A wide star-black-hole binary system from radial-velocity measurements.

All stellar-mass black holes have hitherto been identified by X-rays emitted from gas that is accreting onto the black hole from a companion star. These systems are all binaries with a black-hole mass that is less than 30 times that of the Sun1-4. Theory predicts, however, that X-ray-emitting systems form a minority of the total population of star-black-hole binaries5,6. When the black hole is not accreting gas, it can be found through radial-velocity measurements of the motion of the companion star. Here we report radial-velocity measurements taken over two years of the Galactic B-type star, LB-1. We find that the motion of the B star and an accompanying Hα emission line require the presence of a dark companion with a mass of [Formula: see text] solar masses, which can only be a black hole. The long orbital period of 78.9 days shows that this is a wide binary system. Gravitational-wave experiments have detected black holes of similar mass, but the formation of such massive ones in a high-metallicity environment would be extremely challenging within current stellar evolution theories.

Magnetosome-inspired synthesis of soft ferrimagnetic nanoparticles for magnetic tumor targeting.

Magnetic targeting is one of the most promising approaches for improving the targeting efficiency by which magnetic drug carriers are directed using external magnetic fields to reach their targets. As a natural magnetic nanoparticle (MNP) of biological origin, the magnetosome is a special "organelle" formed by biomineralization in magnetotactic bacteria (MTB) and is essential for MTB magnetic navigation to respond to geomagnetic fields. The magnetic targeting of magnetosomes, however, can be hindered by the aggregation and precipitation of magnetosomes in water and biological fluid environments due to the strong magnetic attraction between particles. In this study, we constructed a magnetosome-like nanoreactor by introducing MTB Mms6 protein into a reverse micelle system. MNPs synthesized by thermal decomposition exhibit the same crystal morphology and magnetism (high saturation magnetization and low coercivity) as natural magnetosomes but have a smaller particle size. The DSPE-mPEG-coated magnetosome-like MNPs exhibit good monodispersion, penetrating the lesion area of a tumor mouse model to achieve magnetic enrichment by an order of magnitude more than in the control groups, demonstrating great prospects for biomedical magnetic targeting applications.

Gradient Alloy Shell Enabling Colloidal Quantum Wells Light-Emitting Diodes with Efficiency Exceeding 22.

Colloidal quantum well (CQW) based light emitting diodes (LEDs) possess extra-high theoretical efficiency, but their performance still lags far behind conventional LEDs due to severe exciton quenching and unbalanced charge injection. Herein, we devised a gradient composition CdxZn1-xS shell to address these issues. The epitaxial shell with gradient composition was achieved through controlling competition between Cd2+ and Zn2+ cations to preferentially bind to the anions S2-. Thus, exciton quenching was suppressed greatly by passivating defects and reducing nonradiative recombination, thereby achieving near-unity photoluminescence quantum yield (PLQY). The gradient energy level of the shell reduced the hole injection barriers and increased the hole injection efficiency to balance the charge injection of LEDs. As a result, the LEDs achieved a high external quantum efficiency (EQE) of 22.83%, luminance of 111,319 cd/m2 and a long operational lifetime (T95@100 cd/m2) over 6,500 h, demonstrating the state-of-the-art performance for the CQW based LEDs.

Constructing ZnTe Spherical Quantum Well for Efficient Light Emission.

ZnTe colloidal semiconductor nanocrystals (NCs) have shown promise for light-emitting diodes (LEDs) and displays, because they are free from toxic heavy metals (Cd). However, so far, their low photoluminescence (PL) efficiency (∼30%) has hindered their applications. Herein, we devised a novel structure of ZnTe NCs with the configuration of ZnSe (core)/ZnTe (spherical quantum well, SQW)/ZnSe (shell). The inner layer ZnTe was grown at the surface of ZnSe core with avoiding using highly active and high-risk Zn sources. Due to the formation of coherently strained heterostructure which reduced the lattice mismatch, and the thermodynamic growth of ZnTe, the surface or interface defects were suppressed. A high PL efficiency of >60% was obtained for the green light-emitting ZnSe/ZnTe/ZnSe SQWs after ZnS outer layer passivation, which is the highest value for colloidal ZnTe-based NCs. This work paves the way for the development of novel semiconductor NCs for luminescent and display applications.

