Tryptophan and Cortisol Modulate the Kynurenine and Serotonin Transcriptional Pathway in the Kidney of Oncorhynchus kisutch.

Aquaculture fish are kept for long periods in sea cages or tanks. Consequently, accumulated stress causes the fish to present serious problems with critical economic losses. Fish food has been supplemented to reduce this stress, using many components as amino acids such as tryptophan. This study aims to determine the transcriptional effect of tryptophan and cortisol on primary cell cultures of salmon head and posterior kidney. Our results indicate activation of the kynurenine pathway and serotonin activity when stimulated with tryptophan and cortisol. An amount of 95% of tryptophan is degraded by the kynurenine pathway, indicating the relevance of knowing how this pathway is activated and if stress levels associated with fish culture trigger its activation. Additionally, it is essential to know the consequence of increasing kynurenic acid "KYNA" levels in the short and long term, and even during the fish ontogeny.

Scale Measurement of Health Primary Service Utilization among the Migrant International Population.

In this article, we analyze the internal structure of the scale for experience in exercising the right to health care (EERHC), based on the focus from the World Health Organization (WHO) on the right to health care, from the perspective of international migrants, in Chile. The methodology was an instrumental study (n = 563) conducted to analyze the psychometric properties of the EERHC scale. Its reliability and internal consistency were evaluated, while the exploratory structural equation modeling (ESEM) model and confirmatory factor analysis (CFA) were used to identify the structure of relationships between the variables measured. The item-dimension correlations obtained present levels of r ≥ 0.3, and the Cronbach's α and McDonald's ω presented ranges >0.9, considered to be acceptable on all models. Results: the model was selected for presenting a good fit index χ2 = 24,850, df = 300, p = 0.000; RMSEA = 0.07; CFI = 0.97; TLI = 0.95; and SRMR = 0.03. The evidence obtained lets us conclude that the scale has forty-five items and four dimensions. The findings demonstrate a good internal structure and are useful to measure primary health care service utilization based on the framework.

Live and inactivated Piscirickettsia salmonis activated nutritional immunity in Atlantic salmon (Salmo salar).

Nutritional immunity regulates the homeostasis of micronutrients such as iron, manganese, and zinc at the systemic and cellular levels, preventing the invading microorganisms from gaining access and thereby limiting their growth. Therefore, the objective of this study was to evaluate the activation of nutritional immunity in specimens of Atlantic salmon (Salmo salar) that are intraperitoneally stimulated with both live and inactivated Piscirickettsia salmonis. The study used liver tissue and blood/plasma samples on days 3, 7, and 14 post-injections (dpi) for the analysis. Genetic material (DNA) of P. salmonis was detected in the liver tissue of fish stimulated with both live and inactivated P. salmonis at 14 dpi. Additionally, the hematocrit percentage decreased at 3 and 7 dpi in fish stimulated with live P. salmonis, unchanged in fish challenged with inactivated P. salmonis. On the other hand, plasma iron content decreased during the experimental course in fish stimulated with both live and inactivated P. salmonis, although this decrease was statistically significant only at 3 dpi. Regarding the immune-nutritional markers such as tfr1, dmt1, and ireg1 were modulated in the two experimental conditions, compared to zip8, ft-h, and hamp, which were down-regulated in fish stimulated with live and inactivated P. salmonis during the course experimental. Finally, the intracellular iron content in the liver increased at 7 and 14 dpi in fish stimulated with live and inactivated P. salmonis, while the zinc content decreased at 14 dpi under both experimental conditions. However, stimulation with live and inactivated P. salmonis did not alter the manganese content in the fish. The results suggest that nutritional immunity does not distinguish between live and inactivated P. salmonis and elicits a similar immune response. Probably, this immune mechanism would be self-activated with the detection of PAMPs, instead of a sequestration and/or competition of micronutrients by the living microorganism.

Transcriptional modulation of immune genes in gut of Sub-Antarctic notothenioid fish Eleginops maclovinus challenged with Francisella noatunensis subsp. noatunensis.

