Impact of capping agent on structural and optical properties of ZnS nanoparticles

Nanocrystalline samples of pristine capped and uncapped zinc sulphide were synthesized via the sol-gel technique. The nanocrystallinity of the samples were confirmed by the X-ray diffraction technique, where size of the particle size decreases with the increasing of mol. concentration (x = 0.00, 0.02, 0.03, 0.04 Mol). of capping agent sodium dodecyle sulphate. The obtained crystallite sizes were found to be in the range 4.6 nm to 2.7 nm respectively. The optical band gaps of the samples were estimated by using ultra-violet visible spectroscopic techniques and the band gap values were in the range 3.8 eV to 4.4 eV. All the samples showed quantum confinement behavior compared to bulk sample. Fluorescence (FL) spectra showed three emission peaks at the emission wavelengths around 434 nm, 520 nm, 545 nm, 628 nm, and 694 nm. The FL intensities were proportional to the concentration of capping agent.Comment: 11 pages, 6 figures, conferenc

Graphene oxide coated aluminium as an efficient antibacterial surface

Antimicrobial coatings on metallic surfaces are rapidly emerging to combat bacterial pathogens. The excess use of conventional antibiotics increases the number of resistant strains at an alarming rate, which in turn leads to detrimental implications in the healthcare sector. Hence, it is of great importance in developing a new class of material with inherent bactericidal activity and good biocompatibility. In the present study, we have modified the aluminium surfaces by a coating of graphene oxide (GO) due to its excellent physicochemical properties, water dispersity and low cytotoxicity. Coatings were developed through facile and enviornment-friendly transfer method. The antimicrobial properties of GO coated aluminium are investigated against Gram-negative strain E. coli through agar plate counting and ‘Live/Dead’ fluorescence staining. Further, to shed light into the mechanism of antibacterial activity of GO at the molecular level, we have performed X-ray reflectivity (XRR) study considering a phospholipid multilayer as a model system to mimic bacteria cell membrane. Results show a significant bactericidal activity of the GO coatings compared to uncoated aluminium with lower concentration showing slightly better antibacterial property due to higher roughness. The obtained results may pave the way for engineering graphene-based antimicrobial coatings on a material surface using an easy, environment-friendly, cost-effective and straight forward processing route

Partitioning of a Hybrid Lipid in Domains of Saturated and Unsaturated Lipids in a Model Cellular Membrane

The cellular membranes are composed of hundreds of components such as lipids, proteins, and sterols that are chemically and physically distinct from each other. The lipid−lipid and lipid−protein interactions form domains in this membrane, which play vital roles in membrane physiology. The hybrid lipids (HLs) with one saturated and one unsaturated chain can control the shape and size of these domains, ensuring the thermodynamic stability of a membrane. In this study, the thermodynamics of mixing of a HL and its structural effects on the phase separated domains in a model membrane composed of a saturated and an unsaturated lipid have been investigated. The HL is observed to mix into an unsaturated lipid reducing the Gibbs free energy, whereas the mixing is unfavorable in a saturated lipid. The presence of an HL in an unsaturated lipid tends to increase its area fraction, which is reflected in the enhanced correlation length across the bilayers in a multilayered sample. There is a feeble effect on the domain structure of the saturated lipid due to the presence of the HLs at the phase boundary. This study concludes that the HLs preferentially participate in the unsaturated lipid regions compared to that of a saturated lipid

New bounds of extended energy of a graph

Extended adjacency matrix of a graph with $n$ vertices is a real symmetric marix of order $n\times n$ whose $(i,j)$-th entry is the average of the ratio of the degree of the vertex $i$ to that of the vertex $j$ and its reciprocal when $i,j$ are adjacent, and zero otherwise. Aggregate of absolute eigenvalues of the extended adjacency matrix is termed as the extended energy. In this paper, the concept of extended vertex energy is introduced and some bounds of extended vertex energy are obtained. From there, we obtain some new upper bounds of the extended energy of a graph. Next, we obtain two inequalities which relate the extended energy with the ordinary graph energy. One of those inequalities resolves a conjecture which states that for every graph, ordinary energy can never exceed the extended energy. Using the relationships of extended energy and ordinary energy, we obtain new bounds of extended energy involving the order, size, largest and smallest degree of the graph. We show that these new bounds are improvements of some existing bounds. Finally, some improved bounds of Nordhaus-Gaddum-type are also found.Comment: 17 page

