Contact Exposure Research Articles

Evaluation of Micro-Needling Followed by Metformin Solution versus Micro-Needling Followed by Tranexamic Acid Solution in Treatment of Melasma: A Comparative Split Face Study

Abstract Background Melasma is a common acquired pigmentary disorder that manifests as symmetric hyperpigmented macules and patches on the face, more frequently affecting women of reproductive age. Various underling risk factors have been implicated in the etiology of melasma including; Genetic factors, pregnancy, oral contraceptives, endocrine dysfunction, hormone treatments, cosmetic contact sensitivity and exposure to ultraviolet (UV) light. Management of melasma is a frustrating experience both for the treating doctors and patients because of its recurrent and often recalcitrant nature. Numerous therapeutic modalities have been tried for this condition such as hydroquinone, kligman’s formula (hydroquinone + steroid + tretinoin), kojic acid, azelaic acid, arbutin, ascorbic acid, chemical peels, lasers, tranexamic acid, rucinol, oligopeptides, silymarin, orchid extracts, and various botanical extracts with variable success rates. Objectives Our aim was to assess and compare the therapeutic effects of topical metformin solution 30% with microneedling versus topical tranexamic acid (4mg\ml) solution with microneedling in treating patients with facial melasma. Patients and Methods This is a split-face study included 35 patients with facial melasma. The patients recruited from the Outpatient Dermatology Clinic at Ain Shams University Hospitals. Topical metformin 30% solution with microneedling sessions were done for the right side of the face (4sessions - two weeks apart), and topical tranexamic acid solution (4mg/ml) with microneedling on the left side of the face (4 sessions – two weeks apart). The patients were followed up for 3 months. The response of treatment was evaluated by Hemi MASI score and Antera 3D camera. Results Our study revealed that both microneedling followed by topical metformin solution and microneedling followed by topical TXA solution were efficient in treatment of facial melasma as shown by significant decrease in h-MASI score and average melanin level assessed by Antera camera. Although statistically insignificant, the percentage of change in h- MASI score was more evident with TXA treatment than metformin treatment. The side effects were limited and transient in the form of erythema, burning sensation, and xerosis. The main problem with either treatment was the high relapse rate. Conclusion Both metformin and tranexamic acid applied topically following microneedling sessions led to statistically significant improvement of melasma according to Hemi MASI scores. Topical metformin appears to be a promising therapeutic option in the treatment of melasma without serious adverse effects.

Biological Medicines Prepared Using Vibration Processing Are Able to Influence Their Targets Without Direct Contact With Them.

Recently, there has been a radical change in understanding of the nature of drugs based on highly diluted solutions. It has been established that their activity does not depend on the content of the original substance in dilutions, but is a consequence of the technological processing (TP) of dilutions with vibration, which accompanies each dilution during the preparation of solutions and, among others, leads to the formation of nanoparticles with certain properties. Repeated vibration treatment leads to the appearance of modifying activity that is absent in the original substance, and these effects of TP solutions can be exerted without direct contact with their targets, which clearly indicates the physical nature of the TP solution's activity. In the framework of this article, a statistically significant effect of TP antibodies to the insulin receptor on glucose consumption by CHO cells both with and without contact exposure, as compared with control (P < 0.05) was shown in the vast majority of the experiments. The obtained results shed light on a possible source of activity of drugs based on TP antibodies, which should be associated with the applied vibration effect and can manifest itself both with contact exposure and without it.

Methodologies for the collection of parameters to estimate dust/soil ingestion for young children.

