bluuebunny/crossref_metadata_2025 huggingface dataset:
Alterations in Antioxidant Enzyme Activities in Cerebrospinal Fluid Related with Severity of Hypoxic Ischemic Encephalopathy in Newborns
Authors: Gulcan Hande , Ozturk I.Cetin , Arslan Selda
Published: April 2005

Background: The antioxidant status of the tissue affected by ischemia-reperfusion is of great importance for the primary endogenous defense against the free-radical-induced injury. Objective: In this study, we aimed to evaluate the relationship between the activities of antioxidant enzymes [superoxide dismutase (SOD)[, ]glutathione peroxidase (GPX)[, ]and catalase (CAT)] in cerebrospinal fluid (CSF) and severity of hypoxic-ischemic encephalopathy (HIE) in newborns. Methods: Thirty full-term asphyxiated infants (gestational age >37 weeks) and 11 full-term infants (none of whom showed any signs of asphyxia) were included in this study. Activities of SOD, GPX, and CAT in CSF were measured within the first 72 h of life in infants with HIE and controls. Results: Activity of SOD in CSF was significantly higher in infants with HIE compared with controls (p<0.05). GPX and CAT activities were higher in infants with HIE than they were in controls; however, the differences were not statistically significant (p > 0.05). The activities of GPX and CAT were significantly increased in severe HIE as compared with mild HIE and controls (p < 0.05). Conclusion: Both the duration of the hypoxic-ischemic insult and the severity of HIE modulate elevations of enzymatic activity as an adaptive response to excessive free radical production in CSF in newborn infants with HIE. The activities of antioxidant enzyme alterations in CSF correspond highly to the severity of HIE, and these patterns may be useful for diagnostic and prognostic purposes.
Does Glucose Present in the Dialysate Limit Oxidative Stress in Patients Undergoing Regular Hemodialysis?
Authors: Bober Joanna , Kwiatkowska Ewa , Kedzierska Karolina , Olszewska Maria , Dolegowska Barbara , Domanski Leszek , Herdzik Edyta , Ciechanowski Kazimierz , Chlubek Dariusz
Published: April 2005

Background: Decreased glucose concentration in the blood causes the inhibition of the hexose monophosphate (HMP) cycle in the erythrocyte. NADPH, which is the source of the reductive equivalents necessary for the reproduction of glutathione (GSH), is not regenerated. The presence of glucose in dialysate should provide the stability of its concentration in the blood of patients undergoing hemodialysis (HD). The aim of the study was to assess the influence of glucose in the dialysate on the intensity of oxidative stress in patients undergoing regular HD. Methods: The study comprised 43 patients hemodialyzed with dialysate containing (HD-g(+)) or not containing glucose (HD-g(–)). The concentrations of the products of reaction with thiobarbituric acid-reactive substance (TBARS) and GSH as well as the activity of erythrocyte superoxide dismutase were determined. Glucose concentrations in the blood before and immediately after dialysis were also measured. Results: After flow-through dialysis the glucose concentration in the blood decreases both when dialysate does not contain glucose (4.8 vs. 1.6 mmol/l) and when dialysate contains glucose (6.6 vs. 5.8 mmol/l). HD caused changes in the TBARS concentration: in the HD-g(+) group the concentration decreased after HD, whereas in the HD-g(–) group it increased. In both groups of patients studied the GSH concentration changed after HD; in the HD-g(–) group it decreased and in the HD-g(+) group it increased. The results obtained in the groups of patients examined were confirmed by in vitro studies. Conclusions: The presence of glucose in the dialysate guarantees the normal activity of the HMP cycle, which provides the production of reductive equivalents for the regeneration of reduced GSH – free radicals scavenger – and therefore the limitation of oxidative stress.
"The Other ΛoΓoΣ" at the End of Heb. 4:13
Authors: Smillie Gene
Published: April 2005

The final usage of ı λóγoζ in Heb. 4:12-13, at the very end of the pericope, appears to be closely related to the better-known first occurrence of the term at the beginning of it. Many translations of the phrase πρòζ öv ημîv ı λóγoζ do not reflect this continuity of subject matter between the two instances of ı λóγoζ. While some translators opt for the commercial idiom, "to whom we must give account," study of that idiom throughout the NT shows that it is untenable. The second "word" is one of response, by the hearer, to the first word.
European Hoteliers’ Environmental Attitudes
Authors: Bohdanowicz Paulina
Published: April 2005

Although many hotels rely on the natural environment to attract guests, a survey of European hoteliers finds that environmental stewardship has taken a backseat to other operational concerns in many cases. Nevertheless, the surveyed hoteliers recognized that the hotel industry would do well to be more environmentally conscious. Managers in chain-affiliated hotels were generally more likely to pay attention to environmental issues than were independent operators, many of whom run small properties. The respondents noted that few hotel guests demand that hotels maintain environmental programs.
Exporting a North American Concept to Asia
Authors: Harrison Jeffrey S. , Chang Eun-Young , Gauthier Carina , Joerchel Todd , Nevarez Jorge , Wang Meng
Published: April 2005

