bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polarimetrische Untersuchungen in einem diffusen Koronastrahl und die Form der nördlichen Polarstrahlen am 15. 2. 1961
Authors: Scholz G. 
Published: July 2007

AbstractAus Polarisationsaufnahmen der Korona während der totalen Sonnenbedeckung am 15. 2. 1961 werden die Intensitäten, Polarisationsgrade, Polarisationsrichtungen und Elektronendichten für ein Gebiet verstärkter Koronastrahlung und einen intermediären Bereich bestimmt.Geometrische Untersuchungen an den nördlichen Polarstrahlen ergeben keinen Zusammenhang zwischen dem Verlauf der Polarstrahlen und den Kraftlinien eines Dipolfeldes oder eines anderen Magnetfeldes einfacher Struktur.The corona was photographed at the solar eclipse of 1961 February 15 with a quadruple camera. Three plates were obtained, each with four corona images, three through polaroids and one without polaroid. The photometry has provided the intensities, the amount and direction of polarisation, and the electron densities for a diffuse coronal ray and an intermediary region.We obtain from geometrical examinations on the northern polar rays no connection between the direction of the polar rays along the sun's limb and the lines of force of a dipole field or a magnetic field with a simple structure.
Library selection and directed evolution approaches to engineering targeted viral vectors
Authors: Jang Jae‐Hyung , Lim Kwang‐il , Schaffer David V. 
Published: July 2007

AbstractGene therapy, to delivery of genetic material to a patient for therapeutic benefit, has significant promise for translating basic knowledge of disease mechanism into biomedical treatments. The clinical development of the field has been slowed, however, by the need for improvements in the properties and capabilities of gene delivery vehicles. Vehicles based on viruses offer the potential for efficient gene delivery, but because viruses did not evolve to serve human therapeutic needs, many of their properties require significant improvement, including their safety, efficiency, and capacity for targeted gene delivery. Since viruses are highly complex biological entities, engineering such properties at the molecular level can be challenging. However, there has been significant progress in developing approaches that mimic the mechanisms by which viruses arose in the first place. In particular, library‐based selection, the generation of one diverse genetic library and selection for new properties, and directed evolution, based on the multiple rounds of library generation and selection for iterative improvement of function, have strong potential in engineering novel properties into these complex biomolecular assemblies. This review will discuss progress in the application of peptide display, library selection, and directed evolution technologies toward engineering vectors based on retrovirus, adeno‐associated virus, and adenovirus that are capable of targeted delivery to specific cell types. In addition to creating biomedically useful products, these approaches have future potential to yield novel insights into viral structure–function relationships. Biotechnol. Bioeng. 2007;98:515–524. © 2007 Wiley Periodicals, Inc.
Oxygen transport and consumption by suspended cells in microgravity: A multiphase analysis
Authors: Kwon Ohwon , Devarakonda Surendra B. , Sankovic John M. , Banerjee Rupak K. 
Published: July 2007

AbstractA rotating bioreactor for the cell/tissue culture should be operated to obtain sufficient nutrient transfer and avoid damage to the culture materials. Thus, the objective of the present study is to determine the appropriate suspension conditions for the bead/cell distribution and evaluate oxygen transport in the rotating wall vessel (RWV) bioreactor. A numerical analysis of the RWV bioreactor is conducted by incorporating the Eulerian–Eulerian multiphase and oxygen transport equations. The bead size and rotating speed are the control variables in the calculations. The present results show that the rotating speed for appropriate suspensions needs to be increased as the size of the bead/cell increases: 10 rpm for 200 µm; 12 rpm for 300 µm; 14 rpm for 400 µm; 18 rpm for 600 µm. As the rotating speed and the bead size increase from 10 rpm/200 µm to 18 rpm/600 µm, the mean oxygen concentration in the 80% midzone of the vessel is increased by ∼85% after 1‐h rotation due to the high convective flow for 18 rpm/600 µm case as compared to 10 rpm/200 µm case. The present results may serve as criteria to set the operating parameters for a RWV bioreactor, such as the size of beads and the rotating speed, according to the growth of cell aggregates. In addition, it might provide a design parameter for an advanced suspension bioreactor for 3‐D engineered cell and tissue cultures. Biotechnol. Bioeng. 2008;99: 99–107. © 2007 Wiley Periodicals, Inc.
A predictive nutritional model for plant cells and hairy roots
Authors: Cloutier M. , Bouchard‐Marchand É. , Perrier M. , Jolicoeur M. 
Published: July 2007