The search for functional foods that improve the immune response has traditionally been focused on lymphoid tissue and the intestinal mucosa. However, it is unknown whether there is a different immune response in different portions of the gut following exposure to a bacterial pathogen. We challenged Eleginops maclovinus intraperitoneally (i.p) with Francisella noatunensis subsp. noatunensis and measured mRNA transcripts related to innate and adaptive immune responses in different parts of the gut (foregut, midgut and hindgut). We used control (i.p only with bacterial culture medium), low dose (i.p of F. noatunensis at 1 × 101 bact/µL), medium dose (i.p of F. noatunensis at 1 × 105 bact/µL) and high dose (i.p of F. noatunensis at 1 × 1010 bact/µL) groups in our experiments. We sampled fish at days 1, 3, 7, 14, 21, and 28 post-injection. We observed tissue-specific expression of TLR1, TLR5, TLR8, MHCI, MHCII and IgM, and transcription of these immune markers was lower in foregut and higher in midgut and hindgut. We detected Francisella genetic material (DNA) in fish stimulated with a high dose from day 1-28 in foregut, midgut, and hindgut. However, we could only detect Francisella DNA in fish stimulated the medium and low dose at later timepoints in the foregut (21-28 days post injection "dpi") and hindgut (low dose from day 7-28 dpi). Our results suggest that the immune responses to bacterial pathogens occur throughout the gut, but certain segments may be more susceptible to infection because of their cellular morphology (anterior, middle and posterior).

Brain immunity response of fish Eleginops maclovinus to infection with Francisella noatunensis.

The brain's immune system is selective and hermetic in most species, including fish, favoring immune responses mediated by soluble immunomodulatory factors such as serotonin and the availability of nutrients against infectious processes. Francisella noatunensis coexist with fish such as Eleginops maclovinus, which raises questions about the susceptibility and immune response of the brain of E. maclovinus against Francisella. In this study, we inoculated fish with different doses of Francisella and took samples for 28 days. We detected bacteria in the brain of fish injected with a high concentration of Francisella at all time points. qPCR analysis of immune genes indicated a response mainly in the medium-dose and early expression of genes involved in iron metabolism. Finally, brain serotonin levels were higher than in uninfected fish in all conditions, suggesting possible immunomodulatory participation in an infectious process.

Francisella noatunensis subsp. noatunensis triggers calcium metabolism gene modulation in Eleginops maclovinus.

Francisella noatunensis subsp. noatunensis is the responsible agent of Francisellosis, a bacterial disease that affects an important amount of aquatic farmed species. Eleginops maclovinus is a fish that cohabits with salmonids cages in Chile and can also act as a vector of this bacterial disease. In the present study, we evaluated calcium metabolism in the liver of E. maclovinus injected intraperitoneally with different doses of F. noatunensis subsp. noatunensis (low 1.5 × 101, medium 1.5 × 105 and high doses 1.5 × 1010 cells/µL). Fish were sampled at 1, 3, 7, 14, 21 and 28 days post injection (dpi). No mortalities nor clinical signs were observed. Plasma calcium levels were higher in the high doses group of F. noatunensis subsp. noatunensis at day 7 and 14 compared to the control group (fish injected with bacterial medium alone). Hypercalcemic factors increased at day 14 and 21 for the medium and low dose (parathyroid hormone-related protein precursor), while vitamin D3 receptor increased its expression at times 1, 3 and 7 for the low dose. On the other hand, hypocalcemic factors such as calcitonin receptor and stanniocalcin increased its expression at time 7 and 14, respectively. Calmodulin involved in calcium storage decreased its expression during all experimental days in fish subjected to high bacterial dose. Proteins involved in calcium transport, such as L-type voltage-gated calcium channel and trpv5 increased their transcription at day 1 and 14, compared to calcium sensing-receptor and plasma membrane Ca2 +- ATPase that showed peak expression at times 14 and 28. The results suggest a clear alteration of calcium metabolism, mainly in high bacterial doses. This study provides new knowledge about the calcium metabolism in fish infected with bacteria.

