bluuebunny/crossref_metadata_2025 huggingface dataset:
Indoor Human Wayfinding Performance Using Vertical and Horizontal Signage in Virtual Reality
Authors: Vilar Elisângela , Rebelo Francisco , Noriega Paulo
Published: May 2012

Disorientation has many costs. It may lead to physical fatigue, stress, and frustration and can also jeopardize people's safety. Designing wayfinding aids to fit people's needs can facilitate their environmental knowledge acquisition and, therefore, improve their wayfinding performance. The scope of this article is human wayfinding in unfamiliar buildings, considering only individual pedestrian movement in an immersive virtual environment. The purpose is to investigate the use of external information at a higher level of awareness (e.g., signage) as a wayfinding aid, as well as the use of immersive virtual reality (VR) to study indoor wayfinding. Fifty‐four volunteers accomplished a wayfinding task (i.e., finding a room from the building's entrance) within a virtual building, employing two types of signage systems (i.e., vertical and horizontal conditions). A neutral condition (no signage) was also considered as a control condition to be used as a baseline. Aside from the success of the wayfinding task (getting to the destination), other performance metrics (distance traveled, time spent, number of pauses, and average speed) were analyzed and compared. Although the differences found are not statistically significant, findings suggest that participants assigned to the horizontal condition traveled smaller distances, spent less time, made fewer pauses, and moved at higher average speed than those assigned to vertical and neutral conditions. Gender‐related differences were found statistically significant only in the average speed variable (females were faster than males). © 2012 Wiley Periodicals, Inc.
On the attribution of changing pan evaporation in a nature reserve in SW China
Authors: You Guangyong , Zhang Yiping , Liu Yuhong , Song Qinghai , Lu Zhiyun , Tan Zhenghong , Wu Chuansheng , Xie Youneng
Published: May 2012

Negative trends of measured pan evaporation are widely reported. Studies of the factors that underlie this reduction in pan evaporation have not reached a consensus about the controlling factors. Most studies employ statistical analysis (correlation analysis or stepwise regression) to identify the controlling climatic variables; in contrast, few studies have employed physical‐based theories. In addition, observations of pan evaporation and related climatic variables are reported to be influenced by anthropogenic activities. Consequently, the observed trends of climatic variables in a nature reserve would be useful for understanding regional climate change. The present study site is located in Ailaoshan National Nature Reserve, SW China, which is free of anthropogenic activity. In this study, we firstly applied the adjusted PenPan model to estimate the pan evaporation. Then, using this physical‐based model, we identified a positive trend in pan evaporation, with a much larger increase in the dry season than in the wet season. The model results indicate that the change in the aerodynamic component is larger than that in the radiative component. In contrast to the reduction in wind speed and sunshine hours that has been reported in previous studies at various sites, we found that wind speed and sunshine hours have increased in recent decades, thereby explaining the increase of the pan evaporation rate. Wind speed made the greatest contribution to the change in pan evaporation, followed by sunshine duration. This study indicates that the potential evaporation has increased at this site despite the widely reported reduction in measured pan evaporation. During the dry season, the availability of water for agriculture and agroforestry could be threatened. Copyright © 2012 John Wiley & Sons, Ltd.
Influence of extracellular matrix proteins in enhancing bacterial adhesion to titanium surfaces
Authors: Mahmoud Hanan , Williams David W. , Hannigan Ailish , Lynch Christopher D.
Published: May 2012

Aim:

To examine the influence of extracellular matrix (ECM) proteins in enhancing bacterial adhesion and biofilm formation on titanium surfaces.

Materials and methods:

The adherence of 21 bacterial isolates to prepolished 1 cm2 titanium samples was screened using fluorescence microscopy. Three isolates that exhibited “low” (Porphyromonas gingivalis R17870), “moderate” (Porphyromonas gingivalis 5335), and “extensive” (Prevotella denticola R9102) adherence to titanium were then examined for titanium adherence in the presence of the ECM proteins vitronectin, fibronectin, laminin, collagen type I, and collagen type IV.

Results:

Several ECM proteins had a considerable effect on increasing adherence of the bacteria to titanium compared to a control (no protein treatment). The most significant difference was seen with vitronectin for P. gingivalis 5335 (p < 0.001 at 4 h, 24‐h incubation times) and P. gingivalis R17870 (p < 0.05 at 4 h, 24 h incubation times). For P. denticola R9102, vitronectin was not found to enhance adherence at 4 h, (p > 0.05), whilst collagen type I and fibronectin did result in significantly enhanced adherence (p < 0.05, 24 h).

