Design of Mixed-Matrix MOF Membranes with Asymmetric Filler Density and Intrinsic MOF/Polymer Compatibility for Enhanced Molecular Sieving.

The separation of high-value-added chemicals from organic solvents is important for many industries. Membrane-based nanofiltration offers a more energy-efficient separation than the conventional thermal processes. Conceivably, mixed-matrix membranes (MMMs), encompassing metal-organic frameworks (MOFs) as fillers, are poised to promote selective separation via molecular sieving, synergistically combining polymers flexibility and fine-tuned porosity of MOFs. Nevertheless, conventional direct mixing of MOFs with polymer solutions results in underutilization of the MOF fillers owing to their uniform cross-sectional distribution. Therefore, in this work, a multizoning technique is proposed to produce MMMs with an asymmetric-filler density, in which the MOF fillers are distributed only on the surface of the membrane, and a seamless interface at the nanoscale. The design strategy demonstrates five times higher MOF surface coverage, which results in a solvent permeance five times higher than that of conventional MMMs while maintaining high selectivity. Practically, MOFs are paired with polymers of similar chemical nature to enhance their adhesion without the need for surface modification. The approach offers permanently accessible MOF porosity, which translates to effective molecular sieving, as exemplified by the polybenzimidazole and Zr-BI-fcu-MOF system. The findings pave the way for the development of composite materials with a seamless interface.

Global trends of pyrolysis research: a bibliometric analysis.

Pyrolysis has become an interesting waste valorization method leading to an increasing number of research studies in this field in the last decade. The present study aims to provide a comprehensive knowledge map of scientific production in pyrolysis, discuss the current state of research, and identify the main research hotspots and trends in recent years. The systematic review, supported by analysis of countries and institutions, keyword co-occurrence analysis, analysis of keyword trends, journal analysis, and article impact, was carried out on 6234 journal articles from the Science Citation Index Expanded database of the Web of Science Core Collection. As a result, four main research hotspots were identified: 1) characterization techniques and pyrolysis kinetic models, 2) biochar production and its main applications, 3) bio-oil production and catalytic pyrolysis, and 4) co-pyrolysis, which has become a consolidated research hotspot since 2018. Additionally, the main challenges and opportunities for future research have been identified, such as 1) the development of multi-step kinetic models for studying complex wastes, 2) the integration of biochar into other valorization processes, such as anaerobic digestion, and 3) the development of catalytic hydropyrolysis for the valorization of organic waste. This bibliometric analysis provides a visualization of the current context and future trends in pyrolysis, facilitating future collaborative research and knowledge exchange.

Pyrolysis of municipal solid waste: A kinetic study through multi-step reaction models.

The present study endeavors to establish a comprehensive kinetic analysis of Municipal Solid Waste residue pyrolysis. As the sample exhibits four distinct degradation stages, it has been carried out by adopting a multi-step process behavior. Different approaches have been compared, including five isoconversional methods (Kissinger-Akahira-Sunose, Ozawa-Flynn-Wall, Starink, Friedman and Advanced integral Vyazovkin), Mathematical Deconvolution Analysis, and Independent Parallel Reaction Model. The study focuses on the two active pyrolysis steps, the first one corresponds to the biomass components between 150 and 400 °C, with the decomposition peak between 300 and 350 °C, whereas the second corresponds to the plastic fraction with temperature ranging between 400 and 520 °C. The activation energy values obtained from the different kinetic methods for both steps are estimated at 240 and 250 kJ/mol, respectively. It was observed that the biomass components degradation obeys a third-order kinetic model, while the plastic fraction follows a first-order kinetic model. The analytical pyrolysis of the two main stages allows for the identification and semi-quantification of the compounds produced during municipal solid waste pyrolysis. Through analytical pyrolysis, it has been determined that up to 64 % of hydrocarbons are produced, of which 24 % correspond to aromatic compounds. Meanwhile, 20 % of oxygenated compounds were obtained, with ketones, furans, and acids being the most predominant families.

Hydrogen Bonds in Lead Halide Perovskites: Insights from Ab Initio Molecular Dynamics.

