bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of minimal residual disease in pediatric acute lymphoblastic leukemia
Authors: Gaipa Giuseppe , Basso Giuseppe , Biondi Andrea , Campana Dario
Published: June 2013

Minimal residual disease (MRD) is a powerful predictor of the overall response to treatment in childhood acute lymphoblastic leukemia (ALL). The most reliable and validated methods to assess MRD in ALL are flow cytometric (FCM) analysis of leukemia‐associated immunophenotypes and polymerase chain reaction (PCR) amplification of antigen–receptor gene rearrangements. Results of studies correlating MRD with clinical outcome and technical improvements in FCM technology support the implementation of MRD studies by this method in the clinic. Gene expression profiling of leukemic and normal cells has identified new MRD markers, which can be incorporated to improve the applicability and sensitivity of FCM‐based MRD monitoring. The combined use of MRD and emerging information on genetic lesions of ALL offers the possibility of further refining risk‐assignment approaches. © 2013 International Clinical Cytometry Society
A distributed polling service‐based MAC protocol testbed
Authors: Huang Yingsong , Walsh Phillip A. , Li Yihan , Mao Shiwen
Published: June 2013

Medium access control (MAC) protocols play a vital role in wireless networking. It is well‐known that the high control overhead of IEEE 802.11 MAC is the limiting factor on the throughput and delay performance of wireless networks. In our prior work, three polling service‐based medium access control protocols (PSMACs) are developed to amortize the high control overhead over multiple frame transmissions, thus achieving higher efficiency. Both analysis and simulations are conducted to validate the efficacy of the proposed protocols. In this paper, we extend this work by implementing the distributed version of PSMAC, i.e., PSMAC 2, on the GNU Radio and universal software radio peripheral (GNU Radio/USRP) platform. We discuss various design considerations and challenges of prototyping PSMAC 2 and carry out extensive experimental studies with the GNU Radio/USRP PSMAC testbed. Our experimental results are found to be consistent with the theoretical study reported in our prior work and validate the advantages of PSMAC under a realistic wireless channels. Copyright © 2013 John Wiley & Sons, Ltd.
Brandschutz mit Mauerwerk aus Planziegeln nach DIN 105‐6
Authors: Mittmann Thorsten , Meyer Udo
Published: June 2013

Die Planziegelnorm DIN 105‐6 [1] wurde überarbeitet und im Juni 2013 veröffentlicht. Einstufungen zum Feuerwiderstand für Mauerwerk aus diesen Ziegeln enthalten sowohl die entsprechenden allgemeinen bauaufsichtlichen Zulassungen des Deutschen Instituts für Bautechnik (DIBt) als auch die DIN 4102‐4/A1; 2004‐11 [2]. Im vorliegenden Beitrag werden aktuelle Prüfergebnisse vorgestellt und ein Vorschlag für eine künftige Klassifizierung in DIN EN 1996‐1‐2/NA [3] erarbeitet.

Fire resistance of high precision clay unit masonry. The standard DIN 105‐6 [1] has been revised and published in June 2013. Classifications of the fire resistance for this type of masonry are available in the corresponding national technical approvals as well as in DIN 4102‐4/A1; 2004‐11 [2]. This paper summarizes latest test results and gives a proposal for a future classification in DIN EN 1996‐1‐2/NA [3].
Brandprüfungen an historischen Deckenkonstruktionen
Authors: Bermes Burkhard , Mittmann Thorsten
Published: June 2013

Die brandschutztechnische Bewertung von bestehenden Deckenkonstruktionen stellt Planer und Ausführende immer wieder vor Herausforderungen. Sofern die heute erforderliche Feuerwiderstandsklasse nicht nachgewiesen werden kann, sind brandschutztechnische Ertüchtigungen unumgänglich. Bei der Ertüchtigung von derartigen Deckenkonstruktionen mit Bekleidungen oder Unterdecken ist die Nachweisführung einschließlich des Befestigungsmittels schwierig, da diese im Regelfall nicht detailliert in einem bauaufsichtlichen Nachweis enthalten ist.

In einer Serie von Brandprüfungen wurden historische Deckenkonstruktionen untersucht. Dabei ging es vor allem darum, ein Gesamtsystem aus einer Brandschutzbekleidung und einer praxisgerechten Befestigung dieser Bekleidung nachzuweisen. Der Artikel dokumentiert neben den bisherigen Bewertungen solcher Deckenkonstruktionen auch die Besonderheiten des Versuchsaufbaus für die durchgeführten Brandprüfungen sowie Auswertung dieser Versuche.

Fire tests on historic floor structures. The assessment in respect of fire resistance of existing floor constructions is a challenge to planners and executioners. If the today’s required fire resistance class cannot be proven, an improvement for the floor system is essential. This is done in most cases by additional claddings or suspended ceilings. The verification of the fixing of those systems is difficult because this is often not in the scope of approvals.

A series of fire tests has been performed to investigate the behavior of historic floor structures under fire exposure. The complete system of fire protective cladding and its practice‐oriented fixing was subjected to these tests. The present paper explains the former approach to assess the fire behavior of historic floors, characteristics of the test specimens and the evaluation of the tests.
Verformungsberechnung von Mauerwerksscheiben: Anwendung des klassischen Druckfeldmodells auf Mauerwerk
Authors: Weber Marius , Stempfle Hartwig
Published: June 2013

Die Berechnung der Verformungen von schubbeanspruchten Mauerwerksscheiben basiert bisher auf empirischen Beziehungen, welche je nach Ansatz Streuungen in den Ergebnissen aufweisen und Interpretationsspielraum offen lassen.

