Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 190
Filtrar
1.
Nature ; 632(8026): 782-787, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39143208

RESUMO

Hot-carrier transistors are a class of devices that leverage the excess kinetic energy of carriers. Unlike regular transistors, which rely on steady-state carrier transport, hot-carrier transistors modulate carriers to high-energy states, resulting in enhanced device speed and functionality. These characteristics are essential for applications that demand rapid switching and high-frequency operations, such as advanced telecommunications and cutting-edge computing technologies1-5. However, the traditional mechanisms of hot-carrier generation are either carrier injection6-11 or acceleration12,13, which limit device performance in terms of power consumption and negative differential resistance14-17. Mixed-dimensional devices, which combine bulk and low-dimensional materials, can offer different mechanisms for hot-carrier generation by leveraging the diverse potential barriers formed by energy-band combinations18-21. Here we report a hot-emitter transistor based on double mixed-dimensional graphene/germanium Schottky junctions that uses stimulated emission of heated carriers to achieve a subthreshold swing lower than 1 millivolt per decade beyond the Boltzmann limit and a negative differential resistance with a peak-to-valley current ratio greater than 100 at room temperature. Multi-valued logic with a high inverter gain and reconfigurable logic states are further demonstrated. This work reports a multifunctional hot-emitter transistor with significant potential for low-power and negative-differential-resistance applications, marking a promising advancement for the post-Moore era.


Assuntos
Temperatura Alta , Transistores Eletrônicos , Grafite/química
2.
Plant Physiol ; 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39041422

RESUMO

The WRINKLED1 (WRI1) and LAFL [LEAFY COTYLEDON1 (LEC1), ABSCISIC ACID INSENSITIVE3 (ABI3), FUSCA3 (FUS3), and LEC2] transcription factors play essential roles in governing seed development and oil biosynthesis. To gain a comprehensive understanding of the transcriptional regulation of WRI1 and LAFL, we conducted genome-wide association studies for the expression profiles of WRI1 and LAFL in developing seeds at 20 and 40 days after flowering (DAF) using 302 rapeseed (Brassica napus) accessions. We identified a total of 237 expression quantitative trait nucleotides (eQTNs) and 51 expression QTN-by-environment interactions (eQEIs) associated with WRI1 and LAFL. Around these eQTNs and eQEIs, we pinpointed 41 and 8 candidate genes with known transcriptional regulations or protein interactions with their expression traits, respectively. Based on RNA-seq and ATAC-seq data, we employed the XGBoost and Basenji models which predicted 15 candidate genes potentially regulating the expression of WRI1 and LAFL. We further validated the predictions via tissue expression profile, haplotype analysis, and expression correlation analysis, and verified the transcriptional activation activity of BnaC03.MYB56 (R2R3-MYB transcription factor 56) on the expression of BnaA09.LEC1 by dual-luciferase reporter and yeast one-hybrid assays. BnaA10.AGL15 (AGAMOUS-LIKE 15), BnaC04.VAL1 (VIVIPAROUS1/ABSCISIC ACID INSENSITIVE3-LIKE 1), BnaC03.MYB56, and BnaA10.MYB56 were co-expressed with WRI1 and LAFL at 20 DAF in M35, a key module for seed development and oil biosynthesis. We further validated the positive regulation of MYB56 on seed oil accumulation using Arabidopsis (Arabidopsis thaliana) mutants. This study not only delivers a framework for future eQEI identification but also offers insights into the developmental regulation of seed oil accumulation.

3.
Methods ; 228: 22-29, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38754712

RESUMO

Drug-drug interaction (DDI) prediction is crucial for identifying interactions within drug combinations, especially adverse effects due to physicochemical incompatibility. While current methods have made strides in predicting adverse drug interactions, limitations persist. Most methods rely on handcrafted features, restricting their applicability. They predominantly extract information from individual drugs, neglecting the importance of interaction details between drug pairs. To address these issues, we propose MGDDI, a graph neural network-based model for predicting potential adverse drug interactions. Notably, we use a multiscale graph neural network (MGNN) to learn drug molecule representations, addressing substructure size variations and preventing gradient issues. For capturing interaction details between drug pairs, we integrate a substructure interaction learning module based on attention mechanisms. Our experimental results demonstrate MGDDI's superiority in predicting adverse drug interactions, offering a solution to current methodological limitations.