In the past decade U.S.-based Starbucks has expanded internationally, including opening coffee shops in the People’s Republic of China. Still a tiny part of the Chinese beverage market, Starbucks hopes to trade on the growing popularity of Western brands among China’s growing middle class. By focusing its attention on its employees, Starbucks has created a strong service culture that fits well in China.
Persons with Disabilities
Authors: Gröschl Stefan
Published: April 2005

An exploratory study of fourteen Toronto hotels found that these hotels employ relatively few persons with disabilities. While responding human resources managers agree that hiring those with disabilities is a good practice, they noted numerous barriers to increased employment. Among the barriers is the fact that many people do not know how effective persons with disabilities can be in the hotel setting. Other barriers to be overcome are the lack of communication among employee groups and a failure of local employment agencies to work with hotels in placing persons with disabilities, as well as the physical layout of the hotels themselves. While the study is specific to Toronto, it seems reasonable to believe that the underlying causes of failure to employ persons with disabilities extend to other Canadian markets and, indeed, to other markets in North America.
Gram-Negative Resistance in the Intensive Care Unit
Authors: Patel Gourang P. , Crank Christopher W.
Published: April 2005

Gram-negative resistance is an increasingly important consideration when initiating empiric antimicrobial therapy in intensive care units. Infection with a resistant organism has been associated with increased morbidity and mortality as well as increased hospital cost. Gram-negative resistance in intensive care units will likely continue to increase. Clinicians must aggressively manage infections in the intensive care unit while practicing the appropriate steps to minimize future resistance. This review article summarizes the epidemiology, risk factors, mechanisms of resistance, and management of infections due to resistant gram-negative organisms.
The Effects of Continuous Renal Replacement on Anti-infective Therapy in the Critically Ill
Authors: Kubin Christine , Dzierba Amy
Published: April 2005

Acute renal failure represents a frequent, severe complication in critically ill patients leading to a direct increase in mortality and resource utilization. Today, continuous renal replacement therapy (CRRT) has replaced traditional hemodialysis, providing more precise fluid and metabolic control and decreased hemodynamic instability. There are a limited number of studies conducted for the ideal dosing of individual anti-infective agents for patients receiving CRRT. However, knowledge of the basic principles of CRRT, in conjunction with pharmacokinetics and pharmacodynamics of anti-infectives, allows sound dosing recommendations to be formulated to ensure maximal killing effects with minimal risk of toxicity in patients receiving CRRT.
Online/In-Store Integration and Customer Retention
Authors: Bendoly Elliot , Blocher James D. , Bretthauer Kurt M. , Krishnan Shanker , Venkataramanan M. A.
Published: April 2005

Reducing the risks believed to be associated with product availability can be critical to increasing consumer retention rates. This study considers the role that perceptions of channel integration have on such beliefs and their impact on purchasing decisions. Surveys distributed to purchasers of specific goods both online and in-store provide data used in the analysis of these effects. The findings suggest that firms simultaneously managing both online and in-store channels should not only reassess the repercussions of availability failures but also consider efforts that encourage the transparency of channel integration.
Silent Voices
Authors: Chebat Jean-Charles , Davidow Moshe , Codjovi Isabelle
Published: April 2005

Although noncomplaining dissatisfied consumers represent a vast majority of the dissatisfied consumers, they have not yet received adequate attention from marketing researchers. To understand the paradoxical combination of dissatisfaction and absence of complaint, the authors use the Lazarus cognitive-emotive model of coping with situational challenge. They added a moderator, the Seeking Redress Propensity (SRP) to this model and then developed a theoretical model and a set of hypotheses. A sample of consumers who had experienced a negative incident with the bank were administered a questionnaire by telephone. The sample was designed in such a way that half of them had complained and half had not. It was found that SRP is a significant moderator. In addition, SRP is shown to be strongly related to the likelihood of complaining. Lazarus’s model is basically supported, mostly for the customers scoring higher on SRP. Theoretical and managerial implications are proposed.
Service Product Configurations in Electronic Business-to-Consumer Operations
Authors: Heim Gregory R. , Sinha Kingshuk K.
Published: April 2005

The authors develop a taxonomy of electronic service products, defined as bundles of physical goods, offline services, and digital content. The taxonomy is founded on a conceptual classification scheme in the form of a 2 2 matrix—namely, the electronic service product structure—that differentiates electronic service products according to their digital content (either static or dynamic) and target market segment (either unique or broad). The cells of the matrix correspond to four categories of service products: niche market (static content-unique market), market extender (dynamic content-broad market), dynamic mass market (dynamic content-broad market), and customized megamarket (dynamic content-unique market). Two hypotheses are proposed that posit that the ordering of the service product categories in the sequence that was just stated will be positively associated with customer satisfaction and loyalty. The results of the empirical analysis of data from 255 electronic food retailers, the study sample, support the two hypotheses.
Early molecular response to posttransplantation imatinib determines outcome in MRD+ Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL)
Authors: Wassmann Barbara , Pfeifer Heike , Stadler Michael , Bornhaüser Martin , Bug Gesine , Scheuring Urban J. , Brück Patrick , Stelljes Matthias , Schwerdtfeger Rainer , Basara Nadezda , Perz Jolanta , Bunjes Donald , Ledderose Georg , Mahlberg Rolf , Binckebanck Anja , Gschaidmeier Harald , Hoelzer Dieter , Ottmann Oliver G.
Published: April 2005

