bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of chronic polybrominated diphenyl ether exposure on gonadal development in the northern leopard frog, Rana pipiens
Authors: Van Schmidt Nathan D. , Cary Tawnya L. , Ortiz-Santaliestra Manuel E. , Karasov William H.
Published: November 2011

Polybrominated diphenyl ethers (PBDEs) are bioaccumulative, persistent organic pollutants used as flame retardants in consumer goods. Concentrations of PBDEs in North American wildlife have been increasing for decades and been shown to have estrogenic effects on sexual development. No studies, however, have examined the effects of PBDEs on the sexual development of North American frogs at ecologically relevant concentrations. This study examined the effects of five dietary concentrations of DE-71 (0, 1.1, 6.1, 71.4, and 634 ng ΣPBDEs/g diet), a technical PBDE mixture, on the gonadal development of the northern leopard frog, Rana pipiens. Tadpoles were exposed chronically from the time they became free-swimming until metamorphosis. Frogs were killed either at metamorphic climax or 10 weeks after completing metamorphosis, processed for histology, and examined for alterations in sexual development. The experimental group exposed to PBDEs at 1.1 ng/g had a significantly larger proportion of females compared with the expected 50:50 sex ratio. At 10 weeks post-metamorphosis, male frogs exposed to 6.1 and 71.4 ng/g had significantly smaller testes, but all other measure of gonadal development tested showed no effects. No intersex or increased incidence of gonadal abnormality were detected. These findings indicate that PBDEs may disrupt sexual differentiation in frogs at low, environmentally relevant concentrations. Environ. Toxicol. Chem. 2012;31:347–354. © 2011 SETAC
Targeting tumor hypoxia in nasopharyngeal carcinoma
Authors: Hong Bo , Lui Vivian Wai Yan , Hashiguchi Masumi , Hui Edwin Pun , Chan Anthony Tak‐Cheung
Published: November 2011

Background

Nasopharyngeal carcinoma (NPC) is an endemic head and neck cancer in Southeast Asia. Although concurrent chemoradiotherapy generally results in good clinical response for early diseases, posttreatment relapse and distant metastasis are major causes for NPC deaths. There is an urgent need for more effective therapies for advanced NPC. Recent studies have demonstrated tumor hypoxia can be a therapeutic target in NPC.

Methods

A Medline review of articles published on clinical and preclinical studies targeting tumor hypoxia was performed.

Results

Studies published to date showed that tumor hypoxia is common in NPC and it is associated with disease progression and resistance to therapy. Several mechanisms have been proposed on the role of tumor hypoxia in NPC cell survival, angiogenesis, and metabolism. Studies reported by us and by others have demonstrated the therapeutic potential of targeting tumor hypoxia in NPC.

Conclusions

Cumulative studies indicate that targeting tumor hypoxia could be an effective approach for NPC treatment. © 2011 Wiley Periodicals, Inc. Head Neck, 2013
Variant in the glucokinase regulatory protein ( GCKR ) gene is associated with fatty liver in obese children and adolescents
Authors: Santoro Nicola , Zhang Clarence K. , Zhao Hongyu , Pakstis Andrew J. , Kim Grace , Kursawe Romy , Dykas Daniel J. , Bale Allen E. , Giannini Cosimo , Pierpont Bridget , Shaw Melissa M. , Groop Leif , Caprio Sonia
Published: November 2011

Recently, the single nucleotide polymorphism (SNP) identified as rs1260326, in the glucokinase regulatory protein (

GCKR

), was associated with hypertriglyceridemia in adults. Because accumulation of triglycerides in hepatocytes represents the hallmark of steatosis, we aimed to investigate whether this variant might be associated with fatty liver (hepatic fat content, HFF%). Moreover, because recently rs738409 in the

PNPLA3

and rs2854116 in the

APOC3

were associated with fatty liver, we explored how the

GCKR

SNP and these two variants jointly influence hepatosteatosis. We studied 455 obese children and adolescents (181 Caucasians, 139 African Americans, and 135 Hispanics). All underwent an oral glucose tolerance test and fasting lipoprotein subclasses measurement by proton nuclear magnetic resonance. A subset of 142 children underwent a fast gradient magnetic resonance imaging to measure the HFF%. The rs1260326 was associated with elevated triglycerides (Caucasians

P

= 0.00014; African Americans

P

= 0.00417), large very low-density lipoprotein (VLDL) (Caucasians

P

= 0.001; African Americans,

P

= 0.03), and with fatty liver (Caucasians

P

= 0.034; African Americans

P

= 0.00002; and Hispanics

P

= 0.016). The

PNPLA3

, but not the

APOC3

rs2854116 SNP, was associated with fatty liver but not with triglyceride levels. There was a joint effect between the

PNPLA3

and

GCKR

SNPs, explaining 32% of HFF% variance in Caucasians (

P

= 0.00161), 39.0% in African Americans (

P

= 0.00000496), and 15% in Hispanics (

P

= 0.00342).

Conclusion :

The rs1260326 in

GCKR

is associated with hepatic fat accumulation along with large VLDL and triglyceride levels.