AbstractA structured nutritional model is proposed to describe growth and nutritional behavior of Eschscholtzia californica suspension cells and Catharanthus roseus and Daucus carota hairy roots in in vitro culture. The model describes the cells specific growth rate from concentration of intracellular nutrients such as inorganic phosphate (Pi), nitrogen sources (NO and NH) and sugars. Two‐level Michaelis–Menten kinetics are used to describe Pi and NO uptake and simple Michaelis–Menten kinetics for description of sugars uptake. Model parameters for each cell line were calibrated using data from batch cultures. The predictive capacity of the model was tested using data from medium exchange hairy root cultures. The model describes growth and nutritional behavior for the cell and hairy root lines. A sensitivity analysis was performed to identify critical model parameters and effect of initial conditions. The cell and hairy roots lines are also compared from their kinetic parameters. The kinetic model is efficient for describing and predicting growth and nutritional behaviors of suspension cells and hairy roots. Biotechnol. Bioeng. 2008;99: 189–200. © 2007 Wiley Periodicals, Inc.
Infrared picosecond laser for perforation of single plant cells
Authors: Schinkel Helga , Jacobs Philipp , Schillberg Stefan , Wehner Martin 
Published: July 2007

AbstractThe functional analysis of plant cells at the cellular and subcellular levels requires novel technologies for the directed manipulation of individual cells. In this report, we demonstrate the use of an infrared (1,064 nm) picosecond laser for the perforation of tobacco cell protoplasts. A single pulse was sufficient to perforate the plasma membrane enabling the uptake of dye from the surrounding medium into the cytosol. Moreover, the procedure was shown to be suitable for the efficient delivery of DNA expression constructs to the nucleus, as demonstrated by the subsequent expression and correct targeting of a recombinant fluorescent protein. Single cell perforation using this novel optoporation method shows that isolated plant cells can be permeabilized without direct manipulation. This is a valuable procedure for cell‐specific applications, particularly where the import of specific molecules into plant cells is required for functional analysis. Biotechnol. Bioeng. 2008;99: 244–248. © 2007 Wiley Periodicals, Inc.
Storage and growth of denitrifiers in aerobic granules: Part I. model development
Authors: Ni Bing‐Jie , Yu Han‐Qing 
Published: July 2007

AbstractA mathematical model, based on the Activated Sludge Model No.3 (ASM3), is developed to describe the storage and growth activities of denitrifiers in aerobic granules under anoxic conditions. In this model, mass transfer, hydrolysis, simultaneous anoxic storage and growth, anoxic maintenance, and endogenous decay are all taken into account. The model established is implemented in the well‐established AQUASIM simulation software. A combination of completely mixed reactor and biofilm reactor compartments provided by AQUASIM is used to simulate the mass transport and conversion processes occurring in both bulk liquid and granules. The modeling results explicitly show that the external substrate is immediately utilized for storage and growth at feast phase. More external substrates are diverted to storage process than the primary biomass production process. The model simulation indicates that the nitrate utilization rate (NUR) of granules‐based denitrification process includes four linear phases of nitrate reduction. Furthermore, the methodology for determining the most important parameter in this model, that is, anoxic reduction factor, is established. Biotechnol. Bioeng. 2008;99: 314–323. © 2007 Wiley Periodicals, Inc.
Methylene blue protection against hypoxic injury in primary cultures of rat hepatocyte monolayers
Authors: Muratsubaki Haruhiro , Yajima Nozomi , Yoneda Hitomi , Enomoto Keiichiro , Tezuka Toshiharu 
Published: July 2007

AbstractMitochondrial respiration is inhibited in cells exposed to hypoxia, and the oxidation of NADH to NAD+ is blocked. As a result, oxidation reactions requiring NAD+ are blocked, disrupting cellular metabolism. We studied the influence of methylene blue, which oxidizes NADH, on hypoxic damage to primary cultures of rat hepatocyte monolayers. During hypoxic treatment of hepatocytes, aspartate aminotransferase leaked out of the cells into the culture medium. However, addition of methylene blue to the medium repressed the hypoxic leakage of the enzyme. The exposure of hepatocytes to hypoxia decreased the acetoacetate/β‐hydroxybutyrate ratio which reflects the redox state of the cell. The level of the acetoacetate/β‐hydroxybutyrate ratio in hypoxic cells was increased by the addition of methylene blue. These results suggest that methylene blue protects against hypoxic injury due to its oxidation of NADH. Copyright © 2007 John Wiley & Sons, Ltd.
Electronic and Optical Properties of Ladder‐Type Heteraborins
Authors: Agou Tomohiro , Kobayashi Junji , Kawashima Takayuki 
Published: July 2007

