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1.
J Comput Chem ; 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39012324

RESUMO

The electronic structure of the strongly correlated electron system plutonium hexaboride is studied by using single-particle approximations and a many-body approach. Imaginary components of impurity Green's functions show that 5fj=5/2 and 5fj=7/2 manifolds are in conducting and insulating regimes, respectively. Quasi-particle weights and their ratio suggest that the intermediate coupling mechanism is applicable for Pu 5f electrons, and PuB6 might be in the orbital-selective localized state. The weighted summation of occupation probabilities yields the interconfiguration fluctuation and average occupation number of 5f electrons n5f ~ 5.101. The interplay of 5f-5f correlation, spin-orbit coupling, Hund's exchange interaction, many-body transition of 5f configurations, and final state effects might be responsible for the quasiparticle multiplets in electronic spectrum functions. Prominent characters in the density of state, such as the coexistence of atomic multiplet peaks in the vicinity of the Fermi level and broad Hubbard bands in the high-lying regime, suggest that PuB6 could be identified as a Racah material. Finally, the quasiparticle band structure is also presented.

2.
Exp Eye Res ; 244: 109919, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38729254

RESUMO

Age-related macular degeneration (AMD) is the leading cause of vision loss among the elderly, which is primarily attributed to oxidative stress-induced damage to the retinal pigment epithelium (RPE). Human amniotic mesenchymal stem cells (hAMSC) were considered to be one of the most promising stem cells for clinical application due to their low immunogenicity, tissue repair ability, pluripotent potential and potent paracrine effects. The conditional medium (hAMSC-CM) and exosomes (hAMSC-exo) derived from hAMSC, as mediators of intercellular communication, play an important role in the treatment of retinal diseases, but their effect and mechanism on oxidative stress-induced retinal degeneration are not explored. Here, we reported that hAMSC-CM alleviated H2O2-induced ARPE-19 cell death through inhibiting mitochondrial-mediated apoptosis pathway in vitro. The overproduction of reactive oxygen species (ROS), alteration in mitochondrial morphology, loss of mitochondrial membrane potential and elevation of Bax/Bcl2 ratio in ARPE-19 cells under oxidative stress were efficiently reversed by hAMSC-CM. Moreover, it was found that hAMSC-CM protected cells against oxidative injury via PI3K/Akt/FoxO3 signaling. Intriguingly, exosome inhibitor GW4869 alleviated the inhibitory effect of hAMSC-CM on H2O2-induced decrease in cell viability of ARPE-19 cells. We further demonstrated that hAMSC-exo exerted the similar protective effect on ARPE-19 cells against oxidative damage as hAMSC-CM. Additionally, both hAMSC-CM and hAMSC-exo ameliorated sodium iodate-induced deterioration of RPE and retinal damage in vivo. These results first indicate that hAMSC-CM and hAMSC-exo protect RPE cells from oxidative damage by regulating PI3K/Akt/FoxO3 pathway, suggesting hAMSC-CM and hAMSC-exo will be a promising cell-free therapy for the treatment of AMD in the future.


Assuntos
Âmnio , Exossomos , Proteína Forkhead Box O3 , Células-Tronco Mesenquimais , Estresse Oxidativo , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , Degeneração Retiniana , Epitélio Pigmentado da Retina , Transdução de Sinais , Humanos , Células-Tronco Mesenquimais/metabolismo , Exossomos/metabolismo , Âmnio/citologia , Meios de Cultivo Condicionados/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Degeneração Retiniana/metabolismo , Degeneração Retiniana/patologia , Degeneração Retiniana/etiologia , Proteína Forkhead Box O3/metabolismo , Epitélio Pigmentado da Retina/metabolismo , Epitélio Pigmentado da Retina/patologia , Apoptose , Células Cultivadas , Espécies Reativas de Oxigênio/metabolismo , Potencial da Membrana Mitocondrial , Western Blotting , Animais , Sobrevivência Celular , Peróxido de Hidrogênio/toxicidade
3.
Environ Sci Technol ; 58(4): 2102-2111, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38238255

