bluuebunny/crossref_metadata_2025 huggingface dataset:
Catalytic Addition of Aromatic Carbon–Hydrogen Bonds to Olefins with the Aid of Ruthenium Complexes
Authors: Kakiuchi Fumitoshi , Sekine Shinya , Tanaka Yasuo , Kamatani Asayuki , Sonoda Motohiro , Chatani Naoto , Murai Shinji
Published: July 2006

Ruthenium complexes, e.g., Ru(H)2(CO)(PPh3)3, have been found to catalyze the addition of ortho C–H bonds of aromatic ketones to olefins with a high degree of efficiency and selectivity. 2′-Methylacetophenone reacts with various types of terminal olefins to give 1 : 1 coupling products in good to excellent yields. The C–C bond formation takes place exclusively at the terminal carbon atom of olefins except for styrene which affords a mixture of two regioisomers. Acetylnaphthalenes, cyclic aromatic ketones, and heteroaromatic ketones also react with triethoxyvinylsilane to give 1 : 1 addition products in virtually quantitative yields. From 2′-acetonaphthone or 3-acetylthiophene, in which two different reaction sites are available, only one out of four possible regioisomers is obtained. The importance of the coordination of the oxygen atom of the ketone to ruthenium and the intervention of a cyclometallation intermediate are suggested. A deuterium labeling experiment using acetophenone-d5 and triethoxyvinylsilane shows that an H/D exchange between the aromatic and olefinic positions takes place to some extent, even prior to the formation of the product. This implies that the rate-determining step is not the C–H bond cleavage step, but the product forming step.
An Investigation of the Conformation of β-Carrageenan by Molecular Mechanics and Molecular Dynamics Simulations
Authors: Ueda Kazuyoshi , Ochiai Hiroshi , Imamura Akira , Nakagawa Setsuko
Published: July 2006

Carrageenan is known to change its conformation from coil to helix and to form a gel. However, the accurate conformation and the transition mechanism have not yet been detailed. In this work, the conformational behavior of β-carrageenan (a copolymer with a carrabiose repeating unit, 1,4-linked 3,6-anhydro-α-d-galactose (A) and 1,3-linked β-d-galactose (B)), was studied by using molecular mechanics and molecular dynamics simulation methods with the program CHARMM22. The energy maps of the carrabiose as a function of the dihedral angles of the glycosidic linkages between the A–B (1–3 linkage) and B–A (1–4 linkage) carrabiose units were calculated. Both carrabiose units were found to have five deep potential energy minima. Based on these carrabiose conformations, 25 conformers of the single helical chain carradodecaose were constructed and their minimum energy conformations were investigated by molecular mechanics and molecular dynamics simulations. From the results of these analyses, a possible single helical structure of β-carrageenan was elucidated. The stability of this helical conformation is discussed by comparing it with a double helical conformation, which was found from X-ray diffraction analyses of oriented fiber samples of κ-and ι-carrageenans, which are well-studied members of the carrageenan family.
Stochastic Comparisons in Airline Revenue Management
Authors: Cooper William L. , Gupta Diwakar
Published: July 2006

Consider two markets of different sizes but similar costs and fare structure. All other things being equal, is an airline’s expected revenue larger in the market with larger demand? If not, under what circumstances is it possible to compare expected revenues without carrying out a detailed analysis? In this article, we provide answers to these questions by studying the relationship between the optimal expected revenue and the demand distributions when the latter are comparable according to various stochastic orders. For the two-fare class problem with dependent demand we obtain three results. We show that airlines should prefer lesser positive dependence between fare classes when marginal demand distributions are the same. We also describe particular dependence structures under which stochastically larger marginal demand distributions improve optimal expected revenue. Finally, when the dependence between effective demands in the two fare classes arises due to “sell ups,” we show that stochastically larger marginal demand distributions should be preferred. (Sell ups occur when some lower-fare-class customers buy higher-fare tickets upon finding that the former tickets are sold out.) For a problem with an arbitrary number of fare classes and independent demands, we show that stochastically larger demand distributions should be preferred. Numerical examples demonstrating the effect of parameterized demand distributions (with appropriate stochastic ordering) and dependence structures are also presented.
The Impact of Increased Employee Retention on Performance in a Customer Contact Center
Authors: Whitt Ward
Published: July 2006

Amathematical model is developed to help analyze the benefit in contact-center performance obtained from increasing employee (agent) retention, which is in turn obtained by increasing agent job satisfaction. The contact-center performance may be restricted to a traditional productivity measure such as the number of calls answered per hour, or it may include a broader measure of the quality of service, e.g., revenue earned per hour or the number of problems successfully resolved per hour. The analysis is based on an idealized model of a contact center in which the number of employed agents is constant over time, assuming that a new agent is immediately hired to replace each departing agent. The agent employment periods are assumed to be independent and identically distributed random variables with a general agent-retention probability distribution, which depends on management policy and actions. The steady-state staff-experience distribution is obtained from the agent-retention distribution by applying renewal theory. An increasing real-valued function specifies the average performance as a function of agent experience. Convenient closed-form expressions for the overall performance as a function of model elements are derived when either the agent-retention distribution or the performance function has exponential structure. Management actions may cause the agent-retention distribution to change. The model describes the consequences of such changes on the long-run average staff experience and the long-run average performance.
Competition, Cooperation, and Information Sharing in a Two-Echelon Assembly System
Authors: Zhang Fuqiang
Published: July 2006

