Pion interferometry in Au plus Au and Cu plus Cu collisions at s(NN)=62.4 and 200 GeV

We present a systematic analysis of two-pion interferometry in Au+Au collisions at s(NN)=62.4 GeV and Cu+Cu collisions at s(NN)=62.4 and 200 GeV using the STAR detector at the Relativistic Heavy Ion Collider (RHIC). The multiplicity and transverse momentum dependences of the extracted correlation lengths (radii) are studied. The scaling with charged particle multiplicity of the apparent system volume at final interaction is studied for the RHIC energy domain. The multiplicity scaling of the measured correlation radii is found to be independent of colliding system and collision energy.

Bose-Einstein correlation measurements at CMS

Multidimensional and one-dimensional quantum-statistical (Bose-Einstein) correlations are measured in proton proton collisions at 0.9, 2.76 and 7 TeV, in proton lead collisions at 5.02 TeV/nucleon pair and peripheral lead lead collisions at 2.76 TeV/nucleon pair center-of-mass energy with the CMS detector at the LHC. The correlation functions are extracted in terms of different components of the relative momentum of the pair, in order to investigate the extension of the emission source in different directions. The results are presented for different intervals of transverse pair momentum, k(T), and charged particle multiplicity of the collision, N-tracks, as well as for their integrated values. Besides inclusive charged particles, charged pions and kaons, identified via their energy loss in the silicon tracker detector, can also be correlated. The extracted source radii increase with increasing multiplicity, and decrease with increasing k(T). The results open the possibility to study scaling and factorization properties of these radii as a function of multiplicity, k(T), colliding system size and center-of-mass energy.

Tracer diffusion at water-oil interfaces studied by fluorescence correlation spectroscopy

The adsorption of particles and surfactants at water-oil interfaces has attracted continuous attention because of its emulsion stabilizing effect and the possibility to form two-dimensional materials. Herein, I studied the interfacial diffusion of single molecules and nanoparticles at water-oil interfaces using fluorescence correlation spectroscopy. rnrnFluorescence correlation spectroscopy (FCS) is a promising technique to study diffusion of fluorescent tracers in diverse conditions. This technique monitors and analyzes the fluorescence fluctuation caused by single fluorescent tracers coming in and out of a diffraction-limited observation volume “one at a time”. Thus, this technique allows a combination of high precision, high spatial resolution and low tracer concentration. rnrnIn chapter 1, I discussed some controversial questions regarding the properties of water-hydrophobic interfaces and also introduced the current progress on the stability and dynamic of single nanoparticles at water-oil interfaces. The materials and setups I used in this thesis were summarized in chapter 2. rnrnIn chapter 3, I presented a new strategy to study the properties of water-oil interfaces. The two-dimensional diffusion of isolated molecular tracers at water/n-alkane interfaces was measured using fluorescence correlation spectroscopy. The diffusion coefficients of larger tracers with a hydrodynamic radius of 4.0 nm agreed well with the values calculated from the macroscopic viscosities of the two bulk phases. However, for small molecule tracers with hydrodynamic radii of only 1.0 and 0.6 nm, notable deviations were observed, indicating the existence of an interfacial region with a reduced effective viscosity. rnrnIn chapter 4, the interfacial diffusion of nanoparticles at water-oil interfaces was investigated using FCS. In stark contrast to the interfacial diffusion of molecular tracers, that of nanoparticles at any conditions is slower than the values calculated in accordance to the surrounding viscosity. The diffusion of nanoparticles at water-oil interfaces depended on the interfacial tension of liquid-liquid interfaces, the surface properties of nanoparticles, the particle sizes and the viscosities of surrounding liquid phases. In addition, the interfacial diffusion of nanoparticles with Janus motif is even slower than that of their symmetric counterparts. Based on the experimental results I obtained, I drew some possibilities to describe the origin of nanoparticle slowdown at water-oil interfaces.

