bluuebunny/crossref_metadata_2025 huggingface dataset:
Quasi-dimensional multizone combustion model for direct injection engines fuelled with dimethyl ether
Authors: Meng Xianghui , Jiang Zuhua , Wang Xibin , Jiang Deming
Published: March 2004

Experimental studies have proved that dimethyl ether (DME) is a promising alternative fuel for compression ignition direct injection (CIDI) engines. To study the mechanisms of DME combustion and the formation of NO x emissions, which becomes the most noticeable pollutant since no soot is produced even under heavy loads for DME operation, a quasi-dimensional multizone combustion model for DI engines fuelled with DME is presented in this paper, together with its application on a DME engine, which is derived by revamping a diesel engine. To validate the model, an extensive experimental investigation has been conducted on the DME engine. By comparing theoretical and experimental results it is revealed that the model predicts with reasonable accuracy NO x emissions and engine performance. Furthermore, the model makes it possible to study the combustion mechanism by visualizing the temperature and fuel distribution at various instances of time from fuel injection. The model also offers a better understanding of the mechanisms of NO x formation by providing information on the areas inside the fuel jet where the pollutants are formed, on the evolution of the jet and on the evolution of the NO x concentration in the jet.
Effect of Injection Temporal Splitting on the Characteristics of Fuel-air Mixture Formation in a Common Rail Diesel Spray
Authors: Zhang Yuyin , Nishida Keiya
Published: March 2004

The mixture formation characteristics in a temporally split injection diesel spray were studied through a series of measurements based on the laser absorption-scattering technique (LAS), which was developed by the authors and adopted the second harmonic (532 nm) and the fourth harmonic (266 nm) of a pulsed Nd:YAG laser as the incident light, and dimethylnaphthalene (DMN) as the test fuel. By applying this technique, imaging was made of DMN sprays injected into a high- temperature (833 K) and high-pressure (4.0 MPa) constant-volume vessel by a single-hole nozzle and a common rail injection system for a direct injection (DI) diesel engine. Quantitative information of the vapour evaporation and fuel distribution was obtained, and furthermore the fuel-air mixture was characterized. The effect of injection temporal splitting on the mixture characteristics was analysed and correlated with the characteristics of NO x formation in a DI diesel engine.
The influence of blow-by on indicated work output from a diesel engine under cold start conditions
Authors: Cheng K Y , Shayler P J , Murphy M
Published: March 2004

The start-up time of automotive, light-duty diesel engines increases as ambient temperature falls. One contributory cause is a reduction in indicated work output. The influence of blow-by in bringing about the reduction has been investigated. The experimental study was carried out at 20° C on four-cylinder direct injection (DI) engines with a capacity of around 2 l. Blow-by losses were inferred from measurements of gas flow from the crankcase. Indicated mean effective pressure was shown to decrease linearly with increasing blow-by rate. The relationship accounts for almost all the reduction in work output at low temperatures. The reduction is associated with the influence of blow-by on heat released during combustion, rather than with the transport of enthalpy from the cylinder.
Near optimal LQR performance for uncertain first order systems
Authors: Luo L. , Miller D. E.
Published: March 2004

In adaptive control, the objective is to provide stability and acceptable performance in the face of significant plant uncertainty. However, often there are large transients in the plant output and the control signal can become excessively large. Here, we consider the first order case with the plant parameters restricted to a compact set; we show how to design a (linear time‐varying) adaptive controller which provides near optimal LQR performance. This controller is periodic with each period split into two parts: during the Estimation Phase, an estimate of the optimal control signal is formed; during the Control Phase, a suitably scaled estimate of this signal is applied to the system. We demonstrate the technique with a simulation and discuss the benefits and limitations of the approach. Copyright © 2004 John Wiley & Sons, Ltd.
Blastic NK‐cell‐like lymphoma with T‐cell receptor gene rearrangement
Authors: Liu Xiao‐Yuan , Atkins Robert C. , Feusner James H. , Rowland Jon M.
Published: March 2004

Blastic natural killer (NK) cell lymphoma is very rare but has been recently classified as a distinct entity in WHO classification. However, the classification remains controversial, and the clinicopathologic spectrum is not completely understood. We report a unique case of cutaneous CD4+ CD56+ malignancy with a typical clinical presentation and immunophenotype of blastic NK‐cell lymphoma in a 15‐year‐old Guamanian girl. The skin was the only site involved by the lymphoma. Molecular study showed clonal T‐cell receptor γ gene rearrangement. The patient has been disease‐free till now (more than 12 months following bone marrow transplant). This case may represent a tumor at an early stage of a common developmental pathway for T‐cells and NK‐cells. Am. J. Hematol. 75:251–253, 2004. © 2004 Wiley‐Liss, Inc.
Myelodysplastic syndrome with central diabetes insipidus manifesting hypodipsic hypernatremia and dehydration
Authors: Nakamura Fumihiko , Kishimoto Yuui , Handa Tomoyuki , Arai Yukihiro , Mitani Kinuko
Published: March 2004

