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1.
Environ Dev Sustain ; 25(1): 734-810, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35035274

RESUMO

A transition towards a circular economy is a challenge. It is vital to know that circularity and sustainability are two different segments. So, circular economy can only be achieved in the long-term perspective. This study investigates accounting and accountability for circular economy and waste. Considering these principles and based on a critical review of the literature, economic gains from the transition toward a circular economy are measurable; the problems for corporations and governments are diverse; the way to handle the stakeholders who are losing control in the circular economy is considerable. Diffusion of innovation theory is used to conduct this study. It is essential that an organisational design built should help implement the circular model. Targeted questions responded by adopting a systematic literature review approach by applying PRISMA protocol. This study examines 78 publications in English between 2012 and 2021, which present a map of the circular economy-related knowledge published in web of science and Scopus. Besides, this study includes 03 European Commission reports, 01 Ellen Macarthur Foundation report, 01 Council for the Environment and Infrastructure report, 01 report from SUN IZA, 01 UN Global Compact and 01 the Brundtland Commission report. The results highlight how circular economy, waste management, sustainability, accountability, and management accounting practices help to develop an ecosystem and achieve sustainable development goals of the United Nations 2030 Agenda. Theoretical and practical implications are discussed.

2.
Hosp Pharm ; 55(5): 292-305, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32999499

RESUMO

Background: Gastroesophageal reflux disease (GERD) is a common gastrointestinal disorder that results from regurgitation of acid from the stomach into the esophagus. Treatment available for GERD includes lifestyle changes, antacids, histamine-2 receptor antagonists (H2RAs), proton pump inhibitors (PPIs), and anti-reflux surgery. Aim: The aim of this review is to assess the cost-effectiveness of the use of PPIs in the long-term management of patients with GERD. Method: We searched in PubMed to identify related original articles with close consideration based on inclusion and exclusion criteria to choose the best studies for this narrative review. The first section compares the cost-effectiveness of PPIs with H2RAs in long-term heartburn management. The other sections shall only discuss the cost-effectiveness of PPIs in 5 different strategies, namely, continuous (step-up, step-down, and maintenance), on-demand, and intermittent therapies. Results: Of 55 articles published, 10 studies published from 2000 to 2015 were included. Overall, PPIs are more effective in relieving heartburn in comparison with ranitidine. The use of PPIs in managing heartburn in long-term consumption of nonsteroidal anti-inflammatory drug (NSAID) has higher cost compared with H2RA. However, if the decision-maker is willing to pay more than US$174 788.60 per extra quality-adjusted life year (QALY), then the optimal strategy is traditional NSAID (tNSAID) and PPIs. The probability of being cost-effective was also highest for NSAID and PPI co-therapy users. On-demand PPI treatment strategy showed dominant with an incremental cost-effectiveness ratio of US$2197 per QALY gained and was most effective and cost saving compared with all the other treatments. The average cost-effectiveness ratio was lower for rabeprazole therapy than for ranitidine therapy. Conclusion: Our review revealed that long-term treatment with PPIs is effective but costly. To achieve long-term cost-effective approach, we recommend on-demand approach to treat heartburn symptoms, but if the symptoms persist, treatment with continuous step-down therapy should be applied.

3.
Nanomaterials (Basel) ; 12(13)2022 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-35808011

RESUMO

α-SiAlON is commonly used to machine superalloys owing to its desirable thermal and structural properties. α-SiAlON is among the crystalline forms of SiAlON and has more favorable properties than ß-SiAlON. However, it becomes fragile during the machining of hard-to-cut materials due to its low fracture toughness and machinability. Recent research efforts focus on improving the thermal and structural properties of α-SiAlON using suitable dopants, nano-sized precursors, and the addition of metallic/ceramic reinforcement particles. The present study presents a material-by-design approach to designing and developing ceramic and metal-particle-reinforced Ca-α-SiAlON composites with properties tailored for the cutting tool applications. The mean-field homogenization theories and effective medium approximations implemented in an in-house code are used to effectively optimize the thermal and structural properties of the Ca-α-SiAlON composite by varying essential parameters such as inclusion material, volume fraction, porosity, particulate size, and thermal interface resistance. Individual properties of the matrix and reinforcements are considered in the computations of effective properties such as thermal conductivity, thermal expansion coefficient, modulus of elasticity, and fracture toughness. The main objective of the study is to enhance the thermal conductivity and fracture toughness of Ca-α-SiAlON, while lowering its thermal expansion coefficient. At the same time, the elastic modulus and hardness/strength must be maintained within an acceptable range. As a validation, Ni/Ca-α-SiAlON and SiC/Ca-α-SiAlON composites are synthesized from the nano-sized precursors, CaO dopant, and Ni/SiC microparticles via spark plasma sintering (SPS) process. The thermal conductivity, coefficient of thermal expansion, and elastic modulus of the composites are measured and compared with the computational predictions. The computational predictions are found to be comparable to that of the experimental measurements. Moreover, the studies show that WC, SiC, and Cr can be suitable reinforcement materials for enhancing the thermal and structural properties of Ca-α-SiAlON material for the cutting tool inserts.