High Diagnostic Accuracy And Reproducibility Of Fine-needle Aspiration Cytology For Diagnosing Salivary Gland Tumors: Cytohistologic Correlation In 182 Cases.

The purpose of this study was to assess the efficacy and reproducibility of the cytologic diagnosis of salivary gland tumors (SGTs) using fine-needle aspiration cytology (FNAC). The study aimed to determine diagnostic accuracy, sensitivity, and specificity and to evaluate the extent of interobserver agreement. We retrospectively evaluated SGTs from the files of the Division of Pathology at the Clinics Hospital of São Paulo and Piracicaba Dental School between 2000 and 2006. We performed cytohistologic correlation in 182 SGTs. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were 94%, 100%, 100%, 100%, and 99%, respectively. The interobserver cytologic reproducibility showed significant statistical concordance (P < .0001). FNAC is an effective tool for performing a reliable preoperative diagnosis in SGTs and shows high diagnostic accuracy and consistent interobserver reproducibility. Further FNAC studies analyzing large samples of malignant SGTs and reactive salivary lesions are needed to confirm their accuracy.

Core-valence Correlation Effects On Ir Calculations: The Bf3 And Bcl3 Cases.

The first theoretical results of core-valence correlation effects are presented for the infrared wavenumbers and intensities of the BF3 and BCl3 molecules, using (double- and triple-zeta) Dunning core-valence basis sets at the CCSD(T) level. The results are compared with those calculated in the frozen core approximation with standard Dunning basis sets at the same correlation level and with the experimental values. The general conclusion is that the effect of core-valence correlation is, for infrared wavenumbers and intensities, smaller than the effect of adding augmented diffuse functions to the basis set, e.g., cc-pVTZ to aug-cc-pVTZ. Moreover, the trends observed in the data are mainly related to the augmented functions rather than the core-valence functions added to the basis set. The results obtained here confirm previous studies pointing out the large descrepancy between the theoretical and experimental intensities of the stretching mode for BCl3.

Measuring The Hydrodynamic Radius Of Quantum Dots By Fluorescence Correlation Spectroscopy.

Fluorescence Correlation Spectroscopy (FCS) is an optical technique that allows the measurement of the diffusion coefficient of molecules in a diluted sample. From the diffusion coefficient it is possible to calculate the hydrodynamic radius of the molecules. For colloidal quantum dots (QDs) the hydrodynamic radius is valuable information to study interactions with other molecules or other QDs. In this chapter we describe the main aspects of the technique and how to use it to calculate the hydrodynamic radius of quantum dots (QDs).

Correlation Between Cephalometric Data And Severity Of Sleep Apnea.

Obstructive sleep apnea syndrome has a high prevalence among adults. Cephalometric variables can be a valuable method for evaluating patients with this syndrome. To correlate cephalometric data with the apnea-hypopnea sleep index. We performed a retrospective and cross-sectional study that analyzed the cephalometric data of patients followed in the Sleep Disorders Outpatient Clinic of the Discipline of Otorhinolaryngology of a university hospital, from June 2007 to May 2012. Ninety-six patients were included, 45 men, and 51 women, with a mean age of 50.3 years. A total of 11 patients had snoring, 20 had mild apnea, 26 had moderate apnea, and 39 had severe apnea. The distance from the hyoid bone to the mandibular plane was the only variable that showed a statistically significant correlation with the apnea-hypopnea index. Cephalometric variables are useful tools for the understanding of obstructive sleep apnea syndrome. The distance from the hyoid bone to the mandibular plane showed a statistically significant correlation with the apnea-hypopnea index.

Histologic Correlation Of Expression Of Ki-67 In Squamous Cell Carcinoma Of The Glottis According To The Degree Of Cell Differentiation.

