Preparation and characterization of pristine and Sn doped copper gallium sulphide (CGS) thin films using spray pyrolysis technique.

With thin film solar cell applications, chalcopyrite semiconductors present enormous potential for usage as an absorber layer. In today's electronics sector, wide band gap semiconductors have extreme demand for applications such as high-power, high-frequency, challenging devices that are resistant to high temperatures, optoelectronic devices, and short-wavelength light-emitting devices. The undoped and tin-doped CGS thin films are the subject of the current investigation. Pure and Tin (Sn) doped CGS thin films were produced on a glass substrate using a low-cost chemical spray pyrolysis technique in a nitrogen atmosphere. Spray pyrolysis is a flexible and efficient method for thin-film deposition. The process parameters, such as the nozzle distance, spray time, spray rate, and temperature, have a significant impact on the films' quality and characteristics. Fundamental characterization techniques, including XRD analysis, Micro Raman analysis, EDAX, UV-VIS-NIR spectroscopy, and Scanning Electron Microscopy (SEM), were used to examine the generated pristine and Sn-doped CGS thin films. The XRD patterns showed that the pristine and Sn-doped CGS thin films exhibit a tetragonal phase and there is a decrease in the crystallite size with increasing dopant concentration. SEM studies revealed that there is a change in the grain size and surface morphology of the film with increasing Sn doping concentration. The presence of copper (Cu), gallium (Ga), sulfur (S), and Sn was further confirmed by studying the EDAX spectrum. SEM results indicate that the surface morphology of the CGS films is modified by Sn doping. Further increasing the dopant percentage caused deformation and fragmentation of the sample. A comparison of the Raman spectra for pristine and Sn-doped CGS revealed that there is some substantial change in the layer composition after adding the dopant. Compared to the pristine CGS, the peak positions of CGS (1 wt %) and CGS (3 wt %) are not shifted but there is a significant change in the relative peak intensities and formation of an additional peak The Sn-doped CuGaS2 thin films had optical band gaps of 2.47 eV (0.0 wt% Sn-doped), 2.33 eV (1 wt% Sn-doped), and 2.58 eV (3 wt% Sn-doped). From this study, we can say that the 1 wt% Sn doped CGS sample is the best for solar cell application. The XRD results indicated that the Sn dopant addition in the CuGaS2 lattice site does not affect the symmetry of the material. Enhancement of absorption is done by the Sn dopant.

Safety and pharmacodynamics of an engineered E. coli Nissle for the treatment of phenylketonuria: a first-in-human phase 1/2a study.

Phenylketonuria (PKU) is a rare disease caused by biallelic mutations in the PAH gene that result in an inability to convert phenylalanine (Phe) to tyrosine, elevated blood Phe levels and severe neurological complications if untreated. Most patients are unable to adhere to the protein-restricted diet, and thus do not achieve target blood Phe levels. We engineered a strain of E. coli Nissle 1917, designated SYNB1618, through insertion of the genes encoding phenylalanine ammonia lyase and L-amino acid deaminase into the genome, which allow for bacterial consumption of Phe within the gastrointestinal tract. SYNB1618 was studied in a phase 1/2a randomized, placebo-controlled, double-blind, multi-centre, in-patient study ( NCT03516487 ) in adult healthy volunteers (n = 56) and patients with PKU and blood Phe level ≥600 mmol l-1 (n = 14). Participants were randomized to receive a single dose of SYNB1618 or placebo (part 1) or up to three times per day for up to 7 days (part 2). The primary outcome of this study was safety and tolerability, and the secondary outcome was microbial kinetics. A D5-Phe tracer (15 mg kg-1) was used to study exploratory pharmacodynamic effects. SYNB1618 was safe and well tolerated with a maximum tolerated dose of 2 × 1011 colony-forming units. Adverse events were mostly gastrointestinal and of mild to moderate severity. All participants cleared the bacteria within 4 days of the last dose. Dose-responsive increases in strain-specific Phe metabolites in plasma (trans-cinnamic acid) and urine (hippuric acid) were observed, providing a proof of mechanism for the potential to use engineered bacteria in the treatment of rare metabolic disorders.

Validation of transcutaneous bilirubinometry during phototherapy for detection and monitoring of neonatal jaundice in a low-income setting.

