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Seroprevalence of Anti-Leptospira IgG and IgM Antibodies and Risk Assessment of Leptospirosis among Urban Poor Communities in Kuala Lumpur, Malaysia
No full textLeptospirosis is a zoonotic bacterial disease caused by pathogenic species of the genus Leptospira. Disease incidenceisknowntobeattributed toenvironmental and social conditions which promote the spread ofreservoir hosts, primarily rodents. A well-being program was conducted to determine the seroprevalence and risk factors associated with leptospirosis inurban poor communities occupying low-cost flat accommodation and squatter settlements in the vicinity of Wilayah Persekutuan, Kuala Lumpur. Blood samples from a total of 532 volunteers were screened for the detection of IgG and IgM antibodies against leptospirosis using ELISA. Demographic data were collected for each participant through a questionnaire survey before blood collection. The overall seroprevalence was low (12.6%, n = 67/532; 95% CI: 9.9-15.7%), with 8.1% (n=43/532) being seropositive for anti-Leptospira Ig G, indicating previous infection, and 4.9% (n = 26/532) for anti-Leptospira Ig M, indicating current infection. Two significant factors such as host age (P ≤ 0.01) and knowledge of disease transmission (P = 0.017) significantly influenced the presence of anti-Leptospira Ig M, whereas the detection of anti-IgG indicated the presence of clean drinking water sources (P = 0.043). Despite the low prevalence, the transmission of leptospirosis does occur among urban poor communities, suggesting the need for undertaking public awareness programs. Copyright © 2019 by The American Society of Tropical Medicine and Hygiene
Prevalence of extracranial carotid atherosclerosis in the patients with coronary artery disease in a tertiary hospital in Malaysia
No full textThere is limited information regarding the prevalence of extracranial carotid atherosclerosis in the patients with coronary artery disease (CAD) undergoing coronary artery bypass graft (CABG) surgery in South East Asia. The primary objective was to assess the prevalence of extracranial carotid stenosis, raised carotid intima media thickness (CIMT), and plaques in the patients with CAD undergoing elective CABG. The secondary objective was to evaluate the risk factors for extracranial carotid atherosclerosis.A total of 119 consecutive patients with CAD undergoing elective CABG in a tertiary hospital in Malaysia were recruited. Data on the demographic characteristics and risk factors were collected. The ultrasound carotid Doppler findings comprising of raised CIMT, plaques, and stenosis in the extracranial carotid vessels were recorded.The mean age of the patients was 64.26 ± 10.12 (range 42-89). Most of the patients were men (73.1%). The patients consisted of 44 (37%) Malays, 26 (21.8%) Chinese, and 49 (41.2%) Indians.A total of 67 (56.3%) patients had raised CIMT, 89 (74.8%) patients had plaques, and 10 (8.4%) patients had stenosis in the internal and common carotid arteries. The mean age of patients with plaques was higher compared to those without plaques (66.00 ± 9.63 vs 59.10 ± 9.92, P = .001). The body mass index (BMI) of patients with stenosis was higher compared to those without stenosis (28.35 ± 4.92 vs 25.75 ± 3.16, P = .02).The patients with plaques were more likely to be older, whereas the patients with carotid stenosis were more likely to have higher BMI
Tungsten disulfide coated microfiber as saturable absorber for Q-switched pulses generation
No full textQ-switched fiber laser was demonstrated by using tungsten disulfide (WS2) two-dimensional nanomaterials as a passive saturable absorber (SA) to modulate the loss inside the laser cavity. The SA was produced by repeatedly dropping and drying the WS2 solution onto microfiber to form a nanosheets layer. The WS2 coated microfiber is inserted into the ring laser cavity configured with a 2.4 m long Erbium-doped fiber (EDF) as the gain medium to generate Q-switching pulses train operating at 1568 nm. The Q-switched laser produced a pulse train, which the repetition rate is tunable from 62.0 kHz to 78.0 kHz as the pump power is raised from 151 to 193 mW. The minimum pulse width of 4.72 μs and the maximum pulse energy of 20.5 nJ was obtained at 193 mW pump power. The generated Q-switching pulses are stable and thus it is suitable for use in many practical applications. © 2019, S.C. Virtual Company of Phisics S.R.L. All right reserved
Exploring ligand-protein interaction: A laboratory exercise on herbicide binding to plasma transport protein
