Analysis Of Distribution Research Articles

Characterization of Corticotropin-releasing Hormone Receptors (CRHRs) and Binding Proteins (CRHBPs) in Nile Tilapia: Molecular Identification, Functional Analysis and Tissue Distribution

Corticotropin-releasing hormone (CRH) mediates various physiological/pathological roles such as stress and reproduction in vertebrates by specifically activating its receptors (CRHRs), and the regulation is intricately intertwined with the CRH binding protein (CRHBP). Although numerous research on mammalian CRHRs and CRHBP has been conducted, reports regarding the teleost CRHRs and CRHBP are limited. Herein, using Nile tilapia (ti-) as a model, we conducted the characterization, functional analysis, and examination of tissue distribution of tiCRHRs and tiCRHBPs. Our study showed that: (1) tiCRHR1a, tiCRHR1b and tiCRHR2 encoded proteins of 432, 436 and 414 amino acids (-aa), while tiCRHBP1 and tiCRHBP2 were predicated to generate a 323- and 322-aa precursor respectively; (2) All tiCRHRs could be activated by tiCRH and subsequently coupled to cAMP/PKA signaling pathways, while only tiCRHR1a and tiCRHR1b could trigger MAPK/ERK signaling cascade; (3) tiCRHBP1 and tiCRHBP2 could does-dependently suppress tiCRH-upregulated luciferase activity in HEK293 cells expressing tiCRHRs; (4) All tiCRHRs mRNA were considerably detected in the central nervous system (CNS), but they exhibited distinct expression pattern in examined peripheral tissues; (5) tiCRHBP1 exhibited an exclusive expression pattern in the pituitary, whereas tiCRHBP2 mRNA was abundantly expressed in the telencephalon. Collectively, our data will help to facilitate a better understanding of the members and functions of CRHRs and CRHBP in teleost.

Neurokinin B in the yellowtail kingfish (Seriola lalandi) and its potential role in controlling reproduction

The neurokinin B (NKB) system acts as a crucial modulator in the regulation of reproduction and feeding in mammals, however limited information is available in teleosts regarding its potential role in reproductive functions. Herein, we have identified its encoding gene, namely tachykinin 3 (tac3), in the yellowtail kingfish. The full-length tac3 cDNA sequence was 372bp in size and encoded a 123-aa preprohormone, including two mature peptides, NKB and NKF. Tissue distribution analysis showed that tac3 was primarily expressed in the intestine of yellowtail kingfish. During embryonic development, the highest mRNA levels of tac3 were observed at stage 4 (16-cell) and stage 14 (newly-hatched larva). The peak of tac3 transcript levels was also noticed at 30 days post-hatching during early ontogeny. The physiological effects of NKB and NKF on expression of brain and pituitary genes along with plasma hormones levels were further analyzed by intraperitoneal injection. NKB exerted a stimulatory effect on gnrh1, gnrh2, gnih, and kiss2r mRNA levels, but suppressed kiss1r, gnihr, gal, gh, lhβ, and fshβ mRNA levels. An evident increase was observed on transcript levels of gnrh1, gnrh2, kiss1, kiss2, gnih, and gnihr after NKF treatment, whereas kiss1r, kiss2r, gh, lhβ, and fshβ mRNA levels were down-regulated. Moreover, NKF, but not NKB, reduced serum estradiol levels, and both of these two peptides suppressed serum 11-keto testosterone levels. Taken together, our results provide preliminary evidence that the NKB system participates in the control of reproduction in yellowtail kingfish via acting on brain, pituitary and gonadal hormones.

Genetic Characterization and Population Structure of Drug-Resistant Mycobacterium tuberculosis Isolated from Brazilian Patients Using Whole-Genome Sequencing

