Local Resistance Research Articles

Navigating antibiotic therapy in acute cholangitis: Best practices and new insights

AbstractGlobally, antibiotic resistance is linked to increased morbidity, mortality, and healthcare costs, which necessitates further research on optimal antibiotic usage. Acute cholangitis (AC), a common cause of community‐acquired bacteremia, often requires antimicrobial therapy. Therefore, studying the appropriate use of antibiotics for AC is considered crucial for suppressing the emergence of resistant bacteria and reducing adverse antibiotic‐associated events. The Tokyo Guidelines 2018 (TG18) recommend 4–7 days of antibiotics post‐biliary drainage. However, this lacks strong evidence and is based primarily on various evidence and expert opinions. Recent retrospective studies advocate for a shorter 1–3‐day antibiotic course for AC, thereby prompting a need to reassess the treatment duration to balance therapeutic efficacy and minimize resistance and adverse effects. Choosing the appropriate duration and antibiotics based on susceptibility to pathogens causing cholangitis is important. Awareness of local resistance patterns and understanding patients' risks of resistant pathogens are prerequisite for effective treatment. We must explore the applicability of these guidelines in specific scenarios such as severe AC, positive blood cultures, fever, or hilar biliary obstructions due to malignancy. This comprehensive review considers both the duration and type of antibiotics and aims to enhance treatment outcomes while reducing the risk of resistant bacterial infections.

Microbial Trends and their Drug Resistance Responsible for Bloodstream Infections in a Superspeciality Transplant Hospital

Background & Objective: Bloodstream infections (BSIs) are critical healthcare-associated infections that lead to high morbidity and mortality, requiring rapid diagnosis and effective antimicrobial treatment. The increasing prevalence of multidrug-resistant organisms (MDROs) exacerbates this issue, particularly in developing countries. The purpose of this study is to assess the bacteriological profile and antimicrobial susceptibility trends of BSIs to establish an antibiogram for effective empirical treatment. Materials and Methods: This study was conducted retrospectively on 3,300 blood culture samples from a multispecialty hospital over 15 months. Cultures were performed using Bactec FX and identification and antibiotic susceptibility determined by Vitek2 and Kirby-Bauer methods following CLSI guidelines. Results: Overall, the positivity rate was (14.3%) with 473 isolates: (400 bacterial and 73 fungal). Gram-negative bacteria were predominant, led by Klebsiella pneumoniae (113 isolates) and Escherichia coli (100 isolates). Among the Gram-negative bacteria, antimicrobial susceptibility was found to be low for Cephalosporins (21%sensitivity) and Fluoroquinolones (19.3% sensitivity), with moderate susceptibility to Carbapenems (51.3%). Sensitivity was high for Colistin (98.9%), Amikacin (91.05%), Tigecycline (100%), Fosfomycin (100%) and Ceftazidime-avibactum Aztreonam (97.7%). Among Gram-positive bacteria, Coagulase-negative Staphylococcal Species (CONS) and Staphylococcus aureus were the most common. The overall sensitivity of Gram-positive bacteria to antibiotics tested was high compared to the Gram-negative bacteria. Sensitivity to antibiotics such as Linezolid was found to be 94.5% and Vancomycin was found to be 93.5%. Conclusion: The high incidence of MDROs especially among the Gram-negative bacteria highlights the need for continuous monitoring and antibiotic stewardship programs. Empirical therapy must consider local resistance patterns, and a multidisciplinary approach is essential to mitigate antimicrobial resistance.

Is It Time to Start Worrying? A Comprehensive Report on the Three-Year Prevalence of ESBL-Producing Bacteria and Their Trends in Antibiotic Resistance from the Largest University Hospital in Slovakia

