Three new compounds of dibutyltin(IV) with N-alkylcyclohexyldithiocarbamate were successfully synthesized using in situ methods. Elemental analysis data of these complexes were in agreement with the general formula of (C4H9)2Sn[S2CNR(C6H11)]2 (R = CH3, C2H5, i-C3H7). Infrared spectra showed that the thioureide bands, ν(C=N) appeared
in the region of 1475 - 1479 cm-1, ν(C=S) bands in the region of 978 - 998 cm-1 and ν(Sn-S) bands in the region of 375 – 389 cm-1. Crystal structure of dibutyltin(IV) ethylcyclohexyldithiocarbamate showed a triclinic system and space group P-1. The crystal structure of the dithiocarbamate ligands were bidentically chelated to the tin atom with Sn-S unsymmetrical: Sn(1)-S(1) = 2.9255(11) and Sn(1)-S(2) = 2.5419(10); Sn(1)-S(3) = 2.8922(9) and Sn(1)-S(4) = 2.5293(10)Å. These compounds were screened for antibacterial activity against four bacteria species using the disc diffusion method. The results showed that (C4H9)
2Sn[S2CN(i-C3H7)(C6H11)]2 was mildly active against those three bacteria. Whereas all of
these compounds exhibited in vitro cytotoxicity activity toward human leukemic promyelocites HL-60 cell line with CD50 values lower than 1.00 µg/mL.
Gynura procumbens, a medicinal plant locally known as Sambung nyawa, is widely used traditionally in South East Asia as a remedy to alleviate symptoms of various ailments including diabetes mellitus. Previous investigators reported that the ethanol plant extract was hypoglycemic in streptozotocin (STZ)-induced diabetic rats and suggested the blood glucose-reducing effect could be due to G. procumbens mimicking insulin effects. Our present study aimed to reevaluate the hypoglycemic effect(s) of G. procumbens and to ascertain the involvement of glycogen synthase kinase (GSK3), a key component of insulin biosignaling in the plant activity. A cell-based assay showed that the three G. procumbens fractions tested did not exhibit anti-GSK3 activities. Oral administrations of hexane, ethyl acetate, n-butanol fractions of G. procumbens (250 mg/kg b.w.) and Glibenclamide (5 mg/kg b.w.) for 14 days in STZ-induced diabetic rats reduced blood glucose levels by 29.7%, 60.1%, 33.5% and 61.7% (p<0.05), respectively compared to diabetic control. Liver glycogen contents were elevated (p<0.05), following administration of the three fractions of
G. procumbens in diabetic rats when analysed after 14 days of treatment. Western blot analysis also showed GSK3β in the liver of G. procumbens fractions-treated and Glibenclamide-treated animals were phosphorylated at Ser-9. The above findings indicated that the hypoglycemic action of G. procumbens fractions resulted in the inactivation of
GSK3β in liver of diabetic rats. Since G. procumbens fractions did not exhibit GSK3 inhibitory properties, it is possible that the hypoglycemic action of the fractions observed here could be due to direct or indirect effects on upstream components of the insulin biosignaling pathway.
Many challenges arise in candidaemia treatment which involves emergence of antifungal resistance. New species have been identified due to improved methods of detection and some are resistant to commonly prescribed antifungal agents such as fluconazole and amphotericin B. Therefore, the objective of the study was to observe any changes in the susceptibility patterns and distribution of Candida species. This cross sectional study was conducted at the Department of Medical Microbiology and Immunology in UKMMC, a tertiary teaching hospital. One hundred and fifty one data were collected from the department’s laboratory records from January 2008 to December 2010. The yeasts were identified using ID32C carbohydrate assimilation tests whilst the antifungal susceptibility test was performed using Sensititre® YeastOne® broth microdilution method. Antifungal agents tested included amphotericin B, fluconazole, itraconazole, voriconazole, 5-flucytosine and caspofungin. Out of 151 blood isolates, 47 (31.1%) were Candida albicans and 104 (68.9%) were non-albicans Candida species. Candida tropicalis has surpassed C. albicans as the most commonly isolated Candida species from blood. Overall susceptibility (as compared to 2005-2006 data in brackets) to caspofungin was 99.3% (n/a), 5-flucytosine 97.4% (98%), amphotericin B 94.7% (100%), voriconazole 92.7% (98%), fluconazole 86.8% (90%) and
itraconazole 39.1% (40%). In conclusion, although the isolates were generally still susceptible to amphotericin B and fluconazole, resistance to these drugs is increasing.
