Ionic Covalent Organic Framework as a Dual Functional Sensor for Temperature and Humidity.

Visual sensing of humidity and temperature by solids plays an important role in the everyday life and in industrial processes. Due to their hydrophobic nature, most covalent organic framework (COF) sensors often exhibit poor optical response when exposed to moisture. To overcome this challenge, the optical response is set out to improve, to moisture by incorporating H-bonding ionic functionalities into the COF network. A highly sensitive COF, consisting of guanidinium and diformylpyridine linkers (TG-DFP), capable of detecting changes in temperature and moisture content is fabricated. The hydrophilic nature of the framework enables enhanced water uptake, allowing the trapped water molecules to form a large number of hydrogen bonds. Despite the presence of non-emissive building blocks, the H-bonds restrict internal bond rotation within the COF, leading to reversible fluorescence and solid-state optical hydrochromism in response to relative humidity and temperature.

Differential Efficacy of Storage Temperature and Postharvest Treatment on Shelf Life and Quality of Avocado Fruit (Persea americana Mill.).

Avocado fruit is a rich source of phytonutrients such as vitamins, minerals, carotenoids, carbohydrates, polyphenols and unsaturated fatty acids. However, due to its climacteric nature, fruits are highly susceptible to storage temperature, resulting in poor shelf life and reduced quality. In the present study avocado fruits (Accession CHES-HA-I/I) were stored at different low temperatures (5, 9 and 12 °C with 90-95% relative humidity, RH) to identify optimum low temperature for cold storage. In a further experiment, avocado fruits were treated with 1-methylcyclopropene (1-MCP, 500 ppb) and chitosan (0.5%) to extend the shelf life with better fruit quality. The results showed that storage temperatures had significant effect on physiological, biochemical and antioxidant activities of fruits. Lower physiological loss in weight (PLW), reduced respiration and ethylene production, and higher carbohydrates, protein and fat content were recorded in fruits stored at 9 °C as compared to 12 °C. Similarly, maximum antioxidant properties in terms of free radical scavenging activity (FRSA) and ferric reducing ability of plasma (FRAP) was found in avocado fruits stored at 9 °C. It was also noticed that chilling injury was developed in fruits stored under 5 °C. In addition, exogenous application of 1-MCP significantly reduced respiration and ethylene production rate at 9 °C and extended the shelf life up to 42 days with better fruit quality and more antioxidant activities. However, chitosan treated and control fruits had shelf life up to 28 and 21 days respectively, with minimum nutritional content. From this study it is concluded that a storage temperature of 9 °C and 1-MCP treatment significantly enhanced the shelf life of avocado fruits with better fruit quality as compared to other storage temperatures (5 and 12 °C) and postharvest treatment (chitosan).

Synthesis, in silico and in vitro anti-cancer studies of phosphorylated derivatives of didanosine targeting MDA-MB-231 breast cancer cell lines.

A series of new phosphorylated derivatives of didanosine were designed, synthesized and evaluated their anticancer effects on human breast cancer cells. Their binding affinities were evaluated against aromatase enzyme and the molecular docking studies demonstrated that 9a, 9h and 9i exhibited high binding interactions than the parent molecule (ddI) and other derivatives; evaluated the aromatase enzyme inhibition. The cell viability, cell proliferation, lactate dehydrogenase showed potential anti-proliferative in dose dependent manner, these results were well correlated with hoesch stain and DNA fragmentation on MDA-MB-231 breast cancer cell lines. Cytotoxicity results disclosed that tryptophan amino acid ester substituted derivative 9i showed potential cell death against MDA-MB-231 cancer cell lines. Furthermore, compound 9i has great potential significance for further investigations (in vivo).

Highly Soluble Ambipolar anti-Perylene-3,4 : 9,10-bis(benzimidazole)s Stabilize a Room-Temperature Columnar Hexagonal Phase.

A new series of highly soluble perylene anti-bis(4,5-dialkoxybenzimidazole)s bearing branched flexible chains stabilizing room temperature columnar hexagonal phase and with balanced ambipolar charge carrier mobility is reported for the first time. Only the anti isomer was successfully separated and characterized. These compounds have a high extinction coefficient, small optical band gap and wide absorption range, thus making them a promising class of ambipolar organic semiconductors capable of self-organizing.

