Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
Mais filtros












Base de dados
Intervalo de ano de publicação
1.
J Hazard Mater ; 480: 135903, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39307012

RESUMO

Microbial dehalogenation, using obligate and facultative organohalide-respiring bacteria (OHRB), has been widely used to remediate halohydrocarbon-polluted sites. Owing to the scarcity of OHRB, and poor efficiency in H2-mediating interspecies electron transfer, microbial dehalogenation relying on OHRB is easily disturbed by Fe(III), sulfate, and nitrate as electron competitors. In the present study, pyrogenic carbon, featuring electron snorkeling, was introduced into the process of microbial dehalogenation, which facilitated the electron transfer from electro-active microbes to halohydrocarbon, then invigorating dehalogenation. As a consequence, fine dehalogenation of trichloroethene (TCE, as representative halohydrocarbon) was obtained, expressed as the nearly complete diminishment of 150 µmol L-1 TCE and the sequestration of high contents of ethene (72.2-122.3 µmol L-1 within 80 d). Such fine dehalogenation was ascribed to the synergy between pyrogenic carbon and electro-active microbes. Multiple microbes in mixed cultures, including Clostridium sp., Sporanaerobacter, Sedimentibacter, Paraclostridium, and Tissierella, stimulated TCE dehalogenation by providing electrons to pyrogenic carbon. Redox moieties on pyrogenic carbon enabled it to snorkel electrons, which facilitated the electron transfer from electro-active microbes to TCE, consequently invigorating TCE dehalogenation. Such microbial dehalogenation free of OHRB demonstrates the effectiveness of a novel strategy for remediating halohydrocarbon-polluted environments.

2.
J Hazard Mater ; 477: 135279, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39047569

RESUMO

The weathering process can cause the volatilization of light components in crude oil, leading to the accumulation of total petroleum hydrocarbons (TPH) in weathered oil field soils. These TPH compounds are relatively resistant to biodegradation, posing a significant environmental hazard by contributing to soil degradation. TPH represents a complex mixture of petroleum-based hydrocarbons classified as persistent organic pollutants in soil and groundwater. The release of TPH pollutants into the environment poses serious threats to ecosystems and human health. Currently, various methods are available for TPH-contaminated soil remediation, with bioremediation technology recognized as an environmentally friendly and cost-effective approach. While converting TPH to CO2 is a common remediation method, the complex structures and diverse types of petroleum hydrocarbons (PHs) involved can result in excessive CO2 generation, potentially exacerbating the greenhouse effect. Alternatively, transforming TPH into energy forms like methane through bioremediation, followed by collection and reuse, can reduce greenhouse gas emissions and energy consumption. This process relies on the synergistic interaction between Methanogens archaea and syntrophic bacteria, forming a consortium known as the oil-degrading bacterial consortium. Methanogens produce methane through anaerobic digestion (AD), with hydrogenotrophic methanogens (HTMs) utilizing H2 as an electron donor, playing a crucial role in biomethane production. Candidatus Methanoliparia (Ca. Methanoliparia) was found in the petroleum archaeal community of weathered Oil field in northeast China. Ca. Methanoliparia has demonstrated its independent ability to decompose and produce new energy (biomethane) without symbiosis, contribute to transitioning weathered oil fields towards new energy. Therefore, this review focuses on the principles, mechanisms, and developmental pathways of HTMs during new energy production in the degradation of PHs. It also discusses strategies to enhance TPH degradation and recovery methods.


Assuntos
Biodegradação Ambiental , Hidrocarbonetos , Metano , Petróleo , Poluentes do Solo , Petróleo/metabolismo , Hidrocarbonetos/metabolismo , Poluentes do Solo/metabolismo , Metano/metabolismo , Campos de Petróleo e Gás/microbiologia , Poluição por Petróleo , Bactérias/metabolismo
3.
Nucleic Acids Res ; 52(13): 7556-7571, 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-38783136

