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1.
Hum Mol Genet ; 32(7): 1137-1151, 2023 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-36331344

RESUMO

Mitochondrial dynamics is essential for maintaining the physiological function of the mitochondrial network, and its disorders lead to a variety of diseases. Our previous study identified mitochondrial dynamics controlled anti-tumor immune responses and anxiety symptoms. However, how mitochondrial dynamics affects auditory function in the inner ear remains unclear. Here, we show that the deficiency of FAM73a or FAM73b, two mitochondrial outer membrane proteins that mediate mitochondrial fusion, leads to outer hair cells (HCs) damage and progressive hearing loss in FVB/N mice. Abnormal mitochondrial fusion causes elevated oxidative stress and apoptosis of HCs in the early stage. Thereafter, the activation of macrophages and CD4+ T cell is found in the mutant mice with the increased expression of the inflammatory cytokines IL-12 and IFN-γ compared with control mice. Strikingly, a dramatically decreased number of macrophages by Clophosome®-A-Clodronate Liposomes treatment alleviates the hearing loss of mutant mice. Collectively, our finding highlights that FAM73a or FAM73b deficiency affects HCs survival by disturbing the mitochondrial function, and the subsequent immune response in the cochleae worsens the damage of HCs.


Assuntos
Perda Auditiva , Dinâmica Mitocondrial , Animais , Camundongos , Dinâmica Mitocondrial/genética , Audição , Perda Auditiva/genética , Perda Auditiva/metabolismo , Células Ciliadas Auditivas Externas/metabolismo , Imunidade
2.
Mol Ther ; 32(5): 1387-1406, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38414247

RESUMO

Cisplatin-induced hearing loss is a common side effect of cancer chemotherapy in clinics; however, the mechanism of cisplatin-induced ototoxicity is still not completely clarified. Cisplatin-induced ototoxicity is mainly associated with the production of reactive oxygen species, activation of apoptosis, and accumulation of intracellular lipid peroxidation, which also is involved in ferroptosis induction. In this study, the expression of TfR1, a ferroptosis biomarker, was upregulated in the outer hair cells of cisplatin-treated mice. Moreover, several key ferroptosis regulator genes were altered in cisplatin-damaged cochlear explants based on RNA sequencing, implying the induction of ferroptosis. Ferroptosis-related Gpx4 and Fsp1 knockout mice were established to investigate the specific mechanisms associated with ferroptosis in cochleae. Severe outer hair cell loss and progressive damage of synapses in inner hair cells were observed in Atoh1-Gpx4-/- mice. However, Fsp1-/- mice showed no significant hearing phenotype, demonstrating that Gpx4, but not Fsp1, may play an important role in the functional maintenance of HCs. Moreover, findings showed that FDA-approved luteolin could specifically inhibit ferroptosis and alleviate cisplatin-induced ototoxicity through decreased expression of transferrin and intracellular concentration of ferrous ions. This study indicated that ferroptosis inhibition through the reduction of intracellular ferrous ions might be a potential strategy to prevent cisplatin-induced hearing loss.


Assuntos
Cisplatino , Ferroptose , Perda Auditiva , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosfolipídeo Hidroperóxido Glutationa Peroxidase , Animais , Cisplatino/efeitos adversos , Ferroptose/efeitos dos fármacos , Ferroptose/genética , Camundongos , Perda Auditiva/induzido quimicamente , Perda Auditiva/genética , Perda Auditiva/metabolismo , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/genética , Modelos Animais de Doenças , Receptores da Transferrina/metabolismo , Receptores da Transferrina/genética , Espécies Reativas de Oxigênio/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Células Ciliadas Auditivas Externas/metabolismo , Células Ciliadas Auditivas Externas/efeitos dos fármacos , Células Ciliadas Auditivas Externas/patologia , Ototoxicidade/etiologia , Ototoxicidade/metabolismo , Antineoplásicos/efeitos adversos , Apoptose/efeitos dos fármacos
3.
Proc Natl Acad Sci U S A ; 119(10): e2107357119, 2022 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-35238644

