bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance of the Neonatal Pig Heart Subjected to Oxygen Insufficiency
Authors: Uy Rowena , Tede Nikola , Ross-Ascuitto Nancy , Ascuitto Robert
Published: December 2003

Isolated, paced, isovolumically beating, neonatal pig (n = 32) hearts underwent retrograde aortic perfusion with a solution containing insulin (100 µU/ml), glucose (5.5 mM), and palmitate (0.55 mM). Glycolysis, lactate release, glucose oxidation, palmitate oxidation, and oxygen consumption were assessed. The hearts were perfused during three periods: (1) baseline, pO2 ≈ 500 mm Hg, heart rate 150 bpm; (2) hypoxia, pO2 ≈ 60–80 mm Hg, heart rate 150 bpm, or tachycardia, pO2 ≈ 500 mm Hg, heart rate 300 bpm, and (3) recovery, return to baseline conditions. For hypoxia and tachycardia, the oxygen supply-demand ratio was comparable (≈1 nmol O2/mm Hg/gdry). During baseline, the left ventricular peak systolic pressure (PSP) averaged 126 ± 6 mm Hg, the end-diastolic pressure (EDP) 5 mm Hg, and the relaxation time constant (Tau) 34 ± 2 ms; the coronary flow was 36 ± 2 ml/min/gdry. During hypoxia, the PSP decreased to 70 ± 2 mm Hg, while EDP, Tau, and coronary flow increased to 26 ± 2 mm Hg, 104 ± 14 ms, and 70 ± 2 ml/min/gdry, respectively; palmitate oxidation and oxygen consumption decreased well below baseline. During tachycardia, the PSP decreased to 88 ± 1 mm Hg, and the EDP increased to 11 ± 1 mm Hg, while Tau and coronary flow did not change significantly; palmitate oxidation and oxygen consumption increased above baseline. For both stressors, the predicted lactate release underestimated the measured values by a factor of ≈2, but were comparable during baseline and recovery. Upon recovery, PSP returned to ≈80% of baseline, while EDP remained elevated, for both stressors. Glucose oxidation returned to baseline, but palmitate oxidation became accelerated. We conclude for neonatal pig hearts subjected to oxygen insufficiency: (1) that PSP decreases and (2) that EDP and Tau increase with hypoxia, whereas EDP increases, while Tau remains unchanged with tachycardia. Following both stressors, palmitate oxidation becomes enhanced and dissociated from mechanical activity.
Imbalanced Cytokine Secretion in Newborns
Authors: Kotiranta-Ainamo Anna , Rautonen Jukka , Rautonen Nina
Published: December 2003

In adults, a balance between Th1 and Th2 cytokine networks has been proposed to be associated with a healthy status. Newborn babies are reported to express Th2-type immune reactions. Further, the impaired protection of newborn babies against infections has been attributed to a deficient secretion of interferon gamma (IFN-γ) and interleukin-10 (IL-10). Using IFN-γ and IL-10 as surrogate markers of Th1 and Th2 orientation, we compared the patterns of IFN-γ and IL-10 secretion by peripheral blood mononuclear cells between 52 healthy newborns and 35 adults. The baseline secretion of IFN-γ in adults was similar to that of newborns. The lipopolysaccharide-stimulated IFN-γ secretion was higher in newborns than in adults, whereas the concanavalin-A-stimulated IFN-γ secretion was higher in adults. The unstimulated and stimulated IL-10 secretion was significantly lower in newborns than in adults. Using a threshold level of 1,000 pg/ml, we classified neonates and adults on the basis of their stimulated IL-10 and IFN-γ secretion. Four different groups were identified: IL-10-oriented secretion, IFN-γ- oriented secretion, balanced high secretion, and balanced low secretion. Only 25% of the neonates had a high IL-10 and a high IFN-γ secretion as compared with 77% of the adults. Eight percent of the newborns, but none of the adults, had a low secretion of both cytokines. Thirty-six percent of the neonates, but only 5% of the adults, had a high IL-10 and a low IFN-γ secretion. Thirty-one percent of the neonates and 18% of the adults had a high IFN-γ secretion, but a low IL-10 secretion. We conclude that neonates have an immature IL-10 and IFN-γ response as compared with adults. However, individual neonates may have a mature cytokine secretion, whereas others may have a Th1- or a Th2-directed immune response.
Status epilepticus and Neurodevelopmental Outcome at 2 Years of Age in an Extremely Low Birth Weight Infant
Authors: Latini G. , Verrotti A. , Giannuzzi R. , Del Vecchio A. , Quartulli L. , De Felice C.
Published: December 2003

Neonatal status epilepticus (SE) is very rare and, to date, very little information exists on SE in preterm infants. Here, we report recurrent SE as a result of hypoxic-ischemic encephalopathy in an extremely low birth weight (ELBW) infant, who had favorable neurodevelopment at a corrected age of 2 years. This clinical observation seems to indicate that recurrent SE does not exclude normal long-term neurodevelopment, even in ELBW infants.
Intestinal Development in Neonatal Calves: Effects of Glucocorticoids and Dependence on Colostrum Feeding1
Authors: Sauter S.N. , Roffler B. , Philipona C. , Morel C. , Romé V. , Guilloteau P. , Blum J.W. , Hammon H.M.
Published: December 2003

