Quantum Dots on a String: In Situ Observation of Branching and Reinforcement Mechanism of Electrospun Fibers.

Immobilization of quantum dots (QDs) on fiber surfaces has emerged as a robust approach for preserving their functional characteristics while mitigating aggregation and instability issues. Despite the advancement, understanding the impacts of QDs on jet-fiber evolution during electrospinning, QDs-fiber interface, and composites functional behavior remains a knowledge gap. The study adopts a high-speed imaging methodology to capture the immobilization effects on the QDs-fiber matrix. In situ observations reveal irregular triangular branches within the QDs-fiber matrix, exhibiting distinctive rotations within a rapid timeframe of 0.00667 ms. The influence of FeQDs on Taylor cone dynamics and subsequent fiber branching velocities is elucidated. Synthesis phenomena are correlated with QD-fiber's morphology, crystallinity, and functional properties. PAN-FeQDs composite fibers substantially reduced (50-70%) nano-fibrillar length and width while their diameter expanded by 17%. A 30% enhancement in elastic modulus and reduction in adhesion force for PAN-FeQDs fibers is observed. These changes are attributed to chemical and physical intertwining between the FeQDs and the polymer matrix, bolstered by the shifts in the position of C≡N and C═C bonds. This study provides valuable insights into the quantum dot-fiber composites by comprehensively integrating and bridging jet-fiber transformation, fiber structure, nanomechanics, and surface chemistry.

Nuclear interaction of Arp2/3 complex and BRAFV600E promotes aggressive behavior and vemurafenib resistance of thyroid cancer.

The presence of mutant BRAF V600E correlates with the risk of recurrence in papillary thyroid cancer (PTC) patients. However, not all PTC patients with BRAF V600E are associated with poor prognosis. Thus, understanding the mechanisms by which certain PTC patients with nuclear BRAF V600E become aggressive and develop resistance to a selective BRAF inhibitor, PLX-4032, is urgently needed. The effect of nuclear localization of BRAFV600E using in vitro studies, xenograft mouse-model and human tissues was evaluated. PTC cells harboring a nuclear localization signal (NLS) of BRAFV600E were established and examined in nude mice implanted with TPC1-NLS-BRAFV600E cells followed by PLX-4032 treatment. Immunohistochemical (IHC) analysis was performed on 100 PTC specimens previously confirmed that they have BRAFV600E mutations. Our results demonstrate that 21 of 100 (21%) PTC tissues stained with specific BRAFV600E antibody had nuclear staining with more aggressive features compared to their cytosolic counterparts. In vitro studies show that BRAFV600E is transported between the nucleus and the cytosol through CRM1 and importin (α/ß) system. Sequestration of BRAFV600E in the cytosol sensitized resistant cells to PLX-4032, whereas nuclear BRAFV600E was associated with aggressive phenotypes and developed drug resistance. Proteomic analysis revealed Arp2/3 complex members, actin-related protein 2 (ACTR2 aliases ARP2) and actin-related protein 3 (ACTR3 aliases ARP3), as the most enriched nuclear BRAFV600E partners. ACTR3 was highly correlated to lymph node stage and extrathyroidal extension and was validated with different functional assays. Our findings provide new insights into the clinical utility of the nuclear BRAFV600E as a prognostic marker for PTC aggressiveness and determine the efficacy of selective BRAFV600E inhibitor treatment which opens new avenues for future treatment options.

Tick-borne Diseases in Sheep and Goats in Pakistan: A Systematic Review and Meta-analysis.