RESUMO

The Food and Drug Administration­approved drug sirolimus, which inhibits mechanistic target of rapamycin (mTOR), is the leading candidate for targeting aging in rodents and humans. We previously demonstrated that sirolimus could treat ARHL in mice. In this study, we further demonstrate that sirolimus protects mice against cocaine-induced hearing loss. However, using efficacy and safety tests, we discovered that mice developed substantial hearing loss when administered high doses of sirolimus. Using pharmacological and genetic interventions in murine models, we demonstrate that the inactivation of mTORC2 is the major driver underlying hearing loss. Mechanistically, mTORC2 exerts its effects primarily through phosphorylating in the AKT/PKB signaling pathway, and ablation of P53 activity greatly attenuated the severity of the hearing phenotype in mTORC2-deficient mice. We also found that the selective activation of mTORC2 could protect mice from acoustic trauma and cisplatin-induced ototoxicity. Thus, in this study, we discover a function of mTORC2 and suggest that its therapeutic activation could represent a potentially effective and promising strategy to prevent sensorineural hearing loss. More importantly, we elucidate the side effects of sirolimus and provide an evaluation criterion for the rational use of this drug in a clinical setting.


Assuntos
Perda Auditiva Neurossensorial/metabolismo , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Proteína Companheira de mTOR Insensível à Rapamicina/metabolismo , Transdução de Sinais , Animais , Modelos Animais de Doenças , Perda Auditiva Neurossensorial/induzido quimicamente , Perda Auditiva Neurossensorial/genética , Perda Auditiva Neurossensorial/prevenção & controle , Alvo Mecanístico do Complexo 2 de Rapamicina/genética , Camundongos , Camundongos Knockout , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteína Companheira de mTOR Insensível à Rapamicina/genética , Sirolimo/efeitos adversos , Sirolimo/farmacologia , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
4.
Langmuir ; 40(21): 11196-11205, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38741372

RESUMO

Despite hybrid rocket motors offering distinct advantages over solid or liquid rocket motors, their low regression rate and insufficient combustion efficiency remain significantly unimproved. This study focuses on the effects of the helix lead on the regression rate distribution and combustion efficiency of vat-polymerized fuel grains with a spiral star port for a hybrid rocket. Both experimental and numerical investigations were conducted to study the combustion characteristics and regression rate distribution of three-dimensional (3D) print grains. Spiral star grains with varying helix leads of 60, 90, and 120 mm were fabricated using light-curing 3D printing technology. A 3D simulation model was developed to obtain the temperature distribution, species mass distribution, and combustion efficiency. Furthermore, firing tests were performed on a two-dimensional radial hybrid combustion test stand to measure the regression rate. Digital image processing of computed tomography images was used to determine the regression rate. Simulation results indicated that the spiral star grain port helps to improve the combustion efficiency compared with those seen with round tube and straight star port grains. With an increase in the axial distance, the flame zone gradually shrinks, and the smaller the helix lead, the faster the shrinkage. At a mass flow rate of 1.50 g/s for oxygen, the regression rate of the spiral star grains is significantly higher than that of the straight star grain and the conventional round tubular grains, and the regression rate gradually increases with a decrease in the helix lead. This finding is expected to solve the problem of the low regression rate of solid fuels with spiral star pore-shaped grains prepared by the light-curing 3D printing method.

5.
Toxicol Appl Pharmacol ; 467: 116509, 2023 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-37028458

RESUMO

Oleanolic acid (OA) is a pentacyclic triterpenoid compound used clinically for acute and chronic hepatitis. However, high dose or long-term use of OA causes hepatotoxicity, which limits its clinical application. Hepatic Sirtuin (SIRT1) participates in the regulation of FXR signaling and maintains hepatic metabolic homeostasis. This study was designed to determine whether SIRT1/FXR signaling pathway contributes to the hepatotoxicity caused by OA. C57BL/6J mice were administered with OA for 4 consecutive days to induce hepatotoxicity. The results showed that OA suppressed the expression of FXR and its downstream targets CYP7A1, CYP8B1, BSEP and MRP2 at both mRNA and protein levels, breaking the homeostasis of bile acid leading to hepatotoxicity. However, treatment with FXR agonist GW4064 noticeably attenuated hepatotoxicity caused by OA. Furthermore, it was found that OA inhibited protein expression of SIRT1. Activation of SIRT1 by its agonist SRT1720 significantly improved OA-induced hepatotoxicity. Meanwhile, SRT1720 significantly reduced the inhibition of protein expression of FXR and FXR-downstream proteins. These results suggested that OA may cause hepatotoxicity through SIRT1 dependent suppression of FXR signaling pathway. In vitro experiments confirmed that OA suppressed protein expressions of FXR and its targets through inhibition of SIRT1. It was further revealed that silencing of HNF1α with siRNA significantly weakened regulatory effects of SIRT1 on the expression of FXR as well as its target genes. In conclusion, our study reveals that SIRT1/FXR pathway is crucial in OA-induced hepatotoxicity. Activation of SIRT1/HNF1α/FXR axis may represent a novel therapeutic target for ameliorating OA and other herb-induced hepatotoxicity.