This paper presents the improvement of quality factor (Q) estimation using shift frequency method. A new method was developed based on two previous methods; peak frequency shift (PFS) method and centroid frequency shift (CFS) method. The proposed algorithm has been tested to gauge its performance using three different scenarios; Q variation, travel
time variation, and signal to noise ratio (SNR) variation. The test was performed using the Ricker wavelet with random noise included. Based on the results obtained, it can be concluded that the new proposed method was able to improve Q estimation using shift frequency method. This method can also be implemented in the low and high Q condition, shallow and deep wavelet targets and in the low and high SNR conditions of seismic data. The limitations in the PFS and CFS methods can be reduced by this method.
MeSH terms: Algorithms; Noise; Relative Biological Effectiveness; Signal-To-Noise Ratio
Neenchelys buitendijki Weber and de Beaufort, 1916 from Malaysia is reported for the first time. Five specimens collected
from Matang, Peninsular Malaysia, represent the third record in the Indo-western Pacific region. A detailed description
is provided to document the species into the fish fauna of Malaysia.
Five years of data from 2001 until 2006 of warm unstratified shallow, oligotrophic to mesothropic tropical Putrajaya Lake, Malaysia were used to study pattern discovery and forecasting of the diatom abundance using supervised and unsupervised artificial neural networks. Recurrent artificial neural network (RANN) was used for the supervised artificial neural network and Kohonen Self Organizing Feature Maps (SOM) was used for unsupervised artificial neural network. RANN was applied for forecasting of diatom abundance. The RANN performance was measured in terms of root mean square error (RMSE) and the value reported was 29.12 cell/mL. Classification and clustering by SOM and sensitivity analysis from the RANN were used to reveal the relationship among water temperature, pH, nitrate nitrogen (NO3-N) concentration, chemical oxygen demand (COD) concentration and diatom abundance. The results indicated that the combination of supervised and unsupervised artificial neural network is important not only for forecasting algae abundance but also in reasoning and understanding ecological relationships. This in return will assist in better management of lake water quality.
This study compared the attitudes, practices and perceived barriers among Malaysian dentists and periodontists towards smoking cessation interventions (SCI) for patients. A self-administered questionnaire, which covered respondents beliefs, practices as well as barriers and limitations towards SCI, were posted to 289 dentists from four Malaysian states and 35 Malaysian periodontists. In all, 236 (82%) dentists and 26 (80%) periodontists responded. More periodontists than dentists routinely record patient’s smoking status at first visit (89.3% vs 19.1%) (p<0.001), recommend nicotine replacement aids (37% vs 16.3%) (p=0.031), refer to smoking cessation clinics (40.7% vs 14%) (p=0.001), followed-up smoking cessation with patients (70.4% vs 11.3%) (p<0.001) and described themselves as being committed to patients’ SCI (81.5% vs 53.4%) (p=0.013). Limitations faced by dentists as compared to periodontists in SCI were due to insufficient time (p<0.001) and fear it will affect dentist-patient relationship (p=0.034). The findings in this study emphasize the importance of SCI and the need for further training in SCI among Malaysian periodontists and government dentists.
