RESUMO
Photocatalytic water splitting is a simple means of converting solar energy into storable hydrogen energy. Narrow-band gap oxysulfide photocatalysts have attracted much attention in this regard owing to the significant visible-light absorption and relatively high stability of these compounds. However, existing materials suffer from low efficiencies due to difficulties in synthesizing these oxysulfides with suitable degrees of crystallinity and particle sizes, and in constructing effective reaction sites. The present work demonstrates the production of a Gd2 Ti2 O5 S2 (λ<650â nm) photocatalyst capable of efficiently driving photocatalytic reactions. Single-crystalline, plate-like Gd2 Ti2 O5 S2 particles with atomically ordered surfaces were synthesized by flux and chemical etching methods. Ultrafine Pt-IrO2 cocatalyst particles that promoted hydrogen (H2 ) and oxygen (O2 ) evolution reactions were subsequently loaded on the Gd2 Ti2 O5 S2 while ensuring an intimate contact by employing a microwave-heating technique. The optimized Gd2 Ti2 O5 S2 was found to evolve H2 from an aqueous methanol solution with a remarkable apparent quantum efficiency of 30 % at 420â nm. This material was also stable during O2 evolution in the presence of a sacrificial reagent. The results presented herein demonstrates a highly efficient narrow-band gap oxysulfide photocatalyst with potential applications in practical solar hydrogen production.
RESUMO
Efficient water vapor splitting opens a new strategy to develop scalable and corrosion-free solar-energy-harvesting systems. This study demonstrates highly efficient overall water splitting under vapor feeding using Al-doped SrTiO3 (SrTiO3:Al)-based photocatalyst decorated homogeneously with nano-membrane TiOx or TaOx thin layers (<3 nm). Here, we show the hygroscopic nature of the metal (hydr)oxide layer provides liquid water reaction environment under vapor, thus achieving an AQY of 54 ± 4%, which is comparable to a liquid reaction. TiOx coated, CoOOH/Rh loaded SrTiO3:Al photocatalyst works for over 100 h, under high pressure (0.3 MPa), and with no problems using simulated seawater as the water vapor supply source. This vapor feeding concept is innovative as a high-pressure-tolerant photoreactor and may have value for large-scale applications. It allows uniform distribution of the water reactant into the reactor system without the potential risk of removing photocatalyst powders and eluting some dissolved ions from the reactor.
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Renal anemia is predominantly caused by a relative deficiency in erythropoietin (EPO). Conventional treatment for renal anemia includes the use of recombinant human EPO (rhEPO) or a long-acting erythropoiesis-activating agent named darbepoetin alfa, which is a modified rhEPO with a carbohydrate chain structure that differs from native hEPO. We have developed a biosimilar to darbepoetin alfa designated JR-131. Here, we comprehensively compare the physicochemical and biological characteristics of JR-131 to darbepoetin alfa. JR-131 demonstrated similar protein structure to the originator, darbepoetin alfa, by peptide mapping and circular dichroism spectroscopy. Additionally, mass spectroscopic analyses and capillary zone electrophoresis revealed similar glycosylation patterns between the two products. Human bone marrow-derived erythroblasts differentiated and proliferated to form colonies with JR-131 to a similar degree as darbepoetin alfa. Finally, JR-131 stimulated erythropoiesis and improved anemia in rats similarly to darbepoetin alfa. Our data show the similarity in physicochemical and biological properties of JR-131 to those of darbepoetin alfa, and JR-131 therefore represents a biosimilar for use in the treatment of renal anemia.
