Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 156
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
J Am Chem Soc ; 146(11): 7679-7689, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38448393

RESUMO

The employment of dinuclear Au(I) catalysts in photomediated modern organic transformations has attracted significant attention over the past decade, which commonly demonstrates unique catalytic performance compared with the corresponding mononuclear gold complexes. Nevertheless, detailed mechanisms of dinuclear gold catalysis remain ambiguous, and further mechanistic understanding is highly desirable. Herein, computational studies were carried out to gain mechanistic insights into the photoinduced dinuclear gold-catalyzed divergent dechloroalkylation of gem-dichloroalkanes. Computational results suggest that a proton transfer from the additive, Hantzsch ester (HE), to the base, guanidine, could lead to an ionic pair complex, which is ready to undergo excitation under blue light irradiation to result in the corresponding triplet excited state. Then, the excited complex might undergo oxidative quenching with the dinuclear gold photocatalyst [AuI-AuI]2+, via a single-electron-transfer (SET) step to afford an unusual [Au1/2-Au1/2]+ dinuclear species. The corresponding mononuclear gold catalyst, [AuI]+, however, is not ready to enable the analogous step to give a [Au0] species, which might account for the unique characteristics of dinuclear gold catalysis. Subsequently, the formed [Au1/2-Au1/2]+ intermediate could trigger a Cl-atom transfer from dichloromethane in an inner-sphere manner to furnish a critical chloromethyl radical. Next, the resulting chloromethyl radical could attack the alkenyl moiety of substrates to generate the corresponding alkyl radicals. Then, three possible mechanistic pathways were explored to rationalize the substrate-dependent divergent transformations in this protocol. The main factors responsible for the diversified transformations were discussed.

2.
Small ; 20(19): e2307308, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38126576

RESUMO

Reaction kinetics can be improved by the enhanced electrical contact between different components growing symbiotically. But so far, due to the necessity for material synthesis conditions match, the component structures of cooperative growth are similar, and the materials are of the same type. The collaborative growth of high-reaction kinetics composite homogeneous core-shell heterostructure between various materials is innovatively proposed with different structures in one step. The NiCo-LDH and PPy successfully symbiotically grow on activated carbon fiber fabric in one step. The open channel structure of the NiCo-LDH nanosheets is preserved while PPy effectively wrapped around the NiCo-LDH. The well-defined nanostructure with abundant active sites and convenient ion diffusion paths is favorable for electrolyte entry into the entire nanoarrays. In addition, owing to the enhanced electronic interaction between different components through XPS analysis, the NiCo-LDH@PPy electrode shows outstanding reaction kinetics and structural stability. The as-synthesized NiCo-LDH@PPy exhibited excellent super-capacitive storage capabilities, robust capacitive activity, and good rate survival. Furthermore, an asymmetric supercapacitor (ASC) device made of NiCo-LDH@PPy and activated carbon (AC) is able to maintain a long cycle life while achieving high power and energy densities.

3.
J Med Virol ; 96(6): e29723, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38828911

RESUMO

Hepatitis B virus (HBV) can be completely suppressed after antiviral treatment; however, some patients with chronic hepatitis B (CHB) exhibit elevated alanine aminotransferase (ALT) levels and sustained disease progression. This study provides novel insights into the mechanism and potential predictive biomarkers of persistently elevated ALT (PeALT) in patients with CHB after complete viral inhibition. Patients having CHB with undetectable HBV DNA at least 12 months after antiviral treatment were enrolled from a prospective, observational cohort. Patients with PeALT and persistently normal ALT (PnALT) were matched 1:1 using propensity score matching. Correlations between plasma metabolites and the risk of elevated ALT were examined using multivariate logistic regression. A mouse model of carbon tetrachloride-induced liver injury was established to validate the effect of key differential metabolites on liver injury. Of the 1238 patients with CHB who achieved complete viral suppression, 40 (3.23%) had PeALT levels during follow-up (median follow-up: 2.42 years). Additionally, 40 patients with PnALT levels were matched as controls. Ser-Phe-Ala, Lys-Ala-Leu-Glu, 3-methylhippuric acid, 3-methylxanthine, and 7-methylxanthine were identified as critical differential metabolites between the two groups and independently associated with PeALT risk. Ser-Phe-Ala and Lys-Ala-Leu-Glu levels could be used to discriminate patients with PeALT from those with PnALT. Furthermore, N-acetyl- l-methionine (NALM) demonstrated the strongest negative correlation with ALT levels. NALM supplementation alleviated liver injury and hepatic necrosis induced by carbon tetrachloride in mice. Changes in circulating metabolites may contribute to PeALT levels in patients with CHB who have achieved complete viral suppression after antiviral treatment.


