Positronium Laser Cooling via the 1

We report on laser cooling of a large fraction of positronium (Ps) in free flight by strongly saturating the 1^{3}S-2^{3}P transition with a broadband, long-pulsed 243 nm alexandrite laser. The ground state Ps cloud is produced in a magnetic and electric field-free environment. We observe two different laser-induced effects. The first effect is an increase in the number of atoms in the ground state after the time Ps has spent in the long-lived 2^{3}P states. The second effect is one-dimensional Doppler cooling of Ps, reducing the cloud's temperature from 380(20) to 170(20) K. We demonstrate a 58(9)% increase in the fraction of Ps atoms with v_{1D}<3.7×10^{4} ms^{-1}.

Solvatochromic and single crystal studies of 3-(4-bromophenyl)-5-phenyl-4,5-dihydro-1H-pyrazole-1-carbaldehyde.

The structure of 3-(4-bromophenyl)-5-phenyl-4,5-dihydro-1H-pyrazole-1-carbaldehyde was determined by using X-ray diffraction analysis. Photophysical studies of the title compound were investigated in the solvents with different polarities. The emission spectrum of the compound was recorded in polar solvent DMSO (356 nm). In different solvents the extinction coefficients and quantum yield of the compound vary from 1.88×10(4) to 3.53×10(4) and 0.01 to 0.25, respectively. The ratio of the dipole moment of excited state to the dipole moment of ground state was calculated by using solvatochromic shift methods.

Synthesis, characterization and fluorescence studies of 3,5-diaryl substituted 2-pyrazolines.

A series of 2-pyrazolines have been synthesized from α, ß unsaturated ketones and hydrazine hydrate with acetic/formic acid in ethanol/DMSO. The structures of 2-pyrazolines have been established by spectroscopic techniques i.e. UV, IR, (1)H NMR, (13)C NMR and micro element analysis. Fluorescence spectra were recorded in the solution at fixed concentration and same excitation wavelength at 290 nm. The absorption band positions of all the compounds broadly lie between 280 and 336 nm and fluorescence band positions in the range between 300 and 370 nm, the near ultraviolet region.

Development and evaluation of pharmacosomes of aceclofenac.

Pharmacosomes are amphiphilic lipid vesicular systems containing phospholipid complexes with a potential to improve bioavailability of poorly water soluble as well as poorly lipophilic drugs. To improve the water solubility, bioavailability and minimize the gastrointestinal toxicity of aceclofenac, its pharmacosomes were prepared. Aceclofenac was complexed with phosphatidylcholine (80%) in two different ratios (1:1 and 2:1) using conventional solvent evaporation technique. Pharmacosomes thus prepared were subjected to solubility and drug content evaluation, scanning electron microscopy, differential scanning calorimetry, X ray powder diffraction and in vitro dissolution study. Pharmacosomes of aceclofenac were found to be disc shaped with rough surface in scanning electron microscopy. Drug content was found to be 91.88% (w/w) for aceclofenac phospholipid complex (1:1) and 89.03% (w/w) aceclofenac-phospholipid complex (2:1). Differential scanning calorimetric thermograms and X ray powder diffraction datas confirmed the formation of phospholipid complex. Solubility and dissolution profile of the prepared complex was found to be much better than aceclofenac.

Oesophageal and tracheal perforation in thyroid B-cell lymphoma.

We report an unusual case of spontaneous oesophageal and tracheal perforation secondary to thyroid B-cell lymphoma in a previously healthy 76-year-old woman. Findings on chest radiography, CT and oesophagram are correlated to endoscopy, surgery and pathology. Such perforation is a rare and serious complication that should be specifically considered when a patient with a neck neoplasm develops acute respiratory or gastrointestinal symptoms.

Prevalence of peripheral arterial disease by ankle-brachial index and its correlation with carotid intimal thickness and coronary risk factors in Nepalese population over the age of forty years.

OBJECTIVES: Noninvasive measures of subclinical atherosclerosis such as the ankle brachial index (ABI) and common carotid artery intima-media thickness (CCA IMT) could improve risk prediction and provide more focused primary prevention strategies. This report describes the prevalence of subclinical atherosclerotic vascular disease in a Nepalese population over the age of forty years as measured by ABI and CCA IMT and their association with established cardiovascular risk factors. MATERIALS AND METHODS: Ultrasonic evaluation of ABI and CCA IMT was done in 195 individuals of age 40 years and above who had presented to an outpatient department. Patients with established diagnosis of coronary artery disease or symptomatic for peripheral arterial disease were excluded from the study. RESULTS: The prevalence of atherosclerotic disease as measured by ABI was 18.5% and there was a statistically significant correlation between ABI and CCA IMT and other established cardiovascular risk factors such as smoking, diabetes mellitus and hypertension. CONCLUSIONS: We recommend that ABI as measured by sphygmomanometer be incorporated into routine cardiovascular screening and when found to be abnormal further confirmed by Doppler assessment of ABI and CCA IMT as surrogate markers of atherosclerotic vascular disease.

Colo-colonic intussusception caused by a solitary Peutz-Jeghers polyp.

A case of acute large bowel obstruction by colo-colonic intussusception in a healthy 19-year-old man is presented. The lead point of the intussusception is a rare solitary colonic Peutz-Jeghers polyp in the descending colon of a man without the full Peutz-Jeghers syndrome. The clinical presentation, imaging findings on plain radiographs, single contrast enema and CT, and findings at colonoscopy and surgery are correlated with pathology results and a brief review of the literature.

An echocardiographic study of cardiac changes in hypothyroidism and the response to treatment.

INTRODUCTION: Thyroid Hormones exert a direct cellular effect on almost all the tissues of the body including heart. Limited studies are available in the country to assess the various CVS parameters in hypothyroid patients and none have defined the impact of treatment on these parameters. AIM AND OBJECTIVES: To do an echocardiographic study of the cardiac changes in hypothyroidism and response to treatment. METHODOLOGY: 20 overt hypothyroid patients were selected , 12 males and 8 females and subdivided into 4 groups : untreated patients-A (14) , patients on L-thyroxin >=4 months-B6 , control subjects matched by age and sex-C10 , patient after treatment-D6-a subset of group A. Total T3 T4 was measured by RIA and TSH by IRMA. Echocardiography was done according to the standard protocols. RESULTS: With replacement therapy hypothyroid patients showed a decrease in wall thickness, decrease or disappearance of pericardial effusion and improvement in cardiac output. However no change in systolic function or size of various chambers were noted. Decreased cardiac output seen in untreated patients was mainly due to decreased heart rate. DISCUSSION: Present study showed relatively increased thickness of IVS and LVPW in untreated patients with marked difference in older patients consistent with other studies. There is a striking correlation between severity of disease and pericardial effusion. Following thyroid hormone replacement it was reported to resolve within few months. CONCLUSION: All patients with unexplained PE should be screened for hypothyroidism. Echocardiography is useful in assessing the response to replacement therapy. With replacement therapy hypothyroid patients showed a decrease in wall thickness.

Estimation of trace amounts of benzene in solvent-extracted vegetable oils and oil seed cakes.

A new method is presented for the qualitative and quantitative estimation of trace amounts (up to 0.15 ppm) of benzene in crude as well as refined vegetable oils obtained by extraction with food grade hexane (FGH), and in the oil seed cakes left after extraction. The method involves the selection of two solvents; cyclohexanol, for thinning of viscous vegetable oil, and heptane, for azeotroping out trace benzene as a concentrate from the resulting mixture. Benzene is then estimated in the resulting azeotrope either by UV spectroscopy or by GC-MS subject to availability and cost effectiveness of the latter. Repeatability and reproducibility of the method is within 1-3% error. This method is suitable for estimating benzene in vegetable oils and oil seed cakes.

Value of three-dimensional gradient-echo magnetic resonance cholangiography in diagnosing choledocholithiasis.

OBJECTIVE: To evaluate the role of magnetic resonance cholangiography (MRC) in patients with suspected choledocholithiasis. PATIENTS AND METHODS: Twenty-six consecutive patients with suspected choledocholithiasis (11 men and 15 women ranging in age from 25 to 81 years) underwent three-dimensional gradient-echo MRC; each patient also underwent endoscopic retrograde cholangiography or operative cholangiography. Each set of images for each patient was reviewed independently by a radiologist who was unaware of the results of the other type of imaging. RESULTS: Diagnostic-quality MRC images were obtained for 17 of the patients. Of these, 13 had stones in the common bile duct, as confirmed by another imaging method, and MRC indicated the presence of these stones in all 13 patients. In the other four patients bile duct obstruction was due to either acute pancreatitis (in three) or cholangiocarcinoma (in one). For seven of the nine nondiagnostic-quality MRC studies, the bile duct was not obstructed, so there was no bile stasis and the MRC images could not be obtained. Motion artifacts due to inability to hold the breath were the limiting factors in the other two patients. CONCLUSION: Although MRC has some limitations, this new noninvasive technique may be used as a screening test in selected patients with suspected choledocholithiasis.

Extracranial metastases of meningioma.

We report two unusual cases of intracranial meningioma with extracranial metastases to bone. The diagnosis was made by fine needle aspiration biopsy in both cases and confirmed by open biopsy in one. The lungs were spared in both. A review of the literature is included.

Morphine selectively depresses the slowest, NMDA-independent component of C-fibre-evoked synaptic activity in the rat spinal cord in vitro.

The effects of morphine on the depolarizing synaptic responses produced in motoneurons by electrical stimulation of primary sensory neurones have been recorded in hemisected spinal cord preparations (8- to 12-day-old rat pups). Morphine at concentrations of 0.1-20 microM reduced a slow, long-lasting (latency greater than 1 s, duration up to 10 s) component of the ventral root potential (VRP) evoked by C-fibre strength stimulation of the dorsal root. At 2 microM the reduction in area of this slow synaptic potential was 71.7 +/- 0.9% of control values (n = 15). The earliest components of the C-fibre strength VRP (the first 100 ms) and the responses to A beta strength stimuli were unaffected by the opioid even at 10-20 microM. The intermediate, NMDA receptor antagonist (D-AP5, 40 microM)-sensitive component (which lasts 100-1000 ms) was reduced by 34 +/- 2.2% of control (n = 15), which was significantly less than the reduction of the later NMDA-independent component (P < 0.001). Morphine (0.1-20 microM) also depressed the cumulative depolarization generated by the temporal summation of synaptic responses evoked by brief trains of C-fibre strength stimuli (1 or 10 Hz). A significantly greater reduction at the lower frequency of stimulation (56.3 +/- 2.0%) than at the higher (20.3 +/- 1.69%, n = 10, measured at 2 microM morphine) was found (P < 0.005). The effects of morphine were reversible upon wash-out or superfusion with the opioid receptor antagonist naloxone (2 microM).(ABSTRACT TRUNCATED AT 250 WORDS)

Prevalence of ectoparasites on goats in Dehradun (India).

The prevalence of two phthirapteran species, Bovicola caprae and Linognathus africanus, on 1048 goats from Dehradun (India) was 79.2% and 38% respectively. Prevalence of both species was higher on visibly weaker and less hairy goats. Sex related differences in prevalence were not found. The prevalence of L. africanus was slightly higher on young goats but the same was not true in case of B. caprae. The incidence of B. caprae showed moderately negative correlation with environmental temperature and photoperiod. The relative intensity of B. caprae has been found higher during winter months, followed by summers. Study primarily deals with lice but the information about prevalence of other ectoparasites like ticks, fleas and keds, has also been supplemented.

Case report: rapidly progressive neuropathic arthropathy in syringohydromyelia--radiographic and magnetic resonance imaging findings.

A rapidly progressive neuropathic shoulder joint in a patient with syringohydromyelia is presented. He developed marked destruction of the shoulder joint over 5 weeks. The MRI findings in the pre- and post-resorptive phases of the arthropathy are presented for the first time. Low signal intensity areas are observed in the medullary cavity of the bone on both T1- and T2-weighted spin-echo images even before the actual resorptive process starts. Additional major findings are the joint effusion and synovial thickening.

Population structure of goat biting louse Bovicola caprae (Phthiraptera: Ischnocera).

The population structure of Bovicola caprae on goats has been recorded by examining 57 goatskins (45 by brushing cum searching and 12 by dissolving method). Population composition, sex ratio, adult nymph ratio has been recorded at different levels of infestation. The female dominated over the male population and male: female has been found to be 1:2 by brushing cum searching and 1:1.7 by dissolving method. Likewise, A:N was found to be 1:1.2 by brushing cum searching and 1:17 by dissolving method. The number of males and females follow similar pattern throughout population and were found to exhibit a high degree of correlation.

Optimizing gallbladder stone lithotripsy: an international survey.

Rates of stone clearance with extracorporeal shock wave cholecystolithotripsy (biliary lithotripsy [BL]) initially reported by European groups were encouraging. An American multicenter BL study (the Dornier National Biliary Lithotripsy Study [DNBLS]) did not reproduce these results. The BL treatment strategies and 6-month stone clearance rates of six leading European and Japanese centers were compared with those of DNBLS. All foreign centers used adjuvant oral chemolitholysis and greater shock wave energies from the same lithotriptor as that in DNBLS. Six months after BL, the stone clearance rates at all six centers were higher than those of DNBLS. There were no significant differences in complication rates between centers. These findings suggest that the poor results of DNBLS were chiefly due to the use of low kilovoltage and few BL sessions. Increased energy levels and a fragment size end point of less than 5 mm optimize BL. Despite the popularity of laparoscopic cholecystectomy, BL can be recognized as a successful treatment alternative for patients with a low burden of radiolucent stones.

Incidence of Mallophaga on poultry in Dehradun (India).

The order of abundance of different mallophagan species on poultry birds in Dehradun (India) has been found to be Menopon gallinae greater than Menacanthus cornutus greater than Menacanthus stramineus greater than Goniocotes gallinae greater than Goniodes dissimilis greater than Lipeurus caponis greater than Lipeurus lawrensis tropicalis greater than Goniodes gigas. The intensity of these species upon 1249 birds has been recorded by coding system. The correlation between the monthly incidence of different species and environmental temperature as well as R.H. has been recorded. The degree of association between four most commonly occurring combinations has also been analysed.

Heterogeneity and central modulation of feedback reflexes in crayfish motor pool.

1. Movement of the crayfish thoracocoxal leg joint is monitored by a muscle receptor organ (TCMRO) and a chordotonal organ (TCCO). Both receptors span the joint in parallel but signal opposite directions of leg movement. The TCMRO is innervated by afferents responsive to lengthening, which corresponds to leg remotion, whereas TCCO afferents are responsive to shortening of the chordotonal strand, which corresponds to leg promotion. 2. When both receptors are stimulated in parallel, in an otherwise isolated preparation, reflex responses of coxal promoter and remotor motor neurons occur on both stretch and release. By comparison with experiments where one or the other of these receptors is stimulated selectively, we conclude that reflexes evoked by stretch of the two receptors are due to the TCMRO and reflexes evoked by release are due to the TCCO. 3. Reflexes mediated by these receptors are both state dependent and phase dependent. In preparations that produce patterns of reciprocal motor activity in promotor and remotor motor neurons (the active state), the reflex effect depends on the phase of this centrally generated activity. In preparations that are quiescent, or that produce only tonic motor output (the inactive state), the reflex effect is stable, corresponding to a typical resistance (negative feedback) reflex for both directions of receptor movement. 4. In the active state, coxal promotor motor neurons are both excited and inhibited in a phase-dependent manner by stretching the TCMRO. A subgroup of promotor motor neurons is excited by shortening the TCCO. One subgroup of the antagonistic coxal remotor motor neurons receives phase-dependent excitation from stretch of the TCMRO, whereas a second subgroup receives phase-dependent excitation from shortening the TCCO. 5. There are, therefore, at least two ways in which reflex effects can be modulated. At the level of a single motor neuron, the reflex response can vary in gain, and in some cases in sign, in a manner depending on centrally generated motor activity. In addition, at the level of a pool of synergistic motor neurons, the reflex effect is not uniform; instead, different subgroups of motor neurons display different reflex effects, so that the relative levels of excitability of different motor neuron reflex subgroups can also determine the net reflex effect. 6. Excitation of promotor motor neurons by TCCO shortening and of remotor motor neurons by TCMRO lengthening are positive feedback reflexes. The subgroups of motor neurons in which positive feedback reflexes can be evoked in both promotor and remotor pools are termed group 1.(ABSTRACT TRUNCATED AT 400 WORDS)