Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 58
Filtrar
1.
Micromachines (Basel) ; 15(9)2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-39337735

RESUMO

This study proposes a single-stage lattice-type acoustic filter using an analytical solution method for either a narrow passband filter or a wider passband filter using two kinds of parameter assignments in the Butterworth-Van Dyke (BVD) model. To achieve the goal of a large bandwidth or high return loss, two first-order all-pass conditions are used. For multi-stage lattice-type filters, the cost function is defined and design parameters are extracted by using pattern search, while the initial values are provided through single-stage design to shorten optimization time and allow convergence to a better solution. This method provides the S-parameter frequency response for the filter on the YX 42° cut angle of lithium tantalate (electromechanical coupling coefficient of about 6%) that can meet the system specifications as much as possible. Finally, the three-stage lattice-type was applied to various 5G bands with a fractional bandwidth of 2-5%, resulting in a passband return loss of 10 dB and an out-of-band rejection of 40 dB or more.

2.
BMC Vet Res ; 20(1): 183, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38720324

RESUMO

BACKGROUND: Pigs are susceptible to several ruminant pathogens, including Coxiella burnetti, Schmallenberg virus (SBV) and bovine viral diarrhea virus (BVDV). These pathogens have already been described in the pig population, although the dynamics of the infection and the impact on pig farms are currently unclear. The aim of this work was to evaluate the presence of these infections in the pig population of the Campania region, southern Italy, and to evaluate the risk factors associated with a greater risk of exposure. RESULTS: A total of 414 serum samples belonging to 32 herds were tested for the presence of antibodies against SBV, Coxiella, and BVD using commercial multispecies ELISA kits. SBV (5.3%) was the most prevalent pathogen, followed by Coxiella (4.1%) and BVD (3%). The risk factors included in the study (age, sex, province, farming system, ruminant density and major ruminant species) had no influence on the probability of being exposed to BVD and Coxiella, except for the location, in fact more pigs seropositive to Coxiella were found in the province of Caserta. However, the univariate analysis highlighted the influence of age, location, and sex on exposure to SBV. The subsequent multivariate analysis statistically confirmed the importance of these factors. The presence of neutralizing antibodies for SBV and BVDV, or antibodies directed towards a specific phase of infection for Coxiella was further confirmed with virus-neutralization assays and phase-specific ELISAs in a large proportion of positive samples. The presence of high neutralizing antibody titers (especially for SBV) could indicate recent exposures. Twelve of the 17 positive samples tested positive for antibodies against Coxiella phase I or II antigens, indicating the presence of both acute and chronic infections (one animal tested positive for both phases antibodies). CONCLUSIONS: Our study indicates a non-negligible exposure of pigs from southern Italy to the above pathogens. Further studies are necessary to fully understand the dynamics of these infections in pigs, the impact on productivity, and the public health consequences in the case of Coxiella.


Assuntos
Anticorpos Antivirais , Febre Q , Doenças dos Suínos , Animais , Itália/epidemiologia , Estudos Soroepidemiológicos , Suínos , Fatores de Risco , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/microbiologia , Doenças dos Suínos/virologia , Febre Q/epidemiologia , Febre Q/veterinária , Feminino , Masculino , Anticorpos Antivirais/sangue , Vírus da Diarreia Viral Bovina/imunologia , Anticorpos Antibacterianos/sangue , Orthobunyavirus/imunologia , Orthobunyavirus/isolamento & purificação , Coxiella burnetii/imunologia , Coxiella burnetii/isolamento & purificação , Doença das Mucosas por Vírus da Diarreia Viral Bovina/epidemiologia , Infecções por Bunyaviridae/epidemiologia , Infecções por Bunyaviridae/veterinária , Pseudorraiva/epidemiologia , Ensaio de Imunoadsorção Enzimática/veterinária
3.
Res Vet Sci ; 170: 105183, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38359648

