bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature dependence of exciton–phonon‐induced sidebands in arbitrary carbon nanotubes
Authors: Bobkin Evgeny , Malic Ermin 
Published: October 2011

AbstractWe present a microscopic approach based on the many‐body density matrix formalism for the study of exciton–phonon‐induced features in absorption spectra of carbon nanotubes with an arbitrary chiral angle and diameter. The introduction of excitonic wave functions already containing the influence of the Coulomb interaction allows us to focus on the contribution of phonons. We observe the formation of pronounced sidebands on both sides of the zero‐phonon line. We study the behaviour of exemplary nanotubes belonging to the two semiconducting and one metallic family with respect to the spectral weight transfer from the zero‐phonon line to the exciton–phonon sidebands at different temperatures.
Adaptation of a commercial Raman spectrometer for multiline and broadband laser operation
Authors: Fábián Gábor , Kramberger Christian , Friedrich Alexander , Simon Ferenc , Pichler Thomas 
Published: October 2011

AbstractA commercial single laser line Raman spectrometer is modified to accommodate multiline and tunable dye lasers, thus combining the high sensitivity of such single monochromator systems with broadband operation. Such instruments rely on high‐throughput interference filters that perform both beam alignment and Rayleigh filtering. Our set‐up handles this dual task with two independent elements: a beam splitter and a long pass filter. Filter rotation shifts the transmission passband, effectively expanding the range of operation. Operation is demonstrated on single‐walled carbon nanotubes, for which the set‐up was optimized. As the set‐up operates with standard optical elements it can be customized for specific needs with relative ease.
Electronic properties of hydrogenated quasi‐free‐standing graphene
Authors: Haberer D. , Petaccia L. , Wang Y. , Quian H. , Farjam M. , Jafari S. A. , Sachdev H. , Federov A. V. , Usachov D. , Vyalikh D. V. , Liu X. , Vilkov O. , Adamchuk V. K. , Irle S. , Knupfer M. , Büchner B. , Grüneis A. 
Published: October 2011

AbstractTailoring the electronic properties of graphene is of fundamental interest regarding its application in electronic devices. One of the key strategies is chemical functionalization which modifies the π‐electron system and thus can induce band gaps. However, in order to control the degree of functionalization it is crucial to know the exact amount of the chemisorbed species. We show with angle‐resolved photoemission spectroscopy (ARPES) the formation of a band gap in graphene and estimate the hydrogen coverage from the scattering rate. Using X‐ray photoemission spectroscopy (XPS) we identify the chemical environments in hydrogenated graphene and determine the total hydrogen to carbon (H/C)‐ratio directly from the spectra. We then compare ARPES and XPS as tools for determining the H/C‐ratio and discuss the results from molecular dynamics (MD) simulations.magnified image
Angle‐resolved photoemission spectra of (left panel) pristine graphene intercalated with Au and (right panel) hydrogenated graphene on Au with an estimated H‐coverage of 5.8%. Besides the formation of a band gap, a broadening is observable which can be used to determine the H amount. Both spectra show the π‐band at the K‐point.
Role of nitrogen distribution in asymmetric Stone–Wales defects on electronic transport of graphene nanoribbons
Authors: Zeng Hui , Zhao Jun , Wei Jianwei , Xu Dahai 
Published: October 2011

AbstractThe authors performed first principles calculation to investigate the influences of nitrogen dopant distribution in the asymmetric Stone–Wales (SW) defect on the electronic transport of zigzag‐edged graphene nanoribbon (ZGNR). The stability of doped configurations are evaluated in terms of total energies. It is found that the dopant placed near the edge of the ribbon is the most energetically favorable site. Our results reveal that the doped nanostructures can be substantially modulated as a result of modifications on electronic bands induced by substitutional dopant. Moreover, the individual dopant gives rise to one or two complete electron backscattering centers associated with impurity states in the doped configurations, and the location is determined by the dopant site. magnified image
Schematics of the atomic structure after asymmetric Stone–Wales defects introduced and different nitrogen substitutional sites.
How to obtain and use X‐Ray projection microscopy in the SEM
Authors: Horn H. R. F. , Waltinger H. G. 
Published: October 2011