In adult Philadelphia chromosome–positive acute lymphoblastic leukemia (Ph+ ALL), minimal residual disease (MRD) after stem cell transplantation (SCT) is associated with a relapse probability exceeding 90%. Starting imatinib in the setting of MRD may decrease this high relapse rate. In this prospective multicenter study, 27 Ph+ ALL patients received imatinib upon detection of MRD after SCT. Bcr-abl transcripts became undetectable in 14 (52%) of 27 patients, after a median of 1.5 months (0.9-3.7 months) (earlyCRmol). All patients who achieved an earlyCRmol remained in remission for the duration of imatinib treatment; 3 patients relapsed after imatinib was discontinued. Failure to achieve polymerase chain reaction (PCR) negativity shortly after starting imatinib predicted relapse, which occurred in 12 (92%) of 13 patients after a median of 3 months. Disease-free survival (DFS) in earlyCRmol patients is 91% ± 9% and 54% ± 21% after 12 and 24 months, respectively, compared with 8% ± 7% after 12 months in patients remaining MRD+ (P < .001). In conclusion, approximately half of patients with Ph+ ALL receiving imatinib for MRD positivity after SCT experience prolonged DFS, which can be anticipated by the rapid achievement of a molecular complete remission (CR). Continued detection of bcr-abl transcripts after 2 to 3 months on imatinib identifies patients who will ultimately experience relapse and in whom additional or alternative antileukemic treatment should be initiated.
A crucial role for reactive oxygen species in RANKL-induced osteoclast differentiation
Authors: Lee Na Kyung , Choi Young Geum , Baik Ji Youn , Han Song Yi , Jeong Dae-won , Bae Yun Soo , Kim Nacksung , Lee Soo Young
Published: April 2005

Signaling by receptor activator of NF-κB (nuclear factor-κB) ligand (RANKL) is essential for differentiation of bone marrow monocyte-macrophage lineage (BMM) cells into osteoclasts. Here, we show RANKL stimulation of BMM cells transiently increased the intracellular level of reactive oxygen species (ROS) through a signaling cascade involving TNF (tumor necrosis factor) receptor-associated factor (TRAF) 6, Rac1, and NADPH (nicotinamide adenine dinucleotide phosphate) oxidase (Nox) 1. A deficiency in TRAF6 or expression of a dominant-interfering mutant of TRAF6 blocks RANKL-mediated ROS production. Application of N-acetylcysteine (NAC) or blocking the activity of Nox, a protein leading to the formation of ROS, with diphenylene iodonium (DPI) inhibits the responses of BMM cells to RANKL, including ROS production, activation of c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein (MAP) kinase, and extracellular signal-regulated kinase (ERK), and osteoclast differentiation. Moreover, both RANKL-mediated ROS production and osteoclast differentiation were completely blocked in precursors depleted of Nox1 activity by RNA interference or by expressing a dominant-negative mutant of Rac1. Together, these results indicate that ROSs act as an intracellular signal mediator for osteoclast differentiation.
The Blood Pressure "Uncertainty Range" – a pragmatic approach to overcome current diagnostic uncertainties (II)
Authors: Pater Cornel
Published: April 2005

A tremendous amount of scientific evidence regarding the physiology and physiopathology of high blood pressure combined with a sophisticated therapeutic arsenal is at the disposal of the medical community to counteract the overall public health burden of hypertension. Ample evidence has also been gathered from a multitude of large-scale randomized trials indicating the beneficial effects of current treatment strategies in terms of reduced hypertension-related morbidity and mortality.

In spite of these impressive advances and, deeply disappointingly from a public health perspective, the real picture of hypertension management is overshadowed by widespread diagnostic inaccuracies (underdiagnosis, overdiagnosis) as well as by treatment failures generated by undertreatment, overtreatment, and misuse of medications.

The scientific, medical and patient communities as well as decision-makers worldwide are striving for greatest possible health gains from available resources.

A seemingly well-crystallised reasoning is that comprehensive strategic approaches must not only target hypertension as a pathological entity, but rather, take into account the wider environment in which hypertension is a major risk factor for cardiovascular disease carrying a great deal of our inheritance, and its interplay in the constellation of other, well-known, modifiable risk factors, i.e., attention is to be switched from one's "blood pressure level" to one's absolute cardiovascular risk and its determinants. Likewise, a risk/benefit assessment in each individual case is required in order to achieve best possible results.

Nevertheless, it is of paramount importance to insure generalizability of ABPM use in clinical practice with the aim of improving the accuracy of a first diagnosis for both individual treatment and clinical research purposes. Widespread adoption of the method requires quick adjustment of current guidelines, development of appropriate technology infrastructure and training of staff (i.e., education, decision support, and information systems for practitioners and patients). Progress can be achieved in a few years, or in the next 25 years.
Risk factors for fatal candidemia caused by Candida albicans and non-albicans Candida species
Authors: Cheng Ming-Fang , Yang Yun-Liang , Yao Tzy-Jyun , Lin Chin-Yu , Liu Jih-Shin , Tang Ran-Bin , Yu Kwok-Woon , Fan Yu-Hua , Hsieh Kai-Sheng , Ho Monto , Lo Hsiu-Jung
Published: April 2005

Background

Invasive fungal infections, such as candidemia, caused by Candida species have been increasing. Candidemia is not only associated with a high mortality (30% to 40%) but also extends the length of hospital stay and increases the costs of medical care. Sepsis caused by Candida species is clinically indistinguishable from bacterial infections. Although, the clinical presentations of the patients with candidemia caused by Candida albicans and non-albicans Candida species (NAC) are indistinguishable, the susceptibilities to antifungal agents of these species are different. In this study, we attempted to identify the risk factors for candidemia caused by C. albicans and NAC in the hope that this may guide initial empiric therapy.

