bluuebunny/crossref_metadata_2025 huggingface dataset:
Printed, multi‐loop‐antenna system integrated into a concurrent, dual‐WLAN‐band access point
Authors: Su Saou‐Wen , Hong Tzi‐Chieh
Published: December 2010

A printed, planar multi‐loop‐antenna system having high‐gain, quasi‐dual‐polarized radiation properties for concurrent, dual‐band WLAN operation in the 2.4 and 5.2 GHz bands is presented. The multi‐antenna design comprises four printed loop antennas arranged to be of a orthogonal configuration, printed on the same‐layer of a 1.6‐mm thick FR4 substrate, and one system PCB serving as an efficient reflector for the loops. The four antennas are set within the boundary of the PCB of the typical size for compact, outdoor access‐point (AP) applications and stacked there above by a small distance. In this study, the design integrates the system PCB of an AP into an internal multi‐antenna solution for compact outdoor APs. The results show that good input matching with 10‐dB return loss over the 2.4 and 5.2 GHz bands can be attained. Directional radiation patterns with comparable Eθ and Eφ fields were also obtained. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:317–322, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25736
Improved test structure for on‐wafer microwave characterization of components
Authors: Descamps Philippe , Abessolo‐Bidzo Dolphin , Poirier Patrick
Published: December 2010

This article presents the impact of different test structures on the results of microwave characterization of on‐wafer components. In this study, we focus on the characterization and modeling of NXP Semiconductors Technology Passive Integration Connective Substrate (PICS) capacitor. First, we show the strong dependency of the extracted parameters according to test structure used when utilizing traditional open/short parasitic elements removing method. Second, we propose an optimization of the test structures to reduce their influence on the intrinsic parameters extracted from on‐wafer characterization of the device under test. We also propose a way to improve the accuracy of the modeling of PICS devices in radiofrequency and microwave domains. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:249–254, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25738
Design of a compact ultrawideband slot antenna with dual band‐notched function
Authors: Xue Jin‐Yuan , Gong Shu‐Xi , Fei Peng , Wang Wei , Zhang Fei‐Fei
Published: December 2010

A compact ultrawideband (UWB) microstrip‐fed slot antenna with dual band‐notched function is presented.The prototype consists of an L‐shaped microstrip line, a modified ground plane with T‐shaped slot and a small stub embedded on the ground for impedance matching. The designed antenna satisfies the return loss requirement of larger than 10 dB in UWB frequency range from 3.1 to 10.6 GHz, whereas shows the wireless local area network and worldwide interoperability for microwave access band notched in the frequency band of 5.1–6 GHz and 3.5–4.1 GHz by the inserted rectangle strips. Detailed analysis and experimental results for the design are studied and investigated. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:245–249, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25739
A MIMO antenna with a two‐stage ground for USB dongle applications
Authors: Yu Yeonsik , Kim Giho , Seong Wonmo , Choi Jaehoon
Published: December 2010

A multiband internal multiple‐input multiple‐output (MIMO) antenna for USB dongle applications is proposed. Two types of antenna element are used to construct a MIMO antenna system. The resonance frequencies of the MIMO antenna are controlled by the lengths of the two asymmetric arms or by the number of turns in a helix. The designed antenna provides wide bandwidth to cover LTE, DCN, and PCS‐1900 services, simultaneously. Although the MIMO antenna is installed within an electrically small USB dongle device, the isolation characteristic and antenna performance can be improved by using a two‐stage ground structure. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:418–422, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25742
Multimode broadband bandpass filter using one single square patch resonator
Authors: Xiao Zhongyin
Published: December 2010

A novel multimode broadband square patch bandpass filter is proposed.The return loss of the filter is more than 11 dB and insertion loss is less than 1.2 dB within 3.47–5.22 GHz. This new filter has four transmission poles in the passband and the 3dB bandwidth is 48.9%. Measured results are in good agreement with simulated results. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:385–386, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25744
Design and analysis of a compact ultra‐wideband CMOS low‐noise amplifier
Authors: Seong Nackgyun , Jang Yohan , Choi Jaehoon
Published: December 2010

In this letter, we proposed a low power, high gain, compact ultra‐wideband (UWB) low noise amplifier (LNA) using TSMC 0.18‐μm CMOS technology.To satisfy the wide input matching and high voltage gain requirements with low power consumption, a resistive current reused technique is utilized. The proposed UWB LNA has a voltage gain of 10.4–15.5 dB and a noise figure (NF) of 3.3–4.5 dB over the frequency band of interest (1–8 GHz). The total power consumption of the proposed UWB LNA is 10.4 mW from a 1.4 V supply voltage, and the chip area is 0.8 mm × 0.5 mm. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:345–348, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25747
Design of simple CVTL bandstop filter
Authors: Hassan Essam E. M. , Sheikh Sharif I. , Al‐Sharif Yousef
Published: December 2010

The problem of microwave filters design using non‐uniform transmission line is tackled based on a global solution of the overall filter characteristics rather than localized characteristics. This technique simplifies the design process by significantly reducing the numerical efforts. A bandstop filter is designed using the proposed technique and optimized using genetic algorithm. The experimental results are presented and compared with the predicted response of the S‐band filter. Good agreement is found between the predicted and the experimental results. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:310–312, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25749
The impact of a multidisciplinary pain management model on sickle cell disease pain hospitalizations
Authors: Brandow Amanda M. , Weisman Steven J. , Panepinto Julie A.
Published: December 2010

Background

Sickle cell disease (SCD) pain is acute or chronic, leads to school absenteeism, impaired health‐related quality of life and early mortality. Given that little is known about children with SCD and chronic pain, we (1) described characteristics of these children and (2) evaluated the impact of a multidisciplinary pain management model on health care utilization.

