bluuebunny/crossref_metadata_2025 huggingface dataset:
The acute effect of increased laser energy during the excimer laser‐assisted non‐occlusive anastomosis procedure on the vessel wall of the recipient artery: A histopathological study
Authors: Biesbroek Matthijs , van Doormaal Tristan P.C. , van der Zwan Albert , Tulleken Cornelis A.F. , Regli Luca , Heijnen Harry F.G. , Vink Aryan
Published: July 2011

Background and Objective

The excimer laser‐assisted non‐occlusive anastomosis (ELANA) technique is a way of making an anastomosis of vessels without temporal occlusion that is used for cerebral revascularization. Currently, 10 mJ of laser energy is used during the ELANA procedure. We have recently demonstrated that increasing the laser energy may increase flap retrieval rate. The aim of the present study was to study the acute effect of increased laser energy during the ELANA procedure on the recipient vessel wall.

Materials and Methods

The ELANA technique was performed on the abdominal aortas of rabbits under anesthesia using three categories of laser energy (two laser episodes of 10, 13, and 15 mJ, respectively). The rabbits were subsequently sacrificed and the anastomoses were removed. A non‐lased rabbit aorta was used as control. Recipient arteries were studied using histopathology and transmission electron microscopy.

Results

In all three categories of laser energy and in the control group, the tunica media and adventitia adjacent to the anastomosis were intact, apart from damage caused by sutures. In the control group, the endothelium was fully intact. In the 10 and 13 mJ subgroups, the endothelium was mostly intact [92% (range 85–98) and 87% (range 80–90) for 10 and 13 mJ, respectively]. In the 15 mJ subgroup, most of the endothelium was absent [32% (range 20–40) of endothelium intact], predominantly at the side opposed to the anastomosis.

Conclusion

Increasing the laser energy during the ELANA procedure from 10 to 13 mJ does not cause additional acute damage to the vessel wall. Increasing the laser energy from 13 to 15 mJ results in increased acute damage of the endothelium, whereas tunica media and adventitia remain unaffected. Further studies are required to assess the long‐term effects of increased laser energy during the ELANA technique. Lasers Surg. Med. 43:522–527, 2011. © 2011 Wiley‐Liss, Inc.
Sutureless sealing of penetrating corneal wounds using a laser‐activated thin film adhesive
Authors: Shahbazi Jeyran , Marçal Helder , Watson Stephanie , Wakefield Denis , Sarris Maria , Foster L. John R.
Published: July 2011

Background and Objectives

To demonstrate the feasibility of a novel, thin film, laser‐activated adhesive in sealing penetrative corneal wounds with a view to replacing sutures in ophthalmic operations.

Methods

A previously described thin film adhesive composed of chitosan and indocyanine green activated by infrared laser (808 nm) was used to seal penetrating corneal wounds ranging from 1 to 6 mm in size in enucleated bovine eyes. The excised corneas were subjected to pressure tests to evaluate the strength of the corneal repairs and compared to sutures and commercial fibrin glue, Tisseel®. Temperatures at the adhesive–tissue interface were measured and histological examinations of the repairs performed to investigate potential tissue damage. Biodegradability of the films was monitored in lysozyme solutions at concentrations reported in tears.

Results

The adhesive effectively sealed corneal wounds, withstanding pressures of 140–320 mmHg, far in excess of the normal intraocular pressure. In contrast, pressures of 40–80 mm Hg were determined using a combination of sutures with Tisseel® as a sealant. The laser‐activation process was 1.5–5 times faster than other procedures studied and required no curing time. A transient, mean temperature of 56 ± 2°C was measured at the adhesive–tissue interface while histology showed no tissue damage as a consequence of the irradiation process. Irradiation had no significant influence on adhesive biodegradation in vitro, which lost approximately 30% of their initial weight in a lysozyme solution (6 mg ml−1).

Conclusions

The thin film adhesive was found to be an effective in sealing corneal wounds with considerable advantages over sutures, including speed of application and sealing strength and biodegradability. Lasers Surg. Med. 43:490–498, 2011. © 2011 Wiley‐Liss, Inc.
Laser reshaping of costal cartilage for transplantation
Authors: Baum Olga I. , Soshnikova Yulia M. , Sobol Emil N. , Korneychuk Andrey Ya. , Obrezkova Mariya V. , Svistushkin Valeriy M. , Timofeeva Oxana K. , Lunin Valeriy V.
Published: July 2011

Background and Objective

Laser reshaping of cartilage is a new effective and safe technique for correction of nasal septum and ear deformities. Costal cartilage is a most suitable natural material for transplantation. The problem is to obtain stable proper shape of cartilage implants. The objective of this article is to study reshaping of porcine costal cartilage for larynx stenosis surgery using Erbium glass fiber laser.

Materials and Methods

Porcine cartilage plates 3 mm in thickness were mechanically curved and irradiated (1) on one side (stretched or compressed) and (2) on both sides with different sequence. Irradiation was performed using a 1.56 µm laser with power varied from 1 to 2.5 W, exposure time from 5 to 20 seconds, spot diameter of 2.5 mm, pulse duration of 500 milliseconds, pulse repetition rate of 1.4 Hz. For each laser setting, stable curvature radius was measured during 24 hours after the experiment. Irradiated samples were analyzed by means of differential scanning calorimerty (DSC) to reveal the collagen denaturation degree.