Assuntos
Doença Hepática Crônica Induzida por Substâncias e Drogas , Ácido Oleanólico , Sirtuínas , Camundongos , Animais , Sirtuína 1/genética , Sirtuína 1/metabolismo , Ácido Oleanólico/farmacologia , Sirtuínas/metabolismo , Doença Hepática Crônica Induzida por Substâncias e Drogas/tratamento farmacológico , Doença Hepática Crônica Induzida por Substâncias e Drogas/metabolismo , Camundongos Endogâmicos C57BL , Fígado , Transdução de Sinais , Ácidos e Sais Biliares/metabolismo
6.
FASEB J ; 36(6): e22373, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35621716

RESUMO

Cisplatin is a widely used chemotherapeutic agent. However, its clinical utility is limited because of cisplatin-induced ototoxicity. Glutathione S-transferase (GST) was found to play a vital role in reducing cisplatin ototoxicity in mice. Deletion polymorphisms of GSTM1 and GSTT1, members of the GST family, are common in humans and are presumed to be associated with cisplatin-induced hearing impairment. However, the specific roles of GSTM1 and GSTT1 in cisplatin ototoxicity are not completely clear. Here, under cisplatin treatment, simultaneous deletion of Gstm1 and Gstt1 lead to a more profound hearing loss in CBA/CaJ mice (Gstm1/Gstt1-DKO) than in wild-type mice. The Gstm1/Gstt1-DKO mice, in which phase II detoxification genes were upregulated, exhibited more severe oxidative stress and higher outer hair cell apoptosis in the cochleae than the control mice. Thus, our study revealed that Gstm1 and Gstt1 protect auditory hair cells from cisplatin-induced ototoxicity in the CBA/CaJ mice, and genetic screening for GSTM1 and GSTT1 polymorphisms could help determine a standard cisplatin dose for cancer patients undergoing chemotherapy.


Assuntos
Cisplatino , Glutationa Transferase , Ototoxicidade , Animais , Cisplatino/toxicidade , Glutationa Transferase/genética , Humanos , Camundongos , Camundongos Endogâmicos CBA , Camundongos Endogâmicos , Ototoxicidade/etiologia , Ototoxicidade/genética , Ototoxicidade/prevenção & controle , Polimorfismo Genético
7.
Anticancer Drugs ; 34(7): 852-856, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-36729892

RESUMO

The optimal pharmaceutical regimen for advanced thymic epithelial tumors (TETs) remains controversial when first-line chemotherapy fails. This retrospective study aims to evaluate the efficacy and safety of anlotinib treatment for patients with relapsed and refractory TETs. Patients with progressive disease after failure of platinum-based chemotherapy were enrolled in this study. Anlotinib was orally taken once a day at an initial dose of 12 mg (10 mg when body weight <60 kg). The cycle was repeated every 3 weeks (2 weeks of treatment followed by 1-week rest). Objective response rate (ORR) and progression-free survival (PFS) were recorded as primary endpoints. There were 50 patients enrolled in this study from October 2018 to June 2021 at a median age of 50 (range 23-79) years old. Patients with thymoma and thymic carcinoma were 33 (66%) and 17 (34%), respectively. The ORR in thymoma and thymic carcinoma patients were 33% (11/33) and 41% (7/17), respectively. The median PFS (mPFS) was 7 (95% CI, 5.9-10.2) months in thymoma patients and 6 (95% CI, 4.6-9.3) months in the thymic carcinoma group. Eleven patients experienced dose reduction due to toxicities, among whom, eight patients discontinued treatment even after dose reduction. Six patients with thymoma showed myasthenia gravis deterioration during treatment, and two of them died of myasthenia gravis crisis. Anlotinib is active in patients with advanced TETs refractory to routine chemotherapy. Prescription of anlotinib to patients with myasthenia gravis should be made cautiously.


