bluuebunny/crossref_metadata_2025 huggingface dataset:
Full‐waveform inversion of cross‐hole ground‐penetrating radar data to characterize a gravel aquifer close to the Thur River, Switzerland
Authors: Klotzsche Anja , van der Kruk Jan , Angelo Meles Giovanni , Doetsch Joseph , Maurer Hansruedi , Linde Niklas
Published: January 2011

Cross‐hole radar tomography is a useful tool for mapping shallow subsurface electrical properties viz. dielectric permittivity and electrical conductivity. Common practice is to invert cross‐hole radar data with ray‐based tomographic algorithms using first arrival traveltimes and first cycle amplitudes. However, the resolution of conventional standard ray‐based inversion schemes for cross‐hole ground‐penetrating radar (GPR) is limited because only a fraction of the information contained in the radar data is used. The resolution can be improved significantly by using a full‐waveform inversion that considers the entire waveform, or significant parts thereof. A recently developed 2D time‐domain vectorial full‐waveform cross‐hole radar inversion code has been modified in the present study by allowing optimized acquisition setups that reduce the acquisition time and computational costs significantly. This is achieved by minimizing the number of transmitter points and maximizing the number of receiver positions. The improved algorithm was employed to invert cross‐hole GPR data acquired within a gravel aquifer (4–10 m depth) in the Thur valley, Switzerland. The simulated traces of the final model obtained by the full‐waveform inversion fit the observed traces very well in the lower part of the section and reasonably well in the upper part of the section. Compared to the ray‐based inversion, the results from the full‐waveform inversion show significantly higher resolution images. At either side, 2.5 m distance away from the cross‐hole plane, borehole logs were acquired. There is a good correspondence between the conductivity tomograms and the natural gamma logs at the boundary of the gravel layer and the underlying lacustrine clay deposits. Using existing petrophysical models, the inversion results and neutron‐neutron logs are converted to porosity. Without any additional calibration, the values obtained for the converted neutron‐neutron logs and permittivity results are very close and similar vertical variations can be observed. The full‐waveform inversion provides in both cases additional information about the subsurface. Due to the presence of the water table and associated refracted/reflected waves, the upper traces are not well fitted and the upper 2 m in the permittivity and conductivity tomograms are not reliably reconstructed because the unsaturated zone is not incorporated into the inversion domain.
What do students do? Training, research and learning: developing skills for the next generation of near‐surface geophysicists
Authors: Cassidy Nigel J. , Pringle Jamie K.
Published: January 2011

In the past decade, degree programmes throughout Europe have changed dramatically and near‐surface geophysics is now commonly taught as a minor component of other undergraduate geoscience and related degree programmes. As a consequence, there has been a distinct change in the nature, scope and content of geophysical degrees and the skills set that graduates obtain throughout their studies. As an introduction to the Special Issue on Student‐based Research, this commentary article discusses the expectations of employers, the competencies and skills of our undergraduate and postgraduate students and how these have changed over time. We highlight skill gaps and suggest ways in which the near‐surface geophysical community can address these needs in a pragmatic and cost efficient manner. We hope to illustrate that a greater collaboration between industry and academia is the way forward and that innovative, cross‐sector approaches to student learning and research are the solution to at least some of our problems.
Regulatory T Cells Require Mammalian Target of Rapamycin Signaling To Maintain Both Homeostasis and Alloantigen-Driven Proliferation in Lymphocyte-Replete Mice
Authors: Wang Ying , Camirand Geoffrey , Lin Yan , Froicu Monica , Deng Songyan , Shlomchik Warren D. , Lakkis Fadi G. , Rothstein David M.
Published: January 2011

Rapamycin (Rapa), an immunosuppressive drug that acts through mammalian target of Rapa inhibition, broadly synergizes with tolerogenic agents in animal models of transplantation and autoimmunity. Rapa preferentially inhibits conventional CD4+ Foxp3− T cells (Tconv) and promotes outgrowth of CD4+Foxp3+ regulatory T cells (Treg) during in vitro expansion. Moreover, Rapa is widely perceived as augmenting both expansion and conversion of Treg in vivo. However, most quantitative studies were performed in lymphopenic hosts or in graft-versus-host disease models. We show in this study that in replete wild-type mice, Rapa significantly inhibits both homeostatic and alloantigen-induced proliferation of Treg, and promotes their apoptosis. Together, these lead to significant Treg depletion. Tconv undergo depletion to a similar degree, resulting in no change in the percent of Treg among CD4 cells. Moreover, in this setting, there was no evidence of conversion of Tconv into Treg. However, after withdrawal of Rapa, Treg recover Ag-induced proliferation more quickly than Tconv, leading to recovery to baseline numbers and an increase in the percent of Treg compared with Tconv. These findings suggest that the effects of Rapa on Treg survival, homeostasis, and induction, depend heavily on the cellular milieu and degree of activation. In vivo, the resistance of Treg to mammalian target of Rapa inhibition is relative and results from lymphopenic and graft-versus-host disease models cannot be directly extrapolated to settings more typical of solid organ transplantation or autoimmunity. Moreover, these results have important implications for the timing of Rapa therapy with tolerogenic agents designed to increase the number of Treg in vivo.
Immune Evasion ofMoraxella catarrhalisInvolves Ubiquitous Surface Protein A-Dependent C3d Binding
Authors: Hallström Teresia , Nordström Therése , Tan Thuan Tong , Manolov Taras , Lambris John D. , Isenman David E. , Zipfel Peter F. , Blom Anna M. , Riesbeck Kristian
Published: January 2011

