Molecular delivery to cells facilitated by corona ion deposition

A novel method of inducing the delivery of nonpermeant molecules to the cytosol of cells is presented in this paper. Corona discharge in air was utilized to produce ions that in turn were deposited onto the liquid surface of media containing cultured cells. Murine B16 melanoma cells were used to demonstrate the molecular delivery of fluorescent dye calcein, the drug bleomycin, and a nucleic acid stain SYTOX-green. None of these molecules penetrate cells with intact membranes. Following the corona treatment, cells were observed to admit significant quantities of these molecules from the culture media, relative to control samples. Further, greater than 95% viability of treated cells was observed by Trypan Blue assay. This method may provide an attractive alternative to electroporation where a physical contact between electrodes and cells is needed to deliver molecules to the cytosol.     

Coupling exothermic and endothermic reactions in adiabatic reactors

The steady state and the dynamic behavior of coupling exothermic and endothermic reactions in directly coupled adiabatic packed bed reactors (DCAR) are analyzed using one-dimensional pseudo-homogeneous plug flow model. Two different configurations of DCAR (simultaneous DCAR—SIMDCAR and sequential DCAR—SEQDCAR) are investigated. In SIMDCAR, the catalyst bed favors both exothermic and endothermic reactions and both reactions occur simultaneously. SEQDCAR has alternating layers of catalyst beds for exothermic and endothermic reactions and hence the exothermic and endothermic reactions occur in a sequential fashion. The performance of both reactors, in terms of conversion achieved and manifested hot spot behavior, is compared with that of the co-current heat exchanger type reactor. Various possible operational regimes in SIMDCAR have been classified and the conditions for the existence of hot spots or cold spots in SIMDCAR are obtained analytically for the first order reactions with equal activation energies. The reactor behavior for the reactions with non-equal activation energies is also presented. The preliminary criteria for the selection of suitable reactor type and the general bounds on the reaction parameters to obtain the desired conversion for endothermic reaction with minimal temperature rise are proposed. The dynamic behavior of these reactors is important for control applications and we have reported some of the transient behavior.     

Safety evaluations on ethanolic extract of red cabbage (Brassica oleracea L.) in mice

The present study has carried out safety evaluations on an ethanolic extract of red cabbage (RC) leaves in terms of acute and subchronic oral toxicity tests as per Organisation for Economic Cooperation and Development (OECD) guidelines in Swiss albino mice. Single-dose administration of RC extract (1000, 2000, 3000, 4000, or 5000 mg/kg body weight) to Swiss albino mice did not manifest toxicity or any significant adverse behavioral alterations. Chronic administration of RC extract (1000, 2000, and 3000 mg/kg body weight) for 28 d also did not register any significant alterations in fluid intake, organ weights, plasma lipid profile, plasma creatine kinase-MB, lactate dehydrogenase, aspartate transaminase, alanine transaminase, creatinine, electrolytes, and calcium levels, and the total blood count showed a nonsignificant change. However, significant reduction in body-weight gain, food intake, red blood cell count, and hemoglobin content along with higher alkaline phosphatase, bilirubin, and urea levels was observed in mice treated with 3000 mg/kg body weight for 28 d. Since there was no mortality up to a dose of 5000 mg/kg body weight, 50% lethal dose (LD(50)) could not be determined, and hence, it can be assumed that, LD(50) of RC extract is >5000 mg/kg. No observable adverse effect level dose of the RC extract was found to be 2000 mg/kg body weight. Hence, consumption of RC extract for various medicinal purposes is safe. Practical Application: RC is a popularly consumed foodstuff that has been ubiquitously reported to exert medicinal properties. It is mandatory to understand the highest permissible consumption limit of any food supplement to avoid toxicity. This study establishes the safe dose of RC. These results can be of relevance for the scientific fraternity as well as laymen who consume this vegetable or its phytochemical preparation.     

Modeling a shallow water acoustic communication channel using environmental data for seafloor sensor networks

Development of communication channels for underwater sensor networks holds many unique challenges. Communication near the bottom of the ocean is no exception as the effects of reflection and refraction greatly affect how acoustic waves travel between a source and an intended receiver. Deployment and testing in the ocean are difficult and expensive; thus there is a strong reliance on models to aid in design and development of a potential network. Since each ocean region can present very unique challenges, it is of great value to model an environment based on real environmental parameters whenever available. A well prepared channel model will provide the ability to show channel capacity as it relates to node positions, as well as showing the performance of modulation techniques to an environment with propagation characteristics and path arrivals. This channel model will also be implementable into a simulation package to allow for high quality simulation of higher level protocols. The proposed method has proved to be a useful tool in modeling a particular environment and provides insight into underwater sensor node placement and modulation. Copyright © 2009 John Wiley & Sons, Ltd.     

Epitaxial ZnO/Pt layered structures and ZnO-Pt nanodot composites on sapphire (0001)

We report the epitaxial growth and properties of ZnO-Pt layered structures and ZnO-Pt nanodot composites on sapphire (0001) substrates fabricated by using the pulsed laser deposition (PLD) technique. Heteroepitaxial growth of these structures was accomplished by using domain-matching epitaxy. The heterostructures were characterized using x-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), optical transmittance, photoluminescence, and electrical resistivity measurements. XRD and HRTEM experiments revealed the epitaxial nature of these structures, with orientation relationship between ZnO and Pt, as [0001]_ZnO∥[111]_Pt and [ 110]_ZnO∥[011]_Pt, which is equivalent to no rotation between ZnO and Pt. For Pt epitaxy on (0001) sapphire, the epitaxial relationship was determined to be [001]_Pt∥[0001]_Sap and [110]_Pt∥[01 0]_Sap, which is equivalent to a 30° rotation in the basal plane. Electrical and optical measurements showed that these heterostructures exhibit very high electrical conductivity and at the same time possess interesting optical transmittance spectra and exhibit room temperature photoluminescence characteristics.     