The determination of the high-risk area and clusters of typhoid cases is critical in typhoid control. The purpose of this study was to identify and describe the epidemiology and spatial distribution of typhoid in four selected districts in Kelantan using GIS (geographical information system). A total of 1215 (99%) of the cases were coordinated with GPS (global positioning system) and mapping was done using ArcGIS 9.2. Spatial analysis was performed to determine the cluster and high-risk area of typhoid. Results showed that typhoid incidence was not associated with race and sex. Most affected were from the age group of 5-14 followed by 15-24 year olds. Nine sub-districts were categorized as highly endemic. In addition typhoid has shown a significant tendency to cluster and a total of 22 hotspots were found in Kota Bharu, Bachok and Tumpat with a few sub districts identified as high risk for typhoid. No significant relationships between the treated water ratio and flood risk area were found with the cluster of cases. The cluster of typhoid cases in the endemic area did not appear to be related to environmental risk factors. Understanding the characteristics of these clusters would enable the prevention of typhoid disease in the future.
MeSH terms: Humans; Risk Factors; Typhoid Fever; Incidence; Water Purification; Geographic Information Systems; Continental Population Groups; Floods; Spatial Analysis
In this paper, we presented a new key exchange method based on decomposition problem for elliptic curve cryptography. We showed that our key exchange method was not only an alternative method for designing keys in cryptography, but it also has improved security condition from the previous key exchange based on decomposition problem over noncommutative groups. We proposed elliptic an curve cryptography to be the new platform for our key exchange protocol and showed how it was implemented. The security of our protocol was based on discrete logarithm problem, which was not infeasible and strictly difficult to retrieve in elliptic curve cryptography without any prior knowledge.
Tungsten trioksida (WO3) merupakan salah satu fotomangkin yang berpotensi dalam aplikasi penjanaan gas hidrogen daripada tindak balas pembelahan air. Dalam kajian ini, pelbagai komposisi filem nipis WO3
terdop nikel dihasilkan pada kaca stanum(IV) oksida terdop fluorin (FTO) dengan menggunakan asid tungstik dan nikel(II) asetat sebagai bahan pemula. Selepas disepuhlindap pada 500°C selama 30 min, sampel filem nipis ini dicirikan dengan menggunakan SEM, XRD, spektrofotometer UV-Vis serta analisis fotoelektrokimia (PEC). WO3 terdop nikel mempunyai saiz zarah yang lebih besar berbanding sampel WO3 tulen dan mempunyai struktur hablur monoklinik. Jurang tenaga WO3 terdop nikel yang dianggarkan daripada spektrum UV-Vis dengan menggunakan formula Tauc adalah lebih kecil berbanding jurang tenaga bagi WO3 tulen. Ujian aplikasi PEC di bawah sinaran lampu xenon menunjukkan kecekapan penghasilan gas hidrogen oleh filem WO3 terdop nikel yang digunakan sebagai fotoanod telah dipertingkatkan.
Taguchi orthogonal array design, a statistical software is applied to n-hexane reforming. The purpose is to identify the most significant process variable in reforming conditions favouring n-hexane conversion to high aromatics and isomers and low cracked and coke precursor reformate products. Actual experimental data were used for this study. Three process variables i.e. temperature, contact time and hydrogen partial pressure were investigated. From the study it was found that the contact time was the most critical operating parameter for n-hexane conversion followed by reaction temperature and hydrogen partial pressure. It was also noted that enhanced n-hexane reforming conversion can be achieved by operating the process at reaction temperature 723 K and contact time 7.1 min with a H2 partial pressure 300 kPa. For selectivity to aromatics and isomers lower contact time of 1.07 min with intermediate hydrogen partial pressure of 300 to 500 kPa operating at a reaction temperature of 723 K is most favourable.
The emission of Extreme Ultra Violet (EUV) from plasma produced by vacuum spark discharge using stainless steel as anode material was investigated. The operating pressure for all the experiments carried out was maintained at below 10-4 mbar. The discharge voltage tested was from 8 kV to 20 kV. The inter-electrode distance suitable for high intensity and reproducible EUV emissions was found to be in the range of 2.6 mm to 4.6 mm. The output EUV energy scaled as ~ V02, where V0 is the discharge voltage.
