bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Perchlorate, Thiocyanate, and Nitrate on Thyroid Function in Workers Exposed to Perchlorate Long-Term
Authors: Braverman Lewis E. , He XueMei , Pino Sam , Cross Mary , Magnani Barbarajean , Lamm Steven H. , Kruse Michael B. , Engel Arnold , Crump Kenny S. , Gibbs John P.
Published: February 2005

Perchlorate (ClO4−) and thiocyanate (SCN−) are potent and nitrate (NO3−) a weak competitive inhibitor of the thyroid sodium-iodide symporter. To determine the effects of long-term, high ClO4− exposure on thyroid function, we conducted a study of 29 workers employed for at least 1.7 yr (50% over 5.9 yr) in an ammonium ClO4− production plant in Utah. Serum ClO4−, SCN−, and NO3−; serum T4, free T4 index, total T3, thyroglobulin (Tg), and TSH; 14-h thyroid radioactive iodine uptake (RAIU); and urine iodine (I) and ClO4− were assessed after 3 d off (Pre) and during the last of three 12-h night shifts in the plant (During) and in 12 volunteers (C) not working in the plant. Serum and urine ClO4− were not detected in C; urine ClO4− was not detected in 12 of 29 and was 272 μg/liter in 17 Pre workers; serum ClO4− was not detected in 27 of 29 Pre; and serum and urine ClO4− were markedly elevated during ClO4− exposure to 868 μg/liter and 43 mg/g creatinine, respectively. Serum SCN− and NO3− concentrations were similar in all groups. Thyroid RAIUs were markedly decreased in During compared with Pre (13.5 vs. 21.5%; P < 0.01, paired t) and were associated with an increase in urine I excretion (230 vs. 148 μg I/g Cr; P = 0.02, paired t) but were similar to those in the C group (14.4%). Serum TSH and Tg concentrations were normal and similar in the three groups. Serum T4 (8.3 vs. 7.7 μg/dl), free T4 index (2.4 vs. 2.2), and total T3 (147 vs. 134 ng/dl) were slightly but significantly increased in the During vs. Pre workers (P < 0.01, paired t). Thyroid volumes and patterns by ultrasound were similar in the 29 workers and 12 community volunteers. In conclusion, high ClO4− absorption during three nights work exposure decreased the 14-h thyroid RAIU by 38% in ClO4− production workers compared with the RAIU after 3 d off. However, serum TSH and Tg concentrations and thyroid volume by ultrasound were not affected by ClO4−, suggesting that long-term, intermittent, high exposure to ClO4− does not induce hypothyroidism or goiter in adults.
Migfilin and its binding partners: from cell biology to human diseases
Authors: Wu Chuanyue
Published: February 2005

Links between the plasma membrane and the actin cytoskeleton are essential for maintaining tissue integrity and for controlling cell morphology and behavior. Studies over the past several decades have identified dozens of components of such junctions. One of the most recently identified is migfilin, a widely expressed protein consisting of an N-terminal filamin-binding domain, a central proline-rich domain and three C-terminal LIM domains. Migfilin is recruited to cell-matrix contacts in response to adhesion and colocalizes with β-catenin at cell-cell junctions in epithelial and endothelial cells. Migfilin also travels from the cytoplasm into the nucleus, a process that is regulated by RNA splicing and calcium signaling. Through interactions with multiple binding partners, including Mig-2, filamin and VASP, migfilin links the cell adhesion structures to the actin cytoskeleton. It regulates actin remodeling, cell morphology and motility. In nuclei, migfilin interacts with the cardiac transcriptional factor CSX/NKX2-5 and promotes cardiomyocyte differentiation. It probably functions as a key regulator both at cell adhesion sites and nuclei, coordinating multiple cellular processes, and is implicated in the pathogenesis of several human diseases.
Signaling in stem cell niches: lessons from theDrosophilagermline
Authors: Yamashita Yukiko M. , Fuller Margaret T. , Jones D. Leanne
Published: February 2005

Stem cells are cells that, upon division, can produce new stem cells as well as daughter cells that initiate differentiation along a specific lineage. Studies using the Drosophila germline as a model system have demonstrated that signaling from the stem cell niche plays a crucial role in controlling stem cell behavior. Surrounding support cells secrete growth factors that activate signaling within adjacent stem cells to specify stem cell self-renewal and block differentiation. In addition, cell-cell adhesion between stem cells and surrounding support cells is important for holding stem cells close to self-renewal signals. Furthermore, a combination of localized signaling and autonomously acting proteins might polarize stem cells in such a way as to ensure asymmetric stem cell divisions. Recent results describing stem cell niches in other adult stem cells, including hematopoietic and neural stem cells, have demonstrated that the features characteristic of stem cell niches in Drosophila gonads might be conserved.
Biomechanical characteristics of the normal medial and lateral porcine knee menisci
Authors: Sweigart M A , Athanasiou K A
Published: February 2005

The purpose of this investigation was to examine the compressive properties of the porcine meniscus at a variety of topographical locations using a creep indentation experiment. Three different solution techniques were used to analyse the creep response of the tissue. Specifically, the indentation stiffness, aggregate modulus, permeability, Poisson's ratio, and shear modulus were determined at six different testing locations (anterior, central, and posterior regions; femoral and tibial sides) of both the medial and lateral porcine menisci. Results indicate topographical variations among the testing locations, with the femoral-anterior portion of the medial meniscus having the highest indentation stiffness (350 ± 110 kPa), aggregate modulus (270 ± 90 kPa), and shear modulus (140 ± 40 kPa). The tibial-posterior region of the medial meniscus exhibited the lowest indentation stiffness (170 ± 40 kPa), aggregate modulus (130 ± 30 kPa), and shear modulus (60 ± 20 kPa). No statistical differences were found at the six tested locations of the lateral meniscus.
Rigid-body modelling of shaken baby syndrome
Authors: Wolfson D R , McNally D S , Clifford M J , Vloeberghs M
Published: February 2005

Recent reassessment of the literature on the shaken baby syndrome (SBS) has revealed a lack of scientific evidence and understanding of all aspects of the syndrome. In particular, studies have been unable to clarify the mechanisms of injury, indicating that impact, rather than shaking alone, is necessary to cause the type of brain damage observed.