GCKR

and

PNPLA3

act together to convey susceptibility to fatty liver in obese youths.
In vitro model of stromal and epithelial immortalized endometriotic cells
Authors: Boccellino Mariarosaria , Quagliuolo Lucio , Verde Annarita , La Porta Raffaele , Crispi Stefania , Piccolo Maria Teresa , Vitiello Antonio , Baldi Alfonso , Signorile Pietro Giulio
Published: November 2011

Endometriosis is a relatively common chronic gynecologic disorder that usually presents with chronic pelvic pain or infertility. It results from implantation of endometrial tissue outside the uterine cavity. Despite its frequency and its impact on quality of life, the understanding of pathogenesis of endometriosis remains incomplete and its treatment remains controversial. In this work, we established a suitable in vitro model system of immortalized human endometriotic cell line taking advantage of the human telomerase reverse transcriptase. The results demonstrate that these cells retain the natural characteristics of endometrial cells in term of phenotype and of functional expression of estrogen and progesterone receptors, without chromosomal abnormalities. In conclusion, these cells are potentially useful as an experimental model to investigate endometriosis biology. J. Cell. Biochem. 113: 1292–1301, 2012. © 2011 Wiley Periodicals, Inc.
Clinical and sonographic features of uncommon primary ovarian malignancies
Authors: Alcázar Juan Luis , Guerriero Stefano , Pascual María Ángela , Ajossa Silvia , Olartecoechea Begoña , Hereter Lourdes
Published: November 2011

Purpose.

To describe the gray‐scale and color Doppler ultrasound features of uncommon (<5% prevalence) primary malignant ovarian tumors.

Methods:

Retrospective analysis of 98 masses in 89 patients (median age: 50.4 years old, ranging from 15 to 81 years) diagnosed as having an uncommon primary ovarian malignancy. All patients had undergone transvaginal color Doppler ultrasound according to a standardized protocol prior to surgical tumor removal. Ultrasound features analyzed were laterality, presence of ascites, tumor volume, morphologic appearance (unilocular, multilocular, unilocular‐solid, multilocular‐solid, and solid), and color Doppler score (subjective assessment of the amount of flow as absent, scanty, moderate, or abundant).

Results.

Pathological diagnoses included uncommon epithelial tumors (n = 59), germ cell tumors (n = 10), sex cord‐stromal tumors (n = 11), sarcoma (n = 9), and lymphoma (n = 9). Germ cell tumors presented in younger women (p < 0.001). Germ cell tumors, sex cord‐stromal tumors, sarcomas, and lymphomas were significantly more often solid as compared with epithelial malignancies, which appeared more frequently as complex (cystic‐solid) tumors (p < 0.001). There were no differences in color Doppler score between the various types of tumors.

Conclusions.

Germ cell tumors, sex cord‐stromal tumors, sarcomas, and lymphomas tend to appear as unilateral solid tumors. Color Doppler score is not useful for discriminating among uncommon primary ovarian malignancies. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound, 2012
Laser photostimulation (660 nm) of wound healing in diabetic mice is not brought about by ameliorating diabetes
Authors: Peplow Philip V. , Chung Tzu‐Yun , Baxter G. David
Published: November 2011

Background and Objectives

We have used a 660‐nm laser diode in genetic diabetic mice to stimulate the healing of wounds covered with a Tegaderm HP dressing that causes a retardation of contraction (splinted wounds). It is possible that the stimulation of healing could be due to possible diabetes‐modifying properties of laser light. This has been examined by using the 660 nm laser to irradiate non‐wounded diabetic mice with the same dose and at same location as for wounded diabetic mice.

Materials and Methods

Twenty‐two diabetic mice were used and divided into two equal groups. Body weight and water intake of mice were measured daily for 7 days prior to the start of treatment (Day 0). The left flank of mice in the experimental group was irradiated with 660 nm laser, 100 mW, 20 seconds/day, 7 days; for mice in the control group, the left flank was sham‐treated with the laser power supply not switched on. Body weight and water intake of mice were measured to Day 14. On Day 14, the mice were fasted for 4 hours, anaesthetized with sodium pentobarbitone (i.p.) and blood collected by cardiac puncture into heparinized tubes. The plasma was assayed for glucose and glycated hemoglobin A1c.

Results

There were no significant differences in body weight and water intake over 22 days between mice in the experimental group and control group. On day 14, the mean blood plasma glucose level was not significantly different between the two groups; glycated hemoglobin A1c was not detected in the samples.

Conclusion

Irradiation of the left flank in diabetic mice with 660 nm laser system does not have a significant hypoglycemic effect, and the laser‐stimulated healing of wounds in diabetic mice is due to cellular and biochemical changes in the immediate wound environment. Lasers Surg. Med. 44:26–29, 2012. © 2011 Wiley Periodicals, Inc.
Myocardial electrical conduction block induced by photosensitization reaction in exposed porcine hearts in vivo
Authors: Ito Arisa , Miyoshi Shunichiro , Kimura Takehiro , Takatsuki Seiji , Fukumoto Kotaro , Fukuda Keiichi , Arai Tsunenori
Published: November 2011

Background and Objective

This study proposes photosensitization reaction for non‐thermal cardiac ablation in arrhythmia therapy. Acute and chronic phase experiments were conducted in exposed porcine hearts to demonstrate the photosensitization reaction‐induced myocardial electrical conduction block in vivo.

Study Design/Materials and Methods

The porcine left atrial appendage was exposed under an open‐chest procedure. Then, a water‐soluble chlorin photosensitizer, NPe6, was injected into the pigs intravenously at 5 or 10 mg/kg. About 15 or 30 minutes after the injection, a 663‐nm continuous‐wave diode laser was irradiated on the surface of the atrial appendage through a silica optical fiber. The laser energy was delivered to the tissue point by point at an energy density of 50–208 J/cm2.

