Canonical Wnt signaling directs the generation of functional human PSC-derived atrioventricular canal cardiomyocytes in bioprinted cardiac tissues.

The creation of a functional 3D bioprinted human heart remains challenging, largely due to the lack of some crucial cardiac cell types, including the atrioventricular canal (AVC) cardiomyocytes, which are essential to slow down the electrical impulse between the atrium and ventricle. By utilizing single-cell RNA sequencing analysis and a 3D bioprinting technology, we discover that stage-specific activation of canonical Wnt signaling creates functional AVC cardiomyocytes derived from human pluripotent stem cells. These cardiomyocytes display morphological characteristics and express molecular markers of AVC cardiomyocytes, including transcription factors TBX2 and MSX2. When bioprinted in prefabricated cardiac tissues, these cardiomyocytes successfully delay the electrical impulse, demonstrating their capability of functioning as the AVC cardiomyocytes in vitro. Thus, these findings not only identify canonical Wnt signaling as a key regulator of the AVC cardiomyocyte differentiation in vitro, but, more importantly, provide a critical cellular source for the biofabrication of a functional human heart.

Cross-sectional study on dysphagia evaluation in community-dwelling older adults using the Eating Assessment Tool (EAT) -10, EAT-2, and Water Swallow Test.

BACKGROUND: Dysphagia is a health concern that causes severe complications and affects the life quality of the older population. This study aimed to determine the diagnostic performance of the Eating Assessment Tool (EAT)-2 compared with the EAT-10 and the Water Swallow Test (WST) in screening for dysphagia. METHODS: A cross-sectional study was conducted among 5,090 community-dwelling older adults. Dysphagia was evaluated using both a subjective measure, the 10-item EAT (EAT-10) and an objective measure, the WST. The kappa index in pairs were analyzed. The validity and reliability of EAT-2 were also assessed. RESULTS: The sensitivity and specificity of the EAT-2 were 96.3 % and 94.8 %, respectively. The kappa index between the EAT-2 and EAT-10 was 0.64, whereas it was 0.11 between the EAT-10 and WST. CONCLUSIONS: The EAT-2 was a simpler screening tool for dysphagia. Combining the subjective questionnaire (EAT-10 or EAT-2) and the objective test (WST) is recommended.

Association between health literacy and dysphagia in the community-dwelling older population: a cross-sectional study.

BACKGROUND: Dysphagia, or swallowing disorders, has become a growing concern due to the aging population, and health literacy plays a crucial role in active aging. However, the relationship between them remains unclear. AIMS: To investigate the association between health literacy and dysphagia among community-dwelling older adults in China. METHODS: A survey was conducted on 4462 older adults aged 65 and above in a community in Yiwu City, China, from May 2021 to January 2022. Swallowing problems were assessed using a 30 ml water swallowing test (WST) and the Eating Assessment Tool-10 questionnaire (EAT-10). The participants' health literacy was evaluated using the Chinese Health Literacy Scale (CHLS). Logistic regression and t tests were employed to measure the association between them. RESULTS: The prevalence of dysphagia was 5.70% and 7.85% as determined by EAT-10 and 30 ml-WST, respectively. The health literacy level of community-dwelling older adults was 24.4 ± 4.93 (9-45). Participants with dysphagia exhibited lower levels of health literacy (p < 0.05). The logistic regression model demonstrated an inverse association between health literacy and dysphagia (OR = 0.94, 95%CI = 0.91-0.96 for EAT-10, and OR = 0.93, 95%CI = 0.92-0.95 for WST). Moreover, this association remained significant even after adjusting for covariates. DISCUSSION: Older adults with dysphagia have lower levels of health literacy, particularly in terms of their ability to seek medical advice, acquire and evaluate medical information, and access social support resources. CONCLUSIONS: Health literacy is associated with dysphagia among community-dwelling older adults. Effective interventions should be implemented to provide support in terms of both medical services and social support for this population.

Chiral-at-Ruthenium Catalysts for Nitrene-Mediated Asymmetric C-H Functionalizations.

