bluuebunny/crossref_metadata_2025 huggingface dataset:
Cytotoxic CD4+ T Cells Are Induced during Infection with Chlamydia trachomatis
Authors: Olivas Joanna , Nogueira Caterina , Helble Jennifer , Starnbach Michael N
Published: June 2024

Chlamydia trachomatis is the most common cause of bacterial sexually transmitted infection in both men and women. Immunity to C. trachomatis involves many cell types, but CD4+ T cells play a key role in protecting the host during natural infection. Specifically, IFN-γ production by CD4+ T cells is the main effector responsible for bacterial clearance, yet the exact mechanism by which IFN-γ confers protection is poorly defined. In our efforts to define the specific mechanisms for bacterial clearance, we now show that IFN-γ upregulates expression of MHC class II (MHCII) on nonhematopoietic cells during C. trachomatis infection in vivo. We also find that MHCII expression on epithelial cells of the upper genital tract contributes to the efficient clearance of bacteria mediated by pathogen-specific CD4+ Th1 cells. As we further cataloged the protective mechanisms of C. trachomatis–specific CD4+ T cells, we found that the T cells also express granzyme B (GzmB) when coincubated with infected cells. In addition, during C. trachomatis infection of mice, primed activated-naive CD4+ Th1 cells displayed elevated granzyme transcripts (GzmA, GzmB, GzmM, GzmK, GzmC) compared with memory CD4+ T cells in vivo. Finally, using intracellular cytokine staining and a GzmB−/− mouse strain, we show that C. trachomatis–specific CD4+ Th1 cells express GzmB upon Ag stimulation, and that this correlates with Chlamydia clearance in vivo. Together these results have led us to conclude that Chlamydia-specific CD4+ Th1 cells develop cytotoxic capacity through engagement with nonhematopoietic MHCII, and this correlates to C. trachomatis clearance.
Obesity Inhibits Alveolar Macrophage Responses to Pseudomonas aeruginosa Pneumonia via Upregulation of Prostaglandin E2 in Male, but Not Female, Mice
Authors: Entrup Gabrielle P , Unadkat Aayush , Warheit-Niemi Helen I , Thomas Brooke , Gurczynski Stephen J , Cui Yuxiao , Smith Andrew M , Gallagher Katherine A , Moore Bethany B , Singer Kanakadurga
Published: June 2024

Obesity is associated with increased morbidity and mortality during bacterial pneumonia. Cyclooxygenase-2 (COX-2) and PGE2 have been shown to be upregulated in patients who are obese. In this study, we investigated the role of obesity and PGE2 in bacterial pneumonia and how inhibition of PGE2 improves antibacterial functions of macrophages. C57BL/6J male and female mice were fed either a normal diet (ND) or high-fat diet (HFD) for 16 wk. After this time, animals were infected with Pseudomonas aeruginosa in the lung. In uninfected animals, alveolar macrophages were extracted for either RNA analysis or to be cultured ex vivo for functional analysis. HFD resulted in changes in immune cell numbers in both noninfected and infected animals. HFD animals had increased bacterial burden compared with ND animals; however, male HFD animals had higher bacterial burden compared with HFD females. Alveolar macrophages from HFD males had decreased ability to phagocytize and kill bacteria and were shown to have increased cyclooxygenase-2 and PGE2. Treating male, but not female, alveolar macrophages with PGE2 leads to increases in cAMP and decreased bacterial phagocytosis. Treatment with lumiracoxib-conjugated nanocarriers targeting alveolar macrophages improves bacterial phagocytosis and clearance in both ND and HFD male animals. Our study highlights that obesity leads to worse morbidity during bacterial pneumonia in male mice because of elevated PGE2. In addition, we uncover a sex difference in both obesity and infection, because females produce high basal PGE2 but because of a failure to signal via cAMP do not display impaired phagocytosis.
Protective Effects of Trans-Chalcone on Myocardial Ischemia and Reperfusion Challenge through Targeting Phosphoinositide 3-kinase/Akt-inflammosome Interaction
Authors: Wang Jing , Hussain Shaik Althaf , Maddu Narendra , Li Haijun
Published: June 2024

Ischemia-reperfusion (IR) injury remains a pivotal contributor to myocardial damage following acute coronary events and revascularization procedures. Phosphoinositide 3-kinase (PI3K), a key mediator of cell survival signaling, plays a central role in regulating inflammatory responses and cell death mechanisms. Trans-chalcone (Tch), a natural compound known for its anti-inflammatory activities, has shown promise in various disease models. The aim of the current study was to investigate the potential protective effects of Tch against myocardial injury induced by ischemia and reperfusion challenges by targeting the PI3K-inflammasome interaction. Experimental models utilizing male rats subjected to an in vivo model of IR injury and myocardial infarction were employed. Administration of Tch (100 μg/kg, intraperitoneally) significantly reduced myocardial injury, as indicated by limited infarct size and decreased levels of the myocardial enzyme troponin. Mechanistically, Tch upregulated PI3K expression, thereby inhibiting the activity of the NOD-like receptor protein 3 inflammasome followed by the activation of pro-inflammatory cytokines interleukin-1β (IL-1β) and IL-18. Moreover, it mitigated oxidative stress and suppressed vascular-intercellular adhesion molecules, contributing to its cardioprotective effects. The PI3K/Akt pathway inhibitor LY294002 considerably attenuated the beneficial effects of Tch. These findings highlight the therapeutic potential of Tch in ameliorating myocardial injury associated with IR insults through its modulation of the PI3K/Akt-inflammasome axis. The multifaceted mechanisms underlying its protective effects signify Tch as a promising candidate for further exploration in developing targeted therapies aimed at mitigating ischemic heart injury and improving clinical outcomes in cardiovascular diseases characterized by IR injury.
Impact of coagulopathy assessment with thromboelastography and thromboelastometry on transfusion requirements in critically ill cirrhosis with nonvariceal bleeding: A prospective observational study
Authors: Gopal Nimi , Panwar Shivali , Saluja Vandana , Garg Neha , Gupta Surbhi , Kumar Guresh , Maiwall Rakhi
Published: June 2024