Results

Acute and chronic tissue damages as a result of the photosensitization reaction were determined by electrophysiology and histology, respectively. The change in the myocardial conduction time between two electrodes was measured immediately after the completion of the 35‐mm irradiation line between the electrodes. The conduction delay of 35.5 milliseconds might be due to the change in the conduction pathway induced by transmural acute conduction block with the photosensitization reaction. The tissue temperature increase in the irradiated area was approximately 12.8°C. Azan‐staining revealed about 1‐mm transmural fibrosis of the atrial appendage at 2 weeks after the irradiation (50 J/cm2).

Conclusions

The results suggest that the photosensitization reaction might induce acute and chronic myocardial electrical conduction block. Cardiac ablation with the photosensitization reaction might be a non‐temperature‐mediated methodology for arrhythmia therapy. Lasers Surg. Med. 43:984–990, 2011. © 2011 Wiley Periodicals, Inc.
Laser thermal therapy: Real‐time MRI‐guided and computer‐controlled procedures for metastatic brain tumors
Authors: Carpentier Alexandre , McNichols Roger J. , Stafford R. Jason , Guichard Jean‐Pierre , Reizine Daniel , Delaloge Suzette , Vicaut Eric , Payen Didier , Gowda Ashok , George Bernard
Published: November 2011

Background and Objective

We report the final results of a pilot clinical trial exploring the safety and feasibility of real‐time magnetic resonance‐guided laser‐induced thermal therapy (MRgLITT) for treatment of resistant focal metastatic intracranial tumors.

Study Design

In patients with chemotherapy, whole‐brain radiation, and radiosurgery resistant metastatic intracranial tumors, minimally invasive stereotaxic placement of a saline‐cooled interstitial fiberoptic laser applicator under local anesthesia was followed by laser irradiation during continuous magnetic resonance imaging (MRI) scanning. A computer workstation extracted real‐time temperature‐sensitive information for feedback control over laser delivery. A total of 15 metastatic tumors were treated in 7 patients. Patients were followed with physical exam and imaging for 30 months.

Results

In all cases, the procedure was well tolerated, and patients were discharged home within 24 hours. Follow‐up imaging at up to 30 months showed an acute increase in apparent lesion volume followed by a gradual and steady decrease. No tumor recurrence within thermal ablation zones was noted. Kaplan–Meier analysis indicated that the median survival was 19.8 months.

Conclusion

Real‐time magnetic resonance (MR) guidance of laser‐induced thermal therapy (LITT) offers a high level of control. This tool therefore enables a minimally invasive option for destruction and treatment of resistant focal metastatic intracranial tumors. MR‐guided LITT appears to provide a safe and potentially effective treatment for recurrent focal metastatic brain disease. A larger phase II and III series would be of interest to quantify potential median survival advantage. Lasers Surg. Med. 43:943–950, 2011. © 2011 Wiley Periodicals, Inc.
Stepped‐width planar monopole antenna with circular parasitic plane for wireless local area network/worldwide interoperability for microwave access applications
Authors: Pan Chien‐Yuan , Chiu Kuo‐Yung , Jan Jen‐Yea , Chen Hua‐Ming
Published: November 2011

This article demonstrates a new and simple dual‐band design for the planar monopole antenna.The design basically consists of a stepped‐width radiating monopole element with a microstrip feedline for excitation and a circular parasitic plane for generating a resonant mode in the upper band. The measured impedance bandwidth for 10‐dB return loss is from 1.98 to 3.22 GHz and 4.92 to 6.93 GHz, covering the 2.4/5.2/5.8‐GHz wireless local area network bands and 2.5/5.5‐GHz worldwide interoperability for microwave access bands. The measured radiation patterns are similar to typical monopole‐antenna radiation characteristics. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:219–222, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26447
Design of half elliptical ring monopole antennas with elliptical slot in ground plane for future UWB applications
Authors: Ahmed Osama M. H. , Elboushi Ayman M. , Sebak Abdel‐Razik
Published: November 2011

In this letter, a microstrip fed ultra‐wideband (UWB) antenna with different band rejection techniques is presented. The designed antennas consist of a defected ground plane with an elliptical slot and elliptical shaped radiating element. The measured and calculated impedance bandwidth of the proposed antenna ranges from 3 to 14 GHz for a return loss (S11) less than −10 dB. Also, it has a relatively stable radiation patterns over its whole frequency band of interest. Two different techniques have been proposed to achieve band‐notch characteristic in the 5.0‐ to 6.0‐GHz wireless local area network frequency band. The first one uses L‐shaped parasitic strip into the radiating patch, whereas the other one uses two rectangular slits cut away from the ground plane creating defected ground structure. The proposed antenna is considered a good candidate for UWB applications. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:181–187, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26449
A compact circular corner monopole antenna for UWB application
Authors: Yang Lingsheng , Yoshitomi Kuniaki
Published: November 2011

