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1.
Proc Natl Acad Sci U S A ; 120(39): e2304552120, 2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37725641

RESUMO

Nanosized zero-valent iron (nZVI) is a promising persulfate (PS) activator, however, its structurally dense oxide shell seriously inhibited electrons transfer for O-O bond cleavage of PS. Herein, we introduced sulfidation and phosphorus-doped biochar for breaking the pristine oxide shell with formation of FeS and FePO4-containing mixed shell. In this case, the faster diffusion rate of iron atoms compared to shell components triggered multiple Kirkendall effects, causing inward fluxion of vacancies with further coalescing into radial nanocracks. Exemplified by trichloroethylene (TCE) removal, such a unique "lemon-slice-like" nanocrack structure favored fast outward transfer of electrons and ferrous ions across the mixed shell to PS activation for high-efficient generation and utilization of reactive species, as evidenced by effective dechlorination (90.6%) and mineralization (85.4%) of TCE. [Formula: see text] contributed most to TCE decomposition, moreover, the SnZVI@PBC gradually became electron-deficient and thus extracted electrons from TCE with achieving nonradical-based degradation. Compared to nZVI/PS process, the SnZVI@PBC/PS system could significantly reduce catalyst dosage (87.5%) and PS amount (68.8%) to achieve nearly complete TCE degradation, and was anti-interference, stable, and pH-universal. This study advanced mechanistic understandings of multiple Kirkendall effects-triggered nanocrack formation on nZVI with corresponding rational design of Fenton-like catalysts for organics degradation.

2.
J Am Chem Soc ; 146(13): 9434-9443, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38507716

RESUMO

Electrocatalytic synthesis of hydrogen peroxide (H2O2) in acidic media is an efficient and eco-friendly approach to produce inherently stable H2O2, but limited by the lack of selective and stable catalysts under industrial-relevant current densities. Herein, we report a diatomic cobalt catalyst for two-electron oxygen reduction to efficiently produce H2O2 at 50-400 mA cm-2 in acid. Electrode kinetics study shows a >95% selectivity for two-electron oxygen reduction on the diatomic cobalt sites. In a flow cell device, a record-high production rate of 11.72 mol gcat-1 h-1 and exceptional long-term stability (100 h) are realized under high current densities. In situ spectroscopic studies and theoretical calculations reveal that introducing a second metal into the coordination sphere of the cobalt site can optimize the binding strength of key H2O2 intermediates due to the downshifted d-band center of cobalt. We also demonstrate the feasibility of processing municipal plastic wastes through decentralized H2O2 production.

3.
Breast Cancer Res Treat ; 206(3): 603-614, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38743174

RESUMO

PURPOSE: Many patients with early breast cancer (eBC) undergoing neoadjuvant chemotherapy do not achieve pathological complete response (pCR), which is a prognostic factor. We examined the role of HER2-low expression in predicting pCR and prognosis in HER2-negative eBC. METHODS: We evaluated patients with stage I-III HER2-negative BC, treated between 2013 and 2023 at The Royal Marsden NHS Foundation Trust, London. Tumors were classified based on estrogen receptor (ER) status and into HER2-low and HER2-zero subgroups. We analyzed pCR rates, relapse-free survival (RFS) and overall survival (OS). RESULTS: 754 patients were included in the analysis. pCR rate was 8.9% in the ER+ /HER2-low, 16.5% in the ER+ /HER2-zero, 38.9% in the ER- ER-/HER2-low and 35.9% in the ER-/HER2-zero eBC (p < 0.001). Multivariable analysis showed a significantly lower pCR rate in HER2-low compared to HER2-zero BC in the ER+ subgroup. At a median follow-up of 63.8 months (59.9-67.4), we observed longer OS in HER2-low compared to HER2-zero patients in the overall and in the ER+ population. There was no predictive or prognostic impact of HER2-low status in the ER- population. CONCLUSION: This study supports the interpretation of HER2 status as a possible prognostic and predictive biomarker for HER2-negative eBC, especially among patients with ER+ disease.


