Increase In Resistance Research Articles

Relationship between void characteristics and re-liquefaction resistance: An image analysis study

To scrutinize the impact of void characteristics on re-liquefaction resistance, a series of constant-volume cyclic bi-axial tests was conducted on an assembly of plastic rods. The first and second liquefaction stages involved the application of isotropic compression at 100 kPa followed by constant-volume cyclic loading with the deviator stress set at 30 or 60 kPa. This study introduced an innovative image analysis method to quantify four void characteristics: anisotropy index (Ie) and average void element size (Ae) for the element-based analysis, and local anisotropy index (Ie,ij) and local void ratio (eij) for the grid-based analysis. The newly developed anisotropy index was seen to facilitate the assessment of the primary alignment and degree of anisotropy in void elements. The results confirmed that an increase in re-liquefaction resistance is evident in specimens with lower average eij, coefficient of variation (CV) of eij, and Ie, indicating denser, more homogeneous, and isotropic conditions. Nevertheless, specimens with a greater degree of anisotropy were found to be more susceptible to re-liquefaction. The development of strain in the early stages of cyclic loading was found to be predominantly influenced by the anisotropy index, underscoring the imperative need for an enhanced method that can predict liquefaction resistance, as well as re-liquefaction resistance, and incorporates the anisotropy index.

Effect of grain boundary precipitation on corrosion behaviour of nonisothermally aged Al-Zn-Mg-Cu alloys

The corrosion properties of five nonisothermally aged (NIA) Al-Zn-Mg-Cu alloys with different heating rates are studied and compared with those of the T6-treated alloys by electrochemical experiments and weight loss test. The results show that reducing the heating rate results in an increase in the corrosion resistance of the alloy. The aging treatment at a heating rate of 10℃/h results in an alloy with an excellent corrosion resistance and a low corrosion current density. Additionally, the hardness of the alloy is similar to that of the alloy treated with T6. Coarse precipitates are obtained by 10℃/h aging treatment, with the grain boundaries (GBs) transferring to intermittent phases with narrow precipitation-free zones (PFZs). Therefore, this approach effectively prevents anodic dissolution and improves the corrosion resistance of the alloy. These findings suggest that NIA can enhance the mechanical properties and corrosion resistance of an alloy. Additionally, the 10°C/h aging process reduces the processing time by approximately 50%, compared to that of the T6 treatment, offering a cost-effective alternative. These results provide valuable insights into the processing of large aluminium components.

3D printed high–strength polyimide aerogel metamaterials for sound absorption and thermal insulation

The structural manufacturing of high–performance polyimide (PI) aerogels is challenging because of the insufficient mechanical strength and rheological properties of sol–gel ink, and PI aerogels have limited application. In this study, a PI aerogel–based Helmholtz resonator (PIHM) and its acoustic metamaterial were innovatively constructed using freeze casting–assisted extrusion printing process and building block–assembly strategy, featuring a micro–perforated panel (MPP) sound–absorbing structure. The PIHM with a density of 0.294g·cm−3 achieved a compressive strength of 10.2MPa because of its periodically distributed honeycomb topology. Moreover, the PIHM not only retained the lightweight and thermal insulation characteristics of aerogels but also exhibited excellent sound–absorption performance because of the dual dissipation of sound waves by the MPP structure and PI aerogel framework. By serially connecting PIHMs with different aerogel pore sizes and leveraging the distinct acoustic properties of the layered structure along with the significant increase in relative mass resistance and acoustic impedance, the acoustic metamaterial achieved absorption coefficient peaks of 0.82–0.91 at 622–726Hz, considerably widening the bandwidth with an absorption coefficient greater than 0.8. Finally, the composite sound–absorbing panel fabricated from a PIHM combined with common building materials demonstrated strong practicability and versatility. This research has pioneered a viable method for manufacturing PI aerogels with functional structures through 3D printing, expanding their application in the field of sound absorption and thermal insulation, and paving the way for the study of aerogel metamaterials in construction.