A compact microstrip‐fed planar monopole antenna for ultrawideband application is presented.The antenna is formed with a rectangular patch and two quarter circles at each side of the lower corners of the patch. By applying a notch in the truncated ground to improve the impedance bandwidth, a 4.9:1 (3.0–14.7 GHz) S11 <−10 dB‐bandwidth is realized. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:147–150, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26462
A low‐loss planar goubau line and a coplanar‐PGL transition on high‐resistivity silicon substrate in the 57–64 GHz band
Authors: Emond J. , Grzeskowiak M. , Lissorgues G. , Protat S. , Deshours F. , Richalot E. , Picon O.
Published: November 2011

Planar Goubau line (PGL) structures on high‐resistivity silicon are adapted to the 57–64 GHz frequency band. Simulations and measurements show a lower attenuation than with the coplanar line is obtained. Very low losses are attained with a measured average attenuation of 0.064 dB/mm on the whole band. To allow this measurement, coplanar‐PGL transitions have been optimized. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:164–168, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26470
Small monopole antenna design with band‐notched characteristics using inverted T‐shaped form on the patch
Authors: Moosazadeh M. , Esmati Z.
Published: November 2011

In this letter, a printed monopole antenna, consisting of a square patch and a ground plane truncated with two mirror C‐shaped notches for ultra wideband application with variable frequency band‐notch characteristics, is presented.In this antenna, by inserting a modified T‐shaped form inside a rectangular slot cut with variable dimensions on the radiating patch, frequency band‐stop performance is obtained. The proposed antenna operates in the 3.1–10.6‐GHz band and has small overall dimensions of 12 × 16 × 1.6 mm3, while showing the notched band from 5 to 5.9 GHz. The effect of the ground plane notch on the optimization of the voltage standing wave ratio (VSWR) is discussed in detail. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:100–103, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26472
Compact multiband mimo antenna for next generation USB dongle applications
Authors: Han Minseok , Choi Jaehoon
Published: November 2011

A compact multiband multiple‐input multiple‐output (MIMO) antenna with an embedded chip inductor is proposed for next generation universal serial bus (USB) dongle applications. The proposed MIMO antenna consists of a longer strip with an embedded chip inductor and a shorter radiating strip. The longer radiating strip with a 15‐nH embedded chip inductor has a length of only about 34 mm (about 0.08 wavelength at 0.77 GHz), but it supports a wide resonant mode for long‐term evolution band 13 (LTE Band 13; 0.746–0.787 GHz) and wireless broadband band (WiBro band; 2.3–2.4 GHz) services. The shorter radiating strip has a length of 12 mm (about 0.1 wavelength at 2.0 GHz) and provides a wide resonant mode at about 2 GHz for wideband code division multiple access band (1.92–2.17 GHz) operation. The two radiating strips occupy a small printed area of about 500 mm2 on the system circuit board of a USB dongle. The proposed MIMO antenna has an isolation of approximately 17 dB at LTE band 13 and the envelope correlation coefficient (ECC) of the two antennas is less than 0.4 over the whole LTE band 13. To evaluate the performance of the proposed antenna, key performance parameters such as the total efficiency, ECC, mean effective gain (MEG), and the MEG ratio are analyzed. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:246–250, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26478
Process and temperature insensitive CMOS oscillator using current sinker compensation
Authors: Kim M. , Jung S. , Yang Y.
Published: November 2011

This article presents a simple complementary metal‐oxide‐semiconductor (CMOS) ring oscillator using a voltage‐controlled delay and RS‐latch, including a compensation circuit for the process and temperature variations.The compensation circuit, added to the original bias circuit, is a simple current sinker which is referenced through a current mirror circuit. The proposed oscillator was designed and implemented using a 0.13 μm CMOS process. The oscillator exhibited a significantly improved frequency variation of ±4.25% for a wide temperature range of from −40 to 80°C. Without the compensation circuit, the variation would have been ±13.39% from the center frequency of 2.33 MHz. The oscillator also showed a low sensitivity of 0.084% to process variation, according to a Monte‐Carlo simulation with 1000 iterations. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:160–163, 2012, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26493
A wideband circularly polarized antenna with Γ‐shaped feed
Authors: Fu Guang , Zhang Zhi‐Ya , Zuo Shao‐Li , Lei Juan , Gong Shu‐Xi
Published: November 2011

A wideband circularly polarized antenna with Γ‐shaped feed is presented.The proposed antenna is formed by two shorted bowtie patch antennas and two L‐shaped electric dipoles. It can achieve a measured impedance bandwidth for voltage standing wave ratio (VSWR) ≤ 1.5 of 52% and a 3‐dB axial ratio bandwidth of 55%. For the entire half‐power beamwidth, the axial ratio can be kept below 3 dB. A prototype has been fabricated and tested, and the experimental results validate the design procedure. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:153–156, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26503
Wideband quasi‐yagi antenna fed by microstrip‐to‐slotline transition
Authors: Ta Son Xuat , Kim Byoungchul , Choo Hosung , Park Ikmo
Published: November 2011

This letter presents a wideband quasi‐Yagi antenna fed by a microstrip‐to‐slotline transition. The transition consists of a microstrip radial stub and slot radial stub, both at 90° but with different radii, to achieve wideband impedance matching. The antenna has a measured fractional bandwidth of approximately 46% (4.64–7.42 GHz) for a −10 dB reflection coefficient and a flat gain of 6.0–6.75 dBi with a front‐to‐back ratio and cross‐polarization level better than 17 and −15 dB, respectively, across the bandwidth. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:150–153, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26504
Raman amplified access networks with pump signal recycling for electrical power conversion
Authors: André P.S. , Lima M. J. N. , Rocha A. M. , Fernandes N. , Granada M. , Almeida T. , Chang Jin , Lan Rao , Xiang‐Jun Xin
Published: November 2011

