bluuebunny/crossref_metadata_2025 huggingface dataset:
Anemia in the Intensive Care Unit: How Big Is the Problem?
Authors: Gattinoni Luciano , Chiumello Davide
Published: February 2008

Anemia is a common problem in critically ill patients. After three days in the intensive care unit, over 90% of patients present with anemia. Blood loss through phlebotomy appears to be an important cause of anemia in this setting. Lower hemoglobin concentrations are associated with an increased hospital length of stay and higher mortality. In clinical practice, red blood cell (RBC) transfusions are administered in order to increase the arterial oxygen content and the oxygen delivery so as to preserve tissue oxygenation. However, it is still not clear if RBC transfusions increase oxygen consumption, i.e. improve tissue oxygenation. Based on available data and clinical practice guidelines, the decision to transfuse RBCs should be based not only on a hemoglobin trigger but on the clinical status of the individual patient. Despite available guidelines, the economic impact of inappropriate RBC transfusions has been shown to account for up to 24% of the total cost of all blood component transfused.
Anemia and Blood Transfusion in the Critically Ill:The Role of Erythropoietin
Authors: Corwin Howard L.
Published: February 2008

Blood transfusion has been an integral part of clinical practice for most of the last century. The benefits of RBC (red blood cell) transfusion in surgery as well as other clinical settings were assumed, while the procedure itself was looked upon as relatively risk‐free. Blood transfusion has been used in clinical settings where an increase in oxygen delivery to the tissues is thought to be beneficial, such as sepsis, ischemic cardiac disease, respiratory failure, and mechanical ventilation. A dramatic change in thinking occurred in the early 1980s, largely in response to concerns about transfusion‐related infection, particularly the human immunodeficiency virus (HIV). While advances in transfusion medicine have greatly decreased the risk of viral transmission during blood transfusion, other issues now fuel the debate over transfusion practice and have led to a reexamination of the approach to blood transfusion. This review will focus on anemia and blood transfusion strategies in the critically ill, including the use of erythropoietin (EPO).
Massive Transfusion and Coagulopathy
Authors: Hardy Jean‐François , Samama Marc
Published: February 2008

Coagulopathy associated with massive transfusion remains an important clinical problem. In this paper, the objectives of the authors are two‐fold: to identify the causes of coagulopathy in massively transfused adult and previously hemostatically competent patients and to differentiate between the elective surgical setting and trauma, in order to recommend the most appropriate treatment strategies.

A MEDLINE search was conducted for published articles on massive transfusion, using the terms “transfusion,”“trauma,”“surgery,”“coagulopathy,” and “hemostatic defects.” Articles were organized and reviewed by date of publication in order to better understand the evolution of our thinking on massive transfusion and coagulopathy. Coagulopathy associated with massive transfusion is an intricate, multifactorial, and multicellular event. In trauma patients, tissue trauma and anoxia, shock, and hypothermia contribute to the development of disseminated intravascular coagulation and microvascular bleeding. In patients undergoing elective surgery, a decrease in fibrinogen concentration is observed initially while thrombocytopenia is a late occurrence. Critically low levels of coagulation factors were seldom reported when whole blood was in common use. With the use of packed red cells, however, dilution or consumption of coagulation factors has become a significant issue requiring specific treatment with, primarily, fresh frozen plasma.

Maintaining a normal body temperature is a simple and effective strategy to improve hemostasis during massive transfusion. Red cells play an important role and hematocrit levels as high as 35 to 36% may be required to sustain the process. The administration of platelets and/or fresh frozen plasma should be based on clinical judgment and coagulation testing results, and their use restricted to the treatment of clinical coagulopathies.
Applications of Meta‐Analysis in Transfusion Medicine
Authors: Vamvakas Eleftherios C.
Published: February 2008

SUMMARy

Meta‐analysis, or statistical overview, is the structured and systematic integration of information from different studies of a given problem. When the results are discrepant, the purpose of an overview is to investigate reasons for disagreements among studies. When the results are concordant, the goal of meta‐analysis is to derive, through the application of a number of quantitative techniques, a measure of the effect of an intervention or exposure across the combined investigations. Metaanalysis has been used and misused widely in the medical literature. Readers must develop the skills necessary to comprehend and evaluate published reports of metaanalyses, because health policy guidelines‐and perhaps also recommendations for patient management‐are likely to be increasingly based in the future on input from statistical overviews.
Anemia, Blood Transfusion, and Clinical Outcomes in Patients With Cardiovascular Risk Factors
Authors: Goodnough Lawrence Tim
Published: February 2008

SUMMARy

Increasing evidence indicates that patients known to have cardiovascular risk factors who are anemic should be managed differently from patients not known to be at risk. Clinical studies of patients in critical care units, patients in cardiac care units with acute myocardial infarction, and in Jehovah's Witness patients undergoing surgical procedures have demonstrated that patients at risk suffer adverse clinical consequences with moderate to severe anemia. Studies in a number of clinical settings indicate that morbidity and mortality can be improved with aggressive management of anemia.
Fresh Frozen Plasma: Clinical Guidelines and Use
Authors: Bélisle Sylvain , Hardy Jean‐François
Published: February 2008