Squamous cell carcinoma is the most common neoplasm of the larynx and glottis, and its prognosis depends on the size of the lesion, level of local invasion, cervical lymphatic spread, and presence of distant metastases. Ki-67 (MKI67) is a protein present in the core, whose function is related to cell proliferation. To evaluate the expression of marker Ki-67 in squamous cell carcinoma of the larynx and glottis and its correlation to pathological findings. Experimental study with immunohistochemistry analysis of Ki-67, calculating the percentage of the cell proliferation index in glottic squamous cell carcinomas. Sixteen cases were analyzed, with six well-differentiated and 10 poorly/moderately differentiated tumors. There was a correlation between cell proliferation index and degree of cell differentiation, with higher proliferation in poorly/moderately differentiated tumors. The cell proliferation index, as measured by Ki-67, may be useful in the characterization of histological degree in glottic squamous cell tumors.

Correlation Between Testosterone And Psa Kinetics In Metastatic Prostate Cancer Patients Treated With Diverse Chemical Castrations.

To assess total testosterone and prostatic-specific antigen (PSA) kinetics among diverse chemical castrations, advanced-stage prostate cancer patients were randomized into three groups of 20: Group 1, Leuprolide 3.75 mg; Group 2, Leuprolide 7.5 mg; and Group 3, Goserelin 3.6 mg. All groups were treated with monthly application of the respective drugs. The patients' levels of serum total testosterone and PSA were evaluated at two time periods: before the treatment and 3 months after the treatment. Spearman's rank correlation coefficient was utilized to verify the hypothesis of linear correlation between total testosterone and PSA levels. At the beginning the patients' age, stage, grade, PSA, and total testosterone were similar within the three groups, with median age 72, 70, and 70 years in Groups 1, 2, and 3, respectively. Three months after the treatment, patients who received Leuprolide 7.5 mg presented significantly lower median total testosterone levels compared with Goserelin 3.6 mg and Leuprolide 3.75 mg (9.5 ng/dL vs. 20.0 ng/dL vs. 30.0 ng/dL, respectively; p = .0072), while those who received Goserelin 3.6 mg presented significantly lower PSA levels compared with Leuprolide 7.5 mg and Leuprolide 3.75 mg (0.67 vs. 1.86 vs. 2.57, respectively; p = .0067). There was no linear correlation between total testosterone and PSA levels. Overall, regarding castration levels of total testosterone, 28.77% of patients did not obtain levels ≤50 ng/dL and 47.80% did not obtain levels ≤20 ng/dL. There was no correlation between total testosterone and PSA kinetics and no equivalence among different pharmacological castrations.

Human Herpesvirus-6 And Cytomegalovirus Dna In Liver Donor Biopsies And Their Correlation With Hla Matches And Acute Cellular Rejection.

Herpesvirus reactivation is common after liver transplantation. Analyze the presence of cytomegalovirus (HCMV) and human herpesvirus-6 (HHV-6) DNA in liver donor biopsies, seeking to better understand issues involving human donor leukocyte antigens (HLA)-A, B and DR, as well as correlations with acute cellular rejection. Fifty-nine liver transplantation patients were investigated for the presence of HCMV and HHV-6 DNA in liver donor biopsies, using the Nested-PCR technique. The clinical donor information and HLA matches were obtained from the São Paulo State Transplant System. The recipients' records regarding acute cellular rejection were studied. Seven (11.8%) biopsies were positive for HCMV DNA and 29 (49%) were positive for HHV-6 DNA. In 14 donors with HLA-DR 15 nine had HHV-6 DNA positive liver biopsy with a tendency for significant association (p=0.09), 22 recipients developed acute cellular rejection and 9/22 were positive for HLA-DR 15 (p=0.03; χ(2)=4.51), which was statistically significant in univariate analysis and showed a tendency after multivariate analysis (p=0.08). HHV-6 DNA was prevalent in liver donors studied as well as HLA-DR 15. These findings suggest that patients with HLA-DR 15 in liver donor biopsies develop more rejection after liver transplantation.