Tris(boranil) Columnar Liquid Crystalline Fluorophores: pseudo-Triphenylene Boron(III) Complexes with Peripheral N-B-O Linkages.

The borate complexes derived from salicylaldimine ligands, called boranils, possess a wide range of photophysical and electronic characteristics intrinsically. The unique combination of molecular rigidity, rendered by four-coordinate boron bridges, and extended π-conjugation enable them to serve as technically feasible fluorescent materials (dyes). The incorporation of liquid crystallinity in these boron(III) complexes, especially the columnar (Col) mesomorphism, which is overlooked hitherto, would provide a new dimension to these complexes. Herein, we report the first examples of tris(boranil) discotic liquid crystal (LC) dyes that have been readily synthesized by treating tris(N-salicylideneaniline)s, (TSAN)s, with BF3 .Et2 O in the presence of an acid quencher. These C3 -symmetric borate complexes self-assemble into the Col phase, existing over a wide thermal span including room temperature. The 2D periodic order of the Col phases shows dependence on the length of the peripheral tails. The photophysical measurements reveal the fluorescence emission in their two condensed states viz., solid and Col phase, and in solution. Their electrochemical, two-step oxidation process coupled with the aforesaid features upholds their significance in applied research.

Syntheses, Crystal Structure, and Second Harmonic Generation Response of Noncentrosymmetric Layered Selenites and Tellurites of Antimony(V), ASb3X2O12 (A = K, Rb, Cs, Tl; X = Se, Te).

Eight quaternary selenites and tellurites of antimony(V), ASb3X2O12 (A = K, Rb, Cs, Tl; X = Se, Te), have been synthesized by solid state reactions and structurally characterized by single crystal X-ray diffraction. They are isostructural compounds, which crystallize in the polar noncentrosymmetric P63mc space group with hexagonal unit cell parameter values in the ranges of a = 7.1538(1)-7.2429(1) Å and c = 11.8978(4)-12.0478(3) Å. Their noncentrosymmetric layered structure consists of hexagonal-tungsten-oxide-related (Sb3X2O12)- layers interleaved with A+ ions. They have optical band gap values of 2.90-4.46 eV and showed powder second harmonic generation response equivalent to 1.0-37.2 × KDP.

Noise in supercontinuum generated using PM and non-PM tellurite glass all-normal dispersion fibers.

Intensity fluctuations in supercontinuum generation are studied in polarization-maintaining (PM) and non-PM all-normal dispersion tellurite photonic crystal fibers. Dispersive Fourier transformation is used to resolve the shot-to-shot spectra generated using 225-fs pump pulses at 1.55 µm, with experimental results well reproduced by vector and scalar numerical simulations. By comparing the relative intensity noise for the PM and non-PM cases, supported by simulations, we demonstrate the advantage of the polarization-maintaining property of the PM fibers in preserving low-noise dynamics. We associate the low-noise in the PM case with the suppression of polarization modulation instability.

Anisotropic sol-gel transition: the influence of sample thickness, pressure and strain.

We demonstrate an unprecedented influence of sample thickness (d) and pressure (P) on the gelation of a liquid crystalline nematic host. The temperature at which the anisotropic nematic sol transforms into a nematic gel is weakly dependent on 'd' down to its certain value, but surprisingly exhibits a precipitous drop below about 30 µm thickness. Temperature-dependent laser transmission exhibits characteristics of approach to a tricritical point, when d is varied. While the strain dependence of storage and loss moduli exhibit Payne effect/weak strain overshoot, the magnitudes of the moduli and their thermal variation present explicit dependence on d, both behaviours being well described by power-law expressions. Studies at elevated pressures also corroborate the observations of d-dependence with the nematic sol thermal range increasing with P, suggesting reduced favour for network formation. We strongly believe that these experiments pave a new pathway to realize the formation of gel fibres.

Enzyme engineering improves catalytic efficiency and enantioselectivity of hydroxynitrile lyase for promiscuous retro-nitroaldolase activity.