Procedure

A retrospective cohort study of children with SCD evaluated and treated in our institution's multidisciplinary pain clinic between 1999 and 2008 was conducted. Referrals occur when children require chronic opioids and/or have frequent pain hospitalizations. Descriptive statistics evaluated patient characteristics and Wilcoxon‐Signed Rank evaluated change in median number of pain hospitalizations 1 year before and after referral.

Results

Median age of 19 children identified was 15 years (IQR 11–17); significantly more were female (78.9% vs. 21.1%; P = 0.012). At time of referral, all patients reported taking opioids, 68.4% were taking hydroxyurea, half of those not on hydroxyurea started it (n = 3), none were chronically transfused and one initiated transfusions upon referral. Majority (89.5%) learned non‐pharmacologic pain management techniques. Median number of pain hospitalizations between the year before and after referral significantly decreased [5(IQR 3–6) to 1(IQR 0–4); P = 0.006]. To further delineate the pain clinic's effect, analysis was repeated after removing children initiating hydroxyurea/transfusions upon referral. The significant decrease in hospitalizations persisted [5(IQR 3–6) to 1(IQR 0–4; P = 0.022].

Conclusions A multidisciplinary pain management model appears to have decreased SCD pain hospitalizations. Results of this retrospective study will need to be tested in a prospective randomized trial. Pediatr Blood Cancer 2011;56:789–793. © 2010 Wiley‐Liss, Inc.
Sex cord stromal tumors of the ovary in children: A clinicopathological report from the Italian TREP project
Authors: Cecchetto Giovanni , Ferrari Andrea , Bernini Gabriella , Alaggio Rita , Collini Paola , Virgone Calogero , Terenziani Monica , Dall'Igna Patrizia , Cozza Raffaele , Conte Massimo , Bisogno Gianni
Published: December 2010

Background

Ovarian sex‐cord stromal tumors (SCST) are rare in childhood and include a variety of neoplasms with different clinical features and biologic behavior. Aim of the analysis was to report the clinical findings and treatment results of a series of patients with SCST of the ovary, registered in a multi‐institutional Italian network on rare tumors in children and adolescent between 2000 and 2009.

Methods

Data on 23 patients, 5–176 months old, from 13 Centers were reviewed. All patients were grouped on the basis of the results of the first surgical approach, according to the Children Oncology Group staging system. A cisplatin based chemotherapy was recommended in patients with a localized disease, who had undergone an incomplete excision/initial biopsy, and in case of metastatic spread.

Results

A frequent symptom was abdominal pain; 9/23 cases had signs of hormonal secretion and two patients were hospitalized for acute pain following ovarian torsion. Twelve patients had a Juvenile–Granulosa Cell tumor, six a Sertoli–Leydig Cell tumor, three a Fibrothecoma, and two a Sclerosing‐Stromal tumor. Twenty‐one patients maintained the complete remission (follow‐up: 9–91 months), 2 with a ST II Sertoli–Leydig Cell tumor relapsed and one of them died. Immonohistochemical studies could be done in 10 cases.

Conclusions

Completeness of resection and histology were important prognostic factors; in our series the Sertoli–Leydig Cell tumor was the most aggressive variety. Hormonal signs (precocious puberty, telarca, menarche) were common in younger patients and led to an early diagnosis. Cisplatin based chemotherapy seemed to be effective for locally advanced tumors. Pediatr Blood Cancer 2011;56:1062–1067. © 2010 Wiley‐Liss, Inc.
Targeted large‐scale analysis of protein acetylation
Authors: Mischerikow Nikolai , Heck Albert J. R.
Published: December 2010

Protein modifications are biologically important events that may be studied by mass spectrometry‐based high‐throughput proteome analyses. In recent years, several new technologies have emerged that have widened and deepened the targeted analysis of one important, albeit functionally ill‐defined modification, namely protein acetylation. This modification can take place both co‐ and post‐translationally by the transfer of acetyl groups under the catalysis of acetyltransferases. The acetyl group can modify either the α‐amino group at the N‐terminus, so‐called N‐terminal acetylation, or the ε‐amino group on the side chain of lysine residues. Here, we review several emerging targeted technologies to chart both N‐terminal acetylation as well as acetylation at the lysine side chain, on a proteome‐wide scale, highlighting in particular studies that have expanded the biological knowledge on the appearance and function of these common but functionally still less investigated co‐ and post‐translational modifications.
Comprehensive proteomic and transcriptomic characterization of hepatic expression signatures affected in p14 liver conditional knockout mice
Authors: Prokudin Ivan , Stasyk Taras , Rainer Johannes , Bonn Guenther K. , Kofler Reinhard , Huber Lukas A.
Published: December 2010