Hydrogen bonds (HBs) play an important role in the rotational dynamics of organic cations in hybrid organic/inorganic halide perovskites, thus affecting the structural and electronic properties of the perovskites. However, the properties and even the existence of HBs in these perovskites are not well established. In this study, we investigate HBs in perovskites MAPbBr3 (MA+ = CH3NH3+), FAPbI3 (FA+ = CH(NH2)2+), and their solid solution with composition (FAPbI3)7/8(MAPbBr3)1/8, using ab initio molecular dynamics and electronic structure calculations. We consider HBs donated by X-H fragments (X = N and C) of the organic cations and accepted by the halides (Y = Br and I) and characterize their properties based on pair distribution functions and on a combined distribution function of the hydrogen-acceptor distance with the donor-hydrogen-acceptor angle. By analyzing these functions, we establish geometrical criteria for HB existence based on the hydrogen-acceptor (H-Y) distance and donor-hydrogen-acceptor angle (X-H-Y). The distance condition is defined as d(H - Y) < 3 Å for N-H-donated HBs and d(H - Y) < 4 Å for C-H-donated HBs. The angular condition is 135° < (X - H - Y) < 180° for both types of HBs. A HB is considered to be formed when both angular and distance conditions are simultaneously satisfied. At the simulated temperature (350 K), the HBs dynamically break and form. We compute the time correlation functions of HB existence and HB lifetimes, which range between 0.1 and 0.3 ps at that temperature. The analysis of HB lifetimes indicates that N-H-Br bonds are relatively stronger than N-H-I bonds, while C-H-Y bonds are weaker, with a minimal influence from the halide and cation. To evaluate the impact of HBs on the vibrational spectra, we present the power spectrum in the region of N-H and C-H stretching modes, comparing them with the normal mode frequencies of isolated cations. We show that the peaks associated with N-H stretching modes in perovskites are redshifted and asymmetrically deformed, while the C-H peaks do not exhibit these effects.

Temporal Release and Denature of Several Mediators in Pure Platelet-Rich Plasma and Temperature-Induced Platelet Lysates Derived from a Similar Bovine Platelet Concentrate.

There is scarce information about bovine platelet-rich plasma/platelet-rich gel (PRP/PRG) and related hemocomponents (HCs), such as platelet lysates (PLs), including growth factor (GF) and cytokine concentrations, and how the stability of these biomolecules could be affected by time and temperature. This study aimed to evaluate the release and stability of transforming growth factor beta 1 (TGF-ß 1), interleukin 4 (IL-4), and tumor necrosis factor alpha (TNF-α) contained in bovine pure PRP (P-PRP) and temperature-induced PL (TIPL) coming from a similar platelet concentrate (PC) at 4 and 37°C at 3 and 96 h. Platelet concentrates (PCs) presented a 1.7-fold concentration of platelets (PLTs) with negligible counts of white blood cells (WBCs) when compared to the counts for these cells in whole blood. TGF-ß 1 concentrations were significantly lowest in plasma followed by TIPL, chemical-induced PL (CIPL), and P-PRP. IL-4 and TNF-α concentrations did not differ between HCs. TGF-ß 1 concentrations were negatively affected in P-PRPs stored at 4°C at 3 and 96 h, whereas those from P-PRP maintained at 37°C presented similar concentrations to TIPL stored at both temperatures over time. IL-4 and TNF-α concentrations were not affected by time or temperature in any of the HCs evaluated. Pure PRGs released additional quantities of GF and cytokines over time when compared with HCs stored over 96 h at 4 and 37°C. The method, either chemical or physical, used for platelet activation or damage produces a different GF and cytokine release pattern, which makes to each evaluated HCs different despite they come from a similar bovine PC. P-PRP activated with calcium gluconate and maintained at 37°C, which polymerizes in P-PRG, showed the best GF and cytokine release/denature profile compared with the rest of the HCs evaluated.

Mass effects for thermodiffusion in dilute aqueous solutions.