Background: Severe neonatal jaundice (SNJ) and the associated long-term health sequelae are a significant problem in low-income countries (LIC) where measurement of total serum bilirubin (TSB) is often unavailable. Transcutaneous bilirubinometry (TcB) provides the opportunity for non-invasive, point-of-care monitoring. Few studies have evaluated its agreement with TSB levels during phototherapy in LIC.Aim: To determine agreement between TcB and TSB during phototherapy in a Haitian newborn population and to establish whether TcB can be safely used to guide treatment during phototherapy when TSB is unavailable.Methods: A single-centre prospective study (February to May 2017) in Cap Haïtien, northern Haiti was undertaken. Newborns <7 days of age with clinically detected jaundice were eligible for inclusion. A TcB device (JM-103) was used to screen for newborn jaundice along with a parallel TSB. A strip of black tape was placed across the sternum during phototherapy and uncovered for subsequent TcB measurements. Decisions about phototherapy treatment were based upon UK National Institute of Clinical Excellence (NICE) threshold criteria. Paired TSB and TcB measurements were compared using Bland-Altman methods.Results: The final analysis included 70 parallel TSB/TcB measurements from 35 infants within the first 5 days of life. Nineteen (54.3%) were male and 12 (34.3%) were <35 weeks. Thirty-two (91.4%) were receiving phototherapy. There was good agreement between TSB and TcB. Compared with TSB, TcB tended to over-estimate bilirubin (mean difference 11.1 µmol/L, 95% CI -10.2-32.5 µmol/L). However, at higher bilirubin levels (>250 µmol/L), TcB tended to under-estimate bilirubin compared with TSB and the difference increased.Conclusion: In an LIC setting in which serum bilirubin testing is not commonly available, TcB demonstrates good agreement with TSB and can be safely used to guide jaundice treatment during phototherapy but can lead to over-treatment at lower bilirubin levels and are more inaccurate at higher levels. For TcB levels >250 µmol, confirmation with serum bilirubin should be performed, if available, to avoid under-estimation.Abbreviations: LIC: low income countries; LMIC: low and middle income countries; TcB: transcutaneous bilirubinometry; TSB: transcutaneous serum biliubin.

Single walled carbon nanotube-metal oxide nanocomposites for reversible and reproducible storage of hydrogen.

Composite material consisting of single walled carbon nanotubes (SWCNTs) and metal oxide nanoparticles has been prepared and their hydrogen storage performance is evaluated. Metal oxides such as tin oxide (SnO2), tungsten trioxide (WO3), and titanium dioxide (TiO2) are chosen as the composite constituents. The composites have been prepared by means of ultrasonication. Then, the composite samples are deposited on alumina substrates and at 100 °C in a Sieverts-like hydrogenation setup. Characterization techniques such as transmission electron microscopy (TEM), Raman spectroscopy, scanning electron microscopy (SEM), powder X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, energy dispersive spectroscopy (EDS), CHN elemental analysis, and thermogravimetric (TG) measurements are used to analyze the samples at various stages of experiments. Hydrogen storage capacity of the composites namely, SWCNT-SnO2, SWCNT-WO3, and SWCNT-TiO2 are found to be 1.1, 0.9, and 1.3 wt %, respectively. Hydrogenated composite samples are stable at room temperature and desorption of hydrogen is found to be 100% reversible. Desorption temperature ranges and binding energy ranges of hydrogen have been measured from the desorption studies. The hydrogenation, dehydrogenation temperature, and binding energy of hydrogen fall in the recommended range of a suitable hydrogen storage medium applicable for fuel cell applications. Reproducibility and deterioration level of the composite samples have also been examined.

Early nutritional determinants of intrahepatocellular lipid deposition in preterm infants at term age.

