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1.
Nature ; 630(8015): 198-205, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38720074

RESUMEN

Phosphoinositide-3-kinase-γ (PI3Kγ) is implicated as a target to repolarize tumour-associated macrophages and promote antitumour immune responses in solid cancers1-4. However, cancer cell-intrinsic roles of PI3Kγ are unclear. Here, by integrating unbiased genome-wide CRISPR interference screening with functional analyses across acute leukaemias, we define a selective dependency on the PI3Kγ complex in a high-risk subset that includes myeloid, lymphoid and dendritic lineages. This dependency is characterized by innate inflammatory signalling and activation of phosphoinositide 3-kinase regulatory subunit 5 (PIK3R5), which encodes a regulatory subunit of PI3Kγ5 and stabilizes the active enzymatic complex. We identify p21 (RAC1)-activated kinase 1 (PAK1) as a noncanonical substrate of PI3Kγ that mediates this cell-intrinsic dependency and find that dephosphorylation of PAK1 by PI3Kγ inhibition impairs mitochondrial oxidative phosphorylation. Treatment with the selective PI3Kγ inhibitor eganelisib is effective in leukaemias with activated PIK3R5. In addition, the combination of eganelisib and cytarabine prolongs survival over either agent alone, even in patient-derived leukaemia xenografts with low baseline PIK3R5 expression, as residual leukaemia cells after cytarabine treatment have elevated G protein-coupled purinergic receptor activity and PAK1 phosphorylation. Together, our study reveals a targetable dependency on PI3Kγ-PAK1 signalling that is amenable to near-term evaluation in patients with acute leukaemia.


Asunto(s)
Fosfatidilinositol 3-Quinasa Clase Ib , Leucemia , Transducción de Señal , Quinasas p21 Activadas , Animales , Humanos , Ratones , Línea Celular , Fosfatidilinositol 3-Quinasa Clase Ib/genética , Fosfatidilinositol 3-Quinasa Clase Ib/metabolismo , Citarabina/farmacología , Citarabina/uso terapéutico , Leucemia/tratamiento farmacológico , Leucemia/enzimología , Leucemia/genética , Leucemia/metabolismo , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Fosforilación Oxidativa/efectos de los fármacos , Quinasas p21 Activadas/antagonistas & inhibidores , Quinasas p21 Activadas/metabolismo , Fosforilación , Ensayos Antitumor por Modelo de Xenoinjerto
2.
Proc Natl Acad Sci U S A ; 121(19): e2315348121, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38701117

RESUMEN

Ovarian cancer is an aggressive gynecological tumor characterized by a high relapse rate and chemoresistance. Ovarian cancer exhibits the cancer hallmark of elevated glycolysis, yet effective strategies targeting cancer cell metabolic reprogramming to overcome therapeutic resistance in ovarian cancer remain elusive. Here, we revealed that epigenetic silencing of Otubain 2 (OTUB2) is a driving force for mitochondrial metabolic reprogramming in ovarian cancer, which promotes tumorigenesis and chemoresistance. Mechanistically, OTUB2 silencing destabilizes sorting nexin 29 pseudogene 2 (SNX29P2), which subsequently prevents hypoxia-inducible factor-1 alpha (HIF-1α) from von Hippel-Lindau tumor suppressor-mediated degradation. Elevated HIF-1α activates the transcription of carbonic anhydrase 9 (CA9) and drives ovarian cancer progression and chemoresistance by promoting glycolysis. Importantly, pharmacological inhibition of CA9 substantially suppressed tumor growth and synergized with carboplatin in the treatment of OTUB2-silenced ovarian cancer. Thus, our study highlights the pivotal role of OTUB2/SNX29P2 in suppressing ovarian cancer development and proposes that targeting CA9-mediated glycolysis is an encouraging strategy for the treatment of ovarian cancer.