Disease severity-based subgrouping of type 2 diabetes does not parallel differences in quality of life: the Maastricht Study.

AIMS/HYPOTHESIS: Type 2 diabetes is a highly heterogeneous disease for which new subgroups ('clusters') have been proposed based on disease severity: moderate age-related diabetes (MARD), moderate obesity-related diabetes (MOD), severe insulin-deficient diabetes (SIDD) and severe insulin-resistant diabetes (SIRD). It is unknown how disease severity is reflected in terms of quality of life in these clusters. Therefore, we aimed to investigate the cluster characteristics and cluster-wise evolution of quality of life in the previously defined clusters of type 2 diabetes. METHODS: We included individuals with type 2 diabetes from the Maastricht Study, who were allocated to clusters based on a nearest centroid approach. We used logistic regression to evaluate the cluster-wise association with diabetes-related complications. We plotted the evolution of HbA1c levels over time and used Kaplan-Meier curves and Cox regression to evaluate the cluster-wise time to reach adequate glycaemic control. Quality of life based on the Short Form 36 (SF-36) was also plotted over time and adjusted for age and sex using generalised estimating equations. The follow-up time was 7 years. Analyses were performed separately for people with newly diagnosed and already diagnosed type 2 diabetes. RESULTS: We included 127 newly diagnosed and 585 already diagnosed individuals. Already diagnosed people in the SIDD cluster were less likely to reach glycaemic control than people in the other clusters, with an HR compared with MARD of 0.31 (95% CI 0.22, 0.43). There were few differences in the mental component score of the SF-36 in both newly and already diagnosed individuals. In both groups, the MARD cluster had a higher physical component score of the SF-36 than the other clusters, and the MOD cluster scored similarly to the SIDD and SIRD clusters. CONCLUSIONS/INTERPRETATION: Disease severity suggested by the clusters of type 2 diabetes is not entirely reflected in quality of life. In particular, the MOD cluster does not appear to be moderate in terms of quality of life. Use of the suggested cluster names in practice should be carefully considered, as the non-neutral nomenclature may affect disease perception in individuals with type 2 diabetes and their healthcare providers.

Recent advances in total synthesis of protoberberine and chiral tetrahydroberberine alkaloids.

Covering: Up to 2024Due to the widespread distribution of protoberberine alkaloids (PBs) and tetrahydroberberine alkaloids (THPBs) in nature, coupled with their myriad unique physiological activities, they have garnered considerable attention from medical practitioners. Over the past few decades, synthetic chemists have devised various total synthesis methods to attain these structures, continually expanding reaction pathways to achieve more efficient synthetic strategies. Simultaneously, the chiral construction of THPBs has become a focal point. In this comprehensive review, we categorically summarized the developmental trajectory of the total synthesis of these alkaloids based on the core closure strategies of protoberberine and tetrahydroberberine.

Biogeography and impact of nitrous oxide reducers in rivers across a broad environmental gradient on emission rates.

Microbial communities that reduce nitrous oxide (N2O) are divided into two clades, nosZI and nosZII. These clades significantly differ in their ecological niches and their implications for N2O emissions in terrestrial environments. However, our understanding of N2O reducers in aquatic systems is currently limited. This study investigated the relative abundance and diversity of nosZI- and nosZII-type N2O reducers in rivers and their impact on N2O emissions. Our findings revealed that stream sediments possess a high capacity for N2O reduction, surpassing N2O production under high N2O/NO3- ratio conditions. This study, along with others in freshwater systems, demonstrated that nosZI marginally dominates more often in rivers. While microbes containing either nosZI and nosZII were crucial in reducing N2O emissions, the net contribution of nosZII-containing microbes was more significant. This can be attributed to the nir gene co-occurring more frequently with the nosZI gene than with the nosZII gene. The diversity within each clade also played a role, with nosZII species being more likely to function as N2O sinks in streams with higher N2O concentrations. Overall, our findings provide a foundation for a better understanding of the biogeography of stream N2O reducers and their effects on N2O emissions.

