bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficacy of a multidisciplinary fibromyalgia treatment adapted for women with low educational levels: A randomized controlled trial
Authors: Castel Antoni , Fontova Ramon , Montull Salvador , Periñán Rocío , Poveda Maria José , Miralles Iris , Cascón‐Pereira Rosalia , Hernández Pilar , Aragonés Natalia , Salvat Isabel , Castro Sonia , Monterde Sonia , Padrol Anna , Sala José , Añez Cristóbal , Rull Maria
Published: November 2012

Objective

Multidisciplinary treatments of fibromyalgia (FM) have demonstrated efficacy. Nevertheless, they have been criticized for not maintaining their benefits and for not being studied for specific populations. Our objectives were to determine the efficacy of a multidisciplinary treatment for FM adapted for patients with low educational levels and to determine the maintenance of its therapeutic benefits during a long‐term followup period.

Methods

Inclusion criteria consisted of female sex, a diagnosis of FM (using American College of Rheumatology criteria), age between 18 and 60 years, and between 3 and 8 years of schooling. Patients were randomly assigned to 1 of the 2 treatment conditions: conventional pharmacologic treatment or multidisciplinary treatment. Outcome measures were functionality, sleep disturbances, pain intensity, catastrophizing, and psychological distress. Analysis was by intent‐to‐treat and missing data were replaced following the baseline observation carried forward method.

Results

One hundred fifty‐five participants were recruited. No statistically significant differences regarding pretreatment measures were found between the 2 experimental groups. Overall statistics comparison showed a significant difference between the 2 groups in all of the variables studied (P < 0.0001). Mixed linear model analysis demonstrated the superiority of the multidisciplinary treatment in all of the studied variables at posttreatment. The differences were maintained at 12‐month followup in sleep disturbances (P < 0.0001), catastrophizing (P < 0.0001), and psychological distress (P < 0.01).

Conclusion

Multidisciplinary treatment adapted for individuals with low educational levels is effective in reducing key symptoms of FM. Some improvements were maintained 1 year after completing the multidisciplinary treatment.
Steric and Electronic Effects on the Configurational Stability of Residual Chiral Phosphorus‐Centered Three‐Bladed Propellers: Tris‐aryl Phosphanes
Authors: Rizzo Simona , Benincori Tiziana , Bonometti Valentina , Cirilli Roberto , Mussini Patrizia R. , Pierini Marco , Pilati Tullio , Sannicolò Francesco
Published: November 2012

A series of tris‐aryl phosphanes, structurally designed to exist as residual enantiomers or diastereoisomers, bearing substituents differing in size and electronic properties on the aryl rings, were synthesized and characterized. Their electronic properties were evaluated on the basis of their electrochemical oxidation potential determined by voltammetry. The configurational stability of residual phosphanes, evaluated by dynamic HPLC on a chiral stationary phase or/and by dynamic 1H and 31P NMR spectroscopy, was found to be rather modest (barriers of about 18–20 kcal mol−1), much lower than that shown by the corresponding phosphane oxides (barriers of about 25–29 kcal mol−1). For the first time, the residual antipodes of a tris‐aryl phosphane were isolated in enantiopure state and the absolute configuration assigned to them by single‐crystal anomalous X‐ray diffraction analysis. In this case, the racemization barrier could be calculated also by CD signal decay kinetics. A detailed computational investigation was carried out to clarify the helix reversal mechanism. Calculations indicated that the low configurational stability of tris‐aryl phosphanes can be attributed to an unexpectedly easy phosphorus pyramidal inversion which, depending upon the substituents present on the blades, can occur even on the most stable of the four conformers constituting a single residual stereoisomer.
Guest Covalent Capture by a Host: A Biomimetic Strategy for the Selective Functionalization of a Cavity
Authors: Menard Nicolas , Reinaud Olivia , Colasson Benoit
Published: November 2012

A biomimetic strategy for the monofunctionalization of a calix[6]arene core is described. It is based on host–guest chemistry (mimicking the Michaelis–Menten adduct in enzymes) and allows the finely tuned pre‐organization of the substrate (an alkyne) with respect to the reactant (three azido groups introduced at the calixarene large rim). It is shown that the thermal Huisgen reaction implemented in this work proceeds under very mild conditions with total regioselectivity of the cycloaddition process. The scope of the reaction was explored and the results suggest that such a supramolecular strategy is quite versatile and could be applied to the selective functionalization of other cavitands bearing different recognition patterns. A detailed structural, thermodynamic, and kinetic study is also reported, highlighting interesting biomimetic features: The importance of the host–guest adduct strength, the high sensitivity of the reaction to the pre‐organization of the reactive partners (alkyne vs. azide), and a significant impact of the embedment on the transition state. The self‐coordination of the monofunctionalized products was also studied and an “endo/exo” switch of the internal side‐chain could be triggered by adding competitive ligands.
Light‐Harvesting Ytterbium(III)–Porphyrinate–BODIPY Conjugates: Synthesis, Excitation‐Energy Transfer, and Two‐Photon‐Induced Near‐Infrared‐Emission Studies
Authors: Zhang Tao , Zhu Xunjin , Wong Wai‐Kwok , Tam Hoi‐Lam , Wong Wai‐Yeung
Published: November 2012