Conclusions:

ECM matrix proteins promote adherence of potential periodontal pathogenic bacteria to titanium surfaces. Management of diseases such as peri‐implantitis should focus on limitation of this bacterial adherence to reduce/eliminate biofilms. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
Effects of surface treatments on the susceptibilities of low temperature degradation by autoclaving in zirconia
Authors: Lee Tae‐Hoon , Lee Sang‐Hyuk , Her Soo‐Bok , Chang Won‐Gun , Lim Bum‐Soon
Published: May 2012

The aim of this study was to investigate the effect of surface treatments on the aging susceptibilities by autoclaving in zirconia ceramics. Four commercially available tetragonal zirconia polycrystals and one zirconia‐alumina composite were tested. Disk‐shaped specimens were prepared and the grain sizes were analyzed using a scanning electron microscope and image analyzer. The specimens were divided into three groups based on surface treatments including heat treatment subsequent to mirror polishing, grinding, and sandblasting. Specimens in each group were autoclaved at 134°C for 1, 3, 5, 10, and 15 h. The phases of the specimens were analyzed using an X‐ray diffractometer, and the relative amount of the monoclinic phase was calculated and analyzed using Student's t‐test and Newman–Keuls multiple comparisons test. Single routine autoclave treatment for sterilization did not promote the phase transformation in zirconia. The phase transformations of all specimens by autoclaving were correlated with grain size, except for the zirconia‐alumina composite. Grinding or sandblasting treatments gave rise to increased formation of the monoclinic phase, especially for the zirconia‐alumina composite, which showed the highest fraction for the monoclinic phase. The effects of surface treatments on the aging susceptibilities by autoclaving were different in the experimental groups. It is notable that not all zirconia ceramics show similar phase transformation by autoclaving after surface treatments. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
The effect of diffusion hardened oxidized zirconium wear debris on cell viability and inflammation—An in vitro study
Authors: Rose S. F. , Weaver C. L. , Fenwick S. A. , Horner A. , Pawar V. D.
Published: May 2012

Wear debris generation in total joint replacement remains a concern because of its association with aseptic loosening, osteolysis, and ultimately implant failure. In a quest to develop new implant materials with reduced wear and improved biocompatibility a new composition of oxidized Zr2.5Nb alloy; diffusion hardened oxidized zirconium (DHOxZr) has been developed. In this study, we have determined the in vitro biocompatibility of the wear debris of this new composition and compared it to wear debris particles of Ti6Al4V, Cobalt, and CoCr. The cytotoxicity of these particles on fibroblast‐like cells (L929) and osteoblast‐like cells (SaOS2) was assessed using lactate dehydrogenase and DNA quantification assays. The inflammatory response to these particles was assessed by release of interleukin‐1 beta and tumor necrosis factor from macrophage‐like cells. The results showed that wear debris generated from DHOxZr was less cytotoxic and elicited a reduced inflammatory response as compared to that of Cobalt or CoCr and might therefore offer a benefit as a joint prosthesis. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
Surface modification of magnesium alloys developed for bioabsorbable orthopedic implants: A general review
Authors: Wang Jiali , Tang Jian , Zhang Peng , Li Yangde , Wang Jue , Lai Yuxiao , Qin Ling
Published: May 2012

As a bioabsorbable metal with mechanical properties close to bone, pure magnesium or its alloys have great potential to be developed as medical implants for clinical applications. However, great efforts should be made to avoid its fast degradationin vivofor orthopedic applications when used for fracture fixation. Therefore, how to decease degradation rate of pure magnesium or its alloys is one of the focuses in Research and Development (R&D) of medical implants. It has been recognized that surface modification is an effective method to prevent its initial degradationin vivoto maintain its desired mechanical strength. This article reviews the recent progress in surface modifications for prevention of fast degradation of magnesium or its alloys usingin vitrotesting model, a fast yet relevant model before moving towards time‐consuming and expensivein vivotesting. Pros and cons of various surface modifications are also discussed for the goal to design available products to be applied in clinical trials. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 100B: 1691–1701, 2012.
Degradation of hollow mesoporous silica nanoparticles in human umbilical vein endothelial cells
Authors: Zhai Wanyin , He Changliang , Wu Lei , Zhou Yue , Chen Hangrong , Chang Jiang , Zhang Hongfeng
Published: May 2012

Hollow mesoporous silica nanoparticles (HMSNs) are considered a potential drug delivery system owing to their recognized advantages in drug loading and releasing. However, whether HMSN could be degraded inside the cells remains unknown. In this study, based on the observations by transmission electron microscopy, fluorescence staining, enzymatic proteolysis, and inductively coupled plasma atomic emission spectroscopy, HMSNs were proved to be degradable in human umbilical vein endothelial cells. The degradation first took place in cytoplasm and lysosomes, and secondly in lysosomes only. The Si content in culture medium increased as the time increases, suggesting that the degradation product inside the cells could be excreted into the culture medium. The degrading rate is fast in the first 2 days and slow after 2 days. The present results provided a clue to further research on the metabolic way and cytotoxicity of silica nanoparticles. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
Nucleus pulposus replacement and regeneration/repair technologies: Present status and future prospects
Authors: Lewis Gladius
Published: May 2012

Degenerative disc disease is implicated in the pathogenesis of many painful conditions of the back, chief among which is low back pain. Acute and/or chronic low back pain (A/CLBP) afflicts a large number of people, thus making it a major healthcare issue with concomitant cost ramifications. When conservative treatments for A/CLBP, such as bed rest, anti‐inflammatory medications, and physical therapy, prove to be ineffectual, surgical options are recommended. The most popular of these is discectomy followed by fusion. Although there are many reports of good to excellent outcomes with this method, there are concerns, such as long‐term adverse biomechanical consequences to adjacent functional spinal unit(s). A surgical option that has been attracting much attention recently is replacement or regeneration/repair of the nucleus pulposus, an approach that holds the prospect of not compromising either mobility or function and causing no adjacent‐level injury. There is a sizeable body of literature highlighting this option, comprisingin vitrobiomechanical studies, finite element analyses, animal‐model studies, and limited clinical evaluations. This work is a review of this body of literature and is organized into four parts, with the focus being on replacement technologies, regeneration/repair technologies, and detailed expositions on 14 areas for future study. This review ends with a summary of the salient points made. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 100B: 1702–1720, 2012.
Successful collection and engraftment of autologous peripheral blood progenitor cells in poorly mobilized patients receiving high‐dose granulocyte colony‐stimulating factor
Authors: Cooper Dennis L. , Proytcheva Maria , Medoff Erin , Seropian Stuart E. , Snyder Edward L. , Krause Diane S. , Wu YanYun
Published: May 2012