AbstractLadder‐type π‐conjugated molecules bearing heteraborin (azaborine or thiaborin) units were synthesized, and X‐ray crystallographic analysis of pentacene‐type molecules showed that these molecules have rigid and planar structures. UV‐visible spectroscopy and theoretical calculations revealed the enhancement of electronic interaction between heteraborin units, the decrease in HOMO–LUMO energy gaps, and the strong effect of the bridging main‐group elements (nitrogen or sulfur) on the electronic states. The ladder‐type molecules emitted strong fluorescence both in solution and in the solid state, and the emission‐band shapes were different from each other, indicating the existence of intermolecular interactions in the solid state. Complex formation of the ladder molecules with fluoride ion was monitored by UV‐visible spectroscopy, which revealed that the Lewis acidity of these molecules can be controlled by the elongation of π systems and the change of the bridging main‐group elements.
Sugar derived hexacoordinated phosphates: Chiral anionic auxiliaries with general asymmetric efficiency
Authors: Pérollier Céline , Bernardinelli Gérald , Lacour Jérôme 
Published: July 2007

AbstractMannose‐derived hexacoordinated phosphate anions, prepared in as few as two steps from methyl‐α‐D‐mannopyranoside and tris(dimethylamino)phosphine, are chiral anionic auxiliaries with broad asymmetric efficiency. These chemically robust anions are effective NMR chiral solvating agents and efficient asymmetry‐inducers, able to control the configuration of conformationally labile C2‐symmetric monomethinium cations (organic, helical, charge 1+, P or M enantiomers) and D3‐symmetric iron(II) trisdiimine complexes (metallo‐organic, octahedral, charge 2+, Δ or Λ enantiomers). Diastereomeric control with often unmatched selective levels was achieved with the help of mannopyranoside backbone of the anions and the substituents on the [1,3]dioxane ring that play a key role in the recognition process, something not obvious at first sight. Chirality, 2008. © 2007 Wiley‐Liss, Inc.
Supramolecular tilt chirality in crystals of steroids and alkaloids
Authors: Hisaki Ichiro , Tohnai Norimitsu , Miyata Mikiji 
Published: July 2007

AbstractThe concept of supramolecular chirality has assumed increasing importance in association with the development of supramolecular chemistry over the last two decades. In chiral crystals, 21 helical molecular assemblies are frequently observed as key motifs. Helical handedness of the 21 assemblies, however, has not been determined from the mathematical or crystallographical viewpoints. In this context, we have proposed two new concepts, three‐axial chirality and tilt chirality. On the basis of the concepts, we describe supramolecular chirality and determine the handedness of 21 assemblies that are composed of relatively complicated molecules with multiple stereogenic centers such as brucine, bile acids, and cinchona alkaloids as well as those of simple molecules. Chirality, 2008. © 2007 Wiley‐Liss, Inc.
Analysis of prognostic factors in 146 patients with anterior skull base sarcoma: An international collaborative study
Authors: Gil Ziv , Patel Snehal G. , Singh Bhuvanesh , Cantu Giulio , Fliss Dan M. , Kowalski Luiz P. , Kraus Dennis H. , Snyderman Carl , Shah Jatin P. ,   for the International Collaborative Study Group
Published: July 2007