Rigid-body modelling (RBM) was used to investigate the effect of neck stiffness on head motion and head-torso impacts as a possible mechanism of injury. Realistic shaking data obtained from an anthropometric test dummy (ATD) was used to simulate shaking. In each study injury levels for concussion were exceeded, though impact-type characteristics were required to do so in the neck stiffness study. Levels for the type of injury associated with the syndrome were not exceeded.

It is unlikely that further gross biomechanical investigation of the syndrome will be able to significantly contribute to the understanding of SBS. Current injury criteria are based on high-energy, single-impact studies. Since this is not the type of loading in SBS it is suggested that their application here is inappropriate and that future studies should focus on injury mechanisms in low-energy cyclic loading.
Evaluation of a novel method for measuring tissue blood flow and gases
Authors: Aagaard S R , Damgaard L R , Berg J S , Hasenkam J M
Published: February 2005

In clinical practice a method for assessment of tissue vitality is a sought - after tool. We have developed a new sensor principle, which is able to register changes in tissue concentration of O2 and tissue flow. The technique is based on diffusion of inert gases and mass spectrometer detection of gaseous metabolites. It was hypothesized that the new sensor could register changes in vital parameters after induction and release of an ischaemic insult to muscular tissue. The sensor performance was evaluated in ten anaesthetized pigs subjected to local muscular ischaemia. Preliminary data from this study indicate the validity of registered hypoxia and reduction in tissue flow as a consequence of compromised blood supply. It was concluded that although precise calibration of the technique is not yet established, it holds promise as a technique that can be used to monitor changes in tissue vitality.
Effect of stress ratio on the fatigue behaviour of compact bone
Authors: Ota M , Ishihara S , Fleck C , Goshima T , Eifler D
Published: February 2005

During the fatigue process of bone, cracks generally initiate from the inherent defects existing in the bone. The fatigue lives of bone specimens at different stress levels as well as at different stress ratios R were evaluated using a computer simulation in which the crack propagation behaviour initiated from the inherent defects in the bone are herein considered. The S-N curves as well as the distributions of fatigue lives obtained by the simulations accurately conform with the experimental results. With the strain threshold ɛmax representing fatigue failure of the bone specimen, the values of 1500 μ for R = -1, 2500 μeP for R = 0.1 and 4000 μeP for R = 10 were extrapolated from the simulations. These values conform with experimental values reported in the literature. Such conformity indicates that the strain threshold for fatigue failure is associated with the threshold value for crack propagation.
Impact of the new General Medical Services contract on the clinical laboratory
Authors: Smellie WSA , Roy DV
Published: February 2005

The new General Medical Services contract that has been adopted in England and Wales, with similar contracts in Scotland and Northern Ireland, proposes far-reaching changes to the way in which general practitioners practise and are remunerated. This includes a range of quality indicators, which pay particular attention to chronic disease management.

Among other things, the quality indicators require certain laboratory tests to be performed or result targets to be met in defined proportions of patients in particular disease categories in order to qualify for quality payments.

This is a novel experiment, which may focus general practitioner activity on specific areas of patient management. It has significant potential impact on laboratories: testing activity in some areas may be boosted considerably; assay performance, notably bias, will have direct potential impact on practice earnings and any shift in clinical priorities may have future effects on assay development and repertoires as these become partly financially driven by practice income. The evidence base and research of the available guidance behind the indicators is sketchy in places and although there are 76 indicators several areas of practice are not addressed. The probable further increase in laboratory activity it may generate highlights the need for laboratories to continue to assist in promoting best practice in test requesting.
Lymphocyte PC-1 activity in patients on maintenance haemodialysis treated with human erythropoietin and 1-α-D3
Authors: Stefanovic V , Djordjevic V , Ivic M , Mitic-Zlatkovic M , Vlahovic P
Published: February 2005

Background: Plasma cell differentiation antigen 1 (PC-1) is an inhibitor of insulinreceptor tyrosine-kinase. PC-1 content is elevated in muscle and adipose tissue from insulin-resistant subjects and its elevation correlates with in vivo insulin resistance. It is known that insulin resistance in uraemia may be improved with erythropoietin (EPO) and vitamin D therapy. Therefore, in this study the effects of human recombinant EPO and 1-alpha-D3 treatments on lymphocyte PC-1 expression in patients with end-stage renal failure on haemodialysis (HD) were investigated.

Methods: Lymphocyte basal, concanavalin A (Con A), and phorbol-12-myristate13-acetate (PMA)-stimulated PC-1 activity were investigated in HD patients before and after a two-month treatment with subcutaneous EPO (15 patients, 2000-3000 U thrice weekly) or oral 1-α-D3 (14 patients, 2 μg thrice weekly). Twenty-nine patients (16 men and 13 women), aged 22-68 years (49 ± 7 years), on HD from 13 to 112 months, and 30 healthy controls participated in the study. None was obese and all had normal fasting plasma glucose.

