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1.
J Am Chem Soc ; 145(35): 19396-19404, 2023 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-37606548

RESUMO

Designing Pb-free relaxors with both a high capacitive energy density (Wrec) and high storage efficiency (η) remains a remarkable challenge for cutting-edge pulsed power technologies. Local compositional heterogeneity is crucial for achieving complex polar structure in solid solution relaxors, but its role in optimizing energy storage properties is often overlooked. Here, we report that an exceptionally high Wrec of 15.2 J cm-3 along with an ultrahigh η of 91% can be achieved through designing local chemical clustering in Bi0.5Na0.5TiO3-BaTiO3-based relaxors. A three-dimensional atomistic model derived from neutron/X-ray total scattering combined with reverse Monte Carlo method reveals the presence of subnanometer scale clustering of Bi, Na, and Ba, which host differentiated polar displacements, and confirming the prediction by density functional theory calculations. This leads to a polar state with small polar clusters and strong length and direction fluctuations in unit-cell polar vectors, thus manifesting improved high-field polarizability, steadily reduced hysteresis, and high breakdown strength macroscopically. The favorable polar structure features also result in a unique field-increased η, excellent stability, and superior discharge capacity. Our work demonstrates that the hidden local chemical order exerts a significant impact on the polarization characteristic of relaxors, and can be exploited for accessing superior energy storage performance.

2.
Sensors (Basel) ; 20(6)2020 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-32204490

RESUMO

This paper develops an improved model predictive controller based on the online obtaining of softness factor and fusion velocity for automatic train operation to enhance the tracking control performance. Specifically, the softness factor of the improved model predictive control algorithm is not a constant, conversely, an improved online adaptive adjusting method for softness factor based on fuzzy satisfaction of system output value and velocity distance trajectory characteristic is adopted, and an improved whale optimization algorithm has been proposed to solve the adjustable parameters; meanwhile, the system output value for automatic train operation is not sampled by a normal speed sensor, on the contrary, an improved online velocity sampled method for the system output value based on a fusion velocity model and an intelligent digital torque sensor is applied. In addition, the two improved strategies proposed take the real-time storage and calculation capacities of the core chip of the controller into account. Therefore, the proposed improved strategies (I) have good performance in tracking precision, (II) are simple and easily conducted, and (III) can ensure the accomplishing of computational tasks in real-time. Finally, to verify the effectiveness of the improved model predictive controller, the Matlab/simulink simulation and hardware-in-the-loop simulation (HILS) are adopted for automatic train operation tracking control, and the tracking control simulation results indicate that the improved model predictive controller has better tracking control effectiveness compared with the existing traditional improved model predictive controller.

3.
Lab Chip ; 24(1): 8-19, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-38009064

RESUMO

The closed-open digital microfluidic (DMF) system offers a versatile and powerful platform for various applications by combining the advantages of both closed and open structures. The current closed-open DMF system faces challenges in scaling up due to electrode structural differences between closed and open regions. Here we developed an adjustable closed-open DMF platform by utilizing the modified slippery liquid-infused porous surfaces (SLIPS) with asymmetric electrowetting on dielectric (AEWOD) as a hydrophobic dielectric layer. The consistent electrode structures of the bottom printed circuit board (PCB) electrode array on both the closed and open regions, and the utilization of a transparent acrylic with floating potential as the top plate allow a low-cost and easily scalable closed-open DMF system to be achieved. The impacts of applied voltage, parallel plate spacing, electrode switching interval, and electrode driving strategies on various droplet manipulations were investigated. The results show that the optimal plate spacings range from 340-510 µm within the closed region. Meanwhile, we also studied the influence of the thickness, geometry, and position of the top plate on the droplet movement at the closed-open boundary. Through force analysis and experimentation, it is found that a thin top plate and a bevel of ∼4° can effectively facilitate the movement of droplets at the boundary. Finally, we successfully achieved protein staining experiments on this platform and developed a customized smartphone application for the accurate detection of protein concentration. This innovative closed-open DMF system provides new possibilities for future applications in real-time biological sample processing and detection.