Nowadays, the structure of the passive optical networks is evolving, to keep the network survivability, the powering of some elements in this kind of networks is a key issue. In this work we propose the recycling of the Raman pump remaining optical power at the receiver to be converted to electrical power. With a 24 dBm optical pump signal a 8 dB on/off gain over 25 km of single mode optical fiber was achieved. Also, the recycling of the pump signal generated 18.1 mW of electrical power at the receiver. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:116–119, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26506
A miniaturized wideband coupled‐line microstrip balun using a new defected ground
Authors: Chiu Cheng‐Nan , Yu Shau‐Jiun
Published: November 2011

This letter proposes a new miniaturized wideband coupled‐line microstrip balun and its design procedure based on an original finding. This finding suggests that the coupled‐line microstrip balun can be realized by using a much smaller high‐pass ground defect instead of a bandstop ground defect. The newly proposed balun is derived initially from a coupled‐line microstrip balun with a typical dumbbell‐shaped defected ground. Following the proposed three‐step design procedure, the size of the final balun is only about 8.3% of the size of the initial one (only 0.00512 wavelength square at the central frequency). In addition, the final balun possesses immunity against the influence of the supporting material. Balun prototypes were created and investigated. Both the simulated and measured results demonstrate the compactness and wideband performance. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:254–257, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26518
A note on generating finer‐grain parallelism in a representation tree
Authors: Vömel Christof
Published: November 2011

The representation tree lies at the heart of the algorithm of Multiple Relatively Robust Representations for computing orthogonal eigenvectors of a symmetric tridiagonal matrix without Gram–Schmidt. A representation tree describes the incremental shift relations between relatively robust representations of eigenvalue clusters of an unreduced tridiagonal matrix, which are needed to strongly separate close eigenvalues in the relative sense. At the bottom of the representation tree, each leaf defines a relatively isolated eigenvalue to high relative accuracy.

The shape of the representation tree plays a pivotal role for complexity and available parallelism: a deeper tree consisting of multiple levels of nodes involves tasks associated to more work (i.e., eigenvalue refinement to resolve eigenvalue clusters) and less parallelism (i.e., a longer critical path as well as potential data movement and synchronization). An embarrassingly parallel, ideal tree on the other hand consists of a root and leaves only.

As highly parallel hybrid graphics processing unit/multicore platforms with large memory now become available as commodity platforms, exploiting parallelism in traditional algorithms becomes key to modernizing the components of standard software libraries such as LAPACK. This paper focuses on LAPACK's Multiple Relatively Robust Representations algorithm and investigates the critical case where a representation tree contains a long sequential chain of large (fat) nodes that hamper parallelism. This key problem needs to be addressed as it concerns all sorts of computing environments, distributed computing, symmetric multiprocessor, as well as hybrid graphics processing unit/multicore architectures. We present an improved representation tree that often offers a significantly shorter critical path and finer computational granularity of smaller tasks that are easier to schedule. In a study of selected synthetic and application matrices, we show that an average 75% reduction in the length of the critical path and 82% reduction in task granularity can be achieved. Copyright © 2011 John Wiley & Sons, Ltd.
Spectroscopic studies of protein folding: Linear and nonlinear methods
Authors: Serrano Arnaldo L. , Waegele Matthias M. , Gai Feng
Published: November 2011

Although protein folding is a simple outcome of the underlying thermodynamics, arriving at a quantitative and predictive understanding of how proteins fold nevertheless poses huge challenges. Therefore, both advanced experimental and computational methods are continuously being developed and refined to probe and reveal the atomistic details of protein folding dynamics and mechanisms. Herein, we provide a concise review of recent developments in spectroscopic studies of protein folding, with a focus on new triggering and probing methods. In particular, we describe several laser‐based techniques for triggering protein folding/unfolding on the picosecond and/or nanosecond timescales and various linear and nonlinear spectroscopic techniques for interrogating protein conformations, conformational transitions, and dynamics.
A comprehensive library of blocked dipeptides reveals intrinsic backbone conformational propensities of unfolded proteins
Authors: Oh Kwang‐Im , Lee Kyung‐Koo , Park Eun‐Kyung , Jung Youngae , Hwang Geum‐Sook , Cho Minhaeng
Published: November 2011

Despite prolonged scientific efforts to elucidate the intrinsic peptide backbone preferences of amino‐acids based on understanding of intermolecular forces, many open questions remain, particularly concerning neighboring peptide interaction effects on the backbone conformational distribution of short peptides and unfolded proteins. Here, we show that spectroscopic studies of a complete library of 400 dipeptides reveal that, irrespective of side‐chain properties, the backbone conformation distribution is narrow and they adopt polyproline II and β‐strand, indicating the importance of backbone peptide solvation and electronic effects. By directly comparing the dipeptide circular dichroism and NMR results with those of unfolded proteins, the comprehensive dipeptides form a complete set of structural motifs of unfolded proteins. We thus anticipate that the present dipeptide library with spectroscopic data can serve as a useful database for understanding the nature of unfolded protein structures and for further refinements of molecular mechanical parameters. Proteins 2011; © 2011 Wiley Periodicals, Inc.
Does natural weathering change the stable isotope composition (2H, 13C, 15N, 18O and 34S) of cattle hair?
Authors: Auerswald Karl , Rossmann Andreas , Schäufele Rudi , Schwertl Michael , Monahan Frank J. , Schnyder Hans
Published: November 2011

