bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel quantization‐based spectrum sensing scheme under imperfect reporting channel and false reports
Authors: Birkan Yilmaz H. , Tugcu Tuna , Alagoz Fatih 
Published: July 2012

SUMMARYIn this paper, a novel sensing scheme, uniform quantization for cooperative sensing (UniQCS), that employs a uniform quantizer is proposed. UniQCS is based on energy detection and uses weight vector for global decision function. It performs better than hard decision algorithms such as majority and k‐out‐of‐n in terms of probability of detection and false alarm at the cost of a marginal increase in overhead bits under imperfect reporting channel and false reports. The probability of detection is maximized for a given probability of false alarm constraint by the proposed method. For detailed analysis, the UniQCS is compared with equal gain combiner scheme, which performs far better than hard decision algorithms, via highest bandwidth requirement. The proposed algorithm performs close to equal gain combiner. Moreover, the robustness of UniQCS to sensing error is analyzed when some nodes always report false decisions to the fusion center and the reporting channel is imperfect. For probability of false alarm equal to 0.01, performance gain of UniQCS is at least 45% compared with the other methods when there are two false reporting nodes. UniQCS performance gain is at least 15% compared with other methods for probability of reporting channel error equal to 0.001. Copyright © 2012 John Wiley & Sons, Ltd.
CoII/ZnII–(L‐Tyrosine) Magnetic Metal–Organic Frameworks
Authors: Zhou Bo , Silva Nuno J. O. , Shi Fa‐Nian , Palacio Fernando , Mafra Luís , Rocha João 
Published: July 2012

AbstractThree chiral coordination polymers assembled from L‐tyrosine (L‐tyr) and cobalt, cobalt/zinc and zinc salts, with a new three‐dimensional (3D) structure and formulated as [M(L‐tyr)]n (M = Co, Co/Zn, Zn) have been prepared by mild hydrothermal synthesis. These three compounds are isostructural, crystallize with monoclinic symmetry in the C2 space group and possess four crystallographically unique metal sites in tetrahedral (two) and octahedral (two) coordination environments resulting in two slightly distinct edge‐sharing metal dimers with L‐tyr linking the metal atoms in pillars. These features result in a dense framework. The study of the magnetic properties of the cobalt‐bearing solid reveals a ferromagnetic exchange interaction within the Co2+ dimers. The racemic compound of dl‐tyrosine and cobalt was also synthesized and its structure characterized.
α,ω‐Di([5]trovacenyl) Sulfides TVC–Sn–TVC (n = 1–4) and TVC–SCH2S–TVC: a Study in Intramolecular Communication
Authors: Elschenbroich Christoph , Lu Feng , Harms Klaus , Burghaus Olaf , Pietzonka Clemens , Pebler Jürgen 
Published: July 2012

AbstractThe oligosulfur‐bridged dinuclear paramagnetic complexes di([5]trovacenyl) sulfide (3··), di([5]trovacenyl) trisulfide (5··), di([5]trovacenylthio)methane (6··), and di([5]trovacenyl) tetrasulfide (7··) have been prepared by the metathesis reactions of [5]trovacenyllithium with SCl2, and [5]lithiotrovacenylthiolate (2·) with SCl2, CH2Cl2, and S2Cl2, respectively, in which 2· was obtained by the reaction of [5]trovacenyllithium with 1 equiv. of elemental sulfur at ambient temperature. Combined with the previously reported di([5]trovacenyl) disulfide (4··), these complexes have been systematically investigated by means of cyclic voltammetry, electron paramagnetic resonance (EPR) spectroscopy, magnetic susceptometry, and/or X‐ray diffraction analysis, which reveal weak antiferromagnetic spin–spin exchange interactions. The monosulfur‐bridged 3··, in particular, displays the strongest intramolecular spin–spin exchange interaction of |JEPR| = 2.8 cm–1 and Jχ = –1.39 cm–1. This study also indicates that with an increasing number of sulfur atoms in the bridge, the intramolecular communication of biradicals throught the 1D saturated sulfur atom bridge significantly weakens both in solution and in the solid state compared to those of unsaturated carbon‐based bridges.
Palladium‐Catalyzed Improved Regio‐ and Stereoselective O‐Glycosylation of D‐Glucal‐Derived β‐ and α‐Vinyl Oxiranes
Authors: Reddy Y. Suman , Lahiri Rima , Vankar Yashwant D. 
Published: July 2012