RESUMO

Non-genetic variations derived from expression noise at transcript or protein levels can result in cell-to-cell heterogeneity within an isogenic population. Although cells have developed strategies to reduce noise in some cellular functions, this heterogeneity can also facilitate varying levels of regulation and provide evolutionary benefits in specific environments. Despite several general characteristics of cellular noise having been revealed, the detailed molecular pathways underlying noise regulation remain elusive. Here, we established a dual-fluorescent reporter system in Saccharomyces cerevisiae and performed experimental evolution to search for mutations that increase expression noise. By analyzing evolved cells using bulk segregant analysis coupled with whole-genome sequencing, we identified the histone deacetylase Hos2 as a negative noise regulator. A hos2 mutant down-regulated multiple ribosomal protein genes and exhibited partially compromised protein translation, indicating that Hos2 may regulate protein expression noise by modulating the translation machinery. Treating cells with translation inhibitors or introducing mutations into several Hos2-regulated ribosomal protein genes-RPS9A, RPS28B and RPL42A-enhanced protein expression noise. Our study provides an effective strategy for identifying noise regulators and also sheds light on how cells regulate non-genetic variation through protein translation.


Assuntos
Regulação Fúngica da Expressão Gênica , Histona Desacetilases , Biossíntese de Proteínas , Proteínas Ribossômicas , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Histona Desacetilases/metabolismo , Histona Desacetilases/genética , Mutação , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
4.
Children (Basel) ; 11(4)2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38671703

RESUMO

This case report sheds light on the management of skeletal deformity in a young child with X-linked hypophosphatemia (XLH), emphasizing the significance of a timely orthotic intervention alongside pharmacological treatment, which is a strategy not frequently highlighted in the XLH literature. The patient, a 2-year-and-7-month-old female, presented with classic XLH symptoms, including short stature, pronounced genu varum, and hypophosphatemia, with deformities observed in both the coronal and sagittal planes of the femur and tibia. Despite initial reliance on pharmacotherapy, which proved insufficient for skeletal realignment, the integration of orthotic treatment at age 3 marked a pivotal turn in the management strategy. By the age of 5 years and 9 months, this combined approach yielded significant improvements: the deformities in the femur and tibia were notably corrected, tibial torsion was addressed, and enhanced limb alignment was achieved, as corroborated by radiographic evidence. This case underscores the effectiveness of orthotic intervention as a critical and underemphasized adjunct to pharmacological therapy in managing XLH in early childhood. It advocates for the early inclusion of orthotic measures to optimize treatment outcomes and expand the range of management strategies for limb deformities.

5.
Biofabrication ; 16(1)2023 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-37906964

RESUMO

While the field of tissue engineering has progressed rapidly with the advent of 3D bioprinting and human induced pluripotent stem cells (hiPSCs), impact is limited by a lack of functional, thick tissues. One way around this limitation is to 3D bioprint tissues laden with hiPSCs. In this way, the iPSCs can proliferate to populate the thick tissue mass prior to parenchymal cell specification. Here we design a perfusion bioreactor for an hiPSC-laden, 3D-bioprinted chamber with the goal of proliferating the hiPSCs throughout the structure prior to differentiation to generate a thick tissue model. The bioreactor, fabricated with digital light projection, was optimized to perfuse the interior of the hydrogel chamber without leaks and to provide fluid flow around the exterior as well, maximizing nutrient delivery throughout the chamber wall. After 7 days of culture, we found that intermittent perfusion (15 s every 15 min) at 3 ml min-1provides a 1.9-fold increase in the density of stem cell colonies in the engineered tissue relative to analogous chambers cultured under static conditions. We also observed a more uniform distribution of colonies within the tissue wall of perfused structures relative to static controls, reflecting a homogeneous distribution of nutrients from the culture media. hiPSCs remained pluripotent and proliferative with application of fluid flow, which generated wall shear stresses averaging ∼1.0 dyn cm-2. Overall, these promising outcomes following perfusion of a stem cell-laden hydrogel support the production of multiple tissue types with improved thickness, and therefore increased function and utility.


