Characterization, drug loading and antibacterial activity of nanohydroxyapatite/polycaprolactone (nHA/PCL) electrospun membrane

Considering the important factor of bioactive nanohydoxyapatite (nHA) to enhance osteoconductivity or bone-bonding capacity, nHA was incorporated into an electrospun polycaprolactone (PCL) membrane using electrospinning techniques. The viscosity of the PCL and nHA/PCL with different concentrations of nHA was measured and the morphology of the electrospun membranes was compared using a field emission scanning electron microscopy. The water contact angle of the nanofiber determined the wettability of the membranes of different concentrations. The surface roughness of the electrospun nanofibers fabricated from pure PCL and nHA/PCL was determined and compared using atomic force microscopy. Attenuated total reflectance Fourier transform infrared spectroscopy was used to study the chemical bonding of the composite electrospun nanofibers. Beadless nanofibers were achieved after the incorporation of nHA with a diameter of 200–700 nm. Results showed that the fiber diameter and the surface roughness of electrospun nanofibers were significantly increased after the incorporation of nHA. In contrast, the water contact angle (132° ± 3.5°) was reduced for PCL membrane after addition of 10% (w/w) nHA (112° ± 3.0°). Ultimate tensile strengths of PCL membrane and 10% (w/w) nHA/PCL membrane were 25.02 ± 2.3 and 18.5 ± 4.4 MPa. A model drug tetracycline hydrochloride was successfully loaded in the membrane and the membrane demonstrated good antibacterial effects against the growth of bacteria by showing inhibition zone for E. coli (2.53 ± 0.06 cm) and B. cereus (2.87 ± 0.06 cm)

Oblique propagation of arbitrary amplitude electron acoustic solitary waves in magnetized kappa-distributed plasmas

The linear and nonlinear properties of large amplitude electron-acoustic waves are investigated in a magnetized plasma comprising two distinct electron populations (hot and cold) and immobile ions. The hot electrons are assumed to be in a non-Maxwellian state, characterized by an excess of superthermal particles, here modelled by a kappa-type long-tailed distribution function. Waves are assumed to propagate obliquely to the ambient magnetic field. Two types of electrostatic modes are shown to exist in the linear regime, and their properties are briefly analyzed. A nonlinear pseudopotential type analysis reveals the existence of large amplitude electrostatic solitary waves and allows for an investigation of their propagation characteristics and existence domain, in terms of the soliton speed (Mach number). The effects of the key plasma configuration parameters, namely, the superthermality index and the cold electron density, on the soliton characteristics and existence domain, are studied. The role of obliqueness and magnetic field are discussed.Comment: Submitted to Plasma Physics and Controlled Fusio

Zeolite incorporated polycaprolactone/zeolite nanocomposite membranes for silverremoval

The presence of heavy metals in drinking water leads to several health problems. Nano and micro fiber membranes can be used to overcome this through nano or microfiltration process. In this study, polycaprolactone (PCL)/zeolite electrospun composite membranes were fabricated and characterized. PCL is one of the synthetic polymers used in biomedical applications. It has several advantages, including biocompatibility, biodegradability and mechanical flexibility. On the other hand, zeolites are microporous, aluminosilicate minerals commonly used as commercial adsorbents. Electrospinning is a promising technique to produce membranes by applying high voltage electricity. In this research, an electrospinning technique was used to fabricate the electrospun membrane based on PCL and zeolite. In order to produce electrospun membrane, 15% (w/v) of PCL polymer solution was dissolved in acetone and 20% (w/v) zeolite nanoparticles were incorporated into the PCL polymer solution. The diameter range of fiber was 2-6 μm. Zeolite nanoparticles were distributed homogenously into the fibers. EDX spectrum confirmed the presence of zeolite throughout the membrane. From the performance testing, it was revealed that the membrane can be potentially used as microfiltration to entrap silver contaminants in drinking water. Apart of that, the membranes are prepared with biocompatible, non-toxic materials which can be eco-friendly

Effect of delayed icing on the quality of tiger shrimp (Penaeus monodon Fab.)