Assuntos
Biomarcadores Tumorais , Neoplasias da Mama , Estadiamento de Neoplasias , Receptor ErbB-2 , Receptores de Estrogênio , Humanos , Receptor ErbB-2/metabolismo , Receptor ErbB-2/genética , Feminino , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/terapia , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Biomarcadores Tumorais/metabolismo , Biomarcadores Tumorais/genética , Adulto , Idoso , Receptores de Estrogênio/metabolismo , Terapia Neoadjuvante/métodos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico
4.
Glob Chang Biol ; 30(1): e16998, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37899690

RESUMO

Identifying droughts and accurately evaluating drought impacts on vegetation growth are crucial to understanding the terrestrial carbon balance across China. However, few studies have identified the critical drought thresholds that impact China's vegetation growth, leading to large uncertainty in assessing the ecological consequences of droughts. In this study, we utilize gridded surface soil moisture data and satellite-observed normalized difference vegetation index (NDVI) to assess vegetation response to droughts in China during 2001-2018. Based on the nonlinear relationship between changing drought stress and the coincident anomalies of NDVI during the growing season, we derive the spatial patterns of satellite-based drought thresholds (T SM ) that impact vegetation growth in China via a framework for detecting drought thresholds combining the methods of feature extraction, coincidence analysis, and piecewise linear regression. The T SM values represent percentile-based drought threshold levels, with smaller T SM values corresponding to more negative anomalies of soil moisture. On average, T SM is at the 8.7th percentile and detectable in 64.4% of China's vegetated lands, with lower values in North China and Jianghan Plain and higher values in the Inner Mongolia Plateau. Furthermore, T SM for forests is commonly lower than that for grasslands. We also find that agricultural irrigation modifies the drought thresholds for croplands in the Sichuan Basin. For future projections, Earth System Models predict that more regions in China will face an increasing risk for ecological drought, and the Hexi Corridor-Hetao Plain and Shandong Peninsula will become hotspots of ecological drought. This study has important implications for accurately evaluating the impacts of drought on vegetation growth in China and provides a scientific reference for the effective ecomanagement of China's terrestrial ecosystems.


Assuntos
Secas , Ecossistema , Florestas , Solo , China
5.
Waste Manag Res ; 42(1): 74-80, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37102342

RESUMO

Since the majority of valuable components in spent lithium-ion batteries, such as lithium, exists in the electrode materials, common studies focused on the treatment of the cathode materials, which ignored the harm of residual electrolyte. The cavitation and thermal effects produced by ultrasonic can not only be used for the separation of electrode materials, but also have a wide range of applications in the field of sewage pollutant degradation. This work used ultrasonic to treat simulated electrolyte (propylene carbonate (PC)) solution of spent lithium-ion batteries, explored the effect of ultrasonic power, the addition amount of H2O2 solution (30 wt%) and reaction temperature on the degradation of electrolyte, and analysed the ultrasonic degradation reaction from the perspective of reaction kinetics. And the synchronous experiment of cathode material separation and electrolyte degradation was conducted under the optimal conditions. The results showed that the highest degradation efficiency of PC in the electrolyte was 83.08% under the condition of ultrasonic power of 900 W, the addition of H2O2 solution (30 wt%) of 10.2 mL, reaction temperature of 120°C and reaction time of 120 minutes, and the separation efficiency was 100%. This work reduced the environmental and health risks in the cathode material separation process and was conducive to the green development of spent lithium-ion battery recycling technology.