This paper studies a two-echelon assembly system and explores several important issues in managing decentralized supply chains. First, we investigate the behavior of the assembly system under decentralized control. It is shown that the Nash equilibrium of the competitive assembly system exists but is never system optimal. Next, we examine the role of information in the assembly system. We consider horizontal information sharing on the inventory status between the suppliers and demonstrate when information is valuable from the perspectives of the system and the individual player. We find that information sharing mitigates the system’s competition penalty in some cases, but there are also instances in which information sharing can hurt a decentralized system. Although the manufacturer always prefers information sharing, it is sometimes in the interest of the suppliers to refuse to share information. Finally, we propose a demand-independent coordination scheme for managing decentralized supply chains with either a serial or an assembly structure. The coordination scheme has practical value because very often the firm’s head (or the owner of the supply chain) does not have the accurate demand information that the local managers have. Alternatively, the demand varies over time, and the coordination contracts have to be modified. Under the transfer payment contract, the system optimal policy is the unique Nash equilibrium in the decentralized supply chain. Discussion on the relationship between our coordination scheme and existing methods in the literature is also provided.
On the Interactions Between Routing and Inventory-Management Policies in a One-Warehouse N-Retailer Distribution System
Authors: Schwarz Leroy B. , Ward James E. , Zhai Xin
Published: July 2006

This paper examines the interactions between routing and inventory-management decisions in a two-level supply chain consisting of a cross-docking warehouse and N retailers. Retailer demand is normally distributed and independent across retailers and over time. Travel times are fixed between pairs of system sites. Every m time periods, system inventory is replenished at the warehouse, whereupon an uncapacitated vehicle departs on a route that visits each retailer once and only once, allocating all of its inventory based on the status of inventory at the retailers who have not yet received allocations. The retailers experience newsvendor-type inventory-holding and backorder-penalty costs each period; the vehicle experiences in-transit inventory-holding costs each period. Our goal is to determine a combined system inventory-replenishment, routing, and inventory-allocation policy that minimizes the total expected cost/period of the system over an infinite time horizon. Our analysis begins by examining the determination of the optimal static route, i.e., the best route if the vehicle must travel the same route every replenishment-allocation cycle. Here we demonstrate that the optimal static route is not the shortest-total-distance (TSP) route, but depends on the variance of customer demands, and, if in-transit inventory-holding costs are charged, also on mean customer demands. We then examine dynamic-routing policies, i.e., policies that can change the route from one system-replenishment-allocation cycle to another, based on the status of the retailers’ inventories. Here we argue that in the absence of transportation-related cost, the optimal dynamic-routing policy should be viewed as balancing management’s ability to respond to system uncertainties (by changing routes) against system uncertainties that are induced by changing routes. We then examine the performance of a change-revert heuristic policy. Although its routing decisions are not fully dynamic, but determined and fixed for a given cycle at the time of each system replenishment, simulation tests with N = 2 and N = 6 retailers indicate that its use can substantially reduce system inventory-related costs even if most of the time the chosen route is the optimal static route.
An active protein kinase A (PKA) is involved in meiotic arrest of rat growing oocytes
Authors: Kovo Michal , Kandli-Cohen Miri , Ben-Haim Miri , Galiani Dalia , Carr Dan W , Dekel Nava
Published: July 2006

Reinitiation of meiosis in meiotically competent, fully grown mammalian oocytes is governed by a fall in intraoocyte cAMP concentrations and the subsequent inactivation of protein kinase A (PKA). A similar reduction in intraoocyte cAMP concentrations in growing, meiotically incompetent rat oocytes not leading to resumption of meiosis, questions the involvement of PKA in the regulation of meiosis at this early stage of oocyte development. We examined the possibility of whether PKA activity maintains growing oocytes in meiotic arrest and further explored the mode of activation of PKA under conditions of relatively low cAMP concentrations. Our experiment demonstrated that inactivation of PKA stimulates growing rat oocytes to resume meiosis, and elevates the activity of their maturation-promoting factor (MPF). We also found that the expressions of type I and type II regulatory subunits (RI and RII) of PKA are higher in growing and fully grown oocytes, respectively. In addition, we revealed that the common 1:1 ratio between the regulatory (R) and catalytic (C) subunits of PKA is apparently not abrogated and, in accordance PKA activity in growing oocyte - cell extract is fully dependent on cAMP. Finally, we identified in growing oocytes, the A kinase anchoring protein (AKAP) 140, which was previously depicted in fully grown oocytes. We conclude that an active PKA prevents growing oocytes from resuming meiosis. Our findings further suggest that relatively high abundance of the PKAI isoform and/or its subcellular compartmentalization, through interaction with AKAP140, could possibly account for the high basal PKA activity at relatively low intraoocyte cAMP concentrations.
Generation of embryonic stem cell lines from mouse blastocysts developed in vivo and in vitro: relation to Oct-4 expression
Authors: Tielens S , Verhasselt B , Liu J , Dhont M , Van Der Elst J , Cornelissen M
Published: July 2006