Background:

Viscoelastic tests are now routinely used for coagulopathy correction in patients with cirrhosis. Thromboelastography (TEG®) and rotational thromboelastometry (RoTEM®) are the most widely studied tests in this population. However, they have not been compared with each other in critically ill patients with liver disease presenting with nonvariceal bleed. Hence, we aimed to compare these tests for coagulopathy correction in patients with liver disease presenting with nonvariceal bleeding.

Methods:

Sixty adult patients with liver cirrhosis presented to the liver intensive care unit, presenting with a nonvariceal upper gastrointestinal (GI) bleed (diagnosed by doing upper GI endoscopy which revealed bleeding from a nonvariceal source) oral or nasal bleed were enrolled. The patients were allocated to the TEG® group (Group T) or RoTEM® group (Group R) depending on the immediate availability of the viscoelastic test. Coagulopathy correction was done in each group as per established protocols and the results were compared.

Results:

There was a significant difference in the fresh frozen plasma (FFP) transfusion between the groups. The TEG® group received more FFP when compared to the RoTEM® group (P = 0.001).

Conclusion:

RoTEM®-based coagulopathy correction leads to lesser use of blood products with similar control of bleeding when compared to TEG, in critically ill patients with cirrhosis.
Incidence of secondary bacterial infections and risk factors for in-hospital mortality among coronavirus disease 2019 subjects admitted to secondary care hospital: A single-center cross-sectional retrospective study
Authors: Sannathimmappa Mohan Bilikallahalli , Marimuthu Yamini , Al Subhi Shayma Mohsin Mohammed Said , Al Bathari Faiza Awaidhan Mohammed Bakhit , Al Balushi Mariya Ibrahim Ahmed , Al Ghammari Sara Ibrahim Rashid , Al-Risi Elham Said , Al-Maqbali Salima , Nambiar Vinod , Al-Shafaee Mohammad
Published: June 2024

Background:

This study aims to determine the prevalence of secondary bacterial infections (SBIs) in hospitalized coronavirus disease 2019 (COVID-19) subjects and evaluate their antibiotic susceptibility. The study also sought to identify risk factors for the outcome of SBIs in COVID-19 subjects.

Methods:

This single-center cross-sectional retrospective study was carried out at Sohar Hospital in Oman. The study examined hospitalized COVID-19 subjects diagnosed with SBIs during March 2020–December 2022. The relevant subjects’ data were extracted from hospital electronic health records and analyzed using STATA version 14. The Chi-square test or Fisher’s exact test was employed for analyzing categorical variables, and P < 0.05 was deemed statistically significant.

Results:

The research encompassed a total of 817 bacteria recovered from various clinical samples of 421 subjects. The older individuals (39.4%) and men (65.6%) experienced bacterial infections more frequently, with bloodstream and respiratory infections being the most common. Gram-negative bacilli (GNB) were responsible for a higher proportion (85.6%) of infections, with Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae being the most common pathogens. Subjects who underwent mechanical ventilation, received corticosteroid therapy, and who had underlying comorbidities, such as diabetes and chronic renal disease, were found to have higher mortality rates. Neutrophilia, elevated C-reactive protein, lymphocytopenia, decreased serum albumin level, sepsis, and pneumonia were found to be independent contributors to mortality.

Conclusions:

SBI is common among COVID-19-hospitalized subjects. GNB were primarily linked to SBI. The severity and the likelihood of SBI increased in subjects undergoing medical interventions and immunosuppressive therapy.
Feasibility study of treatment of mixed astigmatism with small-incision lenticule extraction (SMILE) by using research software
Authors: Ganesh Sri , Brar Sheetal , Bose Shilpi , Shah Mamta Lakhana
Published: June 2024

Purpose:

To report the preliminary experience and initial clinical results following SMILE for the treatment of mixed astigmatism.

Methods:

Thirteen eyes of nine patients with a mean age of 27 ± 4.36 years were included in the series. In 8/13 eyes, myopic SMILE license and in 4/13 eyes, hyperopic SMILE license (available as part of an open/research software) was used for the treatment. The mean follow-up was 9.5 ± 8.7 (0.5–24) months, and the median follow-up was 6 months.

Setting:

Nethradhama Superspeciality Eye Hospital, Bangalore, India.

Design:

Exploratory study.