The neonatal development of the gastrointestinal tract around parturition in precocious mammals is greatly affected by endocrine factors like glucocorticoids as well as by nutritional factors. We have studied the effects of glucocorticoids and colostrum supply on intestinal morphology, cell proliferation, digestive enzyme activities, and xylose absorption in neonatal calves to test the hypothesis that the intestinal development in neonatal calves is influenced by glucocorticoids, dependent on colostrum feeding. Calves designated GrFD– and GrFD+ were fed a milk-based formula, whereas those designated GrCD– and GrCD+ received colostrum. Dexamethasone (DEXA; 30 µg/kg/day) was injected at feeding times to calves of GrFD+ and GrCD+. On day 3, the D-xylose absorption was measured. The calves were euthanized on day 5 of life. Colostrum feeding increased villus sizes in jejunum and ileum, enhanced xylose absorption capacity, and increased peptidase activities in the ileum. DEXA treatment diminished sizes and cell proliferation rates of Peyer’s patches in the ileum, yet increased proliferation of crypt cells in the ileum of formula-fed calves. DEXA reduced aminopeptidase N activities in the jejunum of formula-fed calves, but increased the peptidase activities mainly of colostrum-fed calves in the ileum. Thus, DEXA effects depended on intestinal segment and on different feeding, resulting in stimulation of crypt cell proliferation in the less mature ileum (of formula-fed calves) and in stimulation of peptidase activities in the more mature ileum (of colostrum-fed calves). We conclude that the effects of DEXA were related to the developmental stage of the neonatal intestine and promoted the intestinal development, depending on the developmental stage.
Aging Increases Neuronal Nitric Oxide Release and Superoxide Anion Generation in Mesenteric Arteries from Spontaneously Hypertensive Rats
Authors: Ferrer Mercedes , Sánchez Margarita , Minoves Nuria , Salaices Mercedes , Balfagón Gloria
Published: December 2003

We hypothesized that neuronal NO release as well as its bioavailability and vasomotor response could be affected when aging and hypertension are present simultaneously. The neuronal nitric oxide (NO) release, its metabolism and vasomotor response induced by electrical field stimulation was analyzed in isolated segments of endothelium-denuded mesenteric arteries from young and old spontaneously hypertensive rats (SHR). The nitric oxide synthase (NOS) inhibitor NG-nitro-arginine-methyl ester (L-NAME) and NOS inhibitor 7-nitroindazole both strengthened electrical field stimulation-elicited contractions more in arteries from young than aged SHR rats. Superoxide dismutase (SOD) potentiated the L-NAME effect in segments from old rats, whereas catalase decreased the contractions induced by electrical field stimulation and noradrenaline but did not modify the L-NAME effect. In noradrenaline-precontracted segments, sodium nitroprusside induced a similar relaxation in arteries from both experimental groups. This relaxation was increased by SOD in old SHR. 8Br cGMP induced greater relaxation in segments from old than from young SHR. Electrical field stimulation induced a tritium release in arteries preincubated with [3H]-noradrenaline, that was similar in both young and old SHR rats. Electrical field stimulation induced NO2– formation, which was greater in segments from old than young SHR rats. Basal cGMP levels and those stimulated with sodium nitroprusside were similar in segments from both groups. Superoxide anion production was greater from old than young SHR rats. Peroxynitrite production induced by electrical field stimulation was only detected in segments from old SHR. The results obtained in mesenteric arteries from old SHR showed increased neuronal NO release and superoxide anion production with respect to those observed in arteries from young SHR rats. This induced decreased NO bioavailability through peroxynitrite formation. The final effect is to decrease the involvement of neuronal NO in electrical field stimulation-induced vasomotor response in arteries from old SHR rats.
Observational Study on the Efficacy of Tibolone in Counteracting Early Carotid Atherosclerotic Lesions in Postmenopausal Women
Authors: Anedda Francesca Maria , Velati Andrea , Lello Stefano , Orrù Marisa , Paoletti Anna Maria , Melis Gian Benedetto , Binaghi Ferdinando
Published: December 2003

Objective: To study whether tibolone affects lipid profile and diffused intima media thickness (IMT) of the common carotid arteries (CCA) in postmenopausal women (PMW). Methods: Twenty-two PMW and 20 premenopausal women participated in the study. The PMW were randomly divided into 11 women who did not receive any treatment and 11 women who received tibolone (2.5 mg once a day). Results: After 6 months the treated women had lipoprotein(a) (Lpa), total-cholesterol (total-C), and LDL-cholesterol (LDL-C) levels lower than before, while in the non-treated women Lpa was increased. The IMT of CCA was unmodified in the treated women, whereas it increased in non-treated women. Conclusions: This preliminary study suggests that a 6-month tibolone treatment could counteract the increase of the IMT of CCA observed in untreated PMW.
Bronchial Hyperreactivity and Spirometric Impairment in Patients with Perennial Allergic Rhinitis
Authors: Ciprandi Giorgio , Cirillo Ignazio , Tosca Maria Angela , Vizzaccaro Andrea
Published: December 2003

Background: Allergic disorders are characterized by a systemic involvement of the immune response. There is a clear link between allergic rhinitis and asthma. Bronchial hyperreactivity (BHR) may be present in rhinitics. Smaller airways may also be impaired in mild asthma. This study aimed at evaluating a group of subjects suffering from perennial allergic rhinitis alone to investigate the presence of BHR and spirometric impairment. Methods: One hundred rhinitics sensitized only to perennial allergens were evaluated. Spirometry and methacholine bronchial challenge were performed. Results: Five rhinitics showed reduced values of forced expiratory volume/1 s (FEV1) without symptoms of asthma. Forty-eight rhinitics had reduced forced expiratory flow at 25 and 75% of pulmonary volume (FEF25–75) values. Seventy-two patients showed a positive methacholine challenge. In this group, reduced values of FVC (p < 0.05), FEV1 (p < 0.05), and FEF25–75 (p < 0.01) were demonstrated in comparison with BHR-negative rhinitics. There was a relationship between the degree of BHR and FEV1 values (p < 0.05) and FEF25–75 values (p < 0.01). Conclusions: This study evidences that an impairment of spirometric parameters may be observed in patients with perennial allergic rhinitis alone. A high percentage of these patients have BHR. Thus, new management strategies should be employed in rhinitics.
Predictors of Outcome in Patients with Normal-Pressure Hydrocephalus
Authors: Meier Ullrich , König Alexander , Miethke Christoph
Published: December 2003