No full textA laboratory exercise on the interaction between the herbicide pendimethalin (PM) and goat serum albumin (GSA), a carrier protein present in mammalian blood circulation, is described. Fluorescence spectroscopy was used to study the binding reaction between PM and GSA. Titration of a constant amount of the protein (GSA) with increasing ligand (PM) concentrations produced a consecutive decrease in the protein's fluorescence. Treatment of the fluorescence quenching data according to the Stern–Volmer equation yielded the values of the Stern–Volmer constant (K sv ) and bimolecular quenching rate constant (k q ), whereas values of the binding constant (K a ) and number of binding sites (n) were obtained from the double logarithmic plot. This experiment provides an exciting opportunity for undergraduate students to independently perform ligand binding studies with a protein, in addition to providing the means for the determination of their binding parameters. © 2019 International Union of Biochemistry and Molecular Biology, 47(2): 156–160, 2019. © 2019 International Union of Biochemistry and Molecular Biolog
InGaAs based heterojunction phototransistors: Viable solution for high-speed and low-noise short wave infrared imaging
No full textHighly sensitive and fast imaging at short-wavelength infrared (SWIR) is one of the key enabling technologies for the direct-imaging of habitable exoplanets. SWIR imaging systems currently available in the market are dominated by imagers based on InGaAs PIN photodiodes. The sensitivity of these cameras is limited by their read-out noise (RON) level. Sensors with internal gain can suppress the RON and achieve lower noise imaging. In this paper, we demonstrate a SWIR camera based on 3D-engineered InP/InGaAs heterojunction phototransistors with responsivities around 2000 A/W which provides a shot-noise limited imaging sensitivity at a very low light level. We present the details of the semiconductor structure, the microfabrication, and the heterogeneous integration of this camera. The low capacitance pixels of the imager achieve 36 electron effective RON at frame rates around 5 kilo-frames per second at an operating temperature of 220 K and a bias voltage of 1.1 V. This is a significant step toward achieving highly sensitive imaging at SWIR at high frame rates and noncryogenic operating temperatures. Based on the proposed modeling and experimental results, a clear path to reach the RON less than 10 electrons is presented. © 2019 Author(s)
A Quantity–Quality Model to Assess the Effects of Source Control Stormwater Management on Hydrology and Water Quality at the Catchment Scale
No full textThe vast development of urban areas has resulted in the increase of stormwater peak runoff and volume. Water quality has also been adversely affected. The best management practices (BMPs) and low impact development (LID) techniques could be applied to urban areas to mitigate these effects. A quantity-quality model was developed to simulate LID practices at the catchment scale using the US Environmental Protection Agency Storm Water Management Model (US EPA SWMM). The purpose of the study was to investigate the impacts of LID techniques on hydrology and water quality. The study was performed in BUNUS catchment in Kuala Lumpur, Malaysia. This study applied vegetated swale and rain garden to assess the model performance at a catchment scale using real field data. The selected LIDs occupied 7% of each subcatchment (of which 40% was swale and 30% was rain garden). The LID removal efficiency was up to 40% and 62% for TN and TSS, respectively. The peak runoff reduction was up to 27% for the rainfall of up to 70 mm, and up to 19% for the rainfall of between 70 and 90 mm, respectively. For the longer storm events of higher than 90 mm the results were not as satisfactory as expected. The model was more effective in peak runoff reduction during the shorter rainfall events. As for the water quality, it was satisfactory in all selected rainfall scenarios. © 2019 by the authors
Indolenine – dibenzotetraaza [14] annulene Ni (II) complexes as sensitizers for dye - sensitized solar cells
No full textA new series of macrocyclic Ni (II) complexes having indolenine and dibenzotetraaza [14] annulene (DBTAA) moieties were synthesized and tested for their application as sensitizers in dye - sensitized solar cells (DSSCs). The structures are furnished with anchoring groups of ethyl ester (8a, 8b, and 8c) or carboxylic acid (9c) on the indolenine moiety and hexyloxy (8b) or neopentyloxy (8c, 9c) groups on the DBTAA moiety. The best performance was exhibited by dye 9c, which under constant AM 1.5G solar simulation (100 mW cm −2 ) using I − /I 3 − electrolyte gave a short-circuit current J sc = 0.43 mA cm −2 , an open-circuit voltage V oc = 0.41 V and a fill factor FF = 0.528, corresponding to an overall conversion efficiency of η = 0.093%. This is the first investigation of macrocyclic DBTAA derivatives as sensitizers for DSSCs applications. © 2019 Elsevier Lt
Baseline Central Visual Field Defect as a Risk Factor For NTG Progression