Embryonic stem (ES) cells are the source of all embryonic germ layer tissues. Oct-4 is essential for their pluripotency. Since in vitro culture may influence Oct-4 expression, we investigated to what extent blastocysts cultured in vitro from the zygote stage are capable of expressing Oct-4 and generating ES cell lines. We compared in vivo with in vitro derived blastocysts from B6D2 mice with regard to Oct-4 expression in inner cell mass (ICM) outgrowths and blastocysts. ES cells were characterized by immunostaining for alkaline phosphatase (ALP), stage-specific embryonic antigen-1 (SSEA-1) and Oct-4. Embryoid bodies were made to evaluate the ES cells’ differentiation potential. ICM outgrowths were immunostained for Oct-4 after 6 days in culture. A quantitative real-time PCR assay was performed on individual blastocysts. Of the in vitro derived blastocysts, 17% gave rise to ES cells vs 38% of the in vivo blastocysts. Six-day old outgrowths from in vivo developed blastocysts expressed Oct-4 in 55% of the cases vs 31% of the in vitro derived blastocysts. The amount of Oct-4 mRNA was significantly higher for freshly collected in vivo blastocysts compared to in vitro cultured blastocysts. In vitro cultured mouse blastocysts retain the capacity to express Oct-4 and to generate ES cells, be it to a lower level than in vivo blastocysts.
Gene expression profiles of Spo11−/− mouse testes with spermatocytes arrested in meiotic prophase I
Authors: Smirnova Natalya A , Romanienko Peter J , Khil Pavel P , Camerini-Otero R Daniel
Published: July 2006

Spo11, a meiosis-specific protein, introduces double-strand breaks on chromosomal DNA and initiates meiotic recombination in a wide variety of organisms. Mouse null Spo11 spermatocytes fail to synapse chromosomes and progress beyond the zygotene stage of meiosis. We analyzed gene expression profiles in Spo11−/ −adult and juvenile wild-type testis to describe genes expressed before and after the meiotic arrest resulting from the knocking out of Spo11. These genes were characterized using the Gene Ontology data base. To focus on genes involved in meiosis, we performed comparative gene expression analysis of Spo11−/ −and wild-type testes from 15-day mice, when spermatocytes have just entered pachytene. We found that the knockout of Spo11 causes dramatic changes in the level of expression of genes that participate in meiotic recombination (Hop2, Brca2, Mnd1, FancG) and in the meiotic checkpoint (cyclin B2, Cks2), but does not affect genes encoding protein components of the synaptonemal complex. Finally, we discovered unknown genes that are affected by the disruption of the Spo11 gene and therefore may be specifically involved in meiosis and spermatogenesis.
Temporal relationship between proliferating and apoptotic hormone-producing and endothelial cells in the equine corpus luteum
Authors: Aguilar J , Fraser H M , Wilson H , Clutton E , Shaw D J , Watson E D
Published: July 2006

The temporal relationship between endothelial cell death, vascular regression and the death of hormone-producing cells in the mare has not been established. To determine the dynamics of cell proliferation and death throughout the luteal phase, corpora lutea were studied at the early, mid- and late luteal phase, and after treatment with cloprostenol in the mid-luteal phase to induce premature luteolysis. Changes in cell proliferation and apoptosis were investigated utilising specific markers (phosphorylated histone-3 and activated caspase-3 respectively). Histone-3 positive cells were most abundant during the early luteal phase, and were mainly present in endothelial cells. Histone-3 activity significantly increased in hormone-producing cells 36 h after cloprostenol treatment. Frequency of activated caspase-3 staining peaked on day 14, and was induced by 36 h after cloprostenol administration in mid-luteal phase. However, cell death occurred simultaneously in the endothelial and hormone-producing cells. These results show that a subset of hormone-producing cells enter the early stages of cell division around luteolysis, while the majority of cells are undergoing cell death. Natural and induced functional and structural luteal regression in the mare can be at least partially attributed to simultaneous apoptosis of endothelial and hormone-producing cells. However, there is no evidence that endothelial cell death is the trigger for naturally occurring luteolysis.
The absence of a Ca2+ signal during mouse egg activation can affect parthenogenetic preimplantation development, gene expression patterns, and blastocyst quality
Authors: Rogers N T , Halet G , Piao Y , Carroll J , Ko M S H , Swann K
Published: July 2006

A series of Ca2+ oscillations during mammalian fertilization is necessary and sufficient to stimulate meiotic resumption and pronuclear formation. It is not known how effectively development continues in the absence of the initial Ca2+ signal. We have triggered parthenogenetic egg activation with cycloheximide that causes no Ca2+ increase, with ethanol that causes a single large Ca2+ increase, or with Sr2+ that causes Ca2+ oscillations. Eggs were co-treated with cytochalasin D to make them diploid and they formed pronuclei and two-cell embryos at high rates with each activation treatment. However, far fewer of the embryos that were activated by cycloheximide reached the blastocyst stagecompared tothose activated by Sr2+ orethanol. Any cycloheximide-activated embryos that reached the blastocyst stage had a smaller inner cell mass number and a greater rate of apoptosis than Sr2+-activated embryos. The poor development of cycloheximide-activated embryos was due to the lack of Ca2+ increase because they developed to blastocyst stages at high rates when co-treated with Sr2+ or ethanol. Embryos activated by either Sr2+ or cycloheximide showed similar signs of initial embryonic genome activation (EGA) when measured using a reporter gene. However, microarray analysis of gene expression at the eight-cell stage showed that activation by Sr2+ leads to a distinct pattern of gene expression from that seen with embryos activated by cycloheximide. These data suggest that activation of mouse eggs in the absence of a Ca2+ signal does not affect initial parthenogenetic events, but can influence later gene expression and development.
Rho A/Rho kinase: human umbilical artery mRNA expression in normal and pre eclamptic pregnancies and functional role in isoprostane-induced vasoconstriction
Authors: Friel Anne M , Sexton Donal J , O’Reilly Michael W , Smith Terry J , Morrison John J
Published: July 2006

