Chiral Aldehyde/Palladium Catalysis Enables Asymmetric Branched-Selective Ring-Opening Functionalization of Methylenecyclopropanes with Amino Acid Esters.

Achieving catalytic asymmetric functionalization of methylenecyclopropanes (MCPs) by selective C-C bond cleavage is a notable challenge due to the intricate reaction partners involved. In this work, we report that chiral aldehyde/palladium combined catalysis enables the asymmetric functionalization of MCPs with NH-unprotected amino acid esters. This reaction proceeds through a regiospecific branched ring-opening mechanism, resulting in optically active α,α-disubstituted α-amino acid esters bearing nonconjugated terminal alkene units.

Biomarkers.

Background: The initiation of cognitive impairment is triggered by a myriad of pathological events occurring decades before clinical symptoms manifest. Perturbed glucose and fatty acid metabolism notably contribute to the development of cognitive impairment, progressing further into clinical dementia. These metabolic alterations are evident in plasma through changes in specific metabolites.

Public Health.

Background: Social connections are linked to brain health. Studies to date have ignored negative social connections and the association between social connections and white matter health. We explored the relationship between positive and negative social connections and brain imaging including white matter health.

Association of the geriatric nutritional risk index with poor outcomes in patients with coronary revascularization: a cohort study.

Background: Poor nutritional status may affect outcomes after coronary revascularization, but the association between nutritional status and outcomes in patients undergoing coronary revascularization has not been fully evaluated. This study was based on the MIMIC-IV database to analyze the impact of baseline nutritional status on poor outcomes in patients with coronary revascularization.

Methods: Patients with coronary revascularization were screened from the MIMIC-IV database.

Hydrological dynamics of the Yangtze river-Dongting lake system after the construction of the three Gorges dam.

The Yangtze River-Dongting Lake link has gotten a lot of attention as a because of the Three Gorges Project. However, the hydrological dynamic process and future direction of the river-lake interaction in the context of sediment reduction are yet unknown. Based on Dongting Lake Basin runoff and sediment data from 1961 to 2020, as well as field monitoring data of turbidity and flow velocity from Yichang to Chenglingji section of the Yangtze River, this paper examines the runoff and sediment variation law and hydrological dynamic process of Chenglingji, the only outlet connecting Dongting Lake to the Yangtze River, and reveals the development trend of the river-lake relationship.

Unraveling the drivers of optimal stomatal behavior in global C plants: A carbon isotope perspective.

Understanding the drivers of stomatal behavior is critical for modeling terrestrial carbon cycle and water balance. The unified stomatal optimization (USO) model provides a mechanistic linkage between stomatal conductance (g) and photosynthesis (A), with its slope parameter (g) inversely related to intrinsic water use efficiency (iWUE), providing a key proxy to characterize the differences in iWUE and stomatal behavior. While many studies have identified multiple environmental factors influencing g, the potential role of evolutionary history in shaping g remains incompletely understood.

Ethylene negatively regulates cold tolerance through HbEIN3-HbICE2 regulatory module in Hevea brasiliensis.

Cold stress can result in reduced growth rates, decreased latex production, and restricted areas for the Para rubber tree (Hevea brasiliensis). However, the molecular mechanisms governing the response of Hevea brasiliensis to cold stress remain elusive. Here, we found that ethylene plays a negative role in Hevea brasiliensis responses to cold stress.

Efficient Electrochemical Coupling of Aptamer to Nanoelectrode for In Situ Detection of ATP in Single Cells.

Nanoelectrodes, renowned for their small size, rapid mass transport, fast response, and high spatiotemporal resolution, have been recognized as a powerful tool in biosensing, especially for single-cell analysis. However, the nanoelectrode itself has no selectivity and cannot respond to nonelectroactive substances, limiting its wide application to some extent. Herein, we propose a simple and efficient electrochemical conjugation strategy to develop an electrochemical aptamer-coupled (E-AC) sensor for detecting adenosine triphosphate (ATP) in single living cells.

A dual-switch electrochemical aptasensor for label-free detection of thrombin and ATP based on split aptamers.

Background: Aptamers, consisting of specialized single-stranded nucleic acids, are engineered through the SELEX technique to recognize specific targets with strong affinity. Aptamers are exceptionally useful in various sensor technologies, such as fluorescence-based sensors, electrochemical sensors, and colorimetric detection systems. Due to its high sensitivity, specificity and fast response, electrochemical aptasensor shows great application prospects in analytical detection, food safety, and environmental monitoring.

Zedoarondiol Inhibits Neovascularization in Atherosclerotic Plaques of ApoE Mice by Reducing Platelet Exosomes-Derived MiR-let-7a.

Objective: To investigate the effect of zedoarondiol on neovascularization of atherosclerotic (AS) plaque by exosomes experiment.

Methods: ApoE mice were fed with high-fat diet to establish AS model and treated with high- and low-dose (10, 5 mg/kg daily) of zedoarondiol, respectively. After 14 weeks, the expressions of anti-angiogenic protein thrombospondin 1 (THBS-1) and its receptor CD36 in plaques, as well as platelet activation rate and exosome-derived miR-let-7a were detected.

