bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of reactive compatibilization on the properties of poly(butylene terephthalate)/acrylonitrile–ethylene–propylene–diene–styrene blends
Authors: Larocca N. M. , Hage E. , Pessan L. A. 
Published: April 2005

AbstractBlends of poly(butylene terephthalate) (PBT) with 30 wt % acrylonitrile–ethylene–propylene–diene–styrene (AES) were prepared with methyl methacrylate (MMA)/glycidyl methacrylate (GMA)/ethyl acrylate (EA) terpolymers (MGEs) as compatibilizing agents. These acrylic terpolymers were miscible with the styrene–acrylonitrile (SAN) phase of AES, whereas the epoxide groups of GMA could react with the PBT end groups; this could lead to the formation of grafted copolymers (PBT‐g‐MGE) at the PBT/AES interface during the melt processing of the blends if at least a fraction of this interface was formed between the PBT and SAN phases. This study found evidence of the aforementioned interfacial structure through the effectiveness of the MGE terpolymers in promoting the compatibilization, as evaluated by dynamical mechanical analysis, through the increase in the viscosity of the blends, and through the reduction of the AES particle size dispersed in the PBT matrix. These effects became more intense with an increase in the overall concentration of GMA in the blends and with a reduction of the molecular weight of MGE. Another effect promoted by the compatibilization was a remarkable reduction of the brittle–ductile transition temperatures of the blends, which was correlated with the reduction of the AES particle size. However, this correlation between the brittle–ductile transition temperatures and particle size did not hold for the blend with the lowest AES particle size, which showed a high ductile–brittle transition temperature. These mechanical behaviors were examined on the basis of the current theory of the toughening of thermoplastics, which takes into account the importance of the rubber interparticle distance and the cavitation process of these particles. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1244–1259, 2005
Applications of fault tree analysis to maintenance interval extension and vulnerability assessment
Authors: Lapp Steven A. 
Published: April 2005

AbstractFault tree analysis is a technique used to quantify the failure rates associated with potentially hazardous systems. The effects and interactions of various process subsystems are explicitly analyzed in a fault tree. Information on how process subsystems interact is extremely useful when decisions are made concerning lengths of maintenance intervals and assessments of vulnerability. This paper shows how that information can be extracted from an existing fault tree and used for decision making. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2005
Extracting phosphor‐scattered photons to improve white LED efficiency
Authors: Narendran N. , Gu Y. , Freyssinier‐Nova J. P. , Zhu Y. 
Published: April 2005

AbstractWhite light‐emitting diode (LED) luminous efficacy must improve significantly if LEDs are to become useful for general lighting. Phosphors commonly used in white LEDs backscatter more than half of the down‐converted light, of which a significant portion is eventually lost within the package, thus reducing the overall efficacy. This letter describes an experi‐mental study that shows by placing the phosphor away from the die, the backscattered photons can be extracted and the ef‐ficacy can be significantly increased. At low currents, the lu‐minous efficacy exceeded 80 lm/W. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical study of the ring‐closing reaction of 5′‐AMP to cAMP and H2O in the gas phase
Authors: Zhang Aihua , Liu Kun , Li Lan , Ma Siyu , Li Zonghe 
Published: April 2005

AbstractThe ring‐closing reaction of 5′‐adenosine monophosphate (5′‐AMP) to generate cyclic 3′, 5′‐adenosine monophosphate (cAMP) and H2O was theoretically investigated at the B3LYP/6‐31G**level. It was found that the ring‐closing reaction of 5′‐AMP may proceed in a synchronous way or in a stepwise way. For the latter, the reaction is a multichannel elimination reaction including inner H transfer. The potential energy surface of Path 3 is lowest in all the ring‐closing reaction paths. In addition, H shuttling reaction with the participation of a water molecule to act as a shuttle were also studied at the same level. The calculations indicate that the participation of a water molecule facilitates hydrogen transfer reaction. Our present calculations rationalized all the possible reaction channels. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Linking model Hamiltonians to ab initio and semiempirical methods in descriptions of impurities in conjugated polymers
Authors: Vilela Alessandra F. Albernaz , Gargano Ricardo , Silva Geraldo Magela E 
Published: April 2005