Background: Granulocyte Colony‐Stimulating Factor (G‐CSF) alone or in conjunction with chemotherapy is commonly used to mobilize hematopoietic progenitor cells (HPC) into peripheral blood for progenitor cell harvest for autologous HPC transplantation. However, in up to 30% of patients, HPC are not effectively mobilized. In this study, we report the efficacy and safety profiles of a mobilization strategy using high‐dose (up to 36 μg/kg) G‐CSF in poorly mobilized patients. Study Design and Methods: Retrospective medical record reviews were performed for 392 patients who underwent autologous peripheral blood progenitor cell collection. A total of 56 patients were given high‐dose G‐CSF due to very ineffective mobilization and 35 of these patients underwent autologous HPC transplantation. The efficacy of mobilization, apheresis collection, and infusion were reviewed and analyzed. Results: More than 2.5 × 106 CD34/Kg were collected in 88% of patients (49 of 56) who were placed on high‐dose G‐CSF due to very ineffective mobilization. Of the 35 patients who underwent HPC transplantation using the progenitor cells that were mobilized with high‐dose G‐CSF due to very ineffective mobilization, all had rapid and complete neutrophil and platelet engraftment comparable with good mobilizers. Conclusion: We conclude that collection of HPC using hyperstimulation with G‐CSF is an effective alternative approach for HPC harvest for poorly mobilized patients. J. Clin. Apheresis 27:235–241, 2012. © 2012 Wiley Periodicals, Inc.
Plerixafor plus G‐CSF in combination with chemotherapy for stem cell mobilization in a pediatric patient with Ewing's sarcoma
Authors: Vives Susana , Sancho Juan‐Manuel , Almazán Francisco , Juncà Jordi , Grifols Joan‐Ramon , Ribera Josep‐Maria
Published: May 2012

Some malignant tumors in childhood require high‐dose chemotherapy with stem cell support to achieve a cure. In patients heavily pretreated with myelosuppressive chemotherapy or irradiation, granulocyte colony‐stimulating factor (G‐CSF) may fail to mobilize stem cells from the bone marrow. Based on the experience with lymphoma and myeloma patients in whom peripheral blood‐derived stem cell (PBSC) collection following mobilization with G‐CSF failed, we successfully employed plerixafor in a 14‐year‐old female diagnosed with Ewing's sarcoma in early relapse treated with three lines of chemotherapy in whom PBSC could not be mobilized using either G‐CSF alone or G‐CSF following chemotherapy. No side effects were observed. Plerixafor may be an effective and safe agent for stem cell collection in pediatric patients with solid tumors, although new studies addressed to evaluate its effectiveness and safety are needed. J. Clin. Apheresis 27:260–262, 2012. © 2012 Wiley Periodicals, Inc.
Some New Results on ‐Cyclic Patterned Starter Whist Tournaments and Related Frames
Authors: Hu Sihuang , Ge Gennian
Published: May 2012

The whist tournament problem was introduced by Moore in 1896. To construct‐cyclic whist tournaments,‐cyclic patterned starter whist tournaments were introduced. The systematic research on‐cyclic patterned starter whist tournaments dates back to 1954. Recently,‐cyclic patterned starter whist tournament frames were shown to be instrumental in the constructions of‐cyclic patterned starter whist tournaments. In this paper, we develop some necessary conditions for the existence of‐cyclic patterned starter whist tournament frames and some new necessary conditions for the existence of‐cyclic patterned starter whist tournaments. An infinite family of‐cyclic patterned starter whist tournament frames is constructed through Weil's theorem on character sums. As a consequence, a new infinite family of‐cyclic patterned starter whist tournaments is obtained. In addition, we also give a near complete solution to the existence of‐cyclic patterned starter whist tournaments on no greater than 300 players.
Glucose transporter 2 expression is down regulated following P2X7 activation in enterocytes
Authors: Bourzac Jean‐François , L'Ériger Karine , Larrivée Jean‐François , Arguin Guillaume , Bilodeau Maude S. , Stankova Jana , Gendron Fernand‐Pierre
Published: May 2012