RESUMO

Waste biomass is one of the promising feedstocks to supply syngas that can be used as fuels, chemicals, reductants, etc. However, the relationship between the component of biomass and the constituent of pyrolysis gas remains unclear. Here, we study the pyrolysis behaviors of various biomasses and reveal the relationship between the biomass components and gas compositions. Further, different pyrolysis gases are applied for the reduction of spent lithium cobalt oxide (LiCoO2) below 500 °C. The pyrolysis gas with a higher concentration of CO has a higher reductivity to convert LiCoO2 to CoO and Li2CO3 with a conversion rate close to 100% in 1 h at 500 °C. The biomass rich in cellulose and with a lower content of lignin tends to produce pyrolysis gas with a high concentration of CO, which comes from the deliberate breakdown of carboxyl, carbonyl, ether, and ester linkages. Moreover, LiCoO2 exerts catalytic functions over the deoxygenation and enhancement of oxygenates and single-ring aromatics. Overall, this paper offers a tailored approach to regulating biomass pyrolysis gases, enabling highly efficient battery recycling and syngas production.


Assuntos
Fontes de Energia Elétrica , Pirólise , Biomassa , Lignina/química , Reciclagem , Gases
4.
Lipids Health Dis ; 23(1): 164, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38831466

RESUMO

OBJECTIVE: Although blood urea nitrogen (BUN) has a crucial impact on many diseases, its effect on outcomes in patients with hyperlipidemia remains unknown. The study aimed to investigate the relationships between BUN levels and all-cause and cardiovascular disease (CVD) mortality in individuals with hyperlipidemia. METHODS: This analysis comprised 28,122 subjects with hyperlipidemia from the National Health and Nutrition Examination Survey (NHANES) spanning 1999 to 2018. The risk of BUN on mortality was evaluated using weighted Cox regression models. Additionally, to illustrate the dose-response association, the restricted cubic spline (RCS) was used. RESULTS: During the observation period, 4276 participant deaths were recorded, of which 1206 were due to CVD. Compared to patients with hyperlipidemia in the third BUN quintile, the hazard ratios (HRs) for all-cause mortality were 1.26 (95% CIs: 1.09, 1.45) and 1.22 (95% CIs: 1.09, 1.37) for patients in the first and fifth quintiles of BUN, respectively. The HRs for CVD mortality among patients in the fifth quintile of BUN were 1.48 (95% CIs: 1.14, 1.93). BUN levels were found to have a U-shaped association with all-cause mortality and a linear association with CVD mortality using restricted triple spline analysis. CONCLUSIONS: This study revealed that both low and high BUN levels in patients with hyperlipidemia are associated with heightened all-cause mortality. Furthermore, elevated BUN levels are also associated with increased CVD mortality. The findings indicate that patients with hyperlipidemia may face an elevated risk of death if they have abnormal BUN levels.


Assuntos
Nitrogênio da Ureia Sanguínea , Doenças Cardiovasculares , Hiperlipidemias , Inquéritos Nutricionais , Humanos , Hiperlipidemias/sangue , Hiperlipidemias/mortalidade , Masculino , Feminino , Pessoa de Meia-Idade , Doenças Cardiovasculares/mortalidade , Doenças Cardiovasculares/sangue , Modelos de Riscos Proporcionais , Idoso , Adulto , Fatores de Risco
5.
Biol Res ; 57(1): 34, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38812057

RESUMO

Studies have suggested that endoplasmic reticulum stress (ERS) is involved in neurological dysfunction and that electroacupuncture (EA) attenuates neuropathic pain (NP) via undefined pathways. However, the role of ERS in the anterior cingulate cortex (ACC) in NP and the effect of EA on ERS in the ACC have not yet been investigated. In this study, an NP model was established by chronic constriction injury (CCI) of the left sciatic nerve in rats, and mechanical and cold tests were used to evaluate behavioral hyperalgesia. The protein expression and distribution were evaluated using western blotting and immunofluorescence. The results showed that glucose-regulated protein 78 (BIP) and inositol-requiring enzyme 1α (IRE-1α) were co-localized in neurons in the ACC. After CCI, BIP, IRE-1α, and phosphorylation of IRE-1α were upregulated in the ACC. Intra-ACC administration of 4-PBA and Kira-6 attenuated pain hypersensitivity and downregulated phosphorylation of IRE-1α, while intraperitoneal injection of 4-PBA attenuated hyperalgesia and inhibited the activation of P38 and JNK in ACC. In contrast, ERS activation by intraperitoneal injection of tunicamycin induced behavioral hyperalgesia in naive rats. Furthermore, EA attenuated pain hypersensitivity and inhibited the CCI-induced overexpression of BIP and pIRE-1α. Taken together, these results demonstrate that EA attenuates NP by suppressing BIP- and IRE-1α-mediated ERS in the ACC. Our study presents novel evidence that ERS in the ACC is implicated in the development of NP and provides insights into the molecular mechanisms involved in the analgesic effect of EA.