Thermodiffusion is the phenomenon by which molecules in a mixture present concentration gradients in response to an imposed temperature gradient. Despite decades of investigations, this effect remains poorly understood at a molecular level. A common, phenomenological approach is to individuate the molecular factors that influence the Soret coefficient, the parameter that quantifies the resulting concentration-gradient. Experimental studies, often performed on organic mixtures, as well as simulations of model particle systems have evidenced that the difference in masses between the mixture components has an important effect on the amplitude of the Soret coefficient. Here, we use molecular dynamics simulations of a thermophoretic setting to investigate the mass dependence of the Soret coefficient in dilute aqueous solutions. An advantage of simulation approaches is that they are not limited in the range of explored molecular masses, which is often limited to isotopic substitutions in the experiments. Our simulations reveal that the mass dependence of the Soret coefficient in these solutions is in agreement with previous experimental and simulation work on molecular-size systems. In particular, it is sensitive to the relative mass difference between the solute and the solvent, but not to their absolute mass. Adjusting the mass of the solvent and of the solute can turn a thermophobic solution into a thermophilic one, where solute accumulation is reversed. This demonstrates that the mass effect can indeed compensate for the other contributions to the Soret coefficient. Finally, we find that changing the molecular moments of inertia has a much more limited impact as compared to a change in the total molecular mass.

Intramammary treatment using allogeneic pure platelet-rich plasma in cows with subclinical mastitis caused by Gram-positive bacteria.

The aims of the study were (1) to compare the cure risk of intramammary treatment of pure platelet rich plasma (P-PRP) or cefquinome sulfate (CS) in cows with subclinical mastitis (SCM) caused by Gram-positive bacteria, evaluated via somatic cell count (SCC) and the microbiological analysis of milk; (2) to compare the inflammatory/anti-inflammatory response of mammary gland to both treatments through the analyses of interleukins (IL), interferon gamma (IFN-γ), and tumour necrosis factor alpha (TNF-α) in milk. A non-inferiority randomized clinical trial was conducted. The null hypothesis was that cure risk in the experimental group (P-PRP) was inferior to the reference group (CS). A total of 103 cows were selected according to SCC and presence of Gram-positive bacteria, 49 cows were treated with CS and 54 cows were treated with P-PRP after determination of its cellular and molecular quality control. Cure was assessed by milk analyses at day 21 and 22 after treatment. Cows that remained with SCM were retreated at day 26, and cure assessed at day 47 and 48. Overall, bacteriological cure was observed in 16 cows (30%) of the P-PRP group, and 35 cows (71%) in CS group. Staphylococcus aureus cure risk was higher in CS group, but inconclusive for Streptococcus spp. The mean SCC increased in relation to time only in the P-PRP group. A direct relation between time and treatment for IL-1, IL-2, and IL-6 was observed, while no differences were observed for IL-4. Furthermore, IL-1 and IL-2 increased in cows treated twice in both groups. IL-8, IFN-γ, and TNF-α showed a significant interaction between time and treatment. IFN-γ concentration was lower in the P-PRP group compared to the CS on days 0 and 22. Leukocyte counts were lower in P-PRP when compared to whole blood. TGF-ß1 and PF4 concentrations were higher in platelet lysates in comparison to P-PRGS and plasma. Moreover, PDGF-BB concentration was significantly higher in platelet lysates in comparison to plasma. Results obtained in this study demonstrate that SCM treated with PRP showed a lower rate of bacteriologic cure when compared to animals treated with CS.

In silico all-atom approach to thermodiffusion in dilute aqueous solutions.

Thermodiffusion (or thermophoresis) is the phenomenon by which the spatial distributions of constituents of liquid or gas phases become inhomogeneous in response to a temperature gradient. It has been evidenced in a variety of systems and has many practical applications as well as implications in the context of the origins of life. A complete molecular picture of thermophoresis is still missing, and phenomenological approaches are often employed to account for the experimental observations. In particular, the amplitude of the resulting concentration-gradients (quantified by the Soret coefficient) depends on many factors that are not straightforwardly rationalized. All-atom molecular dynamics simulations appear as an exquisite tool to shed light on the molecular origins for this phenomenon in molecular systems, but the practical implementation of thermophoretic settings in silico poses significant challenges. Here, we propose a robust approach to tackle thermophoresis in dilute realistic solutions at the molecular level. We rely on a recent enhanced heat-exchange algorithm to generate temperature-gradients. We carefully assess the convergence of thermophoretic simulations in dilute aqueous solutions. We show that simulations typically need to be propagated on long timescales (hundreds of nanoseconds). We find that the magnitude of the temperature gradient and the box sizes have little effect on the measured Soret coefficients. Practical guidelines are derived from such observations. Provided with this reliable setup, we discuss the results of thermophoretic simulations on several examples of molecular, neutral solutes, which we find in very good agreement with experimental measurements regarding the concentration-, mass-, and temperature-dependence of the Soret coefficient.