Studies on the Thermophilic Amylolytic Enzymes of a Strain of Aspergillus niger

A laboratory isolate of Aspergillus niger elaborated considerable quantities of exocellular amylolytic enzymes. The enzymes exhibited a highly thermophilic nature. The culture filtrate exhibited two pH optima for dextrinogenic and one for saccharifying activity. Electrophoretic studies of the culture filtrate revealed three major proteins, two exhibiting α-amylase and one amyloglucosidase activity.     

果胶酶处理对各种棉的影响

果胶质存在于棉纤维的表层,由于其中85%的羧基被甲基化,故它的存在影响着原棉的吸湿性.棉纤维果胶酶处理是利用局部水解破坏表层连续性的原理.过去,棉纱通常由不同种类的棉混合加工而成.分析了果胶酶活性对棉纤维的影响以及酶处理对不同棉纤维、棉纤维重量损失以及棉纤维束纤维强度的影响.     

Fault diagnosis of roller bearing using fuzzy classifier and histogram features with focus on automatic rule learning

Roller bearing is one of the most widely used elements in rotary machines. Condition monitoring of such elements is conceived as pattern recognition problem. Pattern recognition has three main phases: feature extraction, feature selection and feature classification. Histogram features can be used for fault diagnosis of roller bearing. This paper presents the use of decision tree for selecting best few histogram features (bin ranges) that will discriminate the fault conditions of the bearing from given train samples. These features are extracted from vibration signals. A rule set is formed from the extracted features and fed to a fuzzy classifier. The rule set necessary for building the fuzzy classifier is obtained largely by intuition and domain knowledge. This paper also presents the usage of decision tree to generate the rules automatically from the feature set. The vibration signal from a piezoelectric transducer is captured for the following conditions – good bearing, bearing with inner race fault, bearing with outer race fault, and inner and outer race fault. The histogram features were extracted and good features that discriminate the different fault conditions of the bearing were selected using decision tree. The rule set for fuzzy classifier is obtained by once using the decision tree again. A fuzzy classifier is built and tested with representative data. The results are found to be encouraging.     

Dynamic evolution of oxide scale on the surfaces of feed stock particles from cracking and segmenting to peel-off while cold spraying copper powder having a high oxygen content

The oxide scale present on the feedstock particles is critical for inter-particle bond formation in the cold spray(CS)coating process,therefore,oxide scale break-up is a prerequisite for clean metallic contact which greatly improves the quality of inter-particle bonding within the deposited coating.In general,a spray powder which contains a thicker oxide scale on its surface(i.e.,powders having high oxygen content)requires a higher critical particle velocity for coating formation,which also lowers the deposition efficiency(DE)making the whole process a challenging task.In this work,it is reported for the first time that an artificially oxidized copper(Cu)powder containing a high oxygen content of 0.81 wt.%with a thick surface oxide scale of 0.71μm.,can help achieve an astonishing increment in DE.A transition of surficial oxide scale evolution starting with crack initiations followed by segmenting to peeling-off was observed during the high velocity particle impact of the particles,which helps in achieving an astounding increment in DE.Single-particle deposit observations revealed that the thick oxide scale peels off from most of the sprayed powder surfaces during the high-velocity impact,which leaves a clean metallic surface on the deposited particle.This makes the successive particles to bond easily and thus leads to a higher DE.Further,owning to the peeling-off of the oxide scale from the feedstock particles,very few discontinuous oxide scale segments are retained at inter-particle boundaries ensuring a high electrical conductivity within the resulting deposit.Dependency of the oxide scale threshold thickness for peeling-off during the high velocity particle impact was also investigated.     

Dual Defect-Passivation Using Phthalocyanine for Enhanced Efficiency and Stability of Perovskite Solar Cells

Semiconducting molecules have been employed to passivate traps extant in the perovskite film for enhancement of perovskite solar cells (PSCs) efficiency and stability. A molecular design strategy to passivate the defects both on the surface and interior of the CH₃NH₃PbI₃ perovskite layer, using two phthalocyanine (Pc) molecules (NP-SC₆-ZnPc and NP-SC₆-TiOPc) is demonstrated. The presence of lone electron pairs on S, N, and O atoms of the Pc molecular structures provides the opportunity for Lewis acid–base interactions with under-coordinated Pb²⁺ sites, leading to efficient defect passivation of the perovskite layer. The tendency of both NP-SC₆-ZnPc and NP-SC₆-TiOPc to relax on the PbI₂ terminated surface of the perovskite layer is also studied using density functional theory (DFT) calculations. The morphology of the perovskite layer is improved due to employing the Pc passivation strategy, resulting in high-quality thin films with a dense and compact structure and lower surface roughness. Using NP-SC₆-ZnPc and NP-SC₆-TiOPc as passivating agents, it is observed considerably enhanced power conversion efficiencies (PCEs), from 17.67% for the PSCs based on the pristine perovskite film to 19.39% for NP-SC₆-TiOPc passivated devices. Moreover, PSCs fabricated based on the Pc passivation method present a remarkable stability under conditions of high moisture and temperature levels.