Assuntos
Interações Medicamentosas , Redes Neurais de Computação , Humanos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Algoritmos
4.
Nano Lett ; 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38587481

RESUMO

Unlocking the restricted interlayer carrier transfer in a two-dimensional perovskite is a crucial means to achieve the harmonization of efficiency and stability in perovskite solar cells. In this work, the effects of conjugated organic molecules on the interlayer carrier dynamics of 2D perovskites were investigated through nonadiabatic molecular dynamics simulations. We found that elongated conjugated organic cations contributed significantly to the accelerated interlayer carrier dynamics, originating from lowered transport barrier and boosted π-p coupling between organic and inorganic layers. Utilizing conjugated molecules of moderate length as spacer cations can yield both superior efficiency and exceptional stability simultaneously. However, conjugated chains that are too long lead to structural instability and stronger carrier recombination. The potential of conjugated chain-like molecules as spacer cations in 2D perovskites has been demonstrated in our work, offering valuable insights for the development of high-performance perovskite solar cells.

5.
Nano Lett ; 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38620010

RESUMO

Regulating the atomic density of single-atom alloys (SAAs) promotes the potential to significantly enhance the electrocatalytic activity. However, conventional methods for study on the electrocatalytic performance of SAAs versus the intersite distance demand exhaustive experiments and characterization. Herein, we present a combinatorial synthesis and analysis method to investigate the intersite distance effect of SAA electrocatalysts. We employ single-nanoparticle collision electrochemistry to realize in situ electrodeposition of a precisely tunable Au atomic density onto individual parent Ag nanoparticles, followed by instantaneous electrocatalytic measurement of the newborn Au-Ag SAAs. In this work, the utility of our method is confirmed by the identification of intersite distance effects of Au-Ag SAAs toward the oxygen reduction reaction. When the site distance between two neighboring Au atoms is 1.9 nm, Au-Ag SAAs exhibit optimal activity. This work provides a simple and efficient method for screening other SAA electrocatalysts with ideal intersite distance at the single-nanoparticle level.

6.
J Am Chem Soc ; 146(29): 20059-20068, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-38994646

RESUMO

Ultrasmall metallic nanoclusters (NCs) protected by surface ligands represent the most promising catalytic materials; yet understanding the structure and catalytic activity of these NCs remains a challenge due to dynamic evolution of their active sites under reaction conditions. Herein, we employed a single-nanoparticle collision electrochemistry method for real-time monitoring of the dynamic electrocatalytic activity of a single fully ligand-protected Au25(PPh3)10(SC2H4Ph)5Cl22+ nanocluster (Au252+ NC) at a cavity carbon nanoelectrode toward the oxygen reduction reaction (ORR). Our experimental results and computational simulations indicated that the reversible depassivation and passivation of ligands on the surface of the Au252+ NC, combined with the dynamic conformation evolution of the Au259+ core, led to a characteristic current signal that involves "ON-OFF" switches and "ON" fluctuations during the ORR process of a single Au252+ NC. Our findings reinvent the new perception and comprehension of the structure-activity correlation of NCs at the atomic level.

7.
Anal Chem ; 96(10): 4048-4056, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38373182

RESUMO

In this work, we developed an alternative calibration method for measuring N2O5 with an iodide adduct mass spectrometer (I-CIMS). In this calibration method, N2O5 is heated and then quantified based on the decrease in the amount of NO due to its reaction with the pyrolysis product (NO3). This alternative calibration method was compared with the commonly used method utilizing NOx analyzers equipped with a photolytic converter, which gauge NO2 reduction as a result of its reaction with O3 to quantify N2O5. It is notable that the two methodologies demonstrate favorable consistency in terms of calibrating N2O5, with a variance of less than 10 %. The alternative calibration method is a more reliable way to quantify N2O5 with CIMS, considering the instability of the NO2 conversion efficiency of photolytic converters in NOx analyzers and the loss of N2O5 in the sampling line. The effects of O3 and relative humidity (RH) on the sensitivity toward N2O5 were further examined. There was minimal perturbation of N2O5 quantification upon exposure to O3 even at high concentrations. The N2O5 sensitivity exhibited a nonlinear dependence on RH as it initially rose and then fell. Besides I(N2O5)-, the collisional interaction between I(H2O)- and N2O5 also forms I(HNO3)-, which may interfere with the accurate quantification of HNO3. As a consequence of the pronounced dependence on humidity, it is advisable to implement humidity correction procedures when conducting measurements of N2O5.

