Effect of electrode distance in grid electrode: Numerical models and in vitro tests

Electrochemotherapy is an emerging local treatment for the management of superficial tumors and, among these, also chest wall recurrences from breast cancer. Generally, the treatment of this peculiar type of tumor requires the coverage of large skin areas. In these cases, electrochemotherapy treatment by means of standard small size needle electrodes (an array of 0.73 cm spaced needles, which covers an area of 1.5 cm2) is time-consuming and can allow an inhomogeneous coverage of the target area. We have previously designed grid devices suitable for treating an area ranging from 12 to 200 cm2. In this study, we propose different approaches to study advantages and drawbacks of a grid device with needles positioned 2 cm apart. The described approach includes a numerical evaluation to estimate electric field intensity, followed by an experimental quantification of electroporation on a cell culture. The electric field generated in a conductive medium has been studied by means of 3-dimensional numerical models with varying needle pair distance from 1 to 2 cm. In particular, the electric field evaluation shows that the electric field intensity with varying needle distance is comparable in the area in the middle of the 2 electrodes. Differently, near needles, the electric field intensity increases with the increasing electrode distance and supply voltage. The computational results have been correlated with experimental ones obtained in vitro on cell culture. In particular, electroporation effect has been assessed on human breast cancer cell line MCF7, cultured in monolayer. The use of 2-cm distant needles, supplied by 2000 V, produced an electroporation effect in the whole area comprised between the electrodes. Areas of cell culture where reversible and irreversible electroporation occurred were identified under microscope by using fluorescent dyes. The coupling of computation and experimental results could be helpful to evaluate the effect of the needle distance on the electric field intensity in cell cultures in terms of reversible or irreversible electroporation

Dietary Restriction Depends on Nutrient Composition to Extend Chronological Lifespan in Budding Yeast Saccharomyces cerevisiae

10.1371/journal.pone.0064448PLoS ONE85

Development of cluster-based energy management scheme for residential usages in the smart grid community

Several efforts have been taken to promote clean energy towards a sustainable and green economy. Existing sources of electricity present some complications concerning consumers, utility owners, and the environment. Utility operators encourage household applicants to employ residential energy management (REM) systems. Renewable energy sources (RESs), energy storage systems (ESS), and optimal energy allocation strategies are used to resolve these difficulties. In this paper, the development of a cluster-based energy management scheme for residential consumers of a smart grid community is proposed to reduce energy use and monetary cost. Normally, residential consumers deal with household appliances with various operating time slots depending on consumer preferences. A simulator is designed and developed using C++ software to resolve the residential consumer’s REM problem. The benefits of the RESs, ESS, and optimal energy allocation techniques are analyzed by taking in account three different scenarios. Extensive case studies are carried out to validate the effectiveness of the proposed cluster-based energy management scheme. It is demonstrated that the proposed method can save energy and costs up to 45% and 56% compared to the existing methods. © 2020 by the authors. Licensee MDPI, Basel, Switzerland

Detection of Leishmania infantum DNA mainly in Rhipicephalus sanguineus male ticks removed from dogs living in endemic areas of canine leishmaniosis

Background: Sand flies are the only biologically adapted vectors of Leishmania parasites, however, a possible role in the transmission of Leishmania has been proposed for other hematophagous ectoparasites such as ticks. In order to evaluate natural infection by Leishmania infantum in Rhipicephalus sanguineus ticks, taking into account its close association with dogs, 128 adult R. sanguineus ticks removed from 41 dogs living in endemic areas of canine leishmaniosis were studied. Methods: Individual DNA extraction was performed from each tick and whole blood taken from dogs. Dog sera were tested for IgG antibodies to L. infantum antigen by ELISA and L. infantum real-time PCR was performed from canine whole blood samples and ticks. Results: Leishmania infantum PCR was positive in 13 ticks (10.1%) including one female, (2.0%) and 12 males (15.2%), and in only five dogs (12.2%). Male ticks had a significantly higher infection rate when compared to female R. sanguineus. The percentage of L. infantum seroreactive dogs was 19.5%. All but two PCR positive dogs were seroreactive. Leishmania infantum PCR positive ticks were removed from seropositive and seronegative dogs with a variety of PCR results. Conclusions: This study demonstrates high prevalence of L. infantum DNA in R. sanguineus ticks removed from L. infantum seropositive and seronegative dogs. The presence of L. infantum DNA was detected mainly in male ticks possibly due to their ability to move between canine hosts and feed on several canine hosts during the adult life stage. Additional studies are needed to further explore the role of R. sanguineus ticks and in particular, male adults, in both the epidemiology and immunology of L. infantum infection in dogs in endemic areas

The prevalence and risk factors of subclinical mastitis in water buffalo (Bubalis bubalis) in Bangladesh.

