616 research outputs found
Profiling procedures. 1: Anodic oxidation. 2: OLS profile program
Instructions for use of anodic oxidation apparatus in conjunction with computer program to obtain electrically active concentration profiles of doped silicon wafer
Food irradiation: Applications, public acceptance and global trade
Food irradiation is the treatment of food products by a definite kind of energy. The process involves exposing the packed or bulked food to the rays of the sun. Food irradiation processing that entails combating post-harvest losses, curtailing food-borne disease and overcoming quarantine barriers has been pursued since the mid-50s. The scientific basis and technological adaptation of the process have been well established more than any other post-harvest food processing techniques. In 1981, the FAO/IAEA/WHO Joint Expert Committees on the wholesomeness of irradiated food (JECFI) concluded, “the irradiation of any food commodity up to an overall average dose of 10 KGy presents notoxicological hazard”. The benefits of irradiation technology in addressing post-harvest food problems are, in some cases, unique and can improve the quality of a number of food products by eliminating the risk of pathogenic contaminants. The potential of this technology has been well perceived in recent years in the wake of food-borne disease caused by pathogenic organisms. In fact, many parts of the world are considering food irradiation as a technological saviour in finding a suitable solution for the problems caused by pathogens in food. Irradiation can be regarded as a useful tool to attain food security in the 21st century. Many consumers have misconceptions about the technology and suppose that it makes food radioactive. But, when the method is explained to them they become normally more in favor of it. Over 50 countries have regulatory approvals in place for irradiation of one or more food products. 30 countries are practically applying this technology for a number of food items
Delay-Reliability Trade-off in MIMO-Enabled IEEE 802.11-Based Wireless Sensor and Actuator Networks
AbstractOne of the main challenges in Wireless Sensor and Actuator Networks (WSAN) is the delay caused by shared and nondeterministic behavior of wireless communication medium. The Retry-Limit parameter of IEEE 802.11 standard can be used to control packet reliability, whereas other parameters mostly effect on the packet delay. In this paper, at first the delay-reliability trade-off in WSANs based on MIMO-Enabled IEEE 802.11 standard, utilizing Enhanced Distributed Channel Access (EDCA) at Medium Access Control (MAC) layer and Maximum Likelihood Spatial Multiplexing at PHYsical (PHY) Layer is studied. Then two simple adaptive schemes have been proposed to minimize packet delay while satisfying the required reliability at noisy factory environment
Diorganotin(IV) complexes with 2-furancarboxylic acid hydrazone derivative of benzoylacetone : synthesis, X-ray structure, antibacterial activity, DNA cleavage and molecular docking
Two new diorganotin(IV) complexes, Me2SnL and Ph2SnL, have been synthesized from the reaction of
Me2SnCl2 and Ph2SnCl2 with the hydrazone H2L [H2L \ubc (Furan-2-yl) (5-hydroxy-3-methyl-5-phenyl-4,5-
dihydro-1H-pyrazol-1-yl)-methanone] derived from furan-2-carbohydrazide and benzoylacetone. The
new compounds have been characterized by elemental and spectroscopic analyses. The crystal structures
of the monohydrate form of the ligand and of the Me2SnL derivative have been also determined by X-ray
crystallography. Experimental evidences confirm the existence of the hydrazone ligand exclusively in
cyclic form in both solution and solid state. On coordination to tin the hydrazone undergoes a ring
opening reaction and a doubly deprotonation to act as a tridentate ligand via imine nitrogen and enolic
oxygens. The tin atom in the complexes is five coordinate with geometry between square-pyramidal and
trigonal-bipyramidal. The in vitro antibacterial activity of ligand and its complexes has been evaluated
against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli
and Pseudomonas aeruginosa) bacteria. The interaction between compounds with bacterial DNA was also
studied by molecular docking. Our findings indicate that diphenyltin(IV) complex, by binding to DNA via
minor groove to TATA sequence in genes upstream, has good activities along with the standard antibacterial
drugs. Our agarose-gel electrophoresis experiments show that the ligand exert DNA cleavage,
while Me2SnL and Ph2SnL did not
Protection of hippocampal CA1 neurons against ischemia/Reperfusion injury by exercise preconditioning via modulation of Bax/Bcl-2 ratio and prevention of Caspase-3 Activation
Introduction: Ischemia leads to loss of neurons by apoptosis in specific brain regions, especially in the hippocampus. The purpose of this study was investigating the effects of exercise preconditioning on expression of Bax, Bcl-2, and caspase-3 proteins in hippocampal CA1 neurons after induction of cerebral ischemia. Methods: Male rats weighing 260-300 g were randomly allocated into three groups (sham, exercise, and ischemia). The rats in exercise group were trained to run on atreadmill 5 days a week for 4 weeks. Ischemia was induced by the occlusion of both common carotid arteries (CCAs) for 20 min. Levels of expression of Bax, Bcl-2, and caspase-3 proteins in CA1 area of hippocampus were determined by immunohistochemical staining . Results: The number of active caspase-3-positive neurons in CA1 area were significantly increased in ischemia group, compared to sham-operated group (P<0.001), and exercise preconditioning significantly reduced the ischemia/reperfusion-induced caspase-3 activation, compared to the ischemia group (P<0.05). Also, results indicated a significant increase in Bax/Bcl-2 ratio in ischemia group, compared to sham-operated group (P<0.001). Discussion: This study indicated that exercise has a neuroprotective effects against cerebral ischemia when used as preconditioning stimuli
