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To elucidate the significant influence of microorganisms on geographically dependent flavor formation by analyzing microbial communities and volatile flavor compounds (VFCs) in cigar tobacco leaves (CTLs) obtained from China, Dominica, and Indonesia. Microbiome analysis revealed that the predominant bacteria in CTLs were Staphylococcus, Aerococcus, Pseudomonas, and Lactobacillus, while the predominant fungi were Aspergillus, Wallemia, and Sampaiozyma. The microbial communities of CTLs from different origins differed to some extent, and the diversity and abundance of bacteria were greater than fungi. Metabolomic analysis revealed that 64 VFCs were identified, mainly ketones, of which 23 VFCs could be utilized to identify the geographical origins of CTLs. Sixteen VFCs with OAV greater than 1, including cedrol, phenylacetaldehyde, damascone, beta-damascone, and beta-ionone, play important roles in shaping the flavor profile of CTLs from different origins. Combined with the correlation analysis, bacterial microorganisms were more closely related to key VFCs and favored a positive correlation. Bacillus, Vibrio, and Sphingomonas were the main flavor-related bacteria. The study demonstrated that the predominant microorganisms were essential for the formation of key flavor qualities in CTLs, which provided a theoretical reference for flavor control of CTLs by microbial technology. KEY POINTS: ⢠It is the high OAV VFCs that determine the flavor profile of CTLs. ⢠The methylerythritol phosphate (MEP) pathway and the carotenoid synthesis pathway are key metabolic pathways for the formation of VFCs in CTLs. ⢠Microbial interactions influence tobacco flavor, with bacterial microorganisms contributing more to the flavor formation of CTLs.
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Bacillus , Produtos do Tabaco , Norisoprenoides , Correlação de Dados , NicotianaRESUMO
Variations in industrial fermentation techniques have a significant impact on the fermentation of cigar tobacco leaves (CTLs), consequently influencing the aromatic attributes of the resulting cigars. The entire fermentation process of CTLs can be categorized into three distinct phases: phase 1 (CTLs prior to moisture regain), phase 2 (CTLs post-moisture regain and pile fermentation), and phase 3 (CTLs after fermentation and drying). These phases were determined based on the dynamic changes in microbial community diversity. During phase 2, there was a rapid increase in moisture and total acid content, which facilitated the proliferation of Aerococcus, a bacterial genus capable of utilizing reducing sugars, malic acid, and citric acid present in tobacco leaves. In contrast, fungal microorganisms exhibited a relatively stable response to changes in moisture and total acid, with Aspergillus, Alternaria, and Cladosporium being the dominant fungal groups throughout the fermentation stages. Bacterial genera were found to be more closely associated with variations in volatile compounds during fermentation compared to fungal microorganisms. This association ultimately resulted in higher levels of aroma components in CTLs, thereby improving the overall quality of the cigars. These findings reinforce the significance of industrial fermentation in shaping CTL quality and provide valuable insights for future efforts in the artificial regulation of secondary fermentation in CTLs. KEY POINTS: ⢠Industrial fermentation processes impact CTLs microbial communities. ⢠Moisture and total acid content influence microbial community succession in fermentation. ⢠Bacterial microorganisms strongly influence CTLs' aldehyde and ketone flavors over fungi.