8.
Small ; 20(27): e2308641, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38282134

RESUMO

The photonic nose inspired by the olfactory system is an integrated detection platform constructed by multiple sensing units as channels. However, in the detection of volatile organic compounds (VOCs), the sensing results that cannot be directly readable and the poor ability to distinguish analytes with similar chemical properties are the main challenges faced by this sensor. Here, 8 metal-organic frameworks (MOF)-based photonic crystals are used as the basic sensing units to construct a photonic nose detection platform. The microscopic adsorption of VOCs by MOFs enables the photonic crystals (PCs) to produce macroscopic structural color output, and further makes the photonic nose have specific color fingerprints for different VOCs, the response time of all PCs to VOCs can be within 1 s. Through the color fingerprint, the visual identification of VOCs produced by 5 common solvent vapors is realized, and 9 VOCs with similar chemical properties are further distinguished. In addition, the application potential of the photonic nose in the actual environment is verified by identifying different contents of benzene in the paint. It is envisaged that the MOF-based photonic nose has great reference value for the development of intelligent and multi-component synergistic functional gas sensors.

9.
Small ; : e2402793, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38757420

RESUMO

Developing a new end group for synthesizing asymmetric small molecule acceptors (SMAs) is crucial for achieving high-performance organic photovoltaics (OPVs). Herein, an asymmetric small molecule acceptor, BTP-BO-4FO, featuring a new difluoro-methoxylated end-group is reported. Compared to its symmetric counterpart L8-BO, BTP-BO-4FO exhibits an upshifted energy level, larger dipole moment, and more sequential crystallinity. By adopting two representative and widely available solvent additives (1-chloronaphthalene (CN) and 1,8-diiodooctane (DIO)), the device based on PM6:BTP-BO-4FO (CN) photovoltaic blend demonstrates a power conversion efficiency (PCE) of 18.62% with an excellent open-circuit voltage (VOC) of 0.933 V, which surpasses the optimal result of L8-BO. The PCE of 18.62% realizes the best efficiencies for binary OPVs based on SMAs with asymmetric end groups. A series of investigations reveal that optimized PM6:BTP-BO-4FO film demonstrates similar molecular packing motif and fibrillar phase distribution as PM6:L8-BO (DIO) does, resulting in comparable recombination dynamics, thus, similar fill factor. Besides, it is found PM6:BTP-BO-4FO possesses more efficient charge generation, which yields better VOC-JSC balance. This study provides a new ending group that enables a cutting-edge efficiency in asymmetric SMA-based OPVs, enriching the material library and shed light on further design ideas.

10.
Small ; 20(24): e2311561, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38546001

RESUMO

Balancing the rigid backbones and flexible side chains of light-harvesting materials is crucially important to reach optimized intermolecular packing, micromorphology, and thus photovoltaic performance of organic solar cells (OSCs). Herein, based on a distinctive CH-series acceptor platform with 2D conjugation extended backbones, a series of nonfullerene acceptors (CH-6F-Cn) are synthesized by delicately tuning the lengths of flexible side chains from n-octyl to n-amyl. A systemic investigation has revealed that the variation of the side chain's length can not only modulate intermolecular packing modes and crystallinity but also dramatically improve the micromorphology of the active layer and eventual photovoltaic parameters of OSCs. Consequently, the highest PCE of 18.73% can be achieved by OSCs employing D18:PM6:CH-6F-C8 as light-harvesting materials.

