bluuebunny/crossref_metadata_2025_split huggingface dataset:
Screening and isolation of a nematicidal sesquiterpene from Magnolia grandiflora L.
Authors: Hong Linjun , Li Guohong , Zhou Wei , Wang Xinbiao , Zhang Keqin 
Published: February 2007

AbstractThe ethanolic extracts from 30 plant species were tested for their nematicidal activity against nematodes Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle and Panagrellus redivivus (L.) Goodey. The leaf extract of Magnolia grandiflora L. exhibited the strongest nematicidal activity against both nematodes, causing 73 and 100% mortality respectively within 48 h at 5 mg mL−1. A new nematicidal sesquiterpene was obtained from the leaves of M. grandiflora. The compound was determined to be 4,5‐epoxy‐1(10)E,11(13)‐germacradien‐12,6‐olide, based on spectroscopic methods including 2D NMR techniques. The median lethal concentrations (LC50) of the compound against B. xylophilus and P. redivivus were 71 and 46 mg L−1 respectively at 48 h. This is the first report of Magnoliaceae species with nematicidal activity. Copyright © 2007 Society of Chemical Industry
Continuously stratified flows across an Alpine crest with a pass: Shallow and deep föhn
Authors: Armi Laurence , Mayr Georg J. 
Published: February 2007

AbstractShallow and deep Alpine föhn flows are analyzed within the framework of continuously stratified hydraulics. A distinguishing upstream feature of these flows is the presence of stagnant, nearly well‐mixed layers above and beneath the moving stratified fluid. These layers isolate the moving stratified fluid, which has a self‐similar parabolic‐like velocity distribution, from the stratified fluid above and beneath. The shallow and deep realizations of these flows were found on 20 and 21 October 1999 during the Mesoscale Alpine Programme. The temporal evolution from shallow to deep föhn was captured with a sequence of radiosondes, automatic weather stations, an instrumented car, and research aircraft flights. Copyright © 2007 Royal Meteorological Society
Molecular design and synthesis of artificial double helices
Authors: Furusho Yoshio , Yashima Eiji 
Published: February 2007

AbstractThis account describes novel artificial double helices recently developed by our group. We have designed and synthesized the double helices consisting of two complementary, m‐terphenyl‐based strands that are intertwined through chiral amidinium–carboxylate salt bridges. Due to the chiral substituents on the amidine groups, the double helices adopted an excess one‐handed helical conformation in solution as well as in the solid state. By extending the modular strategy, we have synthesized double helices bearing Pt(II) linkers, which underwent the double helix‐to‐double helix transformations through the chemical reactions of the Pt(II) complex moieties. In addition, artificial double‐stranded metallosupramolecular helical polymers were constructed by combining the salt bridges and metal coordination. In contrast to the design‐oriented double helices based on salt bridges, we have serendipitously developed a spiroborate‐based double helicate bearing oligophenol strands. The optical resolution of the helicate was successfully attained by a diastereomeric salt formation. We have also unexpectedly found that oligoresorcinols consisting of a very simple repeating unit self‐assemble into double helices with the aid of aromatic interactions in water. Furthermore, a bias in the twist sense of the double helices can be achieved by incorporating chiral substituents at both ends of the strands. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 7: 1–11; 2007: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20097
Stoichiometric and catalytic oxidations with hypervalent organo‐λ3‐iodanes
Authors: Ochiai Masahito 
Published: February 2007