MeSH terms: Body Fluids; Electrodes; Plasma; Pressure; Stainless Steel; Vacuum
In recent years, issues regading safety and wellness of dietary oils and fats have received major attention. This is particularly so in the case of structured modified fats, which are being used extensively to meet the product-specific demand primarily in bakery industry as shortenings, cocoa butter substitutes in confectionary industry, and in margarine preparation, as butter substitute. During modification stages, native oils and fats are subjected to different physical and chemical treatments such as fractionation, hydrogenation and interesterification in order to produce fats with desirable
physical as well as functional properties. Numerous studies have demonstrated the adverse health effects of these modified oils and fats, especially trans fatty acids, using animal models as well as human volunteers. Consequently, the decadesold process of partial hydrogenation of oils has been abandoned in most nations. However, alternative technologies to hydrogenation are on rise, creating new trends in modified oils and fats synthesis to cater food industry needs that may have unforeseeable consequences on human health.
A study to evaluate the effect of four selected plant powder as rice grain protectant against Sitophilus zeamais adult mortality, F1 progeny production, weight loss and rice grain damaged was conducted. The plant powders used were made from seed of Annona muricata, Jatropha curcas, Azadirachta indica and from leaf of J. curcas at 0.5, 1, 1.5, 2 and 2.5% (w/w) concentrations. Probit analysis showed that J. curcas seed powder was highly toxic (LC50 = 0.28%) to S. zeamais adult followed by A. muricata seed (LC50 = 0.33%), J. curcas leaf (LC50 = 1.15%) and A. indica seed (LC50= 3.63%). The Annona muricata and J. curcas seed had caused the highest mean mortality (100 and 98.85%) at 2% concentration, while the A. indica seed and J. curcas leaf powder had only caused 32.32 and 77.84%, respectively at 2.5% concentration. There was no progeny produced, no weight loss recorded and no rice grain damaged on treated rice grain with A. muricata and J. curcas seed at 1% concentration. In contrast, J. curcas leaf and A. indica seed powder had the least toxicity effect on the weevil as shown by number of progeny produced (167 and 228), total of weight loss (10.04 and 10.49%) and rice grain damaged (19.35 and 21.14%) even at the highest powder concentration (2.5%)
tested. Results of this study revealed the potential of J. curcas and A. muricata seed powder to be used in controlling S. zeamais on stored rice grain.
The first time report on the feeding ecology and food preference of mangrove horseshoe crab Carcinoscorpius rotundicauda (Latreille 1802) at their nesting grounds along the Pahang coast is given. Monthly sampling was carried out between March 2010 and February 2011 covering both monsoonal (March to October) and non-monsoonal (November to February) seasons. Major macrobenthic gut contents (bivalves, gastropods, crustaceans, polychaetes and miscellaneous food items including plant materials) were identified using microscopic examination. An electivity index (E1) was calculated for the frequent food items observed in the gut region of C. rotundicauda during monsoon and non-monsoon seasons. The EI was negative for crustaceans and positive for all the other food items including bivalves, gastropods, polychaetes and miscellaneous food items (which include insects, amphipods, Isopods, larval and juvenile stages of fishes, foraminifera and other Annelid worms). It is interesting to note that C. rotundicauda prefered less number of bivalves than polychaetes during non monsoon seasons but it was the reverse during monsoonal period. Male crabs intensely preyed on gastropods and female prefers polychaete worms during the peak mating/nesting season (June - August 2010). Seasonal variations in food composition showed that mollusks formed the main item especially gastropods. Unidentified organic matters in the gut content analysis of C. rotundicauda showed high preference towards plant materials. Gastro Somatic Index (GaSI) analysis showed that the feeding intensity of male crabs was higher during non-monsoon period while it was higher during monsoonal period in female crabs. In conclusion, the feeding ecology of mangrove horseshoe crabs were more similar to its closer and distant conspecifics. However, it was postulated that the higher preference of polychaete worms by the female C. rotundicauda during the peak mating season indicated its role in regulating the nesting behaviour.