Assuntos
Alanina Transaminase , Antivirais , Biomarcadores , Hepatite B Crônica , Humanos , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/sangue , Hepatite B Crônica/virologia , Masculino , Feminino , Alanina Transaminase/sangue , Antivirais/uso terapêutico , Adulto , Estudos Prospectivos , Pessoa de Meia-Idade , Biomarcadores/sangue , Animais , Camundongos , Vírus da Hepatite B , Resposta Viral Sustentada , DNA Viral/sangue , Modelos Animais de Doenças , Fígado/patologia , Fígado/virologia , Carga Viral
4.
Environ Sci Technol ; 58(25): 11175-11184, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38857431

RESUMO

Arsenic (As)-bearing Fe(III) precipitate groundwater treatment sludge has traditionally been viewed by the water sector as a disposal issue rather than a resource opportunity, partly due to assumptions of the low value of As. However, As has now been classified as a Critical Raw Material (CRM) in many regions, providing new incentives to recover As and other useful components of the sludge, such as phosphate (P) and the reactive hydrous ferric oxide (HFO) sorbent. Here, we investigate alkali extraction to separate As from a variety of field and synthetic As-bearing HFO sludges, which is a critical first step to enable sludge upcycling. We found that As extraction was most effective using NaOH, with the As extraction efficiency increasing up to >99% with increasing NaOH concentrations (0.01, 0.1, and 1 M). Extraction with Na2CO3 and Ca(OH)2 was ineffective (<5%). Extraction time (hour, day, week) played a secondary role in As release but tended to be important at lower NaOH concentrations. Little difference in As extraction efficiency was observed for several key variables, including sludge aging time (50 days) and cosorbed oxyanions (e.g., Si, P). However, the presence of ∼10 mass% calcite decreased As release from field and synthetic sludges considerably (<70% As extracted). Concomitant with As release, alkali extraction promoted crystallization of poorly ordered HFO and decreased particle specific surface area, with structural modifications increasing with NaOH concentration and extraction time. Taken together, these results provide essential information to inform and optimize the design of resource recovery methods for As-bearing treatment sludge.


Assuntos
Álcalis , Arsênio , Água Subterrânea , Esgotos , Esgotos/química , Água Subterrânea/química , Álcalis/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Compostos Férricos/química
5.
Sensors (Basel) ; 24(3)2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38339637

RESUMO

Surface electromyogram (sEMG)-based gesture recognition has emerged as a promising avenue for developing intelligent prostheses for upper limb amputees. However, the temporal variations in sEMG have rendered recognition models less efficient than anticipated. By using cross-session calibration and increasing the amount of training data, it is possible to reduce these variations. The impact of varying the amount of calibration and training data on gesture recognition performance for amputees is still unknown. To assess these effects, we present four datasets for the evaluation of calibration data and examine the impact of the amount of training data on benchmark performance. Two amputees who had undergone amputations years prior were recruited, and seven sessions of data were collected for analysis from each of them. Ninapro DB6, a publicly available database containing data from ten healthy subjects across ten sessions, was also included in this study. The experimental results show that the calibration data improved the average accuracy by 3.03%, 6.16%, and 9.73% for the two subjects and Ninapro DB6, respectively, compared to the baseline results. Moreover, it was discovered that increasing the number of training sessions was more effective in improving accuracy than increasing the number of trials. Three potential strategies are proposed in light of these findings to enhance cross-session models further. We consider these findings to be of the utmost importance for the commercialization of intelligent prostheses, as they demonstrate the criticality of gathering calibration and cross-session training data, while also offering effective strategies to maximize the utilization of the entire dataset.


