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1.
Proc Natl Acad Sci U S A ; 119(39): e2202563119, 2022 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-36122234

RESUMO

Hundreds of members have been synthesized and versatile applications have been promised for endofullerenes (EFs) in the past 30 y. However, the formation mechanism of EFs is still a long-standing puzzle to chemists, especially the mechanism of embedding clusters into charged carbon cages. Here, based on synthesis and structures of two representative vanadium-scandium-carbido/carbide EFs, VSc2C@Ih (7)-C80 and VSc2C2@Ih (7)-C80, a reasonable mechanism-C1 implantation (a carbon atom is implanted into carbon cage)-is proposed to interpret the evolution from VSc2C carbido to VSc2C2 carbide cluster. Supported by theoretical calculations together with crystallographic characterization, the single electron on vanadium (V) in VSc2C@Ih (7)-C80 is proved to facilitate the C1 implantation. While the V=C double bond is identified for VSc2C@Ih (7)-C80, after C1 implantation the distance between V and C atoms in VSc2C2@Ih (7)-C80 falls into the range of single bond lengths as previously shown in typical V-based organometallic complexes. This work exemplifies in situ self-driven implantation of an outer carbon atom into a charged carbon cage, which is different from previous heterogeneous implantation of nonmetal atoms (Group-V or -VIII atoms) driven by high-energy ion bombardment or high-pressure offline, and the proposed C1 implantation mechanism represents a heretofore unknown metal-carbon cluster encapsulation mechanism and can be the fundamental basis for EF family genesis.

2.
Med Res Rev ; 44(6): 2624-2639, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38807483

RESUMO

Amorphous strategies have been extensively used in improving the dissolution of insoluble drugs for decades due to their high free energy. However, the formation of amorphous small-molecule gels (ASMGs) presents a counter-intuitive discovery that significantly limits their practical application. Recently, ASMGs have garnered attention because of their noncovalent structures, excellent biodegradability, and significant potential in various drug delivery systems in the pharmaceutical field. Hence, a comprehensive review is necessary to contribute to a better understanding of recent advances in ASMGs. This review aimed to introduce the main formation mechanisms, summarize possible influencing factors, generalize unique properties, outline elimination strategies, and discuss clinical application potential with preclinical cases of ASMGs. Moreover, few ASMGs are advanced to clinical stages. Intensive clinical research is needed for further development. We hope that this review can provide more efficient and rational guidance for exploring further clinical applications of ASMGs.


Assuntos
Géis , Solubilidade , Água , Géis/química , Humanos , Água/química , Preparações Farmacêuticas/química , Composição de Medicamentos , Animais , Sistemas de Liberação de Medicamentos , Química Farmacêutica , Descoberta de Drogas
3.
Environ Sci Technol ; 58(9): 4281-4290, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38391182

RESUMO

Particulate brown carbon (BrC) plays a crucial role in the global radiative balance due to its ability to absorb light. However, the effect of molecular formation on the light absorption properties of BrC remains poorly understood. In this study, atmospheric BrC samples collected from six Chinese megacities in winter and summer were characterized through ultrahigh-performance liquid chromatography coupled with Orbitrap mass spectrometry (UHPLC-Orbitrap MS) and light absorption measurements. The average values of BrC light absorption coefficient at a wavelength of 365 nm (babs365) in winter were approximately 4.0 times higher than those in summer. Nitrogen-containing organic molecules (CHNO) were identified as critical components of light-absorbing substances in both seasons, underscoring the importance of N-addition in BrC. These nitrogen-containing BrC chromophores were more closely related to nitro-containing compounds originating from biomass burning and nitrogen oxides (NOx)/nitrate (NO3-) reactions in winter. In summer, they were related to reduced N-containing compounds formed in ammonia (NH3)/ammonium (NH4+) reactions. The NH3/NH4+-mediated reactions contributed more to secondary BrC in summer than winter, particularly in southern cities. Compared with winter, the higher O/Cw, lower molecule conjugation indicator (double bond equivalent, DBE), and reduced BrC babs365 in summer suggest a possible bleaching mechanism during the oxidation process. These findings strengthen the connection between molecular composition and the light-absorbing properties of BrC, providing insights into the formation mechanisms of BrC chromophores across northern and southern Chinese cities in different seasons.