The complement system plays an important role in eliminating invading pathogens. Activation of complement results in C3b deposition (opsonization), phagocytosis, anaphylatoxin (C3a, C5a) release, and consequently cell lysis. Moraxella catarrhalis is a human respiratory pathogen commonly found in children with otitis media and in adults with chronic obstructive pulmonary disease. The species has evolved multiple complement evasion strategies, which among others involves the ubiquitous surface protein (Usp) family consisting of UspA1, A2, and A2 hybrid. In the present study, we found that the ability of M. catarrhalis to bind C3 correlated with UspA expression and that C3 binding contributed to serum resistance in a large number of clinical isolates. Recombinantly expressed UspA1 and A2 inhibit both the alternative and classical pathways, C3b deposition, and C3a generation when bound to the C3 molecule. We also revealed that the M. catarrhalis UspA-binding domain on C3b was located to C3d and that the major bacterial C3d-binding domains were within UspA1299–452 and UspA2165–318. The interaction with C3 was not species specific since UspA-expressing M. catarrhalis also bound mouse C3 that resulted in inhibition of the alternative pathway of mouse complement. Taken together, the binding of C3 to UspAs is an efficient strategy of Moraxella to block the activation of complement and to inhibit C3a-mediated inflammation.
The Dual Functions of IL-1 Receptor-Associated Kinase 2 in TLR9-Mediated IFN and Proinflammatory Cytokine Production
Authors: Wan Youzhong , Kim Tae Whan , Yu Minjia , Zhou Hao , Yamashita Michifumi , Kang Zizhen , Yin Weiguo , Wang Jian-an , Thomas James , Sen Ganes C. , Stark George R. , Li Xiaoxia
Published: January 2011

Bone marrow-derived plasmacytoid dendritic cells (pDCs) from IL-1R–associated kinase (IRAK)2-deficient mice produced more IFNs than did wild-type pDCs upon stimulation with the TLR9 ligand CpG. Furthermore, in CpG-stimulated IRAK2-deficient pDCs there was increased nuclear translocation of IFN regulatory factor 7, the key transcription factor for IFN gene transcription in these cells. In IRAK2-deficient macrophages, enhanced NF-κB activation and increased expression of CpG-induced genes were detected within 2 h after treatment. However, at later times, NF-κB activation was decreased and, in contrast to the results with IFN, there was less secretion of other proinflammatory cytokines (such as TNF-α) and chemokines in CpG-stimulated IRAK2-deficient pDCs and macrophages. Therefore, although IRAK2 is a negative regulator of TLR9-mediated IFN production through its modulation of the transcriptional activity of IFN regulatory factor 7, it is also a positive regulator of TLR9-mediated proinflammatory cytokine and chemokine production at some level subsequent to transcription.
5-Lipoxygenase–Deficient Mice Infected withBorrelia burgdorferiDevelop Persistent Arthritis
Authors: Blaho Victoria A. , Zhang Yan , Hughes-Hanks Jennifer M. , Brown Charles R.
Published: January 2011

The enzyme 5-lipoxygenase (5-LO) catalyzes the conversion of arachidonic acid into the leukotrienes, which are critical regulators of inflammation and inflammatory diseases, such as asthma and arthritis. Although leukotrienes are present in the synovial fluid of Lyme disease patients, their role in the development of Lyme arthritis has not been determined. In the current study, we used a murine model of Lyme arthritis to investigate the role 5-LO products might have in the development of this inflammatory disease. After infection of Lyme arthritis-susceptible C3H/HeJ mice with Borrelia burgdorferi, mRNA expression of 5-LO and 5-LO–activating protein was induced in the joints, and the 5-LO product leukotriene B4 was produced. Using C3H 5-LO–deficient mice, we demonstrated that 5-LO activity was not necessary for the induction of Lyme arthritis, but that its deficiency resulted in earlier joint swelling and an inability to resolve arthritis as demonstrated by sustained arthritis pathology through day 60 postinfection. Although production of anti-Borrelia IgG was decreased in 5-LO–deficient mice, bacterial clearance from the joints was unaffected. Phagocytosis of B. burgdorferi and efferocytosis of apoptotic neutrophils was defective in macrophages from 5-LO–deficient mice, and uptake of opsonized spirochetes by neutrophils was reduced. These results demonstrate that products of the 5-LO metabolic pathway are not required for the development of disease in all models of arthritis and that caution should be used when targeting 5-LO as therapy for inflammatory diseases.
Allelic Diversity of Major Histocompatibility Complex Class II DRB Gene in Indian Cattle and Buffalo
Authors: De Sachinandan , Singh Raj Kumar , Brahma Biswajit
Published: January 2011

The present study was conducted to study the diversity ofMHC-DRB3alleles in Indian cattle and buffalo breeds. Previously reportedBoLA-DRBexon 2 alleles of Indian Zebu cattle,Bos tauruscattle, buffalo, sheep, and goats were analyzed for the identities and divergence among various allele sequences. Comparison of predicted amino acid residues ofDRB3exon 2 alleles with similar alleles from other ruminants revealed considerable congruence in amino acid substitution pattern. These alleles showed a high degree of nucleotide and amino acid polymorphism at positions forming peptide-binding regions. A higher rate of nonsynonymous substitution was detected at the peptide-binding regions, indicating thatBoLA-DRB3allelic sequence evolution was driven by positive selection.
Ischemic Stroke during Pregnancy and Puerperium
Authors: Del Zotto Elisabetta , Giossi Alessia , Volonghi Irene , Costa Paolo , Padovani Alessandro , Pezzini Alessandro
Published: January 2011

