bluuebunny/crossref_metadata_2025 huggingface dataset:
Fracture prevention by femoroplasty—cement augmentation of the proximal femur
Authors: Beckmann J. , Springorum R. , Vettorazzi E. , Bachmeier S. , Lüring C. , Tingart M. , Püschel K. , Stark O. , Grifka J. , Gehrke T. , Amling M. , Gebauer M.
Published: April 2011

The prevention of hip fractures is a desirable goal to reduce morbidity, mortality, and socio‐economic burden. We evaluated the influence on femoral strength of different clinically applicable cementing techniques as “femoroplasty.” Twenty‐eight human cadaveric femora were augmented by means of four clinically applicable percutaneous cementing techniques and then tested biomechanically against their native contralateral control to determine fracture strength in an established biomechanical model mimicking a fall on the greater trochanter. The energy applied until fracture could be significantly increased by two of the methods by 160% (53.1 Nm vs. 20.4 Nm, p < 0.001) and 164% (47.1 Nm vs. 17.8 Nm, p = 0.008), respectively. The peak load to failure was significantly increased by three of the methods by 23% (3818.3 N vs. 3095.7 N, p = 0.003), 35% (3698.4 N vs. 2737.5 N, p = 0.007), and 12% (3056.8 N vs. 2742.8 N, p = 0.005), respectively. The femora augmented with cemented double drill holes had a lower fracture strength than the single drilled ones. Experimental femoroplasty is a technically feasible procedure for the prophylactic reinforcement of the osteoporotic proximal femur and, hence, could be an auxiliary treatment option to protect the proximal femur against osteoporotic fractures. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29:1753–1758, 2011
Repair of rat cranial bone defects with nHAC/PLLA and BMP‐2‐related peptide or rhBMP‐2
Authors: Li Jingfeng , Hong Jijun , Zheng Qixin , Guo Xiaodong , Lan Shenghui , Cui Fuzhai , Pan Haitao , Zou Zhenwei , Chen Chao
Published: April 2011

An ideal artificial substitute has good biocompatibility properties and is able to provide for rapid bone formation. Bone morphogenetic protein‐2 (BMP‐2) is considered as one of the most important growth factors for bone regeneration. In this study, a synthetic BMP‐2‐related peptide (designated P24) corresponding to residues of the knuckle epitope of BMP‐2 was introduced into a bioactive scaffold based on nano‐hydroxyapatite/collagen/poly(L‐lactic acid) (nHAC/PLLA); its in vitro release kinetics was then measured. A 5 mm diameter cranial bone defect was created in the calvariae of 30 rats and randomly implanted with three groups of biomaterials: Group A (nHAC/PLLA alone); Group B (P24/nHAC/PLLA composite); and Group C (recombinant human BMP‐2 (rhBMP‐2)/nHAC/PLLA composite). The P24/nHAC/PLLA implants significantly stimulated bone growth similarly to the rhBMP‐2/nHAC/PLLA implants based on the radiographic and three‐dimensional CT evaluation and histological examination, thereby confirming the enhanced bone healing rate of these compounds compared with the stand‐alone nHAC/PLLA scaffold material. The osteoinductive ability of 3 mg P24 was similar to that of 1 µg rhBMP‐2. P24/nHAC/PLLA is a promising scaffold biomaterial for bone tissue regeneration. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29:1745–1752, 2011
Effects of 635nm light‐emitting diode irradiation on angiogenesis in CoCl2‐exposed HUVECs
Authors: Lim Won Bong , Kim Ji Sun , Ko Young Jong , Kwon HyukIl , Kim Sang Woo , Min Heung Kee , Kim Oksu , Choi Hong Ran , Kim Ok Joon
Published: April 2011

Background and Objectives

It is recognized that hypoxic/ischemic conditions leading to production of reactive oxygen species (ROS) are an important mediator of angiogenesis in the wound‐healing process. Recently, low level light irradiation at 635 nm, which is used in many clinical fields, was found to decrease intracellular ROS levels, and consequently alleviate oxidative stress. The purpose of the present study was to investigate the effects of 635 nm light‐emitting diode (LED) irradiation on angiogenesis in human umbilical vein endothelial cells, in an in vitro CoCl2‐induced severe hypoxia model.

Study Design/Materials and Methods

The effects were assessed on cell viability, tube formation, hypoxia‐inducible factor‐1, vascular endothelial growth factor (VEGF), VEGF‐1 and ‐2 protein expression, mitogen‐activated protein kinase (MAPK) phosphorylation, and ROS dissociation.

Results

The results showed that, under hypoxic/ischemic conditions, irradiation with 635 leads to reduced production and increased scavenging of intracellular ROS, which results in alleviation of VEGFR‐1 suppression, enhanced VEGF expression and ERK MAPK activation, and subsequent acceleration of angiogenesis with improved cell viability and tube formation.

Conclusion

Taken together, irradiation with 635 nm was shown to reduce intracellular ROS production, which results in increased angiogenesis. Thus, we suggest that irradiation with 635 nm accelerate angiogenesis under hypoxic/ischemic conditions, and may prove to be a useful alternative tool in wound healing. Lasers Surg. Med. 43:344–352, 2011. © 2011 Wiley‐Liss, Inc.
Determination of coherence length in biological tissues
Authors: Fixler Dror , Duadi Hamootal , Ankri Rinat , Zalevsky Zeev
Published: April 2011

Background and Objective

Lately in phototherapy the use of diodes instead of lasers was suggested for economical and practical reasons. It has been argued that lasers have no preference over diodes since they lose their coherence once penetrating biological tissues. However, this point has never been experimentally proven. In this work we, for the first time, have experimentally validated the conditions affecting the spatial coherence of a laser illumination going through a biological tissue.