AbstractBACKGROUND.Single‐institutional studies lack sufficient power to assess the role of surgery and radiotherapy in the management of sarcomas involving the anterior skull base. For this study, an international collaborative study group analyzed a large cohort of patients who underwent surgery for the treatment of skull base tumors.METHODS.A subset of 146 patients who had a histologic diagnosis of skull base sarcoma (SBS) formed the basis of this report. Most patients were aged ≥21 years (77%) and had stage IV disease (56%). Adjuvant radiotherapy was received by 35% of patients, and chemotherapy was received by 10% of patients.RESULTS.Orbital involvement was encountered in 53% of patients, involvement of the orbital wall was encountered in 46% of patients, and intracranial extension was encountered in 28% of patients. Positive microscopic margins were reported in 43% of patients (51 of 118 patients). Treatment‐related complications were reported in 27% of patients, and postoperative mortality was reported in 1.4% of patients. With a median follow‐up of 34 months, the 5‐year overall, disease‐specific, and recurrence‐free survival rates were 62%, 64%, and 57%, respectively. Tumor grade and adjuvant radiotherapy were not significant predictors of survival. Prior radiotherapy, intraorbital extension, positive margins, and postoperative complications were significant predictors of reduced disease‐specific survival on univariate analysis. The presence of positive/close margins, however, was the only independent predictor of poor overall, recurrence‐free, and disease‐specific survival on multivariate analysis (relative risk, 2.4; P = .006). The 5‐year disease‐specific survival rate was 77%, 43%, and 36% for patients with negative, close, and positive margins, respectively.CONCLUSIONS.The current results indicated that wide craniofacial resection with negative margins is an independent prognostic predictor of better outcome. Patients with positive margins have a high risk for tumor recurrence independent of tumor grade. Cancer 2007. © 2007 American Cancer Society.
Increased bone marrow iron stores is an independent risk factor for invasive aspergillosis in patients with high‐risk hematologic malignancies and recipients of allogeneic hematopoietic stem cell transplantation
Authors: Kontoyiannis Dimitrios P. , Chamilos Georgios , Lewis Russell E. , Giralt Sergio , Cortes Jorge , Raad Issam I. , Manning John T. , Han Xin 
Published: July 2007

AbstractBACKGROUND.Invasive aspergillosis (IA) is a leading cause of death in patients with leukemia and those who have undergone hematopoietic stem cell transplantation. Laboratory studies have demonstrated that iron is essential for Aspergillus growth and virulence.METHODS.In the current study, the authors retrospectively evaluated the bone marrow iron stores (BMIS) in patients with leukemia as well as recipients of allogeneic hematopoietic stem cell transplantation with IA (n = 33) and those without fungal infections (n = 33). The first available bone marrow biopsy specimens prior to the IA diagnosis or date of hospitalization (control group) were assessed in a blinded fashion using a standardized scoring system (0–4). Both groups were comparable with regard to clinical characteristics and classic risk factors for IA.RESULTS.The majority of patients with IA (70%) were found to have increased BMIS (score ≥3) compared with the control patients (16%) (P < .0001). Increased BMIS was found to be an independent risk factor for IA on multivariate analysis (P < .0001).CONCLUSIONS.The prospective validation of BMIS for risk stratification in patients with leukemia or those who undergo allogeneic hematopoietic stem cell transplantation is needed. Cancer 2007. © 2007 American Cancer Society.
Sub‐Picosecond Mid‐Infrared Spectroscopy of Phytochrome Agp1 from Agrobacterium tumefaciens
Authors: Schumann Christian , Groß Ruth , Michael Norbert , Lamparter Tilman , Diller Rolf 
Published: July 2007

AbstractThe photoinduced primary reaction of the biliverdin binding phytochrome Agp1 (Agp1‐BV) from Agrobacterium tumefaciens was investigated by sub‐picosecond time‐resolved Vis pump–IR probe spectroscopy. Three time constants of τ1=0.7±0.05 ps, τ2=3.3±0.2 ps and τ3=33.3±1.5 ps could be isolated from the dynamics of structurally specific marker bands of the BV chromophore. These results together with those of accompanying sub‐picosecond Vis pump–Vis probe spectroscopy allow the extension of the reaction scheme for the primary process by a vibrationally excited electronic ground state. The isomerization at the C15C16 bond occurs within the lifetime of the excited electronic state. A quantum yield of 0.094 for the primary reaction is determined, suggesting that the quantum yield of formation of the Pfr far‐red‐absorbing form is already established in the primary photoreaction of the Pr (red‐absorbing) form.
A calculation method of the mutual and self‐inductances generated by currents on a cylinder
Authors: Yoda Kiyoshi 
Published: July 2007

AbstractConventional calculation methods of aircore inductance utilized Neumann's equation for solenoidal coils and Fourier series for saddle coils. However, inductance formulas for arbitrarily shaped coils on a cylinder have not been well known.In this paper, mutual and self‐inductances generated by any currents on a cylinder are expressed using Fourier‐Bessel expansion of the vector potential. An experiment shows the validity of the proposed formulas.
Annealing effect on a boundary layer between oxide superconducting films and a substrate
Authors: Fuchino Shuichiro , Agatsuma Ko , Ohara Takeshi , Kaiho Katsuyuki , Tateishi Hiroshi 
Published: July 2007

