Tracking Resistance Research Articles

Comprehensive genomic surveillance reveals transmission profiles of extensively drug-resistant tuberculosis cases in Pará, Brazil.

Bedaquiline, an antimicrobial used to treat drug-resistant tuberculosis (DR-TB), was introduced in Brazil in October 2021. Monitoring the emergence and transmission of DR-TB is crucial for implementing public health to control the spread of DR strains of Mycobacterium tuberculosis. To measure its impact on the multi-drug treatment scheme in the state of Pará, we aimed to conduct genomic surveillance of DR-TB after bedaquiline was introduced in Brazil. Individuals treated for DR-TB between October 2021 and December 2022, in the reference hospital to treat DR-TB cases from the state of Pará, were included in the study. Clinical and bacteriological information was obtained from the National Laboratory Management Environment and the Special TB Treatment Information System. Genomic DNA was extracted from bacterial cultures performed at the Pará Central Laboratory (LACEN-PA). Whole-genome sequencing (WGS) was obtained using Illumina Nextera-XT and NextSeq 550 and genomes were analyzed using the MAGMA and TB-Profiler pipelines interpreted according to the World Health Organization (WHO) mutations catalog 2nd edition. Geoprocessing was performed based on the patient's residences. Cutoffs of 5-12 single nucleotide polymorphisms (SNPs) were used for transmission analysis. From the 103 patients reported as DR-TB, viable cultures were obtained from 67. Forty isolates were selected randomly for WGS. Among these, a mixed infection of M. tuberculosis L1 and L4 and a co-infection of M. tuberculosis and Mycobacterium chelonae were observed. The genotypic drug susceptibility profile of TB stains (39/40) was as follows: sensitive (1/2, 5%), rifampicin mono-resistant (RR) (4/10%), isoniazid mono-resistant (1/2%), multidrug-resistant (MDR) (21/52%), extensively drug-resistant (XDR) (3/7%), pre-XDR (8/20%), and other (1/2%). Among the 38 isolates of M. tuberculosis strains without mixed infection, using a cutoff of 12 SNPs and suggestive of recent TB transmission, 14 (37%) were grouped into five clusters (C1-C5) and included RR (C5), MDR (C3, C4, C5), pre-XDR, and XDR (C2) strains. We recommend greater attention from the regional public health authorities to detect and track resistance to new drugs, especially in areas with pre-XDR and XDR cases. This is the first report on the detection and transmission of XDR-TB in Pará, Brazil, after the recent re-definition of XDR-TB by the WHO in 2021.

Study on the Effects of CeO2 on the Micro-Structure and Wear Resistance of CuCrZr Plasma Cladding Coatings

The electromagnetic railgun, a novel kinetic energy weapon, has found utility in military operations due to its enhanced safety features and superior precision. This study investigates the enhancement of wear resistance in CuCrZr rails through the plasma cladding of CuCrZr-CeO2 coatings with a varying Cerium dioxide (CeO2) content. To enhance the wear resistance of the CuCrZr track, plasma cladding of CuCrZr-CeO2 coatings with varying CeO2 content was investigated. The impact of CeO2 content (0%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%) on the microstructure, phase composition, and mechanical properties of the CuCrZr coating was assessed using scanning electron microscopy (SEM), X-ray diffraction (XRD), EDS(Energy Dispersive Spectrometer) surface scanning, friction and wear tests, and hardness analysis. The findings indicate that a CeO2 content of 0.15% leads to a transition in the coating’s microstructure from columnar to equiaxed crystals, with the densest grain structure. Beyond 0.15% CeO2, pore defects in the coating increase, compromising mechanical properties. The coating containing 0.15% CeO2 exhibits optimal performance, with a hardness of 75.3, representing a 5.31% increase compared to CeO2-free CuCrZr coatings. Under a 10 N load, the friction coefficient decreases by approximately 17.9% to about 0.64. Moreover, the minimum wear mass is reduced by 44.7% to 3.87 mg. The aforementioned research findings hold immense importance in extending the lifespan of the electromagnetic railgun and improving its operational efficiency.