Ischemic stroke during pregnancy and puerperium represents a rare occurrence but it could be a serious and stressful event for mothers, infants, and also families. Whenever it does occur, many concerns arise about the safety of the mother and the fetus in relation to common diagnostic tests and therapies leading to a more conservative approach. The physiological adaptations in the cardiovascular system and in the coagulability that accompany the pregnant state, which are more significant around delivery and in the postpartum period, likely contribute to increasing the risk of an ischemic stroke. Most of the causes of an ischemic stroke in the young may also occur in pregnant patients. Despite this, there are specific conditions related to pregnancy which may be considered when assessing this particular group of patients such as pre-eclampsia-eclampsia, choriocarcinoma, peripartum cardiomiopathy, amniotic fluid embolization, and postpartum cerebral angiopathy. This article will consider several questions related to pregnancy-associated ischemic stroke, dwelling on epidemiological and specific etiological aspects, diagnostic issue concerning the use of neuroimaging, and the related potential risks to the embryo and fetus. Therapeutic issues surrounding the use of anticoagulant and antiplatelets agents will be discussed along with the few available reports regarding the use of thrombolytic therapy during pregnancy.
Rocks and minerals for the collector: Buckingham-Mont-Laurier-Grenville, Quebec; Hawkesbury-Ottawa, Ontario
Authors: Sabina A P
Published: January 2011

Occurrences of rocks, minerals and fossils are described from over one hundred and fifty localities from Buckingham to Mont-Laurier, St-Jovite and Grenville in Quebec, and in Ontario between Hawkesbury and Ottawa. These occurrences provide a variety of specimens
including some potential ornamental types such as feldspar, serpentine, marble and granite. Probably the best known area is the du Lièvre River valley where the intense mining activity that began nearly a century ago has left numerous former apatite, mica, feldspar and graphite mines. Their
dumps still furnish the collector with good specimens of the ore minerals as well as a variety of accessory minerals. Other deposits in the region yield specimens of hematite, asbestos, barite, galena, etc. In the region between Mont-Laurier, St-Jovite and Grenville, dumps of old mines and quarries
contain specimens of ilmenite, graphite, garnet, serpentine, kaolinite, marble, granite, etc. Only the serpentine and marble occur in specimens sufficiently large to be used for lapidary purposes. Ordovician limestones containing some fossils are exposed along the highway, the shoreline, and
in quarries between Hawkesbury and Ottawa. These rocks are not rich in minerals except for calcite.
Geological and geochemical data from the Canadian Arctic Islands. Part X: Core petrophysical data from petroleum exploration boreholes
Authors: Hu K , Dewing K
Published: January 2011

Conventional core petrophysical analyses have been compiled for 4369 samples from 80 wells in the Canadian Arctic Islands.
The dataset contains porosity, permeability, grain density, residual oil and water saturation measurements. Core data distributions are displayed in various histograms and cross plots for different reservoir lithologies and stratigraphic units.
Establishment of community-based permafrost monitoring sites and initial ground thermal data, Baffin region, Nunavut
Authors: Ednie M , Smith S L
Published: January 2011

The Geological Survey of Canada collaborated with communities and the Government of Nunavut Departments of Environment and community and Government Services to establish six new permafrost monitoring sites in communities in the Baffin Region. The new monitoring
sites provide information to improve the characterization of permafrost thermal state and terrain sensitivity in the communities. Initial data from 2008-2009 are now available from the monitoring sites that indicate that mean annual ground temperatures range from -5.2°C in the southern Baffin
Region at Pangnirtung to -12.3°C at Resolute.
The Haar System in the Preduals of Hyperfinite Factors
Authors: Potapov D. , Sukochev F.
Published: January 2011

We shall present examples of Schauder bases in the preduals to the hyperfinite factors of types II1, II∞, IIIλ, 0 ≤ 1. In the semifinite (respectively, purely infinite) setting, these systems form Schauder bases in any associated separable symmetric space of measurable operators (respectively, in any non-commutative Lp-space).
Brake Squeal - Modeling and Experimental Investigation Using a Work Criterion
Authors: Wagner Utz von , Godecker Holger , Schlagner Stefan
Published: January 2011

Squealing automotive brakes are usually not accepted by customers. However, squealing is an omnipresent phenomenon in disc brakes at least in certain operation states. During the development process of new brakes, engineers succeed more or less in covering this phenomenon with tools like using shims, modifying the structure or varying the mounted pads. In 2002 Popp et al. [1] described the pre-conditions for positive work of the friction forces (i.e. excitation of squeal) based on a very simple model. The essential point in this model is a phase shift between the in-plane movement of the pad and the friction force. In [2] it was shown that it is possible to suppress actively brake squeal using this approach. Active pads with integrated piezoceramics were used as actuators. The authors of the present paper use multi body brake models for the investigation of the origin of the excitation mechanism by observing the work per period of the friction forces and comparing the results with the classic stability analysis. A measurement technique based on these theoretical investigations is developed for detecting parameter regions (e.g. for the brake pressure and corresponding squealing frequencies) which are suspicious for squeal. Considering two models of the brake, phase shifts between signals and measuring the work of the nonconservative forces are considered with respect to the question of detecting the tendency to squeal. Based on these theoretical results measurement procedures are developed and tested at test rigs at TU Berlin and TU Darmstadt. The results of this procedure coincide with results of state of the art experimental investigations but can be performed much faster. This new procedure yields even more significant results than the ones described in [2].
Disc Brake Squeal Suppression Through Chamfered and Slotted Pad
Authors: Chun Lin Saw , Chee Guan Choong , Abu Bakar Abd Rahim , Jamaluddin Mohd Rahimi , Wan Harujan Wan Mohd Musyris , Ghani Badri Abd
Published: January 2011