Despite emerging knowledge of over 40 years, the postoperative results after shunt implantations in patients diagnosed for normal-pressure hydrocephalus (NPH) have not improved significantly in the last decade. For this reason, predictors have to be identified in order to preoperatively predict the course of disease. From 1982 to 2000, we examined in a prospective study 200 patients diagnosed for NPH. Of the patients who were surgically treated by a shunt implantation we could re-examine 155 (78%) in a mean time interval of 7 months after operation. The NPH was graduated according to the results of the intrathecal infusion test in an early state NPH (without brain atrophy) and late state NPH (with brain atrophy). In the study we focused our attention on the possible predictors: patient’s age, length of disease, clinical signs – like gait ataxia, dementia and bladder incontinence, etiology idiopathic/secondary as well as implanted valve type and the value of resistance to cerebrospinal fluid outflow. To measure the outcome we used the NPH recovery rate, as statistical test the χ2 according to Pearson. In 80 patients with an early stage NPH (without cerebral atrophy) and a short course of disease (<1 year), slightly distinct dementia and an implanted Miethke Dual-Switch valve were significant predictors for a positive postoperative outcome. The outflow resistance measured in the intrathecal infusion test showed only a minimal relevance for the outcome. Those 75 patients with a late state NPH (with cerebral atrophy) had a better outcome when dementia was not present, the outflow resistance was >20 mm Hg·min/ml, the CSF tap test was positive and a Miethke Dual-Switch valve was implanted.
Association between IL-1ra Gene Polymorphism and Premature Delivery
Authors: Bessler H. , Osovsky M. , Sirota L.
Published: December 2003

IL-1 receptor antagonist (IL-1ra) gene polymorphism was examined in 95 Israeli preterm newborns and compared to that of adult volunteers. The genotype was determined using PCR amplification of the variable region of intron 2 of the IL-1ra gene. The IL-1raA1 allele was found to be predominant in the two groups. However, a significant higher frequency of IL-1raA2 allele was found in preterm newborns. The difference was mainly due to higher proportion of homozygous for IL-1raA2 in the preterm neonates (19%) as compared with adults (7%). No such association could be demonstrated between IL-1raA2 allele and severe sepsis in preterm newborns. The frequency of IL-1raA2 allele among preterms with a septic episode did not differ significantly from that found in newborns without sepsis. The results suggest an association between the IL-1ra genotype and the incidence of premature delivery.
Cortical Orofacial Motor Representation in Old World Monkeys, Great Apes, and Humans
Authors: Sherwood Chet C. , Holloway Ralph L. , Erwin Joseph M. , Hof Patrick R.
Published: December 2003

This study presents a comparative stereologic investigation of neurofilament protein- and calcium-binding protein-immunoreactive neurons within the region of orofacial representation of primary motor cortex (Brodmann’s area 4) in several catarrhine primate species (Macaca fascicularis, Papio anubis, Pongo pygmaeus, Gorilla gorilla, Pan troglodytes, and Homo sapiens). Results showed that the density of interneurons involved in vertical interlaminar processing (i.e., calbindin- and calretinin-immunoreactive neurons) as well pyramidal neurons that supply heavily-myelinated projections (i.e., neurofilament protein-immunoreactive neurons) are correlated with overall neuronal density, whereas interneurons making transcolumnar connections (i.e., parvalbumin-immunoreactive neurons) do not exhibit such a relationship. These results suggest that differential scaling rules apply to different neuronal subtypes depending on their functional role in cortical circuitry. For example, cortical columns across catarrhine species appear to involve a similar conserved network of intracolumnar inhibitory interconnections, as represented by the distribution of calbindin- and calretinin-immunoreactive neurons. The subpopulation of horizontally-oriented wide-arbor interneurons, on the other hand, increases in density relative to other interneuron subpopulations in large brains. Due to these scaling trends, the region of orofacial representation of primary motor cortex in great apes and humans is characterized by a greater proportion of neurons enriched in neurofilament protein and parvalbumin compared to the Old World monkeys examined. These modifications might contribute to the voluntary dexterous control of orofacial muscles in great ape and human communication.
Explaining How “High-Grade” Systemic Inflammation Accelerates Vascular Risk in Rheumatoid Arthritis
Authors: Sattar Naveed , McCarey David W. , Capell Hilary , McInnes Iain B.
Published: December 2003

There is intense interest in mechanisms whereby low-grade inflammation could interact with conventional and novel vascular risk factors to promote the atheromatous lesion. Patients with rheumatoid arthritis (RA), who by definition manifest persistent high levels of inflammation, are at greater risk of developing cardiovascular disease. Mechanisms mediating this enhanced risk are ill defined. On the basis of available evidence, we argue here that the systemic inflammatory response in RA is critical to accelerated atherogenesis operating via accentuation of established and novel risk factor pathways. By implication, long-term suppression of the systemic inflammatory response in RA should be effective in reducing risk of coronary heart disease. Early epidemiological observational and clinical studies are commensurate with this hypothesis. By contrast, risk factor modulation with conventional agents, such as statins, may provide unpredictable clinical benefit in the context of uncontrolled systemic inflammatory parameters. Unraveling such complex relationships in which exaggerated inflammation–risk factor interactions are prevalent may elicit novel insights to effector mechanisms in vascular disease generally.
FLT3 mutations in childhood acute lymphoblastic leukemia
Authors: Armstrong Scott A. , Mabon Meghann E. , Silverman Lewis B. , Li Aihong , Gribben John G. , Fox Edward A. , Sallan Stephen E. , Korsmeyer Stanley J.
Published: December 2003