Assuntos
Modelos Animais de Doenças , Eletroacupuntura , Estresse do Retículo Endoplasmático , Giro do Cíngulo , Neuralgia , Ratos Sprague-Dawley , Animais , Eletroacupuntura/métodos , Giro do Cíngulo/metabolismo , Neuralgia/terapia , Masculino , Estresse do Retículo Endoplasmático/fisiologia , Ratos , Western Blotting , Proteínas de Choque Térmico/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Hiperalgesia/terapia , Chaperona BiP do Retículo Endoplasmático
6.
Acta Biochim Biophys Sin (Shanghai) ; 56(1): 34-43, 2024 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-38151998

RESUMO

Cisplatin resistance is a major obstacle in the treatment of non-small cell lung cancer (NSCLC). p32 and OPA1 are the key regulators of mitochondrial morphology and function. This study aims to investigate the role of the p32/OPA1 axis in cisplatin resistance in NSCLC and its underlying mechanism. The levels of p32 protein and mitochondrial fusion protein OPA1 are higher in cisplatin-resistant A549/DDP cells than in cisplatin-sensitive A549 cells, which facilitates mitochondrial fusion in A549/DDP cells. In addition, the expression of p32 and OPA1 protein is also upregulated in A549 cells during the development of cisplatin resistance. Moreover, p32 knockdown effectively downregulates the expression of OPA1, stimulates mitochondrial fission, decreases ATP generation and sensitizes A549/DDP cells to cisplatin-induced apoptosis. Furthermore, metformin significantly downregulates the expressions of p32 and OPA1 and induces mitochondrial fission and a decrease in ATP level in A549/DDP cells. The co-administration of metformin and cisplatin shows a significantly greater decrease in A549/DDP cell viability than cisplatin treatment alone. Moreover, D-erythro-Sphingosine, a potent p32 kinase activator, counteracts the metformin-induced downregulation of OPA1 and mitochondrial fission in A549/DDP cells. Taken together, these findings indicate that p32/OPA1 axis-mediated mitochondrial dynamics contributes to the acquired cisplatin resistance in NSCLC and that metformin resensitizes NSCLC to cisplatin, suggesting that targeting p32 and mitochondrial dynamics is an effective strategy for the prevention of cisplatin resistance.


Assuntos
Antineoplásicos , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Metformina , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Cisplatino/farmacologia , Cisplatino/uso terapêutico , Dinâmica Mitocondrial , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Resistencia a Medicamentos Antineoplásicos , Linhagem Celular Tumoral , Apoptose , Células A549 , Proteínas , Metformina/farmacologia , Trifosfato de Adenosina , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Proliferação de Células , GTP Fosfo-Hidrolases/genética
7.
Mol Cell Biochem ; 478(7): 1519-1531, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36413334

RESUMO

Triple negative breast cancer (TNBC) is a kind of refractory cancer with poor response to conventional chemotherapy. Recently, the combination of baicalein and doxorubicin was reported to exert a synergistic antitumor effect on breast cancer. However, the underlying mechanism how baicalein sensitizes breast cancer cells to doxorubicin remains to be elucidated. Here, it was found that 20 µM baicalein increased the autophagy markers including the ratio of LC3B II/I, GFP-LC3 punctate aggregates and down-regulation of p62 expression, and up-regulated mitophagy marker PINK1 and Parkin in TNBC MDA-MB-231 cells as well. In contrast, doxorubicin decreased the levels of autophagy markers, and significantly up-regulated CDK1 in MDA-MB-231 cells. Pretreatment with baicalein markedly inhibited the doxorubicin-induced decrease in autophagy markers and up-regulation of CDK1, which was reversed by the autophagy inhibitor 3-Methyladenine. Moreover, baicalein alleviated the doxorubicin-induced expression and phosphorylation (at Ser616) of mitochondrial fission protein Drp1. Intriguingly, the autophagy inhibitor 3-Methyladenine also significantly weakened the effect of baicalein on doxorubicin-induced viability decrease and apoptosis in MDA-MB-231 cells. Taken together, our data indicate that baicalein improves the chemosensitivity of TNBC cells to doxorubicin through promoting the autophagy-mediated down-regulation of CDK1, also suggest a novel strategy for prevention of TNBC in the future.