AbstractIsolation, characterization, and reaction of the activated iodosylbenzene monomer, hydroxy(phenyl)iodonium ion, as a complex with 18‐crown‐6 (18C6) are reported. The reaction of iodosylbenzene with HBF4 in the presence of 18C6 afforded the hydroxy‐λ3‐iodane complex PhI(OH)BF4·18C6 as stable yellow prisms. X‐ray structure analysis indicated that the close contacts between the iodine(III) and the three adjacent oxygen atoms of 18C6 will be responsible for the increased stability of the complex compared to the uncomplexed PhI(OH)BF4. The aqua complex of the activated iodosylbenzene, PhI(OH)OTf·18C6·H2O, with a water molecule coordinated to iodine(III) was also prepared. These crown ether complexes are highly reactive and serve as versatile stoichiometric oxidants, especially in water. Thus, the complexes undergo oxidative transformations of a variety of functional groups such as olefins, alkynes, enones, silyl enol ethers, sulfides, and phenols under mild conditions. The latter part reports on the iodobenzene‐catalyzed α‐oxidation of ketones, in which diacyloxy(phenyl)‐λ3‐iodanes generated in situ act as real oxidants of ketones and m‐chloroperbenzoic acid (m‐CPBA) serves as a terminal oxidant. The oxidation of a ketone with m‐CPBA in acetic acid in the presence of a catalytic amount of iodobenzene, BF3‐Et2O, and water at room temperature affords an α‐acetoxy ketone in good yield. It is noted that the use of water and BF3‐Et2O is crucial to the success of this α‐acetoxylation. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 7: 12–23; 2007: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20104
A third type of hydrogenase catalyzing H2 activation
Authors: Shima Seigo , Thauer Rudolf K. 
Published: February 2007

AbstractThe activation of molecular hydrogen is of interest both from a chemical and biological viewpoint. The covalent bond of H2 is strong (436 kJ mol−1). Its cleavage is catalyzed by metals or metal complexes in chemical hydrogenation reactions and by metalloenzymes named hydrogenases in microorganisms. Until recently only two types of hydrogenases are known, the [FeFe[‐hydrogenases and [NiFe[‐hydrogenases. Both types, which are phylogenetically unrelated, harbor in their active site a dinuclear metal center with intrinsic CO and cyanide ligands and contain iron–sulfur clusters for electron transport as revealed by their crystal structures. Fifteen years ago a third type of phylogenetically unrelated hydrogenase was discovered, which has a mononuclear iron active site and is devoid of iron–sulfur clusters. It was initially referred to as “metal free” hydrogenase, but was later renamed iron–sulfur cluster‐free hydrogenase or [Fe[‐hydrogenase. In this review, we introduce first the [FeFe[‐hydrogenases and [NiFe[‐hydrogenases, and then focus on the structure and function of the iron–sulfur cluster‐free hydrogenase (Hmd) and show that this enzyme contains an iron‐containing cofactor. The low‐spin iron is complexed by two intrinsic CO‐, one sulfur‐ and one or two N/O ligands and has one open coordination site, which is proposed to be the location of H2 binding. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 7: 37–46; 2007: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20111
Proliferation of inscriptions and transformations among preservice science teachers engaged in authentic science
Authors: Lunsford Eddie , Melear Claudia T. , Roth Wolff‐Michael , Perkins Matthew , Hickok Leslie G. 
Published: February 2007

AbstractInscriptions are central to the practice of science. Previous studies showed, however, that preservice teachers even those with undergraduate degrees in science, generally do not spontaneously produce inscriptions that economically summarize large amounts of data. This study was designed to investigate the production of inscription while a group of 15 graduate‐level preservice science teachers engaged in a 15‐week course of scientific observation and guided inquiry of two organisms. The course emphasized the production of inscriptions as a way of convincingly supporting claims when the students presented their results. With continuing emphasis on inscriptional representations, we observed a significant increase in the number and type of representations made as the course unfolded. The number of concrete, text‐based inscriptions decreased as the number of graphs, tables and other sorts of complex inscriptions increased. As the students moved from purely observational activities to guided inquiry, they made many more transformations of their data into complex and abstract forms, such as graphs and concept maps. The participants' competencies to cross‐reference ultimate transformations to initial research questions improved slightly. Our study has implications for the traditional methods by which preservice science teachers are taught in their science classes. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 44: 538–564, 2007.
Teacher and school characteristics and their influence on curriculum implementation
Authors: Roehrig Gillian H. , Kruse Rebecca A. , Kern Anne 
Published: February 2007

