Energy measurement of 241Am-9Be neutrons by tagged neutron time-of-flight.

Neutron energy spectrum of a 241Am-9Be source was measured in the energy range of 0.3 to ∼ 6.5 MeV using γ-ray tagged neutron time-of-flight method. BC501A type organic liquid scintillator detector was used at a flight path of 175 cm to detect neutrons with good energy resolution. The de-excitation γ-ray emitted in coincidence with neutrons was detected using a fast BaF2 detector. The measured data has been compared with the ISO 8529-2 standard neutron reference spectrum and found good agreement in the overlapping energy region. Present measurement applied efficiency correction to the data and extended up to 0.3 MeV in the lower energy region compared to earlier reported measurement using similar technique.

Development of a time of flight spectrometer based on position sensitive multi-wire proportional counters for fission fragment mass distribution studies.

Characteristics and performance of a time of flight (TOF) spectrometer developed for performing fission mass distribution studies are presented. The spectrometer contains two TOF arms based on multi-wire proportional counters (MWPCs). Each arm has two MWPCs to form a start-stop detection system for TOF measurements. The start detector has an active area of 4 × 4 cm2. The stop detector is a two-dimensional position sensitive MWPC with an active area of 16 × 11 cm2. Salient features of the MWPCs are the use of reduced sub-millimeter wire pitches of 0.635 and 0.317 mm in the electrodes along with the use of gold plated tungsten wires of diameters 10 and 20 µm. A delay line for position electrodes is prepared using chip inductors and capacitors. Ten different configurations of MWPC were investigated for the start detector, which involved the use of three and four electrode geometries, use of different wire pitches, and use of aluminized mylar for timing electrodes. Performance results close to micro-channel plate detectors have been observed with some designs of MWPC, displaying rise times better than 2 ns with an estimated inherent time resolution of ∼100 ps FWHM. A position resolution of ∼1 mm (FWHM) has been observed. Design features of the MWPCs and their test performance results are described in this article.

Electromagnetic transition from the 4+ to 2+ resonance in 8Be measured via the radiative capture in 4He + 4He.

An earlier measurement on the 4+ to 2+ radiative transition in 8Be provided the first electromagnetic signature of its dumbbell-like shape. However, the large uncertainty in the measured cross section does not allow a stringent test of nuclear structure models. This Letter reports a more elaborate and precise measurement for this transition, via the radiative capture in the 4He + 4He reaction, improving the accuracy by about a factor of 3. Ab initio calculations of the radiative transition strength with improved three-nucleon forces are also presented. The experimental results are compared with the predictions of the alpha cluster model and ab initio calculations.

Mudi-chood: on the forearm.

Mudi-Chood is a strange dermatosis affecting the nape of the neck and upper back of young women in Kerala State of south India. It was first described by us in 1972. Here we report one more such case recently seen by us.

Localised acquired trichorrhexis nodosa of the scalp hair induced by a specific comb and combing habit - a report of three cases.

Trichorrhexis nodosa is a hair shaft disorder often encountered in clinical practice. Acquired trichorrhexis is commoner of the two types and is most often due to weathering from physical or chemical causes. We report three representative cases of localized acquired trichorrhexis encountered in our clinic attributable to a specific comb, used commonly in Kerala, a Southern state of India.

Galenicals in the treatment of crusted scabies.

Crusted scabies is rare. It is a therapeutic challenge, as the common drugs used against scabies are unsatisfactory. The successful use of galenicals in a 10-year-old girl with crusted scabies is reported.

Red baby syndrome a new disease due to parvovirus B-19 observed in Kerala.

Red Baby Syndrome is a new disease seen in infants and young children. Dramatic onset of clinical symptoms with high intensity, short duration and lack of similarity with other cutaneous lesions makes it distinct. Of 50 such patients studied over a period of 5 years, half were below one year of age. Abrupt onset of high fever and generalized erythema involving the entire skin, which is swollen and tender is characteristic. These children were highly irritable and had paradoxical cry when cuddled. Rapid resolution of symptoms occurred in 7-10 days with extensive desquamation. Routine investigations were normal, C-reactive protein was raised only in 10 patients. Human Parvo virus B-19 IgM antibodies were positive in 15 out of 24 patients. Real time polymerase chain reaction was positive for human parvovirus B 19 DNA in one. Histopathological changes in the skin biopsy showed post infectious vascular injury pattern.

Compact multiwire proportional counters for the detection of fission fragments.

Two large area multistep position sensitive (two dimensional) multiwire proportional counters have been developed for experiments involving study of fission dynamics using general purpose scattering chamber facility at IUAC. Both detectors have an active area of 20x10 cm(2) and provide position signals in horizontal (X) and vertical (Y) planes, timing signal for time of flight measurements and energy signal giving the differential energy loss in the active volume. The design features are optimized for the detection of low energy heavy ions at very low gas pressures. Special care was taken in setting up the readout electronics, constant fraction discriminators for position signals in particular, to get optimum position and timing resolutions along with high count rate handling capability of low energy heavy ions. A custom made charge sensitive preamplifier, having lower gain and shorter decay time, has been developed for extracting the differential energy loss signal. The position and time resolutions of the detectors were determined to be 1.1 mm full width at half maximum (FWHM) and 1.7 ns FWHM, respectively. The detector could handle heavy ion count rates exceeding 20 kHz without any breakdown. Time of flight signal in combination with differential energy loss signal gives a clean separation of fission fragments from projectile and target like particles. The timing and position signals of the detectors are used for fission coincidence measurements and subsequent extraction of their mass, angular, and total kinetic energy distributions. This article describes systematic study of these fission counters in terms of efficiency, time resolution, count rate handling capability, position resolution, and the readout electronics. The detector has been operated with both five electrode geometry and four electrode geometry, and a comparison has been made in their performances.

Hand-foot-and-mouth disease in Calicut.

OBJECTIVE: Hand-Foot-and-Mouth Disease (HFMD) is a mild exanthematous illness seen worldwide, affecting mainly children under ten years of age. The causative agents were initially Coxsackie virus type A 16 and related serotypes. The situation changed drastically about thirty years ago with the advent of a new aetiological agent, Enterovirus type 71 (EV 71), which has caused very large outbreaks with severe complications and many deaths. METHODS: The authors report an outbreak of papulovesicular lesions on the skin and oral mucosa compatible with the diagnosis of HFMD in children in and around Calicut in October 2003. Clinical and laboratory study in collaboration with the National Institute of Communicable Diseases, Delhi. Eighty one children with the syndrome were examined and followed up from October 2003 to February 2004, when the outbreak subsided. RESULT: The outbreak was mild and all children recovered within 1 to 2 weeks. CONCLUSION: Acute and convalescent paired serum samples collected from 19 patients were examined at the NICD for IgM antibody against EV 71 by microneutralisation test in cell culture. All the paired samples tested showed significant rise in titre of antibodies, confirming the diagnosis of EV 71 infection in each of them.

Massive infestation of cutanea larva migrans.

Cutaneous larva migrans is a tropical disease that typically is acquired on exposed surfaces in patients who have been sitting or lying on moist ground or other surfaces which have been contaminated by dog or cat feces. A patient is reported who presented with typical, severely pruritic, migratory plaques after sleeping on a wet, bus station floor.

The blue neck syndrome : nematode larvae in skin scrapings.

A novel non-inflammatory type of pigmentation of the neck associated with nematode larvae on affected skin is described. The name 'Blue neck syndrome' is suggested for this condition because of the characteristic clinical appearance. Antinematode agents such as albendazole and neem oil have been found to be effective in the treatment.

Mudi-chood disease.

Mudi-chood disease is a distinct clinical entity seen nearly exclusively in young women in Kerala State, India. Traditional hair grooming methods that utilize various plant oils along with the natural environmental heat and humidity create the conditions necessary to produce a lichenoid dermatitis on the neck and upper back.

Effect of dialysis on psoriasis : A clinical study.

Twenty patients with extensive psoriasis of more than three years duration not responding to conventional medical treatment were studied to assess the effect of dialysis. Ten patients were subjected to haemodialysis and ten to peritoneal dialysis. Patients were periodically assessed regarding responses by standard critera. At the end of six months 4/8 (50%) in haemodialysis group and 6/10(60%) in peritoned dialysis group showed improvement. One patient in haemodialysis group developed exfoliative dermatitis eleven days after onset of dialysis. In this study though a beneficial effect in psoriasis was noted following dialysis, the effect was temporary.

Heparin in psoriasis.

Ten patients with chronic stable psoriasis of more than three years duration were treated with injection heparin 2500 IU subcutaneously twice a day for 7 days. Six patients showed aggravation. Three showed no response and one patient improved and went into remission after 6 months.

Piracetam for the treatment of sickle cell disease in children- a double blind test.

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