Asunto(s)
Anhidrasa Carbónica IX , Mitocondrias , Neoplasias Ováricas , Femenino , Neoplasias Ováricas/genética , Neoplasias Ováricas/metabolismo , Neoplasias Ováricas/patología , Neoplasias Ováricas/tratamiento farmacológico , Humanos , Mitocondrias/metabolismo , Mitocondrias/efectos de los fármacos , Anhidrasa Carbónica IX/metabolismo , Anhidrasa Carbónica IX/genética , Línea Celular Tumoral , Animales , Ratones , Antígenos de Neoplasias/metabolismo , Antígenos de Neoplasias/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Glucólisis/efectos de los fármacos , Silenciador del Gen , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Resistencia a Antineoplásicos/genética , Resistencia a Antineoplásicos/efectos de los fármacos , Reprogramación Metabólica
3.
J Virol ; 97(5): e0020923, 2023 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-37120831

RESUMEN

Human adenoviruses type 3 (HAdV-3) and type 55 (HAdV-55) are frequently encountered, highly contagious respiratory pathogens with high morbidity rate. In contrast to HAdV-3, one of the most predominant types in children, HAdV-55 is a reemergent pathogen associated with more severe community-acquired pneumonia (CAP) in adults, especially in military camps. However, the infectivity and pathogenicity differences between these viruses remain unknown as in vivo models are not available. Here, we report a novel system utilizing human embryonic stem cells-derived 3-dimensional airway organoids (hAWOs) and alveolar organoids (hALOs) to investigate these two viruses. Firstly, HAdV-55 replicated more robustly than HAdV-3. Secondly, cell tropism analysis in hAWOs and hALOs by immunofluorescence staining revealed that HAdV-55 infected more airway and alveolar stem cells (basal and AT2 cells) than HAdV-3, which may lead to impairment of self-renewal functions post-injury and the loss of cell differentiation in lungs. Additionally, the viral life cycles of HAdV-3 and -55 in organoids were also observed using Transmission Electron Microscopy. This study presents a useful pair of lung organoids for modeling infection and replication differences between respiratory pathogens, illustrating that HAdV-55 has relatively higher replication efficiency and more specific cell tropism in human lung organoids than HAdV-3, which may result in relatively higher pathogenicity and virulence of HAdV-55 in human lungs. The model system is also suitable for evaluating potential antiviral drugs, as demonstrated with cidofovir. IMPORTANCE Human adenovirus (HAdV) infections are a major threat worldwide. HAdV-3 is one of the most predominant respiratory pathogen types found in children. Many clinical studies have reported that HAdV-3 causes less severe disease. In contrast, HAdV-55, a reemergent acute respiratory disease pathogen, is associated with severe community-acquired pneumonia in adults. Currently, no ideal in vivo models are available for studying HAdVs. Therefore, the mechanism of infectivity and pathogenicity differences between human adenoviruses remain unknown. In this study, a useful pair of 3-dimensional (3D) airway organoids (hAWOs) and alveolar organoids (hALOs) were developed to serve as a model. The life cycles of HAdV-3 and HAdV-55 in these human lung organoids were documented for the first time. These 3D organoids harbor different cell types, which are similar to the ones found in humans. This allows for the study of the natural target cells for infection. The finding of differences in replication efficiency and cell tropism between HAdV-55 and -3 may provide insights into the mechanism of clinical pathogenicity differences between these two important HAdV types. Additionally, this study provides a viable and effective in vitro tool for evaluating potential anti-adenoviral treatments.


Asunto(s)
Infecciones por Adenovirus Humanos , Adenovirus Humanos , Antivirales , Células Madre Embrionarias Humanas , Adulto , Niño , Humanos , Infecciones por Adenovirus Humanos/tratamiento farmacológico , Infecciones por Adenovirus Humanos/virología , Adenovirus Humanos/clasificación , Adenovirus Humanos/fisiología , Antivirales/farmacología , Pulmón/virología , Organoides , Neumonía , Especificidad de la Especie
4.
Opt Express ; 32(11): 19467-19479, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38859081

