bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sensitivity and Specificity of Various Tests for the Diagnosis ofHelicobacter pyloriin Egyptian Children
Authors: Frenck Robert W. , Fathy Hanan Mohamed , Sherif May , Mohran Zaynab , El Mohammedy Hanan , Francis Wagdy , Rockabrand David , Mounir Bahaa Ihab , Rozmajzl Patrick , Frierson Henry F. 
Published: September 2006

OBJECTIVES. Many noninvasive methods (using breath, blood, and stool samples) are available to diagnose Helicobacter pylori. However, because the noninvasive tests are proxy measures of the infection, they need validation before use. Factors that may affect test validity include patient age, gender, and geographic location. Because no data were available on the validation of noninvasive tests for the diagnosis of H pylori among children in the Middle East, this study was performed.METHODS. Children between 2 and 17 years of age evaluated at the Cairo University School of Medicine pediatric gastroenterology clinic who were already scheduled for upper endoscopy were eligible for enrollment in the study. At the time of endoscopy, 3 biopsies were collected and used for rapid urease, histology, and culture, respectively. All children also donated a sample of stool and blood and had a urea breath test performed. Stool and serum samples were tested for the presence of H pylori by using commercially available enzyme-linked immunosorbent assay–based technology. The sensitivity, specificity, and positive and negative predictive values were calculated for each noninvasive test used in the study. Receiver operating curves also were charted to determine optimal cut points for the various tests when used in the current study cohort.RESULTS. One hundred eight children were enrolled in the study, with 52 children being under 6 years of age. The urea breath test and HpStar (DakoCytomation, Norden, Denmark) stool enzyme-linked immunosorbent assay kit had the highest sensitivity and specificity (sensitivity and specificity: 98 and 89 [urea breath test] and 94 and 81 [HpStar], respectively), whereas the serologic kit had an unacceptably low sensitivity (50%). The sensitivity of neither the urea breath test nor the HpStar tests was affected by subject age, but specificity of the HpStar test, although still high, was significantly lower among children under 6 years. Receiver operating curves found optimal cut points of the urea breath test at 6.2 δ over baseline and of the HpStar at 0.25 enzyme-linked immunosorbent assay units.CONCLUSION. The urea breath test and HpSTAR stool antigen kit are reliable tests for the noninvasive diagnosis of H pylori among children living in the Middle East.
Applications of Underbalanced-Drilling Reservoir Characterisation for Water Shutoff in a Fractured Carbonate Reservoir - A Project Overview
Authors: Murphy Darren , Al-Busaidi Rashid , Wind Jan , Davidson Ian , Mykytiw Clayton , Kennedy _ , Arseneault Leo 
Published: September 2006

Summary
Following successful implementation of underbalanced drilling (UBD) in Petroleum Development Oman (PDO), an evaluation of the value of UBD in a carbonate field was commissioned. The study showed that there was a production upside to developing the reservoir with UBD. A four-well trial campaign was conducted between June and October 2004 to assess the potential.
The trial campaign was implemented following a structured program built from PDO's previous experience. During this campaign, a reservoir-characterization (RC) system allowing identification of multiple high-permeability features was developed. Water-shutoff devices were installed in two wells on the basis of the results of the RC system. Production from the four wells was equivalent to or greater than the field average, and the campaign scope has been increased. The campaign was also a stepping stone toward the goal of integrating UBD, RC, and water-shutoff techniques.
Empowerment: A Patient's Perspective
Authors: Weiss Michael A. 
Published: September 2006

In Brief
The most significant innovation in diabetes management during the past 20 years has been the acceptance and application of the empowerment approach to diabetes education and treatment. This method acknowledges the way in which behavioral changes occur by casting patients as the central figures in the design and implementation of their diabetes care plans. The many scientific and technological developments that have been made during this same period have strengthened patients' ability to pursue effective self-management programs under this approach.
Diabetes BASICS: Education, Innovation, Revolution
Authors: Powers Margaret A. , Carstensen Karol , Colón Katherine , Rickheim Patti , Bergenstal Richard M. 
Published: September 2006

In BriefThis article describes the Type 2 Diabetes BASICS curriculum, an evidence-based education program that, when used in educator programs, has reduced hemoglobin A1c and body weight in people with type 2 diabetes in both individual and group education. This curriculum has also served as a model for the Insulin BASICS and Gestational Diabetes BASICS programs and has been implemented in various education and research settings,including work sites. These curriculums provide all of the needed materials for an education program, as well as extensive tips and guides to increase individualization of information and activities to engage program participants in transferring knowledge and skills in a variety of situations.
Use of Exenatide in Patients With Type 2 Diabetes
Authors: Hood Robert , Valentine Virginia , Mac Susanna , Polonsky William H 
Published: September 2006

