.2-, 0.5- and 0.8-kb DNAs of Cyp6a8 showed 13–24-, 4–5- and 2.2–2.7-fold induction with caffeine, PB and DDT, respectively. These DNAs also showed a 2–3-fold synergistic effect of caffeine and PB but not of caffeine and DDT. The results suggest that the cis-regulatory elements for all three chemicals are located within the -11/-199 DNA of Cyp6a8. Furthermore, caffeine and PB inductions appear to be mediated via different cis-elements, whereas caffeine and DDT induction may involve common regulatory elements. These stably transformed cell lines should help understand the mechanism of resistance-associated Cyp gene overexpression in Drosophila. [ABSTRACT FROM AUTHOR]

Flame impingement heat transfer has widespread industrial and domestic applications and attaining high heat flux as well as low emission of pollutants is the important prerequisite for all such applications. In this article, the heat transfer and emission characteristics of a laminar flame jet impinging on a flat target plate have been investigated experimentally. The effect of reactant jet Reynolds number, equivalence ratio and burner to plate separation distance on the average heat flux, and emissions of CO and NOx are studied using methane and ethylene fuels. Results indicate that the heat flux is maximized under certain operating conditions of jet Re, equivalence ratio, and separation distance between the burner and the target. Fuel type is found to have an effect on the heat transfer rate because of the varying luminosity of the flame with different fuels. Operating regimes that produce lower emission of pollutants are also identified. Findings of this article have direct industrial relevance to flame impingement heat transfer applications that have small target plate-to-burner port diameter ratios. [ABSTRACT FROM AUTHOR]

Objective: Cancer stem cells have been identified as the growth root for various malignant tumours and are thought to be responsible for cancer recurrence following treatment. Materials and methods: Here, a predictive mathematical model for the cancer stem cell hypothesis is used to understand tumour responses to chemotherapeutic drugs and judge the efficacy of treatments in arresting tumour growth. The impact of varying drug efficacies on different abnormal cell populations is investigated through the kinetics associated with their decline in response to therapy. Results and conclusions: The model predicts the clinically established ‘dandelion phenomenon’ and suggests that the best response to chemotherapy occurs when a drug targets abnormal stem cells. We compare continuous and periodic drug infusion. For the latter, we examine the relative importance of the drug cell-kill rate and the mean time between successive therapies, to identify the key attributes for successful treatment. [ABSTRACT FROM AUTHOR]

Polyunsaturated fatty acids (PUFAs) have significant, cardioprotective effects against ischemia. Hempseed contains a high proportion of the PUFAs linoleic acid (LA) and α-linolenic acid (ALA), which may have opposing effects on postischemic heart performance. There are no reported data concerning the cardiovascular effects of dietary hempseed intake. A group of 40 male Sprague-Dawley rats were distributed evenly into four groups that were fed for 12 wk a normal rat chow supplemented with hempseed (5% and 10%), palm oil (1%), or a 10% partially delipidated hempseed that served as a control. Plasma ALA and γ-linolenic acid levels were significantly elevated in the rats that were fed a 5% or 10% hempseed-supplemented diet, but in heart tissue only ALA levels were significantly elevated in the rats fed these diets compared with control. After the dietary interventions were completed, postischemic heart performance was evaluated by measuring developed tension, resting tension, the rates of tension development and relaxation, and the number of extrasystoles. Hearts from rats fed a hempseed-supplemented diet exhibited significantly better postischemic recovery of maximal contractile function and enhanced rates of tension development and relaxation during reperfusion than hearts from the other groups. These hearts, however, were not protected from the occurrence of extrasystoles, nor were the increases in resting tension altered during ischemia or reperfusion as a function of any dietary intervention. Our data demonstrate that dietary hempseed can provide significant cardioprotective effects during postischemic reperfusion. This appears to be due to its highly enriched PUFA content. [ABSTRACT FROM AUTHOR]