Stable isotope analysis of hair has found applications in many fields of science because it provides a temporally resolved, fairly stable isotopic archive of mammalian individuals. We investigated whether this hair archive is modified by natural weathering while attached to a living animal. We analyzed the tail switch hairs of one suckler cow, sampled seven times over a period of four annual summer pasture–winter stall feeding cycles. We compared relative isotope ratios (δ2H, δ13C, δ15N, δ18O and δ34S) of sections of hair that grew simultaneously but were exposed to natural weathering conditions over different periods of time. Natural wear caused a loss of mass of approx. 0.13% day–1, with no apparent effect of environmental conditions. Changes in δ2H, δ13C, δ15N and δ18O were below the detection limit, indicating that hair is a reliable archive for the isotopes of these elements. In contrast, δ34S values increased during the grazing period by about 1 ‰, with exposure to UV radiation appearing to have a major influence on this result. The δ34S values decreased during the subsequent stall period, probably due to abrasion. Seasonal variation in δ34S may indicate alternating environments that differ in their weathering conditions. Copyright © 2011 John Wiley & Sons, Ltd.
Estimation of damping ratio of TV towers based on ambient vibration monitoring
Authors: Amiri Mohammad Mahdi , Yahyai Mahmood
Published: November 2011

Damping ratio is an important component in the dynamic analysis and plays a key role in design of supertall buildings. It is necessary to have reliable field measurement records for estimation of structural dynamic characteristics. The main objective of this paper is to estimate eigen mode damping ratio of TV towers as a kind of supertall buildings with the height of more than 250 m. In this regard, field measurements were performed on Milad TV tower, located in Tehran, which has a height of 435 m by ambient vibration monitoring. Damping ratio of this tower is determined using random decrement technique and compared with available data of a few other TV towers.

For proposing eigen mode damping ratio of TV towers, it is shown that Rayleigh damping coefficients could not be calibrated properly for tall slender TV towers. A damping estimation chart of TV tower that is a function of natural frequency and structural aspect ratio is proposed, and the chart validity has been checked with field measurement results of other TV towers. The chart shows that structural damping for wind analysis proposed in design codes and standards is overestimated for tall slender TV towers. Copyright © 2011 John Wiley & Sons, Ltd.
Modeling soil–foundation–structure interaction
Authors: Finn WD Liam , Pandey Bishnu H , Ventura Carlos E
Published: November 2011

This paper offers a guided tour through the various ways, used in practice, of accounting for soil–structure interaction in design and analysis, ranging from a complete analysis of the total combined system of foundation, soil and structure to approximate models of the system. The focus is on three types of structures: bridges on pile foundations, tall buildings with several levels of underground parking and large basement slabs with shallow embedment. The paper also reports on preliminary results from the study of seismic pressures against deep basement walls commissioned by the Structural Engineers Association of British Columbia. Copyright © 2011 John Wiley & Sons, Ltd.
Polish artificial heart program
Authors: El Fray Miroslawa , Czugala Monika
Published: November 2011

Despite significant advances in the development of artificial heart substitutes, anthrombogenic materials and surfaces remain to be the main challenge for implants, which can prevent thrombosis that leads to rejection. The goal of material engineering is essentially to design polymeric materials of high durability and optimal thrombogenicity in mechanical heart prosthesis, being developed recently in a frame of the polish artificial heart program. For these reasons, various surface modifications are being continuously developed for a ‘gold standard’ material, which is a polyurethane (PU) thermoplastic elastomer and they will be shortly reviewed. However, new polymeric materials can meet medical word's attention if they are able to provide similar or better characteristics in term of bulk and surface properties. Specifically, if they will show appropriate surface topography, which is the most influential in determining the response of live tissues toward biomaterials. Nanostructured polyester thermoplastic elastomers of high biodurability as an alternative to PU materials for artificial heart are challenging new materials, and they will be discussed briefly.WIREs Nanomed Nanobiotechnol2012, 4:322–328. doi: 10.1002/wnan.175

This article is categorized under:

Implantable Materials and Surgical Technologies > Nanomaterials and Implants

Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement
Mixed Micellization Behavior of m‐2‐m Gemini Surfactants with Some Conventional Surfactants at Different Temperatures
Authors: Sood Ashwani K. , Singh Kultar , Kaur Jasbir , Banipal Tarlok S.
Published: November 2011