Activating mutations of the FLT3 receptor tyrosine kinase are common in acute myelogenous leukemia (AML) but are rare in adult acute lymphoblastic leukemia (ALL). We have recently shown that FLT3 is highly expressed and often mutated in ALLs with rearrangement of the mixed lineage leukemia (MLL) gene on chromosome 11q23. Because hyperdiploid ALL samples also show high-level expression of FLT3, we searched for the presence of FLT3 mutations in leukemic blasts from 71 patients with ALL. The data show that approximately 25% (6 of 25) of hyperdiploid ALL samples possess FLT3 mutations, whereas only 1 of 29 TEL/AML1-rearranged samples harbored mutations (P = .04, Fisher exact test). Three mutations are novel in-frame deletions within a 7-amino acid region of the receptor juxtamembrane domain. Finally, 3 samples from patients whose disease would relapse harbored FLT3 mutations. These data suggest that patients with hyperdiploid or relapsed ALL might be considered candidates for therapy with newly described small-molecule FLT3 inhibitors. (Blood. 2004;103: 3544-3546)
The bortezomib/proteasome inhibitor PS-341 and triterpenoid CDDO-Im induce synergistic anti–multiple myeloma (MM) activity and overcome bortezomib resistance
Authors: Chauhan Dharminder , Li Guilan , Podar Klaus , Hideshima Teru , Shringarpure Reshma , Catley Laurence , Mitsiades Constantine , Munshi Nikhil , Tai Yu Tzu , Suh Nanjoo , Gribble Gordon W. , Honda Tadashi , Schlossman Robert , Richardson Paul , Sporn Michael B. , Anderson Kenneth C.
Published: December 2003

The synthetic triterpenoid 2-cyano-3, 12-dioxooleana-1, 9-dien-28-oic acid (CDDO) induces apoptosis in leukemic cells. Here we show that CDDO and its new derivative CDDO-imidazolide (CDDO-Im) trigger apoptosis in multiple myeloma (MM) cells resistant to conventional therapies including melphalan (LR-5), doxorubicin (Dox-40), and dexamethasone (MM.1R, U266, RPMI 8226) without affecting the viability of normal cells. CDDO-IM also triggers apoptosis in bone marrow stromal cells (BMSCs) and decreases interleukin-6 (IL-6) secretion induced by MM cell adhesion to BMSCs. Moreover, CDDO-Im–induced apoptosis in MM cells is not blocked by IL-6 or insulin growth factor-1 (IGF-1). Importantly, CDDO-Im and bortezomib/proteasome inhibitor PS-341 trigger synergistic apoptosis in MM cells associated with loss of mitochondrial membrane potential, superoxide generation, release of mitochondrial proteinscytochrome c/second mitochondria-derived activator of caspases (cyctochrome c/Smac), and activation of caspase-8, -9, and -3. Conversely, the pancaspase inhibitor Z-VAD-fmk abrogates the CDDO-Im + bortezomib–induced apoptosis. Low doses of CDDO-Im and bortezomib overcome the cytoprotective effects of antiapoptotic proteins Bcl2 and heat shock protein-27 (Hsp27) as well as nuclear factor–kappa B (NF-κB)–mediated growth/survival and drug resistance. Finally, combining CDDO-Im and bortezomib induces apoptosis even in bortezomib-resistant MM patient cells. Together, these findings provide the framework for clinical evaluation of CDDO-Im, either alone or in combination with bortezomib, to overcome drug resistance and improve patient outcome in MM. (Blood. 2004;103: 3158-3166)
Resistance spot welding of aluminium and steel: A comparative experimental study
Authors: Cho Y , Hu S J , Li W
Published: December 2003

Abnormal process conditions or faults exist in production. This paper investigates the effect of these abnormal conditions on the quality of resistance spot welding of selected steel and aluminium alloys and compares the results. Various process variables including abnormal process conditions are selected and analysed by using a two-stage, sliding-level experimental method. According to the experiment matrix, acceptable ranges of welding current in their lobe curves and corresponding button diameters are obtained. The effects of the factors and their levels on the welding current and button diameter are discussed and evaluated for both steel and aluminium welding. It is concluded that any abnormal process condition can decrease the width of suitable current ranges in the lobe curve. Among the abnormal process conditions, button diameter is greatly influenced by the electrode size in steel and the poor fit-up condition in aluminium. It is also shown that aluminium has a larger variance in button diameter, showing a less robust process in resistance spot welding.
Some aspects of the electrochemical machining process supported by electrode ultrasonic vibrations optimization
Authors: Ruszaj A , Zybura M , Żurek R , Skrabalak G
Published: December 2003

Primary investigations of the electrochemical micromachining process supported by electrode ultrasonic vibrations have been carried out. As a result the basic characteristic of this process and optimal process parameters for which surface roughness is minimal have been found. It has been proved that electrode ultrasonic vibrations help to decrease the surface roughness parameter Ra in comparison to the classical electrochemical process. The analyses of phenomena occurring in the machined area and indications for further investigations have been also presented.
Analysis of the deformation mechanism of void generation and development around inclusions inside the sheet during sheet rolling processes
Authors: Hwang Y-M , Chen D-C
Published: December 2003

