Stability of vitamin A at critical points in pet-feed manufacturing and during premix storage

The objective of this research was to assess and quantify the potential vitamin A losses that occur during the manufacturing of pet feed and premix, as well as during their extended storage periods. This trial was conducted at a commercial feeder mill that utilized a standard commercial dog feed along with a corresponding vitamin-mineral premix. The calculated amount of vitamin A supplemented in the feed, in addition to the endogenous vitamins present in the ingredients, was adjusted to 18,000 IU/kg of feed. Five 500 g feed samples were collected at each of the predefined critical points throughout the manufacturing process (after mixing, milling, preconditioner, and extrusion/drying processes) to verify the stability of vitamin A during feed production. Additionally, various samples were collected at regular intervals of 30, 60, 90, 120, and 180 days during the storage of the premix to assess the stability of vitamin A. Vitamin A analyses in the samples were performed using high-performance liquid chromatography. The variables were assessed for normality using the Shapiro-Wilk test, followed by analysis of variance (ANOVA) and Tukey's test to compare the differences between the manufacturing process and premix shelf life. The statistical significance was set at 95%. The vitamin losses during the pre-conditioning process were 26%, and during the extrusion-drying processes, the losses were 34% when compared to the initial analyzed value. However, no differences were observed in other processes. There were no significant differences observed in recovered vitamin levels in the premix during its shelf-life (p = 0.484). The study indicated that the primary vitamin A losses in pet feed manufacturing processes occur during the pre-conditioning and drying/extrusion steps. However, it is worth noting that no significant losses of vitamin A were found during the premix storage phase.

Promotional Effects on the Catalytic Activity of Co-Fe Alloy Supported on Graphitic Carbon for CO2 Hydrogenation

Starting from the reported activity of Co-Fe nanoparticles wrapped onto graphitic carbon (Co-Fe@C) as CO₂ hydrogenation catalysts, the present article studies the influence of a series of metallic (Pd, Ce, Ca, Ca, and Ce) and non-metallic (S in various percentages and S and alkali metals) elements as Co-Fe@C promoters. Pd at 0.5 wt % somewhat enhances CO₂ conversion and CH₄ selectivity, probably due to H₂ activation and spillover on Co-Fe. At similar concentrations, Ce does not influence CO₂ conversion but does diminish CO selectivity. A 25 wt % Fe excess increases the Fe-Co particle size and has a detrimental effect due to this large particle size. The presence of 25 wt % of Ca increases the CO₂ conversion and CH₄ selectivity remarkably, the effect being attributable to the CO₂ adsorption capacity and basicity of Ca. Sulfur at a concentration of 2.1% or higher acts as a strong poison, decreasing CO₂ conversion and shifting selectivity to CO. The combination of S and alkali metals as promoters maintain the CO selectivity of S but notably increase the CO₂ conversion. Overall, this study shows how promoters and poisons can alter the catalytic activity of Co/Fe@C catalysts, changing from CH₄ to CO. It is expected that further modulation of the activity of Co/Fe@C catalysts can serve to drive the activity and selectivity of these materials to any CO₂ hydrogenation products that are wanted.

High C2-C4 selectivity in CO2 hydrogenation by particle size control of Co-Fe alloy nanoparticles wrapped on N-doped graphitic carbon

A catalyst based on first-row Fe and Co with a record of 51% selectivity to C₂-C₄ hydrocarbons at 36% CO₂ conversion is disclosed. The factors responsible for the C₂₊ selectivity are a narrow Co-Fe particle size distribution of about 10 nm and embedment in N-doped graphitic matrix. These hydrogenation catalysts convert CO₂ into C₂-C₄ hydrocarbons, including ethane, propane, n-butane, ethylene and propylene together with methane, CO. Selectivity varies depending on the catalyst, CO₂ conversion, and the operation conditions. Operating with an H₂/CO₂ ratio of 4 at 300°C and pressure on 5 bar, a remarkable combined 30% of ethylene and propylene at 34% CO₂ conversion was achieved. The present results open the way to develop an economically attractive process for CO₂ reduction leading to products of higher added value and longer life cycles with a substantial selectivity.