Interfacial effects of gold on PEDOT nanotubes modified electrodes employed for the adsorption of micropollutants

In this work poly(3,4-ethylenedioxythiophene) nanotubes (PEDOT-NTs) containing gold nanoparticles (AuNPs) were electrochemically synthesized and characterized in detail by using in situ Raman spectroelectrochemistry. Combining conducting polymers and metallic nanoparticles (AuNPs) enhanced conductivity and superficial area of PEDOT-NTs, key factors for electrochemical sensors. In order, to better understand the modified electrodes behavior, two different micropollutants, butylparaben and triclosan, were added onto the electrode surface and the spectroelectrochemical characterization was done. The Raman imaging showed that micropollutants adsorption increases the presence of partially oxidized segments in PEDOT nanotubes, showing that PEDOT-NTs/AuNPs modified electrodes has sensitivity to micropollutants presence. In this regard the electrochemical impedance spectroscopy characterization was performed and agrees with the spectroelectrochemical characterization results, in which the charge-transfer resistance increase proportionally with the micropollutants concentration. Therefore, the present work shows the potentiality of combining the unique characteristics of the PEDOT nanotubes decorated with AuNPs nanoparticles to develop devices for detection of organic molecules of environmental interest.

Corrosion, Impact Toughness and Tensile Properties of Duplex Stainless Steels Manufactured by Directed Energy Deposition

AbstractDuplex stainless steels provide a desirable combination of corrosion resistance, strength and toughness. Additive manufacturing of duplex stainless steels can be challenging due to high cooling rates and repeated reheating, which can produce detrimental microstructural constituents. In this study, a coaxial directed energy deposition system with laser and wire was used to deposit 2205, 2209 and 2509 duplex stainless steels. Corrosion resistance, strength and impact toughness in both as-built and solution annealed condition was tested and the microstructure was characterized. Solution annealing improved impact toughness considerably, produced a slight increase in corrosion resistance and a slight decrease in tensile strength. The 2205 material surpassed all common requirements and exhibited better corrosion resistance than 2209 due to less segregation between austenite and ferrite. Segregation of alloying elements was lower in intragranular austenite than grain boundary allotriomorph and Widmanstätten austenite. The 2209 and 2509 materials provided relatively low strength, especially in the solution annealed condition. For the 2509 material, sigma phase caused low as-built corrosion resistance and impact toughness. Overmatching welding consumables were found to be less suitable as feedstock for additive manufacturing due to high austenite content in the deposited material and lower corrosion resistance than conventional duplex compositions.

PASS-ASSISTED PREDICTION OF NOVEL TETRACYCLINE HYBRIDS

Objective: The study aimed to determine the biological activity of various novel tetracycline hybrids using way 2 drug platform's online pass software. Methods: Novel structures were designed computationally by hybridization of 9-amino tetracycline with various phyotchemicals using various covalent linkers and prediction of biological activity was done using online pass software. Results: The study investigated showed the antibacterial activity of almost all hybridized tetracycline compounds. The PASS predictions suggested that modifications at the 9th position of tetracycline with various phytochemicals enhanced the antibacterial activity or retained the antibacterial activity for several of the designed structures when compared with standard tetracycline. Conclusion: With an alarming increase of antibiotic resistance, we must identify ways to combat these diseases. This work implies that combining antimicrobials with phytochemicals can create new antimicrobial-photochemical conjugates, potentially addressing antimicrobial resistance in bacteria. Tetracycline hybrids can be used in the future to produce many more hybrids, potentially embarking in a new era of medicine research.

Proton irradiation Of Ga2O3 Schottky diodes and NiO/Ga2O3 heterojunctions.

p-NiO/n-Ga2O3 heterojunction (HJ) diodes exhibit much larger changes in their properties upon 1.1MeV proton irradiation than Schottky diodes (SDs) prepared on the same material. In p-NiO/Ga2O3 HJ diodes, the narrow region adjacent to the HJ boundary is found to contain a high density of relatively deep centers with levels near EC-0.17eV and a depleted region in the immediate vicinity of the HJ boundary. The series resistance of the HJ diodes is slightly higher than for the Schottky diodes and shows a temperature dependence with activation energy ~ 0.12eV, like the temperature dependence of the NiO film resistivity. Irradiation with 1.1MeV protons leads to a decrease of the hole concentration in the NiO, with a high carrier removal rate of ~ 1.3 × 105cm-1 and a strong compensation of the interfacial region where the concentration of the EC-0.17eV centers decreases with a high rate of ~ 7 × 103cm-1. The combined action of these two effects gives rise to the much stronger increase of the series resistance of the HJ diodes compared to Schottky diodes. The observed differences between the radiation response of the HJs and SDs cannot be credibly attributed to the changes of the density of any of the deep electron and hole traps detected in our experiments.

