Enhancing Direction-of-Arrival Estimation with Multi-Task Learning.

There are numerous methods in the literature for Direction-of-Arrival (DOA) estimation, including both classical and machine learning-based approaches that jointly estimate the Number of Sources (NOS) and DOA. However, most of these methods do not fully leverage the potential synergies between these two tasks, which could yield valuable shared information. To address this limitation, in this article, we present a multi-task Convolutional Neural Network (CNN) capable of simultaneously estimating both the NOS and the DOA of the signal.

New lipophilic glycomimetic DC-SIGN ligands: Stereoselective synthesis and SPR-based binding inhibition assays.

The design and synthesis of efficient ligands for DC-SIGN is a topic of high interest, because this C-type lectin has been implicated in the early stages of many infection processes. DC-SIGN membrane-protein presents four carbohydrate-binding domains (CRD) that specifically recognize mannose and fucose. Therefore, antagonists of minimal disaccharide epitope Manα(1,2)Man, represent potentially interesting antibacterial and antiviral agents.

Medicinal clays improve the endurance of loaded inspiratory muscles in COPD: a randomized clinical trial of nonpharmacological treatment.

Background: Inspiratory resistive breathing (IRB) challenges affect respiratory muscle endurance in healthy individuals, which is considered to be an interleukin 6 (IL-6)-dependent mechanism. Whether nonpharmacological thermal therapies promote the endurance of loaded inspiratory muscles in chronic obstructive pulmonary disease (COPD) is unclear. The objectives of this study were to compare the effects of two thermal interventions on endurance time (ET) and plasma IL-6 concentration following an IRB challenge.

The mediating role of cytokine IL-6 on the relationship of FEV₁ upon 6-minute walk distance in chronic obstructive pulmonary disease.

Objectives: To explore the mediating role of protein interleukin-6 (IL-6) on the relationship between forced expiratory volume in 1 second (FEV1) and 6-minute walk distance (6MWD) and, further, to determine whether status variables (such as age, sex, and body mass index [BMI]) operate as moderators of this mediation relationship.

Design: Moderated mediation model.

Setting: An inpatient pulmonary rehabilitation center in Italy.

Enantiopure cis-2,5-disubstituted 2,5-dihydropyrroles from D-glycal-derived vinyl aziridines.

Upon treatment with the K- and Li-enolates of a methylene active compound, such as dimethyl malonate and dibenzoylmethane, D-allal- and D-galactal-derived vinyl N-mesyl aziridines are stereoselectively transformed, in a unique step, into diastereoisomeric, highly functionalized, enantiopure cis-2,5-disubstituted N-mesyl-2,5-dihydropyrroles.

Stereodivergent synthesis of diastereoisomeric carba analogs of glycal-derived vinyl epoxides: a new access to carbasugars.

A convenient method for the stereoselective synthesis of diasteroisomeric vinyl epoxides (-)-2α and (-)-2β, the carba analogs of D-galactal and D-allal-derived vinyl epoxides 1α and 1β, has been elaborated starting from tri-O-acetyl-D-glucal. The key step of this synthesis is an application of the known Claisen thermal rearrangement of a glucal derivative, the vinyl allyl ether (+)-3b, which allows to switch the glycal structure into the corresponding carba analog scaffold. Epoxides (-)-2α and (-)-2β derive from the same synthetic intermediate, the trans diol (+)-5.

Copper-catalyzed divergent kinetic resolution of racemic allylic substrates.

When a racemic mixture is fully consumed the products may still be enantiomerically enriched. In particular, the regiodivergent kinetic resolution is a process in which a single chiral catalyst or reagent reacts with a racemic substrate to form regioisomers possessing an opposite configuration on the newly-formed stereogenic centers. This review reports the major advances in the field of the copper-catalyzed regiodivergent and stereodivergent kinetic resolution of allylic substrates with organometallic reagents.

Tracheostomy and mechanical ventilation weaning in children affected by respiratory virus according to a weaning protocol in a pediatric intensive care unit in Argentina: an observational restrospective trial.

We describe difficult weaning after prolonged mechanical ventilation in three tracheostomized children affected by respiratory virus infection. Although the spontaneous breathing trials were successful, the patients failed all extubations. Therefore a tracheostomy was performed and the weaning plan was begun.

Critical issues in radiology requests and reports.

Purpose: This study evaluated the appropriateness and accuracy of 500 radiology requests and their matched reports in order to identify recurring errors in both areas.

Materials And Methods: A randomly chosen sample consisting of 167 computed tomography (CT), 166 ultrasonography (US) and 167 radiographic examinations were collected and analysed according to national referral guidelines and to the principles of justification and optimisation (Law no. 187/2000).

Stereoselective synthesis of beta-phenylselenoglycosides from glycals and rationalization of the selenoglycosylation processes.

Beta-phenylselenoglycosides have been efficiently and stereoselectively synthesized by direct oxidative glycosylation of benzenselenolate (PhSe(-)) with glycals. A rationalization of the presently described beta-selectivity and the opposite alpha-selectivity reported by Danishefsky in the ring-opening of epoxy glycals with benzeneselenol (PhSeH) is proposed.

Stereoselective synthesis of 4-amino-2,3-unsaturated-N-Cbz-imino-O-glycosides via new diastereoisomeric N-Cbz-imino glycal-derived allyl N-nosyl aziridines.

The glycosylation of alcohols by the new diastereoisomeric d,l-6-deoxy-N-Cbz-imino glycal-derived allyl N-nosyl aziridines 5 and 6 affords, after deprotection of the 4-(N-nosylamino) group, the corresponding 2,3-unsaturated-N-Cbz-imino-O-glycosides bearing a free amino group on C(4) through a completely 1,4-regio- and substrate-dependent stereoselective glycosylation process.