With the diabetes epidemic affecting the world population, there is an increasing demand for means to regulate glycemia. Dietary glucose is first absorbed by the intestine before entering the blood stream. Thus, the regulation of glucose absorption by intestinal epithelial cells (IECs) could represent a way to regulate glycemia. Among the molecules involved in glycemia homeostasis, extracellular ATP, a paracrine signaling molecule, was reported to induce insulin secretion from pancreatic β cells by activating P2Y and P2X receptors. In rat's jejunum, P2X7 expression was previously immunolocalized to the apex of villi, where it has been suspected to play a role in apoptosis. However, using an antibody recognizing the receptor extracellular domain and thus most of the P2X7 isoforms, we showed that expression of this receptor is apparent in the top two‐thirds of villi. These data suggest a different role for this receptor in IECs. Using the non‐cancerous IEC‐6 cells and differentiated Caco‐2 cells, glucose transport was reduced by more than 30% following P2X7 stimulation. This effect on glucose transport was not due to P2X7‐induced cell apoptosis, but rather was the consequence of glucose transporter 2 (Glut2)'s internalization. The signaling pathway leading to P2X7‐dependent Glut2 internalization involved the calcium‐independent activation of phospholipase Cγ1 (PLCγ1), PKCδ, and PKD1. Although the complete mechanism regulating Glut2 internalization following P2X7 activation is not fully understood, modulation of P2X7 receptor activation could represent an interesting approach to regulate intestinal glucose absorption. J. Cell. Physiol. 228: 120–129, 2013. © 2012 Wiley Periodicals, Inc.
Pharmacological inhibition of HSP90 and ras activity as a new strategy in the treatment of HNSCC
Authors: Misso Gabriella , Giuberti Gaia , Lombardi Angela , Grimaldi Anna , Ricciardiello Filippo , Giordano Antonio , Tagliaferri Pierosandro , Abbruzzese Alberto , Caraglia Michele
Published: May 2012

Advanced head and neck squamous cell cancer (HNSCC) is currently treated with taxane‐based chemotherapy. We have previously shown that docetaxel (DTX) induces a ras‐dependent survival signal that can be antagonized by farnesyl transferase inhibitors (FTI) such as tipifarnib (TIP). Here we show that the synergistic TIP/DTX combination determines synergistic apoptotic conditions but, at the same time, it modulates the expression of the components of the multichaperone complex that is, in turn, involved in the regulation of the stability of members of the ras‐mediated pathway. Therefore, we have stably transfected HNSCC KB and Hep‐2 cells with a plasmid encoding for HSP90. The expression of the protein was increased in both transfected cell lines but its activation status was increased in Hep‐2 clones and decreased in KB clones. On the basis of these results, we have treated both parental and HSP90‐transfected cells with a HSP90 inhibitor geldanamycin (GA). We have found that the antiproliferative activity of GA is dependent upon the activation status of HSP90 and that it is strongly synergistic when added in combination with TIP but not with DTX in cells overexpressing HSP90 and even more in cells with increased HSP90 activity. These data were paralleled by the decreased expression and activity of the components belonging to the ras→mediated signal transduction pathway. The present results suggest that multichaperone complex activation could be a resistance mechanism to the anti‐proliferative and apoptotic effects induced by TIP and that the combination of FTIs such as TIP with GA could be a suitable therapeutic strategy in the treatment of HSP90‐overexpressing HNSCC. J. Cell. Physiol. 228: 130–141, 2013. © 2012 Wiley Periodicals, Inc.
Predation by coyotes on white‐tailed deer neonates in South Carolina
Authors: Kilgo John C. , Ray H. Scott , Vukovich Mark , Goode Matthew J. , Ruth Charles
Published: May 2012

Coyotes (Canis latrans) are novel predators throughout the southeastern United States and their depredation of white‐tailed deer (Odocoileus virginianus) neonates may explain observed declines in some deer populations in the region, but direct evidence for such a relationship is lacking. Our objective was to quantify neonate survival rates and causes of mortality at the United States Department of Energy's Savannah River Site (SRS), South Carolina to directly evaluate degree of predation in this deer population. From 2006 to 2009, we radio‐monitored 91 neonates captured with the aid of vaginal implant transmitters in pregnant adult females and opportunistic searches. Overall Kaplan–Meier survival rate to 16 weeks of age was 0.230 (95% CI = 0.155–0.328), and it varied little among years. Our best‐fitting model estimated survival at 0.220 (95% CI = 0.144–0.320). This model included a quadratic time trend variable (lowest survival rate during the first week of life and increasing to near 1.000 around week 10), and Julian date of birth (survival probability declining as date of birth increased). Predation by coyotes was the most frequent cause of death among the 70 monitored neonates that died, definitively accounting for 37% of all mortalities and potentially accounting for as much as 80% when also including probable coyote predation. Predation by bobcats (Felis rufus) accounted for 7% (definitive) to 9% (including probable bobcat predation) of mortalities. The level of coyote‐induced mortality we observed is consistent with the low recruitment rates exhibited in the SRS deer population since establishment of coyotes at the site. If representative of recruitment rates across South Carolina, current harvest levels appear unsustainable. This understanding is consistent with the recent declining trend in the statewide deer population. The effects of coyote predation on recruitment should be considered when setting harvest goals, regardless of whether local deer population size is currently above or below desired levels, because coyotes can substantially reduce fawn recruitment. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.
The subcutaneous melolabial island flap for nasal alar reconstruction: A clinical review with nuances in technique
Authors: Arden Richard L. , Miguel George S.
Published: May 2012

Objectives/Hypothesis:

To describe our experience with surgical reconstruction of whole subunit nasal alar skin losses following Mohs ablative surgery, using a subcutaneous melolabial island flap with emphasis on a simplified technique to minimize facial scarring and optimize facial contour.