BACKGROUND: Ticks are blood-sucking ectoparasites and transmit various types of protozoal, bacterial, and viral diseases in a wild as well as domestic animals and humans globally. Only a few  published reports are avaliable on the prevalence of tick-borne diseases in sheep and goats in Pakistan. AIM AND OBJECTIVE: The aim of this systematic review and meta-analysis was to evaluate the prevalence (2000-2020) of tick-borne disease (theileriosis, babesiosis, Crimean-Congo hemorrhagic fever infection, and anaplasmosis) in sheep and goats in Pakistan. METHODS: A systematic review of articles published in English language (since 2000-2020) was conducted using PubMed and Google Scholar. Diagnostic methods used in the original reference articles were PCR, PCR-RLB, microscopy, and ELISA. RESULTS: The overall prevalence of theileriosis, babesiosis, anaplasmosis, and Crimean-Congo hemorrhagic fever (CCHF) infections was 15.40%, 21.18%, 26.78%, and 11.62%, respectively. The prevalence of anaplasmosis was 22.06% (90/408) in sheep, 21.11% (76/360) in goats, and 40% (120/300) in both sheep and goats with substantial differences (P < 0.001). The prevalence of babesiosis among sheep was 29.88% (104/348) with highly significant differences (P < 0.001), in goats was 29.88% (25/60) with slightly significant differences (P < 0.031%), and in both sheep and goats were 7% (21/300) with highly significant differences (P < 0.001) according to subgroup analysis. The percentage of prevalence of theileriosis was 17.70% (207/1169) in sheep with highly substantial differences (P < 0.001), 4.51% (31/687) in goats with significant differences (P < 0.133), and 25% (125/500) in both sheep and goats with a significant difference among them (P < 0.001). The prevalence of CCHF among sheep was 18.63% (149/800) and 4.63% (37/800) in goats, respectively. The widely used detection method was microscopy (45.56%) followed by ELISA (38.38%), PCR (12.56%), and PCR-RLB (3.48%) test, respectively. This is a comprehensive report on the status of tick-borne disease in sheep and goats in Pakistan. CONCLUSION: Based on our results, among tick-borne diseases anaplasmosis had the highest prevalence rate in sheep and goats. Due to its high prevalence, control measures should be taken to diagnose and prevent it.

From virus to inflammation, how influenza promotes lung damage.

Despite seasonal vaccines, influenza-related hospitalization and death rates have remained unchanged over the past 5 years. Influenza pathogenesis has 2 crucial clinical components; first, influenza causes acute lung injury that may require hospitalization. Second, acute injury promotes secondary bacterial pneumonia, a leading cause of hospitalization and disease burden in the United States and globally. Therefore, developing an effective therapeutic regimen against influenza requires a comprehensive understanding of the damage-associated immune-mechanisms to identify therapeutic targets for interventions to mitigate inflammation/tissue-damage, improve antiviral immunity, and prevent influenza-associated secondary bacterial diseases. In this review, the pathogenic immune mechanisms implicated in acute lung injury and the possibility of using lung inflammation and barrier crosstalk for developing therapeutics against influenza are highlighted.

Cyclic Deformation Behavior of A Heat-Treated Die-Cast Al-Mg-Si-Based Aluminum Alloy.

The purpose of this investigation was to study the low-cycle fatigue (LCF) behavior of a newly developed high-pressure die-cast (HPDC) Al-5.5Mg-2.5Si-0.6Mn-0.2Fe (AlMgSiMnFe) alloy. The effect of heat-treatment in comparison with its as-cast counterpart was also identified. The layered (α-Al + Mg2Si) eutectic structure plus a small amount of Al8(Fe,Mn)2Si phase in the as-cast condition became an in-situ Mg2Si particulate-reinforced aluminum composite with spherical Mg2Si particles uniformly distributed in the α-Al matrix after heat treatment. Due to the spheroidization of intermetallic phases including both Mg2Si and Al8(Fe,Mn)2Si, the ductility and hardening capacity increased while the yield stress (YS) and ultimate tensile strength (UTS) decreased. Portevin-Le Chatelier effect (or serrated flow) was observed in both tensile stress-strain curves and initial hysteresis loops during cyclic deformation because of dynamic strain aging caused by strong dislocation-precipitate interactions. The alloy exhibited cyclic hardening in both as-cast and heat-treated conditions when the applied total strain amplitude was above 0.4%, below which cyclic stabilization was sustained. The heat-treated alloy displayed a larger plastic strain amplitude and a lower stress amplitude at a given total strain amplitude, demonstrating a superior fatigue resistance in the LCF regime. A simple equation based on the stress amplitude of the first and mid-life cycles ((Δσ/2)first, (Δσ/2)mid) was proposed to characterize the degree of cyclic hardening/softening (D): D=±(Δσ/2)mid - (Δσ/2)first(Δσ/2)first, where the positive sign "+" represents cyclic hardening and the negative sign "-" reflects cyclic softening.