Central diabetes insipidus (DI) is a rare but recognized complication of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) that is caused by leukemic infiltration to the hypothalamo‐neurohypophyseal system. In rare patients in whom a wide region of the hypothalamus is involved, central DI results in hypodipsic hypernatremia and dehydration. Typical DI symptoms such as polydipsia, polyuria, and marked thirst are concealed in these cases, because the hypothalamic “thirst center” cannot send thirst stimuli to the cerebral cortex. Herein we describe a patient with MDS developing into AML, who presented with hypodipsic hypernatremia and dehydration. A diagnosis of central DI was made on the ground of a low level of serum anti‐diuretic hormone (ADH) despite high serum osmolality. A magnetic resonance imaging study revealed attenuation of a physiological “bright spot” of the neurohypophysis. An induction course chemotherapy including regular‐dose cytarabine and daunorubicin produced a rapid improvement of hypernatremia. The bone marrow aspirate after two courses of chemotherapy showed complete remission. At that point, ADH release and the “bright spot” were recovered. In order to correctly diagnose central DI in association with hematological malignancies, we should not overlook this atypical type of DI. Am. J. Hematol. 75:213–216, 2004. © 2004 Wiley‐Liss, Inc.
Prenatal origin of chromosomal translocations in acute childhood leukemia: Implications and future directions
Authors: McHale Cliona M. , Smith Martyn T.
Published: March 2004

We, and others, have demonstrated an in utero origin for translocations associated with childhood leukemia, with latency periods in some cases exceeding 10 years. The mechanism of generation of most of the translocations is thought to be aberrant repair following abortive apoptosis, rather than V(D)J recombination or exposure to topoisomerase II inhibitors. Folate supplementation may prevent some of the chromosome breakage leading to translocation formation. Translocations t(8;21) and t(12;21) have been shown to occur in the normal population (before birth) at a frequency that is 100‐fold greater than the risk of developing the corresponding leukemia. In most instances, additional genetic changes are required for progression to leukemia. Tyrosine kinase receptor (RTK) mutations, which give cells a survival/proliferative advantage, are proposed to act cooperatively with fusion genes, leading to transformation. However, translocations and cooperating RTK mutations have not been identified for all leukemia subtypes, particularly in acute myeloid leukemia. The core binding transcriptional pathway is frequently targeted by translocation in utero. We propose that this pathway is highly sensitive during fetal hematopoiesis and may be targeted by mechanisms other than translocation. For each leukemia subtype it is important to characterize the corresponding leukemic stem cell, which is thought to be the initial target for translocation. This would help to elucidate the molecular pathways involved in the progression from preleukemic clone harboring a translocation to fully disseminated leukemia. Am. J. Hematol. 75:254–257, 2004. © 2004 Wiley‐Liss, Inc.
Prompt response to rituximab of severe hemolytic anemia with both cold and warm autoantibodies
Authors: Webster Duncan , Ritchie Bruce , Mant Michael J.
Published: March 2004

A 71‐year‐old male with severe autoimmune hemolysis with both cold agglutinins and warm antibodies was intolerant of prednisone and cyclophosphamide. Rituximab was given during a 60‐day period when he required 41 units of packed cells to maintain hemoglobin above 75 g/l. Two weeks later hemoglobin stabilized at 95 g/l, and further transfusions were not required. A second course of rituximab was given 4 months later for continued hemolysis. A satisfactory hemoglobin was maintained for 9 months from initial treatment, when hemoglobin again fell to 65 g/L. A prompt response to a third course of rituximab was obtained. This is the second patient with both cold agglutinins and warm antibodies with severe hemolytic anemia who has had a prompt response to rituximab. This treatment should be considered when a rapid response is needed or when a patient has failed to respond to more standard therapies. Am. J. Hematol. 75:258–259, 2004. © 2004 Wiley‐Liss, Inc.
Psychotic disorders in Prader–Willi syndrome
Authors: Vogels A. , Hert M. De , Descheemaeker M.J. , Govers V. , Devriendt K. , Legius E. , Prinzie P. , Fryns J.P.
Published: March 2004

The Prader–Willi syndrome (PWS) is a genetically determined developmental disorder caused by abnormalities of the proximal region of chromosome 15q11‐13. In a previous study, we reported that psychotic episodes, occurring in 16% of persons with PWS, had an onset in adolescence, never occurred in persons with paternal deletion, and were exclusively associated with maternal uniparental disomy (UPD) or imprinting abnormalities (IM). In order to gain a better understanding of the psychopathology and to further refine the psychiatric diagnosis, we describe in more detail the psychopathological manifestations of six adults with a history of psychotic episodes. All these individuals had a detailed psychiatric examination, including the use of the operational criteria (OPCRIT) checklist. An identifiable subtype of psychotic disorder was associated with PWS. Characteristics include early age of onset, acute onset, polymorphous, and shifting symptomatology and a need for psychiatric hospitalization. The presence of precipitating stress factors and a prodromal phase with physiological symptoms was reported in all patients. Current diagnostic categories do not allow an unequivocal psychiatric diagnosis. © 2004 Wiley‐Liss, Inc.
Leukoencephalopathy, arthritis, colitis, and hypogammaglobulinemia (LACH) in two brothers: A novel syndrome?
Authors: Bonkowsky Joshua L. , Bohnsack John F. , Pennington Mary J. , Viskochil David , Thompson Joel A.
Published: March 2004

We report a pair of brothers who have leukoencephalopathy, arthritis, colitis, and hypogammaglobulinemia. Both presented initially with seizures in the early postnatal period. They have significant developmental delay, and brain MRIs demonstrate leukoencephalopathy, characterized by profound hypomyelination. They have developed arthritis, which in one brother has required chronic treatment; and persistent intermittent diarrhea, necessitating treatment for inflammatory bowel disease. Finally, they have had multiple hospitalizations, including several for sepsis; an immunological analysis revealed that they have IgG1‐subclass hypogammaglobulinemia and low B cell levels. There is no family history of similar problems, and these brothers have an unaffected brother. We believe this constellation of symptoms represents a novel syndrome: LACH syndrome (leukoencephalopathy, arthritis, colitis, and hypogammaglobulinemia). The etiology of this syndrome remains unknown despite extensive investigations. © 2004 Wiley‐Liss, Inc.
Unusual features in a patient with neurofibromatosis type 1: Multiple subcutaneous lipomas, a juvenile polyp in ascending colon, congenital intrahepatic portosystemic venous shunt, and horseshoe kidney
Authors: Oktenli Cagatay , Gul Davut , Deveci M. Salih , Saglam Mutlu , Upadhyaya Meena , Thompson Peter , Consoli Claudia , Kocar Ismail H. , Pilarski Robert , Zhou Xiao‐Ping , Eng Charis
Published: March 2004