Optimization of loop mediated isothermal amplification assay (LAMP) for detection of chloroquine resistance in P. vivax malaria

Chloroquine is still used as a first-line treatment for uncomplicated Plasmodium vivax malaria in India and resistance to this therapy can act as a major hurdle for malaria elimination. It is difficult to monitor drug-efficacy and drug resistance through in vivo and in vitro studies in case of Plasmodium vivax so analysis of molecular markers serves as an important tool to track resistance. Molecular methods that are currently in use for detecting single nucleotide polymorphisms in resistant genes including Polymerase chain reaction (PCR), Realtime-Polymerase chain reaction require highly sophisticated labs and are time consuming. So, with this background the study has been designed to optimize Loop Mediated Isothermal Amplification Assay to detect single nucleotide polymorphisms in chloroquine resistance gene of Plasmodium vivax in field settings. Eighty-eight Plasmodium vivax positive samples were collected. Pvmdr1 gene was amplified for all the samples and sequenced. Obtained sequences were analyzed for the presence of single nucleotide polymorphisms in the target gene. Further Loop Mediated Isothermal Amplification Assay primer sets were designed for the target mutants and the assay was optimized. Clinical as well as analytical sensitivity and specificity for the assay was calculated. Double mutants with variations at T958M and F1076L were detected in 100% of the Plasmodium vivax clinical isolates with haplotype M958 Y976 Y1028 L1076. Designed primers for Loop Mediated Isothermal Amplification Assay successfully detected both the mutants (T958M and F1076L) in 100% of the isolates and do not show cross-reactivity with other strains. So, the assay was 100% sensitive and specific for detecting single nucleotide polymorphisms in the target Pvmdr1 gene. Limit of detection was found to be 0.9 copies/µl and lowest DNA template concentration detected by designed assay was 1.5 ng/µL. Observed prevalence of single nucleotide polymorphisms in Pvmdr 1 gene is indicating a beginning of trend towards chloroquine resistance in Plasmodium vivax. The present study optimized LAMP for detecting single nucleotide polymorphisms in Plasmodium vivax cases in field settings, thus would help in finding significant hubs of emerging chloroquine drug resistance and ultimately helping in the management of suitable antimalarial drug policy.

Aminopropyltriethoxysilane-modified MXene for remarkably enhancing tracking resistance and flame retardancy of silicone rubber

The preparation of silicone rubber with excellent tracking resistance and flame retardancy is of great significance for application in high-voltage electrical insulation. Unfortunately, to date there lacks an effective strategy to simultaneously endow silicone rubber with satisfied tracking resistance and flame retardancy. In this work, aminopropyltriethoxysilane-modified MXene (APTES-MXene) was prepared by dehydrative condensation between the Si-OH in the hydrolyzed aminopropyltriethoxysilane (APTES) and the hydroxyl groups in MXene. The APTES-MXene was homogeneously dispersed in addition-cure liquid silicone rubber (ALSR). The effects of APTES-MXene on the tracking resistance and flame retardancy of ALSR were investigated. Incorporating 0.175 phr APTES-MXene and 15 ppm Pt catalyst enabled ALSR to pass 1A4.5 level, with a low erosion rate of only 0.29 %, indicating a significantly improved tracking resistance. Meanwhile, the 0.175 phr APTES-MXene also endowed ALSR a UL-94 V-0 rating and the limiting oxygen index (LOI) value reached 32.8 %. It was found that APTES-MXene and Pt catalyst synergistically promoted ALSR forming ceramic layer at elevated temperature. The mechanism for APTES-MXene improving the tracking resistance of ALSR was also proposed. This work provided new insights for high performance high-voltage insulation silicone rubber.

