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1.
J Cell Physiol ; 239(1): 124-134, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37942832

RESUMEN

Studies regarding age-related erectile dysfunction (ED) based on naturally aging models are limited by their high costs, especially for the acquisition of primary cells from the corpus cavernosum. Herein, d-galactose ( d-gal) was employed to accelerate cell senescence, and the underlying mechanism was explored. As predominant functional cells involved in the erectile response, corpus cavernosum smooth muscle cells (CCSMCs) were isolated from 2-month-old rats. Following this, d-gal was introduced to induce cell senescence, which was verified via ß-galactosidase staining. The effects of d-gal on CCSMCs were evaluated by terminal deoxynucleoitidyl transferase dUTP nick-end labeling (TUNEL), immunofluorescence staining, flow cytometry, western blot, and quantitative real-time polymerase chain reaction (qRT-PCR). Furthermore, RNA interference (RNAi) was carried out for rescue experiments. Subsequently, the influence of senescence on the corpus cavernosum was determined via scanning electron microscopy, qRT-PCR, immunohistochemistry, TUNEL, and Masson stainings. The results revealed that the accelerated senescence of CCSMCs was promoted by d-gal. Simultaneously, smooth muscle alpha-actin (alpha-SMA) expression was inhibited, while that of osteopontin (OPN) and Krüppel-like factor 4 (KLF4), as well as fibrotic and apoptotic levels, were elevated. After knocking down KLF4 expression in d-gal-induced CCSMCs by RNAi, the expression level of cellular alpha-SMA increased. Contrastingly, the OPN expression, apoptotic and fibrotic levels declined. In addition, cellular senescence acquired partial remission. Accordingly, in the aged corpus cavernosum, the fibrotic and apoptotic rates were increased, followed by downregulation in the expression of alpha-SMA and the concurrent upregulation in the expression of OPN and KLF4. Overall, our results signaled that d-gal-induced accelerated senescence of CCSMCs could trigger fibrosis, apoptosis and phenotypic switch to the synthetic state, potentially attributed to the upregulation of KLF4 expression, which may be a multipotential therapeutic target of age-related ED.


Asunto(s)
Disfunción Eréctil , Galactosa , Miocitos del Músculo Liso , Animales , Masculino , Ratas , Disfunción Eréctil/metabolismo , Disfunción Eréctil/terapia , Galactosa/farmacología , Galactosa/metabolismo , Miocitos del Músculo Liso/citología , Miocitos del Músculo Liso/metabolismo , Pene , Fenotipo , Ratas Sprague-Dawley , Actinas
2.
J Am Chem Soc ; 146(9): 5908-5915, 2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38391353

RESUMEN

Unconventional superconductivity in bulk materials under ambient pressure is extremely rare among the 3d transition metal compounds outside the layered cuprates and iron-based family. It is predominantly linked to highly anisotropic electronic properties and quasi-two-dimensional (2D) Fermi surfaces. To date, the only known example of a Co-based exotic superconductor is the hydrated layered cobaltate, NaxCoO2·yH2O, and its superconductivity is realized in the vicinity of a spin-1/2 Mott state. However, the nature of the superconductivity in these materials is still a subject of intense debate, and therefore, finding a new class of superconductors will help unravel the mysteries of their unconventional superconductivity. Here, we report the discovery of superconductivity at ∼6.3 K in our newly synthesized layered compound Na2CoSe2O, in which the edge-shared CoSe6 octahedra form [CoSe2] layers with a perfect triangular lattice of Co ions. It is the first 3d transition metal oxychalcogenide superconductor with distinct structural and chemical characteristics. Despite its relatively low TC, this material exhibits very high superconducting upper critical fields, µ0HC2(0), which far exceeds the Pauli paramagnetic limit by a factor of 3-4. First-principles calculations show that Na2CoSe2O is a rare example of a negative charge transfer superconductor. This cobalt oxychalcogenide with a geometrical frustration among Co spins shows great potential as a highly appealing candidate for the realization of unconventional and/or high-TC superconductivity beyond the well-established Cu- and Fe-based superconductor families and opens a new field in the physics and chemistry of low-dimensional superconductors.

