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Biomedical subjects

K Ramachandran

Publications and source records attributed to K Ramachandran.

At least 19 recordsLinked to original sources
PubMed2006

Molecular interaction studies of acrylic esters with 1-alcohols.

Hydrogen bonding between 1-alcohols and acrylic esters in n-heptane has been studied by FTIR spectroscopic method. The formation constant of the 1:1 complexes has been calculated using Nash method. The values of formation constant and free energy change vary with alcohol and ester chain length, which suggests that the strengths of the intermolecular O-H...O=C bonds are shown to be dependent on the alkyl group of acrylic esters and the 1-alcohols and the results shows that the proton donating ability of 1-alcohols is in the order: 1-propanol<1-butanol<1-pentanol and the accepting ability of acrylic esters is in the order: methyl methacrylate<ethyl methacrylate<butyl methacrylate.

1-Butanol↗
PubMed2006

Hydrogen bonding interaction between acrylic esters and monohydric alcohols in non-polar solvents: An FTIR study.

The association between acrylic esters (methyl methacrylate, ethyl methacrylate and butyl methacrylate) and some monohydric (primary, secondary and tertiary) alcohols in non-polar solvents, viz. n-heptane, CCl4 and benzene has been investigated by means of FTIR spectroscopy. The most likely association complex between alcohol and acrylic ester is 1:1 stoichiometric complex through the hydroxyl group of alcohol and the carbonyl group of acrylic ester. The formation constant of the 1:1 complexes has been calculated using Nash method. It appears that the primary alcohols have larger formation constant than the secondary and tertiary alcohols. The results show that the proton donating power of the alcohols decreases in the order primary>secondary>tertiary and the association constant increases with the increase in carbon chain of the alkyl group of acrylic esters and alcohols. Also the results show a significant dependence of the association constant upon the solvents used. The solvent effect on the formation of hydrogen bond equilibria is discussed in terms of specific interaction between the solute and solvent.

Acrylates↗
PubMed2005

Kerion: an unusual presentation in the otolaryngology department.

A 19-year-old farmer was referred by his general practitioner as an emergency to our otolaryngology department complaining of marked breathlessness of a few hours duration. He gave a three-day history of painful swelling and hair loss in the beard area of the right side of the neck. His upper airway was compromised unless extension of the neck was maintained. Larynx and pharynx were normal. The acute symptoms settled with intravenous antibiotics and hydrocortisone. Culture of skin scrapings revealed a growth of Tricophyton verrucosum. The neck swelling subsided after a course of oral griseofulvin followed by terbinafine. Difficulty in breathing due to fungal infection of the neck has not been previously reported in the English literature.

Adult↗
PubMed2004

Actinomycosis of the parotid masquerading as malignant neoplasm.

BACKGROUND: Primary actinomycosis of the parotid gland is of rare occurrence and can mimic a malignant neoplasm both clinically as well as radiologically. CASE PRESENTATION: We present here a case of primary actinomycosis of the parotid gland presenting with a parotid mass lesion with erosion of skull bones. CONCLUSIONS: Clinical presentation of cervico-facial actinomycosis is characterized by the presence of a suppurative or indurative mass with discharging sinuses. The lesion demonstrates characteristic features on fine needle aspiration cytology and histology, however at times the findings are equivocal.

Actinomycosis↗
PubMed2004

Unusual complication of parotid abscess.

Temporal lobe abscess as a complication of parotid abscess is not described in the English literature. In this case report a 66-year-old gentleman is described who presented with a left-sided parotid abscess, which extended to other deep neck spaces, and advanced to develop a temporal lobe abscess and subdural parietal empyema. Treatment included intravenous antibiotics, incision and drainage of parotid abscess, and burr hole aspiration of the temporal lobe abscess. The importance of imaging to evaluate the extent of deep neck abscess and brain abscess is highlighted in this report.

Abscess↗
PubMed2003

Botulinum toxin injection for failed tracheo-oesophageal voice in laryngectomees: the Sunderland experience.

Spasm of the pharyngo-oesophageal segment is one of the important causes of tracheo-oesophageal voice failure. Traditionally it has been managed by either prolonged speech therapy, surgical pharyngeal myotomy or pharyngeal plexus neurectomy with varying degrees of success. Botulinum neurotoxin has been found to be effective in relieving pharyngo-oesophageal segment spasm. Since 1995, we have used botulinum toxin injection on 10 laryngectomees with either aphonia or hypertonicity due to pharyngo-oesophageal segment spasm. Early results were analysed by the Sunderland Surgical Voice Restoration Rating scale. Seven of the 10 patients, who were previously completely aphonic, developed voice following this therapy and are using their valve choice as their only method of communication. Out of the three patients who were treated for hypertonic voice, two did derive some benefit from the procedure. One patient developed a hypotonic voice, which lasted for a few months.

Aged↗
PubMed2002

Angular momentum and cross sections for fusion with weakly bound nuclei: breakup, a coherent effect.

Results for the cross section and average angular momentum for complete fusion at energies around the Coulomb barrier are presented for 7Li with 165Ho. Comparison of the cross sections with a one-dimensional barrier penetration model, using a potential consistent with the measured elastic scattering, showed a reduction above the barrier and an enhancement below it. An increase in the measured average angular momentum, , above the barrier and its consistency with that obtained from the fusion excitation function for weakly bound nuclei, is reported. These results together with a reanalysis of existing data conclusively demonstrate that the effect of breakup on fusion is coherent, like coupling to any nonelastic channel.

Journal Article↗
PubMed2002

An unusual bilateral cervical paraganglioma: a case report.

Paragangliomas are neoplasms originating from paraganglion tissue derived from mesoderm, the most common location being adjacent to carotid bifurcation. Rarely these tumours can be bilateral. We present here a case of bilateral paraganglioma occurring in a young woman. On one side the tumour was arising from the vagus nerve and on the other, from the carotid body. Clinical, radiological and histopathological features and treatment dilemmas are discussed.

Adult↗
PubMed2001

N-methylated 5-alkenyloxazolium salt transformations.

[reaction: see text] In the course of natural product synthetic studies, 5-(4-pentenyl)oxazole and 5-(5-hexenyl)oxazole were N-methylated. The initial N-methylated 5-alkenyloxazolium salt adducts were found to be only intermediates and were ultimately transformed into hydroindole and hydroisoquinoline compounds, respectively.

Crystallography, X-Ray↗
PubMed2000

Primary osteosarcoma of metatarsal bone.

Primary osteosarcomas of the short tubular bones of hands and feet are rare. We describe a 46-year-old woman with osteosarcoma of the left metatarsal bone with pulmonary metastases. This is the first reported case of osteosarcoma at this site.

Biopsy↗