Single-channel fits and K-matrix constraints

A K-matrix formalism is used to relate single-channel and multi-channel fits. We show how the single-channel formalism changes as new hadronic channels become accessible. These relations are compared to those commonly used to fit pseudoscalar meson photoproduction data.Comment: 9 pages, 2 figures. A numerical example has been adde

Time-delay in a multi-channel formalism

We reexamine the time-delay formalism of Wigner, Eisenbud and Smith, which was developed to analyze both elastic and inelastic resonances. An error in the paper of Smith has propagated through the literature. We correct this error and show how the results of Eisenbud and Smith are related. We also comment on some recent time-delay studies, based on Smith's erroneous interpretation of the Eisenbud result.Comment: 4 pages, no figure

Progress in High Resolution Scanning Ion Microscopy and Secondary Ion Mass Spectrometry Imaging Microanalysis

The performance of a new high resolution scanning ion microprobe (SIM) is elucidated with regard to imaging capabilities using the ion-induced secondary electron (ISE) or secondary ion (ISI) signals, and the mass-resolved signal from a secondary ion mass spectrometry (SIMS) system. The new instrument focuses a beam extracted from a liquid metal ion source (LMIS) to a range of spot sizes reaching the 20 nm level. The probe current (1.6 pA) available at this level of lateral resolution, which approaches the theoretical resolution limits of the SIMS method, is still adequate to obtain detailed isotopic maps for surfaces rich in the elements of low ionization potential (positive ISI), or high electron affinity (negative ISI). In addition to examples of high resolution ISE and ISI images of objects displaying sufficiently small topographic detail, mass spectra and isotopic maps are shown, testing both the lateral and depth resolution attained. The latter results belong with a program of interdisciplinary research applications of the new microprobe, which include studies of e.g., the monolayer lateral distribution of intercalant in SbCl5 intercalated graphite and of silicate minerals and iron distribution in sections of chondrules and their rims (components of chondrites, a class of stoney meteorites). In the biomedical field, the new microprobe finds application in e.g., the study of human renal calculi and bone. Most promising is the use of stable isotope tracers (e.g., Ca44) to unravel the dynamics of bone mineralization, as thus far shown with the in-vitro culture of the skull bone of neonatal mice

Dendritic Oxide Growth on the Surface of Liquid Gallium

We have studied the oxidation of a liquid gallium surface with a high spatial resolution scanning ion microprobe. A 40 keV focused gallium ion beam, extracted from a liquid metal ion source, was employed, first, to sputter clean a 40 x 40 μm2 area on a drop of liquid gallium, in a ultra high vacuum (UHV) specimen chamber. It was then used to monitor the oxide growth by secondary ion mass spectrometry imaging microanalysis while the chamber was gradually back-filled with oxygen. In the initial stages, gallium oxide grew in a dendritic pattern from the edge of the cleaned area where oxide preexisted. Gradually the oxide layer grew in thickness and covered the entire area leaving only small islands and channels uncovered. Computer simulations based on aggregation of two dimensional random walkers (or diffusion limited aggregation) show similar dendritic patterns in the initial stages of growth. The similarity is also reflected by their comparable fractal dimensions. For the final stages, qualitative discrepancies between the experimental and simulated patterns are discernible

A Proposal for a High Resolution Scanning Ion Microprobe Based on Laser Non-Resonant Post-Ionization of Sputtered Atoms

A new high resolution scanning ion microprobe (SIM) is described which combines laser non-resonant multiphoton ionization (MPI) and time of flight (ToF) spectroscopy. The proposed instrument is designed to overcome limitations of the conventional secondary ion mass spectrometry (SIMS) method. A pulsed ion probe (with current 1 - 100 pA) is extracted from a liquid metal ion source (LMIS). This beam is purified by a Wien filter, focused to a spot (15 - 150 nm), and scanned across a sample in a raster pattern (512 x 512 pixels). A high power (200 mJ, 193 nm, 500 Hz) ArF pulsed laser -an off-axis ellipsoidal reflector is planned to boost its power density - intercepts the sputtered neutrals, ionizing a large fraction for detection. The resultant ions are collected by a spherical sector energy analyzer and mass resolved by either a reflectron or Poschenrieder type ToF spectrometer. The laser pulse defines the time base for the spectrometer; mass resolution of more than 3000 is feasible. Detailed calculations of the neutrals\u27 sputtering and photoionization yields are given. In particular, an analytical expression for two-photon ionization of sputtered atoms, which optimizes the photon-neutrals overlap, is derived and results plotted. This technique, post-ionization of sputtered atoms (PISA), is shown to permit several high statistical accuracy, high mass and lateral resolution images to be obtained simultaneously, even for elements with high ionization potential or low electron affinity, elements difficult to examine with SIMS. Compared to SIMS, PISA greatly reduces the range of the variation in detected signal as a function of atomic number, facilitating quantification

