Fotodegradasi fenol dan 4-klorofenol dalam air menggunakan titanium dioksida

Pencemaran sumber air merupakan masalah utama kepada keperluan air minuman dan kehidupan akuatik pada masa kini. Pelbagai teknologi digunakan untuk merawat sumber air. Salah satu kaedah tersebut ialah dengan menggunakan semikonduktor TiO₂ sebagai fotomangkin dalam fotodegradasi sebatian organik. Dalam kajian ini fotodegradasi fenol dan 4-klorofenol menggunakan serbuk mangkin TiO₂ dan TiO₂ (sol-gel) yang dipegunkan di atas kaca (TiO₂/kaca) digunakan. Pemegunan Ti02/kaca dilakukan dengan dua kaedah; iaitu berdasarkan bilangan celupan TiO₂/kaca dan berdasarkan amaun TiO₂. Didapati dengan menggunakan serbuk mangkin TiO₂ kadar fotodegradsi 20 ppm fenol mencapai 73.0% dan 4-klorofenol ialah 97.4%. Kadar fotodegradasi fenol mencapai 30.5% dengan menggunakan kaedah bilangan celupan TiO₂/kaca dimana pencelupan kaca dilakukan sebanyak 8x. Manakala dengan menggunakan kaedah berdasarkan amaun TiO₂/kaca didapati kadar fotodegradasi fenol mencapai 43.4% apabila jisim TiO₂ yang dipegunkan di atas kaca mencapai jisim maksimum iaitu 0.077 ± 0.003 g. Apabila amaun TiO₂/kaca meningkat kadar fotodegradasi fenol juga meningkat. Peningkatan suhu pengkalsinan TiO₂/kaca memberikan keputusan perkadaran songsang dim ana peningkatan suhu pengkalsinan mengurangkan kadar fotodegradasi fenol. Pada suhu pengkalsinan yang tinggi didapati berlakunya penanggalan TiO₂ yang dipegunkan ke atas kaca. Namun kesan kenaikan suhu larutan fenol dan 4-klorofenol menunjukkan perkadaran terus, dim ana kenaikan suhu 30°C hingga 50°C masing-masing dapat meningkatkan kadar fotodegradasi fenol sebanyak 15.8% dan 12.2% bagi 4-klorofenol. Kesan penambahan ion-ion K⁺, Na⁺, Ca²⁺ dan Zn²⁺ kepada larutan fenol terhadap kadar fotodegradasi juga dikaji. Didapati dengan menggunakan serbuk TiO₂ kadar fotodegradasi meningkat apabila ion K⁺ dan Ca²⁺ dengan kepekatan 0.01 M dan ion Zn²⁺ dengan kepekatan 0.001 M ditambahkan. Tetapi dengan penambahan ion Na+ ianya didapati merencatkan kadar fotodegradasi fenol. Manakala dengan menggunakan amaun TiO₂/kaca pula, penambahan ion Ca 2⁺ merencatkan kadar fotodegradasi fenol dan 4-klorofenol. Sementara penambahan ion K⁺ pada kepekatan 0.01 M pula dapat meningkatkan kadar fotodegradasi 4-klorofenol