The present study aimed to determine the genetic diversity of isolates of Mycobacterium tuberculosis (Mtb) from presumed drug-resistant tuberculosis patients from several states of Brazil. The isolates had been submitted to conventional drug susceptibility testing for first- and second-line drugs. Multidrug-resistant (MDR-TB) (54.8%) was the most frequent phenotypic resistance profile, in addition to an important high frequency of pre-extensive resistance (p-XDR-TB) (9.2%). Using whole-genome sequencing (WGS), we characterized 298 Mtb isolates from Brazil. Besides the analysis of genotype distribution and possible correlations between molecular and clinical data, we determined the performance of an in-house WGS pipeline with other online pipelines for Mtb lineages and drug resistance profile definitions. Sub-lineage 4.3 (52%) was the most frequent genotype, and the genomic approach revealed a p-XDR-TB level of 22.5%. We detected twenty novel mutations in three resistance genes, and six of these were observed in eight phenotypically resistant isolates. A cluster analysis of 170 isolates showed that 43.5% of the TB patients belonged to 24 genomic clusters, suggesting considerable ongoing transmission of DR-TB, including two interstate transmissions. The in-house WGS pipeline showed the best overall performance in drug resistance prediction, presenting the best accuracy values for five of the nine drugs tested. Significant associations were observed between suffering from fatal disease and genotypic p-XDR-TB (p = 0.03) and either phenotypic (p = 0.006) or genotypic (p = 0.0007) ethambutol resistance. The use of WGS analysis improved our understanding of the population structure of MTBC in Brazil and the genetic and clinical data correlations and demonstrated its utility for surveillance efforts regarding the spread of DR-TB, hopefully helping to avoid the emergence of even more resistant strains and to reduce TB incidence and mortality rates.

Tick distribution and comparative analysis of bovine blood microbiome in two provinces of South Africa using 16S rRNA PacBio sequencing approach

IntroductionTicks are obligate ectoparasites recognized worldwide as major vectors of several disease-causing pathogens and are good indicators of disease distribution and epidemiology. Recent years have seen a growing concern regarding emerging and re-emerging of economically important tick-borne pathogens of livestock and humans worldwide. The overall objective of the study was to give an insight into current tick distribution and associated bacterial pathogens that may pose a threat to cattle in the sampled study sites.MethodsA total of 150 cattle were randomly selected from three study sites, Harrismith and Phuthaditjhaba in Free State Province and Bergville in KwaZulu Natal Province, South Africa. Blood samples were collected from the cattle and DNA was subjected to the 16S rRNA gene microbiome sequencing on the circular consensus PacBio sequencing platform. Ticks were also collected from various predilection sites of the sampled animals.ResultsA total of eight tick species were identified and Rhipicephalus evertsi evertsi (79.4%) was the most abundant followed by R. appendiculatus (11.7%), R. afranicus (2.6%), R. simus (2.6%), Hyalomma rufipes (1.2%), R. decoloratus (1.0%), H. truncatum (0.7%) and R. microplus (0.7%). The bacterial microbiome sequence analysis revealed up to 16 phyla and 30 classes in the three study sites. Proteobacteria was the most dominant bacterial phyla with a relative abundance of 67.2% (Bergville), 73.8% (Harrismith) and 84.8% (Phuthaditjhaba), followed by Firmicutes at 9.6% (Phuthaditjhaba), 18.9% (Bergville) and 19.6% (Harrismith).Conclusion and perspectivesThe Chao 1 index estimator revealed significant differences in the α-diversity of microbial communities among three study sites. This study expands the knowledge on tick fauna and microbial communities in the three study sites.

Consensus holistic virtual screening for drug discovery: a novel machine learning model approach

In drug discovery, virtual screening is crucial for identifying potential hit compounds. This study aims to present a novel pipeline that employs machine learning models that amalgamates various conventional screening methods. A diverse array of protein targets was selected, and their corresponding datasets were subjected to active/decoy distribution analysis prior to scoring using four distinct methods: QSAR, Pharmacophore, docking, and 2D shape similarity, which were ultimately integrated into a single consensus score. The fine-tuned machine learning models were ranked using the novel formula “w_new”, consensus scores were calculated, and an enrichment study was performed for each target. Distinctively, consensus scoring outperformed other methods in specific protein targets such as PPARG and DPP4, achieving AUC values of 0.90 and 0.84, respectively. Remarkably, this approach consistently prioritized compounds with higher experimental PIC50 values compared to all other screening methodologies. Moreover, the models demonstrated a range of moderate to high performance in terms of R2 values during external validation. In conclusion, this novel workflow consistently delivered superior results, emphasizing the significance of a holistic approach in drug discovery, where both quantitative metrics and active enrichment play pivotal roles in identifying the best virtual screening methodology.Scientific contributionWe presented a novel consensus scoring workflow in virtual screening, merging diverse methods for enhanced compound selection. We also introduced ‘w_new’, a groundbreaking metric that intricately refines machine learning model rankings by weighing various model-specific parameters, revolutionizing their efficacy in drug discovery in addition to other domains.Graphical