ConspectusAsymmetric transition metal catalysis is an indispensable tool used both in academia and industry for forging chiral molecules in an enantioselective fashion. Its advancement relies in large part on the design and discovery of new chiral catalysts. In contrast to conventional endeavors of generating chiral transition metal catalysts from carefully tailored chiral ligands, the development of chiral transition metal catalysts containing solely achiral ligands (chiral-at-metal catalysts) has been neglected. This Account presents our recent work on the synthesis and catalytic applications of a new class of C2-symmetric chiral-at-ruthenium catalysts. These octahedral ruthenium(II) complexes are constructed from two achiral bidentate N-(2-pyridyl)-substituted N-heterocyclic carbene (PyNHC) ligands and two monodentate acetonitriles, and the dicationic complexes are typically complemented with two hexafluorophosphate anions. The chirality of these complexes originates from the helical cis-arrangement of the bidentate ligands, thereby generating a stereogenic metal center as the exclusive stereocenter in these complexes. The strong σ donor and π acceptor properties of the PyNHC ligands provide a strong ligand field that ensures a high constitutional and configurational inertness of the helical Ru(PyNHC)2 core, while at the same time, the trans-effect exerted by the σ-donating NHC ligands results in high lability of the MeCN ligands and, therefore, provides high catalytic activity. As a result, this chiral-at-ruthenium catalyst scaffold combines formidable structural robustness with high catalytic activity in a unique fashion. Asymmetric nitrene C-H insertion constitutes an efficient strategy for accessing chiral amines. The direct conversion of C(sp3)-H bonds into amine functionality circumvents the need for using functionalized starting materials. Our C2-symmetric chiral-at-ruthenium complexes display exceptionally high catalytic activity and excellent stereocontrol for various asymmetric nitrene C(sp3)-H insertion reactions. The ruthenium nitrene species can be generated from nitrene precursors, such as organic azides and hydroxylamine derivatives, which undergo ring-closing C-H aminations to afford chiral cyclic pyrrolidines, ureas, and carbamates in high yields and with excellent enantioselectivities at low catalyst loadings. Mechanistically, the turnover-determining C-H insertion is proposed to proceed in a concerted or stepwise fashion, depending on the nature of intermediate ruthenium nitrenes (singlet or triplet). Computational studies revealed that the stereocontrol originates from a better steric fit in combination with favorable catalyst/substrate π-π stacking effects for aminations at benzylic C-H bonds. In addition, we also present our research for exploring novel reaction patterns and reactivities of intermediate transition metal nitrenes. First, we discovered a novel chiral-at-ruthenium-catalyzed 1,3-migratory nitrene C(sp3)-H insertion to convert azanyl esters into nonracemic α-amino acids. Second, we found a chiral-at-ruthenium-catalyzed intramolecular C(sp3)-H oxygenation, thereby allowing for the construction of chiral cyclic carbonates and lactones via nitrene chemistry. We expect that our research program on catalyst development and reaction discovery will inspire the creation of novel types of chiral-at-metal catalysts and drive the development of new applications for nitrene-mediated asymmetric C-H functionalization reactions.

Developing strategies "SATIA": How to manage dysphagia in older people? A Delphi panel consensus.

AIM: To develop a set of evidence-informed strategies to assist older people to improve swallowing functions and prevent further damage from complications. DESIGN: A two-round Delphi survey. METHODS: An initial set of dysphagia care strategies with 74 relevant items for older people was formed based on a literature review by seven researchers. An online survey was conducted by 21 panellists, and data of experts' opinions were collected and analysed by improved Delphi method. RESULTS: The positive coefficients in the two rounds of expert consultation were 85.71% and 83.33%, respectively. Consensus was reached with 53 items included and was allocated into the following five sections: (1) screening, (2) assessment, (3) training, (4) interventions and (5) management. These strategies were named with the acronym of each section-"SATIA". The management strategy can be applied to guide the management of older people with dysphagia.

Enhancing photoelectrochemical CO2 reduction with silicon photonic crystals.