We report a case that draws attention to a hitherto undescribed association of neurofibromatosis type 1 (NF1) with juvenile polyp, congenital intrahepatic portosystemic venous shunt, multiple subcutaneous lipomas, and horseshoe kidney. Our patient has fulfilled the National Institutes of Health consensus conference criteria for NF1 by having neurofibromas, axillary freckling, Lisch nodules, and café‐au‐lait spots. There is no family history of NF1 and his 7‐year‐old son has no stigmata of NF1. On the other hand, the patient's family had a presumably dominant inheritance of horseshoe kidney: the father, proband, sister, and son of the other sister had a horseshoe kidney. The patient was investigated for mutations in the NF1 gene and PTEN, but no germline mutations were detected. The differential diagnosis for such a collection of hamartomatous, cutaneous, and vascular disorders includes the Proteus, Bannayan–Riley–Ruvalcaba, and Cowden syndromes. None of these diagnoses was convincingly confirmed in this patient. © 2004 Wiley‐Liss, Inc.
DNA studies of mono‐ and pseudodicentric isochromosomes 18q
Authors: Bugge Merete , Brandt Carsten A. , Petersen Michael B.
Published: March 2004

The description of isochromosomes 18 has so far mainly been by cytogenetic studies and based on identical banding pattern of the two arms. However, only molecular techniques are capable to distinguish an isochromosome from a translocation, whole arm or reciprocal, between two chromosomes 18. We have used 23 PCR‐based DNA polymorphisms to determine the parental origin and mechanisms of formation in four patients with isochromosomes 18q and to demonstrate that they were consistent with true isochromosomes. Three of the probands were liveborn children with clinical features characteristic of Edwards syndrome, one proband was a fetus diagnosed at prenatal diagnosis. In one case the isochromosome was monocentric with two identical q arms of maternal origin, formed by misdivision of the centromere and loss of p arm material. Another monocentric case had 47 chromosomes with isochromosomes i(18p) and i(18q) formed by maternal postzygotic centromeric misdivision and segregation of both isochromosomes, or by meiosis II centromeric misdivision and nondisjunction (without recombination in meiosis I). In two cases, the isochromosomes were dicentric with genetically identical arms composed of a part of the short and the whole long arm of chromosome 18 of paternal origin. The formation of the fused chromosomes can be explained by postzygotic exchange of sister chromatids on the short arm of chromosome 18, followed by breakage and U‐shape reunion of sister chromatids. © 2004 Wiley‐Liss, Inc.
Prostanoids, not reactive oxygen species, mediate COX‐2–dependent neurotoxicity
Authors: Manabe Yasuhiro , Anrather Josef , Kawano Takayuki , Niwa Kiyoshi , Zhou Ping , Ross M. Elizabeth , Iadecola Costantino
Published: March 2004

The prostaglandin synthesizing enzyme cyclooxygenase‐2 (COX‐2) has emerged as a critical pathogenic factor in brain diseases associated with activation of N‐methyl‐D‐aspartate (NMDA) receptors, including stroke and neurodegenerative diseases. However, the COX‐2 reaction products responsible for these deleterious effects have not been identified. In particular, the relative contribution to the neurotoxicity of COX‐2–derived prostanoids and reactive oxygen species has not been defined. We found that the brain damage produced by direct injection of NMDA into the somatosensory cortex is attenuated by the COX‐2 inhibitor NS‐398 or in COX‐2–null mice, but that the associated production of free radicals is not. Furthermore, COX‐2 inhibition reduces the lesions even if the deleterious effects of free radicals are eliminated by the scavenger superoxide dismutase. The protection exerted by NS‐398 is counteracted by a stable analog of prostaglandin E2. The findings directly implicate COX‐2–derived prostanoids, rather then radicals, in the COX‐2–dependent component of the damage mediated by NMDA receptors and strengthen the rationale for using COX‐2 inhibitors in the treatment of neurological diseases associated with glutamate neurotoxicity. Ann Neurol 2004
Cover Picture: Excess Electron Transport Through DNA: A Single Electron Repairs More than One UV‐Induced Lesion (Angew. Chem. Int. Ed. 14/2004)
Authors: Giese Bernd , Carl Barbara , Carl Thomas , Carell Thomas , Behrens Christoph , Hennecke Ulrich , Schiemann Olav , Feresin Emiliano
Published: March 2004

Electron‐catalyzed repair of thymine dimers in double‐stranded DNA is described by B. Giese, T. Carell, O. Schiemann, and co‐workers on page 1848 ff. Transport of an electron from a remote modified thymine base through DNA occurs in a multistep hopping process. When the electron meets a thymine dimer, which is generated by photocycloaddition of adjacent thymine residues, the two thymine bases are repaired through a retro‐cyclization reaction, while the electron continues along the DNA.
Analysis of failure of crosslinked polyethylene cables because of electrical treeing: A physicochemical approach
Authors: Sarathi R. , Das Supriyo , Anil Kumar C. R. , Velmurugan R.
Published: March 2004