Application of udder surface temperature by infrared thermography for diagnosis of subclinical mastitis in Holstein cows located in tropical highlands.

Several reports have indicated that udder surface temperature (UST) can be a useful indicator of subclinical mastitis (SCM). The objective was to evaluate UST by infrared thermography (IRT) as a diagnostic tool for SCM and intramammary infection (IMI), and to assess the influence of environmental conditions in the potential diagnosis of this disease in dairy cows located at high-altitude tropical regions. A total of 105 cows (397 quarters) from 3 dairy farms with mechanical and manual milking methods were enrolled in the study. Subclinical mastitis was diagnosed when quarter samples had a somatic cell count (SCC) ≥200 × 103 cells/mL, microbial growth (MG) was defined when a major pathogen (≥1 cfu/plate) or Corynebacterium spp. (≥10 cfu/plate) was isolated, and IMI was defined as the presence of MG and SCC ≥100 × 103 cells/mL. Infrared images were taken with a thermal camera placed 1 m away from the udder, and shots of the rear and left and right lateral view were made during the morning milking, before any manipulation of the udder and employing dark cardboard on the contralateral side to avoid artifacts in the background. A multilevel mixed effects linear regression model clustered within cows and herd was performed to evaluate the associations with UST. Clinical performance was evaluated using the Youden index to establish the optimum UST thresholds, which were set at 32.6°C for any case definition when milking was by hand, at 33.7°C for MG, and at 34°C for SCM and IMI in machine-milked quarters. Sensitivity (Se), specificity (Sp), area under curve (AUC), and positive likelihood ratio (+LR) were also assessed. Test agreement was assessed by kappa coefficient (κ). The UST of healthy quarters ranged between (95% CI) 32.4 and 32.6°C, lower than SCM quarters (n = 88) at 32.9°C (95% CI: 32.7-33.1 °C), MG quarters (n = 56) at 33.5°C (95% CI: 33.3-33.7°C), and IMI quarters (n = 50) at 33.5°C (95% CI: 33.2-33.7 °C). The UST was also related to the milking method: higher temperatures were observed for hand milking (n = 90) compared with machine milking (n = 185). No relation between environmental conditions such as wind speed, atmospheric temperature, relative humidity, and temperature-humidity index and UST were observed during this study. For hand milking, the optimal UST threshold was 32.6°C; for SCM, Se = 0.53, Sp = 0.89, AUC = 0.71, κ = 0.4; for MG, Se = 0.83, Sp = 0.93, AUC = 0.88, κ = 0.77; and for IMI, Se = 0.82, Sp = 0.92, AUC = 0.87, κ = 0.74. The machine milking threshold for SCM resulted in Se = 0.42, Sp = 0.97, AUC = 0.70, κ = 0.47; for MG, Se = 0.82, Sp = 0.89, AUC = 0.85, κ = 0.60; and for IMI, Se = 0.82, Sp = 0.98, AUC = 0.90, κ = 0.79. These findings suggest that UST determined by IRT is higher in machine-milked cows and in quarters with MG and IMI than in healthy quarters; therefore, UST by IRT is a reliable, clinically useful method for MG and IMI diagnosis.

Psychiatric disorders in children and adolescents during the COVID-19 pandemic. / Trastornos psiquiátricos en los niños y adolescentes en tiempo de la pandemia por COVID-19.

INTRODUCTION: The Covid-19 pandemic has generated an unprecedented multimodal (health, occupational, economic, and social crisis, which will impact developing countries. Confinement as a preventive measure is itself a threat that produces a social impact. Pandemic and confinement have become a psychosocial adversity factor that affects families and their children. During the pandemic, children and adolescents with a psychiatric disorder may experience exacerbation of their symptoms. However, little is known about this, since studies on this population during the pandemic are scarce. OBJECTIVE: To review the data available in the current literature on the effect of the pandemic on children and adolescents with a previous psychiatric disorder. METHODS: A literature search was carried out using PubMed, Scielo and, due to the exceptional conditions of the pandemic situation, directly using internet search engines. Both English and Spanish papers were included. RESULTS: The information found is presented in the following sections: family and children during the pandemic, evaluation of mental disorders in children and young people during the pandemic, pre-existing psychiatric disorders during the pandemic, and telepsychiatric care. Specific information is presented on attention deficit hyperactivity disorder, autism spectrum disorder, intellectual disability, anxiety disorder, obsessive compulsive disorder, and post-traumatic stress disorder. The current pandemic due to COVID-19 and confinement are a psychosocial adversity that threatens the stability of the family. Such a stressor can cause exacerbation of symptoms of a previous mental disorder. Children and adolescents with psychiatric disorders are a vulnerable population and require specialised care. Telepsychiatry is becoming a modality with multiple advantages.