Pre eclampsia represents a state of increased or prolonged vasoconstriction, partially linked to the potent vasocontractile effect of isoprostanes. The process of Rho A-mediated calcium sensitisation is inherent to a state of prolonged contractility in many smooth muscle types. The aim of this study was (1) to investigate mRNA expression levels of Rho A and Rho kinase isoforms (I and II) in the umbilical artery from normotensive and pre eclamptic women and (2) to determine whether the effects of two isoprostanes, 8-iso prostaglandin F2α (8-iso PGF2α) and 8-iso prostaglandin E2 (8-iso PGE2), on umbilical artery tone, were mediated via the Rho kinase pathway. Real-time RT-PCR using primers for Rho A, ROCK I and ROCK II was performed on total RNA isolated from umbilical artery specimens obtained from normotensive and pre eclamptic women. The effects of both isoprostanes (n = 6) (in the absence and presence of the specific Rho kinase inhibitor Y-27632), on umbilical artery tone were measured, and compared with control recordings. Rho A mRNA expression levels were significantly lower in umbilical artery samples obtained from pre eclamptic women (n = 4) in comparison to those from normotensive women (n = 6) (P < 0.05). ROCK I and ROCK II mRNA levels were similar in both vessel types (P > 0.05). Both isoprostanes exerted a significant concentration-dependent vasocontractile effect (n = 7) (P < 0.001) on umbilical artery. For 8-iso PGE2, this effect was antagonised by Y-27632 (n = 6) (P < 0.01). The significant reduction of Rho A mRNA levels in umbilical arteries from pregnancies complicated by pre eclampsia may serve to counteract the diminished perfusion associated with the pathophysiology of pre eclampsia. The vasocontractile effect of 8-iso PGE2 in pre eclampsia may in part be mediated via the Rho kinase pathway.
Cytoplasmic polyadenylation controls cdc25B mRNA translation in rat oocytes resuming meiosis
Authors: Gershon Eran , Galiani Dalia , Dekel Nava
Published: July 2006

Resumption of meiosis in oocytes represents the entry into M-phase of the cell cycle and is regulated by the maturation-promoting factor (MPF). Activation of MPF is catalyzed by the dual specificity phosphatase, cdc25. In mammals, cdc25 is represented by a multigene family consisting of three isoforms: A, B and C. A recent report that female mice lacking cdc25B exhibit impaired fertility suggests a role for this isoform in regulating the G2- to M-transition in mammalian oocytes. Supporting the above-mentioned observation, we demonstrate herein that microinjection of neutralizing antibodies against cdc25B interfered with the ability of rat oocytes to undergo germinal vesicle breakdown (GVB). We also show accumulation of cdc25B in GVB oocytes and a transient reduction in its amount at metaphase I of meiosis. The accumulation of cdc25B was associated with its mRNA cytoplasmatic polyadenylation and was prevented by the protein synthesis inhibitor cyclohexamide as well as by the polyadenylation inhibitor cordycepin. Immunofluorescence staining revealed translocation of cdc25B to the metaphase II spindle apparatus. Taken together, our findings provide evidence that cdc25B is involved in resumption of meiosis in rat oocytes. We further demonstrate for the first time, a periodic accumulation of cdc25B throughout meiosis that is translationally regulated and involves cdc25B mRNA polyadenylation.
Duplicated insertion mutation in the microtubule-associated protein Spag5 (astrin/MAP126) and defective proliferation of immature Sertoli cells in rat hypogonadic (hgn/hgn) testes
Authors: Suzuki Hiroetsu , Yagi Mio , Suzuki Katsushi
Published: July 2006

Male rats with hypogonadism (hgn/hgn) experience sterility from testicular dysplasia, which is controlled by a single recessive gene, hgn. The postnatal growth of the seminiferous tubules was severely affected. In this study, we localized the hgn locus to a 320 kb region on rat chromosome 10 and detected the insertion of a 25 bp duplication into the sixth exon of the sperm-associated antigen 5 (Spag5/astrin/MAP126) gene, which codes for a microtubule-associated protein. This mutation results in a truncated Spag5 protein lacking the primary spindle-targeting domain at the C terminus. Immunological staining with antibodies to markers for Sertoli and germ cells during the early postnatal period indicated that the abnormal mitosis with dispersed chromosomes in hgn/hgn testes occurs in proliferating Sertoli cells. Therefore, apoptotic Sertoli cell death would result from the disorganization of the spindle apparatus caused by defective Spag5. These findings suggested that the Spag5 is essential for testis development in rats and that the hgn/hgn rat is a unique animal model for studying the function of Spag5.
Quantification of healthy follicles in the neonatal and adult mouse ovary: evidence for maintenance of primordial follicle supply
Authors: Kerr J B , Duckett R , Myers M , Britt K L , Mladenovska T , Findlay J K
Published: July 2006