The present work investigated the breakdown characteristics of high‐voltage crosslinked polyethylene (XLPE) cable by electrical trees under ac and composite voltages. The electrical trees resemble either a tree or a bushy structure. The importance of the Weibull parameters for the present study was emphasized. The failure zone of the XLPE cables was characterized by experimental techniques such as wide‐angle X‐ray diffraction, differential scanning calorimetry, and thermogravimetric–differential thermal analysis, to understand the phase constituents affected by electrical trees. The impact test and flexural test results indicate that material with high stiffness/toughness allows tree formation and causes early failure of the material. The characteristic variation of the aged XLPE cables was investigated by a dynamic mechanical analyzer (DMA). The activation energy values were calculated from the DMA data. The rate of tree propagation was found to be less for materials (XLPE) with high activation energy. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2169–2178, 2004
Preparation and properties of elastic polyimide‐silica composites using silanol sol from water glass
Authors: Inoue Shin‐Ichi , Morita Kazuhisa , Asai Kiyotsugu , Okamoto Hiroshi
Published: March 2004

A new approach for obtaining elastic polyimide‐silica composites using a silanol sol prepared from water glass and the imide‐containing elastic polymers (IEPs) with polytetramethyleneoxide (PTMO) soft‐segment was investigated. Methods of increasing the degree of compatibility between the silica phase prepared from a silanol sol and IEPs obtained via elastic polyureas were examined. Elastic polyimide‐silica composites were obtained by the thermal treatment at 200°C for 4 h in vacuo after N‐methyl‐2‐pyrrolidone was evaporated from the IEP precursor solutions to which the silanol tetrahydrofuran solution and Bis(trimethoxysilylpropyl)amine (BisA) were added. The use of BisA possessing a reaction site with a carboxylic acid group on the IEP precursors improved the degree of compatibility between the IEPs and silica. Transparent composites were obtained when the concentration of SiO2 was below 22 wt %. FT‐IR analyses confirmed that the composite was a segmented hybrid material composed of the PTMO segment, the imide segment, and SiO2. The silica matrix obtained via silanol sol from water glass and the silica matrix obtained by the conventional sol‐gel process with an alkoxysilane were essentially the same, and there was no significant loss of silicon due to incomplete hydrolysis of the alkoxides when preparing composites via the water glass route, in contrast to the situation that can occur in the case of the sol‐gel route. Dynamic mechanical and thermal analyses suggested that microphase separation between the imide segment and the PTMO segment occurred in the composites and that there was a substantial amount of phase mixing at the same time. The formation of the silica composite had a great influence on the mobility of the segmnets in the phase‐mixing domain. TGA analyses indicated that the formation of the 10 wt % silica hybrid gave a composite with a 50°C higher degradation temperature. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2211–2219, 2004
Spatiotemporal analysis of programmed cell death during mouse cardiac septation
Authors: Sharma Pundrique R. , Anderson Robert H. , Copp Andrew J. , Henderson Deborah J.
Published: March 2004

Cell death is thought to play an important role in mammalian cardiogenesis, although a precise map of its distribution during the crucial period of cardiac septation has so far been lacking. In this study, the spatiotemporal distribution of programmed cell death (PCD) during mouse cardiac septation is described between embryonic days 10.5 and 13.5. Two types of foci of cell death can be demonstrated in the developing heart. Those with high‐intensity, with a PCD index greater than 1%, are clearly visible on individual TUNEL‐assayed sections. Low‐intensity foci, with a PCD index of less than 1%, become visible only following summation of data. High‐intensity foci occur exclusively within the endocardial cushions of the outflow tract and atrioventricular region, appearing at the 52–54 somite stage (late E11.5), concomitant with the formation of the central mesenchymal mass. Low‐intensity foci are present throughout the period of cardiac development from E10.5 to E13.5 and are frequently localized to regions of septation, such as the muscular ventricular septum and the mesenchymal cap of the primary atrial septum. Expression of Fas and FasL corresponds to these low‐intensity foci, but not those with high‐intensity, suggesting that activation of this death receptor may be specifically involved in molecular control of the low‐intensity foci. Anat Rec Part A 277A:355–369, 2004. © 2004 Wiley‐Liss, Inc.
Occurence of lipid bodies in canine type II pneumocytes during hypothermic lung ischemia
Authors: Ochs Matthias , Fehrenbach Heinz , Richter Joachim
Published: March 2004

Type II pneumocytes defend the pulmonary alveolus by synthesis and secretion of surfactant and by contributing to alveolar epithelial regeneration. Lipid bodies are regarded as intracellular domains for the synthesis of eicosanoid mediators that can be induced by inflammatory stimuli. The aim of the present study was to establish whether hypothermic ischemic lung storage without further preservation measures leads to an induction of lipid body formation in canine type II pneumocytes. The lungs of 18 dogs were fixed for transmission electron microscopy (TEM) immediately after cardiac arrest (six double lungs) and after ischemic storage in Tutofusin solution at 4°C for 20 min, 4 hr, 8 hr, and 12 hr (six single lungs, respectively). Type II pneumocytes were analyzed qualitatively by conventional TEM (CTEM) and quantitatively by stereology. The relative phosphorus content of surfactant containing lamellar bodies, lipid bodies, and intermediate forms was investigated by energy‐filtering TEM (EFTEM). By CTEM, lipid bodies as well as forms intermediate between lipid bodies and lamellar bodies were already noted in the control group but were more pronounced in the ischemia groups. Beginning at 20 min of ischemic storage, a significant increase in the volume density of lipid bodies was noted in the ischemic groups as compared to the control group. By EFTEM, the highest intracellular phosphorus signals were recorded over lamellar bodies and lamellar areas of intermediate forms in all experimental groups, while lipid bodies and homogeneous areas of intermediate forms did not show a clear phosphorus signal. These results indicate that the formation of lipid bodies in canine type II pneumocytes is induced early during ischemic lung storage. Anat Rec Part A 277A:287–297, 2004. © 2004 Wiley‐Liss, Inc.
Immunohistochemical distribution of growth‐associated protein 43 (GAP‐43) in developing rat nasoincisor papilla
Authors: El‐Sharaby Ashraf , Ueda Katsura , Wakisaka Satoshi
Published: March 2004

