Valence and Rydberg excitations of 4-fluorotoluene in the 4.3-10.8 eV photoabsorption energy region

© 2024 The Authors. Published by Elsevier Ltd.This work reports on the first measurements of the lowest-lying singlet states as studied by photon spectroscopy for para-fluorotoluene, 4-C7H7F. Here we present the high-resolution vacuum ultraviolet photoabsorption spectrum in the 4.3–10.8 eV energy-range, with assignments supported by ab initio calculations (vertical excitation energies and oscillator strengths) at two different levels of theory, equation-of-motion coupled-cluster singles and doubles (EOM-CCSD) and time-dependent density functional theory (TD-DFT). The electronic state spectroscopy of 4-C7H7F reveals the main character of the transitions to be valence, mixed valence-Rydberg and Rydberg, with the associated vibronic series. The absolute cross-section measurements were obtained and used to estimate the photolysis lifetime of 4-fluorotoluene from the sea level up to limit of the stratopause (50 km) in the Earth's atmosphere.publishersversionpublishe

Site-directed mutations in the C-terminal extension of human aB-Crystalline affect chaperone function and block amyloid fibril formation

Copyright: 2007 Treweek et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background. Alzheimer’s, Parkinson’s and Creutzfeldt-Jakob disease are associated with inappropriate protein deposition and ordered amyloid fibril assembly. Molecular chaperones, including aB-crystallin, play a role in the prevention of protein deposition. Methodology/Principal Findings. A series of site-directed mutants of the human molecular chaperone, aBcrystallin, were constructed which focused on the flexible C-terminal extension of the protein. We investigated the structural role of this region as well as its role in the chaperone function of aB-crystallin under different types of protein aggregation, i.e. disordered amorphous aggregation and ordered amyloid fibril assembly. It was found that mutation of lysine and glutamic acid residues in the C-terminal extension of aB-crystallin resulted in proteins that had improved chaperone activity against amyloid fibril forming target proteins compared to the wild-type protein. Conclusions/Significance. Together, our results highlight the important role of the C-terminal region of aB-crystallin in regulating its secondary, tertiary and quaternary structure and conferring thermostability to the protein. The capacity to genetically modify aB-crystallin for improved ability to block amyloid fibril formation provides a platform for the future use of such engineered molecules in treatment of diseases caused by amyloid fibril formation

Tryptophan and Non-Tryptophan Fluorescence of the Eye Lens Proteins Provides Diagnostics of Cataract at the Molecular Level

The chemical nature of the non-tryptophan (non-Trp) fluorescence of porcine and human eye lens proteins was identified by Mass Spectrometry (MS) and Fluorescence Steady-State and Lifetime spectroscopy as post-translational modifications (PTM) of Trp and Arg amino acid residues. Fluorescence intensity profiles measured along the optical axis of human eye lenses with age-related nuclear cataract showed increasing concentration of fluorescent PTM towards the lens centre in accord with the increased optical density in the lens nucleolus. Significant differences between fluorescence lifetimes of “free” Trp derivatives hydroxytryptophan (OH-Trp), N-formylkynurenine (NFK), kynurenine (Kyn), hydroxykynurenine (OH-Kyn) and their residues were observed. Notably, the lifetime constants of these residues in a model peptide were considerably greater than those of their “free” counterparts. Fluorescence of Trp, its derivatives and argpyrimidine (ArgP) can be excited at the red edge of the Trp absorption band which allows normalisation of the emission spectra of these PTMs to the fluorescence intensity of Trp, to determine semi-quantitatively their concentration. We show that the cumulative fraction of OH-Trp, NFK and ArgP emission dominates the total fluorescence spectrum in both emulsified post-surgical human cataract protein samples, as well as in whole lenses and that this correlates strongly with cataract grade and age

Global, regional, and national burden of upper respiratory infections and otitis media, 1990-2021: a systematic analysis from the Global Burden of Disease Study 2021

