bluuebunny/crossref_metadata_2025_split huggingface dataset:
Arresting and releasing Staphylococcal α‐hemolysin at intermediate stages of pore formation by engineered disulfide bonds
Authors: Kawate Toshimitsu , Gouaux Eric 
Published: April 2003

Abstractα‐Hemolysin (αHL) is secreted by Staphylococcus aureus as a water‐soluble monomer that assembles into a heptamer to form a transmembrane pore on a target membrane. The crystal structures of the LukF water‐soluble monomer and the membrane‐bound α‐hemolysin heptamer show that large conformational changes occur during assembly. However, the mechanism of assembly and pore formation is still unclear, primarily because of the difficulty in obtaining structural information on assembly intermediates. Our goal is to use disulfide bonds to selectively arrest and release αHL from intermediate stages of the assembly process and to use these mutants to test mechanistic hypotheses. To accomplish this, we created four double cysteine mutants, D108C/K154C (αHL‐A), M113C/K147C (αHL‐B), H48C/ N121C (αHL‐C), I5C/G130C (αHL‐D), in which disulfide bonds may form between the pre‐stem domain and the β‐sandwich domain to prevent pre‐stem rearrangement and membrane insertion. Among the four mutants, αHL‐A is remarkably stable, is produced at a level at least 10‐fold greater than that of the wild‐type protein, is monomeric in aqueous solution, and has hemolytic activity that can be regulated by the presence or absence of reducing agents. Cross‐linking analysis showed that αHL‐A assembles on a membrane into an oligomer, which is likely to be a heptamer, in the absence of a reducing agent, suggesting that oxidized αHL‐A is halted at a heptameric prepore state. Therefore, conformational rearrangements at positions 108 and 154 are critical for the completion of αHL assembly but are not essential for membrane binding or for formation of an oligomeric prepore intermediate.
Magnetic and Gas-Occlusion Properties and Catalytic Activity of Microporous Materials: Dinuclear Ruthenium(II,II) Dicarboxylates
Authors: Ohmura Tetsushi , Mori Wasuke , Hiraga Hiroki , Ono Masato , Nishimoto Yuko 
Published: April 2003

Abstract
A new series of dinuclear ruthenium(II,II) dicarboxylates, but not dinuclear ruthenium(II,III) dicarboxylates, have been prepared. Dinuclear ruthenium(II,II) dicarboxylates, which have a regular two- or three-dimensional network structure, occlude large amounts of gas. The maximum amount of N2 gas that can be occluded by these complexes is 1.0–1.7 moles per mole of ruthenium atoms, indicating the presence of a large number of micropores. These complexes exhibited pore volume-dependent catalytic activity for the hydrogenation of ethylene.
A description of cloud production by non‐uniformly distributed processes
Authors: Bushell Andrew C. , Wilson Damian R. , Gregory David 
Published: April 2003

AbstractPrognostic cloud‐fraction and condensate equations, for the case in which a source injects condensate‐laden, saturated air into a volume, are derived by considering the response of a general distribution of thermodynamic variables within the volume. These prognostic equations are compared with those derived by assuming that condensate is added uniformly to both clear and cloudy parts of the region. For non‐uniform forcing, the local condensate mixing ratio associated with the condensate source is important in controlling the rate of change of cloud fraction and in‐cloud condensate. For the case of a convective condensate source, the cloud‐fraction equation is contrasted with previously derived alternatives. Lastly, the validity of a prognostic equation for cloud fraction is discussed in the light of a different approach in which the moments of a distribution of thermodynamic variables are specified from prognostic equations and used to calculate cloud fraction and condensate diagnostically. © Crown copyright, 2003. Royal Meteorological Society
Process variables and their effects on grafting reactions of styrene and methyl methacrylate onto natural rubber
Authors: Arayapranee W. , Prasassarakich P. , Rempel G. L. 
Published: April 2003