Results

The optimum laser setting for stable reshaping of costal cartilage without visual thermal damage of cartilage matrix was established: laser power of 2.2 W, exposure time of 6 seconds. Nonlinear thermomechanical behavior of cartilage in the course of its laser reshaping is experimentally revealed. The influence of irradiation sequence on the curvature radius of cartilage implant is found for the first time. It is shown that (1) it is possible to use laser reshaping technique for making stable proper shape of costal cartilage, and (2) primary irradiation of compressed side followed with an irradiation of stretched side is more effective than reverse sequence of laser treatment. DSC analysis showed that thermal effect of irradiated specimens (2.58–3.79 J/g) was slightly lower that that for intact cartilage specimens and considerably lower than that for denaturation of collagen (65 ± 5 J/g).

Conclusions

It is possible to use laser reshaping technique for preparation of stable cartilage implants. Nonlinear thermomechanical behavior of cartilage is experimentally revealed. The influence of irradiation sequence on curvature radius of cartilage grafts is established for the first time. Lasers Surg. Med. 43:511–515, 2011. © 2011 Wiley‐Liss, Inc.
Continuous wave terahertz transmission imaging of nonmelanoma skin cancers
Authors: Joseph Cecil S. , Yaroslavsky Anna N. , Neel Victor A. , Goyette Thomas M. , Giles Robert H.
Published: July 2011

Background and Objective

Continuous wave terahertz imaging has the potential to offer a safe, noninvasive medical imaging modality for delineating human skin cancers. Terahertz pulse imaging (TPI) has already shown that there is contrast between basal cell carcinoma and normal skin. Continuous‐wave imaging offers a simpler, lower cost alternative to TPI. The goal of this study was to investigate the feasibility of continuous wave terahertz imaging for delineating skin cancers by demonstrating contrast between cancerous and normal tissue in transmission mode.

Materials and Methods

Two CO2 optically pumped far‐infrared molecular gas lasers were used for illuminating the tissue at two frequencies, 1.39 and 1.63 THz. The transmitted signals were detected using a liquid Helium cooled Silicon bolometer. Fresh skin cancer specimens were obtained from Mohs surgeries. The samples were processed and imaged within 24 hours after surgery. During the imaging experiment the samples were kept in pH‐balanced saline to prevent tissue dehydration. At both THz frequencies two‐dimensional THz transmission images of nonmelanoma skin cancers were acquired with spatial resolution of 0.39 mm at 1.4 THz and 0.49 mm at 1.6 THz. For evaluation purposes, hematoxylin and eosin (H&E) histology was processed from the imaged tissue.

Results

A total of 10 specimens were imaged and it was determined that for both frequencies, the areas of decreased transmission in the THz image correlated well with cancerous areas in the histopathology. Two negative controls were also imaged. The difference in transmission between normal and cancerous tissue was found to be approximately 60% at both frequencies, which suggests that contrast between normal and cancerous tissue at these frequencies is dominated by differences in water content.

Conclusions

Our results suggest that intraoperative delineation of nonmelanoma skin cancers using continuous‐wave terahertz imaging is feasible. Lasers Surg. Med. 43:457–462, 2011. © 2011 Wiley‐Liss, Inc.
The adverse events of deep fractional CO2: A retrospective study of 490 treatments in 374 patients
Authors: Shamsaldeen Omar , Peterson Jennifer D. , Goldman Mitchel P.
Published: July 2011

Background

Fractionated carbon dioxide CO2 laser resurfacing unites the idea of fractional photothermolysis with an ablative 10,600‐nm wavelength. This technology permits effective treatment of deeper rhytides, photodamaged skin, and scars, with shorter recovery and a decreased side effect profile as compared to traditional CO2 laser resurfacing.

Objectives

To study the rate of the adverse events associated with the use of deep fractional CO2 laser.

Methods

A retrospective study of 490 fractionated CO2 laser treatments in 374 patients by ten physicians within one practice was performed between March 3, 2008 and July 28, 2010. Treatment areas included the face, neck, chest, hands, back, and abdomen.

Results

Of the 490 treatments, 365 were of both superficial and deep fractional treatments while 125 treatments were deep. Patients treated were of Fitzpatrick skin types I–IV. Four hundred ninety treatments resulted in 67 adverse events (13.6%) in 63 patients (16.8%), the most frequent adverse events were acneiform eruption (5.3%), herpes simplex outbreak (2.2%), bacterial infections (1.8%), yeast infections (1.2%), hyperpigmentation (1.2%), prolonged erythema beyond 1 month (0.8%), and (0.8%) contact dermatitis. There were no reports of scarring or hypopigmentation.

Conclusions

Fractional deep CO2 laser is a safe method for treating rhytides, photodamaged skin, and scars with a low incidence of adverse events. Lasers Surg. Med. 43:453–456, 2011. © 2011 Wiley‐Liss, Inc.
Fluorescence localization and kinetics of mTHPC and liposomal formulations of mTHPC in the window‐chamber tumor model
Authors: de Visscher Sebastiaan A. H. J. , Kaščáková Slávka , de Bruijn Henriëtte S. , van den Heuvel Angélique van der Ploeg ‐ , Amelink Arjen , Sterenborg Henricus J. C. M. , Robinson Dominic J. , Roodenburg Jan L. N. , Witjes Max J. H.
Published: July 2011

Background and Objective

Foslip® and Fospeg® are liposomal formulations of the photosensitizer mTHPC, intended for use in Photodynamic Therapy (PDT) of malignancies. Foslip consists of mTHPC encapsulated in conventional liposomes, Fospeg consists of mTHPC encapsulated in pegylated liposomes. Possible differences in tumor fluorescence and vasculature kinetics between Foslip, Fospeg, and Foscan® were studied using the rat window‐chamber model.