Trastornos psiquiátricos en los niños y adolescentes en tiempo de la pandemia por COVID-19

Introducción: La pandemia por Covid-19 ha generado una crisis multimodal inédita: sanitaria, laboral, económica, social, que repercutirá especialmente a los países en vía de desarrollo. El confinamiento como medida preventiva es su vez una amenaza que producen un impacto social. Pandemia y confinamiento se han convertido en un factor de adversidad psicosocial que afecta las familias y sus hijos. Durante la pandemia, los niños y adolescentes con un trastorno psiquiátrico podrían presentar exacerbación de sus síntomas. Sin embargo, poco se conoce al respecto, pues los estudios sobre esta población durante la pandemia son escasos. Objetivo: Revisar los datos disponibles en la literatura actual acerca del efecto de la pandemia sobre los niños y adolescentes que presentan un trastorno psiquiátrico previo. Métodos: Se realizó una búsqueda de la literatura a través de PubMed, Scielo y, por las condiciones excepcionales de la situación de pandemia, de manera directa en buscadores de internet. Se incluyeron artículos en ingles y español. Resultados: La información encontrada se presenta en los siguientes apartados: la familia y los hijos durante la pandemia, evaluación de los trastornos mentales en niños y jóvenes durante la pandemia, trastornos psiquiátricos preexistentes durante la pandemia, y atención en telepsiquiatría. Se presenta información específica sobre el trastorno por déficit de atención e hiperactividad, trastorno del espectro autista, discapacidad intelectual, trastorno de ansiedad, trastorno obsesivo compulsivo y el trastorno por estrés postraumático. La pandemia actual por COVID-19 y el confinamiento son una adversidad psicosocial que atenta contra la estabilidad de la familia. Tal estresor pude causar exacerbación de los síntomas de un trastorno mental previo. Los niños y adolescentes con trastornos psiquiátricos son una población vulnerable que requiere de una atención especializada. La telepsiquiatría se convierte en una modalidad con múltiples ventajas.

Introduction: The Covid-19 pandemic has generated an unprecedented multimodal (health, occupational, economic, and social crisis, which will impact developing countries. Confinement as a preventive measure is itself a threat that produces a social impact. Pandemic and confinement have become a psychosocial adversity factor that affects families and their children. During the pandemic, children and adolescents with a psychiatric disorder may experience exacerbation of their symptoms. However, little is known about this, since studies on this population during the pandemic are scarce. Objective: To review the data available in the current literature on the effect of the pandemic on children and adolescents with a previous psychiatric disorder. Methods: A literature search was carried out using PubMed, Scielo and, due to the exceptional conditions of the pandemic situation, directly using internet search engines. Both English and Spanish papers were included. Results: The information found is presented in the following sections: family and children during the pandemic, evaluation of mental disorders in children and young people during the pandemic, pre-existing psychiatric disorders during the pandemic, and telepsychiatric care. Specific information is presented on attention deficit hyperactivity disorder, autism spectrum disorder, intellectual disability, anxiety disorder, obsessive compulsive disorder, and post-traumatic stress disorder. The current pandemic due to COVID-19 and confinement are a psychosocial adversity that threatens the stability of the family. Such a stressor can cause exacerbation of symptoms of a previous mental disorder. Children and adolescents with psychiatric disorders are a vulnerable population and require specialised care. Telepsychiatry is becoming a modality with multiple advantages.

New records and range extension of the Portuguese dogfish Centroscymnus coelolepis in the south-western Atlantic Ocean, with comments on its morphology.