AbstractA Pd0‐catalyzed glycosylation of D‐glucal‐derived vinyloxiranes as excellent glycosyl donors has been accomplished in a regio‐ and stereoselective manner. Various glycosyl acceptors upon reaction with vinyl oxiranes 1a and 1b produced the corresponding 2,3‐unsaturated O‐glycosides in good to excellent yields within five minutes. The above reaction has also been utilized in the synthesis of 2,3‐unsaturated trisaccharides, which are potential precursors of fully oxygenated, deoxy and dideoxy sugars.
Seismic response of a bridge–soil–foundation system under the combined effect of vertical and horizontal ground motions
Authors: Wang Zhenghua , Dueñas‐Osorio Leonardo , Padgett Jamie E. 
Published: July 2012

SUMMARYDifferent levels of model sophistication have recently emerged to support seismic risk assessment of bridges, but mostly at the expense of neglecting the influence of vertical ground motions (VGMs). In this paper, the influence of VGMs on bridge seismic response is presented and the results are compared with the case of horizontal‐only excitations. An advanced finite element model that accounts for VGMs is first developed. Then, to investigate the effect of soil–structure interaction (SSI) including liquefaction potential, the same bridge with soil‐foundation and fixed boundary conditions is also analyzed. Results show that the inclusion of the VGMs has a significant influence on the seismic response, especially for the axial force in columns, normal force of bearings, and the vertical deck bending moments. However, VGMs do not have as much influence on the seismic demand of the pile cap displacements or pile maximum axial forces. Also, the significant fluctuation of the column axial force can reduce its shear and flexural capacity, and a heightened reversal of flexural effects may induce damage in the deck. In addition, relative to the fixed base case, SSI effects tend to reduce response quantities for certain ground motions while increasing demands for others. This phenomenon is explained as a function of the frequency content of the ground motions, the shift in natural vertical periods, and the VGM spectral accelerations at higher modes. Moreover, the mechanisms of liquefaction are isolated relative to SSI effects in nonliquefiable soils, revealing the influence of liquefaction on bridge response under VGMs. Copyright © 2012 John Wiley & Sons, Ltd.
Analysis of the sources of uncertainty for portfolio‐level earthquake loss estimation
Authors: Aslani Hesaam , Cabrera Carlos , Rahnama Mohsen 
Published: July 2012

SUMMARYEarthquake catastrophe models provide probabilistic estimations of building portfolio losses that result from seismic hazards. Models that are designed to be used with large numbers of buildings often implicitly account for uncertainty associated with model components, but do not allow for an explicit comparison of different sources of uncertainty. We propose probabilistic methodologies that allow for explicit differentiation of the uncertainty in estimated portfolio losses as a function of the uncertainties associated with seismic hazard and building vulnerability. Our work is motivated by recent earthquakes in New Zealand and Japan, which highlighted the importance of understanding the sources of uncertainty that contribute to portfolio‐level loss estimates. The proposed methodologies allow us to differentiate seismic risk between building portfolios as a function of the level of knowledge (epistemic) uncertainty associated with modeling seismic rates and the levels of aleatory variability and epistemic uncertainty associated with the buildings' vulnerabilities. A sample analysis incorporates epistemic uncertainty corresponding to Southern California's seismic rates into modeled losses for a Southern California building portfolio and then compares the impact of that particular source of uncertainty to the results from a portfolio in Northern California. For sources of uncertainty associated with buildings' vulnerability, we use our methodology to compare the impacts of aleatory and epistemic uncertainties on estimated portfolio losses as a function of the buildings' attributes, including their types of construction and numbers of stories. Component uncertainties (i.e., uncertainties corresponding to the seismic hazard and vulnerability) are assumed for our analyses so that the methodologies can be demonstrated. Copyright © 2012 John Wiley & Sons, Ltd.
Viral load, physical status, and E6/E7 mRNA expression of human papillomavirus in head and neck squamous cell carcinoma
Authors: Deng Zeyi , Hasegawa Masahiro , Kiyuna Asanori , Matayoshi Sen , Uehara Takayuki , Agena Shinya , Yamashita Yukashi , Ogawa Kazuhiko , Maeda Hiroyuki , Suzuki Mikio 
Published: July 2012