RESUMO

The role of wildlife in maintaining infectious diseases in veterinary medicine is often neglected, although the disease eradication process in domestic animals is continuously affected by the risk of pathogens transmission from wildlife as a primary source. The main aim of this paper was to estimate the prevalence and distribution of selected infectious diseases in wild ruminants in Serbia. In total, 259 sera from wild ruminants were tested for specific antibodies to bluetongue virus, Schmallenberg virus, Bovine viral diarrhea/border disease virus, Capripox virus, West Nile fever virus, Bovine herpes virus-1, Coxiella burnetii, Brucella spp., and Leptospira spp. Specific Capripox virus and Leptospira spp. antibodies were not detected in any of the 259 wild ruminant samples. Although one animal was detected positive for BVDV/BDV specific antibodies, with 99.8% confidence, the prevalence of BVD within this population could be very low i.e. essentially free from BVD infection. One and three positive animals were detected for Brucella spp. and Coxiella burnetii antibodies, respectively. Bovine herpes virus-1 specific antibodies were detected in 20.85% of the samples. The estimated seroprevalence of vector-borne diseases was 20.5% for Schmallenberg disease, 34.3% for West Nile fever, and 38.6% for Bluetongue. Considering the reported results, wildlife health status is a result of different factors in complex relation, such as the presence of disease in domestic animals, disease nature, pathogen characteristics, environmental factors, presence, and vector competence. Wildlife should be considered not only as a risk but as a source of important information on disease distribution and its indicators.


Assuntos
Doenças Transmissíveis , Febre do Nilo Ocidental , Animais , Sérvia/epidemiologia , Estudos Soroepidemiológicos , Estudos Transversais , Febre do Nilo Ocidental/veterinária , Ruminantes , Animais Selvagens , Animais Domésticos , Doenças Transmissíveis/veterinária , Anticorpos Antivirais
4.
N Z Vet J ; 72(2): 66-78, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38212951

RESUMO

AIM: To determine which genotypes of bovine viral diarrhoea virus (BVDV) circulate among cattle in New Zealand. METHODS: Samples comprised BVDV-1-positive sera sourced from submissions to veterinary diagnostic laboratories in 2019 (n = 25), 2020 (n = 59) and 2022 (n = 74) from both beef and dairy herds, as well as archival BVDV-1 isolates (n = 5). Fragments of the 5' untranslated region (5' UTR) and glycoprotein E2 coding sequence of the BVDV genome were amplified and sequenced. The sequences were aligned to each other and to international BVDV-1 sequences to determine their similarities and phylogenetic relationships. The 5' UTR sequences were also used to create genetic haplotype networks to determine if they were correlated with selected traits (location, type of farm, and year of collection). RESULTS: The 5' UTR sequences from New Zealand BVDV were closely related to each other, with pairwise identities between 89% and 100%. All clustered together and were designated as BVDV-1a (n = 144) or BVDV-1c (n = 5). There was no evidence of a correlation between the 5' UTR sequence and the geographical origin within the country, year of collection or the type of farm. Partial E2 sequences from New Zealand BVDV (n = 76) showed 74-100% identity to each other and clustered in two main groups. The subtype assignment based on the E2 sequence was the same as based on the 5' UTR analysis. This is the first comprehensive analysis of genomic variability of contemporary New Zealand BVDV based on the analysis of the non-coding (5' UTR) and coding (E2) sequences. CONCLUSIONS AND CLINICAL RELEVANCE: Knowledge of the diversity of the viruses circulating in the country is a prerequisite for the development of effective control strategies, including a selection of suitable vaccines. The data presented suggest that New Zealand BVDV are relatively homogeneous, which should facilitate eradication efforts including selection or development of the most suitable vaccines.


Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina , Doenças dos Bovinos , Vírus da Diarreia Viral Bovina Tipo 1 , Vírus da Diarreia Viral Bovina , Vacinas , Bovinos , Animais , Vírus da Diarreia Viral Bovina/genética , Filogenia , Regiões 5' não Traduzidas , Nova Zelândia/epidemiologia , Doença das Mucosas por Vírus da Diarreia Viral Bovina/epidemiologia , Doença das Mucosas por Vírus da Diarreia Viral Bovina/prevenção & controle , Vírus da Diarreia Viral Bovina Tipo 1/genética , Genótipo
5.
Animals (Basel) ; 13(24)2023 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-38136837

RESUMO

An important factor for dairy cattle farmers is the profitability of cattle rearing, which is influenced by the animals' health and reproductive parameters, as well as their genomic stability and integrity. Bovine viral diarrhea (BVD) negatively affects the health of dairy cattle and causes reproductive problems. The aim of the study was to identify genomic instability in cows with reproductive disorders following infection with the BVD virus. The material for analysis was peripheral blood from Holstein-Friesian cows with reproductive problems, which had tested positive for BVD, and from healthy cows with no reproductive problems, which had tested negative for BVD. Three cytogenetic tests were used: the sister chromatid exchange assay, fragile sites assay, and comet assay. Statistically significant differences were noted between the groups and between the individual cows in the average frequency of damage. The assays were good biomarkers of genomic stability and enabled the identification of individuals with an increased frequency of damage to genetic material that posed a negative impact on their health. The assays can be used to prevent disease during its course and evaluate the genetic resistance of animals. This is especially important for the breeder, both for economic and breeding reasons. Of the three assays, the comet assay proved to be the most sensitive for identifying DNA damage in the animals.

6.
Vopr Virusol ; 68(6): 465-478, 2023 Dec 26.
Artigo em Russo | MEDLINE | ID: mdl-38156563

RESUMO

The review provides an analysis of literature data on the persistent form of Bovine Viral diarrhea/Mucosal disease (BVD) and is focused on virus and host factors, including those related to immune response, that contribute the persistence of the virus. BVD is a cattle disease widespread throughout the world that causes significant economic damage to dairy and beef cattle. The disease is characterized by a variety of clinical signs, including damage to the digestive and respiratory organs, abortions, stillbirths and other failures of reproductive functions.


Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina , Doenças dos Bovinos , Vírus da Diarreia Viral Bovina , Animais , Gravidez , Feminino , Bovinos , Vírus da Diarreia Viral Bovina/genética , Doença das Mucosas por Vírus da Diarreia Viral Bovina/diagnóstico , Diarreia/veterinária
7.
Pharmacol Res ; 197: 106955, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37820855

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive and lethal malignancies lacking effective therapies. KRAS mutations that occur in over 90% of PDAC are major oncogenic drivers of PDAC. The MAPK signaling pathway plays a central role in KRAS-driven oncogenic signaling. However, pharmacological inhibitors of the MAPK pathway are poorly responded in KRAS-mutant PDAC, raising a compelling need to understand the mechanism behind and to seek new therapeutic solutions. Herein, we perform a screen utilizing a library composed of 800 naturally-derived bioactive compounds to identify natural products that are able to sensitize KRAS-mutant PDAC cells to the MAPK inhibition. We discover that tetrandrine, a natural bisbenzylisoquinoline alkaloid, shows a synergistic effect with MAPK inhibitors in PDAC cells and xenograft models. Mechanistically, pharmacological inhibition of the MAPK pathway exhibits a double-edged impact on the TRAIL-death receptor axis, transcriptionally upregulating TRAIL yet downregulating its agonistic receptors DR4 and DR5, which may explain the limited therapeutic outcomes of MAPK inhibitors in KRAS-mutant PDAC. Of great interest, tetrandrine stabilizes DR4/DR5 protein via impairing ubiquitination-mediated protein degradation, thereby allowing a synergy with MAPK inhibition in inducing apoptosis in KRAS-mutant PDAC. Our findings identify a new combinatorial approach for treating KRAS-mutant PDAC and highlight the role of TRAIL-DR4/DR5 axis in dictating the therapeutic outcome in KRAS-mutant PDAC.