Assuntos
Miastenia Gravis , Neoplasias Epiteliais e Glandulares , Timoma , Neoplasias do Timo , Humanos , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Timoma/tratamento farmacológico , Timoma/patologia , Estudos Retrospectivos , Neoplasias do Timo/tratamento farmacológico , Neoplasias do Timo/patologia , Neoplasias Epiteliais e Glandulares/tratamento farmacológico
8.
Future Oncol ; 19(34): 2291-2296, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37937444

RESUMO

This randomized phase II trial (NCT05978193) combines low-dose radiotherapy (LDRT) and conventionally fractionated radiotherapy (CFRT) with immunochemotherapy for metastatic esophageal squamous cell carcinoma, aiming to assess the potential enhanced effect of radiotherapy on immunotherapy. Patients are administered a PD-1 inhibitor along with paclitaxel and platinum-based chemotherapy (arm B), or combined with LDRT and CFRT (arm A). Immunotherapy is given every 3 weeks with chemotherapy for 4 cycles, followed by immunotherapy maintenance therapy for up to 24 months. In arm A, LDRT (2 Gy, 2 fractions; delivered to the primary and all metastatic tumors) precedes each immunochemotherapy cycle for 4 cycles, followed by CFRT (40-50 Gy, 20-25 fractions; delivered to the primary tumor) starting from the fifth immunotherapy cycle. The primary end point is median progression-free survival. Clinical Trial Registration: NCT05978193 (clinicaltrials.gov).


Assuntos
Carcinoma de Células Escamosas , Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Humanos , Carcinoma de Células Escamosas do Esôfago/tratamento farmacológico , Carcinoma de Células Escamosas/patologia , Neoplasias Esofágicas/patologia , Paclitaxel/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Imunoterapia/efeitos adversos , Ensaios Clínicos Fase II como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Multicêntricos como Assunto
9.
J Appl Toxicol ; 43(8): 1201-1213, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36846903

RESUMO

Natural pentacyclic triterpenoid oleanolic acid (OA) is used as an over-the-counter drug for acute and chronic hepatitis. However, clinical use of OA-containing herbal medicines has been reported to cause cholestasis, and the specific mechanism is unknown. The purpose of this study was to explore how OA causes cholestatic liver injury via the AMP-activated protein kinase (AMPK)-farnesoid X receptor (FXR) pathway. In animal experiments, it was found that OA treatment activated AMPK and decreased FXR and bile acid efflux transport proteins expression. When intervened with the specific inhibitor Compound C (CC), it was observed that AMPK activation was inhibited, the reduction of FXR and bile acid efflux transport protein expression was effectively alleviated, serum biochemical indicators were significantly reduced, and liver pathological damage brought about by OA was effectively ameliorated. In addition, OA was found to downregulate the expression of FXR and bile acid efflux transport proteins by activating the ERK1/2-LKB1-AMPK pathway in cellular experiments. The ERK1/2 inhibitor U0126 was used to pretreat primary hepatocytes, and this drastically reduced the phosphorylation levels of LKB1 and AMPK. The inhibition effects of OA on FXR and bile acid efflux transport proteins were also effectively alleviated after pretreatment with CC. In addition, OA-induced downregulation of FXR gene and protein expression levels was significantly prevented after silencing AMPKα1 expression in AML12 cells. Our study demonstrated that OA inhibited FXR and bile acid efflux transporters through the activation of AMPK, thus leading to cholestatic liver injury.


Assuntos
Doença Hepática Crônica Induzida por Substâncias e Drogas , Colestase , Hepatopatias , Ácido Oleanólico , Animais , Camundongos , Proteínas Quinases Ativadas por AMP , Ácido Oleanólico/farmacologia , Ácido Oleanólico/metabolismo , Ácido Oleanólico/uso terapêutico , Doença Hepática Crônica Induzida por Substâncias e Drogas/tratamento farmacológico , Doença Hepática Crônica Induzida por Substâncias e Drogas/metabolismo , Fígado , Colestase/induzido quimicamente , Hepatopatias/metabolismo , Proteínas de Transporte/metabolismo , Proteínas de Transporte/farmacologia , Proteínas de Transporte/uso terapêutico , Ácidos e Sais Biliares/metabolismo , Camundongos Endogâmicos C57BL
10.
Plant Dis ; 2023 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-36774581

