High Performance Concretes with Highly Reactive Rice Husk Ash and Silica Fume.

The search for new sources of high-quality non-crystalline silica as a construction material for high-performance concrete has attracted the interest of researchers for several decades. Numerous investigations have shown that highly reactive silica can be produced from rice husk, an agricultural waste that is abundantly available in the world. Among others, the production of rice husk ash (RHA) by chemical washing with hydrochloric acid prior to the controlled combustion process has been reported to provide higher reactivity because such a process removes alkali metal impurities from RHA and provides an amorphous structure with higher surface area. This paper presents an experimental work in which a highly reactive rice husk ash (TRHA) is prepared and evaluated as a replacement for Portland cement in high-performance concretes. The performance of RHA and TRHA was compared with that of conventional silica fume (SF). Experimental results showed that the increase in compressive strength of concrete with TRHA was clearly observed at all ages, generally higher than 20% of the strength obtained with the control concrete. The increase in flexural strength was even more significant, showing that concrete with RHA, TRHA and SF increased by 20%, 46%, and 36%, respectively. Some synergistic effect was observed when polyethylene-polypropylene fiber was used for concrete with TRHA and SF. The chloride ion penetration results also indicated that the use of TRHA had similar performance compared to that of SF. Based on the results of statistical analysis, the performance of TRHA is found to be identical to that of SF. The use of TRHA should be further promoted considering the economic and environmental impact that will be achieved by utilizing agricultural waste.

Comparison of three different self-expanding metal stents using rabbit models for the treatment of tracheal collapse.

PURPOSE: To identify an optimal self-expandable metallic stent (SEMS) and verify whether a mechanically superior SEMS would result in better clinical outcomes in the treatment of tracheal collapse. METHODS: We selected three SEMS (n = 8 each), including an S-type stent with a wire diameter of 0.006 inches (S6) and two D-type stents with wire diameters of 0.006 (D6) and 0.007 inches (D7). Twenty-four New Zealand White rabbits were divided into three equal groups. After the stents were deployed, the clinical signs were recorded daily, and radiographic examinations were performed monthly. All rabbits were euthanized after three months. RESULTS: Two rabbits with S6 stents and one rabbit with a D7 stent died within three months because of stent migration or pneumonia. All rabbits with D6 stents survived for three months. On histological examination, the D6 group had the lowest inflammation score. CONCLUSIONS: Both clinically and histopathologically, the results with D-type stents with a wire diameter of 0.006 inches were superior to those of the other groups (p = 0.001). The use of an optimal intraluminal stent may improve the long-term clinical outcomes in the treatment of tracheal collapse in dogs.

Comparison of three different self-expanding metal stents using rabbit models for the treatment of tracheal collapse

Purpose: To identify an optimal self-expandable metallic stent (SEMS) and verify whether a mechanically superior SEMS would result in better clinical outcomes in the treatment of tracheal collapse. Methods: We selected three SEMS (n = 8 each), including an S-type stent with a wire diameter of 0.006 inches (S6) and two D-type stents with wire diameters of 0.006 (D6) and 0.007 inches (D7). Twenty-four New Zealand White rabbits were divided into three equal groups. After the stents were deployed, the clinical signs were recorded daily, and radiographic examinations were performed monthly. All rabbits were euthanized after three months. Results: Two rabbits with S6 stents and one rabbit with a D7 stent died within three months because of stent migration or pneumonia. All rabbits with D6 stents survived for three months. On histological examination, the D6 group had the lowest inflammation score. Conclusions: Both clinically and histopathologically, the results with D-type stents with a wire diameter of 0.006 inches were superior to those of the other groups (p = 0.001). The use of an optimal intraluminal stent may improve the long-term clinical outcomes in the treatment of tracheal collapse in dogs.