Heavy metals, pesticides and a host of contaminants found in dust and soil pose a health risk to young children through ingestion. Dust/soil ingestion rates for young children can be estimated using micro-level activity time series (MLATS) as model inputs. MLATS allow for the generation of frequency and duration of children's contact activities, along with sequential contact patterns. Models using MLATS consider contact types, and transfer dynamics to assign mechanisms of contact and appropriate exposure factors for cumulative estimates of ingestion rates. The objective of this study is to describe field implementation, data needs, advanced field collection, laboratory methodologies, and challenges for integrating into and updating a previously validated physical-stochastic MLATS-based model framework called the Child-Specific Aggregate Cumulative Human Exposure and Dose (CACHED) model. The manuscript focuses on describing the methods implemented in the current study. This current multidisciplinary study (Dust Ingestion childRen sTudy [DIRT]) was implemented across three US regions: Tucson, Arizona; Miami, Florida and Greensboro, North Carolina. Four hundred and fifty participants were recruited between August 2021 to June 2023 to complete a 4-part household survey, of which 100 also participated in a field study. The field study focused on videotaping children's natural play using advanced unattended 360° cameras mounted for participants' tracking and ultimately conversion to MLATS. Additionally, children's hand rinses were collected before and after recording, along with indoor dust and outdoor soil, followed by advanced mass analysis. The gathered data will be used to quantify dust/soil ingestion by region, sociodemographic variables, age groups (from 6 months to 6 years), and other variables for indoor/outdoor settings within an adapted version of the CACHED model framework. New innovative approaches for the estimation of dust/soil ingestion rates can potentially improve modeling and quantification of children's risks to contaminants from dust exposure.

Barcoded SARS-CoV-2 viruses define the impact of time and route of transmission on the transmission bottleneck in a Syrian hamster model.

The transmission bottleneck, defined as the number of viruses that transmit from one host to infect another, is an important determinant of the rate of virus evolution and the level of immunity required to protect against virus transmission. Despite its importance, SARS-CoV-2's transmission bottleneck remains poorly characterized, in part due to a lack of quantitative measurement tools. To address this, we adapted a SARS-CoV-2 reverse genetics system to generate a pool of >200 isogenic SARS-CoV-2 viruses harboring specific 6-nucleotide barcodes inserted in ORF10, a non-translated ORF. We directly inoculated donor Syrian hamsters intranasally with this barcoded virus pool and exposed a paired naïve contact hamster to each donor. Following exposure, the nasal turbinates, trachea, and lungs were collected, viral titers were measured, and the number of barcodes in each tissue were enumerated to quantify the transmission bottleneck. The duration and route (airborne, direct contact, and fomite) of exposure were varied to assess their impact on the transmission bottleneck. In airborne-exposed hamsters, the transmission bottleneck increased with longer exposure durations. We found that direct contact exposure produced the largest transmission bottleneck (average 27 BCs), followed by airborne exposure (average 16 BCs) then fomite exposure (average 8 BCs). Interestingly, we detected unique BCs in both the upper and lower respiratory tract of contact animals from all routes of exposure, suggesting that SARS-CoV-2 can directly infect hamster lungs. Altogether, these findings highlight the utility of barcoded viruses as tools to rigorously study virus transmission. In the future, barcoded SARS-CoV-2 will strengthen studies of immune factors that influence virus transmission.

Performance of and Severe Acute Respiratory Syndrome Coronavirus 2 Diagnostics Based on Symptom Onset and Close Contact Exposure: An Analysis From the Test Us at Home Prospective Cohort Study.

Understanding changes in diagnostic performance after symptom onset and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exposure within different populations is crucial to guide the use of diagnostics for SARS-CoV-2. The Test Us at Home study was a longitudinal cohort study that enrolled individuals across the United States between October 2021 and February 2022. Participants performed paired antigen-detection rapid diagnostic tests (Ag-RDTs) and reverse-transcriptase polymerase chain reaction (RT-PCR) tests at home every 48 hours for 15 days and self-reported symptoms and known coronavirus disease 2019 exposures immediately before testing. The percent positivity for Ag-RDTs and RT-PCR tests was calculated each day after symptom onset and exposure and stratified by vaccination status, variant, age category, and sex. The highest percent positivity occurred 2 days after symptom onset (RT-PCR, 91.2%; Ag-RDT, 71.1%) and 6 days after exposure (RT-PCR, 91.8%; Ag-RDT, 86.2%). RT-PCR and Ag-RDT performance did not differ by vaccination status, variant, age category, or sex. The percent positivity for Ag-RDTs was lower among exposed, asymptomatic than among symptomatic individuals (37.5% (95% confidence interval [CI], 13.7%-69.4%) vs 90.3% (75.1%-96.7%). Cumulatively, Ag-RDTs detected 84.9% (95% CI, 78.2%-89.8%) of infections within 4 days of symptom onset. For exposed participants, Ag-RDTs detected 94.0% (95% CI, 86.7%-97.4%) of RT-PCR-confirmed infections within 6 days of exposure. The percent positivity for Ag-RDTs and RT-PCR tests was highest 2 days after symptom onset and 6 days after exposure, and performance increased with serial testing. The percent positivity of Ag-RDTs was lowest among asymptomatic individuals but did not differ by sex, variant, vaccination status, or age category.