Background/Objectives: Over the past few decades, extended-spectrum β-lactamase (ESBL)-producing bacteria have become a great concern in healthcare systems worldwide, imposing large burdens by increasing antimicrobial resistance and patient morbidity. Given the high mortality rates and emergence of multidrug-resistant (MDR) strains, monitoring ESBL prevalence and resistance patterns is crucial. This study aimed to evaluate ESBL-producing Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae over three years, focusing on phenotypic distribution and resistance profiles. Methods: A total of 1599 ESBL-producing bacterial samples were collected and analysed. A panel of 20 antibiotics was tested to determine resistance traits. Data were recorded on phenotypical distribution, isolation types, changes in antibiotic resistance, and the relation of such changes to antibiotic consumption (defined daily dose) from clinical isolates. Results: Phenotypical analysis revealed the minimal presence of the Cefotaximase from Munich (CTX-M) phenotype in E. coli and K. pneumoniae, creating a distinct epidemiological profile compared to global patterns. Shifts in isolation trends, particularly in P. mirabilis, suggest an expected increase in associated-mortality-rate in the coming years. While resistance trends were not statistically significant, MDR and extensively drug-resistant (XDR) strains were identified across all three bacteria. Only meropenem showed consistent 100% efficacy against E. coli, with other antibiotics displaying only partial effectiveness. Conclusions: These findings highlight the need for ongoing surveillance of ESBL-producing bacteria and underscore challenges in managing antibiotic resistance due to limited efficacy of last-resort treatments. The unique phenotypical distribution observed could impact local resistance management strategies in hospital settings in the coming years.

Rubber-based piezoresistive sensing: a new approach based on hydrodynamic flow of material deformation describing nonlinear signals in stretchable sensors

AbstractThe nonlinearity of piezoresistive response is critical in developing strain sensors, various self-monitoring applications and wearable electronics based on filled rubbers. This parameter could change dramatically when scaling up from small-size prototypes to full-scale production. The present work focuses on the nonlinear signals in stretchable rubber-based sensors, their origin and dependence on size of samples. Thus, a set of rectangular, piezoresistive samples differing in width was prepared from natural rubber reinforced with carbon black filler. Their electric resistance was tested under planar strain/recovery conditions at 25 and 50% strain amplitudes. It was found that piezoresistance and the related nonlinear phenomena significantly depended on the size of the samples. For the first time, hydrodynamic flow of deformed material was used to explain the nonlinearities of the piezoresistive signal. The trajectory, velocity, and magnitude of this flow were accounted for by a newly developed empirical equation describing the evolution of local resistivity under the strain/recovery process.

Fabrication of Mo-encapsulated stainless steel by powder metallurgy and assessment of localized corrosion resistance

As a source of corrosion inhibitors, 2.5% Mo powder was mixed with Type 304L stainless steel powder and spark-plasma sintered to a fabricate Mo-encapsulated Type 304L stainless steel. The Mo particles formed a core/shell structure. The localized corrosion resistance of the fabricated Mo-encapsulated Type 304L stainless steel was compared with those of spark-plasma-sintered Type 304L and Type 316L stainless steels. Potentiodynamic polarization in 0.1 M NaCl suggested that the Mo cores could release molybdate, which acts as an inhibitor. However, the shells did not dissolve, preventing the Mo-enriched particles from acting as pit initiation sites. Similarly, the surface of the Mo core dissolved during dip-and-dry cycles using 0.1 M NaCl, but the shell was less prone to dissolution. Although the fabricated Mo-encapsulated stainless steel did not contain Mo as a solid solution, its rust resistance was equivalent to that of spark-plasma-sintered Type 316L stainless steel. In potentiodynamic polarization, the initiation potential for localized corrosion of the Mo-encapsulated Type 304L stainless steel was remarkably higher than those of the sintered Type 304L and Type 316L stainless steels. The corrosion inhibition mechanism of the Mo-encapsulated Type 304L stainless steel was discussed from three viewpoints: (1) passive film modification on the steel matrix, (2) cathodic protection of the steel matrix by the Mo core dissolution, and (3) corrosion inhibition by molybdate dissolved from the Mo-enriched particles, and the last one appeared to be the most likely.

National goal, local resistance: How institutional gaps hinder local renewable energy development in Taiwan