RESUMEN

Computational micro-spectrometers comprised of detector arrays and encoding structure arrays, such as on-chip Fabry-Perot (FP) cavity filters, have great potential in many in-situ applications owing to their compact size and snapshot imaging ability. Given manufacturing deviation and environmental influence are inevitable, easy and effective calibration for spectrometer is necessary, especially for in-situ applications. Currently calibration strategies based on iterative algorithms or neural networks require accurate measurements of pixel-level (spectral) encoding functions through monochromator or large amounts of standard samples. These procedures are time-consuming and expensive, thereby impeding in-situ applications. Meta-learning algorithms with few-shot learning ability can address this challenge by incorporating the prior knowledge in the simulated dataset. In this work, we propose a meta-learning algorithm free of measuring encoding function or large amounts of standard samples to calibrate a micro-spectrometer with manufacturing deviation effectively. Our micro-spectrometer comprises 16 types of FP filters covering a wavelength range of 550-720 nm. The center wavelength of each filter type deviates from the design up to 6 nm. After calibration with 15 different color data, the average reconstruction error on the test dataset decreased from 7.2 × 10-3 to 1.2 × 10-3, and further decreased to 9.4 × 10-4 when the calibration data increased to 24. The performance is comparable to algorithms trained with measured encoding function both in reconstruction error and generalization ability. We estimated that the cost of in-situ calibration through reflectance measurements of color chart decreased to one percent of the cost through monochromator measurements. By exploiting prior deviation information in simulation data with meta-learning, the efficiency and cost of calibration are significantly improved, thereby facilitating the large-scale production and in-situ application of micro-spectrometers.

5.
Chemistry ; 30(10): e202302552, 2024 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-37997029

RESUMEN

This work demonstrated the first synthetic application of direct C-H olefinations in the step-saving preparation of various hole-transporting materials (HTM) for efficient perovskite solar cells (PSC). Cross-dehydrogenative couplings of naphthodithiophene (NDT) with vinyl arenes under palladium-catalysis facilely generated various new oligo(hetero)aryls with internal alkenes. Reaction conditions were optimized, which gave the product isolated yields of up to 71 % with high (E)-stereoselectivity. These readily accessible NDT core-based small molecules involving olefin as π-spacers displayed immediate power conversion efficiencies of up to 17.2 % without a device oxidation process that is required for the commercially available spiro-OMeTAD and most other existing HTMs while fabricated in corresponding PSC devices.

6.
Anal Biochem ; 692: 115552, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38718956

RESUMEN

The reactive nitrogen species (RNS) in lysosomes play a major role during the regulation of lysosomal microenvironment. Nitroxyl (HNO) belongs to active nitrogen species (RNS) and is becoming a potential diagnostic and therapeutic biomarker. However, the complex synthesis routes of HNO in biosystem always hinder the exact determination of HNO in living cells. Here, a rhodamine-based fluorescent probe used to determine nitroxyl (HNO) in lysosomes was constructed and synthesized. 2-(Diphenylphosphino)benzoate was utilized as the sensing unit for HNO and morpholine was chose as the targeting group for lysosome. Before the addition of HNO, the probe displayed a spirolactone structure and almost no fluorescence was found. After the addition of HNO, the probe existed as a conjugated xanthene form and an intense green fluorescence was observed. The fluorescent probe possessed fast response (3 min) and high selectivity for HNO. Furthermore, fluorescence intensity of the probe linearly related with the HNO concentration in the range of 6.0 × 10-8 to 6.0 × 10-5 mol L-1. The detection limit was found to be 1.87 × 10-8 mol L-1 for HNO. Moreover, the probe could selectively targeted lysosome with excellent biocompatibility and had been effectually utilized to recognize exogenous HNO in A549 cells.


Asunto(s)
Colorantes Fluorescentes , Lisosomas , Óxidos de Nitrógeno , Rodaminas , Colorantes Fluorescentes/química , Colorantes Fluorescentes/síntesis química , Lisosomas/metabolismo , Óxidos de Nitrógeno/análisis , Óxidos de Nitrógeno/química , Humanos , Rodaminas/química , Rodaminas/síntesis química
7.
J Sleep Res ; : e14190, 2024 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-38453144