AbstractReform‐based curriculum materials have been suggested as a mechanism to make inquiry‐based instruction more prevalent in secondary science classrooms, specifically when accompanied by comprehensive professional development (Loucks‐Horsley, Hewson, Love, & Stiles, 1998; Powell & Anderson, 2002). This research examines the implementation of a reform‐based high school chemistry curriculum in a large, urban school district. We explicitly consider the role of the teachers' knowledge and beliefs in their implementation of the reform‐based chemistry curriculum, as well as school level factors. Qualitative and quantitative data were collected in the form of beliefs interviews and classroom observations from 27 high school chemistry teachers. Analysis of the data revealed that implementation of the curriculum was strongly influenced by the teachers' beliefs about teaching and learning, and the presence of a supportive network at their school sites. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 44: 883–907, 2007
The Role of Prophylactic Surgery in Cancer Prevention
Authors: You Y. Nancy , Lakhani Vipul T. , Wells Samuel A. 
Published: February 2007

AbstractBackgroundSince the human genome has been sequenced many mysteries of cell biology have been unravelled, thereby clarifying the pathogenesis of several diseases, particularly cancer. In members of kindreds with certain hereditary diseases, it is now possible early in life to predict with great certainty whether or not a family member has inherited the mutated allele causing the disease. In hereditary malignancies this has been particularly important, because in affected family members there is the possibility of removing the organ destined to develop cancer before malignancy develops or while it is in situ. At first consideration, it would appear that “prophylactic surgery” would have a place in many hereditary malignancies; however, the procedure has applicability only if certain criteria are met: (1) the genetic mutation causing the hereditary malignancy must have a very high penetrance and be expressed regardless of environmental factors; (2) there must be a highly reliable test to identify patients who have inherited the mutated gene; (3) the organ must be removed with minimal morbidity and virtually no mortality; (4) there must be a suitable replacement for the function of the removed organ; and (5) there must be a reliable method of determining over time that the patient has been cured by “prophylactic surgery.”ConclusionsIn this monograph we review several hereditary malignancies and consider those where prophylactic surgery might be useful. As we learn, there are various barriers to performing the procedure in many common hereditary cancer syndromes. The archetype disease syndromes, which meet each of the five criteria mentioned above and where prophylactic surgery is most useful, are the type 2 multiple endocrine neoplasia (MEN) syndromes: MEN2A, MEN2B, and the related familial medullary thyroid carcinoma. An additional benefit of the Human Genome Project, has been the development of pharmacologic and biologic compounds that block the metabolic pathway(s) activated by specific genetic mutations. Many of these compounds have shown efficacy in patients with locally advanced or metastatic cancers, and there is the likelihood that they will prove beneficial in preventing the outgrowth of malignant cells in patients destined to develop a hereditary cancer.
Nitric Oxide Accelerates the Recovery from Burn Wounds
Authors: Zhu Haifeng , Ka Bian , Murad Ferid 
Published: February 2007

AbstractA full‐thickness burn wound model was used to evaluate the effects of a topically applied gel‐based nitric oxide donor on wound healing in rats. The histological study demonstrated that the nitric oxide (NO) application significantly promoted re‐epithelization that resulted in a fast recovery of burn wound. The histological sections further revealed that inflammatory cell infiltration in the NO‐treated group was significantly increased in comparison to the control group. The enhanced accumulation of inflammatory cells resulted in a higher expression of myeloperoxidase (MPO) that was detected with imunoblotting. An immunohistochemistry study with CD31, a specific marker for endothelial cells, indicated that NO treatment markedly stimulated angiogenesis. Evaluation of collagen synthesis by immunohistochemistry with procollagen antibody demonstrated a significantly increased collagen synthesis in NO‐treated wound bed. We concluded that NO treatment promoted re‐epithelialization and wound closure by means of enhanced inflammatory cell infiltration, and that it promoted angiogenesis and facilitated collagen synthesis in the wound bed.
Clinical response to persistent, low‐level β‐glucuronidase expression in the murine model of mucopolysaccharidosis type VII
Authors: Donsante A. , Levy B. , Vogler C. , Sands M. S. 
Published: February 2007