Contact exposure of honey bees and social stingless bees to fungicide sprayed on cotton and soybean in a controlled field simulation system

AbstractBees can be exposed to pesticides when visiting crops or plants in adjacent areas affected by spray drift. Among pesticide categories, fungicides tend to be considered relatively safe, though they also can negatively affect pollinators. Most evidence of damage by fungicides to bees comes from laboratory tests; there is little information concerning contamination levels in the field. We examined exposure of honey bees (Apis mellifera L.) (Hymenoptera: Apidae) and a common Brazilian native species of social stingless bees (Scaptotrigona postica Latreille; Hymenoptera: Apidae), which is about a third the size of a honey bee, to a commercial fungicide (Fox Xpro), with three active ingredients (trifloxystrobin, bixafen, and prothioconazole), applied to crops they often visit according to label directions. A spraying apparatus mounted on tracks in a laboratory spray room was used to simulate field conditions. Soybean and cotton plants grown in pots were transferred to the spray room when the plants were in flower. Anaesthetized bees were attached with insect pins at the top and middle of the plants, on leaves and flowers. The fungicide was applied using fine or coarse droplets. The amounts of the individual active ingredients absorbed by bees were then quantified. Concentrations of trifloxystrobin were highest in both honey bees and stingless bees, followed by bixafen, and then prothioconazole, which was detected in the bees at much lower levels. Overall, bees at the top of the plants and those sprayed with fine droplets absorbed more pesticide. As a function of body mass, the stingless bees were more heavily contaminated than the larger honey bees. Tests using spraying systems that simulate field conditions can better estimate the actual doses that contaminate bees to help determine the impact of fungicides and other pesticides applied to crops.

Non-target effects of neurotoxic insecticides on Ganaspis cf. brasiliensis, a classical biological control agent of the spotted wing Drosophila

BackgroundThe spotted wing drosophila, Drosophila suzukii, is an invasive pest causing significant economic losses worldwide. Current pest control strategies mainly rely on insecticides, which negatively impact fruit marketability and the sustainability of integrated pest management (IPM) programs. In addition, pesticides can have dramatic consequences on non-target species when persisting in the environment at low concentrations after field applications. In this context, chemical control can strongly interfere with the releases of the G1 strain of the Asian larval parasitoid Ganaspis cf. brasiliensis, which is currently the adopted classical biological control agent to manage D. suzukii infestations worldwide.MethodsProbit analysis was used to assess the baseline toxicity of acetamiprid, cyazypyr, lambda-cyhalothrin, phosmet, and spinosad on G1 G. cf. brasiliensis adults through residual contact exposure in the laboratory. Then, adult parasitoids were exposed to insecticide low Lethal Concentrations (LC5 and LC30) and their mortality was checked daily to assess the survival of treated wasps.ResultsLambda-cyhalothrin showed the highest toxicity on the parasitoid with a LC50 of 1.38 × 10–3 g active ingredient (a.i.) /L, while cyazypyr seemed the safer active ingredient with an estimated LC50 of 0.20 g a.i./L without affecting parasitoids at sublethal doses. Spinosad and phosmet significantly reduced wasp survival at both LC30 and LC5, while lambda-cyhalothrin and acetamiprid affected parasitoid lifespan only at LC30. Spinosad, lambda-cyhalothrin and phosmet LC30 caused the major survival reductions, followed by acetamiprid LC30. The least significant reduction in parasitoid survival was 21.6% by spinosad LC5.ConclusionsOverall, this study highlighted the importance of carefully selecting insecticides to minimize adverse effects on non-target organisms. In particular, cyazypyr was the most promising candidate to integrate inoculative biological control with chemical treatments. By contrast, the application of phosmet, spinosad and lambda-cyhalothrin should be avoided alongside parasitoid field releases. Although acetamiprid is less used against D. suzukii in the field than the other tested molecules, it should be used with caution due to its sublethal toxicity on the parasitoid. These results provide the first evidence of G. cf. brasiliensis susceptibility to insecticides in order to promote sustainable and efficient pest management strategies.

