bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemical Biology Approaches Reveal Conserved Features of a C‐Terminal Processing PDZ Protease
Authors: Weski Juliane , Meltzer Michael , Spaan Lina , Mönig Timon , Oeljeklaus Julian , Hauske Patrick , Vouilleme Lars , Volkmer Rudolf , Boisguerin Prisca , Boyd Dana , Huber Robert , Kaiser Markus , Ehrmann Michael
Published: January 2012

Several proteases like the high temperature requirement A (HtrA) protein family containing internal or C‐terminal PDZ domains play key roles in protein quality control in the cell envelope of Gram‐negative bacteria. While several HtrA proteases have been extensively characterized, many features of C‐terminal processing proteases such as tail‐specific protease (Tsp) are still unknown. To fully understand these cellular control systems, individual domains need to be targeted by specific peptides acting as activators or inhibitors. Here, we describe the identification and design of potent inhibitors and activators of Tsp. Suitable synthetic substrates of Tsp were identified and served as a basis for the generation of boronic acid‐based peptide inhibitors. In addition, a proteomic screen of E. coli cell envelope proteins using a synthetic peptide library was performed to identify peptides capable of amplifying Tsp's proteolytic activity. The implications of these findings for the regulation of PDZ proteases and for future mechanistic studies are discussed.
CuII Coordination Chemistry of Patellamide Derivatives: Possible Biological Functions of Cyclic Pseudopeptides
Authors: Comba Peter , Dovalil Nina , Gahan Lawrence R. , Haberhauer Gebhard , Hanson Graeme R. , Noble Christopher J. , Seibold Björn , Vadivelu Prabha
Published: January 2012

Two synthetic derivatives of the naturally occurring cyclic pseudooctapeptides patellamide A–F and ascidiacyclamide, that is, H4pat2, H4pat3, as well as their CuII complexes are described. These cyclic peptide derivatives differ from the naturally occurring macrocycles by the variation of the incorporated heterocyclic donor groups and the configuration of the amino acids connecting the heterocycles. The exchange of the oxazoline and thiazole groups by dimethylimidazoles or methyloxazoles leads to more rigid macrocycles, and the changes in the configuration of the side chains leads to significant differences in the folding of the cyclic peptides. These variations allow a detailed study of the various possible structural changes on the chemistry of the CuII complexes formed. The coordination of CuII with these macrocyclic species was monitored by high‐resolution electrospray mass spectrometry (ESI‐MS), spectrophotometric (UV/Vis) and circular dichroic (CD) titrations, and electron paramagnetic resonance (EPR) spectroscopy. Density functional theory (DFT) calculations and molecular mechanics (MM) simulations have been used to model the structures of the CuII complexes and provide a detailed understanding of their geometric preferences and conformational flexibility. This is related to the CuII coordination chemistry and the reactivity of the dinuclear CuII complexes towards CO2 fixation. The variation observed between the natural and various synthetic peptide systems enables conclusions about structure–reactivity correlations, and our results also provide information on why nature might have chosen oxazolines and thiazoles as incorporated heterocycles.
Borromean‐Entanglement‐Driven Assembly of Porous Molecular Architectures with Anion‐Modified Pore Space
Authors: Sun Jian‐Ke , Yao Qing‐Xia , Tian Yu‐Yang , Wu Lei , Zhu Guang‐Shan , Chen Rui‐Ping , Zhang Jie
Published: January 2012

A series of metal–organic frameworks based on a flexible, highly charged Bpybc ligand, namely 1⋅Mn⊃OH−, 2⋅Mn⊃SO42−, 3⋅Mn⊃bdc2−, 4⋅Eu⊃SO42− (H2BpybcCl2=1,1′‐bis(4‐carboxybenzyl)‐4,4′‐bipyridinium dichloride, H2bdc=1,4‐benzenedicarboxylic acid) have been obtained by a self‐assembly process. Single‐crystal X‐ray‐diffraction analysis revealed that all of these compounds contained the same n‐fold 2D→3D Borromean‐entangled topology with irregular butterfly‐like pore channels that were parallel to the Borromean sheets. These structures were highly tolerant towards various metal ions (from divalent transition metals to trivalent lanthanide ions) and anion species (from small inorganic anions to bulky organic anions), which demonstrated the superstability of these Borromean linkages. This non‐interpenetrated entanglement represents a new way of increasing the stability of the porous frameworks. The introduction of bipyridinium molecules into the porous frameworks led to the formation of cationic surface, which showed high affinities to methanol and water vapor. The distinct adsorption and desorption isotherms of methanol vapor in four complexes revealed that the accommodated anion species (of different size, shape, and location) provided a unique platform to tune the environment of the pore space. Measurements of the adsorption of various organic vapors onto framework 1⋅Mn⊃OH− further revealed that these pores have a high adsorption selectivity towards molecules with different sizes, polarities, or π‐conjugated structures.
Radical 4‐exoCyclizations via Template Catalysis
Authors: Gansäuer Andreas , Knebel Karsten , Kube Christian , van Gastel Maurice , Cangönül Asli , Daasbjerg Kim , Hangele Tim , Hülsen Michael , Dolg Michael , Friedrich Joachim
Published: January 2012

