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This note discusses the application of a Minisci-type reaction for the direct alkylation of azoles with carboxylic acids as radical precursors. Different reaction conditions were investigated to achieve high yield of the desired products, focusing on acid strength and solvent screening. Moreover, the reactivity of imidazoles with various carboxylic acids was investigated, showing good yield for most cases. The study reveals the potential of this approach for late-stage functionalization in drug discovery.
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Synergistic catalysis offers the unique possibility of simultaneous activation of both the nucleophile and the electrophile in a reaction. A requirement for this strategy is the stability of the active species towards the reaction conditions and the two concerted catalytic cycles. Since the beginning of the century, aminocatalysis has been established as a platform for the stereoselective activation of carbonyl compounds through HOMO-raising or LUMO-lowering. The burgeoning era of aminocatalysis has been driven by a deep understanding of these activation and stereoinduction modes, thanks to the introduction of versatile and privileged chiral amines. The aim of this review is to cover recent developments in synergistic strategies involving aminocatalysis in combination with organo-, metal-, photo-, and electro-catalysis, focusing on the evolution of privileged aminocatalysts architectures.
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Aminas , CatáliseRESUMO
The versatility of olefin metathesis is evident from its successful applications ranging from natural product synthesis to the valorization of renewable feedstocks. On the other side, flow chemistry has recently gained particular interest among the synthetic community, offering valuable alternatives to classic batch chemistry and paving the way to the development of new transformations. The application of continuous-flow methods to olefin metathesis represents one of the most promising evolutions in the field at the interface of industrially relevant synthesis and reactor engineering, significantly improving some of the typical problems such as undesired self-reactions and ethylene-mediated catalyst deactivation. This Minireview aims to provide a brief survey covering the major aspects of those techniques which we hope may be of interest for the chemical community as well as those interested in catalysis, continuous processing, enabling technologies and reactor design.
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Produtos Biológicos , Rutênio , Alcenos , CatáliseRESUMO
C-H activation has emerged as one of the most efficient tools for the formation of carbon-carbon and carbon-heteroatom bonds, avoiding the use of prefunctionalized materials. In spite of tremendous progress in the field, stoichiometric quantities of toxic and/or costly chemical redox reagents, such as silver(I) or copper(II) salts, are largely required for oxidative C-H activations. Recently, electrosynthesis has experienced a remarkable renaissance that enables the use of storable, safe and waste-free electric current as a redox equivalent. While major recent momentum was gained in electrocatalyzed C-H activations by 4d and 5d metals, user-friendly and inexpensive nickela-electrocatalysis has until recently proven elusive for oxidative C-H activations. Herein, the early developments of nickela-electrocatalyzed reductive cross-electrophile couplings as well as net-redox-neutral cross-couplings are first introduced. The focus of this Minireview is, however, the recent emergence of nickel-catalyzed electrooxidative C-H activations until April 2020.
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A transition-metal-free carbon isotope exchange procedure on phenyl acetic acids is described. Utilizing the universal precursor CO2 , this protocol allows the carbon isotope to be inserted into the carboxylic acid position, with no need of precursor synthesis. This procedure enabled the labeling of 15 pharmaceuticals and was compatible with carbon isotopes [14 C] and [13 C]. A proof of concept with [11 C] was also obtained with low molar activity valuable for distribution studies.