The Ice Berge of Cholera in Hodeidah , Yemen : The Contact Exposure

Cholera is a diarrheal disease caused by a bacterial infection of the intestine. The bacterium is Vibrio cholerae, which can either be of type O1 or O139. It can infect both children and adults . A cross sectional design was carried out to investigate the variations between cholera patients and control (contacts). Data were collected from a total of 15 suspected cases from 7 districts in Hodeidah, Yemen and 16 contacts from the same houses of the patients. Data at first fed to the excel program then imported to the SPSS version 23 for statistical analysis. Most of the patients were under 5 years of age with the mean age was 2.1 years (±1.2) with a great variation ,the median age of patients was 5 years. It was a great difference with contact age where the mean age was 34 years (±13) (p-value = 0.000) . Al though watery diarrhea was present in 13 out of 15 patients (68.4%) and being more than contacts (6/16; 37.5%) (p-value = 0.006) . Two controversial observations were reported in this study regarding history of vaccination and the laboratory result of the stool culture for V. cholerae. Most of the patients were vaccinated (86.6%) than contacts (p- value = 0.000) and the accepted explanation for this difference is that it may be due that the contacts are adults and may they did not remind their history of vaccination. But the presence of positive culture result for V. cholerae in one contacts (6.3%) and never in any of suspected cholera patients raining the questions either of the performance of the laboratory diagnosis of the surveillance or both .

Repellent activity of essential oils to the Lone Star tick, Amblyomma americanum

BackgroundThe Lone Star tick, Amblyomma americanum is important to human health because of a variety of pathogenic organisms transmitted to humans during feeding events, which underscores the need to identify novel approaches to prevent tick bites. Thus, the goal of this study was to test natural and synthetic molecules for repellent activity against ticks in spatial, contact and human fingertip bioassays.MethodsThe efficacy of essential oils and naturally derived compounds as repellents to Am. americanum nymphs was compared in three different bioassays: contact, spatial and fingertip repellent bioassays.ResultsConcentration response curves after contact exposure to 1R-trans-chrysanthemic acid (TCA) indicated a 5.6 μg/cm2 concentration required to repel 50% of ticks (RC50), which was five- and sevenfold more active than DEET and nootkatone, respectively. For contact repellency, the rank order of repellency at 50 μg/cm2 for natural oils was clove > geranium > oregano > cedarwood > thyme > amyris > patchouli > citronella > juniper berry > peppermint > cassia. For spatial bioassays, TCA was approximately twofold more active than DEET and nootkatone at 50 μg/cm2 but was not significantly different at 10 μg/cm2. In spatial assays, thyme and cassia were the most active compounds tested with 100% and 80% ticks repelled within 15 min of exposure respectively and was approximately twofold more effective than DEET at the same concentration. To translate these non-host assays to efficacy when used on the human host, we quantified repellency using a finger-climbing assay. TCA, nootkatone and DEET were equally effective in the fingertip assay, and patchouli oil was the only natural oil that significantly repelled ticks.ConclusionsThe differences in repellent potency based on the assay type suggests that the ability to discover active tick repellents suitable for development may be more complicated than with other arthropod species; furthermore, the field delivery mechanism must be considered early in development to ensure translation to field efficacy. TCA, which is naturally derived, is a promising candidate for a tick repellent that has comparable repellency to commercialized tick repellents.Graphical

Different Sensitivity of Flower-Visiting Diptera to a Neonicotinoid Insecticide: Expanding the Base for a Multiple-Species Risk Assessment Approach.