Assuntos
Poluentes Atmosféricos , Carbono , Cidades , Nitrogênio/análise , Aerossóis/análise , Carvão Mineral/análise , Nitrocompostos , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Material Particulado/análise
4.
Environ Sci Technol ; 58(36): 16006-16015, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39051771

RESUMO

Ship emissions are a significant source of air pollution, and the primary policy to control is fuel oil quality improvement. However, the impact of this policy on particle size distribution and composition characteristics remains unclear. Measurements were conducted on nine different vessels (ocean-going vessels, coastal cargo ships, and inland cargo ships) to determine the impact of fuel upgrading (S < 0.1% m/m marine gas oil (MGO) vs S < 0.5% m/m heavy fuel oil (HFO)) on elemental carbon (EC) and polycyclic aromatic hydrocarbons (PAHs) emitted by ships. (1) Fuel improvement significantly reduced EC and PAH emission, by 31 ± 25 and 45 ± 38%, respectively. However, particle size distributions showed a trend toward finer particles, with the peak size decreasing from DP = 0.38-0.60 µm (HFO) to DP = 0.15-0.25 µm (MGO), and the emission factor of DP < 100 nm increased. (2) Changes in emission characteristics led to an increase in the toxicity of ultrafine particulate matter. (3) Ship types and engine conditions affected the EC and PAH particle size distributions. Inland ships have a more concentrated particle size distribution. Higher loads result in higher emissions. (4) The composition and engine conditions of fuel oils jointly affected pollutant formation mechanisms. MGO and HFO exhibited opposite EC emissions when emitting the same level of PAHs.


Assuntos
Carbono , Óleos Combustíveis , Tamanho da Partícula , Hidrocarbonetos Policíclicos Aromáticos , Navios , Material Particulado , Poluentes Atmosféricos , Emissões de Veículos , Poluição do Ar
5.
Environ Sci Technol ; 2024 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-39096310

RESUMO

Polyhalogenated dibenzo-p-dioxins/dibenzofurans (PXDD/Fs) are commonly released into the environment as byproducts of combustion processes, accompanied by flue gases. Chlorinated (Cl) and brominated (Br) precursors play crucial roles in forming PXDD/Fs. However, the specific contributions of Cl-precursors and Br-precursors to PXDD/Fs formation have not been fully elucidated. Herein, we demonstrate that the formation of Br-precursors can increase the fraction of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) congeners substituted at specific positions, such as 1,2,3,4,6,7,8-HpCDD, OCDD, 2,3,4,7,8-PeCDF, and 2,3,4,6,7,8-HxCDF. This is attributed to the electrophilic chlorination reaction of the Br-precursors, which includes the Br-to-Cl transformation pathway, following the principle of regioselectivity. The observed formation of polybrominated/chlorinated dibenzo-p-dioxins/benzofurans (PBCDD/Fs) from 1,2-dibromobenzene (1,2-DiBBz) as a Br precursor provides direct evidence supporting the proposed Br-to-Cl transformation. Quantum chemical calculations are employed to discuss the principle of regioselectivity in the Br-to-Cl transformation, clarifying the priority of the position for electrophilic chlorination. Additionally, the concentration of PCDD/Fs formed from 1,2-DiBBz is 1.6 µg/kg, comparable to that of polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) (2.4 µg/kg), highlighting the potential of brominated organic pollutants as precursors for PCDD/Fs formation. This study provides three potential pathways for PCDD/Fs formation from Br-precursors, establishing a theoretical foundation for elucidating the formation mechanism of PXDD/Fs in the coexistence of Cl and Br.

6.
Nano Lett ; 23(4): 1289-1297, 2023 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-36749085

RESUMO

Ceramic nanofibrous nanostructure-based sponges have attracted significant attention due to ultrahigh porosity, low thermal conductivity, large specific area, and chemical stability. From the regulation of the fiber itself to the construction method of 3D networks, efforts are being made to improve the mechanical properties of ceramic sponges for practical applications. So far resilient compressibility has been realized in ceramic nanofibrous-based sponges via structural design, but they still show brittle fracture under a more complex stress state. Herein, we introduced a highly aligned and interwoven Si3N4 nanofiber sponge, which exhibits superflexibility, large break elongation (>80%), large-strain reversible stretch (20%), and good resistance to tensile fatigue. The ceramic sponge also displays reversible compressibility up to 60% strain, puncture resistance, high air filtration efficiency (>99.8%), and low pressure drop (38% of cotton fiber), making the ceramic sponge a high-performance wearable respirator to protect us from harm due to PM2.5 pollution and possible microorganisms.