Hierarchical-Bioinspired MOFs Enhanced Electromagnetic Wave Absorption.

Proteins exhibit complex and diverse multi-dimensional structures, along with a wide range of functional groups capable of binding metal ions. By harnessing the unique characteristics of proteins, it is possible to enhance the synthesis of metal-organic frameworks (MOFs) and modify their morphology. Here, the utilization of biomineralized bovine serum albumin (BSA) protein as a template for synthesizing Mil-100 with superior microwave absorption (MA) properties is investigated. The multi-dimensional structure and abundant functional groups of biomineralized BSA protein make it an ideal candidate for guiding the synthesis of Mil-100 with intricate network structures. The BSA@Mil-100 synthesized using this method exhibits exceptional uniformity and monodispersity of nanocrystals. The findings suggest that the BSA protein template significantly influences the regulation of nanocrystal and microstructure formation of Mil-100, resulting in a highly uniform and monodisperse structure. Notably, the synthesized 2-BSA@Mil-100 demonstrates a high reflection loss value of -58 dB at 8.85 GHz, along with a maximum effective absorption bandwidth value of 6.79 GHz, spanning from 6.01 to 12.8 GHz. Overall, this study highlights the potential of utilizing BSA protein as a template for MOF synthesis, offering an effective strategy for the design and development of high-performance MA materials.

Multi-Component Lithiophilic Alloy Film Modified Cu Current Collector for Long-Life Lithium Metal Batteries by a Novel FCVA Co-Deposition System.

Surface modification of Cu current collectors (CCs) is proven to be an effective method for protecting lithium metal anodes. However, few studies have focused on the quality and efficiency of modification layers. Herein, a novel home-made filtered cathode vacuum arc (FCVA) co-deposition system with high modification efficiency, good repeatability and environmental friendliness is proposed to realize the wide range regulation of film composition, structure and performance. Through this system, ZnMgTiAl quaternary alloy films, which have good affinity with Li are successfully constructed on Cu CCs, and the fully enhanced electrochemical performances are achieved. Symmetrical cells constructed with modified CCs maintained a fairly low voltage hysteresis of only 13 mV after 2100 h at a current density of 1 mA cm-2. In addition, the capacity retention rate is as high as 75.0% after 100 cycles in the full cells. The influence of alloy films on the dynamic evolution process of constructing stable artificial solid electrolyte interphase (SEI) layer is revealed by in situ infrared (IR) spectroscopy. This work provides a promising route for designing various feasible modification films for LMBs, and it displays better industrial application prospects than the traditional chemical methods owing to the remarkable controllability and scale-up capacity.

Magnetic detection under high pressures using designed silicon vacancy centres in silicon carbide.

Pressure-induced magnetic phase transitions are attracting interest as a means to detect superconducting behaviour at high pressures in diamond anvil cells, but determining the local magnetic properties of samples is a challenge due to the small volumes of sample chambers. Optically detected magnetic resonance of nitrogen vacancy centres in diamond has recently been used for the in situ detection of pressure-induced phase transitions. However, owing to their four orientation axes and temperature-dependent zero-field splitting, interpreting these optically detected magnetic resonance spectra remains challenging. Here we study the optical and spin properties of implanted silicon vacancy defects in 4H-silicon carbide that exhibit single-axis and temperature-independent zero-field splitting. Using this technique, we observe the magnetic phase transition of Nd2Fe14B at about 7 GPa and map the critical temperature-pressure phase diagram of the superconductor YBa2Cu3O6.6. These results highlight the potential of silicon vacancy-based quantum sensors for in situ magnetic detection at high pressures.

Quantitative anatomy of the large variant right hepatic vein: A systematic three-dimensional analysis.