Assuntos
Neoplasias de Mama Triplo Negativas , Humanos , Neoplasias de Mama Triplo Negativas/metabolismo , Células MDA-MB-231 , Regulação para Baixo , Linhagem Celular Tumoral , Doxorrubicina/farmacologia , Autofagia , Apoptose , Proliferação de Células , Proteína Quinase CDC2/metabolismo , Proteína Quinase CDC2/farmacologia
8.
Environ Sci Technol ; 57(19): 7599-7611, 2023 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-37140343

RESUMO

Spent lithium-ion batteries (LIBs) and benzene-containing polymers (BCPs) are two major pollutants that cause serious environmental burdens. Herein, spent LIBs and BCPs are copyrolyzed in a sealed reactor to generate Li2CO3, metals, and/or metal oxides without emitting toxic benzene-based gases. The use of a closed reactor allows the sufficient reduction reaction between the BCP-derived polycyclic aromatic hydrocarbon (PAH) gases and lithium transition metal oxides, achieving the Li recovery efficiencies of 98.3, 99.9, and 97.5% for LiCoO2, LiMn2O4, and LiNi0.6Co0.2Mn0.2O2, respectively. More importantly, the thermal decomposition of PAHs (e.g., phenol and benzene) is further catalyzed by the in situ generated Co, Ni, and MnO2 particles, which forms metal/carbon composites and thus prevent the emissions of toxic gases. Overall, the copyrolysis in a closed system paves a green way to synergistically recycle spent LIBs and handle waste BCPs.


Assuntos
Benzeno , Lítio , Plásticos , Compostos de Manganês , Óxidos , Metais , Fontes de Energia Elétrica , Reciclagem , Polímeros
9.
BMC Infect Dis ; 23(1): 830, 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-38012576

RESUMO

BACKGROUND: We investigated the associations between the different doses of tigecycline, its efficacy and safety, and the role of tigecycline therapeutic drug monitoring for patients in the intensive care unit. METHODS: This study was a single-center cohort including patients infected with multidrug-resistant Acinetobacter baumannii (MDR-AB) and multidrug-resistant Klebsiella pneumoniae (MDR-KP) causing pulmonary infections. The steady-state plasma concentration after tigecycline administration was determined by High-Performance Liquid Chromatography (HPLC) in patients admitted to the ICU between October 2020 and December 2021. Multivariate analyses of tigecycline's clinical efficacy and safety were performed to control confounding factors. RESULTS: For this study, we included 45 patients and 45 blood samples to determine steady-state trough concentrations of tigecycline. All patients were divided into the High Dose (HD) and Standard Dose (SD) groups. The median trough concentration of tigecycline was 0.56 µg/mL in the HD group, which was higher than in the SD group (0,21 µg/mL), p = 0.000. There was no significant difference between the two groups of patients in terms of bacterial eradication rate, mortality rate, and clinical efficacy. Multiple regression analysis showed that the ICU days were correlated with mortality OR 1.030(1.005-1.056), p = 0.017. APACHE II was significantly associated with clinical efficacy OR 0.870(0.755-1.002), p = 0.045. The level of fibrinogen decline in the HD group was significantly higher than in the SD group (-3.05 ± 1.67 vs -1.75 ± 1.90), p = 0.038. We identified that age and tigecycline treatment duration influenced fibrinogen decline. CONCLUSIONS: Tigecycline plasma concentrations are significantly increased when using a high dose. However, the plasma concentration of tigecycline is not correlated with clinical efficacy and adverse reactions. Fibrinogen decline appears to be related to the patient's age and days of tigecycline. Large sample data are still needed to confirm the clinical guidance significance of tigecycline TDM.


