bluuebunny/crossref_metadata_2025 huggingface dataset:
Coping with academic failure, a study of Dutch children with dyslexia
Authors: Singer Elly
Published: October 2007

This paper reports the results of a study of strategies that Dutch children with dyslexia employ to cope with recurrent academic failure. All of the students in the study had developed strategies for protecting their self‐esteem. Using Harter's theory of coping with discrepancies between performance and standards, we distinguish four strategies: (1) working hard and committing to standards, (2) lowering standards, (3) seeking support from significant others (i.e. parents and teachers), and (4) avoiding comparisons with significant others (i.e. peers). Although self‐talk emerged as an important component of all four strategies, it was employed both adaptively (e.g. to preserve the students' belief in their own academic capacities) and maladaptively (e.g. to devalue the importance of learning). The students relied most strongly on support from their parents; teachers and peers were more likely to be seen as threats to self‐esteem. Strategies of teachers and parents to encourage adaptive coping with recurrent academic failure are confirming the student's self‐worth, explaining dyslexia, showing faith in the student's capacities, fostering adaptive self‐talk, providing educational treatment, and preventing teasing and bullying. Besides that, teachers and parents should cooperate. Copyright © 2007 John Wiley & Sons, Ltd.
Generalized Pareto models with application to drought data
Authors: Nadarajah Saralees
Published: October 2007

Generalized Pareto distributions are some of the most applied distributions in environmental sciences. In this paper, a drought application is described by deriving the exact distributions of the sum X + Y, the product XY, and the ratio X/(X + Y) when X and Y are independent generalized Pareto random variables. Drought data from the State of Nebraska are used. Copyright © 2007 John Wiley & Sons, Ltd.
New compounds from the essential oil of Vetiveria nigritana roots from Mali
Authors: Champagnat Pascal , Bessière Jean‐Marie , Chezal Jean‐Michel , Chalchat Jean‐Claude , Carnat André‐Paul
Published: October 2007

Essential oil from roots (2% w/w) of Vetiveria nigritana (Benth.) Stapf (Poaceae) from Mali was analysed by GC–MS. Among the components, four new compounds were isolated from the oil and identified by combination of EI–MS and NMR data; they were two norsesquiterpene hydrocarbons, 9,9‐dimethyl‐8‐methylenetricyclo[5.2.2.03,7]undec‐3‐ene (dehydronigritene 1) and 8,9,9‐trimethyltricyclo[5.2.2.03,7]undec‐3‐ene (nigritene 2), and two sesquiterpene acids : 2,6,6‐trimethyltricyclo[5.3.1.01,5]undec‐8‐ene‐8‐carboxylic acid (cedren‐15‐oic acid 3) and 6,6‐dimethyl‐7‐methylenetricyclo[6.2.1.01,5]undecane‐2‐carboxylic acid (2‐epi‐prezizanoic acid 4). The percentages in oil of compounds 1, 2, 3 and 4 were 0.9%, 2.2%, 7.5% and 15%, respectively, of the total amount of components. Copyright © 2007 John Wiley & Sons, Ltd.
In situ SAXRD study of sol–gel induced well‐ordered mesoporous bioglasses for drug delivery
Authors: Zhao Y. F. , Loo S. C. J. , Chen Y. Z. , Boey F. Y. C. , Ma J.
Published: October 2007

In this work, two systems of mesoporous bioglasses (MBGs) were sol–gel derived using block copolymer pluronic F127 and P123, respectively, as templates. A two‐dimensional hexagonal (P6mm) mesoporous structure was obtained for the two systems, with d‐spacing in (100) reflection of 8.49 nm for P123‐templated MBG (P123‐MBG) and 10.26 nm for F127‐templated MBG (F127‐MBG). The phase transformation behavior for the systems was elucidated using an in situ synchrotron small angle X‐ray diffraction approach, with the corresponding mechanisms proposed. It was indicated that both systems go through a complicated phase transformation, from a disordered to a finely ordered hexagonal structure during the self‐evaporation process. The surfactants not only acted as templates for the ordered structure, but also enhanced the rigidity of SiO network, which prevented disruption to the ordered SiO arrangement by the Ca2+ and PO group. In vitro bioactivity study showed similar bioactivity for both the P123‐MBG and F127‐MBG systems. Drug loading and release studies using a model metoclopramide drug showed that both MBGs presented better loading and release compared to normal bioglass (BG). The significantly higher loading and better sustained release for P123‐MBG, compared to F127‐MBG, is attributed to its higher pore volume and surface area. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Cell adhesion resistance mechanisms using arrays of dextran‐derivative layers
Authors: Monchaux Emmanuelle , Vermette Patrick
Published: October 2007

To control interactions at the cell–material interface, low‐fouling polymer coatings are used to prevent nonspecific interactions. Subsequent biosignals may be grafted on these low‐fouling layers to induce specific biological responses. A polymer array technology was developed to study structural diversity of carboxy‐methyl‐dextran (CMD) grafted layers in connection with their cell repulsion ability. Arrays of CMD layers were exposed to fibroblasts to screen for cell resistant layers according to the immobilization conditions used to produce these surfaces. Cell cytoskeleton and fibronectin matrix deposition and reorganization were labeled in short‐term (4 and 12 h) and long‐term (3 days of cell confluence) cell adhesion assays. Results suggest that CMD layers that were resistant to cell adhesion were dense, flexible, and presented a regular (i.e., defect‐free) hydrated surface. Cell‐resistant CMD layers prevented cell matrix deposition and assembly, affecting cell–substrate adhesion and cytoskeletal organization. Finally, an optimized CMD layer was chosen and proved to be as resistant as a poly(ethylene glycol) layer. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Investigation of epidermal growth factor containing liposome formulation effects on burn wound healing
Authors: Alemdaroğlu Ceren , Degim Zelihagül , Celebi Nevin , Şengezer Mustafa , Alömeroglu Melih , Nacar Ahmet
Published: October 2007