RESUMEN

The presence of a circadian cycle of cerebral blood flow may have implications for the occurrence of daily variations in cerebrovascular events in humans, but how cerebral blood flow varies throughout the day and its mechanism are still unclear. The study aimed to explore the diurnal variation of cerebral blood flow in healthy humans and its possible mechanisms. Arterial spin labelling images were collected at six time-points (09:00 hours, 13:00 hours, 17:00 hours, 21:00 hours, 01:00 hours, 05:00 hours) from 18 healthy participants (22-39 years old; eight females) to analyse diurnal variations in cerebral blood flow. Resting heart rate and blood pressure at six time-points and blood indicators (20-hydroxyeicosatetraenoic acid, epoxyeicosatrienoic acids, prostaglandin E2, noradrenaline and nitric oxide) related to cerebral vascular tone at two time-points (09:00 hours and 21:00 hours) were collected to analyse possible influences on diurnal variations in cerebral blood flow. From 21:00 hours to 05:00 hours, parietal cortical relative cerebral blood flow tended to increase, while frontal cortical and cerebellar relative cerebral blood flow tended to decrease. There was a time-dependent negative correlation between parietal cortical relative cerebral blood flow and resting heart rate, whereas there was a time-dependent positive correlation between cerebellar relative cerebral blood flow and resting heart rate. The change of parietal cortical relative cerebral blood flow was positively correlated with the change of nitric oxide. There was also a time-dependent positive correlation between mean arterial pressure and mean whole-brain cerebral blood flow. The findings indicated that parietal cortical relative cerebral blood flow and frontal cortical/cerebellar relative cerebral blood flow showed roughly opposite trends throughout the day. The diurnal variations in relative cerebral blood flow were regional-specific. Diurnal variation of nitric oxide and neurogenic regulation may be potential mechanisms for diurnal variation in regional relative cerebral blood flow.

8.
J Clin Gastroenterol ; 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38457411

RESUMEN

BACKGROUND AND AIMS: Many studies have shown a link between physical activity (PA) and nonalcoholic fatty liver disease (NAFLD). However, more research is needed to investigate the relationship between different types of PA and NAFLD. This study aimed to explore the potential link between different types of PA, hepatic steatosis, and liver fibrosis. STUDY: A cross-sectional study was conducted using the data set from the National Health and Nutrition Examination Survey (NHANES) from 2017 to 2020. A multiple linear regression model was used to examine the linear relationship between different types of PA, the controlled attenuation parameter (CAP), and liver stiffness measurement (LSM). In addition, smoothing curve fitting and threshold effect analysis were used to depict their nonlinear relationship. RESULTS: This study involved 5933 adults. Multiple linear regression analysis revealed a significantly negative correlation between leisure-time PA and CAP, while the relationship between occupation-related PA, transportation-related PA, and CAP was not significant. Subgroup analysis further revealed that leisure-time PA was significantly negatively correlated with CAP in women and younger age groups (under 60 y old), while the relationship was not significant in men and older age groups. In addition, there was a significant negative correlation between leisure-time PA and liver fibrosis in men. CONCLUSIONS: Leisure-time PA can prevent hepatic steatosis, and women and young people benefit more. Occupation-related PA is not associated with hepatic steatosis and cannot replace leisure-time PA. In men, increasing leisure-time PA is more effective in preventing liver fibrosis.

9.
Mol Ther ; 31(2): 552-568, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36245126

RESUMEN

Inducing cancer cell apoptosis through cytotoxic reagents is the main therapeutic strategy for diverse cancer types. However, several antiapoptotic factors impede curative cancer therapy by driving cancer cells to resist cytotoxic agent-induced apoptosis, thus leading to refractoriness and relapse. To define critical antiapoptotic factors that contribute to chemoresistance in esophageal squamous cell carcinoma (ESCC), we generated two pairs of parental and apoptosis-resistant cell models through cisplatin (DDP) induction and then performed whole-transcriptome sequencing. We identified the long noncoding RNA (lncRNA) histocompatibility leukocyte antigen complex P5 (HCP5) as the chief culprit for chemoresistance. Mechanistically, HCP5 interacts with UTP3 small subunit processome component (UTP3) and prevents UTP3 degradation from E3 ligase tripartite motif containing 29 (TRIM29)-mediated ubiquitination. UTP3 then recruits c-Myc to activate vesicle-associated membrane protein 3 (VAMP3) expression. Activated VAMP3 suppresses caspase-dependent apoptosis and eventually leads to chemoresistance. Accordingly, the expression level of the HCP5/UTP3/c-Myc/VAMP3 axis in chemoresistant patients is significantly higher than that in chemosensitive patients. Thus, our study demonstrated that the HCP5/UTP3/c-Myc/VAMP3 axis plays an important role in the inhibition of cancer cell apoptosis and that HCP5 may be a promising chemosensitivity target for cancer treatment.


