Conjugating binary systems for spacecraft thermal control

The materials search was directed to liquid pairs which can form hydrogen bonds of just the right strength, i.e., strong enough to give a high heat of mixing, but weak enough to enable phase change to occur. The cursory studies performed in the area of additive effects indicate that Conjugating Binary (CB) performance can probably be fine-tuned by this means. The Fluid Loop Test Systems (FLTS) tests of candidate CBs indicate that the systems Triethylamine (TEA)/water and propionaldehyde/water show close to the ideal, reversible behavior, at least initially. The Quick Screening Tests QSTs and FLTS tests, however, both suffer from rather severe static due either to inadequate stirring or temperature control. Thus it is not possible to adequately evaluate less than ideal CB performers. Less than ideal performers, it should be noted, may have features that make them better practical CBs than ideal performers. Improvement of the evaluation instrumentation is thus indicated

Two-substrate enzyme engineering using small libraries that combine the substrate preferences from two different variant lineages

Improving the range of substrates accepted by enzymes with high catalytic activity remains an important goal for the industrialisation of biocatalysis. Many enzymes catalyse two-substrate reactions which increases the complexity in engineering them for the synthesis of alternative products. Often mutations are found independently that can improve the acceptance of alternatives to each of the two substrates. Ideally, we would be able to combine mutations identified for each of the two alternative substrates, and so reprogramme new enzyme variants that synthesise specific products from their respective two-substrate combinations. However, as we have previously observed for E. coli transketolase, the mutations that improved activity towards aromatic acceptor aldehydes, did not successfully recombine with mutations that switched the donor substrate to pyruvate. This likely results from several active site residues having multiple roles that can affect both of the substrates, as well as structural interactions between the mutations themselves. Here, we have designed small libraries, including both natural and non-natural amino acids, based on the previous mutational sites that impact on acceptance of the two substrates, to achieve up to 630× increases in kcat for the reaction with 3-formylbenzoic acid (3-FBA) and pyruvate. Computational docking was able to determine how the mutations shaped the active site to improve the proximity of the 3-FBA substrate relative to the enamine-TPP intermediate, formed after the initial reaction with pyruvate. This work opens the way for small libraries to rapidly reprogramme enzyme active sites in a plug and play approach to catalyse new combinations of two-substrate reactions

The matrilineal society of Meghalaya: trends of family planning and its implications on maternal health

Background: The key health indicators pertaining to maternal health are TFR, contraceptive usage and MMR. As per the NFHS V, the use of any contraceptive method is 27.4% and total fertility rate is 2.9 in Meghalaya, which reflects on the poor performance of the state towards achieving the goals set by the National Health Policy 2017. The current MMR of Meghalaya is 211/1 lakh live birth, one of the highest amongst the Indian states. The two most important causes of maternal mortality in Meghalaya are post-partum haemorrhage and anaemia- both avoidable causes of maternal mortality related to higher order pregnancies and lack of adequate spacing between two consecutive pregnancies, thereby increasing the importance of contraceptive use. The aim of the study was to identify factors associated with poor uptake of contraceptive measures and their implications on maternal health in a matrilineal society. Methods: A cross sectional study was conducted in the department of obstetrics and gynaecology, NEIGRIHMS where 200 patients, indigenous to Meghalaya, were recruited over a period of one year and were interviewed using a validated questionnaire pertaining to family planning practices. Results: Factors such as number of live births, religion and residence were seen to influence the utilization of contraceptive methods. Conclusions: There is still a wide gap to be filled- more sincere and dedicated efforts are needed to empower women to make informed decisions by   increasing awareness about the importance of family planning and its implications on maternal health

Low infra red laser light irradiation on cultured neural cells: effects on mitochondria and cell viability after oxidative stress

<p>Abstract</p> <p>Background</p> <p>Considerable interest has been aroused in recent years by the well-known notion that biological systems are sensitive to visible light. With clinical applications of visible radiation in the far-red to near-infrared region of the spectrum in mind, we explored the effect of coherent red light irradiation with extremely low energy transfer on a neural cell line derived from rat pheochromocytoma. We focused on the effect of pulsed light laser irradiation vis-à-vis two distinct biological effects: neurite elongation under NGF stimulus on laminin-collagen substrate and cell viability during oxidative stress.</p> <p>Methods</p> <p>We used a 670 nm laser, with extremely low peak power output (3 mW/cm²) and at an extremely low dose (0.45 mJ/cm²). Neurite elongation was measured over three days in culture. The effect of coherent red light irradiation on cell reaction to oxidative stress was evaluated through live-recording of mitochondria membrane potential (MMP) using JC1 vital dye and laser-confocal microscopy, in the absence (photo bleaching) and in the presence (oxidative stress) of H₂O₂, and by means of the MTT cell viability assay.</p> <p>Results</p> <p>We found that laser irradiation stimulates NGF-induced neurite elongation on a laminin-collagen coated substrate and protects PC12 cells against oxidative stress.</p> <p>Conclusion</p> <p>These data suggest that red light radiation protects the viability of cell culture in case of oxidative stress, as indicated by MMP measurement and MTT assay. It also stimulates neurite outgrowth, and this effect could also have positive implications for axonal protection.</p

Exposure to sixty minutes of hyperoxia upregulates myocardial humanins in patients with coronary artery disease - A pilot study

In experimental setting the concept of myocardial preconditioning by hyperoxia has been introduced and different intracellular protective mechanisms and their effects have been described. To study whether similar protective phenotype can be induced by hyperoxia also in humans, gene expression profile after hyperoxic exposure was analyzed. Adult patients were randomized to be ventilated with either FiO2 0.4 (n = 14) or 1.0 (n = 10) for 60 minutes before coronary artery bypass grafting. A tissue sample from the right atrial appendage was taken for gene analysis and expression profile analysis on genome wide level by RNA-seq analysis was applied. Exposure to > 96% oxygen for 60 minutes significantly changed the expression of 20 different genes, including upregulation of two different humanins - MTRNR2L2 and MTRNR2L8, and activated a "cell survival" network as detected by Ingenuity Pathway Analyses. We concluded that administration of > 96% oxygen for 1 hour changes gene expression in the myocardium of the patients with coronary artery disease and may enhance cell survival capability

External Reserves and Selected Key Macroeconomic Variables in Nigeria: An Empirical Analysis (2000-2018)

The paper determines empirically the interactive influence of external reserves and selected key macroeconomic variables in Nigeria using an autoregressive distributive lag (ARDL) model, cointegration and error correction model anticipated by Pesaran, Shin and Smith (2001) with quarterly data between 2000 and 2018 sourced from Central Bank statistics portal on data warehouse pro platform at https://cbnstatistics.datawarehousepro.com. The paper applied the Augmented Dickey-Fuller (ADF) unit root in testing variables stationarity. The Cumulative sum (CUSUM) as well as the Cumulative sum of square (CUSUMSQ) display some recursive outstanding schemes of the external reserve function that remain within the 5% critical positions, and therefore gave an indication of steady external reserve purpose for Nigeria during the study period. The key variables trade openness that captured the total imports and exports by way of proportion of gross domestic product (GDP), exchange rate, direct investment, portfolio investment, oil price, consumer price index, interest rates have correct signs and the ARDL regression analysis indicates that the descriptive variables elucidate and accounted for 99% disparities in external reserves model. The bounds cointegration test exhibited that the variables are cointegrated. The paper demonstrated several empirical supports for the theoretical implications. Precisely, the log of direct investment, portfolio investment, trade openness and interest rate have positive effect, statistically significant and contributes to the external reserves position in Nigeria on the short- run. Jel. Classification Numbers: F21, F32, F34 DOI: 10.7176/JESD/11-10-08 Publication date:May 31st 202

LC-MS analysis to determine the biodistribution of a polymer coated ilomastat ocular implant

