Complete xylan utilization pathway and regulation mechanisms involved in marine algae degradation by cosmopolitan marine and human gut microbiota.

β-1,3-xylan, typically found in marine algae as a major cell wall polysaccharide, represents an overlooked pool of organic carbon in global oceans. Whilst our understanding of microbial catabolism of xylans has improved significantly, particularly from biotransformations of terrestrial plant biomass that are typically composed of β-1,4-xylans, knowledge on how microbes utilize β-1,3-xylan remains limited. Here, we describe the discovery of a complete pathway for β-1,3-xylan catabolism and its regulation in a marine bacterium, Vibrio sp.

Nickel-Catalyzed Gas-Free Reductive Carbonylation of Aryl Thianthrenium Salts to Access Aryl Amides and Aryl Thioesters.

A nickel-catalyzed site-selective reductive carbonylation of arenes via aryl thianthrenium salts is described. Using Mo(CO) as a convenient solid CO source and reductant and employing nitroarenes and sulfonyl chlorides as readily available nitrogen and sulfur sources, a range of aryl amides and aryl thioesters were successfully synthesized in moderate to good yields. The utility of this transformation is demonstrated through the synthesis of antimicrobial agents and the late-stage functionalization of biorelevant molecules.

Palladium/norbornene cooperative catalysis triple functionalization: carbamoylation/double-annulation of (hetero)aryl iodides.

A novel Pd/NBE-catalyzed intermolecular dehydrobicyclization of heteroaryl iodides for the synthesis of polycyclic nitrogen-containing heterocycles is reported. In this work, the -protected aryl carbamoyl chloride serves as a source of acylation. The products resulting from the direct C-H functionalization of heteroaryl iodides are smoothly obtained without catalyst poisoning by heteroatoms.

Photocatalytically switchable chemoselective difluoramidation of olefins for the synthesis of diversified difluoro-γ-lactams.

Herein, we describe a visible light-promoted intramolecular difluoramidation reaction of olefins. By precisely adjusting the reaction conditions, the difficult-to-control olefin radical addition process was effectively controlled. Heck-type coupling of olefins and hydrofluoroamidation of olefins, as well as difunctionalization of olefins, were successfully achieved with good selectivity.

Palladium/Norbornene Cooperative Catalysis 2-Fold C-H/C-X Coupling: Construction of Polycyclic Aromatic Hydrocarbons from Brominated Benzimidazoles.

A palladium/norbornene (NBE)-catalyzed 2-fold C-H/C-X coupling reaction of aryl iodides is reported. Bromine-substituted benzimidazoles were chosen as electrophilic and termination reagents, and the versatile polycyclic aromatic hydrocarbon products were successfully obtained. The strategy overcomes the challenge of catalyst poisoning by heterocyclic substrates.

Relationship between difference in endotracheal tube cuff area and airway area with minimum cuff pressure for adequate airway sealing: a prospective observational study.

It is essential for clinicians to select the appropriate endotracheal tube to ensure effective airway management. However, an unmatched endotracheal tube cuff area to the airway area can lead to air or secretion leakage, even at the recommended cuff pressure of 20-30 cmHO. The present multicenter prospective observational study aimed to determine the relationship between the difference in cuff area and airway area with the minimum cuff pressure to avoid airway leakage.

5-Aminopyrazole Dimerization: Cu-Promoted Switchable Synthesis of Pyrazole-Fused Pyridazines and Pyrazines via Direct Coupling of C-H/N-H, C-H/C-H, and N-H/N-H Bonds.

A Cu-promoted highly chemoselective dimerization of 5-aminopyrazoles to produce pyrazole-fused pyridazines and pyrazines is reported. The protocol generates switchable products via the direct coupling of C-H/N-H, C-H/C-H and N-H/N-H bonds, with the merits of broad substrate scope and high functional group compatibility. Gram-scale experiments demonstrated the potential applications of this reaction.

[Role of the nuclear factor-kappa B signaling pathway in the repair of white matter injury in neonatal rats through human umbilical cord mesenchymal stem cell transplantation].

Objectives: To observe the reparative effects of human umbilical cord mesenchymal stem cell (hUC-MSC) transplantation on white matter injury (WMI) in neonatal rats and explore its mechanism through the nuclear factor-kappa B (NF-κB) signaling pathway mediated by microglial cells.

Methods: Sprague-Dawley rats, aged 2 days, were randomly divided into three groups: sham-operation,WMI, and hUC-MSC (=18 each). Fourteen days after modeling, hematoxylin-eosin staining was used to observe pathological changes in the white matter, and immunofluorescence staining was used to measure the expression level of ionized calcium-binding adapter molecule 1 (Iba1).

One-Pot Total Synthesis of Natural Products Nitramarine, Nitraridine, and Analogues via a Cascade Oxidation/Pictet-Spengler Condensation/Annulation Process.