Material and Methods

In 18 rats a dorsal skin fold window chamber was installed and a mammary carcinoma was transplanted in the subcutaneous tissue. The dosage used for intravenous injection was 0.15 mg/kg mTHPC for each formulation. At seven time‐points after injection (5 minutes to 96 hours) fluorescence images were made with a CCD. The achieved mTHPC fluorescence images were corrected for tissue optical properties and autofluorescence by the ratio fluorescence imaging technique of Kascakova et al. Fluorescence intensities of three different regions of interest (ROI) were assessed; tumor tissue, vasculature, and surrounding connective tissue.

Results

The three mTHPC formulations showed marked differences in their fluorescence kinetic profile. After injection, vascular mTHPC fluorescence increased for Foslip and Fospeg but decreased for Foscan. Maximum tumor fluorescence is reached at 8 hours for Fospeg and at 24 hours for Foscan and Foslip with overall higher fluorescence for both liposomal formulations. Foscan showed no significant difference in fluorescence intensity between surrounding tissue and tumor tissue (selectivity). However, Fospeg showed a trend toward tumor selectivity at early time points, while Foslip reached a significant difference (P < 0.05) at these time points.

Conclusions

Our results showed marked differences in fluorescence intensities of Fospeg, Foslip, and Foscan, which suggest overall higher bioavailability for the liposomal formulations. Pegylated liposomes seemed most promising for future application; as Fospeg showed highest tumor fluorescence at the earlier time points. Lasers Surg. Med. 43:528–536, 2011. © 2011 Wiley‐Liss, Inc.
Photothermolysis of sebaceous glands in human skin ex vivo with a 1,708 nm Raman fiber laser and contact cooling
Authors: Alexander Vinay V. , Ke Kevin , Xu Zhao , Islam Mohammed N. , Freeman Michael J. , Pitt Bertram , Welsh Michael J. , Orringer Jeffrey S.
Published: July 2011

Background and Objectives

Wavelengths near ∼1,720 nm are of interest for targeting fat/lipid‐rich tissues due to the high absorption coefficient of human fat and low water scattering and absorption. In this study, a 1,708 nm laser was built and shown to selectively target fat/lipid adjacent to porcine heart and dermis and then used to damage dermal sebaceous glands in human skin.

Study Design and Materials

An all‐fiber 1,708 nm laser with ∼4 W maximum power was designed and built. Selectivity for targeting fat/lipid was studied by exposing porcine heart and skin tissue cross‐sections to the 1,708 nm laser. Human skin treatments to damage sebaceous glands were performed both with and without cold window cooling. Histochemical evaluation on the frozen sections was performed using methylthiazolyldiphenyl‐tetrazolium bromide (MTT) assay.

Results

Histochemical analysis of porcine tissue cross‐sections showed that 1,708 nm laser can selectively damage pericardial fat(heart) and subcutaneous fat(skin) with little to no damage to the myocardium and the dermis, respectively. In human skin, histochemical evaluation without contact cooling showed damage to both epidermis and dermis. With cooling, epidermis was spared and damage was observed in dermis extending ∼0.4–1.65 mm from the skin surface at an average laser fluence of ∼80 J/cm2. Selective damage of sebaceous glands was suggested but not definitively demonstrated.

Conclusions

We have developed an all‐fiber 1,708 nm laser capable of damaging majority of the sebaceous glands in the dermis and thus may have potential applications in the treatment of conditions such as acne vulgaris whose pathophysiology involves disorders of sebaceous glands. Lasers Surg. Med. 43:470–480, 2011. © 2011 Wiley‐Liss, Inc.
Fast radio‐frequency enforced steady state (FRESS) spin echo MRI for quantitative T2 mapping: minimizing the apparent repetition time (TR) dependence for fast T2 measurement
Authors: Cheung Jerry S. , Wang Enfeng , Zhang XiaoAn , Mandeville Emiri , Lo Eng H. , Sorensen A. Gregory , Sun Phillip Zhe
Published: July 2011

Transverse relaxation time (T2) is a basic but very informative MRI parameter, widely used in imaging to examine a host of diseases, including multiple sclerosis, stroke, and tumor. However, short repetition time (TR) is often used to minimize scan time, which may introduce non‐negligible errors in T2 measurement. Specifically, due to the use of refocusing pulse, the steady state magnetization depends not only on TR but also on the TE. Hence, if the TE dependence is not properly accounted for, it may be mistaken as T2‐induced signal attenuation, leading to non‐negligible T2 underestimation. Our study proposed a fast radio‐frequency enforced steady state (FRESS) spin echo (SE) MRI sequence, which saturates the magnetization after the echo and ensures a TE‐independent steady state. The proposed FRESS‐SE MRI was evaluated with numerical simulation, implemented with echo planar imaging readout, and validated by both phantom and in vivo experiments. In summary, FRESS‐SE T2 MRI technique was developed for fast and accurate T2 imaging, suitable for in vivo applications. Copyright © 2011 John Wiley & Sons, Ltd.
Development of a fast method for quantitative measurement of hyperpolarized 129Xe dynamics in mouse brain
Authors: Imai Hirohiko , Kimura Atsuomi , Akiyama Kazue , Ota Chikako , Okimoto Kazuki , Fujiwara Hideaki
Published: July 2011