Study Design:

Retrospective review of case series.

Methods:

A single surgeon's results in 48 consecutive patients spanning 7 years were analyzed by comprehensive chart review. Details of wound site and flap‐specific complications were noted. Favorable nuances in surgical technique differing from standard approaches are graphically described.

Results:

Loss of melolabial sulcal depth was the most commonly seen donor‐site complication (8%). No cases of flap compromise were seen. An unexpectedly high frequency of subjective nasal obstruction was seen (37%) after the second stage, more common when cartilage grafts were underutilized, and with through‐and‐through defects at inception. External contour was uniformly good to excellent.

Conclusions:

The described variation in subcutaneous melolabial island flap transfer provides reliable soft tissue replacement for whole subunit alar skin losses with favorable donor‐site scarring and resultant contour. Attention to proper utilization of supportive cartilage grafts and ancillary debulking procedures is often necessary to optimize functional outcomes. Laryngoscope, 2012
Poly (zinc phthalocyanine) Nanoribbons and Their Application in the High‐Sensitive Detection of Lead Ions
Authors: Deng Juan , Wang Bin , Shi Yubai , Song Qi , Wang Ali , Hao Long , Luo Bin , Li Xianglong , Wang Zhaohui , Wang Feng , Zhi Lin Jie
Published: May 2012

Novel poly (zinc phthalocyanine) (poly(ZnPc)) nanoribbons have been obtained by polycyclotetramerization of bifunctional ZnPc monomers. The microstructures of poly(ZnPc) nanoribbons are characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, and thermalgravimetry. Due to its unique two‐dimensional structure and rich functionality, the poly(ZnPc) nanoribbons exhibit excellent sensitivity in detecting lead ions (Pb2+) by using anodic stripping voltammetry (ASV) method, and the detection limit for Pb2+ is 10−10 mol L−1 in aqueous media, which is much attractive for the development of portable and highly sensitive heavy metal ion sensors.
The Fabrication, Properties, and Uses of Graphene/Polymer Composites
Authors: Du Jinhong , Cheng Hui‐Ming
Published: May 2012

Graphene is a potential nanofiller that can dramatically improve the properties of polymer‐based composites at a very low loading. This article reviews the state‐of‐the‐art progress in the fabrication, properties, and uses of polymer composites with different kinds of graphene fillers. The results so far reported in the literature indicate that graphene/polymer composites are promising multifunctional materials with significantly improved tensile strength and elastic modulus, electrical and thermal conductivity, etc. Despite some challenges and the fact that carbon naotube/polymer composites are sometimes better in some particular performance, graphene/polymer composites may have wide potential applications due to their outstanding properties and the availability of graphene in a large quantity at low cost.
Prospective motion correction in brain imaging: A review
Authors: Maclaren Julian , Herbst Michael , Speck Oliver , Zaitsev Maxim
Published: May 2012

Motion correction in magnetic resonance imaging by real‐time adjustment of the imaging pulse sequence was first proposed more than 20 years ago. Recent advances have resulted from combining real‐time correction with new navigator and external tracking mechanisms capable of quantifying rigid‐body motion in all 6 degrees of freedom. The technique is now often referred to as “prospective motion correction.” This article describes the fundamentals of prospective motion correction and reviews the latest developments in its application to brain imaging and spectroscopy. Although emphasis is placed on the brain as the organ of interest, the same principles apply whenever the imaged object can be approximated as a rigid body. Prospective motion correction can be used with most MR sequences, so it has potential to make a large impact in clinical routine. To maximize the benefits obtained from the technique, there are, however, several challenges still to be met. These include practical implementation issues, such as obtaining tracking data with minimal delay, and more fundamental problems, such as the magnetic field distortions caused by a moving object. This review discusses these challenges and summarizes the state of the art. We hope that this work will motivate further developments in prospective motion correction and help the technique to reach its full potential. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Conversion of arterial input functions for dual pharmacokinetic modeling using Gd‐DTPA/MRI and 18F‐FDG/PET
Authors: Poulin Eric , Lebel Réjean , Croteau Etienne , Blanchette Marie , Tremblay Luc , Lecomte Roger , Bentourkia M'hamed , Lepage Martin
Published: May 2012

Reaching the full potential of magnetic resonance imaging (MRI)‐positron emission tomography (PET) dual modality systems requires new methodologies in quantitative image analyses. In this study, methods are proposed to convert an arterial input function (AIF) derived from gadolinium‐diethylenetriaminepentaacetic acid (Gd‐DTPA) in MRI, into a 18F‐fluorodeoxyglucose (18F‐FDG) AIF in PET, and vice versa. The AIFs from both modalities were obtained from manual blood sampling in a F98‐Fisher glioblastoma rat model. They were well fitted by a convolution of a rectangular function with a biexponential clearance function. The parameters of the biexponential AIF model were found statistically different between MRI and PET. Pharmacokinetic MRI parameters such as the volume transfer constant (Ktrans), the extravascular–extracellular volume fraction (νe), and the blood volume fraction (νp) calculated with the Gd‐DTPA AIF and the Gd‐DTPA AIF converted from 18F‐FDG AIF normalized with or without blood sample were not statistically different. Similarly, the tumor metabolic rates of glucose (TMRGlc) calculated with 18F‐FDG AIF and with 18F‐FDG AIF obtained from Gd‐DTPA AIF were also found not statistically different. In conclusion, only one accurate AIF would be needed for dual MRI‐PET pharmacokinetic modeling in small animal models. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Stimulus duration and pain in nerve conduction studies
Authors: Tamura Akiko , Sonoo Masahiro , Hoshino Satoshi , Iwanami Tomoko , Shimada Hiroyuki , Miki Takami , Shimizu Teruo
Published: May 2012