Scaffold proteins regulate intracellular MAP kinase signaling by providing critical spatial and temporal specificities. We have shown previously that the scaffold protein MEK1 partner (MP1) is localized to late endosomes by the adaptor protein p14. Using conditional gene disruption of p14 in livers of mice (p14Δhep) we analyzed protein and transcript signatures in tissue samples. Further biological network analysis predicted that the differentially expressed transcripts and proteins are involved in cell cycle progression and regulation of cellular proliferation. Although some of the here identified signatures were previously linked to phospho‐ERK activity, most of them were novel targets of the late endosomal p14/MP1/MEK/ERK signaling module. Finally, the proliferation defect was confirmed in a chemically induced liver regeneration model in p14Δhep knockout mice.
Mapping of the secretome of primary isolates of mammalian cells, stem cells and derived cell lines
Authors: Skalnikova Helena , Motlik Jan , Gadher Suresh Jivan , Kovarova Hana
Published: December 2010

Within a mammalian organism, the interaction among cells both at short and long distances is mediated by soluble factors released by cells into the extracellular environment. The secreted proteins may involve extracellular matrix proteins, proteinases, growth factors, protein hormones, immunoregulatory cytokines, chemokines or other bioactive molecules that have a direct impact on target cell phenotype. Stem cells of mesenchymal, adipose, neural and embryonic origin, fibroblast feeder cells as well as primary isolates of astrocytes, endothelial and muscle cells have recently become targets of intensive secretome profiling with the search for proteins regulating cell survival, proliferation, differentiation or inflammatory response. Recent advances and challenges of the stem cell and primary cell secretome analysis together with the most relevant results are discussed in this review.
Proteomics of human embryonic stem cells
Authors: Hughes Chris S. , Nuhn Amelia A. , Postovit Lynne M. , Lajoie Gilles A.
Published: December 2010

Human embryonic stem cells (hESCs) offer exciting potential in regenerative medicine for the treatment of a host of diseases including cancer, Alzheimer's and Parkinson's disease. They also provide insight into human development and disease and can be used as models for drug discovery and toxicity analyses. The key properties of hESCs that make them so promising for medical use are that they have the ability to self‐renew indefinitely in culture and they are pluripotent, which means that they can differentiate into any of more than 200 human cell types. Since proteins are the effectors of cellular processes, it is important to investigate hESC expression at the protein level as well as at the transcript level. In addition, post‐translational modifications, such as phosphorylation, may influence the activity of pivotal proteins in hESCs, and this information can only be determined by studying the proteome. In this review, we summarize the results obtained from several proteomics analyses of hESCs that have been reported in the last few years.
Energy matters: Mitochondrial proteomics for biomedicine
Authors: Gianazza Elisabetta , Eberini Ivano , Sensi Cristina , Barile Maria , Vergani Lodovica , Vanoni Maria Antonietta
Published: December 2010

This review compiles results of medical relevance from mitochondrial proteomics, grouped either according to the type of disease – genetic or degenerative – or to the involved mechanism – oxidative stress or apoptosis. The findings are commented in the light of our current understanding of uniformity/variability in cell responses to different stimuli. Specificities in the conceptual and technical approaches to human mitochondrial proteomics are also outlined.
Proteomics insights into plant signaling and development
Authors: Kaufmann Kerstin , Smaczniak Cezary , de Vries Sacco , Angenent Gerco C. , Karlova Rumyana
Published: December 2010

Mass spectrometry‐based proteomics is used to gain insight into the abundance and subcellular localization of cellular signaling components, the composition of molecular complexes and the regulation of signaling pathways. Multicellular organisms have evolved signaling networks and fast responses to stimuli that can be discovered and monitored by the use of advanced proteomics techniques in combination with traditional functional analysis. Plants are multicellular organisms and products of tightly regulated developmental programmes that respond to environmental conditions and internal cues. Plant development is orchestrated by inter‐ and intracellular signaling molecules, receptors and transcriptional regulators, which act in a temporal and spatially coordinated manner. Here we review recent advances in proteomics applications used to understand complex cellular signaling processes in plants.
Glycan analysis by modern instrumental methods
Authors: Pabst Martin , Altmann Friedrich
Published: December 2010

The oligosaccharides attached to proteins or lipids are among the most challenging analytical tasks due to their complexity and variety. Knowing the genes and enzymes responsible for their biosynthesis, a large but not unlimited number of different structures and isomers of such glycans can be imagined. Understanding of the biological role of structural variations requires the ability to unambiguously determine the identity and quantity of all glycan species. Here, we examine, which analytical strategies – with a certain high‐throughput potential – may come near this ideal. After an expose of the relevant techniques, we try to depict how analytical raw data are translated into structural assignments using retention times, mass and fragment spectra. A method's ability to discriminate between the many conceivable isomeric structures together with the time, effort and sample amount needed for that purpose is suggested as a criterion for the comparative assessment of approaches and their evolutionary stages.
Indacaterol: a long‐acting beta2‐ agonist taken once daily
Authors: Chaplin Steve , Roberts Michael
Published: December 2010

Indacaterol (Onbrez) is a new long‐acting beta2‐agonist taken once daily for the treatment of COPD. In our New products review, Steve Chaplin presents the clinical data relating to its efficacy and adverse effects, and Professor Michael Roberts assesses its place in therapy compared with current treatments. Copyright © 2010 Wiley Interface Ltd
LDA + U and hybrid functional calculations for defects in ZnO, SnO2, and TiO2
Authors: Janotti Anderson , Van de Walle Chris G.
Published: December 2010

We describe and compare defect calculations based on density functional theory within the local density approximation (LDA), the orbital‐dependent LDA + U, and using hybrid functionals. Limitations of the LDA in describing defect formation energies and transition levels are discussed, followed by corrections based on the LDA + U, and the use of the hybrid functional of Heyd, Scuseria, and Ernzerhof (HSE). The band‐gap error in LDA leads to large uncertainties not only in defect transition levels but also in formation energies.