A fast method has been established for the precise measurement and quantification of the dynamics of hyperpolarized (HP) xenon‐129 (129Xe) in the mouse brain. The key technique is based on repeatedly applying radio frequency (RF) pulses and measuring the decrease of HP 129Xe magnetization after the brain Xe concentration has reached a steady state due to continuous HP 129Xe ventilation. The signal decrease of the 129Xe nuclear magnetic resonance (NMR) signal was well described by a simple theoretical model. The technique made it possible to rapidly evaluate the rate constant α, which is composed of cerebral blood flow (CBF), the partition coefficient of Xe between the tissue and blood (λi), and the longitudinal relaxation time (T1i) of HP 129Xe in the brain tissue, without any effect of depolarization by RF pulses and the dynamics in the lung. The technique enabled the precise determination of α as 0.103 ± 0.018 s‐1 (± SD, n = 5) on healthy mice. To investigate the potential of this method for detecting physiological changes in the brain of a kainic acid (KA) ‐induced mouse model of epilepsy, an attempt was made to follow the time course of α after KA injection. It was found that the α value changes characteristically with time, reflecting the change in the physiological state of the brain induced by KA injection. By measuring CBF using 1H MRI and 129Xe dynamics simultaneously and comparing these results, it was suggested that the reduction of T1i, in addition to the increase of CBF due to KA‐induced epilepsy, are possible causes of the change in 129Xe dynamics. Thus, the present method would be useful to detect a pathophysiological state in the brain and provide a novel tool for future brain study. Copyright © 2011 John Wiley & Sons, Ltd.
Outcome of pregnancies complicated by oligohydramnios or anhydramnios of renal origin
Authors: Grijseels E. W. M. , van‐Hornstra PTM Echteld , Govaerts L. C. P. , Cohen‐Overbeek T. E. , de Krijger R. R. , Smit B. J. , Cransberg K.
Published: July 2011

Objective

To evaluate the outcome of fetuses with oligohydramnios due to kidney anomalies.

Methods

A retrospective study was performed of all pregnancies diagnosed with oligohydramnios and associated kidney anomalies during the period 2000–2008.

Outcome included pregnancy outcome, mortality, and morbidity. Morbidity included renal function based on the glomerular filtration rate (GFR) during follow‐up.

Results

A total of 71 pregnancies were evaluated; 36 fetuses presented on ultrasound with cystic dysplasia, 15 with polycystic kidney disease (PKD) and 20 with hydronephrosis. Twenty‐three (32%) had associated anomalies. In 49 fetuses (69%), the diagnosis had been made before 24 weeks of gestational age (GA); 41 of those pregnancies were terminated.

Twenty‐five neonates were live born: 10 survived, 15 died. Prognostic factors for survival included GA at diagnosis (32.2 weeks for survivors vs 28.1 weeks for non‐survivors; P = 0.02), diagnosis of hydronephrosis (7 in the survivors vs 4 in the non‐survivors: P = 0.05), isolated anomaly (9 in the survivors vs 7 in the non‐survivors: P = 0.04). Severity of oligohydramnios (1 case of anhydramnios in the survivors vs 7 in the non‐survivors: P = 0.08) was not significant. The 1‐year GFR was below 50 mL/min.1.73 m2 in four of the ten survivors.

Conclusion

The prognosis of early onset renal oligohydramnios is poor. Predictive determinants of survival are: GA at diagnosis, nature of renal anomaly (hydronephrosis vs other), and presence of associated anomalies. Copyright © 2011 John Wiley & Sons, Ltd.
Differences and over‐time changes in levels of prescription opioid analgesic dispensing from retail pharmacies in Canada, 2005–2010
Authors: Fischer Benedikt , Jones Wayne , Krahn Murray , Rehm Jürgen
Published: July 2011

Purpose

To examine qualitative and quantitative levels and trends of prescription opioid analgesics (“opioids”) use and the potential impact of prescription monitoring programs (PMPs), in the 10 Canadian provinces, for 2005–2010.

Methods

Opioid dispensing data from a representative sample of 2700 retail pharmacies were obtained. Individual opioid dispensing values were translated into defined daily doses per day/1000 population and categorized into “weak opioids” and “strong opioids” by standardized methods. Opioid prescription rates between provinces and over time, as well as the impact of PMPs, were examined using regression analyses techniques (i.e., Poisson, ANOVAs).

Results

Significant differences between provinces in the overall standardized rates of dispensing for total opioids, as well as for “weak opioids” and “strong opioids” categories, were found. The majority of provinces featured increases or curvilinear trends in the standardized amounts of opioids dispensed over time, mainly driven by increases in “strong opioids” use. In addition, significant inter‐provincial differences in the levels of dispensing of individual opioids were found. Comparisons of changes in opioid dispensing between provinces with and without PMPs did not indicate significant differences.