Targeted Sonodynamic Therapy Platform for Holistic Integrative Helicobacter pylori Therapy.

Helicobacter pylori (H. pylori) is a primary pathogen associated with gastrointestinal diseases, including gastric cancer. The increase in resistance to antibiotics, along with the adverse effects caused by complicated medication protocols, has made the eradication of H. pylori a more formidable challenge, necessitating alternative therapeutics. Herein, a targeted nanoplatform is reported based on sonodynamic therapy, the chitosan-conjugated fucose loaded with indocyanine green (ICG@FCS). It penetrates the gastric mucosa and homes in on H. pylori through dual targeting mechanisms: molecular via fucose and physical via ultrasound. Upon ultrasound activation, it generates singlet oxygen, effectively attacking planktonic bacteria, disrupting biofilms, and facilitating the clearance of intracellular bacteria by promoting autophagy, including multidrug-resistant strains. The ICG@FCS nanoplatform minimally affects the gut microbiota and aids in gastric mucosa repair. a holistic integrative H. pylori therapy strategy is proposed that targets eradication while preserving gastrointestinal health. This strategy emphasizes the importance of maintaining patient health while eradicating the pathogen. This advancement is set to refine the comprehensive antibacterial approach, offering a promising horizon in the ongoing battle against antibiotic resistance and more effective gastric cancer prevention strategies.

Evaluation of cactus mucilage as a green corrosion inhibitor for copper in sulfuric acid environment

This study investigates the corrosion inhibition performance of cactus mucilage for copper in 0.5 M H2SO4 solution. The cactus mucilage was extracted using a pure water extraction method and characterized using FTIR and GC-MS analyses. The inhibition efficiency was evaluated using potentiodynamic polarization and EIS techniques, while surface morphology was analyzed using SEM and AFM. The potentiodynamic polarization results revealed that cactus mucilage acts as a mixed-type inhibitor, with inhibition efficiency increasing from 78.6% at 100 mg L-1 to 94.5% at 600 mg L-1. The EIS measurements showed a significant increase in charge transfer resistance from 0.56 k? cm-2 in the uninhibited solution to 8.26 k? cm-2 with 600 mg L-1 cactus mucilage. The adsorption of cactus mucilage on the copper surface followed the Langmuir isotherm model, with a strong adsorption equilibrium constant of 23.6 × 103 M. Compared to other green inhibitors, cactus mucilage exhibited superior inhibition efficiency and sustainability advantages, making it a promising eco-friendly alternative for copper corrosion protection.

Decreasing Carrier Mobility under Concentrated Illumination and Its Effect on the Series Resistance and Conversion Efficiency of Silicon Concentrator Solar Cells

The carrier mobility of solar cell materials is a critical physical parameter that determines the series resistance. Furthermore, series resistance is an essential factor affecting the conversion efficiency of concentrator solar cells under high sunlight illumination. However, there has been slight discussion regarding the relationship between these factors. In the previous study, it was reported that concentrated illumination decreased carrier mobility; however, the scattering mechanism has not yet been clarified. Moreover, carrier–carrier scattering was discussed; however, it did not cause a mobility reduction. Thus effective mass changes are discussed as a possible cause of the decrease in carrier mobility under concentrated illumination. The cause of the decrease in mobility under concentrated sunlight illumination cannot be fully elucidated; however, it is a change in lattice scattering. Furthermore, the effect of the decrease in mobility due to concentrated illumination on the series resistance and conversion efficiency of Si solar cells using numerical calculations is clarified. The increase in the series resistance caused by the mobility reduction is ≈10% under 30 suns.