SUMMARy

Fresh frozen plasma (FFP) is the liquid portion of one unit of human blood that contains the labile and stable components of the coagulation, fibrinolytic and complement systems, as well as the proteins that maintain oncotic pressure and modulate immunity. The clinician must remember that a unit of single‐donor allogeneic plasma is a heterogeneous solution of proteins. Infusion of FFP normalizes abnormal tests efficaciously in patients with hereditary coagulopathies. However, its benefit in the treatment of excessive bleeding remains unclear and variable. In clinical practice, indication to transfuse FFP is based on a double threshold: a combination of abnormal coagulation tests plus excessive bleedings. FFP is not the first‐line option in the prevention of hemorrhage and in emergency reversal of oral anticoagulation for life‐threatening complications.
The Contribution of a Blood Establishment to the Increased Use of Intraoperative Cell Salvage in Hospitals: A Pilot Study From the National Blood Service, England
Authors: James Virge , Lamb Jo
Published: February 2008

This paper describes a strategy developed and implemented in 5 major hospitals in a health region in the center of England jointly by the hospitals and the National Blood Service (NBS).The aim was to increase the use of intraoperative cell salvage (ICS). Hospital managers were asked to nominate “lead clinicians” and the NBS provided the funding. Equipment was leased from 3 companies which also provided the initial training for operatives. A single audit form was devised and completed for every procedure; these were analyzed by the NBS. Preliminary results showed that the strategy achieved its aims both in encouraging increased use and demonstrating savings in donor blood. Detailed cost/benefit analyses are ongoing. The pilot has spawned numerous further initiatives
Plasma Procurement and Self‐Sufficiency
Authors: Hossenlopp Claudine , Velati Claudio , Rouger Philippe
Published: February 2008

EuroNet‐TMS, the European Network of Transfusion Medicine Societies, was constituted in early 2002. During 2003, EuroNet‐TMS committees worked on a broad survey aimed at drawing a map of the situation in the European Union (EU) on issues of immediate relevance. Nine questionnaires were drafted by EuroNet‐TMS committees and sent out to the seventeen countries who wished to be part of this survey. The results shown here represent a first broad outline of the situation in Europe in terms of plasma procurement and self‐sufficiency. Further details are still to be obtained before the official publication of EuroNet‐TMS in the second semester of 2004. The data reflect a heterogeneous situation mainly observed in all other fields, most obviously related to discrepancies in the blood transfusion organizations throughout Europe and in their health policies in general. The application of the EU directive on blood in 2005 might affect these data, as general regulations will be the same for all 15 + 10 EU countries.
Novel Hemostatic Agents: A Focus on Recombinant Factor VIIa and Factor XIII
Authors: Young Guy
Published: February 2008

Excessive bleeding accounts for a significant incidence of morbidity and mortality resulting from a variety of conditions including congenital and acquired bleeding disorders, trauma, and surgery. A complex network of cellular and plasma components are involved in the process of controlling excessive bleeding, a process known as hemostasis. When excessive bleeding does occur, there are a wide variety of agents with diverse mechanisms of action that can promote hemostasis. These agents include blood products, biologicals such as recombinant proteins, synthetic medications, and topical agents. Historically, non‐specific agents such as fresh frozen plasma, cryoprecipitate and antifibrinolytic agents have been the standard therapies for the management of excessive bleeding. These, however, all have significant limitations. Recently, recombinant factor VIIa (rFVIIa) was licensed for use in patients with hemophilia and inhibitors to factors VIII or IX. Since its licensure, it has been used in a wide variety of conditions with excessive bleeding leading to often dramatic results. Another novel agent is factor XIII (FXIII) which is currently in clinical trials. Although data regarding its use in conditions other than FXIII deficiency is lacking, it is expected that FXIII will become another effective agent in the management of excessive bleeding.
Treatment of Hemophilia With Genetic Engineering
Authors: Axsom Kelly M. , Manno Catherine S.
Published: February 2008

Hemophilia is a disorder characterized by decreased amounts of functional, circulating coagulation proteins VIII or IX. It has been well documented that by maintaining factor levels at ≥ 1% the major complications of severe disease, such as spontaneous bleeding, are averted. Successful gene transfer for hemophilia would result in persistent transgene expression at levels ≥ 1%. Hemophilia is an ideal candidate for the application of gene transfer because of the wide therapeutic window for the relevant factors, the availability of animal models, the ability of many tissues other than the liver to produce the coagulation proteins, and the desire for more convenient and cost‐efficient treatments. For these reasons, hemophilia has the potential to be one of the first severe genetic disorders to be treated, if not cured, with gene therapy. This paper summarizes the progress and challenges of gene transfer studies for hemophilia.
Aprotinin and Major Orthopedic Surgery
Authors: Samama Charles Marc
Published: February 2008