The effectiveness of silicon (Si) and silicon-based materials in catalyzing photoelectrochemistry (PEC) CO2 reduction is limited by poor visible light absorption. In this study, we prepared two-dimensional (2D) silicon-based photonic crystals (SiPCs) with circular dielectric pillars arranged in a square array to amplify the absorption of light within the wavelength of approximately 450 nm. By investigating five sets of n + p SiPCs with varying dielectric pillar sizes and periodicity while maintaining consistent filling ratios, our findings showed improved photocurrent densities and a notable shift in product selectivity towards CH4 (around 25% Faradaic Efficiency). Additionally, we integrated platinum nanoparticles, which further enhanced the photocurrent without impacting the enhanced light absorption effect of SiPCs. These results not only validate the crucial role of SiPCs in enhancing light absorption and improving PEC performance but also suggest a promising approach towards efficient and selective PEC CO2 reduction.

Case Report: Transcatheter closure of a giant post-traumatic femoral arteriovenous fistula using ventricular septal occluder.

Giant femoral arteriovenous fistulas are comparatively uncommon, typically treated through covered stents, coil embolization, and open surgical repair. Nevertheless, these options may not be appropriate for all patients. Herein, we describe a case of traumatic femoral arteriovenous fistulas that led to drastic dilatation of the femoral arteriovenous system and considerable heart failure symptoms due to prolonged lack of treatment. Given the intricate anatomical location of the fistula and the patient's severe cardiac dysfunction, surgical repair is often unfeasible. Consequently, we adopted an innovative approach in this case, utilizing a ventricular septal occluder device for fistula closure. This constitutes the first report of an arteriovenous fistula transcatheter closure with a septal occluder.

Nitrene-Mediated C-H Oxygenation: Catalytic Enantioselective Formation of Five-Membered Cyclic Organic Carbonates.

The synthesis of non-racemic 5-membered cyclic carbonates from abundant alcohols is reported. Conversion of the alcohol into an azanyl carbonate is followed by a chiral-at-ruthenium catalyzed cyclization to provide chiral cyclic carbonates in yields of up to 95 % and with up to 99 % ee. This new synthetic method is proposed to proceed through a nitrene-mediated intramolecular C(sp3 )-H oxygenation which includes an unusual 1,7-hydrogen atom transfer within a ruthenium nitrene intermediate. The method is applicable to the synthesis of non-racemic chiral mono-, di- and trisubstituted cyclic alkylene carbonates.

Stereocontrolled 1,3-nitrogen migration to access chiral α-amino acids.

α-Amino acids are essential for life as building blocks of proteins and components of diverse natural molecules. In both industry and academia, the incorporation of unnatural amino acids is often desirable for modulating chemical, physical and pharmaceutical properties. Here we report a protocol for the economical and practical synthesis of optically active α-amino acids based on an unprecedented stereocontrolled 1,3-nitrogen shift. Our method employs abundant and easily accessible carboxylic acids as starting materials, which are first connected to a nitrogenation reagent, followed by a highly regio- and enantioselective ruthenium- or iron-catalysed C(sp3)-H amination. This straightforward method displays a very broad scope, providing rapid access to optically active α-amino acids with aryl, allyl, propargyl and alkyl side chains, and also permits stereocontrolled late-stage amination of carboxylic-acid-containing drugs and natural products.

iTRAQ-based proteomic analysis provides insights into the molecular mechanisms of rice formyl tetrahydrofolate deformylase in salt response.

