bluuebunny/crossref_metadata_2025_split huggingface dataset:
Introduction of Surface Functional Groups onto Biomaterials by Glow Discharges
Authors: Sharma Chandra P. , Jayasree G. , Najeeb P.P. 
Published: January 2008

An attempt was made to graft the monomer HEMA to the polymer surface by "Glow discharge" technique. Experiments were carried out for different surfaces varying the exposure times of samples to HEMA and also as a function of glow discharge time. It was found that as the percentage of grafting increases the hydrophilicity also increases. Contact angle measurements were performed on these substrates, which confirmed the hydrophilic nature of the grafted samples compared to the controls. The role of protein adsorption and their effects to modulate the blood polymer interaction is briefly discussed. When a foreign material comes in contact with blood, the initial event is the adsorption of plasma proteins in parallel with the adhesion of platelets to the material. Albuminated surfaces discourage platelet adhesion while fibrinogen enhances the platelet attachment and thrombosis. Hence a decreased ratio of fibrinogen to albumin on a substrate can be correlated as an indication to its improved blood compatibility. Fibrinogen to albumin ratios of the grafted samples showed a reduction, indicating that albumin adsorption is high; which may make the modified surfaces non-thrombogenic.
Antithrombogenic Heparin-Bound Polyurethanes
Authors: Ito Y. 
Published: January 2008

Many kinds of heparin-bound polyurethanes have been developed. Polyurethanes are a family of elastomers displaying better blood-compatibility than other polymeric materials. It is useful to modify this material by heparinization. Several approaches to heparinization have been devised: 1) a general method of heparinization, applicable to all polymeric materials, 2) a heparinization method specific to polyurethanes, and 3) the design of heparinizable polyurethane derivatives. These three approaches are first explained in detail. Then, the antithrombogenic mechanism of the heparinized polymers is discussed. Finally, the interactions of the heparinized polymers with blood coagulation factors, plasma proteins, and platelets are discussed.
Biomaterials Entrepreneurship
Authors: Ellis Jeffrey R. 
Published: January 2008

Entrepreneurial companies in biomaterials serve a valuable function in lowering the risk of developing new products and devices. In many cases liability considerations and a pragmatic conservatism make it difficult for established health-care products suppliers to develop new products directly. Biomaterials entrepreneurs encounter more difficulties in achieving commercial success than do entrepreneurs in other fields. For any reasonable profit to be made, the entrepeneur must be able to convert the biomaterial into a useful device. Safety and toxicity test data collection take a minimum of three years to collect, and it is often five or more years before a positive cash flow can be obtained. Start-up funding can be obtained from government agencies, charitable foundations, and private investment capital. A major health-care company can often be attracted once initial successes have been achieved. Biomaterials usage and device design is specific for each function or need. Specific devices that are currently needed are small (c. 4 mm) diameter artificial blood vessels, synthetic skin, and internal prosthetic devices which have better tissue compatibility, abrasion, corrosion, and wear resistance especially for flexing devices such as artificial joints, ligaments and tendons.
Factors and Interactions Affecting the Performance of Polyurethane Elastomers in Medical Devices
Authors: Coury Arthur J. , Slaikeu Paul C. , Cahalan Patrick T. , Stokes Kenneth B. , Hobot Christopher M. 
Published: January 2008

Polyurethanes offer the greatest versatility in compositions and properties of any family of polymers. For implantable medical devices, a few specific elastomeric polyurethane compositions have demonstrated a combination of toughness, durability, biocompatibility and biostability not achieved by any other available material. Because of the complex behavior of implantable polyurethanes in the body environment, designers and fabricators of polyurethane-containing devices must pay particular attention to the choice of composition and design of components. Subsequent treatment during qualification, fabrication, sterilization, storage, implantation, in vivo operation and explantation also determine the performance and provide the means for assessing the efficacy of the polyurethane in the implanted device.
Bacterial Polymers: Physicochemical Aspects of Their Interactions at Interfaces
Authors: Neu Thomas R. , Marshall Kevin C. 
Published: January 2008

How do bacteria stick to a surface? There is still not enough information about to answer this question especially at the molecular level. This question only gives rise to more questions. What is the structure of the true adhesive bacterial polymer? Is only one bacterial polymer or several polymers involved in the adhesion process? What is the role of proteins associated with the bacterial polysaccharides? What type of polymer is produced for the adhesion to hydrophobic surfaces? Is the polymer produced as a response to the surface ? This review is an attempt to summarize the physicochemical aspects of bacterial polymers and their interaction with surfaces. It was tried to give an overview of the literature published in this field. The article is divided into the following sections: first, the forces involved in bacterial adhesion are described. Second, the theoretical approaches to bacterial adhesion are discussed. Third, different fluid conditions are investigated. Fourth, the nature of different bacterial polymers which are important for the interaction with a surface is elaborated. Fifth, the current knowledge about biological polymers at interfaces is shown. And sixth, the role of polymers in the adhesion of bacteria available to date is highlighted.
Surface Proteins of Coagulase-Negative Staphylococci: Their Role in Adherence to Biomaterials and in Opsonization
Authors: Fleer A. , Timmerman C.P. , Besnier J.M. , Pascual A. , Verhoef J. 
Published: January 2008

