bluuebunny/crossref_metadata_2025 huggingface dataset:
THE DIVERSITY–VALIDITY DILEMMA: BEYOND SELECTION—THE ROLE OF AFFIRMATIVE ACTION
Authors: KRAVITZ DAVID A.
Published: February 2008

Several of the most valid predictors used to make employment decisions create a diversity–validity dilemma (Pyburn, Ployhart, & Kravitz, this issue, 2008). This diversity–validity dilemma can be resolved by (a) reducing adverse impact through a variety of technical steps (Ployhart & Holtz, this issue, 2008) or (b) using affirmative action to increase representation of the disadvantaged groups. This paper focuses on the second approach. The paper begins with a very brief review of the legal bases of affirmative action and a summary of the research on affirmative action attitudes. This is followed with reviews of research on the ongoing existence of workplace discrimination, the economic impact of affirmative action on target groups and organizations, and stigmatization of target group members by others and by target group members themselves. Most problems with affirmative action apply only or primarily to preference‐based forms, so nonpreferential approaches to affirmative action are recommended to increase the attraction, selection, inclusion, and retention of underrepresented group members.
Chiral N‐Phosphonyl Imine Chemistry: Asymmetric Aza‐Henry Reaction
Authors: Kattuboina Adiseshu , Kaur Parminder , Ai Teng , Li Guigen
Published: February 2008

A series of chiral N‐phosphonyl imines have been synthesized and utilized successfully in asymmetric aza‐Henry reaction. The chiral auxiliary was optimized for this reaction by varying different R groups on the nitrogen atoms. The reaction is convenient to perform to give excellent yields and good diastereoselectivities. The absolute stereochemistry was unambiguously determined by converting a resulting vicinal nitroamine into its N‐Boc derivative which serves as a known compound.
Fidelity in interpretation: Lord Hoffmann and The Adventure of the Empty House
Authors: Lee James
Published: February 2008

This paper explores Dworkin's ‘law as a chain novel’ analogy and considers the recent work of Dworkin and MacCormick through close scrutiny of two recent judgments of Lord Hoffmann, in Barlow Clowes v Eurotrust International [2005] UKPC 37 and Barker v Corus [2006] UKHL 20. The aim is to examine Dworkin's theory in the context of recent English private law decisions and determine whether Lord Hoffmann's approach to interpretation is consistent with that of Dworkin (as his Lordship has contended in the past). It is argued that Lord Hoffmann's treatment of recent decisions on which he himself sat raises significant questions regarding fidelity, coherence and the institutional structure of the House of Lords.
Noninvasive measures of blood volume and oxygen saturation of human Achilles tendon by red laser lights
Authors: Kubo K. , Ikebukuro T. , Tsunoda N. , Kanehisa H.
Published: February 2008

Aim:  Spectroscopic measurement using near‐infrared spectroscopy and red laser lights was performed to investigate the blood volume (total haemoglobin; THb) and oxygen saturation (oxygenated haemoglobin saturation; StO2) of the human Achilles tendon during single and repetitive isometric contractions.

Methods:  Twelve men performed isometric plantar flexion exercises at intensities of 10% (3 min), 30% (2 min), 50% (1 min) and 70% (30 s) of the maximum voluntary contraction (MVC). In addition, they performed 50 repetitions at 70% of the MVC with 5‐s contractions and a 5‐s gap between repetitions for 10 min. The probes were positioned on the Achilles tendon and medial gastrocnemius muscle.

Results:  THb and StO2 of the Achilles tendon decreased during ‘single’ contraction at all force levels. On the other hand, after the end of the repetitive exercises, THb and StO2 of the Achilles tendon increased gradually, and remained at this level until the end of the recovery period.

Conclusion:  The blood volume and oxygen saturation within the human Achilles tendon increased after the ‘repetitive’ muscle contractions, while they decreased after the ‘single’ contraction. Furthermore, the increases in blood volume and oxygen saturation within the tendon after repetitive contractions may be related to tendon repair after exercises involving mechanical loading of the tendon.
PHOTIC RELATIONS AND EXPERIMENTAL DISSOCIATION OF CIRCADIAN RHYTHMS IN PINEAL COMPOSITION AND RUNNING ACTIVITY IN RATS*
Authors: Quay W. B.
Published: February 2008

Abstract— It has been shown previously that pineal composition and some of its enzyme activities in mammals appear to be responsive to light and darkness in vivo, possibly indirectly. One such possible indirect mechanism would be by whole animal activity and the sympathetic innervation of the pineal. Study of the rhythmic changes in the pineal ethanol‐soluble fraction (mostly lipid) and in whole animal running activity in normal, adult male rats in standard daily photocycle and then in continuous light, shows rapid dissociation of the two rhythms in continuous light, with pineal composition being more light‐dependent.