Abstract 4137845: A single-cell lung atlas of human pulmonary arterial hypertension

Introduction: Pulmonary arterial hypertension (PAH) is a disaster disease characterized by obliterative vascular remodeling and persistent increase of vascular resistance, leading to right heart failure and premature death. Understanding the cellular and molecular mechanisms will help develop novel therapeutic approaches for PAH patients. Hypothesis: We hypothesis that single-cell RNA sequencing analysis can help understand the cellular and molecular mechanisms that drive the disease initiation and progression. Methods: 10 healthy donors, 10 idiopathic PAH, 10 drug and toxin induced PAH, 10 systemic and pulmonary shunting induced PAH patients from both male and female, and different ethical groups and races, and ages were obtained from PHBI. Lung tissue specimens were processed for fixed scRNA-seq. The cell proportion change, gene expression, and pathway analysis were evaluated between different disease subclasses, sex, age on different cell types. Results: Our analysis reveals 317,414 cells, 33 clusters and 9 major cell types, including endothelial cells (ECs), alveolar cells, fibroblast, smooth muscle cells (SMCs), pericytes, myeloid cells, lymphocytes, airway epithelial cells, platelet. Cell proportion analysis demonstrated an increase in the proportions of venous ECs, adventitial fibroblasts and myofibroblasts, alveolar macrophages, B cells, plasma cells and a reduction in capillary ECs 2 and pericytes in PAH lungs. KEGG Pathway analysis showed that upregulated pathways related Herpes simplex virus 1 infection, ECM-receptor interaction, Complement and coagulation cascades, Hedgehog signaling, TGF-beta signaling pathway, and downregulated pathways related to IL-17 signaling, TNF signaling, MAPK signaling pathway were enriched in the PAH patients. Female PAH patients exhibit an increase of myofibroblasts and platelets proportion compared to male PAH patients. MsigDB Hallmark Pathway analysis showed that p53 pathway was upregulated, whereas Inflammatory Response, Hypoxia, Epithelial Mesenchymal Transition were downregulated in female PAH patients. PAH patients older than 21 years exhibit an increase in the cell proportion of Platelet, SMCs, Arterial ECs and Venous ECs, and alveolar macrophages and a reduction of B cells and plasma cells. Conclusions: Our integrated analysis of human PAH lung atlas dataset provides a comprehensive understanding of lung cell populations and molecular signature in PAH patients with different sex, age and subclasses

ROLE OF ISCHEMIA IN THE PATHOGENESIS OF DIABETIC VITREOPAPILLARY TRACTION SYNDROME

Objective: to evaluate the role of ischemia in the pathogenesis of diabetic vitreopapillary traction syndrome.Material and methods: The analysis is based on a sample of 30 patients with diabetic vitreopapillary traction syndrome. The study included a standard ophthalmological examination, color doppler mapping, fluorescent angiography. All patients underwent three-port vitrectomy to eliminate traction syndrome.Results: The results of the obtained data indicated that patients with diabetic vitreopapillary traction syndrome had significant changes in the hemodynamics of the eye compared to the normal parameters. А significant difference in a blood flow parameters in the posterior short ciliary arteries system was recorded in eyes with vitreopapillary traction syndrome compaired to paired eyes.Conclusion: The results of the studies indicate that patients with diabetic vitreopapillary traction syndrome have significant changes in regional hemodynamics: a decrease in blood flow velocity in the central retinal artery, posterior short ciliary arteries and an increase in peripheral vascular resistance, which indicates ischemia of the optic nerve head and may also be one of the reasons for the development of vitreopapillary traction.

Bioengineered Probiotics for Clostridioides difficile Infection: An Overview of the Challenges and Potential for This New Treatment Approach.

The rapid increase in microbial antibiotic resistance in Clostridioides difficile (C. difficile) strains and the formation of hypervirulent strains have been associated with a global increase in the incidence of C. difficile infection (CDI) and subsequently, an increase in the rate of recurrence. These consequences have led to an urgent need to develop new and promising alternative strategies to control this pathogen. Engineered probiotics are exciting new bacterial strains produced by editing the genome of the original probiotics. Recently, engineered probiotics have been used to develop delivery vehicles for vaccines, diagnostics, and therapeutics. Recent studies have demonstrated engineered probiotics may potentially be an effective approach to control or treat CDI. This review provides a brief overview of the considerations for engineered probiotics for medicinal use, with a focus on recent preclinical research using engineered probiotics to prevent or treat CDI. We also address the challenges faced in the production of engineered strains and how they may be overcome in the application of these agents to meet patient needs in the future.

Coordination-Driven in Situ Grown Copper Peroxide in Mesoporous Dopamine with Self-Supplied H2O2 for Synergistic Enhanced PTT/CDT Antibacterial Treatment and Wound Healing.