Based on a donor–acceptor framework, several conjugates have been designed and prepared in which an electron‐donor moiety, ytterbium(III) porphyrinate (YbPor), was linked through an ethynyl bridge to an electron‐acceptor moiety, boron dipyrromethene (BODIPY). Photoluminescence studies demonstrated efficient energy transfer from the BODIPY moiety to the YbPor counterpart. When conjugated with the YbPor moiety, the BODIPY moiety served as an antenna to harvest the lower‐energy visible light, subsequently transferring its energy to the YbPor counterpart, and, consequently, sensitizing the YbIII emission in the near‐infrared (NIR) region with a quantum efficiency of up to 0.73 % and a lifetime of around 40 μs. Moreover, these conjugates exhibited large two‐photon‐absorption cross‐sections that ranged from 1048–2226 GM and strong two‐photon‐induced NIR emission.
Evidence of stable genetic structure across a remote island archipelago through self‐recruitment in a widely dispersed coral reef fish
Authors: Priest Mark A. , Halford Andrew R. , McIlwain Jennifer L.
Published: November 2012

We used microsatellite markers to assess the population genetic structure of the scribbled rabbitfish Siganus spinus in the western Pacific. This species is a culturally important food fish in the Mariana Archipelago and subject to high fishing pressure. Our primary hypothesis was to test whether the individuals resident in the southern Mariana Island chain were genetically distinct and hence should be managed as discrete stocks. In addition to spatial sampling of adults, newly‐settled individuals were sampled on Guam over four recruitment events to assess the temporal stability of the observed spatial patterns, and evidence of self‐recruitment. We found significant genetic structure in S. spinus across the western Pacific, with Bayesian analyses revealing three genetically distinct clusters: the southern Mariana Islands, east Micronesia, and the west Pacific; with the southern Mariana Islands being more strongly differentiated from the rest of the region. Analyses of temporal samples from Guam indicated the southern Mariana cluster was stable over time, with no genetic differentiation between adults versus recruits, or between samples collected across four separate recruitment events spanning 11 months. Subsequent assignment tests indicated seven recruits had self‐recruited from within the Southern Mariana Islands population. Our results confirm the relative isolation of the southern Mariana Islands population and highlight how local processes can act to isolate populations that, by virtue of their broad‐scale distribution, have been subject to traditionally high gene flows. Our results add to a growing consensus that self‐recruitment is a highly significant influence on the population dynamics of tropical reef fish.
Metal‐Cation‐Directed Synthesis, Structures, and Optical Properties of Mo(W)/S(Se)/Ag Clusters: A Brief Overview
Authors: Li Jianghua , Zhang Jinfang , Humphrey Mark G. , Zhang Chi
Published: November 2012

This article provides a concise summary of recent research progress, including synthetic strategies, structural diversity, theoretical studies, and third‐order nonlinear optical (NLO) properties, on Mo(W)/S(Se)/Ag heterobimetallic clusters. It offers a preliminary analysis of their metal‐cation‐directed synthesis, structures, and the subtle interplay of structural–functional relationships. Furthermore, DFT was used to provide an insight into the electronic transitions and spectral characterization of these clusters. Recent trends and perspectives of these clusters as NLO materials are also described.
Explanation of Different Regioselectivities in the ortho‐Lithiation of Ferrocenyl(phenyl)methanamines
Authors: Almássy Ambroz , Škvorcová Andrea , Horváth Branislav , Bilčík Filip , Bariak Vladimír , Rakovský Erik , Šebesta Radovan
Published: November 2012

Diastereoselective ortho‐lithiation of ferrocenes is a principal strategy for the synthesis of chiral ferrocene ligands. Dilithiation of (R)‐1‐(2‐bromophenyl)‐1‐ferrocenyl‐N,N‐dimethylmethanamine leads to a dilithium intermediate, which can be transformed to a Taniaphos ligand with (R,Rp)‐configuration. On the other hand, lithiation of (R)‐1‐phenyl‐1‐ferrocenyl‐N,N‐dimethylmethanamine affords a lithiated product with opposite configuration of the stereogenic plane. Presumably, the second lithium atom attached at the ortho‐position of the phenyl ring is responsible for this difference through the intramolecular multicenter arrangement involving both lithium atoms and their adjacent carbon atoms, the iron atom of the ferrocenyl moiety, and the nitrogen atom of the amino group. This hypothesis has been supported also by quantum chemical calculations.
Safety of thromboprophylaxis after oncologic head and neck surgery. Study of 1018 patients
Authors: Gavriel Haim , Thompson Evan , Kleid Stephen , Chan SorWay , Sizeland Andrew
Published: November 2012

Background

Deep venous thrombosis (DVT) and pulmonary embolism (PE) are significantly reduced with appropriate use of thromboprophylaxis and scarcely evaluated in patients undergoing oncologic head and neck surgery (OHNS).

Methods

A retrospective study on 1018 patients who underwent oncologic head and neck surgery. The records of patients with venous thromboembolism (VTE) or postoperative bleeding were reviewed for the cancer grading, management, previous known coagulopathy, anticoagulation, and general demographics.

Results

Of a total of 1018 patients undergoing oncologic head and neck surgery, 450 patients had no chemoprophylaxis and 568 received it. The rate of a VTE event in our cohort was 0%. Twelve patients presented with hematoma or bleeding from the surgical site, 11 in the group that received chemoprophylaxis (p = .006).