Results:

The mean preoperative sphere, cylinder, and spherical equivalent (SE) were 1.44 ± 1.63, −2.70 ± 2.30, and −0.24 ± 1.14 D, which changed to −0.03 ± 0.30, −0.28 ± 0.48, and −0.18 ± 0.49 D, respectively, 6 months postoperatively. Furthermore, 85% (11/13) eyes were within ± 0.50 D, 92% (12/13) eyes were within ± 1.00 D, while all eyes were within ± 1.50 D of SE correction. All eyes were within ± 1.00 D of cylinder correction. In addition, 92% (12/13) eyes had UDVA better than 20/32, with 54% (7/13) eyes having UDVA 20/20 or better. Safety and efficacy indices were 1.08 and 0.92, respectively. No eyes lost more than 1 line of CDVA. The mean corneal higher order aberrations (HOA) increased from 0.111 ± 0.048 to 0.209 ± 0.056 (P < 0.001). The mean objective scatter index (OSI) did not show a significant change (pre = 0.71 ± 0.69, 6 months = 0.89 ± 0.20; P = 0.35).

Conclusion:

Early experience showed that SMILE was feasible for the management of eyes with mixed astigmatism, without any intraoperative complications, unique to the procedure.
Association of digital device usage and dry eye disease in school children
Authors: Jadeja Jagruti N , Shroff Kruti V , Shah Ashka , Pandey Ashish , Dubey Shubhra
Published: June 2024

Purpose:

To investigate the influence of digital device use (computers, laptops, tablets, smartphones) on dry eye disease (DED) in a pediatric population.

Settings and Design:

This was a cross-sectional study. School children studying in grades 5–9 at two private schools in the city of Ahmedabad, the capital city of Gujarat, India were invited to participate in the study.

Methods:

In this study, 462 children underwent ocular examination including tear film breakup time (TBUT) and Schirmer’s test. Questionnaires were administered for collecting information on the type and duration of digital device usage separately for academic and leisure activities and the Ocular Surface Disease Index (OSDI) score.

Results:

The mean age of participants was 11.2 + 1.4 years, and 63% were boys. The mean OSDI score was 37.2 + 11.8, and 90.5% had symptoms of DED. Children with moderate to severe DED (n = 88, 19%) had longer daily duration of device use and lower Schirmer’s test and TBUT values compared to children with mild DED (P = 0.001). A cumulative exposure time of more than 3–3.5 h per day had a significantly increased risk of DED. Multivariable logistic regression analysis showed that increment in computer usage (odds ratio [OR] 1.94 for every half an hour increase, 95% confidence interval [CI] = 1.2–3.1) and children studying in higher grades (OR 1.30, 95% CI = 1.1–1.6) had a higher risk of moderate to severe dry eye.

Conclusion:

Cumulative device exposure time of more than 3–3.5 h per day had a significantly increased risk of pediatric DED. Children with an increment in computer usage by half an hour per day had a higher chance of experiencing moderate to severe dry eye. Policymakers should aim to restrict the screen time below 3 h on a daily basis.
Correlation between Clinical and Audiological Factors with Ossicular Chain Continuity in Chronic Otitis Media
Authors: Pandey Kartikey , Baisakhiya Nitish , Batni Gaurav , Mishra Ankit , Patil Anmol
Published: June 2024

Introduction:

Chronic otitis media (COM) with the perforation of the tympanic membrane, myringoplasty is preferred treatment, but if ossicles are involved, myringoplasty is done with ossiculoplasty which is termed as tympanoplasty. Preoperative assessment of ossicular status is important to decide the type of tympanoplasty. Ossicular chain continuity is generally seen in the patient who has short duration of disease and smaller air–bone gap. Our study was conducted to support the relationship between preoperative clinical, audiological, and other factors in relation to the ossicular chain status.

Materials and Methods:

This was a prospective, cross-sectional study conducted at a tertiary care center, for 2-year duration (November 2019 to November 2021), on 100 patients who presented with COM (mucosal type). Preoperative diagnosis and assessment based on the clinical examination and investigations were compared with operative findings.

Results:

Thirty percent of the patients had ear discharge duration <1 year, 28% had 1–5 years, and 18% patients had 6–10-year duration. Hearing loss was present in 80% of the cases. Correlation of pure-tone average (PTA) with ossicular chain status was significant with P = 0.028. The majority of patients were in the moderate category 31% and 19.36% of patients had ossicular chain defect. The second common category was mild hearing loss (24%), of which 4.17% of patients showed ossicular chain defect.

Conclusion:

Maximum percentages of patients with severe hearing loss had ossicular chain discontinuity followed by profound hearing loss. Most of cases had moderate to moderately severe conductive hearing loss in PTA. As the air–bone gap increases, the possibility of ossicular discontinuity increases.
Public Organization Participation in the Prevention of Sexual Crimes against Minors and Adolescents: International Practices
Authors: Azhibekova Saltanat , Kulmukhanbetova Bibigul
Published: June 2024

Background:

The study of how to prevent crimes against kids’ and adolescents’ sexual freedom and inviolability is an ongoing topic of interest for scientific-legal doctrine. In Kazakhstan, the trend of the dynamics of committing such crimes is relatively high, as in other countries, which indicates the need to change approaches and means to prevent such sexual offenses.

Aim and Objective:

The goal of this study is to analyze statistical data on the number of crimes against minors and adolescents’ sexual integrity in Kazakhstan, as well as the effectiveness of domestic and international best practices in combating this issue, as well as the level of public sector involvement in this process.