Recent research on the origin of brain cancer has implicated a subpopulation of self-renewing brain cancer stem cells for malignant tumour growth. Various genes that regulate self-renewal in normal stem cells are also found in cancer stem cells. This implies that cancers can occur because of mutations in normal stem cells and early progenitor cells. A predictive mathematical model based on the cell compartment method is presented here to pose and validate non-intuitive scenarios proposed through the neural cancer stem cell hypothesis. The growths of abnormal (stem and early progenitor) cells from their normal counterparts are ascribed with separate mutation probabilities. Stem cell mutations are found to be more significant for the development of cancer than a similar mutation in the early progenitor cells. The model also predicts that, as previously hypothesized, repeated insult to mature cells increases the formation of abnormal progeny, and hence the risk of cancer. [ABSTRACT FROM AUTHOR]

Abstract The study of the early stages of speciation can benefit from examination of differences between populations of known history that have been separated for a short time, such as a few thousands of generations. We asked whether two lines of Drosophila melanogaster that were isolated more than 40 years ago have evolved differences in life-history characters, or have begun to evolve behavioural or postzygotic isolation. One line, which is resistant to DDT, showed lower egg production and a shorter lifespan than a susceptible line. These differences are not a pleiotropic effect of resistance because they are not attributable to the chromosome that contains the resistance factors. The two lines have begun to become behaviourally isolated. Again, the isolation is not attributable to genes on the chromosome that contains resistance factors. The lines show only prezygotic isolation; there is no evidence of reduced fitness of F1 or F2 hybrids. These lines and others like them, should be excellent subjects for analyses of genetic changes that could lead to speciation. [ABSTRACT FROM AUTHOR]

Background – Undocumented observations of ours suggested increased occurrence of strokes in the early hours of the morning and in the toilets where most Indians still squat. The present study has been designed to assess the validity of this observation and to identify the likely triggering factor in stroke onset in such situations. Material and methods – Part A of the study looked into stroke onset data of 100 consecutive CT-confirmed stroke patients specially in relation to time of day, place, posture and activity of the individual. Part B of the study included 67 healthy volunteers (age 24–49 years) whose supine and squatting blood pressure (BP) were measured and the differences noted. Part C of the study consisted of repeating the same procedure in 104 known hypertensives on treatment (age 28–60 years). Results – Part A of the study revealed that most strokes (52%) occurred in the morning and at home (86%) and over a third (36%) while in toilets. Thirty-six per cent of the strokes occurred while the subjects squatted, mostly during the act of defecation. More than half of the haemorrhagic strokes occurred while the subjects were in squatting position. In normal healthy volunteers squatting produced a small (8.09 ± 7.04 mmHg) but significant rise in systolic blood pressure (SBP) but not in diastolic blood pressure (DBP) (0.9 ± 7.38 mmHg). In contrast, in treated hypertensives squatting produced a significantly higher rise in both SBP (14.49 ± 11.63 mmHg) and DBP(9.10 ± 9.19 mmHg). Conclusion – The relationship of the clinical observations regarding stroke onset with the BP changes noted on squatting in healthy as well as hypertensive subjects appears to be more than fortuitous. Squatting induced rise in BP appears to be an important triggering factor for stroke onset in subjects at risk in India. [ABSTRACT FROM AUTHOR]

Objective: To survey university students regarding hepatitis B virus (HBV) infection risks and factors affecting immunization status against the disease. Methods: Data from 467 students were analyzed using descriptive statistics, t tests, and a discriminant function analysis. Results: Only 19.1% students had received the HBV vaccine. Vaccination status was related to preventive health care values and knowledge about the disease. Following a brief educational intervention, 28.6% of the unimmunized students were willing to be vaccinated. Barriers to vaccination were high vaccine costs and lack of doctors' recommendations. Conclusion: Subsidized vaccine costs, doctors' recommendations, and more health education could increase HBV vaccination rates among university students. [ABSTRACT FROM AUTHOR]

The structural characteristics of La1.85Sr0.15Cu1− xZn xO4 have been investigated over a wide composition range, viz. for x = 0.0, 0.1, 0.2, and 0.4, using powder neutron diffraction. The strong influence of substitution of the nonmagnetic Zn, which destroys superconductivity in the parent phase for rather low dopant concentration x ≲ 0.1, and the change of symmetry from the tetragonal to orthorhombic structure for x ≤ 0.2, are discussed. [ABSTRACT FROM AUTHOR]