Study Design/Materials and Methods

In our experiments we measured the spatial coherence of the light passing through phantoms containing intralipid and ink component as well as through uncooked turkey meat. We do this measuring the changes of the contrast of the speckle patterns generated due to laser illumination. Flow tunnels inside the phantoms were generated by needles in two different diameters. The measurements were performed for varied integration time, varied thickness of phantoms, and for varied flow rates. The measurement system included two excitation sources: a green doubled Nd:YAG laser at wavelength of 532 nm and an ultra high power green LED at a wavelength of 520 nm.

Results

It was experimentally validated that the thickness of the tissue does not change the coherence while there is no flow. Furthermore, the flow velocity and the flow volumetric rate highly affect the coherence length. Previously developed mathematical expression, in which the contrast depends on the correlation and the exposure time, was found to be compatible with the obtained experimental results.

Conclusions

We found that the coherence of the laser is not lost when the light goes through a static tissue but it is partially lost when there is a flow of fluid through the tissue. The volumetric flow rate is directly correlated to the loss of spatial coherence. Higher flow rate produces shorter coherence length. Lasers Surg. Med. 43:339–343, 2011. © 2011 Wiley‐Liss, Inc.
Photodynamic therapy: The minimally invasive surgical intervention for advanced and/or recurrent tongue base carcinoma
Authors: Jerjes Waseem , Upile Tahwinder , Hamdoon Zaid , Abbas Syedda , Akram Sarah , Mosse Charles Alexander , Morley Simon , Hopper Colin
Published: April 2011

Introduction

The management of tongue base carcinoma continues to be a major challenge in head and neck oncology. Our aim in this prospective study was to evaluate the outcome following ultrasound‐guided interstitial photodynamic therapy (US‐iPDT) of stage IV tongue base carcinoma patients. Patients' reports on quality of life with clinical and radiological evaluation were the main end point parameters used to assess the outcome.

Material and Methods

Twenty‐one consecutive patients referred to the UCLH Head and Neck Centre for treatment of advanced and/or recurrent tongue base cancer were included in this study. Two‐thirds of the referred patients had not been offered further conventional therapeutic options apart from palliative treatment. It was decided, by the multidisciplinary team, that the only available option was to offer US‐iPDT under general anesthesia, using mTHPC (Foscan®) as the photosensitizing agent. Following treatment, patients were followed‐up for a mean of 36 months (min. 21, max. 45).

Results

Nine of the 11 patients who presented with breathing problems reported improvement after treatment. Also, 19 of the 21 patients reported improvement of swallowing. Improvement of speech was reported by 11 of 13 patients. Clinical assessment showed that more than half of the patients had “good response” to the treatment and about a third reported “moderate response.” Radiological assessment comparing imaging 6‐week post‐PDT to the baseline showed stable pathology with no change in size in four patients, minimal response in seven patients, moderate response in six patients, and significant response in two patients. Eight patients died; four of which due to loco‐regional disease; and two from distant tumor spread. Kaplan–Meir survival curve was generated from the survival and follow‐up data.

Conclusions

Photodynamic therapy is a successful palliative modality in the treatment of advanced and/or recurrent tongue base carcinoma. Lasers Surg. Med. 43:283–292, 2011. © 2011 Wiley‐Liss, Inc.
Effective photosensitization and selectivity In Vivo of Candida Albicans by meso‐tetra (N‐methyl‐4‐pyridyl) porphine tetra tosylate
Authors: Mitra Soumya , Haidaris Constantine G. , Snell Sara B. , Giesselman Benjamin R. , Hupcher Steven M. , Foster Thomas H.
Published: April 2011

Background and Objective

The fungus Candida albicans commonly causes mucosal and cutaneous infections in patients with impaired immunity. We investigated the effectiveness of the photosensitizer meso‐tetra (N‐methyl‐4‐pyridyl) porphine tetra tosylate (TMP‐1363) in the photodynamic treatment (PDT) of C. albicans infection in vitro and its selectivity in an animal model.

Materials and Methods

The efficacy of TMP‐1363 in PDT of C. albicans in vitro was compared to that of methylene blue (MB) using a colony forming unit (CFU) assay. In vivo infection in the mouse was established by inoculation of C. albicans yeast in the intradermal space of the ear pinna. Two days post‐infection, 0.3 mg ml−1 TMP‐1363 was administered topically. Thirty minutes after TMP‐1363 application, the ears were irradiated at 514 nm using a fluence of 90 J cm−2 delivered at an irradiance of 50 mW cm−2. The ears were excised 2 hours post‐irradiation, homogenized, and the organism burden was determined by a CFU assay. In vivo wide field and confocal fluorescence imaging assessed the localization of the photosensitizer in relationship to C. albicans.

Results

Photosensitization with TMP‐1363 resulted in a greater than three‐log increase in killing of C. albicans in vitro compared to MB. In vivo fluorescence imaging demonstrated a high degree of selective labeling of C. albicans by TMP‐1363. PDT of infection using TMP‐1363 resulted in a significant reduction in CFU/ear relative to untreated controls. Infected ears subjected to PDT displayed complete healing over time with no observable damage to the pinna.

Conclusion

Our in vitro and in vivo findings support TMP‐1363‐mediated PDT as a viable therapeutic approach for the PDT of candidiasis. Lasers Surg. Med. 43:324–332, 2011. © 2011 Wiley‐Liss, Inc.
A comparative study on ocular damage induced by 1319nm laser radiation
Authors: Chen Hongxia , Yang Zaifu , Wang Jiarui , Chen Peng , Qian Huanwen
Published: April 2011

Background and Objectives

High energy loss of 1,319 nm laser due to pre‐retinal water absorption makes the ocular axial length more critical, while the relative low absorbance of melanin makes retinal pigmented epithelium less contributing, to retinal damage threshold. However, both have never been illustrated experimentally. Here we determined and compared the retinal damage thresholds at this wavelength in three species with different axial lengths and retinal pigmentations. The corneal damage threshold was also determined for further comparative analysis.