Glucose homeostasis is regulated by a complex interplay of multiple hormones, including hormones from the pancreas (insulin, glucagon, and amylin)and the gut (glucagon-like peptide 1 [GLP-1] and glucose-dependent insulinotropic polypeptide). Most therapeutic options are focused on abnormal insulin secretion and signalling and do not address the role these other hormones play in glucoregulation and the diabetic state.The inability to control glycemia over the long term utilizing single oral agents is reflected by the need to use various agents, alone or in combination, over time. In addition, the presence of associated side effects and clinical shortcomings of many therapies has prompted the search for new therapeutic agents that address the underlying dysregulation of multiple hormones found in people with diabetes. One of these agents, exenatide, mimics several of the actions of GLP-1 and is the first agent in a new class called incretin mimetics.Exenatide was approved by the Food and Drug Administration in 2005 as an adjunctive therapy to metformin and/or sulfonylurea regimens for individuals with type 2 diabetes who have not achieved adequate glycemic control. Clinical trials indicate that subjects taking 10 μg of exenatide twice daily for 6 months had hemoglobin A1c (A1C) reductions of ∼1% and body weight reductions of ∼2 kg. After 1.5 years of exenatide treatment,reductions in A1C were sustained (1.1%), and body weight reductions were progressive (4.4 kg). In addition, exenatide treatment for 1.5 years resulted in improvements in some cardiovascular risk factors. For individuals with type 2 diabetes not achieving adequate glucose control with metformin and/or sulfonylureas, incretin mimetics such as exenatide may offer the opportunity for improved glycemic control with fewer clinical shortcomings than other available treatments.
Effects of Photo‐oxidation on the Performance of Poly[2‐methoxy‐5‐(3′,7′‐dimethyloctyloxy)‐1,4‐phenylene vinylene]:[6,6]‐Phenyl C61‐Butyric Acid Methyl Ester Solar Cells
Authors: Pacios R. , Chatten A. J. , Kawano K. , Durrant J. R. , Bradley D. D. C. , Nelson J. 
Published: September 2006

AbstractA study of the photo‐oxidation of films of poly[2‐methoxy‐5‐(3′,7′‐dimethyloctyloxy)‐1,4‐phenylene vinylene] (MDMO‐PPV) blended with [6,6]‐phenyl C61‐butyric acid methyl ester (PCBM), and solar cells based thereon, is presented. Solar‐cell performance is degraded primarily through loss in short‐circuit current density, JSC. The effect of the same photodegradation treatment on the optical‐absorption, charge‐recombination, and charge‐transport properties of the active layer is studied. It is concluded that the loss in JSC is primarily due to a reduction in charge‐carrier mobility, owing to the creation of more deep traps in the polymer during photo‐oxidation. Recombination is slowed down by the degradation and cannot therefore explain the loss in photocurrent. Optical absorption is reduced by photo‐bleaching, but the size of this effect alone is insufficient to explain the loss in device photocurrent.
Controlled Encapsulation of Hydrophobic Liquids in Hydrophilic Polymer Nanofibers by Co‐electrospinning
Authors: Díaz J. E. , Barrero A. , Márquez M. , Loscertales I. G. 
Published: September 2006

AbstractThere are many technical situations, such as various biological or medical applications, in which a hydrophobic fluid must be encapsulated inside a hydrophilic polymer shell in the form of tiny microscopic pieces. A novel approach is presented, based on the co‐electrospinning of the hydrophilic polymer melt (outside) and the hydrophobic fluid (inside), which results in beaded micro‐ and nanofibers, such that the hydrophobic fluid is efficiently encapsulated inside the beads. For the selected fluid couple, the low liquid–liquid surface tension and the high viscosity of the melt prevent the varicose break‐up of inner fluid in the coaxial electrified jet until the very end of the co‐electrospinning process. The resulting fibers present beads filled with the hydrophobic fluid, separated by a rather uniform distance whose length depends partially on the melt flow rate. The bead diameter grows with the inner flow rate, going from a monosized to a bisized distribution. In the case under study, the maximum relative (inner‐to‐outer) flow rate is one. The diameter of the solid fibers between beads scales well with existing theories for simple electrospinning.
Intrinsic Dinitrogen Activation at Bare Metal Atoms
Authors: Himmel Hans‐Jörg , Reiher Markus 
Published: September 2006