AbstractSince the discovery of the new high Tc superconductor, various kinds of film growth techniques have been reported on fabrication of an oxide superconducting film, especially YBCO and BSCCO above liquid nitrogen temperature. All these techniques require the so‐called post‐growth heat treatment or a heating of the substrate during the deposition to grow an adequate polycrystal which can realize the superconducting state in the oxide. Such a heating process, however, yields some intermediate products at a boundary layer between the starting materials and the substrate, and the products result in degradation of the superconducting property.In this paper, the annealing effect on the growth of YBCO or BSCCO oxide superconducting film and the substrate is investigated by using EDX analysis and SEM examination. To enhance the annealing effect, relatively thin YBCO and BSCCO films are fabricated with the starting materials pasted on substrates, and rather than sputtered thin films used for the analysis. MgO, Al2O3, SrTiO3, 5 or 8 percent Y stabilized ZrO2 (YTZ or YSZ), and so on, are chosen as a substrate.The results show that the heat treatment yields Ba compounds between YBCO and the substrates and Sr and Bi compounds between BSCCO and the substrates. Since the product boundary layer of the intermediate product is the thinnest, MgO substrate can be recommended for YBCO film, and SrTiO3 substrate for BSCCO film.
Development of advanced generator excitation control regulator (PSVR) for improving voltage stability of a bulk power transmission system
Authors: Michigami Tsutomu , Onizuka Naganori , Kitamura Satoshi 
Published: July 2007

AbstractEarlier generator excitation control systems were based on AVR control of generator terminal voltage. This system cannot accommodate reactive power up to the facility limit even when the power system voltage decreases to the limit for stable operation. An attempt was made to develop an advanced excitation control system (PSVR) to achieve higher constant sending end voltage of power stations. The intent was to apply the system to the generator connected to a 500‐kV system which contributes most effectively to the voltage stability of a bulk power transmission system. This PSVR produces higher control gains than the AVR, and the following functions were adopted: (1) AVR gain reduction circuit; (2) phase compensation circuit; and (3) damping improvement by enlarging the limiter of the PSS. In addition, various functions were provided, e.g., voltage slope characteristics to balance the reactive power of adjacent generators and PSVR output and terminal voltage limiter to stabilize the generator operation. Before application to a real system, a transient response test was performed by combining the PSVR and a generator simulator to verify the damping improvement and stability of the voltage control.
Experiments on dependency of metal mixing ratio in Ag‐Pd alloy contacts on breaking arc duration, metal erosion and transfer
Authors: Ishida Hiroyuki , Sone Hideaki , Takagi Tasuku 
Published: July 2007

AbstractBreaking arc durations and the differences between the mass of a contact before and after an experiment which is a quantity of metal erosion and transfer (QMET) were measured in Ag‐Pd alloy contacts. The experiments were performed in air under particular combinations of voltage, current, and opening speed. The effects produced on arc duration and QMET by different proportions of metals were investigated.In a practical Ag 40 wt% contact, the arc duration was not especially longer and the metal loss was not more than the other ratios. In an Ag 90 wt% contact, the arc duration had a large tendency to become longer under certain conditions and the metal loss was large. The arc duration of Ag 20 wt% had a tendency to become long with the number of operations. The characteristics of arc durations and QMET were different due to two ways of fixing a columnar contact from one side to a holder and from two sides. The curves of QMET were zero‐crossed and the mixing ratio for QMET became zero for one of the two electrodes.This paper possibly suggests some way to design electrodes for heat produced in the Ag‐Pd alloy contact, and the possibility of zero QMET.
Development of a knowledge‐based system for voltage/reactive power operation planning
Authors: Kono Yoshiyuki , Doi Atsushi , Omichi Yuichi 
Published: July 2007

AbstractVoltage/reactive power planning is a tremendous process which requires a planner to have intellectual expertise. This paper presents a large knowledge‐based system that can make voltage/reactive power planning. The knowledge acquisition has been completed on the basis of interview and protocol analysis methods. The result shows that the voltage/reactive power planning is composed of three phases: the first is reactive power adjustment where overall reactive power balance is investigated; the second is voltage adjustment where all bus voltages are tuned within the permissible operational range; and the third is voltage adjustment with a single fault of all major lines. The knowledge base is coded by about 700 production rules. It can succeed in making a voltage/reactive power plan for a very large power system.