The Portuguese dogfish Centroscymnus coelolepis is a wide-ranging deep-water shark and a common by-catch component of the catches of several mid- to deep-water fisheries. In the present study, two new records from the south-western Atlantic Ocean are reported based on specimens caught by bottom-longline fishing vessels operating in the Argentinean-Uruguayan Common Fishing Zone. Species identification based on morphology and detailed morphometrics, as well as molecular data are presented for one of the specimens. The distribution of the species over the south-western Atlantic is discussed on the basis of the available bibliography and a thorough revision of museum collections. The records presented here expand the species' previously acknowledged distribution southwards, from around 21° S to at least 38° S, suggesting it occurs continuously along the shelf break of eastern South America. However, given the limited access to specimens of deep-water sharks in the region, the abundance and real extent of C. coelolepis distribution in the south-western Atlantic as well as its interaction with deep-water fisheries remain to be fully assessed.

Características sociodemográficas y clínicas de pacientes atendidos en urgencias con diagnóstico de cáncer de novo / Socio-demographic and clinical characteristics of patients with de novo cancer diagnosis, admitted trough emergency services

Objetivo: caracterizar sociodemográfica y clínicamente los pacientes que después de ingresar a servicios de urgencias de dos centros de tercer nivel de atención de la ciudad de Manizales (Colombia), se les diagnosticó alguno de los tipos de cáncer más frecuentes según el Registro Poblacional de Cáncer de Manizales. Materiales y métodos: con base a la información aportada por el Registro Poblacional de Cáncer de Manizales entre los años 2008 y 2012, se escogieron los cinco tipos de cáncer más frecuentes en cada género para la realización del estudio. Fueron incluidos 116 casos de los que ingresaron por servicios de urgencias para extraer información a partir de las historias clínicas, la cual posteriormente fue tabulada y analizada mediante estadística descriptiva. Resultados: la mayoría los pacientes provenían de Manizales (60,3%), y pertenecían al régimen contributivo de seguridad social (50,0%). El promedio de edad fue de 72,4 años. El promedio de duración de los síntomas antes de consultar fue de 2,3 meses y los cánceres más frecuentes fueron el gástrico (41,4%), de colon (25,9%), CP (23,3%), cérvix (6%) y recto (3,5%) en estadios avanzados. Conclusiones: se continúan diagnosticando casos de cáncer de novo en estadio tardío, al ingresar por los servicios de urgencias. Resulta muy importante conocer la epidemiología de estos tipos de cáncer en cada una de las regiones y mejorar la formación médica con el fin de implementar estrategias para disminuir su aparición..(AU)

Objective: to characterize sociodemographicly and clinically those patients, who after admission by the emergency services of two tertiary level centers in Manizales (Colombia), were diagnosed with some of the most frequent cancers according to the Manizales Population Cancer Registry. Materials and methods: based on the information provided by the Manizales Population Cancer Registry between the years of 2008 to 2012, the five most frequent types of cancer in each gender were chosen for the study. There were 116 cases of those admitted through the emergency services for data extraction from the clinical record, which was later tabulated and analyzed using descriptive statistics. Results: most of the patients came from Manizales (60.3%), covered by the contributory social security scheme (50.0%), with a mean age of 72.4 years. The mean duration of symptoms before consulting the emergency service was 2.3 months. The most frequent cancers were gastric (41.4%), colon (25.9%) lung (23.3%), cervix (6%) and rectal cancer (3.5%) in advanced stages. Conclusions: new cases of late-stage cancer are still being diagnosed upon admission to emergency services. It is important to know the epidemiology of these cancers in each of the regions and to improve medical training in order to implement strategies to reduce their presentation..(AU)

Blood ß-hydroxybutyrate concentrations and early lactation management strategies on pasture-based dairy farms in Colombia.