AbstractThere is ongoing interest in metal complexes which bind dinitrogen and facilitate either its reduction or oxidation under mild conditions. In nature, the enzyme nitrogenase catalyzes this process, and dinitrogen fixation occurs under mild and ambient conditions at a metal–sulfur cluster in the center of the MoFe protein, but the mechanism of this process remains largely unknown. In the last few years, new important discoveries have been made in this field. In this review are discussed recent findings on the interaction of N2 with metal atoms and metal‐atom dimers from all groups of the periodic table as provided by gas‐phase as well as matrix‐isolation experiments. Intrinsic dinitrogen activation at such bare metal atoms is then related to corresponding processes at complexes, clusters, and surfaces.
Biologische Kampfstoffe: Nachweis und Bekämpfung: Strategien gegen Milzbrand, Pocken & Co.
Authors: Richardt André , Russman Heiko 
Published: September 2006

AbstractDie Erreger von infektiösen Krankheiten können trotz internationaler Ächtung für kriminelle Zwecke missbraucht werden. Deshalb ist eine genaue Kenntnis der Detektion und der Dekontamination von biologischen Erregern für den militärischen und zivilen Katastrophenschutz von elementarem Interesse. Für die Detektion und Dekontamination dieser Erreger existiert eine Vielzahl unterschiedlicher Methoden. Der Detektion kommt dabei eine Schlüsselrolle zu. Je schneller und genauer bestimmt wird, um welchen Krankheitserreger es sich handelt, desto eher kann situationsbezogen reagiert und eine auf den jeweiligen Erreger abgestimmte Dekontaminationsmethode angewendet werden.
Warum wird das Blattgrün im Herbst abgebaut?
Authors: Krupinska Karin 
Published: September 2006

AbstractDas Grün der Blätter wird durch komplex aufgebaute Farbstoffe, die Chlorophylle, verursacht. Während die Biosynthese der Chlorophylle bereits vor 20 Jahren in ihren wesentlichen Schritten aufgeklärt wurde, war die Biochemie ihres Abbaus bis vor kurzem unbekannt. Früher nahm man an, dass die Chlorophylle abgebaut werden, damit die Pflanze den darin enthaltenen Stickstoff zurückgewinnen kann – doch neue Forschungsergebnisse zeigen, dass der Abbau nicht zum Recycling, sondern zum Entgiften dient.
Sir Charles Scott Sherrington begründete die moderne Physiologie des Nervensystems
Authors: Penzlin Heinz 
Published: September 2006

AbstractVor hundert Jahren erschien das Buch “The integrative action of the nervous system”, mit dem Charles Scott Sherrington, der zu dieser Zeit als Professor für Physiologie an der Universität Liverpool lehrte und forschte, eine neue Epoche der neurobiologischen Forschung einleitete. Auf der Grundlage einer großen Anzahl von Laborversuchen entwickelte er eine Theorie der wechselseitigen Abhängigkeiten der Reflexaktivitäten, der reflexiven Erregung und Hemmung und damit der “integrativen Wirkung” des Nervensystems. Er erhielt im Jahre 1932 gemeinsam mit Edgar Douglas Adrian den Nobelpreis für Physiologie.
Investigation of Guanosine‐Quartet Assemblies by Vibrational and Electronic Circular Dichroism Spectroscopy, a Novel Approach for Studying Supramolecular Entities
Authors: Setnička Vladimír , Urbanová Marie , Volka Karel , Nampally Sreenivasachary , Lehn Jean‐Marie 
Published: September 2006

AbstractThe self‐assembly of guanosine‐5′‐hydrazideG‐1in D2O, in the presence and absence of sodium cations, has been investigated by chiroptical techniques: electronic (ECD) and the newly introduced vibrational (VCD) circular dichroism spectroscopy. Using a combination of ECD and VCD with other methods such as IR, electron microscopy, and electrospray ionization mass spectrometry (ESI‐MS) it was found thatG‐1produces long‐range chiral aggregates consisting of G‐quartets, (G‐1)4, subsequently stacked into columns, [(G‐1)4]n, induced by binding of metal cations between the (G‐1)4species. This process, accompanied by gelation of the sample, is highly efficient in the presence of an excess of sodium cations, leading to aggregates with strong quartet–quartet interaction. Thermally induced conformational changes and conformational stability of guanosine‐5′‐hydrazide assemblies were studied by chiroptical techniques and the melting temperature of the hydrogels formed was obtained. The temperature‐dependent experiments indicate that the long‐range supramolecular aggregates are dissociated by increasing temperature into less ordered species, monomers, or other intermediates in equilibrium, as indicated by MS experiments.
Olefin Epoxidation with Hydrogen Peroxide Catalyzed by Lacunary Polyoxometalate [γ‐SiW10O34(H2O)2]4−
Authors: Kamata Keigo , Kotani Miyuki , Yamaguchi Kazuya , Hikichi Shiro , Mizuno Noritaka 
Published: September 2006