The purpose of this paper is to explore the deformation mechanism of void generation and development around inclusions inside sheets during sheet rolling processes. The plastic deformation and flow pattern of sheets with inclusions inside during sheet rolling were simulated by the finite element method. The influences of various rolling conditions, such as the sheet thickness reduction, frictional factors, the ratio of the inclusion diameter to sheet thickness, etc., on the generation and development of voids anticipated to occur in the front and rear of the inclusion are discussed. The critical thickness reductions under which void generation can be avoided are also investigated. Furthermore, experiments on sheet rolling with an inclusion inside the sheet are conducted. The theoretical predictions of the dimensions of the voids after rolling are compared with experimental results and relatively good agreement between them is found.
Reheating process for thixoforging of metal matrix composites fabricated by induction heating and the mechanical stirring process
Authors: Jeon Y P , Kang C G
Published: December 2003

The forming process of metal matrix composites by the die casting and squeeze casting process is limited in size and dimension in terms of final parts. The melt stirring method has problems owing to the fact that the homogeneous distribution of the reinforcements is difficult due to low weldability and the density difference between the molten metal and the reinforcement. The thixoforming process for metal matrix composites has numerous advantages compared to die casting, squeeze casting and compocasting. However, for the thixoforming process, the billet with the desired volume fraction must be heated to obtain a uniform temperature distribution over the entire cross-sectional area.

To obtain the reheating conditions of composites, the particulate reinforced metal matrix composites for thixoforming were fabricated by a combined stirring process with simultaneous electromagnetic and mechanical stirring. The matrix alloy and reinforcement were aluminium alloy (A357) and SiC particle with diameters of 14 and 25 üm respectively. The microstructure characteristics were investigated by changing the volume fraction and reinforcement size. The reheating conditions used to obtain the uniform temperature distribution over the cross-sectional area of the fabricated metal matrix composites billet were suggested with variations in the heating time, the heating temperature and the holding time.
Automatic adjustment of cutting conditions in rough turning
Authors: Ghasempoor A , Jeswiet J , Moore T N
Published: December 2003

This paper describes a system for on-line adjustment of the cutting conditions in a turning operation. Cutting conditions are set based on an adaptive model of the cutting operation taking into consideration the gradual wear of the tool. The objective is to control the rough turning operation for a predetermined tool life under varying cutting conditions. Two case studies show the feasibility of the proposed methodology.
Lean engineering in the aerospace industry
Authors: Haque B
Published: December 2003

While lean principles (developed by Womack and Jones) have been applied successfully to manufacturing and operations processes in many companies their application to engineering or new product introduction processes has been lacking. This paper introduces the principles of ‘lean engineering’ through some simple definitions, based on the original lean principles, and by describing applications of those principles in the aerospace industry via three case studies. The three case studies demonstrated the application of lean at three different levels of ‘process’ hierarchy, a detailed design activity level, a project management level and a design strategy level. The study concluded that while the application of lean principles in aerospace engineering processes (within new product introduction) is feasible for both large and small companies, the presence of a coherent and sustainable methodology was missing, as well as proper application of supporting management tools and technology.
Nesting strategy for standard parts under variable demand
Authors: Niemi E
Published: December 2003

Optimization of the cutting of sheet metal parts involves the arrangement of parts to be cut on sheets for a minimal trim loss. In addition, the number of parts of different types in any nesting layout must be selected so that an appropriate combination of such nesting layouts results in the required quantity of any part type and in a minimal amount of extra parts cut. The creation of high-quality nesting layouts of arbitrarily shaped parts is difficult, and therefore the number of nesting layouts created should be kept low and the nesting layouts should perform adequately under uncertain demand conditions. In this paper, a nesting strategy and methods for its practical implementation are presented for selecting the candidate parts to be included in each nesting layout and for choosing a combination of layouts to be cut. As another aspect, such a grouping of the parts in subsets of layouts is studied, in which the parts of each type are present in one subset only. By means of such a nesting strategy, the problem can be divided into smaller subproblems, which are solved more easily. Examples of results of numerical experiments made are given.
Dynamic and distributed early planning assessment by a hybrid simulated annealing and greedy algorithm
Authors: Maropoulos P G , McKay K , Bramall D G , Rogers B , Chapman P
Published: December 2003

This paper describes a novel methodology for optimizing the wide range of early planning choices available for the manufacture of complex products, across a distributed and dynamically changing enterprise. A hybrid simulated annealing and greedy algorithm has been developed to optimize such planning decisions. The hybrid algorithm and associated methods detailed within the paper allow the utilization of key attributes from the core product, process and resource digital models to create an initial valid plan and a dynamic ‘manufacturing phase space’. Within this phase space, the detailed methods, heuristics and algorithms are deployed in order to optimize the initial plan by evaluating alternative processes and resources. The evaluation is based on an alternative's impact on the overall solution obtained by applying user-defined cardinal weightings on quality, cost, delivery and knowledge (QCD + K) metrics. To enable the application of business objectives on QCD + K, methods were developed for the conversion of quality, delivery and knowledge into a cost equivalent. The paper is concluded with an example based upon the collaborating company's aerospace products.
Scheduling of flexible manufacturing systems: An ant colony optimization approach
Authors: Kumar R , Tiwari M K , Shankar R
Published: December 2003