Assuntos
Acinetobacter baumannii , Pneumonia Bacteriana , Humanos , Tigeciclina/farmacologia , Antibacterianos/uso terapêutico , Antibacterianos/farmacologia , Carbapenêmicos/uso terapêutico , Carbapenêmicos/farmacologia , Monitoramento de Medicamentos , Estudos Retrospectivos , Pneumonia Bacteriana/tratamento farmacológico , Resultado do Tratamento , Bactérias Gram-Negativas , Unidades de Terapia Intensiva , Fibrinogênio , Farmacorresistência Bacteriana Múltipla , Minociclina/uso terapêutico
10.
Phys Chem Chem Phys ; 25(25): 16952-16961, 2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37326588

RESUMO

Two-dimensional carbon-based materials have great potential for electrocatalysis. Herein, we screen 12 defective and doped C3N nanosheets by evaluating their CO2RR and NRR activity and selectivity vs. the HER based on density functional theory calculations. The calculation results suggest that all 12 C3Ns can enhance CO2 adsorption and activation. And PN-VC-C3N is the best electrocatalyst for the CO2RR towards HCOOH with UL = -0.17 V, which is much more positive than most of the reported values. BN-C3N and PN-C3N are also good electrocatalysts that promote the CO2RR towards HCOOH (UL = -0.38 V and -0.46 V). Moreover, we find that SiC-C3N can reduce CO2 to CH3OH, adding an alternative option to the limited catalysts available for the CO2RR to CH3OH. Furthermore, BC-VC-C3N, BC-VN-C3N, and SiC-VN-C3N are promising electrocatalysts for the HER with |ΔGH*| ≤ 0.30 eV. However, only three C3Ns of BC-VC-C3N, SiC-VN-C3N, and SiC-VC-C3N can slightly improve N2 adsorption. And none of the 12 C3Ns are found to be suitable for the electrocatalytic NRR because all the ΔeNNH* values are larger than the corresponding ΔGH* values. The high performance of C3Ns in the CO2RR stems from the altered structure and electronic properties, which result from the introduction of vacancies and doping elements into C3N. This work identifies suitable defective and doped C3Ns for excellent performance in the electrocatalytic CO2RR, which will inspire relevant experimental studies to further explore C3Ns for electrocatalysis.

11.
J Nanobiotechnology ; 21(1): 497, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-38124097

RESUMO

Photothermal therapy (PTT) and photodynamic therapy (PDT) are effective method for tumor treatment. However, the limited variety and quantity of photothermal agents (PTAs) and photosensitizer (PSs) are still major challenges. Moreover, the cell apoptosis mechanism induced by PDT and PTT is still elusive. A fused-ring small molecule acceptor-donor acceptor' donor-acceptor (A-DA'D-A) type of Y5 (Scheme 1) has a narrow band-gap and strong light absorption. Herein, we used Y5 to polymerize with thiophene unit to obtain polymer PYT based on polymerized small molecule strategy, and PYT nanoparticles (PYT NPs) was prepared via one-step nanoprecipitation strategy with DSPE-PEG2000. PYT NPs had excellent biocompatibility, good photostability, high photothermal conversion efficiency (67%) and reactive oxygen species (ROS) production capacity under 808 nm laser irradiation (PYT NPs + NIR). In vitro and in vivo experiments revealed that PYT NPs + NIR had the ability to completely ablate tumor cells. It was demonstrated that cell apoptosis induced by PYT NPs + NIR was closely related to mitochondrial damage. This study provides valuable guidance for constructing high-performance organic PTAs and PSs for tumor treatment. Scheme 1 PYT enabled by polymerized small molecule strategy for tumor photothermal and photodynamic therapy.


Assuntos
Nanopartículas , Neoplasias , Fotoquimioterapia , Humanos , Polímeros , Neoplasias/tratamento farmacológico , Fototerapia , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico
12.
Arch Gynecol Obstet ; 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37910196

RESUMO

PURPOSE: Acute fatty liver of pregnancy (AFLP) is a relatively rare obstetric emergency usually accompanied by fatal complications. Numerous studies have evaluated the potential risk factors for outcomes in patients with AFLP. But rare studies evaluated the predictive ability, sensitivity and specificity of the risk factors for maternal mortality. Thus, in this multicenter research, we aimed to further prove the predictive ability of the MELD model, investigated the prognostic value of history of abortion (HOA), total bilirubin (TBiL) and serum creatinine (SCr) and explored new predictive models for predicting maternal mortality in patients with AFLP. METHODS: We performed a retrospective cohort study of 133 hospitalised patients with AFLP in four Chinese tertiary hospitals between January 2009 and April 2014. RESULTS: The maximal AUC amongst three independent risk factors for maternal death was TBiL with a cut-off point of > 131.9 µmol/L, showing a sensitivity of 100% and a specificity of 55.9%. The threshold of the RF model for maternal mortality was - 1.629 and the AUC was 0.876, with an 81.8% sensitivity and an 80.2% specificity. The AUC for MELD model to predict maternal death was 0.894, and the best cut-off point was 28 with a sensitivity of 81.8% and a specificity of 84.7%. CONCLUSIONS: Both the MELD model and the RF model showed good efficacy in predicting the maternal mortality in patients with ALFP (AUC = 0.894 and 0.876, respectively).