Protein engineering to improve promiscuous catalytic activity is important for biocatalytic application of enzymes in green synthesis. We uncovered the significance of binding site residues in Arabidopsis thaliana hydroxynitrile lyase (AtHNL) for promiscuous retro-nitroaldolase activity. Engineering of AtHNL has improved enantioselective retro-nitroaldolase activity, a synthetically important biotransformation, for the production of enantiopure ß-nitroalcohols having absolute configuration opposite to that of the stereopreference of the HNL. The variant F179A has shown âˆ¼ 12 fold increased selectivity towards the retro-nitroaldol reaction over cyanogenesis, the natural activity of the parent enzyme. Screening of the two saturation libraries of Phe179 and Tyr14 revealed several variants with higher kcat, while F179N showed âˆ¼ 2.4-fold kcat/Km than the native enzyme towards retro-nitroaldol reaction. Variants F179N, F179M, F179W, F179V, F179I, Y14L, and Y14M have shown > 99% ee in the preparation of (S)-2-nitro-1-phenylethanol (NPE) from the racemic substrate, while F179N has shown the E value of 138 vs. 81 by the wild type. Our molecular docking and dynamics simulations (MDS) studies results provided insights into the molecular basis of higher enantioselectivity by the F179N toward the retro-nitroaldolase activity than the other mutants. Binding energy calculations also showed the higher negative binding free energy in the case of F179N-(R)-NPE compared to other complexes that support our experimental low Km by the F179N for NPE. A plausible retro-nitroaldol reaction mechanism was proposed based on the MDS study of enzyme-substrate interaction.

Regular exercise and patterns of response across multiple cardiometabolic traits: the HERITAGE family study.

OBJECTIVES: We investigated whether high responsiveness or low responsiveness to exercise training aggregates in the same individuals across seven cardiometabolic traits. METHODS: A total of 564 adults (29.2% black, 53.7% female) from the HERITAGE family study completed a 20-week endurance training programme (at 55%-75% of participants' maximal oxygen uptake (VO2max)) with VO2max, per cent body fat, visceral adipose tissue, fasting levels of insulin, high-density lipoprotein cholesterol, small low-density lipoprotein particles and inflammatory marker GlycA measured before and after training. For each exercise response trait, we created ethnicity-specific, sex-specific and generation-specific quintiles. High responses were defined as those within the 20th percentile representing the favourable end of the response trait distribution, low responses were defined as the 20th percentile from the least favourable end, and the remaining were labelled as average responses. RESULTS: Only one individual had universally high or low responses for all seven cardiometabolic traits. Almost half (49%) of the cohort had at least one high response and one low response across the seven traits. About 24% had at least one high response but no low responses, 24% had one or more low responses but no high responses, and 2.5% had average responses across all traits. CONCLUSIONS: Interindividual variation in exercise responses was evident in all the traits we investigated, and responsiveness did not aggregate consistently in the same individuals. While adherence to an exercise prescription is known to produce health benefits, targeted risk factors may not improve.

Retention of freshness and isothiocyanates in fresh-cut radish (Raphanus sativus var. Longipinnatus) through glucose dip treatment.

Experiments were carried out with the objective of enhancing shelf life and maintain quality of fresh-cut radish slices during storage at 8 °C. Dip treatment of radish slices in 20 g/L glucose solution for five minutes retained the quality attributes viz., surface colour, sensory properties and antioxidant capacity of the slices till six days of storage. Isothiocyanates were also retained better due to glucose dip. Biplot generated through principal component analysis of head space volatiles from fresh and stored radish slices showed that fresh and glucose treated slices grouped together with 4-methyl thio-3-butenyl isothiocyanate. Accumulation of sulphurous volatiles such as methyl disulphide, dimethyl trisulphide, 2-pentanethiol was observed in control (undipped) radish slices, indicating their probable role as spoilage indicator volatiles. Thus, glucose pre-treatment can be considered as a practical method for quality retention of fresh-cut radish. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13197-021-05276-1.

Realizing 1,1-Dehydration of Secondary Alcohols to Carbenes: Pyrrolidin-2-ols as a Source of Cyclic (Alkyl)(Amino)Carbenes.