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Microbiota , Produtos do Tabaco , Fermentação , Nicotiana , AldeídosRESUMO
The toxic additives that leach from tire wear particles (TWPs) cause mass die-offs in fish and impact zooplankton as secondary consumers in the aquatic food web. In addition to the direct impacts of TWP leachate on a single generation, there may be potential delayed carryover effects across multiple generations from parental exposure, which may amplify the adverse effects of the leachate on individual reproduction and, consequently, on the entire population. In this study, the single, multiple, and transgenerational effects of TWP leachate at various concentrations on the reproduction and lifespan of the rotifer Brachionus calyciflorus were investigated. The results indicated that the lifespan and reproductive output of rotifers exposed to TWP leachate (0-1500 mg/L) decreased as the concentration increased above 250 mg/L. There was a clear multigenerational effect of TWP leachate on rotifer reproduction. The inhibition rates were consistently greater at 500 mg/L than at 250 mg/L leachate. Although the reproduction of rotifers exposed to 250 mg/L TWP leachate increased in the first two generations (P and F1), it was inhibited in subsequent generations. The inhibitory effect of 500 mg/L TWP leachate persisted across all generations, leading to population extinction by the F4 generation. A significant transgenerational effect of TWP leachate was found on reproduction. The adverse impact of exposure to 250 mg/L leachate for fewer than three generations could be reversed when offspring were transferred to clean media. However, this recovery was not observed after continuous exposure for more than four generations. Exposure to high-dose TWP leachate also caused irreversible damage to reproduction. Therefore, TWP leachate can result in cascading toxicity on zooplankton populations through carryover and cumulative effects on reproduction.
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Global warming is profoundly impacting snowmelt runoff processes in seasonal freeze-thaw zones, thereby altering the risk of rain-on-snow (ROS) floods. These changes not only affect the frequency of floods but also alter the allocation of water resources, which has implications for agriculture and other key economic sectors. While these risks present a significant threat to our lives and economies, the risk of ROS floods triggered by climate change has not received the attention it deserves. Therefore, we chose Changbai Mountain, a water tower in a high-latitude cold zone, as a typical study area. The semi-distributed hydrological model SWAT is coupled with CMIP6 meteorological data, and four shared socioeconomic pathways (SSP126, SSP245, SSP370, and SSP585) are selected after bias correction, thus quantifying the impacts of climate change on hydrological processes in the Changbai Mountain region as well as future evolution of the ROS flood risk. The results indicate that: (1) Under future climate change scenarios, snowmelt in most areas of the Changbai Mountains decreases. The annual average snowmelt under SSP126, SSP245, SSP370, and SSP585 is projected to be 148.65 mm, 135.63 mm, 123.44 mm, and 116.5 mm, respectively. The onset of snowmelt is projected to advance in the future. Specifically, in the Songhua River (SR) and Yalu River (YR) regions, the start of snowmelt is expected to advance by 1-11 days. Spatially, significant reductions in snowmelt were observed in both the central part of the watershed and the lower reaches of the river under SSP585 scenario. (2) In 2021-2060, the frequency of ROS floods decreases sequentially for different scenarios, with SSP 126 > SSP 245 > SSP 370 > SSP 585. The frequency increments of ROS floods in the source area for the four scenarios were 0.12 days/year, 0.1 d/yr, 0.13 days/year, and 0.15 days/year, respectively. The frequency of high-elevation ROS events increases in the YR in the low emission scenario. Conversely, in high emission scenarios, YR high-elevation ROS events will only increase in 2061-2100. This phenomenon is more pronounced in the Tumen River (TR), where floods become more frequent with increasing elevation.
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Altitude , Mudança Climática , Inundações , Chuva , Neve , HidrologiaRESUMO
In order to obtain long-lived charge separated (CS) states in electron donor-acceptor dyads, herein we prepared a series of anthraquinone (AQ)-phenothiazine (PTZ) dyads, with adamantane as the linker. UV-vis absorption spectra show negligible electronic interaction between the AQ and PTZ units at ground state, yet charge transfer (CT) emission bands were observed. Nanosecond transient absorption shows that the 3 AQ state is populated upon photoexcitation for AQ-PTZ in cyclohexane (CHX), but in acetonitrile (ACN) a 3 CS state is formed. Similar results were observed for AQ-PTZ-M. The 3 CS state lifetimes were determined as 0.52â µs and 0.49â µs, respectively. Upon oxidation of the PTZ unit, the 3 AQ state was observed in both polar and non-polar solvents. For AQ-PTZ, femtosecond transient absorption spectra show fast formation of the 3 AQ state in all solvents, with no charge separation in CHX, while formation of the 3 CS state takes 106â ps in ACN. For AQ-PTZ-M, a 3 CS state is formed in CHX within 241â ps. Time-resolved electron paramagnetic resonance (TREPR) spectra show that a radical ion pair with electron exchange energy of |2â J|≥5.68â mT was observed for AQ-PTZ and AQ-PTZ-M, whereas in the dyads with the PTZ unit oxidized, only the 3 AQ state was observed.