Um diesen Umstand zu verbessern, wird im vorliegenden Artikel das Last‐Verformungsverhalten von unbewehrten Mauerwerksscheiben mithilfe des aus dem Stahlbeton bekannten klassischen Druckfeldmodells beschrieben. Als Grundlage wird ein geeignetes Stoffgesetz für Mauerwerk entwickelt, welches die inhomogenen und anisotropen Eigenschaften von Mauerwerk berücksichtigt und die auf der Plastizitätstheorie basierenden Bruchbedingungen zur Bestimmung der Bruchlast verwendet.

Zur Verifizierung des Modells werden ausgewählte Mauerwerksscheibenversuche aus der Literatur bezüglich ihres effektiven Kraft‐Verformungsverhaltens nachgerechnet. Es wird gezeigt, dass eine nicht auf empirischen Formeln beruhende Beurteilung des Verformungsvermögens von Mauerwerk möglich ist.

Deformation calculation of masonry walls: Application of the compression field theory on Masonry. To calculate the thereby necessary deformations of masonry walls under normal force and shear, empirical relations are available. Depending on the approach, they exhibit scattering in their results and leave much room for interpretation open.

In order to amend this, this paper describes the load deformation behaviour of non‐reinforced masonry walls by means of the original compression field model, which is familiar from reinforced concrete. As a basis, it develops a material law for masonry, which takes into account its anisotropic and inhomogeneous properties, and employs fracture conditions, which are based on the theory of plasticity, in order to determine its strength.

To verify this model, selected masonry slab tests from the literature are recalculated with respect to their actual force‐deflection behaviour. It is shown that it is possible to evaluate the deformation capacity of masonry without depending on empirical formulas.
Einführung mineralwollegefüllter Ziegel in Österreich – Optimierung und Prüfung des Brandverhaltens
Authors: Kubista Mario , Jäger Andreas , Lehmden Alexander
Published: June 2013

Jährlich verunglücken in den Ländern der Europäischen Union 3600 Menschen tödlich bei Brandunfällen. Mehr als ein Drittel der Brände passieren in Gebäuden. Baukonstruktionen mit hohem Brandwiderstand und nicht brennbare Bauprodukte wie der Ziegel können also einen wesentlichen Beitrag für mehr Sicherheit in Gebäuden leisten. Andererseits fordern Vorschriften wie die Europäische Gebäuderichtlinie immer energieeffizientere Baustoffe – ab 2020 sollen nur noch Niedrigstenergiegebäude in Europa neu errichtet werden. In monolithischer Ziegelbauweise wird dieses Ziel besonders mit dämmstoffgefüllten Ziegeln umsetzbar sein. Aus diesem Grund wurde in Österreich ähnlich wie in Deutschland ein Sortiment mineralwollegefüllter Ziegel für das Einfamilienhaus‐, aber auch Objektsegment entwickelt, welches diesen Ansprüchen gerecht wird. Da Brandprüfungen kosten‐ und zeitintensiv sind, wurde vorab durch numerische Simulationen auch der Brandschutz des neuen Ziegels analysiert und optimiert, um Fehlentwicklungen zu vermeiden. Eine im Anschluss durchgeführte Prüfserie hat gezeigt, dass die gestellten Brandschutzziele übererfüllt wurden. Alle Ziegel des neuen Sortiments werden mit REI 90 klassifiziert. Es wurde abschließend sogar die mechanische Stoßprüfung mit den neu entwickelten Ziegeln erfüllt. Der vielversprechende Einsatz von Finite‐Elemente‐Simulationen zur Produktoptimierung scheint richtungsweisend für den zukünftigen Entwicklungsprozess von Ziegeln zu sein.

Launching of insulation filled clay blocks in Austria – optimization and test of fire resistance. In the member states of the European Union every year about 3,600 people get killed by fire. More than one third of fires happen in buildings. It is obvious that building constructions with high fire resistance and noncombustible building products highly contribute to fire security in buildings. On the other hand new regulations like the European energy performance of buildings directive (EPBD) demand for more energy efficient building products – after 2020 all new buildings in Europe must fulfill “Nearly Zero Energy Building” standard. This ambitious energy target will be fulfilled especially by insulation filled clay blocks. For this reason Wienerberger Austria developed similar to Wienerberger Germany a new assortment of insulation filled clay blocks for single family houses and multifamily houses. As fire tests are very costly and time consuming the fire performance was already optimized with numerical simulations in the development process. Afterwards, the numerical simulations were successfully evaluated by a series of fire tests. The new assortment of insulation filled clay blocks fulfills the fire classification REI 90 for construction products as planned. This new development process based on numerical simulations is very promising for optimizing clay blocks economically and efficient in future.
Spinal cord regeneration: Lessons for mammals from non‐mammalian vertebrates
Authors: Lee‐Liu Dasfne , Edwards‐Faret Gabriela , Tapia Víctor S. , Larraín Juan
Published: June 2013

Unlike mammals, regenerative model organisms such as amphibians and fish are capable of spinal cord regeneration after injury. Certain key differences between regenerative and nonregenerative organisms have been suggested as involved in promoting this process, such as the capacity for neurogenesis and axonal regeneration, which appear to be facilitated by favorable astroglial, inflammatory and immune responses. These traits provide a regenerative‐permissive environment that the mammalian spinal cord appears to be lacking. Evidence for the regenerative nonpermissive environment in mammals is given by the fact that they possess neural stem/progenitor cells, which transplanted into permissive environments are able to give rise to new neurons, whereas in the nonpermissive spinal cord they are unable to do so. We discuss the traits that are favorable for regeneration, comparing what happens in mammals with each regenerative organism, aiming to describe and identify the key differences that allow regeneration. This comparison should lead us toward finding how to promote regeneration in organisms that are unable to do so. genesis 51:529–544. © 2013 Wiley Periodicals, Inc.
Interactive effects of global climate change and pollution on marine microbes: the way ahead
Authors: Coelho Francisco J. R. C. , Santos Ana L. , Coimbra Joana , Almeida Adelaide , Cunha Ângela , Cleary Daniel F. R. , Calado Ricardo , Gomes Newton C. M.
Published: June 2013