RESUMO

Water lettuce (Pistia stratiotes L.), is one of the emerging invasive weeds for inland water bodies in Asia and become a major problem for local water ecosystem. Biocontrol of water lettuce by mycobiota is being considered as a promising and sustainable method (Kongjornrak et al. 2019). During July 2021, a leaf blight of water lettuce was observed within about 1.5 ha in Shenxi stream (N25°66', E119°05') in Putian, Fujian, China. The disease severity was about 100% with 80% incidence, early symptoms appeared as small irregularly yellow or brown blight, severely infected leaves turned to be rot, then death and sink. Small pieces (5 × 5 mm) of symptomatic leaves were excised and surface disinfected with 75% ethanol and 0.1% HgCl2 solution, air dried and plated on potato dextrose agar (PDA). 3~5 days after incubation at 28°C, six fungal pure cultures showing similar morphology were obtained from the infected leaves. On PDA, colonies were flat, aerial mycelium grew sparsely, most of it grew inside the agar medium, it reverses white to grey to black with age. Hyphae were branched, septate, smooth and hyaline. Conidiophores mostly reduced to conidiogenous cells and setae were not observed. Conidiogenous cells were monoblastic, discrete and solitary, at first hyaline, subspherical, then turning to pale brown, ampulliform, 4.5-10 × 3.5-6 µm in size. Conidia were solitary, globose or ellipsoidal, black, smooth, some of it formed directly from the mycelia, aseptate, 8-12 µm diam (n=10). Genomic DNA was extracted from one of the representative isolate Z1. ITS1/ITS4 (Mills et al. 1992), Bt-2a/Bt-2b (Glass and Donaldson 1995) and EF1-728F/EF-2 (O'Donnell et al. 1998) primer pairs were used to amplify the isolate's internal transcribed spacer (ITS), the Beta-tubulin fragment (TUB) and the partial translation elongation factor (TEF1), respectively. The isolate's sequences were deposited in the GenBank with accession numbers of OM279539 (ITS), OM296034 (TUB) and OM296035 (TEF1). Phylogenetic analysis using maximum likelihood based on the ITS-TUB-TEF1 concatenated sequences from Nigrospora species revealed that isolate Z1 is closely clustered with N. osmanthi strain LC4487. The fungus was identified as N. osmanthi based on the morphological characteristics and molecular analyses (Hao et al. 2020; Wang et al. 2017). Pathogenicity test were performed using twenty inoculated and control plants, respectively. Conidial suspensions (107 CFU/ml) of Z1 isolate were spray-inoculated on the leaves of healthy water lettuce seedlings, while sterile distilled water was used as control. Inoculated and control plants were kept in the differential 50-liter plastic tanks and maintained in a greenhouse at room temperature (19 to 24°C) for one month. Symptoms appeared 7 days post inoculation, which was similar to what occurs in the field. No symptoms occurred on controls. Pathogen was reisolated and confirmed by morphology and molecular analysis. Koch's postulates were conducted twice. N. osmanthi is a pathogenic fungus of many crop plants, such as buckwheat (Shen et al 2021), Java tea (Ismail et al. 2022) or buffalograss (Mei et al. 2019) in Asia and particularly in China. However, to our knowledge, this is the first report of N. osmanthi causing leaf blight on water lettuce. Further studies on how to apply formulated N. osmanthi will be required so that the strain could be effectively used to control water lettuce, moreover, its environmental safety also need a rigorous experimental evaluation.

11.
Mikrochim Acta ; 190(6): 217, 2023 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-37173583

RESUMO

Serum levels of uric acid (UA) play an important role in the prevention of diseases. Developing a rapid and accurate way to detect UA is still a meaningful task. Hence, positively charged manganese dioxide nanosheets (MnO2NSs) with an average latter size of 100 nm and an ultra-thin thickness of below 1 nm have been prepared. They can be well dispersed in water and form stable yellow-brown solutions. The MnO2NSs can be decomposed by UA via redox reaction, leading to a decline of a characteristic absorption peak (374 nm) and a color fading of MnO2NSs solution. On this basis, an enzyme-free colorimetric sensing system for the detection of UA has been developed. The sensing system shows many advantages, including a wide linear range of 0.10-50.0 µmol/L, a limit of quantitation (LOQ) of 0.10 µmol/L, a low limit of detection (LOD) of 0.047 µmol/L (3σ/m), and rapid response without need of strict time control. Moreover, a simple and convenient visual sensor for UA detection has also been developed by adding an appropriate amount of phthalocyanine to provide a blue background color, which helps to increase visual discrimination. Finally, the strategy has been successfully applied to detect UA in human serum and urine samples.


Assuntos
Colorimetria , Ácido Úrico , Humanos , Óxidos , Compostos de Manganês
12.
Sensors (Basel) ; 23(12)2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37420783

RESUMO

In the electronic warfare environment, the performance of ground-based radar target search is seriously degraded due to the existence of smeared spectrum (SMSP) jamming. SMSP jamming is generated by the self-defense jammer on the platform, playing an important role in electronic warfare, making traditional radars based on linear frequency modulation (LFM) waveforms face great challenges in searching for targets. To solve this problem, an SMSP mainlobe jamming suppression method based on a frequency diverse array (FDA) multiple-input multiple-output (MIMO) radar is proposed. The proposed method first uses the maximum entropy algorithm to estimate the target angle and eliminate the interference signals from the sidelobe. Then, the range-angle dependence of the FDA-MIMO radar signal is utilized, and the blind source separation (BSS) algorithm is used to separate the mainlobe interference signal and the target signal, avoiding the impact of mainlobe interference on target search. The simulation verifies that the target echo signal can be effectively separated, the similarity coefficient can reach more than 90% and the detection probability of the radar is significantly enhanced at a low signal-to-noise ratio.