As antibiotic resistance increases, alternative antimicrobial methods become essential. Chemical dynamics therapy (CDT) utilizing copper peroxide (CuO2) nanodots shows significant potential in antibacterial applications due to its ability to self-supply hydrogen peroxide (H2O2) on its own. This characteristic effectively addresses the challenges of low H2O2 levels and high glutathione (GSH) expression in the bacterial infection microenvironment. However, its tendency to aggregate and instability greatly affect its effectiveness. Therefore, this study developed a coordination-driven strategy to prepare copper peroxide-loaded mesoporous polydopamine nanomaterials (CuO2@MPDA) through in situ growth of CuO2 in mesoporous polydopamine utilizing the chelating interaction between amino and catechol structures of MPDA with copper ions. This strategy not only ensures that copper peroxide is evenly distributed within the pores of mesoporous polydopamine but also protects it through the shielding effect of pores, greatly enhancing its dispersibility and stability. More notably, the loading of CuO2 enhances the photothermal performance of MPDA by broadening its light absorption range, and MPDA-mediated photothermal therapy (PTT) can accelerate CuO2 to produce more hydroxyl radicals by speeding up chemical reactions, resulting in a combined boost in PTT and CDT. The developed CuO2@MPDA nanomaterials at very low concentrations exhibit improved antibacterial efficiency both in vitro and in vivo. Overall, this study provides an innovative strategy to construct an antibacterial nanoplatform for synergistically enhanced PTT/CDT dual-mode antibacterial treatment, exhibiting great potential for future biomedical applications.

Correction for Pérez-Viso et al., "A long-term survey of Serratia spp. bloodstream infections revealed an increase of antimicrobial resistance involving adult population".

Correction for Pérez-Viso et al., "A long-term survey of Serratia spp. bloodstream infections revealed an increase of antimicrobial resistance involving adult population".

Does corporate ESG performance promote export resilience? New insights from risk resistance and resilience

World economic uncertainty adds to the external risks of enterprises, and export resilience directly impacts enterprises' ability to withstand external risks. This paper examines the effect of ESG performance on export risk resilience using a sample of Chinese-listed A-shares from 2008 to 2021. We found that good ESG performance promotes corporate export resilience as evidenced by an increase in export resistance and resilience, a finding that still holds after robustness tests. Mechanism tests reveal that ESG performance can positively promote export resilience by strengthening corporate reputation and alleviating financing constraints. Firms' digital transformation has a moderating influence, and the higher its degree, the greater the positive effect of ESG performance on export resilience. T Heterogeneity tests show that the effect of firms' ESG performance on export resilience is more pronounced among non-state, growth, and mature firms. The above study is innovative in corporate ESG practice, and the findings offer a reference for corporates to participate in ESG practice and enhance export risk resistance.

Numerical investigation on boiling crisis characteristic of a 7-rod HCF assembly in hexagonal lattice

Helical cruciform fuel (HCF) has the advantages of larger heat transfer area, enhanced coolant mixing and self-supporting, which contribute to increasing power density and safety margins. Compared with the square lattice configuration, the hexagonal arrangement of HCF assembly is more compact, which can help achieve a higher power density. In this paper, the flow characteristics and heat transfer behaviors of HCF in hexagonal lattice were predicted at high and low vapor quality during boiling crisis based on Eulerian two-fluid model. The influence of twist pitches and cross-sections of the fuel rod on heat transfer efficiency and fuel temperature was also studied. The cross-flow intensity changed periodically with a 30° cycle at low vapor quality, and did not fluctuate periodically at high vapor quality, which decreased with the increase of flow resistance. The highest heat flux of HCF rod was the at the blade root and the lowest was at the blade tip, and the maximum to average heat flux ratio was about 1.8. The peak vapor fraction and temperature occurred at leeside side of the fuel rods. The increase of the twist pitch reduced the critical heat flux (CHF), and the increase of blade length enhanced the non-uniformity of heat flux distribution. During boiling crisis, the maximum temperature of the fuel was lower than the phase transition temperature of U-50 wt%Zr alloy, which means the cladding meltdown caused by boiling crisis will occur before phase transition of the fuel.