A cascade oxidation/Pictet-Spengler condensation/annulation process has been developed for the one-pot total synthesis of nitramarine, nitraridine, and their analogues. The procedure proceeded with easily available quinolines and tryptophan derivatives. A simple and metal-free approach, wide substrate scope, and functional group tolerance make it applicable for the synthesis of diverse bioactive nitramarine, nitraridine, and their derivatives.

Effect of varying cuff sizes with identical inner diameter on endotracheal intubation in critically ill adults: A sealed tracheal controlled trial.

Background: The present study aims to determine the impact of different cuff diameters on the cuff pressure of endotracheal tubes (ETTs) when the trachea is adequately sealed.

Methods: In the present single-center clinical trial, adult patients who underwent cardiothoracic surgery were assigned to use ETTs from 2 brands (GME and GZW). The primary endpoint comprised of the following: cuff diameter, inner diameter of the ETT, manufacturer, and the number of subjects with tracheal leakage when the cuff pressure was 30 cm H2O.

[Repair effect of different doses of human umbilical cord mesenchymal stem cells on white matter injury in neonatal rats].

Objectives: To compare the repair effects of different doses of human umbilical cord mesenchymal stem cells (hUC-MSCs) on white matter injury (WMI) in neonatal rats.

Methods: Two-day-old Sprague-Dawley neonatal rats were randomly divided into five groups: sham operation group, WMI group, and hUC-MSCs groups (low dose, medium dose, and high dose), with 24 rats in each group. Twenty-four hours after successful establishment of the neonatal rat white matter injury model, the WMI group was injected with sterile PBS via the lateral ventricle, while the hUC-MSCs groups received injections of hUC-MSCs at different doses.

-Butyl Nitrite-Induced Radical Nitrile Oxidation Cycloaddition: Synthesis of Isoxazole/Isoxazoline-Fused Benzo 6/7/8-membered Oxacyclic Ketones.

A practical metal-free and additive-free approach for the synthesis of 6/7/8-membered oxacyclic ketone-fused isoxazoles/isoxazolines tetracyclic or tricyclic structures is reported through C-H bond radical nitrile oxidation and the intramolecular cycloaddition of alkenyl/alkynyl-substituted aryl methyl ketones. This convenient approach enables the simultaneous formation of isoxazole/isoxazoline and 6/7/8-membered oxacyclic ketones to form polycyclic architectures by using -butyl nitrite (TBN) as a non-metallic radical initiator and N-O fragment donor.

Palladium/Norbornene Cooperative Catalysis Bifunctionalization: Acylation/Cyanation of Aryl Iodides by Cleaving C-CN Bond of Aryl Acyl Nitrile.

A palladium/norbornene catalyzed two-component coupling process involving acylation/cyanation of aryl iodides is reported. In this work, aryl acyl nitrile compounds are cleverly selected to provide both nitrile and acyl sources by palladium-catalyzed cleavage of the C-CN bond as both an electrophilic reagent and a termination reagent. This is the first example of C-CN bond cleavage bifunctionalization of aryl iodides.

[Clinical features of 23 neonates infected with Omicron variant of severe acute respiratory syndrome coronavirus 2].

Objectives: To summarize the clinical features of neonates infected with Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Methods: The medical data of 23 neonates with Omicron variant of SARS-CoV-2 infection admitted to the City North Campus of Urumqi First People's Hospital from October to December 2022 were retrospectively reviewed.

Results: All 23 infants had a history of exposure to confirmed caregivers with SARS-CoV-2 infection after birth, and none of them was vertically transmitted.

Synthesis of Diversified Pyrazolo[3,4-]pyridine Frameworks from 5-Aminopyrazoles and Alkynyl Aldehydes via Switchable C≡C Bond Activation Approaches.

A cascade cyclization reaction was developed for the switchable synthesis of halogen and non-halogen-functionalized pyrazolo[3,4-]pyridines from 5-aminopyrazoles and alkynyl aldehydes via C≡C bond activation with silver, iodine, or NBS. In addition to its wide substrate scope, the reaction showed good functional group tolerance as well as excellent regional selectivity. This new protocol manipulated three natural products, and the arylation, alkynylation, alkenylation, and selenization of iodine-functionalized products.

Iodine-Promoted Oxidative Cyclization of Methyl Azaarenes and α-Amino Ketones for One-Pot Synthesis of 2-Azaaryl-5-aryl Oxazoles.

A high efficiency protocol was developed for the synthesis of 2,5-disubstituted oxazoles via iodine-promoted oxidative domino cyclization. These reactions were performed with readily available methyl azaarenes and α-amino ketones under metal-free conditions. This protocol is a simple method with high functional group compatibility, a wide range of substrates, and excellent yield, providing a new way to synthesize azaarene-attached oxazoles.