Materials and Methods

The retinal damage thresholds of albino rat, non‐pigmented and pigmented rabbit, and the corneal damage threshold of non‐pigmented rabbit were determined for 0.2 and/or 0.4‐second exposure durations. The incident beam diameter on cornea was 5 mm for rabbit retinal and 2 mm for rat retinal and rabbit corneal lesion. Minimum visible lesions were examined 1‐ and 24‐hour post‐exposure. Probit analysis was used to establish the estimated damage threshold for 50% of exposures (ED50). The direct transmittance of pre‐retinal eye media was used for further comparative analysis.

Results

The retinal ED50 of albino rat for 0.2 seconds, non‐pigmented rabbit for 0.2 seconds, 0.4 seconds, pigmented rabbit for 0.4 seconds was 8.8, 12.1, 22.5, 18.5 J/cm2 (0.28, 2.4, 4.4, 3.6 J in total intraocular energy (TIE)). The corneal ED50 was 86.1 J/cm2. Under the condition of 5 mm beam diameter and 0.4‐second exposure duration, the calculated retinal ED50 of human was higher, while that of rhesus monkey was lower than the corneal ED50.

Conclusion

For 1,319 nm laser radiation, the ocular axial length has great, while the retinal pigmentation has only slight influence on retinal damage threshold. The relative lower direct transmittance of human eye media makes the retina more resistant to laser lesion, which should be considered when deriving human maximum permissible exposure (MPE). Lasers Surg. Med. 43:306–312, 2011. © 2011 Wiley‐Liss, Inc.
1.9 µm diode laser assisted vascular microanastomoses: Experience in 40 clinical procedures
Authors: Leclère Franck Marie P. , Schoofs Michel , Buys Bruno , Mordon Serge R.
Published: April 2011

Background

Since the initial work of Jacobson and Suarez in 1960, microsurgery has evolved greatly. In 2009, we reported our clinical experience with 1.9 µm diode laser‐assisted vascular microanastomoses (LAMA) for free flap reconstruction. In this report, the ongoing study is now expanded to include 11 additional procedures which were analyzed prospectively with a focus on the duration of the LAMA technique.

Methods

In total, 40 clinical procedures with LAMA have been performed since 2005. Mean follow‐up was 3.3 years (range 0.5–5.5 years). Among those, 11 procedures were performed and prospectively analyzed during the period 2008–2009. LAMA was performed with a 1.9 µm diode laser after placement of equidistant stitches. For vessels size <1.5 mm, the following laser parameters were used: spot size 400 µm, five spots for each wall, power 125 mW, arterial/venous fluence 100/90 J/cm2 (spot duration 1/0.9 seconds).

Results

For the last observed 11 procedures, mean occlusion time of the flap arterial and venous anastomoses was 5.4 ± 0.4 and 6.8 ± 0.7 minutes respectively. One anastomosis required a secondary laser application. Arterial and venous patency rates were 100% at the time of surgery. The success rate for the 11 procedures was 100%. The global success rate of the series (97.5%) is discussed and compared with the literature.

Conclusion

The success rates for reconstructive free flap surgery realized with LAMA appear excellent. Technical innovation will most likely lead to widespread use of the handpiece laser in the operating room. Lasers Surg. Med. 43:293–297, 2011. © 2011 Wiley‐Liss, Inc.
Photodynamic inactivation of bacteria using polyethylenimine–chlorin(e6) conjugates: Effect of polymer molecular weight, substitution ratio of chlorin(e6) and pH
Authors: Huang Liyi , Zhiyentayev Timur , Xuan Yi , Azhibek Dulat , Kharkwal Gitika B. , Hamblin Michael R.
Published: April 2011

Background and Objectives

Antimicrobial photodynamic therapy (APDT) is a novel technique to treat local infections. Previously we reported that the attachment of chlorin(e6) to polyethylenimine (PEI) polymers to form PEI‐ce6 conjugates is an effective way to improve ce6 PDT activity against bacteria. The aim of this work was to explore how the polymer molecular weight, substitution ratio (SR) of ce6 and pH value affect the PDT efficacy.

Study Design/Materials and Methods

We have synthesized PEI‐ce6(10) (MW = 60,000, SR = 1) and PEI‐ce6(11) (MW = 60,000, SR = 5) and compared these with the previous PEI‐ce6(9) (MW = 10,000, SR = 1). We tested the PDT efficacy of these three conjugates against Gram‐negative E. coli and Gram‐positive bacteria (S. aureus and E. fecalis) at three different pH values (5.0, 7.4, 10.0) that may affect the charge on both the bacterial cells and on the conjugate (that has both basic and acidic groups).

Results

PEI‐ce6(9) and PEI‐ce6(10) were the most effective against these tested bacteria. The PDT effect of all three conjugates depended on pH values. The effective order was pH = 10.0 > pH = 7.4 > pH = 5.0 on E. coli. For S. aureus and E. fecalis the order was pH = 5.0 > pH = 10.0 > pH = 7.4. PEI‐ce6(11) PDT activity was worse than PEI‐ce6(10) activity which is probably connected to the fact that ce6 molecules are self‐quenched within the PEI‐ce6(11) molecule. Ce6 quenching within the PEI‐ce6 molecules was proved by analyzing fluorescence spectra of PEI‐ce6 conjugates at different pH values. There were no differences in bacterial uptake between different pH values in three PEI‐ce6 conjugates.