Aprotinin is a potent pharmacological agent which reduces bleeding and limits blood transfusion in current surgical practice. Many studies have been conducted in orthopedic surgery. Several trials have been performed in total hip replacement and total knee replacement patients, and aprotinin only moderately decreased blood loss requirements in these patients. Conversely, when aprotinin was used in patients with a high bleeding risk (cancer, sepsis, redo surgery, etc.), it developed a potent hemostatic activity and significantly decreased transfusion requirements. No increase in deep vein thrombosis and pulmonary embolism was observed. The only major side effect could be the potential occurrence of an anaphylactoid reaction. Prophylactic administration of aprotinin should be considered in extensive spine surgery and in high‐risk major orthopedic operations. The decision to use aprotinin will be guided by a risk/benefit analysis.
Immunomodulatory Effects of Stored Packed Red Blood Cells in the Injured Patient
Authors: Silliman Christopher C.
Published: February 2008

Despite the advent of new detection techniques for viral pathogens, which has markedly decreased the risk of infectious transmission and increased safety, transfusions are strongly associated with immunosuppression in the host. The best described immunomodulatory effect of blood administration is the increased acceptance and prolonged survival of renal allografts in previously transfused patients. Such transfusion‐related immunomodulation may lead to bacterial infections, increased growth and dissemination of tumor cells, and viral reactivation. This review discusses the known clinical immunomodulatory consequences of transfusion, reviews relevant animal studies and immunologic mechanisms, including the effects of older, stored blood, with special emphasis on the injured patient. In addition, possible strategies to ameliorate transfusion‐related immunomodulation are examined with particular emphasis on prestorage leukoreduction and the use of fresh or washed cellular components.
Management of Postinjury Coagulopathy
Authors: Zimrin Ann B. , Dutton Richard P. , McCunn Maureen , Hess John R.
Published: February 2008

Coagulopathy is commonly seen in seriously injured patients and can make control of hemorrhage more difficult. An observed defect in blood clotting may be preexisting, due to severe injury, a result of delayed treatment, or exacerbated by resuscitation efforts. Factors that promote coagulopathy include hypothermia, acidosis, intravascular consumption and extravascular loss of coagulation factors and platelets, reduced platelet effectiveness secondary to low hematocrit, interactions of coagulation proteins and platelets with volume expanders, and the hemodilution associated with massive transfusion. Management of the hemorrhagic diathesis involves treatment of hypothermia, avoidance of excessive colloid and crystalloid volume in the resuscitation effort, damage‐control surgery, appropriate use of blood products and, in selected cases, the use of tissue sealants and recombinant factor VIIa.
Adjuncts for Tissue stasis
Authors: Acheson Eric M. , Kheirabadi Bijan S. , Holcomb John B.
Published: February 2008

Despite advances in surgical tools and techniques and the development of rapid transport systems to highly specialized medical centers, mortality rates from exsanguination due to injuries sustained in military and civilian trauma have not improved appreciably in the last 150 years. Scientists and clinicians, motivated by the promise of new hemorrhage control adjuncts, have recently increased research and development in an effort to combat this problem. This review describes the epidemiology of hemorrhagic death in both the military and civilian populations, the research implications of these injury patterns, and some of the most promising products – whether already in use or under evaluation – for the control of bleeding. A survey of fibrinogen‐based products, recombinant factor VIIa, antifibrinolytic agents, products containing poly‐N‐acetyl glucosamine and other novel agents are presented. Preclinical and clinical data of products are outlined and the physical properties, mechanisms of action, and safety issues for each hemorrhage‐control agent are discussed.
Traumatic Brain Injury and Use of Hypertonic Solutions
Authors: Berger Steffen , Härtl Roger
Published: February 2008

Hypertonic saline (HS) solutions are increasingly used for reduction of elevated intracranial pressure in head‐injured children and adults. Advantages over other hypertonic solutions such as mannitol were demonstrated in experimental and clinical studies with respect to intracranial pressure reduction, improvement of cerebral perfusion pressure, and cerebral oxygenation. However, there remains considerable uncertainty about the indications for the use of HS, the appropriate administration protocol, and the potential risks of using HS. The rationale of this article is to bring a systematic order into the currently available results and to help develop a protocol for the indication and application of HS solutions in adults and children with severe brain injury. Furthermore, fields of necessary future research are outlined.
Acute Normovolemic Hemodilution in Cardiac Surgery
Authors: Linden Philippe Van der , Sakr Paola
Published: February 2008

Acute normovolemic hemodilution (ANH), which was introduced into surgical practice in the 1970s, involves the removal of blood from a patient either immediately before or shortly after induction of anesthesia and the simultaneous replacement with an appropriate volume of plasma substitute to maintain normovolemia. It therefore aims at reducing allogeneic blood exposure through a reduction in the net red blood cell mass lost during surgery. It can be performed safely in patients with coronary and/or valvular disease undergoing cardiac surgery, providing adequate knowledge of physiological response and limits to normovolemic anemia. Experience in its practical aspects is also important. The efficacy of the technique essentially depends on the amount of blood collected and on the amount of blood volume lost by the patients. It appears relatively modest in cardiac surgery, although well‐designed studies are warranted. AN H has a place cardiac surgery but should rather be regarded as an integral part of a blood conservation strategy tailored to the patient's needs and adapted to specific surgical procedures.
An Update on Perioperative Blood Salvage in Cardiac Surgery
Authors: Rubens Fraser D.
Published: February 2008