Results: A two-month EPO treatment produced a 41% haematocrit increase, with a rise in haemoglobin from 6.51 ± 0.18 g/dL to 9.69 ± 0.14 g/dL. Basal lymphocyte PC-1 activity in HD patients was found to be significantly increased ( P < 0.005) over the level in healthy controls. Treatment of patients with EPO decreased unstimulated lymphocyte PC-1 activity to values significantly lower than before the treatment ( P < 0.001). Lymphocyte Con A and PMA-stimulated PC-1 activity in patients on HD was found to be slightly increased over the level in healthy controls, but significantly reduced ( P < 0.005 and 0.05, respectively) after the EPO treatment. A two-month pulse oral 1-α-D3 treatment increased haematocrit by 21% and raised haemoglobin from 7.11 ± 0.32 g/dL to 8.80 ± 0.39 g/dL. This treatment normalized serum alkaline phosphatase activity and slightly reduced serum parathyroid hormone concentration. PC-1 in unstimulated and PMA-stimulated lymphocytes was unchanged, but significantly decreased ( P < 0.05) in Con A-stimulated lymphocytes after 1-α-D3 treatment. Fasting plasma glucose was not changed by the treatment.

Conclusion: An increased lymphocyte PC-1 activity over control was found in HD patients. A two-month EPO therapy significantly decreased PC-1 activity to the control values, suggesting that an effect on PC-1 expression could be implicated in the amelioration of insulin resistance in uraemic patients treated with EPO. Treatment with pulse oral 1-α-D3 had an effect only on PC-1 of Con A-transformed lymphocytes of haemodialysed patients and requires further investigation.
Japanese standard reference material for JDS Lot 2 haemoglobin A1c. I: comparison of Japan Diabetes Society-assigned values to those obtained by the Japanese and USA domestic standardization programmes and by the International Federation of Clinical Chemistry reference laboratories
Authors: Tominaga Makoto , Makino Hideichi , Yoshino Gen , Kuwa Katsuhiko , Takei Izumi , Aono Yukuko , Hoshino Tadao , Umemoto Masao , Shimatsu Akira , Sanke Tokio , Kuwashima Masamichi , Taminato Tomohiko , Ono Junko
Published: February 2005

Background: The Committee on Standardization of Laboratory Testing Related to Diabetes Mellitus of the Japan Diabetes Society (JDS) previously recommended use of the primary calibrator (JDS Lot 1) prepared by the former Committee for Standardization of Glycohemoglobin for standardizing the measurement of haemoglobin A1c (HbA1c). Owing to the depletion of vials of Lot 1 in March 2001, the present committee certified a new reference material, Lot 2, now distributed by the Health Care Technology Foundation (HECTEF). The standardization programme for HbA1c measurement in Japan is currently based on Lot 2, which has values assigned from within Lot 1; the Lot 1 values were consensus values based on assays by laboratories in the Japanese national quality control programme. In this study, for the purpose of international comparison and standardization, Lot 2 was assayed by the JDS reference laboratories, the National Glycoprotein Standardization Program (NGSP) in the USA, and by reference laboratories approved by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC).

Method: The HbA1c values of JDS Lot 2 were transferred from those assigned to Lot 1 using KO500, a high-resolution HPLC method, at three laboratories approved by the JDS committee. Subsequently, vials of JDS Lot 2 were shipped to and assayed by the NGSP in the USA and 10 IFCC reference laboratories.

Result: The JDS-assigned HbA1c values (from Lot 1) are 4.04 for Level 1, 5.38 for Level 2, 7.32 for Level 3, 9.88 for Level 4, and 12.63 for Level 5, all expressed as a percentage of total haemoglobin. The values obtained by NGSP and the IFCC laboratories gave the following formulas: NGSP value (%) = JDS value (%) + 0.3%; IFCC value (%) = 1.068 x JDS value (%) -1.741%.

Conclusion: Although the values obtained by the IFCC laboratories are significantly lower than the values assigned to Lot 2 by the JDS, the relationship is linear. In addition, standardization of HbA1c based on JDS Lot 2 is currently at a satisfactory level in Japan. As a result, the reassignment of values for Lot 2 to agree with the IFCC values should be relatively easy and will be done after all relevant parties agree to the change.
Susceptibility of glomerular filtration rate estimations to variations in creatinine methodology: a study in older patients
Authors: Lamb Edmund J , Wood Joanna , Stowe Helen J , O'Riordan Shelagh E , Webb Michelle C , Dalton R Neil
Published: February 2005

Background: It is recommended that measurement of serum creatinine should be supplemented with a creatinine-based estimation of glomerular filtration rate (GFR). The influence of creatinine methodology on these estimates is not always appreciated. We have studied differences in creatinine methods and their influence on GFR estimation specifically in older people.

Methods: In all, 46 older patients (mean age 80 y, range 69-92 y) with predominantly mild or moderate kidney disease were studied. Serum creatinine was measured using a rate Jaffe method and two different enzymatic methods. Isotope dilution mass spectrometry served as the reference creatinine method. GFR was estimated using both the Modification of Diet in Renal Disease (MDRD) and Cockcroft and Gault formulae: a 51Cr-EDTA GFR estimation served as the reference GFR method.