Rheological and mechanical evaluation of a novel fast curing cold asphalt concrete made with asphalt emulsion, by-products and magnetic induction

This work studies the feasibility of a new cold asphalt concrete with 5 % voids with fast curing, developed with asphalt emulsion and magnetic induction. Until now, it was impossible to produce fast curing cold asphalt concretes due to the impossibility of compacting and evaporating the water in the asphalt emulsion quickly. Therefore, the aim of this work is to solve the impossibility of compacting the cold asphalt concrete and thus reduce the long curing times. For this purpose, at laboratory level, an experimental cold asphalt concrete was designed with magnetic induction and compared with two reference hot asphalt concretes manufactured according to Spanish standards without magnetic induction (one with 50–70 grade bitumen and another with a PMB45/80–65 type polymer-modified bitumen). The research was carried out in two stages. First, the new cold asphalt concrete was rheologically characterized, the binder recovered from the asphalt concrete was analyzed according to the tests of ring and ball, penetration, dynamic shear rheometer (DSR) and multiple stress creep and recovery (MSCR). Secondly, the new cold concrete asphalt was mechanically characterized, the mechanical performance of the cold asphalt concrete was analyzed by evaluating stability and deformation, dry and wet indirect tensile strengths (ITS), wheel tracking test, stiffness modulus and resistance to raveling dry and wet conditions. Based on the rheological analysis results, the asphalt emulsion recovered from the cold asphalt concrete is extremely soft with a low softening point and a high penetration rate. On the other hand, the values of viscosity, phase angle, stiffness and non-recoverable creep compliance are between those of the bitumen 50/70 and the PMB45/80–65, but closer to bitumen 50/70. As for their mechanical performance, the novel cold asphalt concrete studied presents better resistance to water damage and particle loss, both in dry and wet conditions, but also high permanent deformations and low ITS, probably due to the fact that the residual binder of the emulsion used is softer than the others.

Antibiotic susceptibility of Pseudomonas aeruginosa in Saudi Arabia: a national antimicrobial resistance surveillance study.

Pseudomonas aeruginosa is a common pathogen causing healthcare-associated infections. Most surveillance studies from Saudi Arabia that assessed the resistance by P. aeruginosa were conducted in single centers or did not use broth microdilution (BMD), the gold standard test. This is the first national multicenter study to assess the resistance profiles of P. aeruginosa isolates in Saudi Arabia using BMD. Between 2022 and 2023, isolates from various infection sites were collected from seven hospitals in seven different regions of Saudi Arabia. The isolates were shipped to an academic microbiology lab, where their susceptibility was tested by BMD following Clinical Laboratory Standards Institute guidelines using Sensititre GNX3F plates. %Susceptibility to each antibiotic, and MIC50 and MIC90 were determined. In total, 185 P. aeruginosa isolates were collected. Most isolates came from respiratory specimens (34.1%), followed by urine (21.1%) and skin/soft tissue (17.8%). The highest susceptibility was to amikacin (76.8%). Concurrently, susceptibility to meropenem was 52%, but it was 43.8% to colistin. While all P. aeruginosa isolates met the definition of multidrug-resistance, 41 (22.2%) were difficult-to-treat and 10 (5.4%) were pandrug-resistant. Difficult-to-treat isolates made up 30.3% of skin and soft tissue isolates, 25.4% of respiratory isolates, 21.7% of blood isolates, and 17.9% of urine isolates. Pseudomonas aeruginosa demonstrated an unexpectedly high level of resistance to several commonly used antibiotics. Therefore, antimicrobial stewardship and infection control policies should be strictly enforced by hospitals across the country to optimize treatment, prevent the emergence and spread of resistant strains, and track resistance trends with local antibiograms.

Tracking Response and Resistance in Acute Myeloid Leukemia through Single-Cell DNA Sequencing Helps Uncover New Therapeutic Targets.