Lipoprotein(a) is Associated with Sarcopenia in Patients with Type 2 Diabetes: A cross-Sectional Study.

Background: The association between lipoprotein(a) (Lp(a)) and sarcopenia in T2DM patients of general age is unclear, and whether this association differs by sex remains uncertain. We intend to analyze the association between Lp(a) and sarcopenia in patients with type 2 diabetes mellitus (T2DM) and whether this association differs by sex.

Methods: T2DM patients between December 2021 and December 2022 were consecutively enrolled.

Beclin 1 prevents ISG15-mediated cytokine storms to secure fetal hematopoiesis and survival.

Proper control of inflammatory responses is essential for embryonic development, but the underlying mechanism is poorly understood. Here, we show that under physiological conditions, inactivation of ISG15, an inflammation amplifier, is associated with the interaction of Beclin 1 (Becn1), via its ECD domain, with STAT3 in the major fetal hematopoietic organ of mice. Conditional loss of Becn1 caused sequential dysfunction and exhaustion of fetal liver hematopoietic stem cells, leading to lethal inflammatory cell-biased hematopoiesis in the fetus.

Assessment of Coronary Microvascular Dysfunction by Angiography-Based Index of Microcirculatory Resistance: An Indirect Meta-Analysis.

Introduction: There is a lack of consensus on diagnosing coronary microvascular dysfunction (CMD) using the angiography-based index of microcirculatory resistance (Angio-IMR) due to the absence of evidence. This study aimed to explore the efficacy of Angio-IMR in diagnosing CMD.

Methods: A systematic search was conducted in PubMed, Embase, Scopus, and the Cochrane Library for studies primarily focusing on Angio-IMR diagnosing CMD, using IMR as the gold standard.

MicroRNA in prostate cancer: from biogenesis to applicative potential.

Prostate cancer is the most common solid malignant tumor in men, characterized by high morbidity and mortality. While current screening tools, such as prostate-specific antigen (PSA) testing and digital rectal examination, are available for early detection of prostate cancer, their sensitivity and specificity are limited. Tissue puncture biopsy, although capable of offering a definitive diagnosis, has poor positive predictive rates and burdens the patient more.

Multispatially Localized DNA Walker Coupling Covalent Organic Framework for Dual-Mode Detection of Nucleocapsid Protein Using the Walking-Recycling-Conversion Strategy.

DNA walkers have emerged as a powerful tool in bioanalysis; however, many existing approaches are still restricted by low reaction kinetics and inaccurate single-mode detection. Herein, a fluorescence (FL) and electrochemical (EC) dual-mode biosensor was proposed based on a multispatially localized DNA walker (m-DNA walker) coupling covalent organic framework (COF) using the walking-recycling-conversion strategy. Specifically, the functionalized COF not only served as a three-dimensional nanocarrier but also acted as an effective quencher of the walking tracks.

White matter microstructure in obesity and bipolar disorders: an ENIGMA bipolar disorder working group study in 2186 individuals.

Although specific risk factors for brain alterations in bipolar disorders (BD) are currently unknown, obesity impacts the brain and is highly prevalent in BD. Gray matter correlates of obesity in BD have been well documented, but we know much less about brain white matter abnormalities in people who have both obesity and BD. We obtained body mass index (BMI) and diffusion tensor imaging derived fractional anisotropy (FA) from 22 white matter tracts in 899 individuals with BD, and 1287 control individuals from 20 cohorts in the ENIGMA-BD working group.

Hyperuricaemia elevates risk of short-term readmission and mortality in patients with heart failure.

Background: Heart failure (HF) is a leading cause of morbidity and mortality worldwide. Serum uric acid (SUA), a product of purine metabolism, has been implicated in HF progression. However, the association between hyperuricaemia and the short-term readmission and mortality in patients with HF remains controversial.

Anion-substituted Hybrid Zinc Halides with Remarkable Dielectric Switches.

Thermo-responsive dielectric switching hybrid halides, displaying reversible dielectric bistability, have recently made them highly versatile and attractive for their structural tunability and rich functional properties. However, the substantial improvement of the dielectric switching operating range is limited near room temperature, and obtaining ultra-wide dielectric switching temperature region is a major challenge. Herein, a remarkable dielectric switching effect is reported with ultra-wide dielectric switching temperature region in a hybrid halide system, caused by dipolar orientational polarization ascribing order-disorder phase transitions.

Molecular characterization of oxidized organic nitrogen in the polluted urban atmosphere of Beijing.

Oxidized organic nitrogen (OON) serves as a crucial link between volatile organic compounds (VOCs), nitrogen oxides, ozone, and secondary organic aerosol (SOA). However, the comprehension of the molecular composition, formation mechanism, and implications of OON remains limited, particularly in urban environments influenced heavily by anthropogenic emissions. This study presents the field measurements of OON conducted at an urban site in Beijing using chemical ionization mass spectrometry with nitrate as the reagent ion.