MAIN CONCLUSION: A new molecular mechanism of tetrahydrofolate deformylase involved in the salt response presumably affects mitochondrial and chloroplast function by regulating energy metabolism and accumulation of reactive oxygen species. High salinity severely restrains plant growth and development, consequently leading to a reduction in grain yield. It is therefore critical to identify the components involved in plant salt resistance. In our previous study, we identified a rice leaf early-senescence mutant hpa1, which encodes a formyl tetrahydrofolate deformylase (Xiong et al. in Sci China Life Sci 64(5):720-738, 2021). Here, we report that HPA1 also plays a role in the salt response. To explore the molecular mechanism of HPA1 in salt resistance, we attempted to identify the differentially expressed proteins between wild type and hpa1 mutant for salinity treatment using an iTRAQ-based comparative protein quantification approach. A total of 4598 proteins were identified, of which 279 were significantly altered, including 177 up- and 102 down-regulated proteins. A functional analysis suggested that the 279 differentially expressed proteins are involved mainly in the regulation of oxidative phosphorylation, phenylpropanoid biosynthesis, photosynthesis, posttranslational modifications, protein turnover and energy metabolism. Moreover, a deficiency in HPA1 impaired chlorophyll metabolism and photosynthesis in chloroplasts and affected the electron flow of the electron transport chain in mitochondria. These changes led to abnormal energy metabolism and accumulation of reactive oxygen species, which may affect the permeability and integrity of cell membranes, leading to cell death. In addition, the results were verified by transcriptional or physiological experiments. Our results provide an insight into a new molecular mechanism of the tetrahydrofolate cycle protein formyl tetrahydrofolate deformylase, which is involved in the salt response, presumably by affecting mitochondrial and chloroplast function regulating energy metabolism and accumulation of reactive oxygen species under salt stress.

Catalytic α-Deracemization of Ketones Enabled by Photoredox Deprotonation and Enantioselective Protonation.

This study reports the catalytic deracemization of ketones bearing stereocenters in the α-position in a single reaction via deprotonation, followed by enantioselective protonation. The principle of microscopic reversibility, which has previously rendered this strategy elusive, is overcome by a photoredox deprotonation through single electron transfer and subsequent hydrogen atom transfer (HAT). Specifically, the irradiation of racemic pyridylketones in the presence of a single photocatalyst and a tertiary amine provides nonracemic carbonyl compounds with up to 97% enantiomeric excess. The photocatalyst harvests the visible light, induces the redox process, and is responsible for the asymmetric induction, while the amine serves as a single electron donor, HAT reagent, and proton source. This conceptually simple light-driven strategy of coupling a photoredox deprotonation with a stereocontrolled protonation, in conjunction with an enrichment process, serves as a blueprint for other deracemizations of ubiquitous carbonyl compounds.

Atroposelective Synthesis of Axially Chiral N-Arylpyrroles by Chiral-at-Rhodium Catalysis.

A transformation of fluxional into configurationally stable axially chiral N-arylpyrroles was achieved with a highly atroposelective electrophilic aromatic substitution catalyzed by a chiral-at-metal rhodium Lewis acid. Specifically, N-arylpyrroles were alkylated with N-acryloyl-1H-pyrazole electrophiles in up to 93 % yield and with up to >99.5 % ee, and follow-up conversions reveal the synthetic utility of this new method. DFT calculations elucidate the origins of the observed excellent atroposelectivity.

Asymmetric Photocatalysis by Intramolecular Hydrogen-Atom Transfer in Photoexcited Catalyst-Substrate Complex.

3-(2-Formylphenyl)-1-pyrazol-1-yl-propenones undergo an asymmetric photorearrangement to benzo[d]cyclopropa[b]pyranones with up to >99 % ee, which is catalyzed by a bis-cyclometalated rhodium catalyst in the presence of visible light. Mechanistic experiments and DFT calculations support a mechanism in which a photoexcited catalyst/substrate complex triggers an intramolecular hydrogen-atom transfer followed by a highly stereocontrolled hetero-Diels-Alder reaction. In this reaction scheme, the rhodium catalyst fulfills multiple functions by 1) enabling visible-light π→π* excitation of the catalyst-bound enone substrate, 2) facilitating the hydrogen-atom transfer, and 3) providing the asymmetric induction for the hetero-Diels-Alder reaction.

Association of the gene polymorphisms of BMPR2, ACVRL1, SMAD9 and their interactions with the risk of essential hypertension in the Chinese Han population.

Objective: Genetic factors are involved in the occurrence, development, and progression of essential hypertension (EH). To study the association between single nucleotide polymorphisms (SNPs) of the rs6435156 and rs1048829 loci of the bone morphogenetic protein receptor type 2 (BMPR2) gene, the rs121909287 and rs121909284 loci of the activin receptor-like kinase 1 (ACVRL1) gene, and the rs397514716 and rs121918359 loci of the mothers against decapentaplegic homolog 9 (SMAD9) gene with the risk of EH in the Chinese Han population. Materials and methods: A total of 460 EH patients and 460 healthy controls were recruited for the study. Genomic DNA of white blood cells was extracted, and the genotypes were analyzed by Sanger sequencing after polymerase chain reaction amplification. Multi-factor dimensionality reduction (MDR) was used to analyze the effect of gene-environment interactions on EH risk. Results: The risk of EH increased in the BMPR2 gene rs6435156 locus dominant model (adjusted odds ratio [OR] = 1.572, 95% confidence interval [CI]: 1.385-1.765, P<0.001) and recessive model (adjusted OR = 1.926, 95% CI: 1.693-2.067, P<0.001). The risk of EH increased in the rs1048829 recessive model (adjusted OR = 1.444, 95% CI: 1.142-1.696, P=0.003). The risk of EH increased in the recessive model of the ACVRL1 gene rs121909287 locus (adjusted OR = 1.403, 95% CI: 1.101-1.660, P=0.008). The risk of EH increased in the SMAD9 gene rs397514716 locus dominant model (adjusted OR = 1.370, 95% CI: 1.183-1.559, P<0.001) and recessive model (adjusted OR = 1.803, 95% CI: 1.470-1.983, P<0.001). The CG haplotype of the rs6435156 and rs1048829 loci of the BMPR2 gene, the CC haplotype of the ACVRL1 gene rs121909287 and rs121909284 loci, and the CC haplotype of the rs397514716 and rs121918359 loci of the SMAD9 gene were factors that protect against EH, whereas the TT haplotype of the rs6435156 and rs1048829 loci in the BMPR2 gene was a risk factor for EH. MDR analysis showed that the BMPR2 gene rs6435156 locus TT genotype carriers, the SMAD9 gene rs397514716 locus TT genotype carriers, and alcohol drinkers had the highest EH risk (OR = 4.523, 95% CI: 2.235-6.871, P<0.001). Conclusion: The SNPs of the rs6435156 and rs1048829 locus in the BMPR2 gene, the rs121909287 loci in the ACVRL1 gene, and the rs397514716 locus in the SMAD9 gene were associated with a risk of EH in Han Chinese.

Dual catalysis for enantioselective convergent synthesis of enantiopure vicinal amino alcohols.

Enantiopure vicinal amino alcohols and derivatives are essential structural motifs in natural products and pharmaceutically active molecules, and serve as main chiral sources in asymmetric synthesis. Currently known asymmetric catalytic protocols for this class of compounds are still rare and often suffer from limited scope of substrates, relatively low regio- or stereoselectivities, thus prompting the development of more effective methodologies. Herein we report a dual catalytic strategy for the convergent enantioselective synthesis of vicinal amino alcohols. The method features a radical-type Zimmerman-Traxler transition state formed from a rare earth metal with a nitrone and an aromatic ketyl radical in the presence of chiral N,N'-dioxide ligands. In addition to high level of enantio- and diastereoselectivities, our synthetic protocol affords advantages of simple operation, mild conditions, high-yielding, and a broad scope of substrates. Furthermore, this protocol has been successfully applied to the concise synthesis of pharmaceutically valuable compounds (e.g., ephedrine and selegiline).

SmI2-mediated radical coupling strategy to Securinega alkaloids: total synthesis of (-)-14,15-dihydrosecurinine and formal total synthesis of (-)-securinine.

The asymmetric total synthesis of (-)-14,15-dihydrosecurinine and the formal total synthesis of (-)-securinine were accomplished starting from an easily available malimide. A concise SmI2-mediated radical coupling strategy has been developed to construct the bridged α-hydroxy 6-azabicyclo[3.2.1]octanone in four steps with high diastereoselectivity.