Asunto(s)
Antineoplásicos , Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , MicroARNs , ARN Largo no Codificante , Humanos , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Apoptosis/genética , Línea Celular Tumoral , Proliferación Celular , Proteínas de Unión al ADN/metabolismo , Neoplasias Esofágicas/genética , Carcinoma de Células Escamosas de Esófago/tratamiento farmacológico , Regulación Neoplásica de la Expresión Génica , MicroARNs/genética , Recurrencia Local de Neoplasia/genética , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Factores de Transcripción/genética , Ubiquitinación , Proteína 3 de Membrana Asociada a Vesículas/genética , Proteína 3 de Membrana Asociada a Vesículas/metabolismo
10.
Small ; 19(50): e2304406, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37616512

RESUMEN

Defect-rich carbon materials are considered as one of the most promising anodes for potassium-ion batteries due to their enormous adsorption sites of K+ , while the realization of both rate capability and cycling stability is still greatly limited by unstable electrochemical kinetics and inevitable structure degradation. Herein, an Fe3+ -induced hydrothermal-pyrolysis strategy is reported to construct well-tailored hybrid carbon nanotubes network architecture (PP-CNT), in which the short-range graphitic nanodomains are in-situ localized in the pea pod shape hypocrystalline carbon. The N,O codoped hypocrystalline carbon region contributes to abundant defect sites for potassium ion storage, ensuring high reversible capacity. Meanwhile, the short-range graphitic nanodomains with expanded interlayer spacing facilitate stable K+ migration and fast electron transfer. Furthermore, the finite element analysis confirms the volume expansion caused by K+ intercalation can be availably buffered due to the multidirection stress release effect of the unique porous pea pod shape, endowing carbon nanotubes with superior structural integrity. Consequently, the PP-CNT anode exhibits superior potassium-storage performance, including high reversible capacity, exceptional rate capability, and ultralong cycling stability. This work opens a new avenue for the fabrication of advanced carbon materials for achieving durable and fast potassium storage.

11.
Appl Environ Microbiol ; 89(3): e0196322, 2023 03 29.
Artículo en Inglés | MEDLINE | ID: mdl-36853033

RESUMEN

In this study, a new cytochrome P450 enzyme, namely, CYP68J5_Fusarium graminearum (CYP68J5_fg), was identified from Fusarium graminearum via a combination of transcriptome sequencing and heterologous expression in Saccharomyces cerevisiae. The biotransformation of progesterone by whole-cells of S. cerevisiae expressing CYP68J5_fg revealed that the CYP68J5_fg possessed steroidal 12ß- and 15α-hydroxylase activities. To the best of our knowledge, this is the first time that a fungal P450 enzyme with 12ß-hydroxylase activity has been identified. This advance offers opportunities to boost the efficiency and selectivity of the CYP68J5_fg hydroxylating system and thus shows great potential for further applications of this enzyme for the synthesis of steroid drugs. IMPORTANCE Regioselective and stereoselective hydroxylation is of vital importance in the functionalization of steroids, which remains challenging in organic synthesis. In particular, the C12-hydroxy steroids play a significant role in the synthesis of many important steroidal drugs. In this study, a novel fungal P450 enzyme with 12ß-hydroxylation activity was identified, and it shows different substrate specificity and regioselectivity, compared to the bacterial and fungal steroidal hydroxylases that are known to date. This lays the foundation for the creation of effective biocatalysts for the process of 12ß-hydroxylation, although further understanding of the molecular structural basis of this fungal P450 is needed to facilitate the engineering of this enzyme for industrial applications.


Asunto(s)
Sistema Enzimático del Citocromo P-450 , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Hidroxilación , Sistema Enzimático del Citocromo P-450/metabolismo , Esteroides/metabolismo
12.
Langmuir ; 39(20): 7221-7230, 2023 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-37167614

RESUMEN

Micro-structural evolution mechanisms of next-generation ultra-high-energy all-nitrogen materials under the extreme conditions of high temperature coupled with high pressure were revealed by state-of-the-art ab initio molecular dynamics studies based on highest-nitrogen-content energetic material 2,2'-azobis(5-azidotetrazole). The results indicate that there are three primary initial uni-molecular decomposition pathways, namely, tetrazole ring opening, azido group elimination, and the breaking of the N-N bond between the azo group and azidotetrazole. In complicated global decomposition reactions, there exists the formation of nitrogen-rich clusters and all-nitrogen species. Lowering the temperature or increasing the pressure is conducive to increasing the N content in the nitrogen-rich cluster and widening the time distribution for the cluster. Abundant all-nitrogen species N4, N5, N6, N7, N8, N9, N10, and N13 were formed, and their detailed evolutionary process and construction mechanisms were enunciated. We innovatively constructed a series of next-generation ultra-high-energy all-nitrogen materials, which are expected to realize the controllable construction of next-generation ultra-high-energy all-nitrogen materials under extreme conditions.