It was aimed to develop liposome formulations containing epidermal growth factor (EGF) and to investigate the healing effects of these formulations on second‐degree burn wounds in rats. Multilamellar type liposomes containing EGF were prepared by film formation method. In vitro releases of EGF from liposome formulations were determined using spectrofluorometer. Second‐degree standard burn wounds were formed on rats and liposome formulations containing 10 μg/mL EGF (ELP group), EGF solution (ES group), liposome without containing EGF (LP group), and Silverdine® ointment (SIL group) were applied daily. Untreated control groups [unburned (S) and untreated (Y) rats] were also evaluated. Biopsies were taken at the 3rd, 7th, and 14th day of the treatment from the wounds and histological observations were performed under transmission electron microscope. Bromodeoxyuridine (BrdU) staining technique was used for immunohistochemical analysis. After trichrome stainings, the thicknesses of the epidermis and the areas of the fibroblast nucleus were measured using a light microscope and Vision Screening Analysis Program. It was observed that the healing in the ELP group was the fastest among all groups (p < 0.05) at the 14th day of therapy. The healing effect in order from highest to lowest efficacy was found to be ELP>SIL>ES groups, respectively, at the 14th day. All results indicated that the EGF‐liposome formulation is effective and can be used for the treatment of burn wounds. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Inverse opal hydrogel‐collagen composite scaffolds as a supportive microenvironment for immune cell migration
Authors: Stachowiak Agnieszka N. , Irvine Darrell J.
Published: October 2007

Immunotherapies harness the inherent potential of the body to destroy foreign or infected cells, and are currently being investigated as treatments for cancer. One way to boost native immune responses might be to engineer ectopic lymphoid tissue, providing a supportive microenvironment for immune cell priming, and/or bringing together immune cells at a desired location (e.g., solid tumor sites). Here we describe the development and in vitro testing of composite macroporous poly(ethylene glycol) (PEG) hydrogel scaffolds infused with collagen as a tissue engineering platform for immunotherapy. The PEG hydrogel with ordered, interconnected pores provided mechanical stability and the potential to depot supporting cytokines/chemokines, while an infused collagen matrix supported intra‐scaffold migration of loaded T cells and dendritic cells. Rapid, nearly unconstrained T cell migration through scaffolds was achieved by using inverse opal supporting structures with 80 μm macropores. In addition, we demonstrated that the lymphoid tissue chemokine CCL21 could be bound to the inverse opal gel walls of these scaffolds, to provide motility‐inducing cues for T cells within these structures. This hybrid scaffold approach combines the strengths of the synthetic and biopolymer hydrogels used in a highly synergistic fashion, allowing each material to compensate for limiting properties of its partner. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Macrophage depletion diminishes implant‐wear‐induced inflammatory osteolysis in a mouse model
Authors: Ren Weiping , Markel David C. , Schwendener Reto , Ding Yunhong , Wu Bin , Wooley Paul H.
Published: October 2007

The purpose of this study was to determine whether macrophage depletion using clodronate liposomes diminishes wear‐debris‐induced inflammatory osteolysis in a murine osteolysis model. Ultra high molecular weight polyethylene (UHMWPE) particles were introduced into established air pouches on BALB/c mice, followed by implantation of calvaria bone from syngeneic littermates. Macrophages were depleted by the intraperitoneal injection of clodronate liposome (2 mg) 2 days before bone implantation and re‐injection every 3 days (1 mg) until the sacrifice of the mice. Mice without clodronate liposome therapy or treated with empty liposome as well as mice injected with saline alone were included in this study as controls. Pouch tissues were collected 14 days after bone implantation for molecular and histology analysis. Our findings indicated that (1) macrophage depletion in clodronate‐liposome‐treated mice was achieved, as illustrated by F4/80 immunostaining in both pouch and spleen tissues; (2) clodronate‐liposome treatment significantly reduced UHMWPE‐induced tissue inflammation, with diminished pouch membrane thickness, reduced inflammatory cellular infiltration, and lowered interleukin 1β (IL‐1β) and tumor necrosis factor α (TNFα) expression; (3) clodronate‐liposome treatment markedly reduced the number of TRAP+cells in pouch tissues and protected against bone collagen depletion. In conclusion, this study demonstrates that macrophage depletion using clodronate‐liposome reduces UHMWPE particle‐induced inflammatory osteolysis. This observation supports the hypothesis that macrophages contribute to the severity of UHMWPE particles induced inflammatory osteolysis, and suggest that macrophage depletion represents a viable therapeutic approach to the prevention and treatment of patients with aseptic loosening. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Growth of keratinocytes on porous films of poly(3‐hydroxybutyrate) and poly(4‐hydroxybutyrate) blended with hyaluronic acid and chitosan
Authors: Peschel Gundela , Dahse Hans‐Martin , Konrad Anke , Wieland Gerhard Dieter , Mueller Peter‐Juergen , Martin David P. , Roth Martin
Published: October 2007