The mechanism of catalytic 4‐exocyclizations withoutgem‐dialkyl substitution was investigated by a comparison of cyclic voltammetry, EPR, and computational studies with previously published synthetic results. The most active catalyst is a super‐unsaturated 13‐electron titanocene(III) complex that is formed by supramolecular activation through hydrogen bonding. The template catalyst binds radicals via a two‐point binding that is mandatory for the success of the 4‐exocyclization. The computational investigations revealed that formation of the observedtrans‐cyclobutane product is not possible from the most stable substrate radical. Instead, the most stable product is formed with the lowest energy of activation from a disfavored substrate in a Curtin–Hammett related scenario.
Iterative Sinc−convolution method for solving planar D‐bar equation with application to EIT
Authors: Abbasi Mahdi , Naghsh‐Nilchi Ahmad‐Reza
Published: January 2012

The numerical solution of D‐bar integral equations is the key in inverse scattering solution of many complex problems in science and engineering including conductivity imaging. Recently, a couple of methodologies were considered for the numerical solution of D‐bar integral equation, namely product integrals and multigrid. The first one involves high computational complexity and other one has low convergence rate disadvantages. In this paper, a new and efficient sinc‐convolution algorithm is introduced to solve the two‐dimensional D‐bar integral equation to overcome both of these disadvantages and to resolve the singularity problem not tackled before effectively. The method of sinc‐convolution is based on using collocation to replace multidimensional convolution‐form integrals‐ including the two‐dimensional D‐bar integral equations ‐ by a system of algebraic equations. Separation of variables in the proposed method allows elimination of the formulation of the huge full matrices and therefore reduces the computational complexity drastically. In addition, the sinc‐convolution method converges exponentially with a convergence rate of . Simulation results on solving a test electrical impedance tomography problem confirm the efficiency of the proposed sinc‐convolution‐based algorithm. Copyright © 2012 John Wiley & Sons, Ltd.
Long‐term strategies for the treatment of Refsum's disease using therapeutic apheresis
Authors: Zolotov D. , Wagner S. , Kalb K. , Bunia J. , Heibges A. , Klingel R.
Published: January 2012

Refsum's disease is a rare autosomal recessive disorder of fatty acid metabolism. Poorly metabolized phytanic acid accumulates in fatty tissues, including myelin sheaths and internal organs, leading to retinitis pigmentosa, peripheral polyneuropathy, cerebellar ataxia, and renal, cardiac or liver impairment. Dietary restriction of phytanic acid in some cases is not sufficient to prevent acute attacks and stabilize the progressive course. Phytanic acid bound to large low density lipoproteins (LDL) and very low density lipoproteins (VLDL) molecules offers the possibility of extracorporeal elimination by lipid apheresis. We report on the long‐term lipid apheresis treatment of four patients with severe Refsum's disease. Retinitis pigmentosa, peripheral polyneuropathy, cerebellar ataxia, anosmia, and sensorineural hearing loss were major symptoms exhibiting a progressive course. Lipid apheresis was performed for 5–13 years without severe complications. Maximum levels of phytanic acid before commencing chronic lipid apheresis were >300 mg/l. During steady state with lipid apheresis, mean phytanic acid before treatments was 87 mg/l and was reduced to 36 mg/l. Mean reduction rate was 59% per treatment. In all patients, abnormal motor nerve conduction velocity with signs of chronic denervation improved, morphological and functional stabilization of eye involvement was observed. Lipid apheresis prevented the extension of the disease to previously unaffected organs in three patients. Extracorporeal elimination of lipoprotein‐phytanic acid complexes by lipid apheresis represents a pathophysiologically guided therapeutic approach, resulting in long‐term improvement or stabilization of overall rehabilitation in patients with progressive Refsum's disease. J. Clin. Apheresis, 2012. © 2012 Wiley Periodicals, Inc.
Chimeric antigen receptors for T cell immunotherapy: current understanding and future directions
Authors: Curran Kevin J. , Pegram Hollie J. , Brentjens Renier J.
Published: January 2012

Background

The genetic engineering of T cells through the introduction of a chimeric antigen receptor (CAR) allows for generation of tumor‐targeted T cells. Once expressed by T cells, CARs combine antigen‐specificity with T cell activation in a single fusion molecule. Most CARs are comprised of an antigen‐binding domain, an extracellular spacer/hinge region, a trans‐membrane domain and an intracellular signaling domain resulting in T cell activation after antigen binding.

Methods

We performed a search of the literature regarding tumor immunotherapy using CAR‐modified T cells to provide a concise review of this topic.

Results

This review aims to focus on the elements of CAR design required for successful application of this technology in cancer immunotherapy. Most notably, proper target antigen selection, co‐stimulatory signaling, and the ability of CAR‐modified T cells to traffic, persist and retain function after adoptive transfer are required for optimal tumor eradication. Furthermore, recent clinical trials have demonstrated tumor burden and chemotherapy conditioning before adoptive transfer as being critically important for this therapy. Future research into counteracting the suppressive tumor microenvironment and the ability to activate an endogenous anti‐tumor response by CAR‐modified T cells may enhance the therapeutic potential of this treatment.