AbstractSemiempirical and ab initio electronic structure and model Hamiltonian calculations of the undoped and doped polyacetylene (PA) chain are presented. As a general model Hamiltonian we use the Su–Schrieffer–Heeger (SSH) model combined with the Pariser–Parr–Pople (PPP) model with site‐type impurities. More precisely, band gap and charge distributions of a single conducting PA chain bonding with several atomic and molecular radicals as impurities were investigated. From a comparison between the electronic and SSH‐PPP calculation it was possible to determine what impurity actually corresponds to the charge distribution obtained with model calculations. Therefore, it is shown within the present results what impurities are being represented in model calculations. This correspondence is fundamental in determining the behavior of molecular circuits and molecular devices. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Full configuration interaction pseudopotential determination of the ground‐state potential energy curves of Li2 and LiH
Authors: Maniero Angelo M. , Acioli Paulo H. 
Published: April 2005

AbstractA full configuration interaction (CI) with a norm‐conserving pseudopotential procedure to determine potential energy surfaces is proposed. Analysis of the potentiality and the possible sources of inaccuracies of the methodology is given in terms of its application to the generation of the ground‐state potential energy curves of the LiH and Li2 molecules. The vibrational energy levels were obtained using the discrete variable representation. The agreement between our results and those from Rydberg–Klein–Ress‐derived potentials is very good. The extension of this procedure to larger systems is straightforward. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Low‐lying stepwise paths for ethylene 1,3‐dipolar cycloadditions: A DFT study
Authors: Kavitha K. , Venuvanalingam P. 
Published: April 2005

AbstractEthylene reacts with 1,3‐dipoles such as diazomethane, nitrile oxide, and nitrone to give a single adduct and the potential energy surfaces of these reactions were completely surveyed with Density Functional Theory at the B3LYP/6‐31G(d) level; B3LYP/6‐311+G(d,p), QCISD/6‐31G(d) level calculations were performed for comparison. These reactions were found to have one concerted and four stepwise paths and all of them were thoroughly examined. Calculations show that anti and syn approaches in the stepwise paths merge at one point in the potential energy surface and the stepwise processes (i.e., through syn transition states) are low‐lying and concerted paths that are in close competition with them. A closer examination of the computed barriers of the reactions of ethylene with the above dipoles, cyclopentadiene, 1,3‐butadiene, and allyl anion reveals that there is a mechanistic cross‐over from concerted to stepwise path. While the neutral cycloaddition partners prefer a concerted path, the charged partners strongly favor a stepwise path. The dipoles have both concerted and stepwise (syn) paths in close competition. Such a mechanistic cross‐over has been induced by the polar influence of the charged species and this change‐over in mechanism could not be observed with allene cycloadditions with the same set of partners because allene is strongly biased towards the stepwise mechanism. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Civil War Vascular Injuries
Authors: Blaisdell F. William 
Published: April 2005

AbstractAs the result of the insistence of the Surgeon General during the United States Civil War, there was extensive documentation of injuries to major blood vessels and their resulting complications. The specific treatment of vascular injuries during the Civil War was ligation of the injured vessel or amputation. This was before there was any knowledge of the cause and prevention of infection. Overall, the results were dismal, with a mortality rate of nearly 60% for the more than 1000 soldiers treated by arterial ligation. The most important contribution of these medical reports was to define how the injuries should be diagnosed and managed. Many of the principles that developed as the result of this post‐war review are as valid today as they were then. Unfortunately, it seems that many of these lessons have had to be relearned by the surgeons who have participated in each of our subsequent military conflicts.
In Situ Saphenous Vein Bypass—Forty Years Later
Authors: Connolly John E. 
Published: April 2005