In most countries, energy transitions are well supported by the public; however, the implementation of renewable energy policies at the local level is often beset with resistance. Previous research has mainly focused on factors influencing community acceptance and strategies to improve social acceptance. Meanwhile, there has been limited analysis of the institutional gaps that lead to local resistance and the dynamic effects of institutional factors on renewable energy implementation at the local level. This paper thus investigates Taiwan's regulations for renewable energy development, presenting a detailed case study from a local context. It examines the factors contributing to local resistance to the implementation of national renewable energy policy targets and explores the dynamics of these resistance actions. Furthermore, through the lens of multi-level governance, the study reveals the institutional gaps and interactions that influence the execution of national policy at the local level. Six major institutional gaps in Taiwan's renewable energy governance were identified, including the lack of energy governance authorizations for local governments, a lack of superordinate site selection criteria and evaluation mechanisms for development zones, lack of governance systems that can address multiple issues, lack of scientific and academic information, lack of information disclosure and public participation mechanisms, and the burden of carbon reduction responsibilities and costs on local communities with few or no benefits. Compounded together, these six institutional gaps lead to the buildup of negative experiences interacting with the government and the renewable energy industry and feelings of worry, panic, distrust, and injustice among the local populace. These ultimately trigger resistance attitudes and the adoption of protest actions, hindering solar farm developments from reaching national policy targets. This study highlights the critical role of multi-level governance in facilitating the energy transition, emphasizing that the successful development of renewable energy requires a robust institutional framework. Such a framework is essential for addressing the complex governance challenges that arise during this transition, particularly aspects supporting local engagement. The six institutional gaps identified from the Taiwan case can serve as policy references for countries or cities intending to promote ground-mounted solar power.

"Molecular Characterization of Extended Spectrum Beta-Lactamase Resistance in Pediatric Shigella Isolates in Egypt".

Shigellosis is a major cause of morbidity and mortality among children, especially in developing countries. The increased extended-spectrum beta-lactamase (ESBL) resistance in Shigella poses a challenge for effective treatment. To examine the antibiotic resistance and ESBL profile of Shigella isolates from children with acute diarrhea. Shigella was isolated from stool cultures from pediatric patients suffering from acute diarrhea. The isolates were identified by bacteriological tests, serotyping, and multiplex polymerase chain reaction (PCR). The antimicrobial resistance was examined by disc diffusion. Phenotypic tests and PCR examined the ESBLs and CTX-M, SHV, and TEM genes. A total of 100 Shigella (10% prevalence rate) were isolated. The S. sonnei and S. dysenteries were the most prevalent species (33% and 31%, respectively), followed by S. flexneri (27%), and only 9% were S. boydii. The isolates had complete resistance (100%) to ampicillin. There was lower resistance to ciprofloxacin (24%), and no resistance to imipenem. By phenotypic tests, 54% of isolates had ESBL. By PCR, bla-CTX-M gene was the most prevalent (50%), followed by bla-TEM (48.1%). Only one isolate (1.9%) had the bla-SHV gene. The alarmingly high rates of antibiotic resistance and ESBL resistance among Shigella spp highlight the urgent need to restrict the unguided use of these drugs. Continuous monitoring of local and global antibiotic resistance patterns is required to prevent the spread of resistance.

Migrated silicon dioxide nanoparticles activates the rice immunity for systemic resistance against two pathogens

Rice, the world's primary staple food, is under severe threat from several devastating diseases. To sustainably management rice diseases, developing safe, environmentally friendly alternatives urgently need to be developed. In this study, we synthesized two silicon dioxide nanoparticles, spherical mesoporous silica nanoparticles (MSNs) and virus-like mesoporous silica nanoparticles (VMSNs), and we performed a resistance assay on rice for two major diseases, bacterial blight caused by Xanthomonas oryzae pv. oryzae and sheath blight caused by Rhizoctonia solani. Compared to the control, the two nanoparticle treatments increased rice resistance, with VMSNs exhibiting the highest efficacy in controlling these two diseases, causing a shorter lesion length than those plants treated by MSNs. Coincidentally, the foliar application of VMSNs activates a higher expression level of several pathogenesis-related (PR) genes compared to those of MSNs and SiO2 treatment. By using fluorescein isothiocyanate (FITC)-labeled VMSNs (VMSNs-FITC) to soak the top expanded leaf tips or roots, we observed that the fluorescence of the nanoparticles firstly accumulated at the local site of the top leaves or roots, rapidly migrated to the hypocotyl of rice, and then redistributed sequentially from the bottom leaves to the upper leaves. Furthermore, the foliar or root application of VMSNs-FITC could trigger the local and systemic resistance to PXO99. Notably, no significant toxicity was observed on plants and mice after excessive foliar treatment or feeding tests, respectively. Overall, our research revealed that VMSNs are an effective, systemic, and safe nano-pesticides for controlling rice diseases. Boosting the immune responses may be associated with the transporting of nanoparticles.

