Reduction-Triggered Doxorubicin Delivery by Self-Assembled Nanospheres of Lipoylated Caffeine

This study reports a new amphiphilic bioconjugate (CAFF-LA) derived from the lipoylation of a hydroxyethyl derivative of caffeine. In water, CAFF-LA self-assembles into nanospheres with an average size of 155 nm, as evidenced from dynamic light scattering and electron microscopy studies. The nanospheres are stable in serum and could be disintegrated upon exposure to the reducing environment of dithiothreitol (DTT; 10 mM) and glutathione (GSH; 10 mM). These nanospheres easily encapsulate the chemotherapy medication, doxorubicin (DOX), and demonstrate an efficacious transport into doxorubicin-resistant cervical cancer (HeLa) cells, wherein a marked induction in apoptosis and significantly lower IC₅₀ have been observed when compared to that of free drug. The in vitro assessment of cell viability and hemocompatibility present these nanospheres as potentially safe and efficient intracellular reduction stimulus-responsive drug-delivery vehicles.     

Studien zur Biochemie holzzerstörender Pilze—Vierte Mitteilung Zersetzung von Holz und anderen Stoffen

Zusammenfassung Das Wachstum von Polystictus sanguineus auf flüssig Pepton, sowie auf Holz in Form von S?gemehl, Hobelsp?nen und Holzst?ben wurde verfolgt. Glucose wurde mehr aufgezehrt als Pepton. Reine Cellulose wurde in Peptonkultur nicht angegriffen. Das Pilzwachstum endete nach etwa 4 bis 4 1/2 Monaten. N?here Untersuchung der Holzf?ule ergab, da? der Pilz ein „Wei?f?ulepilz” ist insofern, als Lignin mehr angegriffen wird als die Cellulose im Holz. Das Verh?ltnis Cellulose/Lignin w?chst mit zunehmender F?ulnis und betr?gt nach 4 Monaten bei S?gemehl und Hobelsp?nen etwa 50% mehr als ursprünglich und bei Holzst?ben etwa 13% mehr als ursprünglich.     

A Computer Interface for Data Acquisition from a Pulsed Nuclear Magnetic Resonance Spectrometer

ABSTRACT

A interface is described for rapid data acquisition from a pulsed nuclear magnetic resonance (NMR) spectrometer. The system is built using an IBM compatible PC/XT and a commercial data acquisition card. The computerization has been accomplished without making any changes in the commercial spectrometer. The data acquisition program is written in Basic using the driver routines supplied along with the data acquisition card. The data analysis is carried out using a non-linear, least square curve fitting procedure.     

A BBO-based algorithm for slope stability analysis by locating critical failure surface

Neural Computing and Applications - Determination of the critical failure surface is performed in stability evaluation process for road cut slope, embankments, dam, excavations, retaining walls and...     

Conifer-Derived Metallic Nanoparticles: Green Synthesis and Biological Applications

The use of metallic nanoparticles in engineering and biomedicine disciplines has gained considerable attention. Scientists are exploring new synthesis protocols of these substances considering their small size and lucrative antimicrobial potential. Among the most economical techniques of synthesis of metallic nanoparticles via chemical routes, which includes the use of chemicals as metal reducing agents, is considered to generate nanoparticles possessing toxicity and biological risk. This limitation of chemically synthesized nanoparticles has engendered the exploration for the ecofriendly synthesis process. Biological or green synthesis approaches have emerged as an effective solution to address the limitations of conventionally synthesized nanoparticles. Nanoparticles synthesized via biological entities obtained from plant extracts exhibit superior effect in comparison to chemical methods. Recently, conifer extracts have been found to be effective in synthesizing metallic nanoparticles through a highly regulated process. The current review highlights the importance of conifers and its extracts in synthesis of metallic nanoparticles. It also discusses the different applications of the conifer extract mediated metallic nanoparticles.     

A dual photoelectrode-based double-chambered microbial fuel cell applied for simultaneous COD and Cr (VI) reduction in wastewater

Cerium oxide (CeO₂) and cuprous oxide (Cu₂O) were used for the first time as photoanode and photocathode, respectively, in a microbial fuel cell (MFC) for simultaneous reduction of chemical oxygen demand (COD) and Cr(VI) in wastewater. The photoelectrodes, viz. Photoanode and photocathode were separately prepared by impregnating activated carbon fiber (ACF) with the respective metal oxide nanoparticles, followed by growing carbon nanofibers (CNFs) on the ACF substrate using catalytic chemical vapor deposition. The MFC, operated under visible light irradiation, showed reduction in COD and Cr(VI) by approximately 94 and 97%, respectively. The MFC also generated high bioelectricity with a current density of ~6918 mA/m² and a power density of ~1107 mW/m². The enhanced performance of the MFC developed in this study was attributed to the combined effects of the metal oxide photocatalysts, the graphitic CNFs, and the microporous ACF substrate. The MFC based on the inexpensive transition metal oxides-based photoelectrodes developed in this study has a potential to be used at a large scale for treating the industrial aqueous effluents co-contaminated with organics and toxic Cr(VI).     