Introduction: It is generally believed that a shorter stimulus duration is less painful in nerve conduction studies (NCS). We investigated whether a shorter duration stimulus is actually less painful when the same physiological effect, such as supramaximal stimulation, is achieved in motor NCS. Methods: The tibial nerve was stimulated at the ankle in 14 control subjects and the median nerve at the wrist in 20 subjects. Two stimulations of different durations were given blindly, and each subject was asked to report which was more painful. Results: A 0.2‐ms‐duration stimulus was significantly less painful than those with longer or shorter durations for the tibial nerve. For the median nerve, the 0.05‐ and 0.2‐ms durations were equally less painful than a 1‐ms‐duration stimulus. Conclusions: As a common duration for motor NCS, 0.2 ms seems appropriate, because the tibial nerve stimulation was more painful than the median nerve stimulation. Muscle Nerve, 2013
Limb‐girdle myasthenia with tubular aggregates associated with novel GFPT1 mutations
Authors: Huh So‐Young , Kim Hyang‐Sook , Jang Ho‐Jung , Park Yeong‐Eun , Kim Dae‐Seong
Published: May 2012

Introduction:

Limb‐girdle myasthenia with tubular aggregates (LGM with TAs) is a subtype of congenital myasthenic syndrome caused by recessive mutations of glutamine–fructose‐6‐phosphate transaminase 1 (GFPT1).

Methods:

Clinical and neurophysiological assessment was made in a Korean boy who had proximal limb muscle weakness. Findings suggested a diagnosis of congenital myasthenic syndrome.

Results:

Muscle biopsy disclosed numerous TAs in muscle fibers, and DNA sequence analysis disclosed 2 novel missense mutations (p.E256Q and p.M499T) in GFPT1. Treatment with oral cholinesterase inhibitors produced a dramatic improvement in muscle strength.

Conclusions:

GFPT1 is the key enzyme in the hexosamine biosynthesis pathway, and mutations in GFPT1 cause defective glycosylation in the proteins of the neuromuscular junction. Identification of LGM with TAs among patients with congenital myasthenic syndrome is important because treatment with cholinesterase inhibitors can produce symptomatic improvement. Muscle Nerve 46: 599–602, 2012
Inventory pooling games for expensive, low‐demand spare parts
Authors: Karsten Frank , Slikker Marco , van Houtum Geert‐Jan
Published: May 2012

We consider several independent decision makers who stock expensive, low‐demand spare parts for their high‐tech machines. They can collaborate by full pooling of their inventories via free transshipments. We examine the stability of such pooling arrangements, and we address the issue of fairly distributing the collective holding and downtime costs over the participants, by applying concepts from cooperative game theory. We consider two settings: one where each party maintains a predetermined stocking level and one where base stock levels are optimized. For the setting with fixed stocking levels, we unravel the possibly conflicting effects of implementing a full pooling arrangement and study these effects separately to establish intuitive conditions for existence of a stable cost allocation. For the setting with optimized stocking levels, we provide a simple proportional rule that accomplishes a population monotonic allocation scheme if downtime costs are symmetric among participants. Although our whole analysis is motivated by spare parts applications, all results are also applicable to other pooled resource systems of which the steady‐state behavior is equivalent to that of an Erlang loss system. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012
Prediction of pathologic response to neoadjuvant chemotherapy in patients with breast cancer using diffusion‐weighted imaging and MRS
Authors: Shin Hee Jung , Baek Hyeon‐Man , Ahn Jin‐Hee , Baek Seunghee , Kim Hyunji , Cha Joo Hee , Kim Hak Hee
Published: May 2012