AbstractThe tetra‐n‐butylammonium (TBA) salt of the divacant Keggin‐type polyoxometalate [TBA]4[γ‐SiW10O34(H2O)2] (I) catalyzes the oxygen‐transfer reactions of olefins, allylic alcohols, and sulfides with 30 % aqueous hydrogen peroxide. The negative Hammett ρ+ (−0.99) for the competitive oxidation of p‐substituted styrenes and the low value of (nucleophilic oxidation)/(total oxidation), XSO=0.04, for I‐catalyzed oxidation of thianthrene 5‐oxide (SSO) reveals that a strongly electrophilic oxidant species is formed on I. The preferential formation of trans‐epoxide during epoxidation of 3‐methyl‐1‐cyclohexene demonstrates the steric constraints of the active site of I. The I‐catalyzed epoxidation proceeds with an induction period that disappears upon treatment of I with hydrogen peroxide. 29Si and 183W NMR spectroscopy and CSI mass spectrometry show that reaction of I with excess hydrogen peroxide leads to fast formation of a diperoxo species, [TBA]4[γ‐SiW10O32(O2)2] (II), with retention of a γ‐Keggin type structure. Whereas the isolated compound II is inactive for stoichiometric epoxidation of cyclooctene, epoxidation with II does proceed in the presence of hydrogen peroxide. The reaction of II with hydrogen peroxide would form a reactive species (III), and this step corresponds to the induction period observed in the catalytic epoxidation. The steric and electronic characters of III are the same as those for the catalytic epoxidation by I. Kinetic, spectroscopic, and mechanistic investigations show that the present epoxidation proceeds via III.
Cytoskeletal asymmetry in Zea mays subsidiary cell mother cells: A monopolar prophase microtubule half‐spindle anchors the nucleus to its polar position
Authors: Panteris Emmanuel , Apostolakos Panagiotis , Galatis Basil 
Published: September 2006

AbstractDouble labeling of microtubules and actin filaments revealed that in prophase subsidiary mother cells of Zea mays a monopolar prophase microtubule “half‐spindle” is formed, which lines the nuclear hemisphere distal to the inducing guard mother cell. The nuclear hemisphere proximal to the guard mother cell is lined by an F‐actin cap, consisting of a cortical F‐actin patch and actin filaments originating from it. The microtubules of the “half‐spindle” decline from the nuclear surface and terminate to the preprophase microtubule band. After disintegration of the latter, a bipolar metaphase spindle is organized. The polar F‐actin cap persists during mitosis and early cytokinesis, extending to the chromosomes and the subsidiary cell daughter nucleus. In oryzalin treated subsidiary mother cells the prophase nuclei move away from the polar site. Cytochalasin B and latrunculin‐B block the polar migration of subsidiary mother cell nuclei, but do not affect those already settled to the polar position. The prophase nuclei of latrunculin‐B treated subsidiary mother cells are globally surrounded by microtubules, while the division plane of latrunculin‐B treated subsidiary mother cells is misaligned. The prophase nuclei of brick 1 mutant Zea mays subsidiary mother cells without F‐actin patch are also globally surrounded by microtubules. The presented data show that the prophase microtubule “half‐spindle”‐preprophase band complex anchors the subsidiary mother cell nucleus to the polar cell site, while the polar F‐actin cap stabilizes the one metaphase spindle pole proximal to the inducing guard mother cell. Cell Motil. Cytoskeleton 2006. © 2006 Wiley‐Liss, Inc.
Assembling microtubules disintegrate the postsynaptic density in vitro
Authors: Lo Li‐Ping , Liu Szu‐Heng , Chang Yen‐Chung 
Published: September 2006