ELICITATION OF TRIGONELLINE, A HYPOGLYCEMIC AGENT IN FENUGREEK SPROUTS BY CALCIUM AND NITRIC OXIDE PRIMING

Objective: This work was performed to evaluate the effect of priming with exogenous sources of calcium ion and nitric oxide on the antidiabeticactivity and the alkaloid contents of fenugreek sprouts along with isolation and identification of trigonelline, a bioactive alkaloid responsible for hypoglycemic property of fenugreek.Methods: The fenugreek seeds were pre-treated with calcium chloride (CC), lanthanum chloride (LC) a calcium channel blocker; ethylene glycol-bis (2-aminoethylether) -N, N, N´, N tetra acetic acid (EG) a calcium chelator; sodium nitroprusside (SNP) and 2-(4-carboxyphenyl) -4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (CP) a nitric oxide scavenger and germinated for 72 hrs. The sprout extracts were evaluated for their in vitro antidiabetic potential by α-amylase and α-glucosidase inhibition along with their trigonelline content. Trigonelline was isolated from fenugreek sprouts and identified by Infrared analysis and nuclear magnetic resonance (NMR) spectroscopy.Results: The results revealed that sprouts pre-treated with CC and SNP exhibited enhanced antidiabetic potential as well as alkaloid content overcontrol; on the other hand, their action was reversed by their antagonists, EG, LC, and CP. The sprouts pre-treated with 2mM CC showed the best elicitation of alkaloid content and antidiabetic activity followed by SNP-20 mM.Conclusions: The study suggests probable involvement of the signaling molecules, calcium ion, and nitric oxide in pathways associated withbiosynthesis of bioactive compounds responsible for hypoglycemic activity of fenugreek sprouts one of which being trigonelline. Â

Effect of low protein diets and lysine supplementation on growth performance and carcass characteristics of growing pigs

The present study was to assess the effect of feeding low protein diet with or without supplemental lysine to meet NRC (1998) requirement on growth performance, carcass trait, meat composition, and meat quality of pigs. An experiment of 126 days was conducted on 21 crossbred Landrace pigs (average weight 11.72 ± 0.57 kg, average age 7.59 ± 0.14 weeks). Animals were randomly assigned to three dietary treatment groups T0, T1 and T2 each comprising 7 animals. A basal diet (T0) was formulated as per NRC (1998). Basal diet (T1) reduced crude protein by 10% with supplemental lysine identical in T0; while without supplemental lysine in T2 (that is, reduced protein by 10% and lysine by 15%). All the diets were iso-caloric and offered in phases according to change in body weight (10 to 20, 20 to 50, 50 to 80 and >80 kg). Growth performance, carcass parameters, meat composition and meat quality were evaluated at the end of the trial on four animals per group. The results show no significant difference on growth parameters and carcass and meat quality traits among the groups. Thus, it was concluded that the crude protein and lysine concentration can be reduced safely by 10 and 15%, respectively to that of NRC (1998) in diet of crossbred Landrace pigs without any compromise on performance during growing and fattening stage of production.Keywords: Carcass trait, low protein, lysine, meat quality, pig

Experiences and views of patients, carers and healthcare professionals on using modems in domiciliary non-invasive ventilation (NIV): a qualitative study

BACKGROUND: Advances in technology means that domiciliary non-invasive ventilation (NIV) devices can be remotely monitored via modems in patients' homes. Possible benefits and challenges of modem technology have yet to be established. This study explored the perspectives and experiences of patients, their carers and healthcare professionals (HCPs) on the addition of modem technology in managing home NIV. METHODS: A qualitative study using a combination of focus groups for HCPs and interviews for carers/patients was undertaken. 12 HCPs and 22 patients/carers participated. These focus groups and interviews were audio-recorded, transcribed verbatim and analysed thematically. RESULTS: Five main themes were identified. 'Surveillance: a paradox of findings': HCPs were concerned about unduly scrutinising patients' lives, potentially impacting on HCP patient relationships. Conversely, patients welcomed modem monitoring and did not express concerns regarding invasion of privacy. 'Sanctions': HCPs reported the modem increased access to care and allowed appropriate assessment of ongoing treatment. 'Complacency and ethics': HCPs expressed concerns patients may become complacent in seeking help due to expectations of modem monitoring, as well as being concerned regarding the ethics of modems. There was a suggestion patients and carers' expectations of monitoring were different to that of clinical practice, resulting in complacency in some cases. 'Increased time for patient focused care': HCPs in the focus groups described a number of ways in which using modems was more efficient. 'Confidence: can be improved with technology': patients and carers were positive about the impact of the modems on their health and well-being, particularly their confidence. CONCLUSION: HCPs expressed concerns about surveillance were not corroborated by patients, suggesting acceptability of remote monitoring. Data suggests a need for increased clarity to patients/carers regarding clinical practice relating to responsiveness to modem data. The issue of complacency requires further consideration. Modem technology was acceptable and considered a useful addition by HCPs, patients and carers. TRIAL REGISTRATION NUMBER: NCT03905382

Current treatment strategies in managing side effects associated with domiciliary positive airway pressure (PAP) therapy for patients with sleep disordered breathing: A systematic review and meta-analysis

Sleep disordered breathing is commonly treated with positive airway pressure therapy. Positive airway pressure therapy is delivered via a tight-fitting mask with common side effects including: leak, ineffective treatment, residual sleep disordered breathing, eye irritation, nasal congestion, pressure ulcers and poor concordance with therapy. This systematic review and meta-analysis aimed to identify the effectiveness of current treatment strategies for managing side effects associated with positive airway pressure therapy. Five databases were searched and 10,809 articles were screened, with 36 articles included in the review. Studies investigated: dressings, nasal spray/douche, chin straps, heated humidification and interfaces. No intervention either improved or detrimentally affected: positive airway pressure concordance, Epworth Sleepiness Score, residual apnoea hypopnea index or interface leak. The review was limited by study heterogeneity, particularly for outcome measures. Additionally, patient demographics were not reported, making it difficult to apply the findings to a broad clinical population. This review highlights the paucity of evidence supporting treatment strategies to manage side effects of positive airway pressure therapy