Conclusions

Opioid use featured significant quantitative and qualitative differences between provinces in Canada and showed an overall increasing trend mainly driven by changes in “strong opioids” in the study period. Reasons for the observed differences are not clear yet require systematic examination to allow evidence‐based interventions in the interest of equitable pain treatment as well as the reduction of high levels of opioid‐related morbidity and mortality in Canada. Copyright © 2011 John Wiley & Sons, Ltd.
Copolyesters as non‐toxic plasticizers
Authors: Zhou Jiawen , Ritter Helmut
Published: July 2011

Plasticized polymer materials have taken an enormous role in our everyday life. Most of the common plasticizers are aromatics, esters of phthalic acid. Since they are not chemically bonded to the polymer matrix, they can be released from material while being used. The concerns raised about toxicity led to a large demand for producing biodegradable and non‐toxic plasticizers. We investigated aliphatic copolyesters synthesized via ring opening polymerization of lactones as plasticizers for poly(vinyl chloride). The material properties of the formulations, such as glass transition temperature and mechanical performance, were studied. Copyright © 2011 Society of Chemical Industry
Oncologists' use of patient educational materials about cancer and fertility preservation
Authors: Quinn Gwendolyn P. , Vadaparampil Susan T. , Malo Teri , Reinecke Joyce , Bower Bethanne , Albrecht Terrance , Clayman Marla L
Published: July 2011

Background

This study sought to determine the prevalence of distribution of fertility preservation (FP) materials, source of the materials, and providers' perceived relevance of the materials among a sample of US oncologists.

Methods

A 53‐item survey was administered via mail and the Web to a stratified sample of oncologists from the American Medical Association Masterfile. This study represents a subset of results, reporting on three survey items.

Results

Among the 511 oncologists (32% response rate), only 13.5% (n = 69) reported ‘always or often’ giving their patients educational materials about FP. Among those who reported ever distributing materials, 39.5% used American Cancer Society materials, 11.0% used Fertile Hope, 6.4% used Lance Armstrong Foundation, and 11.8% used ‘other’. Among those who provided materials, only 27.4% believe the FP materials they provide are ‘relevant to patient's specific cancer diagnosis’.

Conclusion

There is need to improve oncologists' distribution of FP educational materials to patients with cancer. Copyright © 2011 John Wiley & Sons, Ltd.
The retest reliability of the six‐minute walk test in patients referred to a cardiac rehabilitation programme
Authors: Hanson Lisa C. , McBurney Helen , Taylor Nicholas F.
Published: July 2011

Background and Purpose

The purpose of this paper was to determine if the Six‐minute Walk Test (6MWT) was a reliable exercise test for patients referred to cardiac rehabilitation when up to three tests were performed and to determine if test scores differed according to between‐test time interval.

Methods

Thirty adults aged 63 ± 7.9 years referred to cardiac rehabilitation participated in a repeated measures reliability trial. Participants completed three 6MWTs within a one‐week period. Participants were randomly allocated to one of three groups: on the first day, Group A completed three walks, Group B completed two walks and Group C completed one walk. Relative reliability was expressed in a ratio (ICC2,1), and absolute reliability was expressed in metres (95% confidence intervals) for group and individuals.

Results

The 6MWT demonstrated a high level of relative reliability (intraclass correlation coefficients [ICC] = 0.94) across the three walks. There was no statistically significant difference between the test scores of the three groups. However, there was an increase in distance walked from the first to the second to the third 6MWT. Absolute reliability indicated that a change of at least 44 m would be required to be interpreted as true change in a group, and at least 95 m to be interpreted as true change in an individual with 95% confidence.

Conclusion

Three 6MWTs completed in relatively short timeframes were not sufficient for reliable results as there was an increase in the distance walked, and relatively large increases in distances would be required to be interpreted as change. It did not make any difference whether the tests were all completed on one day or over one week. This study highlighted problems that may arise when relying on reliability coefficients alone to interpret reliability. These results suggest that the 6MWT may not have sufficient reliability to be a suitable test to evaluate exercise tolerance in patients referred to cardiac rehabilitation. Copyright © 2011 John Wiley & Sons, Ltd.
Inherently safer design–not only about reducing consequences!
Authors: Hendershot Dennis C.
Published: July 2011

Process risk is a function of both the likelihood of occurrence of an incident, and of the consequences of the incident. There is a common perception that inherently safer design focuses solely on reducing or eliminating the consequences. However, an inherently safer design can also focus on the frequency part of the risk equation. An inherently safer design can make an incident inherently less likely to occur, although the consequences of the incident, should it occur, would be unchanged. In event tree or Layer of Protection (LOPA) terms, this may be thought of as a design modification which reduces the frequency of the initiating event, rather than improving the reliability of, or increasing the number of, layers of protection. Several examples of inherently safer designs which reduce the likelihood of an incident are discussed. © 2011 American Institute of Chemical Engineers Process Saf Prog, 2011
The effect of defects on the electronic and magnetic properties of Fe2MnSi Heusler alloy
Authors: Hamad Bothina , Hu Qing‐Miao
Published: July 2011

Density functional theory (DFT) calculations were performed by using FP‐LAPW method to investigate the effect of defects on the electronic and magnetic structure of Fe2MnSi Heusler alloy. The formation energies were calculated for antisite, swap, and vacancy defects. We found that three defects, namely MnFe and MnSi antisite as well as Fe–Mn swap defects may spontaneously occur as they have negative formation energies. Whereas, Mn and Si vacancies, Fe–Si swap, and FeMn antisite defects are unlikely to occur. However, the rest of the defects (FeSi, MnSi, and SiFe) antisites, Mn–Si swap, and Fe vacancy defects have relatively low formation energies that suggest higher probabilities to occur. The band gaps of the defected structures are found to be smaller than the ideal structure with almost zero values in the cases of FeSi antisite and Fe–Si swap defects. The structure with Fe vacancy defect, however, exhibits almost the same energy gap as that of the ideal structure. The magnetic structure was also affected by the presence of defects except for Fe–Mn and Mn–Si swap defects that show the same total magnetic moment of 3 µB/f.u. as the ideal structure.
Physico‐chemical and optical properties of Sahelian and Saharan mineral dust: in situ measurements during the GERBILS campaign
Authors: Klaver Anne , Formenti Paola , Caquineau Sandrine , Chevaillier Servanne , Ausset Patrick , Calzolai Giulia , Osborne Simon , Johnson Ben , Harrison Mark , Dubovik Oleg
Published: July 2011