AbstractIn situ saphenous vein bypass, which was performed first by Rob in 1959, but introduced by Hall in. 1962, has been widely applied as an alternative to the reversed bypass. Now, forty years later, it seems appropriate to review its current place and technique. Of the presumed original benefits of the in situ operation, it is now clear that the hemodynamic flow of converging (in situ) versus diverging vein (reversed) boundaries plus better vein/artery size match are the main advantages. It is now popular belief that the reversed saphenous vein graft to the popliteal artery has no significant hemodynamic disadvantage because the vein is of comparable diameter at the knee and in the groin. In contrast, vein bypass from the groin to the ankle strongly favors the in situ procedure because of the convergence of the walls of the vein below the knee and better vein/artery size match. The most controversial facet of the in situ operation has been the question of valvulotome is superior to lyse valves and whether to perform the operation open as originally described, or closed to avoid skin complications from a long groin to ankle incision. Preoperative vein mapping is advantageous for all saphenous vein conduit operations. For open leg in situ procedures, skin bridges and incisions made directly over the vein, directed by mapping, will minimize skin complications. Use of endoscopic in situ techniques is ideal but only with an experienced endoscopist. Valve lysis has improved but is still not foolproof.
Noninvasive Vascular Testing—A 35‐Year Reflection
Authors: Lavenson George S. 
Published: April 2005

AbstractNoninvasive vascular testing has made a major contribution to the care of vascular surgery patients. This article a reflection on a 35‐year corroborative association with Doctor Norman Rich, during which many of the advances in noninvasive vascular testing have been witnessed and effected. I served my vascular surgery fellowship under Doctor Rich in 1967–68 at Walter Reed Army Hospital. The only noninvasive vascular equipment then was a pencil probe Doppler. The value of the Doppler in the management of peripheral vascular disease that year and in determining limb viability in combat surgery in Vietnam the following year was established, and both experiences were published. Later, Doctor Rich established the annual Military Vascular Surgery Meeting and was appointed as the first Chair of the Department of Surgery at the Uniformed Services University for Health Sciences (USU). I entered private practice in Central California in 1976, and ultrasonic imaging was developed which allowed noninvasive examination of the carotid arteries. I then developed a protocol to screen for the three silent, immediate causes of stroke, employing a “a quick carotid scan” for carotid artery disease, a lead II rhythm strip for atrial fibrillation, and blood pressure determination for hypertension so that these common causes of strokes could be recognized and treated, and potentially prevent the majority of strokes. My association with USU, Doctor Rich, and others involved proved instrumental in initiating implementation of stroke prevention screening. The structure established at USU provides a means of establishing the protocol nationally. Noninvasive vascular testing is an addition to Medical Science that has led to significant improvements in individual patient care and that has the potential of allowing a major reduction in death and disability from stroke and other vascular diseases. Throughout a 35‐year collaborative association with Doctor Norman M. Rich, I have witnessed and developed many of these advances. These contributions to noninvasive vascular testing reflect the value of our collaboration.
Abdominal War Wounds—Experiences from Red Cross Field Hospitals
Authors: Leppäniemi Ari K. 
Published: April 2005

AbstractThe traditional approach to abdominal war wounds consists of triage, eche‐loned care, and mandatory laparotomy for penetrating abdominal injuries, and it remains valid in modern conventional wars with well‐organized evacuation and surgical services. Expectant management of abdominal casualties can be considered under difficult circumstances with a high influx of patients exhausting the available resources. This can occur in regional conflicts associated with mass movements of people and with collapsed infrastructure. While always combined with adequate fluid resuscitation, antibiotic treatment, and other supportive care, the expectant approach in patients with penetrating abdominal injuries could be indicated for asymptomatic patients with multiple fragment wounds or for patients presenting several days post‐injury in good condition. The focus of surgical resources and competence should be on the majority of patients with intestinal perforation only, who need surgery to save life—but not necessarily on an urgent basis—and who have a good chance of survival. The limited availability of blood products to correct blood loss and coagulation factor deficiencies, and the lack of sophisticated monitoring of hemodynamic variables that call into question the value of a damage‐control approach for the most severely injured. Even if the bleeding could be temporarily controlled, the subsequent need for adequate resuscitation before returning the patient to the operating room could be difficult to achieve and would result in incompletely resuscitated patients being reoperated while acidotic, coagulopathic, and even hypothermic. Perhaps, in mass casualty situations these patients should be recognized during triage or at least early during operation, and aggressive surgery should be replaced with adequate expectant management with sedation and analgesics.
Cardiopulmonary Assessment: Is Improvement Needed?
Authors: Van De Water Joseph M. , Dalton Martin L. , Parish David C. , Vogel Robert L. , Beatty John C. , Adeniyi Said O. 
Published: April 2005