Contributions to our knowledge on avian louse flies (Hippoboscidae: Ornithomyinae) with the first European record of the African species Ornithoctona laticornis

BackgroundLouse flies (Diptera, Hippoboscidae) are important blood-sucking parasites of birds and mammals with a worldwide distribution. The aim of our study was to collect louse flies from birds across multiple sites in Hungary and evaluate the effects of avian traits on louse fly–host relationships.MethodsBetween 2015 and 2022, 237 louse flies were collected from birds at multiple locations in Hungary. The louse flies were identified to species level by morphological and molecular methods. Louse fly species and their seasonal dynamics were analyzed.ResultsSix louse fly species were identified: Ornithomya avicularia, Ornithomya fringillina, Ornithomya biloba, Ornithomya chloropus, Ornithoica turdi and Ornithoctona laticornis. Results of statistical analyses indicated that habitat, migration habits and the feeding places of birds have significant effects on their possible role as hosts of O. avicularia, O. fringillina and O. turdi. Analysis of the temporal distribution of avian louse flies showed different seasonal patterns according to species. Phylogenetic analyses highlighted that O. turdi clustered separately from other members of the subfamily Ornithomyinae which thus did not form a monophyletic group.ConclusionsThis study presents one of the longest continuous collections of ornithophilic louse fly species in Europe so far. Avian traits were shown to influence louse-fly infestation. To our best knowledge, this is the first report on O. laticornis in Europe. The ability of this African louse fly species to survive in Europe, as demonstrated in the present study, may be an indication of its future establishment. Our findings, in accordance with previous reports, also indicated that the subfamily Ornithomyinae should be taxonomically revised.Graphical

Illumination matters part I: comparative analysis of light sources and illumination in flexible ureteroscopy-fundamental findings from a PEARLS analysis

PurposeIllumination characteristics of flexible ureteroscopes have been evaluated in air, but not in saline, the native operative medium for endourology. The aim was to evaluate light properties of contemporary ureteroscopes in air versus saline, light distribution analysis, and color temperature.MethodsWe evaluated the Storz Flex-Xc and Flex-X2s, Olympus V3 and P7, Pusen 7.5F and 9.2F, and OTU WiScope using a 3D printed black target board in-vitro model submerged in saline. A spectrometer was used for lux and color temperature measurements at different opening locations.ResultsIlluminance was higher in saline compared to air (5679 vs. 5205 lx with Flex-Xc, p = 0.02). Illuminance in saline differed between ureteroscopes (ANOVA p < 0.001), with highest for the Flex-Xc at 100% brightness setting (5679 lx), followed by Pusen 9.2F (5280 lx), Flex-X2s (4613 lx), P7 (4371 lx), V3 (2374 lx), WiScope (582 lx) and finally Pusen 7.5F (255 lx). The same ranking was found at 50% brightness setting, with the highest ureteroscope illuminance value 34 times that of the scope with lowest illuminance.Most scopes had maximum illuminance off center, with skewness. Three scopes had two light sources, with one light source for all other scopes. Inter-scope comparisons revealed significant differences of color temperature (ANOVA p < 0.001).ConclusionThe study demonstrates the presence of inhomogeneous light spread as well as large differences in illumination properties of ureteroscopes, possibly impacting on the performance of individual scopes in vivo. Additionally, the study suggests that future studies on illumination characteristics of flexible ureteroscopes should ideally be done in saline, and no longer in air.