We employed immunohistochemistry of growth‐associated protein 43 (GAP‐43) to trace the early development of gustatory nerves and α‐gustducin to demonstrate mature taste buds in the rat nasoincisor papilla (NP). The sequential changes of gustatory structures revealed eight characteristic stages. One, at embryonic day 16 (E16), GAP‐43‐immunoreactive (IR) nerve fibers were observed in close relation with presumptive taste buds in the lateral apical epithelium on each side of NP; meanwhile, no immunoreactivity could be observed in the papillary epithelium. Two, at E17, fine GAP‐43‐IR nerve fibers first invaded the apical epithelium of the papilla. Three, at E19, GAP‐43‐IR nerve fibers were extensive in apical epithelium and colonized in immature taste buds. Four, at E20, GAP‐43‐IR nerve fibers were first observed in ductal epithelium (lining the medial wall of nasoincisor ducts). Five, at postnatal day 1 (P1), immunoreactive nerve fibers first coincided with immature taste buds in the ductal epithelium. Six, at P3, α‐gustducin‐IR cells identical for mature taste buds were simultaneously demonstrated in both apical and ductal epithelium. Seven, at P14, progressive taste bud proliferation and maturation as well as neural invasion were demonstrated in all regions of the epithelium. Eight, during advanced stage in adult animals, extensive innervation was traced especially in close relation with taste buds. The sequential topographic patterns of NP gustatory structures seem very specific as compared to those in other locations of mammalian gustatory system. The present study reveals that gustatory nerves preceded the development of taste buds. However, further investigations are required to examine such a characteristic model for the neurogenic theory of taste induction. Anat Rec Part A 277A:370–383, 2004. © 2004 Wiley‐Liss, Inc.
Morphometric analysis of embryonic rat trigeminal neurons treated with different neurotrophins
Authors: Ulupinar Emel , Ünal Nedim , Erzurumlu Reha S.
Published: March 2004

In whole‐mount explant cultures of the trigeminal ganglion (TG) with intact peripheral and brainstem targets, exogenous application of nerve growth factor (NGF) and neurotrophin‐3 (NT‐3) leads to elongation and precocious arborization of embryonic trigeminal axons, respectively. In addition, neurotrophins play a major role in survival and differentiation of distinct classes of TG neurons. In the present study, we conducted morphometric analyses of trigeminal neurons exposed to exogenous NGF or NT‐3 in whole‐mount explant cultures. Explants dissected from embryonic day (E) 13 and E15 rats were cultured in the presence of serum‐free medium (SFM) or in SFM supplemented with NGF or NT‐3 for 3 days. TG neurons were then retrogradely labeled with lipophilic tracer DiI and their soma size distributions were compared following different treatments. The mean diameters of E13 and E15 trigeminal neurons grown in the presence of NT‐3 were similar to those grown in SFM. On the other hand, in cultures supplemented with NGF, the mean diameters of neurons were larger at E13, but smaller at E15. Double immunolabeling with TrkA and TrkC antibodies confirmed the presence of large‐diameter TrkA‐positive neurons in E13 TG, but not in E15 TG. At both ages, other large‐diameter neurons expressed only TrkC. These results show that exposure to NGF leads to phenotypic changes in TrkA‐expressing trigeminal neurons at early embryonic development, but selective survival of small diameter neurons at later ages. Anat Rec Part A 277A:396–407, 2004. © 2004 Wiley‐Liss, Inc.
Functional neural anatomy of talent
Authors: Kalbfleisch M. Layne
Published: March 2004

The terms gifted, talented, and intelligent all have meanings that suggest an individual's highly proficient or exceptional performance in one or more specific areas of strength. Other than Spearman's g, which theorizes about a general elevated level of potential or ability, more contemporary theories of intelligence are based on theoretical models that define ability or intelligence according to a priori categories of specific performance. Recent studies in cognitive neuroscience report on the neural basis of g from various perspectives such as the neural speed theory and the efficiency of prefrontal function. Exceptional talent is the result of interactions between goal‐directed behavior and nonvolitional perceptual processes in the brain that have yet to be fully characterized and understood by the fields of psychology and cognitive neuroscience. Some developmental studies report differences in region‐specific neural activation, recruitment patterns, and reaction times in subjects who are identified with high IQ scores according to traditional scales of assessment such as the WISC‐III or Stanford‐Binet. Although as cases of savants and prodigies illustrate, talent is not synonymous with high IQ. This review synthesizes information from the fields of psychometrics and gifted education, with findings from the neurosciences on the neural basis of intelligence, creativity, profiles of expert performers, cognitive function, and plasticity to suggest a paradigm for investigating talent as the maximal and productive use of either or both of one's high level of general intelligence or domain‐specific ability. Anat Rec (Part B: New Anat) 277B:21–36, 2004. © 2004 Wiley‐Liss, Inc.
Pharmacokinetic tracer kinetics analysis of changes in erythropoietin receptor population in phlebotomy‐induced anemia and bone marrow ablation
Authors: Veng‐Pedersen P. , Chapel S. , Al‐Huniti N.H. , Schmidt R.L. , Sedars E.M. , Hohl R.J. , Widness J.A.
Published: March 2004

Objectives—The objective was to studyin vivoerythropoietin (Epo) progenitor cell surface receptors (EpoR) in the bone marrow (BM) after phlebotomy and bone marrow ablation.