The scheduling problem for flexible manufacturing systems (FMSs) has been attempted in this paper using the ant colony optimization (ACO) technique. Since the operation of a job in FMSs can be performed on more than one machine, the scheduling of the FMS is considered as a computationally hard problem. Ant algorithms are based on the foraging behaviour of real ants. The article deals with the ant algorithm with certain modifications that make it suitable for application to the required problem. The proposed solution procedure applies a graph-based representation technique with nodes and arcs representing operation and transfer from one stage of processing to the other. Individual ants move from the initial node to the final node through all nodes desired to be visited. The solution of the algorithm is a collective outcome of the solution found by all the ants. The pheromone trail is updated after all the ants have found out their respective solutions. Various features like stagnation avoidance and prevention from quick convergence have been incorporated in the proposed algorithm so that the near-optimal solution is obtained for the FMS scheduling problem, which is considered as a non-polynomial (NP)-hard problem. The algorithm stabilizes to the solution in considerably lesser computational effort. Extensive computational experiments have been carried out to study the influence of various parameters on the system performance.
Sustaining changeover improvement
Authors: Culley S J , Owen G W , Mileham A R , McIntosh R I
Published: December 2003

The role of rapid changeover in today's manufacturing environment is widely acknowledged. Tools to improve changeovers—typically Shingo's ‘SMED’ methodology—are well known. However, little work has been done to establish whether changeover gains have been sustained in differing industrial environments once initial improvement has been achieved. This paper investigates sustaining changeover improvement, investigating factors that contribute to this outcome.
An aggregate resource model for the provision of dynamic ‘resource-aware’ planning
Authors: Maropoulos P G , Bramall D G , McKay K R , Rogers B , Chapman P
Published: December 2003

The realization of agile enterprises requires substantial development of the underpinning modelling, information management and knowledge representation technologies. This paper introduces a resource model that has been developed to support the dynamic, aggregate planning of manufacturing operations within large, complex production networks during the formative stages of design. The main goal of aggregate planning is the measurement of product manufacturability and the evaluation of alternative design configurations and manufacturing scenarios, through the allocation of multiple parts to remote facilities within the supply network. The term ‘resource aware’ planning is used to indicate the creation of a dynamic interrelationship between the planning entities (products and processes) and the enterprise resources, including humans and machines. The technologies employed for implementing the pilot methods include the aggregate resource modelling methodology, a web-centric co-development environment, unique methods for enriching planning entities with knowledge and evolutionary computing methods for the rapid generation and optimization of production routes. A pilot resource aware planning system has been implemented that supports many innovative modes of operation, the initial testing of which was very encouraging.
Semi-automatic extraction of primitive geometric entities from unstructured point clouds
Authors: Goussard C L , Basson A H
Published: December 2003

The extraction of planes, cylinders and spheres from unstructured, unsegmented point clouds in reverse engineering is considered. Novel procedures to determine initial estimates for the fitting of cylinders and spheres and a grow algorithm with four intuitive parameters, which automatically identifies entity boundaries, starting with three seed points, are described.
From How to Why. Graph-Theoretical Verification of Quantum-Mechanical Aspects of π-Electron Behaviors in Conjugated Systems
Authors: Hosoya Haruo
Published: December 2003

A number of empirically known rules of the π-electronic stability of conjugated hydrocarbon molecules caused by their topological structure were analyzed for the first time systematically with the graph-theoretical molecular orbital theory developed by the author’s group. The main tool in this analysis is the topological index (or Z index) proposed by the present author for characterizing the topological nature of the structural formula of a hydrocarbon molecule, coupled with the perturbation theory of the Hückel molecular orbital method proposed by Coulson and Longuet-Higgins. A mathematical foundation was given to the global quantum-mechanical aspects of π-electron behaviors in conjugated systems and also to the diagrammatic recipe of the classical organic electron theory proposed by Robinson and Ingold. Through this analysis the specific “How” obtained by quantum chemical calculations is now explained by mathematically reasonable “Why”.
Recent Progress in the Chemistry of Rare Earth Metal Alkyl and Hydrido Complexes Bearing Mono(cyclopentadienyl) Ligands
Authors: Hou Zhaomin
Published: December 2003

The acid–base reactions between rare earth tris(alkyl) complexes and silylene-linked cyclopentadiene–amines and –phosphines afford straightforwardly the corresponding cyclopentadienyl–amido and –phosphido rare earth alkyl complexes, respectively. This method can also be utilized for the synthesis of rare earth bis(alkyl) complexes bearing mono(cyclopentadienyl) ligands such as C5Me4SiMe3. The reaction of the alkyl complexes with H2 or PhSiH3 readily gives the corresponding hydrido complexes; in the case of the bis(alkyl) complexes bearing the C5Me4SiMe3 ligand, a novel type of rare earth polyhydrido cluster has been isolated and structurally characterized. The silylene-linked cyclopentadienyl–arylamido and –phosphido rare earth alkyl complexes act as excellent catalyst precursors for the dimerization of terminal alkynes and hydrosilylation of olefins, respectively. The rare earth polyhydrido clusters exhibit unique reactivities toward unsaturated organic substrates such as lactones, nitriles, and olefins.
p-tert-Butylthiacalix[6]arene as a Clustering Ligand. Syntheses and Structures of CoII5, NiII4, and Mixed-Metal MIINiII4 (M = Mn, Co, and Cu) Cluster Complexes, and a Novel Metal-Induced Cluster Core Rearrangement
Authors: Kajiwara Takashi , Shinagawa Reiko , Ito Tasuku , Kon Noriyoshi , Iki Nobuhiko , Miyano Sotaro
Published: December 2003