Herein we report secondary pyrrolidin-2-ols as a source of cyclic (alkyl)(amino)carbenes (CAAC) for the synthesis of CAAC-CuI -complexes and cyclic thiones when reacted with CuI -salts and elemental sulfur, respectively, under reductive elimination of water from the carbon(IV)-center. This result demonstrates a convenient and facile access to CAAC-based CuI -salts, which are well known catalysts for different organic transformations. It further establishes secondary alcohols to be a viable source of carbenes-realizing after 185 years Dumas' dream who tried to prepare the parent carbene (CH2 ) by 1,1-dehydration of methanol. Addressed is also the reactivity of water towards CAACs, which proceeds through an oxidative addition of the O-H bond to the carbon(II)-center. This emphasizes the ability of carbon-compounds to mimic the reactivity of transition-metal complexes: reversible oxidative addition and reductive elimination of the O-H bond to/from the C(II)/C(IV)-centre.

Identifying blood pressure loci whose effects are modulated by multiple lifestyle exposures.

Although multiple lifestyle exposures simultaneously impact blood pressure (BP) and cardiovascular health, most analysis so far has considered each single lifestyle exposure (e.g., smoking) at a time. Here, we exploit gene-multiple lifestyle exposure interactions to find novel BP loci. For each of 6,254 Framingham Heart Study participants, we computed lifestyle risk score (LRS) value by aggregating the risk of four lifestyle exposures (smoking, alcohol, education, and physical activity) on BP. Using the LRS, we performed genome-wide gene-environment interaction analysis in systolic and diastolic BP using the joint 2 degree of freedom (DF) and 1 DF interaction tests. We identified one genome-wide significant (p < 5 × 10-8 ) and 11 suggestive (p < 1 × 10-6 ) loci. Gene-environment analysis using single lifestyle exposures identified only one of the 12 loci. Nine of the 12 BP loci detected were novel. Loci detected by the LRS were located within or nearby genes with biologically plausible roles in the pathophysiology of hypertension, including KALRN, VIPR2, SNX1, and DAPK2. Our results suggest that simultaneous consideration of multiple lifestyle exposures in gene-environment interaction analysis can identify additional loci missed by single lifestyle approaches.

Biocatalytic approaches for enantio and diastereoselective synthesis of chiral ß-nitroalcohols.

Chiral ß-nitroalcohols find significant application in organic synthesis due to the versatile reactivity of hydroxyl and nitro functionalities attached to one or two vicinal asymmetric centers. They are key building blocks of several important pharmaceuticals, bioactive molecules, and fine chemicals. With the growing demand to develop clean and green methods for their synthesis, biocatalytic methods have gained tremendous importance among the existing asymmetric synthesis routes. Over the years, different biocatalytic strategies for the asymmetric synthesis of ß-nitroalcohol stereoisomers have been developed. They can be majorly classified as (a) kinetic resolution, (b) dynamic kinetic resolution, (c) Henry reaction, (d) retro-Henry reaction, (e) asymmetric reduction, and (f) enantioselective epoxide ring-opening. This review aims to provide an overview of the above biocatalytic strategies, and their comparison along with future prospects. Essentially, it presents an enzyme-toolbox for the asymmetric synthesis of ß-nitroalcohol enantiomers and diastereomers.

Functional Exploration of Chaperonin (HSP60/10) Family Genes and their Abiotic Stress-induced Expression Patterns in Sorghum bicolor.

BACKGROUND: Sorghum, the C4 dry-land cereal, important for food, fodder, feed and fuel, is a model crop for abiotic stress tolerance with smaller genome size, genetic diversity, and bio-energy traits. The heat shock proteins/chaperonin 60s (HSP60/Cpn60s) assist the plastid proteins, and participate in the folding and aggregation of proteins. However, the functions of HSP60s in abiotic stress tolerance in Sorghum remain unclear. METHODS: Genome-wide screening and in silico characterization of SbHSP60s were carried out along with tissue and stress-specific expression analysis. RESULTS: A total of 36 HSP60 genes were identified in Sorghum bicolor. They were subdivided into 2 groups, the HSP60 and HSP10 co-chaperonins encoded by 30 and 6 genes, respectively. The genes are distributed on all the chromosomes, chromosome 1 being the hot spot with 9 genes. All the HSP60s were found hydrophilic and highly unstable. The HSP60 genes showed a large number of introns, the majority of them with more than 10. Among the 12 paralogs, only 1 was tandem and the remaining 11 segmental, indicating their role in the expansion of SbHSP60s. Majority of the SbHSP60 genes expressed uniformly in leaf while a moderate expression was observed in the root tissues, with the highest expression displayed by SbHSP60-1. From expression analysis, SbHSP60-3 for drought, SbHSP60-9 for salt, SbHSP60-9 and 24 for heat and SbHSP60-3, 9 and SbHSP10-2 have been found implicated for cold stress tolerance and appeared as the key regulatory genes. CONCLUSION: This work paves the way for the utilization of chaperonin family genes for achieving abiotic stress tolerance in plants.