Conclusion

We assume high pH (rather than low pH as was hypothesized) disaggregates the conjugates, so the higher pH was more effective than the lower pH against E. coli. But for Gram‐positive bacteria, low pH was more effective possibly due to more overall positive charge on the conjugate. Lasers Surg. Med. 43:313–323, 2011. © 2011 Wiley‐Liss, Inc.
Combining confluent and fractionally ablative modalities of a novel 2790nm YSGG laser for facial resurfacing
Authors: Munavalli Girish S. , Turley Ayse , Silapunt Sirunya , Biesman Brian
Published: April 2011

Background

Several laser technologies exist for improving rhytides, pigmentation, and skin texture. Recent advances in technology introduced a new wavelength, 2,790 nm, erbium:yttrium–scandium–galium–garnet (Er:YSGG) for treatment of photoaging. 2,790 nm Er:YSGG has a water absorption coefficient between CO2 laser and Er:YAG laser and has both ablative and fractional‐ablative capabilities.

Objectives

To evaluate the efficacy and safety of combining the ablative (confluent) and fractional‐ablative modes of 2,790 nm Er:YSGG laser for treatment of photoaging.

Study Design/Materials and Methods

In this uncontrolled, open label, prospective study, 10 subjects were enrolled and had a single treatment of combined confluent and fractional‐ablative 2,790 nm lasers for photoaging. The primary clinical end point of the study was the change in Fitzpatrick wrinkle score from baseline at different time points as determined by blinded reviewer assessments. Secondary clinical end points were the improvement in fine lines, tone/texture, and pigmentation; the subjects' self assessment; the incidence of side effects; and the tolerability of treatments.

Results

Based on blinded photo‐assessments by two independent dermatologists, subjects showed clinically and statistically significant mean improvement of 1.9 (95% CI: 1.1–2.6), 1.6 (95% CI: 0.8–2.3), and 1.2 (95% CI: 0.5–2.0) in Fitzpatrick wrinkle scores at 6 weeks, 3 and 6 months, respectively. Of the 90% of subjects who showed improvement in Fitzpatrick wrinkle scores, 78% continued to have improvement at the 6‐month follow‐up visit. Mild erythema observed post‐treatment was resolved by the 6‐week follow‐up visit in all subjects. No transient or permanent post‐inflammatory hyperpigmentation (PIH); or serious adverse events were reported.

Conclusion

A combined confluent and fractional‐ablative 2,790 nm Er:YSGG laser treatment improves photodamaged skin for at least 6 months. The treatment was well‐tolerated and PIH was not found in our study. Lasers Surg. Med. 43:273–282, 2011. © 2011 Wiley‐Liss, Inc.
Enhanced photoacoustic detection of melanoma cells using gold nanoparticles
Authors: McCormack Devin R. , Bhattacharyya Kiran , Kannan Raghuraman , Katti Kattesh , Viator John A.
Published: April 2011

Background and Objectives

We tagged melanoma cells with gold nanoparticles to show their viability for increasing sensitivity in a photoacoustic detection system. Ultimately, this study models the detection of circulating tumor cells, which are an important prognostic factor in the progress of melanoma.

Study Design/Materials and Methods

A Q‐switched, tunable Nd:YAG laser was used to irradiate cells in both a stationary and flow set‐up. Photoacoustic signals were measured using a polyvinylidene fluoride (PVDF) film in the stationary test, and a commercially available ultrasonic probe for flow tests. Both unmodified melanoma cells and gold nanoparticle (AuNP) tagged melanoma were tested.

Results

AuNP tagged melanoma in a stationary set‐up showed an average of 0.227 mV/mJ larger signal than the untagged, indicating a signal increase of 34%. At 500 nm there is a maximum difference of 0.295 mV/mJ, or a 41% increase. In flow tests, the ultrasound probe was able to detect single cells, but the increased signal from AuNP tagging was minimal.

Conclusion

AuNP tagging proved to give an increased photoacoustic signal allowing greater sensitivity in stationary metastasized melanoma detection systems using photoacoustics. Lasers Surg. Med. 43:333–338, 2011. © 2011 Wiley‐Liss, Inc.
Multiscale Modeling of Branch Length in Butyl Acrylate Solution Polymerization: Molecular Versus Continuum Kinetics
Authors: Rawlston Jonathan A. , Schork Francis Joseph , Grover Martha A.
Published: April 2011

A well‐mixed kinetic Monte Carlo (KMC) simulation is used to examine branch formation by both backbiting and intermolecular chain transfer to polymer in the solution polymerization of butyl acrylate. The results of the KMC simulations are compared to those of a rate‐equation simulation based on ordinary differential equations. The rate‐equation simulation is modified based on insight gained from the KMC simulation. While the KMC simulation requires significantly more computational time, its high resolution is advantageous when studying the branching topology of individual molecules.

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Thalamic neuronal and EMG activity in psychogenic dystonia compared with organic dystonia
Authors: Kobayashi Kazutaka , Lang Anthony E. , Hallett Mark , Lenz Frederick A.
Published: April 2011

Background:

This is a retrospective analysis of thalamic neuronal and electromyogram activities between subjects with organic dystonia and a subject with psychogenic dystonia in whom a thalamotomy was carried out before the diagnosis of psychogenic dystonia was made.