Materials and Methods:

The issue under study is quite broad in its content; therefore, several scientific and methodological tools were used for its in-depth study. The functional and dialectical approaches are specifically mentioned, along with the methods of analysis and synthesis, comparison, formal-legal procedure, and generalization.

Results:

Both theoretical and practical facets of the issue under investigation were examined as a result of the research that was done. Accordingly, at the beginning of the study, all the necessary theoretical foundations for a qualitative understanding of the research object are covered.

Conclusions:

The practical part of the study determines the effectiveness of the available methods for preventing sexual crimes against minors and adolescents, considers the regulations governing this type of criminal offense, and analyses the approaches and tools used by foreign countries in this area.
Atropine: Updates on myopia pharmacotherapy
Authors: Shahsuvaryan Marianne L.
Published: June 2024

The prevalence of myopia has rapidly increased over the last 30 years, with the World Health Organization estimating a worldwide incidence of 23%, projected to increase to 50% by 2050. The myopia epidemic has prompted a reincarnation in efforts to overcome this challenge. The exploration of atropine use in myopia was a result due to a lack of treatment in effect. This study aimed at reviewing the role of atropine in the management of myopia worldwide based on currently available findings. A literature search was conducted using PubMed/MEDLINE and Google Scholar for studies published up to April 2022 inclusive. Articles with high or medium clinical relevance were selected for this review. Multiple studies have demonstrated the relevance and efficacy rates of different concentrations of atropine, despite still insufficiently explained the exact site and mechanism of action of atropine in slowing myopia progression. Currently available findings highlight that topical atropine opened a new page in pharmacotherapy of myopia and have shown a high therapeutic effect on myopia progression in Asian and European child population, irrespective of ethnicity. There is potential for myopia control with fewer side effects using lower concentrations but still exists a room for improvement, underscoring the requirement of modified atropine topical preparations with increased bioavailability, potentially with nanoparticle formulations, to enable the effective management of myopia.
Tracing Hydrological Processes: Insights from Hydrochemical and Isotopic Investigations in the Northern Part of Croatian Dinaric Karst
Authors:   Croatian Geological Survey, Zagreb, Croatia, Boljat Ivana , Terzić Josip ,   Croatian Geological Survey, Zagreb, Croatia, Duić Željko ,   University of Zagreb, Faculty of Mining, Geology and Petroleum Engineering, Zagreb, Croatia, Lukač Reberski Jasmina ,   Croatian Geological Survey, Zagreb, Croatia, Selak Ana ,   Croatian Geological Survey, Zagreb, Croatia, Briški Maja ,   Croatian Geological Survey, Zagreb, Croatia
Published: June 2024

This study presents the findings derived from a three-year monitoring programme focusing on the hydrochemical composition and stable isotope signatures (δ18O, δ2H) within the vulnerable karst groundwater system in Croatia's northern Dinaric karst region. Covering an area of 1980 km2 across Kapela Mountain and its foothills, this groundwater system falls within the Kupa River basin and encompasses the catchment areas of the main springs across two spring levels of the Dobra, Mrežnica, and Slunjčica Rivers (namely the Vitunj, Zagorska Mrežnica, Dretulja, Veliko Vrelo, Gojak, Tounjčica, Mrežnica, and Slunjčica springs). Given the complex hydrogeological framework, prior studies have not extensively addressed the hydrochemical characteristics of this region, thereby necessitating a comprehensive investigation to elucidate system dynamics. This paper outlines the first investigation employing stable isotopic analyses within the karst groundwater system of Kapela Mt. The main results and conclusions of the research include: (i) the aquifers across Kapela Mt. drain mainly limestones, (ii) water–rock interaction and carbonate weathering are significant contributors to water geochemistry, (iii) there is a slight human impact on the Gojak and Tounjčica spring waters, (iv) the mean residence time of water in the observed aquifer is up to 1.5 years, (v) the new LMWL was calculated for Kapela Mt. based on a three-year dataset (June 2018 – May 2021), (vi) in the north Dinaric karst, the predominant origin of precipitation is from the Mediterranean air mass, (vii) Velebit Mt. has a strong influence on the precipitation isotopic composition of the study area.
Hydrochemical characterization of a Dinaric karst catchment in relation to emerging organic contaminants
Authors:   Croatian Geological Survey, Zagreb, Croatia, Selak Ana , Lukač Reberski Jasmina ,   Croatian Geological Survey, Zagreb, Croatia, Briški Maja ,   Croatian Geological Survey, Zagreb, Croatia, Selak Lorena ,   Aarhus University, Department of Biology, Aarhus C, Denmark
Published: June 2024