•

Co-Fe nanoparticles wrapped on N-doped graphitic carbon catalyzes CO₂ hydrogenation

•

Co-Fe@(N)Carbon affords 51% selectivity to C₂-C₄ hydrocarbons at 36% CO₂ conversion

•

At H₂/CO₂ 4, 300°C and 5 bar, a combined 30% of CH₂ = CH₂ and MeCH = CH₂ is achieved

•

Particle size (10 nm) and N-doping are crucial to achieve high C₂₊ selectivity

Co-Fe Nanoparticles Wrapped on N-Doped Graphitic Carbons as Highly Selective CO2 Methanation Catalysts

Pyrolysis of chitosan containing various loadings of Co and Fe renders Co-Fe alloy nanoparticles supported on N-doped graphitic carbon. Transmission electron microscopy (TEM) images show that the surface of Co-Fe NPs is partially covered by three or four graphene layers. These Co-Fe@(N)C samples catalyze the Sabatier CO₂ hydrogenation, increasing the activity and CH₄ selectivity with the reaction temperature in the range of 300-500 °C. Under optimal conditions, a CH₄ selectivity of 91% at an 87% CO₂ conversion was reached at 500 °C and a space velocity of 75 h^-1 under 10 bar. The Co-Fe alloy nanoparticles supported on N-doped graphitic carbon are remarkably stable and behave differently as an analogous Co-Fe catalyst supported on TiO₂.

Uso potencial de la tecnología NIRS en la determinación de la calidad de los recursos naturales (bellotas y pastos) de dehesa destinados a la alimentación del cerdo Ibérico

La tecnología NIRS se utilizó como alternativa a los métodos convencionales para determinar el contenido de nutrientes en bellotas y pastos de la dehesa. Materia seca (MS), contenido en grasa (G), proteína total (TP), almidón, compuestos fenólicos totales (FT), α-tocoferol, γ-tocoferol, ácidos grasos, fibra neutro detergente (FND), actividad antioxidante total (AAT) y energía total (ET) fueron determinadas por métodos convencionales para el posterior desarrollo de las ecuaciones de predicción del NIRS. Se han realizado todos los espectros NIR de cada una de las muestras para todos los parámetros estudiados obteniendo un modelo predictivo y una validación externa. Se han obtenido buenas ecuaciones de predicción para la humedad, contenido en grasa, proteína total, energía total y γ –tocoferol en muestras de bellotas obteniendo un alto coeficiente de correlación (1-VR) y un bajo error estándar de predicción (SEP) (1-VR=0.81, SEP=2.62; 1-VR=0.92, SEP=0.54; 1-VR=0.86, SEP=0.47; 1-VR=0.84, SEP=0.2; 1-VR=0.88, SEP=5.4, respectivamente), así como la proteína total, NDF, α-tocoferol y contenido de ácido linolénico en muestras de pasto (1-VR=0.9, SEP=1.99; 1-VR=0.87, SEP=4.13; 1-VR=0.76, SEP=10.9; 1-VR=0.82, SEP=0.6, respectivamente). Por lo tanto, estos modelos de predicción podrían ser utilizados para determinar la composición nutricional de los recursos naturales de la Montanera.

Acrylate formation from CO2 and ethylene: catalysis with palladium and mechanistic insight

The first palladium catalyst for the reaction of CO₂, alkenes and a base to acrylates is reported (TON up to 50).

Mechanistic studies on the Pd-catalyzed vinylation of aryl halides with vinylalkoxysilanes in water: the effect of the solvent and NaOH promoter