The increasing global demand for food requires sustainable solutions to close the gap in agricultural yield between industrialized and non-industrialized countries. Our objectives in this cross-sectional study were to: 1) characterize farm populations, milk yield, and early lactation management strategies of dairy cows in three different regions of Colombia, and 2) determine the association of these management strategies with blood ß-hydroxybutyrate (BHB) concentrations in the first 42 days in milk (DIM). Dairy herds (n = 56) in the Antioquia, Caldas, and Cundinamarca regions of Colombia were visited once from May through July 2018. A survey was administered to farm owners to collect demographic, management, and herd nutrition information. Blood samples from dairy cows (n = 880) between calving and 42 DIM were used to measure blood BHB concentration. Associations between management and nutritional strategies and blood BHB concentration were examined using mixed models. Prevalence of hyperketonemia was calculated as the number of samples with BHB concentration ≥1.2 mmol/L divided by the total number of samples. The estimated diet composition for early lactation dairy cows was 65.5% pasture and 31.8% commercial concentrates. The farm median milk yield, protein concentration, and fat concentration were 21.0 kg (range = 13.1-36 kg), 3.2% (range = 2.7-4.1%), and 3.5% (range = 3.0-4.1%), respectively. Milk yield least squares means (95% confidence interval; CI) differed by region: 21.7 (20.3, 23.2), 18.5 (17.0, 20.2), and 20.3 (18.5, 22.4) kg in Antioquia, Caldas, and Cundinamarca, respectively. Median blood BHB concentration was 0.5 and ranged from 0.1-4.4 mmol/L; blood BHB concentration was not different among the three regions. Pasture fertilization, increased parity, and BCS were associated with changes in blood BHB concentration. The overall prevalence of hyperketonemia was 4.5%. Geographical region affected the prevalence of hyperketonemia at 2.5%, 4.0%, and 10.2% in Antioquia, Caldas, and Cundinamarca, respectively. Mean stocking density (95% CI) was greater in Cundinamarca than Antioquia or Caldas at 3.3 (2.2, 5.0), 2.8 (2.1, 3.9) and 1.7 (1.2, 2.6) animals per ha, respectively, and was associated with hyperketonemia prevalence. Farms that abruptly stop milking cows at dry-off had 80% of the hyperketonemia events in the study. Pasture-based dairies in Colombia had lower blood BHB concentrations and estimated milk yield compared with confined production systems in temperate zones. However, geographical region, stocking density, and abrupt cessation of milking at dry-off were associated with prevalence of hyperketonemia in pasture-based dairies.

Potential group B Streptococcus interspecies transmission between cattle and people in Colombian dairy farms.

Group B Streptococcus (GBS), is a leading cause of neonatal death and an emerging pathogen in adults. Additionally, GBS is a bovine pathogen causing intramammary infections. The likelihood of GBS interspecies transmission is largely unknown. We explored the potential transmission of GBS between cattle and people on dairy farms in Colombia and compared the antimicrobial resistance (AMR) profiles of isolates from both host species. Across 33 farms, throat swabs and rectal swabs were collected from 191 people, and rectal swabs and composite milk samples from 2092 cattle, yielding 60 human isolates and 301 bovine isolates. The majority (64%) of isolates belonged to shared sequence types (ST). Sequence type (ST) 1 was the most common strain in both host species, suggesting that interspecies transmission may be possible. Two members of the bovine-specific clonal complex 61/67 were detected in human samples (ST718 and ST1175), providing evidence for the lack of genuine species barriers. Apparent prevalence of penicillin resistance was surprisingly high in human and bovine isolates. Further investigation of this phenomenon is needed and could lead to modification of standard testing and treatment recommendations in human and veterinary medicine.

Time-dependent effects of heat shock on the zona pellucida ultrastructure and in vitro developmental competence of bovine oocytes.

The aim of this study was to determine the effects of different exposure lenght to heat shock (HS) during in vitro maturation (IVM) on zona pellucida (ZP) ultrastructure and developmental competence of bovine oocytes. Cumulus-oocyte complexes (COCs) were matured in vitro (IVM) at 38.5 °C for 24 h (control group, CG), or incubated at 41 °C (HS) for 6 h (HS-6h), 12 h (HS-12h), 18 h (HS-18h), and 22h (HS-22h) followed by incubation at 38.5 °C to complete a full 24-h period of maturation. After IVM, oocytes were subjected to scanning electron microscopy (SEM) or in vitro fertilization and culture until the blastocyst stage. For heat-shocked oocytes, with exception of those in the HS-6h group, SEM examinations revealed that ZP surfaces were rough and characterized by a presence of spongy network. Oocytes from the HS-22h group displayed an increase in the number of pores, as well as a higher proportion of oocytes with amorphous ZPs. The proportion of oocytes that reached metaphase II (MII) stage decreased in all HS groups, regardless of the duration of exposure to 41 °C. These results provide evidence that HS during IVM for 12-22 h reduces the developmental competence of bovine oocytes, increasing the percentage of oocytes with abnormal chromosomal organization, and reducing fertilization and blastocysts formation rate. The effects of HS were more pronounced for the 22-h exposure group. The damage induced by HS on oocyte function clearly increased upon exposure to elevated temperature.

