RESUMO
A high strength of polyving alcohol/polyacrylic acid double network gel (PVA/PAA gel) adsorbent was successfully prepared by a simple two-step method in this study. The gel adsorbent possessed the advantages of low cost and high adsorptivity for heavy metals in solution. The maximum uptake capacities of PVA/PAA gel were 194.99 mg/g for Pb(II) and 115.88 mg/g for Cd(II) inferred from the Langmuir model at 303 K. At the concentration levels of Pb(II)<150 mg/L and Cd(II)<100mg/L, the Pb(II) and Cd(II) could be completely adsorbed, showing a great potential of removing heavy metals from wastewater. Simultaneously, the PVA/PAA gel adsorbent exhibited an excellent reusability. Even in the fifth cycle, the removal efficiencies of both Pb(II) and Cd(II) remained nearly 100%. Significantly, the gel adsorbent displayed a satisfactory performance of removing heavy metals in actual industrial effluent. The results reveal that the double network gel can be considered as a potential candidate for practical application.
Assuntos
Ecossistema , Política Ambiental/legislação & jurisprudência , Poluição Ambiental/análise , Poluição Ambiental/legislação & jurisprudência , Indústrias/legislação & jurisprudência , Pobreza , China , Política Ambiental/economia , Poluição Ambiental/economia , Poluição Ambiental/prevenção & controle , Migração Humana , Resíduos Industriais/análise , Resíduos Industriais/economia , Resíduos Industriais/legislação & jurisprudência , Indústrias/tendênciasRESUMO
UNLABELLED: Assessment of Ventricular Electrophysiological Characteristics. INTRODUCTION: The aim of this study was to investigate the characteristics of ventricular electrophysiology following stellate ganglion block (SGB) at periinfarct zone in rabbits with myocardial infarction (MI). METHODS AND RESULTS: Sixty-four rabbits were randomly assigned to 2 groups: MI (n = 32), ligation of the anterior descending coronary and sham operation (SO) (n = 32), without coronary ligation. Both MI and SO groups were divided into 4 subgroups according to right or left SGB and corresponding control (n = 8, each). After 8 weeks, 90% of monophasic action potential duration (MAPD90) of epicardium, midmyocardium and endocardium, transmural dispersion of repolarization (TDR), effective refractory period (ERP), and ventricular fibrillation threshold (VFT) were measured at the infarct border zone (MI group) and corresponding zone (SO group) following SGB. For SGB, 0.5 mL of 0.25% bupivacaine was used. Compared with the corresponding control group, in both the MI and SO groups, left SGB (LSGB) prolonged the MAPD90 of the 3 layers, reduced TDR, and increased ERP and VFT (P < 0.05). However, right SGB (RSGB) shortened MAPD90, increased TDR, and reduced ERP and VFT (P < 0.05). CONCLUSION: The results of this study demonstrate that LSGB can increase the electrophysiological stability of ventricular myocardium.
Assuntos
Arritmias Cardíacas/prevenção & controle , Bloqueio Nervoso Autônomo , Técnicas Eletrofisiológicas Cardíacas , Ventrículos do Coração/fisiopatologia , Infarto do Miocárdio/fisiopatologia , Gânglio Estrelado/fisiopatologia , Função Ventricular , Potenciais de Ação , Anestésicos Locais , Animais , Arritmias Cardíacas/etiologia , Arritmias Cardíacas/fisiopatologia , Bloqueio Nervoso Autônomo/métodos , Bupivacaína , Modelos Animais de Doenças , Endocárdio/patologia , Endocárdio/fisiopatologia , Feminino , Ventrículos do Coração/inervação , Ventrículos do Coração/patologia , Masculino , Infarto do Miocárdio/complicações , Infarto do Miocárdio/patologia , Miocárdio/patologia , Pericárdio/patologia , Pericárdio/fisiopatologia , Coelhos , Período Refratário Eletrofisiológico , Fatores de TempoRESUMO
Primula nutans Georgi is widely distributed in hummock-and-hollow wetlands on the Qinghai-Tibetan Plateau. To assess the ecophysiology of this species in responding to microenvironments, we examined the photosynthetic characteristics and individual carbon gain of plants growing in different microsites from a hummock-and-hollow wetland on the Qinghai-Tibetan Plateau and under laboratory conditions. Plants from wetland hummock microsites showed significantly higher light-saturated photosynthetic CO(2) uptake (A (max)) than those from microsites in hollows at a controlled temperature of 15 degrees C in leaf chamber. Leaf dark respiration rate (R) was only significantly higher in plants from hummocks than hollows at the measuring temperature of 35 degrees C. Optimum temperature for A (max) was 15 degrees C for all plants in the field despite different microsites. In plants growing under laboratory conditions differing in light and temperature, both A (max) and R were significantly higher under higher growth light (photosynthetic photon flux density, PPFD: 800 or 400 micromol m(-2) s(-1)) than low light of 90 micromol m(-2) s(-1). No statistically significant differences in A (max) and R existed in plants differing in growing temperatures. Estimates derived from the photosynthetic parameters of field plants, and microsite environmental measures including PPFD, air temperature and soil temperature showed that the optimum mean daily temperature for net daily carbon gain was around 10 degrees C and the net daily carbon gain was largely limited under lower daily total PPFD. These results suggest that the differences in A (max) and R in P. nutans are strongly affected by growing light regimes but not by temperature regimes.