Background: Gamma-glutamyltransferase is recognised as a biomarker to assess the harms associated with alcohol misuse. The objective ways to measure GGT in areas lacking central lab facilities are desirable. This stud...Background: Gamma-glutamyltransferase is recognised as a biomarker to assess the harms associated with alcohol misuse. The objective ways to measure GGT in areas lacking central lab facilities are desirable. This study aims to measure GGT from dried serum spots and its storage from dried serum spots. Method: The study was approved by the institutional ethical committee. One hundred and eighty (180) patients were included in the study. Their blood samples were collected. The serum samples were spotted onto filter paper (Whatman 903) dried and stored at 4°C. The GGT levels were measured on the day of collection and at various time periods to assess the effect of storage. All the analysis was performed on SPSS version 21. Result: The GGT levels measured from fresh serum GGT levels mean (SD) 286.5 (539.4) correlated well with their respective dried serum levels 287.18 (538.2) (P = 0.80). The mean recovery of GGT from dried serum was observed to be 103.3%. A sub-sample (n = 12) was stored at 4°C. The dried serum spots were found to be stable at the end of four weeks using repeated measure analysis of variance (ANOVA) (P = 0.39). Conclusion: This method has the potential to be used for epidemiological or field based studies to assess harms associated with alcohol use.展开更多
The present study aims at understanding the electrochemical impedance and biocorrosion characteristics of AZ91 Mg-alloy in Ringer’s solution.As-cast AZ91 Mg-alloy was subjected to T4 heat treatment in a way to homoge...The present study aims at understanding the electrochemical impedance and biocorrosion characteristics of AZ91 Mg-alloy in Ringer’s solution.As-cast AZ91 Mg-alloy was subjected to T4 heat treatment in a way to homogenize its microstructure by dissolving most of theβ-Mg 17 Al 12 phase at the vicinity of grain boundaries.The electrochemical impedance and biocorrosion performances of these two different microstructures(as-cast and T4 heat treated AZ91 Mg-alloys)in Ringer solution were evaluated by electrochemical impendence spectroscopy,potentiodynamic polarization and weight loss method.EIS spectra showed that both microstructures exhibit similar dynamic response as a function of the immersion time;however,the value of impedance and maximum phase angle are about 50%higher in as-cast AZ91 Mg-alloy as compared to that of homogenized AZ91 Mg-alloy.Weight loss measurement indicated that corrosion resistance of as-cast AZ91 was significantly better than that of homogenized AZ91.Microstructural and XRD analysis revealed that as-cast AZ91 contains a passive film of MgCO_(3)and CaCO_(3)precipitates with near spherical morphologies,whereas homogenized AZ91 comprised mainly unstable Mg(OH)_(2)film featured by irregular plate-like morphologies.展开更多
Received 16 July 2016;revised 24 January 2017;accepted 7 February 2017 Available online 22 February 2017 Abstract Microstructural evolution of die-cast and homogenized AZ91 Mg-alloys was investigated during dry slidin...Received 16 July 2016;revised 24 January 2017;accepted 7 February 2017 Available online 22 February 2017 Abstract Microstructural evolution of die-cast and homogenized AZ91 Mg-alloys was investigated during dry sliding wear condition.Tribological tests were performed using a pin-on-disc(EN8 steel)configuration with a normal load of 50 N at a constant sliding speed of 2.5 ms^(−1) under ambient environment.Delamination was recognized as a predominant wear mechanism in both of these materials.The die-cast AZ91 Mg-alloy exhibits lower coefficient of friction and higher wear rate.This can be ascribed to increase in the intensity of load bearing capacity of hardβ-Mg_(17)Al_(12) phase,and crack formation/de-cohesion at the interface between primaryα-Mg and discontinuousβ-Mg_(17)Al_(12) phases.On the contrary,the homogenized AZ91 Mg-alloy experiences higher coefficient of friction and lower wear rate.The friction-induced microstructural evolution(supersaturatedα-Mg to eutectic(α+β-Mg_(17)Al_(12)))tending to minimize the wear rate by providing barrier to material removal in the near surface region of homogenized AZ91 Mg-alloy.Therefore,experimental observation revealed that an inverse relationship exists between wear rate and coefficient of friction for the investigated materials.The analysis of worn surfaces and subsurfaces by electron microscopy provided evidence to delamination wear and microstructural evolution.展开更多
Larvae of several mosquito species being vectors of infectious diseases as adults feed on algae in their natural habitat. Algal food comes along with bioactive compounds providing important chemical defenses against p...Larvae of several mosquito species being vectors of infectious diseases as adults feed on algae in their natural habitat. Algal food comes along with bioactive compounds providing important chemical defenses against predators, competitors, and pathogens. Aedes aegypti (Linnaeus in Hasselquist, 1762) is commonly called yellow fever mosquito, being a vector of several fatal diseases such as dengue fever, zika fever, chikungunya, and yellow fever. In this study, we have investigated the susceptibility of larvae of A. aegypti mosquitos to three most commonly studied diatom aldehydes-2-trans, 4-trans heptadienal (HD), 2-trans, 4-trans octadienal (OD), and 2-trans, 4-trans-decadienal (DD). In the experiments, instar-I and -IV larvae of Ae. aegypti were exposed to above PUAs for different time intervals. Both mosquito instars were susceptible to HD, OD and DD. Instar-I larvae were more susceptible compared to instar-IV. The percentage of mortality of both instar larvae was higher with greater concentrations of each tested PUA. Furthermore, mosquito larvae, tested on DD applied medium was estimated to be more susceptible followed by OD and then by HD. After 24 h observation, LC 50 value was the lowest for DD (0.64 μL/40mL), followed by OD (0.88 μL/40mL) and HD (1.47 μL/40mL) respectively. In current scenarios, our results suggest that natural aldehydes from diatoms could provide promising public health benefits by controlling mosquito vector populations. Furthermore, an in-depth study of the interaction between primary producers and mosquito immatures in nature could provide several advancements in vector control research and management.展开更多
文摘Background: Gamma-glutamyltransferase is recognised as a biomarker to assess the harms associated with alcohol misuse. The objective ways to measure GGT in areas lacking central lab facilities are desirable. This study aims to measure GGT from dried serum spots and its storage from dried serum spots. Method: The study was approved by the institutional ethical committee. One hundred and eighty (180) patients were included in the study. Their blood samples were collected. The serum samples were spotted onto filter paper (Whatman 903) dried and stored at 4°C. The GGT levels were measured on the day of collection and at various time periods to assess the effect of storage. All the analysis was performed on SPSS version 21. Result: The GGT levels measured from fresh serum GGT levels mean (SD) 286.5 (539.4) correlated well with their respective dried serum levels 287.18 (538.2) (P = 0.80). The mean recovery of GGT from dried serum was observed to be 103.3%. A sub-sample (n = 12) was stored at 4°C. The dried serum spots were found to be stable at the end of four weeks using repeated measure analysis of variance (ANOVA) (P = 0.39). Conclusion: This method has the potential to be used for epidemiological or field based studies to assess harms associated with alcohol use.