Imaging-SIMS (Secondary Ion Mass Spectroscopy) Studies of Advanced Materials

This article describes the application of scanning ion microprobe (SIM) microanalysis for the characterization of advanced engineered materials. In conjunction with secondary ion mass spectrometry (SIMS), scanning ion microprobes can image elemental distributions over surfaces with high lateral resolution (50-100 nm). With this technique, most elements, including isotopes, can be detected with good sensitivity. The principles and instrumentation associated with the SIM/SIMS technique are briefly described and ongoing developments are outlined. The analytical capabilities of the technique are illustrated by case studies of aluminum-lithium alloys, zinc oxide varistors, aluminum matrix composites, and photographic materials

Resonance parameters from K-matrix and T-matrix poles

We extract K-matrix poles from our fits to elastic pion-nucleon scattering and eta-nucleon production data in order to test a recently proposed method for the determination of resonance properties, based on the trace of the K-matrix. We have considered issues associated with the separation of background and resonance contributions, the correspondence between K-matrix and T-matrix poles, and the complicated behavior of eigenphases.Comment: 11 pages, 1 figur

Ion Microscopy: A New Approach for Subcellular Localization of Labelled Molecules

Secondary ion mass spectroscopy (SIMS) was used to obtain images representing the intracellular distribution of molecules labelled with carbon 14. Deoxyadenosine labelled with carbon 14 was added to a cultured human fibroblast cell medium, and the intracellular distribution of this molecule was studied using three different SIMS instruments: the CAMECA IMS 3F and SMI 300 ion microscopes and the UC-HRL scanning ion microprobe. Carbon 14 distribution images obtained by this method show that deoxyadenosine U-C14 is present in the cytoplasm as well as the nucleus, with a higher concentration in\u27 the nucleoli. Our study clearly demonstrates that ion microscopy is well suited for carbon 14 detection and localization at the subcellular level, permitting a wide variety of microanalytical tracer experiments

Pro-inflammatory M1/Th1 type immune network and increased expression of TSG-6 in the eutopic endometrium from women with endometriosis

Objective The study aimed to explore the type 1 and type 2 cytokines expression in the endometrium from women affected by endometriosis compared to controls. The expression of TSG-6, a multifunctional protein involved in several inflammatory disease, was also evaluated. Study Design Setting Experimental clinical study. Patients 10 patients affected by endometriosis and 11 controls. Interventions Patients underwent to an ultrasound transvaginal examination and a diagnostic hysteroscopy in order to exclude any uterine abnormality. All patients underwent endometrial biopsy using a Novak's curette. Main outcome measures The endometrial expression of type 1 (IL- 1 β TNF-α, IL-8) and type 2 (IL-10) cytokines, and of TSG-6 was evaluated by immunohistochemistry and by real time PCR. The expression of TSG-6 was confirmed by western blot. Results Results of PCR analysis and of immunohistochemistry revealed an increased expression of IL-1β, TNF-α, IL-8 and of TSG-6 in the endometrium of endometriosic patients. IL-10 expression did not show any difference. Conclusions An increased expression of pro-inflammatory type 1 cytokines was demonstrated in the endometrium from endometriosic patients, suggesting an endometrial environment harmful for implantation due to the prevalence of Th1 related immunity. An increased expression of TSG-6 was also demonstrated for the first time. Our findings concur to better define the inflammatory imbalance and the abnormal endometrial receptivity, reported in literature, of the eutopic endometrium of women affected by endometriosis

Contribution of cryopreservation to the cumulative live birth rate: a large multicentric cycle-based data analysis from the Italian National Registry

Purpose: To estimate the contribution of cryopreservation to the cumulative live birth rate (CLBR) after law modification in Italy in the era of vitrification and freeze-all. Methods: The Italian National Registry performed a cycle-based data collection. Nine Italian IVF clinics were involved incorporating a total of 10,260 fresh cycles performed between January 2015 and April 2016 resulting in 9273 oocyte retrievals and 3266 subsequent warming cycles from the same oocyte retrievals performed up to December 2016. Mean female age was 37 \ub1 4.3\ua0years. Primary outcome measure was CLBR per oocyte retrieval. Confounding factors were tested in multivariate regression analysis, and the relative impact of cryopreservation to the CLBR in different patient categories was calculated. Results: CLBR per oocyte retrieval was 32.6%, 26.5%, 18.7%, 13.0%, and 5.5% for women younger than 36, aged 36\u201339, 40\u201341, and older than 41\ua0years, respectively. The total relative contribution of oocyte/embryo cryopreservation was 40.6% (95% CI 38.41\u201342.75). An association between maternal age, number of oocytes retrieved, fertilization rate, cryopreservation, and cumulative live birth was shown. When adjusted for confounders, a 2.3-fold increase was observed in the chance of live birth when cryopreservation was performed (OR 2.3; 95% CI 1.99\u20132.56). In high responder patients (> 15 oocytes retrieved) where freeze-all was applied in 67.6% of cycles to avoid the risk of hyper stimulation syndrome, the relative contribution of vitrification to the CLBR was 80.6%. Conclusions: Cryopreservation is essential in IVF and should always be available to patients to optimize success rates. Multicentric, cycle-based data analyses are crucial to provide infertile couples, clinicians, and regulatory bodies with accurate information on IVF effectiveness including fresh and cryopreserved cycles