Blood conservation technologies are now the subject of increasing scrutiny in cardiovascular surgical care. In particular, positive outcomes in previous trials related to the collection and reinfusion of blood collected from the surgical wound (cell salvage) have now led this latter strategy to become a key component in modern surgical practice. Although intuitively attractive, there are, however, potential drawbacks relating to its usage including the risks of induced coagulopathy, infection and hemolysis. In this review, the principles and mechanics of cell salvage (processed, i.e. centrifugally washed, and unprocessed) as they relate to cardiac surgery, will be discussed. The impact of these techniques on the quality of harvested blood will be reviewed. Finally, the efficacy of this technology as a blood conservation strategy to limit the need for homologous transfusion as demonstrated in randomized clinical trials in cardiac surgery will be reviewed.
Oxygen Carriers in Cardiac Surgery
Authors: Larbuisson Robert , Deby‐Dupont Ginette , Lamy Maurice
Published: February 2008

Artificial oxygen carriers – the hemoglobin‐based oxygen carriers (HBOCs) and the perfluorocarbon (PFC) emulsions – have been developed with the aim of avoiding the risks associated with allogeneic blood transfusions. H BOCs are solutions of free human or bovine hemoglobin, modified by internal crosslinking and by polymerization so as to avoid renal toxicity and to increase the intravascular lifetime. Last‐generation PFC emulsions are formed by lipid particles enclosing a synthetic hyperfluorinated, chemically inert hydrocarbon, perflubron, which dissolves gases without binding them. In order to be efficient, the emulsions must be used with 100% oxygen.

HBOCs and PFC emulsions were found to be safe and to reduce allogeneic blood transfusions in preclinical and clinical phase I/II studies. One PFC emulsion (Oxygent®) and three H BOCs (DCLHb, Hemolink® and Hemopure®) were used in phase II and III clinical trials in cardiac surgery with cardiopulmonary bypass (CPB). HBOCs were well tolerated but increased the number of adverse events, mainly hypertension, jaundice‐like syndrome and elevation of the blood levels of hepatic and pancreatic enzymes. The effects of HBOCs on transfusion avoidance were modest, limited to the first postoperative days, without decreasing the total number of transfused red blood cell (RBC) units. Oxygent® was used in combination with acute normovolemic hemodilution in phase II studies. It was safe, had modest effects on transfusion avoidance in the post‐CPB period (until 5 days for the highest administered dose), but did not decrease the number of allogeneic red blood cell units transfused per patient. A phase III clinical trial was voluntarily stopped before completion because of an increased incidence of adverse events (stroke). More evidence is warranted before oxygen carriers can be recommended for routine use in cardiac surgery.
Computational Machining of Titanium Alloy—Finite Element Modeling and a Few Results
Authors: Obikawa T. , Usui E.
Published: February 2008

A Finite element modeling was developed for the computational machining of titanium alloy Ti-6Al-4V. The chip formation in metal cutting is one of the large deformation problems, thus, in the formulation of the elastic-plastic deformation analysis, geometrical nonlinearity due to the large shape change of the finite elements was taken into account and the over-constraint of incompressibility on the deformation of ordinary finite elements in the plastic range was relaxed to make the elements deformable as a real continuum. A ductile fracture criterion on the basis of strain, strain rate, hydrostatic pressure and temperature was applied to the crack growth during the chip segmentation. The temperature field in the flowing chip and workpiece and the fixed tool was calculated simultaneously by an unsteady state thermal conduction analysis and the remeshing of tool elements. The serrated chips predicted by the computational machining showed striking resemblances in the shape and irregular pitch of those obtained by actual cutting. The mean cutting forces and the amplitude of cutting force vibration in the computational machining were in good agreement with those in the actual machining.
Assuring the Matchable Degree in Selective Assembly via a Predictive Model Based on Set Theory and Probability Method
Authors: Fang X. D. , Zhang Y.
Published: February 2008

The major advantage of using selective assembly in manufacturing is that it allows the use of low precision parts to achieve high precision assembly. However, two problems arise: (a) the surplus parts due to unbalanced mating parts in some selective groups (b) there is no quantitative method to predict the matchable degree before assembly, and correspondingly no quantitative criterion on how to adjust manufacturing processes so that the desired match between mating parts could be guaranteed. By adopting the concepts of intersection and union from set theory and incorporating with the probability method, this paper develops a predictive model for quantitatively estimating the matchable degree between mating parts for selective assembly. Based on such a quantitative reference, together with the criterion for guaranteeing process capability index Cpk, an optimal algorithm for adjusting biases of dimensional distributions can be achieved to assure the matchable degree, thus improving the effectiveness of selective assembly.
Modeling of Tool Forces for Worn Tools: Flank Wear Effects
Authors: Elanayar S. , Shin Y. C.
Published: February 2008

