Biomedical subjects

A Kam

Publications and source records attributed to A Kam.

6 recordsLinked to original sources

PubMed2006

Stability diagram of a few-electron triple dot.

Individual and coupled quantum dots containing one or two electrons have been realized and are regarded as components for future quantum information circuits. In this Letter we map out experimentally the stability diagram of the few-electron triple dot system, the electron configuration map as a function of the external tuning parameters, and reveal experimentally for the first time the existence of quadruple points, a signature of the three dots being in resonance. In the vicinity of these quadruple points we observe a duplication of charge transfer transitions related to charge and spin reconfigurations triggered by changes in the total electron occupation number. The experimental results are largely reproduced by equivalent circuit analysis and Hubbard models. Our results are relevant for future quantum mechanical engineering applications within both quantum information and quantum cellular automata architectures.

Journal Article↗

PubMed2002

Nasal septum buttons: symptom scores and satisfaction.

Patients with symptomatic septal perforations require treatment, with many surgeons advocating primary treatment with an obturator if conservative measures fail. Twenty nasal Button Outcome Questionnaires were sent to patients who had undergone insertion of a septal button between 1990 and 2000 in our unit. Fourteen questinnaires were returned. This study reveals that despite a reduction in symptom score in nine patients, septal buttons are poorly tolerated by patients with only 45 per cent of obturators ultimately being in situ. In view of these findings, patients are now offered a choice between primary surgical and mechanical closure in our unit.

Adult↗

PubMed2001

Microsurgical anatomy of the superior and recurrent laryngeal nerves.

OBJECTIVE: To study the microsurgical anatomy of the superior laryngeal nerve (SLN) and recurrent laryngeal nerve (RLN) with respect to anatomic landmarks, and to identify their vascular supplies. METHODS: The microsurgical anatomy of the anterior neck, the course of the right and left SLN and RLN and their variations were studied in 21 cadavers. Fresh cadavers were perfused with colored silicon dye to investigate the microvasculature in detail. RESULTS: SLN originates from the inferior vagal ganglion at the C2 level and descends medially toward the thyrohyoid membrane. It branches into an external and an internal branch deep to the internal carotid artery at the C3 level. The external branch, along with the cricothyroid artery, descends deep to the superior thyroid artery toward the cricothyroid muscle. Accompanied by the superior laryngeal artery, the internal branch passes deep to the loop of the superior thyroid artery and pierces the thyrohyoid membrane. Both nerves reside in the fascia covering longus colli muscles and are supplied by their accompanying arteries. The loop of RLN is found at the T1-T3 level on the right, and more caudally at the T3-T6 level on the left, entering the larynx between C5-C7 levels on both sides. RLN receives arterial supply from the esophageal and tracheal branches of the inferior thyroid artery proximally, and by the inferior laryngeal artery distally. CONCLUSION: Incidental intraoperative injury to the SLN and RLN potentially could be avoided by understanding the detailed course of each nerve with respect to the surrounding anatomic landmarks and by recognizing their blood supplies.

Aged↗

PubMed1999

Case report: inappropriate use of percutaneous drainage in the management of pancreatic necrosis.

We describe three cases of severe necrotizing pancreatitis, with Apache II scores of 11, 17 and 22, respectively. There was no significant pancreatic parenchymal perfusion in any of the three patients on contrast-enhanced computed tomography. All three patients were primarily treated with percutaneous drains and all three subsequently required open laparotomies. We do not recommend percutaneous drainage as a definitive therapy for severe necrotizing pancreatitis.

Aged↗

PubMed1993

Torsion of accessory fallopian tube: ultrasound findings in two premenarchal girls.

The ultrasound findings of two cases of fallopian tube duplication, both of which had undergone torsion, are described. Two premenarchal girls were examined with ultrasound because of clinical evidence of pelvic pathology. Both were found to have complex cystic structures that on surgery and subsequent pathological examination were shown to be twisted accessory fallopian tubes. Accessory fallopian tubes have been reported to occur in 6-13% of selected patient groups. To our knowledge, torsion of an accessory tube has not been reported in the literature.

Child↗

PubMed1991

Ureteric sludge syndrome.

Four cases of a form of obstructive uropathy previously unreported in children are described. All presented with oligoanuria and either flank pain or fluid retention and had evidence of crystalline sludge in their lower ureters. Three cases had an underlying crystalluria.

Adolescent↗