Conclusions

In conclusion, CAR‐modified T cell therapy is a highly promising treatment for cancer, having already demonstrated both promising preclinical and clinical results. However, further modification and additional clinical trials will need to be conducted to ultimately optimize the anti‐tumor efficacy of this approach. Copyright © 2012 John Wiley & Sons, Ltd.
Gradient‐based optimization using parametric sensitivity macromodels
Authors: Chemmangat Krishnan , Ferranti Francesco , Dhaene Tom , Knockaert Luc
Published: January 2012

A new method for gradient‐based optimization of electromagnetic systems using parametric sensitivity macromodels is presented. Parametric macromodels accurately describe the parameterized frequency behavior of electromagnetic systems and their corresponding parameterized sensitivity responses with respect to design parameters, such as layout and substrate parameters. A set of frequency‐dependent rational models is built at a set of design space points by using the vector fitting method and converted into a state‐space form. Then, this set of state‐space matrices is parameterized with a proper choice of interpolation schemes, such that parametric sensitivity macromodels can be computed. These parametric macromodels, along with the corresponding parametric sensitivity macromodels, can be used in a gradient‐based design optimization process. The importance of parameterized sensitivity information for an efficient and accurate design optimization is shown in the two numerical microwave examples. Copyright © 2012 John Wiley & Sons, Ltd.
Meteorological environments associated with medicane development
Authors: Tous M. , Romero R.
Published: January 2012

Medicanes are ‘Mediterranean tropical‐like cyclones’, warm‐core cyclones that occasionally put in danger the islands and coastal regions. In spite of large geographical differences between the Mediterranean Sea and the tropical oceans, their genesis mechanisms, based on the thermodynamical disequilibrium between the sea and the atmosphere, are similar.

The special characteristics of the medicanes make their detection difficult: only with high resolution meteorological analysis data and dense maritime observations that task would be possible. An alternative method, using satellite data and restricted criteria about the disturbance symmetry, size and lifespan, has been successfully used to detect 12 medicanes from 1982 to 2003.

To enhance the medicane prediction capability or even to assess the risk potential in future climates, it is necessary to characterize the special conditions of the synoptic‐scale meteorological environments that are needed for their development and maintenance. By comparing these environments against the bulk of Mediterranean cyclonic situations, high values of mid‐tropospheric relative humidity, significant diabatic contribution to the surface level equivalent potential temperature, and low values of tropospheric wind shear, are revealed as important parameters involved in medicane genesis, as in tropical cyclones. An empirical genesis index previously derived for the tropical cyclones is also tested in the study, and its behaviour is revealed as a possible discriminative parameter of the precursor environments.

In the context of the growing concern about how climate change will affect the number and intensity of hurricanes, a preliminary analysis for medicanes has been done here. By projecting the previous empirical index into three different global climate model (GCM)‐simulated climates, spatial distributions of the monthly index values have been evaluated. The monthly mean values and the frequency of extreme values of this index tend to decrease, showing that the number of days with a medicane risk tends to reduce at the end of the 21st century. Copyright © 2012 Royal Meteorological Society
Zingiber officinaleextract exhibits antidiabetic potential via modulating glucose uptake, protein glycation and inhibiting adipocyte differentiation: anin vitrostudy
Authors: Rani M Priya , Krishna Mahesh S , Padmakumari Keezheveettil P , Raghu K Gopal , Sundaresan Andikannu
Published: January 2012

BACKGROUND:Ginger, the rhizome ofZingiber officinaleRoscoe (Zingiberaceae), a perennial herbaceous plant is native to Southern Asia. Study was aimed to evaluate antioxidant and antidiabetic potential of ginger extract and its characterization. Possible mode of action to elicit antidiabetic activity was also evaluated.

METHODS AND RESULTS:Ethyl acetate extract of ginger (EAG) was evaluated for its antioxidant activity in terms of DPPH radical scavenging potential with an IC50value of 4.59 µg/ml. Antidiabetic activity of EAG was evaluated by estimating antiglycation potential (IC50290.84 µg/ml). HPLC profiling of EAG revealed the presence of phenolic components, gingerol and shoagol as major constituents. After determining sub‐toxic concentration of EAG (50 µg/ml), efficacy of extract to enhance glucose uptake in cell lines were checked in L6 mouse myoblast and myotubes. EAG was effective at 5 µg/ml concentration in both cases. Antibody based studies in treated cells revealed the effect of EAG in expressing Glut 4 in cell surface membrane compared to control.

CONCLUSION:The antidiabetic effect of ginger was experimentally proved in the study and has concluded that the activity is initiated by antioxidant, antiglycation and potential to express or transport Glut4 receptors from internal vesicles. Copyright © 2012 Society of Chemical Industry
Intellectual Capital and Business Performance: What Structural Relationships Do They Have in Upper‐Upscale Hotels?
Authors: Kim Taegoo (Terry) , Kim Woo Gon , Park Simon Si‐Sa , Lee Gyehee , Jee Bonggu
Published: January 2012

The purpose of this study is to investigate the structural relationships among intellectual capital (INCAP) dimensions and business performance (BUPER) in upper‐upscale hotels. This study classified INCAP into three dimensions: human capital (HUCAP), organizational capital (ORCAP) and customer capital (CUCAP). This study applied a structural equation modeling to investigate the proposed model and hypotheses. The results showed that HUCAP affects ORCAP and CUCAP and that ORCAP influences CUCAP. INCAP dimensions, with the exception of HUCAP, directly affect BUPER; however, HUCAP indirectly affects BUPER via ORCAP and CUCAP. This study helps upper‐upscale hotel managers identify relevant INCAP dimensions and their indicators to enhance BUPER. Copyright © 2012 John Wiley & Sons, Ltd.
Influence of UV irradiation in low frictional performance of CNx coatings
Authors: Tokoroyama Takayuki , Kamiya Makoto , Umehara Noritsugu , Wang Chao , Diao Dongfeng
Published: January 2012