The main findings of a hydrochemical investigation conducted within a typical Dinaric karst catchment located in Southern Croatia are outlined. The studied aquifer is drained by the Jadro and Žrnovnica springs, which are important for the regional and local water supplies, respectively. Presumably, there is intercatchment groundwater flow coming from the neighbouring Cetina River catchment. Various factors governing aquifer hydrochemistry and their interplay with emerging organic contaminants (EOCs) that were detected at different water resources in ng/L concentrations was assessed. A total of 26 sampling campaigns (October 2019 – October 2022) were conducted at two springs, in a river and at a deep borehole, all representative of this complex hydrogeological system. Assessment of major ion constituents and saturation indices calculated with PHREEQC revealed the sampled water resources are of a Ca-HCO3 type due to the predominant weathering of the carbonate mineral calcite. Sharp spikes observed in chemographs indicated a highly karstified system with an effective conduit network allowing rapid spring responses to precipitation events. Water resources are of good chemical status, as affirmed by anthropogenic contamination indicators, with nitrates, chlorides and sulphates all below maximum threshold values. Strong positive correlations were found between EOCs concentration, number of detected compounds, and nitrates in the Cetina River, indicating a common origin, most likely wastewater. Identification of persistent EOCs including widely used repellent N,N-diethyl- metatoluamide (DEET) during base flow conditions and its strong positive correlation with the Ca2+ content in both the Cetina and Jadro samples, suggests potential storage in the epikarst and aquifer matrix. This coupling of conventional hydrochemical indicators and novel markers of anthropogenic impacts, including EOCs, in vulnerable karst water resources is a crucial advancement in the assessment and management of emerging environmental and potential human health risks. Such an approach is pivotal for the sustainable protection of hydrogeologically intricate sites.
Tracing the evolution of the world's first mined bauxite from palaeotopography to pyritization: Insights from Minjera deposits, Istria, Croatia
Authors:   Faculty of Mining Geology and Petroleum Engineering, University of Zagreb, Croatia, Perković Ivor , Martinuš Maja ,   Department of Geology, Faculty of Science, University of Zagreb, Croatia, Cvetko Tešović Blanka ,   Department of Geology, Faculty of Science, University of Zagreb, Croatia, Vlahović Igor ,   Faculty of Mining Geology and Petroleum Engineering, University of Zagreb, Croatia, Matešić Darko ,   Faculty of Mining Geology and Petroleum Engineering, University of Zagreb, Croatia, Newton Robert J. ,   School of Earth and Environment, University of Leeds, United Kingdom, He Tianchen ,   College of Oceanography, Hohai University, Nanjing, China, Šoufek Marin ,   Croatian Natural History Museum, Zagreb, Croatia, Razum Ivan ,   Croatian Natural History Museum, Zagreb, Croatia, Durn Goran ,   Faculty of Mining Geology and Petroleum Engineering, University of Zagreb, Croatia
Published: June 2024

The Minjera bauxites are the first analysed and mined bauxites in the world. They are a group of pyritised bauxites situated in northern Istria, developed during the subaerial exposure phase which marked a major part of the Late Cretaceous and Palaeocene in northern Istria. In this study, the morphology, petrography, mineralogy, geochemistry as well as stable sulphur isotopes of the D-1 and D-15 deposits from Minjera were studied, as well as the evolution of their bedrock and cover. This study found that those two deposits differ in morphology, mineralogy and geochemistry as a consequence of their different palaeotopographical positions, with the D-1 deposit located at a higher position at the time of its formation compared to D-15, which led to the higher degree of leaching and desilicification in the D-1 deposit. The pyritisation in the studied deposits was a multi-phase process, which began with the deposition of framboidal pyrite and micrometre-sized anhedral pyrite, over which colloform pyrite was precipitated. This indicates that the solutions were initially supersaturated with iron sulphide, saturation of which subsequently changed, as finally euhedral, dendritic and acicular pyrite were deposited, indicating undersaturated conditions. The final stage was marked by deposition of pyrite veins. This formational sequence of pyrites is also supported by stable sulphur isotopes, as the δ34S values exhibit a wide range from -40.86 to 2.32 ‰, where lower values indicate an open system with an unrestricted sulphate supply in which supersaturated conditions could have been achieved, while the higher values indicate a change towards a closed system with limited sulphate supply. The organic matter necessary for microbial sulphate reduction was derived from the marshy environment established atop of the bauxite. The initial flooding started in the Palaeocene, with the first part of the sequence being deposited under lacustrine conditions, which changed towards fully marine with the deposition of Foraminiferal limestones.
Coupled variational inequalities and application in electroelasticity
Authors: Bensaada Azzeddine , Essoufi El-Hassan , Zafrar Abderrahim
Published: June 2024

This work is devoted to the mathematical and numerical study of a framework handling a system of coupled variational inequalities. We prove both the existence and the uniqueness of a weak solution to the problem. Then, we introduce a convergent iterative scheme. Using this latter, we decouple the problem into further subproblems and derive their corresponding minimization problems. As a practical application of this class of coupled abstract variational inequalities, we consider a class of problems that model an electroelastic body coming into frictional contact with a rigid electrically conductive foundation. Both electrical and mechanical contacts are of Signorini type. In other words, our model prescribes the mechanical response produced by the foundation and the outflow of the free charges across the contact zone. The last part of this paper is mainly reserved for the numerical resolution of the problem at hand. For this purpose, we have developed an alternating direction method of multipliers and convex dualities to compute and illustrate the solutions.
Estimation of Wheel Loads using a Mathematical Model and Correlation with Vehicle Measurements on Motorcycles
Authors: Balakrishnan Sivakumar , Chavan Chandan B. , Srinivasan Karthikeyan , Kharul Ravi , Chandra Rakesh
Published: June 2024