Acute myeloid leukemia (AML) is an aggressive hematologic neoplasia with a complex polyclonal architecture. Among driver lesions, those involving the FLT3 gene represent the most frequent mutations identified at diagnosis. The development of tyrosine kinase inhibitors (TKIs) has improved the clinical outcomes of FLT3-mutated patients (Pt). However, overcoming resistance to these drugs remains a challenge. To unravel the molecular mechanisms underlying therapy resistance and clonal selection, we conducted a longitudinal analysis using a single-cell DNA sequencing approach (MissionBioTapestri® platform, San Francisco, CA, USA) in two patients with FLT3-mutated AML. To this end, samples were collected at the time of diagnosis, during TKI therapy, and at relapse or complete remission. For Pt #1, disease resistance was associated with clonal expansion of minor clones, and 2nd line TKI therapy with gilteritinib provided a proliferative advantage to the clones carrying NRAS and KIT mutations, thereby responsible for relapse. In Pt #2, clonal architecture was less complex, and 1st line TKI therapy with midostaurin was able to eradicate the leukemic clones. Our results corroborate previous findings about clonal selection driven by TKIs, highlighting the importance of a deeper characterization of individual clonal architectures for choosing the best treatment plan for personalized approaches aimed at optimizing outcomes.

Ballast stiffness estimation based on measurements during dynamic track stabilization

Ballast compaction with the Dynamic Track Stabilizer (DTS) is known to improve the lateral track resistance by increasing the stiffness of the ballast. This paper presents two approaches for estimating the strain dependent ballast shear modulus G based on measurements during dynamic track stabilization. One approach uses the Hardin equation with its enhancement for coarse-grained soils to estimate the small strain shear modulus for a given grain size distribution curve. Since different shear strains are induced on an observed sleeper (with fixed location) by a bypassing DTS, the measurement of ballast shear strains with accelerometers on the top and the bottom edge of the ballast layer yield shear modulus degradation curves G/Gmax. It is shown for data from a regular maintenance operation, that these shear modulus degradation curves are in accordance with previous research. For the second approach, a SDOF model for the track-ballast interaction under harmonic loading (caused by the dynamic track stabilizer) is developed. Influence lines are used to estimate the mass, the mass moment of inertia and the geometry of an equivalent machine foundation (with spring and dashpot coefficients according to the Hall analog). An optimization algorithm is used to fit the model response to the measured data from field tests with the DTS. The resulting shear moduli show plausible values for loose and compacted ballast conditions, which proves the potential of the presented method as a basis for a future system for Intelligent Compaction (IC) with the DTS.

A data-driven approach to quantify track buckling strength through the development and application of a Track Strength Index (TSI)

Railroads are increasingly adopting advanced technologies to enhance safety and state of good repair of their track infrastructure, some of which employ artificial intelligence-based inspection methods. The objectivity of these inspection techniques, along with their detailed measuring capabilities, has created opportunities for railroads to improve both inspection and operational efficiency. This is achieved through more frequent and precise track data collections and technical data aggregations. This paper explores the potential of these track inspection methods to address one of the few drawbacks of continuous welded rail (CWR): track buckling. While track buckling mechanics and prevention have been the subject of numerous studies, the need for a practical and objective method to assess resistance to buckling remains. Numerous track health indices for geometry parameters and some for railway components have been developed and utilized in various applications. Yet, the opportunity exists to develop a metric that combines geometric parameters with the condition levels of railway components, particularly designed to quantify the resistance of track to buckling. Such a holistic view of the track and network-wide time series analyses of the proposed metric demonstrate whether the buckling resistance improves, remains in a steady state, or declines. In this study, a sensitivity analysis conducted using CWR-Risk software identified misalignment amplitude, track curvature, lateral resistance, torsional resistance, and longitudinal resistance as the main factors contributing to buckling resistance. Based on the sensitivity study and with a focus on the capacity side of the track buckling equation, a methodology was proposed for converting inspection data into 10-point scales that were combined through weighted averaging into a single Track Strength Index (TSI) to quantitatively assess the resistance to buckling at a track-system level. The influence of ballast condition on TSI output was evaluated using 15 ballast configuration scenarios, ensuring that the index accurately reflects ballast deficiencies in a proportionate manner. Lastly, the proposed metric was tested leveraging revenue service data collected from a Class I railroad mainline in the United States.