Methods—Serial tracer interaction method experiments were conducted in adult sheep at baseline and after phlebotomy (PH) and ablation (AB). PH was done 10 days after phlebotomy (to 3–4 g/dl Hb), and the AB was done 8 days after a 3‐day oral treatment with bulsulfan (11 mg/kg/day).

Results—Bone marrow ablation changed the elimination from non‐linear to linear, consistent with an abolition of the non‐linear elimination via BM EpoRs. The phlebotomy increased the linear clearance of the ablated elimination pathway (from 63.6±12 to 126±64 ml/h/kg), consistent with an up‐regulation of the erythroid progenitor BM‐based EpoR pool, but did not change the clearance of the non‐ablated elimination pathway(p>0.05). The EpoR pool size remaining after BM ablation was 7.4±2.7% of the pre‐ablation pool.

Conclusions—Erythropoietin elimination via EpoR in the bone marrow was non‐linear and increased following phlebotomy‐induced anemia. This is consistent with an up‐regulation of the erythropoietic EpoR pool in BM. Assuming that the elimination of Epo after BM ablation was via non‐hematopoietic EpoR, then this post‐ablation EpoR population was not significantly up‐regulated by the phlebotomy. Copyright © 2004 John Wiley & Sons, Ltd.
Total synthesis of artificial zinc‐finger proteins: Problems and perspectives
Authors: Futaki Shiroh , Tatsuto Kiwada , Shiraishi Yasuhisa , Sugiura Yukio
Published: March 2004

The total synthesis of a peptide segment corresponding to the DNA‐binding segment of Sp1 (positions 532–623) using a native chemical ligation approach is described. The folding of the synthetic segment in the presence of Zn(II) gave a zinc‐coordinated protein. The dissociation constant (KD) for the DNA binding of the resulting protein, determined by a gel mobility shift assay, was 130 nM, almost nine times higher than that of the genetically prepared protein. However, methylation interference assay showed an identical sequence specificity of both proteins in DNA recognition. The chemical ligation method to connect the respective zinc‐finger units was also accomplished. Successive ligation between a cysteine‐containing peptide segment and a chloroacetylated peptide segment gave an artificial three‐finger protein, which corresponds to the above DNA‐binding segment of Sp1. However, this protein failed to bind DNA, even at 1.25 mM. Assessment of their folding structure based on the absorption spectra of their Co(II) complexes showed that the linker design to connect the respective finger units is critical for the proper folding of the proteins as well as the occurrence of the DNA‐binding function. © 2004 Wiley Periodicals, Inc. Biopolymers (Pept Sci), 2004
Growth behavior of microorganisms using UV‐Vis spectroscopy:Escherichia coli
Authors: Alupoaei Catalina E. , García‐Rubio Luis H.
Published: March 2004

Multiwavelength transmission spectra of microorganisms and cell suspensions consist of combined absorption and scattering phenomena resulting from the interaction of light with microorganisms or cells typically suspended in a nonabsorbing media. The distribution of intensities as a function of wavelength depends on the size, shape, and optical properties of the sample. The optical properties are functions of the chemical composition and the state of aggregation, or association, of the chromophoric groups contained in the microorganisms. This article explores the growth behavior of Escherichia coli from the perspective of multiwavelength UV‐Vis spectroscopy. Experimentally, it is demonstrated that the spectral signatures of the microorganism evolve as a function of time. It is also demonstrated that the spectral changes observed during growth are consistent with data reported elsewhere. From the theoretical point of view, it is demonstrated that the spectral signatures can be adequately represented with an interpretation model based on light‐scattering theory. The parameters from the interpretation model reflect changes in size and chemical composition known to take place in the microorganisms during growth. © 2004 Wiley Periodicals, Inc.
Activity and enantioselectivity of wildtype and lid mutated Candida rugosa lipase isoform 1 in organic solvents
Authors: Secundo Francesco , Carrea Giacomo , Tarabiono Chiara , Brocca Stefania , Lotti Marina
Published: March 2004

The activity and enantioselectivity of lipase 1 from Candida rugosa and of a chimera enzyme obtained by replacing the lid of isoform 1 with the lid of isoform 3 were compared in organic solvents. The alcoholysis of chloro ethyl 2‐hydroxy hexanoate with methanol and of vinyl acetate with 6‐methyl‐5‐hepten‐2‐ol were used as model reactions in different reaction conditions. The chimera enzyme was less active and enantioselective than the wildtype in all the conditions tested. A rationale for such decreases could be that the chimera lipase has a lower proportion of enzyme molecules in the open form. This might lead to a hindered access to the enzyme active site, thus affecting the catalytic activity. © 2004 Wiley Periodicals, Inc.
Fundamental Escherichia coli biochemical pathways for biomass and energy production: creation of overall flux states
Authors: Carlson Ross , Srienc Friedrich
Published: March 2004