BACKGROUND: We have previously shown that by term age, preterm infants have elevated intrahepatocellular lipid (IHCL) content and altered regional adiposity, both of which are risk factors for cardiometabolic illness in adult life. Preterm nutritional intake is a plausible determinant of these aberrant trajectories of development. OBJECTIVE: We aimed to establish if macronutritional components of the preterm diet were determinants of IHCL deposition measured at term equivalent age, using (1)H Magnetic Resonance spectroscopy (MRS). METHODS: Prospective observational case-control study in a single UK neonatal unit. (1)H MR spectra were acquired from 18 preterm infants (<32 weeks gestational age at birth) at term age and 31 healthy term infants, who acted as a control group. Neonatal nutritional information was collected from birth to 34(+6) weeks postmenstrual age. RESULTS: IHCL (median, interquartile range) was significantly higher in preterm-at-term infants compared with term-born infants: 0.735, 0-1.46 versus 0.138, 0-0.58; P=0.003. In preterm infants, IHCL was positively correlated with lipid intake in the first week of life (r=0.52, P=0.04). CONCLUSIONS: This study confirms our previous observation of elevated IHCL in preterm infants at term and suggests that early lipid intake may be a determinant. Future work is warranted to establish the clinical relevance and the role of nutritional intervention in attenuating or exacerbating this effect in preterm infants.

Outbreak of a South West Pacific clone Panton-Valentine leucocidin-positive meticillin-resistant Staphylococcus aureus infection in a UK neonatal intensive care unit.

BACKGROUND: Panton-Valentine leucocidin-positive meticillin-resistant Staphylococcus aureus (PVL-MRSA) has become a globally common cause of community-acquired infections. AIM: We report an outbreak of PVL-MRSA in a regional neonatal unit in the UK involving three babies and three staff members. METHODS: Quinolone susceptibility was helpful in identifying potential PVL-MRSA but toxin gene profiling and sequence-based typing were required to distinguish between two PVL-MRSA strains present in the unit. FINDINGS: All three symptomatic babies and two staff carriers, one of whom was symptomatic, were found to be carrying the South West Pacific (SWP) clone of PVL-MRSA (ST30). One of the staff carriers had recently visited the Philippines and was thought to be the source of the outbreak. Control was established using standard infection control procedures but one baby with relapsing MRSA colonization has required more than 100 days in isolation. CONCLUSION: This is the first reported neonatal outbreak associated with the SWP clone in the UK. Our study highlights the potential risk of further introductions of this organism by healthcare staff or patients epidemiologically linked with the Philippines.

Using the Lomb periodogram for non-contact estimation of respiration rates.

We describe a contact-less method for measurement of respiration rate during sleep using a 5.8GHz radio-frequency bio-motion sensor. The sensor operates by sensing phase shifts in reflected radio waves from the torso caused by respiratory movements and other bodily movements such as twitches, positional changes etc. These non-respiratory motion artefacts can obscure reliable estimation of breathinig rates if conventional spectral analysis is used. This paper reports on the accuracy of the respiration rate estimates obtained via algorithmic approaches using Lomb-periodogram based analysis (which can deal with missing or corrupted data), as compared to conventional spectral analysis. Gold-standard respiration rates are derived by expert scoring of respiration rates measured through polysomnography (PSG) from sensors (Respiratory Inductance Plethysmography (RIP) belts) in contact with the subject in an accredited sleep laboratory. Specifically, respiration rates for 15-minute segments chosen from 10 subjects free of Sleep-Disorded Breathing (AHI〈5) were selected for analysis in this paper. Comparison to the expert annotation indicates strong agreement, with the Lomb-periodogram respiration rates with the average error between the measurements being less than 0.4 breaths/min and a standard deviation of 0.3 breaths/minute. Moreover, we showed that the proposed algorithm could track respiration rate over the complete night's recordings for those 10 subjects. We conclude that the non-contact biomotion sensor may provide a promising approach to continuous respiration rate monitoring of reasonable accuracy.

Novel surgical technique for insertion of pleuroperitoneal shunts for bilateral chylous effusions in Ex preterm infant at term corrected age.

Neonatal chylothorax is a relatively uncommon condition. Here we describe the case of an extremely preterm infant with bilateral chylous effusions which were resistant to conventional medical management and were ultimately managed with the insertion of pleuroperitoneal shunts using a novel surgical technique. Subsequently the infant recovered and the shunts could be removed. We report this case to highlight that such shunts can be inserted even in tiny preterm infants with minimally invasive techniques, and be extremely successful in managing chylothorax, pending spontaneous recovery.

Detection of cardiac activity using a 5.8 GHz radio frequency sensor.