11.
Small ; 20(33): e2400962, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38511578

RESUMO

Bioelectrochemical reactions using whole-cell biocatalysts are promising carbon-neutral approaches because of their easy operation, low cost, and sustainability. Bidirectional (outward or inward) electron transfer via exoelectrogens plays the main role in driving bioelectrochemical reactions. However, the low electron transfer efficiency seriously inhibits bioelectrochemical reaction kinetics. Here, a three dimensional and artificial nanoparticles-constituent inverse opal-indium tin oxide (IO-ITO) electrode is fabricated and employed to connect with exoelectrogens (Shewanella loihica PV-4). The above electrode collected 128-fold higher cell density and exhibited a maximum current output approaching 1.5 mA cm-2 within 24 h at anode mode. By changing the IO-ITO electrode to cathode mode, the exoelectrogens exhibited the attractive ability of extracellular electron uptake to reduce fumarate and 16 times higher reverse current than the commercial carbon electrode. Notably, Fe-containing oxide nanoparticles are biologically synthesized at both sides of the outer cell membrane and probably contributed to direct electron transfer with the transmembrane c-type cytochromes. Owing to the efficient electron exchange via artificial and biosynthetic nanoparticles, bioelectrochemical CO2 reduction is also realized at the cathode. This work not only explored the possibility of augmenting bidirectional electron transfer but also provided a new strategy to boost bioelectrochemical reactions by introducing biohybrid nanoparticles.


Assuntos
Eletrodos , Nanopartículas , Shewanella , Transporte de Elétrons , Shewanella/metabolismo , Nanopartículas/química , Compostos de Estanho/química , Técnicas Eletroquímicas/métodos , Eletroquímica , Dióxido de Carbono/metabolismo , Dióxido de Carbono/química , Fontes de Energia Bioelétrica
12.
Fungal Genet Biol ; 171: 103874, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38307402

RESUMO

Aspergillus cristatus is a probiotic fungus known for its safety and abundant secondary metabolites, making it a promising candidate for various applications. However, limited progress has been made in researching A. cristatus due to challenges in genetic manipulation. The mitogen-activated protein kinase (MAPK) signaling pathway is involved in numerous physiological processes, but its specific role in A. cristatus remains unclear. In this study, we successfully developed an efficient polyethylene glycol (PEG)-mediated protoplast transformation method for A. cristatus, enabling us to investigate the function of Pmk1, Mpk1, and Hog1 in the MAPK signaling pathway. Our findings revealed that Pmk1, Mpk1, and Hog1 are crucial for sexual reproduction, melanin synthesis, and response to external stress in A. cristatus. Notably, the deletion of Pmk1, Mpk1, or Hog1 resulted in the loss of sexual reproduction capability in A. cristatus. Overall, this research on MAPK will contribute to the continued understanding of the reproductive strategy and melanin synthesis mechanism of A. cristatus.


Assuntos
Proteínas Quinases Ativadas por Mitógeno , Proteínas de Saccharomyces cerevisiae , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Melaninas/genética , Sistema de Sinalização das MAP Quinases/genética , Aspergillus/genética , Aspergillus/metabolismo , Fosforilação , Proteínas de Saccharomyces cerevisiae/metabolismo
13.
J Med Virol ; 96(2): e29470, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38362933

RESUMO

The 2022 multi-country mpox outbreak raised public concern globally. Self-isolation and informing close contacts after developing mpox-related symptoms are critical measures in controlling the outbreak. This study investigated behavioral intentions of self-isolation and informing close contacts after developing mpox-related symptoms and associated factors among young men who have sex with men (YMSM) aged 18-29 years in China. The cross-sectional study was conducted among 2493 YMSM in six provincial regions in China from September 10th to 30th, 2022. Descriptive and logistic analyses were applied, using the intentions of self-isolation and informing close contacts after developing mpox-related symptoms as binary outcomes. The mean age of the participants was 24.6 (SD = 2.9) years. The prevalence of having intentions of self-isolation and informing close contacts after developing mpox-related symptoms was 88.6% (95% CI: 87.3%-89.9%) and 84.9% (95% CI: 83.5%-86.3%). Participants who were employed (adjusted odds ratio (AOR) = 1.474, 95% CI: 1.035-2.097; AOR = 1.371, 95% CI:1.002, 1.876), had higher mpox knowledge scores (AOR = 1.474, 95% CI: 1.035-2.097; AOR = 1.371, 95% CI: 1.002-1.876), and had higher perceived threats of mpox (AOR = 1.079, 95% CI: 1.030-1.130; AOR = 1.045, 95% CI: 1.002-1.090) were more likely to intend to self-isolate and inform close contacts. Participants who had MSM in-person gatherings in the past 6 months were more likely to intend to self-isolate (AOR = 1.392, 95% CI: 1.066-1.208). Participants with higher depression scores (AOR = 0.968, 95% CI: 0.948-0.989) and self-stigma (AOR = 0.975, 95% CI: 0.954-0.997) were less likely to intend to self-isolate and inform close contacts, respectively. Self-isolation and informing close contacts when developing disease-related symptoms are acceptable measures in response to mpox in China. Strengthening targeted risk communication and self-efficacy, raising disease knowledge, providing mental support, and reducing stigma toward the affected community are warranted.