The influence of ultraviolet (UV) irradiation on low frictional performance of CNx coatings with 100 nm thickness having nitrogen contents of 9%, 14% and 19% deposited on Si(100) substrate by ion beam mixing was investigated in N2 atmosphere environment. Three UV lights of 254, 312 and 365 nm were used to irradiate the surface of CNx / Si(100) for 60 min. The changes of N / C ratio and atomic binding energy in the coating were analysed using Auger electron spectroscopy and X‐ray photoelectron spectroscopy, respectively. The friction coefficient of Si3N4 ball sliding against CNx was measured by a pin‐on‐disc tribometer, and wear tracks were analysed by the transmission electron microscope image. The results showed that UV irradiation on CNx coating can decrease the critical frictional cycles for low friction coefficient and that the mechanism is due to the formation of graphite‐like structure in the topmost CNx coating. Copyright © 2012 John Wiley & Sons, Ltd.
Effect of molybdenum and chromium contents on sliding wear of high‐chromium white cast iron at high temperature
Authors: Pinho Karin Faria , Boher Christine , Scandian Cherlio
Published: January 2012

High‐chromium white cast irons are commonly used in applications requiring excellent abrasion resistance, as in the mining and mineral ore processing industry. Their excellent abrasion resistance is mainly due to their solidification microstructures. In this study, 15 experimental high‐chromium white cast alloys containing different chromium and molybdenum contents and a ratio Cr/C of 10 are examined. The wear experiments were carried out on a pin‐on‐disc tribometer at 700°C. Microstructure has the most important role in dictating friction. It was observed that the wear loss was insignificant compared with that obtained at room temperature. The mean friction coefficient was also lower than that observed at room temperature sliding wear. Copyright © 2012 John Wiley & Sons, Ltd.
Laser doppler perfusion imaging of skin territory to reflect autonomic functional recovery following sciatic nerve autografting repair in rats
Authors: Hu Wen , Yang Min , Chang Jingjian , Shen Zhongyi , Gu Tianwen , Deng Aidong , Gu Xiaosong
Published: January 2012

Peripheral nerve repair requires comprehensive evaluation of functional outcomes of nerve regeneration; however, autonomic nerve function is seldom evaluated probably due to lack of suitable quantitative methods. This study sought to determine whether autonomic functional recovery could be reflected by cold‐induced vasodilation (CIVD) within target skin territory, as monitored by laser Doppler perfusion imaging (LDPI). Rats with sciatic nerve defect injury received autologous nerve grafting, and the plantar surface of the hind feet was subjected to LDPI analysis following nerve repair. The results indicated that at 3 and 6 months after autologous nerve grafting, the plantar surface of the hind foot exhibited the same level of CIVD as contralateral normal side, whereas rats in nerve defect group (negative control) showed significantly reduced CIVD. In addition, suitable nerve regeneration and functional recovery were achieved as assessed by pain sensation tests as well as electrophysiological and immunohistological examinations. Based on the potential influence of local autonomic nerve signals on CIVD, it was possible to evaluate functional recovery of autonomic nerves by using LDPI measurements of dermal CIVD. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.
Lymphaticovenular anastomoses for lymphedema treatment: 18 months postoperative outcomes
Authors: Auba Cristina , Marre Diego , Rodríguez‐Losada Gonzalo , Hontanilla Bernardo
Published: January 2012

The purpose of this work was to report our initial experience with lymphaticovenular anastomoses (LVA), a controversial technique for lymphedema treatment. Although LVA technique was described many years ago, the procedure is not as widespread as it was supposed to be, taking into account the high impact that lymphedema has in the quality of life of patients. Thus, 12 patients, 5 with lower limb and 7 with upper limb lymphedema, underwent LVA surgery under local anesthesia. Two patients were excluded from the study due to the lack of follow‐up. At 18 months, 8 out 10 patients showed a variable objective reduction of the perimeter of the limbs and 9 patients presented a subjective clinical improvement. These results joined to the outcomes of the most experienced surgeons in this field are encouraging, although there are still many issues that need to be addressed with research to optimize the efficacy of this technique. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.
Formation of resonance states due to interaction between resonators in arrays used in dielectric metamaterials
Authors: Chen Fang , Wang Xiaohui , Semouchkina Elena
Published: January 2012

Electromagnetic responses of 1D dielectric resonator arrays variously positioned with respect to the incident wave are investigated in standard waveguides and free space. It is demonstrated that interaction between resonators causes splitting of the array resonance with the formation of several states that exhibit different capabilities for supporting wave transfer. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:555–560, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26596
Widely tunable multiwavelength Brillouin–erbium fiber laser by eliminating self‐lasing cavity modes
Authors: Zhao Junfa , Yang Xiufeng , Zhang Cheng , Tong Zhengrong
Published: January 2012

A linear multiwavelength Brillouin/erbium fiber laser (MWBEFL) with 40 nm tuning range is presented.The characteristic of opposite transmission of Brillouin Stokes (BS) signals in stimulated Brillouin scattering is used as reflector in one end of the fiber laser. The influence of the self‐lasing modes existing in conventional MWBEFLs is eliminated, because there is no physical mirror at one end of the linear cavity. The threshold power is reduced, and the generation of BS signals is enhanced owing to the double‐pass preamplification for the Brillouin pump by the erbium‐doped fiber amplifier before entering the single‐mode fiber. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:612–614, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26604
A silicon quasi‐DOS based on reverse‐biased pn diode
Authors: Zhao Yong , Shao Haifeng , Hu Ting , Yu Ping , Yang Jianyi , Wang Minghua , Jiang Xiaoqing
Published: January 2012