7.
Aesthetic Plast Surg ; 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38727847

RESUMO

BACKGROUND: The mechanism underlying the formation of upper eyelid creases has been the subject of extensive study and ongoing debate. This research aims to elucidate the principles of upper eyelid creases formation, leveraging the membrane bending theory from engineering mechanics. METHODS: We developed an anatomical model of the eyelid and implemented the finite element analysis. Preprocessing and mesh division were conducted using HyperMesh, followed by computational analysis with Abaqus. This approach enabled the observation of dynamic changes in the upper eyelid during eye opening and closing. RESULTS: The study reveals that natural upper eyelid crease formation is influenced by multiple factors. These include the softer texture of the upper eyelid skin and the suborbicularis oculi fat, reduced rigidity at the eyelid crease, optimal contraction force of the upper eyelid, and the strategic placement of the pre-tarsal fat pad just above the eyelid crease. CONCLUSIONS: Ultimately, our findings demonstrate the effectiveness of finite element analysis, grounded in membrane bending theory, in elucidating the dynamics of upper eyelid crease formation. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors   www.springer.com/00266 .

8.
J Environ Manage ; 366: 121925, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39029167

RESUMO

The construction and operation of the construction and demolition waste (C&DW) landfills often encounter significant opposition from nearby residents, which is called the "not in my backyard" (NIMBY) effect. However, little is known about the formation mechanism of the NIMBY effect in C&DW landfilling, so this research was conducted for this purpose. First, the influencing factors leading to the NIMBY effect were determined based on a literature review and questionnaire survey. Then, the interrelationship and influencing path of critical factors were revealed using expert interviews and Interpretative Structural Modelling. The results shown that 12 factors from four levels (including residents, society, government, and enterprises) caused the NIMBY effect in C&DW landfilling. These factors formed a complex network comprising 18 influencing paths. Notably, policy and responding measures as pivotal bottom-level factors that trigger the NIMBY effect by indirectly impacting residents' rights awareness and shaping public perception towards C&DW landfill operation enterprises through directly affecting personal interest, cognitive bias, distrust, disposal technology, management level, opinion leader, and other intermediate factors, ultimately triggering the NIMBY effect. Moreover, strategies for mitigating or resolving the NIMBY effect were proposed, such as protecting personal reasonable interests, understanding the potential risks of C&DW landfills rationally, reporting the C&DW landfills from an objective perspective, improving policies and promoting public participation, and enhancing supervision of the C&DW landfills. The study added new knowledge to the current public's NIMBY effect in C&DW landfilling. Meanwhile, it also provided a reference for formulating C&DW landfilling policies and selecting landfill sites.


Assuntos
Eliminação de Resíduos , Instalações de Eliminação de Resíduos , Gerenciamento de Resíduos , Gerenciamento de Resíduos/métodos , Inquéritos e Questionários , Humanos
9.
Molecules ; 29(15)2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39124863

RESUMO

Hexagonal boron nitride (h-BN) nanoparticles have attracted increasing attention due to their unique structure and properties. However, it is difficult to synthesize h-BN nanoparticles with uniform spherical morphology due to their crystal characteristic. The morphology control by tuning their precursor synthesis is a promising and effective strategy to solve this problem. Especially, the treatment temperature of precursors plays an important role in the morphology and surface area of h-BN nanoparticles. Herein, h-BN nanoparticles with different morphologies were synthesized via regulating the treatment temperature of precursors. The result shows that treatment temperature will affect the microstructure and state of precursor and further influence the morphology of h-BN products. Benefiting from the unique structure, the h-BN obtained using 250 °C precursors shows higher specific surface area (61.1 m2 g-1) than that of 85 °C (36.5 m2 g-1) and 145 °C (27.9 m2 g-1). h-BN products obtained using 250 °C precursors show higher specific surface area than that of 85 °C and 145 °C. The optimal condition for obtaining high-quality spherical h-BN is the pretreatment temperature of 250 °C and sintering temperature of 1300 °C. Importantly, compared with commercial h-BN nanoparticles, the synthesized h-BN nanoparticles show more uniform structure and larger specific surface area, indicating that sintering activity will be greatly improved. Furthermore, the reaction pathway and formation mechanism of h-BN was revealed by DFT calculations. The result shows that the five stationary states and five transition states exist in the reaction pathway, and the energy barrier can be overcome at high temperatures to form a ring h-BN. In view of its simplicity and efficiency, this work is promising for designing and guiding the synthesis of h-BN nanoparticles with uniform morphology.