Results: Both enzymatic methods produced creatinine results that were significantly different ( P < 0.001) from the reference method. The Jaffe method over- and underestimated creatinine at low and high concentrations, respectively. The most likely explanation for these differences relates to standardization of the assays. Irrespective of creatinine method, the Cockroft and Gault formula tended to underestimate GFR, and the MDRD formula to overestimate GFR. Use of the differing creatinine methods to estimate GFR produced predictable biases of the estimate, with mean GFR estimates varying by 14% across the creatinine methods.

Conclusion: Estimates of GFR depend critically upon the accuracy and precision of the creatinine measurement used in their calculation.
The importance of the interpretation of urine catecholamines is essential for the diagnosis and management of patient with dopamine-secreting paraganglioma
Authors: Tam Vicki , Ng KF , Fung LM , Wong YY , Chan Michael HM , Lam CW , Tam Sidney , Lam Christopher WK
Published: February 2005

Phaeochromocytoma or paraganglioma that exclusively secretes dopamine is very rare. This case illustrates its atypical presentation and the importance of interpretative reporting for urine catecholamines leading to the diagnosis and subsequent management of a patient with this condition. We report a 71-year-old Chinese woman with a large dopamine-secreting paraganglioma. She presented with low back pain for six months. On examination, a right abdominal mass was palpable incidentally. Her blood pressure was normal throughout. Serial 24-h urine collections for catecholamines showed enormous elevation of urine dopamine excretion to 80.7 μmol/day (normotensive: < 2.6 m mol/day). However, the daily excretions of urine adrenaline and noradrenaline, as well as their metabolites were within their respective reference intervals. Good communication between chemical pathologists and physicians prompted the arrangement of the whole body 131I-meta-iodobenzylguanidine (MIBG) scintigraphy, which showed a large signal in the right upper quadrant of the abdomen corresponding to a large extra-adrenal tumour detected by both ultrasonography and computerized tomography (CT) of the abdomen. Histological section of the tumour tissue revealed paraganglioma, which stained positive for chromogranin and neuron-specific enolase. After four months, the patient presented with chest symptoms and CT of the thorax revealed multiple nodules. Lung metastases were suspected. However, follow-up urine catechola- mine and dopamine excretions were again within their respective normotensive reference intervals. A second MIBG scintigraphy was performed, but no specific uptake at either the thorax or the abdomen could be demonstrated. Fine-needle aspiration cytology using the thoracoscopic technique was performed and immunochemical staining of the biopsy specimen showed the presence of non- small-cell carcinoma of the lung.
The comparative analytical performance of four troponin I assays at low concentration
Authors: Koerbin G , Tate JR , Potter JM , Hickman PE
Published: February 2005

Background: Low troponin concentrations have been shown to be informative in the prognosis of acute coronary syndrome. We have investigated the analytical performance of four commonly used cardiac troponin I methods at concentrations approaching their analytical limit of detection.

Method: We assayed 167 patient samples within 24 h of collection using the Beckman Coulter AccuTnI, Dade Behring Dimension, Abbott AxSYM and Bayer Centaur methods and compared their relative analytical performance.

Results: Of the four assays compared, the AccuTnI was observed to have greater sensitivity at low concentrations. Using the limit of detection as the threshold, the Beckman assay showed superior performance at concentrations corresponding to a 20% coefficient of variation (CV), the Dade assay had a similar performance; and at concentrations corresponding to 10% CV most assays provide similar information.

Conclusion: The newer or recently modified assays such as the Beckman Coulter AccuTnI and Dade Behring assays are best able to identify very low concentrations of troponin.
Thermal-Electricity Power Plants in Turkey
Authors: Balat Mustafa , Balat Havva , Acici Neslihan
Published: February 2005

In Turkey, the most significant development in production is observed in thermal power sector. In 2003, its share is about 74.78% (104,898 GWh/year) of total production (140,283 GWh) of the country. Turkey is mainly focused on increased natural gas use for Thermal Electric Power Plant production. In 2003, natural gas share is about 44.41% (62,300 GWh/year) of the total electricity production of the country. Electricity production from lignite in Turkey is 23,630 GWh and share of lignite in total generated electricity is 16.85% in 2003. Consumption of lignite for electricity generation is 82% of total lignite production. The Pliocene aged Elbistan coal field the largest lignite basin of Turkey where there are 4 sectors and only one of them is in production. Thermal power stations, having an installed capacity of power 4×340 MW, are based on lignite in this area.
Adsorption of Ammonium Ions onto a Natural Zeolite: Transcarpathian Clinoptilolite
Authors: Lebedynets Mariya , Sprynskyy Myroslav , Sakhnyuk Iryna , Zbytniewski Radoslaw , Golembiewski Roman , Buszewski Boguslaw
Published: February 2005

A study was carried out of ammonium ion sorption from synthetic aqueous solutions by Transcarpathian clinoptilolite, a natural zeolite, under static conditions. The main physical properties of the clinoptilolite and the basic parameters of its porous structure were determined. Values of the specific surface area and of the pore volume occupied by sorbed substances were calculated using the relative moisture content established and the maximum sorption capacity exhibited towards ammonium ions as well as a nitrogen adsorption/desorption method. Ammonium ion sorption by the zeolite appeared to be complete within 24 h for all fraction sizes, initial NH4+ ion concentration and adsorbate volumes. The amounts of NH4+ ions sorbed increased with increasing initial NH4+ concentration and decreasing adsorbate volumes, with the maximum sorption capacity exhibited by the clinoptilolite being 0.64 mequiv/g. The sorption effectiveness decreased somewhat with increasing fraction size. The Langmuir and Freundlich models were applied to the data obtained from the batch studies with the first model exhibiting the more satisfactory correlation coefficient value (0.996 and 0.959, respectively).
Wind Tunnel Analysis of Concentrators for Augmented Wind Turbines
Authors: Anzai Ayumu , Nemoto Yasuyuki , Ushiyama Izumi
Published: February 2005