The Use of Prasugrel and Ticagrelor in Pipeline Flow Diversion

Background: Despite the routine clopidogrel/aspirin anti-platelet therapy, complications like thromboembolism, continue to be encountered with PED. We studied the safety and the efficacy of prasugrel in the management of clopidogrel non-responders treated for intracranial aneurysms. Methods: 437 consecutive neurosurgery patients were identified between January 2011 and May 2016. Patients allergic or having \u3c30% platelet-inhibition with a daily 75mg of clopidogrel were dispensed 10mg of prasugrel daily (n=20) or 90mg of ticagrelor twice daily (n=2). The average follow-up was 15.8 months (SD=12.4 months). Patient clinical well being was evaluated with the modified Rankin Scale (mRS) registered before the discharge and at each follow-up visit. To control confounding we used multivariable mixed-effects logistic regression and propensity score conditioning. Results: 26 of 437(5.9%) patients (mean of age 56.3 years; 62 women [14,2%]) presented with a sub-arachnoid hemorrhage. 1 patient was allergic to clopidogrel and prasugrel simultaneously. All the patients receiving prasugrel (n=22) had a mRS\u3c2 on their latest follow-up visit (mean=0.67; SD=1.15). In a multivariate analysis, clopidogrel did not affect the mRS on last follow-up, p=0.14. Multivariable logistic regression showed that clopidogrel was not associated with an increased long-term recurrence rate (odds ratio[OR], 0.17; 95%Confidence Interval [CI95%], 0.01-2.70; p=0.21) neither with an increased thromboembolic accident rate (OR, 0.46; CI95%, 0.12-1.67; p=0.36) nor with an increased hemorrhagic event rate (OR, 0.39; CI95%,0.91-1.64; p=0.20). None of the patients receiving prasugrel deceased or had a long-term recurrence nor a hemorrhagic event, only 1 patient suffered from mild aphasia subsequent to a thromboembolic event. 3 patients on clopidogrel passed during the study: (2) from acute SAH and (1) from intra-parenchymal hemorrhage. Clopidogrel was not associated with an increased mortality rate (OR, 2.18; CI95%,0.11-43.27; p=0.61). The same associations were present in propensity score adjusted models. Conclusion: In a cohort of patients treated with PED for their intracranial aneurysms, prasugrel (10mg/day) is a safe alternative to clopidogrel resistant, allergic or non-responders

Effect of iron on photocatalytic properties of titanium dioxide

Technological advancements and population growth are placing enhanced stress on global energy resources. At the same time, the increasingly apparent negative effects of climate change indicate the need to generate clean energy, such as solar energy. This thesis is an attempt in making a contribution towards the development of materials for solar energy conversion. The present technology of solar devices is focused on silicon-based solar cells. Awareness is growing, however, that titanium dioxide, TiO2, is a promising candidate as a raw material for processing a new generation of solar materials that can be applied for solar-to-chemical energy conversion. The pioneering work of Fujishima and Honda [1] indicates that TiO2 may be used as photo-electrode for the generation of hydrogen fuel by water oxidation. The report of Fujishima and Honda resulted in intensive studies on processing TiO2 with enhanced performance in solar energy conversion. TiO2 exhibits an outstanding stability in water and, at the same time, strong reactivity with water upon UV irradiation leading to its oxidation. The main shortcoming of TiO2 for sunlight absorption is its relatively large band gap, which is 3.0 eV and 3.2 eV for rutile and anatase, respectively, while the maximum efficiency of solar energy conversion can be achieved at 1.5 eV. Therefore, the most commonly reported research aims at reduction of the band gap of TiO2 by incorporation of extrinsic ions The recent progress in photocatalysis indicates that the efficiency of solar-to chemical energy conversion by TiO2-based semiconductors is determined by a range of key performance-related properties (KPPs), including the concentration of surface active sites, Fermi level, charge transport, and charge transfer, in addition to the band gap [4, 5]. All these KPPs are defect-related. Therefore, processing the TiO2-based photocatalysts with enhanced performance imposes the need to better understand the effect of defect disorder on the reactivity of TiO2 and its solid solutions with water. When considering the effect of extrinsic ions on properties of TiO2, it is important to realize that the surface composition, which is mainly responsible for photocatalytic activity, is entirely different from that of the bulk phase as a result of segregation [6]. Recognition of this effect imposes the need to understand the effect of segregation on surface vs. bulk composition of TiO2-based solid solutions. The present work aims at understanding the effect of extrinsic ions, specifically iron ions, on electronic structure, surface vs. bulk composition, and photocatalytic activity of TiO2

Assessing a 600-mg Loading Dose of Clopidogrel 24 Hours Prior to Pipeline Embolization Device Treatment