Anatomical variations of the right hepatic vein, especially large variant right hepatic veins (≥5 mm), have important clinical implications in liver transplantation and resection. This study aimed to evaluate anatomical variations of the right hepatic vein using quantitative three-dimensional visualization analysis. Computed tomography images of 650 patients were retrospectively analyzed, and three-dimensional visualization was applied using the derived data to analyze large variant right hepatic veins. The proportion of the large variant right hepatic vein was 16.92% (110/650). According to the location and number of the variant right hepatic veins, the configuration of the right hepatic venous system was divided into seven subtypes. The length of the retrohepatic inferior vena cava had a positive correlation with the diameter of the right hepatic vein (rs = 0.266, p = 0.001) and the variant right hepatic veins (rs = 0.211, p = 0.027). The diameter of the right hepatic vein was positively correlated with that of the middle hepatic vein (rs = 0.361, p < 0.001), while it was inversely correlated with that of the variant right hepatic veins (rs = -0.267, p = 0.005). The right hepatic vein diameter was positively correlated with the drainage volume (rs = 0.489, p < 0.001), while the correlation with the variant right hepatic veins drainage volume was negative (rs = -0.460, p < 0.001). The number of the variant right hepatic veins and their relative diameters were positively correlated (p < 0.001). The volume and percentage of the drainage area of the right hepatic vein decreased significantly as the number of the variant right hepatic vein increased (p < 0.001). The findings of this study concerning the variations of the hepatic venous system may be useful for the surgical planning of liver resection or transplantation.

Enhancement of silicon vacancy fluorescence intensity in silicon carbide using a dielectric cavity.

Over the past decades, spin qubits in silicon carbide (SiC) have emerged as promising platforms for a wide range of quantum technologies. The fluorescence intensity holds significant importance in the performance of quantum photonics, quantum information process, and sensitivity of quantum sensing. In this work, a dual-layer Au/SiO2 dielectric cavity is employed to enhance the fluorescence intensity of a shallow silicon vacancy ensemble in 4H-SiC. Experimental results demonstrate an effective fourfold augmentation in fluorescence counts at saturating laser power, corroborating our theoretical predictions. Based on this, we further investigate the influence of dielectric cavities on the contrast and linewidth of optically detected magnetic resonance (ODMR). There is a 1.6-fold improvement in magnetic field sensitivity. In spin echo experiments, coherence times remain constant regardless of the thickness of dielectric cavities. These experiments pave the way for broader applications of dielectric cavities in SiC-based quantum technologies.

A new preparation method of covalent annular nanodiscs based on MTGase.

The preservation of the native conformation and functionality of membrane proteins has posed considerable challenges. While detergents and liposome reconstitution have been traditional approaches, nanodiscs (NDs) offer a promising solution by embedding membrane proteins in phospholipids encircled by an amphipathic helical protein MSP belt. Nevertheless, a drawback of commonly used NDs is their limited homogeneity and stability. In this study, we present a novel approach to construct covalent annular nanodiscs (cNDs) by leveraging microbial transglutaminase (MTGase) to catalyze isopeptide bond formation between the side chains of terminal amino acids, specifically Lysine (K) and Glutamine (Q). This methodology significantly enhances the homogeneity and stability of NDs. Characterization of cNDs and the assembly of membrane proteins within them validate the successful reconstitution of membrane proteins with improved homogeneity and stability. Our findings suggest that cNDs represent a more suitable tool for investigating interactions between membrane proteins and lipids, as well as for analyzing membrane protein structures.

Consolidated Health Economic Evaluation Reporting Standards for Interventions That Use Artificial Intelligence (CHEERS-AI).

