Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 550
Filtrar
1.
PLoS One ; 19(4): e0295335, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38635824

RESUMO

The corn planthopper, Peregrinus maidis, is an economically important pest of corn and sorghum. Here we report the initial steps towards developing a CRISPR-based control method, precision guided sterile insect technique (pgSIT), for this hemipteran pest. Specifically, we evaluated the potential of transformer-2 (tra-2) as a target for sterilizing insects. First, we identified tra-2 transcripts within our P. maidis transcriptome database and performed RNA interference (RNAi) to confirm functional conservation. RNAi-mediated knockdown of Pmtra-2 in nymphs transformed females into pseudomales with deformed ovipositors resembling male claspers. While males showed no overt difference in appearance, they were indeed sterile. Importantly, the results were similar to those observed in another planthopper, Nilaparvata lugens. We also used CRISPR/Cas9 genome editing to assess the impact of tra-2 knockout in injectees. CRISPR-mediated knockout of Pmtra-2 had lethal effects on embryos, and hence not many injectees reached adulthood. However, mosaic knockout of Pmtra-2 did impact female and male fertility, which supports the use of tra-2 as a target for pgSIT in this hemipteran species.


Assuntos
Hemípteros , Feminino , Masculino , Animais , Interferência de RNA , Hemípteros/genética , Edição de Genes , Ninfa
2.
Org Lett ; 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38639551

RESUMO

A formal [3 + 2] annulation of cyclohexadienone-tethered ynals is enabled by an N-heterocyclic carbene (NHC) catalyst, affording a tricyclo[6.2.1.04,11]undecane framework. This study represents the first demonstration of using C═C double bonds as the reaction partner in the NHC-catalyzed annulation of ynals. This strategy is characterized by mild reaction conditions and 100% atom economy as well as high catalytic performance and efficiency.

3.
Food Chem ; 450: 139392, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38640546

RESUMO

The combinational effects of kojic acid and lauroyl arginine ethyl ester hydrochloride (ELAH) on fresh-cut potatoes were investigated. Kojic acid of 0.6% (w/w) effectively inhibited the browning of fresh-cut potatoes and displayed antimicrobial capacity. The color difference value of samples was decreased from 175 to 26 by kojic acid. In contrast, ELAH could not effectively bind with the active sites of tyrosinase and catechol oxidase at molecular level. Although 0.5% (w/w) of ELAH prominently inhibited the microbial growth, it promoted the browning of samples. However, combining kojic acid and ELAH effectively inhibited the browning of samples and microbial growth during the storage and the color difference value of samples was decreased to 52. This amount of kojic acid inhibited enzyme activities toward phenolic compounds. The results indicated that combination of kojic acid and ELAH could provide a potential strategy to extend the shelf life of fresh-cut products.

4.
Theor Appl Genet ; 137(5): 105, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38622387

RESUMO

KEY MESSAGE: Two major-effect QTL GlcA07.1 and GlcA09.1 for green leaf color were fine mapped into 170.25 kb and 191.41 kb intervals on chromosomes A07 and A09, respectively, and were validated by transcriptome analysis. Non-heading Chinese cabbage (NHCC) is a leafy vegetable with a wide range of green colors. Understanding the genetic mechanism behind broad spectrum of green may facilitate the breeding of high-quality NHCC. Here, we used F2 and F7:8 recombination inbred line (RIL) population from a cross between Wutacai (dark-green) and Erqing (lime-green) to undertake the genetic analysis and quantitative trait locus (QTL) mapping in NHCC. The genetic investigation of the F2 population revealed that the variation of green leaf color was controlled by two recessive genes. Six pigments associated with green leaf color, including total chlorophyll, chlorophyll a, chlorophyll b, total carotenoids, lutein, and carotene were quantified and applied for QTL mapping in the RIL population. A total of 7 QTL were detected across the whole genome. Among them, two major-effect QTL were mapped on chromosomes A07 (GlcA07.1) and A09 (GlcA09.1) corresponding to two QTL identified in the F2 population. The QTL GlcA07.1 and GlcA09.1 were further fine mapped into 170.25 kb and 191.41 kb genomic regions, respectively. By comparing gene expression level and gene annotation, BraC07g023810 and BraC07g023970 were proposed as the best candidates for GlcA07.1, while BraC09g052220 and BraC09g052270 were suggested for GlcA09.1. Two InDel molecular markers (GlcA07.1-BcGUN4 and GlcA09.1-BcSG1) associated with BraC07gA023810 and BraC09g052220 were developed and could effectively identify leaf color in natural NHCC accessions, suggesting their potential for marker-assisted leaf color selection in NHCC breeding.