Global climate change has the potential to seriously and adversely affect marine ecosystem functioning. Numerous experimental and modeling studies have demonstrated how predicted ocean acidification and increased ultraviolet radiation (UVR) can affect marine microbes. However, researchers have largely ignored interactions between ocean acidification, increasedUVRand anthropogenic pollutants in marine environments. Such interactions can alter chemical speciation and the bioavailability of several organic and inorganic pollutants with potentially deleterious effects, such as modifying microbial‐mediated detoxification processes. Microbes mediate major biogeochemical cycles, providing fundamental ecosystems services such as environmental detoxification and recovery. It is, therefore, important that we understand how predicted changes to oceanic pH,UVR, and temperature will affect microbial pollutant detoxification processes in marine ecosystems. The intrinsic characteristics of microbes, such as their short generation time, small size, and functional role in biogeochemical cycles combined with recent advances in molecular techniques (e.g., metagenomics and metatranscriptomics) make microbes excellent models to evaluate the consequences of various climate change scenarios on detoxification processes in marine ecosystems. In this review, we highlight the importance of microbial microcosm experiments, coupled with high‐resolution molecular biology techniques, to provide a critical experimental framework to start understanding how climate change, anthropogenic pollution, and microbiological interactions may affect marine ecosystems in the future.
Embryonic lethality leads to hybrid male inviability in hybrids between Drosophila melanogaster and D. santomea
Authors: Gavin‐Smyth Jackie , Matute Daniel R.
Published: June 2013

The study of the morphological defects unique to interspecific hybrids can reveal which developmental pathways have diverged between species. Drosophila melanogaster and D. santomea diverged more than 10 million years ago, and when crossed produce sterile adult females. Adult hybrid males are absent from all interspecific crosses. We aimed to determine the fate of these hybrid males. To do so, we tracked the development of hybrid females and males using classic genetic markers and techniques. We found that hybrid males die predominantly as embryos with severe segment‐specification defects while a large proportion of hybrid females embryos hatch and survive to adulthood. In particular, we show that most male embryos show a characteristic abdominal ablation phenotype, not observed in either parental species. This suggests that sex‐specific embryonic developmental defects eliminate hybrid males in this interspecific cross. The study of the developmental abnormalities that occur in hybrids can lead to the understanding of cryptic molecular divergence between species sharing a conserved body plan.
Using GPS telemetry to validate least‐cost modeling of gray squirrel (Sciurus carolinensis) movement within a fragmented landscape
Authors: Stevenson Claire D. , Ferryman Mark , Nevin Owen T. , Ramsey Andrew D. , Bailey Sallie , Watts Kevin
Published: June 2013

In Britain, the population of native red squirrels Sciurus vulgaris has suffered population declines and local extinctions. Interspecific resource competition and disease spread by the invasive gray squirrel Sciurus carolinensis are the main factors behind the decline. Gray squirrels have adapted to the British landscape so efficiently that they are widely distributed. Knowledge on how gray squirrels are using the landscape matrix and being able to predict their movements will aid management. This study is the first to use global positioning system (GPS) collars on wild gray squirrels to accurately record movements and land cover use within the landscape matrix. This data were used to validate Geographical Information System (GIS) least‐cost model predictions of movements and provided much needed information on gray squirrel movement pathways and network use. Buffered least‐cost paths and least‐cost corridors provide predictions of the most probable movements through the landscape and are seen to perform better than the more expansive least‐cost networks which include all possible movements. Applying the knowledge and methodologies gained to current gray squirrel expansion areas, such as Scotland and in Italy, will aid in the prediction of potential movement areas and therefore management of the invasive gray squirrel. The methodologies presented in this study could potentially be used in any landscape and on numerous species.
Lapatinib and doxorubicin enhance the Stat1‐dependent antitumor immune response
Authors: Hannesdóttir Lára , Tymoszuk Piotr , Parajuli Nirmala , Wasmer Marie‐Helene , Philipp Sonja , Daschil Nina , Datta Sebak , Koller Johann‐Benedikt , Tripp Christoph H. , Stoitzner Patrizia , Müller‐Holzner Elisabeth , Wiegers Gerrit Jan , Sexl Veronika , Villunger Andreas , Doppler Wolfgang
Published: June 2013

The dual erbB1/2 tyrosine kinase inhibitor lapatinib as well as the anthracycline doxorubicin are both used in the therapy of HER2‐positive breast cancer. Using MMTV‐neu mice as an animal model for HER2‐positive breast cancer, we observed enhanced tumor infiltration by IFN‐γ‐secreting T cells after treatment with doxorubicin and/or lapatinib. Antibody depletion experiments revealed a contribution of CD8+ but not CD4+ T cells to the antitumor effect of these drugs. Doxorubicin treatment additionally decreased the content of immunosuppressive tumor‐associated macrophages (TAMs) in the tumor bed. In contrast, Stat1‐deficient mice were resistant to tumor growth inhibition by lapatinib and/or doxorubicin and exhibited impaired T‐cell activation and reduced T‐cell infiltration of the tumor in response to drug treatment. Furthermore, Stat1‐deficiency resulted in reduced expression of the T‐cell chemotactic factors CXCL9, CXCL10, and CXCL11 in the tumor epithelium. The inhibition of TAM infiltration of the tumor by doxorubicin and the immunosuppressive function of TAMs were found to be Stat1 independent. Taken together, the results point to an important contribution toward enhancing T‐cell and IFN‐γ‐based immunity by lapatinib as well as doxorubicin and emphasize the role of Stat1 in building an effective antitumor immune response.
From AlCp*‐ and GaCp*‐Ligated Ruthenium Hydrides to Zinc‐Rich Heterometallic Complexes
Authors: Molon Mariusz , Gemel Christian , Fischer Roland A.
Published: June 2013