13.
J Theor Biol ; 565: 111467, 2023 05 21.
Artículo en Inglés | MEDLINE | ID: mdl-36963627

RESUMEN

Estimating microbial mutation rates is an essential task in evolutionary biology, with wide range applications in related fields such as virology, epidemiology, clinic and public health, and antibiotic research. Significant progress has been made on this research since 1943 when Luria-Delbrück fluctuation analysis was first introduced. However, existing estimators of mutation rates are heavily reliant on model assumptions in fluctuation analysis, and become less applicable to real microbial experiments which deviate from the model assumptions. To overcome this difficulty, we propose to model fluctuation experimental data by a two-type Markov branching process (MBP) and use approximate Bayesian computation (ABC) to estimate the mutation probability parameters. Such an ABC-based mutation rate estimator is based on intensive simulations from the mutation process, thereby taking advantage of modern computing power. Most importantly, its likelihood-free feature allows more complex and realistic setups of the mutation process, especially when the distribution of the number of mutants cannot be easily derived. To further improve computation efficiency, we use a Gaussian process surrogate to substitute the simulator in the ABC algorithm, and call the resulting estimator GPS-ABC. Simulation studies show that, when used to estimate constant mutation rate in MBP, ABC-based estimators generally outperform traditional moment or likelihood-based estimators. When mutations occur in two stages, i.e., in MBP with a piece-wise constant mutation rate function, traditional mutation rate estimators become not applicable, yet GPS-ABC still achieves reasonable estimates. Finally, the proposed GPS-ABC estimator is used to analyze real fluctuation experimental datasets for studying drug resistance.


Asunto(s)
Tasa de Mutación , Funciones de Verosimilitud , Teorema de Bayes , Simulación por Computador , Mutación
14.
Inorg Chem ; 62(36): 14559-14567, 2023 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-37647244

RESUMEN

The construction and design of pyrotechnics with superior performance is not only a task of great significance but also a tremendous challenge. In this regard, we present the syntheses of novel green primary colors pyrotechnics (red, green, and blue light-generating pyrotechnics) by employing 4-chloro-3,5-dinitropyrazole (CDNP) as a multifunctional raw material. CDNP contains a flame enhancer, oxygen-rich functional group, and nitrogen heterocyclic combustibles, which contribute to the high performance of the pyrotechnics. The characteristic elements (strontium, barium, and copper) that impart color to the flame are combined with the CDNP to synthesize the primary colors pyrotechnics by an "all-in-one" strategy. The structures of three energetic metal salts (EMS-1, EMS-2, and EMS-3) are completely characterized, and their thermal stability, sensitivity, ignition performance, and color purity are systematically evaluated. All EMSs show excellent thermal stability and low mechanical sensitivities (>330 °C, >40 J, >360 N). Moreover, the EMSs demonstrate successful ignition and combustion under laser conditions and roasting test conditions, producing bright characteristic flames. Chromaticity analysis reveals that the three EMSs possess good color purities of 91, 80, and 70%, respectively. Consequently, the three integrated pyrotechnics exhibit exceptional combustion properties, highlighting their potential for use in various pyrotechnic applications.