Assuntos
Células-Tronco Pluripotentes Induzidas , Células-Tronco Pluripotentes , Humanos , Alicerces Teciduais/química , Engenharia Tecidual , Perfusão , Diferenciação Celular , Hidrogéis , Reatores Biológicos
6.
J Environ Manage ; 346: 118978, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37742566

RESUMO

Owing to the strong C-F bond in nature and the rigidity of the poly-fluoroalkyl chain, perfluorooctanoic acid (PFOA) is difficult to be eliminated by reactive species and microbes in environments, thus posing a serious threat to ecosystems. Vitamin B12 as a cofactor for enzymes, and biochar as the electron providers and conductors, were integrated to enhance PFOA biodegradation. The raw material of biochar was the sludge after dewatering by adding 50 mg/g DS of Fe(III). After pyrolysis under high temperature (800 °C), biochar (SC800) detected high content of Fe(II) (197.64 mg/g) and abundant oxygen-containing functional groups, thus boosting PFOA biodegradation via donating electrons. 99.9% of PFOA could be removed within 60 d as 0.1 g/L SC800 was presented in the microbial systems containing vitamin B12. Moreover, vitamin B12 facilitated the evolution of Sporomusa which behaved the deflorination. Via providing reactive sites and mediating direct inter-species electron transfer (DIET), SC800 boosted PFOA biodegradation. Corresponding novel results in the present study could guide the development of bioremediation technologies for PFOA-polluted sites.


Assuntos
Ferro , Esgotos , Biodegradação Ambiental , Elétrons , Vitamina B 12 , Ecossistema , Carvão Vegetal/química , Vitaminas
7.
J Environ Manage ; 347: 119058, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37757689

RESUMO

Soil and groundwater contamination caused by petroleum hydrocarbons is a severe environmental problem. In this study, a novel electrolyzed catalytic system (ECS) was developed to produce nanobubble-contained electrolyzed catalytic (NEC) water for the remediation of petroleum-hydrocarbon-contaminated soils and groundwater. The developed ECS applied high voltage (220 V) with direct current, and titanium electrodes coated with iridium dioxide were used in the system. The developed ECS prototype contained 21 electrode pairs (with a current density of 20 mA/cm2), which were connected in series to significantly enhance the hydroxyl radical production rate. Iron-copper hybrid oxide catalysts were laid between each electrode pair to improve the radical generation efficiency. The electron paramagnetic resonance (EPR) and Rhodamine B (RhB) methods were applied for the generated radical species and concentration determination. During the operation of the ECS, high concentrations of nanobubbles (nanobubble density = 3.7 × 109 particles/mL) were produced due to the occurrence of the cavitation mechanism. Because of the negative zeta potential and nano-scale characteristics of nanobubbles (mean diameter = 28 nm), the repelling force would prevent the occurrence of bubble aggregations and extend their lifetime in NEC water. The radicals produced after the bursting of the nanobubbles would be beneficial for the increase of the radical concentration and subsequent petroleum hydrocarbon oxidation. The highly oxidized NEC water (oxidation-reduction potential = 887 mV) could be produced with a radical concentration of 9.5 × 10-9 M. In the pilot-scale study, the prototype system was applied to clean up petroleum-hydrocarbon polluted soils at a diesel-oil spill site via an on-site slurry-phase soil washing process. The total petroleum hydrocarbon (TPH)-contaminated soils were excavated and treated with the NEC water in a slurry-phase reactor. Results show that up to 74.4% of TPH (initial concentration = 2846 mg/kg) could be removed from soils after four rounds of NEC water treatment (soil and NEC water ratio for each batch = 10 kg: 40 L and reaction time = 10 min). Within the petroleum-hydrocarbon plume, one remediation well (RW) and two monitor wells (located 1 m and 3 m downgradient of the RW) were installed along the groundwater flow direction. The produced NEC water was injected into the RW and the TPH concentrations in groundwater (initial concentrations = 12.3-15.2 mg/L) were assessed in these three wells. Compared to the control well, TPH concentrations in RW and MW1 dropped to below 0.4 and 2.1 mg/L after 6 m3 of NEC water injection in RW, respectively. Results from the pilot-scale study indicate that the NEC water could effectively remediate TPH-contaminated soils and groundwater without secondary pollution production. The main treatment mechanisms included (1) in situ chemical oxidation via produced radicals, (2) desorption of petroleum hydrocarbons from soil particles due to the dispersion of nanobubbles into soil pores, and (3) enhanced TPH oxidation due to produced radicals and energy after nanobubble bursting.