Assuntos
Medicamentos Biossimilares/farmacologia , Darbepoetina alfa/farmacologia , Eritropoese/efeitos dos fármacos , Anemia/tratamento farmacológico , Animais , Células CHO , Cricetinae , Cricetulus , Darbepoetina alfa/química , Modelos Animais de Doenças , Eletroforese Capilar , Glicosilação/efeitos dos fármacos , Rim/patologia , Masculino , Peso Molecular , Nefrectomia , Mapeamento de Peptídeos , Estrutura Secundária de Proteína , Ratos Sprague-Dawley , Açúcares/análise , Resultado do TratamentoRESUMO
Since liposome-encapsulated hemoglobin with high O2 affinity (h-LEH, P50 O2 = 10 mm Hg) has been reported to accelerate skin wound healing in normal mice, it was tested in dB/dB mice with retarded wound healing, as seen in human diabetics. Two full-thickness dorsal wounds 6 mm in diameter encompassed by silicone stents were created in dB/dB mice. Two days later (day 2), the animals were randomly assigned to receive intravenous h-LEH (2 mL/kg, n = 7) or saline (2 mL/kg, n = 7). The same treatment was repeated 4 days after wounding (day 4), and the size of the skin lesions was analyzed by photography, surface perfusion was detected by Laser-Doppler imager, and plasma cytokines and chemokines were determined on days 0, 2, 4, and 7, when all animals were euthanized for morphological studies. The size of the ulcer compared to the skin defect or silicone stent became significantly reduced on days 4 and 7 in mice treated with h-LEH (47 ± 8% of original size), similar to the level in wild-type mice, compared to saline-treated dB/dB mice (68 ± 18%, P < 0.01). Mice treated with h-LEH had significantly attenuated inflammatory cytokines, increased surface perfusion, and increased Ki67 expression on day 7 in accordance with the ulcer size reduction, while there was no significant difference in chemokines, histological granulation, epithelial thickness, and granulocyte infiltration detected by immunohistochemical staining in the ulcer between the treatment groups. The results suggest that h-LEH (2 mL/kg) early after wounding may accelerate skin wound healing in dB/dB mice to levels equivalent to wild-type mice probably via mechanism(s) involving reduced hypoxia, increased surface perfusion, suppressed inflammation, accelerated in situ cell proliferation and protein synthesis.
Assuntos
Substitutos Sanguíneos/farmacologia , Diabetes Mellitus Tipo 2/fisiopatologia , Hemoglobinas/farmacologia , Fenômenos Fisiológicos da Pele/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Aerobiose/efeitos dos fármacos , Animais , Substitutos Sanguíneos/administração & dosagem , Modelos Animais de Doenças , Hemoglobinas/administração & dosagem , Humanos , Hipóxia/tratamento farmacológico , Subunidade alfa do Fator 1 Induzível por Hipóxia , Lipossomos , Masculino , Camundongos , Microcirculação/efeitos dos fármacos , Distribuição AleatóriaRESUMO
Recently, animal studies have demonstrated the efficacy of endothelial progenitor cell (EPC) therapy for diabetic wound healing. Based on these preclinical studies, we performed a prospective clinical trial phase I/IIa study of autologous G-CSF-mobilized peripheral blood (PB) CD34(+) cell transplantation for nonhealing diabetic foot patients. Diabetic patients with nonhealing foot ulcers were treated with 2 × 10(7) cells of G-CSF-mobilized PB CD34(+) cells as EPC-enriched population. Safety and efficacy (wound closure and vascular perfusion) were evaluated 12 weeks posttherapy and further followed for complete wound closure and recurrence. A total of five patients were enrolled. Although minor amputation and recurrence were seen in three out of five patients, no death, other serious adverse events, or major amputation was seen following transplantation. Complete wound closure was observed at an average of 18 weeks with increased vascular perfusion in all patients. The outcomes of this prospective clinical study indicate the safety and feasibility of CD34(+) cell therapy in patients with diabetic nonhealing wounds.
Assuntos
Antígenos CD34/metabolismo , Terapia Baseada em Transplante de Células e Tecidos/métodos , Fator Estimulador de Colônias de Granulócitos/farmacologia , Adulto , Idoso , Feminino , Úlcera do Pé/metabolismo , Úlcera do Pé/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Células-Tronco/citologia , Células-Tronco/metabolismo , Cicatrização/fisiologiaRESUMO
Effects of liposome-encapsulated hemoglobin with high O2 affinity (m-LEH, P50O2 = 17 mm Hg) on skin wound healing in mice were examined. Two full-thickness dorsal wounds 6 mm in diameter encompassed by silicone stents were created in Balb/c mice. Two days later (day 2), the animals randomly received intravenous m-LEH (2 mL/kg, n = 12), homologous blood transfusion (red blood cell [RBC], n = 11), or saline (n = 12). The same treatment was repeated 4 days after wounding (day 4), and the sizes of the skin defects and ulcers were monitored on days 0, 2, 4, and 7, when all animals were euthanized for morphological studies. While the size of the skin defect in relation to the stent ring remained the same in all groups, the size of the ulcer compared with the skin defect (or silicone stent) became significantly reduced on days 4 and 7 in mice treated with m-LEH (46 ± 10% of pretreatment size, P < 0.01) compared with mice treated with RBC transfusion (73 ± 6%) or saline (76 ± 7%). m-LEH treatment significantly accelerated granulation, increased epithelial thickness, suppressed early granulocyte infiltration, and increased Ki67 expression in accordance with the ulcer size reduction, while there was no difference in surface blood flow or CD31 expression among the groups. The results suggest that m-LEH (2 mL/kg) may accelerate skin wound healing in Balb/c mice via mechanism(s) involving reduced inflammation and increased metabolism, but not by improved hemodynamics or endothelial regeneration.