Conclusions

Our analysis shows no benefit from chemoprophylaxis in oncologic head and neck surgery patients, with no VTE events. Our analysis shows higher rates of morbid side effects from using chemoprophylaxis, and we therefore conclude that chemoprophylaxis should not be routinely used. © 2012 Wiley Periodicals, Inc. Head Neck 35: 1410–1414, 2013
The effect of plaster (CaSO4·1/2H2O) on the compressive strength, self‐setting property, and in vitro bioactivity of silicate‐based bone cement
Authors: Liu Wenjuan , Wu Chengtie , Liu Weining , Zhai Wanyin , Chang Jiang
Published: November 2012

Bone cements have been widely used for orthopedic applications. Previous studies have shown that calcium silicon‐based bone cements (CSC) were injectable, bioactive, biodegradable, and mechanically strong in the long term, while their short‐term compressive strength was low and setting time was too long. On the other hand, plaster (CaSO4·1/2H2O, POP) sets quickly upon contact with water and has excellent short‐term compressive strength. The aim of this study is to prepare CSC/POP composite cements and investigate the effect of POP on the compressive strength, setting time, injectability, degradation, and in vitro bioactivity of the composite cements. The results have shown that POP content plays an important role to modulate the physicochemical property of CSC. The addition of POP into CSC significantly decreased the initial and final setting time and enhanced the short‐term compressive strength and degradation rate. The obtained composite cement with 30% POP has been found to possess optimal setting time and short‐term compressive strength. In addition, the prepared composite cements still maintain apatite‐mineralization ability in simulated body fluids and their ionic extracts have no significant cytotoxicity to L929 cells. The results suggested that the addition of POP into CSC is a viable method to improve their setting properties and short‐term compressive strength. The obtained composite cements with the optimized composition of 70% CSC and 30% POP could be potentially used for bone repair application. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
Corrosion behavior of novel Ti‐24Nb‐4Zr‐7.9Sn alloy for dental implant applications in vitro
Authors: Cheng Yicheng , Hu Jiang , Zhang Chunbao , Wang Zhongyi , Hao Yulin , Gao Bo
Published: November 2012

Ti‐24Nb‐4Zr‐7.9Sn (TNZS) alloy is a newly developed β‐titanium alloy considered suitable for dental implant applications due to its low elastic modulus and high strength. The aim of this study was to investigate the corrosion behavior of TNZS alloy through a static immersion test in various simulated physiological solutions, namely, artificial saliva, lactic acid solution, fluoridated saliva, and fluoridated acidified saliva for 7 days. The corrosion behavior of commercially pure titanium and Ti‐6Al‐4V alloy were also examined for comparison. The elemental release was measured with inductively coupled plasma mass spectroscopy, and the changes of alloy surface were observed with scanning electron microscopy (SEM). The test results showed that the quantity of each metal element released from TNZS alloy into fluoridated solutions was much higher than the solutions without fluoride ions. It was highest in fluoridated acidified saliva and lowest in artificial saliva (p < 0.01). The total elemental release from TNZS alloy was lower than commercially pure titanium and Ti‐6Al‐4V alloy in the same solution (p < 0.01). SEM micrographs indicated that TNZS alloy possessed better corrosion resistant performance. It can be concluded that fluoridated solutions have a negative influence on the corrosion behavior of TNZS alloy. Compared with commercially pure titanium and Ti‐6Al‐4V alloy, TNZS alloy demonstrates better corrosion resistance in various simulated physiological solutions, so it has greater potential for dental implant applications. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
Peak stress intensity factor governs crack propagation velocity in crosslinked ultrahigh‐molecular‐weight polyethylene
Authors: Sirimamilla Abhiram , Furmanski Jevan , Rimnac Clare
Published: November 2012

Ultrahigh‐molecular‐weight polyethylene (UHMWPE) has been successfully used as a bearing material in total joint replacement components. However, these bearing materials can fail as a result of in vivo static and cyclic loads. Crack propagation behavior in this material has been considered using the Paris relationship which relates fatigue crack growth rate, da/dN (mm/cycle) versus the stress intensity factor range, ΔK (Kmax − Kmin, MPa√m). However, recent work suggests that the crack propagation velocity of conventional UHMWPE is driven by the peak stress intensity (Kmax), not ΔK. The hypothesis of this study is that the crack propagation velocity of highly crosslinked and remelted UHMWPE is also driven by the peak stress intensity, Kmax, during cyclic loading. To test this hypothesis, two highly crosslinked (65 kGy and 100 kGy) and remelted UHMWPE materials were examined. Frequency, waveform, and R‐ratio were varied between test conditions to determine the governing factor for fatigue crack propagation. It was found that the crack propagation velocity in crosslinked UHMWPE is also driven by Kmax and not ΔK, and is dependent on loading waveform and frequency in a predictable quasistatic manner. This study supports that crack growth in crosslinked UHMWPE materials, even under cyclic loading conditions, can be described by a relationship between the velocity of crack growth, da/dt and the peak stress intensity, Kmax. The findings suggest that stable crack propagation can occur as a result of static loading only and this should be taken into consideration in design of UHMWPE total joint replacement components. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 101B: 430–435, 2013.
Mitogen-activated protein kinase 2 regulates physiological and pathological bone turnover
Authors: Braun Tobias , Lepper Johannes , Ruiz Heiland Gisela , Hofstetter Willy , Siegrist Mark , Lezuo Patrick , Gaestel Matthias , Rumpler Monika , Thaler Roman , Klaushofer Klaus , Distler Jörg HW , Schett Georg , Zwerina Jochen
Published: November 2012