Methods

A retrospective chart review was conducted during 1996 to 1999 at the Veterans General Hospital-Taipei.

Results

There were 130 fatal cases of candidemia, including 68 patients with C. albicans and 62 with NAC. Candidemia was the most likely cause of death in 55 of the 130 patients (42.3 %). There was no significant difference in the distribution of Candida species between those died of candidemia and those died of underlying conditions. Patients who had one of the following conditions were more likely to have C. albicans, age ≧ 65 years, immunosuppression accounted to prior use of steroids, leukocytosis, in the intensive care unit (ICU), and intravascular and urinary catheters. Patients who had undergone cancer chemotherapy often appeared less critically ill and were more likely to have NAC.

Conclusion

Clinical and epidemiological differences in the risk factors between candidemia caused by C. albicans and NAC may provide helpful clues to initiate empiric therapy for patients infected with C. albicans versus NAC.
First Dominique Dormont international conference on "Host-pathogen interactions in chronic infections – viral and host determinants of HCV, HCMV, and HIV infections"
Authors: Menu Elisabeth , Müller-Trutwin Mickaela C , Pancino Gianfranco , Saez-Cirion Asier , Bain Christine , Inchauspé Geneviève , Gras Gabriel S , Mabondzo Aloïse M , Samri Assia , Boutboul Françoise , Grand Roger Le
Published: April 2005

The first Dominique Dormont International Conference on "Viral and host determinantsof HCV, HCMV, and HIV infections "was held in Paris, Val-de-Grâce, on December 3–4, 2004. The following is a summary of the scientific sessions of this meeting (http://www.congres-evenement.fr/ddormont).
Social Cognition as a Mediator of the Influence of Family and Community Violence on Adolescent Development: Implications for Intervention
Authors: BRADSHAW CATHERINE P. , GARBARINO JAMES
Published: April 2005

Abstract:Several studies have shown that exposure to family and community violence during childhood and adolescence is associated with an increased risk for development of externalizing behavior problems, but less is known about specific mechanisms that mediate this relation. Variations in social cognition serve as one possible mechanism by which these environmental experiences influence aggressive behavior during adolescence. Children who have been maltreated tend to display negatively biased social‐cognitive processing styles, which may in turn increase their likelihood of reacting aggressively in ambiguous social situations. Similarly, witnessing community violence is associated with aspects of social cognition, including beliefs that support aggressive responses to threat. Recent studies also suggest that exposure to extreme forms of stress and violence can produce changes in children's neurobiology that may increase their hypersensitivity and reactivity to interpersonal threat. Some of the strongest evidence of the role of social cognition as a mechanism in this association comes from intervention studies which reduced aggressive behavior by targeting negatively biased social‐cognitive processing styles.
Escalated Aggressive Behavior: New Pharmacotherapeutic Approaches and Opportunities
Authors: MICZEK KLAUS A. , FACCIDOMO SARA , De ALMEIDA ROSA M. M. , BANNAI MAKOTO , FISH ERIC W. , DEBOLD JOSEPH F.
Published: April 2005

Abstract: Psychopharmacologic studies of aggressive behavior in animals under controlled laboratory conditions have been instrumental in developing and evaluating specific and effective novel drug treatments that reduce aggressive behavior. An initial contribution of this research is to create experimental conditions that enable the display of aggressive and defensive acts and postures in species that engage in either dominance or territorial or maternal aggression. Quantitative ethological analyses allow the precise delineation of the sequential organization of aggressive bursts, providing a benchmark for assessing excessive or pathological forms of aggressive behavior. A second contribution of preclinical research is the development of experimental models of escalated forms of aggressive behavior, such as focusing on genetic predispositions or social provocations and frustrative experiences. A critical role of preclinical research is in the pharmacological and neurochemical analysis of aggressive behavior; for example, a host of undesirable side effects prompted a shift from classic dopaminergic neuroleptic compounds to the more recently developed atypical neuroleptics with effective and more specific anti‐aggressive effects. The long‐established role of brain serotonin in impulsive and escalated forms of aggressive behavior continues to be a focus of preclinical studies. New evidence differentiates dynamic state changes in corticolimbic serotonergic neurons during the termination of aggressive behavior from the deficient‐serotonin trait in violence‐prone individuals. It can be anticipated that currently developed tools for targeting the genes that code for specific subtypes of serotonin receptors will offer new therapeutic options for reducing aggressive behavior, and the 5‐HT1B receptor appears to be a promising target. The modulation of GABA and GABAA receptors by 5‐HT in corticolimbic neurons promises to be particularly relevant for specific forms of escalated aggressive behavior such as alcohol‐heightened aggression.
Catecholamines and Aggression: The Role of COMT and MAO Polymorphisms
Authors: VOLAVKA JAN , BILDER ROBERT , NOLAN KAREN
Published: April 2005