AbstractClinical parameters alone have repeatedly been proven unreliable in assessing cardiopulmonary status, especially in hemodynamically unstable patients. To learn if we had a diagnostic problem in our hospital, we compared physician assessment of cardiac index (CI) and thoracic fluid content (TFC) to values obtained using impedance cardiography (ICG). We selected the newest available ICG monitor, the BioZ, which employs this noninvasive technology. For CI measurements we have shown it to be equivalent to thermodilution and to be more reproducible (variability: 6.3% vs. 24.7%). Physician assessment of CI and TFC (high, normal, or low) was compared to the BioZ monitor’s results in 186 patients, considered to be hemodynamically unstable, from the emergency room, the intensive care units, and the floors. Normal values were defined for CI (2.5–4.2 L/min m2) and for TFC (males: 30–50 kohm−1 and females: 21–37 kohm−1). The concordance between physician assessment and the BioZ was 51% for CI with Kappa of 0.14 and 58% for TFC with Kappa of 0.19. Attendings did slightly better than the surgical residents with CI (52% vs. 48%) but slightly worse with TFC (57% vs. 61%). The potentially serious conditions of low CI and high TFC were misdiagnosed 42% and 46% of the time, respectively, by all physicians. Analysis of the data revealed that physician use of clinically available objective hemodynamic data, such as heart rate, blood pressure, and pulse pressure index, would not have been helpful. Furthermore, assistance from the pulmonary artery catheter (PAC) is often not available in our hospital, which has experienced a 90% decrease in its utilization over the past six years. Considering the increasing acuity of our aging patient population, accurate assessment of cardiopulmonary status is needed. The use of ICG could be a valuable addition to the physician’s armamentarium.
Publications as a measure of scientific advancement and of scientists' productivity
Authors: Daniel Hans‐Dieter 
Published: April 2005

ABSTRACTRobert Merton's norm of communalism states that academic scientists are obliged to publish their research findings; in order to ensure that credible knowledge is published, peer review is used for pre‐publication evaluation of manuscripts. The present system of journal peer review has, however, been much criticized. The paper summarizes research on reliability, fairness and predictive validity of journal peer review. The review of the research literature concludes that journal peer review is valid and does in fact function as a quality filter. However, since there is a lot of ambiguity in the literature as well, pre‐publication peer review should be supplemented with post‐publication evaluation to find out which publications and scientists have contributed most to the scientific advancement.
Institutional repositories: is the open access door half open or half shut?
Authors: MP Evan Harris 
Published: April 2005

ABSTRACTThe response of the UK Government to the Report on science publishing by the Science and Technology Select Committee of the House of Commons is criticized for failing to take the necessary action to research or help catalyse a change in the publishing model. The initiatives of the National Institutes of Health and the Wellcome Foundation in setting up central archives are examined and their utility questioned. The evidence base for a change to open access is explored.
Primary and secondary thrombocytosis in childhood
Authors: Dame Christof , Sutor Anton Heinz 
Published: April 2005