LDA + U provides a partial correction to the band gap and, when combined with LDA, provides an accurate method for predicting transition levels. Formation energies obtained from the LDA + U/LDA approach depend on the ability of LDA + U to correctly describe the position of the band edges on an absolute energy scale. Although computationally demanding, HSE is demonstrated to be a reliable method for predicting structure and electronic properties of semiconductors, including transition levels and formation energies of defects.
Magnetic field induced thermal effect of phonons in graphene
Authors: Peng Feng
Published: December 2010

We investigate the effect of a magnetic field on the thermal properties of phonons in graphene. We calculate the heat capacity of the phonons using a generating functional technique, and find a new phenomenon that a staircase‐like behaviour appears in the change of the phonon heat capacity as well as the thermal conductivity with the temperature. The width and height of each step are related to the magnetic field and the temperature. This may provide a scheme of controlling the thermal properties of graphene by a weak magnetic field.
Catalytic oxidation of CO on Ir(100)
Authors: Erikat I. A. , Hamad B. A. , Khalifeh J. M.
Published: December 2010

Density functional theory (DFT) calculations are performed to investigate the CO oxidation on Ir(100) surface at different CO coverages, 0.125, 0.25, and 0.5 monolayers (ML). The reaction pathway and transition state (TS) are determined using constrained minimization and nudged elastic band (NEB) methods. We found that the CO molecule is significantly more mobile toward O atoms, which causes a weakening of the Ometal bond. The increase of CO coverage leads to a decrease in the activation energy of the reaction and an increase of OaCO distance where O coverage is kept at 0.25 ML.
Stereo vision–based navigation for autonomous surface vessels
Authors: Huntsberger Terry , Aghazarian Hrand , Howard Andrew , Trotz David C.
Published: December 2010

This paper describes a stereo vision–based system for autonomous navigation in maritime environments. The system consists of two key components. The Hammerhead vision system detects geometric hazards (i.e., objects above the waterline) and generates both grid‐based hazard maps and discrete contact lists (objects with position and velocity). The R4SA (robust, real‐time, reconfigurable, robotic system architecture) control system uses these inputs to implement sensor‐based navigation behaviors, including static obstacle avoidance and dynamic target following. As far as the published literature is concerned, this stereo vision–based system is the first fielded system that is tailored for high‐speed, autonomous maritime operation on smaller boats. In this paper, we present a description and experimental analysis of the Hammerhead vision system, along with key elements of the R4SA control system. We describe the integration of these systems onto a number of high‐speed unmanned surface vessels and present experimental results for the combined vision‐based navigation system. © 2010 Wiley Periodicals, Inc.
A learning perspective on intraorganizational knowledge spill‐ins
Authors: Oldroyd James B. , Gulati Ranjay
Published: December 2010

This exploratory study examines the role of intraorganizational knowledge spill‐ins in the process of inferential learning. Drawing on the notions of knowledge reliability (the creation of shared meanings) and validity (the understanding of cause and effect), we explore how organizations learn inferentially in dynamic environments, where active experimentation rather than past experience is the underlying basis for learning. We find that intraorganizational knowledge spill‐ins transfer heuristics crafted by one unit under local conditions of reliability and validity to other units, where they are reinterpreted and repurposed. Intraorganizational knowledge spill‐ins emerge as a mechanism through which reliability and validity are enhanced for organizational learning. Copyright © 2010 Strategic Management Society.
Spillovers, spill‐ins, and strategic entrepreneurship: America's first commercial jet airplane and Boeing's ascendancy in commercial aviation
Authors: Kotha Suresh
Published: December 2010

Building on recent studies on knowledge spillovers and spill‐ins, this study traces the post‐World War II knowledge spillovers during the early days of the modern commercial aviation industry. It examines the impact these spillovers had on opportunity‐ and advantage‐seeking behaviors (i.e., strategic entrepreneurship) of the leading American incumbents: Douglas, Lockheed, Boeing, and a new entrant, de Havilland of Great Britain. Specifically, it highlights the processes triggered by knowledge spillovers that led to internal knowledge generation, innovations and, ultimately, Boeing's ascendancy in commercial aviation. It shows that knowledge spillovers and the concomitant processes they trigger can provide a powerful lens for studying opportunity‐ and advantage‐seeking behavior in incumbents and entrants and the resultant outcomes of this dynamic. This study sensitizes researchers to examine the nuanced and complex interplay among knowledge generation, knowledge spillovers and spill‐ins, and strategic entrepreneurship within a specific industry context to explain performance outcomes. Copyright © 2010 Strategic Management Society.
Rigid Dimers Formed through Strong Interdigitated H‐Bonds Yield Compact 1D Supramolecular Helical Polymers
Authors: Ciesielski Artur , Stefankiewicz Artur R. , Hanke Felix , Persson Mats , Lehn Jean‐Marie , Samorì Paolo
Published: December 2010

