Synthesis of Tetrasubstituted Enamines Using Secondary Amines and In Situ-Generated Allenes from Nitrocyclopropanes.

A novel reaction of cyclic and acyclic secondary amines with in situ-generated allene intermediate species from nitro-substituted donor-acceptor cyclopropanes is reported. In the presence of a simple inorganic base, NaOH, tetrasubstituted enamine derivatives can be obtained in moderate to excellent yields. The reaction is operationally easy, features mild reaction conditions and simple inorganic bases, and is free of transition metals.

An internet-based platform with a low-calorie dietary intervention improves cardiometabolic risk factors in overweight and obese people in China: Half-year follow-up results of a randomized controlled trial.

AIM: To explore the effectiveness of the Metawell programme on cardiometabolic risk factors in China, which combines meal replacement biscuits, a wireless scale, and a mobile phone application. METHODS: In this two-arm, parallel-design randomized study, 220 participants were randomly assigned to an intervention (n = 110) and a control (n = 110) group. Participants in the intervention group were instructed to use meal replacement products and scales for weight loss and monitoring, whereas participants in the control group received printed materials containing a sample diet and face-to-face weight loss education at enrolment. The trial lasted 6 months, including a weight loss period in Months 1-3 and a weight maintenance period in Months 3-6. Generalized estimating equations were used to compare differences between the two groups. RESULTS: The median (interquartile range) ages of the intervention and control groups were 32.00 (28.00, 39.00) years and 33.00 (28.25, 41.00) years, with body mass indices of 28.20 (26.30, 30.95) kg/m2 and 27.70 (26.02, 29.70) kg/m2, respectively. Participants in the intervention group experienced significantly greater decreases in waist circumference, hip circumference, triglycerides, total cholesterol: high-density lipoprotein cholesterol ratio, fasting blood glucose, fasting insulin, and homeostatic model assessment of insulin resistance index compared to the control group (p < 0.01). Among participants who did not regain weight during the maintenance period after weight loss, the reductions in systolic and diastolic blood pressure were significantly greater in the intervention group than in the control group (p < 0.05). CONCLUSIONS: The Metawell programme of caloric restriction and remote monitoring can be adapted to overweight and obese people in China to reduce their cardiometabolic risk factors. Furthermore, there was a better improvement in blood pressure in participants who maintained the effects of weight loss.

Extending Shelf-life of Two-step Method Precursor Solutions through Targeted Regulation for Highly Efficient and Reproducible Perovskite Solar Cells.

Precursor solution aging process can cause significant influence on the photovoltaic performance of perovskite solar cells (PVSCs). Notably, we first observe that the aging phenomenon is more severe in the precursor of two-step sequential method compared to that in one-step method due to that the protic solvent isopropanol facilitates amine-cation side reaction and iodide ions oxidation. Herein, we report a novel approach for selectively stabilizing both organic amine salt and lead iodide (PbI2) precursor solutions in two-step method. The introduction of benzene-1,3-dithiol into organic amine salt solution can mitigate amine-cation side reactions due to the formation of an acidic and reducing environment. Simultaneously, decamethylferrocene (FcMe10/FcMe+10) pair can act as a redox shuttle in PbI2 solution to concurrently oxidize Pb0 and reduce I2 in cyclic manner. Consequently, the PVSCs device fabricated from ameliorative precursor solutions demonstrates superior power conversion efficiency of 25.31%, retaining 95% of its efficiency after 21 days of solution aging. Moreover, the unencapsulated devices maintain 85% of primitive efficiency for 1500 h at maximum power point tracking under continuous illumination. This work establishes a fundamental guidance and scientific direction for the stabilization of two-step perovskite precursor solutions.

Ampere-Level Hydrogen Generation via 1000 H Stable Seawater Electrolysis Catalyzed by Pt-Cluster-Loaded NiFeCo Phosphide.