Assuntos
Amputados , Membros Artificiais , Humanos , Eletromiografia/métodos , Calibragem , Reconhecimento Automatizado de Padrão/métodos , Extremidade Superior , Algoritmos
6.
Int J Mol Sci ; 25(17)2024 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-39273159

RESUMO

Southern root-knot nematodes are among the most pernicious phytoparasites; they are responsible for substantial yield losses in agricultural crops worldwide. The limited availability of nematicides for the prevention and control of plant-parasitic nematodes necessitates the urgent development of novel nematicides. Natural products have always been a key source for the discovery of pesticides. Waltherione A, an alkaloid, exhibits potent nematocidal activity. In this study, we designed and synthesized a series of quinoline and quinolone derivatives from Waltherione A, leveraging a strategy of structural simplification. Bioassays have revealed that the quinoline derivatives exhibit better activity than quinolone derivatives in terms of both nematocidal and fungicidal activities. Notably, compound D1 demonstrated strong nematocidal activity, with a 72 h LC50 of 23.06 µg/mL, and it effectively controlled the infection of root-knot nematodes on cucumbers. The structure-activity relationship suggests that the quinoline moiety is essential for the nematocidal efficacy of Waltherione A. Additionally, compound D1 exhibited broad-spectrum fungicidal activity, with an EC50 of 2.98 µg/mL against Botrytis cinerea. At a concentration of 200 µg/mL, it significantly inhibited the occurrence of B. cinerea on tomato fruits, with an inhibitory effect of 96.65%, which is slightly better than the positive control (90.30%).


Assuntos
Antinematódeos , Antinematódeos/farmacologia , Antinematódeos/síntese química , Antinematódeos/química , Relação Estrutura-Atividade , Animais , Desenho de Fármacos , Doenças das Plantas/parasitologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Cucumis sativus/parasitologia , Cucumis sativus/microbiologia , Fungicidas Industriais/farmacologia , Fungicidas Industriais/síntese química , Fungicidas Industriais/química , Quinolinas/química , Quinolinas/farmacologia , Quinolinas/síntese química , Nematoides/efeitos dos fármacos , Tylenchoidea/efeitos dos fármacos , Botrytis/efeitos dos fármacos , Quinolonas/farmacologia , Quinolonas/química , Quinolonas/síntese química , Estrutura Molecular
7.
Angew Chem Int Ed Engl ; 63(3): e202317132, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38038249

RESUMO

While the hydrogen atom abstraction (HAA) from C(sp3 )-H bond has been well explored, the radical-mediated chemo- and regio-selective functionalization of allenic C(sp2 )-H bond via direct HAA from C(sp2 )-H bond of allene remains an unsolved challenge in synthetic chemistry. This is primarily due to inherent challenges with addition of radical intermediates to allenes, regioselectivity of HAA process, instability of allenyl radical toward propargyl radical et al. Herein, we report a copper catalyzed allenic C(sp2 )-H cyanation of an array of tri- and di-substituted allenes with exceptional site-selectivity, while mono-substituted allene was successfully cyanated, albeit with a low yield. In the developed strategy, steric N-fluoro-N-alkylsulfonamide, serving as precursor of hydrogen atom abstractor, plays a crucial role in achieving the desired regioselectivity and avoiding addition of N-centered radical to allene.

8.
Biotechnol Bioeng ; 120(4): 1015-1025, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36522163

RESUMO

Microbial oils produced by Yarrowia lipolytica offer an environmentally friendly and sustainable alternative to petroleum as well as traditional lipids from animals and plants. The accurate measurement of fermentation parameters, including the substrate concentration, dry cell weight, and lipid accumulation, is the foundation of process control, which is indispensable for industrial lipid production. However, it remains a great challenge to measure the complex parameters online during the lipid fermentation process, which is nonlinear, multivariate, and characterized by strong coupling. As a type of AI technology, the artificial neural network model is a powerful tool for handling extremely complex problems, and it can be employed to develop a soft sensor to monitor the microbial lipid fermentation process of Y. lipolytica. In this study, we first analyzed and emphasized the volume of sodium hydroxide and dissolved oxygen concentration as central parameters of the fermentation process. Then, a soft sensor based on a four-input artificial neural network model was developed, in which the input variables were fermentation time, dissolved oxygen concentration, initial glucose concentration, and additional volume of sodium hydroxide. This provides the possibility of online monitoring of dry cell weight, glucose concentration, and lipid production with high accuracy, which can be extended to similar fermentation processes characterized by the addition of bases or acids, as well as changes of the dissolved oxygen concentration.