The objective of this study was to investigate the role of the serine-threonine kinase mitogen-activated protein kinase 2 (MK2) in bone homeostasis. Primary bone cell cultures from MK2+/+ and MK2–/– mice were assessed for osteoclast and osteoblast differentiation, bone resorption, and gene expression. Bone architecture of MK2+/+ and MK2–/– mice was investigated by micro–computed tomography and histomorphometry. Ovariectomy was performed in MK2+/+ and MK2–/– mice to assess the role of MK2 in postmenopausal bone loss. Osteoclastogenesis, bone resorption, and osteoclast gene expression were significantly impaired in monocytes from MK2–/– compared to MK2+/+ mice. Mechanistically, loss of MK2 causes impaired DNA binding of c-fos and nuclear factor of activated T cells cytoplasmic 1 (NFATc1) to tartrate-resistant acid phosphatase (TRAP) and the calcitonin receptor gene promoter. In addition, MK2–/– mice showed an age-dependent increase in trabecular bone mass and cortical thickness, fewer osteoclasts, and lower markers of bone resorption than MK2+/+ mice. Furthermore, MK2–/– mice were protected from ovariectomy-induced bone loss. Osteoblastogenesis and bone formation were unchanged in MK2–/– mice, whereas osteoblast expression of osteoprotegerin (OPG) and serum levels of OPG were higher in MK2–/– than in MK2+/+ mice. Loss of MK2 effectively blocks bone resorption and prevents the development of postmenopausal bone loss. Small-molecule inhibitors of MK2 could thus emerge as highly effective tools to block bone resorption and to treat postmenopausal bone loss. © 2013 American Society for Bone and Mineral Research.
Amyloid toxicity and platelet‐activating factor signaling
Authors: Sirangelo Ivana , Irace Gaetano , Balestrieri Maria Luisa
Published: November 2012

Amyloidosis is the accumulation of insoluble proteinaceous aggregates in vivo and is implicated in many neurodegenerative diseases, including Alzheimer's, Huntington's, and Parkinson's diseases. This article briefly reviews the current knowledge of amyloid aggregate toxicity and inflammatory signaling in the nervous system. In particular, we focus our attention on the role of platelet‐activating factor (PAF) as mediator of amyloid cytotoxicity. J. Cell. Physiol. 228: 1143–1148, 2013. © 2012 Wiley Periodicals, Inc.
Effects of low concentrations of Regorafenib and Sorafenib on human HCC cell AFP, migration, invasion, and growth in vitro
Authors: Carr Brian I. , D'Alessandro Rosalba , Refolo Maria G. , Iacovazzi Palma A. , Lippolis Catia , Messa Caterina , Cavallini Aldo , Correale Mario , Di Carlo Antonio
Published: November 2012

Sorafenib was shown in clinical trial to enhance survival in hepatocellular carcinoma (HCC) patients, but with minimal tumor shrinkage. To correlate several indices of HCC growth at various drug concentrations, HCC cells were grown in various low concentrations of two multikinase inhibitors, Regorafenib (Stivarga) and Sorafenib (Nexavar) and their effects were examined on alpha‐fetoprotein (AFP), cell growth, migration, and invasion. In two AFP positive human HCC cell lines, AFP was inhibited at 0.1–1 µM drug concentrations. Cell migration and invasion were also inhibited at similar low drug concentrations. However, 10‐fold higher drug concentrations were required to inhibit cell growth in both AFP positive and negative cells. To investigate this concentration discrepancy of effects, cells were then grown for prolonged times and sub‐cultured in low drug concentrations and then their growth was re‐tested. The growth in these drug‐exposed cells was found to be slower than cells without prior drug exposure and they were also more sensitive to subsequent drug challenge. Evidence was also found for changes in cell signaling pathways in these slow‐growth cells. Low multikinase inhibitor concentrations thus modulate several aspects of HCC cell biology. J. Cell. Physiol. 228: 1344–1350, 2013. © 2012 Wiley Periodicals, Inc.
Pharmacological characterization of 18F‐labeled vorozole analogs
Authors: Hall Håkan , Takahashi Kayo , Erlandsson Maria , Estrada Sergio , Razifar Pasha , Bergström Elisabeth , Långström Bengt
Published: November 2012