For decades, it has been a challenging task for brake engineers to reduce or totally eliminate squeal that emanates from brake systems. Despite the large number of proposals that have been implemented in tackling disc brake squeal, very few solutions are totally effective to reduce or suppress it. This paper presents an approach to tackle disc brake squeal through chamfered and slotted pad. A three-dimensional FE model of an actual disc brake system is developed. The baseline FE model is first simulated using complex eigenvalue and transient analysis to predict squeal and compared to the squeal tests data obtained in the brake dynamometer. A reasonable correlation is found between these results. Then, three different pad modifications are proposed, simulated and tested. It is shown that pad with chamfers and diagonal slot can totally suppress squeal both in prediction and squeal test.
Finite Element Model of a Fuzzy Damper for the Beam-on-Disc Setup
Authors: Giannini Oliviero
Published: January 2011

Brake squeal is a complicated research topic because, on one hand, it involves several disciplines, and on the other, it deals with a complex and variable system. In fact, while there is agreement in the scientific community that squeal is a dynamic instability triggered by the modal coupling between two or three modes of the system, the interaction between the dynamics of the brake apparatus, the nonlinear aspects of the contact between disc and pad, and the tribological aspects of the wear is still object of research studies. On the other hand, when dealing with remedies to squeal occurrences, one faces the problem that any solution should be effective in different operative conditions and different environments for all the commercial life of the brake; thus, the robustness of any system for squeal suppression is a key factor. For these reasons, several researchers, focused on more simple systems that exhibit the same instability mechanism, such as the beam-on-disc setup, that is a valuable benchmark to test both effectiveness and robustness of new devices to suppress squeal. This paper presents a numerical study on the effectiveness of a fuzzy damper, based on the theory of apparent damping, that can be able to suppress squeal on the beam-on-disc setup; moreover, the numerical analysis focuses on the relation between the performances of the device and its key design parameters, showing how such a device can either work as a tuned device able to suppress a specific squeal condition, or as a wide band device able to reduce the occurrence of squeal in large frequency ranges.
The Influence of Pad Abutment on the Generation of Brake Noise
Authors: Fieldhouse John D. , Bryant David , Talbot Chris J.
Published: January 2011

The paper overviews the modes of vibration of the principal component parts of a brake and their contribution to system instability during noise generation. It is shown that both in-plane and out-of-plane vibration is present and that both can be related to the vibration of the pad. It is further shown that the pad and its region often provide a solution or 'fix' towards noise prevention and it is this area that forms the focus of this investigation. The collective evidence, proposals and associated theory are applied to real brake case studies when it is demonstrated that disc/pad interface 'spragging' may be the source of brake noise. Measurements of the position of the dynamic centre of pressure (CoP) support the theoretical predictions that a leading CoP induces brake noise. Design proposals are suggested that may be applied early in the design phase as a means to reduce the propensity of a brake to generate noise.
Brake Judder - An Investigation of the Thermo-elastic and Thermo-plastic Effects during Braking
Authors: Bryant David , Fieldhouse John D. , Talbot Chris J.
Published: January 2011

This paper considers a study of the thermo-elastic behaviour of a disc brake during heavy braking. The work is concerned with working towards developing design advice that provides uniform heating of the disc, and equally important, even dissipation of heat from the disc blade. The material presented emanates from a combination of modeling, on-vehicle testing but mainly laboratory observations and subsequent investigations. The experimental work makes use of a purpose built high speed brake dynamometer which incorporates the full vehicle suspension for controlled simulation of the brake and vehicle operating conditions. Advanced instrumentation allows dynamic measurement of brake pressure fluctuations, disc surface temperature and discrete vibration measurements. Disc run-out measurements using non-contacting displacement transducers show the disc taking up varying orders of deformation ranging from first to third order during high speed testing. This surface interrogation during braking identifies disc deformation including disc warping, 'ripple' and the effects of 'hot spotting'. The mechanical measurements are complemented by thermal imaging of the brake, these images showing the vane and vent patterns on the surface of the disc. The results also include static surface scanning, or geometry analysis, of the disc which is carried out at appropriate stages during testing. The work includes stress relieving of finished discs and subsequent dynamometer testing. This identifies that in-service stress relieving, due to high heat input during braking, is a strong possibility for the cause of disc 'warping'. It is also seen that an elastic wave is established during a braking event, the wave disappearing on release of the brake.
Emerging from the Depths: On the Intensive Creativity of Historical Events
Authors: Lundy Craig
Published: January 2011

This paper will explore the possibility of a creative philosophy of history in the work of Gilles Deleuze. It will do so by focusing on Deleuze’s concepts of ‘intensity’ and ‘depth’, as discussed in his seminal work Difference and Repetition. By analysing these concepts in light of several historical thinkers whom Deleuze significantly draws upon (Bergson, Péguy and Braudel), I will show in this paper how Deleuze promotes a theory of history that is not opposed to his philosophy of becoming and creativity, but in concert with it.
The Stirrings of a Stubborn and Difficult Freedom: Assimilation, Education, and Levinas’s Crisis of Humanism
Authors: Katz Claire
Published: January 2011

In several places, Levinas identifies the problem that concerns him as a “crisis of humanism.”  This problem finds its seeds in modernity but comes to fruition in the inhumanities of the 20th century. Like his philosophical predecessors, Levinas offers an educational model as a solution to a problem he has identified.   But this model--Jewish education—is uniquely different from those offered by those who came before him. This essay examines Levinas‘s interest in Jewish education as a solution to this crisis in humanism and considers what the implications of this solution are for his project as a whole.
Ultrasound Biomicroscopic Assessment of Angle Parameters in Patients with Primary Angle Closure Glaucoma Undergoing Phacoemulsification
Authors: Dada Tanuj , Mohan Shalini , Bali Shveta Jindal , Bhartiya Shibal , Sobti Amit , Panda Anita
Published: January 2011

Purpose

To evaluate the effect of phacoemulsification and foldable intraocular lens (IOL) implantation on biometric determinants of the anterior chamber angle in primary angle closure glaucoma (PACG) using ultrasound biomicroscopy (UBM).