10.
J Sci Food Agric ; 104(11): 6584-6593, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-38521988

RESUMO

BACKGROUND: The biological functions of ferulic acid (FA) have garnered significant interest but its limited solubility and stability have led to low bioavailability. Hydroxypropyl-ß-cyclodextrin (HP-ß-CD), with its distinctive hollow structure, offers the potential for encapsulating hydrophobic molecules. The formation of an inclusion complex between FA and HP-ß-CD may therefore be a viable approach to address the inherent limitations of FA. To investigate the underlying mechanism of the FA/HP-ß-CD inclusion complex formation, a combination of spectral analyses and computer simulation was employed. RESULTS: The disappearance of the characteristic peaks of FA in Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) confirmed the formation of an inclusion complex between FA and HP-ß-CD. Thermogravimetry-derivative thermogravimetry (TG-DTG) studies demonstrated that the thermal stability of FA was enhanced due to the encapsulation of FA within HP-ß-CD. Molecular dynamics simulation also provided evidence that FA successfully penetrated the HP-ß-CD cavity, primarily driven by van der Waals interactions. The formation of the complex resulted in more compact HP-ß-CD structures. The bioavailability of FA was also strengthened through the formation of inclusion complexes with HP-ß-CD. CONCLUSIONS: The findings of this study have contributed to a deeper understanding of the interactions between FA and HP-ß-CD, potentially advancing a delivery system for FA and enhancing the bioavailability of insoluble active components. © 2024 Society of Chemical Industry.


Assuntos
2-Hidroxipropil-beta-Ciclodextrina , Disponibilidade Biológica , Simulação por Computador , Ácidos Cumáricos , Solubilidade , Ácidos Cumáricos/química , 2-Hidroxipropil-beta-Ciclodextrina/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X , Simulação de Dinâmica Molecular , Interações Hidrofóbicas e Hidrofílicas , Termogravimetria
11.
Yi Chuan ; 46(8): 627-639, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39140143

RESUMO

Heterosis is the phenomenon that the hybrid offspring outperform two-parent population. Hybridisation has been widely used in plant and animal production as it effectively improves the growth and developmental performance, reproductive performance and disease resistance of the offspring. Hybridization can effectively improve the growth and development performance, reproductive performance and disease resistance of offspring, so it is widely used in animal and plant production. Researchers have used cross-breeding techniques to cultivate excellent new agricultural and animal husbandry strains and supporting lines such as super-excellent Chaoyou 1000 hybrid rice, Xiaoyan No.6 hybrid wheat, Dumeng sheep, and Shanxia black pigs. However, there are still some urgent problems in the current hybrid dominance research: the existing hybrid dominance theory can only partially explain the phenomenon of plant and animal hybrid dominance, and the theory of animal hybrid dominance is less researched, and the accuracy of the existing hybrid dominance prediction methods is limited. China is the world's largest pork production and consumption country. Heterosis can effectively improve the production performance of pigs, and its application in the pig industry has important economic and research value. However, the existing research on pig hybrid production is in its infancy and needs to be further studied. In this review, we summarize the existing heterosis theory, heterosis prediction methods, and their application in pig production, to provide a reference for the application of heterosis in pig breeding.