The aim of this study was to determine whether tumor size, MRS parameters and apparent diffusion coefficient (ADC) measurements could be applied to predict pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC). Ninety patients with breast cancer (median size, 4.5 cm; range, 1.6–9.5 cm) were evaluated with single‐voxel 1H MRS and dynamic contrast‐enhanced MRI. Diffusion‐weighted imaging was performed in 41 of these patients using a 1.5‐T scanner before and after completion of NAC. Pre‐ and post‐treatment measurements and changes in tumor size, MRS parameters [absolute and normalized total choline‐containing compound (tCho) integral and tCho signal‐to‐noise ratio (SNR)] and ADCs in pCR versus non‐pCR were compared using the nonparametric Mann–Whitney test. Receiver operating characteristic (ROC) curve analysis was performed to assess the diagnostic performance of each parameter. After NAC, 30 patients (33%) showed pCR and 60 (67%) showed non‐pCR. At pretreatment, ADC was the only significant parameter in differentiating between pCR and non‐pCR [(0.83 ± 0.05) × 10–3 versus (0.97 ± 0.14) × 10–3 mm2/s] (p = 0.014). Post‐treatment measurements after completion of NAC and changes in tumor size (both p < 0.001), MRS parameters (p = 0.027 and p = 0.020 for absolute tCho integral, p = 0.036 and p = 0.023 for normalized tCho integral, and p = 0.032 and p = 0.061 for tCho SNR) and ADC (p = 0.003 and p < 0.001) were significantly different between the pCR and non‐pCR groups, except for changes in tCho SNR. In ROC analysis, the areas under the ROC curve (AUCs) of 0.63–0.73 were obtained for tumor size and MRS parameters. AUCs for pre‐ and post‐treatment ADC and changes in ADC were 0.75, 0.80 and 0.96, respectively. The optimal cut‐off of the percentage change in ADC for predicting pCR was 40.7%, yielding 100% sensitivity and 91% specificity. Patients with pCR showed significantly lower pretreatment ADCs than those with non‐pCR. The change in ADC after NAC was the most accurate predictor of pCR. Copyright © 2012 John Wiley & Sons, Ltd.
Satisfaction with life for patients undergoing hemodialysis and patients suffering from osteoarthritis
Authors: Laborde Joyce M. , Powers Marjorie J.
Published: May 2012

Two groups of chronically ill patients, alike in some respects of psychological stress and physical limitations but differing in degrees of physical threat to life because of treatment, were compared in terms of quality of life. Twenty patients undergoing hemodialysis at a satellite center and 20 patients with severe osteoarthritis receiving care at a hospital clinic, ranging in age from 40 to 60 years, were randomly selected and asked to rate themselves on Cantril's self‐anchoring scale in relation to past, present, and future life satisfaction. An ANOVA for simple main effects indicated that patients undergoing hemodialysis viewed present life satisfaction significantly higher, F = 4.81, p < .05, than did patients with arthritis. Expectation for greater life satisfaction tended to be slightly better for dialysis patients, but not significantly so; past life satisfaction was the same for both groups. Dialysis patients viewed their present life better than past life, whereas arthritis patients had the opposite viewpoint. The increased life satisfaction among dialysis patients may be the result of an increased sense of physical well‐being because of the dialysis procedure, and chronic pain may be a factor in the decreased life satisfaction among arthritis patients.
A critique of several conceptions of practice theory in nursing
Authors: Beckstrand Jan
Published: May 2012

The thesis of this article is that the Dickoff, James, and Wiedenbach (1968a, 1968b) conception of a practice theory is roughly equivalent to a plan of action. This idea is contrasted with other conceptions of a prescriptive practice theory, especially the set‐of‐rules conception described by Jacox (1974). The set‐of‐rules conception is shown to be untenable, and other conceptions of practice theory are shown to be nothing more than examples of established forms of knowledge.
The stress process in family caregivers of persons receiving chemotherapy
Authors: Schumacher Karen L. , Dodd Marylin J. , Paul Steven M.
Published: May 2012

The purpose of this analysis was to explore strain and depression among family caregivers of persons receiving chemotherapy for cancer using the Pearlin Stress Process Model. Seventy‐five family caregivers of persons receiving chemotherapy participated, completing the Caregiver Strain Index and the Depression Subscale of the Profile of Mood States within 3 weeks of the initiation of chemotherapy. Hierarchical regression analyses indicated that 44% of the variance in strain and 40% of the variance in depression were explained by the antecedent variables of caregiver age and gender, patient age and gender, patient functional status, the presence of recurrent disease, perceived efficacy of coping strategies, and perceived adequacy of social support. Further analysis aimed at delineating the mechanisms through which coping and social support operate in the model found no evidence for a moderating or stress‐buffering effect. However, coping mediated the relationship between strain and depression and social support mediated the relationship between functional status and depression.
Assessing Executive and Community Functioning Among Homeless Persons with Substance Use Disorders Using the Executive Function Performance Test
Authors: Raphael‐Greenfield Emily
Published: May 2012

This study investigates the utility of an occupational therapy assessment of executive and performance functioning and indicators of community adjustment among adults with histories of homelessness and substance abuse.

A sample of 60 individuals living in a supported housing programme was interviewed about community living experiences and was assessed using the Executive Function Performance Test (EFPT). A descriptive and correlational study design was used.

Measurable levels of cognitive and task impairment were documented, in older adults, non‐US citizens and those diagnosed with cognitive impairments. Those who had completed a supported education/employment programme (Total EFPT t = −2.83, 0.008) performed better as did those who were employed (Total EFPT t = −2.33, 0.03), met regularly with their case managers (cooking t = −2.07, 0.04), had hobbies (paying bills r = −0.31, 0.02) and had longer periods of abstinence (organization/planning t = −3.59, 0.001).