Stereoselective synthesis of 2,3-unsaturated 1,6-oligosaccharides by means of a glycal-derived allyl epoxide and N-nosyl aziridine.

beta-D-threo- and 4-deoxy-4-amino-alpha-D-erythro-hex-2-enopyranosyl di- (n = 0) and trisaccharides (n = 1) of types A and B were synthetized by means of a reiterative, completely stereoselective glycosylation process which makes use of the D-galactal-derived allyl epoxide 1beta and D-allal-derived allyl N-nosyl aziridine 2alpha, respectively.

Stereoselective synthesis of 2,3-unsaturated-aza-O-glycosides via new diastereoisomeric N-Cbz-imino glycal-derived allyl epoxides.

Diastereoisomeric D,L-N-Cbz-imino glycal-derived allyl epoxides 5 and 6 have been synthesized, and their addition reactions with alcohols examined. The reactions lead to the corresponding 2,3-unsaturated-aza-O-glycosides through a new, completely regioselective 1,4-addition process which proceeds with complete substrate-dependent stereoselectivity.

Synthesis and cyclodehydration of hydroxyphenols: a new stereoselective approach to 3-aryl-2,3-dihydrobenzofurans.

A novel and simple method for the stereoselective synthesis of substituted 3-aryl-2,3-dihydrobenzofurans by intramolecular cyclization of hydroxyphenols is described. The stereoselective ortho-C-alkylation of phenols allows a novel and stereoselective access to a diverse array of polyfunctionalized products containing a diarylmethane stereogenic center without the need for time-consuming protection-deprotection steps.

Facile regio- and stereoselective carbon-carbon coupling of phenol derivatives with aryl aziridines.

A chemo-, regio-, and stereoselective direct carbon-carbon coupling of readily available aryl borates with N-protected aryl aziridines provides a method for the synthesis of new 2-(o-hydroxyaryl)-2-aryl ethylamines which can be used, in a novel annulation sequence, to give stereodefined substituted 3-aryl indolines. [reaction: see text]

Stereoselective uncatalyzed synthesis of 2,3-unsaturated-4-n-substituted-beta-O-glycosides by means of a new D-galactal-derived N-(mesyl)-aziridine.

The reaction of the new D-galactal-derived allylic aziridine 1beta with O-nucleophiles (alcohols and monosaccharides) affords, in a high to complete beta-stereoselectivity, the corresponding 2,3-unsaturated-beta-O-glycosides bearing a beta-N-functionality at C4.

Catalytic asymmetric ring opening of 2,3-substituted norbornenes with organometallic reagents: a new formal aza functionalization of cyclopentadiene.

An unprecedented regioselective and anti stereoselective asymmetric ring opening of 1,3-cyclopentadiene-heterodienophile cycloadducts, including also 2,3-diazabicyclo[2.2.1]heptenes, with hard alkylmetals and copper-phosphoramidite catalysts, is reported.

Nutritional status and airflow obstruction: two independent contributors to CO diffusing capacity impairment in COPD.

Background: The association between weight loss and Chronic Obstructive Pulmonary Disease (COPD) has been recognised from many years. Based on the evidence that nutritional status reflects metabolic disturbances in COPD, the relationship between body mass index (BMI), severity of airflow obstruction and CO diffusing capacity (DL(CO)), that is the functional hallmark of emphysema, is relevant to the management of COPD phenotypes.

Methods: We reviewed 104 patients with COPD (82 males), aged 66 +/- 9 years (mean +/- SD).

Stereoselective synthesis of 4-(N-mesylamino)-2,3-unsaturated- alpha-O-glycosides via a new glycal-derived vinyl alpha-N-(mesyl)-aziridine.

[reaction: see text] N-Mesyl aziridine 7alpha, a new activated vinyl aziridine derived from d-glucal, has been synthesized by cyclization of trans-N,O-dimesylate 6 with t-BuOK in anhydrous benzene. The reaction of 7alpha with alcohols, phenol, and monosaccharides (O-nucleophiles) leads to the corresponding 4-N-(mesylamino)-2,3-unsaturated-O-glycosides and disaccharides through a completely regioselective 1,4-addition process that proceeds with high or complete alpha-stereoselectivity.

Mild metal-free syn-stereoselective ring opening of activated epoxides and aziridines with aryl borates.

A conceptually new, simple and practical method for the syn-nucleophilic displacement of aryl and vinyl epoxides and aryl aziridines with (substituted) phenols, using aryl borates as activating nucleophiles under neutral conditions, is reported.

Regio- and stereoselectivity of the addition of O-, S-, N-, and C-nucleophiles to the beta vinyl oxirane derived from D-glucal.

6-O-Trityl- (1a) and 6-(O-benzyl)-substituted epoxide (1b) derived from D-glucal were examined in their addition reactions with O-, C-, N-, and S-nucleophiles. A 1,4-regio- and beta-stereoselective or an anti 1,2-addition pathway is commonly observed depending on the ability of the nucleophile to coordinate with the oxirane oxygen. When TMSN(3) or LiN(3) are used as azide-based nucleophiles, a 1,2-syn-addition pathway is also observed.

Stereospecific uncatalyzed alpha-O-glycosylation and alpha-C-glycosidation by means of a new D-Gulal-derived alpha vinyl oxirane.

The reaction of alpha vinyl oxirane 5, prepared through a new route to the d-gulal system, with O-nucleophiles (alcohols and di-O-isopropylidene-alpha-d-monosaccharides) and C-nucleophiles (lithium alkyls) affords, in a completely stereoselective way, the corresponding 2-unsaturated alpha O- and C-glycosides having the same configuration as the starting epoxide.