Antibodies to single-stranded and double-stranded DNA in antinuclear antibody-positive type 1-autoimmune hepatitis

To determine the significance of antibodies to single-stranded (anti-ssDNA) and double-stranded DNA (anti-dsDNA) in antinuclear antibody (ANA)-positive type 1 autoimmune hepatitis, sera from 53 patients were tested by enzyme immunosorbent assay (ELISA) and indirect immunofluorescence using the Crithidia luciliae substrate. Anti-dsDNA were detected in 18 patients (34%) by ELISA and 12 patients (23%) by the Crithidia-based assay. Twenty patients with anti-dsDNA by either assay (38%) had higher serum levels of immunoglobulin G (3971 +/- 270 mg/dL vs. 3201 +/- 247 mg/dL, P = .05) than seronegative patients. They also had human leukocyte antigen (HLA) DR4 more commonly than other patients (83% vs. 41%, P = .006) and normal subjects (83% vs. 30%, P = .00007). In contrast to patients seropositive by the Crithidia-based assay, those seropositive by ELISA failed corticosteroid therapy more commonly (24% vs. 3%, P = .04). Anti-ssDNA were found in 45 patients (85%) and they did not distinguish patients with different clinical features or outcomes. We conclude that anti-dsDNA are common in ANA-positive type 1 autoimmune hepatitis. HLA DR4 is associated with their production, and seropositivity by ELISA characterizes patients who have a poorer immediate response to corticosteroid treatment. Anti-ssDNA are common but they do not have important clinical implications.     

Examining the relationship between free recall and immediate serial recall: The effect of concurrent task performance.

In 3 experiments, participants saw lists of 16 words for free recall with or without a 6-digit immediate serial recall (ISR) task after each word. Free recall was performed under standard visual silent and spoken-aloud conditions (Experiment 1), overt rehearsal conditions (Experiment 2), and fixed rehearsal conditions (Experiment 3). The authors found that in each experiment, there was no effect of ISR on the magnitude of the recency effect, but interleaved ISR disrupted free recall of those words that would otherwise be rehearsed. The authors conclude that ISR and recency cannot both be outputs from a unitary limited-capacity short-term memory store and discuss the possibility that the process of rehearsal may be common to both tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bacteriocin‐capped silver nanoparticles for enhanced antimicrobial efficacy against food pathogens

Bacteriocins produced by lactic acid bacteria are safer alternatives to the more popularly used chemical preservatives which exhibit several adverse effects. The bacteriocins have an advantage of being efficient in controlling food pathogens without possessing any side‐effects. However, the bacteriocins have a limitation of exhibiting a narrow antimicrobial spectrum and having a high‐dosage requirement. With an aim to combat these limitations, the present study involved the biosynthesis of bacteriocin‐capped nanoparticles, using two bacteriocins (Bac4463 and Bac22) extracted and purified from Lactobacillus strains. Nanoconjugates synthesised at optimum conditions were characterized using various physico‐chemical techniques. The interaction of bacteriocin‐capped silver nanoparticles with the pathogenic bacteria was observed using scanning electron microscopy, wherein the deformed and elongated cells were clearly visible. In vitro antimicrobial efficacy of both Bac4463‐capped silver nanoparticles and Bac22‐capped silver nanoparticles against different food pathogens was observed to be enhanced in comparison to the antimicrobial activity of bacteriocins alone. Minimum inhibitory concentration was observed to be as low as 8 μg/ml for Bac4463‐capped silver nanoparticles against Staphylococcus aureus, and 2 μg/ml for Bac22‐capped silver nanoparticles against Shigella flexneri. This study, therefore, recommends the use of bacteriocin‐capped nanoparticles as food preservatives to control the growth of food spoiling bacteria.Inspec keywords: preservatives, elongation, food safety, silver, biotechnology, antibacterial activity, food preservation, nanoparticles, nanofabrication, food products, scanning electron microscopy, microorganismsOther keywords: bacteriocins, chemical preservatives, food pathogens, bacteriocin‐capped nanoparticles, bacteriocin‐capped silver nanoparticles, Bac4463‐capped silver nanoparticles, Bac22‐capped silver nanoparticles, enhanced antimicrobial efficacy     