Assuntos
Algoritmos , Radar , Simulação por Computador , Eletrônica , Entropia
13.
Molecules ; 28(7)2023 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-37049973

RESUMO

Boron powder is a kind of metal fuel with high gravimetric and volumetric calorific values, which has been widely used in military fields such as solid propellants, high-energy explosives, and pyrotechnics. However, the easily formed liquid oxide layer can adhere to the surface of boron powder and react with the hydroxyl (-OH) group of hydroxyl-terminated polybutadiene (HTPB) binder to form a gel layer that is detrimental to propellant processing and restricts the complete oxidation of boron powder. Therefore, to improve the combustion efficiency of boron powder, the ignition and combustion mechanisms of boron powder have been studied, and surface coating modification strategies have been developed by researchers worldwide, aiming to optimize the surface properties, improve the reaction activity, and promote the energy release of boron powder. In this review, recent studies on the ignition and combustion mechanisms of boron powder are discussed. Moreover, the reported boron powder coating materials are classified according to the chemical structure and reaction mechanism. Additionally, the mechanisms and characteristics of different coating materials are summarized, and the mechanism diagrams of fluoride and metal oxide are provided. Furthermore, promising directions for modification methods and the potential application prospects of boron powder are also proposed.

14.
BMC Cancer ; 22(1): 96, 2022 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-35065627

RESUMO

BACKGROUND: To explore the maximum tolerated dose (MTD) and evaluate the safety of dose escalation using hypofractionated simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) concurrent with chemotherapy for unresectable stage III non-small cell lung cancer (NSCLC). METHODS: Four escalating radiation dose levels were used. This study included 25 patients with previously untreated NSCLC who received six concurrent weekly chemotherapy cycles comprising cisplatin and docetaxel. Dose-limiting toxicity (DLT) was defined as any acute toxicity that interrupted radiotherapy for more than 1 week. MTD was defined as the highest dose level that didn't induce DLT or grade 5 toxicity in two patients. RESULTS: All 25 patients received the prescribed escalating radiation dose from the start dose up to LEVEL 4. Two patients experienced DLT at dose LEVEL 4. One patient died because of upper gastrointestinal hemorrhage within 6 months after radiotherapy, whereas another patient among the additional five patients died because of grade 5 radiation pneumonitis within 2 months after radiotherapy. Dose LEVEL 3 was defined as MTD. The 1- and 2-year local controls were 82.8 and 67.8%, respectively. The median progression-free survival was 15.4 months, whereas the median overall survival was 27.3 months. CONCLUSIONS: Dose escalation was safely achieved up to LEVEL 3 [the planning gross target volume (PTVG) 60.5 Gy/22 Fx, 2.75 Gy/Fx; the planning clinical target volume (PTVC) 49.5 Gy/22 Fx] using SIB-IMRT concurrently with chemotherapy for unresectable stage III NSCLC, and the acute toxicities were generally well tolerated. Further prospective studies on long-term outcomes and late toxicities are warranted. TRIAL REGISTRATION: Retrospective registration, ChiCTR1900027290 (08/11/2019).


Assuntos
Carcinoma Pulmonar de Células não Pequenas/terapia , Neoplasias Pulmonares/terapia , Hipofracionamento da Dose de Radiação , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Adulto , Idoso , Antineoplásicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/patologia , Quimiorradioterapia , Cisplatino/uso terapêutico , Docetaxel/uso terapêutico , Feminino , Humanos , Neoplasias Pulmonares/patologia , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Resultado do Tratamento
15.
Langmuir ; 38(48): 14959-14968, 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36416737