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Bispecific T cell engagers (TCEs) are an emerging anti-cancer modality that redirects cytotoxic T cells to tumor cells expressing tumor-associated antigens (TAAs), thereby forming immune synapses to exert anti-tumor effects. Designing pharmacokinetically acceptable TCEs and optimizing their size presents a considerable protein engineering challenge, particularly given the complexity of intercellular bridging between T cells and tumor cells. Therefore, a physiologically-relevant and clinically-verified computational modeling framework is of crucial importance to understand the protein engineering trade-offs. In this study, we developed a quantitative, physiologically-based computational framework to predict immune synapse formation for a variety of molecular formats of TCEs in tumor tissues. Our model incorporates a molecular size-dependent biodistribution using the two-pore theory, extravasation of T cells and hematologic cancer cells, mechanistic bispecific intercellular binding of TCEs, and competitive inhibitory interactions by shed targets. The biodistribution of TCEs was verified by positron emission tomography imaging of [89Zr]AMG211 (a carcinoembryonic antigen-targeting TCE) in patients. Parameter sensitivity analyses indicated that immune synapse formation was highly sensitive to TAA expression, degree of target shedding, and binding selectivity to tumor cell surface TAAs over shed targets. Notably, the model suggested a "sweet spot" for TCEs' CD3 binding affinity, which balanced the trapping of TCEs in T-cell-rich organs. The final model simulations indicated that the number of immune synapses is similar (~55/tumor cell) between two distinct clinical stage B cell maturation antigen (BCMA)-targeting TCEs, PF-06863135 in an IgG format and AMG420 in a BiTE format, at their respective efficacious doses in multiple myeloma patients. This result demonstrates the applicability of the developed computational modeling framework to molecular design optimization and clinical benchmarking for TCEs, thus suggesting that this framework can be applied to other targets to provide a quantitative means to facilitate model-informed best-in-class TCE discovery and development.
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Antígeno de Maturação de Linfócitos B , Mieloma Múltiplo , Linfócitos T , Anticorpos Monoclonais/uso terapêutico , Antígeno de Maturação de Linfócitos B/metabolismo , Antígeno de Maturação de Linfócitos B/uso terapêutico , Humanos , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/patologia , Radioisótopos/uso terapêutico , Distribuição Tecidual , Zircônio/uso terapêuticoRESUMO
An axially chiral indolyl-pyrroloindole scaffold, a new member of axially chiral indole-based scaffolds, has been designed, and the catalytic asymmetric construction of this scaffold has been established by the strategy of organocatalytic asymmetric (2 + 3) cycloaddition of 3,3'-bisindoles with isoindolinone-based propargylic alcohols. By this approach, a series of indolyl-pyrroloindole derivatives bearing both axial chirality and central chirality were synthesized in high yields with excellent diastereo- and enantioselectivities (up to 95% yield, 91:9 dr, 99% ee). This reaction not only realizes the first catalytic asymmetric (2 + n) cycloaddition of 3,3'-bisindoles as 1,2-dinucleophiles but also provides a new strategy for atroposelective construction of axially chiral indole-based scaffolds bearing five-five-membered rings, thus solving the challenges in constructing this class of axially chiral indole-based scaffolds.