Assuntos
Infecções por HIV , Mpox , Minorias Sexuais e de Gênero , Masculino , Humanos , Adulto Jovem , Adulto , Homossexualidade Masculina , Estudos Transversais , Intenção , China/epidemiologia , Infecções por HIV/epidemiologia
14.
Plant Cell Environ ; 47(9): 3590-3604, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39031544

RESUMO

The response of mesophyll conductance (gm) to CO2 plays a key role in photosynthesis and ecosystem carbon cycles under climate change. Despite numerous studies, there is still debate about how gm responds to short-term CO2 variations. Here we used multiple methods and looked at the relationship between stomatal conductance to CO2 (gsc) and gm to address this aspect. We measured chlorophyll fluorescence parameters and online carbon isotope discrimination (Δ) at different CO2 mole fractions in sunflower (Helianthus annuus L.), cowpea (Vigna unguiculata L.), and wheat (Triticum aestivum L.) leaves. The variable J and Δ based methods showed that gm decreased with an increase in CO2 mole fraction, and so did stomatal conductance. There were linear relationships between gm and gsc across CO2 mole fractions. gm obtained from A-Ci curve fitting method was higher than that from the variable J method and was not representative of gm under the growth CO2 concentration. gm could be estimated by empirical models analogous to the Ball-Berry model and the USO model for stomatal conductance. Our results suggest that gm and gsc respond in a coordinated manner to short-term variations in CO2, providing new insight into the role of gm in photosynthesis modelling.


Assuntos
Dióxido de Carbono , Helianthus , Células do Mesofilo , Estômatos de Plantas , Triticum , Dióxido de Carbono/metabolismo , Estômatos de Plantas/fisiologia , Células do Mesofilo/fisiologia , Células do Mesofilo/metabolismo , Triticum/fisiologia , Triticum/metabolismo , Helianthus/fisiologia , Helianthus/metabolismo , Isótopos de Carbono , Fotossíntese/fisiologia , Fabaceae/fisiologia , Clorofila/metabolismo , Folhas de Planta/fisiologia , Folhas de Planta/metabolismo
15.
Sex Transm Dis ; 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39102512

RESUMO

BACKGROUND: Online support groups afford new opportunities to help individuals affected by HIV/AIDS to seek social support from peers. The study aimed to understand the willingness and associated factors of joining online support groups among men who have sex with men (MSM) living with HIV. METHODS: The study followed a mixed method approach, with qualitative in-depth interviews followed by a quantitative cross-sectional survey in three cities of Shandong Province, China from 2019 to 2020. The in-depth interviews were audio-taped, transcribed verbatim and analyzed using thematic approach. In the quantitative analysis, explanatory variables included sociodemographic, behavioral, clinical, psychological, and demand factors. Univariate and multivariable logistic regressions were conducted to examine the associated factors of willing to join online support groups. RESULTS: A total of 576 and 20 participants were included in the quantitative survey and qualitative interviews, respectively. Only 24.7% (142/576) of participants in the quantitative study were willing to join the online support group. Multivariable analysis showed the associated factors included income level, sexual orientation and availability of information. The barriers to joining online support groups included privacy disclosure concern and psychological pressure exposed to HIV-related information. Facilitators included information acquisition, mutual medication reminding, and emotional support. CONCLUSIONS: MSM living with HIV in China had relatively low willingness to join the online support groups. This study highlighted the importance of safeguarding privacy, involving professional mental health providers, and providing high-quality information when establishing online support groups for people living with HIV.