Seawater electrolysis can generate carbon-neutral hydrogen but its efficiency is hindered by the low mass activity and poor stability of commercial catalysts at industrial current densities. Herein, Pt nanoclusters are loaded on nickel-iron-cobalt phosphide nanosheets, with the obtained Pt@NiFeCo-P electrocatalyst exhibiting excellent hydrogen evolution reaction (HER) activity and stability in alkaline seawater at ampere-level current densities. The catalyst delivers an ultralow HER overpotential of 19.7 mV at -10 mA cm-2 in seawater-simulating alkaline solutions, along with a Pt-mass activity 20.8 times higher than Pt/C under the same conditions, while dropping to 8.3 mV upon a five-fold NaCl concentrated natural seawater. Remarkably, Pt@NiFeCo-P offers stable operation for over 1000 h at 1 A cm-2 in an alkaline brine electrolyte, demonstrating its potential for efficient and long-term seawater electrolysis. X-ray photoelectron spectroscopy (XPS), in situ electrochemical impedance spectroscopy (EIS), and in situ Raman studies revealed fast electron and charge transfer from the NiFeCo-P substrate to Pt nanoclusters enabled by a strong metal-support interaction, which increased the coverage of H* and accelerated water dissociation on high valent Co sites. This study represents a significant advancement in the development of efficient and stable electrocatalysts with high mass activity for sustainable hydrogen generation from seawater.

Bridging Innovations of Phase Change Heat Transfer to Electrochemical Gas Evolution Reactions.

Bubbles play a ubiquitous role in electrochemical gas evolution reactions. However, a mechanistic understanding of how bubbles affect the energy efficiency of electrochemical processes remains limited to date, impeding effective approaches to further boost the performance of gas evolution systems. From a perspective of the analogy between heat and mass transfer, bubbles in electrochemical gas evolution reactions exhibit highly similar dynamic behaviors to them in the liquid-vapor phase change. Recent developments of liquid-vapor phase change systems have substantially advanced the fundamental knowledge of bubbles, leading to unprecedented enhancement of heat transfer performance. In this Review, we aim to elucidate a promising opportunity of understanding bubble dynamics in electrochemical gas evolution reactions through a lens of phase change heat transfer. We first provide a background about key parallels between electrochemical gas evolution reactions and phase change heat transfer. Then, we discuss bubble dynamics in gas evolution systems across multiple length scales, with an emphasis on exciting research problems inspired by new insights gained from liquid-vapor phase change systems. Lastly, we review advances in engineered surfaces for manipulating bubbles to enhance heat and mass transfer, providing an outlook on the design of high-performance gas evolving electrodes.

Regulating Surface Metal Abundance via Lattice-Matched Coordination for Versatile and Environmentally-Viable Sn-Pb Alloying Perovskite Solar Cells.

Narrow-bandgap Sn-Pb alloying perovskites showcased great potential in constructing multiple-junction perovskite solar cells (PSCs) with efficiencies approaching or exceeding the Shockley-Queisser limit. However, the uncontrollable surface metal abundance (Sn2+ and Pb2+ ions) hinders their efficiency and versatility in different device structures. Additionally, the undesired Pb distribution mainly at the buried interface accelerates the Pb leakage when devices are damaged. In this work, a novel strategy is presented to modulate crystallization kinetics and surface metal abundance of Sn-Pb perovskites using a cobweb-like quadrangular macrocyclic porphyrin material, which features a molecular size compatible with the perovskite lattice and robustly coordinates with Pb2+ ions, thus immobilizing them and increasing surface Pb abundance by 61%. This modulation reduces toxic Pb leakage rates by 24-fold, with only ∼23 ppb Pb in water after severely damaged PSCs are immersed in water for 150 h.This strategy can also enhance chemical homogeneity, reduce trap density, release tensile strain and optimize carrier dynamics of Sn-Pb perovskites and relevant devices. Encouragingly, the power conversion efficiency (PCEs) of 23.28% for single-junction, full-stack devices and 21.34% for hole transport layer-free Sn-Pb PSCs are achieved.Notably, the related monolithic all-perovskite tandem solar cell also achieves a PCE of 27.03% with outstanding photostability.

One new species of Pseudopoda Jäger, 2000 from Shennongjia, Central China (Araneae, Sparassidae).