Assuntos
Água Subterrânea , Petróleo , Poluentes do Solo , Poluição Ambiental , Hidrocarbonetos , Solo , Poluentes do Solo/análise , Biodegradação Ambiental , Microbiologia do Solo
8.
Chemosphere ; 334: 138859, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37169093

RESUMO

Owing to its inertness toward refractory organic pollutants and the release of Mn2+, the use of permanganate was limited in soil and groundwater remediation. The present study proposed an improvement strategy based on glucose-derived carbonaceous materials, which enhanced the potential of permanganate degrading organic pollutants. The glucose-derived carbonaceous material with 1000 °C charring temperature was named C1000, which was exploited in activating KMnO4 for the elimination of refractory organic contaminants. The addition of C1000 in the KMnO4 system triggered the degradation of refractory p-nitrophenol and quicken phenol degradation. Unlike the detection of Mn(III) species in a solo KMnO4 system, the presence of C1000 facilitated the formation of •OH in the KMnO4 system, which was confirmed by the use of quenchers such as methanol, benzoic acid, tertiary butanol, and carbonate. Additionally, the glucose-derived carbonaceous material played multiple roles in improving the performance of permanganate, including the enrichment of organic pollutants, donation of electrons to permanganate, and acting as an electron shuttle to facilitate the oxidation of organic pollutants by permanganate. The study's novel findings have the potential to expand the use of permanganate in the remediation of organic pollutants.


Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Radical Hidroxila , Fenol , Fenóis
9.
J Environ Manage ; 339: 117947, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37075632

RESUMO

Cr(VI) bioreduction has become a remedial alternative for Cr(VI)-polluted site cleanup. However, lack of appropriate Cr(VI)-bioreducing bacteria limit the field application of the in situ bioremediation process. In this study, two different immobilized Cr(VI)-bioreducing bacterial consortia using novel immobilization agents have been developed for Cr(VI)-polluted groundwater remediation: (1) granular activated carbon (GAC) + silica gel + Cr(VI)-bioreducing bacterial consortia (GSIB), and (2) GAC + sodium alginate (SA) + polyvinyl alcohol (PVA) + Cr(VI)-bioreducing bacterial consortia (GSPB). Moreover, two unique substrates [carbon-based agent (CBA) and emulsified polycolloid substrate (EPS)] were developed and used as the carbon sources for Cr(VI) bioreduction enhancement. The microbial diversity, dominant Cr-bioreducing bacteria, and changes of Cr(VI)-reducing genes (nsfA, yieF, and chrR) were analyzed to assess the effectiveness of Cr(VI) bioreduction. Approximately 99% of Cr(VI) could be bioreduced in microcosms with GSIB and CBA addition after 70 days of operation, which caused increased populations of total bacteria, nsfA, yieF, and chrR from 2.9 × 108 to 2.1 × 1012, 4.2 × 104 to 6.3 × 1011, 4.8 × 104 to 2 × 1011, and 6.9 × 104 to 3.7 × 107 gene copies/L. In microcosms with CBA and suspended bacteria addition (without bacterial immobilization), the Cr(VI) reduction efficiency dropped to 60.3%, indicating that immobilized Cr-bioreducing bacteria supplement could enhance Cr(VI) bioreduction. Supplement of GSPB led to a declined bacterial growth due to the cracking of the materials. The addition of GSIB and CBA could establish a reduced condition, which favored the growth of Cr(VI)-reducing bacteria. The Cr(VI) bioreduction efficiency could be significantly improved through adsorption and bioreduction mechanisms, and production of Cr(OH)3 precipitates confirmed the occurrence of Cr(VI) reduction. The main Cr-bioreducing bacteria included Trichococcus, Escherichia-Shigella, and Lactobacillus. Results suggest that the developed GSIB bioremedial system could be applied to cleanup Cr(VI)-polluted groundwater effectively.