We have previously shown that the metabolism for most efficient cell growth can be realized by a combination of two types of elementary modes. One mode produces biomass while the second mode generates only energy. The identity of the four most efficient biomass and energy pathway pairs changes, depending on the degree of oxygen limitation. The identification of such pathway pairs for different growth conditions offers a pathway‐based explanation of maintenance energy generation. For a given growth rate, experimental aerobic glucose consumption rates can be used to estimate the contribution of each pathway type to the overall metabolic flux pattern. All metabolic fluxes are then completely determined by the stoichiometries of involved pathways defining all nutrient consumption and metabolite secretion rates. We present here equations that permit computation of network fluxes on the basis of unique pathways for the case of optimal, glucose‐limited Escherichia coli growth under varying levels of oxygen stress. Predicted glucose and oxygen uptake rates and some metabolite secretion rates are in remarkable agreement with experimental observations supporting the validity of the presented approach. The entire most efficient, steady‐state, metabolic rate structure is explicitly defined by the developed equations without need for additional computer simulations. The approach should be generally useful for analyzing and interpreting genomic data by predicting concise, pathway‐based metabolic rate structures. © 2004 Wiley Periodicals, Inc.
The capillary electrophoresis separation of benzodiazepine drug using dextran sulfate and SDS as running buffer
Authors: Suzuki Yoshio , Arakawa Hidetoshi , Maeda Masako
Published: March 2004

Capillary electrophoresis has been applied the analyses of many clinical drugs due to its rapid, high‐resolution separation. In this study, electrokinetic chromatography involving the combination of SDS and dextran sulfate, which are synthetic polymers, was examined in order to obtain high resolution. Use of 2% dextran sulfate (10,000 molecular weight), 20 mm SDS running buffer containing boric acid solution (pH 9.2) and a silica capillary (inner diameter of 75 µm, effective length of 50 cm, 57 cm overall length) afforded separation of 10 kinds of benzodiazepines. The detection limit was 0.2 µg/mL; additionally, reproducibilities were deﬁned as the peak height and migration time. The average peak height was 5.92% (2.46–17.61), whereas the average migration time was 0.44% (0.18–0.76; n = 5). This separations system can be applied to the analysis and measurement of other pharmaceuticals as well. Copyright © 2004 John Wiley & Sons, Ltd.
A validated HPLC method with ultraviolet detection for the determination of buformin in plasma
Authors: Chou Chen‐Hsi , Cheng Ching‐Ling , Huang Chien‐Chen
Published: March 2004

A sensitive and rapid high‐performance liquid chromatographic assay is developed and validated for the determination of buformin in plasma. After addition of metformin as the internal standard, the analytes were deproteinated with acetonitrile, washed with dichloromethane, and the resulting supernatant injected. Chromatography was performed at ambient temperature by pumping a mobile phase of 0.03 m diammonium hydrogen phosphate buffer (pH 7, 250 mL) in methanol (750 mL) at a ﬂow rate of 1 mL/min through a silica column. Buformin and metformin were detected at 236 nm, and eluted 9.8 and 15.4 min, respectively. No endogenous substances were found to interfere. Calibration curves were linear over the concentration range of 20–2000 ng/mL. The limit of quantitation was 20 ng/mL. The intra‐ and inter‐day relative standard deviation (RSD) was 8.3%, or less, and the accuracy was within 10.1% of the relative error (RE). The method is suitable in pharmacokinetic investigation of buformin. Copyright © 2004 John Wiley & Sons, Ltd.
Characterization of amyloidogenic immunoglobulin light chains directly from serum by on‐line immunoafﬁnity isolation
Authors: Bergen H. Robert , Abraham Roshini S. , Johnson Kenneth L. , Bradwell Arthur R. , Naylor Stephen
Published: March 2004

Primary systemic amyloidosis (AL) is characterized by the overproduction of immunoglobulin light chain proteins by a monoclonal, terminally differentiated B‐lymphocyte or plasma cell clone. The free immunoglobulin light chains are deposited in an abnormal conformation as amyloid in a variety of organs in the body. The mechanism of amyloid formation is not well understood, but appears to be associated with some form of cleavage of the immunoglobulin light chain with subsequent aggregate formation. In an attempt to characterize the structure of amyloid‐forming light chain proteins we developed an on‐line immunoafﬁnity puriﬁcation and subsequent characterization of free κ and free λ immunoglobulin light chains by electrospray ionization mass spectrometry. The methodology is totally automated and requires 20 µL of serum. Mass spectral analysis of Bence Jones proteins under non‐denaturing conditions was also utilized to examine the tertiary and quaternary structure of light chain proteins and clearly shows covalent dimer formation of lambda type light chain. This type of on‐line assay may prove helpful in elucidating distinguishing features capable of discriminating AL from benign monoclonal gammopathies of undetermined signiﬁcance as well as diagnosing AL. Copyright © 2004 John Wiley & Sons, Ltd.
Liquid chromatographic and mass spectrometric analysis of human serum acid alpha‐1‐glycoprotein
Authors: Kremmer T. , Szöllösi É. , Boldizsár M. , Vincze B. , Ludányi K. , Imre T. , Schlosser G. , Vékey K.
Published: March 2004

Human serum acid alpha‐1‐glycoprotein (AGP, orosomucoid) content of healthy individuals and cancer patients was measured, isolated and puriﬁed using a protocol of fast and biocompatible sample preparation, ion exchange and dye‐ligand afﬁnity chromatographic methods. In comparison to the healthy individuals signiﬁcantly higher serum AGP levels were found in a wide spectrum of cancer patients, indicating its diagnostic value in the malignant disease. Oligosaccharide content of AGP samples was separated following PNGase F enzyme digestion and analysed by RP‐HPLC and MALDI‐TOF mass spectrometry. RP‐HPLC and MALDI‐TOF mass spectrometric analysis of sugar constituents of AGP specimen originated from selected cancer patients with high serum AGP levels indicated the appearance of anomal distribution of bi‐, tri‐ and tetra‐antennary oligosaccharide structures compared to the healthy controls. Copyright © 2004 John Wiley & Sons, Ltd.
Quantitative analysis of phytoestrogens in kudzu‐root, soy and spiked serum samples by high‐pressure liquid chromatography
Authors: Benlhabib Elhabib , Baker John I. , Keyler Daniel E. , Singh Ashok K.
Published: March 2004

