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1.
Chemosphere ; 314: 137492, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36481170

RESUMO

The n-type Ce doped ZnO (Ce-ZnO) and p-type polyaniline (PANI) heterojunction were successfully synthesized via simple chemical solution method for sensing liquefied petroleum gas (LPG) at standard environment. The morphology and structures of as-prepared Ce-ZnO & PANI nanoparticles were analyzed by numerous kinds of techniques. Ce-ZnO & PANI nanoparticles were mixed with n-methylpyrrolidone (NMP) which is coated over the gold coated PET electrode by doctor blade method and dried overnight at 60 °C to form p-n junction. The as-formed p-n junction is to be driven with the help of 1.5 V potential at ambient temperature. X-ray photoelectron spectroscopy results of Ce-ZnO nanoparticles confirmed the existence of Ce4+ and the improved amount of both chemisorbed oxygen and oxygen vacancy after the formation of Ce-ZnO heterojunction. The maximum response of 80% was realized for hollow Ce-ZnO/PANI sensor at 100 ppm. The proposed material is a novel candidate to detect the LPG even at low (30) ppm and this study reveals the possibility of developing a potentially inexpensive hollow Ce-ZnO/PANI sensor for sensing LPG efficiently.


Assuntos
Petróleo , Óxido de Zinco , Oxigênio , Tomografia por Emissão de Pósitrons
2.
Mater Sci Eng C Mater Biol Appl ; 75: 1472-1479, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28415439

RESUMO

A non-enzymatic glucose biosensor was developed by utilizing the zinc oxide nanoparticles (ZnO NPs) synthesized by a novel green method using the leaf extract of Ocimum tenuiflorum. The structural, optical and morphological properties of ZnO NPs characterized by means of X-ray diffraction (XRD), ultraviolet-visible (UV-vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray (EDAX) spectroscopy, and transmission electron microscopy (TEM). The XRD analysis revealed that the ZnO NPs were crystalline and had a hexagonal wurtzite structure. The crystallite size measured by XRD was the same as that measured using SEM and TEM. The UV-vis absorption spectrum estimates the band gap of ZnO NPs present in the range of 2.82 to 3.45eV. The reduction and formation of ZnO NPs mainly due to the involvement of leaf extract bio-molecular compounds analyzed from the FTIR spectra. The SEM result confirms the morphology of the NPs responsible from the various concentration of leaf extract in the synthesis process. HRTEM analysis depicts the spherical structure of ZnO NPs. The synthesized NPs have the average size ranges from 10 to 20nm. The fabricated GCE/ZnO glucose sensor represents superior electro catalytic activity that has been observed for ZnO NPs with a reproducible sensitivity of 631.30µAmM-1cm-2, correlation coefficient of R=0.998, linear dynamic range from 1-8.6mM, low detection limit of 0.043µM (S/N=3) and response time<4s.


Assuntos
Técnicas Biossensoriais/métodos , Glucose/análise , Nanopartículas/química , Ocimum sanctum/química , Extratos Vegetais/química , Folhas de Planta/química , Óxido de Zinco/química
3.
J Invasive Cardiol ; 29(3): 97-103, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28089998

RESUMO

AIMS: To evaluate the feasibility and safety of a novel targeted neuromodulatory treatment for sympathetic hypertension involving a one-time local injection of neurotropic agents near renal nerves. METHODS AND RESULTS: Seven patients suffering from uncontrolled hypertension per ESH-ESC guidelines were treated using a single dose of NW2013, a neurotropic Na+/K+ ATPase antagonist. A microneedle catheter was used to administer 1.2 mL of NW2013 (0.6 mL per artery) to the perivascular space surrounding renal arteries using percutaneous endovascular procedures under fluoroscopic guidance. All patients were successfully treated without any procedural complications. Patients were followed for 12 months post procedure, and office and 24-hour ambulatory blood pressure measurements were made. Both office and ambulatory blood pressures were lower at 24 hours, 1 month, and 3 months after treatment. The decrease in office blood pressure was greater than the decrease in ambulatory blood pressure. A reduction in medication regimen was also observed in 2 patients. One patient suffered a cerebrovascular event after 6-month follow-up and died from stroke, unrelated to the treatment. Overall, the reduction in office and ambulatory blood pressure was sustained over the course of 12 months. CONCLUSIONS: Treatment of hypertension using local administration of NW2013 near renal nerves appears to be feasible and safe. Large, controlled, randomized, and blinded clinical studies with monitoring of patient compliance to daily oral medication are recommended to further establish the efficacy of this novel treatment.


Assuntos
Procedimentos Endovasculares/métodos , Hipertensão/terapia , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Simpatectomia Química/métodos , Assistência ao Convalescente/métodos , Idoso , Pressão Sanguínea/fisiologia , Monitorização Ambulatorial da Pressão Arterial/métodos , Estudos de Viabilidade , Feminino , Humanos , Hipertensão/diagnóstico , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Neurotransmissores/administração & dosagem , Artéria Renal/inervação , Resultado do Tratamento
4.
J Biomech Eng ; 134(2): 021003, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22482670

RESUMO

As endovascular treatment of abdominal aortic aneurysms (AAAs) gains popularity, it is becoming possible to treat certain challenging aneurysmal anatomies with endografts relying on suprarenal fixation. In such anatomies, the bare struts of the device may be placed across the renal artery ostia, causing partial obstruction to renal artery blood flow. Computational fluid dynamics (CFD) was used to simulate blood flow from the aorta to the renal arteries, utilizing patient-specific boundary conditions, in three patient models and calculate the degree of shear-based blood damage (hemolysis). We used contrast-enhanced computed tomography angiography (CTA) data from three AAA patients who were treated with a novel endograft to build patient-specific models. For each of the three patients, we constructed a baseline model and endoframe model. The baseline model was a direct representation of the patient's 30-day post-operative CTA data. This model was then altered to create the endoframe model, which included a ring of metallic struts across the renal artery ostia. CFD was used to simulate blood flow, utilizing patient-specific boundary conditions. Pressures, flows, shear stresses, and the normalized index of hemolysis (NIH) were quantified for all patients. The overall differences between the baseline and endoframe models for all three patients were minimal, as measured though pressure, volumetric flow, velocity, and shear stress. The average NIH across the three baseline and endoframe models was 0.002 and 0.004, respectively. Results of CFD modeling show that the overall disturbance to flow caused by the presence of the endoframe struts is minimal. The magnitude of the NIH in all models was well below the accepted design and safety threshold for implantable medical devices that interact with blood flow.


Assuntos
Simulação por Computador , Procedimentos Endovasculares/efeitos adversos , Hemólise , Fenômenos Mecânicos , Obstrução da Artéria Renal/fisiopatologia , Fenômenos Biomecânicos , Velocidade do Fluxo Sanguíneo , Humanos , Hidrodinâmica , Masculino , Pressão , Fluxo Sanguíneo Regional
5.
Bioorg Med Chem Lett ; 9(12): 1633-8, 1999 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-10397491

RESUMO

A series of 5-C-substituted 20(S)-camptothecin analogues were synthesised and evaluated their in vitro anti-cancer activity. Several of these analogues have showed excellent activity against human tumor cell lines.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Camptotecina/análogos & derivados , Camptotecina/farmacologia , Antineoplásicos Fitogênicos/química , Camptotecina/química , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Relação Estrutura-Atividade , Células Tumorais Cultivadas
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