Aberrant MUC1 accumulation in salivary glands of Sjögren's syndrome patients is reversed by TUDCA in vitro.

OBJECTIVES: Xerostomia in SS patients has been associated with low quality and quantity of salivary mucins, which are fundamental for the hydration and protection of the oral mucosa. The aim of this study was to evaluate if cytokines induce aberrant mucin expression and whether tauroursodeoxycholic acid (TUDCA) is able to counteract such an anomaly. METHODS: Labial salivary glands from 16 SS patients and 15 control subjects, as well as 3D acini or human submandibular gland cells stimulated with TNF-α or IFN-γ and co-incubated with TUDCA, were analysed. mRNA and protein levels of Mucin 1 (MUC1) and MUC7 were determined by RT-qPCR and western blot, respectively. Co-immunoprecipitation and immunofluorescence assays for mucins and GRP78 [an endoplasmic reticulum (ER)-resident protein] were also performed. mRNA levels of RelA/p65 (nuclear factor-κB subunit), TNF-α, IL-1ß, IL-6, SEL1L and EDEM1 were determined by RT-qPCR, and RelA/p65 localization was evaluated by immunofluorescence. RESULTS: MUC1 is overexpressed and accumulated in the ER of labial salivary gland from SS patients, while MUC7 accumulates throughout the cytoplasm of acinar cells; however, MUC1, but not MUC7, co-precipitated with GRP78. TUDCA diminished the overexpression and aberrant accumulation of MUC1 induced by TNF-α and IFN-γ, as well as the nuclear translocation of RelA/p65, together with the expression of inflammatory and ER stress markers in 3D acini. CONCLUSION: Chronic inflammation alters the secretory process of MUC1, inducing ER stress and affecting the quality of saliva in SS patients. TUDCA showed anti-inflammatory properties decreasing aberrant MUC1 accumulation. Further studies are necessary to evaluate the potential therapeutic effect of TUDCA in restoring glandular homeostasis in SS patients.

Intermediary metabolic response and gene transcription modulation on the Sub-Antarctic notothenioid Eleginops maclovinus (Valenciennes, 1930) injected with two strains of Piscirickettsia salmonis.

Pathogen interactions with cultured fish populations are well studied, but their effects on native fishes have not been characterized. In Chile, the disease caused by bacterial species Piscirickettsia salmonis represents one of the main issues and is considered to be one of the important pathogens in the field of aquaculture. They have been found to infect native fish. Therefore, it is necessary to understand the impact of P. salmonis on native species of local commercial value, as well as the potential impact associated with the emergence of antibiotic-resistant strains of P. salmonis. Due to this purpose, the native fish Eleginops maclovinus was used in our study. Fish were randomly distributed in tanks and intraperitoneally inoculated with two strains of P. salmonis. No mortality was recorded during the experiment. Cortisol, glucose and total α-amino acid levels increased in fish injected with AUSTRAL-005 strain compared to sham-injected and LF-89-inoculated fish. Moreover, results showed an increase in the activity of carbohydrates and lipids metabolism in liver; and an increase in the carbohydrates, lipids and total α-amino acid metabolism in muscle after injection with AUSTRAL-005. Our results suggest that P. salmonis modulates the physiology of E. maclovinus and the physiological impact increase in the presence of the antibiotic-resistant strain AUSTRAL-005.

Infección necrotizante de tejidos blandos: experiencia durante 15 años en un hospital pediátrico / Necrotizing soft tissue infections: experience over 15 years in a pediatric hospital