15.
Environ Sci Technol ; 57(5): 1894-1906, 2023 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-36693029

RESUMEN

Polyurethane (PU) synthetic leathers possess an intricate plastic composition, including polyester (PET) base fabrics and upper PU resin, but the release of fragments from the complexes is unclear. Therefore, we investigated the photodegradation trends of PET base fabrics with PU coating (PET-U) as a representative of composite plastics. Attention was paid to the comparison of the photoaging process of PET-U with that of pure PET base fabric (PET-P). To reveal the potential for chain scission, physical and chemical changes (e.g., surface morphology, molecular weight, and crystallinity) of the two fabrics were explored. The generation of microplastic fibers (MPFs) and microplastic particles (MPPs) was distinguished. Compared with PET-P, PET-U showed a similar but delayed trend in various characteristics and debris release rate as the photoaging time prolonged. Even so, after 360 h of illumination, the generated number of MPs (including MPFs and MPPs) rose considerably to 9.32 × 107 MPs/g, and the amount of released nanoplastics (NPs) increased to 2.70 × 1011 NPs/g from PET-U. The suppression of MP formation from PET-U was potentially directed by the physical shielding of the upper PU layer and the dropped MPs, which resisted the photochemical radical effect. The components of dissolved organic matter derived from plastics (P-DOM) were separated by molecular weight using a size-exclusion chromatography-diode array detector-organic carbon detector/organic nitrogen detector (SEC-DAD-OCD/OND), and the results showed that a larger amount of carbon- and nitrogen-containing chemical substances were generated in PET-U, accompanied by more aromatic and fluorescent compounds. The results provided theoretical bases and insights for future research on the risks of plastic debris from PU synthetic leathers on aquatic organisms and indicated feasible directions for exploring combined pollution studies of plastics.


Asunto(s)
Plásticos , Contaminantes Químicos del Agua , Plásticos/química , Microplásticos , Poliuretanos , Poliésteres , Fotólisis , Contaminantes Químicos del Agua/análisis
16.
Phys Chem Chem Phys ; 25(8): 6481-6490, 2023 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-36786002

RESUMEN

A comparative DFT-D study was performed to investigate the external electric field-induced crystal structures, electronic features, Hirshfeld surfaces, vibrational properties and initial decomposition mechanisms of nitrogen-rich binary CN compound 2,2'-azobis(5-azidotetrazole) (C2N16) and its precursor 2-amino-5-azidotetrazole (CH2N8). The results show that there exist phase transitions at the critical points of 0.006 a.u. and 0.008 a.u. for CH2N8 and C2N16, respectively, which are embodied in various properties of these compounds and induce their initial decomposition of the tetrazole ring opening via the breaking of N-N single bonds. The analysis of band gaps and density of states suggests the external electric field-induced enhancing ability for electron transition from the occupied orbitals to empty ones and N-N bond breaking may be the initial decomposition pathway for them. The variations in Hirshfeld surfaces indicate the spatial change and adjustment of non-bonding interactions in the two crystals. The discussions on vibrational properties indicate that IR characteristic peaks of all vibrational modes in the two crystals show a gradual red shift toward a low frequency region. The external electric field-induced initial decomposition pathways of both crystals are tetrazole ring opening via the breaking of a N-N single bond. Our findings provide insights for a comprehensive understanding of external electric field-induced phase transition and initial decomposition mechanisms of nitrogen-rich binary CN energetic compounds.

17.
J Clin Periodontol ; 50(2): 220-231, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36217693

RESUMEN

AIM: Macrophages are closely involved in periodontitis. However, the molecular mechanism by which macrophages influence periodontitis is not well understood. We investigated the effects of phosphatase and tensin homologue (PTEN) on macrophage polarization, the underlying mechanism and the regulatory roles in periodontium regeneration. MATERIALS AND METHODS: PTEN expression in periodontitis macrophages was detected ex vivo. The effects of PTEN on macrophage polarization and the underlying mechanisms were investigated in vitro. We also analysed the ability of PTEN inhibitors to repair periodontitis in vivo in a ligature-induced mouse model of periodontitis. RESULTS: Macrophage PTEN expression in periodontitis patients was significantly higher than that of controls. PTEN inhibition in macrophages induced alternative macrophage polarization, whereas PTEN overexpression facilitated classical polarization. PTEN inhibition facilitated activation of Akt1 while inhibiting expression of Akt2. Furthermore, Akt2 overexpression could rescue the effects of PTEN inhibition on NF-κB. Treatment with a PTEN inhibitor significantly attenuated the local inflammatory status and prevented alveolar bone resorption in the mouse model. CONCLUSIONS: Our findings suggest that PTEN inhibition could induce alternative macrophage polarization by differentially regulating Akt1 and Akt2. This also changed a pro-inflammatory microenvironment to an anti-inflammatory environment by subsequently regulating the expression of NF-κB, thereby attenuating inflammatory alveolar bone resorption induced by ligature.