Methods

Forty-six eyes of 46 patients with chronic PACG and cataract having a patent laser iridotomy were included in this prospective, interventional case series. Angle parameters were measured using UBM before surgery and 3 months after phacoemulsification with IOL implantation. Intraocular pressure (IOP) was measured by applanation tonometer and records of glaucoma medication administered were maintained. Main outcome measures were IOP, central anterior chamber depth (ACD), trabecular iris angle (TIA), and angle opening distance at 250 and 500 μm from scleral spur (AOD250 and AOD500).

Results

The mean age of study participants was 56.5±9.9 years (range 44–75). The preoperative mean IOP was 25.0±5.4 mmHg on maximum antiglaucoma medication, which was reduced to 15.8±3.8 mmHg (p=0.0001) at 3 months. Number of antiglaucoma medications also decreased from 2.4±1.1 to 0.4±1.1 (p=0.0001). There was a significant widening of the anterior chamber angle with the TIA increasing significantly after phacoemulsification (p<0.001) with an associated increase in AOD250, AOD500, and ACD (p<0.001).

Conclusions

Phacoemulsification in eyes with PACG results in significant widening of the anterior chamber angle. This results in better IOP control after surgery and decreases the need for glaucoma medications. These findings are of clinical significance in obviating the need for simultaneous filtering surgery in eyes with PACG undergoing phacoemulsification cataract surgery.
Neck Reconstruction (Aiims Box Technique) in the Management of Large Femoral Neck Defects
Authors: Garg Bhavuk , Upendra Bidre N. , Jayaswal Arvind
Published: January 2011

Large femoral neck defects are frequently associated with neglected femoral neck fractures, sequelae of infection, and failed fixation devices. The AIIMS box technique of neck reconstruction has the objectives of femoral head preservation and restoration of hip function in such cases. 32 patients (age range 20–56, average 38 years) with large femoral neck defects were treated from January 1990 to May 1997 and were followed up for a minimum of 10 years (range 10 to 17 years). The neck defect was converted into a box using osteal flaps (base from greater trochanter, anterior wall from head, quadratus femoris muscle pedicle graft posteriorly), which was filled with cancellous bone autograft, and stabilized with cancellous screws.

Union occurred in all patients in a mean time of 16 weeks (range 12–20 weeks). One patient developed avascular necrosis (AVN) of femoral head. 8 out of 32 results were classified as excellent, 22 good and 2 fair. Good functional mobility was seen in all but two patients. Complications included coxa vara in two patients, and fixation problems in four patients.

Large femoral neck defects can be managed successfully by this technique with preservation of the viability of the femoral head, and therefore the procedure should be considered in appropriate cases, particularly in young adults.
Evaluation of Intra-Pelvic Screw Position Prior to Revision Total Hip Arthroplasty - A Report of 2 Cases
Authors: Hayashi Shinya , Nishiyama Takayuki , Fujishiro Takaaki , Kanzaki Noriyuki , Kihara Shinsuke , Kurosaka Masahiro
Published: January 2011

Neurovascular injury during total hip revision arthroplasty is rare, but potentially catastrophic. We report two patients requiring revision total hip arthroplasty with intrapelvic screw tips located close to the iliac artery. The screw tips were separated from artery by a retroperitoneal exposure prior to revision surgery. Assessment of screw position by computed tomography (CT) is important prior to revision total hip arthroplasty.
Common Genetic Variants of MUTYH are not Associated with Cutaneous Malignant Melanoma: Application of Molecular Screening by Means of High-Resolution Melting Technique in a Pilot Case-Control Study
Authors: Santonocito Concetta , Paradisi Andrea , Capizzi Rodolfo , Torti Eleonora , Lanza-Silveri Sara , Penitente Romina , Zuppi Cecilia , Capoluongo Ettore
Published: January 2011

MUTYH glycosylase recognizes the 8-oxoG:A mismatch and is able to excise the adenine base using proofreading mechanisms. Some papers have reported a strong association between cancer development or aggressiveness and MUTYH gene mutations. The aim of this study was to find a possible association between the most frequent MUTYH mutations and melanoma in the context of a case-control pilot study. One hundred ninety-five melanoma patients and 195 healthy controls were matched for sex and age. Clinical and laboratory data were collected in a specific database and all individuals were analyzed for MUTYH mutations by high-resolution melting and direct sequencing techniques. Men and women had significantly different distributions of tumor sites and phototypes. No significant associations were observed between the Y165C, G382D and V479F MUTYH mutations and risk of melanoma development or aggressiveness. Our preliminary findings therefore do not confirm a role for MUTYH gene mutations in the melanoma risk. Further studies are necessary for the assessment of MUTYH not only in melanoma but also other cancer types with the same embryonic origin, in the context of larger arrays studies of genes involved in DNA stability or integrity.
Isolated del(5q) in myeloid malignancies: Clinicopathologic and molecular features in 143 consecutive patients
Authors: Patnaik Mrinal M. , Lasho Terra L. , Finke Christy M. , Knudson Ryan A. , Ketterling Rhett P. , Chen Dong , Hoyer James D. , Hanson Curtis A. , Tefferi Ayalew
Published: January 2011