Effect of delayed icing on the quality of Penaeus monodon iced after three hours of harvest was studied in plastic and bamboo baskets. After harvest of three hours at ambient temperature (28°-32°C), ice was added to the shrimp at a ratio of 1:1 (shrimp:ice) and stored for 21 hours in both the baskets. Quality evaluation was carried out through visual assessment, biochemical analysis and microbial analysis for 24 hours. The organoleptic evaluation and scoring was done from the time of harvest treated as 0 hour and the average score was 10. At 9th hour after iced condition quality of shrimp was found reduced to the next stage (acceptable) with a score ranged from 8.4-6.5 in both baskets. This acceptable stage was observed throughout the experiment for bamboo basket whereas in the plastic basket the quality was reduced to a small extent with a score of 6.4 (moderately acceptable). Till the end point of the experiment the quality of shrimp was acceptable in respect to biochemical analysis. The microbial load was found log sub(10) 3.99±0.12 cfu/g to log sub(10) 4.33±0.21 cfu/g and log sub(10) 4.01 ±0.12 cfu/g to log sub(10) 4.83±0.19 cfu/g in the bamboo and plastic basket respectively. The importers or buyers suggests for immediate icing to maintain good quality but results of the present experiment suggest that the quality does not vary drastically for first three hours

Sperm cryopreservation of Indian major carp, Labeo rohita: cryodiluents, sperm: cryodiluent dilution ratio and cryoprotectan t concentration

Cryogenic preservation trials of spermatozoa of Labeo rohita were carried out. Twenty four cryodiluents (extender + cryoprotectant), with the combination of six extenders such as egg-yolk citrate, urea-egg-yolk, 0.9% NaCl, Kurokura-2, Ma and Mb and four cryoprotectants viz. DMSO, glycerol, methanol and ethanol, were used to screen out the suitable cryodiluents. Sperm was preserved in 0.25ml plastic straw in programmable freezer. Two step freezing method was followed. Sperm preserved with egg-yolk citrate and urea-egg-yolk containing 10% DMSO showed best post-thaw motility (80%) followed by 0.9% NaCl (60%) and Kurokura-2(30%) solutions. Sperm with the extenders M" and Mb clotted at the time of equilibration and also after few days of preservation. Egg-yolk citrate mixed with ethanol and methanol also showed good percentage of motility (80%) but egg-yolk citrate with glycerol showed less sperm motility (>60%). To determine suitable dilution ratio of milt and cryodiluent two best extender eggyolk citrate and urea-egg-yolk with four cryoprotectants such as DMSO, glycerol, methanol and ethanol at different ratio viz 1:2,1:4,1:7,1:10,1:15 and 1:20 were used. Highest post-thaw motility (>80%) was observed when milt was preserved with egg-yolk citrate containing 10% DMSO at 1:2, 1:4, 1:7 and 1:10 dilutions. Meanwhile using glycerol as cryoprotectants provided less post thaw motility at lower dilution ratio but with the increase of its dilution showed good sperm motility compared with other cryoprotectants. Finally, evaluation on the effect of cryoprotectant concentration on post-thaw sperm motility was conducted. Egg-yolk citrate and four cryoprotectant i.e. DMSO, glycerol, methanol and ethanol with six different concentrations namely 5%,7%, 10%, 15%, 20% and 30%.were evaluated. Among the cryoprotectants DMSO, methanol and ethanol showed highest post-thaw motility (about 80%) at 7% and 10% concentrations. Although glycerol was not suitable at low concentration but its 20% and 30% concentration levels provided best post-thaw motility. No post-thaw motility was obtained with DMSO at 30% concentration. The overall analysis on cryoprotectant concentration indicated that below 5% and above 20% cryoprotectant concentrations could not be suitable for effective cryopreservation of spermatozoa

Surface Integrity of Holes Machined by Orbital Drilling of Composites with Single Layer Diamond Tools

AbstractOrbital drilling of composites was investigated to observe hole surface integrity in terms of surface roughness, delamination, surface burning, and geometric accuracy. Experiments were conducted with a brazed single layer diamond tool of ball-end geometry to drill 220 holes. Cutting forces and temperatures were measured. Micro-observations were made of the hole surface. The results showed that the forces increased sharply during drilling of the first 44 holes followed by a gradual rise. Part temperatures varied between 98-184°C. Surface roughness Ra varied from 13-17μm. Almost 99% of the holes were drilled without exit delamination; however, 2.3% of the holes showed entrance delamination

Induction of white cell proliferation due to haematopoietic growth factors is associated with an increase in multiple forms of dihydrofolate reductase in non-neutropenic cancer patients