Using p-tert-butylthiacalix[6]arene (H6L) as a clustering ligand, five cluster complexes having CoII5 (2), NiII4 (3) and MIINiII4 (M = CoII (4), MnII (5), and CuII (6)) cores were synthesized. In all the complexes except for 3, a pinched conic L6− acts as a pentanucleating ligand that involves a similar pyramidally arranged cluster core. Each mixed metal complex 4–6 involves four tetragonally arranged NiII ions occupying the basal plane of the pyramid and a MII ion placed at the apex position. In 3, H2L4− is in a cone conformation and the four NiII ions are arranged on the donor surface of H2L4− in a zigzag manner. The mixed metal complexes 4–6 are synthesized by reacting 3 and the appropriate M(AcO)2 in a 1:1 ratio with a novel metal-induced core rearrangement occurring. In this reaction, the insertion of a MII ion at the apex position forces the calixarene to take a cone conformation and the NiII4 array rearranges to form a tetragonal cluster.
Merocyanine Dye-Sensitization of Polythiophene in a Conjugated Polymer/TiO2 p–n Hetero-Junction Solar Cell
Authors: Imoto Kiyoaki , Takahashi Kohshin , Yamaguchi Takahiro , Komura Teruhisa , Nakamura Jun-ichi , Murata Kazuhiko
Published: December 2003

In the blended solid of merocyanine (MC) and polythiophene (PTh)/TiO2 p–n hetero-junction solar cells, a hole-transfer from the excited state of MC to the ground-state of PTh accelerated the charge separation in the depletion layer formed at the TiO2/MC+PTh interface, enhancing the photovoltaic properties. That is, the blended solar cell is not a so-called Grätzel cell being sensitized by mono-layer dyes chemically adsorbed on the TiO2 electrode, but rather the enhanced photovoltaic properties are attributable to the dye-sensitization of the conjugated polymer.
Molecular Modeling of the Solvent Structuring of Chloroform around Cellulose Triacetate
Authors: Yu Isseki , Iwata Kazuyuki , Ueda Kazuyoshi , Nakayama Haruo
Published: December 2003

A molecular dynamics simulation of the hexamer units of cellulose triacetate (CTA) in chloroform was performed to investigate the solvent structuring and dynamics behavior of chloroform molecules around the CTA polymer. During the simulation, a large fluctuation in the main chain conformation of CTA was observed in this solvent. Moreover, ring puckering of the glucose unit was also observed. In order to investigate the solvent structuring of chloroform around the solute molecule, the site-specified radial distribution function and the average velocity of the solvent atoms were precisely analyzed as a function of the distance from the CTA site. The results were compared with that obtained in our previous simulation of CTA in DMSO. The comparison showed that some DMSO molecules were strongly attracted by CTA sites, such as acetyl methyl residue, while the chloroform molecules were weakly attracted by the carbonyl oxygen of CTA. These differences affect the stability of the conformation of CTA in different solvents. In chloroform, the conformation of acetyl residues, especially at the 6 position, were rotating widely in every monomer unit, which caused a large fluctuation on the main-chain conformation. On the other hand, all acetyl side chains maintained a stable conformation in DMSO because of the strong association of DMSO molecules to the acetyl residue of CTA. The role of the solvent effects on the conformation of the polymer in solution was considered at the molecular level in this work.
Hydration Structure around the Methylene Group of Glycine Molecule
Authors: Sasaki Motoya , Kameda Yasuo , Yaegashi Masahiro , Usuki Takeshi
Published: December 2003

Neutron diffraction measurements have been carried out on aqueous 4 mol% glycine solutions. The H/D isotopic substitution technique was applied to both methylene-hydrogen (HM) and water-hydrogen (HW) atoms in order to obtain information concerning the hydration structure around the methylene group within the glycine molecule. Structural parameters for the first hydration shell of the methylene-hydrogen atoms were determined as r(HM···OW) = 2.64(1) Å and r(HM···HW) = 2.87(1) Å from the least squares fitting analysis of the observed first-order difference function, 0HΔH(Q), and the partial structure factor, aHMHex(Q), respectively. The first hydration shell of the methylene group involves ca. 2 water molecules per one glycine molecule.
Dynamics of n-Alkylammonium Ions Intercalated in Saponite
Authors: Yamauchi Miho , Ishimaru Shin’ichi , Ikeda Ryuichi
Published: December 2003

Organo-clay composites of saponite intercalated with several kinds of n-alkylmono- and diammonium ions were prepared, and the dynamic properties of the intercalated cations were investigated by solid state NMR. It was found that the cationic motions are characterized by distributed correlation times due to an environmental inhomogeneity of the interlayer space of saponite.
Assemblies Possessing Rich Hydrogen Bonds Derived from trans-Oxamidato-Bridged Dicopper(II) Complexes and Carboxyl Auxiliary Ligands
Authors: Zhang Hua-Xin , Kang Bei-Sheng , Chen Zhong-Ning , Su Cheng-Yong , Yu Kai-Bei
Published: December 2003

Three complexes [{Cu2(trans-oxap)(nic)(H2O)2}n](ClO4)n·0.5nH2O 1, [Cu2(trans-oxen)(nic)2(H2O)2]·2H2O 2, [Cu2(trans-oxen)(hyba)2(H2O)2] 3 have been obtained from reactions of the trans-oxamidato-bridged dicopper(II) unit [Cu2(trans-L)]2+ (L = oxen or oxap, H2oxen = N,N′-bis(2-aminoethyl)oxamide, H2oxap = N,N′-bis(2-aminopropyl)oxamide) with the auxiliary ligands hydroxybenzoic acid (Hhyba) and nicotinic acid (Hnic). Their structures were determined by X-ray crystallography. Results showed that polymeric chains are formed in 1, since the auxiliary ligand nic behaves as the spacer connecting the dicopper units. However, 2 and 3 contain only discrete dinuclear units, since nic in 2 and hyba in 3 are terminal ligands. Chains in 1 and dinuclear units in 2 and 3 further fabricate extended structures through hydrogen bonds. The structural diversity of these complexes results from the different affinity of the coordination donors to the copper(II). The magnetic property is exemplified by 3; thermal behaviors of all complexes have been investigated.
Adsorption of Phenols by Alkylamine-Intercalated α-Zirconium Phosphate
Authors: Hayashi Aki , Nakayama Hirokazu , Tsuhako Mitsutomo
Published: December 2003