We report the synthesis, magnetic characteristics and electron paramagnetic resonance (EPR) data on the new hexacyanometallate-based bimetallic molecular compound [Ni(pn)2]3 [FeCN6]2 12H2O, where pn 1,2-propanediamine, which shows bulk ferromagnetic order below 19K. It is a soft magnet exhibiting a rather weak hysteresis. The EPR spectra show a fine structure, characteristic of an S 3/2 state, in a very narrow temperature region just above Tc that is suggestive of the formation and ordering of S= 3/2 ferromagnetically coupled states of state of Ni2 S 1 and FeIII S 1/2 ions. [ABSTRACT FROM AUTHOR]

A double blind prospective controlled study to evaluate the effect of inosiplex in induced human influenza A infection was carried out. Inosiplex was administered in therapeutic (starting 48 h following challenge) or prophylactic-therapeutic (starting 48 h prior to challenge) manner in a dose of 4 g per day. Although the number of volunteers with clinical illness in the two treatment groups was not significantly different as compared to placebo, the volunteers had significantly fewer and less severe symptoms. Average symptom scores for headache, myalgia and malaise were significantly reduced in both treatment groups as compared to placebo. Rhinorrhoea was significantly reduced in the prophylactic-therapeutic group but not in the therapeutic group otherwise there were no significant differences between the two treatment groups. Enhancement of lymphocyte transformation in presence of PHA was noted at 2 and 4 days post challenge in treatment groups as compared to placebo. Inosiplex was effective in reducing symptoms of influenza. Its effect may be related at least in part to its immunopotentiating activity. [ABSTRACT FROM PUBLISHER]

Lactogenesis in mammary gland of the mouse requires cortisol (or corticosterone) and prolactin. In this paper we review some recent findings in our laboratory regarding influence of the corticosteroid on casein mRNA activity of lactating mammary gland. Adrenal ablation in nursing mothers results in loss of larger ribosomal aggregates (polysomes) from mammary cells; and this is accompanied by virtual abolition of immunologically detectable casein synthesis activity of the polysomes. Immunologically determined casein mRNA activity in phenol-chloroform-extracted lactating mammary cell RNA was assayed in ascites tumor cell ribosome cell-free protein synthesis system. Adrenalectomy induces 90% loss of casein mRNA activity of mammary cells of nursing mothers; this adverse response is also preventable by cortisol therapy of the animal. This suggests that the glucocorticoid influences the concentration of functionally active casein mRNA in the mammary cells. Cortisol treatment of adrenalectomized mothers also causes a pronounced increase of precursor ([H]uridine) incorporation into both rRNA and poly(A) mRNA. The latter includes mRNA species having a sedimentation value lower than 18S rRNA. Isolated nuclei of lactating mammary cells were assayed in an in vitro RNA polymerase system. RNA synthesized by the isolated nuclei in vitro after analysis on Sigmacell revealed that it includes poly(A) mRNA. This finding improves the feasibility of monitoring the influence of the glucocorticoid on mRNA transcriptional activity by the mammary chromatin. In addition results are presented to show that casein mRNA is inducible in the mammary cells in organ culture of the whole mammary gland in medium containing insulin, prolactin and cortisol. The significance of these findings concerning elucidation of the molecular mechanisms of synergism between the glucocorticoid and prolactin on modulation of the milk protein mRNA, and hence the developmental biology of the mammary gland, is discussed. [ABSTRACT FROM AUTHOR]

The effect of various parameters, namely amount of prestrain, time of aging, and temperature of aging on the response, that is the increase in the yield strength, of a dual-phase steel was studied by applying statistical design of experiments. A regression equation was developed between the response and the parameters. The equation was corrected by Student 't' test and was found to be adequate as checked by Fisher 'F' test and random experiment. Within the range of variables studied, the amount of prestrain, the time of aging, and the temperature of aging had negative, insignificant, and very significantly positive influence, respectively. An attempt was made to achieve a maximum for the response surface. The maximum was found to result from a combination of the parameters such as 0.5% tensile prestrain, aging time of 12 min, and aging temperature of 320°C. [ABSTRACT FROM AUTHOR]