Apparent Stability Research Articles

Carbodiimide‐mediated grafting of caffeic acid on chitosan to improve its physicochemical and biological properties: used for Pompano (Trachinotus ovatus) preservation

SummaryChitosan‐grafted caffeic acid (CS‐g‐CA) was successfully prepared using carbodiimide‐based chemical coupling method. The results of UV–vis and FT‐MIR showed that caffeic acid (CA) was successfully grafted onto chitosan (CS). The grafting degree of CA in CS determined by Folin–Ciocalteu scheme was up to 91.26 ± 2.58 mg g−1. Compared with CS solution, CS‐g‐CA solution has lower apparent viscosity and thermal stability. The results of SEM demonstrated that the grafting treatment changed the microstructure of CS. The grafting of the CA on CS enhanced its antioxidant activity. It can be seen that the clearance rate of DPPH (82.52% ± 0.7%), ABTS+ free radicals (88.21% ± 0.26%), T‐AOC (94.91% ± 0.21%) and FRAP (13.51 ± 0.52 mmol L−1 FeSO4) of CS‐g‐CA was similar to ascorbic acid at 2.0 mg mL−1. The results of antibacterial experiments demonstrated that CS‐g‐CA had better antibacterial ability in vitro, and the diameter of inhibition zone of 20.0 mg mL−1 CS‐g‐CA against Pseudomonas fluorescens and Staphylococcus saprophyticus was 16.88 ± 0.05 mm and 19.17 ± 0.09 mm, respectively, and it was significantly higher than CS (11.25 ± 0.04 mm and 13.09 ± 0.07 mm). The texture and freshness of Control group and CS rapidly declines post‐mortem. CS‐g‐CA treatment could effectively retard the deterioration of texture and keep the better quality of Pompanos (Trachinotus ovatus). This study indicates that grafting CA onto CS alters the biological activity and physicochemical properties of CS.

Improvement of the Mechanical Properties of Mortars Manufactured with Partial Substitution of Portland Cement by Kaolinitic Clays

Presently, the search for urgent solutions to mitigate climate change has become a global priority. One of the most important challenges is the characterization, standardization, and technology of sustainable natural raw materials, which will significantly improve the quality of common types of cement, the production process of which emits large amounts of greenhouse gases into the atmosphere. This work is focused on the study of natural kaolinitic clays (NKC) from the eastern part of the Iberian Peninsula and its main objective is to define and normalize their properties as natural pozzolanic materials. This research consists of an initial study to determine the morphological and chemical properties using SEM and XRF. Furthermore, the physical properties of the samples were studied, such as thermic treatment (TT), Blane particle finesse (BPF), real density (RD) and apparent density (AD), porosity (P), volume stability (VS) and start and final setting time (SFST). On the other hand, technological analyses were carried out as follows: chemical analysis (CATQ), pozzolanicity (CAP), mechanical compression strength tests at 7, 28, and 90 days (MCST) as well as the ultrasonic pulse velocity (UPV). XRF results indicated that the SiO2 content (49.9–51.0%) of kaolinitic clay in its natural state (NKC) increases to 57.41 and 58.10%, respectively, when calcined (CKC). The chemical analysis of pozzolanicity established that the NKC does not show pozzolanic activity during the first 8 and 15 days; however, once calcinated, its pozzolanic reactivity increases substantially. On the other hand, the results of the mechanical stress tests (MCST) indicate an exponential increase in mechanical resistance from 7 to 90 days, which is higher in mortars made with CKC; similarly, and according to the results of the calculation of the Resistant Activity Index (RAI), it shows that the substitutions of Portland cement (PC) by NKC are effective between the ranges of 10 and 25%, while in the case of the substitution of PC by CKC, all formulations (10, 25 and 40%) are effective. This research establishes that the kaolinitic clays of the east of the Iberian Peninsula can be considered quality pozzolanic materials, capable of partially replacing Portland cement. The results presented here could be used as guidelines for the understanding and application of natural pozzolanic materials contributing to the improvement of types of cement, mortars, and concretes, which would positively affect the quality and preservation of the environment as well as the sustainability of eco-efficient construction materials.

Hydration effects of insoluble soybean fiber (ISF) on rheological properties and freeze-thaw stability of ISF concentrated emulsions.

Concentrated emulsions have been formulated in many foods. The insoluble soybean fiber (ISF) can be utilized as a particle to stabilize concentrated emulsions. However, the approach to control the rheological properties and stability of the ISF concentrated emulsions is still worth investigating. In this study, alkali-extracted ISF was hydrated by adding sodium chloride or heating and the prepared concentrated emulsions were subjected to freeze-thawing. Compared with the original hydration method, salinization reduced the absolute ζ-potential of the ISF dispersions to 6 mV, resulting in a lower absolute ζ-potential of the concentrated emulsions, which led to a decreased electrostatic repulsion and the largest droplet size, but to the lowest apparent viscosity, viscoelastic modulus, and stability. By contrast, hydration by heating promoted the interparticle interactions, and then a decreased droplet size (54.5 μm) but with a more densely distributed droplets was observed, together with enhanced viscosity and viscoelasticity properties. The fortified network structure improved the stability of the concentrated emulsions both against high-speed centrifugation and long-term storage. Additionally, secondary emulsification after freeze-thaw further improved the performance of the concentrated emulsions. The results suggest that the formation and stability of the concentrated emulsion could be regulated by different hydration methods of particles, which could be adjusted according to the practical applications. © 2023 Society of Chemical Industry.

Spatiotemporal bayesian modelling of scorpionism and its risk factors in the state of São Paulo, Brazil.

Scorpion stings in Brazil represent a major public health problem due to their incidence and their potential ability to lead to severe and often fatal clinical outcomes. A better understanding of scorpionism determinants is essential for a precise comprehension of accident dynamics and to guide public policy. Our study is the first to model the spatio-temporal variability of scorpionism across municipalities in São Paulo (SP) and to investigate its relationship with demographic, socioeconomic, environmental, and climatic variables. This ecological study analyzed secondary data on scorpion envenomation in SP from 2008 to 2021, using the Integrated Nested Laplace Approximation (INLA) to perform Bayesian inference for detection of areas and periods with the most suitable conditions for scorpionism. From the spring of 2008 to 2021, the relative risk (RR) increased eight times in SP, from 0.47 (95%CI 0.43-0.51) to 3.57 (95%CI 3.36-3.78), although there has been an apparent stabilization since 2019. The western, northern, and northwestern parts of SP showed higher risks; overall, there was a 13% decrease in scorpionism during winters. Among the covariates considered, an increase of one standard deviation in the Gini index, which captures income inequality, was associated with a 11% increase in scorpion envenomation. Maximum temperatures were also associated with scorpionism, with risks doubling for temperatures above 36°C. Relative humidity displayed a nonlinear association, with a 50% increase in risk for 30-32% humidity and reached a minimum of 0.63 RR for 75-76% humidity. Higher temperatures, lower humidity, and social inequalities were associated with a higher risk of scorpionism in SP municipalities. By capturing local and temporal relationships across space and time, authorities can design more effective strategies that adhere to local and temporal considerations.

Physicochemical characterization, solubility enhancement, molecular docking, and antibacterial activity of inclusion complexes of naproxen/β-cyclodextrin derivatives: A comparative study

Naproxen (NAP) is a nonsteroidal anti-inflammatory drug. The aim of this work is to enhance the aqueous solubility and dissolution rate of naproxen (NAP) by forming an inclusion complex with β-cyclodextrin derivatives (β-CDs) such as 2-hydroxypropyl-β-cyclodextrin (Hβ-CD), methyl-β-cyclodextrin (Mβ-CD), and sulfated-β-cyclodextrin (Sβ-CD). UV–vis and fluorescence spectroscopic techniques were applied to examine the interaction of the β-CDs:NAP inclusion complexes in pH 7.4 buffer solution. The 1:1 stoichiometry of the β-CDs:NAP inclusion complexes was confirmed by the Benesi-Hildebrand method. The solid-state β-CDs:NAP inclusion complexes were obtained by co-precipitation and were characterized by FTIR, XRD, SEM, and TGA-DSC analyses. Phase solubility diagrams were calculated linearly from the slope and intercept, where the maximum apparent stability constants (Ks) were found to be 1123, 1261, and 1131 M−1 for Hβ-CD, Mβ-CD, and Sβ-CD respectively, indicating formation of the β-CDs:NAP inclusion complexes. Molecular docking was used to systematically validate formation of the β-CDs:NAP inclusion complexes. The antibacterial activity of the β-CDs:NAP inclusion complexes was described here for the first time, and it was shown that the activity of NAP against Staphylococcus aureus (91 ± 0.12%) and Escherichia coli (87 ± 0.14%) was remarkably enhanced by encapsulation in the β-cyclodextrin derivatives. The prepared solid β-CDs:NAP inclusion complexes are highly stable in aqueous media, where the antibacterial activity can be enhanced by increasing the solubility of NAP.

Insight into effect of pigment removal on leaf protein-based bionanocomposite film properties

Capsicum and alfalfa leaves contain numerous leaf proteins (LP) and cellulose resources, making them excellent raw materials for preparing protein-based bionanocomposites films (PBBFs). However, the pigment in LP leads to PBBFs with low light transmission, which limits their application in food packaging. Bleaching can remove pigments; however, its effect on LP and PBBFs remains unknown. This study investigates the effects of pigment removal on the physicochemical and material properties of PBBFs in three dimensions: raw materials, film-forming liquids (FFLs), and PBBFs. The results showed that pigment removal significantly reduced the lignin content of LP, while altering their amino acid composition and thermal properties. The apparent viscosity and stability of FFLs decreased after pigment removal. The PBBF microstructure also changed. The mechanical properties and water sensitivity of PBBFs decreased slightly after pigment removal. This was related to the strength of the hydrogen bonding interactions between the LP and cellulose nanofibers (CNFs), and also to the conformation of the protein and the degree of amino acid exposure within the PBBFs. Pigment removal significantly improved PBBF chromaticity values and light transmission. PBBFs block UV radiation before and after pigment removal and can be used for photochemically sensitive food packaging.

Homelessness In Delaware:: An Assessment.

The authors provide an assessment of trends and dynamics of homelessness in Delaware since 2007, when the last systematic study of this topic was released. Using population data on homelessness in the state, the authors present evidence that, after a period of apparent stability, homelessness in Delaware is currently at levels that are unprecedentedly high, while providers of homeless services have not adapted to this change. As a first step to addressing this alarming trend, the authors call for stakeholders to regroup and develop a coordinated, statewide approach to address this problem.

Significant Microbial Changes Are Evident in the Reproductive Tract of Pregnant Rhesus Monkeys at Mid-Gestation but Their Gut Microbiome Does Not Shift until Late Gestation.

Vaginal and rectal specimens were obtained from cycling, pregnant, and nursing rhesus monkeys to assess pregnancy-related changes in the commensal bacteria in their reproductive and intestinal tracts. Using 16S rRNA gene amplicon sequencing, significant differences were found only in the vagina at mid-gestation, not in the hindgut. To verify the apparent stability in gut bacterial composition at mid-gestation, the experiment was repeated with additional monkeys, and similar results were found with both 16S rRNA gene amplicon and metagenomic sequencing. A follow-up study investigated if bacterial changes in the hindgut might occur later in pregnancy. Gravid females were assessed closer to term and compared to nonpregnant females. By late pregnancy, significant differences in bacterial composition, including an increased abundance of 4 species of Lactobacillus and Bifidobacterium adolescentis, were detected, but without a shift in the overall community structure. Progesterone levels were assessed as a possible hormone mediator of bacterial change. The relative abundance of only some taxa (e.g., Bifidobacteriaceae) were specifically associated with progesterone. In summary, pregnancy changes the microbial profiles in monkeys, but the bacterial diversity in their lower reproductive tract is different from women, and the composition of their intestinal symbionts remains stable until late gestation when several Firmicutes become more prominent.

Survival rates in the world's southernmost forest bird community.

The Magellanic sub-Antarctic Forest is home to the world's southernmost avian community and is the only Southern Hemisphere analogue to Northern Hemisphere temperate forests at this latitude. This region is considered among the few remaining pristine areas of the world, and shifts in environmental conditions are predominantly driven by climate variability. Thus, understanding climate-driven demographic processes is critical for addressing conservation issues in this system under future climate change scenarios. Here, we describe annual survival patterns and their association with climate variables using a 20-year mark-recapture data set of five forest bird species in the Cape Horn Biosphere Reserve. We develop a multispecies hierarchical survival model to jointly explore age-dependent survival probabilities at the community and species levels in a group of five forest passerines. At the community level, we assess the association of migratory behavior and body size with survival, and at the species level, we investigate the influence of local and regional climatic variables on temporal variations of survival. We found a positive effect of precipitation and a negative effect of El Niño Southern Oscillation on juvenile survival in the white-crested Elaenia and a consistent but uncertain negative effect of temperature on survival in juveniles and 80% of adults. We found only a weak association of climate variables with survival across species in the community and no temporal trends in survival for any of the species in either age class, highlighting apparent stability in these high austral latitude forests. Finally, our findings provide an important resource of survival probabilities, a necessary input for assessing potential impacts of global climate change in this unique region of the world.