AbstractThe primary electron beam of an SEM is used to generate a point source of x‐rays, permitting x‐ray microscopy within the SEM.The practical device described fits into the sample chamber of an SEM. Exact and reproducible adjustabilities of the sample support and the film holder allow two x‐ray micrographs, e.g. stereo‐micrographs, to be taken in one run without repressurization of the specimen chamber. By comparing x‐ray and SEM micrographs of the same sample in the identical position it is possible to get additional information concerning surface morphology and inner structure of a specimen.
The tandem scanning reflected light microscope
Authors: Petráň M. , Hadravský M. , Boyde A. 
Published: October 2011

AbstractReflected light microscopy of biological material has been a very difficult task and many different but hardly successful attempts have been made to get usable images. The main reasons for this state are: Weak reflections from the biologically important structures in the object as against strong reflection at its surface; reflections at optical surfaces in the microscope which cause a deterioration of contrast; and the mixing together of reflections from many levels in the object so that the signal coming from the focussed‐on level is lost in noise and d.c. components.We tried, and successfully, to reverse this situation and to make it possible for the signal to overwhelm spurious and scattered light using double, or, as we call it, tandem scanning. The object is illuminated only in small patches lying in one plane and moving across this plane, and only the light reflected from these illuminated patches is allowed to pass into the image plane and participate in image formation. The image consists of points which travel over the image plane and which are geometrical images of the illuminated patches in the focussed‐on object plane. To ensure that only the light belonging to these geometrical images be allowed to enter the image, the image plane is covered with an opaque diaphragm having holes in locations exactly corresponding to the locations of the geometrical images of the illuminated object points; this diaphragm travels in concordance with the first scanning and so the complete image of the focussed‐on object plane is formed successively.Both scans are performed by a single device, a Nipkow disc carrying in its annular periphery several ten thousands of holes arranged in Archimedean spirals. The disc is 100 mm in diameter and rotates about 100 rpm driven by an electric motor. On one side the disc is illuminated in a circle 18 mm in diameter, and the light transmitted through several hundred holes and reflected in a mirror system passes a microscope objective which forms the images of the disc holes in the object plane. The light reflected here passes through the same objective and mirror system (one mirror being a “limitlessly thin” beam splitter) to pass conjugate aperture holes on the observation side of the Nipkow disc. As the disc lies at the intermediate image plane of the objective lens on both its illuminating and observation sides, only light emanating from reflection or fluorescence in the plane of focus can contribute to the image. High contrast images of very thin focussed‐on layers are thus formed.The practical arrangements are such that very large specimens can be examined: The specimens for this microscope need not themselves be microscopic.
Atomistische Simulation von amorphen TiO2‐Strukturen für optische Schichtsysteme
Authors: Köhler Thomas , Dolgonos Grygoriy , Frauenheim Thomas 
Published: October 2011

AbstractZielsetzung des vorliegenden Beitrages ist es, einen kurzen Überblick über die Möglichkeiten der Modellierung oxidischer optischer Materialien, am Beispiel des amorphen Titanoxids (TiO2), zu geben. Im Vordergrund steht hierbei ein effizientes approximatives Dichtefunktional‐basiertes Verfahren (DFTB), mit dem es möglich ist, Einsicht in lokale Struktur‐Eigenschaftsbeziehungen auf atomarer Basis zu bekommen. Perspektivisch werden Wege aufgezeigt, die Erkenntnisse auf andere Problemklassen, z. B. Grenzflächen zu übertragen, deren Optimierung größerskalige Betrachtungen erfordern. Die Studien sind im Rahmen des PLuTO‐Pilotprojektes zur Plasmaabscheidung optischer Schichtsysteme eingebettet.
Vakuum‐ und Plasmagestützte Dünnschichttechnik – wohin geht die Reise?
Authors: Blau Winfried 
Published: October 2011

AbstractDas Programm der V2011 – Industrieausstellung & Workshop‐Woche „Vakuumbeschichtung und Plasmaoberflächentechnik”︁ liegt vor, vgl. S. 42 in diesem Heft. Das Programm ist nach Anwendungsgebieten gegliedert, eine gute Gelegenheit zu fragen, wo liegen auf diesen Gebieten die gegenwärtigen Schwerpunkte, welche davon sind möglicherweise zukunftsträchtig.
Long‐Term Impact of Pretransplant and Posttransplant Diabetes Mellitus on Kidney Transplant Outcomes
Authors: Tsai Jen‐Pi , Lian Jong‐Da , Wu Sheng‐Wen , Hung Tung‐Wei , Tsai Hui‐Ching , Chang Horng‐Rong 
Published: October 2011