Assuntos
Yarrowia , Animais , Fermentação , Yarrowia/metabolismo , Hidróxido de Sódio/metabolismo , Óleos/metabolismo , Glucose/metabolismo , Oxigênio/metabolismo
9.
J Org Chem ; 88(2): 1107-1112, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36604340

RESUMO

Herein, a computational work was carried out to gain mechanistic insights into dual gold and photoredox-catalyzed regioselective thiosulfonylation of alkenes with PhSO2SCF3. Computational results suggest that it is more favorable for the complex of Au(I) with PhSO2SCF3 (INT1), instead of an Au(I) catalyst or individual substrates, to quench the excited *[Ru]II photocatalyst in a single-electron oxidative manner to afford [Ru]III. The complexation of the Au(I) catalyst with PhSO2SCF3 could lead to a substantially lowered energy level of the lowest unoccupied molecular orbital, which may be mainly responsible for the feasibility of INT1 in quenching the excited photocatalyst. The resultant single-electron reduced complex, subsequently, is ready to undergo a S-S bond cleavage to form an Au(I)-SCF3 species and a benzenesulfonyl radical. Next, the yielded Au(I)-SCF3 species could undergo single-electron oxidation by [Ru]III to afford an Au(II) intermediate. Subsequently, the binding with an alkyl radical for the formed Au(II) species could occur to further convert to an Au(III) species, from which the final product can be furnished by a reductive elimination step and the Au(I) catalyst is regenerated. Thus, an Au(I)/Au(II)/Au(III)/Au(I) catalytic cycle is suggested to mainly account for the regioselective thiosulfonylation of alkenes.

10.
Environ Sci Technol ; 2023 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-36617724

RESUMO

Electrochemical reduction (ER) is a promising approach to safely remove pollutants. However, sluggish reaction kinetics and significant side reactions considerably limit the applicability of this green process. Herein, we uncovered the previously ignored role of interfacial hydrophilicity in determining the ER performance through electron microscopy observations, contact angle (CA) analysis, and electrochemical measurements. A Pd/C electrocatalyst forms dense nanopores on the electrode surface, rendering it highly hydrophobic and achieving a CA of up to 145°. This imposes a large mass-transfer barrier for the diffusion of water and pollutants into Pd sites. Moreover, the release of H2 is suppressed, which changes the solid-liquid (Pd-polluted water) interface into a solid-gas (H2)-liquid interface. This further slows down mass transfer and the decontamination process. This dilemma can be easily alleviated by adding hydrophilic polymers like polyethylene glycol to increase hydrophilicity and improve mass transfer. By this way, the activity and Faraday efficiency of Pd/C in the electrochemical hydrodehalogenation of 2,4-dichlorophenol could be increased by 4-5 times. Moreover, this interfacial microenvironment modulation strategy is parallel to other approaches, such as Pd structural engineering, and therefore these strategies can be combined to further increase the electrochemical decontamination performance of electrocatalysts.

11.
Int J Colorectal Dis ; 38(1): 140, 2023 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-37219592

RESUMO

PURPOSE: This study performed an analysis of clinicopathological characteristics, surgical treatment strategy, and survival for CRC patients with LM between China and the USA. METHODS: The CRC patients with simultaneous LM were identified from the Surveillance, Epidemiology, and End Results (SEER) registry and the Chinese National Cancer Center (CNCC) database from 2010 to 2017. We assessed 3-year cancer-specific survival (CSS) according to surgical treatment strategy and time period. RESULTS: Differences in patient age, gender, primary tumor location, tumor grade, tumor histology, and tumor stage were observed between the USA and China. Compared to the USA, a larger proportion of patients in China underwent both primary site resection (PSR) and hepatic resection (HR) (35.1% vs 15.6%, P < 0.001), and fewer patients underwent only PSR in China (29.1% vs 45.1%, P < 0.001). From 2010 to 2017, the proportion of patient who underwent both PSR and HR has increased from 13.9% to 17.4% in the USA and from 25.4% to 39.4% in China. The 3-year CSS were increasing over time in both the USA and China. The 3-year CSS of patients receiving HR and PSR were significantly higher than those receiving only PSR and patients treated with no surgery in the USA and China. There were no significant differences of 3-year CSS between the USA and China after adjustment (P = 0.237). CONCLUSIONS: Despite the distinctions of tumor characteristics and surgical strategy in patients with LM between the USA and China, increased adoption of HR has contributed to the profound improvements of survival during recent decade.