Results:

The signal‐to‐noise ratio in the lowest frequency band (dystonia frequency < 0.76 Hz) in the electromyogram was not significantly different by diagnosis or muscle. The coherence at dystonia frequency for wrist flexors X biceps electromyograms was significantly higher in organic dystonia, whereas the phase was not apparently different from zero for either diagnosis. In a thalamic pallidal relay nucleus (ventral oral posterior), neuronal firing rates were not apparently different between psychogenic and organic dystonia. The neuronal signal‐to‐noise ratio in ventral oral posterior was significantly higher in organic dystonia than in psychogenic dystonia, whereas both were greater than in controls with chronic pain. Spike X electromyogram coherence apparently was not different between psychogenic and organic dystonia. The proportion of thalamic cells responding to joint movements was higher in the cerebellar relay nucleus (ventral intermediate) of psychogenic dystonia than in organic dystonia.

Conclusions:

These results suggest that some features, such as firing rates and thalamic reorganization, are similar in psychogenic and organic dystonia. Other features differ, such as the coherence between the electromyograms from different muscles and the thalamic neuronal signal‐to‐noise ratio, which may reflect pathophysiological factors in organic dystonia. © 2011 Movement Disorder Society
Skin banking: Treatment option for native skin necrosis following skin‐sparing mastectomy and previous breast irradiation
Authors: Reichl Heike , Hladik Michaela , Wechselberger Gottfried
Published: April 2011

Skin flap necrosis, as well as positive resection margins in the context of skin‐sparing mastectomy and immediate breast reconstruction, may require reoperation, potentially associated with tissue loss, and thereby impair the aesthetic result. Skin banking has recently been described as a method for handling skin flaps of uncertain viability. Here, we describe the advantages of skin banking in previously irradiated patients with breast cancer recurrence, which underwent skin‐sparing mastectomy and immediate breast reconstruction. Aside from its utility in the management of skin necrosis, we present this method as an option to conserve the native breast shape in patients with questionable total resection during surgery. © 2011 Wiley‐Liss, Inc. Microsurgery, 2011.
Double‐free, flow‐through flap reconstruction for complex scalp defects: A case report
Authors: Haddock Marie‐Claire , Creagh Terrence , Sivarajan Vivek
Published: April 2011

This case report describes the use of a double‐free, flow‐through flap as a valuable tool in reconstruction following oncological resection of a large, fungating, squamous cell carcinoma extending through the scalp, forehead, skull, and dura. An anterolateral thigh flap was utilized to supply: soft tissue for the forehead reconstruction, vascularized fascia lata for the dural repair, and to act vascular conduit to supply a distally placed latissmus dorsi flap for total scalp reconstruction. We believe this is the first time this combination of double‐free, flow‐through flap design has been published for the reconstruction of complex, composite scalp and calvarial defects. © 2011 Wiley‐Liss, Inc. Microsurgery, 2011.
The sternocleidomastoid myocutaneous “patch esophagoplasty” for cervical esophageal stricture
Authors: Noland Shelley S. , Ingraham John M. , Lee Gordon K.
Published: April 2011

Esophageal strictures may be caused by many etiologies. Patients suffer from dysphagia and many are tube‐feed dependent. Cervical esophageal reconstruction is challenging for the plastic surgeon, and although there are reports utilizing chest wall flaps or even free flaps, the use of a sternocleidomastoid (SCM) myocutaneous flap provides an ideal reconstruction in select patients who require noncircumferential “patch” cervical esophagoplasty. We present two cases of esophageal reconstruction in which we demonstrate our technique for harvesting and insetting the SCM flap, with particular emphasis on design of the skin paddle and elucidation of the vascular anatomy. We believe that the SCM flap is simple, reliable, convenient, and technically easy to perform. There is minimal donor site morbidity with no functional loss. The SCM myocutaneous flap is a viable option for reconstructing partial esophageal defects and obviates the need to perform staged procedures or more extensive operations such as free tissue transfer. © 2011 Wiley‐Liss, Inc. Microsurgery, 2011.
Altered testicular gene expression patterns in mice lacking the polyubiquitin gene Ubb
Authors: Sinnar Shamim A. , Small Christopher L. , Evanoff Ryan M. , Reinholdt Laura G. , Griswold Michael D. , Kopito Ron R. , Ryu Kwon‐Yul
Published: April 2011

Ubiquitin (Ub) is an essential protein found in all eukaryotic cells and plays important roles in a variety of cellular functions including germ cell development. We have previously reported that targeted disruption of the polyubiquitin gene Ubb results in male and female infertility in Ubb−/− mice, with germ cells arrested at meiotic prophase I. Although reduced Ub levels in germ cells are believed to be responsible for the fertility defect in Ubb−/− mice, it is still unclear how reduced Ub levels result in sterility. Here we describe the results of a microarray analysis of the murine testicular transcriptome, which demonstrates dramatically altered gene expression patterns in Ubb−/− mice, possibly related to reduced levels of histone 2A (H2A) ubiquitylation. We find that large numbers of genes related to fertility, metabolism, transcription, and the ubiquitin–proteasome system (UPS) are misregulated in Ubb−/− mice. Such wide‐ranging alterations in gene expression suggest that loss of the Ubb gene does not mimic a single‐gene defect phenotype, but instead may affect gene expression more globally. These dramatic changes in gene expression could, at least in part, contribute to the complex fertility and metabolic phenotypes seen in these mice. Mol. Reprod. Dev. 78:415–425, 2011. © 2011 Wiley‐Liss, Inc.
Effects of filler contents and processing parameters on the weldline strength of compression molded natural rubber
Authors: Patcharaphun S. , Chookaew W. , Tungkeunkunt T. , Na‐Ranong N.
Published: April 2011