No full textPrecis:This 5-year follow-up study on normal-tension glaucoma (NTG) patients demonstrated that those with baseline central visual field (VF) defect progress at a more increased rate compared with those with peripheral field defect.Purpose:The purpose of this study was to investigate the clinical characteristics, including 24-hour ocular perfusion pressure and risk of progression in patients with baseline central VF defect, as compared with those with peripheral VF defect in NTG.Design:This was a prospective, longitudinal study.Methods:A total of 65 NTG patients who completed 5 years of follow-up were included in this study. All the enrolled patients underwent baseline 24-hour intraocular pressure and blood pressure monitoring via 2-hourly measurements in their habitual position and had ≥5 reliable VF tests during the 5-year follow-up. Patients were assigned to two groups on the basis of VF defect locations at baseline, the central 10 degrees, and the peripheral 10-to 24-degree area. Modified Anderson criteria were used to assess global VF progression over 5 years. Kaplan-Meier analyses were used to compare the elapsed time of confirmed VF progression in the two groups. Hazard ratios for the association between clinical risk factors and VF progression were obtained by using Cox proportional hazards models.Results:There were no significant differences between the patients with baseline central and peripheral VF defects in terms of demography, clinical, ocular and systemic hemodynamic factors. Eyes with baseline defects involving the central fields progressed faster (difference: central=-0.78 dB/y, 95% confidence interval=-0.22 to-1.33, P=0.007) and have 3.56 times higher hazard of progressing (95% confidence interval=1.17-10.82, P=0.025) than those with only peripheral defects.Conclusion:NTG patients with baseline central VF involvement are at increased risk of progression compared with those with peripheral VF defect. © 2019 Lippincott Williams and Wilkins. All rights reserved
Genomic analysis of Hepatitis B virus and its association with disease manifestations in Bangladesh
No full textThe direct cytopathic effects of the hepatitis B virus (HBV) on subsequent liver damage are not fully understood in HBV-infected patients. However, associations between the prevalence of various HBV genotypes and the extent of liver damage have been reported from different parts of the world. The purpose of this study was to determine the distribution of HBV genotypes in patients with chronic HBV infection in Bangladesh, a country of 160 million people, of which approximately 3–6 million are chronically infected HBV patients. In addition, whole and partial genome sequencing of HBV was performed to evaluate the relationship between HBV mutations and genotypes. We found that 42% of the patients with low HBV DNA and normal levels of alanine aminotransferase (ALT) had HBV genotype D. In contrast, the HBV genotype C was dominant among patients with high HBV DNA levels (>2000 IU/ ml) and elevated ALT and in patients with liver cirrhosis (LC) and hepatocellular carcinomas (HCC). Whole and partial genome sequences of HBV revealed that most patients with LC and HCC had HBV genotype C with mutations at the T1762/A1764 positions. It seems that Bangladesh represents a borderline country, situated within East Asia, which mainly consists of individuals with HBV genotypes B and C, whereas in the western parts of Asia, HBV genotypes A and D are prevalent. Bangladesh is, therefore, an excellent model for the comparison of the pathophysiology of three major HBV genotypes in a single population. The findings of this study suggest a possible association between HBV viral factors and the extent of liver damage in chronic HBV-infected patients. © 2019 Raihan et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
الصلاح والأصلح عند المعتزلة والماتريديّة: دراسة مقارنة بين الزّمخشريّ في الكشاف والنّسفيّ في مدارك التنزيل = Al-salah wa al-aslah according to al-mu’tazilah and al-maturidiyyah: A comparative study between al-zamakhshari in al-kashshaf and al-nasafi in madarik al-tanzil
No full textAl-Salah wa al-Aslah is the subject of debate between al-Mu’tazilah and al-Maturidiyyah. It was also discussed by al-Zamakhshari in al-Kashshaf and al-Nasafi in Madarik al-Tanzil. This paper uses the method of data collection and comparative analysis to discuss the general concept of al-Salah wa al-Aslah according to al-Mu’tazilah and al-Maturidiyyah by making comparisons between the two figures. The study found that al-Zamakhshari agreed with the majority of al-Mu`tazilah who said that al-Salah wa al-Aslah is obligatory to Allah SWT based on the law of reason which decides that the wisdom of His actions leads to the obligation to protect the maslahah of the servant. Although al-Nasafi and al-Maturidiyyah agreed that Allah’s SWT actions have wisdom, al-Nasafi did not agree that Allah is obliged to al-Salah wa al-Aslah. This is because all the acts of Allah are right and the servants have no right to dispute it. © 2019, University of Malaya. All rights reserved