Enhancement of Valsartan Oral Bioavailability by Preparing a Microwave-Irradiated Inclusion Complex with Sulfobutyl Etherβ-Cyclodextrin Using a Central Composite Face Design for Optimising Process Parameters.

The purpose of the study is to investigate the influence of sulfobutyl ether β-cyclodextrin (SBE7-β-CD) on the bioavailability of valsartan. Phase solubility investigations showed an AL type curve. The estimated apparent stability constant for valsartan SBE7-β-CD is 427 ± 0.32M-1. Inclusion complexes of valsartan SBE7-β-CD in equal molar ratio were prepared by microwave irradiation technique. The process parameters were optimised with a central composite face design. Response surface graphs and contour plots showed how process factors affected drug content. The inclusion complexes prepared by optimising process variables are characterised. The DSC and X-ray diffraction confirm the formation of inclusion complexes and the drug's transition from a crystalline to an amorphous state. FTIR suggests hydrogen bonding between valsartan and SBE7-β-CD. SEM showed changes in drug morphology and shape. The dissolution rate of the prepared SBE7-β-CD complex using microwave irradiation was 2.85 times that of pure valsartan. The inclusion complex was formulated into tablet dosage forms F1 to F4. Furthermore, oral bioavailability studies in rats with tablet formulation F3 were carried out and compared to the marketed Diovan® tablet as a reference standard. The F3 tablet formulation exhibited significantly higher values of AUC0-∞ and Cmax than the reference. Finally, the microwave-irradiated valsartan SBE7-β-CD inclusion complex converted into tablet dosage form may be a promising approach to increasing valsartan oral bioavailability.

Tristhiolato Pseudopeptides Bind Arsenic(III) in an AsS3 Coordination Environment Imitating Metalloid Binding Sites in Proteins.

The AsIII binding of two NTA-based tripodal pseudopeptides, possessing three cysteine (ligand L1) or d-penicillamine residues (ligand L2) as potential coordinating groups for soft semimetals or metal ions, was studied by experimental (UV, CD, NMR, and ESI-MS) and theoretical (DFT) methods. All of the experimental data, obtained with the variation of the AsIII:ligand concentration ratios or pH values in some instances, evidence the exclusive formation of species with an AsS3-type coordination mode. The UV-monitored titration of the ligands with arsenous acid at pH = 7.0 provided an absorbance data set that allowed for the determination of apparent stability constants of the forming species. The obtained stabilities (logK' = 5.26 (AsL1) and logK' = 3.04 (AsL2)) reflect high affinities, especially for the sterically less restricted cysteine derivative. DFT calculated structures correlate well with the spectroscopic results and, in line with the 1H NMR data, indicate a preference for the all-endo conformers resembling the AsIII environment at the semimetal binding sites in various metalloproteins.

Enhanced Thermal Stability and Reduced Aggregation in an Antibody Fab Fragment at Elevated Concentrations.

The aggregation of protein therapeutics such as antibodies remains a major challenge in the biopharmaceutical industry. The present study aimed to characterize the impact of the protein concentration on the mechanisms and potential pathways for aggregation, using the antibody Fab fragment A33 as the model protein. Aggregation kinetics were determined for 0.05 to 100 mg/mL Fab A33, at 65 °C. A surprising trend was observed whereby increasing the concentration decreased the relative aggregation rate, ln(v) (% day-1), from 8.5 at 0.05 mg/mL to 4.4 at 100 mg/mL. The absolute aggregation rate (mol L-1 h-1) increased with the concentration following a rate order of approximately 1 up to a concentration of 25 mg/mL. Above this concentration, there was a transition to an apparently negative rate order of -1.1 up to 100 mg/mL. Several potential mechanisms were examined as possible explanations. A greater apparent conformational stability at 100 mg/mL was observed from an increase in the thermal transition midpoint (Tm) by 7-9 °C, relative to those at 1-4 mg/mL. The associated change in unfolding entropy (△Svh) also increased by 14-18% at 25-100 mg/mL, relative to those at 1-4 mg/mL, indicating reduced conformational flexibility in the native ensemble. Addition of Tween or the crowding agents Ficoll and dextran, showed that neither surface adsorption, diffusion limitations nor simple volume crowding affected the aggregation rate. Fitting of kinetic data to a wide range of mechanistic models implied a reversible two-state conformational switch mechanism from aggregation-prone monomers (N*) into non-aggregating native forms (N) at higher concentrations. kD measurements from DLS data also suggested a weak self-attraction while remaining colloidally stable, consistent with macromolecular self-crowding within weakly associated reversible oligomers. Such a model is also consistent with compaction of the native ensemble observed through changes in Tm and △Svh.