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Indóis , Catálise , Reação de CicloadiçãoRESUMO
INTRODUCTION: Skin is exposed to a wide range of environmental risk factors including ultraviolet (UV) and all kinds of pollutants. Excessive UV exposure contributes to many disorders, such as photoaging, skin inflammation, and carcinogenesis. Previous studies have shown that Tremella fuciformis polysaccharides (TFPS) have protective effects on oxidative stress in cells, but the specific protective mechanism has not been clarified. METHODS: To determine the effects of TFPS on UV-irritated human skin, we conducted a variety of studies, including Cell Counting Kit-8 (CCK-8), trypan blue, Western blot, apoptosis assays, reactive oxygen species (ROS) detection in primary skin keratinocytes, and chronic UV-irradiated mouse model. RESULTS: We first determined that TFPS protects human skin keratinocytes against UV radiation-induced apoptosis and ROS production. Moreover, TFPS regulates thioredoxin interacting protein (TXNIP) and thioredoxin reductase 2 (TXNRD2) levels in primary skin keratinocytes for photoprotection. Last, we found that topical TFPS treatment could alleviate the UV-induced skin damage in chronic UV-irradiated mouse model. CONCLUSION: Collectively, our work indicates the beneficial role of TFPS in UV-induced skin cell damage and provides a novel therapeutic reagent to prevent or alleviate the progress of photoaging and other UV-provoked skin diseases.
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Pele , Tiorredoxina Redutase 2 , Animais , Humanos , Camundongos , Queratinócitos/metabolismo , Estresse Oxidativo , Polissacarídeos/farmacologia , Polissacarídeos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Tiorredoxina Redutase 2/metabolismo , Tiorredoxinas/metabolismo , Raios Ultravioleta/efeitos adversosRESUMO
The purpose of this paper was to explore the significance of basic transcription factor 3 (BTF3) in the process and clinicopathological parameters of gastric cancer (GC) patients. GC tissues were collected in our hospital to detect the mRNA expression of BTF3 by quantitative real-time polymerase chain reaction (Q-PCR). Western blot analysis was performed to detect the protein expression of BTF3. Kaplan-Meier method and Log-rank analysis were used to analyze the progression-free survival time and overall time of GC patients, while the Chi-square test was used to investigate the association between BTF3 and clinicopathological parameters of GC patients. SiRNA was designed to suppress the expression of BTF3. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay and transwell assay were conducted to determine the viability and invasion ability of GC cells. BTF3 was found abnormally up-regulated in GC tissues and cells and was related to the Grade, Lymph node metastasis and stage of GC patients, as well as the poor progression-free survival and overall survival of them. Besides, inhibition of BTF3 in GC cells could trigger the reduction of cell viability and invasion ability. Our results demonstrated that BTF3 played an important role in the process of GC and could be regarded as a new target for the diagnosis and therapy of GC.
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Neoplasias Gástricas , Fatores de Transcrição , Humanos , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Metástase Linfática , Prognóstico , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Neoplasias Gástricas/patologia , Fatores de Transcrição/metabolismoRESUMO
The relative position of the orchard robot to the rows of fruit trees is an important parameter for achieving autonomous navigation. The current methods for estimating the position parameters between rows of orchard robots obtain low parameter accuracy. To address this problem, this paper proposes a machine vision-based method for detecting the relative position of orchard robots and fruit tree rows. First, the fruit tree trunk is identified based on the improved YOLOv4 model; second, the camera coordinates of the tree trunk are calculated using the principle of binocular camera triangulation, and the ground projection coordinates of the tree trunk are obtained through coordinate conversion; finally, the midpoints of the projection coordinates of different sides are combined, the navigation path is obtained by linear fitting with the least squares method, and the position parameters of the orchard robot are obtained through calculation. The experimental results show that the average accuracy and average recall rate of the improved YOLOv4 model for fruit tree trunk detection are 5.92% and 7.91% higher, respectively, than those of the original YOLOv4 model. The average errors of heading angle and lateral deviation estimates obtained based on the method in this paper are 0.57° and 0.02 m. The method can accurately calculate heading angle and lateral deviation values at different positions between rows and provide a reference for the autonomous visual navigation of orchard robots.