The reactivity of ZnMe2 towards heteroleptic (poly)hydride ruthenium complexes was investigated. The Ru centers were coligated with different ligands including reactive low‐valent ECp* (E = Ga, Al; Cp* = pentamethylcyclopentadienyl) ligands and nonreactive phosphane ligands (PCy3, PPh3, Cy = cyclohexyl, Ph = phenyl). The ECp* ligands undergo a redox reaction together with Cp*/Me group exchange when treated with ZnMe2 to form two equivalents of ZnR (R = Cp*, Me) units, and ER3 species are liberated. Similarly, Ru–H moieties react with ZnMe2 to form one equivalent of ZnMe and one equivalent of CH4. The 18‐electron rule proved valid for the rationalization of the obtained compositions; one ECp* or phosphane ligand is equivalent to two one‐electron ZnR or H ligands. The factors that control the exchange of phosphane or hydride ligands are discussed. All compounds were characterized by NMR and IR spectroscopy, liquid injection field desorption ionization (LIFDI) MS analysis, single‐crystal X‐ray diffraction, and elemental analysis.
Structural Diversity of Coordination Cores in Homoleptic Tetraaryltin(IV) Dioxolane, Aldehyde and Imines: The First Octacoordinated Double Helicate Tetraorganotin(IV) Compound
Authors: Barbul Ioana , Varga Richard A. , Silvestru Cristian
Published: June 2013

Invited for the cover of this issue is the group of Cristian Silvestru at the Babes‐Bolyai University, Cluj‐Napoca, Romania. The cover image shows diversity in coordination geometries for relevant homoleptic tetraorganotin(IV) species with aromatic substituents bearing pendant arms able to provide intramolecular coordination.
Theophyllinylpyrimidine Scaffolds Undergo Intramolecular Cyclization Reactions to Form 1,3‐Diazepines and Imidazopurines
Authors: Lebedyeva Iryna O. , Povstyanoy V'yacheslav M. , Ryabitskii Aleksey B. , Panasyuk Oleksandr , Ivahnenko Evgen , Lozova Vera P. , Markevich Igor , Allakhverdova Svitlana , Povstyanoy Mykhaylo V.
Published: June 2013

Polyheterocyclic pyrimidinyltheophyllines have been synthesized from pyrimidine and theophylline precursors. Attempts to cyclize these reactive bis‐heterocyclic systems resulted in the formation of the corresponding diazepine moieties. In addition, modification of the reaction conditions led to the formation of imidazo[2,1‐f]purines.
Total Synthesis of the Phenolic Glycolipid Mycoside B and the Glycosylated p‐Hydroxybenzoic Acid Methyl Ester HBAD‐I, Virulence Markers of Mycobacterium tuberculosis
Authors: Barroso Santiago , Geerdink Danny , ter Horst Bjorn , Casas‐Arce Eva , Minnaard Adriaan J.
Published: June 2013

The phenolic glycolipid mycoside B, present in Mycobacterium bovis and hypervirulent strains of Mycobacterium tuberculosis, has been synthesized for the first time. Multiple methyl groups were introduced by the extensive use of catalytic asymmetric 1,4‐addition reactions, asymmetric hydrogenation of a β‐keto ester afforded the basis for the central 1,3‐diol moiety, and introduction of the 2‐O‐methyl‐α‐L‐rhamnoside unit was achieved by stereoselective glycosylation with p‐iodophenol and subsequent Sonogashira coupling, providing a basis for the generation of analogues. In addition, the related monosaccharide HBAD‐I, present in the same species, has been efficiently synthesized for the first time by selective methylation of the hydroxy group at C‐2 of a rhamnoside.
Changes in ecosystem structure, function and hydrological connectivity control water, soil and carbon losses in semi‐arid grass to woody vegetation transitions
Authors: Puttock Alan , Macleod Christopher J.A. , Bol Roland , Sessford Patrick , Dungait Jennifer , Brazier Richard E.
Published: June 2013

Connectivity has recently emerged as a key concept for understanding hydrological response to vegetation change in semi‐arid environments, providing an explanatory link between abiotic and biotic, structure and function. Reduced vegetation cover following woody encroachment, generally promotes longer, more connected overland flow pathways, which has the potential to result in an accentuated rainfall‐runoff response and fluxes of both soil erosion and carbon.

This paper investigates changing hydrological connectivity as an emergent property of changing ecosystem structure over two contrasting semi‐arid grass to woody vegetation transitions in New Mexico, USA. Vegetation structure is quantified to evaluate if it can be used to explain observed variations in water, sediment and carbon fluxes. Hydrological connectivity is quantified using a flow length metric, combining topographic and vegetation cover data.