Background: Pseudopoda Jäger, 2000 is currently the largest genus in the family Sparassidae Bertkau, 1872, comprising 255 species. Of these, 154 species have been recorded in China, representing 60.4% of the global species.In October 2023, a spider survey was conducted in Shennongjia National Nature Reserve, Hubei Province, China. After examination and morphological comparison, one new species of the genus Pseudopoda was identified and is described here. New information: In this paper, a new species of Pseudopoda collected in Hubei Province, China, is proposed and named Pseudopodaguanmenshan sp. nov. A detailed description, diagnosis, photographs and distribution map of the new species are provided.

Impact of altitude on the development of low bone mineral density and osteoporosis in individuals aged 50 years and older: protocol for a multicentre prospective cohort study.

INTRODUCTION: Osteoporotic fractures are a leading cause of disability and contribute significantly to medical care costs worldwide. Variations in bone mineral density and the risk of osteoporosis are notably influenced by altitude. This study aims to longitudinally examine individuals with osteoporosis and low bone mass at three different altitudes (low, high and very high) to understand the effects of high-altitude environments on bone density. METHODS AND ANALYSIS: This multicentre, prospective cohort study will involve 893 participants divided into three groups based on altitude: low (500-1500 m), high (2500-4500 m) and very high (4500-5500 m). Participants will undergo comprehensive diagnostic assessments, including demographic data collection, structured questionnaires, medical examinations and clinical laboratory tests. Follow-up visits will occur annually for a minimum of 5 years. The primary outcome will be changes in bone mineral density values. Secondary outcomes will include the incidence of osteoporosis and osteoporotic fractures. Cox proportional hazard models will be used to calculate the risk associated with osteoporotic events and related fractures. ETHICS AND DISSEMINATION: The study has been approved by the Institutional Review Board of the Hospital of Chengdu Office of People's Government of Tibetan Autonomous Region (No: 2024-70). The acquired insights will be disseminated via academic forums, scholarly articles and stakeholder engagement sessions. TRIAL REGISTRATIONNUMBER: ChiCTR2300078872.

PlantCircRNA: a comprehensive database for plant circular RNAs.

Circular RNAs (circRNAs) represent recently discovered novel regulatory non-coding RNAs. While they are present in many eukaryotes, there has been limited research on plant circRNAs. We developed PlantCircRNA (https://plant.deepbiology.cn/PlantCircRNA/) to fill this gap. The two most important features of PlantCircRNA are (i) it incorporates circRNAs from 94 plant species based on 39 245 RNA-sequencing samples and (ii) it imports the original AtCircDB and CropCircDB databases. We manually curated all circRNAs from published articles, and imported them into the database. Furthermore, we added detailed information of tissue as well as abiotic stresses to the database. To help users understand these circRNAs, the database includes a detection score to measure their consistency and a naming system following the guidelines recently proposed for eukaryotes. Finally, we developed a comprehensive platform for users to visualize, analyze, and download data regarding specific circRNAs. This resource will serve as a home for plant circRNAs and provide the community with unprecedented insights into these mysterious molecule.

Accelerating the calculation of electron-phonon coupling strength with machine learning.

The calculation of electron-phonon couplings (EPCs) is essential for understanding various fundamental physical properties, including electrical transport, optical and superconducting behaviors in materials. However, obtaining EPCs through fully first-principles methods is notably challenging, particularly for large systems or when employing advanced functionals. Here we introduce a machine learning framework to accelerate EPC calculations by utilizing atomic orbital-based Hamiltonian matrices and gradients predicted by an equivariant graph neural network. We demonstrate that our method not only yields EPC values in close agreement with first-principles results but also enhances calculation efficiency by several orders of magnitude. Application to GaAs using the Heyd-Scuseria-Ernzerhof functional reveals the necessity of advanced functionals for accurate carrier mobility predictions, while for the large Kagome crystal CsV3Sb5, our framework reproduces the experimentally observed double domes in pressure-induced superconducting phase diagrams. This machine learning framework offers a powerful and efficient tool for the investigation of diverse EPC-related phenomena in complex materials.