A 5.8-GHz ISM-Band radio-frequency sensor has been developed for non-contact measurement of respiration and heart rate from stationary and semi-stationary subjects at a distance of 0.5 to 1.5 meters. We report on the accuracy of the heart rate measurements obtained using two algorithmic approaches, as compared to a reference heart rate obtained using a pulse oximeter. Simultaneous Photoplethysmograph (PPG) and non-contact sensor recordings were recorded over fifteen minute periods for ten healthy subjects (8M/2F, ages 29.6 + or - 5.6 yrs) One algorithm is based on automated detection of individual peaks associated with each cardiac cycle; a second algorithm extracts a heart rate over a 60-second period using spectral analysis. Peaks were also extracted manually for comparison with the automated method. The peak-detection methods were less accurate than the spectral methods, but suggest the possibility of acquiring beat by beat data; the spectral algorithms measured heart rate to within + or -10% for the ten subjects chosen. Non-contact measurement of heart rate will be useful in chronic disease monitoring for conditions such as heart failure and cardiovascular disease.

Nitroxide radical TEMPO reduces ozone-induced chemokine IL-8 production in lung epithelial cells.

Exposure to high levels of ozone (O(3)) damages respiratory tract epithelial cells. This research evaluated the ability of TEMPO (2,2,6,6-tetramethylpiperidine-N-oxyl), a stable nitroxide free radical, to decrease O(3)-mediated injury to a respiratory tract-derived cell line (A549 cells) by monitoring in this cell system the interleukine-8 (IL-8) production. TEMPO reduced O(3)-induced IL-8 production in A549 cells, as evidenced by PCR analysis, Western blot and ELISA assays. This behaviour is explainable on the basis of the reactivity between TEMPO with O(3) and/or O(3)-derived free radicals in biological systems. The study provides evidence that TEMPO reacts with O(3) and/or its cytotoxic products and may provide protections against O(3)-induced biotoxicities.

Neonatal intrahepatocellular lipid.

There is increasing evidence that preterm birth is a risk factor for the development of adiposity associated disease, although the pathophysiological basis is unclear. We have previously shown that preterm infants have increased internal abdominal (visceral) adiposity by term. In adults increased internal adiposity is associated with elevated intrahepatocellular lipid (IHCL). We measured IHCL using (1)H NMR spectroscopy in 26 infants (eight healthy preterm-at-term and 18 term-born) and compared values with a reference group of 32 adults. There was no significant difference between adult and term-born IHCL content. In preterm-at-term infants IHCL was significantly elevated when compared with term-born infants and with adults (IHCL CH2/water median (interquartile range): preterm 1.69 (1.04-3.53), term 0.21 (0-0.54) and adult 0.55 (0.08-1.57).

Tocopherol transfer protein deficiency modifies nuclear receptor transcriptional networks in lungs: modulation by cigarette smoke in vivo.

Dietary factors and environmental pollutants initiate signaling cascades that converge on AhR:Nrf2:NF-kappaB transcription factor (TF) networks and, in turn, affect the health of the organism through its effects on the expression of numerous genes. Reactive oxygen metabolites (ROMs) have been hypothesized to be common mediators in these pathways. alpha-Tocopherol (AT) is a potent, lipophilic, scavenger of ROMs in vitro and has been hypothesized to be a major chain-breaking anti-oxidant in lipoproteins and biological membranes in vivo. The lung offers a vital organ to test the various postulated actions of AT in vivo. Lung AT concentrations can be manipulated by several methods that include dietary and genetic techniques. In this study we have used mice with severe AT deficiency inflicted at birth by the deletion of AT transfer protein (ATTP) which is abundantly expressed in the liver and regulates systemic concentrations of AT. Mice and humans deficient in ATTP are AT deficient. Female ATTP-deficient (ATTP-KO) mice and their congenic ATTP normal (WT) mice fed a diet containing 35 IU AT/kg diet were used to test our hypothesis. The mice (n=5/group) were exposed to either air or cigarette smoke (CS, total suspended particles 60 mg/m(3), 6h/day), a source of ROM, for 3 or 10 days. Post-exposure lung tissue was dissected, RNA extracted from each lung and it was pooled group-wise and processed for GeneChip analysis (Affymetrix 430A 2.0). Differential analysis of the transcriptomes ( approximately 16,000 mRNAs) identified CS sensitive genes that were modulated by lung AT-concentration. CS activated AhR driven genes such as cyp1b1 whose induction was augmented in CS-exposed, AT-deficient lungs. However, CS-induced expression of some of the Nrf2 driven genes was not potentiated in the AT-deficient lungs. Largest clusters of CS-AT sensitive genes were lymphocyte and leukocyte specific genes. These gene-clusters included those encoding cytokines and immunoglobulins, which were repressed by CS and were modulated by lung AT concentrations. Our genome-wide analysis suggests reciprocal regulation of xenobiotic and immune response genes by CS and a modulatory role of lung AT concentration on the expression of these clusters of genes. These data suggest that in vivo network of AT, AT-metabolites and ATTP affects the transcription of genes driven by AhR, Nrf2 and NF-kappaB, transcription factor networks that transduce cellular metabolic signals and orchestrate adaptive responses of lungs to inhaled environmental pollutants.