Assuntos
Brassica , Locos de Características Quantitativas , Clorofila A , Melhoramento Vegetal , Folhas de Planta/genética , Carotenoides , Brassica/genética , Estudos de Associação Genética
5.
Angew Chem Int Ed Engl ; : e202404207, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38647637

RESUMO

Alkyl borane compounds-mediated polymerizations have expanded to Lewis pair polymerization, free radical polymerization, ionic ring-opening polymerization, and polyhomologation. The bifunctional organoborane catalysts that contain the Lewis acid and ammonium or phosphonium salt in one molecule have demonstrated superior catalytic performance for ring-opening polymerization of epoxides and ring-opening copolymerization of epoxides and CO2 than their two-component analogues, i.e., the blend of organoborane and ammonium or phosphonium salt. To explore the origin of the differences of the one-component and two-component organoborane catalysts, here we conducted a systematic investigation on the catalytic performances of these two kinds of organoborane catalysts via terpolymerization of epoxide, carbon dioxide and anhydride. The resultant terpolymers produced independently by bifunctional and binary organoborane catalyst exhibited distinct microstructures, where a series of gradient polyester-polycarbonate terpolymers with varying polyester content were afforded using the bifunctional catalyst, while tapering diblock terpolymers were obtained using the binary system. The bifunctional catalyst enhances the competitiveness of CO2 insertion than anhydride, which leads to the premature incorporation of CO2 into the polymer chains and ultimately results in the formation of gradient terpolymers. DFT calculations revealed the role of electrostatic interaction and charge distribution caused by intramolecular synergistic effect for bifunctional organoborane catalyst.

6.
Biol Reprod ; 2024 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-38630889

RESUMO

It has been well-established that there is a connection between polycystic ovary syndrome (PCOS) pathology and gut microbiome dysbiosis. A marine-derived oligosaccharide, GV-971, has been reported to alter gut microbiota and alleviate Aß amyloidosis. In this study, the effects of GV-971 on PCOS-like mice were explored. Mice were randomly assigned into four groups: control, letrozole, letrozole + GV-971, control + GV-971. Glucose metabolism in PCOS-like mice was ameliorated by GV-971, while the reproductive endocrine disorder of PCOS-like mice was partially reversed. The messenger ribonucleic acid levels of steroidogenic enzymes in ovaries of PCOS-like mice were improved. GV-971 restored the fertility of PCOS-like mice and significantly increase the number of litters. Furthermore, GV-971 treatment effectively mitigated abnormal bile acid metabolism. Notably, after GV-971 intervention, gut microbiota alpha-diversity was considerably raised and the relative abundance of Firmicutes was reduced. In conclusion, the hyperinsulinemia and hyperandrogenemia of PCOS-like mice were alleviated by GV-971 intervention, which was associated with mitigating bile acid metabolism and modulating gut microbiota.