OBJECTIVES: Economic evaluations (EEs) are commonly used by decision makers to understand the value of health interventions. The Consolidated Health Economic Evaluation Reporting Standards (CHEERS 2022) provide reporting guidelines for EEs. Healthcare systems will increasingly see new interventions that use artificial intelligence (AI) to perform their function. We developed Consolidated Health Economic Evaluation Reporting Standards for Interventions that use AI (CHEERS-AI) to ensure EEs of AI-based health interventions are reported in a transparent and reproducible manner. METHODS: Potential CHEERS-AI reporting items were informed by 2 published systematic literature reviews of EEs and a contemporary update. A Delphi study was conducted using 3 survey rounds to elicit multidisciplinary expert views on 26 potential items, through a 9-point Likert rating scale and qualitative comments. An online consensus meeting was held to finalize outstanding reporting items. A digital health patient group reviewed the final checklist from a patient perspective. RESULTS: A total of 58 participants responded to survey round 1, 42, and 31 of whom responded to rounds 2 and 3, respectively. Nine participants joined the consensus meeting. Ultimately, 38 reporting items were included in CHEERS-AI. They comprised the 28 original CHEERS 2022 items, plus 10 new AI-specific reporting items. Additionally, 8 of the original CHEERS 2022 items were elaborated on to ensure AI-specific nuance is reported. CONCLUSIONS: CHEERS-AI should be used when reporting an EE of an intervention that uses AI to perform its function. CHEERS-AI will help decision makers and reviewers to understand important AI-specific details of an intervention, and any implications for the EE methods used and cost-effectiveness conclusions.

Leveraging machine learning for predicting acute graft-versus-host disease grades in allogeneic hematopoietic cell transplantation for T-cell prolymphocytic leukaemia.

Orphan diseases, exemplified by T-cell prolymphocytic leukemia, present inherent challenges due to limited data availability and complexities in effective care. This study delves into harnessing the potential of machine learning to enhance care strategies for orphan diseases, specifically focusing on allogeneic hematopoietic cell transplantation (allo-HCT) in T-cell prolymphocytic leukemia. The investigation evaluates how varying numbers of variables impact model performance, considering the rarity of the disease. Utilizing data from the Center for International Blood and Marrow Transplant Research, the study scrutinizes outcomes following allo-HCT for T-cell prolymphocytic leukemia. Diverse machine learning models were developed to forecast acute graft-versus-host disease (aGvHD) occurrence and its distinct grades post-allo-HCT. Assessment of model performance relied on balanced accuracy, F1 score, and ROC AUC metrics. The findings highlight the Linear Discriminant Analysis (LDA) classifier achieving the highest testing balanced accuracy of 0.58 in predicting aGvHD. However, challenges arose in its performance during multi-class classification tasks. While affirming the potential of machine learning in enhancing care for orphan diseases, the study underscores the impact of limited data and disease rarity on model performance.

Neuroprotective azaphilones from a deep-sea derived fungus Penicillium sp. SCSIO41030.

Ten azaphilones including one pair of new epimers and three new ones, penineulones A-E (1-5) with the same structural core of angular deflectin, were obtained from a deep-sea derived Penicillium sp. SCSIO41030 fermented on a liquid medium. Their structures including absolute configurations were elucidated using chiral-phase HPLC analysis, extensive NMR spectroscopic and HRESIMS data, ECD and NMR calculations, and by comparing NMR data with literature data. Biological assays showed that the azaphilones possessed no antitumor and anti-viral (HSV-1/2) activities at concentrations of 5.0 µM and 20 µM, respectively. In addition, azaphilones 8 and 9 showed neuroprotective effects against Aß25-35-induced neurotoxicity in primary cultured cortical neurons at a concentration of 10 µM. Azaphilones 8 and 9 dramatically promoted axonal regrowth against Aß25-35-induced axonal atrophy. Our study indicated that azaphilones could be promising lead compounds for neuroprotection.

Anti-inflammatory and Neuroprotective α-Pyrones from a Marine-Derived Strain of the Fungus Arthrinium arundinis and Their Heterologous Expression.

Fungal linear polyketides, such as α-pyrones with a 6-alkenyl chain, have been a rich source of biologically active compounds. Two new (1 and 2) and four known (3-6) 6-alkenylpyrone polyketides were isolated from a marine-derived strain of the fungus Arthrinium arundinis. Their structures were determined based on extensive spectroscopic analysis. The biosynthetic gene cluster (alt) for alternapyrones was identified from A. arundinis ZSDS-F3 and validated by heterologous expression in Aspergillus nidulans A1145 ΔSTΔEM, which revealed that the cytochrome P450 monooxygenase Alt2' could convert the methyl group 26-CH3 to a carboxyl group to produce 4 from 3. Another cytochrome P450 monooxygenase, Alt3', catalyzed successive hydroxylation, epoxidation, and oxidation steps to produce 1, 2, 5, and 6 from 4. Alternapyrone G (1) not only suppressed M1 polarization in lipopolysaccharide (LPS)-stimulated BV2 microglia but also stimulated dendrite regeneration and neuronal survival after Aß treatment, suggesting alternapyrone G may be utilized as a privileged scaffold for Alzheimer's disease drug discovery.