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BACKGROUND: The application of noninvasive ventilation (NIV) modalities from birth in the delivery room (DR) during fetal-neonatal transition reduces the need for invasive mechanical ventilation, mortality, and bronchopulmonary dysplasia (BPD). The use of a RAM nasal cannula (RAM NC) in the DR for resuscitation results in less need for intubation, chest compressions, and epinephrine administration when compared with using a face mask for PPV in the DR. OBJECTIVE: To evaluate the need for endotracheal intubation in the DR among extremely low gestational age neonates treated at birth with sustained inflation (SI) followed by a nasal continuous positive airway pressure (NCPAP) (range: 6-8 cm of H2O) delivered through the RAM NC. STUDY DESIGN: A retrospective study was conducted to compare the use of NIV techniques in the DR and the need for intubation in the DR in premature infants 23 to 28 weeks' gestational age from December 2016 to July 2018 (group A). These data were compared with those of premature inborn infants with similar GA born between April 2015 and November 2016 (group B). In the DR, immediately after birth, neonates in group A received SI through RAM NC followed by CPAP ranging from 6 to 8 cm H2O, whereas the neonates in group B were treated in the DR with SI administered through a face mask followed by the application of CPAP of 5 cm H2O delivered through a nasopharyngeal tube. RESULTS: A total of 65 preterm infants 23 to 28 weeks of gestational age, 31 in group A and 34 in group B, were included in the study. The percentage of neonates intubated in the DR was significantly lower in group A (p < 0.008). In both groups, no neonates died in the DR, and no one required epinephrine and/or chest compressions. For those neonates who did not require intubation in the DR, there was no significant difference in the average FiO2 on arrival in the neonatal intensive care unit, rate of intubation within 24 hours, and use of surfactant. The incidence of BPD was similar in the two groups. Only one infant in group A developed moderate BPD, and no one needed oxygen and/or ventilatory assistance at discharge. Mortality was similar in the two groups, with a slight prevalence in group B (27.7 vs. 19.2%). CONCLUSION: SI with RAM NC followed by NCPAP ranging from 6 to 8 cm H2O, administered with RAM NC resulted in a significant reduction of intubation in the DR.
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Cânula , Pressão Positiva Contínua nas Vias Aéreas , Lactente Extremamente Prematuro , Ventilação não Invasiva/métodos , Ressuscitação/métodos , Salas de Parto , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Doenças do Prematuro , Intubação Intratraqueal , Masculino , Máscaras , Estudos RetrospectivosRESUMO
Lactoferrin is one of the most represented and important bioactive proteins in human and mammal milk. In humans, lactoferrin is responsible for several actions targeting anti-infective, immunological, and gastrointestinal domains in neonates, infants, and young children. Evidence-based data vouch for the ability of supplemented lactoferrin to prevent sepsis and necrotizing enterocolitis in preterm infants and to reduce the burden of morbidity related to gastrointestinal and respiratory pathogens in young children. However, several issues remain pending regarding answers and clarification related to quality control, correct intakes, optimal schedules and schemes of supplementations, interactions with probiotics, and different types of milk and formulas. This review summarizes the current evidence regarding lactoferrin and discusses the areas in need of further guidance prior to the adoption of strategies that include a routine use of lactoferrin in neonates and young children.
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Anti-Infecciosos/uso terapêutico , Suplementos Nutricionais , Doenças do Prematuro/prevenção & controle , Lactoferrina/uso terapêutico , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Heterocycles play an essential role in modern pharmaceutical and agrochemical developments, representing a very common structural unit in marketed drugs. Over the 46 new drugs approved in 2017 by the FDA, 25 contain in their structure a heterocyclic core. The development of novel and straightforward labeling strategies for the effective insertion of carbon isotopes into heterocylic scaffolds is an inspiring and vibrant field of research. The use of carbon-11, carbon-13, and carbon-14 isotopes is well established in life science and particularly in pharmaceutical and agrochemical industry. Their introduction into small organic molecules represents a crucial step for the radiochemists. Because the labeling should occur in metabolically stable positions and in the shortest synthetic route, their incorporation into the heterocycles represents a viable solution. This review summarizes recent contributions to this area of research through the analysis of different industrial and academic cases.
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Isótopos de Carbono/química , Compostos Heterocíclicos/química , Marcação por Isótopo/métodos , CatáliseRESUMO
Infants born prematurely before 37 weeks of gestational age (GA) have particular anatomical, immunological and metabolic characteristics that predispose them, even in the absence of diseases at birth, to severe morbidity. Respiratory syncytial virus (RSV) is the leading cause of hospitalization for lower respiratory tract infections (LRTI) in the first year of life, as well as an important cause of respiratory outcomes as recurrent wheezing in industrialized countries or mortality in developing countries. Prematurity is an important risk factor for hospitalization for severe RSV disease, but epidemiological, environmental and demographic risk factors also play a role in RSV infection. Currently, there is no effective antiviral therapy for the treatment of RSV infection, nor the possibility of using maternal immunization or vaccination of children to prevent infection, although numerous preclinical and clinical studies are still ongoing. Passive immunization with palivizumab has been shown to be safe and effective in preventing RSV hospitalization in children at greater risk of contracting a serious infection. Costs associated with palivizumab prophylaxis and its monthly intramuscularly administration has prompted many health institutions of different countries to implement specific recommendations, with the aim of protecting at risk infants for whom RSV infection is likely to cause serious illness or death. The cost-effectiveness ratio of prophylaxis, related to reduce hospitalization costs and the impact of the burden of RSV disease worldwide, greatly affects the drafting and the adoption of specific recommendations and the adherence to them, concerning the passive immunization with palivizumab.