文摘The present study aims at understanding the electrochemical impedance and biocorrosion characteristics of AZ91 Mg-alloy in Ringer’s solution.As-cast AZ91 Mg-alloy was subjected to T4 heat treatment in a way to homogenize its microstructure by dissolving most of theβ-Mg 17 Al 12 phase at the vicinity of grain boundaries.The electrochemical impedance and biocorrosion performances of these two different microstructures(as-cast and T4 heat treated AZ91 Mg-alloys)in Ringer solution were evaluated by electrochemical impendence spectroscopy,potentiodynamic polarization and weight loss method.EIS spectra showed that both microstructures exhibit similar dynamic response as a function of the immersion time;however,the value of impedance and maximum phase angle are about 50%higher in as-cast AZ91 Mg-alloy as compared to that of homogenized AZ91 Mg-alloy.Weight loss measurement indicated that corrosion resistance of as-cast AZ91 was significantly better than that of homogenized AZ91.Microstructural and XRD analysis revealed that as-cast AZ91 contains a passive film of MgCO_(3)and CaCO_(3)precipitates with near spherical morphologies,whereas homogenized AZ91 comprised mainly unstable Mg(OH)_(2)film featured by irregular plate-like morphologies.
文摘Received 16 July 2016;revised 24 January 2017;accepted 7 February 2017 Available online 22 February 2017 Abstract Microstructural evolution of die-cast and homogenized AZ91 Mg-alloys was investigated during dry sliding wear condition.Tribological tests were performed using a pin-on-disc(EN8 steel)configuration with a normal load of 50 N at a constant sliding speed of 2.5 ms^(−1) under ambient environment.Delamination was recognized as a predominant wear mechanism in both of these materials.The die-cast AZ91 Mg-alloy exhibits lower coefficient of friction and higher wear rate.This can be ascribed to increase in the intensity of load bearing capacity of hardβ-Mg_(17)Al_(12) phase,and crack formation/de-cohesion at the interface between primaryα-Mg and discontinuousβ-Mg_(17)Al_(12) phases.On the contrary,the homogenized AZ91 Mg-alloy experiences higher coefficient of friction and lower wear rate.The friction-induced microstructural evolution(supersaturatedα-Mg to eutectic(α+β-Mg_(17)Al_(12)))tending to minimize the wear rate by providing barrier to material removal in the near surface region of homogenized AZ91 Mg-alloy.Therefore,experimental observation revealed that an inverse relationship exists between wear rate and coefficient of friction for the investigated materials.The analysis of worn surfaces and subsurfaces by electron microscopy provided evidence to delamination wear and microstructural evolution.
文摘Larvae of several mosquito species being vectors of infectious diseases as adults feed on algae in their natural habitat. Algal food comes along with bioactive compounds providing important chemical defenses against predators, competitors, and pathogens. Aedes aegypti (Linnaeus in Hasselquist, 1762) is commonly called yellow fever mosquito, being a vector of several fatal diseases such as dengue fever, zika fever, chikungunya, and yellow fever. In this study, we have investigated the susceptibility of larvae of A. aegypti mosquitos to three most commonly studied diatom aldehydes-2-trans, 4-trans heptadienal (HD), 2-trans, 4-trans octadienal (OD), and 2-trans, 4-trans-decadienal (DD). In the experiments, instar-I and -IV larvae of Ae. aegypti were exposed to above PUAs for different time intervals. Both mosquito instars were susceptible to HD, OD and DD. Instar-I larvae were more susceptible compared to instar-IV. The percentage of mortality of both instar larvae was higher with greater concentrations of each tested PUA. Furthermore, mosquito larvae, tested on DD applied medium was estimated to be more susceptible followed by OD and then by HD. After 24 h observation, LC 50 value was the lowest for DD (0.64 μL/40mL), followed by OD (0.88 μL/40mL) and HD (1.47 μL/40mL) respectively. In current scenarios, our results suggest that natural aldehydes from diatoms could provide promising public health benefits by controlling mosquito vector populations. Furthermore, an in-depth study of the interaction between primary producers and mosquito immatures in nature could provide several advancements in vector control research and management.