Results demonstrate that the two woody‐dominated sites have significantly longer mean flowpath lengths (4 · 3 m), than the grass‐dominated sites (2 · 4 m). Mean flowpath lengths illustrate a significant positive relationship with the functional response. The woody‐dominated sites lost more water, soil and carbon than their grassland counterparts. Woody sites erode more, with mean event‐based sediment yields of 1203 g, compared to 295 g from grasslands. In addition, the woody sites lost more organic carbon, with mean event yields of 39 g compared to 5 g from grassland sites.

Finally, hydrological connectivity (expressed as mean flowpath length) is discussed as a meaningful measure of the interaction between structure and function and how this manifests under the extreme rainfall that occurs in semi‐arid deserts. In combination with rainfall characteristics, connectivity emerges as a useful tool to explain the impact of vegetation change on water, soil and carbon losses across semi‐arid environments. Copyright © 2013 John Wiley & Sons, Ltd.
Silver nanoparticle toxicity to Daphnia magna is a function of dissolved silver concentration
Authors: Newton Kim M. , Puppala Hema L. , Kitchens Christopher L. , Colvin Vicki L. , Klaine Stephen J.
Published: June 2013

The most persistent question regarding the toxicity of silver nanoparticles (AgNPs) is whether this toxicity is due to the nanoparticles themselves or the silver ions (Ag+) they release. The present study investigates the role of surface coating and the presence of dissolved organic carbon on the toxicity of AgNPs to Daphnia magna and tests the hypothesis that the acute toxicity of AgNPs is a function of dissolved Ag produced by nanoparticle dissolution. Toxicity of silver nitrate (AgNO3) and AgNPs with surface coatings—gum arabic (AgGA), polyethylene glycol (AgPEG), and polyvinylpyrrolidone (AgPVP)—at 48 h was assessed in US Environmental Protection Agency moderately hard reconstituted water alone and augmented with Suwannee River dissolved organic carbon (DOC). As expected, AgNO3 was the most toxic to D. magna and AgPVPs were the least toxic. In general, Suwannee River DOC presence reduced the toxicity of AgNO3, AgGAs, and AgPEG, while the toxicity of AgPVPs was unaffected. The measured dissolved Ag concentrations for all AgNPs and AgNO3 at the 48-h median lethal concentration in moderately hard reconstituted water were similar. The presence of Suwannee River DOC decreased the ratio of measured dissolved Ag to measured total Ag concentration. These results support the hypothesis that toxicity of AgNPs to D. magna is a function of dissolved Ag concentration from these particles. Environ Toxicol Chem 2013;32:2356–2364. © 2013 SETAC
Dysapoptosis of Osteoblasts and Osteocytes Increases Cancellous Bone Formation But Exaggerates Cortical Porosity With Age
Authors: Jilka Robert L , O'Brien Charles A , Roberson Paula K , Bonewald Lynda F , Weinstein Robert S , Manolagas Stavros C
Published: June 2013

Skeletal aging is accompanied by decreased cancellous bone mass and increased formation of pores within cortical bone. The latter accounts for a large portion of the increase in nonvertebral fractures after age 65 years in humans. We selectively deleted Bak and Bax, two genes essential for apoptosis, in two types of terminally differentiated bone cells: the short-lived osteoblasts that elaborate the bone matrix, and the long-lived osteocytes that are immured within the mineralized matrix and choreograph the regeneration of bone. Attenuation of apoptosis in osteoblasts increased their working lifespan and thereby cancellous bone mass in the femur. In long-lived osteocytes, however, it caused dysfunction with advancing age and greatly magnified intracortical femoral porosity associated with increased production of receptor activator of nuclear factor-κB ligand and vascular endothelial growth factor. Increasing bone mass by artificial prolongation of the inherent lifespan of short-lived osteoblasts, while exaggerating the adverse effects of aging on long-lived osteocytes, highlights the seminal role of cell age in bone homeostasis. In addition, our findings suggest that distress signals produced by old and/or dysfunctional osteocytes are the culprits of the increased intracortical porosity in old age. © 2014 American Society for Bone and Mineral Research
Growth From Birth to Adulthood and Bone Phenotype in Early Old Age: A British Birth Cohort Study
Authors: Kuh Diana , Wills Andrew K , Shah Imran , Prentice Ann , Hardy Rebecca , Adams Judith E , Ward Kate , Cooper Cyrus ,   National Survey for Health and Development (NSHD) Scientific and Data Collection Team
Published: June 2013

There is growing evidence that early growth influences bone mass in later life but most studies are limited to birth weight and/or early infant growth and dual-energy X-ray absorptiometry (DXA) measurements. In a British birth cohort study with prospective measures of lifetime height and weight, we investigated the growth trajectory in relation to bone in males (M) and females (F) at 60 to 64 years old. Outcomes were DXA measures of hip and spine areal bone density (aBMD) (n = 1658) and pQCT measures of distal and diaphyseal radius cross-sectional area (CSA), strength, and volumetric bone density (vBMD) (n = 1350 of the 1658). Regression models examined percentage change in bone parameters with standardized measures of birth weight, height, and weight. A series of conditional growth models were fitted for height and weight gain (using intervals: birth–2, 2–4, 4–7, 7–15, 15–20, 20–36, and 36–64 years) and height gain (using intervals: 2–4, 4–7, 7–15, and 15–36 years). Birth weight was positively related to bone CSA (M: 1.4%; 95% confidence interval [CI], 0.3%–2.5%; F: 1.3%; 95% CI, 0.3%–2.4% per 1 SD increase in birth weight for diaphyseal CSA) and strength (M: 1.8%; 95% CI, 0.3–3.4; F: 2.0%; 95% CI, 0.5–3.5). No positive associations were found with trabecular, total, or cortical vBMD. One SD change in prepubertal and postpubertal height and weight velocities were associated with between 2% and 5% greater bone CSA and strength. Height gain in later years was negatively associated with trabecular vBMD. Weight gain velocity during the adult years was positively associated with up to 4% greater trabecular and total BMD, and 4% greater aBMD at hip and spine. In a cohort born in the early post-war period, higher birth weight, gaining weight and height faster than others, particularly through the prepubertal and postpubertal periods, was positively related to bone strength, mostly through greater bone CSA, at 60 to 64 years. © 2014 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.
Vitamin D Supplementation in Young White and African American Women
Authors: Gallagher J Christopher , Jindal Prachi S , Smith Lynette M
Published: June 2013