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Recém-Nascido Prematuro , Palivizumab/administração & dosagem , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Animais , Antivirais/administração & dosagem , Antivirais/economia , Análise Custo-Benefício , Hospitalização/estatística & dados numéricos , Humanos , Recém-Nascido , Palivizumab/economia , Infecções por Vírus Respiratório Sincicial/economia , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/prevenção & controle , Infecções Respiratórias/virologia , Fatores de RiscoRESUMO
A robust, click-chemistry-inspired procedure for radiolabeling of cyclic ureas was developed. This protocol, suitable for all carbon isotopes (11 C, 13 C, 14 C), is based on the direct functionalization of carbon dioxide: the universal building block for carbon radiolabeling. The strategy is operationally simple and reproducible in different radiochemistry centers, exhibits remarkably wide substrate scope with short reaction times, and demonstrates superior reactivity as compared to previously reported systems. With this procedure, a variety of pharmaceuticals and an unprotected peptide were labeled with high radiochemical efficiency.
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Dióxido de Carbono/química , Marcação por Isótopo , Compostos Radiofarmacêuticos/síntese química , Ureia/síntese química , Isótopos de Carbono , Química Click , Estrutura Molecular , Compostos Radiofarmacêuticos/química , Ureia/análogos & derivados , Ureia/químicaRESUMO
Based on small studies and not on statistically valid clinical trials, guidelines for neonatal transfusions remain controversial and practices vary greatly. Premature infants and critically ill neonates in the neonatal intensive care unit (NICU) often require blood transfusions and extremely preterm neonates receive at least one red blood cell transfusion during their hospital stay. Transfusions to neonates convey both benefits and risks and consequently it is imperative to establish specific guidelines to improve practice and avoid unnecessary transfusions. Appropriate and lifesaving platelet transfusion in thrombocytopenic bleeding neonates pertains to 2% of all neonates in NICUs. Inversely, 98% of platelet transfusions are given prophylactically, in the absence of bleeding, with the assumption that this reduces the risk of a serious hemorrhage. To date, no evidence base is available for assigning a platelet transfusion trigger to NICU patients. Each NICU should approve specific guidelines that best suit its local clinical practice. Therefore, whatever guidelines are chosen in deciding when to transfuse, what is most important is to adhere strictly to the guidelines adopted, thus limiting unnecessary transfusions that convey no benefits and carry both known and unknown risks.
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Anemia Neonatal/terapia , Transfusão de Eritrócitos , Hemorragia/terapia , Transfusão de Plaquetas , Trombocitopenia/terapia , Estado Terminal/terapia , Fidelidade a Diretrizes , Humanos , Lactente Extremamente Prematuro , Recém-Nascido , Unidades de Terapia Intensiva NeonatalRESUMO
The synthesis of ruthenium-complexes with cyclic (amino)(barrelene)carbenes (namely CABCs) as ligands is reported. Isolated in moderate to good yields, these new complexes showed impressive thermal stability at 110 °C over several days. Good catalytic performances were demonstrated in various ring-closing metathesis (RCM), macrocyclic-RCM, ring-closing enyne metathesis (RCEYM), cross-metathesis (CM), and ring-opening cross metathesis (ROCM) reactions.
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A selective direct arylation of the different Csp2-H bonds of imidazo[2,1-b]thiazole with (hetero) aryl halides can be achieved simply by switching from a palladium catalyst system to the use of stoichiometric amounts of copper. The observed selectivity, also rationalized by DFT calculations, can be explained by a change in the mechanistic pathways between electrophilic palladation and base-promoted C-H metalation.