During the last decade coagulase-negative staphylococci (CN-Staph) have clearly emerged as pathogens in patients equipped with foreign devices. This has fuelled the interest in these bacteria considerably and as a result, knowledge of the biology of CN-Staph as well as insight into the pathogenesis of biomaterial-associated infections due to these bacteria are rapidly expanding. Adherence of bacteria to biomaterials is a necessary step in the process of these infections. Evidence is accumulating that surface proteins of CN-Staph are essential in the early phases of adherence to biomaterials. By using monoclonal antibodies in immunoblotting and immune electron micrography we have identified a cell wall protein complex apparently located on the surface of CN-Staph and involved in adherence to biomaterials. Further studies will be oriented at characterization of the protein adhesin(s) and at identification of the surface structures with which the adhesion is associated.
Phenyl Alanine, Tryptophan Immobilized Chitosan Beads as Adsorbents for Selective Removal of Immunoproteins
Authors: Beena M.S. , Chandy Thomas , Sharma Chandra P. 
Published: January 2008

The use of adsorbents for the treatment of patients suffering from various immune diseases is still in its infancy. Therefore, the development of selective adsorbents for the removal or decrease of immunoproteins from plasma is of great importance. In this study, chitosan, a natural polysaccharide having structural characteristics similar to glycosamino glycans, which is non-toxic and biocompatible, has been used for protein adsorption studies. Amino acids like phenyl alanine and tryptophan in different ratios are bonded to these polymers to observe immunoadsorption. Several layers of phenyl alanine or tryptophan have been coated covalently on chitosan beads using N2-plasma, carbodiimide or glutaraldehyde treatments. Scanning electron micrographs have revealed the surface morphological changes after such modifications. The surface modified chitosan beads have exhibited high binding affinity for γ-globulin compared to bare beads. It is also observed that the amount of fibrinogen adsorption is reduced on modified substrate. A selective removal of IgG and IgM has also been observed with these modified matrix when tested with human plasma, using immuno diffusion methods. The modified chitosan membranes have demonstrated a reduction in platelet attachment, showing that these substrates have become more blood compatible. Hence, it appears that modified chitosan surfaces may be an excellent sorbent system for haemoperfusion due to their high binding affinity for immunoproteins and blood compatibility. Further studies are needed to determine the behaviour under clinical conditions.
Department Store Apparel Buyers: Relationships Among Environmental Characteristics, Environmental Uncertainty, Boundary Spanning Activities, Managerial Discretion and Power
Authors: Lazorchak Shirley A. , O'Neal Gwendolyn S. 
Published: January 2008

The purpose of the study was to explore the relationships among environmental characteristics, uncertainty, boundary spanning activities, managerial discretion, and power of the department store apparel buyer who assumes combination or independent buyer responsibilities. Almubarek's Model of Organizational Boundary Spanning and Duncan's (1972) Model of Environmental Uncertainty were used as conceptual frameworks. A questionnaire was mailed to buyers who purchased merchandise in the moderate-to-better sportswear areas in the top 10 department store groups in the United States. The results generated support for the nature of relationships found among the variables in Almubarek's Model: a complex, dynamic environment leads to environmental uncertainty and perceptions of uncertainty trigger the use of boundary spanning activities which enhances the power of the buyer. In addition, the placement of apparel retailers within Duncan's (1972) Model should be revised to reflect a highly uncertain environment.
Probability of Being Employed Part-Time in Retail Sales
Authors: Domina Tanya , Paek Soae , Pritchard Mary , McGrath Paul 
Published: January 2008

Since 1980 the percentage of the workforce engaged in part-time employment has increased, attributed to increase in service and retail industries and changing attitudes and lifestyles of workers. The purpose of the present study was to determine characteristics associated with choosing part-time employment in retail sales occupations. The data set was the 1985 Current Population Survey, refined to limit the sample to 849 persons currently employed in retail sales occupations (U.S. Department of Commerce, 1985), 82% who worked in soft goods and 18% in hard goods. Logit regressions tested models of characteristics such as gender, race, presence of children, and potential wage rates as to significance in increasing the probability of choosing part-time employment. Gender was an important predictor of work choice, with women more likely to work part-time than men. Women were more likely to work part-time if they were white, married, had children and lived further from the central city.
Comparison of After-Laundering Residues of Cypermethrin and Cyfluthrin in Fabrics: A Meta-Analytical Approach
Authors: Newburn Kristina , Laughlin Joan 
Published: January 2008