Insects play an essential role as pollinators of wild flowers and crops. At the same time, pollinators in agricultural environments are commonly exposed to pesticides, compromising their survival and the provision of pollination services. Although pollinators include a wide range of species from several insect orders, information on pesticide sensitivity is mostly restricted to bees. In addition, the disparity of methodological procedures used for different insect groups hinders the comparison of toxicity data between bees and other pollinators. Dipterans are a highly diverse insect order that includes some important pollinators. Therefore, in this study, we assessed the sensitivity of two hoverflies (Sphaerophoria rueppellii, Eristalinus aeneus) and one tachinid fly (Exorista larvarum) to a neonicotinoid insecticide (Confidor®, imidacloprid) following a comparative approach. We adapted the standardized methodology of acute contact exposure in honey bees to build dose-response curves and calculate median lethal doses (LD50) for the three species. The methodology consisted in applying 1 µL of the test solution on the thorax of each insect. Sphaerophoria rueppelli was the most sensitive species (LD50 = 10.23 ng/insect), and E. aeneus (LD50 = 18,176 ng/insect) the least. We then compared our results with those available in the literature for other pollinator species using species sensitivity distribution (SSD). Based on the SSD curve, the 95th percentile of pollinator species would be protected by a safety factor of 100 times the Apis mellifera endpoint. Overall, dipterans were less sensitive to imidacloprid than most bee species. As opposed to most bee species, oviposition and fecundity of many dipteran species can be reliably assessed in the laboratory. We measured the number of eggs laid following exposure to different insecticide doses and assessed the potential trade-off between oviposition and survival through the sublethal sensitivity index (SSI). Exposure to imidacloprid had a significant effect on fecundity, and SSI values indicated that oviposition is a sensitive endpoint for the three dipteran species tested. Future studies should integrate this information related to population dynamics in simulation models for environmental risk assessment.

A qualitative study exploring how undergraduate pharmacy students undertake a drug allergy history

Abstract Introduction If antimicrobial resistance (AMR) is not controlled, a post-antibiotic era could result in common infections and minor injuries becoming fatal. One way to combat AMR is the ‘de-labelling’ or removal of incorrect antibiotic allergy labels. At least 92% of labels corresponding to penicillin allergy are incorrect when tested.[1] This means that patients may not be receiving the correct antibiotic treatment and take longer to recover. Therefore, taking an accurate allergy history is important. Pharmacists routinely take drug allergy histories. From 2026, pharmacy students in England will graduate as prescribers, highlighting the importance of drug allergy knowledge and skills. Aim To explore how undergraduate pharmacy students undertake a drug allergy history. Methods A qualitative study utilising a constructivist approach involving a low-fidelity simulation followed by a one-to-one face-to-face semi-structured interview was conducted. Final year undergraduate Master of Pharmacy students of an English school of pharmacy were recruited via email and word-of-mouth to take part in this study. Following informed consent, participants simulated taking a drug allergy history with a student researcher. The simulation was audio-recorded and then played back to the participant as a cue for a subsequent audio-recorded semi-structured interview that explored their thought-process when taking a drug allergy history. All audio-recordings were transcribed verbatim. Transcripts were analysed using reflexive thematic analysis.[2] Results Nine participants took part in the study. The simulation and interview lasted seven minutes on average. Four themes were generated through the analysis. Theme 1: taking drug allergy history is learnt mainly through practice-based learning. Theme 2: nature, type and severity of allergic reactions information were deemed important for making clinical judgements. Theme 3: skills for taking drug allergy history are underdeveloped despite having knowledge. Theme 4: real patient contact exposure is needed to translate learning into practice. Most participants remembered learning about taking drug allergy history through practice-based learning sessions such as workshops, objective structured clinical examinations (OSCEs) and hospital placements. Participants seemed to follow a set of ‘rules’ when undertaking the simulation. For example, they stopped asking questions about allergies and decide not to dispense penicillin when they were informed that the patient was allergic to penicillin. Most participants recognised the risk of serious harm to patients if they made a mistake about patient allergies, and the need to have more real-world experiences to help translate their learning into practice. Conclusion Pharmacy students appeared to have the theoretical knowledge about drug allergies, but they were not yet able to make an appropriate clinical judgement in real-world situations. An increase in real-world clinical experience such as patient consultations in work-based placements can provide pharmacy students with valuable opportunities. By knowing how to undertake an accurate allergy history, fewer people will be inaccurately labelled as allergic, promoting antimicrobial stewardship. To our knowledge, this is the first study investigating how United Kingdom undergraduate pharmacy students undertake a drug allergy history. Our participants studied in one pharmacy school and undergraduate pharmacy students studying in other pharmacy schools may have different experiences around drug allergy history taking.

Identification and health risk evaluation of soil contaminated by polycyclic aromatic hydrocarbons at shale gas extraction sites based on positive matrix factorization

The impact of shale gas extraction on surrounding environmental media remains unclear. In this study, the current state of contamination by polycyclic aromatic hydrocarbons (PAHs), which are high-frequency contaminants of shale gas, was investigated in the soil surrounding emerging shale gas development sites. The source analysis of PAHs was conducted in the soils of shale gas extraction sites using positive matrix factorization (PMF). The health risk assessment (HRA) was calculated for ingestion, dermal contact, and inhalation exposures, and the priority sources of PAHs in the soil were jointly identified by PMF and HRA to refine the contribution level of different individual PAHs to the carcinogenic risk. The results showed that both Sichuan and Chongqing mining site soils were contaminated to different degrees. Shale gas extraction has an impact on the surrounding soil, and the highest contributing source of PAHs in the mining site soil of Sichuan was anthropogenic activity, accounting for 31.6%, whereas that in the mining site soil of Chongqing was biomass combustion and mixed automobile combustion, accounting for 35.9%. At the two mining sites in Sichuan and Chongqing, none of the three exposure pathways (ingestion, dermal contact, and inhalation) posed a carcinogenic risk to children, whereas the dermal exposure pathway posed a carcinogenic risk to adults. Health risk assessments based on specific source assignments indicate that when managing soil pollution, the control of fossil fuel combustion and vehicular emissions should be prioritized.

Evaluation of cytokine profiles related to Mycobacterium tuberculosis latent antigens using a whole-blood assay in the Philippines.

There is no useful method to discriminate between latent tuberculosis infection (LTBI) and active pulmonary tuberculosis (PTB). This study aimed to investigate the potential of cytokine profiles to discriminate between LTBI and active PTB using whole-blood stimulation with Mycobacterium tuberculosis (MTB) antigens, including latency-associated antigens. Patients with active PTB, household contacts of active PTB patients and community exposure subjects were recruited in Manila, the Philippines. Peripheral blood was collected from the participants and used for whole-blood stimulation (WBS) with either the early secretory antigenic target and the 10-kDa culture filtrate protein (ESAT-6/CFP-10), Rv3879c or latency-associated MTB antigens, including mycobacterial DNA-binding protein 1 (MDP-1), α-crystallin (Acr) and heparin-binding hemagglutinin (HBHA). Multiple cytokine concentrations were analyzed using the Bio-Plex™ multiplex cytokine assay. A total of 78 participants consisting of 15 active PTB patients, 48 household contacts and 15 community exposure subjects were eligible. The MDP-1-specific IFN-γ level in the active PTB group was significantly lower than that in the household contact group (p < 0.001) and the community exposure group (p < 0.001). The Acr-specific TNF-α and IL-10 levels in the active PTB group were significantly higher than those in the household contact (TNF-α; p = 0.001, IL-10; p = 0.001) and community exposure (TNF-α; p < 0.001, IL-10; p = 0.01) groups. However, there was no significant difference in the ESAT-6/CFP-10-specific IFN-γ levels among the groups. The patterns of cytokine profiles induced by latency-associated MTB antigens using WBS have the potential to discriminate between LTBI and active PTB. In particular, combinations of IFN-γ and MDP-1, TNF-α and Acr, and IL-10 and Acr are promising. This study provides the first demonstration of the utility of MDP-1-specific cytokine responses in WBS.

Exploring honey bee toxicological data as a proxy for assessing dimethoate sensitivity in stingless bees

The high diversity and distinctive characteristics of stingless bees pose challenges in utilizing toxicity test results for agrochemical registrations. Toxicity assessments were performed on 15 stingless bee species, along with the honey bee, using the insecticide dimethoate, following adapted OECD protocols. Median lethal doses over 24 h (24 h-LD50) were determined for exposure routes (acute oral or contact) and species. Species sensitivity distribution (SSD) curves were constructed and the 5% hazard doses (HD5) were estimated based on 24 h-LD50 values. The SSD curve was adjusted as the body weight and dimethoate response were correlated. Lighter bees (<10 mg) had lower 24 h-LD50 values. Contact exposure for adjusted HD5 suggested insufficient protection for Melipona mondury, whereas the oral exposure HD5 indicated no risks for the other 14 species. Comprehensive risk assessments are crucial for understanding the agrochemical impact on stingless bees, emphasizing the need for a broader species range in formulating conservation strategies.

Micro-Addition of Silver to Copper: One Small Step in Composition, a Change for a Giant Leap in Biocidal Activity.