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Several clinical studies reported an increased prevalence and accelerated progression of aortic valve calcification among patients with end-stage renal disease when compared with subjects with normal kidney function. Recently, mechanisms of calcific valve degeneration have been further elucidated and many of the pathways involved could be amplified in patients with decreased renal function. In particular, calcium-phosphate balance, MGP metabolism, OPG/RANK/RANKL triad, fetuin-A mineral complexes and FGF-23/Klotho axis have been shown to be impaired among patients with advanced chronic kidney disease and could play a role during vascular/valve calcification. The scope of the present review is to summarize the clinical data and the pathophysiological mechanisms potentially involved in the link between renal function decline and the progression of aortic valve disease.
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Estenose da Valva Aórtica/etiologia , Valva Aórtica/patologia , Calcinose/etiologia , Insuficiência Renal Crônica/complicações , Estenose da Valva Aórtica/patologia , Calcinose/patologia , Progressão da Doença , Fator de Crescimento de Fibroblastos 23 , Humanos , Insuficiência Renal Crônica/patologiaRESUMO
Orellanic syndrome is caused by fungi of the Cortinarius orellanus and speciosissimus (Europe) species, Cortinarius fluorescens (South America), and Cortinarius rainierensis (North America). Orellanic syndrome is characterized by initially nonspecific symptoms such as muscle and abdominal pain, and a metallic taste sensation in the mouth. After a few days, more specific symptoms appear, such as intense thirst, headache, chills without fever, and anorexia, followed by a phase of polyuria and then of oligoanuria. Renal failure occurs in 70% of cases and is often irreversible. The clinical case involves a 52-year-old man who developed acute renal failure from Orellanic syndrome, necessitating hemodialysis.
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Injúria Renal Aguda , Intoxicação Alimentar por Cogumelos , Masculino , Humanos , Pessoa de Meia-Idade , Intoxicação Alimentar por Cogumelos/complicações , Intoxicação Alimentar por Cogumelos/diagnóstico , Injúria Renal Aguda/etiologia , Diálise Renal/efeitos adversos , Síndrome , Europa (Continente)RESUMO
Harvesting sunlight to drive carbon dioxide (CO2) valorisation represents an ideal concept to support a sustainable and carbon-neutral economy. While the photochemical reduction of CO2 to carbon monoxide (CO) has emerged as a hot research topic, the full CO2-to-CO conversion remains an often-overlooked criterion that prevents a productive and direct valorisation of CO into high-value-added chemicals. Herein, we report a photocatalytic process that unlocks full and fast CO2-to-CO conversion (<10 min) and its straightforward valorisation into human health related field of radiochemistry with carbon isotopes. Guided by reaction-model-based kinetic simulations to rationalize reaction optimisations, this manifold opens new opportunities for the direct access to 11C- and 14C-labeled pharmaceuticals from their primary isotopic sources [11C]CO2 and [14C]CO2.
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Domperidone and metoclopramide are widely prescribed antiemetic drugs with distinct neurological side effects. The impact of P-glycoprotein (P-gp)-mediated efflux at the blood−brain barrier (BBB) on brain exposure and BBB permeation was compared in vitro and in vivo using positron emission tomography (PET) imaging in rats with the radiolabeled analogs [11C]domperidone and [11C]metoclopramide. In P-gp-overexpressing cells, the IC50 of tariquidar, a potent P-gp inhibitor, was drastically different using [11C]domperidone (221 nM [198−248 nM]) or [11C]metoclopramide (4 nM [2−8 nM]) as the substrate. Complete P-gp inhibition led to a 1.8-fold higher increase in the cellular uptake of [11C]domperidone compared with [11C]metoclopramide (p < 0.0001). Brain PET imaging revealed that the baseline brain exposure (AUCbrain) of [11C]metoclopramide was 2.4-fold higher compared with [11C]domperidone (p < 0.001), consistent with a 1.8-fold higher BBB penetration (AUCbrain/AUCplasma). The maximal increase in the brain exposure (2.9-fold, p < 0.0001) and BBB penetration (2.9-fold, p < 0.0001) of [11C]metoclopramide was achieved using 8 mg/kg of tariquidar. In comparison, neither 8 nor 15 mg/kg of tariquidar increased the brain exposure of [11C]domperidone (p > 0.05). Domperidone is an avid P-gp substrate that was in vitro compared with metoclopramide. Domperidone benefits from a lower brain exposure and a limited risk for P-gp-mediated drug−drug interaction involving P-gp inhibition at the BBB.