Hierarchical self‐assembly of small abiotic molecular modules interacting through noncovalent forces is increasingly being used to generate functional structures and materials for electronic, catalytic, and biomedical applications. The greatest control over the geometry in H‐bond supramolecular architectures, especially in H‐bonded supramolecular polymers, can be achieved by using conformationally rigid molecular modules undergoing self‐assembly through strong H‐bonds. Their binding strength depends on the multiplicity of the H‐bonds, the nature of donor/acceptor pairs and their secondary attractive/repulsive interactions. Here a functionalized molecular module is described, which is capable of self‐associating through self‐complementary H‐bonding patterns comprising four strong and two medium‐strength H‐bonds to form dimers. The self‐association of these phenylpyrimidine‐based dimers through directional H‐bonding between two lateral pyridin‐2(1H)‐one units of neighboring molecules allows the formation of highly compact 1D supramolecular polymers by self‐assembly on graphite. A concentration‐dependent study by scanning tunneling microscopy at the solid–liquid interface, corroborated by dispersion‐corrected density functional studies, reveals the controlled generation of either linear supramolecular 2D arrays, or long helical supramolecular polymers with a high shape persistence.
Preoperative Vitamin D Deficiency Predicts Postoperative Hypocalcemia After Total Thyroidectomy
Authors: Kirkby‐Bott James , Markogiannakis Haridimos , Skandarajah Anita , Cowan Matthew , Fleming Bill , Palazzo Fausto
Published: December 2010

Background

Transient postthyroidectomy hypocalcemia occurs in up to 30% of patients. We evaluated the effect of vitamin D deficiency on postthyroidectomy hypocalcemia.

Methods

Data were collected prospectively between January 2006 and March 2009. A total of 166 consecutive total thyroidectomies were analyzed regarding the relation between preoperative vitamin D3 levels and postoperative corrected calcium levels. Patients were divided into three groups dependent upon the preoperative vitamin D3 level: group 1, <25 nmol/l; group 2, 25–50 nmol/l; group 3, >50 nmol/l (conversion factor of 2.5× between nanomoles per liter and nanograms per milliliter). Hypocalcemia was defined as a postoperative calcium level <2.00 mmol/l (8 mg/dl). Hospital length of stay was recorded.

Results

There was a difference in postoperative hypocalcemia between the three vitamin D3 groups (group 1 (32%) vs. group 2 (24%) vs. group 3 (13%). Hypocalcemia in group 1 (vit D <25 nmol/l, <10 ng/ml) was significantly more likely than in group 3 (vit D >50 nmol/l, >20 ng/ml) (P = 0.025, χ2 test. Vitamin D3 deficiency was also associated with a longer hospital stay (median stay 2 days vs. 1 day, P < 0.001, Wilcoxon rank test).

Conclusions

There is a significant difference in postoperative hypocalcemia rates between those with vitamin D levels >50 nmol/l (>20 ng/ml) and those with a level of <25 nmol/l (<10 ng/ml). Vitamin D deficiency leads to a delay in discharge owing to a higher likelihood of hypocalcemia.
Current Management of Cervical Esophageal Cancer
Authors: Tong Daniel King Hung , Law Simon , Kwong Dora Lai Wan , Wei William I. , Ng Raymond Wai Man , Wong Kam Ho
Published: December 2010

Background

Pharyngo‐laryngo‐esophagectomy (PLE) has been regarded as a standard treatment for cervical esophageal cancer, but the morbidity and mortality rates associated with PLE are substantial. Chemoradiation (CTRT) is widely used to treat esophageal cancer; however, its role in managing cervical esophageal cancer has not been fully elucidated. It was hypothesized that up‐front CTRT could be an effective alternative treatment option to PLE. The purpose of this study was to compare the outcomes of patients with cervical esophageal cancer treated with these two methods.

Methods

Patients with cervical esophageal cancer from 1995 to 2008 were studied. Three main groups were identified: those treated with PLE, those managed with up‐front concurrent chemoradiation, and those not suitable for either PLE or chemoradiation but to whom palliative treatment was offered. The demographics, management strategies, and outcomes of these patients were studied and analyzed.

Results

A total of 107 patients were studied: 87 (81.3%) were men, and the median age was 64 years (range 17–92 years). There were 62 patients who underwent PLE as the primary treatment, 21 had up‐front chemoradiation, and the others had palliative treatment. In the PLE group, curative resection was achieved in 37 (59.7%) patients, 20 of whom had either adjuvant chemoradiation or radiotherapy. The hospital mortality rate was 7.1%. In the chemoradiation group, 10 (47.6%) had tumor down‐staging, 6 of whom achieved a clinically complete response. Among the 11 patients with poor response, 5 required salvage PLE for palliation. Chemoradiation‐associated morbidities included oral mucositis, bilateral vocal cord palsy, esophageal stricture, carotid artery blowout, and permanent hypothyroidism and hypoparathyroidism. The median survival durations of patients in the PLE and chemoradiation groups were 20 and 25 months respectively (P = 0.39).