Synthesis of Diverse Pentasubstituted Pyrroles by a Gold(I)-Catalyzed Cascade Rearrangement-Cyclization of Tertiary Enamide.

An efficient Au(I)-catalyzed intramolecular cascade reaction of tertiary enamides tethered an alkynyl group has been developed. The process is composed of a propargyl-claisen rearrangement and 5--dig cyclization. This protocol provided a powerful method for the preparation of a variety of pentasubstituted pyrroles derivatives with excellent functional group tolerance in excellent yields.

Iodine-catalyzed oxidative annulation: facile synthesis of pyrazolooxepinopyrazolones methyl azaarene sp C-H functionalization.

An iodine-catalyzed methyl azaarene sp C-H functionalization has been developed for the synthesis of a seven-membered -heterocyclic architecture containing three different heterocyclic aromatic hydrocarbons. This method can be applied to a wide range of substituted methyl azaarenes and diverse 2,4-dihydro-3-pyrazol-3-ones, and brings about the efficient preparation of 2,9-dihydrooxepino[2,3-:6,5-']dipyrazol-3(7)-ones in high yields with the merits of low catalyst loading, good functional group tolerance and metal-free conditions.

Iodine-Mediated Domino Cyclization for One-Pot Synthesis of Indolizine-Fused Chromones via Metal-Free sp C-H Functionalization.

An efficient method for the synthesis of new indolizine-fused chromones has been accomplished from ethyl ()-3-(2-acetylphenoxy)acrylates and pyridines in a "one-pot" manner. Facile operation in open-air, metal-free, and mild conditions renders this protocol particularly practical and attractive. Moreover, this method can simultaneously construct two molecular fragments of chromone and indolizine.

Nickel-Catalyzed Arylcarbamoylation of Alkenes of -(-Iodoaryl)acrylamides with Nitroarenes via Reductive Aminocarbonylation: Facile Synthesis of Carbamoyl-Substituted Oxindoles.

Nickel-catalyzed arylcarbamoylation reactions of alkenes of -(-haloaryl)acrylamides with CO and nitroarenes via reductive aminocarbonylation to produce carbamoyl-substituted oxindoles with an all-carbon quaternary stereogenic center are presented. Starting with -(-haloaryl)acrylamides, simple CO, and inexpensive nitroarenes and using a Ni catalyst, a dinitrogen-based ligand, a Zn reductant, a TMSCl additive, and a base system, this protocol enables the synthesis of various carbamoyl-substituted oxindoles and allows the efficient late-stage derivatization of valuable molecules.

Cascade Wolff Rearrangement/Acylation: A Metal-Free and Eco-Friendly Approach for 4-Hydroxy-pyrazolo[3,4-]pyridin-6-ones and -Pyrazole Amides Synthesis from 5-Aminopyrazoles and α-Diazoketones.

A highly chemoselective cascade Wolff rearrangement/acylation reaction between 5-aminopyrazoles and diazo compounds has been developed. The protocol can facilitate the switchable synthesis of 4-hydroxy-pyrazolo[3,4-]pyridin-6-ones and -pyrazole amides with the merits of a broad substrate scope, high functional group compatibility, and green and sustainable performance manner. All reactions proceeded efficiently without any catalyst and additives (acid and base) and resulted in the release of benign N, wherein diethyl carbonate served as a green benign solvent.

Iodine-imine Synergistic Promoted Povarov-Type Multicomponent Reaction for the Synthesis of 2,2'-Biquinolines and Their Application to a Copper/Ligand Catalytic System.

An efficient iodine-imine synergistic promoted Povarov-type multicomponent reaction was reported for the synthesis of a practical 2,2'-biquinoline scaffold. The tandem annulation has reconciled iodination, Kornblum oxidation, and Povarov aromatization, where the methyl group of the methyl azaarenes represents uniquely reactive input in the Povarov reaction. This method has broad substrate scope and mild conditions.

One-Pot Synthesis of Chromone-Fused Pyrrolo[2,1-]isoquinolines and Indolizino[8,7-]indoles: Iodine-Promoted Oxidative [2 + 2 + 1] Annulation of -Acetylphenoxyacrylates with Tetrahydroisoquinolines and Noreleagnines.

An iodine-promoted one-pot cascade oxidative annulation reaction has been developed for the synthesis of chromone-fused-pyrrolo[2,1-]isoquinolines and indolizino[8,7-]indoles from -acetylphenoxyacrylates, tetrahydroisoquinolines, and noreleagnines. This process underwent a logical approach to both chromone-fused-pyrrolo[2,1-]isoquinolines and chromone-fused-indolizino[8,7-]indoles isolamellarin derivatives. Manipulations of l-menthol and dl-α-tocopherol demonstrate the applications of this strategy.