Research of Reducing Liquid Damping of Liquid Inertia Vibration Eliminator

The liquid inertia vibration eliminator (LIVE) is a type of dynamic anti-resonance vibration isolation (DAVI) devices with compact structure and light weight, which is mainly used in vibration control in the main transmission of helicopters. To investigate the influence of damping generated by the internal liquid flow on the vibration isolation performance, a model and the equations of motion of the LIVE system are established. The friction head loss, local resistance loss and damping coefficient caused by liquid movement in the tuning port of LIVE are calculated. The factors affecting the damping coefficient of the liquid are analyzed. Parameter sensitivity analyses are carried out to reveal the order of importance and interaction of the parameters. Results show that the damping of the LIVE has a negative impact on the vibration isolation performance. The liquid damping is affected by many parameters and the model has a high degree of non-linearity and complexity. The liquid damping can be effectively reduced through the selection of appropriate liquid properties and the design of the structural parameters of the LIVE.

Device for preventing the formation of liquid plugs in a gas collection system or in a non-straight gas well

Relevance. Almost all gas fields, both in Russia and in the world, are developed under water-pressure conditions, which means that sooner or later the field operator is faced with the problem of well watering and liquid accumulation at their bottom. The control methods proposed at this stage of development of science and technology and the useful models and inventions applied for this, although they show their effectiveness in removing droplet liquid from the production wellbore, do not contribute to the further advancement of the removed fluid through the system for collecting and preparing products. Because of this fact, a number of problems arise, for example, the formation of local resistance in the form of ice or hydrate plugs, the cause of which is the fluid removed from the wellbore. Aim. Development of a universal device that can be used both in the production collection and preparation system and inside production wells, capable of injecting produced water into the gas flow in order to prevent the formation of “stagnant zones” of liquid. Objects. Flooded gas wells, the gas pressure in which is not enough to remove droplet liquid from the wellbore or transport this liquid to the place of product preparation. Methods. Assessment and analysis of existing devices to prevent the formation of liquid plugs in a gas collection system, identifying their main shortcomings, as well as mathematical modeling of the proposed model, in which these shortcomings are eliminated. Results and conclusions. The paper introduces a brief description of the problem under study and studies and discusses the main methods of preventing the formation of liquid plugs, used in gas fields both in Russia and in other countries. The authors have proposed the design of a universal device, which is devoid of the main identified disadvantages of analogue devices, and carried out its simplified mathematical calculation.

Small War as Global War: Paul Von Lettow-Vorbeck’s Campaign in German East Africa, 1914-1918

This article discusses Paul von Lettow-Vorbeck, who commanded the Schutztruppe for German East Africa between 1914 and 1918, as a strategic thinker who clearly perceived the rupture that the First World War implied for colonial governance and the use of military violence. While local resistance to colonisation had been the predominant security concern before 1914, the globalisation of the First World War meant that many colonies became recruiting grounds for loyalist soldiers as well as battlefields in the clash of arms between colonial powers. Conversely, the possibility of anti-colonial rebellions presented a vulnerability for colonial powers that could have a global impact. Based on new archival material, this article shows how Lettow-Vorbeck recognised that small war had the potential to tip the scales in a global war and linked his efforts in German East Africa to the Imperial German strategic efforts to instigate global jihad against Entente colonial powers.

RNA silencing is activated by N gene-mediated hypersensitive response and plays a key role in local and systemic virus resistance

AbstractIn plants, recognition between resistance gene (R) and virus induces a local hypersensitive response (HR), which is accompanied by systemic acquired resistance (SAR). The dominant resistance gene N in tobacco confers resistance to tobacco mosaic virus (TMV) at both locally inoculated tissues and systemically infected tissues. However, the mechanisms underlying HR- and SAR-mediated viral inhibition are not fully revealed. In this study, we find that Nicotiana glutinosa RNA-binding protein (NgRBP) is an RNA silencing suppressor which enhances TMV-triggered HR. Stronger HR could result in stronger local and systemic RNA silencing as well as SAR. Enhanced RNA silencing in the systemically infected leaves induced by the NgRBP gene is compromised by transient expression of NahG. These results indicate that RNA silencing is activated by HR and plays a crucial role in local and systemic virus resistance. Our results reveal a crosstalk between N gene-mediated virus resistance and RNA silencing which would deepen our understanding of the established HR and SAR models.