The use of copper as an antimicrobial agent has a long history and has gained renewed interest in the context of the COVID-19 pandemic. In this study, the authors investigated the antimicrobial properties of an alloy composed of copper with a small percentage of silver (Cu-0.03% wt.Ag). The alloy was tested against various pathogens, including Escherichia coli, Staphylococcus aureus, Candida albicans, Pseudomonas aeruginosa, and the H1N1 virus, using contact exposure tests. Results showed that the alloy was capable of inactivating these pathogens in two hours or less, indicating its strong antimicrobial activity. Electrochemical measurements were also performed, revealing that the small addition of silver to copper promoted a higher resistance to corrosion and shifted the formation of copper ions to higher potentials. This shift led to a slow but continuous release of Cu2+ ions, which have high biocidal activity. These findings show that the addition of small amounts of silver to copper can enhance its biocidal properties and improve its effectiveness as an antimicrobial material.

Modeling the Peak-Period Bus Commuting Behavior with Staggered Work Hours Using a Regret-Minimizing Learning Method

The staggered work hours (SWH) policy is a practical strategy for managing travel demand, aiming to spread out the temporal distribution of travel volume by adjusting the schedules of travelers’ activities. The influence of the SWH policy on the commuting patterns of passengers using bus transit is not yet clear. We addressed this issue in a many-to-one bus line, treating commuters as Q-learning agents learning to minimize regrets by selecting appropriate bus runs. The learning outcomes reveal a SWH-induced equilibrium, where commuters departing from the same station with the same work start time experience identical minimal commuting costs, regardless of the chosen bus. Subsequently, we investigate the effectiveness of SWH policy by manipulating two key control variables: the division of travel demand between two categories of travelers and the staggered time interval. The results confirm that congestion during peak hours can potentially be mitigated by carefully selecting the above two key parameters. Correspondingly, we provide optimal control boundaries for these two parameters to design an effective SWH policy. Furthermore, we explore the combined impact of physical distancing and SWH policy on traffic flow patterns during an epidemic outbreak. Concurrently, we assess the infection risk through a surrogate index, revealing that the SWH policy has a positive effect in mitigating the risk of contact exposure.

Potential of Ocotea indecora Essential Oil for Controlling Drosophila suzukii: Molecular Predictions for Toxicity and Selectivity to Beneficial Arthropods.

The protection of soft-skinned fruits against Drosophila suzukiihas relied primarily on the efficacy of a few synthetic molecules. Despite their short-term efficacy, these molecules can cause environmental pollution, unintendedly affect non-target organisms, and fail to provide sustainable control. The shortfalls of using synthetic pesticides warrant the search for alternatives, such as essential oils extracted from plants, with greater eco-friendlier properties. Here, we chemically characterized and evaluated the toxicity of the essential oil extracted from leaves of Ocotea indecora (Schott) Mez (Lauraceae) against D. suzukii via two exposure pathways (ingestion and contact). We also assessed the selectivity of the essential oil to two predatory natural enemies, Eriopis connexaand Chrysoperla externaand two pollinator bees, Apis melliferaand Partamona helleri. In addition, we conducted in silico predictions to investigate potential interactions between the major compound of the essential oil and the insects' transient receptor potential (TRP) channels. Our chromatographic analysis revealed sesquirosefuran (87%) as the major compound. Higher toxicity to adults of D. suzukii was observed in contact exposure (LC50 = 0.43 μL mL-1) compared to ingestion (LC50 = 0.72 μL mL-1). However, the essential oil did not cause mortality to the non-target organisms tested here, even when applied at 2.20 μL mL-1. Molecular predictions demonstrated that sesquirosefuran binds more stably to the TRP channels of D. suzukii than to those expressed in beneficial arthropods. Collectively, our findings provide the initial framework for the potential use of O. indecora essential oil as a sustainable alternative for managing D. suzukii infestations.

Advanced Camera-Based Scoliosis Screening via Deep Learning Detection and Fusion of Trunk, Limb, and Skeleton Features.