Nexus between infrastructural development and economic growth: Evidence from Bangladesh through auto-regressive distributive lag and nonlinear auto regressive distributive lag analysis

This study aims to scrutinize the influence of infrastructure on the economic growth of Bangladesh, employing an extensive time series analysis spanning from 1973 to 2020. Utilizing Principle Component Analysis, two distinct indices were constructed to gauge the dimensions of economic and social infrastructure. Subsequently, Auto-Regressive Distributive Lag (ARDL) and Nonlinear Auto Regressive Distributive Lag (NARDL) bound tests were employed to assess the existence of long-run relationships among the variables under examination. The findings indicate a significant and positive contribution of economic infrastructure to both long and short-term production expansion. Upon further disaggregation into negative and positive shocks, consistent results emerge. An increase (decrease) in the economic infrastructure (EI) index by one unit corresponds to an upsurge (subside) of 0.16% (0.17%) in economic growth. In contrast, social infrastructure (SI) exhibits no significant long-run association with GDP growth. The discerned pattern suggests that EI play a pivotal role in driving aggregate output, while SI display a lag. Despite this, it is imperative to underscore the importance of SI for human development. Consequently, adopting a comprehensive and strategic approach, encompassing vision, ensuring quality inclusivity, and anti-corruption measures, is imperative for Bangladesh to fully realize the transformative potential of its infrastructure investments and foster sustained economic growth.

Development and attestation of a standard sample of calcium nadroparin

Introduction. The widespread use of heparin preparations for the treatment and prevention of venous thromboembolic complications is known. One of the low molecular weight heparin drugs successfully used in clinical practice is calcium nadroparin. The modern approach to assessing the quality of medicines involves the use of standards, in comparison with which the quality control of the drug is carried out – standard samples (SS). The most important specific parameter in assessing the authenticity of low molecular weight heparins is the characteristic of the fractional composition.Aim. The aim of the work was to develop, attestation and determine the stability during the shelf life of a secondary standard sample to determine the authenticity of calcium nadroparin as part of improving the quality control system of the enterprise with the prospect of creating a domestic pharmacopoeia standard sample.Materials and methods. The object of development and attestation was the standard sample of the enterprise – low molecular weight heparin, obtained on the basis of the Technology implementation center of Siberian state medical university. The certified standard sample was obtained by purification of calcium nadroparin by solid-phase extraction. The completeness of the purification was confirmed by comparing the chromatograms of the purified samples with the chromatograms of the international standard sample. The characteristics of the molecular weight distribution were determined chromatographically. The stability of the certified SSE (the standard sample of the enterprise) was studied under two storage conditions – at a temperature below 8 °C in a dry state for 16 months and in solution at –40 °C for 6 months by evaluating trends in molecular weight distribution.Results and discussion. For each batch of the certified standard sample, the molecular weight and molecular weight characteristics are calculated in 2 parallel definitions, and a representative chromatogram is presented. The values of the relative standard deviation of the molecular weight of the samples and the content of the controlled fractions did not exceed 2.5 %. A detailed analysis of the molecular weight distribution showed the "classical" dependence of RSD (relative standard deviation) from the average value with a significant increase up to 30 % for small fraction values (less than 0.5 %). It was found that during 16 months at a storage temperature below 8 ºC, the molecular weight and molecular weight characteristics of standard samples of low molecular weight heparin did not significantly change. However, in the SSE solution at a storage temperature of minus 40 °C for 6 months, they degraded by more than 10 %.Conclusion. According to the results of the study, a protocol has been developed for obtaining a standard sample of low-molecular-weight heparin for the standardization of the calcium nadroparin substance according to the indicator "molecular weight distribution". The established shelf life of the sample is at least 16 months at temperatures below 8 °C. The stability of solutions of the standard sample at a storage temperature of –40 °C for 3 months is shown.

Wearable self-powered ballistic signal detectors with ferroelectric composites arrays for cardiovascular and diabetic complication