3.
Chem Res Toxicol ; 37(1): 117-125, 2024 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-38146714

RESUMEN

Ammonia (NH3) is a commonly used industrial chemical to which exposure at high concentrations can result in severe skin damage. Moreover, high levels of ammonia in the human body can lead to hyperammonemia conditions and enhanced cancer metabolism. In this work, the toxicity mechanism of NH3 has been studied against human dermal fibroblast (HDF) cells using surface-enhanced Raman spectroscopy (SERS). For this purpose, gold nanoparticles of size 50 nm have been prepared and used as probes for Raman signal enhancement, after being internalized inside HDF cells. Following the exposure to ammonia, HDF cells showed a significant variation in the protein ternary structure's signals, demonstrating their denaturation and oxidation process, together with early signs of apoptosis. Meaningful changes were observed especially in the Raman vibrations of sulfur-containing amino acids (cysteine and methionine) together with aromatic residues. Fluorescence microscopy revealed the formation of reactive oxygen and nitrogen species in cells, which confirmed their stressed condition and to whom the causes of protein degradation can be attributed. These findings can provide new insights into the mechanism of ammonia toxicity and protein oxidation at a single-cell level, demonstrating the high potential of the SERS technique in investigating the cellular response to toxic compounds.


Asunto(s)
Nanopartículas del Metal , Neoplasias , Humanos , Oro/química , Amoníaco/toxicidad , Espectrometría Raman/métodos , Nanopartículas del Metal/química
4.
Infection ; 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38652225

RESUMEN

PURPOSE: Physicians may administer Nirmatrelvir-ritonavir to patients who have been symptomatic for more than 5 days. There is currently no clear evidence to support this approach. METHODS: A real-world study was conducted to investigate the potential relationship between the administration of Nirmatrelvir-ritonavir and the rates of intubation or in-hospital mortality among COVID-19 patients who experienced symptoms for more than 5 days. The end point was a composite event of intubation or in-hospital mortality. The outcomes between those patients who received Nirmatrelvir-ritonavir and those who did not were compared. RESULTS: A total of 847 patients were included in the analysis. Among them, 312 patients (36.84%) received Nirmatrelvir-ritonavir. Within the entire population, 86 patients (10.15%) experienced intubation or in-hospital mortality. The main analysis indicated that there was a significant association between the application of Nirmatrelvir-ritonavir and intubation or in-hospital mortality, with an odds ratio of 0.50 (95% confidence interval, 0.28 to 0.87; P = 0.0153) using inverse probability of treatment weighting. The finding was consistent with multiple sensitivity analyses. CONCLUSIONS: The application of Nirmatrelvir-ritonavir was associated with a significantly reduced risk of intubation or death in hospitalized COVID-19 patients who experienced symptoms for more than 5 days as compared to those who did not receive the treatment.

5.
Small ; 19(36): e2300286, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37162459

RESUMEN

Lithium-sulfur (Li-S) battery has been considered as a strong contender for commercial aerospace battery, but the commercialization requires Ah-level pouch cells with both efficient discharge at high rates and ultra-high energy density. In this paper, the application of lithium-sulfur batteries for powering drones by using the cathode of highly dispersed sulfur nanoparticles with well-controlled particle sizes have been realized. The sulfur nanoparticles are prepared by a precipitation method in an eco-friendly and efficient way, and loaded on graphene oxide-cetyltrimethylammonium bromide by molecular grafting to realize a large-scale fabrication of sulfur-based cathodes with superior electrochemical performance. A button cell based on the cathode exhibits an excellent discharge capacity of 62.8 mAh cm-2 at a high sulfur loading of 60 mg cm-2 (i.e., 1046.7 mAh g-1 ). The assembled miniature pouch cell (PCmini) shows a discharge capacity of 130 mAh g-1 , while the formed Ah-level pouch cell (PCAh) achieves energy density of 307 Wh kg-1 at 0.3C and 92 Wh kg-1 at 4C. Especially, a four-axis propeller drone powered by the PC has successfully completed a long flight (>3 min) at high altitudes, demonstrating the practical applicability as aviation batteries.

