ABC2-SPH risk score for in-hospital mortality in COVID-19 patients: development, external validation and comparison with other available scores.

OBJECTIVES: The majority of available scores to assess mortality risk of coronavirus disease 2019 (COVID-19) patients in the emergency department have high risk of bias. Therefore, this cohort aimed to develop and validate a score at hospital admission for predicting in-hospital mortality in COVID-19 patients and to compare this score with other existing ones. METHODS: Consecutive patients (≥ 18 years) with confirmed COVID-19 admitted to the participating hospitals were included. Logistic regression analysis was performed to develop a prediction model for in-hospital mortality, based on the 3978 patients admitted between March-July, 2020. The model was validated in the 1054 patients admitted during August-September, as well as in an external cohort of 474 Spanish patients. RESULTS: Median (25-75th percentile) age of the model-derivation cohort was 60 (48-72) years, and in-hospital mortality was 20.3%. The validation cohorts had similar age distribution and in-hospital mortality. Seven significant variables were included in the risk score: age, blood urea nitrogen, number of comorbidities, C-reactive protein, SpO2/FiO2 ratio, platelet count, and heart rate. The model had high discriminatory value (AUROC 0.844, 95% CI 0.829-0.859), which was confirmed in the Brazilian (0.859 [95% CI 0.833-0.885]) and Spanish (0.894 [95% CI 0.870-0.919]) validation cohorts, and displayed better discrimination ability than other existing scores. It is implemented in a freely available online risk calculator (https://abc2sph.com/). CONCLUSIONS: An easy-to-use rapid scoring system based on characteristics of COVID-19 patients commonly available at hospital presentation was designed and validated for early stratification of in-hospital mortality risk of patients with COVID-19.

Direct Synthesis of Indoles from Azoarenes and Ketones with Bis(neopentylglycolato)diboron Using 4,4'-Bipyridyl as an Organocatalyst.

Multifunctionalized indole derivatives were prepared by reducing azoarenes in the presence of ketones and bis(neopentylglycolato)diboron (B2nep2) with a catalytic amount of 4,4'-bipyridyl under neutral reaction conditions, where 4,4'-bipyridyl acted as an organocatalyst to activate the B-B bond of B2nep2 and form N,N'-diboryl-1,2-diarylhydrazines as key intermediates. Further reaction of N,N'-diboryl-1,2-diarylhydrazines with ketones afforded N-vinyl-1,2-diarylhydrazines, which rearranged to the corresponding indoles via the Fischer indole mechanism. This organocatalytic system was applied to diverse alkyl cyclic ketones, dialkyl, and alkyl/aryl ketones, including heteroatoms. Methyl alkyl ketones gave the corresponding 2-methyl-3-substituted indoles in a regioselective manner. This protocol allowed us to expand the preparation of indoles having high compatibility with not only electron-donating and electron-withdrawing groups but also N- and O-protecting functional groups.

4,4'-Bipyridyl-Catalyzed Reduction of Nitroarenes by Bis(neopentylglycolato)diboron.

4,4'-Bipyridyl worked as an organocatalyst for the reduction of nitroarenes by bis(neopentylglycolato)diboron (B2nep2), followed by hydrolysis to give the corresponding anilines. This reduction proceeded under aerobic conditions without any prepurification of substrates and reagents. We found broad functional group tolerance and compatibility for O- and N-protecting groups under the reaction conditions. The key in this catalytic system was the addition of B2nep2 to 4,4'-bipyridyl to form N,N'-bis[(neopentylglycolato)boryl]-4,4'-bipyridinylidene as a deoxygenating reagent of nitroarenes.

Size-Selective Separation of Rare Earth Elements Using Functionalized Mesoporous Silica Materials.

The separation and preconcentration of rare earth elements (REEs) from mineral concentrates in an economically and environmentally sustainable manner are difficult tasks due to their similar physicochemical properties. Herein, a series of tetradentate phenylenedioxy diamide (PDDA) ligands were synthesized and grafted on large-pore three-dimensional KIT-6 mesoporous silica. In solid-phase extraction, the hybrid sorbents enable a size-selective separation of REEs on the basis of the bite angles of the ligands. In particular, smaller REE3+ ions are preferentially extracted by KIT-6-1,2-PDDA, whereas light REEs with larger ionic radius are favored by KIT-6-1,3-PDDA. The exposure of bauxite residue digestion solution containing REEs as well as a number of types of competitive ions (including Th and U) to the sorbents results in selective recovery of target REEs. The possibility of regenerating the mesoporous sorbents through a simple loading-stripping-regeneration process is demonstrated over up to five cycles with no significant loss in REE extraction capacity, suggesting adequate chemical and structural stability of the new sorbent materials.

Metal-free borylative dearomatization of indoles: exploring the divergent reactivity of aminoborane C-H borylation catalysts.

While the dearomatization of indoles by carbon-boron bond forming reactions is new and quite promising, they are so far mainly metal-catalyzed. Here, we establish the use of metal-free catalysts in promoting such reactions in an atom-efficient way. The in situ generated ambiphilic aminoborane catalyst (1-Pip-2-BH2-C6H4)2 (Pip = piperidyl) promotes borylative dearomatization of various 1-arylsulfonyl indoles with pinacolborane in a syn addition fashion, with H and Bpin groups added respectively to the 2 and 3 positions of indoles. Catalysis proceeds with good to excellent conversion and essentially with complete regio- and diastereoselectivity. From mechanistic insights and DFT computations, we realized and established that prototypical boranes can also catalyze this borylative dearomatization.