Assuntos
Cromo , Água Subterrânea , Oxirredução , Cromo/análise , Biodegradação Ambiental , Bactérias/genética
10.
Glycoconj J ; 40(3): 295-303, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37052731

RESUMO

Sialylation is an important terminal modification of glycoconjugates that mediate diverse functions in physiology and disease. In this review we focus on how altered cell surface sialylation status is sensed by cytosolic galectins when the integrity of intracellular vesicles or organelles is compromised to expose luminal glycans to the cytosolic milieu, and how this impacts galectin-mediated cellular responses. In addition, we discuss the roles of mammalian sialidases on the cell surface, in the organelle lumen and cytosol, and raise the possibility that intracellular glycan processing may be critical in controlling various galectin-mediated responses when cells encounter stress.


Assuntos
Galectinas , Polissacarídeos , Animais , Galectinas/metabolismo , Citosol/metabolismo , Polissacarídeos/metabolismo , Glicoconjugados/metabolismo , Organelas , Mamíferos/metabolismo
11.
Chem Commun (Camb) ; 59(10): 1297-1300, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36633138

RESUMO

N-Sulfonylthioimidate was converted to ketenimine under basic conditions. The reaction with vinyl/aryl azides was induced to cause dipolar cycloaddition to form 5-amino-1-vinyl/aryl-1,2,3-triazoles. The advantages of this method are high efficiency, structural diversity of products favorable yields and applicability to gram-scale operations.

12.
ACS Appl Mater Interfaces ; 15(1): 1748-1761, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36576167

RESUMO

Electroluminescence (EL) from the singlet-excited (S1) state is the ideal choice for stable, high-performing deep-blue organic light-emitting diodes (OLEDs) owing to the advantages of an adequately short radiative lifetime, improved device durability, and low cost, which are the most important criteria for their commercialization. Herein, we present the design and synthesis of three donor-acceptor-donor (D-A-D)-configured deep-blue fluorescent materials (denoted as TC-1, TC-2, and TC-3) composed of a thioxanthone or diphenyl sulfonyl acceptor and phenyl carbazolyl donor. These systems exhibit strong deep-blue photoluminescence (422-432 nm) in solutions and redshifted emission (472-486 nm) in thin films. The solid-state photoluminescence quantum yield (PLQY) was estimated to be 78 and 94% for TC-2 and TC-3, respectively. TC-2 and TC-3 possess good molecular packing and large molecular cross-sectional areas, which not only improves the PLQY but enhances the triplet-triplet annihilation up-conversion (TTAUC) efficiency of fluorescent emitters. Furthermore, both compounds were applied as an acceptor for confirming their TTAUC property using bis(2-methyldibenzo[f,h]quinoxaline)(acetylacetonate)iridium(III) (Ir(MDQ)2acac) as the sensitizer. Non-doped OLEDs based on TC-2 and TC-3 exhibit blue EL in the 461-476 nm range. In particular, TC-3 exhibits a maximum external quantum efficiency (EQEmax) of 5.1%, and its EL maximum is 476 nm. In addition, the three emitters were employed as hosts in red OLEDs using bis(1-phenylisoquinoline)(acetylacetonate)iridium(III) (Ir(piq)2acac) as the phosphorescent dopant. The red phosphorescent OLEDs based on TC-1, TC-2, and TC-3 achieve excellent EQEmax values of 21.6, 22.9, and 21.9%, respectively, and peak luminance efficiencies of 12.0, 14.0, and 12.3 cd A-1. These results highlight these fluorophores' versatility and promising prospects in practical OLED applications.