Rhodium-Catalyzed Regioselective [4 + 2] Cycloaddition of Ynamines and 2-(Cyanomethyl)phenylboronates.

A rhodium-catalyzed [4 + 2] cycloaddition of ynamines and 2-(cyanomethyl)phenylboronates has been developed, leading to efficient and excellent regioselective synthesis of valuable indole-linked aromatic compounds in a concise and flexible approach. Interestingly, this strategy was successful in the construction of C···N axially chiral indoles with high enantiocontrol by the introduction of a new phosphoramidite ligand (Xie-Phos).

Design of a Compact Multicyclic High-Performance Atmospheric Water Harvester for Arid Environments.

Water scarcity remains a grand challenge across the globe. Sorption-based atmospheric water harvesting (SAWH) is an emerging and promising solution for water scarcity, especially in arid and noncoastal regions. Traditional approaches to AWH such as fog harvesting and dewing are often not applicable in an arid environment (<30% relative humidity (RH)), whereas SAWH has demonstrated great potential to provide fresh water under a wide range of climate conditions. Despite advances in materials development, most demonstrated SAWH devices still lack sufficient water production. In this work, we focus on the adsorption bed design to achieve high water production, multicyclic operation, and a compact form factor (high material loading per heat source contact area). The modeling efforts and experimental validation illustrate an optimized design space with a fin-array adsorption bed enabled by high-density waste heat, which promises 5.826 Lwater kgsorbent -1 day-1 at 30% RH within a compact 1 L adsorbent bed and commercial adsorbent materials.

PlantSR: Super-Resolution Improves Object Detection in Plant Images.

Recent advancements in computer vision, especially deep learning models, have shown considerable promise in tasks related to plant image object detection. However, the efficiency of these deep learning models heavily relies on input image quality, with low-resolution images significantly hindering model performance. Therefore, reconstructing high-quality images through specific techniques will help extract features from plant images, thus improving model performance. In this study, we explored the value of super-resolution technology for improving object detection model performance on plant images. Firstly, we built a comprehensive dataset comprising 1030 high-resolution plant images, named the PlantSR dataset. Subsequently, we developed a super-resolution model using the PlantSR dataset and benchmarked it against several state-of-the-art models designed for general image super-resolution tasks. Our proposed model demonstrated superior performance on the PlantSR dataset, indicating its efficacy in enhancing the super-resolution of plant images. Furthermore, we explored the effect of super-resolution on two specific object detection tasks: apple counting and soybean seed counting. By incorporating super-resolution as a pre-processing step, we observed a significant reduction in mean absolute error. Specifically, with the YOLOv7 model employed for apple counting, the mean absolute error decreased from 13.085 to 5.71. Similarly, with the P2PNet-Soy model utilized for soybean seed counting, the mean absolute error decreased from 19.159 to 15.085. These findings underscore the substantial potential of super-resolution technology in improving the performance of object detection models for accurately detecting and counting specific plants from images. The source codes and associated datasets related to this study are available at Github.

Dimension Prediction and Microstructure Study of Wire Arc Additive Manufactured 316L Stainless Steel Based on Artificial Neural Network and Finite Element Simulation.

The dimensional accuracy and microstructure affect the service performance of parts fabricated by wire arc additive manufacturing (WAAM). Regulating the geometry and microstructure of such parts presents a challenge. The coupling method of an artificial neural network and finite element (FE) is proposed in this research for this purpose. Back-propagating neural networks (BPNN) based on optimization algorithms were established to predict the bead width (BW) and height (BH) of the deposited layers. Then, the bead geometry was modeled based on the predicted dimension, and 3D FE heat transfer simulation was performed to investigate the evolution of temperature and microstructure. The results showed that the errors in BW and BH were less than 6%, and the beetle antenna search BPNN model had the highest prediction accuracy compared to the other models. The simulated melt pool error was less than 5% with the experimental results. The decrease in the ratio of the temperature gradient and solidification rate induced the transition of solidified grains from cellular crystals to columnar dendrites and then to equiaxed dendrites. Accelerating the cooling rate increased the primary dendrite arm spacing and δ-ferrite content. These results indicate that the coupling model provides a pathway for regulating the dimensions and microstructures of manufactured parts.

