115 research outputs found

    Preparation and In vitro Evaluation of Isoniazid-Containing Dex-HEMA-Co-PNIPAAm Nanogels

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    In this work, Dex-HEMA-Co-PNIPAAm nanogels containing Isoniazid antibiotic were made. Characteristic features of nanogels were studied by Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and scanning electron microscopy (SEM). Drug loading capacity and entrapment efficiency were determined. In vitro drug release amount was estimated at room and body temperature. Biocompatibility of gels was investigated through cytotoxicity assay. Finally antimicrobial properties of synthesized gels were studied. It was shown from the experimental data that the nanogels size after drug loading increased about 1-2%. %Isoniazid loading and %entrapment efficiency were in the range of 15-22% and 37-48% respectively. After 10 days of degradation ca. 80% at 25ºC and ca. 90% at 37ºC of the nanogel structures were destructed. No significant toxic product produced while degradation and all nanogels depicted good biocompatibility. No antimicrobial features observed through the test condition against gram negative E Coli

    Women Volunteerism for Protecting Watershed Ecosystem in Langat Basin

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    Forested watershed provides abundant ecosystem services for water users including catchment area protection, flood regulation, provisioning of clean drinking water and climate regulation. However, the value of ecosystem services only partially takes into account by policy makers and indirectly cause overexploitation of natural resources. This study observes the economic role of women in protecting watershed ecosystem by calculating willingness to pay (WTP). Langat Basin is an imperative watershed that supplying fresh water source and other necessities to approximately 1.2 million people within the catchment area. Langat Basin has getting the effect of hasty growth through industrialization and land development actions. Women within Langat Basin has been selected through face to face interview for measure willingness to pay (WTP) towards ecosystem protection. Single Bounded Dichotomous Choice technique in Contingent Valuation Method (CVM) is engaged to calculate WTP of women. Willingness to pay of women in upstream is RM184.28, followed by women in middle stream is RM168.60 and lastly WTP of women in downstream is RM190.16. The willingness to pay women shows that women has potential to be part of ecosystem protection and signal to policy makers to include women in decision making process especially for environmental perspective

    Road transport system in Southeast Asia; problems and economic solutions

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    In Southeast Asian countries (SEA), road transport accounts for the main energy consumption and CO2 emission. Air pollution is a major concern in densely populated cities such as Bangkok, Manila, and Kuala Lumpur. The main objective of this paper is to give insights on trends of transport development, car ownership, and CO2 emissions in Southeast Asia. This study also attempts to review the successful transportation policies around the globe and to introduce the possible instruments that can help reduce air pollution in Southeast Asian countries. Economic instruments to estimate the benefits of a cleaner environment due to new policies are introduced as well. The results of this research could help policy makers consider approaches that could internalize external costs of transportation and maximize the societal welfare

    Road transport system in Southeast Asia; problems and economic solutions

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    In Southeast Asian countries (SEA), road transport accounts for the main energy consumption and CO2 emission. Air pollution is a major concern in densely populated cities such as Bangkok, Manila, and Kuala Lumpur. The main objective of this paper is to give insights on trends of transport development, car ownership, and CO2 emissions in Southeast Asia. This study also attempts to review the successful transportation policies around the globe and to introduce the possible instruments that can help reduce air pollution in Southeast Asian countries. Economic instruments to estimate the benefits of a cleaner environment due to new policies are introduced as well. The results of this research could help policy makers consider approaches that could internalize external costs of transportation and maximize the societal welfare

    Willingness to pay to improve air quality: a study of private vehicle owners in Klang Valley, Malaysia

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    The growing number of private passenger vehicles in the Klang region of Malaysia has not only resulted in persistent traffic congestion during peak hours, but also resulted in considerable vehicular emissions causing both environmental and human health hazards. To reduce these externalities, this study examines the prospect for a transport modal shift from the use of private vehicles to the public transport system. Contingent valuation method was used to estimate how much current private passenger vehicle users are willing to pay to continue using their private vehicles. On average, private passenger vehicle users were found to be willing to pay a maximum amount of RM 4.99 (USD 1.55) per trip to avoid using the public transport system. Respondents with previous health issues were found more likely to shift to the public transportation system. Public transportation efficiency was found to have a significant impact on the respondents WTP value to maintain the current commuting system

    Economic valuation of Shadegan International Wetland, Iran: notes for conservation

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    Wetlands are among the most productive ecosystems on the earth. They produce various market and non-market goods and services, which have a significant role in human welfare. Despite the great opportunities from sustainable development, wetlands all over the world are under serious threat from a diverse range of non-sustainable activities. One of the major reasons for excessive depletion and the conversion of wetland resources is due to underestimating the non-market values of wetlands during development decisions. Shadegan International Wetland (SIW) in southern Iran is one of these wetland areas that is threatened by undervaluation and overexploitation from commercial activities. This study utilizes the contingent valuation method to estimate the economic benefits of SIW from the view point of peoples’ willingness to pay (WTP). The logit model was defined based on dichotomous choice to measure individuals’ WTP. The estimated mean WTP was US$ 1.74 per household as a onetime donation. This study concludes that the benefits of SIW to society could encourage managers to set priorities to ensure that the health of the ecosystem, its integrity, and its uniqueness would be conserved in a proper manner