This paper aims at the estimation of dynamic wheel loads of a two-wheeler through mathematical modeling that will aid during the initial stages of product development. A half car model that represents a two-wheeler was used for this purpose. Road displacements were given as input to the model and the wheel loads estimated. Actual road data obtained from two-poster rig was used as input to the model thereby making it possible to calculate the wheel loads for different customer usage conditions on different roads. In this paper, a severe rough road was chosen for verification of the model with that of the rig as the rider dynamics on such roads are the most difficult to simulate even on the rigs. The estimated values from model were verified with those measured using a two-poster rig for the same road displacement. Attempt has been further made to establish a correlation between the ride comfort predictions from the model and the two-poster rig. The acceleration levels on the frame were considered for assessment and comparison of comfort. The fact that both the estimation of wheel loads and ride comfort optimization can be accomplished much before building complex multibody models for simulation makes the approach very cost effective and faster. Also, the advantage of predicting the fatigue life of various components that go into a vehicle based on dynamic wheel loads even before the part is made makes this a very useful exercise.
Design and Development of Electronically Assisted Braking System [EABS] For Two Wheeler
Authors: Dhandapani K. , Senthilkumar P. , Tamilporai P.
Published: June 2024

In automotive braking system the main purpose of a brake is to retard or stop the vehicle by converting the kinetic energy of vehicle motion into rotational frictional torque at the brake pads. This energy will then changed to heat energy and dissipated to surrounding air. The most powerful brake itself will not stop the vehicle effectively if the road surface has little wet or no traction and also if the wheels are locked. Mash the brake lever and the wheels will stop turning, but the vehicle will skid along. Many drivers tend to think that the brake skid as a “brake failure” and in fact the situation is really a failure of the driver to understand the traction conditions and to drive accordingly. Front brake is always designed to be stronger than the rear brake. Since when the brakes (front or rear) are applied, the weight of the bike and rider transfers forward and eventually onto the front wheel. This is the reason for a bike's front end dives when driver applies the brake. To address the above issues, a new brake management system called “Electronically Assisted Braking System” (EABS) has been developed to prevent the wheel lock. EABS uses a combination of electronics and hydraulic controls to allow braking right up to the point of wheel lock-up, the system interfere to reduce fluid pressure to the brake and to keep the vehicle deceleration at its maximum at the given road conditions. The Electronic Control Unit (ECU) monitors the vehicle speed continuously at all times using wheel speed sensor, which gives input signal to the ECU, which controls the linear actuator. The linear actuator controls the hydraulic control valve to give variable cut-in pressure according to the vehicle speed which in-turn will reduce the output pressure to the caliper. Experimental results have been obtained for various cut-in pressures by the movement of screw in hydraulic control valve. The results of EABS were compared with the conventional disc braking system. It shows that the maximum deceleration was achieved at very short period of time compared with the conventional braking system.
Development of Snowmobile Technology for Operation on High-Blend Ethanol
Authors: Davis Gregory W. , Sanger Jason , Schickel Brian , Muxlow Jason
Published: June 2024

Kettering University has developed a cleaner and quieter snowmobile using technologies and innovative methods which can be applied in the real world with a minimal increase in cost. Specifically, a commercially available snowmobile using a two cylinder, four-stroke engine has been modified to run on high-blend ethanol (E-85) fuel. Further, a new exhaust system which features customized catalytic converters and mufflers to minimize engine noise and exhaust emissions has developed. A number of additional improvements have been made to the track to reduce friction and diminish noise. This paper provides details of the snowmobile development the results of these efforts on performance and emissions. Specifically, the Kettering University snowmobile achieved reductions of approximately 72% in CO, and 98% in HC+NOx when compared with the 2012 standard. Further, the snowmobile achieved a drive by noise level of 73 dbA while operating on hard packed snow.
Addressing colonial-apartheid legacy and infrastructural barriers in access to substance use disorder treatment in South Africa's Eastern Cape Province
Authors: Bala Samkelo
Published: June 2024

Despite the official end of apartheid in 1994, systemic barriers to accessing resources and human rights continue to exist in certain parts of South Africa. One example of this is inadequate access to substance use disorder treatment, which exacerbates the problem.Substance use disorder is recognised globally as a mulyifactorial health issue, and South Africa's struggle to address this phenomenon is compounded by infrastructural deficits. To gain insight into the problem, a qualitative study was conducted, involving semi- structured interviews and focus group discussions with 15 participants in East London in the Eastern Cape, South Africa. The research findings revealed several problems, including a lack of substance use treatment centres, the impact of colonial and apartheid segregation on access to these centres, inadequate human resources for treating substance use disorder, and insufficient financial support for implementing treatment programmes. Inconsistencies in the treatment of substance use disorder pose a threat to the success of policies. The Eastern Cape is among the most neglected areas in terms of resource allocation and access to substance use treatment centres.
Knowledge, attitude and prevention practice of Rhesus incompatibility among women of childbearing age in Rumueme Community of Port Harcourt
Authors: Itaa Patience , Willy Ngozi Dennis
Published: June 2024