Tracking the scaling of urban open spaces in China from 1990 to 2020.

Urban open spaces (UOS) are crucial for urban life, offering benefits across individual and societal levels. However, the understanding of the systematic dynamic of UOS scaling with city size and its potential non-linear performance remains a limited clarity area. This study bridges this gap by integrating urban scaling laws with remote sensing data from 1990 to 2020, creating a framework to analyze UOS trends in China. Our findings reveal that UOS growth is sub-linear scaling with city size, exhibiting economies of scale with scaling exponents between 0.55 and 0.65 and suggesting potential shortages. The distribution structure of UOS across cities is becoming increasingly balanced, as indicated by the rising Zipf's slope from 0.66 to 0.88. Southeastern coastal cities outperform, highlighting spatial variations and path dependency in UOS development. Additionally, using metrics of Scale-adjusted metropolitan indicator (SAMI) and the ratio of open space consumption to population growth rates (OCRPGR), we observe a trend towards more coordinated development between UOS and population, with a declining proportion of uncoordinated cities. Our long-term, large sample coverage study of UOS in China may offer positive significance for urban ecological planning and management in similar rapidly urbanizing countries, contributing to critical insights for quantifying and monitoring urban sustainable development.

Ironing out Persisters? Revisiting the Iron Chelation Strategy to Target Planktonic Bacterial Persisters Harboured in Carbapenem-Resistant Escherichia coli.

Antibiotic resistance is a global health crisis. Notably, carbapenem-resistant Enterobacterales (CRE) pose a significant clinical challenge due to the limited effective treatment options. This problem is exacerbated by persisters that develop upon antibiotic exposure. Bacteria persisters can tolerate high antibiotic doses and can cause recalcitrant infections, potentially developing further antibiotic resistance. Iron is a critical micronutrient for survival. We aimed to evaluate the utility of iron chelators, alone and in combination with antibiotics, in managing persisters. We hypothesized that iron chelators eradicate CRE persisters in vitro, when administered in combination with antibiotics. Our screening revealed three clinical isolates with bacteria persisters that resuscitated upon antibiotic removal. These isolates were treated with both meropenem and an iron chelator (deferoxamine mesylate, deferiprone or dexrazoxane) over 24 h. Against our hypothesis, bacteria persisters survived and resuscitated upon withdrawing both the antibiotic and iron chelator. Pursuing our aim, we next hypothesized that iron chelation is feasible as a post-antibiotic treatment in managing and suppressing persisters' resuscitation. We exposed bacteria persisters to an iron chelator without antibiotics. Flow cytometric assessments revealed that iron chelators are inconsistent in suppressing persister resuscitation. Collectively, these results suggest that the iron chelation strategy may not be useful as an antibiotic adjunct to target planktonic bacteria persisters.

A Rare Case of Isolated Abducens Nerve Palsy With Contemporaneous Thalamic Infarct.

We report a case of isolated left abducens nerve palsy accompanying a right thalamic infarct. The patient, a 43-year-old Malay male with newly diagnosed hypertension, diabetes mellitus, and dyslipidemia, initially reported binocular diplopia on left lateral gaze persisting for five weeks. Subsequently, he experienced acute left-sided body weakness and slurred speech for over one day. Clinical examination revealed restricted left eye lateral gaze (-3) with no relative afferent pupillary defect. Additionally, decreased power (4/5) was noted in the left upper and lower limbs. Brain magnetic resonance imaging (MRI) revealed restricted diffusion in the right thalamus extending to the right posterior internal capsule, left anterior cingulate gyrus, and left caudate nucleus. The patient was initiated on antiplatelet, antihypertensive, and oral hypoglycemic agents, resulting in symptom improvement. This rare neuroophthalmological finding has not been reported previously.