Abstract Background Flexible and wearable electronic devices with lightweight are needed to monitor and guide treatment in patients with cardiovascular disease and diabetic complication. We aimed to develop self-powered wearable bio-signal sensing arrays for cardiovascular and diabetic complication diagnosis and continuous monitoring. Methods Ferroelectric composites were designed to have piezoelectric property and high flexibility. Detection of arterial pulse as ballistogram (BCG) was simultaneously compared with electrocardiogram (ECG) in 20 controls. Heart rate and components of ECG was compared with those of BCG. Then, 9 ferroelectric BCG sensors as a square type array with self-power generation were fabricated to attachable thin film. Pressure distribution with BCG sensor array attached to socks were compared between 20 controls and 20 patients with diabetic neuropathy or vasculopathy during standing and ambulation for gait pressure distribution. Pressure distribution pattern was compared to neuropathy and vasculopathy parameters. Results Heart rate between BCG and ECG was significantly correlated (interclass correlation coefficient, ICC 0.99, 95% CI 0.98-0.99, p&amp;lt;0.001). QRS and T wave in ECG were correlated to second and third wave in BCG. Radial artery augmentation index by blood pressure monitoring was significantly correlated to BCG pressure (ICC 0.76, 95% CI 0.38-0.90, p=0.002). Analysis of foot pressure distribution demonstrated the highest pressure point at the anterolateral plantar area below a little tow. However, pressure gradient between anterolateral and anteromedial plantar area in diabetic patients was greater than that in controls (42.3±10.2 mV vs. 31.2±8.5 mV, p=0.024). Pressure gradient in diabetic patients was correlated to ankle-brachial index (ICC 0.62, 95% CI 0.32-0.90, p=0.036), but not to neuropathy parameters. Conclusion Wearable BCG sensor could accurately detect heart rate, blood pressure index and significantly correlated to ABI. Pressure distribution pattern and gradient analysis in diabetic patients by wearable BCG sensor arrays might predict diabetic complications. Gait remedial training guided by wearable BCG sensor arrays might aid to prevent diabetic complications.

Functional characterization of the InR/PI3K/AKT signaling pathway in female reproduction of the predatory bug Cyrtorhinus lividipennis (Hemiptera: Miridae).

The insulin signaling (IIS) pathway plays a key role in the regulation of various physiological functions in animals. However, the involvement of IIS pathway in the reproduction of natural enemy insects remains enigmatic. Here, 3 key genes (named ClInR, ClPI3K, and ClAKT) related to IIS pathway were cloned from Cyrtorhinus lividipennis (Reuter) (Hemiptera: Miridae), an important natural enemy in the rice ecosystem. These 3 proteins had the typical features of corresponding protein families and shared high similarity with their respective homologs from the Hemipteran species. The ClInR, ClPI3K, and ClAKT were highly expressed in the adult stage. Tissue distribution analysis revealed that ClInR, ClPI3K, and ClAKT were highly expressed in the midgut and ovary of adults. Silencing of ClInR, ClPI3K, and ClAKT caused 92.1%, 72.1%, and 57.8% reduction in the expression of ClVg, respectively. Depletion of these 3 genes impaired vitellogenin synthesis and ovary development. Moreover, the fecundity in the dsInR, dsPI3K, and dsAKT injected females were 53.9%, 50.8%, and 48.5% lower than the control treatment, respectively. These results indicated that ClInR, ClPI3K, and ClAKT are of great importance for the reproduction of C. lividipennis. Our results advance the knowledge about the molecular mechanism of reproduction regulation in natural enemy insects.

Numerical analysis of stress distribution in the pressurized composite pipe buried in the soil

In the present research work, a comprehensive study on the stress analysis in the two composite pipes bonded by a layer of DP 410 adhesive and a socket buried in the soil has been performed. The pipe material was considered as a four layers of epoxy-fiber glass with different fiber orientations (cross-ply, angle-ply and quasi-isotropic). The soil dimensions and properties as well as the traffic load (H-20) were based on AASHTO. The simulation of the stress analysis was performed using ANSYS software. In the present study, the influences of bed distance, temperature change, internal pressure, traffic load, fiber orientation angle and layups, and gap distance on stress distribution in the buried composite pipe have been investigated. The findings revealed that the annual temperature change in the soil and the pipe enhances the stresses in the joint components to a maximum value of 5.5 MPa at a pipe temperature of −22 °C. Moreover, the outcomes indicated that the adhesive layer is the most sensitive component to any rise in the load prism, as well as other loads, for a buried pipe at a depth of 120 cm. The maximum and minimum state for von Mises stress component were related to, in turn, quasi-isotropic and angle-ply laminations.