Synergistically Improving Tracking Resistance of Addition-Cure Liquid Silicone Rubber with Aminepropyltriethoxysilane-Immobilized Silica and Platinum Catalyst

Synergistically Improving Tracking Resistance of Addition-Cure Liquid Silicone Rubber with Aminepropyltriethoxysilane-Immobilized Silica and Platinum Catalyst

Investigation of Inline Curing System Using Halogen Lamp on PET Substrate

Halogen lamps have been seen producing faster high temperatures, which potentially reduces the curing time even further, but the current application was performed offline, thus causing the increase in manufacturing time and inaccuracy of the dimension of the ink track printed. Furthermore, the sample may also have been cured by surrounding temperature rather than the selected designated curing process. The inline curing process of conductive ink is required to prevent air cured and simultaneously reduce the manufacturing time. This study aims to evaluate the performance of the inline curing process through a halogen lamp on a PET substrate. The important curing parameters were determined, and the effect on manufacturing time, dispersion rate, and resistance were analyzed. The relationship between the significant parameters, including curing time and temperature, has also been established in which the resistance of the ink track is proportionated to the length of curing time and how high the temperature is applied. The conductive properties were increased when the temperature was elevated, reducing the curing time. However, increasing the time taken to cure the ink caused the substrate to wrap, deform a bit, and slightly damage the sample. It was also observed that the hardness and adhesion level became harder and stronger as the temperature increased. This concludes that the inline curing process using a halogen lamp is feasible on a PET substrate.

Emergence of Rarely Reported Extensively Drug-Resistant Salmonella Enterica Serovar Paratyphi B among Patients in East China.

In recent years, global concern over increasing multidrug resistance (MDR) among various Salmonella serotypes has grown significantly. However, reports on MDR Salmonella Paratyphi B remain scarce, let alone the extensively drug-resistant (XDR) strains. In this retrospective study, we investigated the isolates of Salmonella Paratyphi B in Jiangsu Province over the past decade and carried out antimicrobial susceptibility tests, then the strains were sequenced and bioinformatics analyses were performed. 27 Salmonella Paratyphi B strains were identified, of which the predominant STs were ST42 (11), ST86 (10), and ST2814 (5). Among these strains, we uncovered four concerning XDR Salmonella Paratyphi B ST2814 strains (4/5) which were previously unreported. These alarmingly resistant isolates showed resistance to all three major antibiotic classes for Salmonella treatment and even the last resort treatment tigecycline. Bioinformatics analysis revealed high similarity between the plasmids harbored by these XDR strains and diverse Salmonella serotypes and Escherichia coli from China and neighboring regions. Notably, these four plasmids carried the ramAp gene responsible for multiple antibiotic resistance by regulating the AcrAB-TolC pump, predominantly originating from China. Additionally, a distinct MDR ST42(1/11) strain with an ICE on chromosome was also identified. Furthermore, phylogenetic analysis of global ST42/ST2814 isolates highlighted the regional specificity of these strains, with Jiangsu isolates clustering together with domestic isolates and XDR ST2814 forming a distinct branch, suggesting adaptation to local antibiotic pressures. This research underscores the pressing need for closely monitoring the MDR/XDR Salmonella Paratyphi B, particularly the emerging ST2814 strains in Jiangsu Province, to effectively curb its spread and protect public health. Moreover, surveillance should be strengthened across different ecological niches and genera to track resistance genes and horizontal gene transfer elements under the concept of "ONE HEALTH".

Токораспределение в гребенчатых структурах биполярных и гетеробиполярных СВЧ транзисторов с учетом сопротивления дорожек металлизации

Представлен краткий анализ причин неоднородного и неустойчивого распределения тока между элементарными транзисторами в гребенчатых структурах (ГС) биполярных (БТ) и гетеробиполярных (ГБТ) СВЧ транзисторов. Получено выражение для тока, втекающего в элементарный транзистор ГС, с учетом сопротивления эмиттерной дорожки металлизации. Приведена оценка влияния технологического разброса сопротивлений эмиттерных дорожек металлизации на неравномерность распределения полного тока транзистора между элементарными транзисторами. Показано, что сопротивление эмиттерных дорожек металлизации играет стабилизирующую роль и приводит к повышению тепловой устойчивости токораспределения в ГС, при этом наименее устойчивым к тепловому пробою будет элементарный транзистор ГС с наименьшим сопротивлением эмиттерной дорожки и наибольшим тепловым сопротивлением. Предложены рекомендации по выравниванию и повышению устойчивости токораспределения в ГС БТ и ГБТ.