Various power augmentation systems have been studied to improve the performance of wind rotors by increasing the energy density of the wind. One of them is the ducted augmentation system. However, most of the studies of the ducted rotor concern the effect of the diffuser [1] [2] while little research has been done concerning the concentrator (nozzle). This paper analyses the effect of the concentrator and its optimum design. The effect of power augmentation is increased if (a) the position of the rotor is correctly behind the outlet of the concentrator, (b) the outlet diameter of the concentrator is smaller than the rotor diameter, and © the inlet diameter is much larger than the rotor diameter.
Reynolds Number and Roughness Effects on Thick Airfoils for Wind Turbines
Authors: Freudenreich K. , Kaiser K. , Schaffarczyk A.P. , Winkler H. , Stahl B.
Published: February 2005

The effects of increased Reynolds number (Re) on clean and rough airfoils were investigated by wind tunnel experiments and by numerical simulation with an improved Navier-Stokes solver. By cooling the cryogenic wind tunnel in Cologne (KKK) of the German-Dutch Wind-Tunnel (DNW) down to 100 K, values of Re up to 10 × 106 were reached, based on a model chord of 500 mm. Whereas the clean surface configuration shows no drastic loss in maximum lift, the lift-to-drag ratio decreases from 95 to approximately 85, mainly due to an increase of drag. In contrast to that, rough surface configurations, including zig-zag tape for transition fixing and carborundum based distributed roughness around the nose, show increased performance for increased Re. In parallel, numerical simulations were carried out with a boundary layer stability code coupled to a Navier-Stokes solver. The trends in behaviour of the boundary-layer based properties were predicted well, in contrast to the separation pattern responsible for maximum lift.
Efficiency and Consumption: Technology and Practice
Authors: Shove Elizabeth
Published: February 2005

It is probably true that energy policy has paid more attention to resources and resource efficiencies than to overall consumption. Partly because of this, more needs to be done to conceptualise the dynamics of consumer demand. In this article I take stock of what sociological theories of consumption, technology and practice might contribute to energy and environmental policy. Recent research on a) the future of comfort and b) sustainable domestic technology is used to illustrate and elaborate on the part that technical systems (efficient and otherwise) play in redefining concepts of service and thereby structuring patterns of resource consumption.
Carbon Rationing and Personal Energy Use
Authors: Fawcett Tina
Published: February 2005

A new policy approach is needed to deliver carbon dioxide savings in the UK; this paper proposes carbon rationing for personal energy use. Current policies are extremely unlikely to result in sufficient savings to meet the 2010 national reduction target. Indeed, when international air travel emissions are included, carbon equivalent emissions have not actually fallen since 1990. In the domestic sector, energy efficiency is expected to deliver significant carbon savings, but data from recent decades show this to be a triumph of hope over experience. Instead carbon rations for personal transport and household energy use are suggested. Rations would be equal, tradable, mandatory and would decrease year-on-year. The aim would be to make guaranteed carbon savings in an egalitarian way. Practical details of rationing are outlined and concerns about its effects are debated. Finally, it is concluded that rationing has great potential to enable the UK, and other countries, to meet their carbon saving targets.
A preformed compact ribosome-binding domain in the cricket paralysis-like virus IRES RNAs
Authors: COSTANTINO DAVID , KIEFT JEFFREY S.
Published: February 2005

The internal ribosome site RNA of the cricket paralysis-like viruses (CrPV-like) binds directly to the ribosome, assembling the translation machinery without initiation factors. This mechanism does not require initiator tRNA, and translation starts from a non-AUG codon. A wealth of biochemical data has yielded a working model for this process, but the three-dimensional structure and biophysical characteristics of the unbound CrPV-like IRES RNAs are largely unexplored. Here, we demonstrate that the CrPV-like IRESes prefold into a two-part structure in the presence of magnesium ions. The largest part is a prefolded compact RNA domain that shares folding and structural characteristics with other compactly folded RNAs such as group I intron RNAs and RNase P RNA. Chemical probing reveals that the CrPV-like IRES’ compact domain contains RNA helices that are packed tightly enough to exclude solvent, and analytical ultracentrifugation indicates a large change in the shape of the IRES upon folding. Formation of this compact domain is necessary for binding of the 40S subunit, and the structural organization of the unbound IRES RNA is consistent with the hypothesis that the IRES is functionally and structurally preorganized before ribosome binding.
Labelled transition systems as a Stone space
Authors: Huth Michael
Published: February 2005

A fully abstract and universal domain model for modal transition systems and refinement is shown to be a maximal-points space model for the bisimulation quotient of labelled transition systems over a finite set of events. In this domain model we prove that this quotient is a Stone space whose compact, zero-dimensional, and ultra-metrizable Hausdorff topology measures the degree of bisimilarity such that image-finite labelled transition systems are dense. Using this compactness we show that the set of labelled transition systems that refine a modal transition system, its ''set of implementations'', is compact and derive a compactness theorem for Hennessy-Milner logic on such implementation sets. These results extend to systems that also have partially specified state propositions, unify existing denotational, operational, and metric semantics on partial processes, render robust consistency measures for modal transition systems, and yield an abstract interpretation of compact sets of labelled transition systems as Scott-closed sets of modal transition systems.
The Vinylcyclopropane–CyclopenteneRearrangement
Authors: Hudlický Tomáš , Kutchan Toni M. , Naqvi Saiyid M.
Published: February 2005

The vinylcyclopropane‐cyclopentene isomerization was discovered in 1959. After the mechanism was studied in detail, this rearrangement was incorporated into many useful synthetic schemes. Various heterocyclic permutations of the vinylcyclopropane system have also been investigated, yielding several synthetic methods based on the rearrangements of cyclopropyl ketones and cyclopropyl imines to dihydrofurans and dihydropyrroles, respectively. This chapter is concerned only with the rearrangements of vinylcyclopropanes to cyclopentenes. Excluded are Cope rearrangements of divinylcyclopropanes and rearrangements of cyclopropyl compounds not leading to cyclopentenes.