Assuntos
Vigor Híbrido , Animais , Suínos/genética , Hibridização Genética , Criação de Animais Domésticos/métodos , Cruzamento/métodos
12.
Zhonghua Nan Ke Xue ; 30(6): 493-498, 2024 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-39212357

RESUMO

OBJECTIVE: To comprehensively analyze the numbers of involved chromosomes and breakpoints and the clinical phenotypes of the patients with complex chromosome rearrangement (CCR). METHODS: We selected 23 745 patients with abnormal fertility seeking medical care in the Center of Reproductive Medicine of Peking University Third Hospital from 2011 to 2015, and analyzed their peripheral blood chromosomal karyotypes using G-banding, C-banding and fluorescence in situ hybridization (FISH). RESULTS: A total of 28 CCR carriers (0.118%) were detected among the 23 745 patients with abnormal fertility, including 18 males mainly with azoospermia or oligoasthenospermia and 10 females mainly with infertility, recurrent abortion, embryo termination and abnormal birth. Of the 28 cases of CCR, tripartite rearrangement was found in 9 (32.14%), double translocation in 7 (25%) and special translocation in 12 (42.86%). CCR carrier-related chromosomes were all involved but chromosomes 12 and 19, while 2 and 5 were involved most frequently. CONCLUSION: At present, the incidence of CCR is low. CCR carriers with normal phenotypes are often found because of reproductive problems, and their low chance of having a normal baby necessitates the use of preimplantation genetic test to improve the rate of live birth. Due to the diversity of the chromosomes and breakpoints involved in CCR, it is crucial to give each CCR carrier precise genetic counseling.


Assuntos
Hibridização in Situ Fluorescente , Translocação Genética , Humanos , Masculino , Feminino , Aberrações Cromossômicas , Cariotipagem , Adulto , Bandeamento Cromossômico , Azoospermia/genética , Testes Genéticos , Fenótipo , Heterozigoto , Infertilidade/genética
13.
Angew Chem Int Ed Engl ; : e202410519, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39090074

RESUMO

Carbon dots (CDs), as a kind of zero-dimensional nanomaterials, have been widely synthesized by bottom-up methods from various precursors. However, the formation mechanism is still unclear and controversial, which also brings difficulty to the regulation of structures and properties. Only some tentative formation processes were postulated by analyzing the products obtained at different reaction times and temperatures. Here, the effect of crosslinking on the formation of carbonized polymer dots (CPDs) is explored. Crosslinking-induced nucleation and carbonization (CINC) is proposed as the driving force for the formation of CPDs. Under hydrothermal synthesis, the precursors are initiated to polymerize and crosslink. The crosslinking brings higher hydrophobicity to generate the hydrophilic/hydrophobic microphase separation, which promotes dehydration and carbonization resulting in the formation of CPDs. Based on the principle of CINC, the influence factors of size are also revealed. Moreover, the dissipative particle dynamics (DPD) simulation is employed to support this formation mechanism. This concept of CINC will bring light to the formation process of CPDs, as well as facilitate the regulation of CPDs' size and photoluminescence.

14.
Angew Chem Int Ed Engl ; 63(28): e202406535, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38652809

RESUMO

Borophenes have sparked considerable interest owing to their fascinating physical characteristics and diverse polymorphism. However, borophene nanoribbons (BNRs) with widths less than 2 nm have not been achieved. Herein, we report the experimental realization of supernarrow BNRs. Combining scanning tunneling microscopy imaging with density functional theory modeling and ab initio molecular dynamics simulations, we demonstrate that, under the applied growth conditions, boron atoms can penetrate the outermost layer of Au(111) and form BNRs composed of a pair of zigzag (2,2) boron rows. The BNRs have a width self-contained to ∼1 nm and dipoles at the edges to keep them separated. They are embedded in the outermost Au layer and shielded on top by the evacuated Au atoms, free of the need for post-passivation. Scanning tunneling spectroscopy reveals distinct edge states, primarily attributed to the localized spin at the BNRs' zigzag edges. This work adds a new member to the boron material family and introduces a new physical feature to borophenes.