A general procedure for the separation of ploughing forces from shearing forces on the shear plane is outlined. The first part of the paper deals with the experimental separation of these forces using the predictive machining theory developed by Oxley. The forces are decomposed by first separating the shear forces from the total forces and then employing an iterative procedure to calculate the normal forces on the shear plane. All analysis is conducted for three dimensional cutting. The second part of the paper develops a procedure to model the ploughing forces by accounting for the change in geometry with flank wear. The procedure uses the indentation models along with values of tool and workpiece material constants to determine the indentation force. Models for the indentation depth are developed from a few designed experiments and the predictions by the established models are then compared with experimental results obtained for different cutting conditions. The theoretical predictions of the ploughing forces agree closely with results of the experiments. Additional analysis using ceramic tools also show reasonably good agreement between predictions and experimental measurements.
Dynamic Analysis of the Ultrasonic Machining Process
Authors: Wang Z. Y. , Rajurkar K. P.
Published: February 2008

This paper presents a dynamic analysis of the ultrasonic machining process based on impact mechanics. Equations representing the dynamic contact force and stresses caused by the impinging of abrasive grits on the work, are obtained by solving the three-dimensional equations of motion. The factors affecting the material removal rate have been studied. It is found that the theoretical estimates obtained from the dynamic model are in good agreement with the experimental results.
Plant Identification From Leaves Using Quasi-Sensor Fusion
Authors: Shiraishi M. , Sumiya H.
Published: February 2008

The method described here identifies plants by using a machine vision technique. This method achieves effective image detection independent of surrounding conditions, dimensionless image detection in each growth stage, and determination of the critical factor for discriminating individual plants. These are the fundamental factors for successful automatic thinning, cropping, weeding, and harvesting using intelligent agricultural robots. Color, aspect ratio, size, radius permutation in leaf profiles, complexity, and curvature are used to classify each plant. Effective discrimination is obtained by using a quasi-sensor fusion combined with a total occurrence range for decision making.
Theoretical and Experimental Analysis of Failure for the Hemisphere Punch Hydroforming Processes
Authors: Hsu Tze-Chi , Hsieh Shian-Jiann
Published: February 2008

A limit theorem of plasticity has been developed to investigate the hemisphere punch hydroforming process. The limit theorem of plasticity is used to predict the upper and lower bounds of the permissible fluid pressure. Loci representing the critical fluid pressures which result in the rupture and wrinkling are presented. The property of the sheet metal is governed by Hill’s quadratic yield criterion with a power-law hardening for anisotropic material. The premature failure is avoidable if the fluid pressure path is restricted to travel only within the suggested bounds. The theoretical results which include the failure prediction and wrinkling distribution are verified by conducting a serial of hydroforming experiments. The experimental data agrees well with the computed results and demonstrates the technological usefulness of the results.
Determination of Surface Residual Stresses in Machined Ceramics Using Indentation Fracture
Authors: Ahn Y. , Chandrasekar S. , Farris T. N.
Published: February 2008

Machining produces surface residual stresses which significantly influence the strength and wear resistance of ceramic components. As new methods are developed for machining ceramics, a quick and reliable technique for measurement of residual stresses would be valuable in assessing the viability of these methods from a residual stress perspective. The residual stresses on ground and polished (i.e. machined) surfaces of soda-lime glass, Ni-Zn ferrite, and silicon nitride have been measured using an indentation technique with a Vickers indenter. In this technique, the surface extent of the median/radial cracks produced by the Vickers indenter in machined and in annealed ceramics are measured. These are then combined with a fracture mechanics analysis to estimate the surface residual stresses produced by machining. In order to determine the validity of the indentation technique for estimating machining residual stresses, these stresses were also measured using an X-ray diffraction and a deflection method. The residual stress values determined using the indentation technique in the machined ceramics were found to be reasonably close to those obtained from the X-ray diffraction and deflection methods. Since the indentation technique is relatively simple and easily applied, it offers a promising method for evaluating surface residual stresses in machined ceramics.
Modular CNC Design for Intelligent Machining, Part 2: Modular Integration of Sensor Based Milling Process Monitoring and Control Tasks
Authors: Altintas¸ Y. , Munasinghe W. K.
Published: February 2008

Modular integration of sensor based milling process monitoring and control functions to a proposed CNC system architecture is presented. Each sensor based process control algorithm resides in a dedicated processor in the AT bus with a modular software. The CNC system’s motion control module has been designed to accomodate rapid manipulation of feeds, cutting conditions and NC tool path which may be demanded by machining process control modules in real time. Modular integration of adaptive control of cutting forces, tool condition monitoring, chatter detection and suppression tasks are illustrated as examples. The process control and monitoring modules are serviced in the real-time multi-tasking environment within one millisecond time intervals without disturbing the position control system. The paper present constraints and guidelines in designing CNC systems which allow modular integration of user developed real time machining process control and monitoring applications.
Monitoring of Thermal Energy Distribution in Abrasive Waterjet Cutting Using Infrared Thermography
Authors: Kovacevic R. , Mohan R. , Beardsley H. E.
Published: February 2008