Background Upper respiratory infections (URIs) are the leading cause of acute disease incidence worldwide and contribute to a substantial health-care burden. Although acute otitis media is a common complication of URIs, the combined global burden of URIs and otitis media has not been studied comprehensively. We used results from the Global Burden of Diseases, Injuries, and Risk Factors Study 2021 to explore the fatal and non-fatal burden of the two diseases across all age groups, including a granular analysis of children younger than 5 years, in 204 countries and territories from 1990 to 2021. Methods Mortality due to URIs and otitis media was estimated with use of vital registration and sample-based vital registration data, which are used as inputs to the Cause of Death Ensemble model to separately model URIs and otitis media mortality by age and sex. Morbidity was modelled with a Bayesian meta-regression tool using data from published studies identified via systematic reviews, population-based survey data, and cause-specific URI and otitis media mortality estimates. Additionally, we assessed and compared the burden of otitis media as it relates to URIs and examined the collective burden and contributing risk factors of both diseases. Findings The global number of new episodes of URIs was 12·8 billion (95% uncertainty interval 11·4 to 14·5) for all ages across males and females in 2021. The global all-age incidence rate of URIs decreased by 10·1% (–12·0 to –8·1) from 1990 to 2019. From 2019 to 2021, the global all-age incidence rate fell by 0·5% (–0·8 to –0·1). Globally, the incidence rate of URIs was 162 484·8 per 100 000 population (144 834·0 to 183 289·4) in 2021, a decrease of 10·5% (–12·4 to –8·4) from 1990, when the incidence rate was 181 552·5 per 100 000 population (160 827·4 to 206 214·7). The highest incidence rates of URIs were seen in children younger than 2 years in 2021, and the largest number of episodes was in children aged 5–9 years. The number of new episodes of otitis media globally for all ages was 391 million (292 to 525) in 2021. The global incidence rate of otitis media was 4958·9 per 100 000 (3705·4 to 6658·6) in 2021, a decrease of 16·3% (–18·1 to –14·0) from 1990, when the incidence rate was 5925·5 per 100 000 (4371·8 to 8097·9). The incidence rate of otitis media in 2021 was highest in children younger than 2 years, and the largest number of episodes was in children aged 2–4 years. The mortality rate of URIs in 2021 was 0·2 per 100 000 (0·1 to 0·5), a decrease of 64·2% (–84·6 to –43·4) from 1990, when the mortality rate was 0·7 per 100 000 (0·2 to 1·1). In both 1990 and 2021, the mortality rate of otitis media was less than 0·1 per 100 000. Together, the combined burden accounted for by URIs and otitis media in 2021 was 6·86 million (4·24 to 10·4) years lived with disability and 8·16 million (4·99 to 12·0) disability-adjusted life-years (DALYs) for all ages across males and females. Globally, the all-age DALY rate of URIs and otitis media combined in 2021 was 103 per 100 000 (63 to 152). Infants aged 1–5 months had the highest combined DALY rate in 2021 (647 per 100 000 [189 to 1412]), followed by early neonates (aged 0–6 days; 582 per 100 000 [176 to 1297]) and late neonates (aged 7–24 days; 482 per 100 000 [161 to 1052]). Interpretation The findings of this study highlight the widespread burden posed by URIs and otitis media across all age groups and both sexes. There is a continued need for surveillance, prevention, and management to better understand and reduce the burden associated with URIs and otitis media, and research is needed to assess their impacts on individuals, communities, economies, and health-care systems worldwide. Funding Bill & Melinda Gates Foundation

Not Available

Not AvailableWith increasing population size, there is an urgent need to double the global food production by 2050, and the onus is on the agricultural scientists to develop new technologies and varieties to double the production. Development of new varieties in any crop varieties is time-consuming as it is dependent on generation period of a crop. Speed breeding or accelerated plant breeding is an emerging strategy among plant breeders to develop new cultivars in short span of time. Here, the plants are grown in controlled growth chambers or greenhouses using optimal light intensity and quality, particular day length and temperature, which accelerates various physiological processes in plants especially photosynthesis and flowering, thus shortening the generation time. Speed breeding can be used to achieve up to 4–6 generations per year instead of 2–3 generations under normal glasshouse conditions. Speed breeding approaches and protocols are well established and standardized for major crop species like wheat, barley and canola. This strategy is now being applied, and standardization protocols are in progress for other crops including perennial fruit crop like apple. Speed breeding could serve as a basic platform for integrating high-throughput phenotyping and genotyping techniques, marker-assisted/genomic selections and gene editing for improvement of the traits in crop species. The present chapter gives an overlook of speed breeding activities carried out in different crops and its importance in present situation of crop improvement under vagaries of environment due to climate change.Not Availabl

Effect of salinity and use of stress indices of morphological and physiological traits at the seedling stage in rice