15.
BMC Plant Biol ; 23(1): 307, 2023 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-37291504

RESUMO

BACKGROUND: Lavender (genus Lavandula, family Lamiaceae) is an aromatic plant widely grown as an ornamental plant. The chemical composition of lavender is characterized by monoterpenoids, sesquiterpenoids, and other compounds, which are primarily synthesized and stored in epidermal secretory structures called glandular trichomes (GTs). Volatile organic compounds (VOCs) are responsible for the aroma characteristics of plant oil that drive consumer preference. Aroma is usually regarded as a characteristic trait for the classification of aromatic plants. Interestingly, VOCs are synthesized and stored in GTs. Lamiaceae species such as purple perilla, peppermint, basil, thyme, and oregano usually possess two types of GTs: peltate glandular trichomes (PGTs) and capitate glandular trichomes (CGTs). But the development process of PGTs in lavender has been reported in only a few studies to date. RESULTS: In this study, we identified and quantified the VOCs in four lavender cultivars by headspace-solid phase micro extraction-gas chromatography mass spectrometry (HS-SPME-GC-MS). A total of 66 VOCs were identified in these four cultivars, the most prominent of which were linalyl acetate and linalool, and flowers were the main site of accumulation of these VOCs. Here, we examined the developmental process of PGTs, including the formation of their base, body, and apex. The apex cells contained secretory cavities, which produced VOCs. Based on the reference genome sequence of the lavender cultivar 'Jingxun 2', several R2R3-MYB subfamily genes related to GT formation were identified. These results will guide the engineering of GTs and molecular breeding of lavender for improving the VOC content. CONCLUSIONS: In this study, we identified the VOCs in four lavender cultivars. We analyzed the formation of GTs, and compared the number and diameter size of PGTs among four lavender cultivars. Additionally, we identified four candidate genes belonging to the R2R3-MYB family.


Assuntos
Lavandula , Óleos Voláteis , Terpenos , Lavandula/genética , Óleos Voláteis/análise , Tricomas/química , Óleos de Plantas/química
16.
Small ; 19(28): e2301095, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36978248

RESUMO

Low-dimensional sulfur nanomaterials featuring with 0D sulfur nanoparticles (SNPs), sulfur nanodots (SNDs) and sulfur quantum dots (SQDs), 1D sulfur nanorods (SNRs), and 2D sulfur nanosheets (SNSs) have emerged as an environmentally friendly, biocompatible class of metal-free nanomaterials, sparking extensive interest in a wide range application. In this review, various synthetic methods, precise characterization, creative formation mechanism, delicate functionalization, and versatile applications of low dimensional sulfur nanomaterials over the last decades are systematically summarized. Initially, it is striven to summarize the progress of low dimensional sulfur nanomaterials from versatile precursors by using different synthetic approaches and various characterization. Then, a multi-faceted proposed formation mechanism with emphasis on how these different precursors produce corresponding SNPs, SNDs, SQDs, SNRs, and SNSs is highlighted. Besides, it is essential to fine-tune the surface functional groups of low dimensional sulfur nanomaterials to form new complex nanomaterials. Finally, these sulfur nanomaterials are being investigated in bio-sensing, bio-imaging, lithium-sulfur batteries, antibacterial activities, plant growth along with future perspective and challenges in emerging fields. The purpose of this review is to tailor low dimensional nanomaterials through accurately selecting precursors or synthetic approach and provide a foundation for the formation of versatile sulfur nanostructure.

17.
Small ; 19(15): e2207202, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36683197

RESUMO

As an important multiferroic material, pure and low-dimensional phase-stable bismuth ferrite has wide applications. Herein, one-pot hydrothermal method was used to synthesize bismuth ferrite. Almost pure Bi2 Fe4 O9 , BiFeO3 , and their mixture were successfully obtained by controlling the KOH concentration in the hydrothermal solutions. The as-prepared Bi2 Fe4 O9 products were crystalline with Pbam space group, had nanosheet morphology, and tended to aggregate into nanofloret or random stacking. Each Bi2 Fe4 O9 nanosheet was a single crystal with (001) plane as its exposed surface. Single unit-cell layered Bi2 Fe4 O9 nanosheets had a uniform thickness of 1 nm. The surface energies of various (100), (010), and (001) planes were 3.6-4.0, 5.6-15.1, and 1.7-3.0 J m-2 , respectively, in the Bi2 Fe4 O9 crystal. The formation mechanism and structural model of the as-prepared single unit-cell layered Bi2 Fe4 O9 nanosheets have been given. The growth of Bi2 Fe4 O9 nanosheets was discussed. Thermal analysis showed that the Bi2 Fe4 O9 phase was stable up to 1260 K. The thermal expansion behavior of the Bi2 Fe4 O9 nanosheet was nonlinear. The thermal expansion coefficients of the ultrathin Bi2 Fe4 O9 nanosheets on the a-, b-, c-axes, and on the unit-cell volume V were determined, showing an anisotropic thermal expansion behavior. This study is helpful for the controllable synthesis of ultrathin Bi2 Fe4 O9 nanosheets.