Correlation Between Vascular Endothelial Growth Factor Expression And Presence Of Lymph Node Metastasis In Advanced Squamous Cell Carcinoma Of The Larynx.

Squamous cell carcinoma is the most common neoplasm of the larynx, and its evolution depends on tumor staging. Vascular endothelial growth factor is a marker of angiogenesis, and its expression may be related to increased tumor aggressiveness, as evidenced by the presence of cervical lymphatic metastases. To evaluate the expression of the vascular endothelial growth factor marker in non-glottic advanced squamous cell carcinoma of the larynx (T3/T4) and correlate it with the presence of cervical lymph node metastases. Retrospective clinical study and immunohistochemical analysis of vascular endothelial growth factor through the German scale of immunoreactivity in products of non-glottic squamous cell carcinomas. This study analyzed 15 cases of advanced non-glottic laryngeal tumors (T3/T4), four of which exhibited cervical lymphatic metastases. There was no correlation between vascular endothelial growth factor expression and the presence of cervical metastases. Although vascular endothelial growth factor was expressed in a few cases, there was no correlation with the spread of cervical lymph metastases.

ΛΛ Correlation Function In Au+au Collisions At √[s(nn)]=200 gev.

We present ΛΛ correlation measurements in heavy-ion collisions for Au+Au collisions at sqrt[s_{NN}]=200  GeV using the STAR experiment at the Relativistic Heavy-Ion Collider. The Lednický-Lyuboshitz analytical model has been used to fit the data to obtain a source size, a scattering length and an effective range. Implications of the measurement of the ΛΛ correlation function and interaction parameters for dihyperon searches are discussed.

Measurement Of The Hydrodynamic Radius Of Quantum Dots By Fluorescence Correlation Spectroscopy Excluding Blinking.

One of the most important properties of quantum dots (QDs) is their size. Their size will determine optical properties and in a colloidal medium their range of interaction. The most common techniques used to measure QD size are transmission electron microscopy (TEM) and X-ray diffraction. However, these techniques demand the sample to be dried and under a vacuum. This way any hydrodynamic information is excluded and the preparation process may alter even the size of the QDs. Fluorescence correlation spectroscopy (FCS) is an optical technique with single molecule sensitivity capable of extracting the hydrodynamic radius (HR) of the QDs. The main drawback of FCS is the blinking phenomenon that alters the correlation function implicating in a QD apparent size smaller than it really is. In this work, we developed a method to exclude blinking of the FCS and measured the HR of colloidal QDs. We compared our results with TEM images, and the HR obtained by FCS is higher than the radius measured by TEM. We attribute this difference to the cap layer of the QD that cannot be seen in the TEM images.

Partial-hepatectomized (70%) Model Shows A Correlation Between Hepatocyte Growth Factor Levels And Beta-cell Mass.

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Explosive Synchronization With Partial Degree-frequency Correlation.

Networks of Kuramoto oscillators with a positive correlation between the oscillators frequencies and the degree of their corresponding vertices exhibit so-called explosive synchronization behavior, which is now under intensive investigation. Here we study and discuss explosive synchronization in a situation that has not yet been considered, namely when only a part, typically a small part, of the vertices is subjected to a degree-frequency correlation. Our results show that in order to have explosive synchronization, it suffices to have degree-frequency correlations only for the hubs, the vertices with the highest degrees. Moreover, we show that a partial degree-frequency correlation does not only promotes but also allows explosive synchronization to happen in networks for which a full degree-frequency correlation would not allow it. We perform a mean-field analysis and our conclusions were corroborated by exhaustive numerical experiments for synthetic networks and also for the undirected and unweighed version of a typical benchmark biological network, namely the neural network of the worm Caenorhabditis elegans. The latter is an explicit example where partial degree-frequency correlation leads to explosive synchronization with hysteresis, in contrast with the fully correlated case, for which no explosive synchronization is observed.