Metal-Free Borylation of Heteroarenes Using Ambiphilic Aminoboranes: On the Importance of Sterics in Frustrated Lewis Pair C-H Bond Activation.

Two novel frustrated Lewis pair (FLP) aminoboranes, (1-Pip-2-BH2-C6H4)2 (2; Pip = piperidyl) and (1-NEt2-2-BH2-C6H4)2 (3; NEt2 = diethylamino), were synthesized, and their structural features were elucidated both in solution and in the solid state. The reactivity of these species for the borylation of heteroarenes was investigated and compared to previously reported (1-TMP-2-BH2-C6H4)2 (1; TMP = tetramethylpiperidyl) and (1-NMe2-2-BH2-C6H4)2 (4; NMe2 = dimethylamino). It was shown that 2 and 3 are more active catalysts for the borylation of heteroarenes than the bulkier analogue 1. Kinetic studies and density functional theory calculations were performed with 1 and 2 to ascertain the influence of the amino group of this FLP-catalyzed transformation. The C-H activation step was found to be more facile with smaller amines at the expense of a more difficult dissociation of the dimeric species. The bench-stable fluoroborate salts of all catalysts (1F-4F) have been synthesized and tested for the borylation reaction. The new precatalysts 2F and 3F are showing higher reaction rates and yields for multigram-scale syntheses.

Chelation-Assisted Nickel-Catalyzed Oxidative Annulation via Double C-H Activation/Alkyne Insertion Reaction.

A nickel/NHC system for regioselective oxidative annulation by double C-H bond activation and concomitant alkyne insertion is described. The catalytic reaction requires a bidentate directing group, such as an 8-aminoquinoline, embedded in the substrate. Various 5,6,7,8-tetrasubstituted-N-(quinolin-8-yl)-1-naphthamides can be prepared as well as phenanthrene and benzo[h]quinoline amide derivatives. Diarylalkynes, dialkylalkynes, and arylalkylalkynes can be used in the system. A Ni(0)/Ni(II) catalytic cycle is proposed as the main catalytic cycle. The alkyne plays a double role as a two-component coupling partner and as a hydrogen acceptor.

Palladium(II)-catalyzed ortho-C-H arylation/alkylation of N-benzoyl α-amino ester derivatives.

The palladium-catalyzed arylation/alkylation of ortho-C-H bonds in N-benzoyl α-amino ester derivatives is described. In such a system both the NH-amido and the CO2R groups in the α-amino ester moieties play a role in successful C-H activation/C-C bond formation using iodoaryl coupling partners. A wide variety of functional groups and electron-rich/deficient iodoarenes are tolerated. The yields obtained range from 20 to 95%.

Selective switchable iron-catalyzed hydrosilylation of carboxylic acids.

Selective reduction of carboxylic acids either to aldehydes or alcohols is achieved using a one pot procedure based on iron-catalyzed hydrosilylations. Using phenylsilane and (COD)Fe(CO)(3) catalyst under UV-irradiation at rt, alcohols were obtained specifically in good yields, whereas aldehydes were selectively obtained using TMDS and (t-PBO)Fe(CO)(3) catalyst under thermal activation.

NHC-carbene cyclopentadienyl iron based catalyst for a general and efficient hydrosilylation of imines.

A general and efficient hydrosilylation of imines catalysed by a well defined NHC-carbene cyclopentadienyl iron complex has been developed. Both aldimines and ketimines are converted to the corresponding amines under mild conditions, and under visible light activation.

Biphosphonate-induced radiographic changes in two pediatric patients with rheumatic diseases.

Biphosphonates are now being used experimentally in children to increase bone mass, but their long-term effects remain an issue of concern. We report two cases of biphosphonate-induced radiographic changes in children with rheumatic diseases. Our experience supports the view that clinical improvement and radiographic findings after biphosphonate therapy are related to increased bone mineral density, without effects on the inflammatory process itself. Biphosphonates seem to act in rheumatic diseases by reducing bone turnover instead of improving disease activity.

Disminución del daño tisular inducido por la obstrucción intestinal experimental con nalozona y sylfóxido de dimetilo en perros / Use of naloxone and dimethyl sulfoxide to decrease tissue damage due to experimental intestinal obstruction in dogs

Después de la corrección de una obstrucción intestinal se producen radicales libres derivados del oxígeno, que se forman durante la isquemia y la reperfusión del área (síndrome de reperfusión). Para valorar hasta qué punto puede resolverse una obstrucción intestinal contrarrestando estos factores con medicamentos, se indujo una obstrucción intestinal a nivel del yeyuno en 10 perros, que se mantuvo durante 120 minutos. A los 110 minutos se administró una combinación de sulfóxido de dimetilo y naloxona con el objetivo de evaluar su eficacia para contrarrestar los efectos de la reperfusión. Los perros de dividieron en dos grupos de 5 animales cada uno: grupo testigo y grupo experimental. Al primer grupo se le administró solución salina fisiológica en cantidad equivalente al volumen administrado de fármacos que se les aplicó al segundo grupo, a este último se le suministró la combinación sulfóxido de dimetilo (a dosis de 1 g/kg de peso a una dilución de 10 por ciento) y naloxona (a dosis de 0.04 mg/kg de peso). Los resultados sugieren que dicha combinación puede ser eficaz para disminuir las lesiones provocadas por los radicales libres, también es eficaz para mejorar la condición del sujeto, al contrarrestar los efectos sistémicos de la reperfusión