This study is a meta-analysis of four experiments with two pyrethroids, cypermethrin and cyfluthrin, in two formulations, emulsifiable concentrates and wettable powders. Contributions of fabric weight, detergent type, and detergent concentration are evaluated for residue remaining in fabrics after laundering. Each of the four experiments is a factorial experiment, with two fabric weights (10 ozlyd2 and 14.5 ozlyd2), two detergent types (heavy-duty liquid and phosphate) and four detergent concentrations ( 0.0x, 0.5x, 1.0x, and 1.5x, where x = package label recommendations). Fabric specimens were contaminated, laundered, and residues remaining after laundering determined gas chromatographically. The heavier the fabric, the more residues were retained. Cypermethrin was more completely removed by laundering than was cyfluthrin. The emulsifiable concentrate formulation was more difficult to remove than the wettable-powder formulation. The cyfluthrin emulsifiable concentrate residue was greater following laundering than other pesticides. Increasing detergent concentration was effective in reducing cyfluthrin residue. Detergent type should be selected according to pesticide formulation: a heavy-duty liquid detergent for the emulsifiable-concentrate and a phosphate, powdered detergent for the wettable-powder.
Continuity and Change in Nebraska Quiltmakers, 1870-1989
Authors: Cox Crews Patricia , McClaren James Michelle 
Published: January 2008

Using information garnered from questionnaires completed during Nebraska Quilt Project (NQP), we developed a profile of Nebraska quiltmakers in four time periods (1870-1919, 1920-1945, 1946-1969, and 1970-1989) and examined how quiltmaking practices and motivations changed over time. Quiltmaking in Nebraska continues to be predominately an activity of rural women; however, it has become increasingly popular among urban women since the 1970s. The majority of Nebraska quiltmakers of all periods were rural homemakers of German descent, affiliated with either a Methodist or Lutheran church. Proportionately fewer Catholic women quilted than did members of other denominations. And, proportionately more women of English and Scottish ancestry were quiltmakers than would be expected based on percentages of those ancestry groups among Nebraskans as a whole. Of those quiltmakers who were gainfully employed, most worked in fields traditionally chosen by women. These findings are consistent with the conservative nature of the population of an agriculturally-based economy as found in Nebraska. Quiltmaking in Nebraska is a feminine skill usually transmitted by female relatives from generation to generation. There has been, however, a definite trend since the 1970s for quiltmakers to learn quiltmaking skills through formal quiltmaking classes. Most Nebraska quiltmakers began quilting as young adults. A smaller, but significant number of quiltmakers of the 1970s and 1980s began quilting in mid-life, a time when few quiltmakers of the earliest period began to make quilts.
The Privatisation of the Property Services Agency: Risk and Vulnerability in Contract-Related Fraud and Corruption
Authors: Doig Alan 
Published: January 2008

The Property Services Agency was a ‘hived-off’ government organisation responsible for the design, building, renting and maintenance of government property and associated facilities. Its expenditure, and delivery of its functions, were criticised for fraud, waste and inefficiency while it was involved in a number of cases of contract-related fraud and corruption. As the Property Services Agency began to deal with the latter concerns, the government was making it a prime candidate for a purchaser-provider split in relation to funding, the divestment of a number of functions to other agencies and to its client departments, and the introduction of competition in the provision of its services. Finally the Property Services Agency became a candidate for privatisation as its contracting functions were fully transferred to government departments. The responsibilities for combatting corruption and fraud, however, have also been dispersed, leaving HM Treasury to report its concerns over the threat such an area of risk area poses for government departments who have wanted the responsibility for the Agency's functions but, without the awareness, expertise and economies of scale to respond effectively, may be vulnerable to contract-related fraud and corruption. The functions of the Agency, its privatisation, and the implications for dealing with contract-related fraud and corruption provide a case-study in the relationship between different forms of organisation and ownership of the operational and purchasing functions of government, and the ability of governments to control corruption and fraud in public contracting.
Markets, Quasi-Markets and Middle Managers in Local Government
Authors: Keen Linda 
Published: January 2008

Operating as purchasers or providers, middle managers play a key role in the implementation of the new market systems recently introduced within local authorities. However, relatively little empirical investigation has been undertaken into the first-hand experiences of the middle managers who are on the ‘receiving end’ of these market systems. After a brief review of the literature, this paper uses Williamson's (1975; 1985) model of behavioural attributes as an analytical framework for analysing the impact of the new Purchaser and Provider model on the performance of middle line managers working within a local authority well-known for its commitment to market service delivery systems. These managers' responses about the positive and negative aspects of their experiences of market systems varied significantly according to their roles as either Purchaser or Provider managers, and to their location within particular service departments. The paper draws attention to the important differences in the nature of the transactions within each of these departments which appeared to account, at least in part, for the managers' different responses, and argues against the wholesale application of market forms of service delivery across highly differentiated organisations such as local authorities.
Carnitine and septic shock: a review
Authors: Famularo G. , De Simone C. , Arrigoni Martelli E. , Jirillo E. 
Published: January 2008