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Siphonosoma australe, Phascolosoma arcuatum, and Sipunculus nudus are three important sipunculan species in tropical intertidal zones. In this study, the particle size, organic matter content, and bacterial community composition in the gut contents of three different sipunculans and their surrounding sediments were analyzed. The grain size fractions of sipunculans' guts were significantly different from those of their surrounding sediments; particle size fractions < 500 µm were favored by the sipunculans. As for the total organic matter (TOM), higher contents of organic matter were observed in the guts than in the surrounding sediments in all three sipunculan species. The bacterial community composition of all the samples was investigated by 16S rRNA gene sequencing, in which a total of 8974 OTUs were obtained from 24 samples based on a 97% threshold. The predominant phylum identified from the gut contents of three sipunculans was Planctomycetota, while the predominant phylum in their surrounding sediments was Proteobacteria. At the genus level, the most abundant genus was Sulfurovum (average 4.36%) in the surrounding sediments, while the most abundant genus was Gplla (average 12.76%) in the gut contents. The UPGMA tree showed that the samples from the guts of three different sipunculans and their surrounding sediments were clustered separately into two groups, which showed that these three sipunculans had a different bacterial community composition with their surrounding sediments. The grain size and total organic matter (TOM) had the greatest impacts on the bacterial community composition at both the phylum and genus levels. In conclusion, the differences in particle size fractions, organic matter content, and bacterial community composition between the gut contents and surrounding sediments in these three sipunculan species might be caused by their selective ingestion.
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Nematoides , Material Particulado , Animais , RNA Ribossômico 16S/genética , Sedimentos Geológicos , Nematoides/genética , Bactérias/genética , FilogeniaRESUMO
Quinolizidine alkaloids, as essential active ingredients extracted from Sophora alopecuroides Linn (SAL), have been proven to be pharmacologically active in a variety of cancers including non-small cell lung cancer (NSCLC). However, whether these alkaloids have substantial benefits in combination with immune checkpoint blockade (ICB) for the treatment of NSCLC is unknown. Here, we explore the potential of these alkaloids in combination with ICB therapy based on a systems pharmacology and bioinformatics approach. We found that 37 alkaloids in SAL have highly similar characteristics in the molecular skeleton, pharmacological properties, and targets. The expression of targets of these alkaloids are significantly correlated with the infiltration level of tumor infiltrating lymphocytes and the expression levels of multiple immune checkpoints in NSCLC. They share similar molecular mechanisms in antitumor immunity. Sophocarpine (Sop) is one of the most representative constituents of these alkaloids. We demonstrated that the Sop promotes PD-L1 expression to improve the effects of PD-L1 blockade treatment via the ADORA1-ATF3 axis. In conclusion, our study identified these alkaloids as promising candidates for the treatment of NSCLC, either alone or in combination with ICB, with potential value for drug development and may provide a promising strategy for improving the survival of NSCLC patients.
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Alcaloides , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Sophora , Alcaloides/farmacologia , Alcaloides/uso terapêutico , Antígeno B7-H1 , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Humanos , Inibidores de Checkpoint Imunológico , Neoplasias Pulmonares/tratamento farmacológico , Farmacologia em RedeRESUMO
A fire is usually considered a severe disturbance factor in the environment. Globally, rising temperatures and increasing human activities have intensified the severity and frequency of fire incidents, and research on post-fire recovery has inevitably become an important focus for ecologists. In terms of the restoration of burned areas, there are usually two primary approaches: natural recovery and assisted recovery. However, very few relevant studies have systematically compared these recovery alternatives, suggesting which one is more favorable to the overall restoration of an ecosystem, especially to the soil microbes that function as indispensable components of ecosystems. In this study, the restoration of soil nematode-trapping fungi (NTF) in natural and assisted recovery environments was compared. The results showed that although the NTF community structures differed among the sample sites, the counts and diversity of the NTF communities in the upper and lower soil layers in the natural recovery area were higher than those in the assisted recovery and unburned control areas. These findings suggest that artificial efforts to help ecosystem recovery after fire negatively affect the speed and quality of soil NTF community recovery. Instead, natural recovery appears to be a more suitable land management choice after fire disturbance.