Assuntos
Neoplasias Colorretais , Neoplasias Hepáticas , Humanos , China , Neoplasias Colorretais/patologia , Neoplasias Colorretais/terapia , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/secundário , Neoplasias Hepáticas/terapia , Prognóstico , Estados Unidos
12.
J Med Internet Res ; 25: e41283, 2023 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-37223977

RESUMO

BACKGROUND: Obsessive-compulsive disorder (OCD) is a common and chronic mental illness with a high rate of disability. Internet-based cognitive behavioral therapy (ICBT) makes online treatment available to patients and has been shown to be effective. However, 3-arm trials on ICBT, face-to-face cognitive behavioral group therapy (CBGT), and only medication are still lacking. OBJECTIVE: This study is a randomized, controlled, assessor-blinded trial of 3 groups for OCD: ICBT combined with medication, CBGT combined with medication, and conventional medical treatment (ie, treatment as usual [TAU]). The study aims to investigate the efficacy and cost-effectiveness of ICBT related to CBGT and TAU for adults with OCD in China. METHODS: In total, 99 patients with OCD were selected and randomly assigned to the ICBT, CBGT, and TAU groups for treatment for 6 weeks. The primary outcomes were the Yale-Brown Obsessive-Compulsive Scale (YBOCS) and the self-rating Florida Obsessive-Compulsive Inventory (FOCI), compared at baseline, during treatment (3 weeks), and after treatment (6 weeks), to analyze efficacy. The secondary outcome was the EuroQol Visual Analogue Scale (EQ-VAS) scores of the EuroQol 5D Questionnaire (EQ-5D). The cost questionnaires were recorded to analyze cost-effectiveness. RESULTS: Repeated-measures ANOVA was used for data analysis, and the final effective sample size was 93 (ICBT: n=32, 34.4%; CBGT: n=28, 30.1%; TAU: n=33, 35.5%). After 6-week treatment, the YBOCS scores of the 3 groups significantly decreased (P<.001), and there were no significant differences among groups. The FOCI score of the ICBT (P=.001) and CBGT (P=.035) groups was significantly lower than that of the TAU group after treatment. The total cost of the CBGT group (renminbi [RMB] 6678.45, 95% CI 4460.88-8896.01 [US $1010.36, 95% CI 678.87-1345.84]) was significantly higher than that of the ICBT group (RMB 3308.81, 95% CI 2476.89-4140.73[US $500.58, 95% CI 374.72-626.43], P<.001) and the TAU group (RMB 2259.61, 95% CI 2074.16-2445.05 [US $341.85, 95% CI 313.79-369.90], P<.001) after treatment. The ICBT group spent RMB 303.19 (US $45.97) less than the CBGT group and RMB 11.57 (US $1.75) less than the TAU group for each unit reduction in the YBOCS score. CONCLUSIONS: Therapist-guided ICBT combined with medication is as effective as face-to-face CBGT combined with medication for OCD. ICBT combined with medication is more cost-effective than CBGT combined with medication and conventional medical treatment. It is expected to become an efficacious and economic alternative for adults with OCD when face-to-face CBGT is not available. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR1900023840; https://www.chictr.org.cn/showproj.html?proj=39294.


Assuntos
Terapia Cognitivo-Comportamental , Transtorno Obsessivo-Compulsivo , Adulto , Humanos , Análise de Custo-Efetividade , Pessoal Técnico de Saúde , Internet , Transtorno Obsessivo-Compulsivo/terapia
13.
Sensors (Basel) ; 23(12)2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-37420807

RESUMO

Cycle slip detection and repair is a prerequisite to obtain high-precision positioning based on a carrier phase. Traditional triple-frequency pseudorange and phase combination algorithm are highly sensitive to the pseudorange observation accuracy. To solve the problem, a cycle slip detection and repair algorithm based on inertial aiding for a BeiDou navigation satellite system (BDS) triple-frequency signal is proposed. To enhance the robustness, the INS-aided cycle slip detection model with double-differenced observations is derived. Then, the geometry-free phase combination is united to detect the insensitive cycle slip, and the optimal coefficient combination is selected. Furthermore, the L2-norm minimum principle is used to search and confirm the cycle slip repair value. To correct the INS error accumulated over time, the extended Kalman filter based on the BDS/INS tightly coupled system is established. The vehicular experiment is conducted to evaluate the performance of the proposed algorithm from a few aspects. The results indicate that the proposed algorithm can reliably detect and repair all cycle slips that occur in one cycle, including the small and insensitive cycle slips as well as the intensive and continuous cycle slips. Additionally, in signal-challenged environments, the cycle slips occurring 14 s after a satellite signal outage can be correctly detected and repaired.