The effect of palonosetron on rocuronium-induced withdrawal movement / O efeito de palonosetron sobre o movimento de retração induzido por rocurônio

Abstract Background: Rocuronium causes pain and withdrawal movement during induction of anesthesia. In this study, palonosetron was investigated to have analgesic effect on the reduction of rocuronium-induced withdrawal movement. Methods: 120 patients were randomly assigned to one of three groups to receive either saline, lidocaine 20 mg, or palonosetron 0.075 mg with a tourniquet applied two minutes before thiopental sodium (5 mg.kg-1) was given intravenously. After loss of consciousness, rocuronium (0.6 mg.kg-1) was injected and the withdrawal movement was estimated by 4-point scale in a double-blind manner. Results: The overall incidence of rocuronium withdrawal movement was 50% with lidocaine (p = 0.038), 38% with palonosetron (p = 0.006) compared with 75% for saline. The incidence of no pain to mild pain was significantly lower in the lidocaine and palonosetron groups (85% and 92% respectively) than in the saline group (58%). However, there was no significant difference in withdrawal movement between the lidocaine and palonosetron groups. There was no severe movement with palonosetron. Conclusion: Pretreatment of palonosetron with venous occlusion may attenuate rocuronium-induced withdrawal movement as effective as the use of lidocaine. It suggested that peripheral action of palonosetron was effective to reduce rocuronium-induced withdrawal movement.

Resumo Justificativa: Rocurônio provoca dor e reflexo de retirada durante a indução da anestesia. Neste estudo, avaliamos se palonosetron tem efeito analgésico para reduzir esse movimento induzido por rocurónio. Métodos: Cento e vinte pacientes foram randomicamente designados para um de três grupos para receber solução salina, lidocaína (20 mg) ou palonosetron (0.075 mg), com aplicação de torniquete dois minutos antes da administração intravenosa de tiopental sódico (5 mg.kg-1). Após a perda de consciência, rocurônio (0.6 mg.kg-1) foi injetado e o reflexo de retirada foi avaliado com o uso de uma escala de quatro pontos, de modo duplo-cego. Resultados: A incidência global do reflexo de retirada induzido por rocurônio foi de 50% para lidocaína (p = 0,038), 38% para palonosetron (p = 0,006), em comparação com 75% para solução salina. A incidência de dor ausente ou leve foi significativamente menor nos grupos lidocaína e palonosetron (85% e 92%, respectivamente) que no grupo solução salina (58%). Porém, não houve diferença significativa no reflexo de retirada entre os grupos lidocaína e palonosetron. Não houve movimento grave com palonosetron. Conclusão: O pré-tratamento com palonosetron com oclusão venosa pode atenuar o reflexo de retirada induzido por rocurônio de modo tão eficaz como o uso de lidocaína. Sugeriu-se que a ação periférica de palonosetron foi eficaz para reduzir o reflexo de retirada induzido por rocurônio.

[The effect of palonosetron on rocuronium-induced withdrawal movement]. / O efeito de palonosetron sobre o movimento de retração induzido por rocurônio.

BACKGROUND: Rocuronium causes pain and withdrawal movement during induction of anesthesia. In this study, palonosetron was investigated to have analgesic effect on the reduction of rocuronium-induced withdrawal movement. METHODS: 120 patients were randomly assigned to one of three groups to receive either saline, lidocaine 20mg, or palonosetron 0.075mg with a tourniquet applied two minutes before thiopental sodium (5mg.kg-1) was given intravenously. After loss of consciousness, rocuronium (0.6mg.kg-1) was injected and the withdrawal movement was estimated by 4-point scale in a double-blind manner. RESULTS: The overall incidence of rocuronium withdrawal movement was 50% with lidocaine (p=0.038), 38% with palonosetron (p=0.006) compared with 75% for saline. The incidence of no pain to mild pain was significantly lower in the lidocaine and palonosetron groups (85% and 92% respectively) than in the saline group (58%). However, there was no significant difference in withdrawal movement between the lidocaine and palonosetron groups. There was no severe movement with palonosetron. CONCLUSION: Pretreatment of palonosetron with venous occlusion may attenuate rocuronium-induced withdrawal movement as effective as the use of lidocaine. It suggested that peripheral action of palonosetron was effective to reduce rocuronium-induced withdrawal movement.

Complete genome sequence of Streptomyces venezuelae ATCC 15439, a promising cell factory for production of secondary metabolites.

Streptomyces venezuelae ATCC 15439, which produces 12- and 14-membered ring macrolide antibiotics, is a platform strain for heterologous expression of secondary metabolites. Its 9.05-Mb genome sequence revealed an abundance of genes involved in the biosynthesis of secondary metabolites and their precursors, which should be useful for the production of bioactive compounds.