Assuntos
Substitutos Sanguíneos/uso terapêutico , Pele/efeitos dos fármacos , Pele/lesões , Cicatrização/efeitos dos fármacos , Animais , Substitutos Sanguíneos/administração & dosagem , Substitutos Sanguíneos/farmacologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/imunologia , Antígeno Ki-67/imunologia , Lipossomos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Neutrófilos/efeitos dos fármacos , Neutrófilos/imunologia , Neutrófilos/patologia , Molécula-1 de Adesão Celular Endotelial a Plaquetas/imunologia , Pele/imunologia , Pele/patologiaRESUMO
A cranial vault Osteoma is relatively common benign tumor. Mushroom shaped skull osteoma is, however, extremely rare. Twenty seven years old female developed slow growing hard mass posterior to the ear. CT scan revealed a mushroom shaped osseous mass approximately 2.5 cm in diameter protruding from the temporal bone at the site of asterion. And the tumor was located over the right sigmoid sinus. The sigmoid sinus engraved approximately 4mm to the tumor and had a branching to one emissaries' vein. Operation was performed under general anesthesia. The tumor was excised first by cutting the base of the tumor, and then residual tumor was grinded using a round head cutting bar. A chisel dissection was not recommended because of underlining sinus. Histological findings were consistent with a benign osteoma. The postoperative course was uneventful. CT examination immediately done after operation revealed no evidence of intracranial hemorrhage, or injury of vessels. Osetoma was excised, and the surface of cranial bone at the operation site was smooth and cosmetically acceptable. At 6-months follow up, patient remains asymptomatic and recurrence free. CT examination with Multi Planer Reconstruction imaging or 3D reconstruction is highly recommended for the operational planning of cranial osteoma.
Assuntos
Osteoma/patologia , Neoplasias Cranianas/patologia , Osso Temporal/patologia , Adulto , Cavidades Cranianas/diagnóstico por imagem , Cavidades Cranianas/patologia , Cavidades Cranianas/cirurgia , Feminino , Humanos , Osteoma/diagnóstico por imagem , Osteoma/cirurgia , Neoplasias Cranianas/diagnóstico por imagem , Neoplasias Cranianas/cirurgia , Osso Temporal/diagnóstico por imagem , Osso Temporal/cirurgia , Tomografia Computadorizada por Raios XRESUMO
A 80-year-old male was referred for detailed examination of left apical fibrotic changes in the chest radiograph. Six years later, several cavitary lesions with thickening of the pleura developed. Anti tuberculosis therapy had no effects. Despite intravenous administration of antibiotics, the cavities became larger and the infiltrates progressed to the left lower lobe. The air crescent was observed in one of the cavities. Repeated sputum examinations revealed Aspergillus niger only. With administration of anti fungal drug, infiltrates were faded. Four months after the cessation of antifungal drug high fever associated with new infiltrates developed. Sputum culture showed Aspergillus flavus. Infiltrates over the entire left lung field and in the right upper lobe were observed. On CT film necrotic lung tissue was strongly suggested in the cavity. The patients died of respiratory failure. Although initial course of the presented case was compatible with semi-invasive pulmonary aspergillosis (SIPA), fluminant and fatal exacerbations which may be very unusual in SIPA, developed in later. The mycetoma-like ball may be occasionally made of necrotic lung parenchyma instead of fungal mycelia in SIPA.