4.
Curr Drug Deliv ; 4(2): 141-51, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17456033

RESUMO

Delivery of therapeutic proteins/peptides has received a considerable amount of attention over the last 10 years, but there are number of limitations to oral delivery of proteins. The barriers to peptide bioavailability after oral administration are intestinal membrane permeability, size, intestinal and hepatic metabolism and lastly solubility. A number of approaches have been used to overcome these limitations. Poor membrane permeabilities of hydrophilic peptides might be overcome by structurally modifying the compound, thus increasing their membrane partition characteristics and their affinity for carrier proteins. Another approach is site specific delivery of the peptides to the most permeable part of the intestine. Metabolism (hepatic and intestinal) of peptides might be controlled by co-administration of competitive enzyme inhibitors, structural modifications and administration of the compound as well as absorbed prodrug that is converted into therapeutically active agent after its absorption. Various delivery systems like prolease technology, nano-particulate and microparticulate delivery system, mucoadhesive delivery of peptides and microspheres have been developed for the delivery of proteins and peptides. Non-conventional delivery systems for proteins are biodegradable and non-biodegradable systems. Besides these, some other approaches for protein and peptide delivery are vector mediated delivery of proteins using adenovirus, macroflux transdermal patches, pulmonary delivery of proteins, delivery of proteins and peptides across blood brain barrier.


Assuntos
Sistemas de Liberação de Medicamentos/tendências , Peptídeos/administração & dosagem , Proteínas/administração & dosagem , Tecnologia Farmacêutica/tendências , Adesividade , Barreira Hematoencefálica/metabolismo , Química Farmacêutica/tendências , Colo/metabolismo , Preparações de Ação Retardada , Vias de Administração de Medicamentos , Portadores de Fármacos , Combinação de Medicamentos , Composição de Medicamentos/tendências , Gelatina/química , Ácido Láctico/química , Lipídeos/química , Lipossomos , Micelas , Microesferas , Mucosa/metabolismo , Nanopartículas , Peptídeos/química , Peptídeos/metabolismo , Ácido Poliglutâmico/química , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Polímeros/química , Proteínas/química , Proteínas/metabolismo
5.
PDA J Pharm Sci Technol ; 61(2): 88-96, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17479716

RESUMO

The objective of the present study is to develop microspheres for celecoxib to enhance its bioavailability by increasing its gastric residence time. Four different polymers-polyethylene oxide, Eudragit S, cellulose acetate, and Eudragit RL-were used to form the floating microspheres using an emulsion-solvent diffusion technique. The use of two different solvents (dichloromethane and ethanol) that differed in the rate of diffusion led to formation of a hollow core in the microspheres, which was partially responsible for the flotation ability. The formulation was optimized on the basis of in vitro buoyancy and in vitro release in simulated gastric fluid at pH 3. Scanning electron microscopy revealed differences between the formulations in terms of their topography. X-ray diffractometry and differential scanning calorimetry examination showed the amorphous nature of the drug. Microspheres prepared with polyethylene oxide:Eudragit S:celecoxib (2:2:1) gave the best in vitro percentage release and was taken as the optimized formulation. By fitting the data into zero order, first order, and Higuchi model, it could be concluded that the release followed first-order release kinetics. The correlation coefficient (R2 value) was obtained upon fitting the data to Higuchi equation, which signifies that the mechanism of release of celecoxib from the microspheres was diffusion rate-limited.


Assuntos
Inibidores de Ciclo-Oxigenase/química , Portadores de Fármacos , Mucosa Gástrica/metabolismo , Polímeros/química , Pirazóis/química , Sulfonamidas/química , Celecoxib , Celulose/análogos & derivados , Celulose/química , Química Farmacêutica , Inibidores de Ciclo-Oxigenase/metabolismo , Preparações de Ação Retardada , Difusão , Composição de Medicamentos , Etanol/química , Suco Gástrico/química , Concentração de Íons de Hidrogênio , Cinética , Cloreto de Metileno/química , Microesferas , Modelos Químicos , Tamanho da Partícula , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Porosidade , Pirazóis/metabolismo , Solubilidade , Solventes/química , Sulfonamidas/metabolismo , Tecnologia Farmacêutica/métodos
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