Bianchi type-V dark energy cosmological model in general relativity in the presence of massive scalar field.

In this paper, we discuss spatially homogeneous and anisotropic Bianchi type-V dark energy cosmological model in the presence of an attractive massive scalar field in general relativity. We have solved the field equations using (i) the shear scalar of the metric is proportional to the expansion scalar which results a relationship between metric potentials and (ii) a power law between the massive scalar field and the average scale factor. We have computed the cosmological parameters like dark energy density, equation of state parameter, skewness parameters, deceleration parameter and statefinder parameters of our dark energy model with massive strings and discussed their physical significance in the light of the recent scenario of accelerated expansion of the universe and cosmological observations.

Optical and electrical studies of vapour phase grown Cd1-xCoxTe crystals.

The optical properties of vapour phase grown crystals of diluted magnetic semiconductor (DMS) Cd1-xCoxTe were investigated for x=0.001, 0.003, 0.005, 0.007 and 0.009. The reflectivity spectra exhibited a regular shift in the fundamental absorption edge (E0) with composition x. The reflectivity spectra for the present samples of Cd1-xCoxTe of all compositions exhibit broad bands at 5300 and 11,100cm(-1) due to the transitions of 4A2-->4T1 (F) and 4A2-->4T1 (P), respectively. Temperature dependence of resistivity revealed semiconducting behaviour of the samples. Hot probe test revealed that all the samples exhibited p-type conductivity.

ac susceptibility and ESR studies on vapour phase grown Cd(1-x)Mn(x)Te crystals.

Single crystals of Cd(1-x)Mn(x)Te for x = 0.1, 0.2, 0.3, 0.4 and 0.5 were grown by a modified vapour phase growth technique. ac magnetic susceptibility studies were carried out in the temperature range 14-300 K. Both the real and the imaginary parts of susceptibility indicated the formation of spin-glass phase at low temperatures. ESR spectra were recorded at room temperature (300 K) at 9.4 GHz for samples of all compositions. The line width (DeltaH) increased with Mn content.

New molecular arrays based on a tin(IV) porphyrin scaffold.

Two new porphyrin arrays-a hexamer and a nonamer-have been synthesized and characterized by elemental analysis as well as mass, (1)H NMR, and UV-vis spectroscopic methods. The scheme of construction of these arrays employs a synthetic protocol involving sequential "organic" and "inorganic" reactions conducted, respectively, at the peripheral meso-phenyl ring and the central tin(IV) ion of the porphyrin scaffold. The architecture of the hexamer is such that it is based on a covalently linked tin(IV) porphyrin dimer, with each of the two tin(IV) centers trans-axially ligated to two free-base porphyrins, while the higher homologue features a tin(IV) porphyrin trimer as the basal unit, with its central metalloid ions having two free-base porphyrins as axial ligands. This extended, "axial-bonding"-type architecture of the new arrays has been investigated by the (1)H NMR method, which reveals characteristic ring-current-induced shifts and coupling patterns for the resonances due to protons of the axial free-base porphyrin subunits. The presence of any ring-ring (basal-basal, basal-axial, or axial-axial) interaction in these arrays is not obvious from their UV-vis and redox potential data, which are close to those of the corresponding constituent monomeric species. On the other hand, their singlet-state activities are quite different from those of the precursor reference compounds as probed by steady-state fluorescence. The results of the detailed investigations carried out on these hybrid, "bichromophoric" arrays have been interpreted in terms of the occurrence of intraarray, interchromophore energy- and electron-transfer reactions.

Alkaptonuria presenting as lumbar disc prolapse: case report and review of literature.

Alkaptonuria is a rare genetic disorder caused by deficiency of the enzyme homogentisic acid oxidase, resulting in accumulation of homogentisic acid in various body tissue; it produces a multisystemic disorder with a characteristic bluish-black discolouration of the skin and cartilage, termed ochranosis. Ochranosis primarily involves the large joints of the body including the spine. Spinal involvement produces loss of flexibility and ankylosis of the thoracic and lumbar segments. The clinical presentation with spondylosis and canal stenosis is common after the third and fourth decades, but intervertebral disc prolapse is unusual in ochranosis.

Intratumoural injection of gamma leinolenic acid in malignant gliomas.

In vitro and in vivo studies have shown that gamma-leinolenic acid (GLA) can selectively kill tumour cells without harming normal cells. In view of this we have investigated the effect of intratumoural injection of GLA in intracranial gliomas, after reconfirmation of the safety of the drug on normal dog brain (n = 3). Fourteen patients underwent neurosurgical decompression along with placement of a catheter into the tumour bed. At the end of 1 week following surgery the patients were injected with 1 mg of GLA in sterile saline into the tumour bed daily for 10 days through the reservoir placed in the bone flap. Repeat computed tomography scans were obtained both before and after the GLA therapy with and without contrast administration. Necrosis and regression of the tumour have been observed, with reduction in mass effect and shift of midline structures. Two years' follow-up reveals that GLA is safe and tumour recurrence may be less in treated patients.

Cervico-thoracic neurenteric cyst: clinicoradiological correlation with embryogenesis.