Conclusions

Up‐front chemoradiation can be an alternative therapeutic strategy to PLE. However, this method is not without drawbacks. A significant proportion also requires salvage surgery. Both PLE and chemoradiation have significant curative as well as palliative role in the management of cervical esophageal cancer and treatment should be individualized.
State of Surgery in Tropical Africa: A Review
Authors: Lavy Chris , Sauven Kathryn , Mkandawire Nyengo , Charian Meena , Gosselin Richard , Ndihokubwayo Jean Bosco , Parry Eldryd
Published: December 2010

This is a review of recently published literature on surgery in tropical Africa. It presents the current state of surgical need and surgical practice on the continent. We discuss the enormous burden of surgical pathology (as far as it is known) and the access to and acceptability of surgery. We also describe the available facilities in terms of equipment and manpower. The study looked at the effects of the human immunodeficiency virus, the role of traditional healers, anesthesia, and the economics of surgery. Medical training and research are discussed, as are medical migration out of Africa and the concept of task shifting, where surgical procedures are performed by others when surgeons are not available. It closes with recommendations for involvement and action in this area of great global need.
Anatomical Versus Nonanatomical Resection of Colorectal Liver Metastases: Is There a Difference in Surgical and Oncological Outcome?
Authors: Lalmahomed Zarina S. , Ayez Ninos , van der Pool Anne E. M. , Verheij Joanne , IJzermans Jan N. M. , Verhoef Cornelis
Published: December 2010

Background

The increased use of neoadjuvant chemotherapy and minimally invasive therapies for recurrence in patients with colorectal liver metastases (CLM) makes a surgical strategy to save as much liver volume as possible pivotal. In this study, we determined the difference in morbidity and mortality and the patterns of recurrence and survival in patients with CLM treated with anatomical (AR) and nonanatomical liver resection (NAR).

Methods

From January 2000 to June 2008, patients with CLM who underwent a resection were included and divided into two groups: patients who underwent AR, and patients who underwent NAR. Patients who underwent simultaneous radiofrequency ablation in addition to surgery and patients with extrahepatic metastasis were excluded. Patient, tumor, and treatment data, as well as disease‐free and overall survival (OS) were compared.

Results

Eighty‐eight patients (44%) received AR and 113 patients (56%) underwent NAR. NAR were performed for significant smaller metastases (3 vs. 4 cm, P < 0.001). The Clinical Risk Score did not differ between the groups. After NAR, patients received significantly less blood transfusions (20% vs. 36%, P = 0.012), and the hospital stay was significantly shorter (7 vs. 8 days, P < 0.001). There were no significant differences in complications, positive resection margins, or recurrence. For the total study group, estimated 5‐year disease‐free and OS was 31 and 44%, respectively, with no difference between the groups.

Conclusions

Our study resulted in no significant difference in morbidity, mortality, recurrence rate, or survival according to resection type. NAR can be used as a save procedure to preserve liver parenchyma.
Outcomes for Lymph Node‐Positive Cutaneous Melanoma Over Two Decades
Authors: Martinez Steve R. , Tseng Warren H. , Young Shawn E.
Published: December 2010

Background

Our aim was to demonstrate that, despite advances in treatment and surveillance of node‐positive cutaneous melanoma, rates of overall survival (OS) and melanoma‐specific survival (MSS) have not changed over the last two decades.

Methods

We used the Surveillance, Epidemiology, and End Results (SEER) database of the National Cancer Institute to identify patients with node‐positive cutaneous melanoma. Patients were categorized by treatment era; the first era encompassed patients diagnosed from 1988 to 1999 and the second era 2000 to 2006. Multivariate Cox proportional hazards models compared rates of OS and MSS between treatment eras while controlling for known prognostic factors. We reported risks of death as hazard ratios (HR) with 95% confidence intervals (CI) and set significance at P ≤ 0.05.

Results

Entrance criteria were met by 6,868 patients, 1,631 (23.8%) treated in era I and 5,237 (76.3%) treated in era II. On multivariate analysis, era II patients did not demonstrate a significantly different risk of death from any cause (HR 0.89, CI 0.79–1.01; P < 0.08), but they did have a lower risk of melanoma‐specific mortality (HR 0.81, CI 0.71–0.93; P = 0.003) relative to their era I counterparts.

Conclusions

Over nearly two decades, MSS but not OS has improved for AJCC stage III melanoma patients. Stage migration is likely responsible for any improvement in MSS among patients in the most recently diagnosed era.
Current status of endoscopic papillary balloon dilation for the treatment of bile duct stones
Authors: Aiura Koichi , Kitagawa Yuko
Published: December 2010

Background/purpose

While endoscopic sphincterotomy (EST) is performed worldwide for the removal of common bile duct stones, many biliary endoscopists hesitate to regard endoscopic papillary balloon dilation (EPBD) as a standard procedure for treatment. Therefore, the aim of this review is to re‐evaluate the status of EPBD for the treatment of common bile duct stones.

Results

A major benefit of EPBD is preservation of papillary function, which is not complete but may be greater than that after EST. The disadvantages of EPBD compared with EST are that EPBD is difficult to use for the removal of larger stones because of the smaller biliary opening, it requires more frequent use of mechanical lithotripsy, and it is associated with a higher incidence of pancreatitis, although the risks of bleeding and perforation are low. Since the biliary sphincter is easily dilated with a balloon catheter, EPBD may be effective for patients with anatomic anomalies, such as after gastric bypass surgery or in the presence of a periampullary diverticulum. No standard procedure exists to reduce the risk of acute pancreatitis with EPBD.