Optimisation of ISI interval using genetic algorithms for risk informed in-service inspection

Risk Informed In-Service Inspection (RI-ISI) aims at prioritising the components for inspection within the permissible risk level thereby avoiding unnecessary inspections. Various constraints such as risk level, radiation exposure to the workers and cost of inspections are encountered, while planning the inspection programme. This problem has been attempted to solve using genetic algorithms, which has already established its suitability in optimizing Surveillance and Maintenance activities in Nuclear Power Plants. The paper describes the application of genetic algorithm in optimizing the ISI of feeders, which are large in number and also fall in the same inspection category.     

A multiply-by-3 coupled-ring oscillator for low-power frequency synthesis

A frequency-synthesis technique which extracts the Nth harmonic from an N-stage oscillator is presented. This technique enables significant power savings in the prescaler of a frequency synthesizer. The maximum achievable voltage swing from such an oscillator is estimated. To study this technique, a multiply-by-3 circuit with two 180/spl deg/-coupled single-ended three-stage ring oscillators has been fabricated in 0.24-/spl mu/m CMOS, designed to work in the 902-928-MHz ISM band (U.S. and Canada). It provides two outputs: one at the normal operating frequency of the oscillator and the other at three times that frequency. The circuit can work at voltages as low as 1.3 V, while consuming 210 /spl mu/A of current.     

Effects of halothane and isoflurane on carbon monoxide-induced relaxations in the rat aorta

BACKGROUND: Halothane and isoflurane previously were reported to attenuate endothelium-derived relaxing factor/nitric oxide-mediated vasodilation and cyclic guanosine monophosphate (cGMP) formation in isolated rat aortic rings. Carbon monoxide has many chemical and physiologic similarities to nitric oxide. This study was designed to investigate the effects of halothane and isoflurane on carbon monoxide-induced relaxations and cGMP formation in the isolated rat aorta. METHODS: Isometric tension was recorded continuously from endothelium denuded rat aortic rings suspended in Krebs-filled organ baths. Rings precontracted with submaximal concentrations of norepinephrine were exposed to cumulative concentrations of carbon monoxide (26-176 microM). This procedure was repeated three times, with anesthetics delivered 10 min before the second procedure. Carbon monoxide responses of rings contracted with the same concentration of norepinephrine (10(-6) M and 2 x 10(-6) M) used in the anesthetic-exposed preparations also were examined. The concentrations of cGMP were determined in denuded rings using radioimmunoassay. The rings were treated with carbon monoxide (176 microM, 30 s) alone, or carbon monoxide after a 10-min incubation with halothane (0.34 mM or 0.72 mM). To determine whether the sequence of anesthetic delivery influenced results, vascular rings pretreated with halothane were compared with nonpretreated rings. RESULTS: Carbon monoxide (26-176 microM) caused a dose-dependent reduction of norepinephrine-induced tension, with a maximal relaxation of 1.51 +/- 0.07 g (85 +/- 7% of norepinephrine-induced contraction). Halothane (0.34 mM and 0.72 mM) significantly attenuated the carbon monoxide-induced relaxations, but only the highest concentration of isoflurane (0.53 mM) significantly attenuated the carbon monoxide-induced relaxations. Carbon monoxide (176 microM) significantly increased cGMP content (+88.1 +/- 7.1%) and preincubation of the aortic rings with halothane (0.34 mM and 0.72 mM) inhibited this increase (-70.7 +/- 6.8% and -108.1 +/- 10.6%, respectively). When aortic rings and carbon monoxide were added simultaneously to Krebs solution equilibrated with halothane (0.72 mM), no inhibition of cGMP formation occurred. CONCLUSION: Carbon monoxide-induced endothelium-independent relaxations of rat aortic rings were decreased by clinically relevant concentrations of halothane and isoflurane. The carbon monoxide-induced elevations of cGMP were attenuated by halothane only when the anesthetic was incubated with aortic rings before carbon monoxide treatment. The possible clinical significance of the actions of the anesthetics on this endogenous vasodilator is yet to be determined.