Two 18F‐labeled analogs of vorozole ([18F]FVOZ and [18F]FVOO) have been developed as potential tools for the in vivo characterization of aromatase. The pharmacological properties of these radioligands were evaluated using in vitro binding and in vivo distribution studies in the rat and primate. Saturation binding studies using rat ovary gave KD and Bmax values of 0.21 ± 0.1 nM and 210 ± 20 fmol/mg, respectively, for [18F]FVOZ, and 7.6 ± 1 nM and 293 ± 12 fmol/mg, respectively, for [18F]FVOO. Organ distribution studies in rats showed the highest accumulation in the adrenal glands, with standardized uptake values (SUVs) of 15 to 20, followed by ovaries and liver with SUVs of approximately 5. Ex vivo and in vitro autoradiography of the rat brain showed specific binding of both [18F]FVOZ and [18F]FVOO mainly in the amygdala. Positron emission tomography (PET) studies were performed in the Rhesus monkey, and these showed displaceable binding in the amygdala and the hypothalamus preoptic area. The PET images were also analyzed using masked volume‐wise principal component analysis. These studies suggest that [18F]FVOZ might be a suitable tracer for the study of aromatase in vitro and in vivo, and could be an alternative to [11C]vorozole in human PET studies. Copyright © 2012 John Wiley & Sons, Ltd.
Combining targeted and nontargeted data analysis for liquid chromatography/high‐resolution mass spectrometric analyses
Authors: Croley Timothy R. , White Kevin D. , Wong Jon , Callahan John H. , Musser Steven M. , Antler Margaret , Lashin Vitaly , McGibbon Graham A.
Published: November 2012

Increasing importation of food and the diversity of potential contaminants have necessitated more analytical testing of these foods. Historically, mass spectrometric methods for testing foods were confined to monitoring selected ions (SIM or MRM), achieving sensitivity by focusing on targeted ion signals. A limiting factor in this approach is that any contaminants not included on the target list are not typically identified and retrospective data mining is limited. A potential solution is to utilize high‐resolution MS to acquire accurate mass full‐scan data. Based on the instrumental resolution, these data can be correlated to the actual mass of a contaminant, which would allow for identification of both target compounds and compounds that are not on a target list (nontargets). The focus of this research was to develop software algorithms to provide rapid and accurate data processing of LC/MS data to identify both targeted and nontargeted analytes. Software from a commercial vendor was developed to process LC/MS data and the results were compared to an alternate, vendor‐supplied solution. The commercial software performed well and demonstrated the potential for a fully automated processing solution.
Kinetics of hydrolysis of procaine in aqueous and micellar media
Authors: Al‐Blewi Fawzia Faleh , Al‐Lohedan Hamad A. , Rafiquee M. Z. A. , Issa Zuheir A.
Published: November 2012

The kinetics of alkaline hydrolysis of procaine under the pseudo–first‐order condition ([OH−] ≫ [procaine]) has been carried out. N,N‐Diethylaminoethanol and p‐aminobenzoate anion were obtained as the hydrolysis product. The rate of hydrolysis was found to be linearly dependent upon [NaOH]. The addition of cationic cetyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium bromide (DDTAB) and tetradecyltrimethylammonium bromide, and anionic sodium dodecyl sulfate (SDS) micelles inhibited the rate of hydrolysis. The maximum inhibitive effect on the reaction rate was observed for SDS micelles, whereas among the cationic surfactants, CTAB inhibited most. The variation in the rate of hydrolysis of procaine in the micellar media is attributed to the orientation of a reactive molecule to the surfactant and the binding constant of procaine with micelles. The rate of hydrolysis of procaine is negligible in DDTAB micelles. The observed results in the presence of cationic micelles were treated on the basis of the pseudophase ion exchange model. The results obtained in the presence of anionic micelles were treated by the pseudophase model, and the various kinetic parameters were determined. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 45: 1–9, 2013
A New Class of Ultra‐Efficient Supramolecular Nucleating Agents for Isotactic Polypropylene
Authors: Abraham Frank , Kress Roman , Smith Paul , Schmidt Hans‐Werner
Published: November 2012

We present a family of 2,4,6‐trimethyl‐1,3,5‐benzenetrisamides for ultra‐efficient nucleation of isotactic polypropylene (i‐PP). On the basis of a new symmetrically substituted core, in a series of compounds, the chemical structure of peripheral substituents is systematically varied, introducing branched aliphatic, aromatic, and cycloaliphatic moieties. Some of these compounds are found to promote nucleation of the α‐phase in i‐PP at concentrations as low as 0.00003 wt% only, while concomitantly featuring outstanding thermal properties.
Stability analysis in a soliton fiber ring laser with a hybrid saturable absorber
Authors: Moghaddam M. R. A. , Harun S. W. , Lim K. S. , Ahmad H.
Published: November 2012

A stable mode‐locked fiber laser having two rejection ports employing a 4 m long erbium doped fiber is demonstrated. Near transform limited short pulses with a repetition rate of 8.27 MHz are obtained at a wavelength of 1565 nm by using a slow saturable absorber. The pulse width can continuously vary from 1.2 ps to less than 130 fs with a maximum spectral width of 20 nm. Although the changes of the pulse duration over one round‐trip in the resonator is small. However, a comparison of the energy fluctuations from coupler port toward polarizing beam splitter (PBS) port reveals that energy fluctuation is varied from 4.1% to 7.8% and stronger for PBS port. We also find that the low frequency timing jitter for a fixed pump power is stronger for PBS port and the high frequency timing jitter at PBS port is more than twice larger than that of the timing jitter at coupler port. By removing fiber adapters and controlling the environmental airflow in the setup, timing jitter was reduced by an order of magnitude. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:164–170, 2013 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27220
Design of optical engine for LCOS laser display with rotated diffuser plate
Authors: Li Jia
Published: November 2012