Genetic and molecular characterization of metabolic pathway-based clusters in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive types of squamous cell carcinoma and represents a significant proportion of esophageal cancer. Metabolic reprogramming plays a key role in the occurrence and development of ESCC. Unsupervised clustering analysis was employed to stratify ESCC samples into three clusters: MPC1-lipid type, MPC2-amino acid type, and MPC3-energy type, based on the enrichment scores of metabolic pathways extracted from the Reactome database. The MPC3 cluster exhibited characteristics of energy metabolism, with heightened glycolysis, cofactors, and nucleotide metabolism, showing a trend toward increased aggressiveness and poorer survival rates. On the other hand, MPC1 and MPC2 primarily involved lipid and amino acid metabolism, respectively. In addition, liquid chromatography‒mass spectrometry-based metabolite profiles and potential therapeutic agents were explored and compared among ESCC cell lines with different MPCs. MPC3 amplified energy metabolism markers, especially carnitines. In contrast, MPC1 and MPC2 predominantly had elevated levels of lipids (primarily triacylglycerol) and amino acids, respectively. Furthermore, MPC3 demonstrated a suboptimal clinical response to PD-L1 immunotherapy but showed increased sensitivity to the doramapimod chemotherapy regimen, as evident from drug sensitivity evaluations. These insights pave the way for a more personalized therapeutic approach, potentially enhancing treatment precision for ESCC patients.

Flavor Characteristics, Antioxidant Activity and In Vitro Digestion Properties of Bread with Large-Leaf Yellow Tea Powder.

Foods containing tea could be widely utilized due to the addition of good tea ingredients, especially large-leaf yellow tea, which is rich with a good flavor. Applying this change to bread containing tea would improve its product quality. In this research, large-leaf yellow tea bread (LYB), possessing a special flavor, was developed using ultrafine large-leaf yellow tea powder and flour as the main raw materials. The amount of ultrafine large-leaf yellow tea powder added to bread was optimized using texture, sensation, and specific volume as comprehensive evaluation indicators. At the optimal dosage, the free amino acids, volatile flavor compounds, antioxidant activity, and in vitro starch digestibility of LYB were measured. Response surface optimization experimental results showed that the comprehensive score of bread was highest when the added amount of ultrafine large-leaf yellow tea powder was 3%. In particular, compared to blank bread (BB), adding ultrafine large-leaf yellow tea powder into bread could effectively increase its amino acid composition, enhance its volatile flavor compounds, improve the antioxidant capacity, and reduce the digestibility of starch.

A Triggering Event of Central Retinal Artery Occlusion With Concurrent Ischemic Stroke.

We report a case of central retinal artery occlusion with concurrent ischemic stroke in a young patient. A 34-year-old Malay gentleman, an ex-smoker with underlying dyslipidemia, however, not on medication or follow-up, presented with acute, generalized, and painless right eye blurring of vision for one day. He also complained of on-and-off headaches for the past three months prior to the presentation. Visual acuity assessment demonstrated hand movement in the right eye, whereas in the left eye, it was 6/6, along with a right eye relative afferent pupillary defect. His right eye showed reduced optic nerve function and unremarkable anterior segment, with fundus examination revealing the presence of a cherry red spot, pale macula, boxcarring pattern over superior arcuate, and vascularized retina over inferior optic disc with blurred optic disc margin. The left eye examination was unremarkable. All cranial nerves were intact, except for the optic nerve. He was admitted to the ward. While in the ward, he developed a sudden onset of left-sided upper and lower limb weakness and numbness and was diagnosed with acute ischemic stroke. Blood investigations showed raised low-density lipoprotein cholesterol of 3.51 mmol/L, anti-nuclear antibody (ANA) positive, with electrocardiogram (ECG) sinus rhythm, and no atrial fibrillation. The echocardiogram was normal, and computed tomography angiography of the brain showed non-opacification at the origin and proximal part of the right ophthalmic artery, suspicious of thrombosis with distal reconstitution, with no evidence of thrombosis in the rest of neck and intracranial arteries. The patient was started on aspirin 150 mg once a day and atorvastatin 20 mg at night; subsequently, his vision improved slightly.