MULTISCALE SLOPE ANALYSIS AND FUNCTIONAL CORRELATION WITH GLOSS REFLECTANCE FROM PHOTOGRAPHIC PAPERS

Abstract A novel multiscale 3D topographic characterization for slope is introduced. Slope is considered as a crucial parameter linking area-scale and 3D curvature analyses. Relationships between surface topography and gloss reflectance in photographic papers are used for an example application. Directional angles, characterizing slopes, are calculated two ways: normals to triangular facets (method 1), and eigenvectors of a covariance matrix based on nine points (method 2). Slope is the steepness of surface inclinations associated with the orientation of local surface features (facets). The impact of slope on gloss reflectance supports the use of pertinent geometric characterizations, i.e., alignment of geometric characterizations with the physical nature of the topographic interaction phenomena. Topographies of 24 photographic papers, were measured with a laser scanning confocal microscope and their gloss reflectance was measured with a micro-TRI-gloss gloss meter. Analyses of slope distributions with bivariate dispersion measures of directional angles and their trigonometric functions revealed strong correlations (R²&gt;0.6) between slope distributions and gloss. Bivariate median deviation of secant or tangent of directional angles, demonstrated consistently high correlations across scales, magnifications, and filtrations. This study supports pertinent and useful characterizations grounded in the physics of topographic interaction phenomena to provide insights into relationships between surface topography, e.g., slope and gloss reflectance in photographic papers. This nuanced understanding has potential applications for other applications as well.

High-Resolution Depth-Discrete Analysis of PFAS Distribution and Leaching for a Vadose-Zone Source at an AFFF-Impacted Site.

The long-term leaching of polyfluoroalkyl substances (PFAS) within the vadose zone of an AFFF application site for which the depth to groundwater is approximately 100 m was investigated by characterizing the vertical distribution of PFAS in a high spatial resolution. The great majority (99%) of PFAS mass resides in the upper 3 m of the vadose zone. The depths to which each PFAS migrated, quantified by moment analysis, is an inverse function of molar volume, demonstrating chromatographic separation. The PFAS were operationally categorized into three chain-length groups based on the three general patterns of retention observed. The longest-chain (>∼335 cm3/mol molar volume) PFAS remained within the uppermost section of the core, exhibiting minimal leaching. Conversely, the shortest-chain (<∼220 cm3/mol) PFAS accumulated at the bottom of the interval, which coincides with the onset of a calcic horizon. PFAS with intermediate-chain lengths were distributed along the length of the core, exhibiting differential magnitudes of leaching. The minimal or differential leaching observed for the longest- and intermediate-chain-length PFAS, respectively, demonstrates that retention processes significantly impacted migration. The accumulation of shorter-chain PFAS at the bottom of the core is hypothesized to result from limited deep infiltration and potential-enhanced retention associated with the calcic horizon.

The evolutionary novelty of insect defensins: from bacterial killing to toxin neutralization

Insect host defense comprises two complementary dimensions, microbial killing-mediated resistance and microbial toxin neutralization-mediated resilience, both jointly providing protection against pathogen infections. Insect defensins are a class of effectors of innate immunity primarily responsible for resistance to Gram-positive bacteria. Here, we report a newly originated gene from an ancestral defensin via genetic deletion following gene duplication in Drosophila virilis, which confers an enhanced resilience to Gram-positive bacterial infection. This gene encodes an 18-mer arginine-rich peptide (termed DvirARP) with differences from its parent gene in its pattern of expression, structure and function. DvirARP specifically expresses in D. virilis female adults with a constitutive manner. It adopts a novel fold with a 310 helix and a two CXC motif-containing loop stabilized by two disulfide bridges. DvirARP exhibits no activity on the majority of microorganisms tested and only a weak activity against two Gram-positive bacteria. DvirARP knockout flies are viable and have no obvious defect in reproductivity but they are more susceptible to the DvirARP-resistant Staphylococcus aureus infection than the wild type files, which can be attributable to its ability in neutralization of the S. aureus secreted toxins. Phylogenetic distribution analysis reveals that DvirARP is restrictedly present in the Drosophila subgenus, but independent deletion variations also occur in defensins from the Sophophora subgenus, in support of the evolvability of this class of immune effectors. Our work illustrates for the first time how a duplicate resistance-mediated gene evolves an ability to increase the resilience of a subset of Drosophila species against bacterial infection.