The free‐running circadian rhythm in the male rat's running activity in both standard daily photocycle and continuous light is shown to be similar in normal and in pinealectomized animals. This negative finding is relevant with regard to an hypothesized pineal function in lower tetrapods in regulation of locomotor activity in response to solar radiation.
Intramuscular lipid oxidation and obesity
Authors: Houmard Joseph A.
Published: February 2008

There is an accumulating amount of evidence indicating that lipid oxidation is depressed in the skeletal muscle of obese individuals. Decrements in fatty acid oxidation (FAO) have been reported with obesity in models ranging from whole body measurements to isolated skeletal muscle preparations as well as in myotubes raised in culture. This reduction appears to be associated with a depression in the activities of enzymes involved in various steps of lipid oxidation, which subsequently partitions lipid entering the cell toward storage. The defect in FAO in skeletal muscle may be critical in relation to health, as a reduction in the capacity for lipid oxidation could directly or indirectly contribute to the insulin resistance commonly evident with obesity. Although less characterized, a decrement in FAO has also been linked with weight gain, which suggests that this characteristic may be an integral aspect leading to the obese state. In terms of intervention, weight loss does not seem to correct the defect in FAO with obesity. This review will provide evidence supporting a reduction in muscle FAO with obesity.
Explaining the Effect of Gender on Functional Transitions in Older Persons
Authors: Hardy Susan E. , Allore Heather G. , Guo Zhenchao , Gill Thomas M.
Published: February 2008

Background: Women live longer but experience greater disability than men. The reasons for this gender difference in disability are not well understood. Objective: Our objectives were to determine if the higher prevalence of disability in women is due to greater incidence of disability, longer duration of disability, or both, and to identify factors that potentially explain these gender differences. Methods: 754 community-living persons aged 70 and older who were non-disabled (required no personal assistance) in four essential activities of daily living (ADLs) were assessed monthly for disability for up to 6 years. A multi-state extension of the proportional hazards model was used to determine the effects of gender on transitions between states of no disability, mild disability, severe disability, and death, and to evaluate potential mediators of these effects. Results: Women were more likely to make the transition from no disability to mild disability and less likely to make the transitions from mild to no disability and from both mild and severe disability to death. The gender difference in the transitions between no disability and mild disability was largely explained by differences in gait speed and physical activity, but gender difference in transitions to death persisted despite adjustment for multiple potential mediators. Conclusion: The higher prevalence of disability in women versus men is due to a combination of higher incidence and longer duration, resulting from lower rates of recovery and mortality among disabled women.
Comparison of a 51-Member Low-Resolution (TL399L62) Ensemble with a 6-Member High-Resolution (TL799L91) Lagged-Forecast Ensemble
Authors: Buizza Roberto
Published: February 2008

The 51-member TL399L62 ECMWF ensemble prediction system (EPS51) is compared with a lagged ensemble system based on the six most recent ECMWF TL799L91 forecasts (LAG6). The EPS51 and LAG6 systems are compared to two 6-member ensembles with a “weighted” ensemble-mean: EPS6wEM and LAG6wEM. EPS6wEM includes six members of EPS51 and has the ensemble mean constructed giving optimal weights to its members, while LAG6wEM includes the LAG6 six members and has the ensemble mean constructed giving optimal weights to its members. In these weighted ensembles, the optimal weights are based on 50-day forecast error statistics of each individual member (in EPS51 and LAG6 the ensemble mean is constructed giving the same weight to each individual member). The EPS51, LAG6, EPS6wEM, and LAG6wEM ensembles are compared for a 7-month period (from 1 April to 30 October 2006—213 cases) and for two of the most severe storms that hit the Scandinavian countries since 1969.

The study shows that EPS51 has the best-tuned ensemble spread, and provides the best probabilistic forecasts, with differences in predictability between EPS51 and LAG6 or LAG6wEM probabilistic forecasts of geopotential height anomalies of up to 24 h. In terms of ensemble mean, EPS51 gives the best forecast from forecast day 4, but before forecast day 4 LAG6wEM provides a slightly better forecast, with differences in predictability smaller than 2 h up to forecast day 6, and of about 6 h afterward. The comparison also shows that a larger ensemble size is more important in the medium range rather than in the short range.

Overall, these results indicate that if the aim of ensemble prediction is to generate not only a single (most likely) scenario but also a probabilistic forecast, than EPS51 has a higher skill than the lagged ensemble system based on LAG6 or LAG6wEM.
The Effect of Middle Temporal Spike Phase on Sensory Encoding and Correlates with Behavior during a Motion-Detection Task
Authors: Masse Nicolas Y. , Cook Erik P.
Published: February 2008

Previous studies have shown that sensory neurons that are the most informative of the stimulus tend to be the best correlated with the subject's perceptual decision. We wanted to know whether this relationship might also apply to short time segments of a neuron's response. We asked whether spikes that conveyed more information about a motion stimulus were also more tightly linked to the perceptual behavior. We examined single-neuron activity in middle temporal (MT) area while monkeys performed a motion-detection task. Because of a slow stimulus update (every 27 ms), activity in many MT neurons was entrained and phase-locked to the stimulus. These stimulus-entrained neuronal oscillations allowed us to separate spikes based on phase. We observed a large amount of variability in how spikes at different phases of the oscillation encoded the stimulus, as revealed by the spike-triggered average of the motion. Spikes during certain phases of the cycle were much more informative about the presence of coherent motion than others. Importantly, we found that the phases that were the most informative about the motion stimulus were also more correlated with the behavioral performance and reaction time of the animal. Our results suggest that the relationship between a neuron's spikes, the stimulus, and behavior can vary on a time scale of tens of milliseconds.
Quantitative Cortical Mapping of Fractional Anisotropy in Developing Rat Brains
Authors: Huang Hao , Yamamoto Akria , Hossain Mir Ahamed , Younes Laurent , Mori Susumu
Published: February 2008

Cortical development is associated with a series of events that involve axon and dendrite growth and synaptic formation. Although these developmental processes have been investigated in detail with histology, three-dimensional and quantitative imaging methods for rodent brains may be useful for genetic and pharmacological studies in which cortical developmental abnormalities are suspected. It has been shown that diffusion tensor imaging (DTI) can delineate the columnar organization of the fetal and early neonatal cortex based on a high degree of diffusion anisotropy along the columnar structures. This anisotropy is known to decrease during brain development. In this study, we applied DTI to developing rat brains at five developmental stages, postnatal days 0, 3, 7, 11 and 19, and used diffusion anisotropy as an index to characterize the structural change. Statistical analysis reveals four distinctive cortical areas that demonstrate a characteristic time course of anisotropy loss. This method may provide a means to delineate specific cortical areas and a quantitative method to detect abnormalities in cortical development in rodent pathological models.
Remarkable Efficiency Improvement in the Preparation of Insoluble Polymer‐Bound (IPB) Enantioselective Catalytic Systems by the Use of Silicone Chemistry
Authors: Mandoli Alessandro , Lessi Marco , Pini Dario , Evangelisti Claudio , Salvadori Piero
Published: February 2008

The use of platinum‐catalyzed hydrosilylation chemistry of silicones greatly simplifies the preparation of bis‐oxazoline (box) ligands covalently bound to an insoluble polymeric support. The use of such immobilized chiral ligands in different copper‐catalyzed asymmetric transformations (carbonyl‐ene, Mukaiyama aldol and olefin cyclopropanation reactions) allows the attainment of high levels of enantioselectivity (91–99 % ee).
Asymmetric Bioreduction of CC Bonds using Enoate Reductases OPR1, OPR3 and YqjM: Enzyme‐Based Stereocontrol
Authors: Hall Mélanie , Stueckler Clemens , Ehammer Heidemarie , Pointner Eva , Oberdorfer Gustav , Gruber Karl , Hauer Bernard , Stuermer Rainer , Kroutil Wolfgang , Macheroux Peter , Faber Kurt
Published: February 2008

Three cloned enoate reductases from the “old yellow enzyme” family of flavoproteins were investigated in the asymmetric bioreduction of activated alkenes. 12‐Oxophytodienoate reductase isoenzymes OPR1 and OPR3 from Lycopersicon esculentum (tomato), and YqjM from Bacillus subtilis displayed a remarkably broad substrate spectrum by reducing α,β‐unsaturated aldehydes, ketones, maleimides and nitroalkenes. The reaction proceeded with absolute chemoselectivity – only the conjugated CC bond was reduced, while isolated olefins and carbonyl groups remained intact – with excellent stereoselectivities (ees up to >99%). Upon reduction of a nitroalkene, the stereochemical outcome could be determined via choice of the appropriate enzyme (OPR1 versus OPR3 or YqjM), which furnished the corresponding enantiomeric nitroalkanes in excellent ee. Molecular modelling suggests that this “enzyme‐based stereocontrol” is caused by subtle differences within the active site geometries.
Stature estimation in ancient Egyptians: A new technique based on anatomical reconstruction of stature
Authors: Raxter Michelle H. , Ruff Christopher B. , Azab Ayman , Erfan Moushira , Soliman Muhammad , El‐Sawaf Aly
Published: February 2008

Trotter and Gleser's (Trotter and Gleser: Am J Phys Anthropol 10 (1952) 469–514; Trotter and Gleser: Am J Phys Anthropol 16 (1958) 79–123) long bone formulae for US Blacks or derivations thereof (Robins and Shute: Hum Evol 1 (1986) 313–324) have been previously used to estimate the stature of ancient Egyptians. However, limb length to stature proportions differ between human populations; consequently, the most accurate mathematical stature estimates will be obtained when the population being examined is as similar as possible in proportions to the population used to create the equations. The purpose of this study was to create new stature regression formulae based on direct reconstructions of stature in ancient Egyptians and assess their accuracy in comparison to other stature estimation methods. We also compare Egyptian body proportions to those of modern American Blacks and Whites. Living stature estimates were derived using a revised Fully anatomical method (Raxter et al.: Am J Phys Anthropol 130 (2006) 374–384). Long bone stature regression equations were then derived for each sex. Our results confirm that, although ancient Egyptians are closer in body proportion to modern American Blacks than they are to American Whites, proportions in Blacks and Egyptians are not identical. The newly generated Egyptian‐based stature regression formulae have standard errors of estimate of 1.9–4.2 cm. All mean directional differences are less than 0.4% compared to anatomically estimated stature, while results using previous formulae are more variable, with mean directional biases varying between 0.2% and 1.1%, tibial and radial estimates being the most biased. There is no evidence for significant variation in proportions among temporal or social groupings; thus, the new formulae may be broadly applicable to ancient Egyptian remains. Am J Phys Anthropol, 2008. © 2008 Wiley‐Liss, Inc.
Viscoelastic properties of blends of poly(methyl methacrylate) and poly(styrene‐co‐acrylonitrile) having various acrylonitrile contents
Authors: Aoki Yuji
Published: February 2008

Dynamic viscoelastic properties of blends of poly(methyl methacrylate) (PMMA) and poly(styrene‐co‐acrylonitrile) (SAN) with various AN contents were measured to evaluate the influence of SAN composition, consequently χ parameter, upon the melt rheology. PMMA/SAN blends were miscible and exhibited a terminal flow region characterized by Newtonian flow, when the acrylonitrile (AN) content of SAN ranges from 10 to 27 wt %. Whereas, PMMA/SAN blends were immiscible and exhibited a long time relaxation, when the AN content in SAN is less than several wt % or greater than 30 wt %. Correspondingly, melt rheology of the blends was characterized by the plots of storage modulus G′ against loss modulus G″. Log G′ versus log G″ plots exhibited a straight line of slope 2 for the miscible blends, but did not show a straight line for the immiscible blends because of their long time relaxation mechanism. The plateau modulus, determined as the storage modulus G′ in the plateau zone at the frequency where tan δ is at maximum, varied linearly with the AN content of SAN irrespective of blend miscibility. This result indicates that the additivity rule holds well for the entanglement molecular weights in miscible PMMA/SAN blends. However, the entanglement molecular weights in immiscible blends should have “apparent” values, because the above method to determine the plateau modulus is not applicable for the immiscible blends. Effect of χ parameter on the plateau modulus of the miscible blends could not be found. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
ChemInform Abstract: Ligand‐ and Base‐Free Synthesis of 1,3‐Diynes Catalyzed by Low Loading of Heterogeneous Pd/C and CuI.
Authors: Kurita Takanori , Abe Masami , Maegawa Tomohiro , Monguchi Yasunari , Sajiki Hironao
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
MOFs – Metallorganische Gerüststrukturen. Funktionale poröse Materialien
Authors: Bauer Sebastian , Stock Norbert
Published: February 2008

MOFs (metal‐organic frameworks) gehören zur Klasse der anorganisch‐organischen Gerüstverbindungen. Sie sind hochkristallin und bestechen durch ihren modularen Aufbau aus Metallionen, Metall‐Sauerstoff‐Clustern, ‐Ketten oder ‐Schichten, die über funktionalisierbare organische Linker zu porösen dreidimensionalen Gerüsten verknüpft sind. Die Poren stehen für zahlreiche Anwendungen zur Verfügung und können mit Hilfe des Prinzips der isoretikulären Synthese bezüglich ihrer Größe und Polarität gezielt verändert und damit für spezielle Anwendungen maßgeschneidert werden. MOFs stellen eine neue Klasse poröser kristalliner Verbindungen dar. Aufgrund zahlreicher potentieller Anwendungen z.B. zur Gasspeicherung, in der Katalyse, als Nanoreaktoren oder bei der Wirkstofffreisetzung und wegen ihrer teilweise ungewöhnlichen Eigenschaften sind sie sowohl für die Industrie als auch für die universitäre Forschung von großem Interesse.
Positive Troponin in Diabetic Ketoacidosis without Evident Acute Coronary Syndrome Predicts Adverse Cardiac Events
Authors: Al‐Mallah Mouaz , Zuberi Omar , Arida Muhammad , Kim Henry E.
Published: February 2008

Background

Elevated troponin I has been associated with increased mortality in critically ill patients without acute coronary syndrome (ACS). However, the prognostic significance of troponin elevation in patients with diabetic ketoacidosis (DKA) without evident ACS has not been studied.

Methods

Retrospective study of all patients admitted to a U.S. tertiary center between 01/98 and 12/00 with DKA and had troponin I level measured. Patients with evidence of ACS or who met the American College of Cardiology/European Society of Cardiology (ACC/ESC) definition for myocardial infarction were excluded. Baseline characteristics, cardiac evaluation and 2 year major adverse coronary event (MACE) rate were compared between patients with positive and negative troponin.

Results

Ninety‐six patients fulfilled the inclusion criteria of this study, 26 had positive troponin. There were no differences in baseline characteristics between the two groups. After a 2 year follow‐up, there was significantly increased mortality in patients with elevated troponin (50.0% versus 27.1%, hazard‐ratio (HR) 2.3, 95% confidence intraval (CI) 1.2–4.8, p = 0.02). Patients with elevated troponin also had significantly increased MACE rate at 2 years (50.0% versus 28.6%, HR 2.6, 95% CI 1.3–5.3, p = 0.007) driven primarily by mortality. Using Cox Proportional Hazard Analysis, elevated troponin was a predictor of increased MACE after adjusting for confounding variables. (Adjusted HR 2.3, 95% CI 1.1–4.6, p = 0.02)

Conclusions

Elevated troponin I in diabetic patients admitted with DKA identifies a group at very high risk for future cardiac events and mortality. Whether cardiac risk stratification of these patients will improve long term outcome remains to be studied. Copyright © 2008 Wiley Periodicals, Inc.
ProApolipoprotein A1
Authors: Marchi Nicola , Mazzone Peter , Fazio Vincent , Mekhail Tarek , Masaryk Thomas , Janigro Damir
Published: February 2008

BACKGROUND

Central nervous system (CNS) diagnostics is a promising tool for detection of neurological disorders, including brain metastases. One of the earliest applications of CNS diagnostics was based on serum markers of blood‐brain barrier (BBB) dysfunction, which often correlates with acute, chronic, or incipient brain disease. In the case of brain metastases, serum levels of S100β demonstrated a good negative predictive value comparable to radiologic investigations. However, a confounding factor was the presence of BBB changes due to cerebrovascular disease.

METHODS

Of 103 patients enrolled in a lung cancer study, greater than 50% presented with magnetic resonance imaging (MRI) changes consistent with chronic cerebrovascular disease and reflected by elevated serum S100β. To unveil serum protein, the authors used proteomic techniques that allow discrimination between patients with brain metastases and lung cancer patients affected by cerebrovascular ischemic changes without infiltrating tumor.

RESULTS

ProApolipoprotein A1, transferrin, haptoglobin, and transthyretin were upregulated in patients affected by chronic cerebrovascular disease and brain metastases compared with those affected only by vascular diseases. ProApolipoprotein A1 was significantly increased (p < .05) in patients with CNS disease.

CONCLUSIONS

In conclusion, these data support the use of serum markers for the early detection of brain metastases. ProApolipoprotein A1 may be used in conjunction with S100β for serum‐based, MRI‐independent diagnosis of metastatic brain tumors. Cancer 2008. ©2008 American Cancer Society.
Measurement of Transcutaneous Oxygen Tension in Limbs with Arteriovenous Hemodialysis Access
Authors: Harissis Haralampos , Koliousi Eli , Matsagas Miltiadis , Batsis Haralampos , Fatouros Michalis , Siamopoulos Konstantinos
Published: February 2008

BACKGROUND

The purpose of the present study was to investigate hypoxemic complications of limbs with arteriovenous access by means of transcutaneous oximetry.

METHODS

The study was a prospective assessment of 31 limbs with arteriovenous access using transcutaneous oximetry. Each limb was measured 4 times: before arteriovenous construction, the first post‐operative day, the first post‐operative month, and the fourth post‐operative month. The contralateral limb was used as control for every measurement.

RESULTS

The first postoperative day was characterized by an acute drop in the tissue oxygenation of the limb with arteriovenous access (p = 0.03). This hypoxia was compensated for in the first month by a gradual return of transcutaneous oxygen values to pre‐operative levels. Two patients developed a steal syndrome, characterized by abnormally low transcutaneous oxygen (< 40 mmHg).

CONCLUSION

Transcutaneous oximetry is a simple and accurate method for objectively assessing the whole spectrum of alterations in tissue oxygenation (from transient hypoxia to steal syndrome) caused by arteriovenous access.
Hypouricemia linked to an overproduction of nitric oxide is an early marker of oxidative stress in female subjects with type 1 diabetes
Authors: Pitocco Dario , Di Stasio Enrico , Romitelli Federica , Zaccardi Francesco , Tavazzi Barbara , Manto Andrea , Caputo Salvatore , Musella Tittania , Zuppi Cecilia , Santini Stefano A. , Ghirlanda Giovanni
Published: February 2008

Objective

The aim of this study is to verify whether, early in the course of type 1 diabetes and assuming hyperglycemia as the only risk factor, women demonstrate a change in oxidative status due to an interaction between nitric oxide (NO) and uric acid production.

Methods

Thirty‐eight women with type 1 diabetes of less than 10 years' duration and with no diabetic complications were compared with 25 matched healthy female controls. Insulin, C‐peptide, NO, HbA1c and oxidative stress metabolites were determined from venous blood samples taken from all patients after a 12 h overnight fast. Urine samples were used for urinary uric acid determination.

Results

Most oxidative stress metabolites were significantly increased (p < 0.0001), while plasmatic and urinary uric acid levels were significantly lower (p < 0.0001) in patients with type 1 diabetes compared with controls. Mean NO levels were inversely related to uricemia. Bivariate regression analysis showed a significant correlation between plasmatic uric acid and NO (p = 0.004), ascorbic acid (p = 0.042), triglycerides (p = 0.014) and HbA1c (p < 0.0001). Linear multivariate regression analysis showed a significant relationship between HbA1c and plasmatic uric acid (beta = − 0.465, p = 0.0004).

Conclusions

Oxidative stress is already present in the early stages of type 1 diabetes. We conclude that the initial increase in oxidative stress could be linked to a reduction in plasmatic levels of uric acid, which is probably directly caused by an overproduction of NO. Copyright © 2008 John Wiley & Sons, Ltd.
On the pretreatment process for the object extraction in color image of wear debris
Authors: Hu Xianguo , Huang Peng , Zheng Shousen
Published: February 2008

In this article, some pretreatment techniques used for the object extraction in color debris image were introduced, which was an important basic work in ferrographic technology to identify precisely wear debris produced by friction and wear from the relative motions between machine parts. These pretreatment techniques included image enhancement, image segmentation, filling pore, image erosion, and recognition of wear debris. The results showed that these methods were feasible and effective, which could be applied to extract object of color wear debris image successfully and precisely. It provided an important basis for the recognition technique of wear debris which was related to monitoring machine operation state and fault diagnosis. © 2008 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 17, 277–284, 2007
Electrospinning of photocrosslinked and degradable fibrous scaffolds
Authors: Tan Andrea R. , Ifkovits Jamie L. , Baker Brendon M. , Brey Darren M. , Mauck Robert L. , Burdick Jason A.
Published: February 2008

Electrospun fibrous scaffolds are being developed for the engineering of numerous tissues. Advantages of electrospun scaffolds include the similarity in fiber diameter to elements of the native extracellular matrix and the ability to align fibers within the scaffold to control and direct cellular interactions and matrix deposition. To further expand the range of properties available in fibrous scaffolds, we developed a process to electrospin photocrosslinkable macromers from a library of multifunctional poly(β‐amino ester)s. In this study, we utilized one macromer (A6) from this library for initial examination of fibrous scaffold formation. A carrier polymer [poly(ethylene oxide) (PEO)] was used for fiber formation because of limitations in electrospinning A6 alone. Various ratios of A6 and PEO were successfully electrospun and influenced the scaffold fiber diameter and appearance. When electrospun with a photoinitiator and exposed to light, the macromers crosslinked rapidly to high double bond conversions and fibrous scaffolds displayed higher elastic moduli compared to uncrosslinked scaffolds. When these fibers were deposited onto a rotating mandrel and crosslinked, organized fibrous scaffolds were obtained, which possessed higher moduli (∼4‐fold) in the fiber direction than perpendicular to the fiber direction, as well as higher moduli (∼12‐fold) than that of nonaligned crosslinked scaffolds. With exposure to water, a significant mass loss and a decrease in mechanical properties were observed, correlating to a rapid initial loss of PEO which reached an equilibrium after 7 days. Overall, these results present a process that allows for formation of fibrous scaffolds from a wide variety of possible photocrosslinkable macromers, increasing the diversity and range of properties achievable in fibrous scaffolds for tissue regeneration. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Technique for preparation and characterization in cross‐section of oral titanium implant surfaces using focused ion beam and transmission electron microscopy
Authors: Jarmar Tobias , Palmquist Anders , Brånemark Rickard , Hermansson Leif , Engqvist Håkan , Thomsen Peter
Published: February 2008

The surface properties of materials are believed to control most of the biological reactions toward implanted materials. To study the surface structure, elemental distribution, and morphology, using transmission electron microscopy (TEM) techniques, thin foils of the surface (in cross‐section) are needed. These have been cumbersome to produce, in particular, from the normally irregular screw‐shaped metal implants. Focused ion beam (FIB) microscopy has been developed partly for TEM sample preparation, mainly within the microelectronics industry. Our study describes a method based on FIB for producing electron transparent foils/sections from a metal implant for TEM analysis. Using a screw‐shaped titanium dental implant, it was demonstrated that thin foils can be prepared with submicron specificity and from almost any surface geometry. A comparison of different lift‐out techniques showed that the in situ lift‐out preparation technique allowed plasma cleaning and produced particularly good samples with excellent yield. The titanium oxide on the implant surface was analyzed using energy‐filtered TEM (EFTEM) and high‐resolution TEM (HRTEM) and the TiO2 rutile phase being determined via the lattice parameters. This study provides the first set of data for the optimization of a new route for preparation and analysis of biomaterial surfaces and interfaces. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Stress corrosion cracking of an aluminum alloy used in external fixation devices
Authors: Cartner Jacob L. , Haggard Warren O. , Ong Joo L. , Bumgardner Joel D.
Published: February 2008

Treatment for compound and/or comminuted fractures is frequently accomplished via external fixation. To achieve stability, the compositions of external fixators generally include aluminum alloy components due to their high strength‐to‐weight ratios. These alloys are particularly susceptible to corrosion in chloride environments. There have been several clinical cases of fixator failure in which corrosion was cited as a potential mechanism. The aim of this study was to evaluate the effects of physiological environments on the corrosion susceptibility of aluminum 7075‐T6, since it is used in orthopedic external fixation devices. Electrochemical corrosion curves and alternate immersion stress corrosion cracking tests indicated aluminum 7075‐T6 is susceptible to corrosive attack when placed in physiological environments. Pit initiated stress corrosion cracking was the primary form of alloy corrosion, and subsequent fracture, in this study. Anodization of the alloy provided a protective layer, but also caused a decrease in passivity ranges. These data suggest that once the anodization layer is disrupted, accelerated corrosion processes occur. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Postdischarge follow‐up visits for medical and pharmacy students on an inpatient medicine clerkship
Authors: Lai Cindy J. , Nye Heather E. , Bookwalter Thomas , Kwan Anson , Hauer Karen E.
Published: February 2008

BACKGROUND

Teaching medical and pharmacy students to collaborate on discharge planning for chronically ill patients may facilitate their ability to provide quality care.

OBJECTIVE

To determine whether a discharge curriculum would improve students' attitudes and self‐assessed skills in interdisciplinary collaboration and transitional care for chronically ill patients.

DESIGN

The discharge curriculum of an inpatient medicine clerkship focused on safe patient transitions after hospitalization. Curricular components included an interdisciplinary workshop, follow‐up visits with discharged patients, a final group debriefing, and letters to patients' primary care providers. Preassigned medical and pharmacy student partners coordinated discharges and conducted postdischarge visits. The change in students' attitudes and skills in interdisciplinary collaboration and discharge planning was assessed using a 5‐point Likert‐scaled survey given before and after the curriculum, and students reported their satisfaction using additional Likert‐scaled and open‐ended questions.

RESULTS

The program was completed by 97% of students (37 of 39 medical, 22 of 22 pharmacy). The postcurriculum survey response rates were 92% and 86%, respectively; matched response rates were 58% and 59%. The attitudes and self‐assessed skills of both medical and pharmacy students significantly improved for most survey items after the curriculum. Students also reported that the curriculum had a favorable impact on their learning about interdisciplinary care (4.3, SD 0.72), humanism (4.3, SD 0.63), and discharge planning (4.4, SD 0.70). Ninety‐three percent reported that the curriculum was valuable to their education.

CONCLUSIONS

A clinically oriented curriculum with postdischarge visits improved students' attitudes and self‐assessed skills in interdisciplinary collaboration and transitional care and fostered a patient‐centered approach to care. Journal of Hospital Medicine 2008;3:20–27. © 2008 Society of Hospital Medicine.
Tailored thermal expansivity in particulate composites for thermal stress management
Authors: Miller W. , Smith C. W. , Dooling P. , Burgess A. N. , Evans K. E.
Published: February 2008

Only few composites with tailored thermal expansivity exist, even fewer with negative thermal expansivity fillers, and none are well characterised. Zirconium tungstate has an isotropic negative coefficient of thermal expansivity, and the overall coefficient of thermal expansivity (CTE) of a range of zirconium tungstate/epoxy composites was measured in order to examine the effects of volume fraction and particle surface treatment on the overall expansivity of the composite. This provides an improved understanding of how particulate composites, with negative CTE fillers behave on heating. The thermal expansivity of the composites containing negative thermal expansivity (NTE) fillers is shown to agree with a simple volume fraction model. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fourth‐rank tensors of [[V2]2]‐type and elastic material constants for 2D crystals
Authors: Jasiukiewicz Cz. , Paszkiewicz T. , Wolski S.
Published: February 2008

Fourth‐rank symmetric tensors, that embody the elastic properties of crystalline anisotropic substances, were constructed for all 2D crystal systems. Using them we obtained explicit expressions for inverse of Young's modulus E (n), inverse of shear modulus G (m, n) and Poisson's ratio ν (m, n), which depend on components of the elastic compliances tensor S, on direction cosines of vectors n of uniaxial load and the vector m of lateral strain with crystalline symmetry axes. All 2D crystal systems are considered. Such representation yields decomposition of the above elastic characteristics to isotropic and anisotropic parts. Expressions for Poisson's coefficient are well suited for studying the property of auxeticity and anisotropy of 2D crystals. Christoffel's tensor is calculated for all 2D crystal classes. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fine structure of the electrostatic energetic disorder at the interface between disordered organic material and metal electrode
Authors: Novikov Sergey V.
Published: February 2008

The physics of organic disordered materials is dominated by the effects of energetic disorder. We show that image forces reduce the electrostatic component of the total energetic disorder near an interface with a metal electrode. Typically, the standard deviation of energetic disorder is dramatically reduced at the first few layers of organic semiconductor molecules adjacent to the metal electrode and correlation properties of the disorder are different from the bulk properties. This means that the use of bulk disorder parameters (such as standard deviation of disorder) for description of the energetic disorder at the interface is poorly justified even in the case of identical spatial and chemical structure of the organic material at the interface and in the bulk of the transport layer. Implications for charge injection into organic semiconductors are discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical study of relaxation in Coulomb glasses
Authors: Ortuño M. , Caravaca M. , Somoza A. M.
Published: February 2008

We present a kinetic Monte Carlo algorithm to study relaxation of Coulomb glasses at low temperatures. The algorithm can integrate out exactly fast transitions avoiding repetitive hops characteristic of metastable states, so that it does not get stuck in most of them. The present implementation of the method can follow the dynamics of systems with up to 1000 sites to macroscopic times. This is a general procedure that can be extended to most slow relaxation systems. We present results for energy relaxation. We also discuss a temperature definition during the non equilibrium relaxation process and show preliminary results on aging. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The theoretical study on anionic polymerization mechanism of maleimide: Chain propagation by p‐π conjugation process
Authors: Hua Xiao , Bei Feng‐Li , Wang Xin , Yang Xu‐Jie , Lu Lu‐De
Published: February 2008

A complete research on the mechanism of the anionic polymerization of maleimide was performed, not only including the chain initiation, but the propagation as well. The density functional theory method is employed to investigate the reaction pathway using 6‐311+G* basis set, and the Onsager model is also applied to imitate the effect of solvent on the structures and thermodynamic functions of the key steps. It is found that the initiation starts with a nucleophilic reaction, in which the key transition state shows a π‐complex structure. In contrast, the calculated chain propagation (both dimer and trimer process) employs a p‐π conjugation chain propagation mechanism (p‐π CCPM), characterized by the formation of p‐π conjugation orbital between the chain terminal C atom and monomer CC double bond. This mechanism is in good agreement with the frontier molecular theory and the principle of conservation of molecular orbital symmetry. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Comparison of nuchal and detailed morphology ultrasound examinations in early pregnancy for fetal structural abnormality screening: a randomized controlled trial
Authors: Chen M. , Lee C. P. , Lam Y. H. , Tang R. Y. K. , Chan B. C. P. , Wong S. F. , Tse L. H. Y. , Tang M. H. Y.
Published: February 2008

Objective

To compare the effectiveness of a nuchal scan at 10 to 14 + 6 weeks and a detailed morphology scan at 12 to 14 + 6 weeks in screening for fetal structural abnormalities.

Methods

From March 2001 to November 2004, 8811 pregnant women were randomized into either the control group (10 to 14 + 6‐week nuchal scan followed by routine 16–23‐week scan) or the study group (10 to 14 + 6‐week nuchal scan and 12 to 14 + 6–week detailed scan followed by routine 16–23‐week scan).

Results

We analyzed 7642 cases of singleton pregnancies with viable fetuses at first‐trimester ultrasound examination and with known pregnancy outcome. In the control group, the detection rate of structural abnormalities in the first trimester was 32.8% (21/64; 95% CI, 21.6–45.7%) and the overall detection rate was 64.1% (41/64; 95% CI, 51.1–75.7%). In the study group, the detection rate in the first trimester was 47.6% (30/63; 95% CI, 34.9–60.6) and the overall detection rate was 66.7% (42/63; 95% CI, 53.7–78.0%). The overall detection rate in the control group did not differ significantly from that in the study group (P > 0.05).

Conclusions

When the nuchal scan is offered, a basic anatomical survey can be done in conjunction with nuchal translucency thickness measurement. A detailed ultrasound examination at this early gestational age may not be superior to the nuchal scan in screening for fetal abnormalities in the low‐risk population. Though a wide range of abnormalities can be detected at 10 to 14 + 6 weeks, the routine 16–23‐week scan cannot be abandoned. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Influence of adult Schwann cells and olfactory ensheathing glia on axontarget cell interactions in the CNS a comparative analysis using a retinotectal cograft model
Authors: Vukovic Jana , Plant Giles W. , Ruitenberg Marc J. , Harvey Alan R.
Published: February 2008

We used an in vivo transplant approach to examine how adult Schwann cells and olfactory ensheathing glia OEG influence the specificity of axontarget cell interactions when they are introduced into the CNS. Populations of either Schwann cells or OEG were mixed with dissociated fetal tectal cells presumptive superior colliculus and, after reaggregation, pieces were grafted onto newborn rat superior colliculus. Both glial types were prelabeled with lentiviral vectors encoding green fluorescent protein. Grafts rapidly established fiber connections with the host and retinal projections into cografts were assessed 656 days posttransplantation by injecting cholera toxinB into host eyes. In control rats that received pure dissociatedreaggregated tectal grafts, retinal ganglion cell RGC axons selectively innervated defined target areas, corresponding to the retinorecipient layer in normal superior colliculus. The pattern of RGC axon ingrowth into OEG containing cografts was similar to that in control grafts. However, in Schwann cell cografts there was reduced host retinal input into presumptive target areas and many RGC axons were scattered throughout the neuropil. Given that OEG in cografts had minimal impact on axontarget cell recognition, OEG might be an appropriate cell type for direct transplantation into injured neuropil when attempting to stimulate specific pathway reconstruction.
Gliosis alters expression and uptake of spinal glial amino acid transporters in a mouse neuropathic pain model
Authors: Cavaliere Carlo , Cirillo Giovanni , Rosaria Bianco Maria , Rossi Francesco , De Novellis Vito , Maione Sabatino , Papa Michele
Published: February 2008

Gliosis is strongly implicated in the development and maintenance of persistent pain states following chronic constriction injury of the sciatic nerve. Here we demonstrate that in the dorsal horn of the spinal cord, gliosis is accompanied by changes in glial amino acid transporters examined by immunoblot, immunohistochemistry and RT-PCR. Cytokines, proinflammatory mediators and microglia increase up to postoperative day (pd) 3 before decreasing on pd 7. Then, spinal glial fibrillary acidic protein increases on pd 7, lasting until pd 14 and later. Simultaneously, the expression of glial amino acid transporters for glycine and glutamate (GlyT1 and GLT1) is reduced on pd 7 and pd 14. Consistent with a reduced expression of GlyT1 and GLT1, high performance liquid chromatography reveals a net increase in the concentration of glutamate and glycine on pd 7 and pd 14 in tissue from the lumbar spinal cord of neuropathic mice. In this study we have confirmed that microglial activation precedes astrogliosis. Such a glial cytoskeletal rearrangement correlates with a marked decrease in glycine and glutamate transporters, which might, in turn, be responsible for the increased concentration of these neurotransmitters in the spinal cord. We speculate that these phenomena might contribute, via over-stimulation of NMDA receptors, to the changes in synaptic functioning that are responsible for the maintenance of persistent pain.
Effect of diffuse sky brightness on the spectrophotometry of rough Martian surfaces
Authors: Thomas Nicolas , Jorda Laurent , Markiewicz Wojciech J.
Published: February 2008

The Martian Surface is illuminated both by the direct solar flux and by a diffuse flux originating from scattering by dust in the Martian atmosphere. The fact that the diffuse flux varies in intensity and color across the sky leads to nonsolar total illumination of surfaces. This, in turn, can lead to interesting phenomena such as the apparent color changes of rock surfaces with time of day [Thomas et al., 1999]. A further consequence is the possibility that two surfaces, in an identical orientation and of identical color when illuminated by a direct beam, can change color relative to one another when viewed under Martian conditions if the two surfaces are of different surface roughness. This is a natural consequence of microshadowing combined with the diffuse illumination of those shadows. In this paper, we demonstrate the phenomenon with a numerical model, show an example from the Mars Pathfinder landing site where it could be of significance, and discuss its implications for spectrophotometric studies of Martian rocks.