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Incêndios , Nematoides , Animais , Ecossistema , Fungos , Humanos , Solo/químicaRESUMO
Chimeric antigen receptor (CAR) T cell therapies have revolutionized the treatment of hematologic malignancies and have potentials for solid tumor treatment. To overcome limited CAR T cell infiltration to solid tumors, local delivery of CAR T cells is a practical strategy that has shown promising therapeutic outcome and safety profile in the clinic. It is of great interest to understand the impact of dosing routes on CAR T cell distribution, subsequent proliferation and tumor killing in a quantitative manner to identify key factors that contribute to CAR T efficacy and safety. In this study, we established mouse minimal physiologically-based pharmacokinetic (mPBPK) models combined with pharmacodynamic (PD) components to delineate CAR T cell distribution, proliferation, tumor growth, and tumor cell killing in the cases of pleural and liver tumors. The pleural tumor model reasonably captured published CAR T cellular kinetic and tumor growth profiles in mice. The mPBPK-PD simulation of a liver tumor mouse model showed a substantial increase in initial tumor infiltration and earlier CAR T cell proliferation with local hepatic artery delivery compared to portal vein and intravenous (i.v.) injections whereas portal vein injection showed little difference from i.v. administration, suggesting the importance of having the injection site close to tumor for maximal effect of non-systemic administration. Blood flow rate in the liver tumor was found to be a sensitive parameter for cellular kinetics and efficacy, indicating a potential role of tumor vascularization in the efficacy of CAR T cell therapies.
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Neoplasias Hepáticas , Receptores de Antígenos Quiméricos , Animais , Proliferação de Células , Modelos Animais de Doenças , Imunoterapia Adotiva , Camundongos , Linfócitos TRESUMO
BACKGROUND: Sperm DNA is essential in embryo development. The sperm DNA fragmentation index (DFI), which reflects the degree of sperm DNA fragmentation (SDF), is a crucial biomarker in evaluating the sperm quality. However, whether SDF influences the clinical outcomes after in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) remains controversial. OBJECTIVE: This study aimed to investigate the relationship between sperm DNA SDF and clinical outcomes of vitrified-warmed single-blastocyst transfer cycles. MATERIALS AND METHODS: A total of 2034 vitrified-warmed single-blastocyst transfer cycles (536 from ICSI and 1498 from IVF) were included in this analysis. According to the sperm DFI, all cycles were divided into two groups (DFI < 27.3% group and DFI ≥ 27.3% group). The Mann-Whitney and chi-squared tests were used to compare patient characteristics and clinical outcomes between the two groups. Furthermore, logistic regression analysis was performed to analyze the association between SDF and clinical outcomes. RESULTS: The chi-squared test showed no differences in positive human chorionic gonadotropin (HCG) rate, clinical pregnancy rate, miscarriage rates, and live birth rate between the two groups. Logistic regression analysis indicated that SDF was not a prognostic predictor of positive HCG, clinical pregnancy, miscarriage, and live birth. CONCLUSION: SDF was not associated with clinical outcomes either in ICSI or IVF cycles during vitrified-warmed single-blastocyst transfer cycles.
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Aborto Espontâneo , Blastocisto , Gonadotropina Coriônica , DNA , Fragmentação do DNA , Transferência Embrionária , Feminino , Fertilização in vitro , Humanos , Masculino , Gravidez , Taxa de Gravidez , Estudos Retrospectivos , EspermatozoidesRESUMO
Invited for the cover of this issue is Qinghua Gong, Guowei Zhou, and co-workers at Qilu University of Technology. The dial represents the etching time of SiOx yolk in NaOH solution and the brightness of the Chinese red lantern represents the electrochemical performance of the composites. Read the full text of the article at 10.1002/chem.202003246.