Triage tools for detecting cervical spine injury in paediatric trauma patients.

BACKGROUND: Paediatric cervical spine injury (CSI) after blunt trauma is rare but can have severe consequences. Clinical decision rules (CDRs) have been developed to guide clinical decision-making, minimise unnecessary tests and associated risks, whilst detecting all significant CSIs. Several validated CDRs are used to guide imaging decision-making in adults following blunt trauma and clinical criteria have been proposed as possible paediatric-specific CDRs. Little information is known about their accuracy. OBJECTIVES: To assess and compare the diagnostic accuracy of CDRs or sets of clinical criteria, alone or in comparison with each other, for the evaluation of CSI following blunt trauma in children. SEARCH METHODS: For this update, we searched CENTRAL, MEDLINE, Embase, and six other databases from 1 January 2015 to 13 December 2022. As we expanded the index test eligibility for this review update, we searched the excluded studies from the previous version of the review for eligibility. We contacted field experts to identify ongoing studies and studies potentially missed by the search. There were no language restrictions. SELECTION CRITERIA: We included cross-sectional or cohort designs (retrospective and prospective) and randomised controlled trials that compared the diagnostic accuracy of any CDR or clinical criteria compared with a reference standard for the evaluation of paediatric CSI following blunt trauma. We included studies evaluating one CDR or comparing two or more CDRs (directly and indirectly). We considered X-ray, computed tomography (CT) or magnetic resonance imaging (MRI) of the cervical spine, and clinical clearance/follow-up as adequate reference standards. DATA COLLECTION AND ANALYSIS: Two review authors independently screened titles and abstracts for relevance, and carried out eligibility, data extraction and quality assessment. A third review author arbitrated. We extracted data on study design, participant characteristics, inclusion/exclusion criteria, index test, target condition, reference standard and data (diagnostic two-by-two tables) and calculated and plotted sensitivity and specificity on forest plots for visual examination of variation in test accuracy. We assessed methodological quality using the Quality Assessment of Diagnostic Accuracy Studies Version 2 tool. We graded the certainty of the evidence using the GRADE approach. MAIN RESULTS: We included five studies with 21,379 enrolled participants, published between 2001 and 2021. Prevalence of CSI ranged from 0.5% to 1.85%. Seven CDRs were evaluated. Three studies reported on direct comparisons of CDRs. One study (973 participants) directly compared the accuracy of three index tests with the sensitivities of NEXUS, Canadian C-Spine Rule and the PECARN retrospective criteria being 1.00 (95% confidence interval (CI) 0.48 to 1.00), 1.00 (95% CI 0.48 to 1.00) and 1.00 (95% CI 0.48 to 1.00), respectively. The specificities were 0.56 (95% CI 0.53 to 0.59), 0.52 (95% CI 0.49 to 0.55) and 0.32 (95% CI 0.29 to 0.35), respectively (moderate-certainty evidence). One study (4091 participants) compared the accuracy of the PECARN retrospective criteria with the Leonard de novo model; the sensitivities were 0.91 (95% CI 0.81 to 0.96) and 0.92 (95% CI 0.83 to 0.97), respectively. The specificities were 0.46 (95% CI 0.44 to 0.47) and 0.50 (95% CI 0.49 to 0.52) (moderate- and low-certainty evidence, respectively). One study (270 participants) compared the accuracy of two NICE (National Institute for Health and Care Excellence) head injury guidelines; the sensitivity of the CG56 guideline was 1.00 (95% CI 0.48 to 1.00) compared to 1.00 (95% CI 0.48 to 1.00) with the CG176 guideline. The specificities were 0.46 (95% CI 0.40 to 0.52) and 0.07 (95% CI 0.04 to 0.11), respectively (very low-certainty evidence). Two additional studies were indirect comparison studies. One study (3065 participants) tested the accuracy of the NEXUS criteria; the sensitivity was 1.00 (95% CI 0.88 to 1.00) and specificity was 0.20 (95% CI 0.18 to 0.21) (low-certainty evidence). One retrospective study (12,537 participants) evaluated the PEDSPINE criteria and found a sensitivity of 0.93 (95% CI 0.78 to 0.99) and specificity of 0.70 (95% CI 0.69 to 0.72) (very low-certainty evidence). We did not pool data within the broader CDR categories or investigate heterogeneity due to the small quantity of data and the clinical heterogeneity of studies. Two studies were at high risk of bias. We identified two studies that are awaiting classification pending further information and two ongoing studies. AUTHORS' CONCLUSIONS: There is insufficient evidence to determine the diagnostic test accuracy of CDRs to detect CSIs in children following blunt trauma, particularly for children under eight years of age. Although most studies had a high sensitivity, this was often achieved at the expense of low specificity and should be interpreted with caution due to a small number of CSIs and wide CIs. Well-designed, large studies are required to evaluate the accuracy of CDRs for the cervical spine clearance in children following blunt trauma, ideally in direct comparison with each other.