4.
Environ Int ; 182: 108313, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37984293

RESUMO

Eight emerging and six traditional organophosphate esters (OPEs) were investigated in office air from Hangzhou China with all the traditional OPEs and 5 out of 8 emerging OPEs detected. The median concentrations of ∑traditional OPEs and ∑emerging OPEs were 61,200 and 5.81 pg/m3, respectively. Butylphenyl diphenyl phosphate (BPDPP) and trisisopropyltrisphenyl phosphate (TIPPP) were observed for the first time in indoor air and Chinese office, respectively. The levels of ∑traditional OPEs decreased in the following order: summer > autumn > spring > winter. Conversely, no obvious trends were observed for emerging OPEs. ∑traditional OPEs (p < 0.001) and tri(chloroisopropyl) phosphate (TCIPP) (p < 0.01) concentrations were positively correlated with temperature. Interestingly, ∑emerging OPEs and the individual emerging OPEs analytes had no significant correlations with temperature (p > 0.05). ∑traditional OPEs, tris(2-chloroethyl) phosphate (TCEP) and TCIPP levels were significantly positively correlated with relative humidity (p < 0.05), while ∑emerging OPEs levels were negatively correlated with relative humidity (p < 0.05). Median intakes of traditional OPEs were estimated to be several orders of magnitude lower than the corresponding Reference Dose (RfD) values. The distinct environmental behaviors of emerging OPEs compared to traditional OPEs, coupled with the lack of established RfD values for them, underscore the need for their risk evaluations in future.


Assuntos
Monitoramento Ambiental , Retardadores de Chama , Humanos , Poeira/análise , Estações do Ano , Retardadores de Chama/análise , Ésteres/análise , Organofosfatos/análise , China , Fosfatos
5.
Medicine (Baltimore) ; 98(38): e16980, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31567933

RESUMO

RATIONALE: Gastric glomus tumor (GGT) is a rare gastrointestinal tumor and its preoperative imaging features are significant to make a correct diagnosis, while the assessment of the pathological and immunohistochemical characteristics of the specimen are the main methods used for its diagnosis. This study introduces the clinical uniqueness, endoscopic ultrasonography, radiology, histology and immunohistochemistry results of a patient with GGT to discuss the imaging and clinico-pathological features, diagnosis and differential diagnosis of GGT. PATIENT CONCERNS: The patient expressed a complaint concerning an "intermittent abdominal pain for 4 months". DIAGNOSES: The patient was diagnosed with gastric stromal tumor according to the clinical manifestations and imaging examination before the operation. The pathological examination of an intra-operative frozen sample confirmed the benign nature of the tumor, while post-operative immunohistochemistry results indicate the presence of a GGT. The postoperative histology revealed a tumor tissue composed of irregular blood vessels and glomus cells of same size with interstitial hyaline and mucoid degeneration. Immunohistochemical staining showed positivity for SMA (+), vimentin (3+), CD 34 (vascular +), and Factor VIII (vascular +). INTERVENTIONS: The tumor was completely removed by surgery. OUTCOMES: The patient recovered well, and was discharged from the hospital. Five months after the operation, a normal gastric mucosa was observed by gastroscopic examination. LESSONS: Most of the GGTs are benign lesions, surgical resection is the preferred treatment and they result in a good prognosis. However, malignant GGT should be treated as soon as possible because of its metastatic potential and recurrence. Adjuvant radiotherapy or chemotherapy might be useful after operation.