Токораспределение в гребенчатых структурах биполярных и гетеробиполярных СВЧ транзисторов с учетом сопротивления дорожек металлизации

A brief analysis of the causes of inhomogeneous and unstable current distribution between elementary transistors in comb structures (CS) of bipolar (BT) and heterobipolar (HBT) microwave transistors is presented. An expression for the current flowing into a CS elementary transistor, taking into account the emitter track metallization resistance, is derived. An estimation of the influence of technological variation of emitter metallization track resistances on the non-uniformity of the transistor total current distribution between elementary transistors is given. It is shown that resistance of emitter tracks of metallization plays a stabilizing role and leads to increase of thermal stability of current distribution in CS, thus the least stable to thermal breakdown will be elementary transistor of CS with the least resistance of emitter track and the greatest thermal resistance. Recommendations on equalization and increase of stability of current distribution in CS of BT and HBT are offered.

Mechanical behavior and performance evolution of railway ballast track under dynamic stabiliser based on the hybrid MBD-DEM simulation

The uncertainty in local structure and time-variable compaction of ballast aggregates poses challenges in selecting suitable stabilization methods and parameters for ballast tracks in practical engineering, often resulting in suboptimal operational outcomes. To address this issue comprehensively, the spatial hybrid model of the double dynamic stabilisers-ballast track (MBD-DEM) is proposed in this paper. Subsequent numerical simulations of stabilisation operations are conducted to elucidate ballast vibration, migration behavior and the evolution of ballast track resistance under varying initial conditions of the ballast bed. Initially, leveraging multibody dynamics theory (MBD) and discrete element method (DEM), a MBD model of double stabilisers and a DEM ballast track model containing 6 sleepers were established respectively. Using the coupling interface, the real-time hybrid calculation of these two models is achieved through 6 sleepers in the middle of the ballast bed. Subsequently, the model's accuracy was validated by comparing test data from stabilisation vehicle operations on a Kunming Railway Bureau test line with simulation data from the dynamic double stabilisers-ballast track spatial hybrid model. Finally, utilizing the proposed hybrid model, the dynamic behavior, contact states, and movement rules of ballast particles during stabilisation operations on both loose and initially stable ballast beds (LBB and ISBB) were investigated at the mesoscopic scale. Concurrently, an in-depth analysis of lateral resistance changes in the ballast bed before and after the stabilisation operation is presented. The relevant findings effectively unveil the evolution of dynamic behavior in the ballast bed during stabilisation operations, concluding with practical suggestions for on-site operations. Simulation results illustrate that the rotation of ballast particles in the XY plane beneath each sleeper is predominantly characterized by harmonic rotation. With an increase in the depth of the ballast bed, the range of the rotation axis for combined angular velocity diminishes, leading to the phenomenon of rotation axis deflection. To ensure operational safety and efficiency, a minimum of two-times stabilization operations is recommended for loose ballast beds (LBB), with three-times operations considered optimal. For initially stable ballast beds (ISBB), one-time stabilization operation is basically sufficient.

Controllable release of Cu ions contributes to the enhanced environmentally-friendly performance of antifouling Cu-bearing stainless steel coating prepared using high-velocity air fuel

Organic antifouling coatings represent an economical and efficient solution for addressing the marine biofouling. However, their application is constrained by issues of durability and toxicity. Therefore, this study has developed a metal-based antifouling coating by utilizing pre-alloyed copper-bearing stainless steel (Cu-bearing SS) powder in conjunction with high-velocity air fuel (HVAF) technology, aiming to achieve an environmentally-friendly and long-lasting antifouling coating. Compared to the self-polishing copolymer (SPC) coating, the adhesion strength of Cu-bearing SS coating increased to 69.0 MPa, which is approximately a 33-fold increase. The coating also exhibited enhanced wear resistance, the width and depth of the wear track for the Cu-bearing SS coating decreased 42.9 % and 81.0 %, respectively. Furthermore, the coating still demonstrated strong inhibitory effects on typical fouling microorganisms and algae adhesion due to Cu ions release process environmentally-friendly. The electrochemical techniques coupling with surface morphology observations were used to elucidate the antifouling mechanism. The variation trend of coating corrosion current was consistent with the release process of Cu ions, which was directly related to the evolution of the coating surface morphology. The three-stage change in the surface morphology of the 304 L-Cu SS coating contributes to the formation of a cyclic variation trend process of Cu ions. The evolution of surface morphology, accompanied by the controlled release process of Cu ions, had become a distinctive feature of antifouling properties for a metal-based coating.