Objektif kajian ini adalah untuk menunjukkan pembangunan kaedah berangka untuk menilai keboleharapan cerun tanah dan menentukan kebarangkalian permukaan gelonsoran genting. Fungsi prestasi dirumuskan menggunakan kaedah had keseimbangan Bishop mudah untuk mengira indeks keboleharapan. Indeks keboleharapan yang ditakrifkan oleh Hasofer dan Lind digunakan sebagai indeks ukuran keselamatan. Pencarian permukaan gelonsoran genting secara kebarangkaliannya yang berkaitan dengan indeks keboleharapan terendah dirumuskan sebagai masalah pengoptimuman.
Seterusnya pengoptimuman kelompok zarah digunakan untuk mengira indeks keboleharapan Hasofer dan Lind dan kebarangkalian permukaan kegagalan genting. Penggunaan algorithma ini ditunjukkan melalui tiga contoh berangka daripada kajian terdahulu. Keputusan menunjukkan bahawa kaedah yang dicadangkan berupaya untuk memberikan penyelesaian yang lebih baik bagi analisis keboleharapan cerun tanah berbanding dengan kaedah yang dilaporkan dalam kajian-kajian terdahulu.
MeSH terms: Autonomic Nervous System Diseases; Diabetic Neuropathies
Pemantauan air dan tanah tercemar di sekitar tapak pelupusan sampah selalunya dilakukan dengan analisis kimia air permukaan, bahan larut resap dan tanah serta pengukuran geofizik. Air larut resap merupakan cecair yang berasal daripada hasil larutan air hujan terhadap sisa-sisa buangan di tapak pelupusan, yang terkumpul dan meresap masuk ke dalam liang-liang tanah. Satu kajian untuk mengesan pergerakan cecair larut resap telah dilakukan di tapak pelupusan sampah Sungai Sedu yang terletak atas tanah seluas 10 ekar berhampiran pekan Banting. Geologi kawasan kajian dibahagikan kepada formasi Beruas dan Gula iaitu aluvium berusia Kuaterner terdiri daripada lempung samudera yang terendap di atas batuan dasar metasedimen Formasi Bukit Kenny. Survei geofizik dengan teknik pengimejan keberintangan geoelektrik 2D, keberintangan profil menegak (VRP) dan analisis geokimia terhadap sampel tanah dan air telah dijalankan untuk mengetahui tahap migrasi bahan larut resap di sekitar tapak pelupusan tersebut. Tahap migrasi bahan pencemaran akan dikaji melalui hasil analisis seperti nilai model keberintangan elektrik dan kepekatan logam berat berbanding dengan nilai latar belakang. Dalam kajian ini, survei pengimejan elektrik 2D telah dilakukan di sepanjang 8 garis rentasan dan pengukuran VRP telah dilakukan di dalam 6 lubang gerudi. Analisis geokimia untuk mengetahui kepekatan unsur-unsur tertentu telah dilakukan ke atas 33 sampel tanah dan 7 sampel air. Keratan rentas keberintangan menunjukkan bahawa bahan larut resap telah meresap sehingga kedalaman 3-5 m berdasarkan nilai keberintangan elektrik yang rendah secara relatif iaitu kurang daripada 1 ohm m. Kepekatan unsur-unsur yang disukat pula menunjukkan bahan larut resap telah bergerak ke arah sungai yang terletak di sebelah kawasan kajian. Kepekatan logam berat dalam sampel-sampel air sungai dan tanah adalah tinggi dan melebihi nilai latar belakang terutama bagi unsur Ni, Mn, Cr, Zn dan As. Konduktiviti elektrik sampel tanah tebing sungai, air sungai dan air larut resap yang diukur di lapangan adalah masing-masing 6600 µS/cm, dan 20000-50000 µS/cm manakala julat pH bagi semua sampel tersebut adalah di antara 3-5. Nilai konduktiviti dan kepekatan logam berat yang tinggi membuktikan bahawa bahan larut resap telah bergerak dari tapak pelupusan untuk mencemari air sungai, air tanah dan tanah di kawasan sekitar.