The isomerization of 2,2‐dichlorovinylcyclopropane was described in 1959. The rearrangement of the parent hydrocarbon was reported independently by two laboratories a year later. Although no prior mention of this rearrangement exists in the literature, it appears likely that it occured unobserved as early as 1922 during the preparation of vinylcyclopropane by drastic methods. The presence of cyclopentene in the reaction mixtures resulting from the Hofmann elimination of a β‐cyclopropylethylammonium salt is a likely possibility, considering the low temperature at which vinylcyclopropane rearranges. The detection and identification of reaction products by refractive indices only may have prevented recognition of the isomerization at that time.

During the decade following the discovery of the rearrangement, virtually every simple vinylcyclopropane was studied in an attempt to settle the question of biradical versus concerted mechanism. Later there was intense activity in the applications of this rearrangement and many of its analogs to organic synthesis. Studies have also emphasized transition‐metal‐catalyzed rearrangements of vinylcyclopropanes.
Tandem Vicinal Difunctionalization: β‐Addition to α,β‐Unsaturated Carbonyl Substrates Followed by α‐Functionalization
Authors: Chapdelaine Marc J. , Hulce Martin
Published: February 2005

Vicinal difunctionalization reactions play an important role in modern synthetic organic chemistry. They provide access to complex structures in a stereocontrolled fashion and act as powerful, attractive, convergent elements in synthetic strategy. Consequently, examples of these reactions are numerous. Among them may be cited the Diels–Alder reaction, which results in vicinal dialkylation of a dienophile; epoxidation–functionalization of alkenes which results in 2‐substituted alkanols carbenoid additions to alkenes resulting in cyclopropanes; organometalation–functionalization of alkynes giving vicinally disubstituted alkenes, and the additions of halides and acyl halides to alkenes using Friedel–Crafts catalysts. [2 + 2] Photocycloadditions and 1,3‐dipolar cycloadditions are but two of many more examples. New reactions are introduced regularly, such as radical cyclization–trapping, which recently has been applied to a synthesis of prostaglandin F2α.
TheBiginelli Dihydropyrimidine Synthesis
Authors: Kappe C. Oliver , Stadler Alexander
Published: February 2005

The cyclocondensation of suitable CH‐acidic carbonyl compounds, aldehydes, and urea‐type blocks under acidic conditions provides multifunctionalized derivatives. The discovery of this three‐component condensation process was made by Biginelli in 1893, therefore this reaction is called the “Biginelli reaction,” “Biginelli condensation,” or the “Biginelli dihydropyrimidine synthesis.” While the early examples of this cyclocondensation process typically involved a beta‐ketoester, aromatic aldehyde, and urea, the scope has now been extended considerably by variation of three building blocks, allowing access to a large number of multifunctionalized pyridmidine derivatives. The importance of multicomponent reactions in combinatorial chemistry has generated a renewed interest in the Biginelli reaction and the number of patents and publications on this subject is growing.

In this chapter, all three‐component condensations involving suitable CH‐acidic carbonyl compounds, aldehydes, and urea‐type building blocks following the Biginelli concept are covered. Therefore, reactions involving 1,3‐diketones or nitroacetone as building blocks leading to dihydropyrimides that follow the discussed substitution pattern are included in contrast to earlier articles. Patents are only cited if they contain information not otherwise available.
Cu,Ni, andPdMediated Homocoupling Reactions in Biaryl Syntheses: TheUllmann Reaction
Authors: Nelson Todd D. , Crouch R. David
Published: February 2005

The traditional Ullman reaction is the homocoupling of aromatic halides mediated by copper at elevated temperatures. Ullman first reported this reaction in 1901. Although the coupling conditions first reported are still widely used, a host of modifications have been made to these reactions. Some of these modifications include the use of activated and alternative metals, often resulting in much lower coupling temperatures. Nickel and palladium are the most utilized source of alternative metals, Periodic reviews have been published. This chapter covers the literature on copper, nickel, and palladium mediated homocoupling reactions in biaryl synthesis from 1901 to 2000. The focus of this chapter is the scope and limitation of these processes, preparation of the activated metal, and mechanism of the homocoupling process
Phase Transformations in Co‐Cu‐Ni Alloys
Authors: Guillon I. , Servant C. , Lyon O.
Published: February 2005

Two of the binary phase diagrams of the Co‐Cu‐Ni ternary one, Co‐Cu and Cu‐Ni, present a miscibility gap in the solid state. Several techniques were used in order to characterize the phase transformations occurring in this alloy during an ageing treatment: the Anomalous Small‐Angle X‐ray Scattering, the anomalous scattering around the Bragg peaks or Anomalous Wide‐Angle X‐ray Scattering, the Transmission Electron Microscopy, the dilatometry, and the thermomagnetometry.
Cyclic Deformation Characteristics of Titanium‐Matrix Composite Reinforced with In‐situ TiB Whiskers
Authors: Tjong S. C. , Wang G.
Published: February 2005