6.
Sensors (Basel) ; 23(14)2023 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-37514941

RESUMEN

To make unmanned surface vehicles that are better applied to the field of environmental monitoring in inland rivers, reservoirs, or coasts, we propose a global path-planning algorithm based on the improved A-star algorithm. The path search is carried out using the raster method for environment modeling and the 8-neighborhood search method: a bidirectional search strategy and an evaluation function improvement method are used to reduce the total number of traversing nodes; the planned path is smoothed to remove the inflection points and solve the path folding problem. The simulation results reveal that the improved A-star algorithm is more efficient in path planning, with fewer inflection points and traversing nodes, and the smoothed paths are more to meet the actual navigation demands of unmanned surface vehicles than the conventional A-star algorithm.

7.
Int J Mol Sci ; 24(16)2023 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-37628838

RESUMEN

Hydrolytic reactions taking place at the surface of a silicon nitride (Si3N4) bioceramic were found to induce instantaneous inactivation of Human herpesvirus 1 (HHV-1, also known as Herpes simplex virus 1 or HSV-1). Si3N4 is a non-oxide ceramic compound with strong antibacterial and antiviral properties that has been proven safe for human cells. HSV-1 is a double-stranded DNA virus that infects a variety of host tissues through a lytic and latent cycle. Real-time reverse transcription (RT)-polymerase chain reaction (PCR) tests of HSV-1 DNA after instantaneous contact with Si3N4 showed that ammonia and its nitrogen radical byproducts, produced upon Si3N4 hydrolysis, directly reacted with viral proteins and fragmented the virus DNA, irreversibly damaging its structure. A comparison carried out upon testing HSV-1 against ZrO2 particles under identical experimental conditions showed a significantly weaker (but not null) antiviral effect, which was attributed to oxygen radical influence. The results of this study extend the effectiveness of Si3N4's antiviral properties beyond their previously proven efficacy against a large variety of single-stranded enveloped and non-enveloped RNA viruses. Possible applications include the development of antiviral creams or gels and oral rinses to exploit an extremely efficient, localized, and instantaneous viral reduction by means of a safe and more effective alternative to conventional antiviral creams. Upon incorporating a minor fraction of micrometric Si3N4 particles into polymeric matrices, antiherpetic devices could be fabricated, which would effectively impede viral reactivation and enable high local effectiveness for extended periods of time.


Asunto(s)
Herpesvirus Humano 1 , Humanos , Compuestos de Silicona/farmacología , Antivirales/farmacología , ADN Viral
8.
Int J Mol Sci ; 24(7)2023 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-37047667

RESUMEN

This study probed in vitro the mechanisms of competition/coexistence between Streptococcus sanguinis (known for being correlated with health in the oral cavity) and Streptococcus mutans (responsible for aciduric oral environment and formation of caries) by means of quantitative Raman spectroscopy and imaging. In situ Raman assessments of live bacterial culture/coculture focusing on biofilm exopolysaccharides supported the hypothesis that both species engaged in antagonistic interactions. Experiments of simultaneous colonization always resulted in coexistence, but they also revealed fundamental alterations of the biofilm with respect to their water-insoluble glucan structure. Raman spectra (collected at fixed time but different bacterial ratios) showed clear changes in chemical bonds in glucans, which pointed to an action by Streptococcus sanguinis to discontinue the impermeability of the biofilm constructed by Streptococcus mutans. The concurrent effects of glycosidic bond cleavage in water-insoluble α - 1,3-glucan and oxidation at various sites in glucans' molecular chains supported the hypothesis that secretion of oxygen radicals was the main "chemical weapon" used by Streptococcus sanguinis in coculture.