13.
Front Cell Dev Biol ; 11: 1286011, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38274272

RESUMO

Intervertebral disc (IVD) degeneration is a common pathological condition associated with low back pain. Recent evidence suggests that mesenchymal signaling cells (MSCs) promote IVD regeneration, but underlying mechanisms remain poorly defined. One postulated mechanism is via modulation of macrophage phenotypes. In this manuscript, we tested the hypothesis that MSCs produce trophic factors that alter macrophage subsets. To this end, we collected conditioned medium from human, bone marrow-derived STRO3+ MSCs. We then cultured human bone marrow-derived macrophages in MSC conditioned medium (CM) and performed single cell RNA-sequencing. Comparative analyses between macrophages cultured in hypoxic and normoxic MSC CM showed large overlap between macrophage subsets; however, we identified a unique hypoxic MSC CM-induced macrophage cluster. To determine if factors from MSC CM simulated effects of the anti-inflammatory cytokine IL-4, we integrated the data from macrophages cultured in hypoxic MSC CM with and without IL-4 addition. Integration of these data sets showed considerable overlap, demonstrating that hypoxic MSC CM simulates the effects of IL-4. Interestingly, macrophages cultured in normoxic MSC CM in the absence of IL-4 did not significantly contribute to the unique cluster within our comparison analyses and showed differential TGF-ß signaling; thus, normoxic conditions did not approximate IL-4. In addition, TGF-ß neutralization partially limited the effects of MSC CM. In conclusion, our study identified a unique macrophage subset induced by MSCs within hypoxic conditions and supports that MSCs alter macrophage phenotypes through TGF-ß-dependent mechanisms.

14.
Water Environ Res ; 94(11): e10810, 2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36433735

RESUMO

The Feng-Sang River is a metropolitan river in Kaohsiung City, Taiwan. In this study, Feng-Sang River sediments were analyzed to investigate the distributions and sources of polycyclic aromatic hydrocarbons (PAHs). The Sediment Quality Guidelines (SQGs), potentially carcinogenic PAHs (TEQcarc ), and toxic equivalence quotient (TEQ) were applied to evaluate influences of PAHs on ecosystems and microbial diversities. Results indicate that PAHs concentrations varied between seasons and locations. The concentrations of ∑16 PAHs ranged from 73.6 to 603.8 ng/kg in dry seasons and from 2.3 to 199.3 ng/kg in wet seasons. This could be because of the flushing effect during wet seasons, which caused the movement and dilution of the PAH-contaminated sediments. Diagnostic ratio analysis infers that high PAHs levels were generated by combustion processes and vehicle traffic, and results from multivariate descriptive statistical analysis also demonstrate that the vehicular traffic pollution could be the major emission source of PAHs contamination. Comparisons of PAHs with SQGs indicate that PAHs concentrations in sediment were below the effects range low (ERL) values, and thus, the immediate threat to organisms might not be significant. The diagnostic ratio analyses are effective methods for PAH source appointment. The metagenomic assay results imply that sediments contained essential microbial species with eminent diversity. The detected PAH-degrading bacteria (Desulfatiglans, Dechloromonas, Sphingomonas, Methylobacterium, Rhodobacter, Clostridium, and Exiguobacterium) played a key role in PAHs biotransformation, and Dechloromonas and Rhodobacter had a higher relative abundance. Results of microbial diversity analyses indicate that the contaminated environment induced the changes of governing microbial groups in sediments. PRACTITIONER POINTS: Diagnostic ratio analyses are effective methods for PAHs source appointment. Microbial composition in sediments are highly affected by anthropogenic pollution. Combustion and vehicle traffic contribute to urban river sediments pollution by PAHs. Dechloromonas and Rhodobacter are dominant PAHs-degrading bacteria in sediments.

15.
Int J Mol Sci ; 23(22)2022 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36430922

RESUMO

Bionic-engineered tissues have been proposed for testing the performance of cardiovascular medical devices and predicting clinical outcomes ex vivo. Progress has been made in the development of compliant electronics that are capable of monitoring treatment parameters and being coupled to engineered tissues; however, the scale of most engineered tissues is too small to accommodate the size of clinical-grade medical devices. Here, we show substantial progress toward bionic tissues for evaluating cardiac ablation tools by generating a centimeter-scale human cardiac disk and coupling it to a hydrogel-based soft-pressure sensor. The cardiac tissue with contiguous electromechanical function was made possible by our recently established method to 3D bioprint human pluripotent stem cells in an extracellular matrix-based bioink that allows for in situ cell expansion prior to cardiac differentiation. The pressure sensor described here utilized electrical impedance tomography to enable the real-time spatiotemporal mapping of pressure distribution. A cryoablation tip catheter was applied to the composite bionic tissues with varied pressure. We found a close correlation between the cell response to ablation and the applied pressure. Under some conditions, cardiomyocytes could survive in the ablated region with more rounded morphology compared to the unablated controls, and connectivity was disrupted. This is the first known functional characterization of living human cardiomyocytes following an ablation procedure that suggests several mechanisms by which arrhythmia might redevelop following an ablation. Thus, bionic-engineered testbeds of this type can be indicators of tissue health and function and provide unique insight into human cell responses to ablative interventions.