An interference‐type silicon waveguide device, which uses the particularity of the overlap between the optical field and the depletion layer in the reverse‐biased pn diode, has presented a “digital” response characteristic. Using this characteristic, a quasi‐digital optical switch is proposed and discussed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:635–638, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26618
A 0.18‐μm SiGe BiCMOS HBT VCO using diode degeneration
Authors: Jang Sheng‐Lyang , Hsieh Chao‐Wei , Chang Chia‐Wei , Hsue Ching‐Wen
Published: January 2012

This letter proposes a BiCMOS voltage‐controlled oscillator (VCO), which was implemented in the standard TSMC 0.18 μm SiGe 3P6M BiCMOS process. The VCO consists of an nMOSFET cross‐coupled oscillator stacked in series with source degenerated HBT diodes. SiGe HBT has an inherently low flicker noise compared to CMOS devices. At the supply voltage of 1.5 V, the output phase noise of the VCO is −122.01 dBc/Hz at 1 MHz offset frequency from the carrier frequency of 5.6 GHz, and the figure of merit is −190.43 dBc/Hz. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:605–608, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26619
Fiber birefringence measurement based on a beat‐frequency‐interrogated multilongitudinal‐mode distributed bragg reflector erbium‐doped fiber laser
Authors: Zhang Hao , Liu Bo , Jia Chenglai
Published: January 2012

A novel fiber birefringence measurement scheme based on beat frequency interrogation of a multilongitudinal‐mode distributed Bragg reflector erbium‐doped fiber laser is presented and experimentally demonstrated. By analyzing the laser beat generation mechanism, an analytic expression describing fiber birefringence in terms of laser wavelength, laser beat frequency, and the fiber laser geometry has been obtained. Calculation of fiber birefringence based on the experimental observation of laser beat frequency shift indicates that the strain dependence of fiber birefringence turns out a perfect linear monotone decreasing relationship with a strain coefficient of ∼−2.2 × 10–11/με, which is in good agreement with related reports. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:702–707, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26630
A novel bear‐head‐shaped compact UWB monopole antenna enhanced with variable notch‐bands
Authors: Rezaeieh Sasan Ahdi , Abbak Mehmet
Published: January 2012

A novel bear‐head‐shaped compact UWB antenna, with a variable notch‐band is proposed.It has a compact size of 22.5 × 22.5 × 1 mm3. It has variable stop bands that are obtained through changing U‐slot place on the patch, and it presents the selectable stop band frequency ranges. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:667–670, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26631
Reconfigurable penta‐band PIFA for small and slim mobile handsets
Authors: AbuTarboush Hattan F. , Nilavalan R. , Peter T. , Cheung S. W. , Budimir D.
Published: January 2012

A small ultra‐thin planar inverted‐F antenna (PIFA) which can be switchable or tunable using PIN or varactor diodes, respectively, is proposed. The antenna consists of two radiators and connected together using two PIN or varactors diodes. Frequency reconfigurability is obtained by (i) tuning using varactor diodes or (ii) switching using PIN diodes. In the study, when varactors are used, the PIFA is optimized to operate in five frequency bands centered at 0.72, 1.35, 1.98, 3.6, and 5 GHz. Varying the voltages across the varactors can tune these five bands over the range of 45.33% (0.58–0.92 GHz), 17.77% (1.23–1.47 GHz), 26% (1.57–2.04 GHz), 6.66% (3.48–3.72 GHz), and 0.97% (4.99–5.04 MHz), covering the DVB‐H, GSM 800/900, GPS, PCS, DCS, UMTS, Wibro phase III, WiMAX, WLAN systems, etc. If PIN diode switches are used instead, the frequency bands can be switched among different standards, including the DVB‐H, GSM, UMTS, DCS, GPS, WiMAX, and WLAN systems, depending on the switching states. The two radiators are supported using a shorting wall and a shorting pin connected to a small ground plane. Results of intensive investigations using computer simulations and measurements show that the ground plane size has little effects on the performance of the antenna. The effects of user's hand on the S11, radiation patterns and efficiency are also characterized. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:725–729, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26640
The effect of air bubbles on an underwater optical communications system for wireless sensor network applications
Authors: Hagem Rabee M. , Thiel David V. , O'Keefe Steven G. , Fickenscher Thomas
Published: January 2012

An underwater optical link is proposed for communication between sensors on a swimmer during training.Tests in still‐pool water, still‐spa water, and bubbles‐spa water demonstrated the attenuation of the signal. The system uses a light emitting device (LED) (520 nm) and optical detector and is operating at 520 nm. The attenuation constant was found to increase from 0.09 to 2.9 m−1 when the spa jets were turned on. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:729–732, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26664
Hybrid envelope tracking for efficiency enhancement in concurrent dual‐band PAs
Authors: Chen W. , Kwan A. , Ghannouchi F.M.
Published: January 2012

