Unusual features of long-range density fluctuations in glass-forming organic liquids : a Rayleigh and Rayleigh-Brillouin light scattering in study

A new feature of glass-forming liquids, i.e., long-range density fluctuations of the order of 100 nm, has been extensively characterized by means of static light scattering, photon correlation spectroscopy and Rayleigh-Brillouin spectroscopy in orthoterphenyl (OTP) and 1,1-di(4'-methoxy-5' methyl-phenyl)-cyclohexane (BMMPC). These long-range density fluctuations result in the following unusual features observed in a light scattering experiment. which are not described by the existing theories: (i) strong q-dependent isotropic excess Rayleigh intensity, (ii) additional slow component in the polarized photon correlation function, and (iii) high Landau-Placzek ratio. These unusual features are equilibrium properties of the glass-forming liquids and depend only on temperature, provided that the sample has been equilibrated long enough. The temperature-dependent equilibration times were measured for BMMPC and are about 11 orders of magnitude longer than the a process. It was found that the glass-forming liquid OTP may occur in two states: with and without long-range density fluctuations (''clusters"). We have characterized the two states by static and dynamic light scattering in the temperature range from T-g to T-g + 200 K. The relaxation times of the a process as well as the parameters of the Brillouin line are identical in both OTP with and without clusters. The a process (density fluctuations) in OTP was characterized by measuring either the polarized (VV) or depolarized (VH) correlation function, which are practically identical and a-independent. This feature, which is commonly observed in glass-forming liquids, is not fully explained by the existing theories

Uncommon branching pattern of the hepatic arteries in a living donor: a case report and brief literature review

Numerous variations of the hepatic arteries are common in surgical patients. We present a 35-year-old woman who was admitted to our department in order to assess possibility of becoming living donor. Preoperative computed tomography scan revealed anomalous branching pattern of the hepatic arteries. In this case right posterior sectoral artery has been given off by the greater pancreatic artery, left hepatic artery has been replaced by the artery arising from the left gastric artery and double segment 4 branches have been observed. To the best of our knowledge, this pattern has not been described in the literature, yet

Charge Transfer from Regularized Symmetry-Adapted Perturbation Theory

16 pages, 16 figure

Interparticle correlations due to electrostatic interactions: A small angle x-ray and dynamic light scattering study. I. Apoferritin

The structure and dynamics of the spherical protein Apoferritin in aqueous solution are studied over a wide range of protein concentrations and ionic strengths. At high ionic strength and low protein concentration, the intermolecular forces are screened and, therefore, the proteins behave like uncharged molecules. Under these conditions, the form factor of Apoferritin was measured by means of small angle x-ray scattering ͑SAXS͒ and the hydrodynamic radius was determined by means of dynamic light scattering ͑DLS͒. The sample was found to be highly monodisperse. By decreasing the content of salt added, interactions between the Apoferritin particles were initiated. These intermolecular forces lead to a pronounced maximum in the SAXS intensity. At the same time, a slow mode appears in the relaxation time distribution, additionally to the diffusive mode. The relative amplitudes and correlation times of the diffusive and the slow mode were investigated and compared with predictions of the coupled mode theory. By assuming the slow mode to be related to the correlated motion of ordered domains, the size of these domains was derived from the slow relaxation time. From the x-ray data and the Apoferritin form factor, structure factors of ordered solutions were calculated. The shape of the structure factor peaks was studied as a function of Apoferritin and salt concentration. Finally, by using the DLS information regarding the size of correlated domains, we analyzed the degree of polyelectrolyte ordering within the paracrystalline domains in Apoferritin solutions

Inelastic x-ray scattering reveals the ergodic to nonergodic transition of salol, a liquid with local order

We have studied the high-frequency dynamics of salol by inelastic x-ray scattering over a wide temperature range between 50 and 450 K, across the glass transition. We find that salol efficiently realizes the mechanism of dynamical arrest described by the mode-coupling theory, as manifested by a cusp singularity in the behaviour of the non-ergodicity parameter and a $Q$ dependence of the critical non-ergodicity parameter that is in phase with the static structure factor. These results confront positively the mode-coupling theory with liquids with local order.Comment: 7 pages, 6 figure