Abstract:Catecholaminergic systems are involved in the regulation of aggressive behavior; this regulation is implemented in interactions with other neurobiological mechanisms. Most of the available evidence indicates that norepinephrine and dopamine lower the threshold for an aggressive response to environmental stimuli. Two major enzymes are responsible for catecholamine catabolism in the brain: catechol‐O‐methyltransferase (COMT) and monoamine oxidase A (MAOA). The transcriptional activity of the genes coding for these enzymes is governed by common functional polymorphisms. If aggressive behavior is enhanced by catecholaminergic activity, then the lower activity of COMT and MAOA (resulting in a slower inactivation of catecholamines) should indirectly enhance aggression. This prediction has been supported by most (but not all) observations in rodents and humans. Male mice that have either the COMT or the MAOA gene knocked out show elevated aggression. The allele that codes for the lower enzymatic activity of COMT has been associated with elevated aggressive behavior in several samples of psychiatric patients. Similarly, the alleles that code for the lower activity of MAOA were associated with the development of aggressive behavior in maltreated male children in a large birth cohort study. Collectively, these results suggest that COMT and MAOA polymorphisms represent a basic neurobiological mechanism that contributes to the regulation of aggressive behavior.
Beyond the Prison Paradigm: From Provoking Violence to Preventing It by Creating “Anti‐Prisons” (Residential Colleges and Therapeutic Communities)
Authors: GILLIGAN JAMES , LEE BANDY
Published: April 2005

Abstract:Prisons were supposedly created for the purpose of the tertiary prevention of violence (i.e., reducing the frequency and severity of future violence on the part of people who have already become violent). However, there is much evidence that this method of attempting to prevent violence is often, though not always, either ineffectual or counterproductive, in which case it is either a waste of money or actually exacerbates the problem it was ostensibly intended to solve. This article reviews evidence concerning those questions including an analysis of the effect of punishment (one of the main purposes of prisons) on violent behavior. Punishment—the infliction of pain—will be distinguished from restraint (incapacitation, separation from the community). Successful examples of violence prevention in unconventional prison programs, emphasizing therapy and education rather than punishment, and restorative rather than retributive justice, will be summarized, together with evidence that these programs reduce re‐incarceration rates so substantially that they actually save the taxpayers more money than they cost, in addition to enhancing the safety of the general public. The position is taken that traditional prisons provoke more violence than they prevent and are so fundamentally flawed that they cannot be reformed; we argue that they should instead be abolished and replaced by “anti‐prisons,” that is, locked, secure residential colleges, therapeutic communities, and centers for human development. Prisons will come to be seen as a well‐meaning experiment that failed, rather like the use of leeches in medicine.
Single Cell Array of Biotinylated Cells Using Surface Functionalization and Microcontact Printing
Authors: Lee Zee-Won , Lee Kyung-Bok , Hong Jang-Hee , Kim Jae-Hong , Choi Inpyo , Choi Insung S
Published: April 2005

This paper describes a versatile method for generating single cell arrays on a glass substrate, which could be applicable to any arbitrary cell types, by a combination of surface functionalization, biotinylation of cells, and microcontact printing (μCP).
Detection and Identification of Cations and Anions of Ionic Liquids by Means of Electrospray Ionization Mass Spectrometry and Tandem Mass Spectrometry
Authors: Milman Boris L. , Alfassi Zeev B.
Published: April 2005

Electrospray ionization (ESI) and collision-induced dissociation (CID) spectra of nine ionic liquids have been measured. The main fragmentations of most of these ionic liquid cations were due to the loss of a butene molecule. In contrast to tetraalkylammonium ions, CID spectra of aromatic cations may represent insufficient information for unambiguous identification due to their only partial fragmentation. CID spectra of ionic liquid anions, however, allowed their reliable recognition, since isomers/isobars of such inorganic species are rare. Detection limits of cations and anions in a mixture of different ionic liquids seemed to depend on their surface activity as determined by the hydrophobicity of these species.
Comparison of a + T-Rich Oligonucleotides with and without Self-Complementary Sequence Using Ion-Pair Reversed-Phase High-Performance Liquid Chromatography/Tandem Electrospray Ionization Mass Spectrometry
Authors: Song Renfang , Zhang Wenbing , Chen Huayong , Ma Huimin , Dong Yulian , Sheng Guoying , Zhou Zhen , Fua Jiamo
Published: April 2005