Asunto(s)
Caries Dental , Streptococcus sanguis , Humanos , Streptococcus mutans , Biopelículas , Boca/microbiología , Glucanos/farmacología
9.
Int J Mol Sci ; 24(21)2023 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-37958551

RESUMEN

Raman spectroscopy was applied to study the structural differences between herpes simplex virus Type I (HSV-1) and Epstein-Barr virus (EBV). Raman spectra were first collected with statistical validity on clusters of the respective virions and analyzed according to principal component analysis (PCA). Then, average spectra were computed and a machine-learning approach applied to deconvolute them into sub-band components in order to perform comparative analyses. The Raman results revealed marked structural differences between the two viral strains, which could mainly be traced back to the massive presence of carbohydrates in the glycoproteins of EBV virions. Clear differences could also be recorded for selected tyrosine and tryptophan Raman bands sensitive to pH at the virion/environment interface. According to the observed spectral differences, Raman signatures of known biomolecules were interpreted to link structural differences with the viral functions of the two strains. The present study confirms the unique ability of Raman spectroscopy for answering structural questions at the molecular level in virology and, despite the structural complexity of viral structures, its capacity to readily and reliably differentiate between different virus types and strains.


Asunto(s)
Infecciones por Virus de Epstein-Barr , Herpes Simple , Herpesvirus Humano 1 , Humanos , Herpesvirus Humano 4 , Multiómica
10.
Int J Mol Sci ; 24(17)2023 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-37686157

RESUMEN

The aim of this study was to elucidate the chemistry of cellular degeneration in human neuroblastoma cells upon exposure to outer-membrane vesicles (OMVs) produced by Porphyromonas gingivalis (Pg) oral bacteria by monitoring their metabolomic evolution using in situ Raman spectroscopy. Pg-OMVs are a key factor in Alzheimer's disease (AD) pathogenesis, as they act as efficient vectors for the delivery of toxins promoting neuronal damage. However, the chemical mechanisms underlying the direct impact of Pg-OMVs on cell metabolites at the molecular scale still remain conspicuously unclear. A widely used in vitro model employing neuroblastoma SH-SY5Y cells (a sub-line of the SK-N-SH cell line) was spectroscopically analyzed in situ before and 6 h after Pg-OMV contamination. Concurrently, Raman characterizations were also performed on isolated Pg-OMVs, which included phosphorylated dihydroceramide (PDHC) lipids and lipopolysaccharide (LPS), the latter in turn being contaminated with a highly pathogenic class of cysteine proteases, a key factor in neuronal cell degradation. Raman characterizations located lipopolysaccharide fingerprints in the vesicle structure and unveiled so far unproved aspects of the chemistry behind protein degradation induced by Pg-OMV contamination of SH-SY5Y cells. The observed alterations of cells' Raman profiles were then discussed in view of key factors including the formation of amyloid ß (Aß) plaques and hyperphosphorylated Tau neurofibrillary tangles, and the formation of cholesterol agglomerates that exacerbate AD pathologies.


Asunto(s)
Enfermedad de Alzheimer , Neuroblastoma , Humanos , Porphyromonas gingivalis , Péptidos beta-Amiloides , Lipopolisacáridos , Cuerpos de Inclusión , Vesícula
11.
Aquac Nutr ; 2023: 5545898, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36967811