The presence of weldlines in rubber products is regarded as a one of the most undesirable phenomena, since it results in poor mechanical properties. Compression molding of large or complicated products are prepared by multiple charges, which produces weldlines once the melt fronts are joined by the impingement flow. In this work, the effects of curing systems, processing parameters, filler types, and contents on weldline strength of compression molded natural rubber (NR) were investigated. Furthermore, the effects of curing systems on the aging properties of NR vulcanizates were studied in details. The results show that an increased amount of calcium carbonate does not affect the weldline strength. However, the difference in tensile strength between weldline and nonweldline specimens becomes larger with the high loading of silica and carbon black. In addition, for the factors selected in the experiments, clamping pressure, and curing system were found to be the principal factors affecting the weldline property of vulcanizates. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
The influence of the polymer chain stiffness on tracer diffusion in polymeric matrices
Authors: Tae Jung Hyun , June Sung Bong , Yethiraj Arun
Published: April 2011

The diffusion of penetrants in polymers is of technological importance in many areas including chromatography and fuel cell membranes. In this work, the effect of chain conformations on tracer diffusion is studied using molecular simulations and a percolation theory. The polymeric matrix is composed of tangent hard sphere chains that are fixed in space; conformations are changed by tuning the stiffness of the chains. The tracer diffusion coefficient is relatively insensitive to the chain stiffness when polymer chains are frozen as in polymer glasses with the local chain dynamics switched off. An analysis of the matrix using percolation theory shows that the polymer volume fraction at the free volume percolation threshold is also relatively insensitive to the chain stiffness, consistent with the diffusion results. This is surprising because the site‐site intermolecular pair correlation functions in the matrix are quite sensitive to the chain stiffness. In contrast, the tracer diffusion coefficient in a melt of mobile chains decreases significantly as the chain stiffness is increased. We conclude that tracer diffusion is only weakly correlated with the chain conformations and local chain dynamics plays an important role. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
Low‐temperature Polymer Deposition in Ambient Air Using a Floating‐electrode Dielectric Barrier Discharge Jet
Authors: Tsai Tsung‐Chan , Staack David
Published: April 2011

Plasma‐polymerized PMMA films were obtained by a low‐temperature ambient deposition technique using a floating‐electrode DBD jet with two distinct operation modes, namely a diffuse mode and a concentrated mode. Deposition rates, surface morphologies, atomic compositions, and chemical bond concentrations of the PMMA films showed a dependence on the modes. In the concentrated mode rapid deposition (22 nm · s−1) can be achieved with the substrate temperature merely rising to 39 °C. Besides transparent PMMA films with high quality, opaque films with wrinkled microstructures due to buckling effects were obtained. Similar functional groups to those in pure PMMA were also observed by both XPS and FTIR results. It was demonstrated that PMMA films can be successfully grown on different substrate materials, such as glass, plastic, rubber, onion skin, and fingernail.

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Predicting the Peak Pressure from the Curved Surface of Detonating Cylindrical Charges
Authors: Knock Clare , Davies Nigel
Published: April 2011

Trinitrotoluene (TNT) equivalency depends on knowing the relative strength of different explosives compared to TNT. However, most past work has been carried out only using spherical charges, whereas most military ammunition is cylindrical in shape. It is known that in certain directions, cylindrical charges give an enhanced blast close in when compared to that of spherical charges. This paper examines data for cylindrical explosive charges from the literature for Composition B and pentolite and then describes experimental work carried out on cylindrical PE4 charges. Analysis of the free air experimental and literature data shows that close into the curved side of a cylindrical charge it is possible to predict the peak pressure using an equation of the form Peak pressure=K×mass/distance3, where K is an explosive dependent constant; 2695 Pa m3 kg−1 for Composition B, 2498 Pa m3 kg−1 for pentolite and 2565 Pa m3 kg−1 for PE4, for length to diameter ratios of between 2 : 1 and 10 : 1. For a scaled distance (distance/mass1/3) of less than 3.5 m kg−1/3, the results are very accurate. This means that, provided data for cylindrical charges of TNT is obtained, a simple method of determining the TNT equivalency of a cylindrical charge, perpendicular to the curved surface is given by TNT equivalence=Kexplosive/KTNT. For a more accurate prediction at a scaled distance of greater than 3.5 m kg−1/3 a cubic equation of the form Peak pressure=K1Z−3+K2Z−2+K3Z−1 has been found to apply where Z=distance/mass1/3 and the coefficients K1, K2 and K3 depend on the explosive type.
Effects of spark duration on minimum ignition energy for methane/air mixture
Authors: Zhang Qi , Li Wei , Zhang Shixi
Published: April 2011

This work investigated the effects of spark duration on the minimum ignition energy of methane/air mixtures in the closed vessel. The main findings from these experiments (all with methane/air mixture with the volume fraction 8.5%) are: (a) for given methane/air mixture, the minimum ignition energy is not constant and it changes with the spark duration, (b) the minimum ignition energies decrease from 6.8 mJ to 0.4 mJ as the spark durations increase from 0.657 μs to 4.31 μs, (c) the explosion pressure reaches the highest value when the spark duration is 2.627 μs and the minimum ignition energy 1.3 mJ, (d) the explosion pressures change with the ignition energy value and spark duration, and (e) the explosion temperature reaches the highest value when the spark duration is 2.627 μs and the minimum ignition energy 1.3 mJ. © 2011 American Institute of Chemical Engineers Process Saf Prog, 2011.
Update of CCPS book “guidelines to evaluating vapor cloud explosion, pressure vessel burst, BLEVE and flash fire hazards”
Authors: Baker Quentin A. , Pierorazio Adrian J. , Woodward John L. , Tang Ming Jun
Published: April 2011