Corrosion Characteristics of Copper-Added Austempered Gray Cast Iron (AGCI).

The aim of this investigation was to assess the corrosion behavior of gray cast iron (GCI) alloyed with copper. Alloyed GCI specimens were austempered isothermally at varying temperatures. After austenitizing at 927 °C, the samples were austempered at different temperatures ranging from 260 to 385 °C with an interval of 25 °C for 60 minutes. As a result, these samples developed an ausferrite matrix with different percentages of austenite. The resulting microstructures were evaluated and characterized by optical microscope (OM), scanning electron microscope (SEM), and X-ray diffraction (XRD). The corrosion characteristics were determined using potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS) of these samples. These tests were carried out in a medium of 0.5 M H2SO4 and 3.5% NaCl solution. It was observed from the potentiodynamic polarization results that with increasing austempering temperature, the corrosion rate decreased. All results of the EIS were in accordance with a constant phase element (CPE) model. It was found that with an increase in austempering temperature, the polarization resistance (Rp) increased. The austenite content was also found to influence the corrosion behavior of the austempered gray cast iron (AGCI).

Microstructure characterization and corrosion resistance properties of Pb-Sb alloys for lead acid battery spine produced by different casting methods.

The aim of this study is to find out the microstructure, hardness, and corrosion resistance of Pb-5%Sb spine alloy. The alloy has been produced by high pressure die casting (HPDC), medium pressure die casting (AS) and low pressure die casting (GS) methods, respectively. The microstructure was characterized by using optical microscopy and scanning electron microscopy (SEM). The hardness was also reported. The corrosion resistance of the spines in 0.5M H2SO4 solution has been analyzed by measuring the weight loss, impedance spectroscopy and the potentiodynamic polarization techniques. It has been found that the spine produced by HPDC has defect-free fine grain structure resulting improvement in hardness and excellent corrosion resistance.

Isolation and characterization of antimicrobial compound from the stem-bark of the traditionally used medicinal plant Adenium obesum.

BACKGROUND: Medicinal plants constitute a natural reservoir for medicines worldwide. They serve mainstream therapeutics and are central in folklore medicine. In case of Adenium obesum (Lav, Apocynaceae), indigenous people of Oman use it for the treatment of venereal diseases, wounds, skin diseases, headaches, muscle pain as well as joint pain; yet, the active ingredients have not been classified. To screened the antioxidant and antimicrobial activities of an identified compound that we isolated from the highest active chloroform extract. METHODS: The antioxidant and antimicrobial activities of the extracts and the isolated compound were determined by diphenyl-1-picrylhydrazyl (DPPH) and disc diffusion methods. To characterize the compound, we used TLC, column, 1H-NMR, 13C-NMR, 2D-NMR, IR and MS. RESULTS: The highest antioxidant activity was found in chloroform extract with EC50 value of 28.32 µg/ml followed by water, methanol, butanol, ethyl acetate and hexane extracts, their IC50 being 29.95, 39.17, 42.40, 43.20 and 57.00 µg/ml respectively. All crude extracts and pure compound displayed moderate antimicrobial activity against one Gram positive Staphylococcus aureus and three Gram negative Escherichia coli, Pseudomonas aeruginosa and Proteus vulgaris within growth inhibition range of 0-13 mm. The active metabolite was identified as 3,4-dihydroxycinnamic acid (R)-1-carboxy-2-(3,4-dihydroxyphenyl) ethyl ester which is a common plant ingredient known as rosmarinic acid. CONCLUSION: The results indicate that walnut chloroform fraction may contain effective compounds with a broad spectrum of curative applications. This is the first report on isolation and characterization of a compound from chloroform crude extract of A. obesum.