Impact of an enhanced anti-infection prophylaxis strategy for pancreatoduodenectomy: a single centre analysis

Introduction Surgical site infection (SSI) after pancreatoduodenectomy (PD) is a significant concern. Targeted antibiotic prophylaxis (pAP) has been tested to mitigate antibiotic resistance patterns, especially after preoperative bile duct stenting. The aim of this study was to investigate the effect of enhanced anti-infective prophylaxis (EAP) on the incidence of superficial and intraabdominal SSI.MethodsAll patients who underwent PD at a single centre between May 2018 and May 2021 were retrospectively analysed. A control cohort of patients who received pAP with intravenous cefuroxime and metronidazole and routine intraoperative abdominal lavage according to the surgeons’ preferences. Since March 2020, pAP has been changed to piperacillin/tazobactam according to local resistance patterns and combined with routine intraoperative extended abdominal lavage (EIPL). Preoperative selective decontamination of the digestive tract (SDD) has been applied routinely since Jan 2019.ResultsIn total, 163 patients were included. The standard (n = 100) and EAP (n = 63) groups did not significantly differ with regard to pertinent patient and operative characteristics. In the EAP group, the rates of SSI (14% vs. 37%, p = 0.002, total rate: 28%) and urinary tract infection (24% vs. 8%, p = 0.011, total rate 18%) were significantly lower. Other septic complications were not significantly different. In addition, the risk of developing gastrointestinal bleeding and delayed gastric emptying was significantly lower in the EAP group. Multivariate analysis showed that an age > 67 years was a significant risk factor for SSI.ConclusionThe results indicate that enhanced anti-infective prophylaxis may significantly decrease the incidence of SSI in patients after PD.

FREQUENCY OF PIPERACILLIN/TAZOBACTAM RESISTANCE IN SPONTANEOUS BACTERIAL PERITONITIS PATIENTS

Spontaneous bacterial peritonitis (SBP) is a serious infection in patients with chronic liver disease, requiring prompt antibiotic therapy. Due to growing resistance to first-line antibiotics like ceftriaxone, piperacillin/tazobactam is often used as a second-line treatment. However, emerging resistance to piperacillin/tazobactam poses a significant clinical challenge. Identifying local resistance patterns is crucial for optimizing treatment, particularly in resource-limited settings like Peshawar, Pakistan. Objective: To determine the frequency of piperacillin/tazobactam resistance among patients with spontaneous bacterial peritonitis at a tertiary care hospital in Peshawar, Pakistan. Methods: This cross-sectional study was conducted over five months at Lady Reading Hospital, Peshawar from 18th April to 18th September. A total of 169 patients aged 16 to 75 years with SBP secondary to chronic liver disease were included using non-probability consecutive sampling. Demographic and clinical data were collected, and ascitic fluid samples were cultured to assess resistance to piperacillin/tazobactam. Data were analyzed using descriptive statistics and chi-square tests to examine associations. A p-value < 0.05 was considered statistically significant. Results: Piperacillin/tazobactam resistance was found in 9.5% (16/169) of SBP patients. Resistance was observed in 8.0% (7/88) of Escherichia coli isolates and 11.1% (9/81) of other bacterial isolates (p = 0.04). Resistance rates were slightly higher in the 46–75 age group (11.0%, 11/100) compared to the 16–45 age group (7.3%, 5/69). Male patients had a resistance rate of 10.2% (11/108), while female patients showed 8.2% (5/61). Conclusion: This study highlights significant resistance to piperacillin/tazobactam among SBP patients in Peshawar, particularly in non-E. coli bacteria. These findings underline the need for personalized antibiotic regimens and ongoing surveillance to address growing antimicrobial resistance in chronic liver disease patients.

Comparative analysis of international and Malaysia approaches to the treatment of patients with chronic gastritis from the point of view of evidence-based medicine

Background: Chronic gastritis, often resulting from *Helicobacter pylori* infection, is a widespread gastrointestinal disorder. The condition requires evidence-based treatment approaches to ensure effective management and improved patient outcomes. This study conducts a comparative analysis of the treatment approaches for chronic gastritis in Malaysia and internationally, focusing on adherence to evidence-based medicine (EBM) practices. Understanding the similarities and differences in these approaches is critical for enhancing Malaysia's healthcare strategies. Methods and Materials: The study employed a systematic review of relevant literature sourced from global medical databases, including PubMed, Embase, and Cochrane Library. The review focused on therapeutic options, diagnostic standards, and evidence-based protocols for managing chronic gastritis, with emphasis on both international and Malaysian healthcare systems. Studies included in the review primarily focused on adult patients diagnosed with chronic gastritis and treated using evidence-based methodologies. Results: The analysis revealed significant parallels in the treatment protocols between Malaysia and international guidelines, particularly in the use of proton pump inhibitors (PPIs) and antibiotic regimens for *H. pylori* eradication. However, differences emerged in the implementation of advanced diagnostic tools, accessibility of healthcare services, and the influence of local antibiotic resistance patterns. While Malaysia follows global best practices, rural-urban healthcare disparities impact the consistency of treatment delivery and patient outcomes. Conclusion: Both international and Malaysian approaches to chronic gastritis prioritize evidence-based medicine. The findings suggest that Malaysia effectively adapts international guidelines to its local healthcare context, though improvements are needed in addressing healthcare accessibility and antibiotic resistance. Enhanced implementation of EBM practices, particularly in rural areas, and personalization of treatment based on resistance patterns, could further optimize patient outcomes in Malaysia.

The Role of Lymph-Adipose Crosstalk in Alcohol-Induced Perilymphatic Adipose Tissue Dysfunction.

Chronic alcohol use leads to metabolic dysfunction in adipose tissue. The underlying mechanisms and the contribution of alcohol-induced adipose tissue dysfunction to systemic metabolic dysregulation are not well understood. In our previous studies, we found that chronic alcohol feeding induces mesenteric lymphatic leakage, perilymphatic adipose tissue (PLAT) inflammation, and local insulin resistance in rats. The goal of this study was to further explore the link between alcohol-induced lymphatic leakage and PLAT immunometabolic dysregulation, locally and systemically, using in vivo and ex vivo approaches. Male rats received a Lieber-DeCarli liquid diet, of which 36% of the calories were from alcohol, for 10 weeks. Time-matched control animals were pair-fed. Adipokine levels were measured in PLAT, subcutaneous fat, plasma, and mesenteric lymph samples. Glucose tolerance was assessed after 10 weeks. Further, we used a novel ex vivo lymph-stimulated naïve PLAT explant approach to modeling lymph leakage to assess changes in adipokine secretion and expression of proinflammatory markers after stimulation with lymph from alcohol- or pair-fed animals. Our data show that chronic alcohol-fed rats presented PLAT-specific decreases in adiponectin and leptin levels, alterations in the expression of genes involved in lipid metabolic pathways, and associated impaired whole-body glucose homeostasis. Further, we found that direct naïve PLAT stimulation with lymph contents from alcohol-fed animals increased IL-6 expression in demonstrating the ability of lymph contents to differentially impact naïve adipose tissue. Overall, chronic alcohol feeding leads to depot-specific alterations in metabolic profile, impaired systemic glucose tolerance, and lymph-induced adipose tissue inflammation. The specific lymph components leading to PLAT immunometabolic dysregulation remain to be determined.

Eccentric compression behavior of CFRP-confined reactive powder concrete-filled steel tube slender columns

Ultra high and large-span structural components are needed in urban modernization construction to meet the engineering requirements. Reactive powder concrete-filled steel tubes (RPCFSTs) provide a cost-effective and efficient solution for optimizing space utilization in super high-rise buildings and enhancing the crossing capacity of bridge, which accords with such development. However, these components have inherent drawbacks in terms of local buckling and corrosion resistance. The use of carbon fiber reinforced polymer (CFRP) confinement to suppress this innate deficiency has been proven to show great advantages in limited trial results. This article establishes a comprehensive test scheme to investigate the eccentric compression performance of CFRP-confined RPCFST columns. A total of 11 specimens were prepared and subjected to biased compression test by varying the component length (400, 800, 1200, and 1600 mm), number of CFRP layers (0–3), and load eccentricity (0, 10, 20, 30, and 40 mm). The results showed that the CFRP confinement could effectively enhance the bearing capacity and energy dissipation capability of RPCFST columns while delaying the local buckling of slender specimens with low slenderness ratios. The improvement of ultimate load due to CFRP confinement exceeded 42.5 %. However, in specimens with higher slenderness ratios and with increasing load eccentricity, the confinement effect of the steel tube on the core RPC tended to weaken. An N–M interaction model for slender CFRP-confined RPCFST columns was established, and this model was validated to be in good agreement with the experimental results. The conclusions drawn from this study might given a solid foundation for the future application of CFRP-confined RPCFST structures.

Effect of Vitamin D3 on Uterine Morphology and Insulin Signaling in a Polycystic Ovary Syndrome (PCOS) Rat Model

Abstract Polycystic ovary syndrome (PCOS) is a common endocrinopathy in women of reproductive age leading to infertility. Besides reproductive and hormonal disturbances, PCOS is often characterized by vitamin D3 (VD) deficiency. This study aimed to determine the effect of VD on uterine histoarchitecture, the biochemical composition of gland secretions, and the insulin signal transduction pathway using a PCOS rat model. The experiment was conducted on four animal groups (n=8/group): control (C), VD supplemented (VD; 500 IU/day), letrozole-treated (PCOS; 1 mg/kg body weight), and VD-treated PCOS (PCOS+VD) group. Herein, VD supplementation did not improve histomorphometric parameters in the PCOS uterus, whereas clearly influenced sugar composition in uterine gland secretions, restoring their content to that observed in the C group. Furthermore, we found that VD can reduce peripheral and local uterine insulin resistance developed in the PCOS rats via activation of the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway and subsequent glucose metabolism in the uterus. To sum up, the present results suggest a possible beneficial role of VD supplementation for the maintenance of uterus functions in PCOS rats.

Drug resistance pattern, prevalence and risk factors for resistance to second line anti-tuberculosis drugs in Balochistan, Pakistan

Background. Pakistan is high burden drug resistant tuberculosis (DR-TB) country. For devising a treatment regimen and optimizing empirical drug therapy, the local epidemiology and drug resistance patterns are needed to be considered. Objectives. To evaluate the drug resistance pattern, prevalence and risk factors for resistance to second line anti-tuberculosis drugs (SLD) among DR-TB patients in Balochistan, Pakistan. Design and setting. This cross-sectional study was carried out at the Fatimah Jinnah Chest and General Hospital in Quetta's programmatic management unit of the DR-TB (PMDT). Methods. This study included all DR-TB patients, regardless of their age, TB location, or medication resistance pattern. The sociodemographic, microbiological, and clinical data of the patients were gathered using a standard data collecting form. SPSS 20 was used to analyze the data. A statistically significant p-value was defined as less than 0.05. Results. A total of 354 patients were included in the final analysis. Among them majority were females (61.7%), belonged to the age group 19-30 years (36.7%), were previously treated for TB (95.8%) at public sector hospital (42.7%) and did not suffer from any other comorbidity(88.7%). The study participants were resistant to a median of three anti-TB drugs (range 1-8). The most common type of DR-TB was multi DR-TB (77.1%), followed by mono DR-TB (18.1%), extensive DR-TB(3.1%) and poly-DR (1.7%). A total of 147 (41.5%) patients were resistant to any second line anti-TB drug (SLD). Among SLD, the resistance was high for fluoroquinolones (38.4%), followed by ethionamide (4.8%) and injectable SLD(4.2%). Upon multivariate binary logistic regression analysis previous treatment of cat-II regimen had statistical significant association with resistance to any SLD (OR=5.273, 95%CI=1.098-25.316). Conclusion. It is concerning to see such a high level of SLD resistance, especially to fluoroquinolones. More stringent regulations are advised to regulate the non-prescription sale and indiscriminate use of fluoroquinolones, as well as testing for drug resistance in cat-I failures instead of placing patients on cat-II therapy.

Spatially Resolved Analysis of the Influence of Three-Dimensional Flow Field Structures on Loss Processes in PEMFCs

This study introduces a novel measurement device and technique to spatially resolve the influence of 3D flow field structures consisting of extended metal meshes on the performance distribution in PEMFCs. The newly designed segmented cell enables not only the measurement of the current distribution but also local electrochemical impedance spectra, subsequently analyzed by the distribution of relaxation times. The 3D flow field structures provide, despite of an increased HFR, an advantage at high current densities. The spatially resolved DRT analysis enabled the identification of polarization processes revealing that the gas diffusion process is greatly reduced compared to a conventional channel-rib design. In particular, the 3D coarse mesh shows promising advantages for application under high current densities. The findings from this study provide valuable insights into the local power and resistance distribution, enabling optimization of the flow field design and improvement of the performance of fuel cells with large active areas.