A hybrid envelope tracking scheme is proposed for concurrent dual‐band power amplifiers (PAs). Ideal power supply sweeping measurement shows this scheme can improve the efficiency of dual‐band PAs effectively. The feasibility of this scheme is validated using baseband and analog co‐simulation with real large signal circuit models. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:662–664, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26667
Cystic Fibrosis: An unusual neonatal presentation
Authors: Sankaran Koravangattu , Kalapurackal Mila , Wiebe Sheldon
Published: January 2012

In mechanically ventilated neonates it is not uncommon to observe obstructive atelectasis from various causes. However it is extremely rare to see mucous plugging and massive pulmonary atelectasis in the absence of infection, aspiration, and respiratory distress syndrome in the first couple of days of life. In this report we describe a neonate born with cystic fibrosis (CF) who presented to us with hypoxic respiratory failure, pulmonary hypertension, and hypercarbia without lactic acedemia from sticky mucous plugging and massive lung collapse. Neonatal respiratory distress and wide spread pulmonary atelectasis has not been reported in infants born with CF. Pediatr Pulmonol. 2012; 47:620–622. © 2012 Wiley Periodicals, Inc.
Fluorine: A new element in protein design
Authors: Buer Benjamin C. , Marsh E. Neil G.
Published: January 2012

Fluorocarbons are quintessentially man‐made molecules, fluorine being all but absent from biology. Perfluorinated molecules exhibit novel physicochemical properties that include extreme chemical inertness, thermal stability, and an unusual propensity for phase segregation. The question we and others have sought to answer is to what extent can these properties be engineered into proteins? Here, we review recent studies in which proteins have been designed that incorporate highly fluorinated analogs of hydrophobic amino acids with the aim of creating proteins with novel chemical and biological properties. Fluorination seems to be a general and effective strategy to enhance the stability of proteins, both soluble and membrane bound, against chemical and thermal denaturation, although retaining structure and biological activity. Most studies have focused on small proteins that can be produced by peptide synthesis as synthesis of large proteins containing specifically fluorinated residues remains challenging. However, the development of various biosynthetic methods for introducing noncanonical amino acids into proteins promises to expand the utility of fluorinated amino acids in protein design.
Design and Assembly of Rotaxane‐Based Molecular Switches and Machines
Authors: Yang Wenlong , Li Yongjun , Liu Huibiao , Chi Lifeng , Li Yuliang
Published: January 2012

Mechanically interlocked molecules, such as catenanes and rotaxanes, are at the heart of the development of molecular machines chemistry. They are able to self‐organize, self‐assemble, and self‐control themselves into new materials with potential application as molecular devices. In this review, an overview of some recent progress on molecular machines is given, including new methodologies for their synthesis and self‐assembly and their recent applications as dual or multilevel fluorescent molecular switches, as potential sensors, and even as a molecular‐level transporter. In one development, a molecular machine containing a charge‐transfer chromophore was designed to generate controllable aggregate structures through the reversible movement of a macrocycle over a thread; this was done in order to better understand the application of a molecular shuttle in solid state. Light is shed on how the novel properties and functions of molecular machines are extended, and examples of the ways in which molecular machines have been applied to the design and process of intelligentized systems are provided.
Microarray application in prenatal diagnosis: a position statement from the cytogenetics working group of the Italian Society of Human Genetics (SIGU), November 2011
Authors: Novelli A. , Grati F. R. , Ballarati L. , Bernardini L. , Bizzoco D. , Camurri L. , Casalone R. , Cardarelli L. , Cavalli P. , Ciccone R. , Clementi M. , Dalprà L. , Gentile M. , Gelli G. , Grammatico P. , Malacarne M. , Nardone A. M. , Pecile V. , Simoni G. , Zuffardi O. , Giardino D.
Published: January 2012

A precise guideline establishing chromosomal microarray analysis (CMA) applications and platforms in the prenatal setting does not exist. The controversial question is whether CMA technologies can or should soon replace standard karyotyping in prenatal diagnostic practice. A review of the recent literature and survey of the knowledge and experience of all members of the Italian Society of Human Genetics (SIGU) Committee were carried out in order to propose recommendations for the use of CMA in prenatal testing. The analysis of datasets reported in the medical literature showed a considerable 6.4% incidence of pathogenic copy number variations (CNVs) in the group of pregnancies with sonographically detected fetal abnormalities and normal karyotype. The reported CNVs are likely to have a relevant role in terms of nosology for the fetus and in the assessment of reproductive risk for the couple. Estimation of the frequency of copy number variations of uncertain significance (VOUS) varied depending on the different CMA platforms used, ranging from 0–4%, obtained using targeted arrays, to 9–12%, obtained using high‐resolution whole genome single nucleotide polymorphism (SNP) arrays. CMA analysis can be considered a second‐tier diagnostic test to be used after standard karyotyping in selected groups of pregnancies, namely those with single (apparently isolated) or multiple ultrasound fetal abnormalities, those with chromosomal rearrangements, even if apparently balanced, and those with supernumerary marker chromosomes. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Callosal dysgenesis in fetuses with ventriculomegaly: levels of agreement between imaging modalities and postnatal outcome
Authors: Li Y. , Estroff J. A. , Khwaja O. , Mehta T. S. , Poussaint T. Y. , Robson C. D. , Feldman H. A. , Ware J. , Levine D.
Published: January 2012

Objective

To assess neurodevelopmental outcome of fetuses diagnosed with callosal abnormalities after referral for ventriculomegaly.