[MutL Protein from the Neisseria gonorrhoeae Mismatch Repair System: Interaction with ATP and DNA].

The mismatch repair system (MMR) ensures the stability of genetic information during DNA replication in almost all organisms. Mismatch repair is initiated after recognition of a non-canonical nucleotide pair by the MutS protein and the formation of a complex between MutS and MutL. Eukaryotic and most bacterial MutL homologs function as endonucleases that introduce a single-strand break in the daughter strand of the DNA, thus activating the repair process. However, many aspects of the functioning of this protein remain unknown. We studied the ATPase and DNA binding functions of the MutL protein from the pathogenic bacterium Neisseria gonorrhoeae (NgoMutL), which exhibits endonuclease activity. For the first time, the kinetic parameters of ATP hydrolysis by the full-length NgoMutL protein were determined. Its interactions with single- and double-stranded DNA fragments of various lengths were studied. NgoMutL was shown to be able to efficiently form complexes with DNA fragments that are longer than 40 nucleotides. Using modified DNA duplexes harboring a 2-pyridyldisulfide group on linkers of various lengths, we obtained NgoMutL conjugates with DNA for the first time. According to these results, the Cys residues of the wild-type protein are located at a distance of approximately 18-50 Šfrom the duplex. The efficiency of the affinity modification of Cys residues in NgoMutL with reactive DNAs was shown to decrease in the presence of ATP or its non-hydrolyzable analog, as well as ZnCl2, in the reaction mixture. We hypothesize that the conserved Cys residues of the C-terminal domain of NgoMutL, which are responsible for the coordination of metal ions in the active center of the protein, are involved in its interaction with DNA. This information may be useful in reconstruction of the main stages of MMR in prokaryotes that are different from γ-proteobacteria, as well as in the search for new targets for drugs against N. gonorrhoeae.

Excited-state electronic properties, structural studies, noncovalent interactions, and inhibition of the novel severe acute respiratory syndrome coronavirus 2 proteins in Ripretinib by first-principle simulations.

Ripretinib is a recently developed drug for the treatment of adults with advanced gastrointestinal stromal tumors. This paper reports an attempt to study this molecule by electronic modeling and molecular mechanics to determine its composition and other specific chemical features via the density-functional theory (DFT), thereby affording sufficient information on the electronic properties and descriptors that can enable the estimation of its molecular bioactivity. We explored most of the physico-chemical properties of the molecule, as well as its stabilization, via the studies of the natural bond orbitals and noncovalent interactions. The electronic excitation, which is a time-dependent process, was examined by the time-dependent DFT with a CAM-B3LYP functional. The molecular docking study indicated that Ripretinib strongly docks with three known novel severe acute respiratory syndrome coronavirus 2 (SARS-n-CoV-2) proteins with a reasonably good docking score.

CFB box wrapping: a new shrink wrapping technology for extension of storage life of colour capsicum (cv. Bachata).

Capsicums lose water very rapidly after harvest and the moisture loss causes severe shriveling making them unmarketable within 2-3 days. The moisture loss occurs even under low temperature conditions, though at lesser rates. Bell peppers packed in corrugated fiber board boxes (CFB) tend to lose moisture continuously as these boxes are permeable to both water vapour and respiratory gases even if they are non-ventilated. To reduce the moisture loss and maintain freshness, yellow colour capsicum (cv. Bachata) were packed in CFB boxes and over wrapped with different semi-permeable films using shrink wrapping technology. This box shrink wrapping significantly lowered the weight loss and maintained firmness of capsicum at ambient (25.7-33.2 °C and 25-63% RH) and low temperature (8 °C ± 0.5 and 80 ± 5% RH) conditions. Yellow colour capsicums packed in this way could be stored for 11 days at ambient temperature with a weight loss of < 6% as compared to about 20% weight loss in non-wrapped fruits. The storage life could be extended to 5 weeks by storing these shrink wrapped boxes at 8 °C without any shriveling and with a weight loss of < 5%. In addition to maintaining high humidity, the lower O2 and higher CO2 levels maintained surrounding the produce in the wrapped boxes helped to avoid shriveling and to retain the quality in terms of surface colour, firmness and other quality traits. The absorption of excessive relative humidity by CFB itself in the over wrapped boxes helped in avoiding condensation of water droplets. This in turn avoided the development of fungal growth and thus the risk of fruit decay.