The mechanism of the Pd-catalyzed vinylation of aryl halides with vinylalkoxysilanes in water has been studied using different catalytic precursors. The NaOH promoter converts the initial vinylalkoxysilane into a highly reactive water-soluble vinylsilanolate species. Similarly, deuterium-labeling experiments have shown that, irrespective of the catalytic precursor used, vinylation occurs exclusively at the CH vinylic functionality via a Heck reaction and not at the C-Si bond via a Hiyama cross-coupling. The involvement of a Heck mechanism is interpreted in terms of the reduced nucleophilicity of the base in water, which disfavors the transmetalation step. The Heck product (β-silylvinylarene) undergoes partial desilylation, with formation of a vinylarene, by three different routes: (a) hydrolytic desilylation by the aqueous solvent (only at high temperature); (b) transmetalation of the silyl olefin on the PdH Heck intermediate followed by reductive elimination of vinylarene; (c) reinsertion of the silyl olefin into the PdH bond of the Heck intermediate followed by β-Si syn-elimination. Both the Hiyama and Heck catalytic cycles and desilylation mechanisms b and c have been computationally evaluated for the [Pd(en)Cl2] precursor in water as solvent. The calculated Gibbs energy barriers support the reinsertion route proposed on the basis of the experimental results.

Consecutive palladium-catalyzed Hiyama-Heck reactions in aqueous media under ligand-free conditions

Symmetric and asymmetric (E)-1,2-diarylethenes are synthesized from aryl bromides by consecutive one-pot Hiyama-Heck reactions carried out in water and under air; the only additives required are sodium hydroxide, palladium acetate and poly(ethylene glycol), and the products are isolable in many cases by simple filtration of the water solution.

[Law courts and clinical documentation]

Background. Until 2004, requests for clinical documentation proceeding from the Judicial Administration on Specialist Care of Pamplona were received in six different centres and were processed independently, with different procedures, and documents were even sent in duplicate, with the resulting work load. This article describes the procedure for processing requests for documentation proceeding from the Law Courts and analyses the requests received. Methods. A circuit was set up to channel the judicial requests that arrived at the Specialist Health Care Centres of Pamplona and at the Juridical Regime Service of the Health System of Navarra-Osasunbidea, and a Higher Technician in Health Documentation was contracted to centralise these requests. A proceedings protocol was established to unify criteria and speed up the process, and a database was designed to register the proceedings. Results. In the course of 2004, 210 requests for documentation by legal requirement were received. Of these, 24 were claims of patrimonial responsibility and 13 were requested by lawyers with the patient's authorisation. The most frequent jurisdictional order was penal (43.33%). Ninety-three point one five percent (93.15%) of the requests proceeded from law courts in the autonomous community of Navarra. The centre that received the greatest number of requests was the "Príncipe de Viana" Consultation Centre (33.73%).The most frequently requested documentation was a copy of reports (109) and a copy of the complete clinical record (39). On two occasions the original clinical record was required. The average time of response was 6.6 days. Conclusions. The centralisation of administration has brought greater agility to the process and homogeneity in the criteria of processing. Less time is involved in preparing and dispatching the documentation, the dispatch of duplicate documents is avoided, the work load has been reduced and the dispersal of documentation is avoided, a situation that guarantees greater privacy for the patient.

C−C Coupling Reactions of Aryl Bromides and Arylsiloxanes in Water Catalyzed by Palladium Complexes of Phosphanes Modified with Crown Ethers

[reaction: see text] The complexes [PdCl2L2], where L is a crown-ether-containing triarylphosphane, catalyze the formation of biaryls from arylsiloxanes and aryl bromides with high yields in water as solvent and under air. The water-insoluble catalysts [PdCl2(PhCN)2] and [PdCl2(PPh3)2] are also efficient, although they decompose more quickly to form black Pd0.

Household health expenditures in Morocco: implications for health care reform

The purpose of this study was to investigate the level and distribution of household health care expenditures in Morocco, and to compare the level of health care funds provided by households with the levels provided by the government and international donors. In addition, the reliance of poor and non-poor households on both public and private providers was investigated. The study was based on data collected in the 1995 Demographic and Health Survey, which included a special supplement on health care expenditures. Descriptive statistics are presented on utilization of out-of-pocket expenditures for antenatal and obstetric care, chronic care, and non-chronic care associated with illness and injury, by urban/rural status and by socio-economic status. The results indicate that government health care providers are an important source of modern health care not only for poor households, but for better-off households as well. While individuals who use private health care providers incur substantially higher costs than those who use public providers, an unexpected finding of the study is the degree to which public clients pay for health care services, despite the fact that public care is nominally priced in Morocco. We conclude by discussing the implications of our results on the design and implementation of health care reform policies.