The objective of this study was to develop novel absorbable films suitable for use as a tissue‐engineering scaffold for keratinocytes as a therapy for replacement of damaged skin. Poly(4‐hydroxybutyrate) (P(4HB)) and poly (3‐hydroxybutyrate) (P(3HB)) were blended with small amounts of the polysaccharides hyaluronic acid (HA), chitosan (CH), pectin and alginic acid, and were solution cast to produce porous films. The resulting composites had favorable mechanical properties, and these films were compared with two commercially available implantable films made of poly(L‐lactide‐co‐D,L‐lactide) (PLA copolymer) and HA benzyl ester. Tensile testing demonstrated that a high level of flexibility of P(4HB) was retained in the P(4HB)‐polysaccharide composite films, whereas the P(3HB) film and its polysaccharide composites were stiffer and more brittle. The proliferation kinetics of adherent HaCaT keratinocytes on the films was examined in vitro. The porous surface of the P(4HB) and P(3HB) films blended with HA or CH promoted the growth of keratinocytes significantly. The order of maximum cell numbers on these films was P(4HB)/HA > P(4HB)/CH > P(3HB)/HA > P(3HB)/CH > P(3HB)/pectin > P(3HB)/alginic acid. Scanning electron microscopy and confocal laser scanning microscopy revealed differences in cell growth. Cells formed clusters on P(3HB) and its composites, while the cells grew as a confluent layer on P(4HB) and its composites. HaCaT cells formed large numbers of filaments only on P(4HB) films, indicating the excellent biocompatibility of this material. For the nonporous PHB films, the proliferation rate of cells was found to increase with decreasing hydrophobicity in the order: P(4HB) > P(3HB)/P(4HB) blend > P(3HB). © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Transformations in CDHA/OCP/β‐TCP scaffold during ageing in simulated body fluid at 36.5°C
Authors: Morejón‐Alonso Loreley , García Carrodeguas Raúl , Delgado García‐Menocal José A.
Published: October 2007

The transformations that took place in a scaffold composed of CDHA/OCP/β‐TCP by ageing in SBF at 36.5° during 14 days were studied. A carbonated‐apatite layer was formed during immersion in SBF on the surface of the scaffold and part of the OCP present in the inner core of the material was also transformed into apatite. The precipitated apatite layer exhibited the typical globular morphology characteristic of bioactive materials. The content of CDHA increased from 14 to 29 wt % at the expense of the content of OCP that decreased from 39 to 29 wt %. β‐TCP content dropped slightly from 47 to 42 wt %. Total porosity (from 56.1% ± 0.6% to 62.4% ± 0.5%) and real density (from 2.58 ± 0.01 to 2.79 ± 0.01 g/cm3) increased, and diametral tensile (from 2.1 ± 0.3 to 0.9 ± 0.1 MPa) and compressive strengths (from 8.5 ± 1.0 to 6.8 ± 0.6 MPa) decreased during ageing. The in vitro results showed that the scaffold composed of CDHA, OCP, and β‐TCP is bioactive and partially resorbable. It seems to be suitable for in situ bone regeneration procedures. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Examining the influence of short‐term implantation on oxidative degradation in retrieved highly crosslinked polyethylene tibial components
Authors: Willie B. M. , Foot L. J. , Prall M. W. , Bloebaum R. D.
Published: October 2007

Concerns remain regarding the oxidative resistance of highly crosslinked polyethylene (PE). The study investigated the in vivo performance of Durasul highly crosslinked PE by comparing the oxidation index, density, and percent crystallinity in the weightbearing and nonweightbearing region of retrieved components with unused time zero tibial components. Retrieved and unused Sulene conventional PE tibial components were examined for comparison and the effects of shelf age, in vivo duration, and ex vivo duration were also investigated. The oxidation index was not significantly different between unused time zero and retrieved Durasul PE components. Regression analysis data supported these findings in that neither shelf age, in vivo duration, nor ex vivo duration was a significant predictor of oxidation index in the retrieved Durasul PE components. In contrast, the retrieved conventional PE components had significantly greater oxidation index, density, and percent crystallinity compared with unused time zero PE components. Regression data suggested that in vivo and ex vivo duration, but not shelf aging, influenced the changes observed in the conventional PE components. These data also showed that in vivo loading did not significantly affect the oxidation index, density, or percent crystallinity in either the retrieved Durasul or conventional PE tibial components. This investigation demonstrates that changes in oxidation index, density, and percent crystallinity of retrieved Durasul PE components after short‐term in vivo durations are likely not a clinical concern. These data should be used as a benchmark to compare with future studies examining the long‐term oxidative resistance of Durasul highly crosslinked PE tibial components. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Comparative study of poly(vinyl alcohol)‐based support materials for the immobilization of glucose oxidase
Authors: Wong Fui‐Ling , Abdul‐Aziz Azila
Published: October 2007

BACKGROUND: The performances of four types of glucose oxidase (GOD) immobilization materials based on poly(vinyl alcohol) (PVA) were compared. The matrices of interest were chemically‐linked PVA, freeze‐thawed PVA cryogel, tetramethoxysilane (TMOS) sol‐gel‐PVA hybrid material, and alumina sol‐gel‐PVA hybrid material.

RESULTS: Overall, the membranes showed good sensitivity except for the chemically cross‐linked PVA. However, the main differences with the enzyme immobilization methods were enzyme leakage and values of Kmapp.

CONCLUSION: Freeze‐thawed PVA‐GOD membranes and TMOS‐PVA, which showed satisfactory sensitivity and adequate value of Kmapp, were quite promising as support materials for immobilizing GOD. Copyright © 2007 Society of Chemical Industry
Benzene removal with vertical‐flow constructed treatment wetlands
Authors: Eke Paul E. , Scholz Miklas
Published: October 2007

BACKGROUND: Twelve vertical‐flow experimental wetlands have been constructed using different compositions, and were operated in batch‐flow mode to reduce pumping costs. Six wetlands were located indoors and six outdoors. Benzene was used as a representative example substance to assess the removal of low molecular weight petroleum compounds.

RESULTS: Findings indicate that the constructed wetlands remove benzene (inflow of approximately 1.3 g L−1) from hydrocarbon‐contaminated wastewater streams with better indoor (controlled environment) than outdoor treatment performances. Overall mean removal efficiencies for the experimental rig placed outside were as follows: benzene 85%, chemical oxygen demand (COD), 70%; ammonia‐nitrogen, 83%; nitrate‐nitrogen, 88%; ortho‐phosphate‐phosphorus, 58%. In comparison, removal efficiencies for the experimental rig placed indoors were higher: benzene 95%, COD, 80%; ammonia‐nitrogen, 90%; nitrate‐nitrogen, 94%; ortho‐phosphate‐phosphorus, 66%. Benzene removal was predominantly due to volatilization after 1 day of retention time.

CONCLUSION: The use of aggregates (sand and gravel) and the presence of Phragmites australis (Cav.) Trin. ex Steud. resulted in no significant difference in terms of benzene, redox potential, dissolved oxygen, 5‐day at 20 °C N‐allylthiourea biochemical oxygen demand, COD and nutrients removal. Statistical differences were assessed by analysis of variance and Tukey HSD tests (P < 0.05). Copyright © 2007 Society of Chemical Industry
Effect of sludge retention time in sludge holding tank on excess sludge production in the oxic‐settling‐anoxic (OSA) activated sludge process
Authors: Ye Fen‐Xia , Zhu Rui‐Fen , Li Ying
Published: October 2007

The activated sludge process is a core technology in wastewater treatment plants. Excess sludge produced in the process must be treated and disposed of properly and may account for up to 60% of total plant operating cost. Therefore, it is necessary to develop new biological concepts to minimize excess sludge production. The oxic‐settling‐anoxic process (OSA process), a modified activated sludge process, may produce less excess sludge than the conventional activated sludge process. The effect of sludge retention time in the sludge holding tank of the OSA process on excess sludge yield has been studied. Four pilot‐scale activated sludge systems were employed, one of which was a conventional activated sludge process, and was used as the control system. The other three were OSA systems operated with different sludge retention times (5.5 h, 7.6 h, and 11.5 h) in the sludge holding tank. All systems were operated with synthetic wastewater for 7 months. Results showed that the three OSA processes with 5.5 h, 7.6 h, and 11.5 h sludge retention time reduced the excess sludge by 33%, 23% and 14%, respectively. Compared to the control process, chemical oxygen demand (COD) removal efficiency and effluent NH3–N concentration were not significantly influenced, but total nitrogen (TN) removal efficiency decreased by 0–9%. Total phosphorus (TP) removal efficiency of OSA processes with 7.6 h and 11.5 h sludge retention time increased by 19%. Sludge settleability was excellent in the three OSA processes. No distinct shift in the diversity of the predominant species was found in microbial populations. We conclude that the OSA system could reduce excess sludge production. Results suggest 6–7 h sludge retention time would be optimal. Copyright © 2007 Society of Chemical Industry
Optimization of cordycepin extraction from cultured Cordyceps militaris by HPLC‐DAD coupled with uniform design
Authors: Song Jiang‐Feng , Liu Chun‐Quan , Li Da‐Jing , Jin Bang‐Quan
Published: October 2007

BACKGROUND: Uniform design was used to optimize the ultrasonic‐assisted extraction of cordycepin from cultured Cordyceps militaris. The peak area of cordycepin identified using high performance liquid chromatography (HPLC) at a detection wavelength of 260 nm was considered the detection index. Three factors, ethanol concentration, extraction time and volume ratio of solvent to sample were studied. Optimal quadric polynomial step by step regression was applied to process the experimental results.

RESULTS: Results show that the main factors affecting cordycepin extraction yield were the volume ratio of solvent to sample, extraction time and ethanol concentration, in that order. Cordycepin extraction yield reached a peak with ethanol concentration 20.21%, extraction time 101.88 min, and volume ratio of solvent to sample 33.13 mL g−1. An extraction model was developed based on the findings.

CONCLUSION: A direct, reliable and accurate assay has been developed for the quantification of cordycepin in cultured Cordyceps militaris by a HPLC‐DAD method. The validation procedure confirmed that this method is appropriate for the quality control of cordycepin. Results show that the uniform experimental design approach is useful for finding polynomial functions describing the relationships between variables and responses and to find the best experimental conditions for the extraction of cordycepin in the experimental domain considered. Copyright © 2007 Society of Chemical Industry
Comparative study of nitrification performances of immobilized cell fluidized bed reactor and contact oxidation biofilm reactor in treating high strength ammonia wastewater
Authors: Qiao Xiang L , Chen Qing X , Zhang Zhen J
Published: October 2007

BACKGROUND: The immobilized cell fluidized bed reactor and contact oxidation biofilm reactor are two common choices for high strength ammonia wastewater treatment, however, comparative study of the nitrification performance of the two reactors has not been thoroughly studied. The nitrification performance of the two bioreactors when treating strong synthetic ammonia wastewater was investigated and compared.

RESULTS: Results demonstrated that the immobilized cell fluidized bed reactor had a shorter acclimation period, and possessed several advantages over the contact oxidation biofilm reactor, in the form of complete oxidation of 150–360 mg L−1 ammonia wastewater in a shorter time, higher ammonia removal rates (from 9.6 to 4.32 × 102 mgN L−1 d−1) over the temperature range 8 to 32 °C, irrespective of organic load. In contrast, a large reduction in ammonia removal was found in the contact oxidation biofilm reactor with chemical oxygen demand (COD) load. The immobilized cell fluidized bed reactor exhibited stable and high rates of nitrification in the long term.

CONCLUSION: These facts demonstrated that the immobilized cell fluidized bed reactor is a suitable selection for high strength ammonia wastewater treatment. Copyright © 2007 Society of Chemical Industry
Intraoperative sonography in patients with colorectal cancer and resectable liver metastases on preoperative FDG‐PET‐CT
Authors: Wildi Stephan M. , Gubler Christoph , Hany Thomas , Petrowsky Henrik , Clavien Pierre A. , Jochum Wolfram , Gerlach Tilman , Fried Michael , Mullhaupt Beat
Published: October 2007

Background

Combined fluorine 18‐fluorodeoxyglucose–positron emission tomography–CT imaging has been shown to be of good diagnostic value in the preoperative evaluation of patients with colorectal cancer and liver metastases. The adjunctive use of intraoperative sonography (IOUS) may have a limited impact on treatment selection in these patients.

Purpose

To compare the diagnostic performance of preoperative positron emission tomography (PET)‐CT alone and PET‐CT combined with IOUS in the evaluation of patients who are considered for curative resection of hepatic metastases from colorectal carcinoma.

Materials and Methods

Patients with colorectal cancer who underwent resection of hepatic metastases and preoperative PET‐CT (with or without contrast‐enhanced CT) and IOUS were identified. The performance of the imaging techniques was evaluated through review of the radiologic reports, correlation with surgical and histopathologic findings, and clinical follow‐up.

Results

Thirty‐one patients (mean age, 63.5 years [range, 53–82 years]) were analyzed. Fifteen patients had received preoperative chemotherapy. The mean interval between PET‐CT and IOUS was 22.6 days (range, 1–56 days). In 4 cases, neither PET‐CT nor IOUS correctly diagnosed the liver metastases. In all 31 patients, the sensitivity of PET‐CT alone and PET‐CT combined with IOUS was 63% (95% CI 44–80%) and 93% (95% CI 78–98%), respectively; the positive predictive value was 81% and 89%, respectively. In patients without preoperative chemotherapy (n = 16), the sensitivity of PET‐CT alone and PET‐CT combined with IOUS was 77% (95% CI 49–94%) and 100% (95% CI 79–100%), respectively. In 11 cases (35%), IOUS altered the surgical strategy.

Conclusion

In patients with colorectal carcinoma and potentially resectable liver metastases on preoperative PET‐CT, IOUS can provide additional information that may alter decision making with regard to surgical technique. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Phase inversion harmonic imaging improves assessment of renal calculi: A comparison with fundamental gray‐scale sonography
Authors: Özdemir Hüseyin , Demir Mustafa Kemal , Temizöz Osman , Genchellac Hakan , Unlu Ercument
Published: October 2007

Purpose

To compare phase inversion harmonic imaging (PIHI) with fundamental imaging (FI) in the evaluation of renal calculi.

Methods

Thirty adult patients with renal calculi (17 men, 13 women; mean age 44 years [range, 25–71]) underwent transabdominal sonographic examination of the urinary system. Both kidneys and renal calculi were examined with PIHI and FI. Overall renal conspicuity, calculus visibility, and clarity of posterior shadowing were assessed subjectively using a 4‐point scale (0 being the worst, 3 being the best). The maximum diameter of the calculi was measured using both techniques. The effect of body mass index on qualitative scoring and quantitative measurements was evaluated.

Results

PIHI improved overall renal conspicuity compared with FI (p < 0.001). The visibility of the calculi and clarity of posterior shadowing were significantly better with PIHI than with FI (p < 0.001 for both parameters). The maximum diameter of calculi was larger with PIHI than with FI (p < 0.001). The superiority of PIHI over FI regarding overall conspicuity of the kidney, visibility of the calculus, and clarity of posterior shadowing scores increased in the obese group (p < 0.001 for all 3 parameters). The mean calculus diameter difference between the 2 techniques was significantly higher in the obese group.

Conclusion

The routine use of PIHI is recommended in the evaluation of renal calculi. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Preparation of smallest microparticles of poly‐D,L‐lactide by modified precipitation method: Influence of the process parameters
Authors: Jovanović Ivana , Jordović Branka , Petković Marijana , Ignjatović Nenad , Uskoković Dragan
Published: October 2007

Biodegradable microspheres such as those made of poly‐D,L‐lactide (PDLLA) are widely investigated delivery systems for drugs or antigens. The aim of this study was to examine experimental conditions in order to produce PDLLA microspheres with the best properties for controlled and sustained drug delivery by the modified precipitation method. For this purpose, the following parameters were varied: co‐solvent (methanol or ethanol), the concentration of stabilizer polyvinyl alcohol (PVA), chloroform‐to‐water ratio and the speed and time of homogenization. Scanning electron microscopy (SEM) and stereological analysis were used to characterize the particles. The average size and morphology of the microspheres varied substantially with preparation conditions from 8.44–1.25 μm. Results showed that the smallest particles were obtained with methanol, 1% PVA and with 10 min of homogenization at 21,000 rpm. Microsc. Res. Tech., 2008. © 2007 Wiley‐Liss, Inc.
Characterization of the surface morphology of durum wheat starch granules using atomic force microscopy
Authors: Neethirajan S. , Thomson D.J. , Jayas D.S. , White N.D.G.
Published: October 2007

Knowledge of the structure and properties of microscopic surfaces of durum wheat starch granules is essential for understanding the functional and physico‐chemical properties. The nanoscale surface undulations on the starch granules inside durum wheat macroscopically influence the milling properties. The objective of this study was to visualize the surface morphology and the size of starch grains of vitreous and nonvitreous durum wheat kernels using atomic force microscopy. The distribution of starch granules in the vitreous and nonvitreous durum wheat starch samples were examined and compared. The results of our study confirm the ‘blocklet’ model of the ultrastructure of the starch granule surface. Image contrast enhancement using UV/ozone treatment of microtomed starch samples improved the imaging of growth rings on the starch samples. The observation of growth rings in the nonvitreous starch granule surfaces indicates that amylopectin is more common than amylose in nonvitreous starch when compared with vitreous starch. Microsc. Res. Tech., 2008. © 2007 Wiley‐Liss, Inc.
An evaluation and comparison of claims made in behavioural investigative advice reports compiled by the National Policing Improvements Agency in the United Kingdom
Authors: Almond Louise , Alison Laurence , Porter Louise
Published: October 2007

This study examined the content of a contemporary sample of behavioural investigative advice reports produced by the National Policing Improvements Agency (NPIA), formally known as the National Centre for Policing Excellence, and compared this sample with previous offender‐profiling samples reported by Alison, Smith, Eastman, and Rainbow in 2003. Forty‐seven reports written in 2005 were content analysed. The reports contained 805 claims, although 96% of the claims contained grounds for their claim, only 34% had any formal support or backing. In terms of confirmability, 70% of the claims were verifiable. However, only 43% were falsifiable, in that they could be objectively measured post‐conviction. Analysis also showed that there were differences when comparing the different types of claims made (i.e. behavioural, temporal) and the different types of reports compiled by the NPIA (i.e. behavioural assessment report, linking report, etc.) Comparisons show that there is a very large positive difference between the contemporary behavioural investigative advice sample and previous non‐NPIA expert advice in terms of the substantiveness of their arguments. Contemporary NPIA behavioural investigative advice has clearer boundaries around the claims made and presents material in a more coherent and evidence‐based format than previous expert advice. Copyright © 2007 John Wiley & Sons, Ltd.
A review of recent climate variability and climate change in southeastern Australia
Authors: Murphy Bradley F. , Timbal Bertrand
Published: October 2007

Southeastern Australia (SEA) has suffered from 10 years of low rainfall from 1997 to 2006. A protracted dry spell of this severity has been recorded once before during the 20th century, but current drought conditions are exacerbated by increasing temperatures. Impacts of this dry decade are wide‐ranging, so a major research effort is being directed to better understand the region's recent climate, its variability and climate change. This review summarizes the conditions of these 10 years and the main mechanisms that affect the climate.

Most of the rainfall decline (61%) has occurred in autumn (March–May). Daily maximum temperatures are rising, as are minimum temperatures, except for cooler nights in autumn in the southwest of SEA closely related to lower rainfall. A similar rainfall decline occurred in the southwest of western Australia around 1970 that has many common features with the SEA decline. SEA rainfall is produced by mid‐latitude storms and fronts, interactions with the tropics through continental‐scale cloudbands and cut‐off lows.

El Niño‐Southern Oscillation impacts on SEA rainfall, as does the Indian Ocean, but neither has a direct influence in autumn. Trends have been found in both hemispheric (the southern annular mode) and local (sub‐tropical ridge) circulation features that may have played a role in reducing the number and impact of mid‐latitude systems around SEA, and thus reducing rainfall. The role of many of these mechanisms needs to be clarified, but there is likely to be an influence of enhanced greenhouse gas concentrations on SEA climate, at least on temperature. Copyright © 2007 Royal Meteorological Society
Recent development of assessment tools for urban climate and heat‐island investigation especially based on experiences in Japan
Authors: Ooka Ryozo
Published: October 2007

In recent years, problems concerning the urban climate–including the urban heat‐island effect and urban air pollution—have attracted much attention in terms of the widespread urbanization in many parts of the world, including Japan. Assessment tools for urban climate are very important to understand effective countermeasures for heat‐island mitigation. In this paper, various assessment tools are introduced and classified according to corresponding modelling scales. Special attention is given to the recent progress in Japan. It is shown that these assessment tools are very powerful at estimating the effectiveness of countermeasures. Furthermore, these assessment tools should become design tools for practical applications in the future. Copyright © 2007 Royal Meteorological Society
Recent trends in the frequencies of extreme values of daily maximum atmospheric pressure at ground level in the central zone of the Iberian Peninsula
Authors: Labajo J. L. , Martín Q. , Labajo A. L. , Piorno A. , Ortega M. , Morales C.
Published: October 2007

Using data sets on the daily data of maximum atmospheric pressure at ground level collected at 14 weather stations located in the central zone of the Iberian Peninsula [Spanish central plateau (SCP)], the series of daily maximum pressure anomalies at each station, together with the difference between the daily value and mean daily value for each day of the year for the period between 1961 and 2003, have been established. The regional series of such anomalies were constructed for the whole study zone and for two differentiated parts of the same. As thresholds for the extreme values of the anomaly series, the values corresponding to the P05 and P95 percentiles were used. The series of annual frequencies of days with anomaly values below and above the threshold values were constructed for each of the weather stations, together with the average series for the whole study zone and each of its two parts. The corresponding regional average series of seasonal frequencies were also constructed.

From an analysis of the trend of the series of the annual frequency of extreme anomaly values in daily maximum pressure it may be deduced that the lowest values show a decreasing annual trend, while the highest ones show an increasing frequency. This indicates that between 1961 and 2003 the number of days per year on the SCP with the highest extreme atmospheric pressure values at ground level increased along the study period. In contrast the number of days per year with lower extreme values decreased. Additionally, analysis of the seasonal frequency series indicated that it was the winter that dictated such behaviour. Copyright © 2007 Royal Meteorological Society
A comparison of flavonoids, carotenoids and vitamin C in commercial organic and conventional marinara pasta sauce
Authors: Koh Eunmi , Wimalasiri Kuruppa MS , Renaud Erica NC , Mitchell Alyson E
Published: October 2007

BACKGROUND: Characterising the levels of key phytochemicals in foods commonly consumed in the Western diet is critical for database development, estimating intake and assessing the potential health benefits associated with the consumption of these products. This paper describes a market‐basket evaluation of the key flavonoids, carotenoids and vitamin C in commercial organic (five brands) and conventional (five brands) marinara pasta sauces.

RESULTS: Levels of ascorbic acid ranged from undetected up to 6.87 mg per 100 g fresh weight. The levels of total vitamin C in six of the ten samples were significantly lower than the amount listed on the Nutrition Facts Panel (P < 0.001 or P < 0.01). The contents of total vitamin C, flavonoids and lycopene were not statistically different between organic and conventional samples. Conventional pasta sauces demonstrated a significantly higher level of all‐trans‐β‐carotene (P < 0.05).

CONCLUSION: This suggests that any beneficial differences in levels of flavonoids, carotenoids and vitamin C gained through cultivation practices are not measurable at the consumer level in processed tomato products. Additionally, the results point to a large disparity between the actual vitamin C content of these products and the content listed on the Nutrition Facts Panel. Copyright © 2007 Society of Chemical Industry
Single mode lasing in polymeric distributed-feedback structure formed on inorganic distributed Bragg reflector
Authors: Takeuchi H , Sakata H
Published: October 2007

We report a vertical microcavity laser that has a double-wavelength active layer inserted between two dissimilar reflectors. The top reflector consists of alternately coated quarter-wave films of cellulose acetate and poly-N-vinylcarbazole, in which pyrromethene 567 is doped. The bottom reflector is made of a TiO2/SiO2 multilayer mirror in order to maximize rear reflectance of the laser resonator. A single mode oscillation was obtained at a wavelength of 573 nm with a spectral width of 0.62 nm. The lasing threshold was found to be 70 nJ/pulse by using a frequency-doubled Nd:YAG laser operating at 532 nm with a 7 ns pulse width.
New nonlinear-laser effects in crystalline fine-grained ceramics based on cubic Sc2O3 and Lu2O3 oxides: second and third harmonic generation, and cascaded self-sum-frequency mixing in UV spectral region
Authors: Kaminskii A A , Rhee H , Eichler H J , Ueda K , Takaichi K , Shirakawa A , Tokurakawa M , Dong J , Yagi H , Yanagitani T
Published: October 2007

We report on the first observation of the nonlinear cascading χ(3) ↔ χ(3) effects in UV spectral range and second harmonic generation stipulated by the ``defect'' nonlinearity under one-micron pumping in crystalline ceramics based on cubic oxides Sc2O3 and Lu2O3. Broadband their multi-wavelength Stokes and anti-Stokes combs with the extension of 10475 cm-1 (for Sc2O3) and 8232 cm-1 (for Lu2O3) were recorded as well.
Single-stage gain-clamped L-band EDFA with C-band ASE self-oscillation in ring cavity
Authors: Mahdi M A , Bakar A A A , Al-Mansoori M H , Shaari S , Zamzuri A K
Published: October 2007

We demonstrate single-stage gain-clamped L-band Er3+-doped fiber amplifier (EDFA) utilizing self-oscillation modes as the control light. The amplifier structure exploits the characteristics of C/L-band coupler to isolate between lasing modes and L-band signal. The self-lasing cavity modes are obtained without any tunable bandpass filter in the loop and generated from the amplified spontaneous emission in the C-band region. The amplifier configuration has lower noise figures as opposed to a dual-stage partially gain-clamped amplifier. The gain and noise figure fluctuations are less than ± 0.4 dB in the gain-clamping region. The transient analysis confirms that the maximum power excursion is less than 0.3 dB for 10-dB add/drop.
Luminescence lifetime determination for oxygen imaging in human tissue
Authors: Lochmann C , Häupl T , Beuthan J
Published: October 2007

Imaging and monitoring of biochemical parameters in vitro and in vivo have become the goal of many investigations in medical physics. The main imaging technique used is laser-induced luminescence due to its cost effectiveness and diversity of applications [1]. One key parameter in medical investigations, for instance to control photodynamic therapy, is the molecular oxygen concentration. The use of optical methods provides possible means of measuring molecular oxygen. The basis of such a method is the measurement of the luminescence lifetime of a dye which is quenched by molecular oxygen. The molecular oxygen concentration can be monitored two-dimensionally by pixel-wise determination of the luminescence lifetime with a CCD-camera. An oxygen imaging system based on this principle was built and tested with a commercially available oxygen sensitive sol gel-layer. The embedded ruthenium complex is quenched by molecular oxygen and because of the oxygen permeability of the layer; it is suitable for oxygen measurements. The characteristics and dependence on the pH-value and temperature of the luminescence lifetime of the layer were examined in preparation for measurements on tissue to exclude cross-correlation of other quenching processes.
Investigation of hybrid gain-clamped Raman-fiber-amplifier/EDFA utilizing pump reuse technique
Authors: Ahmad A , Mahdi M A , Md Ali M I , Zamzuri A K
Published: October 2007

We investigate the performance of hybrid gain-clamped Raman-fiber-amplifier (RFA)/Erbium-doped fiber amplifier (EDFA) with respect to the conventional gain-clamped Raman fiber amplifier. The hybrid gain-clamped amplifier is constructed in two configurations: RFA/EDFA and EDFA/RFA. The conventional gain-clamped RFA produces the lowest gain variation, the lowest noise figure and the highest critical power amongst three amplifier configurations. By cascading the RFA and EDFA in series, the hybrid gain-clamped amplifiers suffer performance degradation due to the unique characteristics of RFA and EDFA. The noise figure degradation is strongly influenced by the performance of the first stage amplifier and the RFA/EDFA configuration produces the highest noise figure. On the other hand, the EDFA/RFA configuration experiences fastest saturation due to the pump depletion in the RFA.
Photostability of different chlorine photosensitizers
Authors: Ferreira J , Menezes P F C , Kurachi C , Sibata C , Allison R R , Bagnato V S
Published: October 2007

In this paper, we report the photodegradation of three different chlorine photosensitizers (Photoditazine®, Radachlorin®, and Foscan®). The photosensitizer degradation was analyzed by changes in the fluorescence spectrum during illumination. The rate of fluorescence variation was normalized to the solution absorption and the photon energy resulting in the determination of the necessary number of photons to be absorbed to induce photosensitizer photodegradation. The parameter for rate of the molecules decay, the photon fluence rate and optical properties of the solution allow us to determine the photosensitizer stability in solution during illumination. The results show that the order of susceptibility for photodegradation rate is: Radachlorin® < Photoditazine® < Foscan®. This difference in the photodegradation rate for Foscan can be explained by the high proportion of aggregates in solution that inhibit the photo-oxidative process that impede the singlet oxygen formation. We hypothesize that there is a correlation between photodegradation rate and photodynamic efficacy witch is governed by the singlet oxygen formation responsible for the most relevant reaction of the cell death photodynamic induction. Then its is important to know the photostability of different types of drugs since the photodegradation rate, the photodegradation as well as the photodynamic efficacy are strong correlated to the oxygen concentration in the tissue.
Linearly polarized all-fiber laser using a short section of highly polarizing microstructured fiber
Authors: Delgado-Pinar M , Díez A , Cruz J L , Andrés M V
Published: October 2007

A linearly polarized all-fiber erbium laser is presented in this work. The polarization selective element consists on a piece of a single-mode, polarizing microstructured fiber, which is placed within the laser cavity. The microstructured fiber shows a regular lattice of air-holes, in which four holes next to the core were enlarged. This fiber shows a polarization dependent loss of 16 dB/m around 1550 nm. The laser cavity presents different losses for each polarization and, as a consequence, a highly polarized emission is obtained. The polarization ratio of the emitted power was in excess of 20 dB.
Strategy matters: strategic positioning and performance in the education services sector
Authors: Mazzarol Timothy W. , Soutar Geoffrey N.
Published: October 2007

The present study explored the strategic positioning behaviour of Australian educational services institutions to see whether their choice of strategy impacted their competitiveness in international markets. A sample of schools, colleges and universities, were asked which of Porter's generic positioning strategies they used. Correspondence and cluster analysis were used to examine these relationships and discriminant analysis was used to see whether there was a relationship between strategy choice and performance. The results showed institutions that lacked a coherent strategy did not perform well, highlighting the importance of educational administrators to develop clear and coherent strategies that position their offerings effectively to targeted market segments. Indeed, a failure to apply strategic principles may risk the long term sustainability of the institution.

Copyright © 2007 John Wiley & Sons, Ltd.