7.
Heliyon ; 10(7): e28526, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38601535

RESUMO

Background: Epidemiological studies on cardiovascular diseases (CVD) among women of childbearing age (WCBA) remain scarce. Our research aims to delineate the prevalence trends of CVD within this population over the past three decades, considering age, period, and birth cohort dynamics. Methods: Estimates of CVD prevalence for WCBA, along with their 95% uncertainty intervals (UI), were extracted from the Global Burden of Diseases 2019 (GBD2019). An age-period-cohort (APC) model was utilized to assess the annual percentage change (net drifts) in overall prevalence, annual percentage changes in prevalence for individual age groups (local drifts), and fitted longitudinal age-specific rates adjusted for age effects and period/cohort relative risks (period/cohort effect). Results: In 2019, the global prevalence of CVD among WCBA was 53.42 million (95% UI: 47.77 to 60.18). Eight countries recorded a prevalence exceeding one million, accounting for 54.17% of the global CVD prevalence in WCBA. Over the past 30 years, the annual net drift in CVD prevalence among the global WCBA was 0.27% (95% CI: 0.25 to 0.29). This value was 0.01% (95% CI: 0.04 to 0.06) in regions with a high sociodemographic index (SDI) and 0.21% (95% CI: 0.19 to 0.22) in those with a low SDI. Seventy-seven countries demonstrated an increasing trend in CVD prevalence, while 53 showed a decrease, and 74 remained relatively stable. Notably, as shown in local drift, there was a rise in CVD prevalence among adolescents aged 15-19 and adults aged 40-49 in regions categorized by five distinct SDI levels. This drift varied by SDI regions. Regions with a high SDI consistently had elevated period risks throughout the study duration, while other regions had lower period risks until 2000-2004 and displayed increased adverse period risks. The prevalence in low-middle and low SDI regions manifested detrimental trends, whereas other regions demonstrated an initial decline followed by a surge in successive birth cohorts. Conclusions: Resources dedicated to CVD care for WCBA are largely insufficient, especially in low SDI regions. Thus, there is an urgent need to allocate cardiovascular healthcare resources variably across different SDI regions, aiming to diminish risks among successively younger birth cohorts. Throughout this endeavor, the formulation of targeted policies and the judicious distribution of resources are essential to reduce risks for women across all age groups.

8.
Front Public Health ; 12: 1322574, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38633238

RESUMO

Background: To describe the burden and examine transnational inequities in overall cardiovascular disease (CVD) and ten specific CVDs across different levels of societal development. Methods: Estimates of disability-adjusted life-years (DALYs) for each disease and their 95% uncertainty intervals (UI) were extracted from the Global Burden of Diseases (GBD). Inequalities in the distribution of CVD burdens were quantified using two standard metrics recommended absolute and relative inequalities by the World Health Organization (WHO), including the Slope Index of Inequality (SII) and the relative concentration Index. Results: Between 1990 and 2019, for overall CVD, the Slope Index of Inequality changed from 3760.40 (95% CI: 3758.26 to 3756.53) in 1990 to 3400.38 (95% CI: 3398.64 to 3402.13) in 2019. For ischemic heart disease, it shifted from 2833.18 (95% CI: 2831.67 to 2834.69) in 1990 to 1560.28 (95% CI: 1559.07 to 1561.48) in 2019. Regarding hypertensive heart disease, the figures changed from-82.07 (95% CI: -82.56 to-81.59) in 1990 to 108.99 (95% CI: 108.57 to 109.40) in 2019. Regarding cardiomyopathy and myocarditis, the data evolved from 273.05 (95% CI: 272.62 to 273.47) in 1990 to 250.76 (95% CI: 250.42 to 251.09) in 2019. Concerning aortic aneurysm, the index transitioned from 104.91 (95% CI: 104.65 to 105.17) in 1990 to 91.14 (95% CI: 90.94 to 91.35) in 2019. Pertaining to endocarditis, the figures shifted from-4.50 (95% CI: -4.64 to-4.36) in 1990 to 16.00 (95% CI: 15.88 to 16.12) in 2019. As for rheumatic heart disease, the data transitioned from-345.95 (95% CI: -346.47 to-345.42) in 1990 to-204.34 (95% CI: -204.67 to-204.01) in 2019. Moreover, the relative concentration Index for overall CVD and each specific type also varied from 1990 to 2019. Conclusion: There's significant heterogeneity in transnational health inequality for ten specific CVDs. Countries with higher levels of societal development may bear a relatively higher CVD burden except for rheumatic heart disease, with the extent of inequality changing over time.


Assuntos
Doenças Cardiovasculares , Cardiopatia Reumática , Humanos , Carga Global da Doença , Anos de Vida Ajustados por Qualidade de Vida , Disparidades nos Níveis de Saúde , Saúde Global
9.
Nano Lett ; 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38656103

RESUMO

The ultrahigh surface area of two-dimensional materials can drive multimodal coupling between optical, electrical, and mechanical properties that leads to emergent dynamical responses not possible in three-dimensional systems. We observed that optical excitation of the WS2 monolayer above the exciton energy creates symmetrically patterned mechanical protrusions which can be controlled by laser intensity and wavelength. This observed photostrictive behavior is attributed to lattice expansion due to the formation of polarons, which are charge carriers dressed by lattice vibrations. Scanning Kelvin probe force microscopy measurements and density functional theory calculations reveal unconventional charge transport properties such as the spatially and optical intensity-dependent conversion in the WS2 monolayer from apparent n- to p-type and the subsequent formation of effective p-n junctions at the boundaries between regions with different defect densities. The strong opto-electrical-mechanical coupling in the WS2 monolayer reveals previously unexplored properties, which can lead to new applications in optically driven ultrathin microactuators.