AbstractBackgroundThe aim of this study was to compare the impact of preexisting diabetes mellitus (pre‐DM), posttransplant DM (PTDM), and non‐DM on the long‐term outcomes of renal transplant recipients (RTRs).MethodsThis is a retrospective observational cohort study of 427 RTRs who underwent transplantation from 1999 to 2008. Patients were divided into non‐DM, pre‐DM, and PTDM groups. The primary outcome was the composite of doubling of the serum creatinine (SCr) level, graft failure, or death. Secondary outcomes were biopsy‐proven acute rejection (BPAR), biopsy‐proven interstitial fibrosis and/or tubular atrophy (IF/TA), and individual components of the primary outcome.ResultsA total of 70 patients (16.4%) had pre‐DM, 104 (24.2%) had PTDM, and 253 (59.3%) had non‐DM. Kaplan–Meier analysis indicated significant differences in the development of the primary outcome: p = 0.003 (log rank test). Relative to the non‐DM group, the pre‐DM group had a 6.36‐fold increased risk [95% confidence interval (CI) 2.43–16.33; p < 0.001), and the PTDM group had a 2.00‐fold increased risk (95% CI 1.08–3.73; p = 0.029) for development of the primary outcome. Patients in the pre‐DM group had 6.73‐fold (95% CI 2.46–18.42; p < 0.001), 4.56‐fold (95% CI 1.77–11.78; p = 0.002), and 13.95‐fold (95% CI 2.96–65.75; p < 0.001) increased risks for the development of SCr doubling, biopsy‐proven IF/TA, and death‐censored graft failure, respectively. Patients in the PTDM group had a 2.09‐fold (95% CI 1.10–3.99; p = 0.025), increased risk for the development of SCr doubling.ConclusionsThe presence of pre‐DM or PTDM significantly impaired kidney allograft outcome.
No Outcome Differences between a Laparoscopic and Retroperitoneoscopic Approach in Synchronous Bilateral Adrenal Surgery
Authors: Miccoli Paolo , Materazzi Gabriele , Brauckhoff Michael , Ambrosini Carlo Enrico , Miccoli Mario , Dralle Henning 
Published: October 2011

AbstractBackgroundTwo main approaches have been described for endoscopic adrenalectomy: the transperitoneal approach with the patient in the lateral decubitus position (LA) and the retroperitoneal approach with the patient in the prone position (ERA). The goal of the present study was to compare the results of LA and ERA for endoscopic bilateral synchronous adrenalectomy.Patients and MethodsBetween 1994 and 2008, 34 patients underwent bilateral synchronous adrenalectomy in two referral centers: 20 patients underwent LA in Pisa (group A), and 14 patients underwent ERA in Halle (group B). Sex, age, preoperative diagnosis, body mass index, preoperative medical treatments, diameter of glands, blood loss, operative time, complications, conversion, intensive care unit stay, day of first oral intake, length of postoperative recovery, histology report, and outcome were analyzed.ResultsThere were 7 men and 13 women in group A and 6 men and 8 women in group B. Mean age was 48.1 years in group A and 38.9 years in group B. Body mass index was similar in the two groups. Diameters of the glands were larger in group A than in group B, at 61.1 versus 42.8 mm for the right side and 64.1 versus 37.4 mm for the left side. Mean hospital stay was longer in group B (8.2 versus 5.25 days; P = 0.002), whereas the intensive care unit stay was longer in group A (1.44 versus 1 day).ConclusionsIt is not possible to determine which of the two approaches is better; both are feasible, safe, and effective and patient outcomes are almost the same.
Cytoplasmic Forkhead Box M1 (FoxM1) in Esophageal Squamous Cell Carcinoma Significantly Correlates with Pathological Disease Stage
Authors: Hui Marco K. C. , Chan Kwok Wah , Luk John M. , Lee Nikki P. , Chung Yvonne , Cheung Leo C. M. , Srivastava Gopesh , Tsao Sai Wah , Tang Johnny C. , Law Simon 
Published: October 2011