RESUMEN

This study is aimed at establishing optimal soybean lecithin (SL) enrichment protocols in Artemia nauplii and at comparing the growth performance, body composition, and liver tissue metabolism in rock bream (Oplegnathus fasciatus) larvae reared on SL-enriched Artemia nauplii or SL-enriched microdiet (MD). The enrichment protocol experiment results indicated 12 h enrichment, and 10 g SL/m3 seawater could obtain desirable results. Rock bream larvae (25 days posthatching (dph)) were fed Artemia nauplii or MD for 30 days with three replicates. At stage 1 (larval 25-40 dph), significantly higher growth performance was observed in larvae fed the live prey (P < 0.05). Conversely, at stage 2 (41-55 dph), feeding with MD significantly increased larval standard length, and specific growth rate compared with those of larvae fed live prey. Larvae fed a MD showed decreased lipolysis-related lipase activity as well as decreased amino acid catabolism-related alanine aminotransferase and aspartate aminotransferase enzyme activities in liver tissue. RNA sequencing revealed that feeding with the MD primarily increased the expression of lipogenesis-related genes and protein translation-related gene expression in the liver tissue. Notably, feeding with MD significantly increased ribosome biogenesis-related genes as well as mitochondria synthesis-related gene expression, indicating a high protein anabolism rate and high energy production in liver tissue. In conclusion, 10 g SL/m3 seawater and 12 h could effectively enrich SL in Artemia nauplii. Retard weaning onto MD led to lower growth performance, which was likely due to the diversity of lipid and protein metabolism.

12.
Ann Noninvasive Electrocardiol ; 27(1): e12889, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34755423

RESUMEN

INTRODUCTION: Long QT syndrome (LQTS) is a life-threatening inherited channelopathy, and prolonged QT intervals easily trigger malignant arrhythmias, especially torsades de pointes and ventricular fibrillation. MATERIALS AND METHODS: The proband with overlapped phenotypes of LQTS and sinoatrial node dysfunction underwent some necessary examinations, including echocardiography, electrocardiogram (ECG), and Holter monitoring. Next, whole-exome sequencing was performed, and candidate genes were validated by Sanger sequencing. RNA secondary structure and protein physical-chemical parameter analyses were used to predict the possible structural change of the proteins induced by the mutations. RESULTS: We identified the digenic heterozygous mutations of KCNH2 p.307_308del (NM_001204798, c.921_923del) and SCN5A p.R1865H (NM_001160160, c.G5594A) in the female and young proband (II: 1) of LQTS and ventricular fibrillation with repeat syncope at rest. Subsequently, she occurred with obvious sinus arrest with persistent ventricular pacing of implantable cardioverter-defibrillator. The heterozygous SCN5Ap.R1865H was carried by her father and sister but not carried by I:2. II:1 carried with KCNH2 p.307_308del as a de novo mutation, but not existed in other family members. RNA secondary structure of KCNH2 p.307_308del showed a false regional double helix, and its amino acids' hydrophobicity was significantly weakened. For the Nav 1.5 protein property, SCN5A p.R1865H slightly increased the molecular weight and aliphatic index but reduced the instability index. CONCLUSIONS: The digenic heterozygous KCNH2 and SCN5A mutations were associated with young early-onset long QT syndrome and sinoatrial node dysfunction.


Asunto(s)
Síndrome de QT Prolongado , Nodo Sinoatrial , Canal de Potasio ERG1/genética , Electrocardiografía , Canales de Potasio Éter-A-Go-Go/genética , Femenino , Humanos , Canal de Potasio KCNQ1/genética , Síndrome de QT Prolongado/genética , Mutación , Canal de Sodio Activado por Voltaje NAV1.5
13.
Int J Mol Sci ; 23(10)2022 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-35628169

RESUMEN

Oral candidiasis, a common opportunistic infection of the oral cavity, is mainly caused by the following four Candida species (in decreasing incidence rate): Candida albicans, Candida glabrata, Candida tropicalis, and Candida krusei. This study offers in-depth Raman spectroscopy analyses of these species and proposes procedures for an accurate and rapid identification of oral yeast species. We first obtained average spectra for different Candida species and systematically analyzed them in order to decode structural differences among species at the molecular scale. Then, we searched for a statistical validation through a chemometric method based on principal component analysis (PCA). This method was found only partially capable to mechanistically distinguish among Candida species. We thus proposed a new Raman barcoding approach based on an algorithm that converts spectrally deconvoluted Raman sub-bands into barcodes. Barcode-assisted Raman analyses could enable on-site identification in nearly real-time, thus implementing preventive oral control, enabling prompt selection of the most effective drug, and increasing the probability to interrupt disease transmission.