Background: Clopidogrel/aspirin antiplatelet therapy routinely is administered 7-10 days before pipeline aneurysm treatment. Our study assessed the safety and efficacy of a 600-mg loading dose of clopidogrel 24 hours before Pipeline Embolization Device (PED) treatment. Methods: In this retrospective cohort study, we included patients treated with PED from October 2010 to May 2016. A total of 39.7% (n = 158) of patients were dispensed a loading dose of 650 mg of aspirin plus at least 600 mg of clopidogrel 24 hours preceding PED deployment, compared to 60.3% (n = 240) of patients who received 81-325 mg of aspirin daily for 10 days with 75 mg of clopidogrel daily preprocedurally. The mean follow-up was 15.8 months (standard deviation [SD] 12.4 months). modified Rankin Scale (mRS) was registered before the discharge and at each follow-up visit. To control confounding, we used multivariable logistic regression and propensity score conditioning. Results: Of 398 patients, the proportion of female patients was ~16.5% (41/240) in both groups and shared the same mean of age ~56.46 years. ~12.2% (mean = 0.09; SD = 0.30) had a subarachnoid hemorrhage. 92% (mean = 0.29; SD = 0.70) from the pretreatment group and 85.7% (mean = 0.44; SD = 0.91) of the bolus group had a mRS ≤2. In multivariate analysis, bolus did not affect the mRS score, P = 0.24. Seven patients had a long-term recurrence, 2 (0.83%; mean = 0.01; SD = 0.10) of which from the pretreatment group. In a multivariable logistic regression, bolus was not associated with a long-term recurrence rate (odds ratio [OR] 1.91; 95% confidence interval [CI] 0.27-13.50; P = 0.52) or with thromboembolic accidents (OR 0.99; 95% CI 0.96-1.03; P = 0.83) nor with hemorrhagic events (OR 1.00; 95% CI 0.97-1.03; P = 0.99). Three patients died: one who received a bolus had an acute subarachnoid hemorrhage. The mean mortality rate was parallel in both groups ~0.25 (SD = 0.16). Bolus was not associated with mortality (OR 1.11; 95% CI 0.26-4.65; P = 0.89). The same associations were present in propensity score-adjusted models. Conclusions: In a cohort receiving PED, a 600-mg loading dose of clopidogrel should be safe and efficacious in those off the standard protocol or showing \u3c30% platelet inhibition before treatment

ファスディルとシルデナフィルの併用療法はモノクロタリン誘発性ラット肺高血圧の予後を改善する

Tohoku University下川宏明課

The Long-run and Causal Relationship among Financial Development, Openness and Economic Growth in Bangladesh: An ARDL Bound Testing and Granger Causality Approach

This study examines the long run and causal relationship between economic growth, financial development and openness in Bangladesh by using autoregressive distributed lag (ARDL) bound testing approach of cointegration and error-correction based Granger causality model. For this purpose, time series data for the relevant variables covering the period 1974 to 2009 are used in the estimation.  The bounds F-test for cointegration test yields evidence of a long-run relationship between economic growth, financial development and openness in Bangladesh. The results show that the long-run estimates of gross domestic product with respect to financial development and trade openness are positive at 1% level of significant. So, an increase in domestic credit to private sector, and foreign trade to GDP ratio, results in an increase in gross domestic product in the long-run. The cumulative sum and cumulative sum of squares tests show that the estimated parameters are stable for the sample period. A causal relationship is found from openness (foreign trade) to financial development and financial development (domestic credit to private sector) to gross domestic product. Keywords: Economic growth, financial development, trade openness, Bangladesh

The Long-Run and Causal Relationship among Financial Development, Openness and Economic Growth in Bangladesh: An ARDL Bound Testing and Granger Causality Approach