Cyclic deformation characteristics of the in‐situ TiBw/Ti composite fabricated via reactive hot pressing and deformed under either strain‐ or stress‐controlled condition were investigated. Low‐cycle fatigue results revealed that the fatigue resistance of the in‐situ TiBw/Ti composite is poorer than pure Ti owing the formation of the in‐situ TiB whiskers. However, in‐situ TiB whiskers enhanced the yield strength of the composite dramatically, thereby improving its high‐cycle fatigue performance.
High‐Porosity Permeable Cellular Metals and Alloys in Catalytic Processes of Gas Cleaning
Authors: Antsiferov V. N. , Makarov A. M. , Khramtsov V. D.
Published: February 2005

During the rotational moulding of plastics there are a number of key temperatures that influence to a large extent the production of good quality parts. Using well established relationships between the structure and processibility of plastics, this paper explains why polyethylene is much easier to process by rotational moulding than other polymers such as polyamides, poly(ethylene terephtalate), poly(vinylchloride) or polypropylene.
Mechanical Integrity of Thermal Barrier Coated Material Systems
Authors: Rösler J.
Published: February 2005

Thermal barrier coatings (TBCs) are of paramount importance for gas turbines as they allow to raise the thermodynamic efficiency and power output at the same time. Two issues are of particular interest as far asthe mechanical integrity of TBC‐coated material systems is concerned. First of all, it is essential to reliably predict the life time of a coated component by careful analysis of the global temperature fields and stresses. Secondly, there is a need for the development of improved coating systems, requiring detailed analysis of the local stress state at the coating interfaces. Thus, macroscopic and microscopic considerations are relevant, even though the focus of interest is quite different. It is the objective of this article to point out some of the important aspects associated with the mechanical loading of thermal barrier coated systems on both size scales.
Effect of Equal Channel Angular Pressing on Microstructure and Mechanical Properties of IF Steel
Authors: Kim H. S. , Ryu W. S. , Janecek M. , Baik S. C. , Estrin Y.
Published: February 2005

The investigation of ECAP of IF steel as a representative of single phase bcc materials demonstrates a practical applicability of this technique for improving its mechanical properties. This paper reports the experimental results on microstructural evolution and the variation of the mechanical properties of IF steel after different ECAP histories.
Nano‐Sized Cobalt Cluster Films: Structure and Functionality
Authors: Palasantzas G. , Koch S. A. , Vystavel T. , De Hosson J. Th. M.
Published: February 2005

An exchange interaction between magnetic clusters at ambient temperature leads to a correlated super‐spin glass state as a result of frustration between inter‐particle exchange interaction and randomly oriented intra‐particle anisotropy. In addition, after cluster oxidation a core‐shell system appears that causes an exchange bias field at cryogenic temperatures due to ferromagnetic‐antiferromagnetic coupling, which is also stabilized by cluster interactions.
Periodical Micro‐Structuring of Hydride Containing Metastable Aluminumoxide using Laser Interference Metallurgy
Authors: Veith M. , Andres K. , Petersen C. , Daniel C. , Holzapfel C. , Mücklich F.
Published: February 2005

Layers of the metastable ceramic HAlO are sensitive to heat: These layers transform to biphasic Al/Al2O3 due to elimination of di‐hydrogen. Using interfering Nd:YAG laser beams, periodic patterns can be produced. By these methods two dimensional structuring is obtained with the characteristics of distinctly different phases and different chemical compositions at periodic places on the layer.
Knowledge Management for Materials Processing
Authors: Rentzsch W. , Shercliff H. , Bréchet Y. , Legras L.
Published: February 2005