10.
Bioresour Technol ; 400: 130689, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38599353

RESUMO

In recent years, manganese (Mn) has emerged as an accelerator for nitrogen metabolism. However, the bioactivity of manganese is limited by the restricted contact between microbes and manganese minerals in the solid phase and by the toxicity of manganese to microbes. To enhance the bioactivity of solid-phase manganese, biomineralized manganese oxide (MnOx) modified by Lactobacillus was introduced. Nitrogen removal performance have confirmed the effective role of biomineralized MnOx in accelerating the removal of total inorganic nitrogen (TIN). Metagenomic analysis has confirmed the enhancement of the nitrogen metabolic pathway and microbial extracellular electron transfer (MEET) in biomineralized MnOx treatment group (BIOA group). Additionally, the enrichment of manganese oxidation and denitrification genus indicates a coupling between nitrogen metabolism and manganese metabolism. One point of views is that biomineralized MnOx-mediated nitrogen transformation processes could serve as a substitute for traditional nitrogen removal processes.

11.
Digit Health ; 10: 20552076241236291, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38465293

RESUMO

Background: Effective medication adherence is vital for older adult stroke survivors, yet 20-33% cease treatment within a year post-discharge, increasing risks of recurrent strokes and mortality. A mobile health (mHealth) app could be a novel tool to improve medication adherence among stroke survivors because of its potential to increase patient empowerment. A few stroke-related apps provide information and support to stroke survivors. However, none have focused on medication adherence and documented their development and evaluation process, particularly those focused on this older population. Objective: This study aims to design and develop a smartphone app called OASapp to improve medication adherence among older adult stroke survivors and evaluate its usability. Methods: OASapp was developed in a three-phase development process. Phase 1 is the exploration phase (including a cross-sectional survey, a systematic review, a search for stroke apps on the app stores of Apple App Store and Google Play Store, and a nominal group technique). In phase 2, a prototype was designed based on the Health Belief Model and Technology Acceptance Model. In phase 3, Alpha and Beta testing was conducted to validate the app. Results: Twenty-five features for inclusion in the app were collected in round one, and 14 features remained and were ranked by the participants during nominal group technique. OASapp included five core components (medication management, risk factor management, health information, communication, and stroke map). Users of OASapp were satisfied based on reports from Alpha and Beta testing. The mean Usability Metric for User Experience (UMUX) score was 71.4 points (SD 14.6 points). Conclusion: OASapp was successfully developed using comprehensive, robust, and theory-based methods and was found to be highly accepted by users. Further research is needed to establish the clinical efficacy of the app so that it can be utilized to improve clinically relevant outcomes.

12.
Int J Biol Macromol ; 265(Pt 2): 131059, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38521338

RESUMO

Bone matrix vesicles are commonly acknowledged as the primary site of biomineralization in human skeletal tissue. Black phosphorus has exhibited favorable properties across various chemical and physical domains. In this investigation, a novel composite microsphere was synthesized through the amalgamation of sodium alginate (ALG) with black phosphorus nanosheets (BP) utilizing the electrospray (ES) technique. These microspheres were tailored to mimic the regulatory function of matrix vesicles (MV) upon exposure to a biomimetic mineralization fluid (SBF) during the biomineralization process. Results revealed that black phosphorus nanosheets facilitated the generation of hydroxyapatite (HA) on the microsphere surface. Live-dead assays and cell proliferation experiments showcased a cell survival rate exceeding 85 %. Moreover, wound healing assessments unveiled that M-ALG-BP microspheres exhibited superior migration capacity, with a migration rate surpassing 50 %. Furthermore, after 7 days of osteogenic induction, M-ALG-BP microspheres notably stimulated osteoblast differentiation. Particularly noteworthy, M-ALG-BP microspheres significantly enhanced osteogenic differentiation of osteoblasts and induced collagen production in vitro. Additionally, experiments involving microsphere implantation into mouse skeletal muscle demonstrated the potential for ectopic mineralization by ALG-BP microspheres. This investigation underscores the outstanding mineralization properties of ALG-BP microspheres and their promising clinical prospects in bone tissue engineering.