14.
J Environ Sci (China) ; 126: 198-210, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36503749

RESUMO

In order to enhance Ni-EDTA decomplexation and Ni recovery via photoelectrocatalytic (PEC) process, TiO2/Ni-Sb-SnO2 bifunctional electrode was fabricated as the photoanode and activated carbon fiber (ACF) was introduced as the cathode. At a cell voltage of 3.5 V and initial solution pH of 6.3, the TiO2/Ni-Sb-SnO2 bifunctional photoanode exhibited a synergetic effect on the decomplexation of Ni-EDTA with the pseudo-first-order rate constant of 0.01068 min-1 with 180 min by using stainless steel (SS) cathode, which was 1.5 and 2.4 times higher than that of TiO2 photoanode and Ni-Sb-SnO2 anode, respectively. Moreover, both the efficiencies of Ni-EDTA decomplexation and Ni recovery were improved to 98% from 86% and 73% from 41% after replacing SS cathode with ACF cathode, respectively. Influencing factors on Ni-EDTA decomplexation and Ni recovery were investigated and the efficiencies were favored at acidic condition, higher cell voltage and lower initial Ni-EDTA concentration. Ni-EDTA was mainly decomposed via ·OH radicals which generated via the interaction of O3, H2O2, and UV irradiation in the contrasted PEC system. Then, the liberated Ni2+ ions which liberated from Ni-EDTA decomplexation were eventually reduced to metallic Ni on the ACF cathode surface. Finally, the stability of the constructed PEC system on Ni-EDTA decomplexation and Ni recovery was exhibited.


Assuntos
Carvão Vegetal , Níquel , Fibra de Carbono , Ácido Edético , Peróxido de Hidrogênio , Aço Inoxidável
15.
Environ Sci Technol ; 56(9): 5602-5610, 2022 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-35417136

RESUMO

In cement-rich radioactive waste repositories, mackinawite (FeS) forms at the steel corrosion interface within reinforced concrete and potentially retards the transport of redox-sensitive radionuclides (e.g., 79Se) in porous cement media. Redox interactions between selenite and mackinawite under hyperalkaline conditions remain unclear and require further investigations. Here, using comprehensive characterization on both aqueous and solid speciation, we successfully monitored the whole interaction process between selenite and mackinawite under hyperalkaline conditions. The results show similar chemical environments for SeO32- and S2-/Sn2- at the mackinawite-water interface, verifying an immediate reduction. After 192 h of reaction, SeO32- was reduced to solid Se0 and SeS2 species, accompanied by the oxidation of S2-/Sn2- to S2O32- and Fe(II) to Fe(III) in mackinawite. Aqueous speciation results showed that ∼99% of aqueous selenium was present as Se4S nanoparticles due to the dissolution of Se from the solid. In parallel, ∼62% of S2-/Sn2- was released into the solution, with mackinawite transforming into magnetite, Fe(OH)3 and FeS2O3+ complexed to Cl- or OH- species, and magnetite subsequently dispersed in the solution. This study provides valuable data about the retardation mechanisms of redox-sensitive radionuclides by soluble iron sulfides, which is critical to advance our understanding of reactive concrete barriers used in nuclear waste disposal systems.

16.
Mol Biol Rep ; 49(7): 5897-5909, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35543827

RESUMO

BACKGROUND: Coix seed oil (CSO) has a wide range of anticancer effects. However, the mechanism of action against pancreatic cancer (PC) and regulation of mitochondria in vitro is still unclear. MATERIALS AND RESULTS: This research investigated the possible mechanism of CSO induction of PC cell apoptosis and regulating mitochondrial functional damage. Proliferation of PC cells, mitochondrial membrane potential (MMP), qualitative and quantitative analysis of PC cell apoptosis, openness of mitochondrial permeability transition pore, related protein expression, generation of reactive oxygen species (ROS), and gene expression were determined by cell counting kit-8, JC-1 staining, acridine orange and ethidium bromide staining, flow cytometry, calcein-AM/cobalt staining, western blotting, dichlorofluorescein diacetate probe, and quantitative real-time reverse transcription-polymerase chain reaction, respectively. We confirmed that PTEN protein was involved in CSO-induced PANC-1 cell apoptosis and mitochondrial functional damage. CSO induced depolarization of MMP, increased opening of the mitochondrial permeability transition pore, increased ROS production, and further increased mitochondrial damage. Additionally, CSO downregulated expression of p-AKT and p-PI3K proteins; upregulated protein expression of cleaved caspase-9, Bax, cleaved caspase-3 and cytochrome c; and downregulated expression of Bcl-2 by upregulating the PTEN gene. The corresponding protein expression was consistent with the gene expression level. Furthermore, the loss of function of PTEN protein reduces the ability of CSO to induce apoptosis of PANC-1 cells and damage to mitochondrial function. CONCLUSIONS: CSO induces apoptosis of PANC-1 PC cells by modulating mitochondrial functional impairment and related apoptotic molecules via PTEN, which may be closely related to the PI3K/AKT signaling pathway.