843-850Rice (Oryza sativa L.) is the most important cereal crop and a major staple food for majority of the human populations worldwide. Rice crop is sensitive to salinity. In spite of large number of studies on salinity tolerance of rice, our knowledge on the overall effect of salinity on rice seedling growth is limited. Improvement in salt tolerance of crop plants remains indescribable, largely due to the fact that salinity is a complex trait which affects almost every aspect of the physiology, biochemistry and genomics of plants. The present investigation was conducted to establish the relationship between various morphological, physiological traits and stress indices. A set of 131 rice accessions was evaluated in two levels namely, non-stress (EC ~ 1.2 dS/m) and saline stress (EC ~ 10 dS/m) in hydroponics at seedling stage. Root length and shoot lengths were reduced by 52 and 50%, respectively in saline stress compared to non-stress conditions. There was a significant correlation between various morphological and physiological parameters in non-saline in addition to saline stress as well as non-stress. The effect of the increased Na+ concentration in the medium is detrimental to root length and shoot length as observed by reduction in root length and a concomitant reduction in shoot length. Increased concentration of Na+ led to augmented Na+/K+ ratio with increased stress in the medium and decreased expression of traits. A significant positive correlation (r=0.60) was noticed between stress tolerance index (STI) of root and shoot length. The stress susceptibility index (SSI) for root length was expressed significant positive correlation with SSI for shoot length (r=0.43). SSI for K+ content was registered significant negative correlation with STI for Na+ content (r=-0.43). The three accessions namely, IC 545004, IC 545486 and IC 545215 were found to be the best performers adjudged on the morphological and physiological criteria in saline stress situation. These three rice accessions could be used as a donor parent or for genotypic studies in future breeding programs

Effect of salinity and use of stress indices of morphological and physiological traits at the seedling stage in rice

Not AvailableRice (Oryza sativa L.) is the most important cereal crop and a major staple food for majority of the human populations worldwide. Rice crop is sensitive to salinity. In spite of large number of studies on salinity tolerance of rice, our knowledge on the overall effect of salinity on rice seedling growth is limited. Improvement in salt tolerance of crop plants remains indescribable, largely due to the fact that salinity is a complex trait which affects almost every aspect of the physiology, biochemistry and genomics of plants. The present investigation was conducted to establish the relationship between various morphological, physiological traits and stress indices. A set of 131 rice accessions was evaluated in two levels namely, non- stress (EC ~ 1.2 dS/m) and saline stress (EC ~ 10 dS/m) in hydroponics at seedling stage. Root length and shoot lengths were reduced by 52 and 50%, respectively in saline stress compared to non-stress conditions. There was a significant correlation between various morphological and physiological parameters in non-saline in addition to saline stress as well as non-stress. The effect of the increased Na concentration in the medium is detrimental to root length and shoot length as observed by reduction in root length and a concomitant reduction in shoot length. Increased concentration of Na led to augmented Na /K ratio with increased stress in the medium and decreased expression of traits. A significant positive correlation (r=0.60) was noticed between stress tolerance index (STI) of root and shoot length. The stress susceptibility index (SSI) for root length was expressed significant positive correlation with SSI for shoot length (r=0.43). SSI for K content was registered significant negative correlation with STI for Na content (r=-0.43). The three accessions namely, IC 545004, IC 545486 and IC 545215 were found to be the best performers adjudged on the morphological and physiological criteria in saline stress situation. These three rice accessions could be used as a donor parent or for genotypic studies in future breeding programs.Not Availabl

The pivotal role of the β7 strand in the intersubunit contacts of different human small heat shock proteins

Human αB-crystallin and small heat shock proteins HspB6 and HspB8 were mutated so that all endogenous Cys residues were replaced by Ser and the single Cys residue was inserted in a position homologous to that of Cys137 of human HspB1, i.e. in a position presumably located in the central part of β7 strand of the α-crystallin domain. The secondary, tertiary, and quaternary structures of thus obtained Cys-mutants as well as their chaperone-like activity were similar to those of their wild-type counterparts. Mild oxidation of Cys-mutants leads to formation of disulfide bond crosslinking neighboring monomers thus indicating participation of the β7 strand in intersubunit interaction. Oxidation weakly affects the secondary and tertiary structure, does not affect the quaternary structure of αB-crystallin and HspB6, and shifts equilibrium between monomer and dimer of HspB8 towards dimer formation. It is concluded that the β7 strand participates in the intersubunit interaction of four human small heat shock proteins (αB-crystallin, HspB1, HspB6, HspB8) having different structure of β2 strand of α-crystallin domain and different length and composition of variable N- and C-terminal tails