AbstractThe graft copolymerization of styrene and methyl methacrylate onto natural rubber latex was studied under various reaction conditions using a cumene hydroperoxide redox initiator. The monomer conversion, graft copolymer compositions, and grafting efficiency were determined. The synthesized graft copolymers were purified and then characterized by proton nuclear magnetic resonance (1H‐NMR) analysis and differential scanning calorimetry (DSC). A 2 fractional factorial experimental design was applied to study the main effects on the grafting. The variables investigated in this work were the amount of the initiator and emulsifier, the presence or absence of a chain‐transfer agent, the styrene‐to‐methyl methacrylate ratio, the monomer‐to‐rubber ratio, and the reaction temperature. The measured response for the experimental design was the grafting efficiency. The analysis of the results from the design showed the sequence of the main effects on the observed response of the grafting of styrene and methyl methacrylate onto natural rubber, in ascending order. The amount of the chain‐transfer agent and the reaction temperature in the range of the test had significant effects and one marginally significant effect was the monomer‐to‐rubber ratio. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 63–74, 2003
Cytologic diagnosis of fibrous hamartoma of infancy: A case report
Authors: Mohanty Sambit K. , Dey Pranab 
Published: April 2003

AbstractFibrous hamartoma of infancy (FHI) is a rare benign lesion in the first 2 years of life with a distinctive histomorphologic appearance. There were only two descriptions of this entity in the cytology literature. In this article, the detailed clinical profile and cytologic features of a case of FHI is described in a 6‐month‐old male infant who presented with a nodular mass in the anterior axillary fold. Fine‐needle aspiration (FNA) cytology smears showed an admixture of adipose tissue fragments, discretely lying, and clusters of fibroblastic cells in association with myxoid and collagenous matrix. FNA cytology features along with proper clinical history, radiological findings, family history, and location of the lesion may be helpful to suggest the probable preoperative diagnosis of this lesion. Diagn. Cytopathol. 2003;28:272–273. © 2003 Wiley‐Liss, Inc.
One‐pot PTC synthesis of polyfused pyrazoles
Authors: El‐Saraf Gamal A. , El‐Sayed Ahmed M. , El‐Saghier Ahmed M. M. 
Published: April 2003

AbstractThienopyrazole 2, 3, 5, or 6 and thienopyrazolothiazepine 7, 9, and 11 derivatives were prepared via the reaction of the 3‐aminopyrazoline‐5‐one 1 with CS2 and different molar ratio of a variety of halo compounds having an active methylene under PTC conditions. Also, treatment of 1 with CS2 and alcoholic KOH in 2:1:1 molar ratio afforded dipyrazolopyridine derivatives 12 and 14. On other hand, the pyrazolothiadiazineone derivative 13 was obtained by treating compound 1 with CS2 and alcoholic KOH in 1:2:2 molar ratio. Under PTC conditions, compound 1, CS2, and ethyl cyanoacetate or malononitrile to gave the pyrazolopyridine derivatives 16 and 17. Coupling of compound 1 with diazonium acetates afforded the hydrazone derivatives 18a,b, which were oxidized with bromine to give pyrazolotriazoles 19a,b or cyclized with aldehydes to give pyrazolotriazine derivatives 20a–e. Bromination of compound 1 afforded monobromopyrazole derivative 21, which could be condensed to a dipyrazolopyrazindione 23. Finally, the dibromopyrazole derivative 22 was cyclized with 2‐mercaptoethanol or o‐phenylenediamine to give the spiropyrazoles 24a,b. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:211–217, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10129
Clinical spectrum of primary mediastinal tumors: A comparison of adult and pediatric populations at a single Japanese institution
Authors: Takeda Shin‐Ichi , Miyoshi Shinichiro , Akashi Akinori , Ohta Mitsunori , Minami Masato , Okumura Meinoshin , Masaoka Akira , Matsuda Hikaru 
Published: April 2003