Conclusion

EPBD is feasible, however, we must pursue less hazardous techniques of papillary balloon dilation. Furthermore, we must understand the benefits and limitations of EPBD and determine whether it could provide clinical benefits for long‐term complications.
Danon disease: intrafamilial phenotypic variability related to a novel LAMP‐2 mutation
Authors: Cottinet Sarah‐Louise , Bergemer‐Fouquet Anne‐Marie , Toutain Annick , Sabourdy Frédérique , Maakaroun‐Vermesse Zoha , Levade Thierry , Chantepie Alain , Labarthe François
Published: December 2010

Danon disease is an X‐linked lysosomal disorder, characterized by hypertrophic cardiomyopathy, skeletal myopathy and mental retardation. We report a family with a novel mutation, in which the mother and her three sons were affected with various clinical presentations. A massive hypertrophy of the left ventricle was the predominant feature in the three male patients, with different degrees of severity of cardiac symptoms, from isolated palpitations to cardiac failure and sudden death. Muscle pain and weakness were also variable, but constantly associated with increased plasma CK levels. Finally, the male patients had variable degree of a mental retardation. The mother had an attenuated phenotype, limited to a mild hypertrophic cardiomyopathy with premature ventricular contractions diagnosed during her 40’s. Microscopy examination of skeletal muscle biopsy, performed in the youngest patient, demonstrated atrophic myofibers with intracytoplasmic vacuoles suggesting lysosomal glycogen storage disease. Immunohistochemistry analyses in muscle specimen showed no detectable Lysosomal‐Associated Membrane Protein‐2 (LAMP‐2), in keeping with the diagnosis of Danon disease. However, a very low expression of a shortened LAMP‐2 protein could be evidenced by Western‐blot in the patient's fibroblasts. Molecular investigations identified a novel splicing mutation (IVS6 + 1delG) in the LAMP‐2 gene. This case report highlights the intrafamilial variability of Danon disease phenotype. In this case, morphological examination of muscle biopsy, showing lysosomal storage myopathy, and immunohistochemistry analyses can provide key elements for orienting etiologic investigations.
Serum Lipoprotein(a) Levels are Greater in Female than Male Patients with Type‐2 Diabetes
Authors: Nakhjavani Manouchehr , Morteza Afsaneh , Esteghamati Alireza , Khalilzadeh Omid , Zandieh Ali , Safari Reza
Published: December 2010

Women with diabetes are faced with a higher risk of dyslipidemia and cardiovascular disorders than men with diabetes. We aimed to study the role of gender and menopausal status in serum Lp(a) levels in patients with type 2 diabetes. We quantified serum Lp(a) levels in a group of 477 patients with type 2 diabetes (men, premenopausal and postmenopausal women with diabetes), as well as in 105 controls. We stratified the patients into two groups of low Lp(a) levels (Lp(a) <35 mg/dl) and elevated Lp(a) levels (Lp(a) >35 mg/dl). Patients with diabetes had higher serum Lp(a) levels than the controls. Serum Lp(a) levels was significantly higher in women with diabetes than men with diabetes. Lp(a) levels did not differ between male and females in the control group. Premenopausal and postmenopausal women with diabetes did not differ significantly in serum Lp(a) levels. The odds ratio of having a serum Lp(a) level higher than 35 was 5.85 in premenopausal women with diabetes, 5.08 in postmenopausal women with diabetes, 2.41 in men with diabetes and 1.9 in the women in the control group compared to the men in the control group, after adjustment for age and BMI. This observational study clearly indicated that serum Lp(a) levels were significantly higher in women and men with diabetes. The increase in women was independent of menopause. The level of serum Lp(a) had no correlation with lipid parameters in men or women.
Hydrolysis of Fish Oil by Lipases Immobilized Inside Porous Supports
Authors: Fernández‐Lorente Gloria , Pizarro Carolina , López‐Vela Dolores , Betancor Lorena , Carrascosa Alfonso V. , Pessela Benevides , Guisan Jose M.
Published: December 2010

A new assay was designed to measure the release of omega‐3 acids [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] from the hydrolysis of sardine oil by lipases immobilized inside porous supports. A biphasic system was used containing the fish oil dissolved in the organic phase and the immobilized lipase suspended in the aqueous phase. The assay was optimized by using a very active derivative of Rhizomucor miehei lipase (RML) adsorbed onto octyl‐Sepharose. Standard reaction conditions were: (a) an organic phase composed by 30/70 (v:v) of oil in cyclohexane, (b) an aqueous phase containing 50 mM methyl‐cyclodextrin in 10 mM Tris buffer at pH 7.0. The whole reaction system was incubated at 25 °C. Under these conditions, up to 2% of the oil is partitioned into the aqueous phase and most of the 95% of released acids were partitioned into the organic phase. The organic phase was analyzed by RP‐HPLC (UV detection at 215 nm) and even very low concentrations (e.g., 0.05 mM) of released omega‐3 fatty acid could be detected with a precision higher than 99%. Three different lipases adsorbed on octyl‐Sepharose were compared: Candida antarctica lipase‐fraction B (CALB), Thermomyces lanuginosa lipase (TLL) and RML. The three enzyme derivatives were very active. However, most active and selective towards polyunsaturated fatty acids (PUFA) versus oleic plus palmitic acids (a fourfold factor) was CALB. On the other hand, the most selective derivatives towards EPA versus DHA (a 4.5‐fold factor) were TLL and RML derivatives.
Measurement of the Oxidation Stability of Biodiesel Using a Modified Karl Fischer Apparatus
Authors: Jain Siddharth , Sharma M. P.
Published: December 2010