INTRODUCCIÓN: La Infección Necrotizante de tejidos blandos (INTB) tiene una elevada morbimortalidad. El objetivo de este trabajo es describir del manejo perioperatorio de menores de 15 años que cursaron con INTB durante 15 años en un Hospital pediátrico. MATERIAL Y MÉTODOS: serie de pacientes identificados INTB entre 2000 y 2015 en el Hospital Roberto del Río. Se describen variables demográficas, clínicas, vacuna, tratamiento, cirugías, complicaciones, microorganismos, seguimiento, y fallecimientos. RESULTADOS: 22 pacientes, con mediana de 2 años y 9 meses de edad. 50% estaban cursando con una varicela. Dos fallecieron. Ninguno era previamente vacunado contra el virus varicela zoster. La localización fue tronco (14), extremidades (7), cuello (1). Los pacientes conscientes presentaron hiperestesia cutánea. Se realizó aseo quirúrgico con una mediana de 6,8 horas desde el inicio de la hiperestesia y 2 horas desde la sospecha diagnóstica. Los microorganismos fueron: S. pyogenes (38%) y E. coli (31%). Los antibióticos más frecuentes fueron penicilina más clindamicina. La herida se manejó con cierre primario, injertos y/o colgajos. Cinco evolucionaron con secuelas que necesitaron tratamiento. CONCLUSIÓN: Se identificó que la INTB puede presentarse con varicela. Debe sospecharse en lesiones cutáneas e hiperestesia desproporcionada. Resección amplia y precoz son fundamentales para el tratamiento.

INTRODUCTION: Necrotizing soft tissue infection (NSTI) has a high morbidity and mortality. The objective of this study is to describe the perioperative management of children under 15 years of age who have had this condition for 15 years in a pediatric hospital. MATERIAL AND METHODS: cases series of patients identified by Pathological Anatomy with NSTI during 2000 and 2015 at the Dr. Roberto del Río Hospital. Demographic variables, treatment, antecedents of vaccination, surgeries, complications, microorganisms, follow-up, and deaths are described. RESULTS: 22 patients were identified, with a median of 2 years 9 months of age (interquartile range: 13 months to 5 years y 10 months). 50% of the cases were associated to chickenpox. Two died. No patient was previously vaccinated against varicella zoster virus. The location was trunk (14), extremities (7) and neck (1). All conscious patients presented cutaneous hyperesthesia. Surgical debridement was performed with a median of 6.8 hours from the onset of hyperesthesia and 2 hours from diagnostic suspicion. The most frequent microorganisms were: Streptococcus pyogenes (38%) and Escherichia coli (31%). The most frequent antibiotics used were penicillin plus clindamycin. The wound was handled with primary closure, grafts and / or flaps. Five patients evolved with sequelae that needed treatment. CONCLUSION: It was identified that STNI in children is associated with chickenpox. It should be suspected in cutaneous lesions and disproportionate hyperesthesia. Aggressive resection is essential for treatment

Association of high 5-hydroxymethylcytosine levels with Ten Eleven Translocation 2 overexpression and inflammation in Sjögren's syndrome patients.

Here, we determined the 5-hydroxymethylcytosine (5hmC), 5-methylcytosine (5mC), Ten Eleven Translocation (TETs), and DNA methyltransferases (DNMTs) levels in epithelial and inflammatory cells of labial salivary glands (LSG) from Sjögren's syndrome (SS)-patients and the effect of cytokines on HSG cells. LSG from SS-patients, controls and HSG cells incubated with cytokines were analysed. Levels of 5mC, 5hmC, DNMTs, TET2 and MeCP2 were assessed by immunofluorescence. In epithelial cells from SS-patients, an increase in TET2, 5hmC and a decrease in 5mC and MeCP2 were observed, additionally, high levels of 5mC and DNMTs and low levels of 5hmC were detected in inflammatory cells. Cytokines increased TET2 and 5hmC and decreased 5mC levels. Considering that the TET2 gene.promoter contains response elements for transcription factors activated by cytokines, together to in vitro results suggest that changes in DNA hydroxymethylation, resulting from altered levels of TET2 are likely to be relevant in the Sjögren's syndrome etiopathogenesis.

Impaired IRE1α/XBP-1 pathway associated to DNA methylation might contribute to salivary gland dysfunction in Sjögren's syndrome patients.