AbstractThe postsynaptic density (PSD), a disk‐shaped protein aggregation of several hundred nm in diameter, plays important roles in the signal transduction and molecular organization of the excitatory synapses in mammalian CNS. The PSD resides in the microfilament‐enriched cytoplasm of dendritic spines where the transient appearance of microtubules has been reported. When PSD isolated from porcine brain was incubated with polymerizing α,β‐tubulins, its turbidity became greater than that of the original PSD, suggesting that the PSD's structure was altered upon incubating with assembling microtubules. By transmission electron microscopy, smaller PSD fragments and several novel structures, including holes and finger‐like extensions, were found in the PSD after incubation with assembling microtubules, but not in the original PSD or in the PSD incubated with α,β‐tubulins pretreated with vincristine. The results suggest that the interactions with assembling microtubules may result in the formation of holes in the PSD, and the rupture of these holes subsequently leads to the formation of smaller PSD fragments. Cell Motil. Cytoskeleton 2006. © 2006 Wiley‐Liss, Inc.
Carbohydrates as Scaffolds in Drug Discovery
Authors: Meutermans Wim , Le Giang Thanh , Becker Bernd 
Published: September 2006

AbstractDrug discovery has long suffered from the difficulty of having to place pharmacophoric groups in just the right spatial arrangement to elicit the desired biological response. Although some molecule classes have been discovered that seem to be privileged structures for at least some drug–receptor interactions, there remains the challenge to design and synthesize molecules with high specific affinity to pharmacologically important targets. With their high density of stereochemical information and their relative rigidity, carbohydrates provide excellent platforms upon which to display a number of substituents in a sterically defined way, hence offering the opportunity to harness their unique features for the drug‐discovery process. This review highlights the progress that has been made in the development of carbohydrate scaffolds for drug discovery.
Phosphorylated 4E binding protein 1: A hallmark of cell signaling that correlates with survival in ovarian cancer
Authors: Castellvi Josep , Garcia Angel , Rojo Federico , Ruiz‐Marcellan Carmen , Gil Antonio , Baselga Jose , Ramon y Cajal Santiago 
Published: September 2006

AbstractBACKGROUND.Growth factor receptors and cell signaling factors play a crucial role in human carcinomas and have been studied in ovarian tumors with varying results. Cell signaling involves multiple pathways and a myriad of factors that can be mutated or amplified. Cell signaling is driven through the mammalian target of rapamycin (mTOR) and extracellular regulated kinase (ERK) pathways and by some downstream molecules, such as 4E binding protein 1 (4EBP1), eukaryotic initiation factor 4E, and p70 ribosomal protein S6 kinase (p70S6K). The objectives of this study were to analyze the real role that these pathways play in ovarian cancer, to correlate them with clinicopathologic characteristics, and to identify the factors that transmit individual proliferation signals and are associated with pathologic grade and prognosis, regardless specific oncogenic alterations upstream.METHODS.One hundred twenty‐nine ovarian epithelial tumors were studied, including 20 serous cystadenomas, 7 mucinous cystadenomas, 11 serous borderline tumors, 16 mucinous borderline tumors, 29 serous carcinomas, 16 endometrioid carcinomas, 15 clear cell carcinomas, and 15 mucinous carcinomas. Tissue microarrays were constructed, and immunohistochemistry for the receptors epidermal growth factor receptor (EGFR) and c‐erb‐B2 was performed and with phosphorylated antibodies for protein kinase B (AKT), 4EBP1, p70S6K, S6, and ERK.RESULTS.Among 129 ovarian neoplasms, 17.8% were positive for c‐erb‐B2, 9.3% were positive for EGFR, 47.3% were positive for phosphorylated AKT (p‐AKT), 58.9% were positive for p‐ERK, 41.1% were positive for p‐4EBP1, 26.4% were positive for p70S6K, and 15.5% were positive for p‐S6. Although EGFR, p‐AKT, and p‐ERK expression did not differ between benign, borderline, or malignant tumors, c‐erb‐B2, p‐4EBP1, p‐p70S6K, and p‐S6 were expressed significantly more often in malignant tumors. Only p‐4EBP1 expression demonstrated prognostic significance (P = .005), and only surgical stage and p‐4EBP1 expression had statistical significance in the multivariate analysis.CONCLUSIONS.In patients with ovarian carcinoma, significant expression of p‐4EBP1 was associated with high‐grade tumors and a poor prognosis, regardless other oncogenic alterations upstream. This finding supports the study of this factor as a hallmark or pivotal factor in cell signaling in ovarian carcinoma that may crucial in the transmission of the proliferation cell signal and may reflect the real oncogenic role of this pathway in ovarian tumors. Cancer 2006. © 2006 American Cancer Society.