RESUMO

Energetic materials are a special class of energy materials composed of C, H, O, and N. Their safety always deteriorates with increasing energy. Regulating the properties of energetic materials to meet application requirements is one of the focuses of research in this field. Energetic metal-organic frameworks (EMOFs) are good candidates as primary explosives to replace lead azide (LA) and other explosives containing toxic metal elements. However, safety remains the biggest concern in applications. In this paper, crystal morphology modulation of EMOF was carried out by stepwise coordination of metal ions and energetic ligands on surfaces of graphene oxide (GO) and amino-functionalized graphene oxide (AGO). Two energetic composite materials, Cu-AFTO@GO and Cu-AFTO@AGO, were successfully synthesized and also the EMOF (Cu-AFTO). The structures and morphologies of these materials were fully characterized. The thermal decomposition behaviors, mechanical sensitivity, and electrostatic discharge sensitivity were investigated in detail. The electric ignition ability of EMOF and two composite materials was tested. This study shows that it is possible to reduce the diameter of EMOF crystals from hundreds of microns to tens of nanometers by a stepwise coordination method. The high electrical conductivity and sensitivity-reducing effect of GO and/or AGO allow the nanosized EMOF crystals to have a lower ignition threshold and lower sensitivity.

16.
Analyst ; 147(2): 247-251, 2022 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-34931211

RESUMO

Herein, a novel and facile dual-wavelength ratiometric electrochemiluminescence-resonance energy transfer (ECL-RET) sensor for hydrogen sulfide (H2S) detection was constructed based on the interaction between S2- and Cd2+-doped g-C3N4 nanosheets (NSs). Cd2+-doped g-C3N4 NSs exhibited a strong ECL emission at 435 nm. In the presence of H2S, CdS was formed in situ on g-C3N4 NSs by the adsorption of S2- and Cd2+, generating another ECL emission at 515 nm. Furthermore, the overlapping of the absorption spectrum of the formed CdS and the ECL emission spectrum of g-C3N4 NSs led to a feasible RET, thus quenching the ECL intensity from g-C3N4 at 435 nm. Through an ECL decrease at 435 nm and an increase at 515 nm, a dual-wavelength ratiometric ECL-RET system for H2S was designed. The sensor exhibited a lower detection limit of 0.02 µM with a wide linear range of 0.05-100.0 µM. In addition, the applicability of the method was validated by plasma sample analysis with a linear range of 80.0-106.0%. We believe that such a proposal would provide new insight into advanced dual-wavelength ECL ratiometric assays.


Assuntos
Técnicas Biossensoriais , Sulfeto de Hidrogênio , Cádmio , Técnicas Eletroquímicas , Limite de Detecção , Medições Luminescentes
17.
Phys Chem Chem Phys ; 24(42): 25885-25894, 2022 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-36259743

RESUMO

A neural network potential (NNP) is developed to investigate the complex reaction dynamics of 1,3,5-trinitro-1,3,5-triazine (RDX) thermal decomposition. Our NNP model is proven to possess good computational efficiency and retain the ab initio accuracy, which allows the investigation of the entire decomposition process of bulk RDX crystals from an atomic perspective. A series of molecular dynamics (MD) simulations are performed on the NNP to calculate the physical and chemical properties of the RDX crystal. The results show that the NNP can accurately describe the physical properties of RDX crystals, such as the cell parameters and the equation of state. The simulations of RDX thermal decomposition reveal that the NNP could capture the evolution of species at ab initio accuracy. The complex reaction network was established, and a reaction mechanism of RDX decomposition was provided. The N-N homolysis is the dominant channel, which cannot be observed in previous DFT studies of isolated RDX molecule. In addition, the H abstraction reaction by NO2 is found to be the critical pathway for NO and H2O formation, while the HONO elimination is relatively weak. The NNP gives an atomic insight into the complex reaction dynamics of RDX and can be extended to investigate the reaction mechanism of novel energetic materials.


Assuntos
Simulação de Dinâmica Molecular , Triazinas , Triazinas/química , Redes Neurais de Computação
18.
Artigo em Inglês | MEDLINE | ID: mdl-33361302

RESUMO

Molecular genotyping holds tremendous potential to detect antimalarial drug resistance (ADR) related to single nucleotide polymorphisms (SNPs). However, it relies on the use of complicated procedures and expensive instruments. Thus, rapid point-of-care testing (POCT) molecular tools are urgently needed for field survey and clinical use. Herein, a POCT platform consisting of multiple-allele-specific PCR (AS-PCR) and a gold nanoparticle (AuNP)-based lateral flow biosensor was designed and developed for SNP detection of the Plasmodium falciparum dihydrofolate reductase (pfdhfr) gene related to pyrimethamine resistance. The multiple-AS-PCR utilized 3' terminal artificial antepenultimate mismatch and double phosphorothioate-modified allele-specific primers. The duplex PCR amplicons with 5' terminal labeled with biotin and digoxin are recognized by streptavidin (SA)-AuNPs on the conjugate pad and then captured by anti-digoxin antibody through immunoreactions on the test line to produce a golden red line for detection. The system was applied to analyze SNPs in Pfdhfr N51I, C59R, and S108N of 98 clinical isolates from uncomplicated P. falciparum malaria patients. Compared with the results from nested PCR followed by Sanger DNA sequencing, the sensitivity was 97.96% (96/98) for N51I, C59R, and S108N. For specificity, the values were 100% (98/98), 95.92% (94/98), and 100% (98/98) for N51I, C59R, and S108N, respectively. The limit of detection is approximately 200 fg/µl for plasmid DNA as the template and 100 parasites/µl for blood filter paper. The established platform not only offers a powerful tool for molecular surveillance of ADR but also is easily extended to interrelated SNP profiles for infectious diseases and genetic diseases.


