Biomedical subjects

C Miron

Publications and source records attributed to C Miron.

At least 19 recordsLinked to original sources

PubMed2002

Anomalous natural linewidth in the 2p photoelectron spectrum of SiF4.

The silicon 2p photoelectron spectra for SiH4, SiF4, and SiCl4 have been analyzed to give the natural linewidths of the Si 2p hole states, which reflect the Auger decay rates of the states. For SiH4 the measured width of 38 meV is in approximate agreement with the prediction of the one-center model (32 meV), but that for SiF4 of 79 meV is more than 5 times the value of 14 meV predicted by this model. Approximate theoretical calculations indicate that valence electrons from the fluorine atoms of SiF4 play an important role in the Auger decay via interatomic processes.

Journal Article↗

PubMed2002

Interference quenching of nu(")=1 vibrational line in resonant photoemission of N2: a possibility to obtain geometrical information on the core-excited state.

An interference quenching of the nu(")=1 vibrational line in the resonant Auger decay of N 1s-->pi(*) core-excited N2 is observed and analyzed. The intensity ratio between the nu(")=1 and nu(")=0 vibrational levels of the X2Sigma(+)(g) final state shows a surprising nonmonotonous variation as a function of frequency detuning, going through a minimum with a complete suppression of nu(")=1. We have developed a simple model which shows a linear relation between the value of the detuning frequency for this minimum and the equilibrium bond distance R(0)(c) of the core-excited state. A new way is thus established of determining the equilibrium bond distance for the core-excited state with a precision deltaR(0)(c)<10(-3) A.

Journal Article↗

PubMed2002

Nondipolar electron angular distributions from fixed-in-space molecules.

The first indication of nondipole effects in the azimuthal dependence of photoelectron angular distributions emitted from fixed-in-space molecules is demonstrated in N (2). Comparison of the results with angular distributions observed for randomly oriented molecules and theoretical derivations for the nondipole correction first order in photon momentum suggests that higher orders will be needed to describe distributions measured in the molecular frame.

Journal Article↗

PubMed2001

Dynamical angular correlation in molecular Auger decay.

The first measurements of the angular distribution of Auger electrons from fixed-in-space molecules have been performed in the C K-shell ionization region of CO, for both parallel and perpendicular orientations of the molecular axis with respect to the light polarization vector. The angular distributions obtained for the CO(2+)B(1)Sigma Auger final state show dramatic spectral variations, which also depend on the initial ionization channels, Sigma or Pi, and on the ionization photon energy. This dynamical angular correlation process strongly suggests the breakdown of a two-step model in which the Auger decay is treated independently of the initial photoionization process.

Journal Article↗

PubMed2000

Observation of a continuum-continuum interference hole in ultrafast dissociating core-excited molecules.

The femtosecond dissociation of HCl after core excitation has been studied through the resonant Auger decay. The spectra contain contributions from decay occurring at both "molecular" and "atomic" internuclear distances. We have observed a new interference mechanism in these spectra: An atomic spectral line develops into a negative spectral contribution, a "hole," when detuning the excitation energy from the maximum of the Cl2p(-1)sigma(*) resonance. Resonant x-ray scattering theory quantitatively explains this behavior as due to a novel destructive continuum-continuum interference between molecular and atomic contributions to the Auger decay.

Journal Article↗

PubMed2000

Doppler splitting of In-flight auger decay of dissociating oxygen molecules: the localization of delocalized core holes

By exploiting the core-excitation-induced dissociation of O2, we find that the Auger emission exhibits a Doppler-like energy shift. We show this to be a manifestation of localization of the core hole and propose that the problem of core-hole localization versus delocalization in core-hole spectroscopies may be resolved by considering the nature of the measurement.

Journal Article↗

PubMed1992

[Surgical landmarks of the temporo-frontal branch of the facial nerve].

The temporal branches of the facial nerve, and in particular the rami for the frontalis muscle, have been the subject of many studies with the main objective of avoiding injury. The usual reference points, sometimes difficult to localise, anatomical variations in their branching and anastomoses are the main points of our investigation. This anatomical dissection study of 30 cadavres, with easy reference points available both superficially and in the depths allow a simple, non complicated localisation of the frontal branch and its anastomosis in a precise way on the mandibular condyle, the zygomatic arch and the temporal region. The distances described a, b, c, are useful in common surgical practice: temporo-mandibular joint surgery, facial lifting, temporal and temporo-parietal fascia flaps, and contralateral neurotomy for frontal symmetrization among others.

Dissection↗

PubMed1991

[Infratemporal extension of tumors of the skull base].

The tumors of the middle and posterior portion of the skull base may extend extracranially. The spread of the tumors towards the infratemporal fossa is rare. Among 23 skull base tumors with extracranial extension which were diagnosed during the last 5 years, only two middle ear epidermoid carcinomas extended into the infratemporal fossa. Subtotal surgical removal of tumors was obtained in both cases through a subtotal petrectomy with an ultrasonic aspiration of the extracranial extension followed by transcutaneous irradiation. One case is followed free of disease 2 years and a half after the beginning of the treatment. The spread of the tumor into the infratemporal fossa might not be of poor prognosis.

Aged↗

PubMed1975

Screening tests for the enzymatic diagnosis in liver diseases and myocardial infarction.

To perform the ever increasing number of analyses with a minimum equipment the tendency all over the world is now to replace the classical tests with screening tests. The laboratory of enzymology of the Institute of Internal Medicine has achieved screening tests for the estimation of alkaline phosphatase, of total lactatedehydrogenase and of its fraction I, whose results are in agreement with the reference methods of Bessy-Lowry-Brock and of Lac-Dehystrate-Goedecke in cases of acute and chronic liver diseases, neoplasms, bone diseases (Paget's disease) and myocardial infarction.

Alkaline Phosphatase↗

PubMed1975

Primary evolution of chronic hepatitis estimated 3 to 14 years after the liver biopuncture.

From over 800 patients with chronic hepatic diseases admitted to the Institute of Internal Medicine between 1960-1969 and in whom diagnosis was assessed by hepatic biopuncture, 180 were reexamined 3-14 years later to estimate the clinical evolution and the prognostic value of the bioptic findings. The evolution was favourable in most of the cases of persistent chronic hepatitis (70%) and of moderate aggressive chronic hepatitis (59%). Severe aggressive chronic hepatitis evaluated favourably in 34% of the cases and was aggravated in 42% of the cases (26% exits). In the patients with cirrhosis the percentage of deaths reached 65 but 30% were still in a stationary form; a single exceptional case was improved 7 years after the hepatic biopuncture. The prognostic value of hepatic biopuncture is much increased if, in addition to the common histological features, other histochemical and morphological criteria such as: structural stability of collagen fibers, importance of cellular infiltrates and presence of plasma cells, nuclear changes, degree of steatosis, amount of glycogen storage, siderosis and cholestasis are also taken into consideration.

Biopsy, Needle↗

PubMed1973