AbstractBackground and ObjectivesThe purpose of this study was to review our Japanese institutional experience of mediastinal tumors and to compare differences in the clinical spectrum between adults and children.MethodsWe retrospectively reviewed the records of 806 patients (676 adults and 130 children) between 1951 and 2000 at our institution.ResultsThere were 244 thymomas (36%), 106 germ cell tumors (16%), 95 congenital cysts (14%), 82 lymphomas (12%), 76 neurogenic tumors (11%), and 24 thyroid tumors (4%) in adult patients. There were 60 neurogenic tumors (46%), 24 germ cell tumor (19%), 17 lymphoma (13%), 10 congenital cysts (8%), and 5 thymomas (4%) in the pediatric patients. There was a significant higher incidence of neurogenic tumors and a lower incidence of thymomas and thyroid tumors in children than adults. The most common location was the anterior compartment (68%) in adults and the posterior compartment in children (52%). The prevalence of malignancy in pediatric patients was lower than adults (37% vs. 47%; P < 0.05). Symptoms due to compression or direct invasion into adjacent structures may have caused the higher incidence of dyspnea or respiratory distress in the pediatric group compared to the adults (15.4% vs. 4.0%; P < 0.001). There were fewer incidences of facial edema in children compared to adults (2.6% vs. 10.7%; P < 0.02). Emergent operations were required more often in the pediatric group than the adult group.ConclusionsWe demonstrated definite differences in histologic distribution, location, and symptomatology in mediastinal tumors between adult and pediatric populations, which should be considered in the evaluation and planning of a therapeutic modality for mediastinal tumors. J. Surg. Oncol. 2003;83:24–30. © 2003 Wiley‐Liss, Inc.
Korean medicinal plants inhibiting to Human Immunodeﬁciency Virus type 1 (HIV‐1) fusion
Authors: Chang Young‐Su , Woo Eun‐Rhan 
Published: April 2003

AbstractIn order to ﬁnd novel anti‐HIV agents from natural products, 80 MeOH extracts of Korean plants were applied to a syncytia formation inhibition assay, which is based on the interaction between the HIV‐1 envelope glycoprotein gp120/41 and the cellular membrane protein CD4 of T lymphocytes. The most potent HIV‐1 fusion inhibition was shown by the stem bark of Ailanthus altissima with 74.9 ± 4.4% at a concentration of 100 µg/mL. Copyright © 2003 John Wiley & Sons, Ltd.
Pharmacological and toxicological properties of Nigella sativa
Authors: Ali B. H. , Blunden Gerald 
Published: April 2003

AbstractThe seeds of Nigella sativa Linn. (Ranunculaceae), commonly known as black seed or black cumin, are used in folk (herbal) medicine all over the world for the treatment and prevention of a number of diseases and conditions that include asthma, diarrhoea and dyslipidaemia. This article reviews the main reports of the pharmacological and toxicological properties of N. sativa and its constituents. The seeds contain both ﬁxed and essential oils, proteins, alkaloids and saponin. Much of the biological activity of the seeds has been shown to be due to thymoquinone, the major component of the essential oil, but which is also present in the ﬁxed oil. The pharmacological actions of the crude extracts of the seeds (and some of its active constituents, e.g. volatile oil and thymoquinone) that have been reported include protection against nephrotoxicity and hepatotoxicity induced by either disease or chemicals. The seeds/oil have antiinflammatory, analgesic, antipyretic, antimicrobial and antineoplastic activity. The oil decreases blood pressure and increases respiration. Treatment of rats with the seed extract for up to 12 weeks has been reported to induce changes in the haemogram that include an increase in both the packed cell volume (PCV) and haemoglobin (Hb), and a decrease in plasma concentrations of cholesterol, triglycerides and glucose. The seeds are characterized by a very low degree of toxicity. Two cases of contact dermatitis in two individuals have been reported following topical use. Administration of either the seed extract or its oil has been shown not to induce signiﬁcant adverse effects on liver or kidney functions. It would appear that the beneﬁcial effects of the use of the seeds and thymoquinone might be related to their cytoprotective and antioxidant actions, and to their effect on some mediators of inﬂammation.Copyright © 2003 John Wiley & Sons, Ltd.
The operations management role in hospital strategic planning
Authors: Butler Timothy W. , Leong G.Keong , Everett Linda N. 
Published: April 2003

AbstractAlthough there is a wealth of research on operations management and strategic planning in hospitals, there has been little if any research on the integration of these two issues. Hospital administrators are being pressured to improve the quality of services and to curb costs ‐ two primary themes within the field of operations management. This leads us to wonder to what extent operations are considered within the strategic planning process and what impact it may have. By surveying the literature, we identify a pattern in hospital management research, and identify articles which address the operations capabilities of quality, flexibility, delivery and cost control. These articles can serve as a springboard for research in hospital operations strategy, an area that is largely neglected in the literature. We also provide examples of how hospitals are addressing operations capabilities, and conclude with implications for hospital administrators and a research agenda for researchers.
Workplace safety: A call for research
Authors: Brown Karen A. 
Published: April 2003