There is limited information on the effects of vitamin D on serum 25 hydroxyvitamin D (25OHD) in young people and none on African Americans. The main objective of this trial was to measure the effect of different doses of vitamin D3 on serum 25OHD and serum parathyroid hormone (PTH) in young women with vitamin D insufficiency (serum 25OHD ≤ 20 ng/mL (50 nmol/L). A randomized double-blind placebo-controlled trial of vitamin D3 was conducted in young white and African American women, age 25 to 45 years. A total of 198 healthy white (60%) and African American (40%) women were randomly assigned to placebo, or to 400, 800, 1600, or 2400 IU of vitamin D3 daily. Calcium supplements were added to maintain a total calcium intake of 1000 to 1200 mg daily. The primary outcomes of the study were the final serum 25OHD and PTH levels at 12 months. The absolute increase in serum 25OHD with 400, 800, 1600, and 2400 IU of vitamin D daily was slightly greater in African American women than in white women. On the highest dose of 2400 IU/d, the mixed model predicted that mean 25OHD increased from baseline 12.4 ng/mL (95% confidence interval [CI], 9.2–15.7) to 43.2 ng/mL (95% CI, 38.2–48.1) in African American women and from 15.0 ng/mL (95% CI, 12.3–17.6) to 39.1 ng/mL (95% CI, 36.2–42.0) in white women. There was no significant effect of vitamin D dose on serum PTH in either race but there was a significant inverse relationship between final serum PTH and serum 25OHD. Serum 25OHD exceeded 20 ng/mL in 97.5% of whites on the 400 IU/d dose and between 800 and 1600 IU/d for African Americans. The recommended dietary allowance (RDA) suggested by the Institute of Medicine for young people is 600 IU daily. The increase in serum 25OHD after vitamin D supplementation was similar in young and old, and in white and African American women. © 2014 American Society for Bone and Mineral Research.
A parallel finite element simulator for ion transport through three‐dimensional ion channel systems
Authors: Tu Bin , Chen Minxin , Xie Yan , Zhang Linbo , Eisenberg Bob , Lu Benzhuo
Published: June 2013

A parallel finite element simulator, ichannel, is developed for ion transport through three‐dimensional ion channel systems that consist of protein and membrane. The coordinates of heavy atoms of the protein are taken from the Protein Data Bank and the membrane is represented as a slab. The simulator contains two components: a parallel adaptive finite element solver for a set of Poisson–Nernst–Planck (PNP) equations that describe the electrodiffusion process of ion transport, and a mesh generation tool chain for ion channel systems, which is an essential component for the finite element computations. The finite element method has advantages in modeling irregular geometries and complex boundary conditions. We have built a tool chain to get the surface and volume mesh for ion channel systems, which consists of a set of mesh generation tools. The adaptive finite element solver in our simulator is implemented using the parallel adaptive finite element package Parallel Hierarchical Grid (PHG) developed by one of the authors, which provides the capability of doing large scale parallel computations with high parallel efficiency and the flexibility of choosing high order elements to achieve high order accuracy. The simulator is applied to a real transmembrane protein, the gramicidin A (gA) channel protein, to calculate the electrostatic potential, ion concentrations and I – V curve, with which both primitive and transformed PNP equations are studied and their numerical performances are compared. To further validate the method, we also apply the simulator to two other ion channel systems, the voltage dependent anion channel (VDAC) and α‐Hemolysin (α‐HL). The simulation results agree well with Brownian dynamics (BD) simulation results and experimental results. Moreover, because ionic finite size effects can be included in PNP model now, we also perform simulations using a size‐modified PNP (SMPNP) model on VDAC and α‐HL. It is shown that the size effects in SMPNP can effectively lead to reduced current in the channel, and the results are closer to BD simulation results. © 2013 Wiley Periodicals, Inc.
Some New Orders of Hadamard and Skew‐Hadamard Matrices
Authors: Đoković Dragomir Ž. , Golubitsky Oleg , Kotsireas Ilias S.
Published: June 2013

We construct Hadamard matrices of ordersand, and skew‐Hadamard matrices of ordersand. As far as we know, such matrices have not been constructed previously. The constructions use the Goethals–Seidel array, suitable supplementary difference sets on a cyclic group and a new efficient matching algorithm based on hashing techniques.
A systematic review of venous thromboembolism prophylaxis strategies in patients with renal insufficiency, obesity, or on antiplatelet agents
Authors: Kebede Sosena , Prakasa Kalpana R. , Shermock Kenneth , Shihab Hasan M. , Brotman Daniel J. , Sharma Ritu , Chelladurai Yohalakshmi , Haut Elliott R. , Singh Sonal , Segal Jodi B.
Published: June 2013

BACKGROUND

There is uncertainty about optimal strategies for venous thromboembolism (VTE) prophylaxis among select populations such as patients with renal insufficiency, obesity, or patients taking antiplatelet drugs including aspirin. Their physiologies make prophylaxis particularly challenging.