Effect of Fluorine Substitution in Li<sub>3</sub>YCl<sub>6</sub> Chloride Solid Electrolytes for All-solid-state Battery

All-solid-state batteries experience irreversible capacity loss particularly in the initial potential cycle, owing to electrolyte decomposition at the electrode/electrolyte interface. A strategy for expanding the oxidation stability of electrolytes is replacing the anion with fluorine. However, fluorine substitution has a negative influence on ionic conductivity. In this study, we introduced trace amounts of fluorine into Li3YCl6 solid electrolytes which exhibit high ionic conductivities and wide potential windows. The effect of replacement on ionic conductivity, oxidation stability, and charge–discharge characteristics were studied. The trace amounts of fluorine in Li3YCl6 did not reduce the conductivity, but improved the apparent oxidation stability. The decomposed product of LiF from the fluorine-substituted electrolyte disturbed the formation of a high-resistance layer at the electrode/electrolyte interface. The initial charge–discharge efficiency of the uncoated LiCoO2 cathode was improved by the trace amount of fluorine replacement in the Li3YCl6 solid electrolyte.

Optimization of Patient Pathway in Heart Failure with Reduced Ejection Fraction and Worsening Heart Failure. Role of Vericiguat.

Heart failure (HF) is a progressive condition with periods of apparent stability and repeated worsening HF events. Over time, unless optimization of HF treatment, worsening HF events become more frequent and patients enter into a cycle of recurrent events with high morbidity and mortality. In patients with HF there is an activation of deleterious neurohormonal pathways, such as the renin angiotensin aldosterone system and the sympathetic system, and an inhibition of protective pathways, including natriuretic peptides and guanylate cyclase. Therefore, HF burden can be reduced only through a holistic approach that targets all neurohormonal systems. In this context, vericiguat may play a key role, as it is the only HF drug that activates the nitric oxide-soluble guanylate cyclase-cyclic guanosine monophosphate system. On the other hand, it has been described relevant disparities in the management of HF population. Consequently, it is necessary to homogenize the management of these patients, through an integrated patient-care pathway that should be adapted at the local level. In this context, the development of new technologies (ie, video call, specific platforms, remote control devices, etc.) may be very helpful. In this manuscript, a multidisciplinary group of experts analyzed the current evidence and shared their own experience to provide some recommendations about the therapeutic optimization of patients with recent worsening HF, with a particular focus on vericiguat, and also about how the integrated patient-care pathway should be performed.

Status and Distribution of Freshwater Mussels in the Louisiana Section of Bayou Bartholomew

As a major tributary to the species-rich Ouachita River and one of the few remaining non-channelized rivers in the Alluvial Plains physiographic division, Bayou Bartholomew is a key ecosystem for the freshwater mussel diversity of southeast Arkansas and northeast Louisiana. Bayou Bartholomew is known to contain 16 mussel Species of Greatest Conservation Need (SGCN) but the mussel assemblage of the Louisiana section of Bayou Bartholomew has not been assessed since the early 2000s. In 2021, we sampled over 100 river km on the main channel of Bayou Bartholomew and four tributaries from just downstream of the Louisiana/Arkansas border to the confluence with the Ouachita River. We used a novel two-phase timed-search protocol to characterize the mussel assemblage and measured shell length (long axis) to determine the size distribution of each species encountered. A suite of relevant habitat variables and site attributes were also quantified or qualitatively noted. One site was selected for sampling using a grid survey to determine quantitative estimates of mussel density. Our survey confirmed the presence of 35 species including 12 SGCN in the Louisiana section of the Bayou Bartholomew drainage. In total, 3,292 live mussels representing 33 species were collected in the main channel, 234 live mussels representing 18 species were found in a quantitative grid, and four species were found in tributaries. Two additional species were only found in tributaries as dead shells. Length frequencies of all common and abundant species indicated ongoing annual recruitment. Patterns of ubiquity in the main channel of Bayou Bartholomew varied by species, and mussels were rare in the tributaries. Generalized linear modelling and non-metric multidimensional scaling analyses identified relationships between mussel assemblage composition and the distance from the confluence with the Ouachita River and habitat variables including substrates, depth, and mesohabitat types. A comparison with previous studies did not provide any evidence of major changes in overall mussel species distributions or occurrence in Bayou Bartholomew in Louisiana. We attribute the apparent stability in the mussel assemblage to the fact that major anthropogenic alterations such as channelization, impoundments, and watershed urbanization have been minimal since the earlier studies, and we conclude that Bayou Bartholomew will likely continue to be a hotspot of regional mussel diversity and a haven for several of Louisiana's SGCN if large-scale anthropogenic alterations to the system do not occur and management actions are taken to protect and allow for the persistence of heterogenous habitats.