    Multivariate Multiscale Dispersion Entropy of Biomedical Times Series

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    Due to the non-linearity of numerous physiological recordings, non-linear analysis of multi-channel signals has been extensively used in biomedical engineering and neuroscience. Multivariate multiscale sample entropy (MSE–mvMSE) is a popular non-linear metric to quantify the irregularity of multi-channel time series. However, mvMSE has two main drawbacks: (1) the entropy values obtained by the original algorithm of mvMSE are either undefined or unreliable for short signals (300 sample points); and (2) the computation of mvMSE for signals with a large number of channels requires the storage of a huge number of elements. To deal with these problems and improve the stability of mvMSE, we introduce multivariate multiscale dispersion entropy (MDE–mvMDE), as an extension of our recently developed MDE, to quantify the complexity of multivariate time series. We assess mvMDE, in comparison with the state-of-the-art and most widespread multivariate approaches, namely, mvMSE and multivariate multiscale fuzzy entropy (mvMFE), on multi-channel noise signals, bivariate autoregressive processes, and three biomedical datasets. The results show that mvMDE takes into account dependencies in patterns across both the time and spatial domains. The mvMDE, mvMSE, and mvMFE methods are consistent in that they lead to similar conclusions about the underlying physiological conditions. However, the proposed mvMDE discriminates various physiological states of the biomedical recordings better than mvMSE and mvMFE. In addition, for both the short and long time series, the mvMDE-based results are noticeably more stable than the mvMSE- and mvMFE-based ones. For short multivariate time series, mvMDE, unlike mvMSE, does not result in undefined values. Furthermore, mvMDE is faster than mvMFE and mvMSE and also needs to store a considerably smaller number of elements. Due to its ability to detect different kinds of dynamics of multivariate signals, mvMDE has great potential to analyse various signals

    Age-specific periictal electroclinical features of generalized tonic-clonic seizures and potential risk of sudden unexpected death in epilepsy (SUDEP)

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    Generalized tonic–clonic seizure (GTCS) is the commonest seizure type associated with sudden unexpected death in epilepsy (SUDEP). This study examined the semiological and electroencephalographic differences (EEG) in the GTCSs of adults as compared with those of children. The rationale lies on epidemiological observations that have noted a tenfold higher incidence of SUDEP in adults.Weanalyzed the video-EEG data of 105 GTCS events in 61 consecutive patients (12 children, 23 seizure events and 49 adults, 82 seizure events) recruited from the Epilepsy Monitoring Unit. Semiological, EEG, and 3-channel EKG features were studied. Periictal seizure phase durations were analyzed including tonic, clonic, total seizure, postictal EEG suppression (PGES), and recovery phases. Heart rate variability (HRV)measures includingRMSSD (root mean square successive difference of RR intervals), SDNN (standard deviation of NN intervals), and SDSD (standard deviation of differences) were analyzed (including low frequency/high frequency power ratios) during preictal baseline and ictal and postictal phases. Generalized estimating equations (GEEs)were used to find associations between electroclinical features. Separate subgroup analyses were carried out on adult and pediatric age groups as well as medication groups (no antiepileptic medication cessation versus unchanged or reduced medication) during admission.Major differences were seen in adult and pediatric seizures with total seizure duration, tonic phase, PGES, and recovery phases being significantly shorter in children (p b 0.01). Generalized estimating equation analysis, using tonic phase duration as the dependent variable, found age to correlate significantly (p b 0.001), and this remained significant during subgroup analysis (adults and children) such that each 0.12-second increase in tonic phase duration correlated with a 1-second increase in PGES duration. Postictal EEG suppression durations were on average 28 s shorter in children. With cessation of medication, total seizure duration was significantly increased by a mean value of 8 s in children and 11 s in adults (p b 0.05). Tonic phase duration also significantly increased with medication cessation, and although PGES durations increased, this was not significant. Root mean square successive difference was negatively correlated with PGES duration (longer PGES durations were associated with decreased vagally mediated heart rate variability; p b 0.05) but not with tonic phase duration. This study clearly points out identifiable electroclinical differences between adult and pediatric GTCSs that may be relevant in explaining lower SUDEP risk in children. The findings suggest that some prolonged seizure phases and prolonged PGES duration may be electroclinical markers of SUDEP risk and merit further study

    Post-ictal Modulation of Baroreflex Sensitivity in Patients With Intractable Epilepsy

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    Objective: Seizure-related autonomic dysregulation occurs in epilepsy patients and may contribute to Sudden Unexpected Death in Epilepsy (SUDEP). We tested how different types of seizures affect baroreflex sensitivity (BRS) and heart rate variability (HRV). We hypothesized that BRS and HRV would be reduced after bilateral convulsive seizures (BCS).Methods: We recorded blood pressure (BP), electrocardiogram (ECG) and oxygen saturation continuously in patients (n = 18) with intractable epilepsy undergoing video-EEG monitoring. A total of 23 seizures, either focal seizures (FS, n = 14) or BCS (n = 9), were analyzed from these patients. We used 5 different HRV measurements in both the time and frequency domains to study HRV in pre- and post-ictal states. We used the average frequency domain gain, computed as the average of the magnitude ratio between the systolic BP (BPsys) and the RR-interval time series, in the low-frequency (LF) band as frequency domain index of BRS in addition to the instantaneous slope between systolic BP and RR-interval satisfying spontaneous BRS criteria as a time domain index of BRS.Results: Overall, the post-ictal modulation of HRV varied across the subjects but not specifically by the type of seizures. Comparing pre- to post-ictal epochs, the LF power of BRS decreased in 8 of 9 seizures for patients with BCS; whereas following 12 of 14 FS, BRS increased. Similarly, spontaneous BRS decreased following 7 of 9 BCS. The presence or absence of oxygen desaturation was not consistent with the changes in BRS following seizures, and the HRV does not appear to be correlated with the BRS changes. These data suggest that a transient decrease in BRS and temporary loss of cardiovascular homeostatic control can follow BCS but is unlikely following FS.Significance: These findings indicate significant post-ictal autonomic dysregulation in patients with epilepsy following BCS. Further, reduced BRS following BCS, if confirmed in future studies on SUDEP cases, may indicate one quantifiable risk marker of SUDEP
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