Objective: Granulocyte-colony stimulating factor (G-CSF) and granulocyte macrophage-colony stimulating factor (GM-CSF) are frequently used in cancer patients to overcome the granulocytopenic effects of chemotherapy, and also to mobilize the stem cells. The mobilized stem cells are collected from the peripheral blood and used for transplantation following high doses of chemotherapy. However, the molecular mechanism by which these colony stimulating factors (CSFs) bring about proliferation of myeloid precursor cells is not clearly known. Dihydrofolate reductase (DHFR), which has an established role in DNA synthesis, could be a link between administration of CSF and stem cell proliferation. The purpose of this study was to investigate whether CSFs induce white cell proliferation by producing multiple forms of DHFR.Methods: Twelve patients with non-haematological malignancies were treated with either G-CSF or GM-CSF to mobilize stem cells. Nine healthy subjects were treated with placebo as controls. Blood samples were obtained before and after stimulation with CSFs or placebo. White blood cells were separated and concentrations of both active DHFR and immunoreactive nonfunctional form of DHFR were determined in their cytoplasm using methotrexate-binding assay and enzyme-linked immunosorbent assay, respectively. Total leucocytes count (TLC) was also monitored before and after stimulation with CSFs or placebo.Results: There was a significant (P \u3c 0.05) increase in concentration of immunoreactive nonfunctional form of DHFR and TLC following stimulation with CSFs. There was an increase in concentration of active DHFR as well, however, this did not reach statistical significance. In the placebo-treated subjects, no significant increase in active DHFR, immunoreactive nonfunctional form of enzyme or TLC was observed. However, it was noticed that the base-line values of active DHFR and immunoreactive nonfunctional form of enzyme in leucocytes of cancer patients were higher than the base-line values in leukocytes of normal healthy subjects.Conclusion: Our data suggest that colony stimulating factors induce white cell proliferation by increasing levels of multiple forms of DHFR

Estimation of Para Red Dye in Chilli Powder and Tomato Sauces by a Simple Spectrophotmetric Method followed by Thin layer Chromatography

A number of grinded chilli powder samples and tomato sauce samples were collected from various localities of Karachi city. All the samples were estimated for the presence of para red which is an azo dye and more specifically belongs from the group of sudan dyes. According to the regulation of various governmental agencies its use in food is strictly prohibited because of its ability to form carcinogenic compounds. Although there were a number of sophisticated chromatographic methods for the estimation of this dye but we developed here a simple, convenient, expeditious spectrophotometric method followed by thin layer chromatography technique and compared the results by single point and multiple point external standard methods. On the basis of these results we also specify the localities of Karachi city where the contamination is more prominent. © JASE

Distribusi Penderita Sindrom Down Berdasarkan Analisis Sitogenetik Di Laboratorium Cebior

Background : Down syndrome is a condition when a person has an extra number of chromosomes 21 in the form of either classical trisomy 21, translocation or mosaic. The age of the mother is one of the factors that increases the risk of having a baby with Down syndrome. Down syndrome is one of indications for cytogenetic analysis in which it shows the chromosome abnormalities. Aim : To determine the distribution of chromosome abnormalities in patients with Down syndrome referred to Cebior Laboratory from 2006 until April 2015. Methods : This study is a prospective and retrospective descriptive with cross-sectional design. Results : Amongst 95 patients, there were 38 (40,0%) patients with karyotype 47,XX, +21; 50 (52,6%) patients with 47,XY, +21; 1 (1,1%) patients with 47,XX+21/ 46,XX; 2 (2,1%) patients with 47,XY, +21/ 46,XY; 1 (1,1%) patient with 46,XY, +21, t(8;21); 2 (2,1%) patient with 46,XX,+21,t(21;21)(q10;q10); and 1 (1,1%) patient with 46, XY, +21,t(21;21)(q10:q10). The distribution of maternal age with Down syndrome in descending order were 36-40 years old (31,6%), 31-35 years old (24,2%), 26-30 years old (22,1%), 41-45 years old (14,7%), and 20-25 years old (7,4%). Conclusion : Most patients with Down syndrome had classical trisomy 21. The majority of babies with Down syndrome were born from mothers aged older than 35 years old. Therefore advanced maternal age have a higher risk for having a baby with Down syndrome