Two cases of cervico-dorsal neurenteric cysts are presented, one located dorsal and the other ventral to the spinal cord, with associated Klippel-Feil anomaly, meningocele, spinal dysraphism and possibly spinal cord malformation. One patient was operated on as a neonate for a cervico-thoracic meningocele and presented during adolescence with spastic quadriparesis. Imaging revealed spina bifida, a dorsally located neurenteric cyst and a tendency towards split cord malformation. The other child presented with cervico-thoracic kyphoscoliosis and paraparesis. Imaging demonstrated persistence of a cervico-thoracic remnant of the primitive neurenteric canal through the upper thoracic spine.

Local application of gamma-linolenic acid in the treatment of human gliomas.

gamma-Linolenic acid (GLA) has been shown to have selective tumoricidal action both in vitro and in vivo. Earlier, in a limited clinical study, we have demonstrated that intra-tumoral administration of GLA can induce regression of human gliomas. In an extension of this study, we evaluated the effect of intra-cerebral injection of GLA on normal dog brain and in 15 patients with malignant gliomas. Histopathological examination revealed that GLA is not cytotoxic to the normal dog brain cells. Administration of 10 mg of GLA via a cerebral reservoir placed in the tumour bed, at the rate of 1 mg/day over a period of 10 days, revealed that GLA is not only safe and non-toxic but can also regress cerebral gliomas as evaluated by computerised tomography and increased survival of the patients by 1.5-2 years. Based on these results and our earlier in vitro study, we suggest that GLA is a safe anti-tumour agent and recommend its use in the management of human gliomas.

Calcified medulloblastoma in a child.

Calcification is an unusual and atypical feature in medulloblastomas. Here we report a case of calcified medulloblastoma in a 5-year-old boy. The clinical correlation of this radiological finding is discussed.

Posttraumatic pseudomenigocoele of cervical spine in a patient with skeletal fluorosis. Case report.

A case of fluorotic cervical compressive myelopathy precipitated by trauma is reported. The delayed neurological deterioration was due to a posttraumatic pseudomenincocele, the prompt treatment of which resulted in recovery. Posttraumatic pseudomeningocele is very rate; and certainly so in fluorosis, and thus has not been reported in the literature to date.

Giant syringobulbia in childhood.

A case of giant syringobulbia with syringomyelia extending to the upper dorsal region is reported. The case occurred in a 3.5-year-old girl who presented with a history of frequent bouts of severe pain in the lower neck and the shoulder blades. Simple decompression of the syrinx by open myelotomy resulted in prompt relief and reversal of symptoms.

Intraspinal tumour presenting as hydrocephalus in childhood.

A case of cervical intramedullary spinal cord tumour presenting with hydrocephalus is reported for its rarity. Possible aetiopathologies and the relevant literature are reviewed.

Neuro-radiology of skeletal fluorosis.

Though fluorosis is prevalent in certain geographic parts of the world, it is likely to occur in other parts due to industrial intoxication and also in people with latent kidney disease even when they consume relatively lower amounts of fluoride than in endemic regions. A sizeable number of patients suffering from ossified posterior longitudinal ligament (OPLL) may have fluoride intoxication as the underlying cause. The clinical, radiologic and pathologic manifestations of OPLL in non-orientals have been reported to be very similar to those in orientals. The question whether all these entities reported from different ecospheres of the globe have common aetiological factors is worthy of further research. Though plain radiology shows the characteristics of fluorosis, CT and MR imaging modalities are very helpful in early diagnosis and also in planning proper surgical intervention.

Unusual non-osseous compression at the craniovertebral junction--a report of four cases.

A variety of congenital and acquired non-osseous compression elements at the craniovertebral junction have been known and a fibrous band among them is unusual. Unaccompanied by any bony abnormality, non-osseous compression due to thickened epidural tissue, possibly congenital, presenting in adulthood is described in four cases. The onset of symptoms was in the fourth and sixth decades. Three were males and one was a female. The clinical picture was a slowly progressive spastic quadriparesis except in the only female patient who developed sudden quadriplegia while carrying a weight over her head. MR tomography was diagnostic while CT scan ruled out any bony pathology. Release of the localised epidural constriction was performed in all; in one transorally. Good recovery ensued postoperatively while histopathology excluded infective or neoplastic pathology.

Large traumatic interhemispheric subdural haematoma : case report.

A case of acute traumatic interhemispheric subdural haematoma treated conservatively is reported. The controversies in its management and the usefulness of CT in planning the treatment are discussed.

[Fluorotic cervical spinal cord disease]. / Myélopathie cervicale fluorosique.

Skeletal fluorosis was reported as a disease endemic to an area in the Madras Presidency of Indian in 1937 and prior to this, it was known as an occasional disease. There are two endemic areas in India, one in Punjab and the other in Andhra Pradesh State. This disease is also endemic in some parts of China and Africa. The manual labourers are more frequently affected as they consume huge quantities of water with high fluoride levels. The cervical spine is often affected, manifesting as cord compression. Forty cases of fluorotic cervical cord compression, who underwent surgery are studied regarding their clinical features, radiological aspects and outcome following surgery. In selected cases of cervical fluorotic myelopathy, surgical decompression appears to be necessary and also rewarding.

Idiopathic massive osteolysis of skull bones: a case report.

A rare case of idiopathic massive osteolysis involving cranial bone is reported. Radiological and computed tomographic findings are discussed, along with a brief review of the literature.