Both A + T-rich oligonucleotides with and without self-complementary sequences were analyzed using ion-pair reversed-phase liquid chromatography/electrospray ionization mass spectrometry (IP-RP-HPLC/ESI-MS) by tryethylammonium acetate (TEAA) and hexafluoroisopropanol (HFIP) buffer systems to study the characteristics of their retention behavior and electrospray ionization tandem mass spectrometry (ESI-MS/MS) response. The results indicated that the chain length had the same effect on the retention of A + T-rich oligonucleotides in both of TEAA and HFIP buffer systems but the sequence had a different impact on the retention in the two buffer systems. A + T-rich oligonucleotides with a self-complementary sequence were much shorter than those without in the TEAA buffer system whereas a slight difference was observed in the HFIP buffer system. Similar total ion current (TIC) intensity was observed both in oligonucleotides with or without self-complementary sequence. The opposite trend of a change in the TIC intensities with increasing chain length were observed in both the TEAA and HFIP buffer systems. A lower charge state was predominant in the TEAA buffer system whereas a higher charge state was mainly distributed in the HFIP buffer system. The oligonucleotides without self-complementary sequences had a higher charge state than those with self-complementary sequences. A- and T- are more esily formed at a higher charge state whereas the sequence fragments will be formed more easily at a lower charge state in both A + T-rich oligonucleotides with and without self-complementary sequences.
Current Trends in Matrix-Assisted Laser Desorption/Ionization of Polymeric Materials
Authors: Montaudo Giorgio , Samperi Filippo , Montaudo Maurizio S. , Carroccio Sabrina , Puglisi Concetto
Published: April 2005

In the last few years, mass spectrometry has rapidly become indispensable in polymer analysis and complements, in many ways, the structural data provided by nuclear magnetic resonance. Mass spectrometry of polymers is emerging as a revolutionary technique, capable of challenging the techniques and protocols established for years for the characterization of synthetic polymers. Matrix-assisted laser desorption/ionization (MALDI) has become a widely applied method for the structural characterization of synthetic polymers. The primary aim of this review is to illustrate some recent advances in the study of macromolecular systems by MALDI. MALDI allows the identification of repeat units and end groups, the structural analysis of linear and cyclic oligomers and the estimate of composition and sequence for co-polymers. MALDI is also quite useful for the measurement of molar mass and bivariate distributions in polymers and for the detection of self-association in macromolecules, performed by coupling MALDI with size exclusion chromatography (SEC). Recently MALDI has been applied, with remarkable success, to the study of thermal and oxidative processes in polymers and to the characterization of co-polymers obtained by reactive polymer blending. Selected applications of MALDI to polymers are illustrated herewith.
Fragmentation of Trimethoprim and other Compounds Containing Alkoxy-Phenyl Groups in Electrospray Ionisation Tandem Mass Spectrometry
Authors: Eckers Christine , Monaghan John J. , Wolff Jean-Claude
Published: April 2005

This work describes electrospray ionisation tandem mass spectrometry studies of trimethoprim and a series of structurally similar compounds containing alkoxy-phenyl groups, using accurate mass measurement to confirm the proposed fragmentations. Radical cations were observed in the spectra obtained for some of the compounds, as well as uncommon fragmentations showing losses of CH4 and C2H6, whereas other compounds showed the formation of even electron ions. Possible structures for the fragment ions have been proposed and explanations for the different types of fragmentation based on the structures of the compounds. In addition an alternate structure for a fragment ion previously reported for tandem mass spectrometry of trimethoprim has been proposed, based on accurate mass measurement.
Electrospray Ionisation Mass Spectrometry of Pyrimidine Base—Rubidium Complexes
Authors: Frańska Magdalena
Published: April 2005

Nucleobases and alkali metal cations, under electrospray ionisation conditions, tend to form the so-called magic number clusters (unusually stable clusters in comparison with the neighbouring ones). The effect of the ion source parameters, namely cone voltage and desolvation temperature and relative concentrations of thymine and RbCl on the [T5 + Rb]+ ion abundance has been studied.
Search and Collusion in Electronic Markets
Authors: Campbell Colin , Ray Gautam , Muhanna Waleed A.
Published: April 2005

We examine the impact of reduced search costs on prices of commodity products in electronic marketplaces. Conventionally, reduced consumer search costs may be expected to engender stronger price competition between firms, resulting in lower prices and improved consumer welfare. This notion was formalized in Stahl (1989, “Oligopolistic pricing with sequential consumer search,” American Economic Review, Vol. 79, No. 4, pp. 700–712) in a model of static firm competition. In this paper, we show that these standard welfare conclusions may be neutralized or reversed in a dynamic environment. We focus on self-enforcing collusion by firms and characterize the conditions under which collusive equilibria exist. We show that less costly consumer search can facilitate firms' abilities to collude, resulting in higher prices and reduced consumer welfare, even with imperfect or no monitoring by sellers of each other's prices. If the same technology that eases consumer search also allows firms to monitor each other's prices more easily, then firms can more easily detect cheating on a collusive price arrangement, allowing an even greater scope for collusion. This raises antitrust concerns with respect to the electronic marketplace and suggests that at least some of the anticipated competitive gains from electronic market systems may be difficult to realize.
Competing Across Technology-Differentiated Channels: The Impact of Network Externalities and Switching Costs
Authors: Viswanathan Siva
Published: April 2005

Technology-driven commerce channels, such as the Web, possess several unique features that differentiate them from traditional channels. The interaction between firms operating across these differentiated channels involves interesting competitive dynamics that cannot be captured by isolated models of electronic markets. This paper develops a stylized spatial differentiation model to examine the impact of differences in channel flexibility, network externalities, and switching costs on competition between online, traditional, and hybrid firms. A basic model highlighting the moderating influence of the hybrid firm on both channels is extended to account for differential network externalities and switching costs across the two channels. Our analysis indicates that while network effects as well as switching costs lead to the tipping of markets, such tipping occurs primarily due to the moderating effects of the competing channel. More importantly, with network effects an increased market share does not translate into higher profits. Contradictory to conventional wisdom, our results indicate that in a static market, consumers rather than firms, benefit from increasing network externalities, with competitive effects outweighing the surplus-extraction abilities of firms. Our results also highlight the importance of alternative revenue streams and provide insights for firms grappling with issues of channel choice as well as integration and divestiture.
Models for Iterative Multiattribute Procurement Auctions
Authors: Parkes David C. , Kalagnanam Jayant
Published: April 2005

Multiattribute auctions extend traditional auction settings to allow negotiation over nonprice attributes such as weight, color, and terms of delivery, in addition to price and promise to improve market efficiency in markets with configurable goods.

This paper provides an iterative auction design for an important special case of the multiattribute allocation problem with special (preferential independent) additive structure on the buyer value and seller costs. Auction Additive&Discrete provides a refined design for a price-based auction in which the price feedback decomposes to an additive part with a price for each attribute and an aggregate part that appears as a price discount for each supplier. In addition, this design also has excellent information revelation properties that are validated through computational experiments. The auction terminates with an outcome of a modified Vickrey-Clarke-Groves mechanism. This paper also develops Auction NonLinear&Discrete for the more general nonlinear case—a particularly simple design that solves the general multiattribute allocation problem, but requires that the auctioneer maintains prices on bundles of attribute levels.
Measuring Item Fill-Rate Performance in a Finite Horizon
Authors: Thomas Douglas J.
Published: April 2005

The standard treatment of fill rate relies on stationary and serially independent demand over an infinite horizon. Even if demand is stationary, managers are held accountable for performance over a finite horizon. In a finite horizon, the fill rate is a random variable. Studying the distribution is relevant because a vendor may be subject to financial penalty if she fails to achieve her target fill rate over a specified finite period. It is known that for a zero lead time, base-stock model, the expected value of a finite-horizon fill rate exceeds the long-run fill rate. In this paper, I investigate the behavior of the distribution of the finite-horizon fill rate when a stationary base-stock policy is used to control inventory. For a vendor facing a finite-horizon, fill-rate-level contract and using a stationary stocking policy, I examine how the the length of the review horizon (i.e., monthly or quarterly), the demand distribution, and the cost of failing to meet the target affect the stocking decision.
WiKo – Eine integrierte Wissens- und Kooperations-Plattform (WiKo – An Integrated Knowledge and Cooperation Platform)
Authors: Fuchs-Kittowski Frank , Faust Daniel , Loroff Claudia , Reuter Patrick
Published: April 2005

Zur Unterstützung von Wissensarbeitern wird eine innovative Wissens- und Kooperations-Plattform (WiKo) für ein interaktionsorientiertes Wissensmanagement vorgestellt. Diese verbindet die Wissensbereitstellung und die Wissenserzeugung zu einem zyklischen Prozess, so dass einerseits das Wissen der Organisation durch den einzelnen Wissensarbeiter genutzt und andererseits darauf aufbauend neues Wissen in einem sozialen, kooperativen Prozess erzeugt werden kann, welches wiederum für die Organisation, die Gruppe und den Einzelnen verfügbar wird. Es wurde eine Web-basierte Plattform konzipiert, implementiert und exemplarisch erprobt, die einerseits Softwarebausteine für die verschiedenen Strategien des Wissensmanagements zur Wissensbereitstellung und -bewahrung sowie andererseits Werkzeuge für verschiedene Formen kooperativer Wissenserzeugung integriert und diese miteinander verbindet.
ContextDrive – Individuelles Informationsmanagement für das Ubiquitous Computing (ContextDrive – Personal Information Management for Ubiquitous Computing)
Authors: Prante Thorsten , Petrovic Kostanija , Stenzel Richard
Published: April 2005

In diesem Beitrag wird das ContextDrive vorgestellt, ein kontext-bewusstes System, das Benutzer in Ubiquitous-Computing Umgebungen beim Rückgriff auf Informationen im Rahmen der Wiederaufnahme von Aufgaben oder allgemein bei der Wiederbenutzung von Informationen unterstützt. Dazu wird werkzeug- und geräteübergreifend hybrider Nutzungskontext protokolliert. Die so aufgebaute Kontexthistorie ist die Basis für den zusammenführenden Rückgriff auf zuvor benutzte Informationen. Dies wird anhand einer zeitorientierten Benutzungsoberfläche und mit Aufgabenkarten exemplarisch gezeigt. Bei dem vorliegenden Artikel handelt es sich um eine aktualisierte und erweiterte Version des Beitrags auf der Mensch-und-Computer-Tagung 2004, der den zweiten Platz im Wettbewerb um den Best-Paper-Award erzielen konnte.
The Extension of the Stability Range of the Reconstructed Au(111) Surface by Propanal
Authors: Skołuda Piotr
Published: April 2005

The impact of propanal on the stability range of the reconstructed Au(111) surface has been investigated by cyclic voltammetry and capacity measurements. The results show that propanal extends the stability of the Au(111) in a larger range than that of Au(100) surface.
Theoretical Study of the Electronically Excited States of B4, B4
+ and B4
−
Authors: Gillery Claire , Linguerri Roberto , Rosmus Pavel , Maier John P.
Published: April 2005

First-principle full valence complete active space calculations (CASSCF) are reported for the electronic states of the D2

h
and C2

v
planar isomers of B4, B4
+ and B4
−. This approach is found to reproduce well the experimentally known transition energies for the two lowest excited triplet states of the most stable rhombic B4 isomer. The pattern of electronic transitions up to about 4.5 eV for B4 singlet and B4
+ doublet states calculated in similar way should guide an UV spectroscopic search.
High prevalence of cyclooxygenase 2 expression in papillary thyroid carcinoma
Authors: Lo Chung-Yau , Lam Kin-Yin , Leung Pauline P , Luk John M
Published: April 2005

Background: Cyclooxygenase-2 (COX-2) seems to play a role in the development and carcinogenesis of papillary thyroid carcinoma. Its incidence of expression and potential application as a tumor marker remain to be elucidated.