Proliferation and partial meiotic maturation of germ cells in fetal ovaries is believed to establish a finite, non-renewable pool of primordial follicles at birth. The supply of primordial follicles in postnatal life should be depleted during folliculogenesis, either undergoing atresia or surviving to ovulation. Recent studies of mouse ovaries propose that intra- and extraovarian germline stem cells replenish oocytes and form new primordial follicles. We quantified all healthy follicles in C57BL/6 mouse ovaries from day 1 to 200 using unbiased stereological methods, immunolabelling of oocyte meiosis (germ cell nuclear antigen (GCNA)) and ovarian cell proliferation (proliferating cell nuclear antigen (PCNA)) and electronmicroscopy. Day 1 ovaries contained 7924±1564 (s.e.m.) oocytes or primordial follicles, declining on day 7 to 1987±203, with 200–800 oocytes ejected from individual ovaries on that day and day 12. Discarded oocytes and those subjacent to the surface epithelium were GCNA-positive indicating their incomplete meiotic maturation. From day 7 to 100 mean numbers of primordial follicles per ovary were not significantly depleted but declined at 200 days to 254±71. Mean numbers of all healthy follicles per ovary were not significantly different from day 7 to 100 (range 2332±349–3007±322). Primordial follicle oocytes were PCNA-negative. Occasional unidentified cells were PCNA-positive with mitotic figures observed in the cortex of day 1 and 12 ovaries. Although we found no evidence for ovarian germline stem cells, our data support the hypothesis of postnatal follicle renewal in postnatal and adult ovaries of C57BL/6 mice.
Immunizations for Patients With Metabolic Disorders
Authors: Kingsley Jeffrey D. , Varman Meera , Chatterjee Archana , Kingsley Rae A. , Roth Karl S.
Published: July 2006

Individuals with underlying metabolic disorders are a potential high-risk group for vaccine-preventable diseases. Newborn metabolic screening has provided a means of early identification and treatment for many of these disorders, whereas childhood immunization is one of the most effective means of decreasing the morbidity and mortality resulting from communicable diseases worldwide. There are very few contraindications to the routine administration of vaccines to the healthy, immunocompetent individual. In certain high-risk groups, such as immunocompromised patients, gravid females, and those with a history of previous anaphylactic reaction to a vaccine or its components, selective withholding of immunizations must be considered to decrease potential adverse events. A detailed analysis of the medical literature revealed few specific recommendations regarding appropriate immunization techniques for patients with metabolic disorders. In this review we detail the major metabolic disorder subtypes, elaborate on the available literature on immunizations for patients with these disorders, and provide suggested vaccine recommendations.
Intracranial Hemorrhage as the Initial Manifestation of a Congenital Disorder of Glycosylation
Authors: Cohn Ronald D. , Eklund Erik , Bergner Amanda L. , Casella James F. , Woods S. Lee , Althaus Janyne , Blakemore Karin J. , Fox Harold E. , Hoover-Fong Julie E. , Hamosh Ada , Braverman Nancy E. , Freeze Hudson H. , Boyadjiev Simeon A.
Published: July 2006

Intracranial hemorrhage in a term neonate is a rare event in the absence of an identifiable precipitating factor such as severe thrombocytopenia, mechanical trauma, asphyxia, infections, or congenital vascular malformations. Congenital disorders of glycosylation are a genetically and clinically heterogeneous group of multisystem disorders characterized by the abnormal glycosylation of a number of glycoproteins. Although bleeding caused by abnormal glycosylation of various coagulation factors is a well-known clinical complication of several types of congenital disorders of glycosylation, intracranial hemorrhage has not been reported as an initial manifestation of this entity. Here we report the detailed history of a family with 2 consecutive male infants, both born at term with intracranial hemorrhage diagnosed within the first 24 hours of life. The diagnosis of a congenital disorder of glycosylation was established in the second infant by an abnormal glycosylation of serum transferrin detected by electrospray-ionization mass spectrometry. Both infants showed significant neurologic deterioration during the first month of life, and both died at 5 months of age. Intracranial hemorrhage in a term neonate without a potential precipitating factor represents yet another clinical feature that should raise the suspicion for a congenital disorder of glycosylation.
Schimke Versus Non-Schimke Chronic Kidney Disease: An Anthropometric Approach
Authors: Lücke Thomas , Franke Doris , Clewing J. Marietta , Boerkoel Cornelius F. , Ehrich Jochen H.H. , Das Anibh M. , Z̆ivičnjak Miroslav
Published: July 2006

Schimke-immuno-osseous dysplasia is a rare autosomal-recessive multisystem disorder with the main clinical features of disproportionate growth deficiency, defective cellular immunity, and progressive renal disease. It is caused by mutations of SMARCAL1, a gene encoding a putative chromatin remodeling protein of unknown function. Because a detailed description of the clinical features is an essential first step in elucidating the function of SMARCAL1, we present the first detailed anthropometric data for Schimke-immuno-osseous dysplasia patients. By comprehensive anthropometric examination (28 parameters) of 8 patients (3 females) with the typical findings of Schimke-immuno-osseous dysplasia (mean age: 14.8 years; range: 4.9–30.5 years) and 304 patients (117 females) with congenital and hereditary chronic kidney disease (mean age: 10.7 ± 4.8 years; range: 3–21.8 years), we show that Schimke-immuno-osseous dysplasia patients differ significantly from those with other forms of chronic kidney disease. z scores were calculated with reference limits derived from 5155 healthy children (2591 females) aged 3 to 18 years. The key finding was that, in the latter group, median leg length was significantly more reduced than sitting height, whereas in Schimke-immuno-osseous dysplasia patients, the reduction of sitting height was significantly more pronounced than for leg length. Therefore, the ratio of sitting height/leg length might be a simple tool for the clinician to distinguish Schimke-immuno-osseous dysplasia from other chronic kidney disease patients. Schimke-immuno-osseous dysplasia is very likely if this ratio is <0.83. However, other forms of chronic kidney disease have to be discussed in case of a ratio >1.01.
Optoelectronic applications of lanthanide‐doped sol‐gel products and porous anodic alumina
Authors: Maliarevich G. K. , Molchan I. S. , Gaponenko N. V. , Mudryi A. V. , Gaponenko S. V. , Lutich A. A. , Thompson G. E.
Published: July 2006