SummaryThis review summarizes current data on the pathomechanisms and clinical aspects of primary and secondary thrombocytosis in childhood. Primary thrombocytosis is extremely rare in childhood, mostly diagnosed at the beginning of the second decade of life. As in adults, the criteria of the Polycythemia Vera Group are appropriate to diagnose primary thrombocytosis. The pathomechansims of non‐familial forms are complex and include spontaneous formation of megakaryopoietic progenitors and increased sensitivity to thrombopoietin (Tpo). Familial forms can be caused by mutations in Tpo or Tpo receptor (c‐mpl) genes. These mutations result in overexpression of Tpo, sustained intracellular signalling or disturbed regulation of circulating Tpo. Treatment of primary thrombocytosis is not recommended if platelet counts are <1500/nl and bleeding or thrombosis did not occur in patient's history. In severe cases, decision on treatment should weigh potential risks of treatment options (hydroxyurea, anagrelide) against expected benefits for preventing thrombosis or haemorrhage. Secondary thrombocytosis is frequent in children, in particular in the first decade of life. Hepatic Tpo production is stimulated in acute response reaction to a variety of disorders. Thrombosis prophylaxis is not required, even at platelet counts >1000/nl, except for cases with additional prothrombotic risk factors.
Gaucher disease: pathological mechanisms and modern management
Authors: Jmoudiak Marina , Futerman Anthony H. 
Published: April 2005

SummaryGaucher disease, the most common lysosomal storage disorder, is caused by the defective activity of the lysosomal enzyme, acid‐β‐glucosidase (GlcCerase), leading to accumulation of glucosylceramide (GlcCer), particularly in cells of the macrophage lineage. Nearly 200 mutations in GlcCerase have been described, but for the most part, genotype‐phenotype correlations are weak, and little is known about the down‐stream biochemical changes that occur upon GlcCer accumulation that result in cell and tissue dysfunction. In contrast, the clinical course of Gaucher disease has been well described, and at least one treatment is available, namely enzyme replacement therapy. One other treatment, substrate reduction therapy, has recently been marketed, and others are in early stages of development. This review, after discussing pathological mechanisms, evaluates the advantages and disadvantages of existing therapies.
Heterogeneous expression pattern of pro‐ and anti‐apoptotic factors in myeloid progenitor cells of patients with severe congenital neutropenia treated with granulocyte colony‐stimulating factor
Authors: Cario Gunnar , Skokowa Julia , Wang Zheng , Bucan Vesna , Zeidler Cornelia , Stanulla Martin , Schrappe Martin , Welte Karl 
Published: April 2005

SummaryApoptosis is accelerated in the myeloid progenitor cells of patients with severe congenital neutropenia (CN). Granulocyte colony‐stimulating factor (G‐CSF) increases neutrophil numbers in most CN patients. The effect of G‐CSF on apoptosis in CN was analysed by apoptosis rate and expression of anti‐ and pro‐apoptotic factors. G‐CSF‐treated patients showed higher apoptosis frequency, lower expression of bcl‐2 and bcl‐xL, but higher expression of bfl‐1/A1 and mcl‐1. Caspase 9 was highly expressed in patients and controls after G‐CSF administration. Thus, G‐CSF acts on apoptosis regulation, but additional mechanisms leading to the increase of neutrophil numbers must be assumed.
Teicoplanin‐dependent antibodies: detection and characterization
Authors: Garner Stephen F. , Campbell Kate , Smith Graham , Hurd Colin , Davidson Simon J. , Treacy Marilyn , Burman John F. , Kroll Hartmut , Ouwehand Willem H. 
Published: April 2005

SummaryThere are only a few reports of thrombocytopenia associated with clinical doses of teicoplanin, a glycopeptide antibiotic used against Gram‐positive bacteria. We investigated 39 patients receiving teicoplanin; 31 were thrombocytopenic with platelet counts between 1–105 × 109/l and 8 were not thrombocytopenic. We identified 14 thrombocytopenic cases (45%) and two (25%) non‐thrombocytopenic cases with IgG teicoplanin‐dependent platelet‐reactive antibodies. Use of glycoprotein (GP) capture enzyme‐linked immunosorbent assay with platelets and GPIIb/IIIa transfected Chinese Hamster Ovary cells as well as flow cytometry with GP‐deficient platelets indicated that the GPIIb/IIIa complex is a major target antigen of these antibodies.