Quantification of Airborne Concentrations of Nanoscale Dusts by Particle Gravimetry Using Ionic‐Liquid Modified Polymeric Electrospun Fibers

AbstractIn this work, functional polymeric filters are prepared by electrospinning using four different non‐ionic polymers or their blends together with deliberately selected additives, and then tested for quantification of the nano‐sized powders. Particle gravimetry is used for the quantitative determination of the dusts. Validation studies are carried out using the ICP‐OES technique. The polymeric fibers prepared with different contents consist of PS/PMMA, PVDF/EC/PMMA, chitosan, chitosan/PMMA and PMMA/PVDF, respectively. The ionic liquids of tetra‐n‐butylammonium tetrafluoroborate, 1‐ethyl‐3‐methylimidazolium hexafluorophosphate and hexadecyltrimethylammonium bromide are used as additives for the preparation of the functional polymeric fibers. The prepared nanoscale dusts and electrospun fibers are characterized by SEM, XRD, XPS, and size distribution analysis techniques, respectively. Among them, the CTAB‐modified chitosan fibers exhibit the highest dust retention efficiency. This study introduces a new approach to the quantification of nano‐sized powders. In addition, it is concluded that the proposed method can be used in pre‐concentration before testing, cleaning powders from the working environment and quantitative analysis of nanoscale powders. The presented materials can also be used to improve indoor air quality and potential worker exposure in workplaces.

Static mechanical properties and failure behaviors of self-piercing riveted joints in aluminum alloy 5A06 after aging

This paper conducts an investigation on the static mechanical properties and failure behavior of self-piercing riveted joints in aluminum alloy 5A06 after being subjected to the aging process. The study involves three distinct categories of joint specimens: original specimens, 1-year aged specimens and 1-year aged specimens that have been additionally heat-treated at 200 °C. The research findings affirm that strain aging is responsible for a reduction in the peak strength of the joints. Furthermore, the weakest failure chain within the self-piercing riveted joint shifts towards the upper sheet due to a more significant reduction in internal stress experienced by the upper plate. This leads to a failure model characterized by upper sheet pull-off. Through Weibull distribution analysis, it has been established that the 5 % lower limit value for the strength of the SPR joint experiences an 86 % decline following 1-year aging. In practical terms, this means that for a vehicle structure with 7000 riveting points will lose an overall structural strength equivalent to the initial strength of 1000 riveting points within one year.

Analysis of Distribution and Drug Susceptibility Test Results of Pathogenic Bacteria in Diabetic Foot Ulcers.

This study aimed to determine the pathogen distribution and drug susceptibility of diabetic foot wound secretions in a tertiary hospital in a coastal area of southeastern China to guide clinical antibiotic selection. A retrospective analysis was conducted on 212 patients with diabetic foot hospitalized at Xiamen Third Hospital from 2018 to 2023, and foot wound secretions were collected for microbial culture and drug susceptibility testing. Among 212 cases of patients with diabetic foot wound secretions, 163 cases (76.9%) were cultured with pathogenic bacteria, and a total of 207 strains of pathogenic bacteria were cultured, including 75 strains (36.23%) of Gram-positive (G+) bacteria, 118 strains of Gram-negative (G-) bacteria (57.00%), 14 strains of fungi (6.76%), 120 cases of single microorganism infection (73.62%), 43 cases of mixed infection (26.38%), and 15 strains of multidrug-resistant bacteria (7.25%). The top three pathogenic bacteria were Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa. G+ bacteria were dominated by S.aureus. Drug susceptibility results showed that G+ bacteria were highly susceptible to vancomycin, linezolid, tigecycline, quinupristin/dalfopristin, rifampicin, and furotoxin, and somewhat resistant to penicillin, erythromycin, clindamycin, and cefoxitin. Among G- bacterial infections, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Proteus were the major species. Drug susceptibility testing indicated that carbapenems such as imipenem and ertapenem were the most effective antibacterial drugs against G- strains, followed by amikacin, piperacillin, and tazabactams to which these bacteria were also relatively sensitive, while resistance to penicillins and first-generation cephalosporins increased significantly. We isolated one strain of pathogenic bacteria from a Wagner grade1 ulcer, which was G+ bacteria. In Wagner grade2 ulcers, the distribution of pathogenic bacteria was mainly G+ bacteria. In Wagner grade3 and 4 ulcers, the distribution of pathogenic bacteria was mainly G- bacteria, and the increased rate of mixed infection was mainly due to mixed infection of G+ and G-. Two strains of pathogenic bacteria were isolated at Wagner grade5, which were mixed infections of G+ and G-. Pathogenic bacteria in diabetic foot wounds are predominantly G- bacteria, followed by G+ bacteria. As the Wagner ulcer grade increases, the distribution of pathogenic bacteria changes from G+ bacteria to G- bacteria, and the mixed infection rate increases. G+ bacteria are highly susceptible to vancomycin, linezolid, tigecycline, quinupristin/dalfopristin, rifampicin, and furotoxin, and somewhat resistant to penicillin, erythromycin, clindamycin, and cefoxitin. G- bacteria are more sensitive to the antimicrobial drugs ertapenem, imipenem, amikacin, piperacillin tazobactam, and have high resistance to penicillin and first-generation cephalosporins.