The activity concentration of 210Po from six different samples consisting of raw charcoal, surface sediment, rainwater (suspended solids (SSrw) and dissolved phase (Drw) and estuarine water (suspended solids (SSew) and dissolved phase (Dew)), were analyzed. The activity concentration of
210Po in solid samples was between 7.63 ± 0.67 and 744.28 ± 21.12 Bqkg-1 and in dissolved samples varied between 0.34 ± 0.03 and 86.33 ± 6.51 mBqL-1. On average, 210Po activity in SSrw sample was the highest, at nearly three times its original form (charcoal). SSew and surface sediment samples were
similarly distributed between 15th March and 1st August samplings, but were relatively lower than charcoal and SSrw samples. The natural meteorological variability also enhanced 210Po distribution and dispersion to a few kilometers from the coal-fired power plant.
The ticto barb Puntius ticto (Hamilton 1822) is a small, indigenous fish species of Bangladesh that is widely distributed in the natural waters of Asian countries. This study describes the relationships between body size, weight, condition (Fulton’s, KF; allometric, KA, KR; and relative weight, WR) and fecundity of the threatened species P. ticto from the Ganges River, northwestern Bangladesh. A total of 24 mature female specimens were collected by the traditional fishing gears from March to August 2006. For each individual, total (TL), fork (FL), standard length (SL), and ovary length (OL)
were measured by digital slide calipers, while body (BW) and ovary weight (OW) were taken by a digital balance. Total fecundity (FT) of each female was calculated as the number of eggs found in each ovary, whereas relative fecundity (FR) was the number of eggs per gram of fish weight. The results showed that TL of P. ticto varied from 9.10 to 10.80 cm, with calculated mean ± SD as 9.77±0.57 cm. Body weights extended from 14.00 to 24.00 g, with calculated mean ± SD as 17.83±3.39 g. The mean FT was 2586±700 and ranged from 1611 to 4130. BW was more significantly correlated with total fecundity (r2>0.633; p<0.001) than various other body metrics. The results also indicated significant correlation between length-weight (df=22, t-test≥8.86, p<0.001); FT -KF (rs=0.473; p=0.019), FT-KA (rs=0.502; p=0.012), and FT-WR (rs=0.483; p=0.016), but insignificant correlations were found between FT-GSI(rs=0.309; p=0.141) and FR-with various other body metrics. The knowledge of fecundity would be useful to impose adequate regulations for the conservation of this threatened species in the Ganges River and nearby areas of Bangladesh.
The present study describes the length-frequency distribution, length-weight (LWR) and length-length relationships (LLR), and condition- and form-factors of Puntius sophore wild population from the Chalan beel, north-central Bangladesh. Sampling was done using traditional fishing gears including jhaki jal (cast net), tar jal (square lift net), and dughair (conical trap) during March 2010 to February 2011. For each individual, the total length (TL), fork length (FL) and standard length (SL) were measured by digital slide calipers. Individual body weight (BW) was also taken by a digital balance. A total of 185 specimens ranging from 3.62-9.02 cm TL and 0.70-13.20 g BW were analyzed in this study. The length-frequency distribution showed that the 6-7 cm TL size group was numerically dominant and constituted 43% of the total population. The coefficient b of the LWRs indicated positive allometric growth (b>3.00) for P. sophore in the Chalan beel. The results also indicated that the LWRs were highly correlated (r2 > 0.945). The calculated Fulton’s condition factor (K) values ranged from 0.69-2.35, with a mean value 1.64±0.30. The relative weight (Wr) was not significantly different from 100 for (p=0.074), indicating the balance habitat with food availability relative to the presence of predators for P. sophore. The estimated values of form factor (a
3.0) were as 0.0138, 0.0345 and 0.0435 for TL, FL and SL of P. sophore, respectively. These results will be useful for fishery biologists and conservationists to suggest adequate regulations for sustainable fishery management and conservation its numerous stocks in the region.