13.
Br J Neurosurg ; 37(5): 1371-1374, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32924632

RESUMO

PURPOSE: Thoracic myelopathy caused by ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine is usually progressive and responds poorly to conservative therapy, making surgery the only effective treatment option. A variety of surgical procedures have been developed to treat thoracic OPLL. However, the optimal surgical approach for removal of thoracic OPLL remains unclear. In the present study, we described a newly modified posterior approach for the removal of OPLL: circular decompression via dural approach, and complete removal of OPLL can be achieved under direct vision and without neurological deficit. MATERIALS AND METHODS: Three patients with beak-type thoracic OPLL presented with progressive thoracic myelopathy and leg weakness. Magnetic resonance imaging showed the spinal cord severely compressed. The surgical management of the three patients involved the 'cave-in' circular decompression and transdural resection of OPLL. RESULTS: Transdural circumferential decompression was successfully performed in all three patients. Clinical outcome measures, including pre- and postoperative radiographic parameters, were assessed. All of the patients were followed up for an average of 12 months (ranging from 10 to 15 months), and no surgery-related complications occurred. Weakness relief and neural function recovery were satisfactorily achieved in all patients by the final follow-up. CONCLUSIONS: Transdural circumferential decompression was an effective method for thoracic spinal stenosis caused by concurrent beak-type OPLL, by which OPLL could be safely removed. It is especially useful when there is a severe adhesion between the dura OPLL.


Assuntos
Ossificação do Ligamento Longitudinal Posterior , Doenças da Medula Espinal , Fusão Vertebral , Estenose Espinal , Animais , Humanos , Ligamentos Longitudinais/cirurgia , Estenose Espinal/diagnóstico por imagem , Estenose Espinal/etiologia , Estenose Espinal/cirurgia , Osteogênese , Descompressão Cirúrgica/métodos , Bico/cirurgia , Fusão Vertebral/métodos , Vértebras Torácicas/diagnóstico por imagem , Vértebras Torácicas/cirurgia , Ossificação do Ligamento Longitudinal Posterior/complicações , Ossificação do Ligamento Longitudinal Posterior/diagnóstico por imagem , Ossificação do Ligamento Longitudinal Posterior/cirurgia , Doenças da Medula Espinal/complicações , Doenças da Medula Espinal/cirurgia , Resultado do Tratamento
14.
Molecules ; 28(14)2023 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-37513478

RESUMO

Following the successful experimental synthesis of single-layer metallic 1T-TaS2 and semiconducting 2H-MoS2, 2H-WSe2, we perform a first-principles study to investigate the electronic and interfacial features of metal/semiconductor 1T-TaS2/2H-MoS2 and 1T-TaS2/2H-WSe2 van der Waals heterostructures (vdWHs) contact. We show that 1T-TaS2/2H-MoS2 and 1T-TaS2/2H-WSe2 form n-type Schottky contact (n-ShC type) and p-type Schottky contact (p-ShC type) with ultralow Schottky barrier height (SBH), respectively. This indicates that 1T-TaS2 can be considered as an effective metal contact with high charge injection efficiency for 2H-MoS2, 2H-WSe2 semiconductors. In addition, the electronic structure and interfacial properties of 1T-TaS2/2H-MoS2 and 1T-TaS2/2H-WSe2 van der Waals heterostructures can be transformed from n-type to p-type Schottky contact through the effect of layer spacing and the electric field. At the same time, the transition from Schottky contact to Ohmic contact can also occur by relying on the electric field and different interlayer spacing. Our results may provide a new approach for photoelectric application design based on metal/semiconductor 1T-TaS2/2H-MoS2 and 1T-TaS2/2H-WSe2 van der Waals heterostructures.