Prolonged outpatient parenteral antimicrobial treatment: frequency and evolution over a six-year period in a Swiss University Hospital

BackgroundEmerging research indicates the potential for early transition from intravenous to oral antimicrobial therapy in certain infections. This trend may have implications for outpatient parenteral antibiotic therapy (OPAT) programs, as the demand for prolonged intravenous treatment could decrease. The objective of this study was to evaluate the frequency and evolution of OPAT courses of ≥ 14 days over the years and determine the medical justification for those prolonged treatments.MethodsAll patients treated intravenously for ≥ 14 days by the OPAT program at Lausanne University Hospital, Switzerland, between 2017 and 2022 were included in the study. Data were extracted from a prospectively established OPAT database. Prevalence of prolonged antibiotic treatment and its clinical and microbiological information were identified.ResultsDuring the study period, a total of 2,448 treatment courses were administered: 1,636 intravenous (IV) and 812 oral treatments. Of the IV treatments courses, 749 (36%) were of a duration of ≥ 14 days, without discernible trend over the 6-year study period. The most common type of infections needing prolonged treatment were bone and joint infections (31%), endovascular infections (18%), complicated intra-abdominal infections (15%), and urinary tract infections (11%), with only minor fluctuations in these proportions during the study period. Finally, the use of second-line antibiotics (piperacillin-tazobactam, carbapenems and vancomycin) did not increase over the years, suggesting that prolonged intravenous antibiotic therapy is not linked to an increase of anti-microbial resistance in our cohort.ConclusionsDespite the general trend towards shorter intravenous treatment courses in infectious diseases, our OPAT unit did not observe a decline in the use of prolonged intravenous antibiotic therapy between 2017 and 2022, suggesting that OPAT units will probably not see a decrease in their activities in the near future.

Edemoascitis decompensation. Is it always liver cirrhosis?

Abstract Portal hypertension (PH) is a clinical syndrome characterized by an increase in the portal hepatic venous pressure gradient (HVPG), defined as the gradient between the portal vein and the inferior vena cava. When there is clinically significant PH, it is usually associated with clinical events such as the development of esophagogastric varices (EGV), oedemoascitic decompensation, encephalopathy... these being more frequent in the case of PH due to liver cirrhosis. In all etiologies of PH there is an increase in resistance to portal blood flow, followed by an increase in said flow. Depending on the location of the increased resistance, it will be classified as prehepatic, intrahepatic or posthepatic PH. Posthepatic portal hypertension occurs when there is a deterioration in hepatic venous outflow, increasing resistance at this level. We present the case of a patient where a striking portal dilation led to the diagnosis of posthepatic PH.

Highly resistant Salmonella Heidelberg circulating in broiler farms in southern Brazil.

Salmonella Heidelberg, a serotype commonly found in Southern Brazil, is characterized by its high resistance and persistence in the poultry production. This study aimed to characterize the antimicrobial resistance of S. Heidelberg strains. In total, 100 strains isolated from poultry between 2020 and 2022 were evaluated. Phenotypic analyses were performed to determine the susceptibility of 16 antimicrobial agents and detect extended-spectrum beta-lactamase (ESBL)-producing strains. Molecular analyses were performed to detect 11 antimicrobial resistance genes (using polymerase chain reaction [PCR]) and integron class 1 genes (using real-time PCR). A total of 98% of isolates was classified as multidrug-resistant. All isolates were resistant to penicillin and lincomycin. High resistance rates (> 85%) were observed for tetracycline, doxycycline, cephalexin, amoxicillin, and ceftiofur. A significant increase (p < 0.05) in antimicrobial resistance is observed for amoxicillin, cephalexin, and ceftiofur between 2020 and 2022. No significant differences (p > 0.05) were observed in antimicrobial resistance with respect to the region of isolation, season, or company. In total, 25% of isolates were ESBL producers. Integron class 1 gene was detected in only one strain, whereas sul2 was detected in 99%, tet(A) in 66%, blaTEM in 37%, strB in 17%, cmlA in 15%, and tet(B) in 11% of the strains. Other genes were not detected or were detected in < 2% of the strains. The results showed a high overall resistance, which increased over the evaluated period. The high proportions of ESBL-producing and antimicrobial resistant strains represent a risk for highly-resistant S. Heidelberg dissemination across broiler flocks.