Conjugated linoleic acid (CLA) reduces HFD-induced obesity by enhancing BAT thermogenesis and iWAT browning via the CD36-AMPK pathway.

The antiobesity effect of conjugated linoleic acid (CLA) has been reported. However, the underlying mechanisms have not been fully clarified. Thus, this study aimed to investigate the effects of CLA on thermogenesis of interscapular brown adipose tissue (iBAT) and browning of inguinal subcutaneous white adipose tissue (iWAT) and explore the possible signaling pathway. The in vivo results showed that CLA enhanced the O2 consumption and heat production in HFD (high-fat diet)-fed female mice by roughly 38%. Meanwhile, CLA increased the average iBAT temperature by 2°C at the room temperature and cold exposure, respectively. Correspondingly, CLA caused 1.6- and 2.4-fold increases in the expression of UCP1 (uncoupling protein 1) of BAT and iWAT, respectively, suggesting the activated iBAT thermogenesis and iWAT browning in HFD-fed female mice. Meanwhile, CLA could promote the formation of brown and beige adipocytes in differentiated stromal vascular cells (SVCs) isolated from iBAT and iWAT (the expressions of UCP1 were promoted by about twofold changes). In possible mechanisms, CLA stimulated the expression of CD36 and the activation of the AMPK pathway in mice iBAT and iWAT as well as the differentiated SVCs. However, inhibition of CD36 and AMPK (adenosine 5'-monophosphate-activated protein kinase) abolished the promotive effects of CLA on brown and beige adipocytes formation. Hence, we showed that CLA reduced HFD-induced obesity through enhancing iBAT thermogenesis and iWAT browning via the  CD36-AMPK pathway.

Aqueous production of secondary organic aerosol from fossil-fuel emissions in winter Beijing haze.

Secondary organic aerosol (SOA) produced by atmospheric oxidation of primary emitted precursors is a major contributor to fine particulate matter (PM2.5) air pollution worldwide. Observations during winter haze pollution episodes in urban China show that most of this SOA originates from fossil-fuel combustion but the chemical mechanisms involved are unclear. Here we report field observations in a Beijing winter haze event that reveal fast aqueous-phase conversion of fossil-fuel primary organic aerosol (POA) to SOA at high relative humidity. Analyses of aerosol mass spectra and elemental ratios indicate that ring-breaking oxidation of POA aromatic species, leading to functionalization as carbonyls and carboxylic acids, may serve as the dominant mechanism for this SOA formation. A POA origin for SOA could explain why SOA has been decreasing over the 2013-2018 period in response to POA emission controls even as emissions of volatile organic compounds (VOCs) have remained flat.