Asunto(s)
Candida , Candidiasis Bucal , Candida/química , Candida/genética , Candida albicans , Candidiasis Bucal/diagnóstico , Quimiometría , Espectrometría Raman/métodos
14.
Int J Mol Sci ; 23(15)2022 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-35897669

RESUMEN

This study presents a set of vibrational characterizations on a nanogel-cross-linked porous freeze-dried gel (NanoCliP-FD gel) scaffold for tissue engineering and regenerative therapy. This scaffold is designed for the in vitro culture of high-quality cartilage tissue to be then transplanted in vivo to enable recovery from congenital malformations in the maxillofacial area or crippling jaw disease. The three-dimensional scaffold for in-plate culture is designed with interface chemistry capable of stimulating cartilage formation and maintaining its structure through counteracting the dedifferentiation of mesenchymal stem cells (MSCs) during the formation of cartilage tissue. The developed interface chemistry enabled high efficiency in both growth rate and tissue quality, thus satisfying the requirements of large volumes, high matrix quality, and superior mechanical properties needed in cartilage transplants. We characterized the cartilage tissue in vitro grown on a NanoCliP-FD gel scaffold by human periodontal ligament-derived stem cells (a type of MSC) with cartilage grown by the same cells and under the same conditions on a conventional (porous) atelocollagen scaffold. The cartilage tissues produced by the MSCs on different scaffolds were comparatively evaluated by immunohistochemical and spectroscopic analyses. Cartilage differentiation occurred at a higher rate when MSCs were cultured on the NanoCliP-FD gel scaffold compared to the atelocollagen scaffold, and produced a tissue richer in cartilage matrix. In situ spectroscopic analyses revealed the cell/scaffold interactive mechanisms by which the NanoCliP-FD gel scaffold stimulated such increased efficiency in cartilage matrix formation. In addition to demonstrating the high potential of human periodontal ligament-derived stem cell cultures on NanoCliP-FD gel scaffolds in regenerative cartilage therapy, the present study also highlights the novelty of Raman spectroscopy as a non-destructive method for the concurrent evaluation of matrix quality and cell metabolic response. In situ Raman analyses on living cells unveiled for the first time the underlying physiological mechanisms behind such improved chondrocyte performance.


Asunto(s)
Cartílago , Andamios del Tejido , Cartílago/metabolismo , Células Cultivadas , Humanos , Nanogeles , Análisis Espectral , Ingeniería de Tejidos/métodos , Andamios del Tejido/química
15.
Int J Mol Sci ; 23(19)2022 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-36233043

RESUMEN

This study targets on-site/real-time taxonomic identification and metabolic profiling of seven different Candida auris clades/subclades by means of Raman spectroscopy and imaging. Representative Raman spectra from different Candida auris samples were systematically deconvoluted by means of a customized machine-learning algorithm linked to a Raman database in order to decode structural differences at the molecular scale. Raman analyses of metabolites revealed clear differences in cell walls and membrane structure among clades/subclades. Such differences are key in maintaining the integrity and physical strength of the cell walls in the dynamic response to external stress and drugs. It was found that Candida cells use the glucan structure of the extracellular matrix, the degree of α-chitin crystallinity, and the concentration of hydrogen bonds between its antiparallel chains to tailor cell walls' flexibility. Besides being an effective ploy in survivorship by providing stiff shields in the α-1,3-glucan polymorph, the α-1,3-glycosidic linkages are also water-insoluble, thus forming a rigid and hydrophobic scaffold surrounded by a matrix of pliable and hydrated ß-glucans. Raman analysis revealed a variety of strategies by different clades to balance stiffness, hydrophobicity, and impermeability in their cell walls. The selected strategies lead to differences in resistance toward specific environmental stresses of cationic/osmotic, oxidative, and nitrosative origins. A statistical validation based on principal component analysis was found only partially capable of distinguishing among Raman spectra of clades and subclades. Raman barcoding based on an algorithm converting spectrally deconvoluted Raman sub-bands into barcodes allowed for circumventing any speciation deficiency. Empowered by barcoding bioinformatics, Raman analyses, which are fast and require no sample preparation, allow on-site speciation and real-time selection of appropriate treatments.