Assuntos
Biônica , Ablação por Cateter , Humanos , Ablação por Cateter/métodos , Miócitos Cardíacos/metabolismo , Engenharia Tecidual/métodos , Arritmias Cardíacas/metabolismo
16.
J Org Chem ; 87(22): 15327-15332, 2022 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-36302512

RESUMO

Hexamethyldisilazane was reacted with formamides to generate N,N-disubstituent formimidamide, after which a reaction with sulfonamides was induced to form sulfonylformamidines. This protocol can be applied for arylformamidine formation in which anilines are used as substrates under optimized conditions. The advantages of this method are high efficiency, structural diversity in products with good yields, and applicability in large-scale operations.


Assuntos
Formamidas , Compostos de Organossilício , Formamidas/química , Aminas/química , Sulfonamidas/química , Sulfanilamida
17.
Glycobiology ; 32(9): 760-777, 2022 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-35789267

RESUMO

Galectin-3 (GAL3) is a ß-galactoside-binding lectin expressed in CD4 T cells infected with human immunodeficiency virus-1 (HIV-1). GAL3 promotes HIV-1 budding by associating with ALIX and Gag p6. GAL3 has been shown to localize in membrane lipid rafts in dendritic cells and positively regulate cell migration. HIV-1 spreads between T cells by forming supramolecular structures (virological synapses [VSs]), whose integrity depends on lipid rafts. Here, we addressed the potential role of GAL3 in cell-to-cell transmission of HIV-1 in CD4 T cells. GAL3 expressed in donor cells was more important for facilitating HIV-1 cell-to-cell transfer than GAL3 expressed in target cells. GAL3 was found to be co-transferred with Gag from HIV-1-positive donor to HIV-1-negative target T cells. HIV-1 infection induced translocation of GAL3 together with Gag to the cell-cell interfaces and colocalize with GM1, where GAL3 facilitated VS formation. GAL3 regulated the coordinated transfer of Gag and flotillin-1 into plasma membrane fractions. Finally, depletion of GAL3 reduced the cholesterol levels in membrane lipid rafts in CD4 T cells. These findings provide evidence that endogenous GAL3 stimulates lipid raft components and facilitates intercellular HIV-1 transfer among CD4 T cells, offering another pathway by which GAL3 regulates HIV-1 infection. These findings may inform the treatment of HIV-1 infection based on targeting GAL3 to modulate lipid rafts.


Assuntos
Infecções por HIV , HIV-1 , Proteínas Sanguíneas , Linfócitos T CD4-Positivos/metabolismo , Galectina 3/genética , Galectina 3/metabolismo , Galectinas , Humanos , Lipídeos de Membrana/análise , Lipídeos de Membrana/metabolismo , Microdomínios da Membrana/química
18.
ACS Appl Mater Interfaces ; 14(13): 15478-15493, 2022 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-35345881

RESUMO

Luminescent carbene-metal-amide complexes bearing group 11 metals (Cu, Ag, Au) have recently attracted great attention due to their exceptional emission efficiency and high radiative decay rates (kr). These materials provide a less costly alternative to organic light-emitting diode (OLED) emitters based on more scarce metals, such as Ir and Pt. Herein, a series of eight Cu(I) complexes bearing as yet unexplored 1,3-thiazoline carbenes have been investigated and analyzed with respect to their light emission properties and OLED application. For the first time among the class of copper-based organometallic compounds the formation of efficient electroluminescent excimers is demonstrated. The prevalence of electroluminescence (EL) from either the monomer (bluish green) or the excimer (orange-red) can be adjusted in vacuum-deposited emissive layers by altering the extent of steric encumbrance of the emitter or its concentration. Optimized conditions in terms of the emitter structure and mass fraction allowed a simultaneous EL from the monomer and excimer, which laid the basis for a preparation of a single-emitter white OLED (WOLED) with external quantum efficiency of 16.5% and a maximum luminance of over 40000 cd m-2. Wide overlapping emission bands of the monomer and excimer ensure a device color rendering index (CRI) of above 80. In such a way the prospects of copper complexes as cost-effective materials for lighting devices are demonstrated, offering expense reduction through a cheaper emissive component and a simplified device architecture.