Methods

This sub‐analysis of a prospective study of 430 fetuses, which were referred for ventriculomegaly and underwent sonography and magnetic resonance imaging (MRI), included those fetuses with a diagnosis of corpus callosal abnormalities after recruitment into the main study. Between three and six radiologists independently reviewed ultrasound and MR images and recorded central nervous system (CNS) abnormalities, with final diagnoses being decided by consensus. Postnatal outcomes of fetuses with callosal abnormalities were compared between those with and those without other abnormalities.

Results

Callosal abnormalities were detected in 13% (58/430) of the fetuses referred with ventriculomegaly. Callosal dysgenesis was isolated in 24% (14/58) of these cases, with the remainder complicated by CNS, karyotypic or other major abnormalities. Five fetuses diagnosed prenatally as having isolated callosal abnormalities had additional CNS findings on postnatal assessment. Preconference kappa for callosal abnormalities was 0.76 for ultrasound and 0.78 for MRI, indicating that these investigations had a similar level of operator dependence. Neurodevelopmental outcome was normal or showed only mild delay that resolved in 67% (8/12) children with isolated callosal abnormalities compared to 7% (2/27) in those with non‐isolated callosal abnormalities (P = 0.003).

Conclusion

Callosal abnormalities are present in a significant proportion of fetuses with a diagnosis of ventriculomegaly. Isolated callosal abnormalities are associated with normal neurodevelopmental outcome in approximately two‐thirds of fetuses.
Upscaling wind turbines: theoretical and practical aspects and their impact on the cost of energy
Authors: Sieros G. , Chaviaropoulos P. , Sørensen J. D. , Bulder B. H. , Jamieson P.
Published: January 2012

Wind turbines with a rated power of 5 to 6 MW are now being designed and installed, mostly for offshore operation. Within the EU supported UpWind research project, the barriers for a further increase of size, up to 20 MW, are considered. These wind turbines are expected to have a rotor diameter up to 250 m and a hub height of more than 150 m. Initially, the theoretical implications of upscaling to such sizes on the weight and loads of the wind turbines are examined, where it is shown that unfavourable increases in weight and load will have to be addressed. Following that, empirical models of the increase in weight cost and loads as a function of scale are derived, based on historical trends. These include the effects of both scale and technology advancements, resulting in more favourable scaling laws, indicating that technology breakthroughs are prerequisites for further upscaling in a cost‐efficient way. Finally, a theoretical framework for optimal design of large wind turbines is developed. This is based on a life cycle cost approach, with the introduction of generic models for the costs, as functions of the design parameters and using basic upscaling laws adjusted for technology improvement effects. The optimal concept or concepts is obtained as the one that minimizes the total expected costs per megawatt hour (levelized production costs). Copyright © 2011 John Wiley & Sons, Ltd.
Structural analysis and optimisation of transverse flux permanent magnet machines for 5 and 10 MW direct drive wind turbines
Authors: Zavvos A. , Bang D. , McDonald A.S. , Polinder H. , Mueller M.
Published: January 2012

The transverse flux permanent magnet generator offers high power density in terms of active mass. Two configurations of this machine topology (referred to as TFPM‐1 and TFPM‐2) are described, and optimised electromagnetic designs are presented. Direct drive generators require a significant support structure, which is designed to minimise the deflection into the air gap due to inherent electromagnetic attraction forces. The design of these structures is also dependant upon the generator topology. Structural design tools, which can be used in a design office environment, have been developed for the transverse flux machine and verified using commercial numerical modelling packages. Generic disc and arm structures are used. Only static analysis has been performed, but this does provide the designer with an estimate for more detailed design. A comparison of mass is made between the two transverse flux machines and a more conventional iron‐cored permanent magnet generator. The comparison shows that TFPM‐2 has the lowest total mass at 5 and 10 MW, but the conventional iron‐cored machine is lighter than TFPM‐1. Copyright © 2012 John Wiley & Sons, Ltd.
A Helical Silver(I) Complex with 2‐Pyrimidylthioacetate: Structure Variation through Partial Change of Ligand
Authors: Huang Yong‐Qing , Zhao Wei , Chen Jian‐Gu , Zhu Zhao‐Jie , Zhang Hui
Published: January 2012

A chiral helical coordination polymer [Ag(pmta)]n (1) was prepared by the reaction of the asymmetric organic spacer 2‐pyrimidylthioacetic acid (Hpmta) with silver(I) acetate. Complex 1 has a hetero‐chiral coaxial helical structure, which is further extended into a 2D network structure by various supramolecular interactions. Furthermore, complex 1 exhibits strong fluorescence emission in the solid state and modest power second‐harmonic‐generation (SHG) efficiency at room temperature.
Inhibition of Macrophage Oxidative Stress Prevents the Reduction of ABCA‐1 Transporter Induced by Advanced Glycated Albumin
Authors: de Souza Pinto Raphael , Castilho Gabriela , Paim Bruno Alves , Machado‐Lima Adriana , Inada Natalia M. , Nakandakare Edna Regina , Vercesi Aníbal Eugênio , Passarelli Marisa
Published: January 2012