Thermal energy distribution in the workpiece cut with abrasive waterjet (AWJ) is analyzed using the technique of infrared thermography through isotherms and linescans. Variation in workpiece temperature with thermal conductivity and cutting conditions is studied. The feasibility of visualization of AWJ cutting mechanisms in opaque materials using infrared thermography is investigated. A novel technique of AWJ nozzle wear monitoring through infrared thermography is proposed. A comparative study of infrared thermography results with the readings of thermocouples and the two-dimensional moving line heat source model show a close correspondence indicating that infrared thermography is a good technique for the above application.
A Theoretical Study of Erosion Phenomenon in Abrasive Jet Machining
Authors: Verma A. P. , Lal G. K.
Published: February 2008

The paper presents a theoretical analysis for estimating the abrasive particle velocity in air-abrasive jet using continuum approach applied to two-phase flow system. Subsequently a theoretical model for predicting the material removal rate in abrasive jet machining (drilling) has been developed using semi-empirical fracture mechanics relationships and quasi-static indentation approach. Numerical results have been computed and compared with experimental results.
Distributed-Parameter Control of the Heat Source Trajectory in Thermal Materials Processing
Authors: Doumanidis C. , Fourligkas N.
Published: February 2008

In thermal manufacturing processes performed by a localized, sequentially moving heat source, simultaneous regulation of multiple thermal quality characteristics requires real-time control of the temperature field developed through the distributed heat input on the part surface. Such control of the thermal field to a desired distribution employs infrared sensing and feedback of the surface temperature hill, to modulate the torch power and motion in-process. The torch trajectory is guided in real time by an efficient optimization algorithm based on the concept of moving complexes. This distributed-parameter control strategy is developed using a numerical simulation model of thermal processing, and its performance is evaluated experimentally in heat treatment of thin stainless steel plates. The thermal controller is applied to the new scan welding process, in which it drives the torch in a reciprocating motion along the weld, yielding a uniform and smooth temperature field, and thus a favorable material structure and mechanical properties. Application of such thermal control to various other material processing methods is also investigated.
Rapid Polymer/Gas Solution Formation for Continuous Production of Microcellular Plastics
Authors: Park C. B. , Suh N. P.
Published: February 2008

An extrusion system that can create a polymer/gas solution rapidly for continuous processing of microcellular plastics is presented. Microcellular plastics are characterized by cell densities greater than 109 cells/cm3 and fully grown cells smaller than 10 μm. Previously these microcellular structures have been produced in a batch process by saturating a polymeric material with an inert gas under high pressure followed by inducing a rapid drop in the gas solubility. The diffusion phenomena encountered in this batch processing is typically slow, resulting in long cycle times. In order to produce microcellular plastics at industrial production rates, a means for the rapid solution formation is developed. The processing time required for completing the solution formation in the system was estimated from experimental data and the dispersive mixing theory based on an order-of-magnitude analysis. A means for promoting high bubble nucleation rates in the gas-saturated polymer via rapid heating is also discussed. The feasibility of the continuous production of microcellular plastics by the rapid polymer/gas solution formation and rapid heating was demonstrated through experiments. The paper includes not only a brief treatment of the basic science of the polymer/gas systems, but also the development of an industrially viable technology that fully utilizes the unique properties of microcellular plastics.
Hybrid Neurons in a MicroRNA Mutant Are Putative Evolutionary Intermediates in Insect CO
2
Sensory Systems
Authors: Cayirlioglu Pelin , Kadow Ilona Grunwald , Zhan Xiaoli , Okamura Katsutomo , Suh Greg S. B. , Gunning Dorian , Lai Eric C. , Zipursky S. Lawrence
Published: February 2008

Carbon dioxide (CO
2
) elicits different olfactory behaviors across species. In
Drosophila
, neurons that detect CO
2
are located in the antenna, form connections in a ventral glomerulus in the antennal lobe, and mediate avoidance. By contrast, in the mosquito these neurons are in the maxillary palps (MPs), connect to medial sites, and promote attraction. We found in
Drosophila
that loss of a microRNA,
miR-279
, leads to formation of CO
2
neurons in the MPs.
miR-279
acts through down-regulation of the transcription factor Nerfin-1. The ectopic neurons are hybrid cells. They express CO
2
receptors and form connections characteristic of CO
2
neurons, while exhibiting wiring and receptor characteristics of MP olfactory receptor neurons (ORNs). We propose that this hybrid ORN reveals a cellular intermediate in the evolution of species-specific behaviors elicited by CO
2
.
Long-Range Order in Electronic Transport Through Disordered Metal Films
Authors: Aigner S. , Pietra L. Della , Japha Y. , Entin-Wohlman O. , David T. , Salem R. , Folman R. , Schmiedmayer J.
Published: February 2008