Acoustic and relaxation processes in supercooled o-ter-phenyl by optical-heterodyne transient grating experiment

The dynamics of the fragile glass-forming o-ter-phenyl is investigated by time-resolved transient grating experiment with an heterodyne detection technique in a wide temperature range. We investigated the dynamics processes of this glass-former over more then 6 decades in time with an excellent signal/noise. Acoustic, structural and thermal relaxations have been clearly identify and measured in a time-frequency window not covered by previous spectroscopic investigations. A detailed comparison with the density response function, calculated on the basis of generalized hydrodynamics model, has been worked out

Molecular excitation in the Interstellar Medium: recent advances in collisional, radiative and chemical processes

We review the different excitation processes in the interstellar mediumComment: Accepted in Chem. Re

Zalecenia ogólne dotyczące postępowania w nowotworach neuroendokrynnych układu pokarmowego (rekomendowane przez Polską Sieć Guzów Neuroendokrynnych)

W ostatnim czasie obserwuje się większe zainteresowanie rzadkimi nowotworami neuroendokrynnymi żołądkowo-jelitowo-trzustkowymi (GEP NEN). Wykrywalność nowotworów neuroendokrynnych w ostatnich latach wzrosła. Ponad 50% GEP NEN stanowią rakowiaki, które najczęściej są znajdowane przypadkowo podczas zabiegu operacyjnego w jelicie cienkim i w wyrostku robaczkowym oraz w momencie rozpoznania przerzutów odległych, głównie do wątroby. Istnieje konieczność współdziałania specjalistów różnych dziedzin medycyny w celu opracowania właściwych zasad postępowania diagnostyczno-leczniczego w tej grupie chorych. W niniejszej publikacji przedstawiono ogólne zalecenia Polskiej Sieci Guzów Neuroendokrynnych dotyczące postępowania u chorych z GEP NEN, opracowane podczas Konferencji, która odbyła się w Kamieniu Śląskim w kwietniu w 2013 roku. Członkowie grup roboczych zaktualizowali rekomendacje z 2008 roku. W kolejnych częściach tego opracowania przedstawiono zasady postępowania w: — nowotworach neuroendokrynnych żołądka i dwunastnicy (z uwzględnieniem gastrinoma); — nowotworach neuroendokrynnych trzustki; — nowotworach neuroendokrynnych jelita cienkiego i wyrostka robaczkowego; — nowotworach neuroendokrynnych jelita grubego. Zaproponowane rekomendacje przez ekspertów polskich i zagranicznych reprezentujących różne dziedziny medycyny (endokrynologię, gastroenterologię, chirurgię, onkologię, medycynę nuklearną i patomorfologię) powinny być pomocne w diagnostyce i leczeniu tych chorych

Diagnostic and therapeutic guidelines for gastro-entero-pancreatic neuroendocrine neoplasms (recommended by the Polish Network of Neuroendocrine Tumours)