AbstractBackgroundThe purpose of this study was to determine prospectively both human papillomavirus (HPV) load and physical status in different types of head and neck squamous cell carcinoma (HNSCC).MethodsHPV DNA, E6/E7 mRNA expression, viral load, and physical status of 184 patients with HNSCC were examined simultaneously by polymerase chain reaction (PCR)‐based methods.ResultsThe HPV genome was detected in 54 HNSCC samples (29.3%), particularly in tonsillar carcinomas (69.6%). Compared with nonoropharyngeal HNSCC, oropharyngeal carcinoma harbored a relatively higher viral load, especially in tonsillar carcinoma. Although integrated or mixed status was observed in 75.6% of HPV‐16–positive samples, E6/E7 mRNA transcripts were detected in only 27.5% of HPV DNA‐positive cases. High HPV‐16 load correlated significantly with E6/E7 mRNA expression.ConclusionE6/E7 mRNA expression in patients with HNSCC with low viral load remains low even in cases of integration to the host genome. Tonsillar carcinomas were significantly associated with HPV among various types of HNSCC. © 2012 Wiley Periodicals, Inc. Head Neck, 2012
Tonsillar carcinoma metastatic to the spleen presenting as trauma: A case report
Authors: Lee Janet T. , Hugec Vladimir , McGuire Warren , Gendron Kristin , Semmler Steven , Endorf Frederick W. 
Published: July 2012

AbstractBackground. Cancers of the head and neck rarely metastasize to the spleen. To the best of our knowledge, there is no reported case of a tonsillar carcinoma metastasizing to the spleen. Method and Results. This patient had a splenic capsular rupture likely related to his metastases that presented as a traumatic splenic injury. The patient had received neoadjuvant chemotherapy followed by concurrent chemoradiotherapy. Two months after completion of radiotherapy, he fell out of bed. The next day he had acute abdominal pain and hypotension. CT findings were consistent with splenic rupture, and he underwent splenectomy. Pathologic assessment of the specimen showed metastatic SCC. Conclusion. New splemic lesions in patients with head and neck cancer should be investigated. Head Neck, 2013
Phase II 2‐arm trial of the proteasome inhibitor, PS‐341 (bortezomib) in combination with irinotecan or PS‐341 alone followed by the addition of irinotecan at time of progression in patients with locally recurrent or metastatic squamous cell carcinoma of the head and neck (E1304): A trial of the Eastern Cooperative Oncology Group
Authors: Gilbert Jill , Lee Ju Whei , Argiris Athanassios , Haigentz Missak , Feldman Lawrence Eric , Jang Minyoung , Arun Pattatheyil , Van Waes Carter , Forastiere Arlene A. 
Published: July 2012

AbstractBackgroundConstitutive activation of nuclear factor κB (NF‐κB) is associated with poor prognosis. Irinotecan demonstrates single‐agent activity in head and neck cancer but activates NF‐κB, promoting cell survival and resistance. Bortezomib is a proteasome inhibitor that inactivates NF‐κB.Patients and MethodsWe performed a randomized phase II trial of bortezomib on days 1, 4, 8, and 11 and irinotecan on days 1 and 8 of each 21‐day cycle or single‐agent bortezomib on days 1, 4, 8, and 11 on a 21‐day cycle. The addition of irinotecan to bortezomib was allowed in patients who progressed on bortezomib alone.ResultsThe response rate of bortezomib and irinotecan was 13%. One patient had a partial response to bortezomib alone (response rate 3%). No responses were seen in patients with addition of irinotecan at time of progression on bortezomib.ConclusionsThe bortezomib‐based regimens evaluated in this study have minimal activity in recurrent or metastatic head and neck cancer. Head Neck, 2013
Intraoperative cone‐beam CT for head and neck surgery: Feasibility of clinical implementation using a prototype mobile C‐arm
Authors: King Emma , Daly Michael J. , Chan Harley , Bachar Gideon , Dixon Benjamin J. , Siewerdsen Jeffrey H. , Irish Jonathan C. 
Published: July 2012

AbstractBackgroundIntraoperative 3‐dimensional (3D) imaging in head and neck surgery was developed using a prototype mobile C‐arm for cone‐beam CT (CBCT). This article summarizes its implementation in a prospective pilot and feasibility study.MethodsThe CBCT C‐arm was used in 12 head and neck surgical oncology cases. Human‐factors engineering methods and expert feedback from surgeons, nurses, and anesthetists were used to evaluate the impact of intraoperative imaging on the surgical environment and clinical workflow. Image quality of CBCT and the perceived clinical utility were evaluated.ResultsThe CBCT C‐arm was successfully incorporated in 12 head and neck cases and streamlined into the surgical environment. Reviewed 3D‐CBCT images were qualitatively sufficient for intraoperative‐guidance for bony detail. Additional artifact management is required to improve soft‐tissue visualization.ConclusionsIntraoperative CBCT provides high‐quality images for visualization of bony detail and is feasible during major head and neck surgery with acceptable workflow interruptions. Operations with significant bone ablation and/or reconstruction involving complex 3D anatomical structures are likely to benefit from the updated imaging. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Orosphere assay: A method for propagation of head and neck cancer stem cells
Authors: Krishnamurthy Sudha , Nör Jacques E. 
Published: July 2012