Assuntos
Tumor Glômico/cirurgia , Neoplasias Gástricas/cirurgia , Diagnóstico Diferencial , Endossonografia , Tumor Glômico/diagnóstico por imagem , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Neoplasias Gástricas/diagnóstico por imagem
6.
Medicine (Baltimore) ; 97(49): e12789, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30544367

RESUMO

BACKGROUND: To evaluate the clinical outcomes of S-1 plus cisplatin (SC) for the treatment of patients with advanced gastric cancer (AGC). METHODS: A systematic literature search was conducted by searching PubMed, the Cochrane Library, Embase, China Biology Medicine disc (CBMdisc), China National Knowledge Infrastructure (CNKI), and WanFang Database, for all year up to January 2017. Pooled analyses of overall survival (OS), progress-free survival rates, and adverse events were performed. RESULTS: A total of 8 random controlled trails (RCTs) consisting of 2699 patients with AGC were selected and included in this meta-analysis. The results of our meta-analysis showed that AGC patients who treated with SC regimen receive a similar OS (HR = 1.01, 95%CI: 0.86-1.18, P = .928), PFS (HR = 0.89, 95%CI: 0.72-1.09, P = .263), and overall response rate (HR = 0.88, 95%CI: 0.70-1.11, P = .283). However, SC regimen may increase the risk of 1 to 2 grade (OR = 1.128, 95%CI: 1.075-1.184, P = .000) and 3 to 4 grade (OR = 1.24, 95%CI: 1.01-1.52, P = .039) adverse events. CONCLUSION: SC chemotherapy showed no difference in survival compared with 5-FU- and S-1-based other therapy, but has a higher rate of adverse events compared with other chemotherapy regimens.


Assuntos
Antineoplásicos/uso terapêutico , Cisplatino/uso terapêutico , Ácido Oxônico/uso terapêutico , Neoplasias Gástricas/tratamento farmacológico , Tegafur/uso terapêutico , Antineoplásicos/efeitos adversos , Cisplatino/efeitos adversos , Combinação de Medicamentos , Humanos , Ácido Oxônico/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Neoplasias Gástricas/mortalidade , Tegafur/efeitos adversos
7.
Clin Hemorheol Microcirc ; 29(3-4): 231-8, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14724346

RESUMO

This study was aimed at investigating the effects of extract of Ginkgo biloba (EGb) on cerebral vasospasm and microcirculatory perfusion after subarachnoid hemorrhage (SAH). An endovascular piercing method was used to induce Wistar rat SAH models, and animals were divided into sham-operated, vehicle controls, and EGb-treated groups. EGb was injected intraperitoneally 30 minutes before operation and was repeated every 6 hours, with a single dose of 15 mg/kg bw. Diameters of basilar arteries before and after operation were measured. Microcirculatory blood perfusion of parietal lobe cortex was detected using a laser Doppler flow-meter probe within 24 hours. Endothelin-1 levels in both plasma and brain tissue were detected at different time points. The results showed that SAH caused an immediate drop in microcirculatory blood flow in vehicle controls, which persisted for 24 hours. Endothelin-1 levels in both plasma and brain tissue increased after SAH. EGb partly reversed spasms of the basilar artery and antagonized a drop in microcirculatory blood flow. EGb also prevented an increase in endothelin-1 both in plasma and in brain tissue. In conclusion, EGb, by antagonizing the overproduction of endo- thelin-1, partly reverses cerebral vasospasm and improves microcirculation, and thus relieves secondary ischemic brain injury after experimental SAH.


Assuntos
Artéria Basilar/efeitos dos fármacos , Circulação Cerebrovascular/efeitos dos fármacos , Ginkgo biloba/química , Fitoterapia , Extratos Vegetais/uso terapêutico , Hemorragia Subaracnóidea/complicações , Vasodilatadores/uso terapêutico , Vasoespasmo Intracraniano/tratamento farmacológico , Animais , Isquemia Encefálica/etiologia , Isquemia Encefálica/prevenção & controle , Avaliação Pré-Clínica de Medicamentos , Endotelina-1/biossíntese , Endotelina-1/sangue , Endotelina-1/genética , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Injeções Intraperitoneais , Masculino , Microcirculação/efeitos dos fármacos , Modelos Animais , Lobo Parietal/irrigação sanguínea , Lobo Parietal/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Ratos , Ratos Wistar , Vasoconstrição/efeitos dos fármacos , Vasodilatadores/administração & dosagem , Vasodilatadores/farmacologia
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