World Health Organization (WHO) criteria were used to identify 143 consecutive patients (median age 73 years; 90 females) with myeloid neoplasms and isolated del(5q) seen between 1989 and 2009. We have previously reported on 88 (61%) of these patients who met criteria for WHO defined “myelodysplastic syndromes (MDS) with isolated del(5q).” The remaining 55 patients were classified as having “other” MDS variants (n = 29; 20%), acute myeloid leukemia (AML; n = 14; 10%), or myeloproliferative neoplasms (MPN; n = 12; 8%). DNA was available in 138 patients and mutation screening revealed 20 cases with JAK2, 6 with IDH, and 3 with MPL mutations; JAK2 and MPL mutations were seen mostly in MPN or “MDS with isolated del(5q)” whereas IDH mutations were frequent in other MDS variants. Overall median survival for the 143 patient cohort was 35 months and leukemic transformation (LT) was documented in 19 (∼13%) cases. “MDS with isolated del(5q)” had the best prognosis with median survival of 66 months and LT rate of ∼6%. Survival was poor among the other myeloid neoplasm subgroups regardless of specific morphologic diagnosis. Multivariable analysis identified higher leukocyte count and percentage of bone marrow and circulating blasts as independent predictors of shortened survival. The first two parameters and the presence of IDH mutations predicted inferior leukemia‐free survival. The current study validates the prognostic relevance of considering “MDS with isolated del(5q)” as a separate WHO subcategory and identifies leukocytosis, higher blast count, and IDH mutations as being prognostically detrimental, in myeloid neoplasms associated with isolated del(5q). Am. J. Hematol. 86:393–398, 2011. © 2011 Wiley‐Liss, Inc.
Long‐term results using hydroxyurea/phlebotomy for reducing secondary stroke risk in children with sickle cell anemia and iron overload
Authors: Greenway Anthea , Ware Russell E. , Thornburg Courtney D.
Published: January 2011

Children with sickle cell anemia (SCA) and a primary overt stroke are at high risk of recurrent (secondary) stroke. Chronic transfusion therapy dramatically reduces but does not eliminate this high risk, and inevitably results in transfusion‐related hemosiderosis. We previously reported the use of hydroxyurea/phlebotomy as an alternative to transfusions to reduce the risk of secondary stroke and improve management of iron overload in 35 children with SCA. To report long‐term results, we retrospectively reviewed clinical and laboratory data through October 2008. With a median of 5.6 years and total of 219 patient‐years of follow‐up, 10 of 35 patients (29%) had recurrent stroke after switching to hydroxyurea; seven were previously reported and three new strokes occurred during extended follow‐up. The overall secondary stroke event rate was 4.6 per 100 patient‐years. Children on hydroxyurea received serial phlebotomy and had lower mean serum ferritin values than children on transfusions (591 ng/mL vs. 3410 ng/mL, P = 0.02). In this cohort, long‐term hydroxyurea treatment reduced but did not eliminate the risk of stroke recurrence and, uniquely, allowed phlebotomy to reduce iron overload. Long‐term assessments of this therapy should evaluate risk factors for secondary stroke and assessments of hemosiderosis, neurocognitive outcome, and health‐related quality of life. Am. J. Hematol. 86:357–361, 2011. © 2011 Wiley‐Liss, Inc.
PEGylated Inorganic Nanoparticles
Authors: Karakoti Ajay S. , Das Soumen , Thevuthasan Suntharampillai , Seal Sudipta
Published: January 2011

Application of inorganic nanoparticles in diagnosis and therapy has become a critical component in the targeted treatment of diseases. The surface modification of inorganic oxides is important for providing diversity in size, shape, solubility, long‐term stability, and attachment of selective functional groups. This Minireview describes the role of polyethylene glycol (PEG) in the surface modification of oxides and focuses on their biomedical applications. Such a PEGylation of surfaces provides “stealth” characteristics to nanomaterials otherwise identified as foreign materials by human body. The role of PEG as structure‐directing agent in synthesis of oxides is also presented.
Polyethylene glycol‐bound Ru catalyst for asymmetric transfer hydrogenation of aromatic ketones in water
Authors: Zhou Zhongqiang , Ma Qiong
Published: January 2011

A new polyethylene glycol‐supported chiral monosulfonamide was synthesized from (R,R)‐1,2‐diaminocyclohexane and shown to act as a ligand for ruthenium(II)‐catalyzed asymmetric transfer hydrogenation of aromatic ketones in neat water using sodium formate as the hydrogen source. Good enantioselectivities were obtained and the catalyst could be easily separated from the reaction mixture and reused several times. Copyright © 2011 John Wiley & Sons, Ltd.
The changing faces of HP1: From heterochromatin formation and gene silencing to euchromatic gene expression
Authors: Kwon So Hee , Workman Jerry L.
Published: January 2011

Heterochromatin protein 1 (HP1) is a positive regulator of active transcription in euchromatin. HP1 was first identified inDrosophila melanogasteras a major component of heterochromatin. Most eukaryotes have at least three isoforms of HP1, which are conserved in overall structure but localize differentially to heterochromatin and euchromatin. Although initial studies revealed a key role for HP1 in heterochromatin formation and gene silencing, recent progress has shed light on additional roles for HP1 in processes such as euchromatic gene expression. Recent studies have highlighted the importance of HP1‐mediated gene regulation in euchromatin. Here, we focus on recent advances in understanding the role of HP1 in active transcription in euchromatin and how modification and localization of HP1 can regulate distinct functions for this protein in different contexts.
Nanoengineered PtVFe/C Cathode Electrocatalysts in PEM Fuel Cells: Catalyst Activity and Stability
Authors: Fang Bin , Luo Jin , Chen Yongsheng , Wanjala Bridgid N. , Loukrakpam Rameshwori , Hong Jian , Yin Jun , Hu Xiang , Hu Peipei , Zhong Chuan‐Jian
Published: January 2011