Oxidative stability is an important parameter in the characterisation of fats and oils. The determination of this parameter with a Rancimat apparatus is very costly. The alternative modified Karl Fischer (KF) apparatus works on the same principle as the Rancimat, i.e., a conductivity based determination of volatile degradation products and automatic plotting of the conductivity against time. The apparatuses were compared by taking five different samples of methyl esters at different temperature ranges. The results indicate that the modified KF apparatus can be used for the determination of oxidation stability of biodiesel with comparable values of sensitivity, repeatability and reproducibility.
Treatment outcome in the most severely affected Legg-Perthes patients, comparing prolonged traction in abduction with femoral varus derotation treatment
Authors: Wagenaar F. B. M. , Maathuis C. G. B. , van Erve R. H. G. P.
Published: December 2010

Purpose

Compare conservative and operative treatment in the most severely affected Legg-Perthes disease patients.

Methods

29 patients (14 conservative and 15 operative) with 32 affected hips (16 conservative and 16 operative) were evaluated, all Catterall 3 or 4. The conservative group, with a median age-at-onset of 4.8 (range, 2.5–9.5) years, was treated by a rigorous regime of traction in abduction for an average of two years. Follow-up was performed at a median of 28.6 (range, 17.4–31.6) years with a median patient age of 34.1 (range, 19.9–39.3) years. The operative group, with a median age-at-onset of 4.7 (range, 2.0–7.8) years, was treated by femoral varus derotation osteotomy. Follow-up was performed at a median of 14 (range, 8–21.4) years, with a median patient age of 20.7 (range, 12.8–28) years.

Results

Median age-at-onset ( P = 0.16) and Catterall classification ( P = 0.29) were comparable. No differences could be found for the Stulberg classification ( P = 0.83), functional parameters (Harris Hip score and Merle d'Aubigné and Postel), and leg–length differences. Career choices were similar for both patient groups, as well.

Conclusions

Given methodological issues, femoral varus derotation osteotomy did not show apparent better results than the conservative containment regime in Catterall 3 and 4 patients with a median age-at-onset around 4.8 years. This result is fairly similar to recent literature suggesting a conservative approach in most severely affected patients with a young age-at-onset. However, based on unacceptable socioeconomic issues, the conservative regime evaluated in the present study cannot be justified, nowadays.
Statistical approaches for reconstructing neuro-cognitive dynamics from high-dimensional neural recordings
Authors: Durstewitz D. , Balaguer-Ballester E.
Published: December 2010

Recent advances in multiple single-unit re­cording and optical imaging techniques now routinely enable observation of the activi­ty from tens to hundreds of neurons simulta­neously. The result is high-dimensional mul­tivariate time series which offer an unprece­dented range of possibilities for gaining in­sight into the detailed spatio-temporal neu­ral dynamics underlying cognition. For in­stance, they may pave the way for reliable single-trial analyses, for investigating the role of higher-order correlations in neural coding, the mechanisms of neural ensemble forma­tion, or more generally of transitions among attractor states accompanying cognitive pro­cesses. At the same time, exploiting the infor­mation in these multivariate time series may require more sophisticated statistical meth­ods beyond the commonly employed rep­ertoire. Here we review, using specific ex­perimental examples, some of these meth­ods for visualizing structure in high-dimen­sional data sets, for statistical inference about the apparent structure, for single-trial analy­sis of neural time series, and for reconstruct­ing some of the dynamical properties of neu­ral systems that can only be inferred from si­multaneous recordings.
Do parents and peers matter? A prospective socio‐ecological examination of substance use and sexual risk among African American youth
Authors: Elkington Katherine S. , Bauermeister José A. , Zimmerman Marc A.
Published: December 2010

We examined the direct contribution of parent and peer risk and promotive factors on youth condom use trajectories, in addition to the indirect influence of these factors via youth's substance use over four years in a sample of urban, African American youth (N = 679; 51% female; M = 14.86 years; SD = 0.65). Growth curve modeling was used to estimate changes in substance use and sexual risk across adolescence and test their association with parent and peer factors. Parent and peer risk factors were strongly associated with increasing substance use as youth aged. Substance use and condom use were interrelated. Parent and peer risk factors were indirectly associated with youth condom use; parent and peer promotive factors were directly associated with condom use, after accounting for substance use. Findings suggest the value of considering multiple influences on youth risk behavior.
Second Wave Reform in Alberta
Authors: Duckett Stephen
Published: December 2010

Alberta Health Services formally came into existence on April 1, 2009, potentially signaling the start of a new wave of health restructuring in Canada. This article situates that change in the context of international trends in health restructuring and reviews some of the challenges faced by the new organization.