This study examines the long run and causal relationship between economic growth, financial development and openness in Bangladesh by using autoregressive distributed lag (ARDL) bound testing approach of cointegration and error-correction based Granger causality model. ARDL bounds test approach for cointegration is run with Microfit software; ADF, PP unit root tests are carried out with STATA12 software and Granger causality test (VEC model) is done with Eviews9 software. The bounds F-test for cointegration test yields evidence of a long-run relationship between economic growth, financial development and openness. The results show that the long-run estimates of gross domestic product with respect to financial development and trade openness are positive at 1% significant level. So an increase in domestic credit to private sector and foreign trade to GDP ratio results in an increase in gross domestic product in the long-run. The cumulative sum and cumulative sum of squares tests show that the estimated parameters are stable for the sample period. A causal relationship is found from openness (foreign trade) to financial development and financial development (domestic credit to private sector) to gross domestic product. Keywords: Economic growth, financial development, trade openness, Bangladesh

Foreign Bias in the Global Portfolio Investment of Selected OIC Countries

Home bias reflects the propensity of investors to invest substantially in the domestic market. When investing abroad investors exhibit foreign bias, a tendency to overweight certain foreign markets based on their preferences. A thorough review of the literature reveals that foreign bias has not been thoroughly investigated in emerging countries, especially in the context of OIC countries.  The purpose of this research is to examine the determinants of foreign bias in the global portfolio investment of selected OIC countries. An unbalanced bilateral panel data of 12 OIC countries’ outward equity investment in 74 host countries from the year 2001 to 2016 is analyzed. Cross-sectional analysis shows that OIC countries exhibit higher foreign bias towards their OIC counterparts especially in the MENA region. The results suggest, OIC countries not only exhibit foreign bias but also demonstrate regional bias. System Generalized Method of Moments (GMM) empirically shows that foreign bias is possibly explained by factors related to financial market openness, familiarity, information asymmetry, and global financial crisis. This study has a significant implication for the investors, fund managers and the regulators of the OIC countries. Investors and fund managers in OIC countries should be aware of the existence of foreign bias in their global portfolio investment that may potentially reduce the benefits of optimal diversification. It is a call for policymakers in the OIC countries to convince their local investors that international portfolio diversification offers risk sharing and eventually increases investment return.&nbsp

Carotid Endarterectomy Under Local Anesthesia: An Alternative Treatment for Carotid Stenosis

Purpose. Carotid artery stenosis accounts for approximately 10% of all ischemic strokes, causing significant morbidity and mortality. Historically the standard of care for surgical candidates for carotid stenosis was carotid endarterectomy, traditionally done under general anesthesia. As carotid stenting becomes an established less invasive modality of treatment, we investigated carotid endarterectomy under local anesthesia as an alternative option. Methods. We conducted a retrospective review of medical charts for patients undergoing carotid endarterectomy at a large community hospital from July 2007 to June 2010. 30-day postoperative myocardial infarctions and strokes were evaluated for patients undergoing carotid endarterectomy under local anesthesia, compared to carotid endarterectomy under general anesthesia. Carotid artery shunting and preoperative stroke were also evaluated as risk factors for postoperative myocardial infarction and stroke. Fisher exact tests were calculated to compare postoperative outcomes between patient groups. Results. A total of 407 carotid endarterectomies under local anesthesia and 256 carotid endarterectomies under general anesthesia were included in the analysis. Age, sex, and occurrence of preoperative stroke were similar between study groups. General anesthesia patients were more likely to receive a shunt (82% vs 11%, P\u3c.001). General anesthesia patients had higher rates of postoperative myocardial infarction (1.2% vs 0%, P=.057) and stroke (2.3% vs 0.7%, P=.095), but these differences were not statistically significant. Patients with a shunt also had non-significantly higher rate of postoperative stroke (2.3% vs 0.7%, P=.096). Conclusions. Our evidence suggests that carotid endarterectomy under local anesthesia can be an effective alternative for carotid stenosis with a possibly better safety profile than carotid endarterectomy under general anesthesia. Larger randomized studies are needed to further evaluate these complications