Based on the theoretical analysis of the generation of laser speckles, a specific scheme is proposed to reduce composite speckles in the tricolor liquid‐crystal‐on‐silicon laser projector.The rotated diffuser is relatively simple in its optical structure which can be easily implemented. Furthermore, the experiment with regard to the detected images at the receiver is also performed to verify the feasibility of our method. It is shown by simulated results that the rotated diffuser plate can effectively suppress the contrast ratio of laser speckles. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:138–141, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27221
Dual band‐notch slot antenna by using a pair of Γ‐shaped slits and Ω–shaped parasitic structure for UWB applications
Authors: Ojaroudi Nasser , Ojaroudi Mohammad
Published: November 2012

In this article, we present a novel design of dual band‐notch printed slot antenna for ultrawideband (UWB) applications. The antenna consists of a square radiating stub and a ground plane structure with two Γ‐shaped slits and Ω‐shaped parasitic structure, which provides a wide usable fractional bandwidth of more than 145% (3.04–17.13 GHz). To increase the impedance bandwidth of the ordinary slot antenna, we use two L‐shaped parasitic structure in the ground plane that with this structure UWB frequency range can be achieved. Additionally, using two Γ‐shaped slits, a single frequency band‐stop performance can be achieved, also to create the second notch frequency, we combine an inverted U‐shaped strip with two L‐shaped parasitic structure, that using this additional inverted U‐shaped strip, Ω‐shaped parasitic structure can be created. Simulated and measured results obtained for this antenna show that the proposed slot antenna offers two notched bands, around 3.67–4.13 GHz and 5.09–5.97 GHz, covering all the 5.2/5.8 GHz WLAN, 3.5/5.5 GHz WiMAX and 4‐GHz C‐band range. The antenna has a small dimension of 20 × 20 mm2. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:102–105, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27223
0.18‐μm CMOS wideband passive mixer
Authors: Song Chenyan , Boric‐Lubecke Olga , Lo Ivy
Published: November 2012

A 0.18‐μm CMOS wideband passive mixer fully integrated with baluns in IBM7HP process is reported. The mixer exhibits wideband operation, despite the intrinsic narrow‐band magnitude balance of passive baluns. Very low DC offset, of less than 3 mV, is achieved without any DC cancellation circuits, due to high LO–RF isolation. At the RF frequency of 2.4 GHz, the combined IF differential outputs provide conversion loss (CL) of 7.5 dB, input 1 dB compression point (IP1dB) of 6.2 dBm, and input third‐order intercept point (IIP3) of 15.5 dBm. This mixer exhibits broad‐band RF impedance matching with reflection coefficient magnitude better than −9.6 dB through the RF frequency range from 1 to 12 GHz. The CL of 10.1–12.9 dB, IP1dB of 8.6–14.4 dBm, and IIP3 of 16–22.2 dBm are achieved at this frequency range for broad‐band applications. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:23–27, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27226
Isolating the singular term of the green's function in the vicinity of the corner formulated by two intersecting waveguides
Authors: Valagiannopoulos Constantinos A.
Published: November 2012

A bent waveguide comprised of two vertically intersected unequal parallel‐plate structures is excited by an elementary singular source located into the corner cavity.The electric field, equaling the Green's function, is computed in each region by considering a common singular quantity, the necessary image terms corresponding to infinite planes and a sum describing the mode matching procedure along the separating boundaries. The final form could be used effectively in implementing the scattering integral equations, due to the isolation of the irregular term that can be handled properly. Several graphs representing the variations of the Green's functions and the propagating powers with respect to the oscillating frequency are shown and discussed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:16–23, 2013;X View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27227
High‐frequency low‐power fractional frequency multiplier
Authors: Miao Yannan N. , Boon Chirn Chye , Do Manh Anh , Yeo Kiat Seng , Lim Wei Meng
Published: November 2012

The topology of fractional frequency multiplier (FFM) is proposed for high‐frequency and low‐power application. Based on the topology, a × (3/2) FFM is designed and fabricated in a 0.18 μm CMOS technology. The FFM's output power is larger than 0 dBm in its operation range from 15.3 to 18.45 GHz. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:146–149, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27236
An etched optical fiber as a vibration sensor
Authors: Kishore Putha , Dinakar Dantala , Vengal Rao P. , Srimannarayana K.
Published: November 2012

A center‐etched single‐mode fiber is designed as a vibration senor to monitor the vibrations of a simply supported beam.The sensor works on transmission power loss due to the mode volume mismatch and flexural strain of the fiber due to the bending in the fiber with respect to the bending of the beam. The sensor has high linear response to axial displacement of about 0.8 mm with sensitivity of 32 mV/10 μm strain. The simple design, small size, immune to electromagnetic interference (EMI), and flexible length are all added advantages that may find a place in industry to monitor the vibrations of the beam structures and bridges. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:75–79, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27240
Magnetic boosters for multiband operation
Authors: Andújar Aurora , Anguera Jaume
Published: November 2012