Assuntos
Coix , Neoplasias Pancreáticas , Apoptose , Coix/metabolismo , Humanos , Poro de Transição de Permeabilidade Mitocondrial , PTEN Fosfo-Hidrolase/metabolismo , Neoplasias Pancreáticas/genética , Fosfatidilinositol 3-Quinases/metabolismo , Óleos de Plantas/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Neoplasias Pancreáticas
17.
BMC Musculoskelet Disord ; 22(1): 733, 2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34452605

RESUMO

BACKGROUND: The position of the head relative to the spine can be used to evaluate the true global balance in patients with degenerative spinal kyphosis (DSK). However, it is still not clear how the position of the head is related to the spinal-pelvic parameters and lumbar muscles, which are most commonly considered. METHODS: Sixty-seven patients with DSK admitted in the hospital from January 2017 to January 2019 were retrospectively analyzed. All patients had whole spine X-ray and lumbar MRI. The head position parameters include: the angles of both lines joining the center of acoustic meati (CAM) to the center of the bi-coxofemoral axis (BA) (CAM-BA) and the most superior point of dentiform apophyse of C2 odontoid (OD) to BA (OD-BA) with the vertical line; the distance between the vertical line passing CAM and the posterior upper edge of the S1 (CAM-SVA). The spinal parameters include: C7 sagittal vertical axis (C7-SVA), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), and lumbar lordosis (LL). The pelvic parameters include: pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS). The relative cross-sectional area (RCSA) of bilateral multifidus, erector spinae and psoas muscle at L3/4 and L4/5 segments were measured. The correlations between head position parameters and the spinal-pelvic parameters and RCSA of lumbar muscles were analyzed, respectively. RESULTS: Significant positive correlations were found between each two of CAM-SVA, C7-SVA, CAM-BA and OD-BA (p < 0.001). SS was found to be significantly positively correlated with CAM-BA (r = 0.377, p = 0.034) and OD-BA (r = 0.402, p = 0.023). CAM-BA was found to be significantly negatively correlated with TK (r = - 0.367, p = 0.039). Significant positive correlations were found between RCSA of multifidus at L3/4 level and CAM-SVA (r = 0.413, p = 0.021), CAM-BA (r = 0.412, p = 0.019) and OD-BA (r = 0.366, p = 0.04). CONCLUSIONS: Our study showed that the head position relative to the spine were significantly correlated to some spinal-pelvic parameters, and the lower lumbar multifidus muscle. The compensatory mechanisms of the global sagittal balance status should also involve the head position area.


Assuntos
Cifose , Lordose , Humanos , Cifose/diagnóstico por imagem , Lordose/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Músculos Paraespinais , Radiografia , Estudos Retrospectivos
18.
Liver Int ; 40(10): 2316-2325, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32666675

RESUMO

Hepatocellular carcinoma (HCC), one of the major malignant lethal tumours, is most prevalent in Asian patients with chronic hepatitis B virus (HBV) infection. Both viral and non-viral factors contribute to the development of HCC. It is established that viral factors associated with HBV DNA level, HBV genotype, designated gene mutation, HBV DNA integration, HBx protein, hepatitis B surface antigen (HBsAg), hepatitis B core-related antigen (HBcrAg) and HBV RNA are correlated with hepatocarcinogenesis. Before the introduction of antiviral therapy, viral factors once attracted more attention during the development of HCC. With the widespread use of antiviral therapy, predominantly nucleos(t)ide analogues (NAs), most patients with chronic hepatitis B (CHB) have achieved sustained viral control. The role of non-viral factors, especially modifiable factors, is anticipated to be reinforced in the future. Herein, we reviewed the modifiable non-viral risk factors of HBV-related HCC, in the hope of providing substantial evidence for further development of novel precautionary measures for HCC. In addition, the therapeutic interventions for reducing the risk of HCC, like potential conventional pharmaceutical interventions and lifestyle modification are also discussed in this review. Future studies that would explore the specific mechanism of HBV-related HCC development in patients with satisfactory viral control and related precision treatment are warranted.