Scoliosis significantly impacts quality of life, highlighting the need for effective early scoliosis screening (SS) and intervention. However, current SS methods often involve physical contact, undressing, or radiation exposure. This study introduces an innovative, non-invasive SS approach utilizing a monocular RGB camera that eliminates the need for undressing, sensor attachment, and radiation exposure. We introduce a novel approach that employs Parameterized Human 3D Reconstruction (PH3DR) to reconstruct 3D human models, thereby effectively eliminating clothing obstructions, seamlessly integrated with an ISANet segmentation network, which has been enhanced by Multi-Scale Fusion Attention (MSFA) module we proposed for facilitating the segmentation of distinct human trunk and limb features (HTLF), capturing body surface asymmetries related to scoliosis. Additionally, we propose a Swin Transformer-enhanced CMU-Pose to extract human skeleton features (HSF), identifying skeletal asymmetries crucial for SS. Finally, we develop a fusion model that integrates the HTLF and HSF, combining surface morphology and skeletal features to improve the precision of SS. The experiments demonstrated that PH3DR and MSFA significantly improved the segmentation and extraction of HTLF, whereas ST-based CMU-Pose substantially enhanced the extraction of HSF. Our final model achieved a comparable F1 (0.895 ±0.014) to the best-performing baseline model, with only 0.79% of the parameters and 1.64% of the FLOPs, achieving 36 FPS-significantly higher than the best-performing baseline model (10 FPS). Moreover, our model outperformed two spine surgeons, one less experienced and the other moderately experienced. With its patient-friendly, privacy-preserving, and easily deployable solution, this approach is particularly well-suited for early SS and routine monitoring.

Serological survey on Hepatitis E virus in Namibian dogs, cats, horses, and donkeys.

The present study investigated the seropositivity rate of Hepatitis E virus (HEV) in domestic and working animals in Namibia, which included dogs, cats, horses, and donkeys. HEV poses a growing threat as a significant cause of human hepatitis globally and has several genotypes of varying zoonotic potential. As epidemiological data on the seroprevalence of HEV in Namibia is scarce, a serosurvey was conducted on archived serum samples of 374 dogs, 238 cats, 98 horses, and 60 donkeys collected between 2018 and 2022 from different regions, to assess the potential of these animals as sources of HEV infection. The findings revealed that 10.43% (n = 39/374) canine and 5.88% (n = 14/238) feline samples tested positive for HEV antibodies, whereas no seropositivity was detected in horses and donkeys. The study further examined the risk factors associated with HEV seropositivity, including animal sex, age, and geographical region, and noted a higher prevalence in dogs living in areas with intensive pig farming. Although there is no direct evidence indicating that these animals served as major reservoirs for HEV transmission to humans, the study underscores the importance of preventive measures to minimize contact exposure with pets considering the potential zoonotic risk, especially for susceptible risk groups. Further research is needed to explore the zoonotic potential of domestic animals and the epidemiological links between animal and human HEV transmissions in Namibia.

ОЦЕНКА ТОКСИЧЕСКОГО ДЕЙСТВИЯ ИНСЕКТИЦИДА БОВЕРИКС, Ж НА МЕДОНОСНЫХ ПЧЕЛ А. MELLIFERA MELLIFERA L.

The article presents the results of studies on the evaluation of the toxic effect of the biological insecticide Boveriks, G on honey bees A. mellifera mellifera L. Boveriks, G – bioinsecticide developed by research and development enterprise "BashIncom". It includes the entomopathogenic fungus Beaveria bassiana, strain VKPM F-1357. Biological fungicide BioSleep BW was used as a reference substance. The experiment used honey bees Apis mellifera mellifera L. of the Carpathian breed, which were kept in wooden cages. Acute oral toxicity was studied by feeding sugar syrup to bees with the addition of insecticides at concentrations of 10, 50 and 100 ml per 1 liter of syrup. For the test for acute contact toxicity, the anesthetized bees of the experimental groups were treated individually by applying 1 µl of an aqueous solution of insecticides in the same concentrations with a microapplicator to the upper part of the thorax of each bee. At the end of the experiment, 96 hours after feeding the bees with sugar syrup containing the insecticide Boveriks, G in different dosages, the mortality rate of bees in the experimental groups did not reach the level of 50 %. The maximum mortality rate was 16.7 %. There were no significant differences with the control and with the reference substance in terms of mortality in the experimental groups. The analysis of the data obtained allows us to conclude that the studied doses of the bioinsecticide Boveriks, G are not toxic to bees both during oral and contact exposure of the drug. The lethal dose LD50 in determining the acute oral toxicity of the active substance of the drug lies above the value of 1 × 105 CFU/bee; lethal concentration of LK50 – above the value of 100 ml/l, when determining acute contact toxicity LD50 – above the value of 1 × 104 CFU / bee; LK50 – above 100 ml/l.