Ultracold atom magnetic field microscopy enables the probing of current flow patterns in planar structures with unprecedented sensitivity. In polycrystalline metal (gold) films, we observed long-range correlations forming organized patterns oriented at ±45° relative to the mean current flow, even at room temperature and at length scales larger than the diffusion length or the grain size by several orders of magnitude. The preference to form patterns at these angles is a direct consequence of universal scattering properties at defects. The observed amplitude of the current direction fluctuations scales inversely to that expected from the relative thickness variations, the grain size, and the defect concentration, all determined independently by standard methods. Ultracold atom magnetometry thus enables new insight into the interplay between disorder and transport.
Identification of
Mycobacterium tuberculosis
Ornithine Carboamyltransferase in Urine as a Possible Molecular Marker of Active Pulmonary Tuberculosis
Authors: Napolitano Danielle R. , Pollock Nira , Kashino Suely S. , Rodrigues Virmondes , Campos-Neto Antonio
Published: February 2008

Although the antigen detection assay has the potential to discriminate active tuberculosis from latent infection, development of such a test for the accurate diagnosis of this serious disease has only recently become a matter of interest. Here we present evidence that a
Mycobacterium tuberculosis
protein (ornithine carboamyltransferase, coded for by MT_1694; Rv1656 [
argF
]) is an interesting candidate molecule for this test development. The protein was initially discovered by mass spectroscopy in urine of patients with pulmonary tuberculosis and shown by Western blot analysis to be present in
M. tuberculosis
crude cell extract as well as in the culture supernatant (“secreted” protein). In addition, a recombinant ornithine carboamyltransferase (rMT1694) produced in
Escherichia coli
was recognized by immunoglobulin G (IgG) antibodies from patients with active tuberculosis but not by IgG from uninfected healthy subjects. Moreover, rMT1694 was strongly recognized by peripheral blood mononuclear cells from both healthy tuberculin purified protein derivative (PPD)-positive individuals and patients with pulmonary tuberculosis. More importantly, a capture enzyme-linked immunosorbent assay formatted with rabbit IgG antibodies specific to rMT1694 was able to identify the presence of this antigen in urine samples from 6 of 16 patients with pulmonary tuberculosis and in none of 16 urine samples collected from healthy PPD
+
controls. These results indicate that an improved antigen detection assay based on
M. tuberculosis
ornithine carboamyltransferase may represent an important new strategy for the development of a specific and accurate diagnostic test for tuberculosis.
Fluorometric Assay for Testing Rifampin Susceptibility of
Mycobacterium tuberculosis
Complex
Authors: Hoek K. G. P. , Gey van Pittius N. C. , Moolman-Smook H. , Carelse-Tofa K. , Jordaan A. , van der Spuy G. D. , Streicher E. , Victor T. C. , van Helden P. D. , Warren R. M.
Published: February 2008

The emergence and transmission of multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) have raised concern about diagnostic delay associated with culture-based drug susceptibility testing methods. The association between rifampin resistance and MDR-TB or XDR-TB makes it an important genetic marker for genotypic drug susceptibility testing. In this article, we describe the analysis of the physical properties of the rifampin resistance-determining region (RRDR) in the
rpoB
gene by high-resolution thermal melt analysis as a method for detecting rifampin resistance in
Mycobacterium tuberculosis
complex. The RRDR from the
M. tuberculosis
complex was amplified by PCR from DNA templates extracted from sputum cultures of
M. tuberculosis
or the laboratory strain (H37Rv) in the presence of a fluorescent DNA binding dye. Subsequent mixing of the amplification products from the respective sputum cultures and the laboratory strain and thermocycling allowed the formation of DNA duplexes. The thermal denaturation properties of these DNA duplexes were determined by measuring the derivative of the intensity of fluorescence at different temperatures. Analysis of DNA extracted from 153 sputum cultures showed a sensitivity of 98% and a specificity of 100% for the detection of rifampin resistance compared to the “gold standard” culture-based phenotyping method. No statistical difference was detected in the performance of the method when applied to crude DNA from 134 boiled cultures. This method, named “FAST-Rif” (“
f
luorometric
a
ssay for
s
usceptibility
t
esting of
rif
ampin”), allowed the rapid, reliable, and easy detection of genotypic rifampin resistance as a marker for MDR-TB and XDR-TB.
Mechanisms of Human Papillomavirus Type 16 Neutralization by L2 Cross-Neutralizing and L1 Type-Specific Antibodies
Authors: Day Patricia M. , Gambhira Ratish , Roden Richard B. S. , Lowy Douglas R. , Schiller John T.
Published: February 2008