PURPOSE

We performed a comparative effectiveness review of the literature on efficacy and safety of VTE prophylaxis in these populations.

DATA SOURCES

We searched MEDLINE, EMBASE, SCOPUS, CINAHL, International Pharmaceutical Abstracts, clinicaltrial.gov, and the Cochrane Library through August 2012. Eligible studies included controlled trials and observational studies.

DATA EXTRACTION

Two reviewers evaluated studies for eligibility, serially abstracted data, and independently evaluated the risk of bias and strength of evidence supporting interventions to prevent VTE in these populations.

RESULTS

After a review of 30,902 citations, we identified 9 controlled studies, 5 of which were trials, and the other 4 were observational studies. Five articles addressed prophylaxis of patients with renal insufficiency, 2 addressed obese patients, and 2 addressed patients on antiplatelet agents. No study tested prophylaxis in underweight patients or those with liver disease. The majority of observational studies had a high risk of bias. The strength of evidence ranged from low to insufficient regarding the comparative effectiveness and safety of VTE prophylaxis among these patients.

CONCLUSION

The current evidence is insufficient regarding optimal VTE prophylaxis for patients with renal insufficiency, obesity, or those who are on antiplatelet drugs including aspirin. High‐quality studies are needed to inform clinicians about the best VTE prophylaxis for these patients. Journal of Hospital Medicine 2013;8:394–401. © 2013 Society of Hospital Medicine
Selective determination of tobacco‐specific nitrosamines in mainstream cigarette smoke by GC coupled to positive chemical ionization triple quadrupole MS
Authors: Wu Da , Lu Yifeng , Lin Huaqing , Zhou Wanhong , Gu Wenbo
Published: June 2013

A rapid method for the selective determination of four kinds of tobacco‐specific nitrosamines, N‐nitrosonornicotine, N‐nitrosoanatabine, N‐nitrosoanabasine and 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanone, in mainstream cigarette smoke was developed by GC coupled to positive chemical ionization triple‐quadrupole MS. After mainstream cigarette smoke was collected on a cambridge filter pad, the particulate matter was extracted with 0.1 M HCL aqueous solution, cleaned by positive cation‐exchange solid extraction, and finally injected into GC–MS/MS using isotopically labeled analogues as internal standards. Excellent linearity was obtained over the concentration range of 0.5–200.0 ng mL−1 for all tobacco‐specific nitrosamines with values for correlation coefficient between 0.9996–0.9999. Limits of detection of each tobacco specific nitrosamine varied from 0.023–0.028 ng cig−1, and lower limits of quantification varied from 0.077–0.093 ng cig−1. The recovery of each tobacco specific nitrosamine was from 90.0–109.0%. The relative standard deviations of the intra‐day and inter‐day precisions were 3.1–5.8 and 3.9–6.6, respectively. This method was applied to reference and domestic cigarettes. The result showed that the method was consistent with traditional methods and can be used as an effective approach for the routine analysis of tobacco‐specific nitrosamines.
Application of solid‐phase microextraction to the determination of polycyclic aromatic sulfur heterocycles in Bohai Sea crude oils
Authors: Yang Baijuan , Hou Wei , Zhang Kuiying , Wang Xiaoru
Published: June 2013

A simple and rapid solid‐phase microextraction approach for the isolation of polycyclic aromatic sulfur heterocycles from the aromatic fraction of crude oil is described. 8‐Hydroxyquinoline silica gel impregnated with palladium chloride was used as a sorbent material for extraction. Operational parameters of the extraction solvents have been evaluated and optimized. Benzothiophene, dibenzothiophene, and benzo[b]naphtho[1,2‐d]thiophene and their C1–C4 alkyl derivatives were identified and quantified by GC–MS. Under optimum conditions, the limits of detection for benzothiophene, dibenzothiophene, and benzo[b]naphtho[1,2‐d]thiophene were 0.277, 0.193, and 0.597 μg/g oil, respectively. The recoveries for the polycyclic aromatic sulfur heterocycles ranged from 81.5 to 92.1%, and the linear dynamic range was from 10 to 1000 ng/mL. The developed methodology was tested in the characterization of crude oil samples collected at the DY, SZ, ZH, and HC petroleum oil fields of the Bohai Sea. The results proved that SPE coupled with GC–MS is a promising tool for the quantitative analysis of polycyclic aromatic sulfur heterocycles in crude oils, especially for oil samples with low concentrations of polycyclic aromatic sulfur heterocycles.
Application of anion‐exchange imidazolium silica for the multiphase dispersive extraction of phenolic acids
Authors: Bi Wentao , Row Kyung Ho
Published: June 2013

This paper reports the application of a multiphase dispersive extraction method to the extraction, separation, and determination of the phenolic acids from Salicornia herbacea L. using silica‐confined ionic liquids as sorbents. A suitable sorbent for phenolic acid extraction and separation was first identified based on the adsorption behavior of the phenolic acids on different silica‐confined ionic liquids. The sample was then mixed with the optimized sorbent and solvent to achieve multiphase dispersive extraction. The sample/sorbent ratio was optimized using theoretical calculations from the adsorption isotherm and experiments. After transferring the supernatant to an empty cartridge, an SPE process was used to separate the three phenolic acids from the other interference. Through systematic optimization, the optimal conditions produced high recovery rates of protocatechuic acid (91.20%), caffeic acid (94.03%), and ferulic acid (91.33%). Overall, the proposed method is expected to have wide applicability.
Simultaneous determination of atropine, scopolamine, and anisodamine in Flos daturae by capillary electrophoresis using a capillary coated by graphene oxide
Authors: Ye Nengsheng , Li Jian , Gao Chong , Xie Yali
Published: June 2013