Asunto(s)
Pérdida de Hueso Alveolar , Macrófagos , Fosfohidrolasa PTEN , Periodontitis , Proteínas Proto-Oncogénicas c-akt , Animales , Humanos , Ratones , Modelos Animales de Enfermedad , Macrófagos/metabolismo , FN-kappa B/metabolismo , Periodontitis/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Fosfohidrolasa PTEN/metabolismo
18.
Molecules ; 28(1)2023 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-36615648

RESUMEN

In order to broaden the study of energetic cations, a cation 3,5-diamino-4H-pyrazol-4-one oxime (DAPO) with good thermal stability was proposed, and its three salts were synthesized by a simple and efficient method. The structures of the three salts were verified by infrared spectroscopy, mass spectrometry, elemental analysis, and single crystal X-ray diffraction. The thermal stabilities of the three salts were verified by differential scanning calorimetry and thermos-gravimetric analysis. DAPO-based energetic salts are analysed using a variety of theoretical techniques, such as 2D fingerprint, Hirshfeld surface, and non-covalent interaction. Among them, the energy properties of perchlorate (DAPOP) and picrate (DAPOT) were determined by EXPLO5 program combined with the measured density and enthalpy of formation. These compounds have high density, acceptable detonation performance, good thermal stability, and satisfactory sensitivity. The intermolecular interactions of the four compounds were studied by Hirshfeld surface and non-covalent interactions, indicating that hydrogen bonds and π-π stacking interactions are the reasons for the extracellular properties of perchlorate (DAPOP) and picrate (DAPOT), indicating that DAPO is an optional nitrogen-rich cation for the design and synthesis of novel energetic materials with excellent properties.


Asunto(s)
Percloratos , Sales (Química) , Picratos , Oximas
19.
Environ Monit Assess ; 195(3): 383, 2023 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-36763164

RESUMEN

Microplastic pollution on bathing beaches threatens the health of human beings and coastal organisms. There is a lack of assessment on the level of microplastic pollution and the health risk associated with plastics. As one of the earliest open bathing beaches in China, Liandao is well known as the two high-quality beaches. However, little is known about the extent of microplastic pollution on these bathing beaches. Based on the analysis of microplastic pollution abundance, distribution, shape, size, color, and composition at the Liandao bathing beaches, this study puts forward a novel approach to comprehensively evaluate the microplastic pollution level and risk level by using the Nemerow pollution index (NPI) and polymer hazard index (PHI). The results show that the average abundance of microplastics on the Liandao bathing beaches is 135.42 ± 49.58 items/kg; the main shapes are fibers, fragments, and granules. Most of the microplastics are transparent, brown, and black, accounting for 71.54%, and they have an average particle size of 0.63 ± 0.43 mm. The main components are PE, PP, PS, PET, and nylon, of which nylon appears in the highest proportion (54.77%). The microplastic NPI and PHI values are 0.38 and 74.81, respectively, indicating that the pollution level and health risk index of microplastics on the Liandao bathing beaches are both low. With the increase in population and per capita consumption, plastic waste generated on land will continue to increase. Finally, this study puts forward some suggestions regarding microplastic monitoring, plastic waste management, and environmental attitudes and behavior.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Humanos , Plásticos/análisis , Nylons , Playas , Monitoreo del Ambiente/métodos , Contaminantes Químicos del Agua/análisis , China
20.
BMC Bioinformatics ; 23(1): 535, 2022 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-36494794

RESUMEN

BACKGROUND: Rapidly growing genome-wide ChIP-seq data have provided unprecedented opportunities to explore transcription factor (TF) binding under various cellular conditions. Despite the rich resources, development of analytical methods for studying the interaction among TFs in gene regulation still lags behind. RESULTS: In order to address cooperative TF binding and detect TF clusters with coordinative functions, we have developed novel computational methods based on clustering the sample paths of nonhomogeneous Poisson processes. Simulation studies demonstrated the capability of these methods to accurately detect TF clusters and uncover the hierarchy of TF interactions. A further application to the multiple-TF ChIP-seq data in mouse embryonic stem cells (ESCs) showed that our methods identified the cluster of core ESC regulators reported in the literature and provided new insights on functional implications of transcrisptional regulatory modules. CONCLUSIONS: Effective analytical tools are essential for studying protein-DNA relations. Information derived from this research will help us better understand the orchestration of transcription factors in gene regulation processes.


Asunto(s)
Genoma , Factores de Transcripción , Animales , Ratones , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Unión Proteica/genética , Análisis por Conglomerados , Regulación de la Expresión Génica , Sitios de Unión
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