Deriving stratified effects from joint models investigating gene-environment interactions.

BACKGROUND: Models including an interaction term and performing a joint test of SNP and/or interaction effect are often used to discover Gene-Environment (GxE) interactions. When the environmental exposure is a binary variable, analyses from exposure-stratified models which consist of estimating genetic effect in unexposed and exposed individuals separately can be of interest. In large-scale consortia focusing on GxE interactions in which only the joint test has been performed, it may be challenging to get summary statistics from both exposure-stratified and marginal (i.e not accounting for interaction) models. RESULTS: In this work, we developed a simple framework to estimate summary statistics in each stratum of a binary exposure and in the marginal model using summary statistics from the "joint" model. We performed simulation studies to assess our estimators' accuracy and examined potential sources of bias, such as correlation between genotype and exposure and differing phenotypic variances within exposure strata. Results from these simulations highlight the high theoretical accuracy of our estimators and yield insights into the impact of potential sources of bias. We then applied our methods to real data and demonstrate our estimators' retained accuracy after filtering SNPs by sample size to mitigate potential bias. CONCLUSIONS: These analyses demonstrated the accuracy of our method in estimating both stratified and marginal summary statistics from a joint model of gene-environment interaction. In addition to facilitating the interpretation of GxE screenings, this work could be used to guide further functional analyses. We provide a user-friendly Python script to apply this strategy to real datasets. The Python script and documentation are available at https://gitlab.pasteur.fr/statistical-genetics/j2s.

Linkage disequilibrium mapping for grain Fe and Zn enhancing QTLs useful for nutrient dense rice breeding.

BACKGROUND: High yielding rice varieties are usually low in grain iron (Fe) and zinc (Zn) content. These two micronutrients are involved in many enzymatic activities, lack of which cause many disorders in human body. Bio-fortification is a cheaper and easier way to improve the content of these nutrients in rice grain. RESULTS: A population panel was prepared representing all the phenotypic classes for grain Fe-Zn content from 485 germplasm lines. The panel was studied for genetic diversity, population structure and association mapping of grain Fe-Zn content in the milled rice. The population showed linkage disequilibrium showing deviation of Hardy-Weinberg's expectation for Fe-Zn content in rice. Population structure at K = 3 categorized the panel population into distinct sub-populations corroborating with their grain Fe-Zn content. STRUCTURE analysis revealed a common primary ancestor for each sub-population. Novel quantitative trait loci (QTLs) namely qFe3.3 and qFe7.3 for grain Fe and qZn2.2, qZn8.3 and qZn12.3 for Zn content were detected using association mapping. Four QTLs, namely qFe3.3, qFe7.3, qFe8.1 and qFe12.2 for grain Fe content were detected to be co-localized with qZn3.1, qZn7, qZn8.3 and qZn12.3 QTLs controlling grain Zn content, respectively. Additionally, some Fe-Zn controlling QTLs were co-localized with the yield component QTLs, qTBGW, OsSPL14 and qPN. The QTLs qFe1.1, qFe3.1, qFe5.1, qFe7.1, qFe8.1, qZn6, qZn7 and gRMm9-1 for grain Fe-Zn content reported in earlier studies were validated in this study. CONCLUSION: Novel QTLs, qFe3.3 and qFe7.3 for grain Fe and qZn2.2, qZn8.3 and qZn12.3 for Zn content were detected for these two traits. Four Fe-Zn controlling QTLs and few yield component QTLs were detected to be co-localized. The QTLs, qFe1.1, qFe3.1, qFe5.1, qFe7.1, qFe8.1, qFe3.3, qFe7.3, qZn6, qZn7, qZn2.2, qZn8.3 and qZn12.3 will be useful for biofortification of the micronutrients. Simultaneous enhancement of Fe-Zn content may be possible with yield component traits in rice.