Mixed micellization behavior of dimeric cationic surfactants ethanediyl‐1,2‐bis(dimethyl alkyl ammonium bromide) (m‐2‐m where m = 10, 12) with conventional single chain cationic surfactants like cetyltrimethyl ammonium bromide (CTAB), cetylpyridinium chloride (CPC), tetradecyl dimethyl benzyl ammonium chloride (C14BCl) and cetyl dimethyl benzyl ammonium chloride (C16BCl) were studied in aqueous and aqueous polyethylene glycol (PEG) solutions at 298.15, 308.15 and 318.15 K respectively using conductometric and viscometric methods. In aqueous solutions, all the combinations (except 12‐2‐12 + CTAB) were found to behave nonideally with mutual synergism which decreases with increase in temperature. Various thermodynamic parameters of micellization like , and were evaluated and discussed. Similarly in presence of PEG, the thermodynamic properties like , and associated with the transfer of surfactant monomers from the medium consisting of polymer‐free mixed micelles to polymer‐bound mixed micelles at various temperatures were also calculated. The negative values of show that aggregation process is more exothermic than micellization whereas the negative values of indicate that the presence of polymer bound mixed micelles decreases the degree of randomness of the system. Viscosity studies show that in aqueous solutions all the combinations of 10‐2‐10/12‐2‐12 display negative departure in the relative viscosity (ηr) from additivity rule which decreases with increase in temperature. Similarly in the presence of 5% PEG solutions the magnitude of the negative departure decreases for all the combinations and becomes positive in the case of C14BCl and CPC combinations with the studied gemini surfactants at higher temperatures.
Wie groß sind die kleinen genetischen Risiken?
Authors: Heid I.M. , Winkler T.W. , Grassmann F. , Weber B.H.F.
Published: November 2011

Während Familienstudien sich als sehr geeignet zeigen, um starke genetische Risikovarianten aufzuspüren, sind genomweite Assoziationsstudien mit nichtverwandten Personen besonders effizient in der Identifizierung von moderaten und schwachen genetischen Risiken bei multifaktoriellen Erkrankungen und erkrankungsrelevanten quantitativen Parametern. Hier wird dargestellt, wie das genetische Risiko für solch moderat bis schwach wirkende Varianten berechnet wird. An den Beispielen Adipositas, Diabetes und altersbedingte Makuladegeneration wird gezeigt, welche Modelle Anwendung finden und wie groß diese „kleinen“ genetischen Risiken sind.
Partis, pari et théorie des jeux
Authors: Cléro Jean-Pierre
Published: November 2011

En partant du problème des partis, conçu comme un dialogue entre partenaires, nous ferons ressortir le tissage de sa structure avec des considérations religieuses et éthiques; puis nous reconsidérerons l’argument dit « du pari » en l’interprétant, mutatis mutandis, comme une préfiguration de la théorie des jeux plutôt que comme la résolution d’un problème de probabilité, ce qu’il est plus évidemment sous la plume de Fermat qui, à la limite, ne résout pas le même problème que Pascal, quoique les deux épistoliers aient pu en avoir l’impression.
Tectonics of Proterozoic Cuddapah Basin, Southern India: A Conceptual Model
Authors: Chetty T. R. K.
Published: November 2011

A tectonic map of Cuddapah Basin (CB) and its adjacent regions has been compiled using LANDSAT TM data and the available literature on the prominent tectonic features which include Archaean greenstone belts, disposition of Proterozoic mobile belts along with the associated mid-crustal shear zones, and the mafic dyke swarms. The field characteristics of the two major fault zones: Gudur-Cuddapah and the Veldurti-Kalva-Gani fault system that cut across the CB have been re-examined and are re-interpreted as typical of transfer faults, which are generated exclusively by extensional tectonics. The earlier concept that these fault systems form a conjugate set of “Anderson type” causing the `Cuddapah salient’, needs to be reviewed.

The widespread extension in the upper crust is manifest in the form of normal faulting of ‘listric’ type in the Papaghni basin and a ‘domino’ type in the Nallamalai basin. While extensional tectonics have played a major role in shaping the geometry and kinematics of CB, the intermittent phases of compression seem to have been derived from major shearing events related to Proterozoic collisional processes in the region. A hypothetical crustal-cross section across the CB has been constructed considering the available geological and geophysical data and analogies were drawn from well-studied sedimentary basins of other continents. The presence of low- dipping detachment faults and shear zones in the lower crust, and their possible linkage with the extensional faults in the upper crust have been inferred to explain the evolution of the CB. The fault patterns and kinematic history in conjunction with the crustal architecture strongly suggest that the evolution of CB is genetically related to the Proterozoic collisional processes and associated crustal-scale transpressional tectonics in the basement at the eastern margin.
Posttraumatic stress disorder at the end of life: Extant research and proposed psychosocial treatment approach
Authors: Feldman David B.
Published: November 2011

According to some estimates, 84% of people experience a traumatic event during their lives (Vrana & Lauterbach, 1994), and 15% to 24% then develop posttraumatic stress disorder (PTSD). Many carry with them lasting effects of trauma as they age and enter the last phase of life. PTSD manifests in unique ways at the end of life, possibly disrupting factors associated with a positive dying process, including social support, medical communication, life review, and acceptance of death. Terminally ill people with PTSD may suffer more emotional distress, lower quality of life, and poorer medical prognosis than those without PTSD. Unfortunately, healthcare providers may not be trained to address this issue. This article reviews the literature concerning how PTSD may affect the end of life and proposes an intervention model based on a palliative care philosophy.
Can the discharge of a hyperconcentrated flow be estimated from paleoflood evidence?
Authors: Bodoque Jose M. , Eguibar Miguel A. , Díez‐Herrero Andrés , Gutiérrez‐Pérez Ignacio , Ruíz‐Villanueva Virginia
Published: November 2011