Assuntos
Benzilisoquinolinas , Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Proteínas Proto-Oncogênicas p21(ras)/genética , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/genética , Benzilisoquinolinas/farmacologia , Benzilisoquinolinas/uso terapêutico , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Receptores de Morte Celular , Neoplasias Pancreáticas
8.
Sensors (Basel) ; 23(15)2023 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-37571551

RESUMO

To accurately model the effect of the load caused by a liquid medium as a function of its viscosity, the fractional order Butterworth-Van Dyke (BVD) model of the QCM sensor is proposed in this study. A comprehensive understanding of the fractional order BVD model followed by a simulation of situations commonly encountered in experimental investigations underpins the new QCM sensor approach. The Levenberg-Marquardt (LM) algorithm is used in two fitting steps to extract all parameters of the fractional order BVD model. The integer-order electrical parameters were determined in the first step and the fractional order parameters were extracted in the second step. A parametric investigation was performed in air, water, and glycerol-water solutions in ten-percent steps for the fractional order BVD model. This indicated a change in the behavior of the QCM sensor when it swapped from air to water, modeled by the fractional order BVD model, followed by a specific dependence with increasing viscosity of the glycerol-water solution. The effect of the liquid medium on the reactive motional circuit elements of the BVD model in terms of fractional order calculus (FOC) was experimentally demonstrated. The experimental results demonstrated the value of the fractional order BVD model for a better understanding of the interactions occurring at the QCM sensor surface.

9.
Sensors (Basel) ; 23(10)2023 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-37430852

RESUMO

A research topic of equal importance to technological and application fields related to quartz crystal is the presence of unwanted responses known as spurious resonances. Spurious resonances are influenced by the surface finish of the quartz crystal, its diameter and thickness, and the mounting technique. In this paper, spurious resonances associated with fundamental resonance are studied by impedance spectroscopy to determine their evolution under load conditions. Investigation of the response of these spurious resonances provides new insights into the dissipation process at the QCM sensor surface. The significant increase of the motional resistance for spurious resonances at the transition from air to pure water is a specific situation revealed experimentally in this study. It has been shown experimentally that in the range between the air and water media, spurious resonances are much more attenuated than the fundamental resonance, thus providing support for investigating the dissipation process in detail. In this range, there are many applications in the field of chemical sensors or biosensors, such as VOC sensors, humidity sensors, or dew point sensors. The evolution of D factor with increasing medium viscosity is significantly different for spurious resonances compared to fundamental resonance, suggesting the usefulness of monitoring them in liquid media.

10.
Vet Res ; 53(1): 102, 2022 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-36461110

RESUMO

Considering human decision-making is essential for understanding the mechanisms underlying the propagation of real-life diseases. We present an extension of a model for pathogen spread that considers farmers' dynamic decision-making regarding the adoption of a control measure in their own herd. Farmers can take into account the decisions and observed costs of their trade partners or of their geographic neighbours. The model and construction of such costs are adapted to the case of bovine viral diarrhoea, for which an individual-based stochastic model is considered. Simulation results suggest that obtaining information from geographic neighbours might lead to a better control of bovine viral diarrhoea than considering information from trade partners. In particular, using information from all geographic neighbours at each decision time seems to be more beneficial than considering only the information from one geographic neighbour or trade partner at each time. This study highlights the central role that social dynamics among farmers can take in the spread and control of bovine viral diarrhoea, providing insights into how public policy efforts could be targeted in order to increase voluntary vaccination uptake against this disease in endemic areas.


Assuntos
Fazendeiros , Infecções por Pestivirus , Animais , Humanos , Comportamento Imitativo , Infecções por Pestivirus/veterinária , Vacinação/veterinária , Diarreia/prevenção & controle , Diarreia/veterinária
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA