bluuebunny/crossref_metadata_2025 huggingface dataset:
Developmental and daily expression of the Pax4 and Pax6 homeobox genes in the rat retina: localization of Pax4 in photoreceptor cells
Authors: Rath Martin F. , Bailey Michael J. , Kim Jong‐So , Coon Steven L. , Klein David C. , Møller Morten
Published: November 2008

Pax4 is a homeobox gene encoding Pax4, a transcription factor that is essential for embryonic development of the endocrine pancreas. In the pancreas, Pax4 counters the effects of the related transcription factor, Pax6, which is known to be essential for eye morphogenesis. In this study, we have discovered that Pax4 is strongly expressed in retinal photoreceptors of the rat. Pax4 expression is not detectable in the foetal eye; however, postnatal Pax4 transcript levels rapidly increase. In contrast, Pax6 exhibits an inverse developmental pattern of expression being more strongly expressed in the foetal eye. Histological analysis revealed that Pax4 mRNA is exclusively expressed in the retinal photoreceptors, whereas Pax6 mRNA and protein are present in the inner nuclear layer and in the ganglion cell layer of the mature retina. In the adult retina, Pax4 transcripts exhibit a diurnal rhythm with maximal levels occurring during the light period, whereas retinal Pax6 transcript levels do not change throughout the day. The daily changes in Pax4 expression may contribute to daily changes in function in the differentiated retinal photoreceptor.
Behavioral stress accelerates plaque pathogenesis in the brain of Tg2576 mice via generation of metabolic oxidative stress
Authors: Lee Kang‐Woo , Kim Jung‐Bin , Seo Ji‐Seon , Kim Tae‐Kyung , Im Joo‐Young , Baek In‐Sun , Kim Kyoung‐Shim , Lee Ja‐Kyeong , Han Pyung‐Lim
Published: November 2008

Alzheimer’s disease (AD) is a progressive neurodegenerative disease caused by genetic and non‐genetic factors. Most AD cases may be triggered and promoted by non‐genetic environmental factors. Clinical studies have reported that patients with AD show enhanced baseline levels of stress hormones in the blood, but their physiological significance with respect to the pathophysiology of AD is not clearly understood. Here we report that AD mouse models exposed to restraints for 2 h daily on 16 consecutive days show increased levels of β‐amyloid (Aβ) plaque deposition and commensurable enhancements in Aβ(1–42), tau hyperphosphorylation, and neuritic atrophy of cortical neurons. Repeated restraints in Tg2576 mice markedly increased metabolic oxidative stress and down‐regulated the expression of MMP‐2, a potent Aβ‐degrading enzyme, in the brain. These stress effects were reversed by blocking the activation of the hypothalamus‐pituitary‐adrenal gland axis with the corticotropin‐releasing factor receptor antagonist NBI 27914, further suggesting that over‐activation of the hypothalamic‐pituitary‐adrenal axis is required for stress‐enhanced AD‐like pathogenesis. Consistent with these findings, corticosteroid treatments to cultured primary cortical neurons increased metabolic oxidative stress and down‐regulated MMP‐2 expression, and MMP‐2 down‐regulation was reversed by inhibition of oxidative stress. These results suggest that behavioral stress aggravates AD pathology via generation of metabolic oxidative stress and MMP‐2 down‐regulation.
Building capacity for the children's workforce: findings from the knowledge review of the higher education response
Authors: Taylor Imogen , Sharland Elaine , Whiting Russell
Published: November 2008

In the UK, there is rapid and far‐reaching policy change designed to provide integrated services to children, young people and their families, linking education, social care, health, youth and community, criminal justice and other professions. Higher education institutions must play a significant role in this process given the large proportion of its graduates who will join the Children's Workforce. In 2007, a University of Sussex team was commissioned by the Higher Education Academy Subject Centres for Social Policy and Social Work; Education; Health Sciences and Practice; Medicine, Dentistry and Veterinary Science; and Psychology, in collaboration with the Children's Workforce Development Council and the Children's Workforce Network to undertake a Knowledge Review of integrated children's services in higher education. In this paper, the authors explore the policy context for integrated children's services and its interaction with the educational and workforce agenda. They set out the process of the Knowledge Review and examine its findings thematically, drawing on activity theory. They suggest that to advance the integrated children's services agenda in higher education, four crucial issues need to be addressed: stakeholders need to provide a clear‐cut business case for investment; universities and regulators must address disciplinary and associated cultural barriers to change at all levels; funders must invest in supporting pilot initiatives and their evaluation; and finally, academics need to find ways to engage and sustain children, young people and their families in the development process.
‘A welcome home for identity’: a learning network between children's charities and a university
Authors: Coughlan Tony
Published: November 2008

Across Britain, universities and employers are being encouraged to form partnerships for the development and delivery of workforce development programmes. In the social care sector, discussion about workforce development programmes usually focuses on large employers such as local authorities and children's trusts, overlooking the charities that comprise a significant sector of the workforce.

This paper explores an alternative dispersed model of workforce development that encourages voluntary & community sector children's agencies to share learning and development among volunteers, employees and employers within a learning network created by two children's charities (National Council for Voluntary Child Care Organizations and Barnardo's) and a university (the UK's Open University). This learning network – the Children's Workforce Learning Network (CWLN) – operates through communities of practice, distance learning courses and e‐learning.

Employer and student feedback suggests that a learning network developed through a partnership between children's charities and a university can be effective, particularly in meeting the needs of ‘hard to reach’ learners who are not well served by existing provision. However, it also appears that e‐learning may not yet be a solution to the barriers to learning often faced by isolated, part‐time and volunteer workers.
Use of Empirically Derived Source‐Destination Models to Map Regional Conservation Corridors
Authors: CUSHMAN SAMUEL A. , McKELVEY KEVIN S. , SCHWARTZ MICHAEL K.
Published: November 2008

Abstract: The ability of populations to be connected across large landscapes via dispersal is critical to long‐term viability for many species. One means to mitigate population isolation is the protection of movement corridors among habitat patches. Nevertheless, the utility of small, narrow, linear features as habitat corridors has been hotly debated. Here, we argue that analysis of movement across continuously resistant landscapes allows a shift to a broader consideration of how landscape patterns influence connectivity at scales relevant to conservation. We further argue that this change in scale and definition of the connectivity problem improves one's ability to find solutions and may help resolve long‐standing disputes regarding scale and definition of movement corridors and their importance to population connectivity. We used a new method that combines empirically derived landscape‐resistance maps and least‐cost path analysis between multiple source and destination locations to assess habitat isolation and identify corridors and barriers to organism movement. Specifically, we used a genetically based landscape resistance model for American black bears (Ursus americanus) to identify major movement corridors and barriers to population connectivity between Yellowstone National Park and the Canadian border. Even though western Montana and northern Idaho contain abundant public lands and the largest wilderness areas in the contiguous United States, moving from the Canadian border to Yellowstone Park along those paths indicated by modeled gene flow required bears to cross at least 6 potential barriers. Our methods are generic and can be applied to virtually any species for which reliable maps of landscape resistance can be developed.
Effects of lamotrigine compared with levetiracetam on anger, hostility, and total mood in patients with partial epilepsy
Authors: Labiner David M. , Ettinger Alan B. , Fakhoury Toufic A. , Chung Steve S. , Shneker Bassel , Tatum IV William O. , Mitchell Miller J. , Vuong Alain , Hammer Anne E. , Messenheimer John A.
Published: November 2008

Purpose:  To assess anger/hostility during treatment with lamotrigine adjunctive therapy versus levetiracetam adjunctive therapy in patients with partial seizures.

Methods:  This randomized, double‐blind, parallel‐group study in adults with partial seizures included an 8‐week escalation phase, during which adjunctive lamotrigine (n = 132) or adjunctive levetiracetam (n = 136) was titrated to a target dose, and a 12‐week, double‐blind maintenance phase, during which dosages of study medication and concomitant antiepileptic drugs were maintained. The primary endpoint was change from baseline to the end of the maintenance phase (week 20) in the Anger‐Hostility subscale score of the Profile of Mood States (POMS).

Results:  Improvement with lamotrigine relative to levetiracetam was observed for mean ± SD (standard deviation) change from baseline to the end of the maintenance phase (week 20) on the Anger‐Hostility subscale (lamotrigine −2.0 ± 8.2, levetiracetam −0.3 ± 8.4; p = 0.024) (the primary endpoint); the Anger‐Hostility subscale on weeks 5, 6, 7, 8, 9, 11, 12, 14, 16, 18, and 19; and the Total Mood Disturbance score on weeks 6, 7, 8, 9, 11, 12, 17, 19, and 20. Improvement (p < 0.05) with lamotrigine relative to levetiracetam was also observed on the POMS subscales Depression‐Dejection, Vigor‐Activity, Fatigue‐Inertia, and Confusion‐Bewilderment. No difference in seizure frequency was observed between groups. The most common adverse events with both medications were headache and dizziness.

Discussion:  Adjunctive lamotrigine significantly improved Anger‐Hostility subscale scores relative to adjunctive levetiracetam in patients with partial seizures at the end of 20 weeks. This difference was consistently observed throughout the treatment period. Similar improvement with lamotrigine versus levetiracetam was observed for other mood symptoms.
Does the effectiveness of the ketogenic diet in different epilepsies yield insights into its mechanisms?
Authors: Hartman Adam L.
Published: November 2008

Summary

The ketogenic diet (KD) has been used successfully in a variety of epilepsy syndromes. This includes syndromes with multiple etiologies, including Lennox–Gastaut syndrome and infantile spasms; developmental syndromes of unknown etiology, such as Landau–Kleffner syndrome; and idiopathic epilepsies, such as myoclonic‐astatic (Doose) epilepsy. It also includes syndromes where genetics play a major role, such as Dravet syndrome, tuberous sclerosis, and Rett syndrome. Study of the KD in humans and animals harboring various genetic mutations may yield insights into the diet's mechanisms. Comparison of the diet's effectiveness with other treatments in specific syndromes may be another useful tool for mechanistic studies. The diet's utility in epilepsy syndromes of various etiologies and in some neurodegenerative disorders suggests it may have multiple mechanisms of action.
Mouse models: The ketogenic diet and polyunsaturated fatty acids
Authors: Borges Karin
Published: November 2008

Summary

Literature on the anticonvulsant effects of the ketogenic diet (KD) in mouse seizure models is summarized. Recent data show that a KD balanced in vitamin, mineral, and antioxidant content is anticonvulsant in mice, confirming that the KD's effect in mice can be attributed to the composition of the diet and not other dietary factors. Given that the anticonvulsant mechanism of the KD is still unknown, the anticonvulsant profile of the diet in different seizure models may help to decipher this mechanism. The implications of the findings that the KD is anticonvulsant in electrical seizure models are indicated. Further, the potential involvement of polyunsaturated fatty acids (PUFA) in the KD's anticonvulsant mechanism is discussed.
Peroxisome proliferator‐activated receptor alpha and the ketogenic diet
Authors: Cullingford Tim
Published: November 2008

Summary

Peroxisome proliferator‐activated receptor alpha (PPARα) is a drug/fatty acid‐activated trans cription factor involved in the starvation response, and is thus relevant to the ketogenic diet (KD). This article summarizes research indicating the role of PPARα in central and peripheral nervous system function with particular reference to downstream targets relevant to anticonvulsant action.
Energy metabolism as part of the anticonvulsant mechanism of the ketogenic diet
Authors: Bough Kristopher
Published: November 2008

Summary

The efficacy of the ketogenic diet (KD) develops gradually over a period of 1–3 weeks, suggesting that adaptive changes in gene expression are involved in its anticonvulsant effects. Previously, microarrays were employed to define patterns of gene expression in the hippocampus of rats maintained on either a KD or a control diet for 3 weeks. The density of mitochondria in hippocampal tissue was assessed by electron microscopy. Levels of selected energy metabolites, enzyme activities, and the effect of low glucose on synaptic transmission were also investigated in hippocampal tissue taken from either KD‐ or control‐fed animals. We found a coordinated up‐regulation of transcripts encoding energy metabolism enzymes and a dramatic 46% increase in the density of mitochondria observed in neuronal processes. These changes were accompanied by an increased phosphocreatine (PCr):creatine (Cr) energy‐store ratio. Consistent with heightened energy reserves, hippocampal synaptic transmission in KD‐fed animals was maintained ∼50% longer compared to controls after exposure to a mild metabolic stressor. Taken together, several lines of evidence indicate that the KD enhances energy production in the brain. As a consequence, brain tissue appears to become more resistant to metabolic stress. It is proposed . . . that the observed KD‐induced enhancements in energy metabolism help to compensate for the metabolic deficits exhibited (interictally) within epileptic foci and transient failures of gamma‐aminobutyric acid (GABA) ergic inhibition, which would otherwise favor the initiation and propagation of seizure activity.
Seizure suppression via glycolysis inhibition with 2‐deoxy‐D‐glucose (2DG)
Authors: Stafstrom Carl E. , Roopra Avtar , Sutula Thomas P.
Published: November 2008

Summary

Metabolic regulation of neuronal excitability is increasingly recognized as a factor in seizure pathogenesis and control. Inhibiting or bypassing glycolysis may be one way through which the ketogenic diet provides an anticonvulsant effect. 2‐deoxy‐D‐glucose (2DG), a nonmetabolizable glucose analog that partially inhibits glycolysis, was tested in several acute and chronic seizure models. Acutely, 2DG decreases the frequency of high‐K+‐, bicuculline‐ and 4‐aminopyridine‐induced interictal bursts in the CA3 region of hippocampal slices; 2DG also exerts anticonvulsant effects in vivo against perforant path kindling in rats. Chronically, 2DG has novel antiepileptic effects by retarding the progression of kindled seizures. Finally, 2DG has a favorable preliminary toxicity profile. These factors support the possibility that 2DG or other modifiers of glycolysis can be used as novel treatments for epilepsy.
Diet, ketones, and neurotrauma
Authors: Prins Mayumi
Published: November 2008

Summary

The annual incidence of traumatic brain injury far exceeds the rates of any other disease in the United States, yet progress toward age‐relevant therapies, attention to patients needs, and research funding have all been minimal. Cerebral metabolism of glucose has been shown to be altered after head injury, and increasing cerebral metabolism of alternative substrates (ketones) has been shown to be neuroprotective in several models of traumatic brain injury. This altered dietary approach may have tremendous therapeutic potential for both the pediatric and adult head‐injured populations.
Circadian rhythms, diet, and neuronal excitability
Authors: Allen Charles N.
Published: November 2008

Summary

Many aspects of normal biological function are governed by circadian rhythms, including metabolism, ingestive behaviors, and sleep–wake cycles. Certain pathological processes as well are also affected by the circadian rhythms. For example, it is well known that seizure occurrence can be influenced by the sleep–wake cycle. The ketogenic diet (KD) is a high‐fat, low‐carbohydrate diet with proven efficacy in the treatment of intractable epilepsies. While the mechanisms underlying the clinical effects of the KD remain unclear, there are emerging links between circadian rhythms and KD action. Such factors should be considered when planning and administering the KD to patients.
Use of Pregabalin in Patients with Painful Neuropathic Disorders under the Care of General Practitioners in the U.K.
Authors: Berger Ariel , Sadosky Alesia , Dukes Ellen , Edelsberg John , Oster Gerry
Published: November 2008

Purpose:  To examine the use of pregabalin in patients with painful neuropathic disorders under the care of general practitioners (GPs) in the U.K.

Materials and Methods:  Using a large U.K. database of GP encounters, we identified all persons aged ≥ 18 years with at least one GP encounter with a diagnosis of a painful neuropathic disorder (eg, postherpetic neuralgia, diabetic peripheral neuropathy) between January 1, 2004 and July 31, 2006. Among these patients, we then identified those who initiated therapy with pregabalin; the date of initial receipt of pregabalin was designated the “index date.” We then examined use of pregabalin over the 6‐month period following this date (“follow‐up”), as well as changes in the use of other pain‐related medications (eg, opioids, tricyclic antidepressants [TCAs], other antiepileptics [AEDs]) between the 6‐month period preceding the index date (“pretreatment”) and follow‐up. Patients with less than 6 months of pretreatment and follow‐up data were excluded, as were those without any encounters during pretreatment for a painful neuropathic disorder.

Results:  A total of 1,400 patients (1.4% of all identified patients with painful neuropathic disorders) initiated therapy with pregabalin and met all other entry criteria; mean age was 62 years, and 58% were women. During pretreatment, most (54%) patients received three or more different types of pain‐related medications. During follow‐up, patients averaged four prescriptions for pregabalin, totaling 93 therapy days. Compared with pretreatment, fewer patients received other pain‐related medications during follow‐up, including TCAs (37% during pretreatment vs. 27% during follow‐up), opioids (64% vs. 55%), and AEDs other than pregabalin (36% vs. 16%) (all P < 0.01).

Conclusions:  In the U.K., many patients prescribed pregabalin by their GPs may have been refractory to other pain‐related medications. Use of these medications declined following initiation of pregabalin therapy.
Comparison of the analytical and operational performance of two viral nucleic acid test blood screening systems: Procleix Tigris and cobas s 201
Authors: Assal Azzedine , Barlet Valérie , Deschaseaux Marie , Dupont Isabelle , Gallian Pierre , Guitton Cathy , Morel P. , David Bernard , De Micco Philippe
Published: November 2008

BACKGROUND: The operational and analytical performance of two automated triplex hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) nucleic acid test (NAT) systems were compared in four screening laboratories of the French Blood Service.

STUDY DESIGN AND METHODS: Two laboratories evaluated the Procleix Tigris system (Chiron/Gen‐Probe) in individual donation (ID) format and two sites used the cobas s 201 system (Roche Molecular Systems) on minipools (MPs) of six donations. The analytical sensitivity, the specificity, and operational performance were compared.

RESULTS: The ID to MP‐NAT relative sensitivity factors in standard dilution panels of different genotypes varied between 8.7 and 21.9 for HCV RNA, 6.7 and 14.8 for HIV RNA, and 0.71 and 11.6 for HBV DNA. Tigris was 800‐fold more sensitive than cobas s 201 (1:6) for a HIV group O sample, but did not detect the HIV‐2 sample picked up by cobas s 201 with equal sensitivity as the HIV‐1 group M samples. The specificity of both NAT systems after initial screening of 10,520 donations with Tigris and 1444 test pools on s 201 was 99.9 percent for both systems, but reached 100 percent after the repeat and pool resolution test algorithms. A higher throughput of the pool test protocol on cobas s 201 became apparent when the daily workload was more than 400 donations.

CONCLUSIONS: Tigris ID‐NAT format was significantly more sensitive than cobas s 201 MP‐NAT in detecting HCV RNA and HIV RNA dilution panels, but despite the 1:6 dilution factor in s 201 the difference in sensitivity was not significant for some of the HBV genotype panels. Both NAT systems demonstrated acceptable operational performance, but for routine use further improvement in system reliability is desirable.
Blockade of maternal anti‐HPA‐1a–mediated platelet clearance by an HPA‐1a epitope–specific F(ab′)2 in an in vivo mouse model of alloimmune thrombocytopenia
Authors: Bakchoul Tamam , Boylan Brian , Sachs Ulrich J. H. , Bein Gregor , Ruan Changgeng , Santoso Sentot , Newman Peter J.
Published: November 2008

BACKGROUND: Neonatal alloimmune thrombocytopenia (NAIT) is most commonly caused by transplacental passage of maternal human platelet‐specific alloantigen (HPA)‐1a antibodies that bind to fetal platelets (PLTs) and mediate their clearance. SZ21, a monoclonal antibody (MoAb) directed against PLT glycoprotein IIIa, competitively inhibits the binding of anti‐HPA‐1a alloantibodies to PLTs in vitro. The purpose of this investigation was to determine whether SZ21 F(ab′)2 fragments might be therapeutically effective in inhibiting or displacing maternal HPA‐1a antibodies from the fetal PLT surface and preventing their clearance from circulation.

STUDY DESIGN AND METHODS: Resting human PLTs from HPA‐1ab heterozygous donors were injected into nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice. Purified F(ab′)2 fragments of SZ21 or control immunoglobulin G (IgG) were injected intraperitoneally 30 minutes before introduction of HPA‐1a antibodies. Blood samples were taken periodically and analyzed by flow cytometry to determine the percentage of circulating human PLTs.

RESULTS: Anti‐HPA‐1a IgG from NAIT cases were able to efficiently clear HPA‐1a–positive PLTs from murine circulation. Administration of SZ21 F(ab′)2 fragments not only inhibited binding of HPA‐1a antibodies to circulating human PLTs, preventing their clearance, but also displaced bound HPA‐1a antibodies from the PLT surface.

CONCLUSION: F(ab′)2 fragments of HPA‐1a–selective MoAb SZ21 effectively inhibit anti‐HPA‐1a–mediated clearance of human PLT circulating in an in vivo NOD/SCID mouse model. These results suggest that agents that inhibit binding of anti‐HPA‐1a to PLTs may have therapeutic potential in the treatment of NAIT.
Why RDAs and ULs Are Incompatible Standards in the U‐Shape Micronutrient Model: A Philosophically Orientated Analysis of Micronutrients' Standardizations
Authors: Hanekamp Jaap C. , Bast Aalt
Published: November 2008

Risk assessments of micronutrients are carried out in the customary deficiency‐excess model. It is regarded as straightforward and unambiguous. Nevertheless, it is a problematic amalgamation of two different and to a certain extent contrasting perspectives on risk and science that we will criticize in this contribution. Our critique is framed in a conceptual scheme of opposing perspectives highlighted by the rival characteristics of RDAs and SULs and the role of science therein. The one part of our scheme holds the typically modern approach that centers on risks that can be scientifically assessed more or less confidently. Subsequent policies are aimed at preventing major health problems that affect the majority of the population from early on in life. The RDAs are the ideal type‐case here. The other part of our scheme holds a much more postmodern approach in which health risks are explicitly recognized as “uncertain.” Dealing with those risks has little to do with major health problems from early on in life. Here, we encounter the scientific quandary of disentangling complex factors and impacts that may relate to some extra quality of life later on in life. SULs are exemplarily thereof. We will show that RDAs originally spawned from the scientific aim of securing objective knowledge “to lay down the requirements of an adequate” diet. SULs, conversely, are the upshot of generating acceptable outcomes driven by ever‐increasing safety requirements. This shift from securing objective knowledge to generating acceptable outcomes will be addressed in relation to precautionary culture.
Compositional Stresses in Polycrystalline Titania Films
Authors: Bhatia Sidharth , Sheldon Brian W.
Published: November 2008

Certain transition metal oxides exhibit relatively large compositional changes in response to variations in the oxygen partial pressure. In thin film form, these composition changes can lead to stress because of the constraint imposed by the underlying substrate. To investigate these effects, polycrystalline titania (anatase phase) was grown by metal–organic chemical vapor deposition. The stress changes during oxidation and reduction of these films were then studied by monitoring substrate curvature at elevated temperatures in controlled atmospheres. Variations in the temperature and grain size of the films were investigated. These results were analyzed in terms of point defects. In particular, the total stress change observed during oxidation–reduction cycles increased with decreasing grain size. This suggests that grain boundaries are associated with significantly higher defect concentrations in these materials, and that compositional stress data can provide important information about the nature of these defects.
Tensile Strength of Ni45Al45Cr7.5Ta2.5‐Coated Sapphire Fibers
Authors: Hajas David E. , Gebhardt Thomas , Chen Hao , Schneider Jochen M.
Published: November 2008

Continuous single‐crystal α‐Al2O3 fibers were coated with Ni45Al45Cr7.5Ta2.5 (IP75) alloy by physical vapor deposition (PVD). The strength of the coated fibers was evaluated by tensile testing and compared with the strength of uncoated fibers. The effect of temperature during diffusion bonding as well as the presence of a BN interlayer deposited by chemical vapor deposition (CVD) on the fiber strength was studied. Fibers coated with IP75, but without a BN interlayer, retained 23% of their initial strength after the PVD process and fractured during heat treatment. Evidence for thermal stress induced twin formation is presented. Fibers coated with a BN interlayer retained their initial strength during the coating processes. However, only 13% of their initial strength could be retained after the heat treatment. Here, chemical reactions cause morphological changes of the fiber surface. These may act as stress concentration sites, resulting in the extensive strength reduction reported here. These data are important for formulating future strategies avoiding or minimizing strength degradation during production of intermetallic matrix composites.
Fabrication of La0.8Sr0.2FeO3−δ Porous Ceramics Using a Phase‐Leaching Method
Authors: Wang Bo
Published: November 2008

Porous perovskites ceramics are very important components in solid oxide fuel cells. In the present work, porous ceramics of perovskite‐type La0.8Sr0.2FeO3−δ with a controllable microstructure are successfully fabricated using a phase leaching method. Sodium carbonate and La0.8Sr0.2FeO3−δ are processed to dual‐phase ceramics, and then sodium carbonate is dissolved in water to leave connected pore channels. The La0.8Sr0.2FeO3−δ porous ceramic obtained was characterized with an average pore size of 200 nm and a grain size of 250 nm by the SEM method.
In Situ Reaction Synthesis and Mechanical Properties of V2AlC
Authors: Hu Chunfeng , He Lingfeng , Liu Mingyue , Wang Xiaohui , Wang Jingyang , Li Meishuan , Bao Yiwang , Zhou Yanchun
Published: November 2008

A dense V2AlC ceramic was synthesized by an in situ reaction/hot pressing method using V, Al, and C powders as starting materials. The reaction path was investigated. It was found that V2AlC was produced by a reaction between Al8V5 and C. Single ‐phase V2AlC could be prepared using the optimized molar ratio of V:Al:C=2:1.2:0.9. The grain sizes of as‐prepared V2AlC samples were temperature dependent. On increasing the temperature from 1400° to 1700°C, the mean grain size of V2AlC increased from 49 μm in length and 19 μm in width to 405 μm in length and 106 μm in width. The V2AlC sample sintered at 1500°C exhibited the highest flexural strength of 289 MPa and a fracture toughness of 5.7 MPa·m1/2, while the V2AlC sample prepared at 1400°C showed the highest compressive strength of 742 MPa. The sample sintered at 1700°C possessed the highest damage tolerance. Additionally, V2AlC could retain a high degree of Young's modulus up to 1200°C. Below 800°C, V2AlC showed excellent thermal shock resistance.
Influence of Microstructure on the Ionic Conductivity of Plasma‐Sprayed Yttria‐Stabilized Zirconia Deposits
Authors: Xing Ya‐Zhe , Li Chang‐Jiu , Zhang Qiang , Li Cheng‐Xin , Yang Guan‐Jun
Published: November 2008

Yttria‐stabilized zirconia (YSZ) deposits were prepared by an atmospheric plasma spray (APS) on a stainless‐steel substrate preheated to different temperatures from room temperature to 1100°C. The microstructure of the deposits was characterized from polished and fractured cross sections by scanning electron microscopy (SEM). The ionic conductivity of the deposits was measured using both DC and AC methods, and the relationship between ionic conductivity and microstructure of deposits was examined. SEM observation revealed that the YSZ deposits exhibit different microstructures with different deposition temperatures. With the increase of the deposition temperature, the columnar grain growth across lamellar interfaces was enhanced and subsequently the intersplat bonding ratio in the deposit was improved. The ionic conductivity of YSZ deposits at the direction perpendicular to the deposit surface was significantly increased through the microstructure development on increasing the deposition temperature. However, it was found that the intergrain resistance changed little despite a remarkable change of the deposition temperature. A microstructure model is proposed to correlate the relative conductivity to the mean lamellar interface bonding ratio. The increase in ionic conductivity of the YSZ deposit with the deposition temperature can be attributed to the increase in the lamellar interface bonding ratio.
Electron Field Emission and Photoluminescence of Anatase Nanotube Arrays
Authors: Yang Yang , Wang Xiaohui , Sun Changku , Li Longtu
Published: November 2008

TiO2 nanotube arrays with a high aspect ratio were grown on conductive Ti substrates by anodization in an organic electrolyte. The as‐prepared TiO2 nanotubes were vertically grown and adhered well to the substrates. The photoluminescence spectrum and X‐ray diffraction showed that the crystal structure of the postannealed TiO2 nanotube arrays was oxygen‐defective anatase. This kind of anatase nanotube arrays exhibited efficient electron field emission even at room temperature with a low applied electric field of ∼9 V/μm. The emission current exceeded 70 μA/cm2 at an extraction voltage of 700 V.
Titanium Oxide Nanoparticles Precipitated from Low‐Temperature Aqueous Solutions: I. Nucleation, Growth, and Aggregation
Authors: Zhang Guangneng , Roy Biplab K. , Allard Lawrence F. , Cho Junghyun
Published: November 2008

Titanium oxide (TiO2) thin films can be prepared by controlled hydrolysis of a titanium tetrachloride (TiCl4) precursor in an aqueous solution at temperatures below 100°C. As part of an effort to understand the formation of such TiO2 films, the kinetics of the nucleation, growth, and aggregation of TiO2 nanoparticles in aqueous solutions of TiCl4 were studied using dynamic light scattering and a transmission electron microscope (TEM). A higher degree of supersaturation, produced by a higher solution temperature, a higher concentration of TiCl4, or a higher pH, results in a shorter nucleation induction time, a faster initial growth/aggregation rate, and a larger aggregate size. The interfacial energy of TiO2 nanoparticles was found to be 0.072 J/m2 from the homogeneous nucleation theory. Further investigations by a high‐resolution scanning electron microscope (SEM) and TEM for the as‐deposited films showed the structure hierarchy organized from nanocrystalline particles precipitated in the supersaturated solution. As a result, the effect of solution conditions on the nucleation, growth, and aggregation of TiO2 nanoparticles can provide useful guidance for tailoring of microstructures of the TiO2 films.
Low‐Temperature Sintering and Microwave Dielectric Properties of V2O5‐Added Zn2SiO4 Ceramics
Authors: Kim Jin‐Seong , Song Myung‐Eun , Joung Mi‐Ri , Choi Jae‐Hong , Nahm Sahn , Paik Jong‐Hoo , Choi Byung‐Hyun , Lee Hwack‐Joo
Published: November 2008

V2O5 was added to ceramics of nominal composition Zn1.8SiO3.8 (ZS) in order to decrease their sintering temperature for application to low‐temperature cofired ceramic devices. For the specimens sintered at 875°C, a dense microstructure was developed when the V2O5 content exceeded 9.0 mol% due to the presence of the liquid phase containing SiO2 and V2O5. The microwave dielectric properties of the ZS ceramics were influenced by the V2O5 content. Good microwave dielectric properties of Q×f=17 500 GHz, ɛr=7.3, and τf=−28 ppm/°C were obtained from the specimen containing 12.0 mol% V2O5 sintered at 875°C for 2 h.
Chemical Enhancement Techniques of Bloodstain Patterns and DNA Recovery After Fire Exposure*
Authors: Tontarski Karolyn L. , Hoskins Kyle A. , Watkins Tani G. , Brun‐Conti Leanora , Michaud Amy L.
Published: November 2008

Abstract: It is common in forensic casework to encounter situations where the suspect has set a fire to cover up or destroy possible evidence. While bloodstain pattern interpretation, chemical enhancement of blood, and recovery of deoxyribonucleic acid (DNA) from bloodstains is well documented in the literature, very little information is known about the effects of heat or fire on these types of examinations. In this study, a variety of known types of bloodstain patterns were created in a four‐room structure containing typical household objects and furnishings. The structure was allowed to burn to flashover and then it was extinguished by firefighters using water. Once the structure cooled over night, the interior was examined using a bright light. The bloodstains were evaluated to see if the heat or fire had caused any changes to the patterns that would inhibit interpretation. Bloodstain patterns remained visible and intact inside the structure and on furnishings unless the surface that held the blood was totally burned away. Additionally, a variety of chemical techniques were utilized to better visualize the patterns and determine the possible presence of blood after the fire. The soot from the fire formed a physical barrier that initially interfered with chemical enhancement of blood. However, when the soot was removed using water or alcohol, the chemicals used, fluorescein, luminol, Bluestar®, and Hemastix®, performed adequately in most of the tests. Prior to DNA testing, the combined phenolphthalein/tetramethyl benzidine presumptive test for the presence of blood was conducted in the laboratory on samples recovered from the structure in an effort to assess the effectiveness of using this type of testing as a screening tool. Test results demonstrated that reliance on obtaining a positive presumptive result for blood before proceeding with DNA testing could result in the failure to obtain useful typing results. Finally, two DNA recovery methods (swabbing the stain plus cutting or scraping the stain) were attempted to evaluate their performance in recovering samples in an arson investigation. Recovery of DNA was more successful in some instances with the swabbing method, and in other instances with the cutting/scraping method. Therefore, it is recommended that both methods be used. For the most part, the recovered DNA seemed to be unaffected by the heat, until the temperature was 800°C or greater. At this temperature, no DNA profiles were obtained.
Classification of Glass Fragments Based on Elemental Composition and Refractive Index*
Authors: Zadora Grzegorz
Published: November 2008

Abstract:  The aim of this study was to assess the efficiency of likelihood ratio (LR)‐based measures when they are applied to solving various classification problems for glass objects which are described by elemental composition, and refractive index (RI) values, and compare LR‐based methods to other classification methods such as support vector machines (SVM) and naïve Bayes classifiers (NBC). One hundred and fifty‐three glass objects (23 building windows, 25 bulbs, 32 car windows, 57 containers, and 16 headlamps) were analyzed by scanning electron microscopy coupled with an energy dispersive X‐ray spectrometer. Refractive indices for building and car windows were measured before (RIb), and after (RIa) an annealing process. The proposed scheme for glass fragment(s) classification demonstrates some efficiency, although the classification of car windows (c) and building windows (w) must be treated carefully. This is because of their very similar elemental content. However, a combination of elemental content and information on the change in RI during annealing (ΔRI = RIa−RIb) gave very promising results. A LR model for the classification of glass fragments into use‐type categories for forensic purposes gives slightly higher misclassification rates than SVM and NBC. However, the observed differences between results obtained by all three approaches were very similar, especially when applied to the car window and building window classification problem. Therefore, the LR model can be recommended because of the ease of interpretation of LR‐based measures of certainty.
DNA Analysis of Natural Fiber Rope*
Authors: Dunbar Mignon , Murphy Terence M.
Published: November 2008

Abstract: When rope is found at a crime scene, the type of fiber is currently identified through its microscopic characteristics. However, these characteristics may not always unambiguously distinguish some types of rope from others. If rope samples contain cells from the plants of origin, then DNA analysis may prove to be a better way to identify the type of rope obtained from a crime scene. The objective of this project was to develop techniques of DNA analysis that can be used to differentiate between ropes made fromCannabis sativaL. (hemp),Agave sisalanaPerrine (sisal),Musa textilisNée (abaca, “Manila hemp”),Linum usitatissimumL. (flax), andCorchorus olitorusL. (jute). The procedures included extracting the DNA from the rope, performing polymerase chain reaction (PCR) using the extracted DNA as a template, and analyzing the DNA products. A primer pair for PCR, chosen from within a chloroplast gene for the large subunit of ribulose bisphosphate carboxylase/oxygenase, was designed to be specific for plant DNA and complementary to the genes from all five plants. The resulting PCR fragments were approximately 771 base pairs long. The PCR fragments, distinguished through base sequence analysis or restriction enzyme analysis, could be used to identify the five different rope types. The procedure provides a useful addition to visual methods of comparing rope samples.
Trpv4 induces collateral vessel growth during regeneration of the arterial circulation
Authors: Troidl Christian , Troidl Kerstin , Schierling Wilma , Cai Wei‐Jun , Nef Holger , Möllmann Helge , Kostin Sava , Schimanski Sylvia , Hammer Linda , Elsässer Albrecht , Schmitz‐Rixen Thomas , Schaper Wolfgang
Published: November 2008

The development of a collateral circulation (arteriogenesis), bypassing an arterial occlusion, is important for tissue survival, but it remains functionally defective. Micro array data of growing collateral vessels, exposed to chronically elevated fluid shear stress (FSS), showed increased transcription of the transient receptor potential cation channel, subfamily V, member 4 (Trpv4). Thus, the aim of this study was to investigate the role of the shear stress sensitive Trpv4 in transmitting this physical stimulus into an active growth response. qRT‐PCR at different time points during the growth of collateral vessels after femoral artery ligature (FAL) in rats showed a strong positive correlation of Trpv4 transcription and the intensity of FSS. An increased protein expression of Trpv4 was localized in the FSS‐sensing endothelium by means of confocal immunohistochemistry. Cultured porcine endothelial cells showed a dose‐dependent expression of Trpv4 and an increased level of Ki67‐positive cells upon treatment with 4α‐Phorbol 12,13‐didecanoate (4αPDD), a specific Trpv4 activator. This was also demonstrated by flow culture experiments. These results were confirmed by in vivo application of 4αPDD in rabbit hind limb circulation via an osmotic mini‐pump after FAL. Trpv4 expression as well as Ki67‐positive staining was significantly increased in collateral vessels. Finally, 4αPDD treatment after FAL led to a 61% (215.5 ml/min/mmHg versus 350 ml/min/mmHg) recovery of conductance when compared with the non‐occluded artery. Cell culture and in vivo studies demonstrate that an FSS‐ or a 4αPDD‐induced activation of Trpv4 leads to an active proliferation of vascular cells and finally triggers collateral growth. Trpv4, a well‐known FSS‐sensitive vasodilator, has hitherto not been implicated in active growth processes of collateral arteries. This new function may lead to new therapeutic strategies for the treatment of arterial occlusive diseases.
A case of severe aplastic anemia secondary to treatment with lenalidomide for multiple myeloma
Authors: Dasanu Constantin A. , Alexandrescu Doru T.
Published: November 2008

Lenalidomide is an important contemporary treatment option for patients with multiple myeloma (MM). Rare instances of autoimmune conditions have been observed in association with its use. Although moderate myelosuppression is not uncommonly seen in patients treated with lenalidomide, aplastic anemia has not previously been reported to be associated with this agent. We describe a case of severe aplastic anemia (AA) that was probably induced by lenalidomide. A 64‐year‐old male patient developed progressive pancytopenia three weeks into therapy with lenalidomide for his relapsed MM. A bone marrow aspirate and biopsy confirmed the diagnosis of AA and suggested the existence of an immunological reaction at the level of marrow. A gradual spontaneous recovery of normal hematopoiesis followed after the lenalidomide discontinuation.
The effect of urbanisation on avian morphology and latitudinal gradients in body size
Authors: Evans Karl L. , Gaston Kevin J. , Sharp Stuart P. , McGowan Andrew , Hatchwell Ben J.
Published: November 2008

Urban areas occupy a large and growing proportion of the earth. Such sites exhibit distinctive characteristics relative to adjacent rural habitats, and many species have colonised and now successfully exploit urban habitats. The change in selection pressures as a result of urbanisation has led to trait divergence in some urban populations relative to their rural counterparts, but studies have generally been local in scale and the generality of differentiation thus remains unknown. The European blackbird Turdus merula is one of the commonest urban bird species in the Western Palearctic, but populations vary substantially in the length of time they have been urbanised. Here we investigate patterns of morphological variation in European blackbirds occupying 11 paired urban and rural habitats across much of the urbanised range of this species and spanning 25° of latitude. First, we assessed the extent to which urban and rural blackbirds are differentiated morphologically and the consistency of any differentiation across the range. Paired urban and rural Blackbird populations frequently exhibited significant morphological differences, but the magnitude and direction of differentiation was site dependent. We then investigated whether the nature of latitudinal gradients in body‐size differed between urban and rural populations, as predicted by differences in the climatic regimes of urban and rural areas. Blackbird body‐size exhibited strong latitudinal gradients, but their form did not differ significantly between urban and rural habitats. The latitudinal gradient in body size may be a consequence of Seebohm's rule, that more migratory populations occurring at high latitudes have longer wings. We conclude that while there can be substantial morphological variation between adjacent urban and rural bird populations, such differentiation may not apply across a species’ range. Locality specific differentiation of urban and rural blackbirds may arise if the selection pressures acting on blackbird morphology vary in an inconsistent manner between urban and rural habitats. Alternatively, phenotypic divergence could arise in a stochastic manner depending on the morphological traits of colonists, through founder effects.
Resource availability and ecosystem size predict food‐chain length in pond ecosystems
Authors: Doi Hideyuki , Chang Kwang‐Hyeon , Ando Takamitsu , Ninomiya Ippei , Imai Hiroyuki , Nakano Shin‐ichi
Published: November 2008

Food‐chain length (FCL) in ecosystems has been studied extensively, and numerous hypotheses to predict FCL, productivity, ecosystem size, and productive space have been proposed. For example, the productivity hypothesis suggests that resource availability limits FCL, whereas the productive‐space hypothesis predicts that per‐unit‐size resource availability and ecosystem size equally limit FCL. However, previous studies have only measured total productivity to test FCL and have never tested the impact of resource availability within a system on FCL. Therefore, we estimated FCL in 15 ponds using stable isotope techniques to test the most common hypotheses for predicting FCL. We also measured total productivity, pond volume (ecosystem size), and edible microalgal carbon (resource availability) in each pond. We found that productive‐space (edible carbon+pond volume) was the best model to predict FCL, and FCL was significantly correlated with edible carbon and pond volume. However, factors such as total productivity did not directly predict FCL of the ponds. Therefore, our results suggest that both resource availability and ecosystem size predict FCL in pond ecosystems and play significant roles in maintaining longer FCLs. Furthermore, the productive‐space hypothesis appears to be particularly important for determining the FCL of ponds.