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This work reports the preparation of unique hierarchical yolk/double-shelled SiOx @TiO2 @C nanospheres with different voids by a facile sol-gel method combined with carbon coating. In the preparation process, SiOx nanosphere is used as a hard template. Etch time of SiOx yolk affects the morphology and electrochemical performance of SiOx @TiO2 @C. With the increase in etch time, the yolk/double-shelled SiOx @TiO2 @C with 15 and 30â nm voids and the TiO2 @C hollow nanospheres are obtained. The yolk/double-shelled SiOx @TiO2 @C nanospheres exhibit remarkable lithium-ion battery performance as anodes, including high lithium storage capacity, outstanding rate capability, good reversibility, and stable long-term cycle life. The unique structure can accommodate the large volume change of the SiOx yolk, provide a unique buffering space for the discharge/charge processes, improve the structural stability of the electrode material during repeated Li+ intercalation/deintercalation processes, and enhance the cycling stability. The SiOx @TiO2 @C with 30â nm void space exhibits a high discharge specific capacity of ≈1195.4â mA h g-1 at the current density of 0.1â A g-1 after 300â cycles and ≈701.1â mA h g-1 at 1â A g-1 for over 800 cycles. These results suggest that the proposed particle architecture is promising and may have potential applications in improving various high performance anode materials.
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A base-promoted (4 + 2) cyclization of aza-o-quinone methides (aza-o-QMs) in situ generated from N-(o-chloromethyl)aryl amides was established. In this approach, azlactones were utilized as competent two-atom reaction partners to undergo (4 + 2) cyclization with aza-o-QMs, which afforded a series of dihydroquinolinone derivatives in overall good yields (up to 98%). This protocol has not only advanced the development of aza-o-QM-involved reactions, but also offered a useful method for constructing biologically important dihydroquinolinone frameworks.
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Amidas/química , Iminas/química , Lactonas/química , Quinolonas/síntese química , CiclizaçãoRESUMO
Atroposelective synthesis of axially chiral molecules has attracted substantial attention from chemists because of the importance of such molecules. However, catalytic asymmetric synthesis of axially chiral styrenes or vinyl arenes is underdeveloped and challenging due to the low rotational barrier and weak configurational stability of such molecules. Therefore, the development of powerful strategies for the catalytic atroposelective synthesis of axially chiral styrenes or vinyl arenes is of great importance. In this work, we have accomplished the first atroposelective access to oxindole-based axially chiral styrenes by the strategy of catalytic kinetic resolution, and this strategy offered two kinds of oxindole-based axially chiral styrene derivatives in good diastereoselectivities (up to 94:6 dr) and excellent enantioselectivities (up to 98% ee) with high selectivity factors (S up to 106). This strategy not only provides easy access to oxindole-based axially chiral styrenes but also offers a robust method for synthesizing bisamide derivatives bearing both axial and central chirality. More importantly, this strategy has added a new class of members to the atropisomeric family, especially to the family of axially chiral styrenes.
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Electrochemical CO2 reduction (ECR) to value-added chemicals and fuels is regarded as an effective strategy to mitigate climate change caused by CO2 from excess consumption of fossil fuels. To achieve CO2 conversion with high faradaic efficiency, low overpotential, and excellent product selectivity, rational design and synthesis of efficient electrocatalysts is of significant importance, which dominates the development of ECR field. Individual organic molecules or inorganic catalysts have encountered a bottleneck in performance improvement owing to their intrinsic shortcomings. Very recently, organic-inorganic hybrid nanomaterials as electrocatalysts have exhibited high performance and interesting reaction processes for ECR due to the integration of the advantages of both heterogeneous and homogeneous catalytic processes, attracting widespread interest. In this work, the recent advances in designing various organic-inorganic hybrid nanomaterials at the atomic and molecular level for ECR are systematically summarized. Particularly, the reaction mechanism and structure-performance relationship of organic-inorganic hybrid nanomaterials toward ECR are discussed in detail. Finally, the challenges and opportunities toward controlled synthesis of advanced electrocatalysts are proposed for paving the development of the ECR field.