18.
Crit Rev Food Sci Nutr ; : 1-17, 2023 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-37068005

RESUMO

Fermented foods are important components of the human diet. There is increasing awareness of abundant nutritional and functional properties present in fermented foods that arise from the transformation of substrates by microbial communities. Thus, it is significant to unravel the microbial communities and mechanisms of characteristic flavor formation occurring during fermentation. There has been rapid development of high-throughput and other omics technologies, such as metaproteomics and metabolomics, and as a result, there is growing recognition of the importance of integrating these approaches. The successful applications of multi-omics approaches and bioinformatics analyses have provided a solid foundation for exploring the fermentation process. Compared with single-omics, multi-omics analyses more accurately delineate microbial and molecular features, thus they are more apt to reveal the mechanisms of fermentation. This review introduces fermented foods and an overview of single-omics technologies - including metagenomics, metatranscriptomics, metaproteomics, and metabolomics. We also discuss integrated multi-omics and bioinformatic analyses and their role in recent research progress related to fermented foods, as well as summarize the main potential pathways involved in certain fermented foods. In the future, multilayered analyses of multi-omics data should be conducted to enable better understanding of flavor formation mechanisms in fermented foods.

19.
Crit Rev Food Sci Nutr ; : 1-23, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36919601

RESUMO

Seed mucilages are potential sources of natural polysaccharides. They are biodegradable, biocompatible, sustainable, renewable, and safe for human consumption. Due to the desirable physicochemical and functional properties (e.g. gelling, thickening, stabilizing, and emulsifying), seed mucilages have attracted extensive attention from researchers for utilization as a promising material for the development of advanced carrier systems. Seed mucilages have been utilized as natural polymers to improve the properties of various carrier systems (e.g. complex coacervates, beads, nanofibers, and gels) and for the delivery of diverse hydrophilic and lipophilic compounds (e.g. vitamins, essential oils, antioxidants, probiotics, and antimicrobial agents) to achieve enhanced stability, bioavailability, bioactivity of the encapsulated molecules, and improved quality attributes of food products. This review highlights the recent progress in seed mucilage-based carrier systems for food and nutraceutical applications. The main contents include (1) sources, extraction methods, and physicochemical and functional characteristics of seed mucilages, (2) application of seed mucilages for the development of advanced carrier systems, (3) major issues associated with carrier fabrication, and (4) mechanisms of carrier development, latest improvements in carrier formulation, carrier efficiency in the delivery of bioactive agents, and application in food and nutraceuticals. Furthermore, major challenges and future perspectives of seed mucilage-based carriers for a commercial application are discussed.

20.
Environ Sci Technol ; 57(4): 1646-1657, 2023 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-36681930

RESUMO

Chlorinated organic chemicals are produced and used extensively worldwide, and their risks to the biology and environment are of increasing concern. However, chlorinated byproducts [e.g., polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs)] formed during the commercial manufacturing processes and present in organochlorine products are rarely reported. The knowledge on the occurrences and fate of unintentional persistent organic chemicals in the manufacturing of organochlorine chemical is necessary for accurate assessment of the risks of commercial chemicals and their production. Here, PCDD/Fs were tracked throughout chlorobenzene and chloroethylene production processes (from raw materials to final products) by target analysis. Other byproducts that can further transform into PCDD/Fs were also identified by performing non-target screening. As a result, the PCDD/F concentrations were mostly the highest in bottom residues, and the octachlorinated congeners were dominant. Alkali/water washing stages may cause the formation of oxygen-containing byproducts including PCDD/Fs and acyl-containing compounds, so more attention should be paid to these stages. PCDD/Fs were of 0.17 and 0.21-1.2 ng/mL in monochlorobenzene and chloroethylene products, respectively. Annual PCDD/F emissions (17 g toxic equivalent in 2018) during chlorobenzene and chloroethylene production were estimated using PCDD/F emission factors. The results can contribute to the improvement of PCDD/F inventories for the analyzed commercial chemicals.


Assuntos
Dibenzodioxinas Policloradas , Cloreto de Vinil , Dibenzofuranos/análise , Cloreto de Vinil/análise , Dibenzofuranos Policlorados/análise , Dibenzofuranos Policlorados/química , Monitoramento Ambiental , Clorobenzenos
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