AbstractEsophageal cancer is a deadly cancer with esophageal squamous cell carcinoma (ESCC) as the major type. Until now there has been a lack of reliable prognostic markers for this malignancy. This study aims to investigate the clinical correlation between Forkhead box M1 (FoxM1) and patients’ parameters in ESCC.MethodsImmunohistochemistry was performed to investigate the expression and localization of FoxM1 in 64 ESCC tissues and 10 nontumor esophageal tissues randomly selected from 64 patients before these data were used for clinical correlations.ResultsCytoplasmic and nuclear expressions of FoxM1 were found in 63 and 16 of the 64 ESCC tissues, respectively. Low cytoplasmic expression of FoxM1 was correlated with early pathological stage in ESCC (P = 0.018), while patients with nuclear FoxM1 were younger in age than those without nuclear expression (P < 0.001). Upregulation of FoxM1 mRNA was found in five ESCC cell lines (HKESC‐1, HKESC‐2, HKESC‐3, HKESC‐4, and SLMT‐1) when compared to non‐neoplastic esophageal squamous cell line NE‐1 using quantitative polymerase chain reaction (qPCR). Except for HKESC‐3, all studied ESCC cell lines demonstrated a high expression of FoxM1 protein using immunoblot. A high mRNA level of FoxM1 was observed in all of the ESCC tissues examined when compared to their adjacent nontumor tissues using qPCR.ConclusionCytoplasmic FoxM1 was correlated with pathological stage and might be a biomarker for advanced ESCC.
Left hepatectomy
Authors: Kobayashi Akira , Miyagawa Shinichi 
Published: October 2011

AbstractLeft hepatectomy is one of the most common types of hepatectomy. In order to perform the procedure, surgeons need to possess all the basic skills for accomplishing any liver resection. The most important points to bear in mind in relation to left hepatectomy are: (1) a precise recognition of the surgical anatomy of the vascular structures of the liver, especially the bile duct, because of the wide anatomic variations; (2) recognition that the procedure consists of the following three parts: hilar dissection, mobilization of the left liver, and liver resection; (3) an understanding that these steps need to be accomplished with great care to control bleeding and to avoid injury to the vessels supplying the right hemiliver.
Heterotopic autotransplantation of vitrified mouse ovary
Authors: Eimani Hussein , Behbahanian Arash , Zeinali Bahman , Valoujerdi Mojtaba Rezazade , Eftekhari Poopak , Shahverdi Abdulhussein , Gourabi Hamid , Golkar‐Narenji Afsaneh 
Published: October 2011

AbstractPurposeThe aim of this study was to investigate the survival and development of premature follicles and oocytes from a vitrified‐transplanted ovary in a murine experimental model.MethodsThe 14‐day‐old mice were unilaterally ovariectomized and the separated ovaries were vitrified by cryotop. After 2 weeks the ovaries were warmed and autotransplanted into the gluteus superfiscialis muscle. After 3 weeks, these ovaries (vit‐trans), the ovaries from the opposite side (OPP), and 7‐week fresh mouse ovaries as sham and control group (7 week‐fresh), were recovered and examined histologically and by TUNEL test.ResultsAll 4 vitrified‐autotransplanted ovaries had developing follicles. Primordial, primary, preantral and antral follicles were found in all three groups (7 week‐fresh, OPP and vit‐trans). The rate of apoptosis by TUNEL test was similar in all groups and no significant difference was found between vitrified‐transplanted ovarian tissue and controls.ConclusionsThese data demonstrate successful autotransplantation of vitrified whole mouse ovaries, manifested by the presence of all stages of folliculogenesis. According to the results of this experiment, heterotopic autotransplantation of whole cryopreserved ovary provides the opportunity for follicle development at all stages. However, further experiments are required to improve the efficiency of autotransplantation of cryopreserved ovaries to obtain better results.
Phylogeny of the genusBryoria
Authors: MYLLYS Leena , VELMALA Saara , HOLIEN Håkon , HALONEN Pekka , WANG Li-Song , GOWARD Trevor 
Published: October 2011

AbstractThe phylogenetic relationships of the genusBryoriawere examined using ITS, partial glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and mitochondrial SSU rDNA sequence data in addition to 20 chemical and morphological characters. This first comprehensive molecular study to assessBryoriaphylogeny includes representatives from all the traditionally recognized four sections. Combined cladistic analyses of 88Bryoriaspecimens representing at least 25 species resulted in highly resolved phylogenies. Based on the results, a new infrageneric classification for the genus is proposed. Five sections are recognized, largely corresponding to the existing classification, with the addition of sectionAmericanae. The study shows that while most species with an erect growth-form are clearly monophyletic, current species status of many pendent taxa can be questioned.
The Encyclopedia of Life (EOL) as a scientific resource and outreach medium applied to the lichen family Parmeliaceae (Ascomycota: Lecanorales)
Authors: LÜCKING Robert , SCHULZ Katja , CRESPO Ana , NASH Thomas H. , LUMBSCH H. Thorsten 
Published: October 2011