AbstractMucopolysaccharidosis type VII (MPS VII) is a lysosomal storage disease caused by β‐glucuronidase (GUSB) deficiency. This disease exhibits a broad spectrum of clinical signs including skeletal dysplasia, retinal degeneration, cognitive deficits and hearing impairment. Sustained, high‐level expression of GUSB significantly improves the clinical course of the disease in the murine model of MPS VII. Low levels of enzyme expression (1–5% of normal) can significantly reduce the biochemical and histopathological manifestations of MPS VII. However, it has not been clear from previous studies whether persistent, low levels of circulating GUSB lead to significant improvements in the clinical presentation of this disease. We generated a rAAV2 vector that mediates persistent, low‐level GUSB expression in the liver. Liver and serum levels of GUSB were maintained at ∼5% and ∼2.5% of normal, respectively, while other tissue ranged from background levels to 0.9%. This level of activity significantly reduced the secondary elevations of α‐galactosidase and the levels of glycosaminoglycans in multiple tissues. Interestingly, this level of GUSB was also sufficient to reduce lysosomal storage in neurons in the brain. Although there were small but statistically significant improvements in retinal function, auditory function, skeletal dysplasia, and reproduction in rAAV‐treated MPS VII mice, the clinical deficits were still profound and there was no improvement in lifespan. These data suggest that circulating levels of GUSB greater than 2.5% will be required to achieve substantial clinical improvements in MPS VII.
Glycogen storage disease types I and II: Treatment updates
Authors: Koeberl D. D. , Kishnani P. S. , Chen Y. T. 
Published: February 2007

AbstractPrior to 2006 therapy for glycogen storage diseases consisted primarily of dietary interventions, which in the case of glycogen storage disease (GSD) type II (GSD II; Pompe disease) remained essentially palliative. Despite improved survival and growth, long‐term complications of GSD type I (GSD I) have not responded to dietary therapy with uncooked cornstarch or continuous gastric feeding. The recognized significant risk of renal disease and liver malignancy in GSD I has prompted efforts towards curative therapy, including organ transplantation, in those deemed at risk. Results of clinical trials in infantile Pompe disease with alglucosidase alfa (Myozyme) showed prolonged survival reversal of cardiomyopathy, and motor gains. This resulted in broad label approval of Myozyme for Pompe disease in 2006. Furthermore, the development of experimental therapies, such as adeno‐associated virus (AAV) vector‐mediated gene therapy, holds promise for the availability of curative therapy in GSD I and GSD II/Pompe disease in the future.
Oxidative remodeling in pressure overload induced chronic heart failure
Authors: Henderson Brooke C. , Tyagi Neetu , Ovechkin Alexander , Kartha Ganesh K. , Moshal Karni S. , Tyagi Suresh C. 
Published: February 2007

AbstractDespite extensive strides in understanding pressure overload induced heart failure, there is very little known about oxidative stress induced matrix metalloproteinase (MMP) activation, collagen degradation and remodeling in pressure overload heart failure. We hypothesize that pressure overload leads to redox imbalance causing increased expression/activity of MMP‐2/9 producing collagen degradation and heart failure. To test this hypothesis, we created pressure overload heart failure by abdominal aortic stenosis (AS) in wild‐type C57BL/6J and collagen mutant (Col1a1 with 129 s background) mice. At 4 weeks, post surgery, functional parameters were measured. Left ventricle (LV) tissue sections were analyzed by histology, Western Blot and PCR. The results suggest an increase in iNOS with a decrease in eNOS, an increase in nitrated protein modification and depletion of antioxidants thioredoxin and SOD in pressure overload. MMP‐2/9 expression/activity and collagen degradation were increased in the AS animals. To determine whether a mutation in the collagen gene at the site of MMP cleavage mitigates cardiac hypertrophy, we used Col1a1 mice. In these mice, the AS induced LV hypertrophy (LVH) was ameliorated. In conclusion, our results suggest that AS leads to increased oxidative stress, expression/activity of MMP‐2/9 and a decrease in antioxidant expression producing collagen degradation and heart failure.
Evidence for Holocene environmental changes in the northern Fertile Crescent provided by pedogenic carbonate coatings
Authors: Pustovoytov Konstantin , Schmidt Klaus , Taubald Heinrich 
Published: February 2007