Assuntos
Lítio , Ultrassom , Peróxido de Hidrogênio , Reciclagem/métodos , Fontes de Energia Elétrica , Eletrodos
6.
J Am Chem Soc ; 145(8): 4819-4827, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36790150

RESUMO

Heterogeneous catalysts containing diatomic sites are often hypothesized to have distinctive reactivity due to synergistic effects, but there are limited approaches that enable the convenient production of diatomic catalysts (DACs) with diverse metal combinations. Here, we present a general synthetic strategy for constructing a DAC library across a wide spectrum of homonuclear (Fe2, Co2, Ni2, Cu2, Mn2, and Pd2) and heteronuclear (Fe-Cu, Fe-Ni, Cu-Mn, and Cu-Co) bimetal centers. This strategy is based on an encapsulation-pyrolysis approach, wherein a porous material-encapsulated macrocyclic complex mediates the structure of DACs by preserving the main body of the molecular framework during pyrolysis. We take the oxygen reduction reaction (ORR) as an example to show that this DAC library can provide great opportunities for electrocatalyst development by unlocking an unconventional reaction pathway. Among all investigated sites, Fe-Cu diatomic sites possess exceptional high durability for ORR because the Fe-Cu pairs can steer elementary steps in the catalytic cycle and suppress the troublesome Fenton-like reactions.

7.
Opt Express ; 31(2): 3390-3400, 2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36785333

RESUMO

Compressive ghost imaging (CGI) can effectively reduce the number of measurements required for ghost imaging reconstruction. In most cases, however, when using illumination patterns as measurement matrices, CGI has not demonstrated the ability to reconstruct high-quality images at an ultra-low sampling rate as perfect as claimed by compressive sensing theory. According to our analysis, the reason is that the non-negative nature of light intensity causes measurement matrix in compressive ghost imaging to be inconsistent with the essential requirements of good measurement matrix in compressive sensing theory, leading to low reconstruction quality. Aiming at this point, we propose a bipolar compressive ghost imaging method to improve the reconstruction quality of ghost imaging. The validity of the proposed method is proven by simulations and experiments.

8.
J Org Chem ; 88(15): 10647-10654, 2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37470361

RESUMO

A new approach to oxazolidines and dihydroxazines was developed by regioselective cyclization of α-aminated ketones under transition metal-free conditions. Oxazolidine derivatives were generated in the presence of chloro benziodoxole and TFA, while dihydroxazines were formed without a hypervalent iodine reagent. The reaction was performed under room temperature and gave the products in good to excellent yields.

9.
Appl Opt ; 62(29): 7678-7688, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37855475

RESUMO

Ghost imaging technology has a great application potential in optical security because of its non-local characteristics. In this paper, on the basis of computational ghost imaging, an optical authentication scheme is proposed that utilizes the correspondence imaging technique for the preliminary reconstruction of the object image, and then authenticates the image by a nonlinear correlation algorithm. Different from the previous optical authentication schemes that usually adopted random selection of measurements, this authentication method consciously selects the bucket detector measurement values with large fluctuation and can achieve authentication using ultra-low data volumes less than 1% of the Nyquist limit. In brief, this scheme is easy to implement and has a simpler algorithm and higher stability, which is a tremendous advantage in practical optical authentication systems. The simulation and physical experimental results demonstrate the feasibility of the scheme.

10.
Angew Chem Int Ed Engl ; 62(4): e202214516, 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36420958

RESUMO

Single crystal surfaces with highly coordinated sites very often hold high specific activities toward oxygen reduction reaction (ORR) and others. Transposing their high specific activity to practical high-surface-area electrocatalysts remains challenging. Here, ultrathin Pt(100) alloy surface is constructed via epitaxial growth. The surface shows 3.1-6.9 % compressive strain and bulk-like characteristics as demonstrated by site-probe reactions and different spectroscopies. Its ORR activity exceeds that of bulk Pt3 Ni(100) and Pt(111) and presents a 19-fold increase in specific activity and a 13-fold increase in mass activity relative to commercial Pt/C. Moreover, the electrochemically active surface area (ECSA) is increased by 4-fold compared to traditional thin films (e.g. NSTF), which makes the catalyst more tolerant to voltage loss at high current densities under fuel cell operation. This work broadens the family of extended surface catalysts and highlights the knowledge-driven approach in the development of advanced electrocatalysts.

11.
Inorg Chem ; 61(6): 2824-2834, 2022 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-35104133

RESUMO

The counteranion has a strong influence on the complexation behavior of tridentate phenanthroline carboxamide ligands with actinides and lanthanides, but the thermodynamic and underlying interaction mechanism at the molecular level is still not clear. In this work, a tridentate ligand, N-ethyl-N-tolyl-2-amide-1,10-phenanthroline (Et-Tol-PTA), was synthesized, and the effects of different anions (Cl-, NO3-, and ClO4-) on the complexation behavior of Et-Tol-PTA with typical lanthanides were thoroughly studied by using 1H nuclear magnetic resonance (NMR) spectroscopy, ultraviolet-visible (UV-vis) spectrophotometry, and single-crystal X-ray diffraction. The NMR spectroscopic titration of Lu(III) showed that there were three species (1:1, 2:1, and 3:1 ligand-metal complexes) formed in Cl- solution systems while two species (2:1 and 1:1) were formed in NO3- and ClO4- solution systems. When Et-Tol-PTA was titrated with La(III), two species (2:1 and 1:1) were formed in NO3- systems and only one species (1:1) was formed in Cl- and ClO4- systems. In addition, the stability constant was determined via UV-vis spectroscopic titration, which showed that the complexation strength between Et-Tol-PTA and Eu(III) decreased in the following order: ClO4- > NO3- > Cl-. This indicated that Et-Tol-PTA had the strongest complexation ability with Eu(III) in the ClO4- system. The structures of Et-Tol-PTA complexed with EuCl3, Eu(NO3)3, and Eu(ClO4)3 were further elucidated by single-crystal X-ray diffraction and agreed well with the results of UV-vis titration experiments. The results of this work revealed that the mechanisms of complexation of lanthanides with the asymmetric ligand Et-Tol-PTA were strongly affected by different anionic environments in solution and in the solid state. These findings may lead to the improvement of the separation of trivalent actinides and lanthanides in nuclear waste.

12.
Chemistry ; 27(41): 10717-10730, 2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34002918

RESUMO

Two new phosphine oxide-functionalized 1,10-phenanthroline ligands, tetradentate 2,9-bis(butylphenylphosphine oxide)-1,10-phenanthroline (BuPh-BPPhen, L1 ) and tridentate 2-(butylphenylphosphine oxide)-1,10-phenanthroline (BuPh-MPPhen, L2 ), were synthesized and studied comparatively for their coordination with trivalent actinides and lanthanides. The complexation mechanisms of these two ligands toward trivalent f-block elements were thoroughly elucidated by NMR spectroscopy, UV/vis spectrophotometry, fluorescence spectrometry, single-crystal X-ray diffraction, solvent extraction, and theoretical calculation methods. NMR titration results demonstrated that 1 : 1 and 1 : 2 (metal to ligand) lanthanides complexes formed for L1 , whereas 1 : 1, 1 : 2 and 1 : 3 lanthanide complexes formed for L2 in methanol. The formation of these species was validated by fluorescence spectrometry, and the corresponding stability constants for the complexes of NdIII with L1 and L2 were determined by using UV/vis spectrophotometry. Structures of the 10-coordinated 1 : 1-type complexes of EuL1 (NO3 )3 and [EuL2 (NO3 )3 (H2 O)] Et2 O in the solid state were characterized by X-ray crystallography. In solvent-extraction experiments, L1 exhibited extremely strong extraction ability for both AmIII and EuIII , whereas L2 showed nearly no extraction toward AmIII or EuIII due to its high hydrophilicity. Finally, the structures and bonding natures of the complex species formed between AmIII /EuIII and L1 /L2 were analyzed in DFT calculations.

13.
Inorg Chem ; 60(4): 2805-2815, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33502197

RESUMO

In this work, a tetradentate N,O-hybrid 2,9-bis(diphenylphosphine oxide)-1,10-phenanthroline (Ph2-BPPhen) ligand was studied for the coextraction of trivalent f-block elements from nitric acid media. The extraction as well as the complexation behaviors of Ph2-BPPhen with f-block elements were thoroughly investigated using 31P and 1H NMR spectrometry, UV-vis spectrophotometry, single crystal X-ray diffraction, and density functional theoretical (DFT) calculation. Ph2-BPPhen exhibits remarkably extraction ability for both Am(III) and Eu(III) and more than 99.5% of Am(III) and Eu(III) were extracted from 1.0 M HNO3 solution. Slope analysis suggests that both 2:1 and 1:1 ligand/metal complexes were probably formed during the extraction. The 1:1 and 2:1 Ln(III) complexes with Ph2-BPPhen were also identified in CH3OH solution by NMR spectrometry, and the stability constants were determined via UV-vis spectrophotometry. Structures of the 1:1 Eu(Ph2-BPPhen)(NO3)3 and Am(Ph2-BPPhen)(NO3)3 complexes were further elucidated by single X-ray crystallography and DFT calculations. The higher extractability of Ph2-BPPhen toward trivalent Am(III) and Eu(III) compared with the previously reported phenanthroline-derived amide and phosphonate ligands was attributed to the stronger affinity of the -P═O(R)2 group to metal ions. The results from this work indicate that the N,O-hybrid 1,10-phenanthroline derived phosphine oxide ligand can serve as a new and promising candidate for coextraction of trivalent f-block elements in the treatment of nuclear waste.

14.
Inorg Chem ; 60(12): 8754-8764, 2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-34077191

RESUMO

N,O-hybrid diamide ligands with N-heterocyclic skeletons are one of the promising extractants for the selective separation of actinides over lanthanides in a highly acidic HNO3 solution. In this work, three hard-soft donor mixed diamide ligands, pyridine-2,6-diylbis(pyrrolidin-1-ylmethanone) (Pyr-PyDA), 2,2'-bipyridine-6,6'-diylbis(pyr-rolidine-1-ylmethanone) (Pyr-BPyDA), and (1,10-phenanthroline-2,9-diyl)bis(pyrrolidin-1-ylmethanone) (Pyr-DAPhen), were synthesized and used to probe the influence of N-heterocyclic cores on the complexation and extraction behaviors with trivalent lanthanides and actinides. 1H NMR titration experiments demonstrated that 1:1 metal-to-ligand complexes were mainly formed between the three ligands and lanthanides, but 1:2 type complexes were also formed between tridentate Pyr-PyDA and Lu(III). The stability constants (log ß) of these three ligands with two typical lanthanides, Nd(III) and Eu(III), were determined through spectrophotometric titration. It is found that Pyr-DAPhen formed the most stable complexes, while Pyr-PyDA formed the most unstable complexes with lanthanides, which coincided well with the following solvent extraction results. The solid-state structures of 1:1 type complexes of these three ligands with La(III), Nd(III), and Er(III) in nitrate media were identified by a single-crystal X-ray diffraction technique. Nd(III) and Er(III) were 10-coordinated with Pyr-PyDA, Pyr-BPyDA, and Pyr-DAPhen via one ligand molecule and three nitrate ions. La(III), because of its larger ionic radius, was 11-coordinated with Pyr-DAPhen through one ligand molecule, three nitrate ions, and one methanol molecule. Solvent extraction experiments showed that the preorganized phenanthroline-derived Pyr-DAPhen had the best extraction performance for trivalent actinide among the three ligands tested. This work provides some experimental insights into the design of more efficient ligands for trivalent actinide separation by adjusting the N-heterocyclic cores.

15.
Neoplasma ; 68(1): 23-30, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32977722

RESUMO

Homeobox C4 (HOXC4) belongs to the homeoprotein family of transcription factors, which play a critical role in morphogenesis and differentiation during embryonic development. Aberrant expression of HOXC4 has been reported in several types of cancers. However, the role of HOXC4 in hepatocellular carcinoma (HCC) remains unknown. Here, we reported that HOXC4 is upregulated in HCC tissues and predicts a poor outcome in patients with HCC. HOXC4 promotes HCC progression and induces an EMT-like phenotype both in vitro and in vivo. Furthermore, we demonstrated that the EMT-related transcription factor Snail is a transcriptional target of HOXC4 and HOXC4 regulates EMT by regulation of transforming growth factor ß (TGF-ß) signaling in HCC. Together, our study suggests that HOXC4 as a novel potential therapeutic target for HCC therapy.


Assuntos
Carcinoma Hepatocelular , Proteínas de Homeodomínio , Neoplasias Hepáticas , Fatores de Transcrição da Família Snail , Ativação Transcricional , Carcinoma Hepatocelular/genética , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Progressão da Doença , Transição Epitelial-Mesenquimal , Genes Homeobox , Humanos , Neoplasias Hepáticas/genética , Fatores de Transcrição da Família Snail/genética
16.
Planta ; 241(4): 789-801, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25680351

RESUMO

MAIN CONCLUSION: This review examines the signaling pathways from the developmental and environmental point of view and the interactions among external conditions, hormonal regulations, and sugarsensing in wheat. Grain development is the key phase of reproductive growth that is closely associated with vegetative organ senescence, initiation of grain filling, pre-stored assimilates remobilization, and maturation. Senescence is characterized by loss of chlorophyll and the degradation of proteins, nucleic acids, lipids as well as nutrient exports to the sink. The initiation and progression of vegetative organ senescence are under the control of an array of environmental signals (such as biotic and abiotic stresses, darkness, and nutrient availability) and endogenous factors (including aging, multiple hormones, and sugar availability). This review will discuss the major breakthroughs in signal transduction for the wheat (Triticum aestivum) grain development achieved in the past several years, with focuses on the regulation of senescence, reserves remobilization and biosynthesis of main components of the grain. Different mechanisms of diverse signals in controlling different phrases of wheat grain development, and cross talks between different signaling pathways will also be discussed. For perspectives, key signaling networks for grain development remain to be elucidated, including cross talks and the interactions between various environmental factors and internal signals.


Assuntos
Grão Comestível/fisiologia , Reguladores de Crescimento de Plantas/metabolismo , Transdução de Sinais , Triticum/fisiologia , Senescência Celular , Clorofila/metabolismo , Escuridão , Grão Comestível/crescimento & desenvolvimento , Meio Ambiente , Estresse Fisiológico , Triticum/genética , Triticum/crescimento & desenvolvimento
17.
Sci Total Environ ; 916: 169995, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38242484

RESUMO

Alpine grassland is among the world's most vulnerable ecosystems, characterized by a high sensitivity to climate change (CC) and human activities (HA). Quantifying the relative contributions of CC and HA to grassland change plays a crucial role in safeguarding grassland ecological security and devising sustainable grassland management strategies. Although there were adequate studies focusing on the separate impacts of CC and HA on alpine ecosystem, insufficient attention has been given to investigating the effects of extreme temperatures and soil moisture. In this study, the spatiotemporal variations of alpine grassland were analyzed based on MODIS NDVI during the growing season from 2000 to 2020 in Naqu, using partial least squares regression and residual analysis methods to analyze the importance of climate factors and the impacts of CC and HA on grassland change. The results show that the NDVI during the growing season in Naqu exhibited an increasing trend of 0.0046/10a. At the biome scale, the most significant and rapid increase was observed in alpine desert and alpine desert grassland. Extreme temperature and soil moisture (SM) exerted a more significant importance on alpine grassland at whole scale. SM always showed a significant importance at biome and grid scale. The contributions of CC and HA to the change during the growing season were calculated as 0.0032/10a and 0.0015/10a, respectively, accounting for 68.05 % and 31.05 %. CC dominated the increase in NDVI during the growing season; HA contributed positively to NDVI in most areas of Naqu. The results are expected to enhance our understanding of grassland variations under CC and HA and provide a scientific basis for future ecological conservation in alpine regions.


Assuntos
Ecossistema , Pradaria , Humanos , Temperatura , Mudança Climática , Solo , Tibet
18.
Artigo em Inglês | MEDLINE | ID: mdl-38783351

RESUMO

AIM: School connectedness is related to suicidal ideation (SI) in adolescents. However, little is known about the mediating role of insomnia symptoms in the school connectedness-SI link. This study aimed to examine the longitudinal mediating effect of insomnia symptoms on the relationship between school connectedness and SI as well as the moderating effect of sex using a three-wave longitudinal design. METHODS: A total of 3110 adolescents completed three online surveys. Data were collected over the course of 1 year, in three waves 6 months apart. Participants completed the School Connectedness Scale, Youth Self-Rating Insomnia Scale, Self-rating Idea of Suicide Scale, Beck Depression Inventory and a self-compiled demographic questionnaire. Linear regressions and mediation analyses were performed to examine the associations between school connectedness, insomnia symptoms and SI. RESULTS: School connectedness had a significant mediating effect on SI through insomnia symptoms (ßa×b = -.03, 95% confidence interval = -0.04, -0.02) after controlling for demographics and depressive symptoms. Mediation analyses showed that insomnia symptoms accounted for 23.1% of the total effects in the entire sample, with 13.3% in males and 27.3% in females. Sex had no significant moderating effect on the school connectedness-SI link association. CONCLUSIONS: The association between school connectedness and SI appears to be mediated by insomnia symptoms. Assessing and promoting school connectedness, as well as intervening and treating distress associated with insomnia, may have important clinical implications for reducing the risk of SI in adolescents.

19.
ACS Synth Biol ; 13(2): 590-597, 2024 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-38324606

RESUMO

Pleiotropic drug resistance (PDR) family proteins have been extensively studied for their roles in transporting hydrophobic substances, including carotenoids. Overexpression of the PDR family regulator Pdr3p was recently found to boost the biosynthesis of carotenoids, which could not be explained by enhanced product secretion due to the meager extracellular proportions. To provide insights into the possible mechanism, comparative transcriptomics, reverse metabolic engineering, and electrophoretic mobility shift assay (EMSA) were conducted. Transcriptomic data suggested an unexpected correlation between Pdr3p overexpression and the transcriptional levels of GAL promoter-driven genes. This assumption was verified using mCherry and the lycopene synthetic pathway as the reporters. qRT-PCR and EMSA provided further evidence for the activation of GAL promoters by Pdr3p binding to their upstream activation sequences (UASs). This work gives insight into the mechanism of Pdr3p-promoted carotenoid production and highlights the complicated metabolic networking between transcriptional factors and promoters in yeast.


Assuntos
Proteínas de Saccharomyces cerevisiae , Fatores de Transcrição , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Ligação a DNA/metabolismo , Transativadores/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética
20.
Int J Biol Macromol ; 265(Pt 1): 130936, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38493811

RESUMO

Packaging materials with peculiar antibacterial properties can shield off and inhibit microorganism proliferation, thus achieving packaging goals such as fresh-keeping, good hygiene, and biosafety. Especially, antibacterial films made of biocompatible substances have received wide attentions, which could effectively extend the shelf life, enhance food security, and guarantee economic benefits. Herein, a self-supporting hybrid antibacterial film was prepared based on non-covalently linked choline hydroxide (ChOH) and alginic acid (HAlg). Then tannic acid (TA) and silver ions were added to improve the mechanical and antimicrobial properties of this hybrid film. The rich hydroxyl groups from TA not only form multiple hydrogen bonds with ChAlg, but can also in situ reduce silver ions to silver nanoparticles, which were confirmed with various characterizations. In addition, the quantitative antibacterial test proved that the antibacterial rate was significantly improved after adding silver ions, reaching >60 %. In an actual storage test, we found that choline cation (Ch+) captured in antibacterial film by electrostatic interaction could achieve sustained release, i.e. sustainable bacteriostasis, and keep strawberries fresh for 48 h at room temperature. This work offers a new strategy for preparing antibacterial films via non-covalent weak interactions, explored an alternative antibacterial film for food packaging applications.


Assuntos
Fragaria , Nanopartículas Metálicas , Polifenóis , Prata/química , Nanopartículas Metálicas/química , Alginatos , Antibacterianos/farmacologia , Antibacterianos/química , Embalagem de Alimentos , Íons
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