Abstract— Recent studies on structures, comprising lanthanide‐doped xerogels embedded in porous anodic alumina, are presented. It is shown that a terbium and europium co‐doped sol‐gel film embedded in porous anodic alumina allows a change in the color of the photoluminescence, from red to green, with a change in the excitation wavelength. The possibility of strong erbium‐related 1.53‐μm emission from yttrium‐aluminium garnets in porous anodic alumina is also demonstrated. Visually, it is revealed that the blue alumina‐related emission is predominant over the red europium‐related emission from the structure xerogel/porous anodic alumina structure. Finally, the birefringence effect of a porous anodic alumina membrane is discussed.
Photoinduced ferroelectric parameter changes in liquid‐crystal systems containing chiral α,β‐unsaturated ketones
Authors: Popova Ekaterina V. , Fedoryako Aleksandr P. , Pivnenko Nikolay S. , Kutulya Lidiya A.
Published: July 2006

Abstract— Photoinduced changes that were revealed for ferroelectric liquid‐crystalline systems with helical supra‐molecular structures induced with chiral α,β‐unsaturated ketones have been summarized. Photoinduced inversion of the spontaneous polarization sign and a concomitant increase in its absolute value and other ferroelectric parameters were observed. The E‐Z photoisomerization of the chiral compounds was determined to be responsible for the discovered effects.
Influence of the preparation and excitation conditions of ZnS:Er,F TFELS on the radiative characteristics in the visible and near‐infrared spectral regions
Authors: Vlasenko N. A. , Veligura L. I. , Denisova Z. L. , Mukhlyo M. A. , Tsyrkunov Yu. A. , Zinchenko V. F. , Bagazky A. V.
Published: July 2006

Abstract— The voltage (V) dependences of the luminance and transferred charge of ZnS:Er,F TFELS prepared by varying the annealing temperature (Tann) are given at different frequencies (f). The change in the relative intensity of the green band (523 nm) and the near‐infrared bands (983 and 1530 nm) in the emission spectrum when V, f, and Tann are varied is also considered. The influence of the annealing temperature on the energy spectrum of defects in ZnS:Er,F film was studied by photodepolarization spectroscopy. The revealed effect of the above excitation and preparation conditions on the radiative characteristics is discussed.
Interactive display technologies
Authors: Trofimov Yuri , Posedko Valery , Sivenkov Vladimir , Lishik Sergey , Tsvirko Vitalii , Posedko Alla , Pautino Alexander
Published: July 2006

Abstract—The current state of the art of interactive displays, the main principles of their operation, and their functional characteristics are reviewed. Special attention is given to interactive displays with contactless control; in particular, to photo‐sensitive displays. A number of photo‐sensitive display cell designs are considered, as well as the problems related to the production of such cells. The results of the authors' research in this field are presented.
Spectral‐polarizing properties and light stability of film polarizers with azodyes
Authors: Agabekov V. , Ariko N. , Filippovich L.
Published: July 2006

Abstract— Results of the investigation of film polarizers on a base of polyvinyl alcohol and azobenzeneazonaphtalene dyes are presented. The dependence of the light stability of these polarizers on the structure and concentration of a dye, the stretching and conditions of the chemical treatment of films, as well as the physical state of the polymer matrix have been studied. Based on obtained results, a method for improving the light stability has been proposed.
Dynamic parameters of electrically controlled light scattering in helix FLC cells
Authors: Andreev Alexander L. , Bobylev Yury P. , Fedosenkova Tatiyana B. , Yambaev Ildar B. , Kompanets Igor N. , Pozhidaev Eugene P. , Shoshin Vadim M. , Shumkina Yuliya P.
Published: July 2006

Abstract— The light‐scattering structures in monomeric FLCs have been considered and a mechanism for the scattering on transient domains in the helix layers has been proposed. An optical response with a bistable characteristic of light scattering and transmission was realized at a defined electrical pulse regime and boundary conditions in electro‐optical FLC cells. The total time of the scattering switching on and switching off is less than 400 μsec at ±36 V. They are quite fast, and FLC cells are quite transparent to be used in a stack of 30–100 light‐scattering shutters for a volumetric screen of a 3‐D display.
Light‐scattering liquid‐crystal composites with reduced off‐axis haze
Authors: Dolgov L. O. , Yaroshchuk O. V.
Published: July 2006