Tidal breathing parameters measured using structured light plethysmography in healthy children and those with asthma before and after bronchodilator
Structured light plethysmography (SLP) is a light‐based, noncontact technique that measures tidal breathing by monitoring displacements of the thoracoabdominal (TA) wall. We used SLP to measure tidal breathing parameters and their within‐subject variability (v) in 30 children aged 7–16 years with asthma and abnormal spirometry (forced expiratory volume in 1 sec [FEV1] <80% predicted) during a routine clinic appointment. As part of standard care, the reversibility of airway obstruction was assessed by repeating spirometry after administration of an inhaled bronchodilator. In this study, SLP was performed before and after bronchodilator administration, and also once in 41 age‐matched controls. In the asthma group, there was a significant increase in spirometry‐assessed mean FEV1 after administration of bronchodilator. Of all measured tidal breathing parameters, the most informative was the inspiratory to expiratory TA displacement ratio (IE50SLP, calculated as TIF50SLP/TEF50SLP, where TIF50SLP is tidal inspiratory TA displacement rate at 50% of inspiratory displacement and TEF50SLP is tidal expiratory TA displacement rate at 50% of expiratory displacement). Median (m) IE50SLP and its variability (vIE50SLP) were both higher in children with asthma (prebronchodilator) compared with healthy children (mIE50SLP: 1.53 vs. 1.22, P < 0.001; vIE50SLP: 0.63 vs. 0.47, P < 0.001). After administration of bronchodilators to the asthma group, mIE50SLP decreased from 1.53 to 1.45 (P = 0.01) and vIE50SLP decreased from 0.63 to 0.60 (P = 0.04). SLP‐measured tidal breathing parameters could differentiate between children with and without asthma and indicate a response to bronchodilator
Survey on helminthic and protozoan contaminations in alimentary canal of ostrich at Tehran Province slaughterhouses
Ostrich- farming has been prevalent in South Africa as the main habitat of this bird since several centuries ago and the flocks of ostrich have been reared similar to other herds or tame animals and flocks of birds. It can be also possibly reared in other countries of the world. At present, whereas skin, flesh, and other organs of this bird are consumed thus farming of this bird is vitally important in the world.With respect to growing population of ostrich flocks in Tehran Province and the affiliated towns and importance of this issue in terms of providing meat and protein for the consuming market and in order to improve production yield it requires for diagnosis of and prophylaxis of the related common diseases for this animal particularly the parasitic diseases. It was tried to study by referring to 16 ostrich farming centers and visiting and sample from 55 carcasses of and or fatalities of the animal for this purpose. Then, after washing the contents of intestine of this bird and passing of those through screen (100) and staining with loop they were analyzed. Also lamella was prepared from intestinal wall and after staining the probability of existing protozoans was explored. No helminthic parasite was observed in the samples and Emeria oocyte was seen in three cases.Keywords: Helminthic and protozoan parasites, Ostrich, Tehran Provinc
Temporal visual resolution and disease severity in MS
OBJECTIVE: To examine temporal visual resolution assessed as critical flicker frequency (CFF) in patients with MS and to investigate associations with visual system damage and general disability and cognitive function. METHODS: Thirty-nine patients with MS and 31 healthy controls (HCs) were enrolled in this cross-sectional study and underwent CFF testing, high- and low-contrast visual acuity, alertness and information processing speed using the paced auditory serial addition task (PASAT), and retinal optical coherence tomography (OCT). In patients with MS, visual evoked potentials (VEPs) and Expanded Disability Status Scale (EDSS) scores were assessed. RESULTS: CFF in patients with MS (mean ± SD: 40.9 ± 4.4 Hz) was lower than in HCs (44.8 ± 4.4 Hz, p < 0.001). There was no significant CFF difference between eyes with and without previous optic neuritis (ON). CFF was not associated with visual acuity, VEP latency, the peripapillary retinal nerve fiber layer thickness, and the combined ganglion cell and inner plexiform layer volume. Instead, reduced CFF was associated with worse EDSS scores (r(2) = 0.26, p < 0.001) and alertness (r(2) = 0.42, p = 0.00042) but not with PASAT (p = 0.33). CONCLUSION: CFF reduction in MS occurs independently of ON and structural visual system damage. Its association with the EDSS score and alertness suggests that CFF reflects global disease processes and higher cortical processing rather than focal optic nerve or retinal damage
The iconicity toolbox: empirical approaches to measuring iconicity
Growing evidence from across the cognitive sciences indicates that iconicity plays an
important role in a number of fundamental language processes, spanning learning,
comprehension, and online use. One benefit of this recent upsurge in empirical work is the
diversification of methods available for measuring iconicity. In this paper, we provide an
overview of methods in the form of a ‘toolbox’. We lay out empirical methods for measuring
iconicity at a behavioural level, both in the perception, production and comprehension of
iconic forms. We also discuss large-scale studies that look at iconicity on a system-wide level,
based on objective measures of similarity between signals and meanings. We give a detailed
overview of how different measures of iconicity can better address specific hypotheses,
providing greater clarity when choosing testing methods
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