Asunto(s)
Candidiasis , beta-Glucanos , Antifúngicos/farmacología , Candida auris , Quitina , Glucanos , Agua
16.
Angew Chem Int Ed Engl ; 61(13): e202114953, 2022 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-35104006

RESUMEN

The transformation of methane into high value-added chemicals such as aromatics provides a more desired approach towards sustainable chemistry but remains a critical challenge due to the low selectivity of aromatics and poor stability. Herein, we first report a coupling reaction of CH3 Cl and CO (CCTA) based on methane conversion, which achieves extremely high aromatics selectivity (82.2 %) with the selectivity of BTX up to ca. 60 % over HZSM-5. The promoting effects have been demonstrated on other zeolites especially 10-membered rings (10 MR) zeolites. Multiple characterizations show that 2,3-dimethyl-2-cyclopentene-1-one (DMCPO) is generated from acetyl groups and olefins. Furthermore, isotopic labeling analysis confirms that CO is inserted into the DMCPO and aromatics rings. A new aromatization mechanism is proposed, including the formation of the above intermediates, which conspicuously weakens the hydrogen transfer reaction, leading to a considerable increase of aromatics selectivity and a dramatic drop in alkanes.

17.
Angew Chem Int Ed Engl ; 61(31): e202203859, 2022 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-35638158

RESUMEN

The selective conversion of methane to high value-added chemicals under mild conditions is of great significance for the commercially viable and sustainable utilization of methane but remains a formidable challenge. Herein, we report a strategy for efficiently converting methane to acetic acid via CH3 Cl as an intermediate. Up to 99.3 % acetic acid and methyl acetate (AA+MA) selectivity was achieved over pyridine-pretreated MOR (MOR-8) under moderate conditions of 523 K and 2.0 MPa. Water, conventionally detrimental to carbonylation reaction over zeolite catalysts, was conducive to the production of AA in the current reaction system. In the 100 h continuous test with the MOR-8 catalyst, the average AA+MA selectivity remained over 98 %. AA was formed by carbonylation of methoxy groups within 8-membered rings of MOR followed by hydrolysis. This strategy provided an approach for highly efficient utilization of methane to oxygenates under mild reaction conditions.

18.
Int J Clin Pract ; 75(10): e14571, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34170611

RESUMEN

OBJECTIVES: Coronavirus disease 2019 (Covid-19) is outbreaking globally. We aimed to analyse the clinical characteristics, cardiac injury, electrocardiogram and computed tomography (CT) features of patients confirmed Covid-19 and explored the prediction models for the severity of Covid-19. METHODS: A retrospective and single-centre study enrolled 98 laboratory-confirmed Covid-19 patients. Clinical data, electrocardiogram and CT features were collected and analysed using Statistical Package for the Social Sciences software. RESULTS: There were 46 males and 52 females, with a median age of 44 years, categorised into three groups, including mild, moderate and severe/critical Covid-19. The rate of abnormal electrocardiograms in severe/critical group (79%) was significantly higher than that in the mild group (17%) (P = .027), which (r = 0.392, P = .005) positively related to the severity of Covid-19 (OR: 5.71, 95% CI: 0.45-3.04, P = .008). Age older than 60 years old, comorbidities, whether had symptoms on admission, fatigue, CT features, laboratory test results such as platelet count, lymphocyte cell count, eosinophil cell count, CD3+ cell count, CD4+ cell count, CD8+ cell count, the ratio of albumin/globulin decreased and D-dimer, C-reactive protein (CRP), B-type natriuretic peptide (BNP), cardiac troponin I (cTnI) elevated were the risk factors for the increased severity of Covid-19. The logistic model, adjusted by age, lobular involvement score and lymphocyte cell count, could be applied for assessing the severity of Covid-19 (AUC, 0.903; Sensitivity, 90.9%; Specificity, 78.1%). CONCLUSIONS: Age >60 years old, chronic comorbidities, lymphocytopoenia and lobular involvement score were associated with the Covid-19 severity. The inflammation induced by Covid-19 caused myocardial injury with elevated BNP and cTnI level and abnormal electrocardiograms.