Threshold Voltage Modulation and Gate Leakage Suppression of Enhancement‐Mode GaN HEMT by Metal/Insulator/p‐GaN Gate Structure

Herein, a metal/insulator/p‐GaN gate HEMT (MIP‐HEMT) with Si3N4 gate dielectric layer is fabricated. Compared to the conventional p‐GaN HEMT, the MIP‐HEMT has a higher threshold voltage (Vth) of 4.8 V and better gate leakage suppression. The mechanism of threshold voltage increase in MIP‐HEMT is elucidated through an analysis of the electric field distribution in the gate region and the proposed gate capacitance model. Furthermore, MIP‐HEMTs with gate dielectric layers of varying dielectric constants and thicknesses are designed and simulated. The obtained results lead to the derivation of an empirical formula for the threshold voltage of the MIP‐HEMT under ideal dielectric/p‐GaN interface conditions, in relation to the dielectric constant and thickness of the gate dielectric layer. Additionally, simulations are conducted on the MIP‐HEMT incorporating fixed charges at the dielectric/p‐GaN interface, and the impact of interface charges is investigated. This refinement enables a more accurate prediction of the MIP‐HEMT's threshold voltage. Conclusively, MIP‐HEMTs can effectively modulate the threshold voltage by manipulating the parameters of the gate dielectric layer, thereby extending the threshold voltage range of conventional enhancement‐mode devices.

Multi-proxy record of the Austrian Upper Triassic Polzberg Konservat-Lagerstätte in light of the Carnian Pluvial Episode

We present a multi-proxy investigation of a lower Carnian basinal succession from Polzberg in the Northern Calcareous Alps (Lower Austria). A section comprising a unique Konservat-Lagerstätte was studied based on bio- and chemostratigraphy along with geophysical methods, yielding a detailed and robust stratigraphic calibration of the Polzberg succession. The Polzberg section revealed the paleoceanographic history and helped to identify a global climatic reversal, the Carnian Pluvial Episode. The age of the Upper Triassic Reingraben formation in the Northern Calcareous Alps is refined as the Austrotrachyceras austriacum Zone within the lower Carnian (Julian 2). Ammonoids and conodonts provide a detailed biostratigraphic subdivision that serves as a basis for analyses of the faunal distribution and the paleoenvironmental evolution of the Upper Triassic Reifling Basin. The succession includes lithological and facies changes similar to those of coeval units in the Tethys. The Carnian was characterized by a weak (~ 1‰) positive δ13C trend, punctuated by a negative shift during the lower Carnian corresponding to the initiation of the Carnian Pluvial Episode, a period representing the onset of early/late Carnian transitional global greenhouse conditions. Organic maturity parameters and the conodont alteration index (CAI) show that the thermal overprint of the Polzberg section is low. Biomarker proxies suggest that the organic matter of the uppermost Göstling formation is a mixture of marine and terrestrial material deposited in a dysoxic environment. Within the overlaying Reingraben formation, the amount of marine biomass decreased gradually upwards. Oxygen-depleted conditions, probably due to water-column stratification, continued during deposition of the Reingraben formation. Bacterial sulfate reduction played a major role in organic matter degradation.