AbstractThe purpose of this paper is to call attention to the increased importance of workplace safety in the field of operations management, and to suggest ways in which this topic can be woven into research agendas. A key tenet is the proposition that the competitive priority construct (quality, cost, delivery and flexibility) may need to be expanded to include social responsibility ‐ with workplace safety as one dimension of this new priority. The cost of workplace injuries in the U.S. is increasing at an alarming rate, and accident occurrences have grown steadily over the last several years. The manufacturing sector is especially vulnerable to safety problems and, thus, is the central focus of this paper. A number of new factors are increasing the importance of related issues for operations managers. Three of these factors ‐ the quality movement, changes in technology and changes in operations practices ‐ are embedded within the operations function. Two others ‐ workforce diversity and organized labor interests ‐ are associated with the human resource function but have links with operations. Political, legal and public forces stem from outside the boundaries of the organization, but still have important influences on operations management. Regardless of the origins of these phenomena, all have direct effects on the management of operations and all have significant implications for research in this field.
Characterization of monoamine oxidase activity during early stages of quail embryogenesis
Authors: Pintar John E. , Maxwell Gerald D. , Breakefield Xandra O. 
Published: April 2003

AbstractCatecholamines and other biogenic amines may play a role in early embryogenesis in addition to functioning as neurotransmitters after neuronal differentiation. Regulation of amine levels is mediated by several different parameters including activity levels of degradative enzymes. Since monoamine oxidase (EC 1.4.3.4) is the primary degradative enzyme for these biogenic amines, we have begun to characterize MAO activity during quail embryogenesis. Our results demonstrate that MAO activity is present at all stages of development examined (stages 2–22) and that the MAO specific activity levels are highest during the earliest stages (stages 2–6). Two types of MAO activity similar to adult avian and mammalian MAO‐A and MAO‐B have been demonstrated by differential clorgyline sensitivity of tryptamine deamination. In addition, SDS‐PAGE of embryonic quail [3H]pargyiine‐labeled MAO demonstrates that the quail MAO‐A and MAO‐B flavin‐containing subunits have apparent molecular weights of 63,000 and 62,000 respectively.We have begun to assess the functional significance of embryonic quail MAO activity by daily injection of MAO inhibitors (clorgyline or clorgyline plus deprenyl) into fertilized eggs. Clorgyline injection selectively and completely inhibited MAO‐A activity, while injection of clorgyline and deprenyl inhibited both MAO‐A and MAO‐B activities when embryos were assayed after either 2 or 7 days of embryonic development. This paradigm will allow a detailed examination of the effects of MAO inhibition on the developing embryo.
Cell death during development of the cochlear and vestibular ganglia of the chick
Authors: Ard March D. , Morest D. Kent 
Published: April 2003

AbstractThis report documents and quantitates the naturally occurring death of neurons in the cochlear and vestibular ganglia during the normal development of the chick embryo. The data are compared with the amount of cell loss in the cochlear and vestibular nuclei to evaluate the possibility that the death of the neurons in the same sensory pathway may be related to the formation of their connections. Neurons of the cochlear and vestibular ganglia of the chick were counted and their cell bodies measured with light microscopic methods at the beginning of their period of synapse formation, embryonic day 8 (E8), at the end of the period of synapse formation (E14), and again at a more mature stage, post‐hatching day 14 (P14).The number of neurons declined between E8 and E14 in the cochlear ganglion by 25% (from 11170 to 8353) and in the vestibular ganglion by 24% (from 12687 to 9613). The neuronal population remained relatively stable between E14 and P14. Cell counts at each age were accompanied by morphological descriptions of the neurons and of their synaptic targets in the sensory epithelia of the inner ear. During the period of cell loss the mean diameters of the cell bodies in the cochlear ganglion increased slightly, from 9.5 to 111 μm and reached 17.6 μm at P14, while those in the vestibular ganglion increased from 10.4 to 13.3 μm and reached 20.9 μm at P14. The period of cell loss in the cochlear and vestibular ganglia coincides with the stages in their development when the sensory neurons have already contacted their target cells in the primary sensory nuclei and in the receptor epithelium. It is during this period that the transformation from the immature axonal endings to the definitive types of synapses begins. Thus the present data are consistent with the view that the formation of central as well as peripheral synapses is involved in determining the extent of neuronal death during the development of sensory neurons.
Neurogenesis in the anterior olfactory nucleus and its associated transition areas in the rat brain
Authors: Bayer Shirley A. 
Published: April 2003

AbstractNeurogenesis in the rat olfactory peduncle was examined with [3H]thymidine autoradiography. Animals in the prenatal groups were the offspring of pregnant females given an injection of [3H]thymidine on two consecutive gestation days. Nine groups of embryos were exposed to [3H]thymidine on embryonic days (E) E13–E14, E14–E15, … E21–E22, respectively. One group of postnatal animals was given four consecutive injections of [3H]thymidine on postnatal days (P) P0‐P3. On P60, the percentage of labeled cells and the proportion of cells originating during either 24 or 48 hr periods were quantified at seven anatomical levels through both the anterior olfactory nucleus and the transition areas. A caudal (older) to rostral (younger) neurogenetic gradient is found both within and between structures in the olfactory peduncle. Neurons in the dorsal, lateral, and ventral‐lateral transition areas are generated mainly between E14 and E19, those in the anterior olfactory nucleus mainly between E15 and E21. Only 3–4% of the neurons in the most anterior pars lateralis and pars dorsalis originate after birth. All parts of the anterior olfactory nucleus show a strong superficial (older) to deep (younger) neurogenetic gradient (the “outside‐in” pattern). In contrast, neurons in the ventral—lateral transition area and in the dorsal transition area originate in a deep to superficial neurogenetic gradient (the “inside‐out” pattern), suggesting that these areas are, in reality, primary olfactory cortex. The lateral transition area is truly “transitional”, showing no neurogenetic gradient along the superficial‐deep plane. The medial transition area originates between E15 and E19 in a center (older) to edge (younger) “sandwich” neurogenetic gradient along the rostrocaudal plane, a pattern apparently unrelated to neurogenetic gradients in other olfactory peduncle structures. These data suggest that characteristic patterns of neurogenesis, namely the “insideout” vs the “outside‐in” gradients, permit the assignment of different structures to cortical vs ganglionic cytoarchitectonic components of the olfactory relay system.
Effect of thyroid deficiency on the regional development of glutaminase, a glutamatergic neuron marker, in the rat brain
Authors: Patel Ambrish J. , Hunt Anthony , Hayashi Masao 
Published: April 2003

AbstractThe effect of thyroid deficiency on the activity of phosphate‐activated glutaminase (the marker for glutamatergic neurons) was studied in different parts of the rat brain at ages 5,10, 15 and 25 days and at day 130 following 102 days of rehabilitation. The brain regions investigated were the cerebral cortex, basal forebrain, hippocampus and cerebellum. During normal development, the activity of glutaminase increased relatively earlier in the cerebral cortex and hippocampus than in the cerebellum, while the absolute value reached a much higher level in the hippocampus than in other brain regions. In the basal forebrain, the developmental pattern of glutaminase was bimodal and the rise in enzyme activity after 15 days coincided with the decrease in the cerebral cortex. These regional developmental changes in glutaminase activity correlated well with known information on the formation of glutamatergic cells and pathways in the brain. Neonatal thyroid deficiency had little effect on the developmental patterns of enzyme activity, the exception being a transient decrease in 10‐day‐old hypothyroid hippocampus. The present results, together with previous findings, indicate that the effect of thyroid hormone on neural maturation is cell‐type specific and the glutamatergic neurons are not the main targets of thyroid hormone action.
The neuro‐endocrine ambiguity of sympathoadrenal cells
Authors: Unsicker K. , Seidl K. , Hofmann H. D. 
Published: April 2003

AbstractThis introductory article presents a survey of the principle cellular constituents of the sympathoadrenal section in the peripheral autonomic nervous system, their development and plasticity and factors that govern the expression of particular morphologic and transmitter phenotypes. The article focuses on results obtained in cell culture studies with isolated chromaffin cells that have permitted the analysis of molecular signals possibly serving as environmental cues during the development of sympathoadrenal cells.