15.
Angew Chem Int Ed Engl ; 62(49): e202312581, 2023 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-37853512

RESUMO

In nature, regulation of the spatiotemporal distribution of interfacial receptors and ligands leads to optimum binding kinetics and thermodynamics of receptor-ligand binding reactions within interfaces. Inspired by this, we report a hierarchical fluid interface (HieFluidFace) to regulate the spatiotemporal distribution of interfacial ligands to increase the rate and thermodynamic favorability of interfacial binding reactions. Each aptamer-functionalized gold nanoparticle, termed spherical aptamer (SAPT), is anchored on a supported lipid bilayer without fluidity, like an "island", and is surrounded by many fluorescent aptamers (FAPTs) with free fluidity, like "rafts". Such ligand "island-rafts" model provides a large reactive cross-section for rapid binding to cellular receptors. The synergistic multivalency of SAPTs and FAPTs improves interfacial affinity for tight capture. Moreover, FAPTs accumulate at binding sites to bind to cellular receptors with clustered fluorescence to "lighten" cells for direct identification. Thus, HieFluidFace in a microfluidic chip achieves high-performance capture and identification of circulating tumor cells from clinical samples, providing a new paradigm to optimize the kinetics and thermodynamics of interfacial binding reactions.


Assuntos
Ouro , Nanopartículas Metálicas , Ligantes , Sítios de Ligação , Termodinâmica , Receptores de Superfície Celular , Cinética
16.
J Am Chem Soc ; 144(25): 11120-11128, 2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35709383

RESUMO

Materials containing planar hypercoordinate motifs greatly enriched the fundamental understanding of chemical bonding. Herein, by means of first-principles calculations combined with global minimum search, we discovered the two-dimensional (2D) SrB8 monolayer, which has the highest planar coordination number (12) reported so far in extended periodic materials. In the SrB8 monolayer, bridged B8 units are forming the boron monolayer consisting of B12 rings, and the Sr atoms are embedded at the center of these B12 rings, leading to the Sr@B12 motifs. The SrB8 monolayer has good thermodynamic, kinetic, and thermal stabilities, which is attributed to the geometry fit between the size of the Sr atom and cavity of the B12 rings, as well as the electron transfer from Sr atoms to electron-deficient boron network. Placing the SrB8 monolayer on the Ag(001) surface shows good commensurability of the lattices and small vertical structure undulations, suggesting the feasibility of its experimental realization by epitaxial growth. Potential applications of the SrB8 monolayer on metal ions storage (for Li, Na, and K) are explored.

17.
Exp Eye Res ; 224: 109239, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36067824

RESUMO

Oxidative stress plays a crucial role in the damage of retinal neuronal cells. Curcumin, the phytocompound, has anti-inflammatory and antioxidative properties. It was shown that curcumin exerted a beneficial effect on retinal neuronal cell survival. However, the role of mitochondrial dynamics in curcumin-mediated protective effect on retinal neuronal cells remains to be elucidated. Here, H2O2 was used to mimic the oxidative stress in retinal neuronal R28 cells. Drp1 and Mfn2 are key regulators of mitochondrial fission and fusion. 100 µM of H2O2 significantly increased the cleavage of caspase-3 and Drp1 expression, but downregulated the expression of Mfn2. Pretreatment with 5 µM curcumin effectively alleviated H2O2-induced alterations in the expression of Drp1 and Mfn2 and mitochondrial fission in R28 cells. In addition, curcumin and Drp1 knockdown prevented H2O2-induced intracellular ROS increment and mitochondrial membrane potential disruption. On the contrary, knockdown of Mfn2 diminished curcumin-mediated protection against ROS increment and mitochondrial membrane potential disruption after H2O2. Moreover, curcumin protected R28 cells against H2O2-induced PINK1 expression, mitophagy, caspase-3 cleavage and apoptosis. Knockdown of Mfn2 significantly alleviated the protective effect of curcumin on R28 cells after H2O2. Taken together, our data indicate that curcumin protects against oxidative stress-induced injury in retinal neuronal cells by promoting mitochondrial fusion.


Assuntos
Curcumina , Dinâmica Mitocondrial , Curcumina/farmacologia , Caspase 3/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Peróxido de Hidrogênio/toxicidade , Estresse Oxidativo , Apoptose , Proteínas Quinases/metabolismo , Proteínas Quinases/farmacologia
18.
Acta Pharmacol Sin ; 43(4): 1013-1023, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34267347