Rhesus incompatibility is a condition that occurs during pregnancy if a woman has Rh negative blood and her baby has Rh positive blood. This study adopted a survey design with the aim of investigating the knowledge, attitude and prevention of Rhesus incompatibility among women of childbearing age in Rumueme community of Obio/Akpor Local Government Area of Rivers State. The study employed quantitative approach which allows for the data collected to be analysed numerically, make predictions, test causal relationships and generalize results to wider populations. This study was conducted on 87 pregnant women registered at Primary Health Centre Rumueme, Tombia Street, Port Harcourt, Obio/Akpor Local Government Area between the period of January, 2022 to June, 2023. Findings showed that pregnant women in the study area did not really see maternal-foetal blood incompatibility as a serious problem. Clearly the level of awareness is low and the low level of knowledge must have been responsible for negative attitudes. Therefore, interventions aimed at social and behaviour change should primarily target increasing knowledge, improving attitudes and addressing the gaps in practices highlighted by the study are recommended. It was concluded that more efforts should be made to make the incompatibility test even free to women attending clinics. Community healthcare service providers and churches should include in their services to counsel women on the importance of maternal-fetal blood incompatibility test. Women of childbearing age should check their status and those of their partners in terms of blood group, genotype and rhesus compatibility before engaging in relation for the purpose of procreation.
Monetary resource factors influencing strikes among healthcare workers in public hospitals in Nairobi County, Kenya
Authors: Lifuleze Cyrus Memo , Muhonja Faith Hope , Muchiri Joseph
Published: June 2024

Healthcare workers play a pivotal role in the delivery of essential medical services, and their commitment is critical for the overall functionality of public hospitals. However, persistent strikes among healthcare workers in public hospitals in Nairobi County, Kenya, pose a significant threat to the stability and effectiveness of the healthcare system. The consequences of these strikes are far-reaching, affecting the quality and accessibility of healthcare services, patient outcomes, and the overall reputation of the healthcare system. This research sought to evaluate the Monetary resource factors influencing strikes among healthcare workers in public hospitals in Nairobi County, Kenya. The research was conducted at Kenyatta National Teaching and Referral Hospital, Mbagathi Hospital, Mama Lucy Kibaki Hospital, Ngara Health Center, and Pumwani Maternity Hospital all located in Nairobi County, Kenya. The study employed a descriptive research design and the sampling frame involved 400 Healthcare workers. The study used semi-structured questionnaires with closed-ended items for data collection. The data processed using SPSS, version 26.0, software, and the level of significance was set at 0.05. Both descriptive and inferential statistics were employed in data analysis. From the responses, most of the respondents as shown by 55.2% (191) were female. In terms of the age of the respondents in years, more than half of the respondents as shown by 55.8% (193) were aged 31-40 years. The study found that some of the significant monetary factors that influence strikes by HCWs comprise: salary status (X2(3,N=346)=39.248, p-value<0.001; OR = 3.610; CI = (2.072, 6.289)), status of allowances (X2(3,N=346)=63.457, p-value<0.001; OR = 2.835; CI = (1.692, 4.749)), status of extra work pay (X2(3,N=346)=10.183, p-value=0.017; OR = 1.472; CI = (0.892, 1.764)), and status of bonuses (X2(3,N=346)=59.382, p-values <0.001; OR = 1.708 and CI = (1.435, 2.155)). This study recommends that more resources should be set aside by the government to cater for salary increments, better allowances, and competitive bonuses.
Histopathological changes associated with exposure to some toxic heavy metals in kidneys of albino wistar rats
Authors: Udo E.S. , Ogwu P.A. , Eze V. C.
Published: June 2024

Heavy metals are the most toxic substances of global concern. Since they are not biodegradable they tend to bioaccumulate in the environment producing toxic effects to both plants and animals even in low concentrations resulting in genomic instability. This study was therefore aimed at assessing the histopathological changes associated with exposure of some toxic heavy metals in kidneys of albino wistar rats. Thirty albino wistar rats were used for this study and divided into 6 groups of 5 rats each and were administered 1/10 of the determined LD50 of the respective heavy metal salts of Lead acetate, Chromium sulphide, Cadmium chloride, Arsenic trioxide and Mercury chloride for groups 2,3,4,5 and 6 respectively daily. Group 1 served as the control was given commercial rat chow and water ad libitum. At the end of 45 days animals were sacrificed and kidneys collected for histological assessment using H & E staining technique. All the groups exposed to heavy metals showed histological alterations to include: degenerating tubules with vacuolated ductal and tubular shrinking nuclei, there were also hemorrhagic blood vessels within the renal cortical matrix. In conclusion heavy metal intoxication has been shown to cause histopathological changes in the kidney of experimental rat models.
Restorative effect of Annona muricataextract on histomorphology of testicular tissue of cadmium tumor induced albino rats
Authors: Ehiremen S.E. , Iyare G.I. , Omorodion N.T.
Published: June 2024

Cadmium is a harmful heavy metal that is widely distributed in the environment. This study aimed to investigate the effects of Annona muricata seed extract on cadmium-induced testicular toxicity in adult male Wistar rats. A total of 35 adult male Wistar rats were randomly divided into five groups (A–E)) of 7 rats each. Group A (the control group) received distilled water only; group B-E received 2 mg/kg of cadmium (S.C.) and 100 mg/kg body weight of Annona muricata, 2 mg/kg of cadmium (S.C.) and 200 mg/kg body weight of Annona muricata, and 2 mg/kg of cadmium and 300 mg/kg body weight of Annona muricata respectively. After 17 days of treatment, the animals were brought out, weighed, and sacrificed via cranial dislocation. Testicular, seminal fluid, and blood samples were taken for examination. SPSS version 21 was used in the analysis. The results of the study showed that the Annona muricata aqueous seed extract increased the levels of superoxide dismutase (SOD) and catalase (CAT) in a dose-dependent manner compared to the cadmium-only group. The relative weight of the testis increased significantly in the treated groups compared to the cadmium-only group. Testosterone levels also increased significantly (P < 0.05) in the treated groups compared to the group A (control). The extract showed a significant protective effect against cadmium-induced toxicity, as indicated by the higher testosterone levels in treated groups compared to the untreated group. Medicinal plants like Annona muricata can be used to treat heavy metal toxicity in traditional medicine.
Prevalence and correlates of depression and anxiety among University of Rwanda community during COVID-19 pandemic in 2020
Authors: Sezibera Vincent , Kalisa Joseph , Izabayo Josias , Umubyeyi Benoite , Cheonga Faith , Uwizeye Prince , Banderembaho Felix , Sebatukura Simeon , Rutembesa Eugene
Published: June 2024