The first edition of the CCPS book Guidelines to Evaluating Vapor Cloud Explosions, Flash Fires and BLEVEs was published in 1994. The second edition was completed in October 2010. It is a major revision of the Guideline with contents completely reorganized, recent research results added, revised and new prediction methods inserted, with sample problems worked for each prediction method. The treatment of pressure vessel burst was expanded and placed in a dedicated chapter, resulting in a new name for the second edition of the Guideline. © 2011 American Institute of Chemical Engineers Process Saf Prog, 2011.
Evaluation of offline analysis of archived three‐dimensional volume datasets in the diagnosis of fetal brain abnormalities
Authors: Salman M. M. , Twining P. , Mousa H. , James D. , Momtaz M. , Aboulghar M. , El‐Sheikhah A. , Bugg G. J.
Published: April 2011

Objective

To retrospectively evaluate the reliability of offline manipulation of archived three‐dimensional (3D) ultrasound volumes in the assessment of the normal fetal brain and the diagnosis of fetal brain abnormalities.

Methods

Seventy‐nine 3D volume datasets, archived at the time of scanning, from women attending a tertiary center, were analyzed. They comprised 52 cases with brain abnormalities and 27 normal controls. Postnatal magnetic resonance imaging or postmortem examination confirmed the final diagnosis in all cases with brain anomalies. Offline analysis of the 79 anonymized 3D volume datasets was carried out by three fetal medicine experts, examiner one (E1), examiner two (E2) and examiner three (E3), using 4D View software. The experts were blinded to any prior diagnosis or history. Data were collected on a specially designed data sheet and entered into a specialized database for analysis. Results were compared between examiners, with the initial two‐dimensional (2D) diagnosis and with the final definitive diagnosis by calculation of percentage agreement and kappa coefficients.

Results

Of the 52 cases with brain anomalies, the correct diagnosis was reached in 88.5% (46/52), 98.1% (51/52) and 92.3% (48/52) of cases on analysis of the 3D volumes by E1, E2 and E3, respectively, whereas only 82.7% (43/52) of cases were correctly diagnosed on the initial 2D examination when compared with the definitive diagnosis. Fetuses without brain anomalies were identified as such by the three experts with 100% agreement. There was good agreement between the initial 2D examination and the analysis of 3D volumes by each of the experts: 86.1% for E1 (κ = 0.7), 89.9% for E2 (κ = 0.79) and 88.6% for E3 (κ = 0.76).

Conclusions

3D volume datasets are an appropriate and reliable format for storing data from examination of the fetal brain. Offline analysis of 3D datasets is a reliable method that can be used to help in the assessment of brain anomalies and could be a useful adjunct to realtime 2D ultrasonography. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Cord occlusion followed by laser cord transection in monochorionic monoamniotic discordant twins
Authors: Valsky D. V. , Martinez‐Serrano M.‐J. , Sanz M. , Eixarch E. , Acosta E.‐R. , Martinez J.‐M. , Puerto B. , Gratacós E.
Published: April 2011

Objective

To compare the outcomes of a consecutive case series of monochorionic (MC) monoamniotic (MA) discordant twins treated with umbilical cord occlusion and transection, with those of a cohort of MC diamniotic (DA) twins treated with conventional cord occlusion.

Methods

This study included 17 MCMA twins (12 true MA and five iatrogenic) treated with cord occlusion and transection and a control group of 72 MCDA discordant twins treated during the same period with cord occlusion in a single center. Duration of surgery, rates of preterm delivery (PTD) or preterm premature rupture of membranes (PPROM) < 32 weeks and intrauterine fetal demise (IUFD), perinatal outcome and neonatal survival were prospectively recorded in both groups.

Results

Median durations of surgery were 28.5 (range, 14.0–74.0) min and 24.0 (3.0–60.0) min in the cord transection and control groups, respectively (P = 0.24). There were no significant differences between cord transection and control groups in the rates of PPROM (35.3% vs. 20.8%, P = 0.22), PTD (41.2% vs. 28.2%, P = 0.29), IUFD (0% vs. 2.8%, P = 1.0) and neonatal survival (76.5% vs. 80.6%, P = 1.0). Gestational age at delivery (median 35.0 (24.5–39.0) vs. 37.1 (26.2–41.0) weeks, P = 0.21) and fetal birth weight (2215 (800–3200) g vs. 2605 (588–3830) g, P = 0.51) were similar between study groups.

Conclusion

Cord occlusion and transection in MCMA discordant twins resulted in similar perinatal outcomes to those of MCDA discordant twins treated with cord occlusion. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Development of face processing
Authors: Pascalis Olivier , de Martin de Viviés Xavier , Anzures Gizelle , Quinn Paul C. , Slater Alan M. , Tanaka James W. , Lee Kang
Published: April 2011

This article reviews the development of the face‐processing system from birth, during infancy and through childhood, until it becomes the sophisticated system observed in adults. We begin by discussing the following major theoretical issues concerning the development of face expertise: (1) nature versus nurture or the role of experience in face processing, (2) level of processing (i.e., global, basic, subordinate, individual) and expertise, and (3) type of processing (i.e., holistic, configural, featural). This general overview will be followed by a closer examination of individual studies that investigate the development of face processing. These studies will include a review of (1) development of differential processing of faces and objects, (2) development of differential processing of faces of different species, (3) developmental changes in processing facial identity, and (4) developmental changes in the categorization of faces. Our review of the developmental literature reveals early competence in face‐processing abilities with infants presenting a preference for face stimuli and facial discrimination using featural, configural, and holistic cues. This early competence is then later refined as evidenced by age‐related changes throughout childhood. Some of the refinements are likely due to the development of general cognitive abilities, whereas some others may be face‐specific. WIREs Cogni Sci 2011 2 666–675 DOI: 10.1002/wcs.146