Objectives: Labial salivary glands (LSGs) of SS patients show alterations related to endoplasmic reticulum stress. Glandular dysfunction could be partly the consequence of an altered inositol-requiring enzyme 1α (IRE1α)/X box-binding protein 1 (XBP-1) signalling pathway of the unfolded protein response, which then regulates genes involved in biogenesis of the secretory machinery. This study aimed to determine the expression, promoter methylation and localization of the IRE1α/XBP-1 pathway components in LSGs of SS patients and also their expression induced by IFN-γ in vitro. Methods: IRE1α, XBP-1 and glucose-regulated protein 78 (GRP78) mRNA and protein levels were measured by qPCR and western blot, respectively, in LSGs of SS patients (n = 47) and control subjects (n = 37). Methylation of promoters was evaluated by methylation-sensitive high resolution melting, localization was analysed by immunofluorescence and induction of the IRE1α/XBP-1 pathway components by IFN-γ was evaluated in 3D acini. Results: A significant decrease of IRE1α, XBP-1u, XBP-1s, total XBP-1 and GRP78 mRNAs was observed in LSGs of SS patients, which was correlated with increased methylation levels of their respective promoters, and consistently the protein levels for IRE1α, XBP-1s and GRP78 were observed to decrease. IFN-γ decreased the mRNA and protein levels of XBP-1s, IRE1α and GRP78, and increased methylation of their promoters. Significant correlations were also found between IRE1α/XBP-1 pathway components and clinical parameters. Conclusion: Decreased mRNA levels for IRE1α, XBP-1 and GRP78 can be partially explained by hypermethylation of their promoters and is consistent with chronic endoplasmic reticulum stress, which may explain the glandular dysfunction observed in LSGs of SS patients. Additionally, glandular stress signals, including IFN-γ, could modulate the expression of the IRE1α/XBP-1 pathway components.

[Cleft lip/palate and flour fortification with folic acid in Chile]. / Fisuras labio-palatinas y fortificación de la harina con ácido fólico en Chile: An exploratory study.

BACKGROUND: The effect of food fortification with folic acid on the incidence of lip-palate fissures (FLP) is under discussion. AIM: To calculate the rate of hospital discharges due to cleft lip and palate (CLP) and explore whether they decreased after the start of folic acid fortification in Chile. MATERIAL AND METHODS: The hospital discharge databases published by the Chilean Ministry of Health were analyzed. The trends of discharge rates due to CLP of children of less than one year of life (ICD-10 Q350-379 code) and live births (lb) were calculated from 1986 to 2012. Variables such as incidence of rubella, poverty rate, obesity in pregnant women, and percentage of women who smoked or drank alcohol in the last month were included. The relative risk (RR) of CLP pre-fortification (1986-1999) and post-fortification (2000-2010) was calculated. Mixed and Prais-Winsten models were used to adjust other variables. RESULTS: The hospital discharge rate due to CLP decreased from 1.88 x 1,000 lb during 1986-1996 to 1.68 x 1,000 lb (RR = 1.09 (95% CI 1.05-1.14, p < 0.001). Prais-Winsten and Mixed models, determined that folic acid fortification is the variable explaining this decrease. During 2004-2011, hospital discharge rates for cleft lip decreased but there was an increase in the figures for cleft lip and palate. CONCLUSIONS: The 9% decrease in hospital discharge rates for CLP is concomitant with wheat folic acid fortification.

Identification and expressional analysis of NLRC5 inflammasome gene in smolting Atlantic salmon (Salmo salar).

The NOD-like receptors (NLRs) were recently identified as an intracellular pathogen recognition receptor family in vertebrates. While the immune system participation of NLRs has been characterized and analyzed in various mammalian models, few studies have considered NLRs in teleost species. Therefore, this study analyzed the Atlantic salmon (Salmo salar) NLRC5. Structurally, Atlantic salmon NLRC5 presented leucine-rich repeat subfamily genes. Phylogenetically, NLRC5 was moderately conserved between S. salar and other species. Real-time quantitative PCR revealed NLRC5 expression in almost all analyzed organs, with greatest expressions in the head kidney, spleen, and hindgut. Furthermore, NLRC5 gene expression decreased during smolt stage. These data suggest that NLRC5 participates in the Atlantic salmon immune response and is regulated, at least partly, by the smoltification process, suggesting that there is a depression of immune system from parr at smolt stage. This is the first report on the NLRC5 gene in salmonid smolts.