AbstractHolocene environmental changes in the northern Fertile Crescent remain poorly understood because of the scarcity of local proxy records in the region. In this study we investigated pedogenic (soil-formed) carbonate coatings on stones at the Pre-Pottery Neolithic site Göbekli Tepe as an indicator of local early-mid Holocene environmental changes. The 14C ages and stable isotopic composition of carbon and oxygen in thin (0.2–0.3 mm thick) pedogenic carbonate lamina indicate two main periods of coating formation: the early-Holocene (ca. 10000–6000 cal yr BP) and the mid-Holocene (ca. 6000–4000 cal yr BP). During the first period, there was an inverse relationship between δ13C and δ18O curves: a decrease in δ13C values coincide with an increase in δ18O values. For this period a trend towards higher temperatures is suggested. In the mid-Holocene, the mean rate of coating growth was 2–3 times higher than in the early Holocene. Both δ13C and δ18O reached their maximum values during this time and the direction of changes of the δ13C and δ18O curves became similar. The combination of data suggests that this period was the most humid in the Holocene and on average warmer than the early Holocene. At ca. 4000 cal yr BP secondary accumulation of carbonate ceased, presumably reflecting a shift to a more arid climate.
A Framework for the Prediction of Scale‐Up When Using Compressible Chromatographic Packings
Authors: Tran Richard , Joseph John R. , Sinclair Andrew , Bracewell Daniel , Zhou Yuhong , Titchener‐Hooker Nigel J. 
Published: February 2007

AbstractExperimental data are given for the solid pressure distributions in chromatography columns of various column aspect ratios packed with four types of agarose‐based resin. The loss of column wall support at large scales can result in unexpectedly high pressures caused by the compression of the matrix via drag forces exerted by fluid flow through the bed. The need for an accurate model to predict flow conditions at increasing scale is essential for the scaling‐up of chromatographic processes and for avoiding bed compression during operation. Several studies have generated correlations that allow for the prediction of column pressure drops, but they either are mathematically complex, which impairs their practical use, or require a large number of experiments to be performed before they can be used. In this study an empirical correlation was developed based on a previously proposed model, which links the critical velocity of operation of a chromatographic system (ucrit), to the gravity‐settled bed height (L0), the column diameter (D), the feed viscosity (μ), and the compressibility of the chromatographic media used (u10%). The methodology developed in this study is straightforward to use and significantly reduces the burden of preceding laboratory‐scale experimentation. The approach can be used to predict the critical velocity of any chromatographic system and will be useful in the development of chromatographic operations and for column sizing.
Clinical relevance of hepsin and hepatocyte growth factor activator inhibitor type 2 expression in renal cell carcinoma
Authors: Betsunoh Hironori , Mukai Shoichiro , Akiyama Yutaka , Fukushima Tsuyoshi , Minamiguchi Naoki , Hasui Yoshihiro , Osada Yukio , Kataoka Hiroaki 
Published: February 2007

Cell surface proteolysis is important for the generation of bioactive proteins mediating tumor progression. Recent studies suggest that the membrane‐anchored cell surface proteinases matriptase and hepsin have significant roles in tumors. We analyzed the expression and clinical relevance of matriptase and hepsin, and their inhibitors hepatocyte growth factor activator inhibitor type 1 (HAI‐1) and type 2 (HAI‐2) in 66 cases of conventional renal cell carcinomas (RCC). The mRNA level was evaluated in paired samples from tumor and non‐tumorous renal tissues by real‐time reverse transcription–polymerase chain reaction. As matriptase and hepsin potently activate the proform of hepatocyte growth factor (HGF), the expression of HGF and its receptor, c‐Met, was also analyzed. Although upregulation of matriptase was observed occasionally in RCC, the expression level was not associated with prognostic parameters. Hepsin was downregulated in RCC, particularly in early stage disease, but upregulated in advanced stages. There was a trend of higher hepsin expression in RCC with distant metastasis, and Kaplan–Meier survival curves showed that high hepsin expression was associated with reduced overall survival (P < 0.01, log‐rank test). Moreover, multivariate analysis indicated that hepsin was an independent prognostic factor. Overexpression of HGF or c‐Met also showed reduced overall survival. We also observed a tendency of low HAI‐2 expression with reduced overall survival and a statistical association between high hepsin and low HAI‐2 level. No associations were observed between matriptase and HAI‐1 and HAI‐2. Our findings suggest that the balance between hepsin and its inhibitor, HAI‐2, may have prognostic value in RCC. (Cancer Sci 2007; 98: 491–498)