Pseudovirions of human papillomavirus type 16 (HPV16), the principal etiologic agent in 50% of cervical cancers, were used as a model system to investigate the cell surface interactions involved in the exposure of the broadly cross-neutralizing papillomavirus L2 epitopes. These neutralizing epitopes were exposed only after cell surface binding and a subsequent change in capsid conformation that permitted cleavage by the cellular protease furin at a specific highly conserved site in L2 that is immediately upstream of the cross-neutralizing epitopes. Unexpectedly, binding of L2 antibodies led to the release of the capsid/antibody complexes from the cell surface and their accumulation on the extracellular matrix. Study of the dynamics of exposure of the L2 epitopes further revealed that representatives of the apparently dominant class of L1-specific neutralizing antibodies induced by virus-like particle vaccination prevent infection, not by preventing cell surface binding but rather by preventing the conformation change involved in exposure of the L2 neutralizing epitope. These findings suggest a dynamic model of virion-cell surface interactions that has implications for both evolution of viral serotypes and the efficacy of current and future HPV vaccines.
Epstein-Barr Virus Immediate-Early Protein Zta Co-Opts Mitochondrial Single-Stranded DNA Binding Protein To Promote Viral and Inhibit Mitochondrial DNA Replication
Authors: Wiedmer Andreas , Wang Pu , Zhou Jing , Rennekamp Andrew J. , Tiranti Valeria , Zeviani Massimo , Lieberman Paul M.
Published: February 2008

Disruption of cellular metabolic processes and usurpation of host proteins are hallmarks of herpesvirus lytic infection. Epstein-Barr virus (EBV) lytic replication is initiated by the immediate-early protein Zta. Zta is a multifunctional DNA binding protein that stimulates viral gene transcription, nucleates a replication complex at the viral origin of lytic replication, and inhibits cell cycle proliferation. To better understand these functions and identify cellular collaborators of Zta, we purified an epitope-tagged version of Zta in cells capable of supporting lytic replication. FLAG-tagged Zta was purified from a nuclear fraction using FLAG antibody immunopurification and peptide elution. Zta-associated proteins were isolated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and identified by mass spectrometry. The Zta-associated proteins included members of the HSP70 family and various single-stranded DNA and RNA binding proteins. The nuclear replication protein A subunits (RPA70 and RPA32) and the human mitochondrial single-stranded DNA binding protein (mtSSB) were confirmed by Western blotting to be specifically enriched in the FLAG-Zta immunopurified complex. mtSSB coimmunoprecipitated with endogenous Zta during reactivation of EBV-positive Burkitt lymphoma and lymphoblastoid cell lines. Small interfering RNA depletion of mtSSB reduced Zta-induced lytic replication of EBV but had only a modest effect on transcription activation function. A point mutation in the Zta DNA binding domain (C189S), which is known to reduce lytic cycle replication, eliminated mtSSB association with Zta. The predominantly mitochondrial localization of mtSSB was shifted to partly nuclear localization in cells expressing Zta. Mitochondrial DNA synthesis and genome copy number were reduced by Zta-induced EBV lytic replication. We conclude that Zta interaction with mtSSB serves the dual function of facilitating viral and blocking mitochondrial DNA replication.
IFP35 Is Involved in the Antiviral Function of Interferon by Association with the Viral Tas Transactivator of Bovine Foamy Virus
Authors: Tan Juan , Qiao Wentao , Wang Jian , Xu Fengwen , Li Yue , Zhou Jun , Chen Qimin , Geng Yunqi
Published: February 2008

Interferon-induced proteins (IFPs) exert multiple functions corresponding to diverse interferon signals. However, the intracellular functions of many IFPs are not fully characterized. Here, we report that IFP35, a member of the IFP family with a molecular mass of 35 kDa, can interact with the bovine Tas (BTas) regulatory protein of bovine foamy virus (BFV). The interaction involves NID2 (IFP35/Nmi homology domain) of IFP35 and the central domain of BTas. The overexpression of IFP35 disturbs the ability of BTas to activate viral-gene transcription and inhibits viral replication. The depletion of endogenous IFP35 by interfering RNA can promote the activation of BFV, suggesting an inhibitory function of IFP35 in viral-gene expression. In addition, IFP35 can interact with the homologous regulatory protein of prototype FV and arrest viral replication and repress viral transcription. Our study suggests that IFP35 may represent a novel pathway of interferon-mediated antiviral activity in host organisms that plays a role in the maintenance of FV latency.
The Ezrin-Radixin-Moesin Family Member Ezrin Regulates Stable Microtubule Formation and Retroviral Infection
Authors: Haedicke Juliane , de los Santos Kenia , Goff Stephen P. , Naghavi Mojgan H.
Published: February 2008

We recently identified the cytoskeletal regulatory protein moesin as a novel gene that inhibits retroviral replication prior to reverse transcription by downregulation of stable microtubule formation. Here, we provide evidence that overexpression of ezrin, another closely related ezrin-radixin-moesin (ERM) family member, also blocks replication of both murine leukemia viruses and human immunodeficiency virus type 1 (HIV-1) in Rat2 fibroblasts before reverse transcription, while knockdown of endogenous ezrin increases the susceptibility of human cells to HIV-1 infection. Together, these results suggest that ERM proteins may be important determinants of retrovirus susceptibility through negative regulation of stable microtubule networks.