This article is categorized under:

Psychology > Development and Aging
Agent‐based modeling and biomedical ontologies: a roadmap
Authors: An Gary , Christley Scott
Published: April 2011

The translational dilemma represents a foundational challenge for the biomedical research community. Addressing the dilemma will require an enhancement in the throughput capacity of the expression and evaluation of mechanistic hypotheses. Doing so will require the ability to place biomedical knowledge into a format where hypotheses can be readily instantiated such that the dynamics inherent to biological systems can be represented, and also technological enhancement of the generation of such dynamic models. We suggest that the former goal can be approached by using the meta‐structure of agent‐based models (ABMs) to integrate different knowledge hierarchies currently represented with bio‐ontologies and increase the expressiveness of formal knowledge representation to account for mechanistic biological rules. The development of an agent‐based modeling format (ABMF) will provide a bridge between ontological knowledge representation and methods for modeling and simulation (M&S). We further suggest that the latter goal of process enhancement can be targeted by the development of intelligent computational agents that can concatenate bio‐ontologies with M&S ontologies to semiautomate the generation of bio‐simulations. We believe that the application of these two complementary approaches would address the foundational nature of the current throughput bottleneck in the scientific cycle. WIREs Comp Stat 2011 3 343–356 DOI: 10.1002/wics.167

This article is categorized under:

Statistical Models > Agent-Based Models

Applications of Computational Statistics > Computational and Molecular Biology

Software for Computational Statistics > Artificial Intelligence and Expert Systems

Statistical Models > Simulation Models
Statistics in finance
Authors: Tsay Ruey S.
Published: April 2011

This article considers Markov chain simulation and statistical analysis of high‐dimensional financial time series. In particular, we discuss Markov chain Monte Carlo methods, for example, Gibbs sampling and Metropolis‐Hasting algorithm, and multivariate volatility models with applications in finance. Real examples are used to demonstrate statistical applications of the methods discussed in risk management and volatility estimation. WIREs Comp Stat 2011 3 289–315 DOI: 10.1002/wics.168

This article is categorized under:

Applications of Computational Statistics > Computational Finance
Smooth tests of goodness of fit
Authors: Rayner J. C. W. , Thas O. , Best D. J.
Published: April 2011

Smooth tests of goodness of fit assess the fit of data to a given probability density function within a class of alternatives that differs ‘smoothly’ from the null model. These alternatives are characterized by their order: the greater the order the richer the class of alternatives. The order may be a specified constant, but data‐driven methods use the data to select the order and give tests that are unlikely to miss important effects. When testing for distributions within exponential families the test statistic often has a very convenient form, being the sum of squares of components that are asymptotically independent and asymptotically standard normal. The number of components is strongly related to the order of the alternatives. If the data differ from the null model the components provide diagnostics, giving an indication of how they differ. Outside of exponential families generalized smooth tests incorporating a Cholesky decomposition are needed to obtain test statistics with the convenient form mentioned. Using the components to give moment diagnostics of the alternative is more problematic than thought initially. These may be augmented or replaced by model selection methods that give a smooth model and a graphical depiction of the real model. WIREs Comp Stat 2011 3 397–406 DOI: 10.1002/wics.171

This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Nonparametric Methods
Characterization of Fenugreek (Trigonella foenum‐graecum) Seed Lipids
Authors: Ciftci Ozan Nazim , Przybylski Roman , Rudzinska Magdalena , Acharya Surya
Published: April 2011

The composition and content of lipids, fatty acids, triacylglycerols, tocopherols and sterols in nine fenugreek genotypes were analyzed. Lipid content in fenugreek seeds ranged from 5.8 to 15.2%. Major fatty acids were: linoleic acid (45.1–47.5%), α‐linolenic (18.3–22.8%), oleic (12.4–17.0%), palmitic (9.8–11.2%) and stearic (3.8–4.2%) acids. The ratios of n‐6 to n‐3 fatty acids were between 2.1 and 2.7. Similar fatty acid distribution was observed in all analyzed samples with some deviations. α‐Tocopherol was the predominant component found in the fenugreek lipid antioxidants, and it constituted over 84% of the total amounts of tocopherols. It amounts ranged from 620 to 910 mg/kg lipids. β‐Sitosterol was the major sterol in all samples, varying from 14,203 to 18,833 mg/kg of lipids. Campesterol and cycloartenol were other major sterols, and these compounds including β‐sitosterol constituted 56–72% of all sterols. Fenugreek seed lipids consisted predominantly triunsaturated (56.9–66.5%) and diunsaturated (32.2–41.6%) triacylglycerides. Among these components trilinolein (LLL; 12.9–20.5%) dominated followed by PLL (14.0–20.4%), LnLnO (7.8–17.7%), PLO (5.7–11.6%), OLL (6.9–10.6%), LLLn (3.2–9.6%), and LnLnL (3.5–7.6%). Results of the study show that fenugreek seed lipids may be a source of a nutraceutical ingredient for food applications.
Magnetic resonance imaging of abnormal ventricular septal motion in heart diseases: a pictorial review
Authors: Méndez Cristina , Soler Rafaela , Rodriguez Esther , López Marisol , Álvarez Lucia , Fernández Noela , Montserrat Lorenzo
Published: April 2011

The purpose of this article is to illustrate the usefulness of MR imaging in the clinical evaluation of congenital and acquired cardiac diseases characterised by ventricular septal wall motion abnormality. Recognition of the features of abnormal ventricular septal motion in MR images is important to evaluate the haemodynamic status in patients with congenital and acquired heart diseases in routine clinical practice.