Emergent wireless handheld platforms strongly require the integration of a wide variety of services and functionalities in their limited space. These constraints directly affect handset antenna design, which has to address the challenge of providing miniature and multiband antennas by facing the existing trade‐off between antenna performance and size. This article proposes the use of small magnetic boosters to excite the efficient radiating mode that the inherent ground plane of handset platforms features at mobile frequencies. Electrical models are used to provide a physical insight into the behavior of the radiating system and broadband techniques are applied for attaining impedance match. To validate the proposal, simulation results using the software IE3D based on MoM as well as measured results are provided. The outcomes demonstrate that the proposed magnetic boosters featured by considerable reduced dimensions of approximately 0.05λ are able of providing operation in the main communication standards GSM850/900 (824–960 MHz) and DCS/PCS/UMTS (1710–2170 MHz). Thus, the proposal attains a size reduction factor around five with respect to previous solutions based on resonant elements while preserves a suitable electromagnetic performance. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:65–75, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27241
High gain inverted U shaped miniaturized patch antenna for multiband wireless applications
Authors: Beno A. , Emmanuel D.S.
Published: November 2012

A multiband inverted U‐shaped antenna with corrugated slits is proposed. The antenna is designed using small rectangular patch antennas connected with a microstrip feed to operate in the frequency bands from 5 to 10 GHz. The antenna achieves a peak gain of 15.29 dB at 9 GHz and above 8 dB in all the operating bands with good directional pattern of radiation. The antenna operates in the C‐Band, X‐Band covering the bands like WLAN in 5 GHz, satellite band of 5–7 GHz and microwave radar frequencies. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:27–31, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27243
Design of tri‐band microstrip BPF using SLR and quarter‐wavelength SIR
Authors: Deng Hong‐Wei , Zhao Yong‐Jiu , Fu Yong , Zhou Xiao‐Jun , Liu Yan‐Yun
Published: November 2012

A tri‐band microstrip bandpass filter (BPF) with compact size and high selectivity is presented by using the stub‐loaded resonator (SLR) and quarter‐wavelength stepped‐impedance resonator (SIR). The quarter‐wavelength SIR is designed for the first and third passband and the SLR mainly controls second passband performance, so three passband frequencies can be flexibly tuned. Because of the intrinsic characteristics of the resonators and source‐load coupling, multiple transmission zeros can be created to improve the selectivity. Finally, a tri‐band BPF prototype located at 0.98 GHz (FRID application), 3.6 GHz (Wimax application), and 5.8 GHz (WLAN application) is designed. Measurement results agree well with the full‐wave EM simulated results. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:212–215, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27247
CPW‐FED compact bent monopole antenna for UWB applications
Authors: Sreenath S. , Ashkarali P. , Thomas Paulbert , Dinesh R. , Anandan C. K
Published: November 2012

A compact CPW‐fed planar antenna suitable for ultra‐wideband (UWB) applications is presented.The proposed design is a modification of the simple monopole antenna where the monopole is folded and the asymmetric ground plane dimensions are optimized for UWB performance. The simple geometry and its compactness make the antenna good candidate for portable applications involving integration with microwave monolithic integrated circuit (MMIC) devices. The antenna fabricated on FR4 substrate shows almost identical radiation characteristics in the entire band with an average gain of 2.5 dBi. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:56–58, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27252
A reconfigurable wide slot antenna integrated with sirs for UWB/multiband communication applications
Authors: Li Yingsong , Li Wenxing , Ye Qiubo
Published: November 2012

A reconfigurable wide slot antenna integrated with stepped impedance resonators (SIRs) and ideal switches for ultra‐wideband (UWB) and multiband communication applications is proposed. The proposed reconfigurable antenna can be used as a UWB antenna, a dual notch‐band UWB antenna, and multiband antennas. The dual notch‐band functions are obtained by using two stepped impedance stub‐loaded SIRs. The reconfigurable characteristics are achieved by using two ideal switches on SIRs. The measurement and simulation results show that the proposed reconfigurable antenna has good switchable characteristics and dual notch‐band functions. The designed reconfigurable antenna is suitable for future multimode wireless communications systems. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:52–55, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27253
Crosstalk penalties analysis in mixed line transmission rates (10G‐OOK/40G‐DQPSK/112G‐DP‐QPSK/224G‐DP‐16‐QAM) optical flexible grid networks
Authors: Oliveira J. C. R. F. , Silva R. , Silva E.P. , Carvalho L. H. H. , Silva M. L. , Neto J. M. C. , Paradisi A.
Published: November 2012

Crosstalk penalties in flexible grid networks with mixed rates lead to system degradation due to add/drop in‐band residual power or nonuniform channel grid allocation. These penalties are quantified for 112G‐DP‐QPSK test channel with 10G‐OOK, 40G‐DQPSK, 112G‐DP‐QPSK, and 224G‐DP‐16‐QAM simultaneous optical transmission. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:119–122, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27269
Investigation of bending and temperature effects in optical fibers
Authors: Golnabi H. , Sharifian M.
Published: November 2012

Fiber bending and temperature loss mechanisms in plastic optical fibers are reported.A simple arrangement is used to monitor the fiber bending and temperature by output power variation. Powers in the fibers in bend‐free situation at room temperature and under rolling deforming force at different water bath temperatures (20–60°C) are measured and compared. Reported arrangements can be used as a temperature sensor. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:82–86, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27271
A novel design of compact wideband hexagonal antenna
Authors: Mondal Santanu , Sarkar Partha P.
Published: November 2012