Manufacturing knowledge is often embedded in the minds of different experts or is not effectively shared between manufacturing stages. Many companies are therefore running the risk of missing or loosing critical information. This study discusses the concept of “knowledge maps” to document the interactions between all stages of the manufacturing process and all product attributes. Potential applications of knowledge maps in manufacturing are discussed and explored in a detailed case study.
Crystal Structure, Magnetic and Electric Properties of Ternary Neodymium Stannides.
Authors: Babyuk V. , Staszczuk P. , Bodak O. , Gorelenko Yu. , Romaka L. , Stadnyuk Yu.
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
X‐Ray Single Crystal Investigation of the NdOsSi3‐x Compound.
Authors: Rizzoli C. , Salamakha P. S. , Sologub O. L. , Zaplatynsky O. V.
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
A New Superconducting Phase of Sodium Cobalt Oxide.
Authors: Takada Kazunori , Sakurai Hiroya , Takayama‐Muromachi Eiji , Izumi Fujio , Dilanian Ruben A. , Sasaki Takayoshi
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Giant Magnetoresistance and Magnetocaloric Effects of the Mn1.82V0.18Sb Compound.
Authors: Zhang Yu Qin , Zhang Zhi Dong
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Phase Relations in the Y2O3—BaO—B2O3 System.
Authors: Li X. Z. , Chen X. L. , Jian J. K. , Wu L. , Xu Y. P. , Cao Y. G.
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Self‐Assembly of the Mesoporous Electrode Material Li3Fe2(PO4)3 Using a Cationic Surfactant as the Template.
Authors: Zhu Shenmin , Zhou Haoshen , Miyoshi Toshikazu , Hibino Mitsuhiro , Honma Itaru , Ichihara Masaki
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Comparison of Pb—Sm—Sn and Pb—Ca—Sn Alloys for the Positive Grids in a Lead Acid Battery.
Authors: Zhou Yan‐Bao , Yang Chun‐Xiao , Zhou Wei‐Fang , Liu Hou‐Tian
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Readily Available Biaryl P,N Ligands for Asymmetric Catalysis.
Authors: Knoepfel Thomas F. , Aschwanden Patrick , Ichikawa Takashi , Watanabe Takumi , Carreira Erick M.
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Anodic Coupling Reactions: The Use of N,O‐Ketene Acetal Coupling Partners.
Authors: Huang Yung‐tzung , Moeller Kevin D.
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Catalytic Action of Cobalt and Nickel Complexes of Porphyrins and Their Polymer‐Bound Derivatives in Epoxidation Reaction of Styrene.
Authors: Nikolaeva O. I. , Kurek S. S. , Ageeva T. A. , Koifman O. I.
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
A Simple and Efficient Radical Reduction Using Water‐Soluble Radical Initiator and Hypophosphorous Acid in Aqueous Alcohol.
Authors: Nambu Hisanori , Alinejad Anahita Hessamian , Hata Kayoko , Fujioka Hiromichi , Kita Yasuyuki
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Fe‐Pillared Bentonite — An Efficient Catalyst for Sulfonylation of Arenes Using Aryl and Alkyl Sulfonyl Chlorides.
Authors: Singh Devendrapratap U. , Singh Pankajkumar R. , Samant Shriniwas D.
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Stereoselective Preparation of Functionalized Acyclic Alkenylmagnesium Reagents Using i‐PrMgCl×LiCl.
Authors: Ren Hongjun , Krasovskiy Arkady , Knochel Paul
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Chelation‐Assisted Hydrative Dimerization of 1‐Alkyne Forming α,β‐Enones by an Rh(I) Catalyst.
Authors: Park Young Jun , Kwon Bong‐Il , Ahn Jeong‐Ae , Lee Hyuk , Jun Chul‐Ho
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
2‐Nitroguanidine Derivatives. Part 6. Synthesis and Chemical Properties of Hydrazo‐ and Azobis(nitroformamidine).
Authors: Metelkina E. L.
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Oxidative Cross‐Coupling of Acrylates with Vinyl Carboxylates Catalyzed by a Pd(OAc)2/HPMoV/O2 System.
Authors: Hatamoto Yuji , Sakaguchi Satoshi , Ishii Yasutaka
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Nitroguanidine‐Containing Oxamide Derivatives
Authors: Novikova T. A. , Metelkina E. L. , Efimova T. P. , Berestovitskaya V. M.
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Sn/NH4Br Assisted Selective Reduction of Nitroarenes into Anilines under Neutral Conditions.
Authors: Pasha M. A. , Jayashankara V. P.
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Potassium Dodecatungstocobaltate Trihydrate (K5CoW12O40×3H2O) as an Efficient Catalyst for Aminolysis of Epoxides.
Authors: Rafiee E. , Tangestaninejad Shahram , Habibi M. H. , Mirkhani V.
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Selective Synthesis of α,β‐Unsaturated Ketones by Dibutyltin Dimethoxide Catalyzed Condensation of Aldehydes with Alkenyl Trichloroacetates.
Authors: Yanagisawa Akira , Goudu Riku , Arai Takayoshi
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Enantioselective Fluorescent Recognition of Chiral Acids by 3‐ and 3,3′‐Aminomethyl Substituted BINOLs.
Authors: Lin Jing , Rajaram Amaresh R. , Pu Lin
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Reductive Opening of 2,7‐Dihydrodinaphthoxepin and Thiepin: Easy Regioselective Preparation of 2,2′‐Difunctionalized Binaphthyls.
Authors: Foubelo Francisco , Moreno Benjamin , Yus Miguel
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
A Practical Procedure for the Synthesis of 3‐((E)‐5‐(2,3,4,5‐Tetramethoxy‐6‐methylphenyl)‐3‐methylpent‐3‐enyl) ‐2,2‐dimethyloxirane.
Authors: Chu Yong , Kuang Yunyan , Dai Huifang , Lu Liang , Chen Fen‐er
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Asymmetric Synthesis of Highly Substituted β‐Lactones by Nucleophile‐Catalyzed [2 + 2] Cycloadditions of Disubstituted Ketenes with Aldehydes.
Authors: Wilson Jonathan E. , Fu Gregory C.
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Conjugate Addition of Organocopper Reagents to γ‐Alkoxybutenolides and Application to the Synthesis of Non‐racemic Alkyl Cyclopentenones.
Authors: Robertson Jeremy , Menard Morgan , Ford Rhonan , Bell Stephen
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Novel Three‐Component Reactions Based on a Heck Carbopalladation/Cyclization Domino Reaction.
Authors: Kressierer Christoph J. , Mueller Thomas J. J.
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Preparation of Phthalide‐Containing Methacrylates.
Authors: Puzin Yu. I. , Chebaeva T. V. , Galinurova E. I. , Muslukhov R. R. , Monakov Yu. B. , Syrkin A. M.
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.
Electrochemical Dimerization of Phenacyl Bromides N‐Acylhydrazones — A New Way to 1‐N‐Acylamino‐2,5‐diaryl‐pyrroles.
Authors: Batanero Belen , Elinson Michail N. , Barba Fructuoso
Published: February 2005

For Abstract see ChemInform Abstract in Full Text.