A novel CE method was developed for the separation and determination of three main tropane alkaloids in Flos daturae with a capillary coated by graphene oxide (GO). The GO‐coated capillary was characterized by SEM, energy dispersive X‐ray spectroscopy, and Raman spectroscopy, and the results indicated that the inner surface of the capillary was partially coated by GO. A phosphate solution (40 mM, pH7.0) containing 20% v/v methanol and 30% v/v acetonitrile was used as the running buffer for the analysis of the atropine, scopolamine, and anisodamine. The linear ranges of atropine, scopolamine, and anisodamine was 0.5–200 μg/mL with satisfactory correlation coefficients (R2) > 0.9987, and this novel method provided an efficient separation for three tropane alkaloids as well as a good reproducibility and stability. Finally, the method was successfully applied for the determination of these three tropane alkaloids in plant extracts.
Microwave‐assisted extraction followed by RP‐HPLC for the simultaneous extraction and determination of forsythiaside A, rutin, and phillyrin in the fruits of Forsythia suspensa
Authors: Fang Xinsheng , Wang Yingzi , Wang Jianhua , Zhang Jin , Wang Xin
Published: June 2013

An optimized microwave‐assisted extraction (MAE) method and RP‐HPLC method were developed for the simultaneous extraction and determination of rutin, forsythiaside A, and phillyrin in the fruits of Forsythia suspensa. The key parameters of the open‐vessel MAE process were optimized. A mixed solvent of methanol and water (70:30, v/v) was most suitable for the simultaneous extraction of the three components. The sample was soaked for 10 min before extraction. The optimized conditions were: microwave power 400 W, temperature 70°C, solvent‐to‐material ratio 30 mL/g, and extraction time 1 min. Compared to conventional extraction methods, the proposed method can simultaneously extract the three components in high yields and was proved to be a more rapid method with a lower solvent consumption. The optimized HPLC–photodiode array detection analysis was validated to have good linearity, precision, accuracy, and sensitivity. The developed MAE followed by RP‐HPLC is a fast and appropriate method for the simultaneous extraction and determination of rutin, forsythiaside A, and phillyrin in the fruits of F. suspensa.
Separation of 1,3‐dimethylamylamine and other polar compounds in a dietary supplement formulation using aqueous normal phase chromatography with MS
Authors: Le Rosie , Young Joshua E. , Pesek Joseph J. , Matyska Maria T.
Published: June 2013

Five ingredients (caffeine, l‐arginine, creatine, β‐alanine, and 1,3‐dimethylamylamine) from a workout supplement were separated by HPLC with UV detection and LC–MS using an analytical column based on silica hydride operating in aqueous normal phase mode. While RP methods were observed to be inadequate for the analysis due to low retention, aqueous normal phase chromatography was able to readily retain and resolve the analytes. After method development on the HPLC–UV system, the conditions were successfully transferred to an LC–MS system for analysis. Based on calibration curve data, estimates of 63.5, 380.3, and 13.1 mg/serving (5.50 g) were obtained for creatine, l‐arginine, and 1,3‐dimethylamylamine, respectively. Standard addition data results were compared to those of the calibration curve study, and the two values differed by less than 1% in the case of creatine. The conditions are suitable for further development as a reliable means of quantitating the analytes in workout supplement formulations.
Highly stable surface modification of hypercrosslinked monolithic capillary columns and their application in hydrophilic interaction chromatography
Authors: Škeříková Veronika , Urban Jiří
Published: June 2013

A two‐step surface modification of poly(styrene‐co‐vinylbenzyl chloride‐co‐divinylbenzene) monolithic stationary phases, including hypercrosslinking and thermally initiated surface grafting of [2‐(methacryloyloxy)ethyl]dimethyl(3‐sulfopropyl)ammonium hydroxide, has been used to prepare capillary columns for the isocratic separation of small polar compounds in hydrophilic interaction chromatography (HILIC). The prepared monolithic columns provided a dual retention mechanism, combining RP and hydrophilic interaction chromatography, controlled by the composition of the mobile phase. By the optimization of the surface grafting reaction using response surface methodology, we have found that the grafting time is the main synergistic effect controlling the retention of polar compounds in HILIC. The prepared monolithic columns achieved long column lifetimes and did not lose their separation power following >10 000 injections. Finally, hypercrosslinked columns have been used in the 1‐ and 2D LC of phenolic compounds.
An MEKC assay for the therapeutic drug monitoring of cefepime
Authors: Theurillat Regula , Sendi Parham , Thormann Wolfgang
Published: June 2013

The development of a robust assay based on MEKC for cefepime in human serum and plasma with internal quality assurance is reported. Sample preparation comprises protein precipitation in the presence of SDS at pH 4.5. This is a gentle approach for which decomposition of cefepime during sample handling is negligible. After hydrodynamic sample injection of the supernatant, analysis occurs in a phosphate/borate buffer at pH 9.1 with 75 mM SDS using normal polarity and analyte detection at 257 nm. The MEKC run time interval and throughput are about 5 min and seven samples per hour, respectively. The calibration range for cefepime is 1–60 μg/mL, with 1 μg/mL being the LOQ. The performance of the assay with multilevel internal calibration was assessed with calibration and control samples. The assay is shown to be simple, inexpensive, reproducible, and robust. It was applied to determine cefepime levels in the sera of critically ill patients and to assess the instability of cefepime in patient and control samples. Our data revealed that serum containing cefepime can be stored at ‒20°C for a short time, whereas for long‐term storage, samples have to be kept at ‒70°C.