Prevalence, characterization and sources of Listeria monocytogenes in blue crab (Callinectus sapidus) meat and blue crab processing plants

Seven blue crab processing plants were sampled to determine the prevalence and sources of Listeria spp. and Listeria monocytogenes for two years (2006–2007). A total of 488 raw crabs, 624 cooked crab meat (crab meat) and 624 environmental samples were tested by standard methods. Presumptive Listeria spp. were isolated from 19.5% of raw crabs, 10.8% of crab meat, and 69.5% of environmental samples. L. monocytogenes was isolated from 4.5% of raw crabs, 0.2% of crab meat, and 2.1% of environmental samples. Ninety-seven percent of the isolates were resistant to at least one of the ten antibiotics tested. Eight different serotypes were found among 76 L. monocytogenes isolates tested with the most common being 4b, 1/2b and 1/2a. Automated EcoRI ribotyping differentiated 11 ribotypes among the 106 L. monocytogenes isolates. Based on ribotyping analysis, the distribution of the ribotypes in each processing plant had a unique contamination pattern. A total of 92 ApaI and 88 AscI pulsotypes among the 106 L. monocytogenes isolates were found and distinct pulsotypes were observed in raw crab, crab meat and environmental samples. Ribotypes and serotypes recovered from crab processing plants included subtypes that have been associated with listeriosis cases in other food outbreaks. Our findings suggest that molecular methods may provide critical information about sources of L. monocytogenes in crab processing plants and will augment efforts to improve food safety control strategies such as targeting specific sources of contamination and use of aggressive detergents prior to sanitizing.     

Nutritional composition of minor indigenous fruits: Cheapest nutritional source for the rural people of Bangladesh

In line of the development of a food composition database for Bangladesh, 10 minor indigenous fruits were analysed for their nutrient composition comprising ascorbic acid, carotenoids and mineral values. Nutrient data obtained have been compared with published data reported in different literatures, book and United States Department of Agriculture-National Nutrient Database for Standard Reference. Ascorbic acid was highest in Wood apple and lowest in Roselle. Monkey jack contained the highest amount of carotenoids, zinc and copper. Content of calcium, magnesium and phosphorous were found highest in Antidesma velutinum. Potassium was the highest in Wood apple followed by in Moneky jack. It was noted that most of the minor fruits have much higher amount of ascorbic acid than the national fruit – Jack fruit ripe, the king fruit – Mango ripe of Bangladesh and exotic fruits – Apple and Grapes. The nutrient values of these minor fruits would make awareness among the people for their mass consumption for healthy life and to grow more minor fruit trees from extinction in order to maintain biodiversity.     

Kozeny–Carman permeability relationship with disintegration process predicted from early dissolution profiles of immediate release tablets

This study was oriented toward the disintegration profiling of the diclofenac sodium (DS) immediate-release (IR) tablets and development of its relationship with medium permeability k_perm based on Kozeny–Carman equation. Batches (L1–L9) of DS IR tablets with different porosities and specific surface area were prepared at different compression forces and evaluated for porosity, in vitro dissolution and particle-size analysis of the disintegrated mass. The k_perm was calculated from porosities and specific surface area, and disintegration profiles were predicted from the dissolution profiles of IR tablets by stripping/residual method. The disintegration profiles were subjected to exponential regression to find out the respective disintegration equations and rate constants k_d. Batches L1 and L2 showed the fastest disintegration rates as evident from their bi-exponential equations while the rest of the batches L3–L9 exhibited the first order or mono-exponential disintegration kinetics. The 95% confidence interval (CI_95%) revealed significant differences between k_d values of different batches except L4 and L6. Similar results were also spotted for dissolution profiles of IR tablets by similarity (f₂) test. The final relationship between k_d and k_perm was found to be hyperbolic, signifying the initial effect of k_perm on the disintegration rate. The results showed that disintegration profiling is possible because a relationship exists between k_d and k_perm. The later being relatable with porosity and specific surface area can be determined by nondestructive tests.     

The Clouding Phenomenon for Anionic Sodium Dodecyl Sulfate + Quaternary Bromides in Polar Nonaqueous-Water-Mixed Solvents

Aqueous sodium dodecyl sulfate (SDS) solutions show clouding in the presence of tetra-n-butylammonium bromide (TBAB) and tetra-n-butylphosphonium bromide (TBPB). In this study, we report the effect of various volume percents of different polar nonaqueous solvents (acetonitrile, AN; dimethylsulfoxide, DMSO; methyl ethylene glycol ether, MC; formamide, FA; ethylene glycol, EG) on the clouding behavior of SDS + quaternary bromide (TBAB or TBPB) systems. The cloud point (CP) was found to decrease with initial increase in the volume percent of the above solvents in mixtures (with water). After a minimum in CP vs. volume percent plots, further increase in the volume percent caused an increase in the CP, followed by a near constant region. The data have been discussed on the basis of the effect of the above solvents on the two types of water present in the system: hydrated water and bulk water. As AN had shown a gradual decrease in the CP to a larger volume percent, it was chosen for detailed studies. Compared to TBAB, TBPB has diminished the effect of AN on CP increase due to its bigger size. The limited CMC data also run parallel to CP results.

Tribological Characterisation of Graphene Oxide as Lubricant Additive on Hypereutectic Al-25Si/Steel Tribopair

The performance of a lubricant greatly depends on the additives it involves. However, recently used additives produce severe pollution when they are burned and exhausted. Therefore, it is necessary to develop a new generation of green additives. Graphene oxide (GO) is considered to be environmentally friendly. The scope of this study is to explore the fundamental tribological behavior of graphene, the first existing 2D material, and evaluate its performance as a lubricant additive. The friction and wear behavior of 0.5 wt% concentrations of GO particles in ethanol and SAE20W50 engine oil on a hypereutectic Al-25Si alloy disc against steel ball was studied at 5 N load. GO as an additive reduced the wear coefficient by 60–80% with 30 Hz frequency for 120 m sliding distance. The minimum value of the coefficient of friction (0.057) was found with SAE20W50 + 0.5 wt% GO. A possible explanation for these results is that the graphene layers act as a 2D nanomaterial and form a conformal protective film on the sliding contact interfaces and easily shear off due to weak Van der Waal's forces and drastically reduce the wear. Scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and Raman spectroscopy were used for characterization of GO and wear scars.     

Field emission of MWCNTs/PANi nanocomposites prepared by ex‐situ and in‐situ polymerization methods

The present work describes the field‐emission properties of multiwalled carbon nanotubes (MWCNTs) coated with conducting polymer polyaniline (PANi). MWCNTs/PANi nanocomposites have been prepared by ex‐ situ polymerization methods and inex‐ situ chemical polymerization and are analyzed by SEM and Raman spectroscopy. It is fairly clear from SEM images that PANi is coated on the surface of MWCNT. SEM image of PANi powder also shows that the powder obtained is PANi nanofibers. It is also observed from SEM images that the shell diameter of MWCNTs depends on PANi content in thenanocomposites. The average outer diameter of MWCNTs increases from 7–15 to 50–80 nm upon PANi coating. Field‐emission study shows that although there is decrease in the value of turnex‐on field E_to and increase in the value field enhancement factor β of the nanocomposites as we go from direct solid‐state mixing method to inex‐ situ chemical polymerization method, the parameters obtained by inex‐ situ polymerization chemical method shows superior field emission. The turn‐on field of the nanocomposites are between 2.5 and 4.5 V/μm and the field enhancement factors are significantly high, between 1.2 × 10³ and 9.2 × 10³ while. PANi nanofibers does not show any field emission. POLYM. COMPOS. 34:1298–1305, 2013. © 2013 Society of Plastics Engineers