Most studies have reported reduced carnitine levels in the tissues of patients with sepsis, probably due to increased urinary excretion. Because of the increased utilization of fatty acids and ketone bodies as sources of energy in sepsis, the carnitine deficiency can further impair the fuel metabolism and contribute to the unregulated lipid metabolism in these patients. Recently, experimental and clinical studies have shown that carnitine and its congeners are able to: (a) downmodulate the spontaneous and endotoxin (LPS)-triggered overproduction of tumor necrosis factor (TNF)-alpha; (b) ameliorate the lipid metabolism; and (c) reduce the severity of illness, accelerate recovery, and, in some cases, improve survival in experimental septic shock. Many questions concerning the ultimate molecular mechanism of action of these compounds in endotoxaemia are still unanswered. Yet, these compounds may be helpful in patients with sepsis, when associated with conventional therapy, in that they can effectively reduce TNF-alpha levels and ameliorate the host's metabolic processes.
Foreign Direct Investment and 'Less Favoured Regions': Greek FDI in Bulgaria and Romania
Authors: Iammarino Simona , Pitelis Christos 
Published: January 2008

During the process of industrialization and afterwards (1960-80), Greek outward investment to Western and developing countries had been marginal, and government policy had only emphasized inward investment. But since the beginning of the nineties the opportunities arising from new investment in Eastern European Countries (EECs) have completely changed the scene. The aim of this article is to shed some light on the foreign direcf investment (FD1) flows from a peripheral European Union (EU) economy such as Greece, to two Less Favoured Regions of Eastern Europe, namely Bulgaria and Romania. In particular, on the basis of the empirical results gathered from a survey carried out in 1995-96, the objective is to analyze key criteria underlying investment choices by Greek firms, in order to help identify their role in the restructuring process and the impact that outward flows might have on the Greek economy.
Negative Political Advertising: Some Effects from the 13th Indian General Election 1999
Authors: Gupta Mukul P. 
Published: January 2008

How does negative political advertising work and how effective is it ? This is a question that does not have mambiguous answers. Most research studies in the past have looked at negative political advertising just as a post-facto phenomenon. The results have been inconsistent. This study looks at the political advertising, some negative, others not too much, used by the two leading political parties in their run up to the 13th general elections in India. Confined to main line English press advertising during 8-9 weeks prior to the date of polling, the study is restricted to the respondents in the seven parliamentary constituencies in Delhi. Using a survey of voters, the study uses the theoretical basis of Hierarchy of Effects model, Cognitive Response model and the Expeclancy theory to look at the effectiveness of such advertising. Proceeding from simple questions, this study is able to articulate the way such advertising works. It also attempts to classify people in terms of their dispositions towards negative advertising.
Student Evaluation in the Hospitality Curriculum
Authors: Hayes David K. , Tanke Mary L. 
Published: January 2008

The authors outline a series of successful techniques they have employed for strengthening their testing and grading procedures. Items of particular note include the evaluation of test reliability, difficulty level, dispersion and the use of standard scores in determining course grades. The intent is to provide information on how sound educational evaluation methods may be developed in a hospitality curriculum. The system described is based on established norm referenced grading techniques, yet is applicable to criterion referenced grading in many respects.
Historical review: megakaryopoiesis and thrombopoiesis
Authors: Kaushansky Kenneth 
Published: January 2008

Abstract
The study of thrombopoiesis has evolved greatly since an era when platelets were termed “the dust of the blood,” only about 100 years ago. During this time megakaryocytes were identified as the origin of blood platelets; marrow-derived megakaryocytic progenitor cells were functionally defined and then purified; and the primary regulator of the process, thrombopoietin, was cloned and characterized and therapeutic thrombopoietic agents developed. During this journey we continue to learn that the physiologic mechanisms that drive proplatelet formation can be recapitulated in cell-free systems and their biochemistry evaluated; the molecular underpinnings of endomitosis are being increasingly understood; the intracellular signals sent by engagement of a large number of megakaryocyte surface receptors have been defined; and many of the transcription factors that drive megakaryocytic fate determination have been identified and experimentally manipulated. While some of these biologic processes mimic those seen in other cell types, megakaryocytes and platelets possess enough unique developmental features that we are virtually assured that continued study of thrombopoiesis will yield innumerable clinical and scientific insights for many decades to come.