AbstractBackgroundRecent evidence suggests that head and neck squamous cell carcinomas (HNSCCs) harbor a small subpopulation of highly tumorigenic cells, designated cancer stem cells. A limiting factor in cancer stem cell research is the intrinsic difficulty of expanding cells in an undifferentiated state in vitro.MethodsHere, we describe the development of the orosphere assay, a method for the study of putative head and neck cancer stem cells. An orosphere is defined as a nonadherent colony of cells sorted from primary HNSCCs or from HNSCC cell lines and cultured in 3‐dimensional soft agar or ultralow attachment plates. Aldehyde dehydrogenase activity and CD44 expression were used here as stem cell markers.ResultsThis assay allowed for the propagation of head and neck cancer cells that retained stemness and self‐renewal.ConclusionThe orosphere assay is well suited for studies designed to understand the pathobiology of head and neck cancer stem cells. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Impact of secondary lymphedema after head and neck cancer treatment on symptoms, functional status, and quality of life
Authors: Deng Jie , Murphy Barbara A. , Dietrich Mary S. , Wells Nancy , Wallston Kenneth A. , Sinard Robert J. , Cmelak Anthony J. , Gilbert Jill , Ridner Sheila H. 
Published: July 2012

AbstractBackgroundLymphedema may disrupt local function and affect quality of life (QOL) in patients with head and neck cancer. The purpose of this study was to examine the associations among severity of internal and external lymphedema, symptoms, functional status, and QOL in patients with head and neck cancer.MethodsThe sample included 103 patients who were ≥3 months after head and neck cancer treatment. Variables assessed included severity of internal and external lymphedema, physical/psychological symptoms, functional status, and QOL.ResultsSeverity of internal and external lymphedema was associated with physical symptoms and psychological symptoms. Patients with more severe external lymphedema were more likely to have a decrease in neck left/right rotation. The combined effects of external and internal lymphedema severity were associated with hearing impairment and decreased QOL.ConclusionsLymphedema severity correlates with symptom burden, functional status, and QOL in patients after head and neck cancer treatment. Head Neck, 2013
Asymmetric Counteranion‐Directed Catalysis (ACDC): A Remarkably General Approach to Enantioselective Synthesis
Authors: Mahlau Manuel , List Benjamin 
Published: July 2012

AbstractAsymmetric counteranion‐directed catalysis (ACDC) is a powerful new concept, which can potentially be used to achieve enantioselectivity in any type of reaction proceeding through positively charged intermediates. It has already been applied in different areas of catalysis, such as organocatalysis, transition‐metal catalysis, and Lewis acid catalysis. Due to its complementarity with traditional approaches to achieve enantioselection, ACDC holds special promise for long‐standing challenges from all areas of catalysis, where matched cases can be designed. ACDC also represents a new way of thinking during method development, which could be of help to chemists from a variety of research areas.
Supramolecular Self‐Assembled Ligands in Asymmetric Transition Metal Catalysis
Authors: Bellini Rosalba , van der Vlugt Jarl Ivar , Reek Joost N. H. 
Published: July 2012

AbstractThe design of novel chiral ligands is at the core of asymmetric catalysis. The catalytic characteristics of a transition metal catalyst such as activity, selectivity and stability can be fine‐tuned by optimization of the steric and electronic properties of the coordinating ligands. In asymmetric transformations, catalyst optimization still relies to a large extent on trial‐and‐error and educated guesses. New strategies based on combinatorial screening and high‐throughput experimentation have been introduced for the design and optimization of new ligands and catalytic systems. Supramolecular bidentate ligands that form by self‐assembly of building blocks are particularly suited for this combinatorial approach as the potential number of catalysts grows exponentially with the number of building blocks synthesized. Catalytic systems based on supramolecular interactions have proven to be highly advantageous in creating large ligand libraries for high‐throughput screening, which allows optimization of activity and selectivity for a variety of reactions. In this review we describe the progress in this field.
Influence of the antifolate drug Methotrexate on the development of murine neural tube defects and genomic instability
Authors: Zhao Jie , Guan Tao , Wang Jianhua , Xiang Qian , Wang Mingsheng , Wang Xiuwei , Guan Zhen , Xie Qiu , Niu Bo , Zhang Ting 
Published: July 2012