Abstract— The majority of liquid‐crystal (LC) composites operating in a light‐scattering mode suffer from scattering of the obliquely incident light in the field on‐state (off‐axis haze effect). This is evident in the angularly selective viewing‐angle characteristic with a maximal transmittance corresponding to the normally incident light. We consider methods to control the viewing‐angle characteristic of polymer‐dispersed LC (PDLC) and filled LC. For PDLC samples, this control is realized by modification of the refractive index of the polymer matrix with highly refractive nanoparticles (NP) having a low rate of aggregation in the polymer. By proper optimization of NP concentration, one can bring the refractive index of the polymer matrix in the range needed to reduce the haze problem. In filled LC, the viewing‐angle curve depends on the refractive‐index mismatch between the LC and NP. By optimization of this parameter, one can flatten the angular characteristic or obtain selectable viewing angles in the desirable range. These results allow for the construction of optical shutters and a scattering‐type LCD with controllable viewing‐angle characteristics, particularly with low off‐axis haze.
British Columbia dentists decide to mediate disputes, and devise a system for addressing consumer and business issues
Authors: Glasner Kenneth
Published: June 2006

Kenneth Glasner, of Vancouver, describes how a society of British Columbia dentists set up a mediation program to deal with a wide variety of patient, insurance, and interoffice disputes. The program could be adapted for other self‐regulating bodies.
Reaction of α,β‐unsaturated ketones with cerium(IV) salts in alcohol
Authors: Horiuchi C. Akira , Saitoh Yoshikazu , Utsukihara Takamitsu , Takahashi Shigeo , Matsushita Masatoshi , He Liangyou , Takahashi T. Tomoyoshi , Hashimoto Chikao , Sugiyama Takashi , Nozaki Sukekatsu
Published: June 2006

Reaction of α,β‐unsaturated ketones with cerium(IV) salts or lanthanide triflates in alcohols gave good yields of the corresponding β‐alkoxy compounds. In the case of 2‐cyclopentenone and 2‐cyclohexenone, the 1,1,3‐trialkoxy acetal derivatives were obtained preferentially accompanied by β‐alkoxyketone, except 2‐cycloheptenone. However, in the reaction of 2‐cycloheptenone with alcohol using cerium(IV) sulfate (CS)‐molecular sieve, 1,1,3‐trialkoxy derivatives were obtained. Also, in the cases of 1‐penten‐3‐one, 4‐hexen‐3‐one and 3‐hepten‐2‐one, 1,1,3‐trialkoxy derivatives were obtained preferentially. Copyright © 2006 John Wiley & Sons, Ltd.
Peptide‐Capped Gold Nanoparticles: Towards Artificial Proteins
Authors: Lévy Raphaël
Published: June 2006

Peptides can be designed to form self‐assembled monolayers on gold nanoparticles to give nanomaterials with some chemical properties analogous to those of proteins. A variety of molecular‐recognition properties are readily integrated within the peptide monolayer. Monofunctionalized nanoparticles are obtained by using separation methods that have been optimized for proteins. Recent applications as artificial enzymes and artificial enzyme substrates are presented. The limitations and long‐term potential of peptide‐capped nanoparticles as artificial proteins are discussed.
Radiation following percutaneous balloon aortic valvuloplasty to prevent restenosis (RADAR pilot trial)
Authors: Pedersen Wes R. , Van Tassel Robert A. , Pierce Talia A. , Pence David M. , Monyak David J. , Kim Tae H. , Harris Kevin M. , Knickelbine Thomas , Lesser John R. , Madison James D. , Mooney Michael R. , Goldenberg Irvin F. , Longe Terrence F. , Poulose Anil K. , Graham Kevin J. , Nelson Richard R. , Pritzker Marc R. , Pagan‐Carlo Luis A. , Boisjolie Charlene R. , Zenovich Andrey G. , Schwartz Robert S.
Published: June 2006

Objectives: We wished to determine the feasibility and early safety of external beam radiation therapy (EBRT) used following balloon aortic valvuloplasty (BAV) to prevent restenosis. Background: BAV for calcific aortic stenosis (AS) has been largely abandoned because of high restenosis rates, i.e., > 80% at 1 year. Radiation therapy is useful in preventing restenosis following vascular interventions and treating other benign noncardiovascular disorders. Methods: We conducted a 20‐patient, pilot study evaluating EBRT to prevent restenosis following BAV in elderly patients with calcific AS. Total doses ranging from 12–18 Gy were delivered in fractions over a 3–5 day post‐op period to the aortic valve. Echocardiography was performed pre and 2 days post‐op, 1, 6, and 12 months following BAV. Results: One‐year follow‐up is completed (age 89 ± 4). There were no complications related to EBRT. Eight patients died prior to 1 year; 5 of 10 (50%) in the low‐dose (12 Gy) group and 3 of 10 (30%) in the high‐dose (15–18 Gy) group. None of these 8 patients had restenosis, i.e., > 50% loss of the initial AVA gain, and only three deaths were cardiac in origin. One patient underwent aortic valve replacement and none repeated BAV. By 1 year, 3 of the initial 10 (30%) in the low‐dose group and 1 of 9 (11%) in the high‐dose group demonstrated restenosis (21% overall). Conclusions: EBRT following BAV in elderly patients with AS is feasible, free of early complications, and holds promise in reducing the 1 year restenosis rate in a dose‐dependent fashion. © 2006 Wiley‐Liss, Inc.
Rapid pacing to facilitate transcatheter prosthetic heart valve implantation
Authors: Webb John G. , Pasupati Sanjeevan , Achtem Leslie , Thompson Christopher R.
Published: June 2006

