A model synthetic approach towards the furanacetal component of azadirachtin: a potent insect antifeedant

In this article, a model synthetic approach towards the furanacetal component of azadirachtin has been described from α-D-glucose. Tandem radical cyclization was the key step for the formation of the desired tricyclic system. The reaction provided a bicyclic system instead of the desired tricyclic molecule. The reason for the unsuccessful tandem cyclization was proposed to be mainly energy factors

Effect of Beam tunnels on Resonant Frequency of Cylindrical Reentrant Cavity

Analytical formulations for the resonant frequency of a reentrant cavity for klystron are available in the literature only for such cavities having a single beam-tunnel. An improved analytical formulation has been proposed in this paper for the calculation of cavity gap-capacitance of reentrant cavities having single and multiple beam-tunnels and its effects on the resonant frequency are studied. The results obtained through analysis have been validated against those obtained from the 3D electromagnetic field simulations and measurements. The proposed analytical formulation provides good estimation of resonant frequency of cavity with single and multiple beam-tunnels

ETHNO-BOTANICAL STUDY OF MEDICINAL PLANTS OF PADDAR VALLEY OF JAMMU AND KASHMIR, INDIA

The Paddar Valley, historically known as Sapphire Valley situated in Kishtwar district, is a prime landmark in the Jammu region of J&K state and is known for its rich cultural and plant diversity because of diverse habitats such as rivers, streams, meadows and steep mountain slopes. The area located in the dry temperate region comprising typical vegetation which disappears completely on the eastern slopes, dominated by a variety of economical species which play an important role in the rural life. The inhabitants are dependent on plant resources for food, fuel, timber, shelter, fodder/forage, household articles and traditional medicines in treating diseases like malaria, cancer, gastro-intestinal ailments, etc. This paper deals with the observations on traditional therapeutic application by the inhabitants of Paddar Valley. The ethno-botanical information on medicinal plants would not only be useful in conservation of traditional cultures and biodiversity but also community health care and drug development. Exploration survey in Paddar Valley has revealed that people collect and sell these medicinal species through local intermediaries / contractors to earn their livelihood. But the scientific cultivation and appropriate post-harvest management would improve employment opportunity and income of local farmers in the region

Design and development of a 60 MHz pre- and IF amplifier with a detector for a microwave receiver

363-366A 60 MHz pre-amplifier and an IF amplifier with a detector designed and fabricated at the National Physical Laboratory, New Delhi , have been described. The amplifiers have been designed for a central frequency of 60 MHz with a bandwidth of 20 MHz and a voltage gain of 35 dB for the pre-amplifier and 50 dB for the IF amplifier. The noise figure achieved was 2.8 dB and gain stability was of the order of ± 0.5 dB . This is followed by a detector and an emitter follower stage. These formed the part of a low noise receiver used in the retrieval of data by microwave radiometers

Design and fabrication of a low noise amplifier for a microwave receiver

172-176A low noise amplifier employed in the microwave/mm-wave radiometers is used to amplify a signal to overcome the inherent drift in the synchronous detector to achieve a higher degree of stability. A low noise amplifier designed and fabricated is described. The amplifier has been designed for a gain of 60 dB with noise less than 10 mV peak-to-peak, having an output impedance of 100Ω and an input impedance of 1.5 MΩ. The supply used for design consideration was 24 V DC

Reaction of epoxides with activated DMSO reagent. General method for synthesis of α-chlorocarbonyl compounds: application in asymmetric synthesis of (3S)-2,3-oxidosqualene

Reaction of a variety of epoxides with DMSO-Oxalyl chloride in the presence of a catalytic amount of methanol and a base was studied. Disubstituted epoxides gave α-chloroketones in high yields. Aliphatic terminal epoxide underwent opening reaction to provide α-chloroketone as a major product. Trisubstututed epoxides provided α-chloroketones as major products through the formation of more stable carbocation. In case of a homoallylic alcohol, enedione was obtained. The efficiency of the method was shown by applying it to the enantioselective synthesis of (3S)-2,3-oxidosqualene

Asymmetric synthesis of 5-hexadecanolide, pheromone of the queen of the Oriental hornet, Vespa orientalis

An efficient asymmetric synthesis of 5-hexadecanolide from a chiral epoxide is described. Both the enantiomeric forms of the chiral epoxide are easily available from mannitol and ascorbic acid. The key step in the synthesis is the formation of δ-lactone from δ-hydroxy acetal using m-CPBA and BF<SUB>3</SUB>·OEt<SUB>2</SUB>

DDQ as a mild and efficient catalyst for deprotection of tetrahydropyranyl ethers

In the presence of a catalytic amount of 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ), tetrahydropyranyl ethers are readily hydrolysed to their corresponding alcohols in wet acetonitrile under mild conditions

Prevalence of dementia among Kashmiri migrants

<b>Background:</b> Neurological diseases are common disorders resulting in the loss of productive life and disability. Dementia is becoming a major public health problem in the developing world also. <b> Aim:</b> To ascertain the prevalence of dementia among Kashmiri Pandit population aged 60 years and above. <b> Materials and Methods:</b> A cross-sectional survey was conducted among the elderly population of the Kashmiris living in a migrant camp. We developed and used a Kashmiri version of the Mini-Mental State Examination as the test instrument, and a score below 24 was considered indicative of dementia. A functional ability questionnaire was also administered to the subjects. A neurologist carried out the examinations. <b>Results:</b> A sample comprising 200 subjects (95 males and 105 females) were evaluated. The prevalence of dementia is 6.5&#x0025; among the Kashmiri Pandit population aged 60 years and above, which is higher than that reported from other parts of India

Template synthesis, characterization and catalytic behaviour of oxovanadium(IV) macro cyclic complexes

995-997The oxovanadium(IV )-directed condensation of 2,4- pentane dione with diamines [ethylenediamine(a), 1,2- diaminopropane(b), 1,3-diaminopropane(c) and o- phenylenediamine(d)] in ethanol produces macrocyclic complexes of the type [VO(L)(SO4)].3H2O [1a-1d] in high yields. The complexes have been characterized by elemental analyses, conductance measurements, IR, electronic and ESR spectra. They act as active catalysts at room temperature for olefin epoxidation in the presence of t-butylhydroperoxide(TBHP). Norbornene gives exo epoxide. Competitive epoxidation of cycloolefins follows the order: norbornene > cyclohexene. The anionic surfactants (SLS) promote epoxide formation when catalysts 1a and 1c are used