Assuntos
Matriz Óssea , Osteogênese , Camundongos , Animais , Humanos , Microesferas , Fósforo , Regeneração Óssea , Alginatos/farmacologia , Alginatos/química
13.
J Biomed Mater Res B Appl Biomater ; 112(4): e35403, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38520706

RESUMO

For decades, titanium implants have shown impressive advantages in bone repair. However, the preparation of implants with excellent antimicrobial properties as well as better osseointegration ability remains difficult for clinical application. In this study, black phosphorus nanosheets (BPNSs) were doped into hydroxyapatite (HA) coatings using electrophoretic deposition. The coatings' surface morphology, roughness, water contact angle, photothermal properties, and antibacterial properties were investigated. The BP/HA coating exhibited a surface roughness of 59.1 nm, providing an ideal substrate for cell attachment and growth. The water contact angle on the BP/HA coating was measured to be approximately 8.55°, indicating its hydrophilic nature. The BPNSs demonstrated efficient photothermal conversion, with a temperature increase of 42.2°C under laser irradiation. The BP/HA composite coating exhibited a significant reduction in bacterial growth, with inhibition rates of 95.6% and 96.1% against Staphylococcus aureus and Escherichia coli. In addition, the cytocompatibility of the composite coating was evaluated by cell adhesion, CCK8 and AM/PI staining; the effect of the composite coating in promoting angiogenesis was assessed by scratch assay, transwell assay, and protein blotting; and the osteoinductivity of the composite coating was evaluated by alkaline phosphatase assay, alizarin red staining, and Western blot. The results showed that the BP/HA composite coating exhibited superior performance in promoting biological functions such as cell proliferation and adhesion, antibacterial activity, osteogenic differentiation, and angiogenesis, and had potential applications in vascularized bone regeneration.


Assuntos
Durapatita , Titânio , Durapatita/farmacologia , Durapatita/química , Titânio/farmacologia , Titânio/química , Osseointegração , Osteogênese , Materiais Revestidos Biocompatíveis/farmacologia , Materiais Revestidos Biocompatíveis/química , Antibacterianos/farmacologia , Água/farmacologia , Propriedades de Superfície
14.
Theranostics ; 14(5): 2036-2057, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38505614

RESUMO

Background: ApoA5 mainly synthesized and secreted by liver is a key modulator of lipoprotein lipase (LPL) activity and triglyceride-rich lipoproteins (TRLs). Although the role of ApoA5 in extrahepatic triglyceride (TG) metabolism in circulation has been well documented, the relationship between ApoA5 and nonalcoholic fatty liver disease (NAFLD) remains incompletely understood and the underlying molecular mechanism still needs to be elucidated. Methods: We used CRISPR/Cas9 gene editing to delete Apoa5 gene from Syrian golden hamster, a small rodent model replicating human metabolic features. Then, the ApoA5-deficient (ApoA5-/-) hamsters were used to investigate NAFLD with or without challenging a high fat diet (HFD). Results: ApoA5-/- hamsters exhibited hypertriglyceridemia (HTG) with markedly elevated TG levels at 2300 mg/dL and hepatic steatosis on a regular chow diet, accompanied with an increase in the expression levels of genes regulating lipolysis and small adipocytes in the adipose tissue. An HFD challenge predisposed ApoA5-/- hamsters to severe HTG (sHTG) and nonalcoholic steatohepatitis (NASH). Mechanistic studies in vitro and in vivo revealed that targeting ApoA5 disrupted NR1D1 mRNA stability in the HepG2 cells and the liver to reduce both mRNA and protein levels of NR1D1, respectively. Overexpression of human NR1D1 by adeno-associated virus 8 (AAV8) in the livers of ApoA5-/- hamsters significantly ameliorated fatty liver without affecting plasma lipid levels. Moreover, restoration of hepatic ApoA5 or activation of UCP1 in brown adipose tissue (BAT) by cold exposure or CL316243 administration could significantly correct sHTG and hepatic steatosis in ApoA5-/- hamsters. Conclusions: Our data demonstrate that HTG caused by ApoA5 deficiency in hamsters is sufficient to elicit hepatic steatosis and HFD aggravates NAFLD by reducing hepatic NR1D1 mRNA and protein levels, which provides a mechanistic link between ApoA5 and NAFLD and suggests the new insights into the potential therapeutic approaches for the treatment of HTG and the related disorders due to ApoA5 deficiency in the clinical trials in future.


Assuntos
Hiperlipidemias , Hepatopatia Gordurosa não Alcoólica , Animais , Cricetinae , Humanos , Camundongos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Fígado/metabolismo , Triglicerídeos/metabolismo , Hiperlipidemias/metabolismo , Dieta Hiperlipídica/efeitos adversos , Mesocricetus , RNA Mensageiro/metabolismo , Camundongos Endogâmicos C57BL , Membro 1 do Grupo D da Subfamília 1 de Receptores Nucleares/metabolismo
15.
Mol Cell Biochem ; 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38443748

RESUMO

Extranodal NK/T cell lymphoma (ENKTCL) is an extremely aggressive form of lymphoma and lacks of specific diagnostic markers. The study intended to unearth the role of interleukin-33 (IL-33) in ENKTCL. RT-qPCR was conducted to assess mRNA levels of ENKTCL tissues and cells, while western blot assay was performed for evaluating protein levels. Plate cloning experiment and transwell assay were employed to measure aggressiveness of ENKTCL. Tube formation assay was executed to determine the angiogenesis ability. Mice ENKTCL xenograft model was designed to probe the impacts of IL-33 in vivo. IL-33 and suppression of tumorigenicity 2 receptor (ST2, receptor of IL-33) were enhanced in ENKTCL. IL-33 inhibition suppressed viability, migration, and invasion of ENKTCL cells. Moreover, IL-33 knockdown restricted angiogenesis in human umbilical vein endothelial cells (HUVECs). Furthermore, Wnt/ß-catenin pathway associated proteins (ß-catenin, c-myc, and cyclin D1) were downregulated by loss of IL-33. However, these impacts were overturned by Wnt/ß-catenin signaling agonist lithium chloride (LiCl). Additionally, IL-33 silencing exerted anti-tumor effect via Wnt/ß-catenin pathway in vivo. Silencing of IL-33 inhibited ENKTCL tumorigenesis and angiogenesis by inactivating Wnt/ß-catenin signaling pathway. As such, IL-33 might be a prospective treatment target for ENKTCL.

16.
Chem Soc Rev ; 53(7): 3384-3456, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38411207

RESUMO

The scientific community has witnessed extensive developments and applications of organoboron compounds as synthetic elements and metal-free catalysts for the construction of small molecules, macromolecules, and functional materials over the last two decades. This review highlights the achievements of organoboron-mediated polymerizations in the past several decades alongside the mechanisms underlying these transformations from the standpoint of the polymerization mode. Emphasis is placed on free radical polymerization, Lewis pair polymerization, ionic (cationic and anionic) polymerization, and polyhomologation. Herein, alkylborane/O2 initiating systems mediate the radical polymerization under ambient conditions in a controlled/living manner by careful optimization of the alkylborane structure or additives; when combined with Lewis bases, the selected organoboron compounds can mediate the Lewis pair polymerization of polar monomers; the bicomponent organoboron-based Lewis pairs and bifunctional organoboron-onium catalysts catalyze ring opening (co)polymerization of cyclic monomers (with heteroallenes, such as epoxides, CO2, CO, COS, CS2, episulfides, anhydrides, and isocyanates) with well-defined structures and high reactivities; and organoboranes initiate the polyhomologation of sulfur ylides and arsonium ylides providing functional polyethylene with different topologies. The topological structures of the produced polymers via these organoboron-mediated polymerizations are also presented in this review mainly including linear polymers, block copolymers, cyclic polymers, and graft polymers. We hope the summary and understanding of how organoboron compounds mediate polymerizations can inspire chemists to apply these principles in the design of more advanced organoboron compounds, which may be beneficial for the polymer chemistry community and organometallics/organocatalysis community.

17.
Nano Lett ; 24(12): 3661-3669, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38408021

RESUMO

The lack of stability of red perovskite nanocrystals (PeNCs) remains the main problem that restricts their patterning application. In this work, the dual-ligand passivation strategy was introduced to stabilize PeNCs and inhibit their halogen ion migration during high-voltage electrohydrodynamic (EHD) inkjet printing. The as-printed red arrays exhibit the highest emisson intensity and least blue shift compared with samples with other passivation strategies under a high electric field during EHD inkjet printing. Combining with blue and green PeNC inks, single-color and tricolor color conversion layer arrays were successfully printed, with minimum pixel size of 5 µm and the highest spatial resolution of 2540 dpi. The color coordinate of CsPbBrI2 NCs arrays are located close to the red point, with a color gumat of 97.28% of Rec. 2020 standard. All of these show great potential in the application of color conversion layers in a near-eye micro-LED display.

18.
J Agric Food Chem ; 72(7): 3633-3643, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38330270

RESUMO

Chlorogenic acid (CGA) has incredible potential for various pharmaceutical, nutraceutical, and agricultural applications. However, the traditional extraction approach from plants is time-consuming, further limiting its production. Herein, we design and construct the de novo biosynthesis pathway of CGA using modular coculture engineering in Escherichia coli, which is composed of MG09 and BD07 strains. To accomplish this, the phenylalanine-deficient MG09 strain was engineered to utilize xylose preferentially and to overproduce precursor caffeic acid, while the tyrosine-deficient BD07 strain was constructed to consume glucose exclusively to enhance another precursor quinic acid availability for the biosynthesis of CGA. Further pathway modularization and balancing in the context of syntrophic cocultures resulted in additional production improvement. The coculture strategy avoids metabolic flux competition in the biosynthesis of two CGA precursors, caffeic acid and quinic acid, and allows for production improvement by balancing module proportions. Finally, the optimized coculture based on the aforementioned efforts produced 131.31 ± 7.89 mg/L CGA. Overall, the modular coculture engineering strategy in this study provides a reference for constructing microbial cell factories that can efficiently biomanufacture complex natural products.


Assuntos
Ácidos Cafeicos , Ácido Clorogênico , Glucose , Glucose/metabolismo , Ácido Clorogênico/metabolismo , Xilose/metabolismo , Ácido Quínico , Engenharia Metabólica/métodos , Escherichia coli/genética , Escherichia coli/metabolismo
19.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 41(1): 191-198, 2024 Feb 25.
Artigo em Chinês | MEDLINE | ID: mdl-38403621

RESUMO

In recent years, bone implant materials such as titanium and titanium alloys have been widely used in the biomedical field due to their excellent mechanical properties and good biocompatibility. However, in clinical practice, bacterial adhesion to the material surface and postoperative infection issues may lead to implantation failure. Based on the antibacterial mechanism, this review elaborated on the antibacterial surface design of titanium implants from the aspects of anti-bacterial adhesion, contact sterilization and photocontrol sterilization. Surface modification of titanium or titanium-based alloy implants with different techniques can inhibit bacteria and promote osseointegration. Thus, the application range of multifunctional titanium-based implants in the field of orthopedics will be expanded.


Assuntos
Antibacterianos , Titânio , Titânio/farmacologia , Propriedades de Superfície , Antibacterianos/farmacologia , Próteses e Implantes , Osseointegração , Ligas
20.
Insects ; 15(2)2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38392531

RESUMO

The co-evolution between symbionts and their insect hosts has led to intricate functional interdependencies. Advances in DNA-sequencing technologies have not only reduced the cost of sequencing but, with the advent of highly accurate long-read methods, have also enabled facile genome assembly even using mixed genomic input, thereby allowing us to more easily assess the contribution of symbionts to their insect hosts. In this study, genomic data recently generated from Peregrinus maidis was used to assemble the genome of a bacterial symbiont, Pm Arsenophonus sp. This ~4.9-Mb assembly is one of the largest Arsenophonus genomes reported to date. The Benchmarking Universal Single-Copy Orthologs (BUSCO) result indicates that this Pm Arsenophonus assembly has a high degree of completeness, with 96% of the single-copy Enterobacterales orthologs found. The identity of the Pm Arsenophonus sp. was further confirmed by phylogenetic analysis. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicates a major contribution by Pm Arsenophonus sp. to the biosynthesis of B vitamins and essential amino acids in P. maidis, where threonine and lysine production is carried out solely by Pm Arsenophonus sp. This study not only provides deeper insights into the evolutionary relationships between symbionts and their insect hosts, but also adds to our understanding of insect biology, potentially guiding the development of novel pest control methods.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...