INTRODUCTION: The COVID-19 pandemic disrupted many aspects of people’s well-being worldwide, including the mental and physical health of university students and staff. The aim of this study was to assess the prevalence and correlates of depression and anxiety during COVID-19 pandemic in students and staff of the University of Rwanda (UR).METHODS: Utilizing an online Google form, this rapid screening cross-sectional study collected and analyzed primary data from 693 participants (students: 73.9% and staff: 26.1%). Data was collected using a sociodemographic characteristic questionnaire and the Hopkins Symptom Checklist-25 (HSCL-25) for anxiety and depression. Multiple logistic regression model was used to test the association between social demographic characteristics, historical background and outcome variables.RESULTS: This study found that about 40.6% of students had anxiety symptoms while 38.5% exhibited depression symptoms. Among staff, 34.8 % reported anxiety and 29.3% reported depression. Associated factors of anxiety included experiencing quarantine, pre-existing mental health conditions, exposure to violence, and belonging to a low-income household. Depression was linked to pre-existing mental health issues, COVID-19 related quarantine, and experiences of violence. Notably, students were more prone presenting with symptoms of depression as opposed to staff.CONCLUSION: The study revealed a high prevalence of anxiety and depression among both students and staff. These findings emphasize the need for mental health services to be made available on campus to support those in the university community who are in need of assistance.
Maciej z Miechowa. Astrolog, medyk, a może jatromatematyk?
Authors: Konarska-Zimnicka Sylwia
Published: June 2024

Maciej of Miechów is one of the most eminent representatives of the Kraków scientifi c community of the second half of the 15th century and the fi rst quarter of the 16th century. He was a versatile scholar, a valued teacher, an excellent administrator (he served eight times as the university’s rector) and a widely respected philanthropist. He gained fame and recognition, as well as a considerable fortune, by practising medicine and astrology. On more than one occasion, he provided medical and astrological advice to representatives of the elite and the poor of Krakow. Rather a practitioner, much less a theoretician, his activities focused on the utilitarian function of both astrology and medicine. He valued both fi elds of cognition, practised both, but could he be called an iatromathematician? An analysis of this thread is undertaken in this article.
Państwowy Zakład Higieny o żywności i odżywianiu w Polsce w latach 1945–1970
Authors: Jarosz Dariusz
Published: June 2024

Surveys of basic foodstuffs (meat and meat products, milk and milk products, fl our and bread) carried out by the State Institute of Hygiene between 1945 and 1970 indicate that their hygienic and sanitary condition raised many concerns. The most serious effect of this neglect in this respect was numerous epidemics and food poisoning, which affected up to several hundred people at a time. In its study of the nutrition of the Polish population, the PZH focused primarily on pupils of rural primary schools and adolescents using school dormitories. Their diets were chaotic and monotonous, often lacking such important ingredients as raw fruit and vegetables and wholesome protein. Their menus were dominated by cabbage and potatoes, often eaten several times a day, although in different forms.
Józef Wiczkowski (1857–1924) – zapomniany lekarz-diagnosta, naukowiec, dydaktyk i społecznik
Authors: Klimasz Katarzyna , Tomasik Przemysław J.
Published: June 2024

Józef Wiczkowski (1857–1924) – physician, scientist, university teacher and social activist. Unjustly forgotten, probably due to the lack of a specific, outstanding discovery that would give him a permanent place in the history. Nevertheless, he was a precursor of analyzing the results of laboratory tests with the actual condition of the patient. He studied diseases that were rarely diagnosed at the end of the 19th century, such as leukemia. He tried to characterize them based on the microscopic image of blood cells and to use the specific features of the cells visible under the microscope in the diagnosis of leukemia. In the second half of his life, he dealt mainly with the treatment of tuberculosis. His approach was systemic and included hospital and sanatorium treatment. Thanks to his efforts, a center for tuberculosis patients was established in Holosko Wielkie near Lviv. Through very good therapeutic effects, he proved to the medical community that sanatoriums for tuberculosis can be built not only in the mountains, but also in lowland, but forested areas. As a social worker, Wiczkowski provided material support to many institutions and societies. He also worked for people with disabilities in the Society for the Care of the Disabled, which aimed to improve the quality of life of these people, as well as make them more independent by learning a specific profession adjusted to the individual possibility of the disabled person. The professor was also a great Polish patriot and a local patriot enchanted by Lviv, where he lived and worked for almost 40 years. His Lviv`s guidebook has been an excellent source of knowledge about this city not only for historians, even nowadays.