Biochemical and biophysical properties of a recombinant serine peptidase from Purpureocillium lilacinum

The industrial uses of peptidases have already been consolidated; however, their range of applications is increasing. Thus, the biochemical characterization of new peptidases could increase the range of their biotechnological applications. In silico analysis identified a gene encoding a putative serine peptidase from Purpureocillium lilacinum (Pl_SerPep), annotated as a cuticle-degrading enzyme. The Pl_SerPep gene product was expressed as a recombinant in a Komagataella phaffii (previously Pichia pastoris) expression system. The enzyme (rPl_SerPep) showed optimal pH and temperature of 8.0 and 60 °C, respectively. Moreover, rPl_SerPep has a higher thermal stability than the cuticle-degrading enzymes described elsewhere. The structural analysis indicated a conformational change in the rPl_SerPep secondary structure, which would allow an increase in catalytic activity at 60 °C. Komagataella phaffii secretes rPl_SerPep with the pro peptide in its inactive form. Low-resolution small-angle X-ray scattering (SAXS) analysis showed little mobility of the pro peptide portion, which indicates the apparent stability of the inactive form of the enzyme. The presence of 20 mM guanidine in the reaction resulted in the maintenance of activity, which was apparently a consequence of pro peptide structure flexibilization.

Assessment of Accuracy in Unmanned Aerial Vehicle (UAV) Pose Estimation with the REAL-Time Kinematic (RTK) Method on the Example of DJI Matrice 300 RTK.

The growing possibilities offered by unmanned aerial vehicles (UAV) in many areas of life, in particular in automatic data acquisition, spur the search for new methods to improve the accuracy and effectiveness of the acquired information. This study was undertaken on the assumption that modern navigation receivers equipped with real-time kinematic positioning software and integrated with UAVs can considerably improve the accuracy of photogrammetric measurements. The research hypothesis was verified during field measurements with the use of a popular Enterprise series drone. The problems associated with accurate UAV pose estimation were identified. The main aim of the study was to perform a qualitative assessment of the pose estimation accuracy of a UAV equipped with a GNSS RTK receiver. A test procedure comprising three field experiments was designed to achieve the above research goal: an analysis of the stability of absolute pose estimation when the UAV is hovering over a point, and analyses of UAV pose estimation during flight along a predefined trajectory and during continuous flight without waypoints. The tests were conducted in a designated research area. The results were verified based on direct tachometric measurements. The qualitative assessment was performed with the use of statistical methods. The study demonstrated that in a state of apparent stability, horizontal deviations of around 0.02 m occurred at low altitudes and increased with a rise in altitude. Mission type significantly influences pose estimation accuracy over waypoints. The results were used to verify the accuracy of the UAV's pose estimation and to identify factors that affect the pose estimation accuracy of an UAV equipped with a GNSS RTK receiver. The present findings provide valuable input for developing a new method to improve the accuracy of measurements performed with the use of UAVs.

Nascent-chain interaction networks and their effect on the bacterial ribosome.

In order to become bioactive, proteins need to be biosynthesized and protected from aggregation during translation. Remarkably, the ribosome contributes to both of these tasks. Some ribosomal proteins (r-proteins) are known to noncovalently interact with ribosome-bound nascent chains (RNCs). Yet, specific interaction networks and their role within the ribosomal machinery remain poorly characterized. Here, we found that empty ribosomes are more sensitive to urea denaturation than ribosomes harboring nascent protein chains, including aminoacyl or short peptidyl-tRNA (snc-tRNA). This result suggests that snc-tRNAs play a ribosome-stabilizing role. On the other hand, RNCs of variable sequence and length do not significantly modify the apparent stability of the peptidyl-transferase center (PTC) and r-proteins, suggesting that RNC/r-protein interaction networks close to the PTC have a negligible effect on the apparent ribosome stability. Fluorescence anisotropy decay, chemical-crosslinking and Western blots show that 140-residue-long RNCs of the foldable protein apoHmp have an N-terminal compact region (63-94 residues) and interact with r-protein L23 but not with L24 or L29. Longer RNCs bear a similar compact region and interact either with L23 or with L23 and another unidentified r-protein or with molecular chaperones. Interestingly, the apparent stability of RNC/r-protein complexes does not depend on RNC sequence or length. Taken together, our findings show that RNCs establish preferential interactions with the L23 ribosomal protein whose strength does not depend on RNC amino-acid sequence and length. As the nascent chain elongates, the interaction network extends to additional r-proteins and chaperones. It follows that the ribosome provides uniform, indiscriminate support to nascent proteins regardless of their sequence and foldability. This result highlights the mode of action of this unbiased molecular machine for cellular health.

Growing Income-Related Disparities in Cardiovascular Hospitalizations Among People With Diabetes, 1995-2019: A Population-Based Study.

Cardiovascular risk reduction is an important focus in the management of people with diabetes. Although event rates have been declining over the long term, they have been observed to plateau or reverse in recent years. Furthermore, the impact of income-related disparities in cardiovascular events is unknown. The objective of this study is to evaluate age-, sex-, and income-related trends in cardiovascular hospitalization rates among people with diagnosed diabetes. We calculated rates of hospitalization for acute myocardial infarction, stroke, heart failure, and lower-extremity amputation in annual cohorts of the entire population of Ontario, Canada, with diagnosed diabetes, from 1995 to 2019. Event rates were stratified by age, sex, and income level. We studied nearly 1.7 million people with diabetes. The rate of acute myocardial infarction declined throughout the 25-year study period (P < 0.0001), such that the rate in 2019 was less than half the rate in 1995. Rates of stroke (P < 0.0001), heart failure (P < 0.0001), and amputation (P < 0.0001) also changed over time, but hospitalization rates stabilized through the 2010s. This apparent stabilization concealed a growing income-related disparity: wealthier patients showed continued declines in rates of these outcomes during the decade, whereas rates for lower-income patients increased (P for interaction < 0.0001 for all four outcomes). During a quarter-century of follow-up, cardiovascular hospitalization rates among people with diabetes fell. However, the apparent stabilization in rates of stroke, heart failure, and amputation in recent years masks the fact that rates have risen for lower-income individuals.

Deciphering the interactions of genistein with β-cyclodextrin derivatives through experimental and microsecond timescale umbrella sampling simulations

Genistein (GEN), an isoflavone, exhibits wide array of biological activities such as antioxidant, anti-inflammatory, cardioprotective and neuroprotective effects. However, despite of tremendous biological activities, its incorporation into functional foods and food supplements is limited due to its low aqueous solubility and instability. The present investigation unveils the molecular mechanism of inclusion of GEN inside the cyclodextrins (CDs) cavities with special emphasis on the correlation of experimental methods with molecular dynamics (MD) simulations. Herein, host – guest inclusion complexes (ICs) of GEN with two modified forms of β-cyclodextrins [Methyl-β-cyclodextrin (M-β-CD) & Hydroxypropyl-β-cyclodextrin (HP-β-CD)] were prepared using spray-drying to improve the aqueous solubility and the apparent stability of GEN. The ICs were characterized by fourier transform infra-red (FT-IR) spectroscopy, powder X-ray diffractometry (PXRD), scanning electron microscopy (SEM) and nuclear magnetic resonance spectroscopy (1H NMR and 2D-NOESY) providing appropriate evidences of the inclusion of GEN inside host cavities (CDs). The results of MD simulations demonstrated multiple conformations obtaining energy minimas of GEN/M-β-CD, whereas GEN/HP-β-CD only showed a single metastable structure. The results were further complemented by enhanced umbrella sampling simulations where GEN/M-β-CD demonstrated lower free energy of binding than GEN/HP-β-CD. Overall, this study presents basic mechanism behind GEN/CD inclusion complexes formation using experimental and computational approaches.