Assuntos
Antimaláricos , Técnicas Biossensoriais , Malária Falciparum , Nanopartículas Metálicas , Alelos , Antimaláricos/farmacologia , Primers do DNA , Resistência a Medicamentos/genética , Ouro , Humanos , Malária Falciparum/tratamento farmacológico , Plasmodium falciparum/genética , Reação em Cadeia da Polimerase , Pirimetamina/uso terapêutico , Sulfadoxina/uso terapêutico , Tetra-Hidrofolato Desidrogenase/genética
19.
Future Oncol ; 17(10): 1143-1153, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33533655

RESUMO

Despite curative-intent treatment, most patients with locally advanced esophageal cancer will experience disease recurrence or locoregional progression, highlighting the need for new therapies. Current guidelines recommend definitive chemoradiotherapy in patients ineligible for surgical resection, but survival outcomes are poor. Pembrolizumab is well tolerated and provides promising antitumor activity in patients with previously treated, advanced, unresectable esophageal/esophagogastric junction cancer. Combining pembrolizumab with chemoradiotherapy may further improve outcomes in the first-line setting. Here, we describe the design and rationale for the double-blind, Phase III, placebo-controlled, randomized KEYNOTE-975 trial investigating pembrolizumab in combination with definitive chemoradiotherapy as first-line treatment in patients with locally advanced, unresectable esophageal/gastroesophageal junction cancer. Overall survival and event-free survival are the dual primary end points. Clinical trial registration: NCT04210115 (ClinicalTrials.gov).


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quimiorradioterapia , Protocolos Clínicos , Neoplasias Esofágicas/terapia , Projetos de Pesquisa , Anticorpos Monoclonais Humanizados/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Terapia Combinada , Neoplasias Esofágicas/diagnóstico , Feminino , Humanos , Masculino
20.
Biomed Eng Online ; 20(1): 54, 2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34082755

RESUMO

BACKGROUND: To develop a novel subjective-objective-combined (SOC) grading standard for auto-segmentation for each organ at risk (OAR) in the thorax. METHODS: A radiation oncologist manually delineated 13 thoracic OARs from computed tomography (CT) images of 40 patients. OAR auto-segmentation accuracy was graded by five geometric objective indexes, including the Dice similarity coefficient (DSC), the difference of the Euclidean distance between centers of mass (ΔCMD), the difference of volume (ΔV), maximum Hausdorff distance (MHD), and average Hausdorff distance (AHD). The grading results were compared with those of the corresponding geometric indexes obtained by geometric objective methods in the other two centers. OAR auto-segmentation accuracy was also graded by our subjective evaluation standard. These grading results were compared with those of DSC. Based on the subjective evaluation standard and the five geometric indexes, the correspondence between the subjective evaluation level and the geometric index range was established for each OAR. RESULTS: For ΔCMD, ΔV, and MHD, the grading results of the geometric objective evaluation methods at our center and the other two centers were inconsistent. For DSC and AHD, the grading results of three centers were consistent. Seven OARs' grading results in the subjective evaluation standard were inconsistent with those of DSC. Six OARs' grading results in the subjective evaluation standard were consistent with those of DSC. Finally, we proposed a new evaluation method that combined the subjective evaluation level of those OARs with the range of corresponding DSC to determine the grading standard. If the DSC ranges between the adjacent levels did not overlap, the DSC range was used as the grading standard. Otherwise, the mean value of DSC was used as the grading standard. CONCLUSIONS: A novel OAR-specific SOC grading standard in thorax was developed. The SOC grading standard provides a possible alternative for evaluation of the auto-segmentation accuracy for thoracic OARs.


Assuntos
Tomografia Computadorizada por Raios X , Humanos , Órgãos em Risco , Planejamento da Radioterapia Assistida por Computador , Tórax
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