Objectives: We describe the technique of, and our experience with, rapid ventricular burst pacing to facilitate transcatheter heart valve implantation. Background: Endovascular therapeutic procedures frequently require the precise placement of implantable devices. The precision of transcatheter device deployment may be hampered by cardiac motion or the effects of intravascular flow. Burst pacing is associated with a reduction in stroke volume, cardiac output, transvalvular flow, and cardiac motion. Methods: Rapid pacing was used in 40 consecutive patients with severe aortic stenosis undergoing implantation of catheter‐delivered prosthetic valves. Clinical, procedural, and hemodynamic records were reviewed. Results: A mean of 5 ± 2 burst pacing sequences at rates of 150–220 min−1 were used during balloon valvuloplasty and valve deployment. The duration of pacing required during valve deployment was 12 ± 3 sec. Pacing was relatively well tolerated when cautiously used with judicious recovery intervals and pressor support. Rapid pacing was associated with a rapid and effective reduction in systemic blood pressure, pulse pressure, transvalvular flow as well as cardiac and catheter motion. Conclusions: Rapid pacing is a relatively reliable technique to facilitate precise transcatheter deployment of prosthetic heart valves and other endovascular therapeutic devices. © 2006 Wiley‐Liss, Inc.
Asymmetric Allylic Substitution Catalyzed by C1‐Symmetrical Complexes of Molybdenum: Structural Requirements of the Ligand and the Stereochemical Course of the Reaction
Authors: Malkov Andrei V. , Gouriou Laure , Lloyd‐Jones Guy C. , Starý Ivo , Langer Vratislav , Spoor Paul , Vinader Victoria , Kočovský Pavel
Published: June 2006

Application of new chiral ligands (R)‐(−)‐12 a and (S)‐(+)‐12 c (VALDY), derived from amino acids, to the title reaction, involving cinnamyl (linear) and isocinnamyl (branched) type substrates (4 and 5 → 6), led to excellent regio‐ and enantioselectivities (>30:1, ≤98 % ee), showing that ligands with a single chiral center are capable of high asymmetric induction. The structural requirements of the ligand and the mechanism are discussed. The application of single enantiomers of deuterium‐labeled substrates (both linear 38 c and branched 37 c) and analysis of the products (41–43) by 2H{1H} NMR spectroscopy in a chiral liquid crystal matrix allowed the stereochemical pathways of the reaction to be distinguished. With ligand (S)‐(+)‐12 c, the matched enantiomer of branched substrate was found to be (S)‐5, which was converted into (R)‐6 with very high regio‐ and stereoselectivity via a process that involves net retention of stereochemistry. The mismatched enantiomer of the branched substrate was found to be (R)‐5, which was also converted into (R)‐6, that is, with apparent net inversion, but at a lower rate and with lower overall enantioselectivity. This latter feature, which may be termed a “memory effect”, reduced the global enantioselectivity in the reaction of the racemic substrate (±)‐5. The stereochemical pathway of the mismatched manifold has been shown also to be one of net retention, the apparent inversion occurring through equilibration via an Mo–allyl intermediate prior to nucleophilic attack. Incomplete equilibration leads to the memory effect and thus to lower enantioselectivity. Analysis of the mismatched manifold over the course of the reaction revealed that the memory effect is progressively attenuated with the nascent global selectivity increasing substantially as the reaction proceeds. The origin of this effect is suggested to be the depletion of CO sources in the reaction mixture, which attenuates turnover rate and thus facilitates greater equilibrium. The linear substrate was also converted into the branched product with net syn stereochemistry, as shown by isotopic labeling. An analogous process operates in the generation of small quantities of linear product from branched substrate.
An Alternative Approach to the g‐Matrix: Theory and Applications
Authors: Bolvin Hélène
Published: June 2006

Starting from the formula proposed by Gerloch and McMeeking in 1975, the electronic g‐matrix is expressed as a sum of two matrices called Λ and Σ describing the orbital and spin contributions respectively. This approach is applied on benchmark diatomic and triatomic molecules, and on TiF3 and Cu(NH3)42+ using either CASPT2 or CCSD(T) methods to calculate the spin‐free states and SO‐RASSI to calculate spin–orbit coupling. Results compare very well to experimental data and to previous theoretical work; and, for each molecule, the anisotropy of the g‐matrix is modeled by the mean of a few parameters.
IL‐4 induces expression of TARC/CCL17 via two STAT6 binding sites
Authors: Wirnsberger Gerald , Hebenstreit Daniel , Posselt Gernot , Horejs‐Hoeck Jutta , Duschl Albert
Published: June 2006

A cardinal feature of allergic disorders and immune responses is enhanced leukocyte trafficking. This is largely orchestrated by chemokines. The CC chemokine thymus‐ and activation‐regulated chemokine (TARC/CCL17) selectively attracts Th2 cells via the G protein‐coupled chemokine receptor CCR4. We show here that TARC/CCL17 is expressed by human T cells upon stimulation with IL‐4. Mapping of the transcriptional start site revealed the presence of two putative STAT6 binding motifs in proximity to the start position. EMSA and chromatin immunoprecipitation experiments demonstrated that STAT6 was able to bind to both motifs. A fragment of the TARC/CCL17 promoter containing both sites was tested in reporter gene assays for IL‐4 inducibility. The promoter was inducible in a STAT6‐deficient cell line only after introduction of functional STAT6. When mutations were inserted into one of the STAT6 motifs, IL‐4‐induced promoter activation was reduced. With both sites mutated, inducibility was completely abrogated. These data demonstrate collectively that T cells serve as a source of TARC/CCL17 when stimulated with IL‐4 and that STAT6 is essential for this.