Assuntos
Carcinoma Hepatocelular , Hepatite B Crônica , Hepatite B , Neoplasias Hepáticas , Antivirais/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/epidemiologia , Carcinoma Hepatocelular/etiologia , DNA Viral , Hepatite B/tratamento farmacológico , Vírus da Hepatite B/genética , Hepatite B Crônica/complicações , Hepatite B Crônica/tratamento farmacológico , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/epidemiologia , Neoplasias Hepáticas/etiologia , Fatores de Risco
19.
Cell Biol Int ; 44(8): 1714-1726, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32339345

RESUMO

The dysregulation of proliferation and migration of vascular smooth muscle cells (VSMCs) contributes to atherosclerosis (AS) and accumulating reports indicate the crucial role of long noncoding RNA in AS. However, the role of small nucleolar RNA host gene 12 (SNHG12) in regulating the phenotypes of VSMCs and AS remains largely unknown. Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was used to detect the expression levels of SNHG12 and miR-199a-5p in an in vivo AS model and VSMCs treated by oxidized low-density lipoprotein (ox-LDL). The proliferation ability, migration ability, and apoptosis of VSMCs were tested by cell counting kit-8, Transwell assay, and terminal deoxynucleotidyl transferase dUTP nick end labeling assay, respectively. StarBase database was used to predict the binding sites between miR-199a-5p and SNHG12. The interaction between miR-199a-5p and SNHG12 was validated by qRT-PCR, western blot, and luciferase reporter assay. Western blot was used to examine the effects of SNHG12 and miR-199a-5p on the expression of hypoxia-inducible factor 1α (HIF-1α). We found that the expression level of SNHG12 was significantly increased in the animal model and VSMCs treated by ox-LDL. Knockdown of SNHG12 suppressed the proliferation and migration abilities of VSMCs, while overexpression of SNHG12 had the opposite effects. Mechanically, we validated that miR-199a-5p was a target of SNHG12, and the target gene of miR-199a-5p, HIF-1α could be indirectly and positively regulated by SNHG12. In conclusion, SHNG12 targeting miR-199a-5p/HIF-1α contributed to the pathophysiological process of AS by regulating the phenotypes of VSMCs, and could be a potential therapy target for this disease.


Assuntos
Aterosclerose/genética , Regulação da Expressão Gênica , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , MicroRNAs/metabolismo , Músculo Liso Vascular/metabolismo , RNA Longo não Codificante/metabolismo , Animais , Apoptose , Aterosclerose/metabolismo , Artérias Carótidas/citologia , Movimento Celular , Proliferação de Células , Células Cultivadas , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Músculo Liso Vascular/citologia
20.
Environ Sci Technol ; 54(4): 2344-2352, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-31971374

RESUMO

Reinforced cementitious structures in nuclear waste repositories will act as barriers that limit the mobility of radionuclides (RNs) in case of eventual leakage. CEM-V/A cement, a ternary blended cement with blast furnace slag (BFS) and fly ash (FA), could be qualified and used in nuclear waste disposal. Chemical interactions between the cement and RNs are critical but not completely understood. Here, we combined wet chemistry methods, synchrotron-based X-ray techniques, and thermodynamic modeling to explore redox interactions and nonredox sorption processes in simulated steel-reinforced CEM-V/A hydration systems using selenite as a molecular probe. Among all of the steel corrosion products analyzed, only the addition of Fe0 can obviously enhance the reducing ability of cement toward selenite. In comparison, steel corrosion products showed stronger reducing power in the absence of cement hydrates. Selenium K-edge X-ray absorption spectroscopy (XAS) revealed that selenite immobilization mechanisms included nonredox inner-/outer-sphere complexations and reductive precipitations of FeSe and/or Se(0). Importantly, the hydrated pristine cement showed a good reducing ability, driven by ferrous phases and (bi)sulfides (as shown by sulfur K-edge XAS) originated from BFS and FA. The overall redox potential imposed by hydrated CEM-V/A was determined, hinting to a redox shift in underground cementitious structures.


Assuntos
Materiais de Construção , Aço , Corrosão , Oxirredução , Ácido Selenioso
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA