Quantum translator-rotator: inelastic neutron scattering of dihydrogen molecules trapped inside anisotropic fullerene cages.

We report an inelastic neutron scattering investigation of the quantum dynamics of hydrogen molecules trapped inside anisotropic fullerene cages. Transitions among the manifold of quantized rotational and translational states are directly observed. The spectra recorded as a function of energy and momentum transfer are interpreted in terms of the rotational potential and the cage dimensions. The thermodynamics of orthohydrogen and parahydrogen are investigated through temperature dependence measurements.

Thermal history effects and methyl tunneling dynamics in a supramolecular complex of calixarene and para-xylene.

The low-temperature structure and dynamics of guest molecules of p-xylene incorporated in the isopropyl-calix[4] arene(2:1) p-xylene complex have been investigated by solid state nuclear magnetic resonance (NMR). Using one-dimensional 1H-decoupled 13C cross-polarization magic-angle-spinning (MAS) NMR and two-dimensional 1H-13C correlation spectroscopy, a full assignment of the 13C and 1H chemical shifts has been made. Using 1H NMR relaxometry, the effects of thermal history on the structure of the system have been investigated. Rapidly cooled samples have 1H spin-lattice relaxation times T1, which at low temperature (T<60 K) are typically two orders of magnitude faster than those observed in annealed samples which have been cooled slowly over many hours. In both forms, the low-temperature relaxation is driven by the dynamics of the weakly hindered methyl rotors of the p-xylene guest. The substantial difference in T1 is attributed in the rapidly cooled sample to disorder in the structure of the complex leading to a wide distribution of correlation times and methyl barrier heights. A comparison of the linewidths and splittings in the high resolution 13C MAS spectra of the two forms provides structural insight into the nature of the disorder. Using 1H field-cycling NMR relaxometry, the methyl dynamics of the p-xylene guest in the annealed sample have been fully characterized. The B-field dependence of the 1H T1 maps out the spectral density from which the correlation times are directly measured. The methyl barrier heights are determined from an analysis of the temperature dependence.

Solid-state NMR of endohedral hydrogen-fullerene complexes.

We present an overview of solid-state NMR studies of endohedral H(2)-fullerene complexes, including (1)H and (13)C NMR spectra, (1)H and (13)C spin relaxation studies, and the results of (1)H dipole-dipole recoupling experiments. The available data involves three different endohedral H(2)-fullerene complexes, studied over a wide range of temperatures and applied magnetic fields. The symmetry of the cage influences strongly the motionally-averaged nuclear spin interactions of the endohedral H(2) species, as well as its spin relaxation behaviour. In addition, the non-bonding interactions between fullerene cages are influenced by the presence of endohedral hydrogen molecules. The review also presents several pieces of experimental data which are not yet understood, one example being the structured (1)H NMR lineshapes of endohedral H(2) molecules trapped in highly symmetric cages at cryogenic temperatures. This review demonstrates the richness of NMR phenomena displayed by H(2)-fullerene complexes, especially in the cryogenic regime.

Solitary jejunal metastasis from renal cell carcinoma.

A metastatic deposit from renal cell carcinoma into the jejunal wall is a rare phenomenon. Among the frequent modes of presentation, bleeding, obstruction and unexplained anaemia are commonly seen. In addition to the conventional contrast studies and computerized tomography (CT), Capsule endoscopy is a useful diagnostic tool. Factors responsible for resistant behaviour of jejunal wall are still not clear, however when it happens it is really a diagnostic challenge. We are reporting this rare case of solitary jejunal metastasis from renal cell carcinoma.

D2 gastrectomy -- a safe operation in experienced hands.

In the contemporary practice, surgery is the only potentially curative treatment available for gastric cancer. However, there is no consensus on the extent of surgical resection. Advantages of D2 gastrectomy in terms of morbidity, mortality, local recurrence and survival are confirmed in Japanese as well as some European trials. In our hospital, all patients with operable gastric cancer are treated with D2 gastrectomy along with splenectomy and distal pancreatectomy followed by jejunal pouch reconstruction. The study was undertaken to evaluate our practice in terms of postoperative morbidity and mortality. All the patients who had total gastrectomy for gastric carcinoma from January 1995 to December 2000 were included in the study. During this 6-year period, 33 patients underwent potentially curative D2 gastrectomy. Postoperative morbidity and mortality were 18 and 9%, respectively. There were no anastomotic leaks. Three (9%) patients developed dysphasia, of which two (6%) had anastomotic stricture requiring dilatation. We feel D2 gastrectomy with splenectomy and distal pancreatectomy when performed electively is a safe procedure in experienced hands. Oesophago-jejunal anastomosis can be safely performed using circular stapler.

Pulmonary infiltrates with eosinophilia syndromes in children.

Pulmonary infiltrates with eosinophilia (PIE) are a group of heterogeneous disorders having the common findings of lung disease and eosinophilia in the peripheral blood, bronchoalveolar lavage fluid, or pulmonary interstitium. Eleven cases of PIE syndromes were identified through a retrospective and prospective chart review: drug-induced (2), acute eosinophilic pneumonia (3), infant pulmonary eosinophilia (2), parasite-induced (2), Churg-Strauss syndrome (1), and atypical chronic PIE (1). Patient demographics, clinical presentation, and disease severity varied considerably among groups. Therapeutic interventions included bronchodilators (10), oxygen (7), corticosteroids (9), and mechanical ventilation (3). A single patient with acute eosinophilic pneumonia died. Our experience suggests that PIE syndromes are rare in childhood and that clinical presentation can vary widely. Because of the potential for significant morbidity and mortality, aggressive diagnostic evaluations are warranted, particularly in children with respiratory failure of unknown etiology.

Liquid-liquid extraction and reversed phase chromatographic behaviour of some 3d metal ions using bis(2,4,4-trimethylpentyl)dithiophosphinic acid (Cyanex 301).

Studies have been carried out on the extraction behavior of some metal ions of the first transition series using bis(2,4,4-trimethylpentyl)dithiophosphinic acid (Cyanex 301) from mineral acid media. The effect of various parameters influencing the extraction such as the nature of the diluent, concentration of the acid and the extractant on the distribution has been investigated. Based on the distribution data some binary separations have been proposed. A flow sheet of a scheme is given for the recovery of manganese free cobalt from a spent catalyst used in the manufacture of poly(ethyleneterepthalate).

Laparoscopic cholecystectomy: experience in a district general hospital.

In many centres laparoscopic cholecystectomy has become the procedure of choice for symptomatic gallbladder stones. By comparison with conventional cholecystectomy it appears to be associated with minimal morbidity, shorter hospital stay, earlier return to work and a better cosmetic result. The present study reviews the results of the first 50 laparoscopic cholecystectomies performed at Altnagelvin Area Hospital.

Subcutaneous herniation of gall-bladder with spontaneous cholecystocutaneous fistula.

Spontaneous cholecystocutaneous fistula is now a clinical rarity due to improvements in the treatment of biliary tract diseases. This case report describes a 67-year-old woman in whom subcutaneous herniation of a pathologically dilated gall-bladder was followed by spontaneous discharge of pus and mucus with formation of a cholecystocutaneous fistula. The use of serial computed tomography examinations enabled this unusual diagnosis to be made.

Scroto-abdominal impalement injury in a skateboard rider.

The injuries sustained by skateboard riders vary from minor cuts and abrasions to fractures. This report describes a unique injury sustained by a young skateboard rider who was impaled on a metal rod. Literature review of over 1,254 skateboard injuries did not reveal any other instances of penetrating abdominal trauma.