Limitations of the study include the unanticipated need by the clients for additional translation services. Future directions include a randomized controlled intervention study using the EFPT. An implication of this study for occupational therapists working with homeless clients who abuse substances is the importance of assessing and treating their cognitive impairments as well as providing these services within housing first agencies. Copyright © 2012 John Wiley & Sons, Ltd.
Combination of nitroxide‐mediated polymerization and SET‐LRP for the synthesis of high molar mass branched and star‐branched poly(n‐butyl acrylate) characterized by size exclusion chromatography and rheology
Authors: Paillet Sabrina , Roncin Armelle , Clisson Gérald , Pembouong Gaëlle , Billon Laurent , Derail Christophe , Save Maud
Published: May 2012

Branched and star‐branched polymers were successfully synthesized by the combination of two successive controlled radical polymerization methods. A series of linear and star poly(n‐butyl acrylate)‐co‐poly(2‐(2‐bromoisobutyryloxy) ethyl acrylate) statistical copolymers, P(nBA‐co‐BIEA)x, were first synthesized by nitroxide‐mediated polymerization (NMP at T > 100 °C). The subsequent polymerization of n‐butyl acrylate by single electron transfer‐living radical polymerization (SET‐LRP at T = 25 °C), initiated from the brominated sites of the P(nBA‐co‐BIEA)x copolymer, produced branched or star‐branched poly(n‐butyl acrylate) (PnBA). Both types of polymerizations (NMP and SET‐LRP) exhibited features of a controlled polymerization with linear evolutions of logarithmic conversion versus time and number‐average molar masses versus conversion for final Mn superior to 80,000 g mol−1. The branched and star‐branched architectures with high molar mass and low number of branches were fully characterized by size exclusion chromatography. The Mark–Houwink Sakurada relationship and the analysis of the contraction factor (g′ = ([η]branched/[η]linear)M) confirmed the elaboration of complex PnBA. The zero‐shear viscosities of the linear, star‐shaped, branched, and star‐branched polymers were compared. The modeling of the rheological properties confirmed the synthesis of the branched architectures. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Synthesis and radical polymerization of styrene‐based monomer having a five‐membered cyclic carbonate structure
Authors: Miyata Takahiro , Matsumoto Kozo , Endo Takeshi , Yonemori Shigeaki , Watanabe Shoji
Published: May 2012

A styrene‐based monomer having a five‐membered cyclic carbonate structure, 4‐vinylbenzyl 2,5‐dioxoran‐3‐ylmethyl ether (VBCE), was prepared by lithium bromide‐catalyzed addition of carbon dioxide to 4‐vinylbenxyl glycidyl ether (VBGE). Radical polymerization of the obtained VBCE was carried out using 2,2′‐azobisisobutyronitrile as an initiator. PolyVBCE with number‐averaged molecular weight higher than 13,800 was obtained by a solution polymerization in N,N‐dimethylformamide, N,N‐dimethylacetamide, dimethyl sulfoxide, and methyl ethyl ketone. The glass transition temperature and 5 wt % decomposition temperature of the polyVBCE were determined to be 52 and 305 °C by differential scanning calorimetry and thermal gravimetry analysis, respectively. It was confirmed that a polymer consisting of the same VBCE repeating unit can be also obtained via chemical modification of polyVBGE, that is, a lithium‐bromide‐catalyzed addition of carbon dioxide to a polyVBGE prepared from a radical polymerization of VBGE. Further copolymerization of VBCE with styrene gave the corresponding copolymer in a high yield. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Spiky nanostructured metal particles as filler of polymeric composites showing tunable electrical conductivity
Authors: Stassi Stefano , Canavese Giancarlo
Published: May 2012

This work presents a comprehensive investigation of the piezoresistive response of a composite material based on conductive nickel filler in a silicone‐insulating matrix. In the absence of a deformation, the prepared composite shows no electric conductivity, even though the metal particle content is well above the expected percolation threshold. Upon samples deformation (compressive or tensile stress), the composite exploits a variation of electrical resistance up to nine orders of magnitude. This huge variation can be explained with the quantum tunnelling mechanism where the probability of an electron to tunnel from a particle to the next one is exponentially proportional to the thickness of the insulating layer between them and strongly enhanced by the morphology of the nickel particles, showing spiky nanostructured tips. Two different conduction theoretical models are proposed and compared with the experimental results. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
Improving the performance of established PSM programs
Authors: Klein James A. , Dharmavaram S.
Published: May 2012

Many facilities have now implemented and maintained process safety management (PSM) programs for 20 years or more, but these facilities continue to have sometimes serious incidents and injuries suggesting a continuing need to improve their PSM performance. Of course, new requirements are often added to upgrade PSM programs, due to near‐miss learnings, audit findings, and new recommended and generally accepted good engineering practices, for example, but often overall performance improvements have not occurred or have not achieved the desired level of performance. How can significant performance improvements be obtained? Although performance issues at different facilities will certainly vary, this article provides several key approaches for improving overall PSM performance and for helping prevent injuries and incidents. © 2012 American Institute of Chemical Engineers Process Saf Prog, 2012
Nernst coefficient and scattering parameter in PbTe films
Authors: Ariga Tomoki , Koyano Mikio , Ishida Akihiro
Published: May 2012

For the study of thermoelectric materials, it is important to determine the carrier‐scattering mechanisms. For this study, we investigated the carrier‐scattering mechanism in doped lead telluride (PbTe) by analyzing the electrical properties and the Nernst coefficient: ANe. The sign of the Nernst coefficient is related not to carrier types but the residual resistivity ratio (RRR). For a high‐RRR sample, the dominant carrier‐scattering mechanism is acoustic phonon scattering. However, the carrier‐scattering mechanism is complicated in low‐RRR samples. The large scattering parameters obtained from ANe indicate that the high‐energy conduction carriers are more difficult to scatter than are low‐energy carriers.