Streptococcus agalactiae is not always an obligate intramammary pathogen: Molecular epidemiology of GBS from milk, feces and environment in Colombian dairy herds.

For many years Streptococcus agalactiae has been considered an obligate intramammary and strictly contagious pathogen in dairy cattle. However, recent reports of S. agalactiae isolation from extramammary sources have contradicted that premise. To gain further insight into the epidemiology of S. agalactiae infection in cattle, we examined its distribution and heterogeneity of strains in bovine milk, bovine feces, and the environment in Colombian dairy farms. First, a longitudinal study was conducted at herd level in 152 dairy herds. Bulk tank milk samples from each herd where collected twice a month for six months. A follow-up study with a cross sectional design at the cow level was conducted in a subset of 25 farms positive for S. agalactiae. Cow-level milk samples from 1712 lactatting cows and 1545 rectal samples were collected, as well as 120 environmental samples. Samples were used for S. agalactiae detection and genotyping using Multi Locus Sequence Typing. Results showed sporadic rather than repeated isolation of S. agalactiae from bulk tank milk in 40% of the positive herds, challenging the idea that S. agalactiae is a highly contagious pathogen causing chronic infections. S. agalactiae was isolated from rectal or environmental samples in 32% and 12% of cross-sectional study farms, respectively, demonstrating that the bacteria can survive in extramammary sources and that S. agalactiae is not an obligate intramammary pathogen. The same strain was isolated from rectal and bulk tank milk samples in eight farms, suggesting that fecal shedding is frequent, and contributes to the presence of S. agalactiae in bulk tank. High within-herd heterogeneity of strains was found, which is distinct from the situation in developed dairy industries. These new epidemiological findings should be considered to adjust surveillance and control recommendations for S. agalactiae.

Distributed Gaussian orbitals for the description of electrons in an external potential.

In this work, we demonstrate the viability of using distributed Gaussian orbitals as a basis set for the calculation of the properties of electrons subjected to an external potential. We validate our method by studying one-electron systems for which we can compare to exact analytical results. We highlight numerical aspects that require particular care when using a distributedGaussian basis set. In particular, we discuss the optimal choice for the distance between two neighboring Gaussian orbitals. Finally, we show how our approach can be applied to many-electron problems.

Staphylococcus aureus Isolates from Bovine Mastitis in Eight Countries: Genotypes, Detection of Genes Encoding Different Toxins and Other Virulence Genes.

Staphylococcus aureus is recognized worldwide as one of the major agents of dairy cow intra-mammary infections. This microorganism can express a wide spectrum of pathogenic factors used to attach, colonize, invade and infect the host. The present study evaluated 120 isolates from eight different countries that were genotyped by RS-PCR and investigated for 26 different virulence factors to increase the knowledge on the circulating genetic lineages among the cow population with mastitis. New genotypes were observed for South African strains while for all the other countries new variants of existing genotypes were detected. For each country, a specific genotypic pattern was found. Among the virulence factors, fmtB, cna, clfA and leucocidins genes were the most frequent. The sea and sei genes were present in seven out of eight countries; seh showed high frequency in South American countries (Brazil, Colombia, Argentina), while sel was harboured especially in one Mediterranean country (Tunisia). The etb, seb and see genes were not detected in any of the isolates, while only two isolates were MRSA (Germany and Italy) confirming the low diffusion of methicillin resistance microorganism among bovine mastitis isolates. This work demonstrated the wide variety of S. aureus genotypes found in dairy cattle worldwide. This condition suggests that considering the region of interest might help to formulate strategies for reducing the infection spreading.

A 0.18 µm CMOS LDO Regulator for an On-Chip Sensor Array Impedance Measurement System.

This paper presents a fully integrated 0.18 μm CMOS Low-Dropout (LDO) Voltage Regulator specifically designed to meet the stringent requirements of a battery-operated impedance spectrometry multichannel CMOS micro-instrument. The proposed LDO provides a regulated 1.8 V voltage from a 3.6 V to 1.94 V battery voltage over a −40 °C to 100 °C temperature range, with a compact topology (<0.10 mm² area) and a constant quiescent current of only 7.45 μA with 99.985% current efficiency, achieving remarkable state-of-art Figures of Merit (FoMs) for the regulating⁻transient performance. Experimental measurements validate its suitability for the target application, paving the way towards the future achievement of a truly portable System on Chip (SoC) platform for impedance sensors.