Alkylamine-intercalated α-zirconium phosphate successfully adsorbed harmful phenols, such as phenol, chlorophenol, and 2,4-dichlorophenol. The adsorption amounts of phenols are in the order; 2,4-dichlorophenol > chlorophenol > phenol. This sequence is related to the degree of hydrophobicity of these phenols. The adsorption amounts of phenols strongly depended on the content of alkylamine in the intercalation compound. In the case of butylamine, maximum adsorptions of phenols were observed when 4.4 mmol of butylamine was intercalated into α-ZrP; above this value, the adsorption amount decreased, and some butylamine was released.
Structure and Electronic Properties of Biferrocene–TCNQ Charge-Transfer Complexes: Effects of Acceptors and Crystal Environment on the Mixed-Valence States
Authors: Mochida Tomoyuki , Yamazaki Shizue , Suzuki Shinya , Shimizu Setsuko , Mori Hatsumi
Published: December 2003

Correlations between the valence states, crystal structure, and electronic states in biferrocenium charge-transfer complexes with tetracyanoquinodimethane (TCNQ) acceptors have been revealed. Structural determination of (1′,1″′-dipropyl-1,1″-biferrocenium)+(TCNQ)3− (1) and (1′,1″′-dibutyl-1,1″-biferrocenium)+(TCNQ)3− (2) showed that these complexes form a 1:3 segregated stack structure, and are semiconductors. Stabilization of the averaged valence states in the biferrocenium cations in 1 and 2 is attributed to the symmetrical environment around the cations and to the shielding of the dipole–dipole interactions by the TCNQ columns. Structural determination of (biferrocenium)+(F4TCNQ)− (3) and (1′,1″′-diethyl-1,1″-biferrocenium)+(F4TCNQ)− (4) revealed that 3 has a segregated structure, while 4 exhibits a 2:2 mixed-stack structure, represented as ...D+D+A−A−D+D+A−A−.... Valence localization in the biferrocenium cations in these complexes can be rationalized by electrostatic interactions between the cations and the anions in addition to the low crystal symmetry. All the complexes show paramagnetic susceptibilities, which mainly arise from the contribution of the donor molecules.
N2O Removal by Catalytic Decomposition and Reduction with CH4 over Fe/Al2O3
Authors: Haneda Masaaki , Shinriki Manabu , Nagao Yukinori , Kintaichi Yoshiaki , Hamada Hideaki
Published: December 2003

N2O removal by catalytic decomposition and reduction with CH4 over Fe/Al2O3 was investigated. The catalytic conversion of N2O to N2 over Fe/Al2O3 was effectively promoted by the addition of CH4. The activity of Fe/Al2O3 normalized on a TOF basis for N2O decomposition increased linearly with the Fe loading, whereas that for N2O reduction increased with an increase in Fe loading up to 2 wt %, then subsequently decreased. Structural characterization by UV–vis and TPR revealed the presence of two types of Fe species, Fe2O3 and FeAlO3, in Fe/Al2O3. It was proposed that the catalytically active species for N2O decomposition and N2O reduction are Fe2O3 and FeAlO3, respectively.
Kinetics and Mechanism of the Oxidation of Some α-Hydroxy Acids by Benzyltrimethylammonium Dichloroiodate
Authors: Goyal Archana , Kothari Seema
Published: December 2003

The oxidation of lactic acid, mandelic acid, and ten monosubstituted mandelic acids by benzyltrimethylammonium dichloroiodate (BTMACI) in glacial acetic acid leads to the formation of the corresponding oxo acid. The reaction is first order with respect to hydroxy acid, BTMACI, and zinc chloride. An addition of benzyltrimethylammonium chloride enhances the rate slightly. [PhCH2Me3N]+[IZn2Cl6]− is postulated to be the reactive oxidizing species. The oxidation of α-deuteriomandelic acid exhibited the presence of a substantial kinetic isotope effect (kH/kD = 5.97 at 298 K). The rate of oxidation of the substituted mandelic acids showed an excellent correlation with Brown’s σ+ values. The reaction constants are negative. A mechanism involving the transfer of hydride ion to the oxidant is postulated.
Synthesis of Tetrahydropyran-2-carboxylic Acid Derivatives of Lipid A Containing an Olefin in Their Chains and Their LPS-Antagonistic Activities
Authors: Watanabe Yukiko , Shiozaki Masao , Tanaka Daisuke , Shimozato Takaichi , Kanai Saori , Kurakata Shin-ichi
Published: December 2003

Four tetrahydropyran-2-carboxylic acid derivatives with 3-(tetradec-7-enyloxy)tetradecyl chains instead of 3-(tetradecanoyloxy)tetradecanoyl chains in lipid A were synthesized and their biological activities toward human U937 cells, human whole blood cells and mouse peritoneal resident macrophages were measured. These compounds showed LPS-antagonistic activity toward these three kinds of cells. The IC50 values (nM) (1 M = 1 mol dm−3) of these four compounds (21, 21′, 24 and 24′) toward human monoblastic U937 cells were 2.2, 1.0, 0.017 and 0.055, respectively. However, the LPS-antagonistic activities (IC50 values) of these four compounds toward human whole blood cells were only 0.28, 0.21, 0.81 and 0.58 μM, respectively. The IC50 values (μM) toward mouse peritoneal resident macrophages were 2.49, 0.49, 0.91 and 0.69, respectively.