This paper presents new results on the composition, size and shape of mineral dust particles from African sources which were obtained by analysis of bulk filter samples collected in June 2007 onboard the BAe‐146 research aircraft of the Facility for Airborne Atmospheric Measurements (FAAM). The aircraft was operated over Mauritania, Mali and Niger during the Geostationary Earth Radiation Budget Intercomparisons of Longwave and Shortwave radiation (GERBILS) campaign. Dust sampled during the campaign originated from various sources, including locally in the Sahel as a result of large‐scale convective activity.

Regardless of origin, clays (illite, kaolinite) dominated the total volume (79–90%); the remainder was composed of quartz, calcium‐rich minerals (calcite, dolomite, gypsum) and alkali feldspars. Iron oxides, measured using a selective chemical extraction method, accounted for 1–3% of the total dust mass. The dependence of particle number size and shape distribution on the origin of dust seems minor too, although our results might be slightly misleading due to the fact that those kinds of data have been gathered on flights when dust had comparable origins and residence time.

Mineral dust is only weakly absorbing in the mid‐visible wavelengths (single scattering albedo ω0 > 0.95 at 550 nm), and ω0 measured values can be reproduced by measuring the bulk fractions of the major minerals, i.e. clays, quartz, calcite and iron oxides. At this wavelength, knowledge of the nature of clays and iron oxides, or the state of mixing of the minerals, does not induce significant differences in the results. A more precise description of the nature of clays and iron oxides is necessary at lower wavelengths owing to larger differences in their spectral optical properties. In particular, knowledge of the nature of the dominant clay is important for determining light scattering in the backward hemisphere. Copyright © 2011 Royal Meteorological Society and British Crown Copyright, the Met Office
Fragmentation characteristics of bn (n = 2–15) ions from protonated peptides
Authors: Rivera‐Tirado Edgardo , Wesdemiotis Chrys
Published: July 2011

The fragmentation reactions of protonated oligoalanines (trialanine, tetraalanine and pentaalanine) and the fragments present in the electrospray ionization (ESI) mass spectrum of polyalanine have been studied by collisionally activated dissociation (CAD) mass spectrometry (MS2 and MS3 experiments). The MSn experiments provided strong evidence that the m/z 71n + 1 ion series in the ESI mass spectrum of polyalanine is a bn series. These ions are formed via the bn–ym pathway of amide bond cleavage, which results in the formation of a proton‐bound complex of an oxazolone and a peptide/amino acid. Also, the MS2 spectra of the bn series from polyalanine revealed that the chain length of bn ions influences significantly the dissociations taking place. For example, bn ions start losing H2O at n ≥5 and the losses of CO and CO + NH3 decrease in intensity from b2 to b15. The elimination of H2O + NH3 and the elimination of 61 mass (HN = C = O + H2O) commence with b6; their abundances initially increase up to ~ b8–b9 and then gradually decrease until b15 (largest fragment studied). The tandem mass spectrometry experiments help to elucidate the dissociation mechanisms of the observed structures of biopolymer fragments. Copyright © 2011 John Wiley & Sons, Ltd.
Spectral analysis software improves confidence in plant and soil water stable isotope analyses performed by isotope ratio infrared spectroscopy (IRIS)
Authors: West A. G. , Goldsmith G. R. , Matimati I. , Dawson T. E.
Published: July 2011

Previous studies have demonstrated the potential for large errors to occur when analyzing waters containing organic contaminants using isotope ratio infrared spectroscopy (IRIS). In an attempt to address this problem, IRIS manufacturers now provide post‐processing spectral analysis software capable of identifying samples with the types of spectral interference that compromises their stable isotope analysis. Here we report two independent tests of this post‐processing spectral analysis software on two IRIS systems, OA‐ICOS (Los Gatos Research Inc.) and WS‐CRDS (Picarro Inc.). Following a similar methodology to a previous study, we cryogenically extracted plant leaf water and soil water and measured the δ2H and δ18O values of identical samples by isotope ratio mass spectrometry (IRMS) and IRIS. As an additional test, we analyzed plant stem waters and tap waters by IRMS and IRIS in an independent laboratory. For all tests we assumed that the IRMS value represented the “true“ value against which we could compare the stable isotope results from the IRIS methods. Samples showing significant deviations from the IRMS value (>2σ) were considered to be contaminated and representative of spectral interference in the IRIS measurement. Over the two studies, 83% of plant species were considered contaminated on OA‐ICOS and 58% on WS‐CRDS. Post‐analysis, spectra were analyzed using the manufacturer's spectral analysis software, in order to see if the software correctly identified contaminated samples. In our tests the software performed well, identifying all the samples with major errors. However, some false negatives indicate that user evaluation and testing of the software are necessary. Repeat sampling of plants showed considerable variation in the discrepancies between IRIS and IRMS. As such, we recommend that spectral analysis of IRIS data must be incorporated into standard post‐processing routines. Furthermore, we suggest that the results from spectral analysis be included when reporting stable isotope data from IRIS. Copyright © 2011 John Wiley & Sons, Ltd.
The molecular and pathophysiological implications of hepatitis B X antigen in chronic hepatitis B virus infection
Authors: Martin‐Vilchez Samuel , Lara‐Pezzi Enrique , Trapero‐Marugán Maria , Moreno‐Otero Ricardo , Sanz‐Cameno Paloma
Published: July 2011

Hepatitis B virus is considered one of the most significant environmental carcinogens in humans. Because the mechanisms of HBV replication and the development of hepatocellular carcinoma (HCC) are partially known, HBV‐associated pathogenesis remains a challenge to increase its understanding. Evidence suggests that the regulatory protein hepatitis B virus X (HBx) mediates the establishment and maintenance of the chronic carrier state. HBx is a multifunctional and potentially oncogenic protein that is conserved among mammalian hepadnaviruses; it is produced very early after infection and throughout the chronic phase. HBx exerts its effects by interacting with cellular proteins and activating various signaling pathways. HBx stimulates the transcription of genes that regulate cell growth, apoptosis, and DNA repair. It also interacts with proteasome subunits and affects mitochondrial stability. Moreover, HBx participates in processes that are associated with the progression of chronic liver disease, including angiogenesis and fibrosis. This review discusses the function of HBx in the life cycle of HBV and its contribution to the pathogenesis of HCC. Copyright © 2011 John Wiley & Sons, Ltd.
Global control of nonlinear systems with uncertain output function using homogeneous domination approach
Authors: Zhai Junyong , Qian Chunjiang
Published: July 2011

This paper addresses the problem of using output feedback to globally control a class of nonlinear systems whose output functions are not precisely known. First, for the nominal linear system, we design a homogeneous state compensator without requiring precise information of the output function, and construct a nonlinear stabilizer with adjustable coefficients by using the generalized adding a power integrator technique. Then based on the homogeneous domination approach, a scaling gain is introduced into the proposed output feedback controller, which can be used by tuning the scaling gain to solve: (i) the problem of global output feedback stabilization for a class of upper‐triangular systems; and (ii) the problem of global practical output tracking for a class of lower‐triangular systems. Copyright © 2011 John Wiley & Sons, Ltd.
Reflections on the foundations of system dynamics
Authors: Richardson George P.
Published: July 2011

Jay W. Forrester's original statement of the foundations of system dynamics emphasized four ‘threads’: computing technology, computer simulation, strategic decision making, and the role of feedback in complex systems. Subsequent work has expanded on these to expose the significance in the system dynamics approach of dynamic thinking, stock‐and‐flow thinking, operational thinking, and so on. But the foundation of systems thinking and system dynamics lies deeper than these and is often implicit or even ignored: it is the “endogenous point of view”. The paper begins with historical background, clarifies the endogenous point of view, illustrates with examples, and argues that the endogenous point of view is the sine qua non of systems approaches. What expert systems teachers and practitioners have to offer their students and the world is a set of tools, habits of thought, and skills enabling the discovery and understanding of endogenous sources of complex system behavior. Copyright © 2011 System Dynamics Society.
Dynamic policy‐driven quality of service in service‐oriented information management systems
Authors: Loyall Joseph P. , Gillen Matthew , Paulos Aaron , Bunch Larry , Carvalho Marco , Edmondson James , Schmidt Douglas C. , Martignoni III Andrew , Sinclair Asher
Published: July 2011

SOA middleware has emerged as a powerful and popular distributed computing paradigm because of its high‐level abstractions for composing systems and encapsulating platform‐level details and complexities. Control of some details encapsulated by SOA middleware is necessary, however, to provide managed QoS for SOA systems that require predictable performance and behavior. This paper presents a policy‐driven approach for managing QoS in SOA systems called QoS enabled dissemination (QED). QED includes services for: (1) specifying and enforcing the QoS preferences of individual clients; (2) mediating and aggregating QoS management on behalf of competing users; and (3) shaping information exchange to improve real‐time performance. We describe QED's QoS services and mechanisms in the context of managing QoS for a set of Publish‐Subscribe‐Query information management services. These services provide a representative case study in which CPU and network bottlenecks can occur, client QoS preferences can conflict, and system‐level QoS requirements are based on higher level, aggregate end‐to‐end goals. We also discuss the design of several key QoS services and describe how QED's policy‐driven approach bridges users to the underlying middleware and enables QoS control based on rich and meaningful context descriptions, including users, data types, client preferences, and information characteristics. In addition, we present experimental results that quantify the improved control, differentiation, and client‐level QoS enabled by QED. Copyright © 2011 John Wiley & Sons, Ltd.
Channel allocation and reallocation for cognitive radio networks
Authors: Jiang Tigang , Wang Honggang , Leng Supeng
Published: July 2011

In this paper, a new channel allocation and re‐location scheme is proposed for cognitive radio users to efficiently utilize available spectrums. We also present a multiple‐dimension Markov analytical chain to evaluate the performance of this scheme. Both analytical results and simulation results demonstrate that the new scheme can enhance the radio system performance significantly in terms of blocking probability, dropping probability, and throughput of second users. The proposed scheme can work as a non‐server‐based channel allocation, which has practical values in real engineering design. Copyright ©2011 John Wiley & Sons, Ltd.
Automatic event‐triggered call‐forwarding mechanism for mobile phones
Authors: Lin Yi‐Bing , Liou Ren‐Huang , Chen Yuan‐Kai , Wu Zheng‐Han
Published: July 2011

Call forwarding is a traditional telecom service that allows a user to forward incoming calls to another telephone number. This service requires the user to manually activate and deactivate the feature and therefore may not be very convenient. This paper proposes an automatic call‐forwarding algorithm (CFA) for mobile phones. By installing a software in a smartphone, call forwarding is automatically triggered (e.g., when the phone is plugged in a charger or is turned off) or disabled (e.g., when the phone is unplugged from the charger or is turned on). We investigate the performance of the CFA through analytic analysis, simulation, and measurement. Our study indicates that CFA is very feasible for commercial usage. Copyright © 2011 John Wiley & Sons, Ltd.
Persistent soil seed banks in old‐growth Hyrcanian Box tree (Buxus hyrcana) stands in northern Iran
Authors: Asadi Hamed , Hosseini Seyed Mohsen , Esmailzadeh Omid , Baskin Carol C.
Published: July 2011

Little is known about the soil seed bank and the influence of plant communities on the interaction between the seed bank and aboveground vegetation in the Hyrcanian temperate deciduous forest. We surveyed species composition and diversity of the persistent soil seed bank and the aboveground vegetation in six community types in old‐growth Hyrcanian Box tree (Buxushyrcana) stands in northern Iran. Fifty‐two species with an average of 3,808 seeds/spores m−2germinated; forbs accounted for 64% of the seed bank flora. Thirty‐four species in the aboveground vegetation were not presented in the seed bank, 32 species in the seed bank were not found in the vegetation, and 20 species were in both. The dominant tree species wereDiospyros lotusandAlnus subcordatawith an average of 17 and 4.6 seeds m−2, respectively. Our results suggest that (1) vernal geophytes and shade‐tolerant perennials are not incorporated in the seed bank, (2) early successional species are well represented in the seed bank, (3) plant community type has significant impacts on seed bank densities, and seed bank richness and diversity were significantly related to presence/absence of Box tree in the aboveground vegetation. The persistent seed bank contained species that potentially have a negative impact on the regeneration of forests, thus forest managers should retain old‐growth Hyrcanian Box tree stands to conserve disturbance‐sensitive indicator forest species.
Family structure, time constraints, and sport participation
Authors: Ruseski Jane E. , Humphreys Brad R. , Hallmann Kirstin , Breuer Christoph
Published: July 2011

Recent research emphasizes the importance of economic factors on sport participation. We extend this by examining the role played by time constraints and family structure in survey data from Rheinberg, Germany. Based on empirical models that account for the two-part decision—the decision to participate and the decision about how long to participate—involved, we find that time constraints in the form of time spent caring for children and relatives and family structure in the form of the presence of children reduce both the likelihood that individuals participate and the time spent taking part in sports.
Synthesis and Surface Activities of Novel Monofluoroalkyl Phosphate Surfactants
Authors: Wang Qiwei , Zhang Shuxiang , Geng Bing , Zhang Luqing , Zhao Junqiang , Shi Jinhui
Published: July 2011

Two novel environmentally friendly fluorinated surfactants, disodium monofluoroalkyl phosphates were synthesized using phosphorus pentoxide, i.e. H(CF2)6CH2OPO(ONa)2 and H(CF2)6CH2OCH2CH2OPO(ONa)2. The novel synthesized fluorinated surfactants have a high thermal stability on the basis of Thermogravimetric Analysis. Their surface properties were also examined with the aim to have similar surface tensions of dilute aqueous solutions when compared with the conventional fluorocarbon surfactants, ammonium perfluorooctanoate. The two synthesized monofluoroalkyl phosphates can respectively reduce the surface tension of water to 23.73 mN/m at 78.3 mmol/L and 21.38 mN/m at 20.93 mmol/L. In addition, the Krafft points are both below 0 °C.
A Comparative Study of the Postoperative Morbidity and Mortality in Femoral Neck Fractures in Elderly Patients Treated with Cemented and Uncemented Thompson Hemiarthroplasty
Authors: Gowtham Kankanala , Gubbi Shivarathre Deepak , Prasad Pidikiti
Published: July 2011

Background

Thompson hip hemiarthroplasty is a well-established procedure for the treatment of displaced intracapsular fracture neck of femur in the elderly. However, considerable debate exists regarding the use of cemented prosthesis in this elderly group of patients. The main purpose of our study was to analyse the outcomes following cemented and uncemented Thompson hemiarthroplasty of the hip with particular reference to cement-related morbidity and 30-day mortality.

Methods

Of the 110 patients who underwent Thompson hemiarthroplasty for intracapsular hip fracture, 30 (27.3%) had cemented and 80 (72.7%) had uncemented prosthesis. The mean age was 83.2 years with 87 female patients. The thigh pain and mobility at discharge, the inpatient complications and the 30-day mortality rates were compared between the cemented and uncemented groups.

Results

The study revealed no statistically significant differences in any of the postoperative outcome measures between the two groups.

Conclusion

Cemented and uncemented Thompson hip hemiarthroplasty have similar outcomes at discharge. Patients who underwent cementation without pressurisation did not show any higher incidence of bone cement implantation syndrome compared to their uncemented counterparts. Uncemented Thompson hemiarthroplasty can be an option in patients with very poor cardiopulmonary reserve without any significant complications in the short term.