A sensitive and reliable HPLC method that allows simultaneous quantiﬁcation of phytoestrogens extracted from kudzu‐root and soy preparations, and serum samples has been developed. Kudzu‐root and soy preparations were mixed with 5 µg ﬂavone and 15 µg rutin (internal standards) and the phytoestrogens were extracted by using solid‐phase (C18) extraction cartridges. Blank or spiked serum samples were extracted by using either C18 cartridges or trichloroacetic acid–methanol extraction. The extracts were analyzed by the HPLC equipped with a reverse‐phase (250 × 4 mm, C18) column and UV, diode‐array or MS detector. A linear gradient of acetic acid and acetonitrile provided excellent separation of glycoside and aglycone‐phytoestrogens from kudzu root and soy preparations. The C18 cartridge extraction of serum yielded excellent recovery of both glycoside‐ and aglycone‐phytoestrogens, while the trichloroacetic acid–methanol extraction yielded excellent recovery of glycoside but poor recovery of aglycone compounds. UV and MS detectors were suitable for phytoestrogen analysis in plant and serum samples, while the diode‐array detector was suitable for generating the UV absorbance curve for phytoestrogens. Copyright © 2004 John Wiley & Sons, Ltd.
Investigation on liquid chromatographic separation of basic compounds using silica column with aqueous/organic mobile phase containing triethylamine and acetic acid
Authors: Wu An‐Bang , Huang Ming‐Chun , Ho Hsiu‐O , Yeh Geng‐Cheng , Sheu Ming‐Thau
Published: March 2004

A high‐performance liquid chromatography (HPLC) method using silica column eluted with aqueous solvent mobile phase containing triethylamine (TEA) and acetic acid (ACH) at trace percentages was characterized for the analysis of basic compounds. The key mechanism of this system is ion‐exchange accompanying interaction of silanol groups. The increase in the ACH concentration in the mobile phase minimizes the ionization of the silanol group, leading to reduced retention time. However, the greater extent of ionization of silanol caused by the increase of TEA concentration helps to retain basic compounds in the column. Further, the protonated TEA that is positively charged also competes for the ionized silanol group with basic compounds, resulting in the modiﬁcation of retention time. On the other hand, the retention becomes longer with increasing proportion of either organic or aqueous solvent in mobile phase, and partial replacement of methanol with acetonitrile. Copyright © 2004 John Wiley & Sons, Ltd.
Identiﬁcation of photoproducts from imazosulfuron by HPLC
Authors: Morrica Patrizia , Fidente Paola , Seccia Serenella
Published: March 2004

Photolysis of imazosulfuron was studied in aqueous solution under UV light. The reaction followed a pseudo‐ﬁrst‐order kinetic with signiﬁcant correlation coefﬁcient.

The major photodegradation products of imazosulfuron after irradiation under UV light were separated and tentatively identiﬁed by HPLC‐MS analysis as (4,6‐dimethoxypyrimidine‐2‐yl)aminocarbonylsulfamic acid, 4,6‐dimethoxy‐2‐ureidopyrimidine and 2,2′‐dichloro‐[3,3′] bi [imidazo[1,2‐a] pyridinyl]. The results indicate that different reaction pathways are followed: (1) cleavage of the sulfonylurea bridge; (2) desulfonylation, which can proceed either by a carbon–sulfur cleavage or a nitrogen–sulfur cleavage. A mechanism for the formation of the photoproducts is proposed. Copyright © 2004 John Wiley & Sons, Ltd.
Simultaneous determination of caffeine, theophylline and theobromine in human plasma by on‐line solid‐phase extraction coupled to reversed‐phase chromatography
Authors: Emara Samy
Published: March 2004

A reversed‐phase liquid chromatographic column switching system was described for the determination of caffeine (CF), theophylline (TH) and theobromine (TB) in human plasma with a direct injection procedure. A short protein‐coated µBondapak CN silica pre‐column (20 × 3 mm, i.d.) was used for enrichment of the drugs and clean up from weakly retained plasma components using phosphate buffer saline pH 7.4. After washing step, the retained drugs were ﬂushed into a reversed‐phase column (5 µm TSK gel ODS‐80 TM, 150 × 4.6 mm i.d.) with a mobile phase of methanol–0.01 m phosphate buffer, pH 3.5 (30:70, v/v) for the ﬁnal separation. The eluent was monitored with a UV detector at 275 nm. The resulting chromatograms showed no interference from endogenous plasma components. A linear relationship between the concentration of drug and peak height was conﬁrmed in the range of 0.5–20 µg/mL for all drugs. High extraction recoveries from plasma ranging from 96.12 to 100.32% were achieved. Validation of the method was examined performing intra‐ and inter‐day accuracy and precision and was found to be satisfactory. The coefﬁcients of variation of the three drugs were less than 3% for intra‐day and less than 4% for inter‐day run assays. Copyright © 2004 John Wiley & Sons, Ltd.
Animating song
Authors: King Scott A. , Parent Richard E.
Published: March 2004

We describe techniques used to create animations of song. Modifications to a text‐to‐audiovisual‐speech system have been made to take the extra information of timing and frequency of the lyrics from a MIDI file. Lip‐synchronized animations of song are then produced. We discuss differences between the production of speech and the production of song. Copyright © 2004 John Wiley & Sons, Ltd.