The understanding of factors controlling electrocatalytic activity and stability of carbon‐supported multimetallic catalysts is essential for advancing the design of fuel‐cell electrocatalysts for oxygen reduction. The structural and compositional changes of trimetallic PtVFe/C catalysts have been investigated by several techniques, including XRD, X‐ray absorption fine structure (XAFS), and inductively coupled plasma (ICP) analyses, in addition to electrochemical and fuel‐cell performance tests. The investigation aims at understanding whether the base metals incorporated into the multimetallic catalysts are stable and how the base metals in the Pt‐alloy are stabilized mechanistically. Changes are detected for the lattice properties and the composition of the base metals in the PtVFe nanoparticles after long‐term exposure to air, after thermal treatment at different temperatures, and after use in proton‐exchange membrane (PEM) fuel cells. These changes show certain correlations with the structure, activity, and stability of the catalysts. The fcc alloy phase is found to be predominant for catalysts treated at low temperature, but changes to a tetragonal‐type alloy phase when the catalysts are treated at a higher temperature. In the low‐temperature‐treated catalyst, Fe has more bonds with O atoms, whereas in the high‐temperature‐treated catalyst, Fe has fewer O neighbors and FeFe bonds are detected. Analysis of the catalysts after testing in fuel cells indicates that the percentage of iron oxide is reduced, reflecting the propensity of dissolution of Fe oxide in the electrolytes. The smaller lattice parameter for the higher‐temperature treated catalyst is considered to be an important factor in determining the catalyst stability under conditions related to fuel‐cell operation.
Oligonuclear Ferrocene Amides: Mixed‐Valent Peptides and Potential Redox‐Switchable Foldamers
Authors: Siebler Daniel , Linseis Michael , Gasi Teuta , Carrella Luca M. , Winter Rainer F. , Förster Christoph , Heinze Katja
Published: January 2011

Trinuclear ferrocene tris‐amides were synthesized from an Fmoc‐ or Boc‐protected ferrocene amino acid, and hydrogen‐bonded zigzag conformations were determined by NMR spectroscopy, molecular modelling, and X‐ray diffraction. In these ordered secondary structures orientation of the individual amide dipole moments approximately in the same direction results in a macrodipole moment similar to that of α‐helices composed of α‐amino acids. Unlike ordinary α‐amino acids, the building blocks in these ferrocene amides with defined secondary structure can be sequentially oxidized to mono‐, di‐, and trications. Singly and doubly charged mixed‐valent cations were probed experimentally by Vis/NIR, paramagnetic 1H NMR and Mössbauer spectroscopy and investigated theoretically by DFT calculations. According to the appearance of intervalence charge transfer (IVCT) bands in solution, the ferrocene/ferrocenium amides are described as Robin–Day class II mixed‐valent systems. Mössbauer spectroscopy indicates trapped valences in the solid state. The secondary structure of trinuclear ferrocene tris‐amides remains intact (coiled form) upon oxidation to mono‐ and dications according to DFT calculations, while oxidation to the trication should break the intramolecular hydrogen bonding and unfold the ferrocene peptide (uncoiled form).
1,2‐Diphosphaacenaphthene 1,2‐Dications: Synthetic, Stereochemical and Computational Study of the Stabilising Role of Naphthalene‐1,8‐diyl Backbone
Authors: Somisara D. M. Upulani K. , Bühl Michael , Lebl Tomas , Richardson Neville V. , Slawin Alexandra M. Z. , Woollins J. Derek , Kilian Petr
Published: January 2011

Syntheses and full characterisation data (including single crystal diffraction) of three 1,2‐diphosphonium dicationic species with the naphthalene‐1,8‐diyl (Nap) backbone are reported. The oxidation of Nap[P(NMe2)2]2 with P2I4 to its 1,2‐dication was achieved. meso‐ and rac‐forms of “all carbon” 1,2‐diphosphonium dications were obtained in good yields and purity by double alkylation of the parent diphosphine (1,2‐diphenyl‐1,2‐diphosphaacenaphthene) with methyl triflate or trimethyloxonium tetrafluoroborate. Each methylating reagent produces one of the rac‐ or meso‐forms of the dication diastereospecifically. Structural parameters of the new dications are discussed with respect to other phosphorus 1,2‐dications. DFT (B3LYP) computations revealed the significant role of the naphthalene backbone in stabilisation of the dicationic motif and helped to assess the energy cost of the steric clash of a variety of groups attached to the peri‐positions of naphthalene. The synthesis and single crystal X‐ray data of the extremely crowded Nap[P(Se)(OiPr)2]2 are discussed, and are contrasted with the unsuccessful synthesis of Nap(PtBu2)2 from NapLi2 and ClPtBu2.
Copper(I) and Copper(II) Inhibit Aβ Peptides Proteolysis by Insulin‐Degrading Enzyme Differently: Implications for Metallostasis Alteration in Alzheimer’s Disease
Authors: Grasso Giuseppe , Pietropaolo Adriana , Spoto Giuseppe , Pappalardo Giuseppe , Tundo Grazia Raffaella , Ciaccio Chiara , Coletta Massimo , Rizzarelli Enrico
Published: January 2011