Ilomastat is a matrix metalloproteinase inhibitor (MMPi) that has shown the potential to inhibit scarring (fibrosis) by mediating healing after injury or surgery. A long lasting ocular implantable pharmaceutical formulation of ilomastat is being developed to mediate the healing process to prevent scarring after glaucoma filtration surgery. The ilomastat implant was coated with water permeable and biocompatible phosphoryl choline polymer (PC1059) displayed extended slow release of ilomastat in vitro and in vivo. The ocular distribution of ilomastat from the implant in rabbits at day 30 post surgery was determined by the extraction of ilomastat and its internal standard marimastat from the ocular tissues, plasma, aqueous humour and vitreous fluid followed by capillary-flow liquid chromatography (cap-LC), the column effluent was directed into a triple quadrupole mass spectrometer operating in product scan mode. The lower limits of quantification (LLOQs) were 0.3 pg/μL for ocular fluids and plasma, and 3 pg/mg for ocular tissues. The extraction recoveries were 90-95% for ilomastat and its internal standard from ocular tissues. Ilomastat was found in ocular fluids and tissues at day 30 after surgery. The level of ilomastat was 18 times higher in the aqueous humour than vitreous humour. The concentration ranking of ilomastat in the ocular tissues was sclera > bleb conjunctiva > conjunctiva (rest of the eye) > cornea. Mass spectrometry analysis to confirm the presence of ilomastat in the ocular tissues and fluids at day 30 post-surgery establishes the extended release of ilomastat can be achieved in vivo, which is crucial information for optimisation of the ilomastat coated implant

A Light‐Induced Decarboxylative‐Elimination of Substituted Maleimides as a Strategy Towards Triggered Photorelease

Herein we report on photodecarboxylations of various substituted maleimides, resulting in an elimination reaction. Furthermore, we establish facile wavelength tunability through modulation of the maleimide double bond substituents. We envisage that these versatile reagents, which are readily constructed and diversified by nucleophilic substitution reactions on bromomaleimides, will offer new opportunities for triggered photorelease

Continuous Single-Phase Synthesis of [Au₂₅(Cys)₁₈] Nanoclusters and their Photobactericidal Enhancement

Thiolate–gold nanoclusters have various applications. However, most of the synthesis methods require prolonged synthesis times from several hours to days. In the present study, we report a rapid synthesis method for [Au25(Cys)18] nanoclusters and their application for photobactericidal enhancement. For [Au25(Cys)18] synthesis, we employed a tube-in-tube membrane reactor using CO as a reducing agent at elevated temperatures. This approach allows continuous generation of high-quality [Au25(Cys)18] within 3 min. Photobactericidal tests against Staphylococcus aureus showed that crystal violet-treated polymer did not have photobactericidal activity, but addition of [Au25(Cys)18] in the treated polymer demonstrated a potent photobactericidal activity at a low white light flux, resulting in >4.29 log reduction in viable bacteria numbers. Steady-state and time-resolved photoluminescence spectroscopies demonstrated that after light irradiation, photoexcited electrons in crystal violet flowed to [Au25(Cys)18] in the silicone, suggesting that redox reaction from [Au25(Cys)18] enhanced the photobactericidal activity. Stability tests revealed that leaching of crystal violet and [Au25(Cys)18] from the treated silicone was negligible and cyclic testing showed that the silicone maintained a strong photobactericidal activity after repeated use

Engineered Antibodies for Monitoring of Polynuclear Aromatic Hydrocarbons

Polynuclear aromatic hydrocarbons (PAHs) are a large class of structurally similar pollutants. Rapid, inexpensive, and high-throughput methods to identify and monitor PAHs are needed in several DOE focus areas, including human and ecosystem health effects, risk and exposure assessment, decontamination and decommissioning, and remediation. DOE has sponsored and participated in several demonstration projects in which commercial immunoassay kits proved useful and cost-effective for detection of PAHs and other pollutants. The emerging generation of sensors and residue recovery methods will require panels of antibodies with relatively subtle differences in cross-reactivity. This project is based on the premise that genetic engineering should be much more successful than conventional polyclonal and monoclonal antibody methods for developing these antibody panels. One objective of this project has been to define the structural basis and mechanisms by which antibodies bind and cross-react with various PAHs. A second objective has been to use this information to produce recombinant antibodies with improved performance in analytical procedures that DOE can use. A third objective has been development of PAH residue recovery and cleanup methods that will be compatible with immunoassays, and make instrumental analysis faster, more accurate, and less expensive