ABSTRACTImpaired folate metabolism is considered a risk factor for neural tube defects (NTDs). However, the relationship between folate deficiency and the risk of NTDs remains unclear, because experimentally induced dietary folate deficiency is insufficient to cause NTDs in non‐mutant mice. Methotrexate (MTX) is a specific folate antagonist that competitively inhibits dihydrofolate reductase (DHFR) activity. The objective of this study was to develop a folate dysmetabolism murine model, and study the development of NTDs and its mechanism. Pregnant mice were injected with different doses of MTX [0, 0.5, 1.0, 3.0, 4.5 and 6.0 mg kg–1 body weight (b/w) intraperitoneally (i.p.)] on gestational day 7.5 and sacrificed on gestational day 11.5. DHFR activity in embryonic tissues was detected, and folate concentrations were analyzed using LC/MS/MS. Copy number variations (CNVs) in neural tube tissues were detected using array comparative genomic hybridization (aCGH). A dose of MTX 4.5 mg kg–1 b/w, resulted in the highest incidence of NTDs (31.4%) compared with the other groups, and DHFR activities, 5‐MeTHF and 5‐FoTHF concentrations in embryonic tissues decreased significantly after MTX injection. Furthermore, we found three high‐confidence CNVs on chromosome X using aCGH, which was confirmed by RT‐PCR and MassARRAY. These results indicate that MTX could cause a folate‐associated dysmetabolism, which is similar to that of dietary folate deficiency in mice. The presence of CNVs in neural tube tissues was associated with the development of NTDs. Copyright © 2012 John Wiley & Sons, Ltd.
Toxicogenomics discrimination of potential hepatocarcinogenicity of non‐genotoxic compounds in rat liver
Authors: Yamada Fumihiro , Sumida Kayo , Uehara Takeki , Morikawa Yuji , Yamada Hiroshi , Urushidani Tetsuro , Ohno Yasuo 
Published: July 2012

ABSTRACTLong‐term carcinogenicity testing of a compound is exceedingly time‐consuming and costly, and requires many test animals, whereas the Ames test, which is based on the assumption that any substance that is mutagenic may also exert carcinogenic potential, is useful as a short‐term screening assay but has major drawbacks. Although, in fact, 90% of compounds that give a positive Ames test cause cancer in laboratory animals, a good proportion of compounds that give a negative Ames test are also carcinogens; that is, there is no good correlation between carcinogenicity and negative Ames test results. As an alternative to these two approaches, we have tried applying toxicogenomics to predict the carcinogenicity of a compound from the gene expression profile induced in vivo. To establish our model, male Sprague–Dawley rats were orally administered test compounds (12 hepatocarcinogens and 26 non‐hepatocarcinogens) for 28 days. Analysis of liver gene expression data by Support Vector Machines (SVM) dividing compounds into ‘for training’ and ‘for test’ (20 cases assigned randomly) allowed a set of marker genes to be tested for prediction of hepatocarcinogenicity. The developed prediction model was then validated with reference to the concordance rate with training data and test data, and a good performance was obtained. We will have new gene expression data and continue the validation of our model. Copyright © 2012 John Wiley & Sons, Ltd.
From molecular structure to tissue architecture: collagen organization probed by SHG microscopy
Authors: Cicchi Riccardo , Vogler Nadine , Kapsokalyvas Dimitrios , Dietzek Benjamin , Popp Jürgen , Pavone Francesco Saverio 
Published: July 2012

AbstractSecond‐harmonic generation (SHG) microscopy is a fantastic tool for imaging collagen and probing its hierarchical organization from molecular scale up to tissue architectural level. In fact, SHG combines the advantages of a non‐linear microscopy approach with a coherent modality able to probe molecular organization. In this manuscript we review the physical concepts describing SHG from collagen, highlighting how this optical process allows to probe structures ranging from molecular sizes to tissue architecture, through image pattern analysis and scoring methods. Starting from the description of the most relevant approaches employing SHG polarization anisotropy and forward – backward SHG detection, we then focus on the most relevant methods for imaging and characterizing collagen organization in tissues through image pattern analysis methods, highlighting advantages and limitations of the methods applied to tissue imaging and to potential clinical applications. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)