Fisuras labio-palatinas y fortificación de la harina con ácido fólico en Chile: an exploratory study / Cleft lip/palate and flour fortification with folic acid in Chile

Background: The effect of food fortification with folic acid on the incidence of lip-palate fissures (FLP) is under discussion. Aim: To calculate the rate of hospital discharges due to cleft lip and palate (CLP) and explore whether they decreased after the start of folic acid fortification in Chile. Material and Methods: The hospital discharge databases published by the Chilean Ministry of Health were analyzed. The trends of discharge rates due to CLP of children of less than one year of life (ICD-10 Q350-379 code) and live births (lb) were calculated from 1986 to 2012. Variables such as incidence of rubella, poverty rate, obesity in pregnant women, and percentage of women who smoked or drank alcohol in the last month were included. The relative risk (RR) of CLP pre-fortification (1986-1999) and post-fortification (2000-2010) was calculated. Mixed and Prais-Winsten models were used to adjust other variables. Results: The hospital discharge rate due to CLP decreased from 1.88 x 1,000 lb during 1986-1996 to 1.68 x 1,000 lb (RR = 1.09 (95% CI 1.05-1.14, p < 0.001). Prais-Winsten and Mixed models, determined that folic acid fortification is the variable explaining this decrease. During 2004-2011, hospital discharge rates for cleft lip decreased but there was an increase in the figures for cleft lip and palate. Conclusions: The 9% decrease in hospital discharge rates for CLP is concomitant with wheat folic acid fortification.

Evaluación de zona dadora en reconstrucción auricular de microtia con técnica suprapericóndrica en la obtención de cartílago costal / Evaluation of donor site in auricular reconstruction of microtia with supraperichondrial costal cartilage harvest technique

Aim: To assess the presence of donor site sequel of patients undergoing ear reconstruction with costal cartilage harvest, using supraperichondrial technique. methods: Cross-sectional study; patients under 15 years. The cartilages were harvested with perichondrium. Three observers performed donor site assessment; they were independent to this study (validated Strasser score: deformity, asymmetry, contour and scar). Children and their mothers were applied satisfaction survey. Analysis of the association between variables: nonparametric tests. Results: 19 reconstructions, 18 patients, age 8 (6-15) years, follow-up 50 (14-96) months; number of rib cartilage harvested 3 (2-4) units. Expert assessment: excellent in 2 (10.5%) cases, good in 10 (52.6%), regular in 7 (36.8%). Most mothers and patients rated the result as good. There was no significant difference in the score, with respect to the number of harvested costal cartilages. To separate them by age, poorer results were obtained at surgery before 10 years of age than in older (p < 0.03). Conclusion: Ear reconstruction and supraperichondrial technique for costal cartilage allows obtain good results in donor site. There is high satisfaction when evaluated by the patient and his mother, as well as observers. The result is not dependent on the number of harvested cartilage, but is related to age at surgery, best results were obtained in patients operated over 10 years of age.