Many flood events involving water and sediments have been characterized using classic hydraulics principles, assuming the existence of critical flow and many other simplifications. In this paper, hyperconcentrated flow discharge was evaluated by using paleoflood reconstructions (based on paleostage indicators [PSI]) combined with a detailed hydraulic analysis of the critical flow assumption. The exact location where this condition occurred was established by iteratively determining the corresponding cross section, so that specific energy is at a minimum. In addition, all of the factors and parameters involved in the process were assessed, especially those related to the momentum equation, existing shear stresses in the wetted perimeter, and nonhydrostatic and hydrostatic pressure distributions. The superelevation of the hyperconcentrated flow, due to the flow elevation curvature, was also estimated and calibrated with the PSI. The estimated peak discharge was established once the iterative process was unable to improve the fit between the simulated depth and the depth observed from the PSI. The methodological approach proposed here can be applied to other higher‐gradient mountainous torrents with a similar geomorphic configuration to the one studied in this paper. Likewise, results have been derived with fewer uncertainties than those obtained from standard hydraulic approaches, whose simplifying assumptions have not been considered.
Stratospheric Halogen Chemistry
Authors: Hobe Marc von , Stroh Fred
Published: November 2011

Halogens are among the most reactive chemical elements. In the atmosphere, chlorine and bromine in particular are among the most efficient catalysts in stratospheric ozone removal mechanisms, and the global thinning of the Earth's ozone shield, including the regular occurrence of an “ozone hole” over Antarctica in winter, observed since the 1980s is almost entirely caused by the increase of stratospheric chlorine and bromine levels due to anthropogenic emissions of CFCs and halons. While in the upper stratosphere, rather simple catalytic cycles involving atomic oxygen prevail, somewhat more complex mechanisms are responsible for ozone removal in the lower stratosphere. Two specific cycles, the ClO dimer cycle and the ClO-BrO-cycle, are responsible for the pronounced ozone loss in both hemispheres in polar winter. The reactivity and partitioning within the inorganic halogen families determines their relative ozone depletion efficiency. Unfortunately, the kinetics of some reactions involved are still poorly understood. In particular, the photolysis rate of the ClO dimer—under most conditions rate-limiting for ozone loss—has not been satisfactorily quantified, but some progress towards a better understanding has been made in recent studies. Bromine released from VSLS and chlorine activated on high altitude cirrus clouds also destroy ozone in the UTLS region, where ozone trends can have a significant impact on radiative forcing and thus climate change.
The Laryngeal Epithelium in Reflux
Authors: Erickson-Levendoski Elizabeth , Sivasankar Mahalakshmi
Published: November 2011

The epithelium plays a critical role in the maintenance of laryngeal health. This is evident in that laryngeal disease may result when the integrity of the epithelium is compromised by insults such as laryngopharyngeal reflux. In this article, we will review the structure and function of the laryngeal epithelium and summarize the impact of laryngopharyngeal reflux on the epithelium. Research investigating the ramifications of reflux on the epithelium has improved our understanding of laryngeal disease associated with laryngopharyngeal reflux. It further highlights the need for continued research on the laryngeal epithelium in health and disease.
Les « états pathogènes » post-orthodontiques. Les anomalies du
squelette et des tissus mous à éviter en fin de traitement orthodontique
Authors: Delaire Jean
Published: November 2011

La parfaite correction des anomalies de la position des dents observées dans les
dysmorphoses dento-faciales ne doit pas être le seul critère de réussite des traitements
d’orthopédie dento-faciale. Il faut aussi, sous peine de graves dysfonctionnements des
articulations temporo-mandibulaires et de troubles apnéiques du sommeil, ultérieurs : (1)
que les têtes condyliennes et les branches montantes mandibulaires soient situées en bonne
position par rapport à l’apophyse basilaire et au rachis cervical; (2) que l’os hyoïde ne
soit pas trop ptôsé par rapport au disque intervertébral C3-C4.
Direct perturbation theory in terms of energy derivatives: Scalar-relativistic treatment up to sixth order
Authors: Schwalbach Werner , Stopkowicz Stella , Cheng Lan , Gauss Jürgen
Published: November 2011

A formulation of sixth-order direct perturbation theory (DPT) to treat relativistic effects in quantum-chemical calculations is presented in the framework of derivative theory. Detailed expressions for DPT6 are given at the Hartree–Fock level in terms of the third derivative of the energy with respect to the relativistic perturbation parameter defined as $\lambda _{\text{rel}}=c^{-2}$λrel=c−2. They were implemented for the computation of scalar-relativistic energy corrections. The convergence of the scalar-relativistic DPT expansion is studied for energies and first-order properties such as dipole moment and electric-field gradient within the series of the hydrogen halides (HX, X = F, Cl, Br, I, and At). Comparison with spin-free Dirac–Coulomb calculations indicates that the DPT series exhibits a smooth and monotonic convergence. The rate of convergence, however, depends on the charge of the involved nuclei and significantly slows down for heavy-element compounds.
Silver as an electron source for photodissociation of hydronium
Authors: Papas B. N. , Whitten J. L.
Published: November 2011

The photochemistry of a solvated hydronium ion near a silver surface is investigated using ab initio self-consistent field and configuration interaction theory. Photoinduced electron attachment can occur at energies in the range of 1.1–1.2 eV depending upon the initial orientation of the hydronium relative to the silver surface. Rearrangement of solvating waters considerably reduces transition state barriers to dissociation on the excited-state potential energy surface, such that fast dissociation of the neutralized hydronium would occur with no barrier. Both the H and H2 product channels are exothermic pathways on the excited state surface and in several instances exothermic compared to the energy of the initial structure.