19.
J Environ Manage ; 311: 114836, 2022 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-35272161

RESUMO

In this study, the developed innovative immobilized Clostridium butyricum (ICB) (hydrogen-producing bacteria) column scheme was applied to cleanup chlorinated-ethene [mainly cis-1,2-dichloroethene (cis-DCE)] polluted groundwater in situ via the anaerobic reductive dechlorinating processes. The objectives were to assess the effectiveness of the field application of ICB scheme on the cleanup of cis-DCE polluted groundwater, and characterize changes of microbial communities after ICB application. Three remediation wells and two monitor wells were installed within the cis-DCE plume. In the remediation well, a 1.2-m PVC column (radius = 2.5 cm) (filled with ICB beads) and 20 L of slow polycolloid-releasing substrate (SPRS) were supplied for hydrogen production enhancement and primary carbon supply, respectively. Groundwater samples from remediation and monitor wells were analyzed periodically for cis-DCE and its degradation byproducts, microbial diversity, reductive dehalogenase, and geochemical indicators. Results reveal that cis-DCE was significantly decreased within the ICB and SPRS influence zone. In a remediation well with ICB injection, approximately 98.4% of cis-DCE removal (initial concentration = 1.46 mg/L) was observed with the production of ethene (end-product of cis-DCE dechlorination) after 56 days of system operation. Up to 0.72 mg/L of hydrogen was observed in remediation wells after 14 days of ICB and SPRS introduction, which corresponded with the increased population of Dehalococcoides spp. (Dhc) (increased from 3.76 × 103 to 5.08 × 105 gene copies/L). Results of metagenomics analyses show that the SPRS and ICB introduction caused significant impacts on the bacterial communities, and increased Bacteroides, Citrobacter, and Desulfovibrio populations were observed, which had significant contributions to the reductive dechlorination of cis-DCE. Application of ICB could effectively result in increased populations of Dhc and RDase genes, which corresponded with improved dechlorination of cis-DCE and vinyl chloride. Introduction of ICB and SPRS could be applied as a potential in situ remedial option to enhance anaerobic dechlorination efficiencies of chlorinated ethenes.

20.
Chemosphere ; 295: 133877, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35131270

RESUMO

Sulfate reducing bacteria (SRB) have the capability of bioreducing hexavalent chromium [Cr(VI)] to trivalent chromium [Cr(III)] under sulfate-reducing conditions for toxicity reduction. However, a high amount of sulfate addition would cause elevated sulfide production, which could inhibit the growth of SRB and result in reduced Cr(VI) bioreduction efficiency. A slow release reagent, viscous carbon and sulfate-releasing colloidal substrates (VCSRCS), was prepared for a long-lasting carbon and sulfate supplement. In the column study, VCSRCS was injected into the column system to form a VCSRCS biobarrier for Cr(VI) containment and bioreduction. A complete Cr(VI) removal was observed via the adsorption and bioreduction mechanisms in the column with VCSRCS addition. Results from X-ray diffractometer analyses indicate that Cr(OH)3(s) and Cr2O3(s) were detected in precipitates, indicating the occurrence of Cr(VI) reduction followed by Cr(III) precipitation. Results from the Fourier-transform infrared spectroscopy analyses show that cell deposits carried functional groups, which could adsorb Cr. Addition of VCSRCS caused increased populations of total bacteria and dsrA, which also enhanced Cr(VI) reduction. Microbial diversity results indicate that VCSRCS addition resulted in the growth of Cr(VI)-reducing bacteria including Exiguobacterium, Citrobacter, Aerococcus, and SRB. Results of this study will be helpful in developing an effective and green VCSRCS biobarrier for the bioremediation of Cr(VI)-polluted groundwater.


Assuntos
Cromo , Água Subterrânea , Biodegradação Ambiental , Cromo/análise , Oxirredução
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...