Accumulation of neurotoxic amyloid‐β peptide (Aβ) and alteration of metal homeostasis (metallostasis) in the brain are two main factors that have been very often associated with neurodegenerative diseases, such as Alzheimer’s disease (AD). Aβ is constantly produced from the amyloidprecursor‐protein APP precursor and immediately catabolized under normal conditions, whereas dysmetabolism of Aβ and/or metal ions seems to lead to a pathological deposition. Although insulin‐degrading enzyme (IDE) is the main metalloprotease involved in Aβ degradation in the brain being up‐regulated in some areas of AD brains, the role of IDE for the onset and development of AD is far from being understood. Moreover, the biomolecular mechanisms involved in the recognition and interaction between IDE and its substrates are still obscure. In spite of the important role of metals (such as copper, aluminum, and zinc), which has brought us to propose a “metal hypothesis of AD”, a targeted study of the effect of metallostasis on IDE activity has never been carried out. In this work, we have investigated the role that various metal ions (i.e., Cu2+, Cu+, Zn2+, Ag+, and Al3+) play in modulating the interaction between IDE and two Aβ peptide fragments, namely Aβ1–16 and Aβ16–28. It was therefore possible to identify the direct effect that such metal ions have on IDE structure and enzymatic activity without interferences caused by metal‐induced substrate modifications. Mass spectrometry and kinetic studies revealed that, among all the metal ions tested, only Cu2+, Cu+, and Ag+ have an inhibitory effect on IDE activity. Moreover, the inhibition of copper(II) is reversed by adding zinc(II), whereas the monovalent cations affect the enzyme activity irreversibly. The molecular basis of their action on the enzyme is also discussed on the basis of computational investigations.
ChemInform Abstract: Magnetic Properties and Structural Transitions of Orthorhombic Fluorite‐Related Compounds Ln3MO7 (Ln = Rare Earths, M = Transition Metals).
Authors: Wakeshima Makoto , Hinatsu Yukio
Published: January 2011

The compounds Ln3MoO7 (Ln: La—Gd) are synthesized using the corresponding rare earth oxides, MoO2, and MoO3 as starting materials (1200 °C, 12 h).
ChemInform Abstract: An Improved Synthesis of Ternary Carbonates: The Examples LiLa(CO3)2 and La(CO3)F.
Authors: Glaser Jochen , Meyer H.‐Juergen
Published: January 2011

A new route to the ternary carbonate (III), previously obtained under supercritical CO2 pressure conditions, is described.
ChemInform Abstract: How Does the Synthesis Temperature Impact Hybrid Organic—Inorganic Molybdate Material Design?
Authors: Dessapt Remi , Kerkern Daniel , Bujoli‐Doeuff Martine , Deniard Philippe , Evain Michel , Jobic Stephane
Published: January 2011

The detailed study of the reactions of MoO42‐ with different ethylenediammonium cations at temperatures in the range 70—180 °C yields a variety of new molybdates with different topologies.
ChemInform Abstract: Solvothermal Synthesis, Crystal Structures, and Magnetic Properties of Two Organically Templated Iron Sulfates with Chain Structures.
Authors: Ma Ling , Liu Dan , Xing Yan , Liu Xianchun , Li Gaijuan
Published: January 2011

The crystal structures of (II) and (III) are determined by single crystal XRD.
ChemInform Abstract: Direct Asymmetric Bromination of Aldehydes Catalyzed by a Binaphthyl‐Based Secondary Amine: Highly Enantio‐ and Diastereoselective One‐Pot Synthesis of Bromohydrins.
Authors: Kano Taichi , Shirozu Fumitaka , Maruoka Keiji
Published: January 2011

The bromination of aldehydes (I) in the presence of a chiral binaphthyl catalyst (BNS) followed by reduction of the intermediate α‐bromoaldehyde gives rise to bromohydrins (II) with high enantioselectivity.
ChemInform Abstract: An Efficient Synthesis of New Thiazole Based Heterocycles.
Authors: Mabkhot Yahia N. , Kheder Nabila A. , Farag Ahmad M.
Published: January 2011

The presented simple syntheses start from the versatile and readily accessible compound (I).
ChemInform Abstract: Mild and Expedient Asymmetric Reductions of α,β‐Unsaturated Alkenyl and Alkynyl Ketones by TarB—NO2 and Mechanistic Investigations of Ketone Reduction.
Authors: Eagon Scott , DeLieto Cassandra , McDonald William J. , Haddenham Dustin , Saavedra Jaime , Kim Jinsoo , Singaram Bakthan
Published: January 2011

The title reactions allow a facile, chemoselective, and enantioselective access to allylic and propargyl alcohols.
ChemInform Abstract: Heck Coupling Reaction Using Monomeric ortho‐Palladated Complex of 4‐Methoxybenzoylmethylenetriphenylphosphorane under Microwave Irradiation.
Authors: Hajipour Abdol R. , Karami Kazem , Tavakoli Ghazal
Published: January 2011

The title reaction can be carried out under both conventional heating and microwave irradiation conditions.
ChemInform Abstract: P[N(i‐Bu)CH2CH2]3N: Nonionic Lewis Base for Promoting the Room‐Temperature Synthesis of α,β‐Unsaturated Esters, Fluorides, Ketones, and Nitriles Using Wadsworth—Emmons Phosphonates.
Authors: Chintareddy Venkat Reddy , Ellern Arkady , Verkade John G.
Published: January 2011

The use of the title base allows convenient access to α,β‐unsaturated esters, fluorides, ketones, and nitriles.