16.
BMC Cancer ; 24(1): 575, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38724921

RESUMO

OBJECTIVE: To identify the risk factors of cervical high-grade squamous intraepithelial lesion(HSIL) complicated with occult cervical cancer and standardize the management of initial treatment for HSIL. METHOD: The clinical data of patients who underwent total hysterectomy directly due to HSIL in the obstetrics and gynecology department of two tertiary hospitals and three secondary hospitals from 2018 to 2023 were collected. Their general characteristics, pathological parameters and survival status were analyzed. Logistic regression model was used to analyze the correlation between clinical parameters and postoperative pathological upgrading. RESULT: 1. Among the 314 patients with HSIL who underwent total hysterectomy directly, 73.2% were from primary hospitals. 2. 25 patients (7.9%) were pathologically upgraded to cervical cancer, all of which were early invasive cancer. 3. Up to now, there was no recurrence or death in the 25 patients with early-stage invasive cancer, and the median follow-up period was 21 months(range 2-59 months). 4. Glandular involvement(OR 3.968; 95%CI 1.244-12.662) and lesion range ≥ 3 quadrants (OR 6.527; 95% CI 1.78-23.931), HPV 16/18 infection (OR 5.382; 95%CI 1.947-14.872), TCT ≥ ASC-H (OR 4.719; 95%CI 1.892-11.766) were independent risk factors that affected the upgrading of postoperative pathology. 5. The area under the curve (AUC) calculated by the Logistic regression model was 0.840, indicating that the predictive value was good. CONCLUSION: There is a risk of occult cervical cancer in patients with HSIL. Glandular involvement, Lesion range ≥ 3 quadrants, HPV 16/18 infection and TCT ≥ ASC-H are independent risk factors for HSIL combined with occult cervical cancer. The prognosis of biopsy-proved HSIL patients who underwent extrafascial hysterectomy and unexpected early invasive cancer was later identified on specimen may be good.


Assuntos
Histerectomia , Neoplasias do Colo do Útero , Humanos , Feminino , Histerectomia/métodos , Estudos Retrospectivos , Pessoa de Meia-Idade , Neoplasias do Colo do Útero/cirurgia , Neoplasias do Colo do Útero/patologia , Adulto , Fatores de Risco , Idoso , Lesões Intraepiteliais Escamosas Cervicais/patologia , Lesões Intraepiteliais Escamosas Cervicais/cirurgia , Lesões Intraepiteliais Escamosas/patologia , Lesões Intraepiteliais Escamosas/cirurgia , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/virologia , Infecções por Papillomavirus/patologia , Displasia do Colo do Útero/cirurgia , Displasia do Colo do Útero/patologia , Gradação de Tumores
17.
Exp Physiol ; 109(7): 1109-1123, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38748896

RESUMO

Osteoporosis is a metabolic bone disease that involves gradual loss of bone density and mass, thus resulting in increased fragility and risk of fracture. Inflammatory cytokines, such as tumour necrosis factor α (TNF-α), inhibit osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), and several microRNAs are implicated in osteoporosis development. This study aimed to explore the correlation between TNF-α treatment and miR-27a-3p expression in BMSC osteogenesis and further understand their roles in osteoporosis. An osteoporosis animal model was established using ovariectomized (OVX) mice. Compared with Sham mice, the OVX mice had a significantly elevated level of serum TNF-α and decreased level of bone miR-27a-3p, and in vitro TNF-α treatment inhibited miR-27a-3p expression in BMSCs. In addition, miR-27a-3p promoted osteogenic differentiation of mouse BMSCs in vitro, as evidenced by alkaline phosphatase staining and Alizarin Red-S staining, as well as enhanced expression of the osteogenic markers Runx2 and Osterix. Subsequent bioinformatics analysis combined with experimental validation identified secreted frizzled-related protein 1 (Sfrp1) as a downstream target of miR-27a-3p. Sfrp1 overexpression significantly inhibited the osteogenic differentiation of BMSCs in vitro and additional TNF-α treatment augmented this inhibition. Moreover, Sfrp1 overexpression abrogated the promotive effect of miR-27a-3p on the osteogenic differentiation of BMSCs. Furthermore, the miR-27a-3p-Sfrp1 axis was found to exert its regulatory function in BMSC osteogenic differentiation via regulating Wnt3a-ß-catenin signalling. In summary, this study revealed that TNF-α regulated a novel miR-27a-3p-Sfrp1 axis in osteogenic differentiation of BMSCs. The data provide new insights into the development of novel therapeutic strategies for osteoporosis.


