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We report influence of magnetic flux on the quantum transport in a aromatic $\pi$ conjugate system made up of two phenyl rings separated by an insulator group. In the presence of a transverse magnetic field the transmission, the dipole moment and the energy of the system gives oscillatory behaviour with flux $\phi$, threaded by the molecular ring showing flux quantum periodicity. This aspect may be utilized in designing nano-scale electronic devices.

Synthesis of electroluminescent ZnS:Cu, Br phosphor by a number of routes has been presented along with their brightness-voltage, brightness-frequency, brightness-waveform and spectral energy distribution studies. The sample fired in N2 atmosphere with aluminum and bromine shows predominantly green emission with a peak around 530 nm whereas the sample prepared under H2S and HBr shows the broadest emission spectrum with multiple peaks. These peaks may arise out of different possible bands of copper, self-activated luminescence of ZnS and association of copper with some of the donor levels formed because of the higher reactivity of HBr. All the samples have been found to obey the relation B=B0 exp.(−b/V0.5) which has been discussed using bipolar tunnel emission model. The frequency variation of brightness is linear. Samples containing bromine show multiple secondary peaks indicating that bromine helps in formation of multiple shallow traps.

1, 3 - Disubstituted- 4 - (1′, 3′- dithiolane /dithiane - 2′- ylidene) - 2 -pyrazolin-5-one derivatives like (1a–c), (2a–c), (3a–c) have been obtained by condensation of 2-pyrazolin-5-ones (1), (2) and (3) with carbon disulfide in presence of triethylamine followed by the reaction with 1,2-dibromoethane (4a), 1,3-dibromopropane (4b) and 1,3-dibromobutane (4c) respectively.

From the point of view of the possibility of the existence of life on Europa, we should consider a lake called Vostok, which is the largest of about 80 subglacial lakes in Antarctica. Its surface is of approximately 14,000 km2and its volume is 1,800 km3. Indeed, this Ontario-sized lake in Eastern Antarctica is also deep, with a maximum depth of 670 m. On the other hand, from the point of view of microbiology, the habitat analogue provided by Lake Vostok for the Europa environment seems appropriate (Chela-Flores, 2001). At the time of writing, the ice above the lake has been cored to a depth of over 3,600 m, stopping just over 100 m over the surface of the lake itself. This work has revealed great diversity of single-celled organisms: yeast, actinomycetes, mycelian fungi (which remain viable for almost 40,000 years), diatoms, and most interestingly, 200,000 year old bacteria. Besides, it appears that water temperatures do not drop too far below zero centigrade, with the possibility of geothermal heating raising the temperatures above this level.

We report an investigation of electron conduction in oligophenyl based double barrier molecular device. We have carried out analytical calculations and numerical simulations on isolated molecules, consisting of aromatic "pi" conjugated system made up of three phenyl rings separated by insulator groups -CH_{2}-, -SiH_{2}-, -GeH_{2}- and -SnH_{2}-. We show analytically as well as numerically that when the two insulator groups are different an asymmetric electron transport in the presence of external electric field is possible,thus resembling a diode which allows one way electron transport., 16 figures

Oxidative stress (OS) is a major concern in idiopathic male infertility as elevated levels of reactive oxygen species (ROS) in the semen is believed to adversely affect sperm functional competence and damage both nuclear and mitochondrial DNA. Therefore, identifying infertile men with seminal OS may be used as a valuable tool in the assessment of male infertility. Semen is a complex mixture of spermatozoa and seminal plasma which is rich in enzymatic and non-enzymatic antioxidants. However, the measurement of ROS in the semen and its application in male infertility assessment is poorly understood. The aim of the present study was to compare the significance of ROS measurement in washed and neat semen. The study included 65 infertile men with abnormal semen (SA) parameters, 17 infertile men with normal semen (NS) parameters and 43 fertile controls (FC). ROS levels in both washed and neat semen were measured by luminol-dependent chemiluminescence assay and the values were expressed as 104 RLU per minute per 20 million spermatozoa. The levels of ROS in both washed and neat semen were found to be significantly higher (P

1, 3 - Disubstituted- 4 - (1′, 3′- dithiolane /dithiane - 2′- ylidene) - 2 -pyrazolin-5-one derivatives like (1a–c), (2a–c), (3a–c) have been obtained by condensation of 2-pyrazolin-5-ones (1), (2) and (3) with carbon disulfide in presence of triethylamine followed by the reaction with 1,2-dibromoethane (4a), 1,3-dibromopropane (4b) and 1,3-dibromobutane (4c) respectively.

The discovery of extreme environments with organisms adapted to these conditions has made them useful analogies for the presence of life beyond the Earth, whether autochthonous, or by the transport of microorganisms between different bodies of the solar system. This latter possibility has been known as the hypothesis of panspermia.