Subclinical mastitis (SCM) in water buffalo is responsible for reduced milk yield and quality. This cross-sectional study was carried out to a) estimate the prevalence of SCM, b) identify risk factors associated with SCM, and c) identify farm-level risk factors associated with bulk milk somatic cell count (BMSCC). The buffalo farms included in this study represented five rearing systems: free-range, semi-free-range, household, semi-intensive, and intensive, providing a total of 3491 functional quarters of 880 lactating buffalo on 248 farms. The California mastitis test score was used to identify SCM. Bulk milk samples (n = 242) were used for farm-level BMSCC. Quarter and buffalo-level risk factors for SCM were measured using questionnaires and observations. The overall SCM prevalence was high at 27.9% at the quarter-level (25th and 75th percentiles: 8.3% and 41.7%) and 51.5% at buffalo-level (25th and 75th percentiles: 33.3% and 66.7%). The geometric mean BMSCC was 217,000 cells/mL of milk (ranging from 36,000-1,213,000 cells/mL), which is low on average, but some farms could improve substantially. The buffalo rearing system, udder location (left versus right), teat shape, udder asymmetry, number of milkers, and having a quarantine facility were associated with buffalo udder health. Our findings suggest that mainly using free-range rearing systems may help decrease the prevalence of SCM primarily by employing buffalo breeding and better farm biosecurity, and udder health control strategies can be designed based on our findings

Pathogen group-specific risk factors for intramammary infection in water buffalo

A cross-sectional study was conducted to estimate the prevalence of intramammary infection (IMI) associated bacteria and to identify risk factors for pathogen group-specific IMI in water buffalo in Bangladesh. A California Mastitis Test (CMT) and bacteriological cultures were performed on 1,374 quarter milk samples collected from 763 water buffalo from 244 buffalo farms in nine districts in Bangladesh. Quarter, buffalo, and farm-related data were obtained through questionnaires and visual observations. A total of 618 quarter samples were found to be culture positive. Non-aureus staphylococci were the predominant IMI-associated bacterial species, and Staphylococcus (S.) chromogenes, S. hyicus, and S. epidermidis were the most common bacteria found. The proportion of non-aureus staphylococci or Mammaliicoccus sciuri (NASM), S. aureus, and other bacterial species identified in the buffalo quarter samples varied between buffalo farms. Therefore, different management practices, buffalo breeding factors, and nutrition were considered and further analyzed when estimating the IMI odds ratio (OR). The odds of IMI by any pathogen (OR: 1.8) or by NASM (OR: 2.2) was high in buffalo herds with poor milking hygiene. Poor cleanliness of the hind quarters had a high odds of IMI caused by any pathogen (OR: 2.0) or NASM (OR: 1.9). Twice daily milking (OR: 3.1) and farms with buffalo purchased from another herd (OR: 2.0) were associated with IMI by any pathogen. Asymmetrical udders were associated with IMI-caused by any bacteria (OR: 1.7). A poor body condition score showed higher odds of IMI by any pathogen (OR: 1.4) or by NASM (OR: 1.7). This study shows that the prevalence of IMI in water buffalo was high and varied between farms. In accordance with the literature, our data highlight that IMI can be partly controlled through better farm management, primarily by improving hygiene, milking management, breeding, and nutrition

Prevalence of foodborne zoonotic pathogens in milk and milk products along the water buffalo milk value chain in Bangladesh

Buffalo milk and milk products are considered highly valued due to their superior nutritional quality and health benefits. Therefore, assessing the prevalence of zoonotic pathogens in buffalo milk is crucial for ensuring the safety of the consumers. The present study aimed to estimate the prevalence of important foodborne zoonotic pathogens in milk and milk products and identify the associated factors in the buffalo milk chain nodes in Bangladesh. One hundred and forty-three samples were collected from farm bulk milk (n = 34), middleman (n = 37), milk collection center (n = 37), and milk product shops (n= 35) and were analyzed using RT-PCR to estimate the prevalence of seven important zoonotic pathogens: Staphylococ cus aureus, Escherichia (E.) coli, Shiga toxin- producing Esch erichia (E.) coli O157:H7, Campylobacter (C.) jejuni, Listeria (L.) monocytogenes, Salmonella (S.) enterica, and Yersinia (Y.) enterocolitica. Escherichia coli was the most prevalent pathogen along the milk chain nodes. The prevalence of the pathogens was high over the buffalo milk value chain. Three classical enterotoxin- encoded genes for E. coli O157:H7 were tested e.g., eae, stx1, and stx2 of which the stx2 genotype was most prevalent and was most common in milk products (74%). The prevalence of L. monocytogenes and Y. enterocolitica were more prevalent on the farms (65 - 79%) than in the later milk value chain nodes. The prevalence of S. enterica was rather low (0 - 2.9%) in all the milk chain nodes and all the samples were negative for C. jejuni. These results suggest that buffalo milk consumers in Bangladesh are at risk for L. monocytogenes and Y. enterocolitica on the farms and E. coli O157:H7 with stx2 genotype at the milk product shops. S. enterica and C. jejuni are not frequent contaminants of the buffalo milk chain in Bangladesh. Avoiding plastic containers and dirty clothes for cleaning milk containers may help reduce contamination in the buffalo milk value chain