RESUMO

Hyperactive signal transducer and activator of transcription 3 (STAT3) signaling is frequently detected in human triple-negative breast cancer (TNBC) and gastric cancer, leading to uncontrolled tumor growth, resistance to chemotherapy, and poor prognosis. Thus, inhibition of STAT3 signaling is a promising therapeutic approach for both TNBC and gastric cancer, which have high incidences and mortality and limited effective therapeutic approaches. Here, we report a small molecule, WZ-2-033, capable of inhibiting STAT3 activation and dimerization and STAT3-related malignant transformation. We present in vitro evidence from surface plasmon resonance analysis that WZ-2-033 interacts with the STAT3 protein and from confocal imaging that WZ-2-033 disrupts HA-STAT3 and Flag-STAT3 dimerization in intact cells. WZ-2-033 suppresses STAT3-DNA-binding activity but has no effect on STAT5-DNA binding. WZ-2-033 inhibits the phosphorylation and nuclear accumulation of pY705-STAT3 and consequently suppresses STAT3-dependent transcriptional activity and the expression of STAT3 downstream genes. Moreover, WZ-2-033 significantly inhibited the proliferation, colony survival, migration, and invasion of TNBC cells and gastric cancer cells with aberrant STAT3 activation. Furthermore, administration of WZ-2-033 in vivo induced a significant antitumor response in mouse models of TNBC and gastric cancer that correlated with the inhibition of constitutively active STAT3 and the suppression of known STAT3 downstream genes. Thus, our study provides a novel STAT3 inhibitor with significant antitumor activity in human TNBC and gastric cancer harboring persistently active STAT3.


Assuntos
Neoplasias Gástricas , Neoplasias de Mama Triplo Negativas , Animais , Linhagem Celular Tumoral , Proliferação de Células , Xenoenxertos , Humanos , Camundongos , Fator de Transcrição STAT3/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia
19.
J Chem Phys ; 156(23): 234104, 2022 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-35732533

RESUMO

We present a formulation and implementation of the density functional theory (DFT)+U method within the framework of linear combination of numerical atomic orbitals (NAO). Our implementation not only enables single-point total energy and electronic-structure calculations but also provides access to atomic forces and cell stresses, hence allowing for full structure relaxations of periodic systems. Furthermore, our implementation allows one to deal with non-collinear spin texture, with the spin-orbit coupling (SOC) effect treated self-consistently. The key aspect behind our implementation is a suitable definition of the correlated subspace when multiple atomic orbitals with the same angular momentum are used, and this is addressed via the "Mulliken charge projector" constructed in terms of the first (most localized) atomic orbital within the d/f angular momentum channel. The important Hubbard U and Hund J parameters can be estimated from a screened Coulomb potential of the Yukawa type, with the screening parameter either chosen semi-empirically or determined from the Thomas-Fermi screening model. Benchmark calculations are performed for four late transition metal monoxide bulk systems, i.e., MnO, FeO, CoO, and NiO, and for the 5d-electron compounds IrO2. For the former type of systems, we check the performance of our DFT+U implementation for calculating bandgaps, magnetic moments, electronic band structures, as well as forces and stresses; for the latter, the efficacy of our DFT+U+SOC implementation is assessed. Systematic comparisons with available experimental results, especially with the results from other implementation schemes, are carried out, which demonstrate the validity of our NAO-based DFT+U formalism and implementation.

20.
Nature ; 528(7581): 249-53, 2015 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-26659186

RESUMO

Intensification of the hydrologic cycle is a key dimension of climate change, with substantial impacts on human and natural systems. A basic measure of hydrologic cycle intensification is the increase in global-mean precipitation per unit surface warming, which varies by a factor of three in current-generation climate models (about 1-3 per cent per kelvin). Part of the uncertainty may originate from atmosphere-radiation interactions. As the climate warms, increases in shortwave absorption from atmospheric moistening will suppress the precipitation increase. This occurs through a reduction of the latent heating increase required to maintain a balanced atmospheric energy budget. Using an ensemble of climate models, here we show that such models tend to underestimate the sensitivity of solar absorption to variations in atmospheric water vapour, leading to an underestimation in the shortwave absorption increase and an overestimation in the precipitation increase. This sensitivity also varies considerably among models due to differences in radiative transfer parameterizations, explaining a substantial portion of model spread in the precipitation response. Consequently, attaining accurate shortwave absorption responses through improvements to the radiative transfer schemes could reduce the spread in the predicted global precipitation increase per degree warming for the end of the twenty-first century by about 35 per cent, and reduce the estimated ensemble-mean increase in this quantity by almost 40 per cent.


Assuntos
Modelos Teóricos , Ciclo Hidrológico , Mudança Climática , Chuva , Temperatura
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