Assuntos
Diferenciação Celular , Modelos Animais de Doenças , Células-Tronco Mesenquimais , MicroRNAs , Osteogênese , Osteoporose , Ovariectomia , Fator de Necrose Tumoral alfa , Animais , MicroRNAs/metabolismo , MicroRNAs/genética , Osteoporose/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Osteogênese/fisiologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , Feminino , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/genética , Camundongos Endogâmicos C57BL , Transdução de Sinais , Células Cultivadas
18.
Langmuir ; 40(21): 11184-11195, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38748593

RESUMO

Photonic crystal-based ethanol concentration indicators with rapid response and brilliant structural color output definitely take a place in colorimetric sensors. Here, based on the H-bond-regulated swelling of acrylate shape memory polymers (SMPs) and the solvent-induced structural color change of the double inverse opal photonic crystals (DIOPCs), new-type photonic crystals (PCs) colorimetric indicators were constructed, exhibiting a span of maximum reflection wavelength (λmax) up to ∼166 nm in response to alcohols with concentrations from 0 to 100 vol %. DIOPC indicators (DIOPCIs) show a rapid response to alcohols (<1.5 s) and output different structural colors (covering from blue to red). The colorimetric sensing mechanism includes the solvent-triggered recovery of the inverse opal skeleton, the cosolvency effect and H-bonds induced swelling/shrinkage of the polymer, the phase separation between polystyrene (PS) microsphere and polymer skeleton, and the light diffraction of DIOPCs. While ensuring a larger λmax span by regulating the H-bond interactions in polymer chains through acrylamide (AAm), AAm-modified DIOPCIs are sensitive to some specific ethanol concentrations. The real-time sensing of ethanol concentration during fermentation verified the practicability of DIOPCIs, thus establishing a visual model between structural color and corresponding fermentation kinetics. We envisage that the DIOPCIs will contribute to the intelligentization of the alcoholic fermentation and distillation industry.

19.
Langmuir ; 40(6): 3231-3240, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38297996

RESUMO

Flocculants are crucial agents in wastewater treatment because they can remove oppositely charged impurities effectively and swiftly. However, flocculation also inevitably causes secondary contamination due to the residual properties, nonreusability, and nondegradability of traditional flocculant molecules. Herein, an ecofriendly starch-based flocculant, i.e., 2,4-bis(dimethylamino)-[1,3,5]-triazine-6-starch, was synthesized via a preactivation-etherification strategy. The large molecular weight property of the flocculant produced by this method enhances the intermolecular hydrophobic association, achieving complete phase separation of all flocculant molecules from water and residue-free flocculation for the first time. Importantly, a large molecular weight tertiary amine starch-based flocculant (LMTS) exhibits a remarkable flocculation capacity of over 1800 mg·g-1 for dye wastewater, which is significantly higher than that of traditional polyacrylamide and polyaluminum chloride flocculants. Furthermore, the LMTS flocculant could be recycled by pH adjustment, and its structural stability ensured sustained reusability. This high-performance residue-free biomass-based flocculant offers a green advance for wastewater treatment.

20.
Anticancer Drugs ; 35(6): 548-555, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38502829

RESUMO

Shwachman-Diamond syndrome (SDS) is an autosomal recessive genetic disease, which is prone to transform into myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). TP53 mutation is a driving factor involved in the transformation of SDS into MDS/AML, and in the evolution of MDS to AML. Allogeneic hematopoietic stem cell transplantation (Allo-HSCT) is the only curable approach, however, challenge remains regarding the balance between efficacy and the high risk from treatment-related toxicity and mortality to achieve temporary disease control before transplantation to gain time and opportunities for transplantation. At present, pre-transplant bridging therapy has emerged as one of the important options with improved efficacy, reduced tumor burden, and less treatment-related toxicity. Here we reported azacitidine combined with venetoclax was used as pre-transplant bridging regimen in a TP53-mutant AML-MR case developed from SDS. He achieved complete remission with incomplete recovery and proceeded to Allo-HSCT. We hope to provide some evidence and insight for in-depth research and clinical treatment by presenting this case.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Azacitidina , Compostos Bicíclicos Heterocíclicos com Pontes , Leucemia Mieloide Aguda , Mutação , Sulfonamidas , Proteína Supressora de Tumor p53 , Humanos , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/administração & dosagem , Azacitidina/uso terapêutico , Azacitidina/administração & dosagem , Sulfonamidas/uso terapêutico , Sulfonamidas/administração & dosagem , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Proteína Supressora de Tumor p53/genética , Masculino , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Transplante de Células-Tronco Hematopoéticas , Síndromes Mielodisplásicas/tratamento farmacológico , Síndromes Mielodisplásicas/genética
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa