bluuebunny/crossref_metadata_2025 huggingface dataset:
Drug-Related Emergency Department Visits in an Elderly Veteran Population
Authors: Yee Jennie L , Hasson Noelle K , Schreiber Donald H
Published: November 2005

BACKGROUND

Given that adverse drug events result in extensive costs and healthcare resource utilization, the goal is to better understand drug-related emergency department (ED) visits so that programs can be implemented to improve the quality of health care.

OBJECTIVE

To (1) determine the incidence of drug-related ED visits at a large, tertiary care, Veterans Affairs hospital; (2) identify causes of these drug-related ED visits; (3) determine patient outcomes, healthcare resource utilization, and costs associated with these visits; and (4) determine the proportion of adverse drug reaction (ADR)–related ED visits that were spontaneously reported to the hospital's ADR reporting program.

METHODS

We conducted a retrospective electronic chart review of all patients who visited the ED during the second week of each month in 2003. Causes for drug-related visits were identified. ADRs in this study included side effects, drug allergies, and drug–drug interactions (DDIs) and were assessed using the Naranjo probability scale.

RESULTS

A total of 2169 patients were included in the study. Drug-related visits accounted for 12.6% of all ED visits. The main causes of drug-related visits were ADRs and nonadherence, which accounted for 33% and 19% of drug-related visits, respectively. Only 11% of these ADRs were spontaneously reported to the hospital's ADR reporting program. Thirty-five percent of drug-related visits led to hospitalizations, which resulted in an average length of stay of 9.3 days. The institution's total cost of drug-related visits was approximately $1.5 million over 12 weeks.

CONCLUSIONS

Many ED visits are drug related and often result in hospitalization and increased healthcare resource utilization. Only a minimal number of the ADRs resulting in ED visits are spontaneously reported to hospital ADR reporting programs.
Myocardial Infarction Associated with Intravenous Immune Globulin
Authors: Stenton Sunita Bond , Dalen Dawn , Wilbur Kerry
Published: November 2005

OBJECTIVE

To report a case of acute myocardial infarction (MI) experienced by a patient receiving intravenous immune globulin (IVIG) and review other published cases of MI associated with IVIG.

CASE SUMMARY

An 81-year-old Vietnamese man was prescribed IVIG for treatment of toxic epidermal necrolysis secondary to allopurinol. Thirty minutes following the start of the IVIG infusion, the patient developed crushing retrosternal chest pain and shortness of breath. The pain improved upon discontinuation of IVIG infusion but recurred when IVIG was restarted. The troponin level reached 140 μg/L, and a persantine sestamibi stress test (MIBI) indicated anterolateral ischemia. The patient was diagnosed with non–ST-elevation MI. An objective causality assessment using the Naranjo probability scale revealed a probable association between this adverse reaction and IVIG treatment.

DISCUSSION

Although an association between IVIG administration and MI has not been demonstrated in clinical trials, accumulating clinical experience suggests that a relationship between IVIG and myocardial ischemia exists. Twenty published case reports were identified. Risk of acute MI seems to be increased with use of high-dose IVIG and in older individuals, especially those with at least one cardiovascular risk factor, such as ischemic heart disease or hypertension.

CONCLUSIONS

Case reports suggest a causal relationship between the use of IVIG and MI and other thrombotic events. While cardiovascular disease is not considered an absolute contraindication to therapy, expanding indications and subsequent use of IVIG merit that clinicians be aware of patient characteristics that may increase the risk for adverse reactions and recognize early signs of infarction.
Providing Patient Care in Community Pharmacies in Spain
Authors: Gastelurrutia Miguel Angel , Faus Maria José , Fernández-Llimós Fernando
Published: November 2005

OBJECTIVE

To review the current status of Spanish community pharmacy, both in practice and research terms, and analyze its future trends.

FINDINGS

Spain has a social security system where all citizens receive health care, social services, and pensions. All medical care and surgery are free for citizens; however, community pharmacies in Spain are privately owned. There are geographic and population standards for the establishment of new pharmacies, resulting in an average of 1 pharmacy per 2000 residents. Almost all pharmacies offer the same services: compounding, weight and blood pressure measurement, and cholesterol and glucose testing. There are also other, less-implemented services, such as methadone supply or directed observed treatments. Most of these services are freely provided, except compounding (fee for service), methadone, and directed observed treatments. University pharmacy practice departments do not exist in Spain, which leads to scarce research in this area.

DISCUSSION

Efforts have been made to describe and measure the prevalence of negative clinical outcomes produced by pharmacotherapy and create an operational procedure to provide pharmacotherapy follow-up.

CONCLUSIONS

Spain has many community pharmacies, but there is little pharmacy practice research. Some advanced cognitive services exist, but few are being remunerated.
Dose Intensification with Infliximab in Patients with Rheumatoid Arthritis
Authors: Berger Ariel , Edelsberg John , Li Tracy T , Maclean John R , Oster Gerry
Published: November 2005

BACKGROUND

Infliximab, in combination with methotrexate, is indicated for the treatment of moderate to severe active rheumatoid arthritis (RA). While there is anecdotal evidence that many patients beginning infliximab therapy have their dose and/or frequency of infusions increased over time (“dose intensification”), relatively little is known about actual patterns of use in clinical practice.

OBJECTIVE

To examine patterns of infliximab use in patients with RA.

METHODS

Using a large US healthcare claims database, all patients with RA who initiated infliximab therapy between January 1, 2000, and September 30, 2001, were identified. The date of each patient's first claim for infliximab was identified and designated as the index date; attention was limited to patients who received infliximab for at least one year. Patterns of infliximab use were then examined over the 12-month period following the index date, based on information on paid claims.

RESULTS

Fifty-three patients met all entry criteria; the mean age was 61 years, and 81% were women. Twenty-eight percent of patients received >8 infusions over 12 months. The mean dose of infliximab at initial infusion was 296.2 mg; at final infusion, it was 401.9 mg (36% increase). One-half of study subjects had their dose of infliximab increased by ≥30% between the initial and final infusions; one-third had their dose increased by ≥50%.

CONCLUSIONS

Many patients with RA beginning treatment with infliximab have their frequency of infusions and/or medication dose increased within the first 12 months.
Effect of Bupropion on Sexual Dysfunction
Authors: Ginzburg Regina , Wong Yvonne , Fader Jonathan S
Published: November 2005

OBJECTIVE

To determine the role of bupropion in treatment of sexual dysfunction.

DATA SOURCES

Studies and case reports were identified through MEDLINE (1970–July 2005) using search terms bupropion, antidepressants, sexual function, and sexual dysfunction.

DATA SYNTHESIS

Bupropion has been shown to have a favorable effect on sexual dysfunction. Several reports and small, short-term trials have examined bupropion as an adjunct or substitute for other antidepressants in sexually dysfunctional patients. Use of bupropion has also been studied in nondepressed patients. Bupropion may be a promising medication for treating sexual dysfunction. However, specific dosing is unclear.

CONCLUSIONS

While the studies reviewed here demonstrated some benefit in using bupropion to treat sexual dysfunction, limitations exist. Future studies should be conducted using larger sample sizes.
Acute Hypersensitivity Reaction to Ferric Gluconate in a Premedicated Patient
Authors: Saadeh Claire E , Srkalovic Gordan
Published: November 2005

OBJECTIVE

To report a case of an acute hypersensitivity reaction to ferric gluconate in a patient premedicated with dexamethasone, diphenhydramine, and prochlorperazine.

CASE SUMMARY

A 38-year-old female with persistent iron deficiency anemia was initiated on parenteral iron therapy with ferric gluconate 125 mg intravenously over 10 minutes. The patient initially tolerated this first dose well; however, she later experienced nausea, dizziness, and minor tongue swelling. On her second course of therapy, the woman was premedicated with dexamethasone, diphenhydramine, and prochlorperazine prior to the same dose of ferric gluconate infused over 30 minutes. Subsequently, the patient developed epigastric pain, nausea, swelling of her lips and tongue, and hypotension. The symptoms abated after administration of diphenhydramine, dexamethasone, morphine, cimetidine, intravenous fluids, and oxygen. She was discharged after a short stay in the emergency department observation unit.

DISCUSSION

Data are limited on the relative safety of ferric gluconate compared with iron dextran. Ferric gluconate does not appear to be associated with severe life-threatening events; however, the possibility of an acute hypersensitivity reaction with this product does exist. In this case, use of the Naranjo probability scale indicated a probable relationship between the hypersensitivity reaction and ferric gluconate.

CONCLUSIONS

Healthcare professionals should be aware of this serious but rare event and encouraged to further document and report these events.
Update in Handheld Electronic Resources for Evidence-Based Practice in the Community Setting
Authors: Burkiewicz Jill S , Vesta Kimi S , Hume Anne L
Published: November 2005

OBJECTIVE

To provide an update on the handheld electronic resources for evidence-based practice (EBP) in the community setting.

DATA SOURCES

Electronic resources for EBP in the community setting were identified by compiling the commonly used, well-established resources and by searching MEDLINE and other Internet sites. Search terms included evidence-based medicine, evidence-based practice, resources, and abstraction. Only sources available for personal digital assistants were included.

DATA EXTRACTION

Three databases were identified that provided abstraction and evaluation of the medical literature for the handheld platform. Content, features, ease of use, system requirements, and costs of each resource were evaluated.

DATA SYNTHESIS

FIRSTConsult, InfoRetriever, and UpToDate were evaluated, and the utility of each in the community pharmacy setting was evaluated by tracking a clinically relevant example through each system. FIRSTConsult provides evidence-based information organized by diagnosis but is not searchable on the handheld platform. InfoRetriever focuses on searchable evidence-based summaries, while UpToDate includes comprehensive topic reviews. The latter 2 platforms have large system memory requirements. All 3 sources provide evidence-based abstraction of the medical literature for the PDA platform, convenient for use at the point of care in community pharmacy.

CONCLUSIONS

While users may select a particular resource based on unique features, each provides evidence-based abstraction of the medical literature that is a practical approach to EBP in the community pharmacy setting.
Vision of Life: A Lesson Learned from a 98-Year-Old Artist on World AIDS Day
Authors: Fan-Havard Patty
Published: November 2005

A large percentage of HIV-infected pregnant women referred to our HIV Pregnancy Program are economically disadvantaged and underserved. Many of these women experience additional psychosocial stressors that include domestic violence, depression, substance abuse, and pregnancy-related dilemmas. The major challenge we face at the clinic is to provide appropriate interventions in a timely manner to minimize perinatal HIV-1 transmission and optimize maternal and fetal well-being. The medical urgency to ensure optimal patient care has led me to become more detached from our patients. The “humanistic” approach to patient care was an important lesson that I recently re-learned from a 98-year-old artist on World AIDS Day.
Stress and coping strategies among Zimbabwean adolescents
Authors: Magaya Lindiwe , Asner‐Self Kimberly K. , Schreiber James B.
Published: November 2005

Background. Stress and social support influence adolescents' coping strategies. Adolescents need to acquire a large repertoire of coping strategies in light of a rapidly changing socio‐economic and political situation.

Aim. This study reports on the coping strategies of Zimbabwean adolescents and highlights some major stressors they face. The interplay among stress, social support and the coping strategies of Zimbabwean adolescents are also reported.

Sample. A sample of 101 Zimbabwean students (ages 17–19) participated in this study.

Method. Participants completed three instruments: the Perceived Stress Scale, the Social Provision Scale and the Ways of Coping Scale.

Results. Zimbabwean adolescents experienced slight stress as measured by the Perceived Stress Scale. Major stressors included schoolwork, relationships, social life and financial hardship. Females reported a higher level of perceived stress than males. Zimbabwean adolescents reported having fewer social provisions than the norm group. Results from the Ways of Coping Scale indicated that Zimbabwean adolescents use emotion‐focused strategies more frequently than problem‐solving strategies.

Conclusion. The implications of the study are that Zimbabwean adolescents may need to acquire a larger repertoire of coping skills adding to what they may already have. Problem‐solving skills need to be employed in face of today's challenging situations.
Coursework selection: A frame of reference approach using structural equation modelling
Authors: Dickhäuser Oliver , Reuter Martin , Hilling Christine
Published: November 2005

Background. Choice behaviour has far‐reaching consequences on students' educational careers. Previous models on course selection for example, the model of achievement‐related choices (Wigfield & Eccles, 2000) and of self‐efficacy theory (Bandura, 1997), stress the importance of ability perceptions (self‐concept of ability) as major determinants of choice.

Aim. This article suggests a model of course selection, which assumes that comparisons within an internal frame of reference (as proposed by Marsh, 1986, for the association between achievement and self‐concepts) can also be applied to the association between self‐concepts and course selection. It is therefore hypothesized that course selection is not only positively influenced by the self‐concept with respect to the corresponding subject, but also negatively with respect to alternative subjects. Moreover, it should be tested whether the effects of previous achievement on course selection are completely mediated by the self‐concepts.

Sample. These assumptions were empirically tested using a sample of 296 students from secondary school classes, who were specializing in, for example, chemistry or biology in the following school term.

Method. Self‐concepts and course selection were assessed via questionnaire. The postulated models were tested using a structural equation modelling approach for ordinal variables.

Results. The core assumption, that course selection is determined by dimensional comparisons, was supported by significant negative paths from self‐concepts on the selection of non‐corresponding subjects. Furthermore, the effects of previous achievement on selection were completely mediated by self‐concepts.

Conclusion. Previous models of choice behaviour should be extended, by considering not only the selected alternatives, but also the unselected ones. The finding that the influence of achievement on choice is completely mediated by self‐concepts, demonstrates that subjective interpretations of previous achievement determine subsequent behaviour.
Confirmatory factor analysis of the Teacher Efficacy Scale for prospective teachers
Authors: Denzine Gypsy M. , Cooney John B. , McKenzie Rita
Published: November 2005

Background. Research on teacher self‐efficacy has revealed substantive problems concerning the validity of instruments used to measure teacher self‐efficacy beliefs. Although claims about the influence of teachers' self‐efficacy beliefs on student achievement, success with curriculum innovation, and so on, may be true statements, one cannot make those claims on the basis of that body of evidence if the instruments are not valid measures of teachers' self‐efficacy beliefs.

Aims. The purpose of this investigation is to employ the use of modern confirmatory factor‐analytic techniques to investigate the validity of the hypothesized dimensions of the Teacher Efficacy Scale (Gibson & Dembo, 1984; Woolfolk & Hoy, 1990).

Sample. Participants for this investigation were 387 prospective teachers recruited from a university located in the south‐western region of the UA. Participants for Study 2 were 131 prospective elementary teachers recruited from the same university as in Study 1.

Results. A confirmatory factor analysis (CFA) procedure was used to evaluate the goodness‐of‐fit for two theoretical models of the TES items. The proposed two‐ and three‐factor models of teacher self‐efficacy for prospective teachers were rejected. A re‐specified three‐factor model of the TES was then derived from theoretical and empirical considerations. The re‐specified model hypothesized three dimensions: self‐efficacy beliefs, outcome expectations, and external locus‐of‐causality. In Study 2, the re‐specified three‐factor measurement model was evaluated in a new sample. Results of the CFA procedure indicated satisfactory fit of the re‐specified model to the data; however, the results were not consistent with predictions derived from social learning theory.

Conclusions. The results of this study call into question the use of the TES and the interpretation of a large body of literature purporting to study the relationship of teachers' self‐efficacy beliefs to important educational outcomes.
Towards more powerful learning environments through combining the perspectives of designers, teachers, and students
Authors: Könings Karen D. , Brand‐Gruwel Saskia , van Merriënboer Jeroen J. G.
Published: November 2005

In order to reach the main aims of modern education, powerful learning environments are designed. The characteristics of the design of PLEs are expected to have positive effects on student learning. Additionally, teachers' conceptions of learning and teaching do influence the implementation of a PLE. Moreover, students' perceptions of a learning environment affect their subsequent learning behaviour and the quality of the learning outcomes. The different perspectives of educational designers, teachers, and students are summarized in the Combination‐of‐perspectives (COOP) model. Combining these perspectives by mutual exchange of conceptions and perceptions is expected to have positive effects on the power of PLEs.
Psychological dynamics affecting traumatic memories: Implications in psychotherapy
Authors: Peres Julio Fernando , Mercante Juliane , Nasello Antonia Gladys
Published: November 2005

The search to understand response to trauma has turned to the contribution of personality factors. The way people process the stressor event is critical in determining whether a trauma will be configured or not. Neuroscience shows that the brain does not store memories, but traces of information that are later used to create memories, which do not always express a completely factual picture of the past experience. Whenever an event is retrieved, it may undergo a cognitive and emotional change. Psychological dynamics – emotional interpretative tendency that affects the internal dialogue related to a meaningful event – may influence the development of positive or negative outcomes after stressor events. We postulate that therapists must see beyond the traumatic event itself and work with the internal dialogues that maintain the pathological relationship with the past episode. Thus, they may better treat traumatized patients by therapeutically rebuilding the memory. A brief clinical case is presented to show how exposure‐based and cognitive restructuring therapy may help trauma victims experience psychological growth from their negative experiences, by fostering healthy psychological dynamics.
Early maladaptive schemas and adult attachment in a UK clinical population
Authors: Mason Oliver , Platts Helen , Tyson Mary
Published: November 2005

Objectives. Both insecure attachment style and early maladaptive schemas have been associated with mental health difficulties. This study aimed to investigate how schemas relate to attachment style classification in mental health service users. A further aim was to investigate the nature of the relationship between psychological distress, common psychological difficulties, and attachment style.

Method. Participants were 72 people in contact with mental health services who completed the short form of Young's schema questionnaire, a measure identifying their attachment style (experience of close relationships), and the clinical outcomes in routine evaluation (CORE; Evans et al., 1998) outcome measure.

Results. Overall, 81% of the participants had an insecure attachment style. The fearful group were the most distressed across several domains of the CORE, followed by the preoccupied group. Schemas differed significantly according to attachment style grouping, with the fearful group possessing the greatest degree of maladaptive schemas, followed by the preoccupied group. Discriminant function analysis identified differing patterns of schemas associated with attachment style.

Conclusions. The results supported the relevance of both attachment style and maladaptive schemas to individuals with mental health difficulties. Importantly, several aspects of the individuals' symptoms and difficulties and their schemas were meaningfully related to their adult attachment style. Limitations included the small number of dismissing individuals identified, the problems of self‐report in this area, and the absence of information about the quality of participants' current relationships.
Factors in outcome of cognitive‐behavioural therapy for psychosis: Users' and clinicians' views
Authors: McGowan John F. , Lavender Tony , Garety Philippa A.
Published: November 2005

Objectives. Despite increasing evidence to suggest that cognitive‐behavioural therapy (CBT) is helpful for a significant proportion of people with psychosis, only limited information is available regarding factors implicated in outcome. The present study investigated factors differentiating outcomes on the basis of accounts from participants in the therapeutic process.

Method. Four therapists and eight of their clients were interviewed about their experiences of CBT. Clients were defined as having progressed or not progressed during therapy. Interview data were analysed using a qualitative ‘grounded theory’ methodology.

Results. A number of major categories differentiated the two client groups, including ability to let go of distressing beliefs, logical thought, holding therapy, and presence of a shared goal. Overall, clients who progressed were better able to move into the therapist's frame of reference. Therapists and clients also felt that non‐specific benefits accrued from the therapy for both groups.

Conclusion. The results were consistent with previous studies suggesting that ability to disengage from distressing beliefs is important in therapeutic progression. Reasons considered for the inability to progress include emotional investment in psychotic beliefs and cognitive processing. Further research is required to clarify the role of logical thought and therapeutic alliance in progress and in predicting outcome.
Vive la France! French Multinationals and Human Rights
Authors: Colonomos Ariel , Santiso Javier
Published: November 2005

This paper focuses on the analysis of corporate responsibility and also examines the question of international diffusion of norms in the context of globalization. It measures the influence of nonstate actors on foreign societies and states. It also draws on firsthand economic and financial empirical data, and then analyzes the reasons why French firms haveadopted this discourse and integrated many practices prevalent in the US private sector. It shows that the globalization of production and capital has created in France a favorable context for the reinterpretation of corporate social responsibility, despite France's political and historical specificity with respect to human rights. As French companies have become increasingly transnational in their operations and reliant on nonresident capital, they have been more willing to take norms of corporate social responsibility into account. This economic context has had three major effects. First, it has influenced the construction of a domestic public space and new social networks—a market of virtue—based on cooperation among nongovernmental organizations, norms activists and businesses. Second, it has influenced some firms in the definition of their international strategy. Finally, it has compelled the French state to react in economic regulatory terms. Nonstate actors are thus constructing new norms, shaping the economic public debate, compelling states to react, and setting new public policies.
Ultrastructural changes in a holocellulose pulp revealed by enzymes, thermoporosimetry and atomic force microscopy
Authors: Fahlén Jesper , Salmén Lennart
Published: November 2005

To increase our knowledge of the ultrastructure within softwood fibres, enzymatic treatment, thermoporosimetry, light microscopy, and atomic force microscopy with image analysis were used to investigate the structure of holocellulose softwood pulp fibres. The size of the average cellulose fibril aggregates and the width of pore and matrix lamellae were found to be uniform across the secondary cell-wall layer in the transverse direction of the wood fibre wall. In holocellulose, these dimensions were very similar to those in the native wood, whereas in kraft pulp the cellulose fibril aggregates were larger and the pore and matrix lamellae broader. These differences between holocellulose and kraft pulp fibres suggest that a high temperature is needed for cellulose fibril aggregation to occur. Neither refining nor drying of the holocellulose pulp changed the cellulose fibril aggregate size. Upon drying and enzymatic treatment, a small decrease in the pore and matrix lamella width was evident throughout the fibre wall. This indicated not only uniform distribution of pores throughout the fibre wall, but also enzymatic accessibility to the entire fibre wall. The holocellulose pulp had a somewhat larger pore volume than the kraft pulp. Refining of the holocellulose pulp led to pore closure, probably due to increased mobility of the fibre wall. The enzymatic treatment revealed that during hydrolysis of one hemicellulose, part of the other was also dissolved, indicating that the two hemicelluloses are to some extent linked to each other in the structure.
Molecular weight-functional group relations in softwood residual kraft lignins
Authors: Koda Keiichi , Koda Keiichi , Gaspar Armindo R. , Yu Liu , Yu Liu , Yu Liu , Argyropoulos Dimitris S.
Published: November 2005

An integrated picture of the distribution of functional groups should be provided as a function of molecular size within residual kraft lignins. With this goal we developed a reliable and reproducible method for determination of the molecular weight and molecular weight distribution of residual kraft lignins (RKLs) over the whole delignification range. In general, our data indicate that for reliable measurement of the molecular weight and its distribution of residual lignin in pulps, the lignin-carbohydrate bonds have to be cleaved prior to size exclusion chromatography. The recently developed method for isolating residual lignins, which involves cellulolytic treatment followed by a mild acid hydrolysis step, was found to be the most suitable approach to achieve this. The molecular weight and polydispersity of all RKLs decreased as a function of delignification. As anticipated, the observed decrease in molecular weight was clearly reflected in the concomitantly decreasing amount of β-O-4 structural linkages present. Similarly, the total phenolic hydroxyl content increased as the molecular weight of the RKLs decreased during kraft pulping. Despite the smaller size of the lignin remaining on the kraft fiber at the end of delignification, the preponderance of condensed phenolic structures within these lignins offers an explanation for delignification problems during bleaching.
Structure-activity relationships of cadinane-type sesquiterpene derivatives against wood-decay fungi
Authors: Wu Chi-Lin , Chien Shih-Chang , Wang Sheng-Yang , Kuo Yueh-Hsiung , Chang Shang-Tzen
Published: November 2005

Cadinane-type sesquiterpenes have a wide spectrum of biological activity, but their use as wood preservatives and the structure-activity relationships of their derivatives have not yet been reported. A total of 13 compounds were synthesized from T-cadinol, T-muurolol, and α-cadinol and their chemical structures were confirmed by IR, MS, and 1H and 13C NMR. The antifungal properties of 16 compounds against three wood-decay fungi were evaluated in vitro. α-Cadinol showed strong antifungal activity against Lenzites betulina, Trametes versicolor, and Laetiporus sulphureus (total mean IC50 0.10 mM). Among the derivatives synthesized, 3β-ethoxy-T-muurolol (0.24 mM), 4ξH-cadinan-10β-ol (0.25 mM), 4ξH-muurolan-10β-ol (0.29 mM), and 4ξH-cadinan-10α-ol (0.25 mM) showed good antifungal activity against all fungi tested. Correlation was observed between the antifungal activity of the compounds tested and log P. Furthermore, the presence of an unsaturated double bond and oxygen-containing functional groups in the compounds plays a key role in their antifungal activity. The stereo configuration of cadinane-type sesquiterpenes also influences their antifungal activity. Understanding how the structure of natural compounds relates to their antifungal function is important and may facilitate their application as novel wood preservatives.
Effect of water on wood liquefaction and the properties of phenolated wood
Authors: Lee Seung-Hwan , Wang Siqun
Published: November 2005

The effects of water on wood liquefaction were investigated under various reaction conditions: reaction temperature, time, and wood/phenol weight ratio. Although the addition of water decreased the reaction temperature and reduced the liquefaction rate and combined phenol content of the resulting phenolated wood, residue of <20% and a combined phenol content of >95% were obtained by controlling the reaction conditions. The addition of water suppressed an increase in the combined phenol content and molecular weight by a recondensation reaction observed in liquefaction in the absence of water under the same reaction conditions. Phenolated wood obtained in the presence of water showed comparable thermoflow properties and slightly higher activation energy for cure when compared with phenolated wood obtained in the absence of water. Moldings from both phenolated woods showed comparable flexural properties to those of moldings from commercial Novolak resin.
Effect of stress levels on compressive low-cycle fatigue behaviour of softwood
Authors: Gong Meng , Smith Ian
Published: November 2005

Low-cycle fatigue (LCF) of spruce under parallel-to-grain compression was investigated to simulate the damage that occurs during extreme events such as hurricanes. Load control was used, with peak stress levels of 75%, 85% and 95% of static compressive strength (Cmax). Changes in the residual cyclic modulus, cyclic creep strain and modified work density were correlated with the number of load cycles to assess their suitability as damage indicators. Creep tests were also carried out and the strain compared with cyclic creep strain under LCF load. Fatigue and creep tests had a total duration of 10 min. A three-element mathematical model was used to predict the cyclic creep strain. Some key findings were that: (1) the residual cyclic modulus varies with the number of load cycles at a given stress level and decreases with an increase in stress level; (2) cyclic creep strain and pure creep strain are strongly influenced by the peak stress level; and creep specimens fail but fatigue specimens do not at a 95% peak stress level; and (3) the three-element mathematical model is appropriate for predicting cyclic creep strain.
Comparison of morphological and chemical properties between juvenile wood and compression wood of loblolly pine
Authors: Yeh Ting-Feng , Goldfarb Barry , Chang Hou-min , Peszlen Ilona , Braun Jennifer L. , Kadla John F.
Published: November 2005

In conifers, juvenile wood (JW) is always associated with compression wood (CW). Due to their similar properties, there is a common belief that JW is the same as CW. To resolve whether JW is identical to CW, 24 rooted cuttings of one loblolly pine clone were planted in growth chambers under normal, artificial bending, and windy environments. The results show that the morphology of JW is significantly different from CW. Furthermore, chemical analyses revealed that JW and CW are significantly different in chemical composition. Our results indicate that JW is different from CW, and the wood formed under a controlled windy environment is a mild type of compression wood.
Ultrastructure of commercial recycled pulp fibers for the production of packaging paper
Authors: Brändström Jonas , Joseleau Jean-Paul , Cochaux Alain , Giraud-Telme Nathalie , Ruel Katia
Published: November 2005

Transmission electron microscopy was used to investigate the ultrastructure of recycled pulp fibers originating from a household collection plant and intended for the production of packaging paper. Three recovered paper grades and recycling processes, including pulping, screening, cleaning and refining, were assessed with emphasis on surface and internal fibrillation as well as xylan localization. Results showed a large heterogeneity with respect to fiber ultrastructure within and between the grades. Screening and cleaning steps had no detectable effects, but refining clearly increased cell-wall delamination and surface fibrillation. Immunolabeling of xylans showed that they were distributed rather evenly across the cell walls. They were also present on fines. Two different mechanisms for fiber delamination and surface fibrillation were found, one which implies that internal and external fibrillation take place simultaneously across the cell wall, and another which implies successive peeling of layers or sub-layers from the outside towards the inside. It is suggested that recycled fibers of chemical pulp origin undergo the former mechanism and recycled fibers that contain lignin binding the cell wall matrix give rise to the latter peeling mechanism. Because several recycled fibers were severely delaminated and almost fractured, we suggest that to produce a good packaging paper, it is important that recycled pulp should contain a significant proportion of fibers with high intrinsic strength.
Pine and spruce roundwood species classification using multivariate image analysis on bark
Authors: Nilsson David , Edlund Ulf
Published: November 2005

Wood discs from 67 pine and 79 spruce logs were collected from a forest clearing. Three different 24-bit red-green-blue (RGB) images were acquired from the radial surface of each disc. The first image contained bark, the second image was a mixture of bark and wood surface, and the third image consisted only of wood surface. The image texture was compressed into vectors of Fourier-transformed wavelet coefficients. These were assembled in matrices and analysed by principal component analysis (PCA) and partial least-squares projections to latent structures (PLS). Classification using Fourier-transformed wavelet scales showed that the wood species could be predicted with 90% accuracy. A thorough examination of this classification showed that the predicting power of these models was mostly due to wavelet scales that represented the mean value of each colour channel. The prediction accuracy that could be obtained from coefficients representing image texture was generally low. The use of grey-level co-occurrence matrices prior to the wavelet transformation showed, however, that it is possible to classify the wood species of pine and spruce with an accuracy approaching 100%.
Detection and species discrimination using rDNA T-RFLP for identification of wood decay fungi
Authors: Råberg Ulrika , Högberg Nils O.S. , Land Carl Johan
Published: November 2005

In the present work PCR technology was used as a tool to detect the early stages of wood decay and was compared with microscopic evaluation. The wood decay fungiPostia placentaandConiophora puteanawere detectable in interior wood samples by terminal restriction fragment length polymorphism (T-RFLP) after 2weeks of incubation with monocultures, while microscopic detection of hyphae was not possible until after 7 weeks. A potential problem when fungal communities are studied with T-RFLPs of rDNA is that intra-specific variation complicates data analysis. In this work, we show that intra-specific sequence variation in the internal transcribed spacer of the rDNA inConiophora puteanaallows T-RFLP identification of this species. This is due to intra-specific variations in fragment length, in combination with the absence of point mutations in the selected restriction sites.
Serotoninergic Modulation of Chloride Homeostasis during Maturation of the Locomotor Network in Zebrafish
Authors: Brustein Edna , Drapeau Pierre
Published: November 2005

During development, neural networks progress through important functional changes such as the generation of spontaneous activity, the expression of a depolarizing chloride gradient, and the appearance of neuromodulation. Little is known about how these processes are integrated to yield mature behaviors. We showed previously that, during the maturation of the locomotor network of the zebrafish, endogenous serotonin (5HT) increased motor activity by reducing intervals of inactivity, without affecting the active swim periods that are the target of 5HT in other and more mature preparations. Because membrane properties were constant during the rest intervals, we examined here whether 5HT modulates chloride homeostasis. We compared the effects of blocking (inward) chloride cotransport with bumetanide to the effects of 5HT and its antagonists, both behaviorally by video imaging and cellularly by whole-cell and gramicidin-perforated patch recordings. Bumetanide mimicked the effects of 5HT antagonists, by prolonging rest intervals without affecting the properties of swim episodes (duration; frequency; extent of depolarization) either behaviorally or during fictive swimming. Furthermore, bumetanide and 5HT antagonists suppressed the amplitude of depolarizing responses evoked by ionophoresis of glycine onto spinal neurons in the presence of tetrodotoxin and transiently suppressed the amplitude of responses to glycine measured after fictive swimming. The effects of bumetanide contrasted with and occluded the effects of 5HT. We suggest that, during development, endogenous 5HT modulates chloride homeostasis during the quiescent intervals and thereby offsets the long periods of quiescence commonly observed in developing networks to allow expression of sustained and behaviorally relevant activity.
Mitogen-Activated Protein Kinase-Mediated Reinforcement of Hippocampal Early Long-Term Depression by the Type IV-Specific Phosphodiesterase Inhibitor Rolipram and Its Effect on Synaptic Tagging
Authors: Navakkode Sheeja , Sajikumar Sreedharan , Frey Julietta Uta
Published: November 2005

Rolipram, a selective inhibitor of cAMP-specific phosphodiesterase 4 (PDE4), has been shown to reinforce an early form of long-term potentiation (LTP) to a long-lasting LTP (late LTP). Furthermore, it was shown that the effects of rolipram-mediated reinforcement of LTP interacts with processes of synaptic tagging (Navakkode et al., 2004). Here we show in CA1 hippocampal slices from adult ratsin vitrothat rolipram also converted an early form of long-term depression (LTD) that normally decays within 2-3 h, to a long-lasting LTD (late LTD) if rolipram was applied during LTD-induction. Rolipram-reinforced LTD (RLTD) was NMDA receptor- and protein synthesis-dependent. Furthermore, it was dependent on the synergistic coactivation of dopaminergic D1and D5receptors. This let us speculate that RLTD resembles electrically induced, conventional CA1 late LTD, which is characterized by heterosynaptic processes and synaptic tagging. We therefore asked whether synaptic tagging occurs during RLTD. We found that early LTD in an S1 synaptic input was transformed into late LTD if early LTD was induced in a second independent S2 synaptic pathway during the inhibition of PDE by rolipram, supporting the interaction of processes of synaptic tagging during RLTD. Furthermore, application of PD 98059 (2′-amino-3′-methoxyflavone) or U0126 (1,4-diamino-2,3-dicyano-1,4-bis[2-aminophenylthio]butadiene), specific inhibitors of mitogen-activated protein kinases (MAPKs), prevented RLTD, suggesting a pivotal role of MAPK activation for RLTD. This MAPK activation was triggered during RLTD by the synergistic interaction of NMDA receptor- and D1and D5receptor-mediated Rap/B-Raf pathways, but not by the Ras/Raf-1 pathway in adult hippocampal CA1 neurons, as shown by the use of the pathway-specific inhibitors manumycin (Ras/Raf-1) and lethal toxin 82 (Rap/B-Raf).
Stable Ensemble Performance with Single-Neuron Variability during Reaching Movements in Primates
Authors: Carmena Jose M. , Lebedev Mikhail A. , Henriquez Craig S. , Nicolelis Miguel A. L.
Published: November 2005

Significant variability in firing properties of individual neurons was observed while two monkeys, chronically implanted with multielectrode arrays in frontal and parietal cortical areas, performed a continuous arm movement task. Although the degree of correlation between the firing of single neurons and movement parameters was nonstationary, stable predictions of arm movements could be obtained from the activity of neuronal ensembles. This result adds support to the idea that movement parameters are redundantly encoded in the motor cortex, such that brain networks can achieve the same behavioral goals through different patterns and relative contribution of individual neuron activity. This has important implications for neural prosthetics, suggesting that accurate operation of a brain-machine interface requires recording from large neuronal ensembles to minimize the effect of variability and ensuring stable performance over long periods of time.
Binding of the Positron Emission Tomography Tracer Pittsburgh Compound-B Reflects the Amount of Amyloid-β in Alzheimer's Disease Brain But Not in Transgenic Mouse Brain
Authors: Klunk William E. , Lopresti Brian J. , Ikonomovic Milos D. , Lefterov Iliya M. , Koldamova Radosveta P. , Abrahamson Eric E. , Debnath Manik L. , Holt Daniel P. , Huang Guo-feng , Shao Li , DeKosky Steven T. , Price Julie C. , Mathis Chester A.
Published: November 2005

During the development ofin vivoamyloid imaging agents, an effort was made to use micro-positron emission tomography (PET) imaging in the presenilin-1 (PS1)/amyloid precursor protein (APP) transgenic mouse model of CNS amyloid deposition to screen new compounds and further study Pittsburgh Compound-B (PIB), a PET tracer that has been shown to be retained well in amyloid-containing areas of Alzheimer's disease (AD) brain. Unexpectedly, we saw no significant retention of PIB in this model even at 12 months of age when amyloid deposition in the PS1/APP mouse typically exceeds that seen in AD. This study describes a series ofex vivoand postmortemin vitrostudies designed to explain this low retention.Ex vivobrain pharmacokinetic studies confirmed the lowin vivoPIB retention observed in micro-PET experiments.In vitrobinding studies showed that PS1/APP brain tissue contained less than one high-affinity (Kd= 1-2 nm) PIB binding site per 1000 molecules of amyloid-β (Aβ), whereas AD brain contained >500 PIB binding sites per 1000 molecules of Aβ. Synthetic Aβ closely resembled PS1/APP brain in having less than one high-affinity PIB binding site per 1000 molecules of Aβ, although the characteristics of the few high-affinity PIB binding sites found on synthetic Aβ were very similar to those found in AD brain. We hypothesize that differences in the time course of deposition or tissue factors present during deposition lead to differences in secondary structure between Aβ deposited in AD brain and either synthetic Aβ or Aβ deposited in PS1/APP brain.
PBK/TOPK, a Proliferating Neural Progenitor-Specific Mitogen-Activated Protein Kinase Kinase
Authors: Dougherty J. D. , Garcia A. D. R. , Nakano I. , Livingstone M. , Norris B. , Polakiewicz R. , Wexler E. M. , Sofroniew M. V. , Kornblum H. I. , Geschwind D. H.
Published: November 2005

We performed genomic subtraction coupled to microarray-based gene expression profiling and identified the PDZ (postsynaptic density-95/Discs large/zona occludens-1)-binding kinase/T-LAK (lymphokine-activated killer T cell) cell originating protein kinase (PBK/TOPK) as a gene highly enriched in neural stem cell cultures. Previous studies have identified PBK/TOPK as a mitogen-activated protein kinase (MAPK) kinase that phosphorylated P38 MAPK but with no known expression or function in the nervous system. First, using a novel, bioinformatics-based approach to assess cross-correlation in large microarray datasets, we generated the hypothesis of a cell-cycle-related role for PBK/TOPK in neural cells. We then demonstrated that both PBK/TOPK and P38 are activated in a cell-cycle-dependant manner in neuronal progenitor cellsin vitro, and inhibition of this pathway disrupts progenitor proliferation and self-renewal, a core feature of progenitors.In vivo, PBK/TOPK is expressed in rapidly proliferating cells in the adult subependymal zone (SEZ) and early postnatal cerebellar external granular layer. Using an approach based on transgenically targeted ablation and lineage tracing in mice, we show that PBK/TOPK-positive cells in the SEZ are GFAP negative but arise from GFAP-positive neural stem cells during adult neurogenesis. Furthermore, ablation of the adult stem cell population leads to concomitant loss of PBK/TOPK-positive cells in the SEZ. Together, these studies demonstrate that PBK/TOPK is a marker for transiently amplifying neural progenitors in the SEZ. Additionally, they suggest that PBK/TOPK plays an important role in these progenitors, and further implicates the P38 MAPK pathway in general, as an important regulator of progenitor proliferation and self-renewal.