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Carbon isotope labeling is a traceless technology, which allows tracking the fate of organic compounds either in the environment or in living organisms. This article reports on a general approach to label urea derivatives with all carbon isotopes, including 14C and 11C, based on a Staudinger aza-Wittig sequence. It provides access to all aliphatic/aromatic urea combinations.
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Dióxido de Carbono/química , Radioisótopos de Carbono/química , Marcação por Isótopo/métodos , Ureia/químicaRESUMO
OBJECTIVES: To assess ductal size correlated to spontaneous closure, pharmacological or surgical treatment; to index ductal diameter to body weight and body surface area; to evaluate the morbidities. STUDY DESIGN: Retrospective study on preterms ≤32 weeks, birth weight ≤1500 g, extremely low birth weight (ELBW) and very low birth weight (VLBW). Inclusion criteria: patent ductus arteriosus (PDA) with a diameter ≥1 millimeter (mm) at 72 h from birth; need for ibuprofen treatment on the basis of a hemodynamically significant ductus arteriosus (HsPDA). RESULTS: One hundred infants with the diagnosis of PDA have been included. We observed a prevalence of spontaneous closure in 34% of newborns (41.3% VLBW versus 26.7% ELBW). The percentage of response to a single course of ibuprofen was of 62% (68.5% ELBW versus 54.3% VLBW). The mean of absolute ductal diameter was of 2.26 ± 0.62 mm in ELBW and 2.18 ± 0.42 mm in VLBW. The indexing of ductus size to body weight demonstrated a higher value in ELBW than VLBW (2.76 ± 0.97 mm/kg versus 1.84 ± 0.40 mm/kg). CONCLUSIONS: Our results confirmed that HsPDA can develop in presence of a ductus >1.5 mm as absolute value or >1.4 mm/kg as indexed to body weight. In ELBW infants the ductal size indexed for body weight and body surface area could be more predictive of spontaneous closure or need for pharmacological treatment compared to the absolute value of ductal size. A strong association between HsPDA and short- or long-term morbidities was confirmed particularly in ELBW.
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Permeabilidade do Canal Arterial , Recém-Nascido Prematuro , Superfície Corporal , Permeabilidade do Canal Arterial/epidemiologia , Humanos , Ibuprofeno , Recém-Nascido de Peso Extremamente Baixo ao Nascer , Recém-Nascido , Morbidade , Estudos RetrospectivosRESUMO
BACKGROUND: Preterm neonates are likely to require red blood cell (RBC) transfusion, and extremely low birth weight infants almost invariably receive multiple transfusions. Transfusion-reduction strategies can reduce transfusion rates, and might diminish certain adverse outcomes associated with transfusions. MATERIALS AND METHODS: In a single centre, we retrospectively evaluated RBC transfusion rates among preterm infants ≤32 weeks' gestational age (GA), over a 6-year period before and after adopting national transfusion-reduction strategies. We compared demographic data, adverse events, and outcomes between transfused vs not-transfused neonates. Univariate logistic regression was used to evaluate associations between dichotomous outcomes and number of transfusions, and day of first transfusion. Multivariate logistic regression evaluated the correlation between dichotomous outcomes and transfusion as an independent risk factor. RESULTS: During the 6 years studied, 181 infants born at ≤32 weeks' GA were admitted to our Neonatal Intensive Care Unit of whom 80 (44%) received at least one RBC transfusion. The transfusion rate tended downwards after adopting transfusion-reduction strategies, reaching 31% in 2018. The reduction was largely due to a marked fall in transfusions of neonates born at 29-32 weeks' GA (p<0.001). The number of transfusions received correlated with odds of having intraventricular haemorrhage (IVH) (OR=1.9; 95% CI: 1.3-2.7; p=0.0001) and the duration of oxygen supplementation (rho=0.51; 95% CI: 0.33-0.66; p≤0.0001). In multivariate logistic regression analysis, transfusion was an independent risk factor for IVH (adjusted OR=7.38; 95% CI: 2.24-24.30; p=0.0001). DISCUSSION: The application of national, standardised transfusion-reduction strategies was associated with a lower transfusion rate in neonates born at 29-32 weeks' GA, but was less effective among neonates ≤28 weeks, in whom transfusions appeared to be an independent risk factor for severe IVH.