We investigated the role of aminoguanidine and benfotiamine on the inhibition of reactive oxygen species (ROS) generation in macrophages induced by advanced glycated albumin (AGE‐albumin) and its relationship with cell cholesterol homeostasis, emphasizing the expression of the ATP binding cassette transporter A‐1 (ABCA‐1). AGE‐albumin was made by incubating fatty acid‐free albumin with 10 mM glycolaldehyde. ROS production and ABCA‐1 protein level were determined by flow cytometry in J774 macrophages treated along time with control (C) or AGE‐albumin alone or in the presence of aminoguanidine or benfotiamine. Mitochondrial function was evaluated by oxygraphy. Compared to C‐albumin, AGE‐albumin increased ROS production in macrophages, which was ascribed to the activities of NADPH oxidase and of the mitochondrial system. Mitochondrial respiratory chain activity was reduced in cells incubated with AGE‐albumin. ROS generation along time was associated with the reduction in macrophage ABCA‐1 protein level. Aminoguanidine prevented ROS elevation and restored the ABCA‐1 content in macrophages; on the other hand, benfotiamine that promoted a lesser reduction in ROS generation was not able to restore ABCA‐1 levels. Inhibition of oxidative stress induced by AGE‐albumin prevents disturbances in reverse cholesterol transport by curbing the reduction of ABCA‐1 elicited by advanced glycation in macrophages and therefore may contribute to the prevention of atherosclerosis in diabetes mellitus.
Characterization of Free and Bound Lipids among Four Corn Genotypes as Affected by Drying and Storage Temperatures
Authors: Rezaei Karamatollah , Beta Trust , Bern Carl J. , White Pamela J.
Published: January 2012

For whole grains, the most sensitive components to the environmental changes are the lipids. In the current study, the effects of drying temperature (27 and 93 °C) and storage temperature (4 and 27 °C) on the fatty acid (FA) levels and lipid classes of endosperm lipids on four selected corn genotypes were investigated during a 12‐month storage period. Storage temperature indicated greater impact on the FA composition than did the drying temperature. The ratio of saturated to unsaturated fatty acids, which was around 0.20–0.22 levels in the free lipid (FL) fractions of all corn types studied here, did not change significantly due to the drying and storage temperatures. However, in the bound lipid (BL) fractions, it was changed by a change in the drying and storage temperature in some of the corn types. Some changes were also found in the lipid classes within the FL and BL fractions of the studied corn samples. No lysophosphatidylcholine (LPC) was found in the FL fractions. In the BL fractions of two of the corn samples, the level of free fatty acids (FFA) increased more likely due to the deterioration of LPC. The results of the current study indicated a possible migration of triglycerides and FFA between the FL and BL fractions due to drying and storage at higher temperatures.
A Retrospective Multi-Centre Study on the Outcome of Laparoscopic Simple Nephrectomies
Authors: El Kafsi Jihène , Sullivan Mark , Jones Adam
Published: January 2012

Objective:

A review of our experience in laparoscopic simple nephrectomies from May 2003 to May 2011 in the Urology Departments in Oxford and Reading.

Method:

A total of 100 patients, median age 46years (IQR = 27, range 17–82) underwent a laparoscopic simple nephrectomy for benign disease in the 8-year period reviewed. Data on patient demographics, pre-operative diagnosis, operating time, operative approach, estimated blood loss, in hospital post-operative complications and length of stay were collected from electronic databases held in the departments and regularly updated.

Results:

100 laparoscopic simple nephrectomies were performed between May 2003 and May 2011. Median operating time was 180min (IQR = 60min, range 75–375min). Median estimated blood loss was 50ml (IQR = 50ml, range 10–1000ml). Median length of stay was 3 days (IQR = 3, range 2–14 days). No patients suffered from significant changes in renal function. Three patients were transfused between 2 and 3 units. 26 complications were recorded for 22 patients. Four were Clavien grade IIIb and 22 were grades I—II.

Conclusion:

Although laparoscopic simple nephrectomy is feasible and confers the usual benefits of laparoscopy it is often a technically challenging procedure. We used the Clavien Classification to standardise complications of laparoscopic simple nephrectomies. The term “simple” nephrectomy is misleading and should be changed.
Prenatal care and basic emergency obstetric care services provided at primary healthcare facilities in rural Nigeria
Authors: Okoli Ugo , Abdullahi Mohammed J. , Pate Muhammad A. , Abubakar Isa S. , Aniebue Nonye , West Charles
Published: January 2012

Objective

To assess the availability of prenatal care and basic emergency obstetric care services at primary healthcare (PHC) facilities in rural Nigeria.

Methods

In total, 652 PHC facilities enrolled in the Midwives Service Scheme, a government‐funded program designed to reduce the national shortage of skilled birth attendants, were surveyed.

Results

In all, 44.0% of the PHC facilities evaluated did not provide all components of prenatal care, and only 39.0% of all pregnant women nationwide attended prenatal care clinics 4 or more times. In addition, 52.2% of the facilities were not distributing insecticide‐treated nets to pregnant women, while only 36.8% of the PHC facilities provided services to prevent mother‐to‐child transmission of HIV. By contrast, 70.0% of the PHC facilities had access to antibiotics for the treatment of uncomplicated sepsis. Only 11.0% of clinics reported the use of vacuum extraction during labor and 36.8% provided post‐abortion care services. Treatment for pre‐eclampsia and eclampsia was initiated at 40.0% and 28.0% of PHC facilities, respectively, prior to referral.

Conclusion

The present study provides useful information on the state of prenatal and basic emergency obstetric care in rural Nigeria. The data obtained indicate that changes are needed to achieve related Millennium Development Goals.