Objetivo: Evaluar presencia de secuela en zona dadora de pacientes sometidos a reconstrucción auricular con cartílago costal con técnica suprapericóndrica. material y método: Corte transversal; pacientes menores de 15 años. Cartílagos fueron levantados con pericondrio. Evaluación de zona dadora fue realizada por tres observadores independientes (escala validada de Strasser: deformidad, asimetría, contorno y cicatriz). A niños y madres se les aplicó encuesta de satisfacción. En el análisis de la asociación entre variables se utilizan pruebas no paramétricas. Resultados: 19 reconstrucciones, 18 pacientes, mediana edad 8 (6-15) años, seguimiento 50 (14-96) meses, número de cartílagos costales obtenidos 3 (2-4) unidades. Evaluación de expertos: excelente en 2 (10,5%) casos, bueno en 10 (52,6%) y regular en 7 (36,8%). La mayoría de las madres y pacientes calificó como bueno el resultado. No hubo diferencia significativa en el puntaje con respecto al número de cartílagos costales cosechados. Al separarlos por edad se obtuvo peores resultados en los intervenidos antes de los 10 años que en mayores (p < 0,03). Conclusión: La reconstrucción auricular con cartílago costal y técnica suprapericóndrica, permite obtener buenos resultados en zona dadora. Existe alta satisfacción al ser evaluada por el paciente y su madre, así como por los observadores. El resultado no es dependiente del número de cartílagos; sí en relación a la edad de la cirugía: mejores resultados en pacientes operados sobre los 10 años de edad, lo que concuerda con otros estudios.

Comparing evolutionary strategies on a biobjective cultural algorithm.

Evolutionary algorithms have been widely used to solve large and complex optimisation problems. Cultural algorithms (CAs) are evolutionary algorithms that have been used to solve both single and, to a less extent, multiobjective optimisation problems. In order to solve these optimisation problems, CAs make use of different strategies such as normative knowledge, historical knowledge, circumstantial knowledge, and among others. In this paper we present a comparison among CAs that make use of different evolutionary strategies; the first one implements a historical knowledge, the second one considers a circumstantial knowledge, and the third one implements a normative knowledge. These CAs are applied on a biobjective uncapacitated facility location problem (BOUFLP), the biobjective version of the well-known uncapacitated facility location problem. To the best of our knowledge, only few articles have applied evolutionary multiobjective algorithms on the BOUFLP and none of those has focused on the impact of the evolutionary strategy on the algorithm performance. Our biobjective cultural algorithm, called BOCA, obtains important improvements when compared to other well-known evolutionary biobjective optimisation algorithms such as PAES and NSGA-II. The conflicting objective functions considered in this study are cost minimisation and coverage maximisation. Solutions obtained by each algorithm are compared using a hypervolume S metric.

Methoxycarbonylation of olefins catalyzed by palladium complexes bearing P,N-donor ligands.

The methoxycarbonylation of alkenes catalyzed by palladium(II) complexes with P,N-donor ligands, 2-(diphenylphosphinoamino)pyridine (Ph2PNHpy), 2-[(diphenylphosphino)methyl]pyridine (Ph2PCH2py), and 2-(diphenylphosphino)quinoline (Ph2Pqn) has been investigated. The results show that the complex [PdCl(PPh3)(Ph2PNHpy)]Cl or an equimolar mixture of [PdCl2(Ph2PNHpy)] and PPh3, in the presence of p-toluensulfonic acid (TsOH), is an efficient catalyst for this reaction. This catalytic system promotes the conversion of styrene into methyl 2-phenylpropanoate and methyl 3-phenylpropanoate with nearly complete chemoselectivity, 98% regioselectivity in the branched isomer, and high turnover frequency, even at alkene/Pd molar ratios of 1000. Best results were obtained in toluene-MeOH (3 : 1) solvent. The Pd/Ph2PNHpy catalyst is also efficient in the methoxycarbonylation of cyclohexene and 1-hexene, although with lower rates than with styrene. Related palladium complexes [PdCl(PPh3)L]Cl (L = Ph2PCH2py and Ph2Pqn) show lower activity in the methoxycarbonylation of styrene than that of the 2-(diphenylphosphinoamino)pyridine ligand. Replacement of the last ligand by (diphenylphosphino)phenylamine (Ph2PNHPh) or 2-(diphenylphosphinoaminomethyl)pyridine (Ph2PNMepy) also reduces significantly the activity of the catalyst, indicating that both the presence of the pyridine fragment as well as the NH group, are required to achieve a high performing catalyst. Isotopic labeling experiments using MeOD are consistent with a hydride mechanism for the [PdCl(PPh3)(Ph2PNHpy)]Cl catalyst.