W ostatnim czasie obserwuje się większe zainteresowanie rzadkimi nowotworami neuroendokrynnymi żołądkowo-jelitowo-trzustkowymi (GEP NEN). Wykrywalność nowotworów neuroendokrynnych w ostatnich latach wzrosła. Ponad 50% GEP NEN stanowią rakowiaki, które najczęściej są znajdowane przypadkowo podczas zabiegu operacyjnego w jelicie cienkim i w wyrostku robaczkowym oraz w momencie rozpoznania przerzutów odległych, głównie do wątroby. Istnieje konieczność współdziałania specjalistów różnych dziedzin medycyny w celu opracowania właściwych zasad postępowania diagnostyczno-leczniczego w tej grupie chorych. W niniejszej publikacji przedstawiono ogólne zalecenia Polskiej Sieci Guzów Neuroendokrynnych dotyczące postępowania u chorych z GEP NEN, opracowane podczas Konferencji, która odbyła się w Kamieniu Śląskim w kwietniu w 2013 roku. Członkowie grup roboczych zaktualizowali rekomendacje z 2008 roku.W kolejnych częściach tego opracowania przedstawiono zasady postępowania w:— nowotworach neuroendokrynnych żołądka i dwunastnicy (z uwzględnieniem gastrinoma);— nowotworach neuroendokrynnych trzustki; — nowotworach neuroendokrynnych jelita cienkiego i wyrostka robaczkowego;— nowotworach neuroendokrynnych jelita grubego.Zaproponowane rekomendacje przez ekspertów polskich i zagranicznych reprezentujących różne dziedziny medycyny (endokrynologię, gastroenterologię, chirurgię, onkologię, medycynę nuklearną i patomorfologię) powinny być pomocne w diagnostyce i leczeniu tych chorych. (Endokrynol Pol 2013; 64 (6): 418–443)An increased interest in gastro-entero-pancreatic neuroendocrine neoplasms (GEP NENs) has recently been observed. These are rare neoplasms and their detection in recent years has improved. Over 50% of GEP NENs are carcinoids, and they are usually found incidentally during surgery in the small intestine and appendix and at diagnosis in distant metastases, mainly to the liver. There is a need for co-operation between specialists in various disciplines of medicine in order to work out the diagnostic and therapeutic guidelines. In this publication, we present general recommendations of the Polish Network of Neuroendocrine Tumours for the management of patients with GEP NENs, developed at the Consensus Conference which took place in Kamień Śląski in April 2013. Members of the guidelines working groups were assigned sections of the 2008 guidance to update.In the subsequent parts of this publication, we present the rules of diagnostic and therapeutic management of:— neuroendocrine neoplasms of the stomach and duodenum (including gastrinoma);— pancreatic neuroendocrine neoplasms;— neuroendocrine neoplasms of the small intestine and the appendix;— colorectal neuroendocrine neoplasms.The proposed recommendations by Polish and foreign experts representing different fields of medicine (endocrinology, gastroenterology, surgery, oncology, nuclear medicine and pathology) will be helpful in the diagnosis and treatment of GEP NENs patients. (Endokrynol Pol 2013; 64 (6): 418–443

Vowel reduction in word-final position by early and late Spanish-English bilinguals

Vowel reduction is a prominent feature of American English, as well as other stress-timed languages. As a phonological process, vowel reduction neutralizes multiple vowel quality contrasts in unstressed syllables. For bilinguals whose native language is not characterized by large spectral and durational differences between tonic and atonic vowels, systematically reducing unstressed vowels to the central vowel space can be problematic. Failure to maintain this pattern of stressed-unstressed syllables in American English is one key element that contributes to a ?foreign accent? in second language speakers. Reduced vowels, or ?schwas,? have also been identified as particularly vulnerable to the co-articulatory effects of adjacent consonants. The current study examined the effects of adjacent sounds on the spectral and temporal qualities of schwa in word-final position. Three groups of English-speaking adults were tested: Miami-based monolingual English speakers, early Spanish-English bilinguals, and late Spanish-English bilinguals. Subjects performed a reading task to examine their schwa productions in fluent speech when schwas were preceded by consonants from various points of articulation. Results indicated that monolingual English and late Spanish-English bilingual groups produced targeted vowel qualities for schwa, whereas early Spanish-English bilinguals lacked homogeneity in their vowel productions. This extends prior claims that schwa is targetless for F2 position for native speakers to highly-proficient bilingual speakers. Though spectral qualities lacked homogeneity for early Spanish-English bilinguals, early bilinguals produced schwas with near native-like vowel duration. In contrast, late bilinguals produced schwas with significantly longer durations than English monolinguals or early Spanish-English bilinguals. Our results suggest that the temporal properties of a language are better integrated into second language phonologies than spectral qualities. Finally, we examined the role of nonstructural variables (e.g. linguistic history measures) in predicting native-like vowel duration. These factors included: Age of L2 learning, amount of L1 use, and self-reported bilingual dominance. Our results suggested that different sociolinguistic factors predicted native-like reduced vowel duration than predicted native-like vowel qualities across multiple phonetic environments