Dose dependent hypoglycemic effect of aqueous extract of Enicostemma littorale blume in alloxan induced diabetic rats.

Previous studies in our lab had confirmed the blood glucose lowering effect of E. littorale Blume in alloxan induced diabetic rats with no change in normoglycemic control rats. Present paper deals with dose dependent (0.5, 1.0, 1.5, 2.5, 3.5 g dry plant equivalent extract/100 g body wt., p.o.) blood glucose lowering effect of aqueous extract of E. littorale Blume in alloxan induced diabetic rats. The effective dose was found to be 1.5 g dry plant equivalent extract/100 g body wt.. The above dose caused significant decrease in glycosylated haemoglobin, liver glucose-6-phosphatase activity and significant increase in serum insulin levels of the diabetic rats. No significant changes were observed in the toxicity parameters of extract treated diabetic rats as compared to diabetic control rats. The above results suggest that E. littorale is a potent antidiabetic agent without any toxic effect at this particular dose (1.5 g dry plant equivalent extract/100 g body wt.).

Powder properties and their influence on dry powder inhaler delivery of an antitubercular drug.

The purpose of this study was to determine if aerosol delivery of drug loaded microparticles to lungs infected with Mycobacterium tuberculosis may be achieved by predicting dispersion of dry powders through knowledge of particle surface properties. Particle sizes of rifampicin-loaded poly(lactide-co-glycolide) microparticles (R-PLGA), rifampicin alone, and lactose and maltodextrin carrier particles (bulk and 75-125- microm sieved fractions) were determined by electron microscopy for the projected area diameter (D(p)) and laser diffraction for the volume diameter (D(v)). Surface energies (gamma) of R-PLGA, rifampicin alone, lactose, and maltodextrin were obtained by inverse phase gas chromatography, surface areas (S(a)) by N2 adsorption, and cohesive energy densities by calculation. Particle dispersion was evaluated (Andersen nonviable impactor) for 10% blends of R-PLGA and rifampicin alone with bulk and sieved fractions of the carriers. D(p) for R-PLGA and rifampicin alone was 3.02 and 2.83 microm, respectively. D(v) was 13 +/- 1 and 2 +/- 1 microm for R-PLGA and rifampicin alone, respectively, indicating that R-PLGA was more aggregated. This was evident in gamma of 35 +/- 1 and 19 +/- 6 mJ/m2 for R-PLGA and rifampicin alone. D(p) for lactose and maltodextrin (sieved and bulk) was approximately 40 mm. Bulk maltodextrin (D(v) = 119 +/- 6 microm) was more aggregated than bulk lactose (D(v) = 54 +/- 2 microm). This was a result of the higher S(a) for maltodextrin (0.54 m2/g) than for lactose (0.21 m2/g). The gamma of bulk lactose and maltodextrin was 40 +/- 4 and 60 +/- 6 mJ/m2 and of sieved lactose and maltodextrin was 39 +/- 1 and 50 +/- 1 mJ/m2. Impaction studies yielded higher fine particle fractions of R-PLGA from sieved lactose, 13% +/- 3%, than from sieved maltodextrin, 7% +/- 1%, at 90 L/min. An expression, based on these data, is proposed as a predictor of drug dispersion from carrier particles. Delivery of dry powder formulations can be achieved by characterizing particle surfaces and predicting impact on dispersion.