AbstractA brief discussion of the Encyclopedia of Life and the LifeDesks websites as a means to assemble and publish species pages and taxonomic information on the internet, for both the scientific community and the public, is provided. The lichen family Parmeliaceae is the first large group of lichenized fungi for which a concerted effort is currently being undertaken to produce substantial content for the EOL.
Phylogenetic relationships of the neuropogonoid core group in the genus Usnea(Ascomycota: Parmeliaceae)
Authors: LUMBSCH H.Thorsten , WIRTZ Nora 
Published: October 2011

AbstractSpecies of Usnea with black pigmentation in the cortex and dark apothecial discs are informally referred to as neuropogonoid lichens. Here we studied the phylogenetic relationships of the core group of neuropogonoid lichens using DNA sequence data of three loci: nuclear ITS and IGS rDNA and RPB1. Maximum likelihood and Bayesian analyses revealed monophyly of 11 neuropogonoid species, with U. ciliata and U. subcapillaris forming a separate lineage. The backbone of the phylogeny of the core group was not resolved with statistical confidence, but relationships of groups of two to three species received strong support (U. acromelana +U. aurantiaco-atra; U. messutiae+U. pallidocarpa; U. sphacelata+U. subantarctica+U. trachycarpa; U. lambii+U. perpusilla+U. ushuaiensis). The new combination U. lambii (Imshaug) Wirtz & Lumbsch comb. nov. is made and U. messutiae Wirtz & Lumbsch sp. nov. is described.
Parmelia sulcata(Ascomycota:Parmeliaceae), a sympatric monophyletic species complex
Authors: MOLINA Maria del Carmen , DIVAKAR Pradeep K. , MILLANES Ana M. , SÁNCHEZ Edinson , DEL-PRADO Ruth , HAWKSWORTH David L. , CRESPO Ana 
Published: October 2011

AbstractRecently, the number of cryptic species known has increased considerably, showing that species diversity has in many cases been underestimated in the past.Parmelia sulcatais a widely distributed species and one of the most common taxa in temperate Europe. The first intra-specific molecular studies onP. sulcatashowed an unexpectedly high genetic variability. In the present work, we study the biodiversity of this taxon including specimens from four continents and using three molecular markers (nuITS, nuIGS rDNA, and partial β-tubulin gene). Two monophyletic groups ofP. sulcatawere encountered; one of these is epitypified asP. sulcatas. str and the other one is segregated as the new cryptic speciesP. encryptatasp. nov. Issues surrounding the lectotypification ofParmelia sulcatahave also been elucidated.
Generic concepts in parmelioid lichens, and the phylogenetic value of characters used in their circumscription
Authors: CRESPO Ana , DIVAKAR Pradeep K. , HAWKSWORTH David L. 
Published: October 2011

AbstractThis article traces the changing systems in the classification of the parmelioid lichens from the early 19th century to the present day. Molecular phylogenetic approaches have enabled the relative importance of traditionally used characters to be objectively re-assessed, and led to the realization of the significance of others that had previously been passed over or dismissed; for example, differences in ascospore and conidium types or the cell-wall constituents. Information on the different characters employed is presented and assessed. It is concluded that characters related to thallus form or chemical products prove to be less informative at the generic level than has sometimes been assumed. Features requiring further study are identified, and in the light of experience in this group, lichenologists should be cautious in translating their results into formal taxonomies.
Subsidiary bifurcations near bifocal homoclinic orbits
Authors: Glendinning Paul 
Published: October 2011

AbstractSuppose that an ordinary differential equation in ℝ4 has an orbit Γ bi-asymptotic to a stationary point O of the flow. If the characteristic equation of the linear flow near O has roots (λ0 ± ιω0, λ1±ιω1) with —λ0 > λ1 > 0 and ωi > 0 for i = 0,1, we show that there are sequences of more complicated orbits bi-asymptotic to O in generic one-parameter perturbations of the equations. When ω0 ≠ 2nω1 for all n ∈ ℕ, there are sequences of such orbits on both sides of the bifurcation value of the parameter, in contrast to a similar case for flows in ℝ3.