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Biomedical subjects

J Parisi

Publications and source records attributed to J Parisi.

At least 19 recordsLinked to original sources
PubMed1997

Self-organization in semiconductor physics.

Non-equilibrium dissipative systems from semiconductor physics have prevailed as a paradigmatic testing field for complex non-linear dynamics during the last decade. Especially, low-temperature impact ionization breakdown in extrinsic germanium crystals displays a variety of interesting nonlinear phenomena, such as spontaneous oscillations and filamentary patterns of the current flow. We report on recent experimental results concerning the interplay between spatial and temporal degrees of freedom during the onset of semiconductor breakdown. Quantitative evaluation of characteristic scaling properties supports the applicability of the model of self-organized criticality.

Biophysical Phenomena↗
PubMed1997

Some remarks on the experimental realization of a mind machine.

The brain not only makes use of measuring apparatuses, but perhaps has the potential to serve as one itself. Since Einstein-Podolsky-Rosen correlations must be absent between observer and object in order for a quantum state to become reducible, it is tempting to perturb measurements by changing the quantum state of the brain. The latter would then be part of the measurement. What kind of effects would one expect? It appears that a new psychophysical problem has been opened up, since any observable consequences would be confined to the subjectivity of the observer.

Brain↗
PubMed1996

Periventricular heterotopia: an X-linked dominant epilepsy locus causing aberrant cerebral cortical development.

Periventricular heterotopia (PH) involves dramatic malformations of the human cerebral cortex. Here we show that PH is closely linked to markers in distal Xq28 (maximal two-point lod score = 4.77 for F8C at theta = 0; maximal multipoint lod score = 5.37), so that affected females are obligatory mosaics for the mutation; that PH is lethal to at least some affected males; that PH malformations consist of well-differentiated cortical neurons filling the adult subependymal zone; and that individuals with PH are at high risk for epilepsy, though they have no other neurological or external stigmata. The PH gene may represent an important epilepsy susceptibility locus in addition to playing a key role in normal cortical development.

Abortion, Habitual↗
PubMed1996

The scleral filet technique for secondary orbital implantation surgery.

OBJECTIVE: To describe a simple procedure, the scleral filet technique, to place a secondary implant and take advantage of the scleral remnant. SETTING: Oculoplastic service at a university-affiliated hospital in Ottawa. PATIENTS: Three patients from Middle Eastern countries who had undergone evisceration following trauma without placement of an orbital implant. All three had a scleral remnant, enophthalmos and poor prosthetic motility. INTERVENTIONS: The scleral remnant was incised (fileted) in a crisscross fashion, allowing access to the retrobulbar space. A hydroxyapatite implant was placed, and the scleral remnants were closed without disrupting the muscle attachments, leaving the socket motility intact. RESULTS: All three patients had an uneventful postoperative course and were fitted with a prosthesis between 6 to 8 weeks. There was no implant exposure during the follow-up period of 8 to 15 months. Implant drilling and peg placement was carried out 6 to 10 months postoperatively. One of the patients had excellent motility, and two had good or fair motility. All were very satisfied with the results. CONCLUSIONS: Advantages of the scleral filet technique include simplicity, ability to use the patient's own vascularized scleral remnant to act as a protective cap over the implant and avoidance of donor material. We advocate the use of this procedure when a scleral remnant is present in a patient presenting for consideration of secondary implantation.

Adult↗
PubMed1990

[Penile erection after spinal anesthesia. Treatment with intracavernous ethyladrianol].

We report on 26 patients with sustained penile erection from spinal anesthesia following the classical technique using 20 mg bupivacaine at 0.25% that were treated by intracavernous injection of 10 mg ethyladrianol. Complete detumescence was achieved in 23 (88.4%); partial detumescence, which permitted transurethral surgery, was achieved in 3 patients (11.6%). No complications were observed apart from mild hematoma at the site of injection in 2 patients. All patients presented easily controllable arterial hypertension. This is a simple, easy and practically risk-free technique that has the advantage of achieving a high response rate thereby permitting surgery.

Aged↗