Materials and methods: Immunohistochemical staining for COX-2 expression was performed for 30 papillary thyroid carcinoma (PTC) and 40 benign thyroid specimens. COX-2 mRNA expression was analyzed using a reverse transcriptase-polymerase chain reaction (RT-PCR) for paired fresh frozen tissues removed from surgically resected PTC specimens.

Results: COX-2 expression was detected by immunohistochemistry in 27 of 30 (90%) PTC but was absent in 40 benign thyroid specimens, including 27 nodular hyperplasia, 7 follicular adenoma and 6 lymphocytic thyroiditis. Two of the three COX-2 negative carcinomas were follicular variant of PTC. RT-PCR analysis confirmed COX-2 mRNA over-expression in 14 of 20 (70%) paired specimens of PTC. Real-time quantitative RT-PCR showed that the level of COX-2 mRNA expression was significantly higher in PTC than in both the adjacent non-cancerous tissues and the benign thyroid specimens.

Conclusion: COX-2 is frequently expressed in PTC but not in benign thyroid specimens. COX-2 expression may serve as a useful molecular marker for PTC in cases of diagnostic difficulty.
Tools for Visualizing Multidimensional Images from Living Specimens
Authors: Eliceiri Kevin W. , Rueden Curtis
Published: April 2005

Over the last 50 years modern cell biology has been driven by the development of powerful imaging techniques. In particular, new developments in light microscopy that provide the potential to image the dynamics of biological events have had significant impact. Optical sectioning techniques allow three‐dimensional information to be obtained from living specimens noninvasively. When used with multimodal fluorescence microscopy, advanced optical sectioning techniques provide multidimensional image data that can reveal information not only about the changing cytoarchitecture of a cell but also about its physiology. These additional dimensions of information, although providing powerful tools, also pose significant visualization challenges to the investigator. Particularly in the current postgenomic era there is a greater need than ever for the development of effective tools for image visualization and management. In this review we discuss the visualization challenges presented by multidimensional imaging and describe three open‐source software programs being developed to help address these challenges: Image J, the Open Microscopy Environment, and VisBio.
Pit-1β reduces transcription and CREB-binding protein recruitment in a DNA context-dependent manner
Authors: Ferry A L , Locasto D M , Meszaros L B , Bailey J C , Jonsen M D , Brodsky K , Hoon C J , Gutierrez-Hartmann A , Diamond S E
Published: April 2005

Many transcription factors are expressed as multiple isoforms with distinct effects on the regulation of gene expression, and the functional consequences of structural differences between transcription factor isoforms may allow for precise control of gene expression. The pituitary transcription factor isoforms Pit-1 and Pit-1β differentially regulate anterior pituitary hormone gene expression. Pit-1 is required for the development of and appropriate hormone expression by anterior pituitary somatotrophs and lactotrophs. Pit-1β differs structurally from Pit-1 by the splice-insertion of the 26-residue β-domain in the trans-activation domain, and it differs functionally from Pit-1 in that it represses expression of the prolactin promoter in a cell-type specific manner. In order to identify signal and promoter context requirements for repression by Pit-1β, we examined its function in the presence of physiological regulatory signals as well as wild-type and mutant Pit-1-dependent target promoters. Here, we demonstrate that Pit-1β impairs recruitment of cAMP response element-binding protein (CREB)-binding protein to the promoters that it represses. In addition, we show that repression of target promoter activity, reduction in promoter histone acetylation, and decrease of CREB-binding protein recruitment all depend on promoter context. These findings provide a mechanism for promoter-specific repression by Pit-1β.
Interdependence of oestrogen and insulin-like growth factor-I in the brain: potential for analysing neuroprotective mechanisms
Authors: Mendez Pablo , Azcoitia Iñigo , Garcia-Segura Luis Miguel
Published: April 2005

The actions of oestradiol in the brain involve interaction with growth factors, such as insulin-like growth factor-I (IGF-I). Many cells in the brain co-express receptors for oestradiol and IGF-I and both factors interact to regulate neural function. The relationship of oestrogen receptor α with IGF-I receptor through the mitogen-activated protein kinase and the phosphoinositide 3-kinase signalling pathways may represent the point of convergence used by these two factors to cooperatively modulate neuritic growth, synaptic plasticity, neuroendocrine events, reproductive behaviour and neuronal survival. In addition, Akt and glycogen synthase kinase 3β are key molecular targets to explain the interaction of oestrogen and IGF-I receptor signalling in the promotion of neuroprotection.