A novel design of planar hexagonal antenna (PHA) fed by a coplanar waveguide has been presented for wideband applications.The semicircular base to upper and lower side of hexagonal radiator increases the impedance bandwidth. A shorting strip is introduced as a top load to the antenna to achieve compactness. The proposed shorted PHA (SPHA) yields bidirectional radiation pattern in both elevation and azimuth plane. The −10 dB return loss of SPHA exhibits from 1.24 to 20 GHz. The simulated results for various characteristics of the antenna have been shown using finite integration technique based commercial software CST MICROWAVE STUDIO. The simulated and measured return loss characteristics of SPHA are in good agreement. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1–4, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27276
Aortic wall shear stress in Marfan syndrome
Authors: Geiger Julia , Arnold Raoul , Herzer Lena , Hirtler Daniel , Stankovic Zoran , Russe Max , Langer Mathias , Markl Michael
Published: November 2012

The aim of this study was to quantify changes in thoracic aortic wall shear stress (WSS) in asymptomatic patients with Marfan syndrome (MFS) compared with healthy controls. WSS in the thoracic aorta was quantified based on time‐resolved 3D phase contrast MRI with three‐directional velocity encoding (4D flow MRI, temporal resolution ∼44 ms, spatial resolution ∼2.5 mm) in 24 patients with confirmed MFS (age = 18 ± 12 years) and in 12 older healthy volunteers (age = 25 ± 3 years). Diameters of the thoracic aorta normalized to body surface area were similar for both groups. Peak systolic velocity, absolute WSS, time‐averaged WSS, circumferential WSS, peak systolic WSS, and WSS eccentricity were calculated in eight analysis planes distributed along the thoracic aorta. Plane‐wise comparison revealed significant differences between MFS patients and volunteers in the proximal ascending aorta for peak systolic velocities (1.11 ± 0.23 m/s vs. 1.34 ± 0.18 m/s, P = 0.004) and circumferential WSS (0.14 ± 0.03 N/m2 vs. 0.11 ± 0.02 N/m2, P = 0.007). WSS eccentricity was altered in most of the ascending aorta and proximal arch (P = 0.009–0.020). MFS patients demonstrated segmental differences in peak systolic WSS with a significantly higher WSS at the inner curvature in the proximal ascending aorta and at the anterior part in the more distal ascending aorta (P < 0.01). These findings indicate differences in WSS associated with MFS despite similar aortic dimensions compared to controls. Magn Reson Med, 70:1137–1144, 2013. © 2012 Wiley Periodicals, Inc.
The detection of mosaicism by prenatal BoBs™
Authors: Cheng Yvonne K.Y. , Wong Cherry , Wong Hoi Kin , Leung Kwok On , Kwok Yvonne K. , Suen Andy , Wang Chi Chui , Leung Tak Yeung , Choy Kwong Wai
Published: November 2012

Objective

The objective of the study was to evaluate the ability of a new prenatal diagnostic platform – prenatal BACs‐on‐Beads™ (BoBs™) in detecting mosaicism by comparison to quantitative fluorescence‐polymerase chain reaction (QF‐PCR).

Methods

A validation study of prenatal BoBs™ was firstly performed using 18 artificially constructing mosaic samples involving various aneuploidies and microdeletion conditions. Additionally, we compared the accuracy between prenatal BoBs™ and QF‐PCR for 18 archived clinical mosaic cases and nine chromosomally abnormal cell lines with reference to conventional karyotype results.

Results

In the validation study, BoBs™ allowed the detection of mosaicism at a level of 20–40%. Among the clinical mosaic cases, 14/18 cases were within the detection of BoBs™, 8/14 (57.1%) could be identified by BoBs™ and 6/9 (66.7%) by QF‐PCR, but 6/14 (42.9%) were missed by both tests. Three cases (16.7%) were detected by prenatal BoBs™ but missed by QF‐PCR, whereas QF‐PCR detected one case that was missed by BoBs™. The overall sensitivity of BoBs™ in detecting mosaicism is 44.4% (8/18), which is slightly higher than that of QF‐PCR (33.3%; 6/18).

Conclusion

Prenatal BoBs™ has a sensitivity of 57.1% in the detection clinical mosaic cases. According to the validation test, mosaicism of 20% or greater is detectable by the BoBs™ assay. © 2012 John Wiley & Sons, Ltd.
The unique optical behaviour of bio‐related materials with organic chromophores
Authors: Ciardelli Francesco , Bertoldo Monica , Bronco Simona , Pucci Andrea , Ruggeri Giacomo , Signori Francesca
Published: November 2012

Molecularly designed materials based on macromolecules and organic dyes offer unique opportunities in connection with the possibility of preparing optically responsive ‘smart’ materials. Indeed macromolecules are able to transmit and amplify small signals reaching sites at interacting distance through the involvement of the whole chain. The corresponding materials can then acquire stimuli‐responsive properties in relation to specific features connected to primary structure and conformation. As a first approach to benefit from the above features for preparing eco‐compatible smart materials, bio‐related polypeptides, polysaccharides and polyesters can be used as the macromolecular partner in combination with a selected dye following different interaction methodologies. Two distinct routes were used to prepare optically responsive products from the above bio‐related polymers, respectively based either on the covalent bonding to the original macromolecules of photochromic molecular species, such as azobenzene and spiropyran, or on the morphology‐modulated dispersion of highly conjugated dyes in the polymer bulk. Examples related to the two different routes have been investigated in our laboratory and are presented and discussed also with reference to selected recent cases from the literature. Copyright © 2012 Society of Chemical Industry