Improving the tracking and erosion resistance of silicone rubber using Fe2O3 and platinum catalyst

AbstractIn typical HTV silicone rubber for composite insulators subjected to a 4.5 kV inclined plane (IP) test, alumina trihydrate loading exceeds 40 wt%, which limits the rubber content and weakens the antiaging properties. This study compares two methods for enhancing tracking and erosion resistance while reducing ATH content to meet IP test requirements. Increasing Fe2O3 content from 1.5 wt% to 3 wt% promotes the formation of mullite. The formed ceramic layer isolates heat and oxygen and hence facilitates the specimen to pass the IP tests with less content of ATH. By contrast, Pt/NS system cannot suppress the tracking efficiently by forming the SiOC ceramics at high ATH loading. The decomposition of ATH will generate water vapor and lead to holes in the surface. Both moisture and oxygen absorbed have a detrimental effect on the suppression mechanism of the Pt/NS system. Consequently, it is recommended that the content of Fe2O3 can be increased slightly to lower the ATH content in the traditional HTV SiR formula used for the composite insulator. Besides, when the content of ATH is relatively high, the use of the Pt/NS system is not recommended.

Analysis of rolling contact fatigue and wear characteristics of aging-treated laminar plasma strip quenching rails

The application of laminar plasma discrete quenching (LPQ) technology to enhance the wear resistance of railway tracks has been a notable advancement. Nonetheless, it has been observed that LPQ-treated rails experience a reduction in rolling contact fatigue (RCF) resistance. Our previous study found that aging treatment can improve the toughness of laminar plasma spot quenched rails. However, the microstructure as well as the mechanical properties of strip quenching are significantly different from those of spot quenching. To tackle this concern, the study delves into the wear and RCF damage mechanisms of aging-treated laminar plasma strip quenching (ALPQ) rails. The findings reveal that the aging process induces the precipitation of supersaturated solid solutions within the hardened layer, consequently elevating the RCF resistance of ALPQ rails. Following appropriate aging treatment, nearly complete elimination of fatigue cracks on the rail surface is achieved.

Emerging bacterial and fungal pathogens in healthcare and the threat of drug resistance

Managing the treatment of fungal infections, in healthcare facilities is extremely important as drug resistance continues to rise. It's crucial to have programs that oversee the use of antibiotics which can help reduce the emergence of resistance. Rapid diagnostic tools like polymerase chain reaction and next generation sequencing (PCR and NGS) are helpful in targeting treatment plans. Implementing rigorous infection control protocols can effectively reduce the transmission of infections, within healthcare facilities. Collaborative efforts between specialists ensure customized treatment plans that address resistance profiles. Combating evolving drug resistance involves approaches such as combination therapy and immunotherapies. Educating healthcare workers and patients about infection prevention and control is essential. Surveillance and epidemiology play a role in tracking resistance patterns, which in turn guide interventions. International cooperation is crucial due to travel patterns. Continuous research and innovation are essential for management providing insights into treatment effectiveness and mechanisms of resistance. The clinical implications of drug resistance such as increased severity, treatment failures and limited options underscore the need, for an approach. In conclusion, it is imperative to have clinical management strategies to tackle the challenges posed by emerging drug pathogens while safeguarding patient outcomes and public health.

Synergistically improved tracking resistance of silicone rubber with ZrP nanosheet and urethane-containing silane

Synergistically improved tracking resistance of silicone rubber with ZrP nanosheet and urethane-containing silane