Asunto(s)
COVID-19 , Adulto , China , Femenino , Humanos , Recuento de Leucocitos , Recuento de Linfocitos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , SARS-CoV-2 , Índice de Severidad de la Enfermedad
19.
Sensors (Basel) ; 21(21)2021 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-34770469

RESUMEN

Heart rate is one of the most important diagnostic bases for cardiovascular disease. This paper introduces a deep autoencoding strategy into feature extraction of electrocardiogram (ECG) signals, and proposes a beat-to-beat heart rate estimation method based on convolution autoencoding and Gaussian mixture clustering. The high-level heartbeat features were first extracted in an unsupervised manner by training the convolutional autoencoder network, and then the adaptive Gaussian mixture clustering was applied to detect the heartbeat locations from the extracted features, and calculated the beat-to-beat heart rate. Compared with the existing heartbeat classification/detection methods, the proposed unsupervised feature learning and heartbeat clustering method does not rely on accurate labeling of each heartbeat location, which could save a lot of time and effort in human annotations. Experimental results demonstrate that the proposed method maintains better accuracy and generalization ability compared with the existing ECG heart rate estimation methods and could be a robust long-time heart rate monitoring solution for wearable ECG devices.


Asunto(s)
Electrocardiografía , Dispositivos Electrónicos Vestibles , Algoritmos , Análisis por Conglomerados , Frecuencia Cardíaca , Humanos , Distribución Normal , Procesamiento de Señales Asistido por Computador
20.
Molecules ; 26(10)2021 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-34069021

RESUMEN

The present work investigated the effect of Polylactic acid (PLA) fibers produced by centrifugal spinning with incorporated BaTiO3 particles to improve their bacteriostatic behavior. The PLA matrix and three composites, presenting three different amounts of fillers, were subjected to UV/O3 treatment monitoring the possible modifications that occurred over time. The morphological and physical properties of the surfaces were characterized by different microscopic techniques, contact angle, and surface potential measurements. Subsequently, the samples were tested in vitro with human dermal fibroblasts (HDF) to verify the cytotoxicity of the substrates. No significant differences between the PLA matrix and composites emerged; the high hydrophobicity of the fibers, derived by the polymer structure, represented an obstacle limiting the fibroblast attachment. Samples underwent bacterial exposure (Staphylococcus epidermidis) for 12 and 24 h. Increasing the concentration of BT, the number of living bacteria and their distribution decreased in comparison with the PLA matrix suggesting an effect of the inorganic filler, which generates a neutralization effect leading to reactive oxygen species (ROS) generation and subsequently to bacterial damages. These results suggest that the barium titanate (BT) fillers clearly improve the antibacterial properties of PLA fibers after aging tests made before bacterial exposure, representing a potential candidate in the creation of composites for medical applications.


Asunto(s)
Antibacterianos/farmacología , Compuestos de Bario/farmacología , Poliésteres/farmacología , Titanio/farmacología , Recuento de Células , Supervivencia Celular/efectos de los fármacos , Centrifugación , Dermis/citología , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Humanos , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana/efectos de los fármacos , Espectrometría por Rayos X , Staphylococcus epidermidis/efectos de los fármacos , Agua/química
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