bluuebunny/crossref_metadata_2025 huggingface dataset:
Methane cycling in the sediments of Lake Washington
Authors: Kuivila K. M. , Murray J. W. , Devol A. H. , Lidstrom M. E. , Reimers C. E.
Published: April 2010

Aerobic oxidation is important in the cycling of methane in the sediments of Lake Washington. About half of the methane flux from depth is oxidized to CO2 in the upper 0.7 cm of the sediments and the remainder escapes into the water column. In terms of the total carbon budget of the lake, the upward flux of methane is insignificant with only about 2% of the carbon fixed by primary production being returned as methane. The upward flux of methane, however, does represent about 20% of the organic carbon decomposed within the sediments. In addition, methane oxidation consumcs 7–10% of the total oxygen flux into the sediments. Measured kinetic parameters suggest that methane oxidation is restricted to the top 6–7 mm of sediment where oxygen is present and that the rate of this process is probably controlled by the concentration of methane.
Stable carbon and nitrogen isotope biogeochemistry in the Delaware estuary
Authors: Cifuentes L. A. , Sharp J. H. , Fogel Marilyn L.
Published: April 2010

Seasonal variability in stable carbon (δ13C) and nitrogen (δ15N) isotope ratios was observed in suspended particulate matter of the Delaware estuary. Two major pools of organic matter were found in the estuary—phytoplankton growing in situ and a mixture of planktonic and terrestrial detritus. In general, the δ13C and δ15N of suspended particulate matter reflected planktonic dominance. With the background chemical and physical information available for the estuary, it is evident that biogeochemical processes influence isotopic distributions in the estuary to a greater extent than does physical mixing. During spring, we postulate that isotopic fractionation of ammonium assimilated at concentrations >20 µM resulted in more negative δ15N values for organic matter fixed by phytoplankton. As algal growth proceeded, the δ15N of seston reached a maximum (+ 18‰) because phytoplankton were using a pool of NH4+ enriched in 15N as a result of previous fractionation during assimilation. Similarly, maximal δ13C values were related to high rates of primary productivity associated with algal growth. Decreased isotopic fractionation occurred at high rates of production, implying that diffusion of CO2 across the cell membrane became increasingly rate limiting.

The δ13C values in bottom sediments were equivalent to those in suspended particulate matter, but a 2‰ difference in δ1 5N was found between suspended and bottom sediments. With nitrogen isotopic differences between water‐column seston and surficial sediments, we estimate that 15– 30% of planktonic production is deposited in the sediments during spring. If this organic matter is remineralized in late summer and fall, it could support up to 20% of primary production at that time.
Vertical distribution of ammonium in stratified oligotrophic waters
Authors: Brzezinski Mark A.
Published: April 2010

A method for measuring nanomolar concentrations of ammonium in seawater was used for the first time under field conditions in the Sargasso Sea and Gulf Stream. Ammonium concentrations ranged from below the limit of detection (3.5 nM) to 164 nM NH4+. Subsurface ammonium maxima (16–59 nM NH4+) occurred within the seasonal thermocline and near the deep chlorophyll a maximum in association with the primary nitrite maximum. The latter feature was observed in both the Sargasso Sea and Gulf Stream, suggesting that it may be common in stratified oligotrophic waters. Vertically integrated nitrite concentrations in the upper 140 m generally exceeded those for ammonium, suggesting more efficient use of reduced nitrogen by the microplankton.
Predation by cutthroat trout on Chaoborus flavicans as revealed by a population budget1
Authors: Luecke Chris
Published: April 2010

A population budget was constructed for Chaoborus flavicans in Lake Lenore, Washington, during the 1985 spring emergence to estimate the proportion of the population consumed by cutthroat trout. Weekly sampling of the population indicated that all individuals were competent to pupate and emerge and that cutthroat trout preyed heavily on the pupal stage. Field measurements of life‐stage transformation rates and rates of fish predation were incorporated into a daily simulation model which indicated that cutthroat trout consumed 33% of all individuals during the spring emergence period. Length of the pupal period shortened as water temperature increased. This decrease in pupal period reduced the probability that individual pupae would be consumed by trout later in the emergence period. The simulation model was used to examine the effect of increased temperature on developmental processes. When lake temperatures were increased 2° and 5°C above measured values, a greater proportion of fourth instar larvae entering an emergence period survived to the adult stage. Consideration of developmental processes may help explain intra‐annual variation in recruitment success of C. flavicans in Lake Lenore.
Hypolimnetic metabolism in Lake Washington: Relative effects of nutrient load and food web structure on lake productivity1
Authors: Lehman John T.
Published: April 2010

The general metabolism of carbon, oxygen, phosphate, nitrate, and silicate in the hypolimnion of Lake Washington is examined from 23 yr of record. Magnitudes of net consumptive and regenerative processes in the water column and sediments are identified and stoichiometries of regeneration in situ are calculated. Aerobic respiration appears to be almost equally divided between the water column and sediment surface. Net nitrification is more rapid in the water column, and silicate regeneration is confined to the sediment surface. Nutrients do not accumulate on average at the Redfield ratio.

Rates of hypolimnetic oxygen consumption are compared to production rates inferred independently from 14C and oxygen bottle assays. A third of all gross primary production is respired in the hypolimnion of Lake Washington during spring and summer, but the proportion was significantly lower during an episode of cultural eutrophication in the 1960s. Rates of primary production and hypolimnetic processes decreased in response to changes in nutrient income when effluents from waste treatment plants were diverted from the lake. After a period of recovery from eutrophication, Lake Washington experienced a second basinwide perturbation involving alteration of the planktonic herbivore community. The change in food web structure failed to produce a response comparable to that of altered nutrient loading. Despite inferred changes in algal growth rates and in species composition, total primary productivity and rates of hypolimnetic metabolism did not change.
Office Assessment of Patient with Head and Neck Cancer
Authors: Pradhan Sultan , Hakeem Arsheed Hussain
Published: April 2010

Evaluation of patients with head and neck cancers is important for proper treatment planning. With advent of advanced fiberoptic system, assessment of the mucosal surfaces of upper aerodigestive tract is much easier and can be performed in office settings.
Imaging in Head and Neck Cancers
Authors: Patkar Deepak , Lawande Malini , Yanamandala Rama
Published: April 2010

This article reviews the role of imaging, imaging characteristics and significance of individual imaging modalities as well as the newer imaging modalities in the evaluation of head and neck cancer. In the pretreatment evaluation, imaging is performed primarily to determine the stage of tumor and to look for an occult primary. It helps in obtaining tissue samples to establish the diagnosis, and treatment planning if radiotherapy is considered. Postsurgery and radiotherapy changes can be differentiated from residual or recurrent pathology on imaging. Imaging also plays an important role in assessing the response to treatment.
Tracheostomy in Head and Neck Cancers
Authors: Rai Reema , Watve Parag , Hathiram Bachi T
Published: April 2010

The term ‘tracheostomy’ or ‘tracheotomy’ refers to the procedure whereby a communication is made between the anterior wall of the trachea and the exterior which bypasses the upper air passages. It results in the formation of a fistulous tract between the anterior aspect of the neck and the trachea allowing air to enter the lower respiratory passages without passing through the nose, pharynx and larynx.

It is performed at all ages, however, there are significant differences in the procedure when performed in adults and children.

‘Laryngotomy’ or ‘cricothyrotomy’ is the emergency operation where the airway is opened through the cricothyroid membrane in case of acute respiratory obstruction where there is no time for tracheostomy or inavailability of a competent surgeon to perform the tracheostomy. It is a relatively simple procedure and life-saving.
Use of Metformin in Clomiphene Citrate (CC) Resistant Polycystic Ovary Syndrome (PCOS)
Authors: Begum Mosammat Rashida , Banu Laila Arjumand , Rahman Ratu Rumana Binte , Dewan Farhana , Rouf Salma
Published: April 2010

Polycystic ovary syndrome (PCOS) is a common endocrine disorder affecting between 4% and 8% of reproductive aged women. Although the symptoms and signs of PCOS are very heterogeneous, the syndrome usually presents with any combination of the following, menstrual irregularities (usually oligomenorrhea or amenorrhea), signs of hyperandrogenism (hirsutism, acne, alopecia) a characteristic appearance of the ovaries on ultrasound examination and an endocrine disturbance often involving high serum concentrations of LH and androgens.

There is a well established association between PCOS, insulin resistance and hyperinsulinemia. Insulin resistance is a pivotal defect in PCOS probably counts as one of the most important advances in the battle to control the disorder. This metabolic abnormality leads to a compensatory increase in circulating insulin and this elevated insulin level directly stimulates the ovary to produce excess androgens. It also decreases hepatic sex hormone binding globulin (SHBG), so increasing biologically available free testosterone concentration in the circulation. This metabolic derangement leads to oligomenorrhea and anovulation.

Different insulin sensitizers are used to revert the hyperinsulinemic condition. Metformin is top of them, which proved to enhance ovulation in insulin resistant PCOS when used with different ovulation inducing agents. Metformin reduces insulin resistance of peripheral tissue and allows muscle and adipose cells to take in glucose at normal insulin levels. It inhibits hepatic glucose production, decreases intestinal absorption and promotes glucose uptake, utilization by peripheral tissues at the postreceptor level. In this way it reduces insulin level and subsequently androgen level. It is easily available, safe and no teratogenic or adverse fetal outcome were reported by any researcher. It can be used safely in clomiphene resistant PCOS patients.
Evaluation of Clinicosocial Factors Associated with Antepartum and Intrapartum Stillbirths at Kathmandu Medical College Teaching Hospital
Authors: Rayamajhi RT , Shreshtha N , Karki C , Padhye SM
Published: April 2010

Objective

To assess the prevalence and biosocial and obstetric risk factors for antepartum and intrapartum stillbirths at a tertiary hospital in Kathmandu, Nepal.

Study Design

A prospective hospital based study during a one year period from 1st November 2007 to 30th October 2008.

Results:18 stillbirths occurred out of the 790 deliveries that took place during the study period giving an overall stillbirth rate of 22.7 per 1000 births of which 22.2% occurred in the intrapartum period. The majority(89.9%) of patients were in the low risk age group, viz. 20-35 years. 62% were overweight, 16% obese and 22% had normal BMI. More than half (56%) were either illiterate or had only primary education and 33.3% were moderate smokers. 66.6% were nullipara and there were no grand multipara in the series. 72% had regular prenatal visits but only 33% presented with a history of loss of fetal movements. 50% delivered preterm and 22.2% were post-term while 66.6% had low birth weights. Hypertensive disorders of pregnancy and IUGR were the leading causes of stillbirths, others being prolonged PROM, cholestasis of pregnancy and congenital anomalies. 11.1% were unexplained and there was one case each of gestational diabetes, antepartum hemorrhage and vaginal breech delivery.

Conclusion

Avoidable intrapartum stillbirths continue to be quite high where timely and appropriate intrapartum intervention must be taken to prevent fetal loss. The identified antenatal risk factors should serve as potential targets for antenatal intervention and due importance of maternal fetal movement scoring must be stressed in the at risk patient.
Visualization of G Protein−Coupled Receptor (GPCR) Interactions in Living Cells Using Bimolecular Fluorescence Complementation (BiFC)
Authors: Vidi Pierre‐Alexandre , Przybyla Julie A. , Hu Cheng‐Deng , Watts Val J.
Published: April 2010

Members of the G protein−coupled receptor (GPCR) superfamily have been shown to homo‐ and hetero‐oligomerize both in vitro and in vivo. Although the functional and pharmacological significance of GPCR oligomerization is far from being completely understood, evidence suggests that, depending on the receptor, oligomerization may influence ligand binding, G protein coupling, and receptor targeting. Bimolecular fluorescence complementation (BiFC) is a technique based on the complementation of fragments from fluorescent proteins that allows the measurement and visualization of protein interactions in living cells. It can be extended to the simultaneous detection of distinct protein‐protein interactions using a multicolor setup. This unit describes the application of BiFC and multicolor BiFC to the visualization of GPCR oligomerization in a neuronal cell model. Oligomerization of GPCR fusions to BiFC tags is visualized and measured using fluorescence microscopy and fluorometry. The effect of ligands on the relative formation of distinct oligomeric species is monitored with a ratiometric multicolor BiFC approach. Curr. Protoc. Neurosci. 51:5.29.1‐5.29.15. © 2010 by John Wiley & Sons, Inc.
Endoglycosidase and Glycoamidase Release of N‐Linked Glycans
Authors: Freeze Hudson H. , Kranz Christian
Published: April 2010

Nearly all proteins entering the lumen of the endoplasmic reticulum (ER) become glycosylated en route to a cellular organelle, the plasma membrane, or the extracellular space. Many glycans can be attached to proteins, but the most common are the N‐linked glycans (oligosaccharides). These chains are added very soon after a protein enters the ER, but they undergo extensive remodeling (processing), especially in the Golgi. Processing changes the sensitivity of the N‐glycan to enzymes that cleave entire sugar chains or individual monosaccharides, which also changes the migration of the protein on SDS gels. These changes can be used to indicate when a protein has passed a particular subcellular location. This unit details some of the methods used to track a protein as it trafficks from the ER to the Golgi toward its final location. Curr. Protoc. Immunol. 89:8.15.1‐8.15.25. © 2010 by John Wiley & Sons, Inc.
Use of the Hemagglutinating Virus of Japan (HVJ) Envelope as a Versatile Delivery System for Nucleic Acids and Proteins to Leukocytes In Vitro
Authors: Kondo Yoshitaka , Miyata Keizo , Kato Fuminori
Published: April 2010

The hemagglutinating virus of Japan (HVJ; also called the Sendai virus) envelope has been developed as a safe and efficient non‐viral vector. Because replication and transcription of genomic RNA is inactivated by β‐propiolactone treatment or UV‐irradiation, the HVJ envelope is extremely safe. This unit describes the method of transfection of siRNA and protein with the HVJ envelope. Curr. Protoc. Immunol. 89:10.17D.1‐10.17D.9. © 2010 by John Wiley & Sons, Inc.
Amnion Epithelial Cell Isolation and Characterization for Clinical Use
Authors: Murphy Sean , Rosli Sharina , Acharya Rutu , Mathias Louisa , Lim Rebecca , Wallace Euan , Jenkin Graham
Published: April 2010

Human amnion epithelial cells (hAECs) are a heterologous population positive for stem cell markers; they display multilineage differentiation potential, differentiating into cells of the endoderm (liver, lung epithelium), mesoderm (bone, fat), and ectoderm (neural cells). They have a low immunogenic profile and possess potent immunosuppressive properties. Hence, hAECs may be a valuable source of cells for cell therapy. This unit describes an efficient and effective method of hAEC isolation, culture, and cryopreservation that is animal product–free and in accordance with current guidelines on preparation of cells for clinical use. Cells isolated using this method were characterized after 5 passages by analysis of karyotype, cell cycle distribution, and changes in telomere length. The differentiation potential of hAECs isolated using this animal product–free method was demonstrated by differentiation into lineages of the three primary germ layers and expression of lineage‐specific markers analyzed by PCR, immunocytochemistry, and histology. Curr. Protoc. Stem Cell Biol. 13:1E.6.1‐1E.6.25. © 2010 by John Wiley & Sons, Inc.
Monotonic and Cyclic Deformation Behaviour of the SiC Particle‐Reinforced Aluminium Matrix Composite AMC225xe
Authors: Smaga Marek , Walther Frank , Eifler Dietmar
Published: April 2010

The monotonic and cyclic deformation behaviour of the aluminium matrix composite AMC225xe – i.e., the aerospace grade aluminium alloy AA 2124 reinforced with 25 vol.‐% ultrafine SiC particles – is characterised in detail on the basis of mechanical stress–strain hysteresis curves as well as temperature and electrical resistance measurements. A pronounced difference in plastic strain response is observed between tension and compression under monotonic and cyclic loading. In fully reversed stress‐controlled constant amplitude tests, negative plastic mean strains developed. The cyclic deformation behaviour of AMC225xe is characterised by pronounced initial cyclic hardening. The endurance limit is reliably estimated in continuous load increase tests. In particular, electrical resistance data are used as input parameters for fatigue life calculations analogous to the Basquin equation. Microstructural details are investigated by light and scanning electron microscopy.
Al and Zn Foams Blown by an Intrinsic Gas Source
Authors: Mukherjee M. , Garcia‐Moreno F. , Jiménez C. , Banhart J.
Published: April 2010

A method was developed to produce Al‐ and Zn‐based foams with a uniform distribution of small cells. Pre‐alloyed AlMg50 powder containing hydrogen was used as a replacement for the usual blowing agent TiH2. AlMg50 powder released gas uniformly in the entire sample, caused the nucleation of a large number of cells and led to simultaneous growth that finally resulted in a uniform cell structure. The expansion behavior of these foams was studied by means of in situ X‐ray radioscopy. The macrostructure of the solidified foams was then analyzed through optical microscopy and X‐ray tomography and proved to be very uniform. The high strength of the foams was demonstrated by uni‐axial compression tests.
Simultaneous Immobilization of Bioactives During 3D Powder Printing of Bioceramic Drug‐Release Matrices
Authors: Vorndran Elke , Klammert Uwe , Ewald Andrea , Barralet Jake E. , Gbureck Uwe
Published: April 2010

The combination of a degradable bioceramic scaffold and a drug‐delivery system in a single low temperature fabrication step is attractive for the reconstruction of bone defects. The production of calcium phosphate scaffolds by a multijet 3D printing system enables localized deposition of biologically active drugs and proteins with a spatial resolution of approximately 300 µm. In addition, homogeneous or localized polymer incorporation during printing with HPMC or chitosan hydrochloride allows the drug release kinetics to be retarded from first to zero order over a period of 3–4 days with release rates in the range 0.68%–0.96% h−1. The reduction in biological activity of vancomycin, heparin, and rhBMP‐2 following spraying through the ink jet nozzles is between 1% and 18%. For vancomycin, a further loss of biological activity following incorporation into a cement and subsequent in vitro release is 11%. While previously acknowledged as theoretically feasible, is its shown for the first time that bone grafts with simultaneous geometry, localized organic bioactive loading, and localized diffusion control are a physical reality. This breakthrough offers a new future for patients by providing the required material function to match patient bone health status, site of repair, and age.
Regioselective and Enantioselective Hydroformylation of Dialkylacrylamides
Authors: Noonan Gary M. , Newton David , Cobley Christopher J. , Suárez Andrés , Pizzano Antonio , Clarke Matthew L.
Published: April 2010

Dimethylacrylamide can be hydroformylated with very high chemo‐ and regioselectivity. Asymmetric hydroformylation of this substrate is possible, provided steps are taken to minimise racemisation of the aldehyde products, and this work demonstrates the effect of various conditions and variables on racemisation. Using the Landis diazaphospholane ligands up to 68% ee can be realised under very mild conditions. Other dialkylacrylamides were also hydroformylated under mild conditions giving similar or better enantioselectivities, including the Weinreb amide of acrylic acid (71% ee), and the asymmetric hydroformylation of diethylacrylamide producing the chiral aldehyde with up to 82% ee.
Iron‐Catalyzed Oppenauer‐Type Oxidation of Alcohols
Authors: Coleman Michael G. , Brown Alec N. , Bolton Brett A. , Guan Hairong
Published: April 2010

A (hydroxycyclopentadienyl)iron dicarbonyl hydride catalyzes the Oppenauer‐type oxidation of alcohols with acetone as the hydrogen acceptor. Many functional groups are tolerant to the oxidation conditions. The same complex also catalyzes the dehydrogenation of diols to lactones. A mechanism involving the formation of iron‐alcohol complexes and their rapid ligand exchange with free alcohols is proposed. The trimethylsilyl groups on the cyclopentadienyl ligand of the catalyst play a critical role in stabilizing the iron hydride and increasing the catalyst lifetime.
An assessment of consumer preference for fair trade coffee in Toronto and Vancouver
Authors: Cranfield John , Henson Spencer , Northey James , Masakure Oliver
Published: April 2010

In this article, the authors use conjoint analysis to elicit the views of coffee consumers on the attributes of Fair Trade coffee using data from the Greater Toronto Area and Vancouver collected through face‐to‐face interviews with consumers. The impact of socioeconomic and demographic factors on respondents' acceptance of Fair Trade coffee is evaluated using cluster analysis and multinomial logit models. The results suggest that, regardless of location, consumers place a strong premium on price and labeling claims. Three consumer segments are identified in each city; in Toronto, these segments are labeled Fair Trade‐Focused, Price Conscious, and Balanced Buyers; for Vancouver these segments are labeled Organic and Fair Trade‐Focused, Price Conscious, and Balanced Buyers. Although a broad spectrum of variables influences segment membership, no single variable explains membership in the same segment in each city. Such a result is rather telling; it suggests deeper constructs underlie segment membership, and presumably consumption behavior with respect to Fair Trade coffee. © 2010 Wiley Periodicals, Inc.
Common recurrent microduplication syndromes: Diagnosis and management in clinical practice
Authors: Berg Jonathan S. , Potocki Lorraine , Bacino Carlos A.
Published: April 2010

Details on the phenotypic consequences of genomic microdeletions and microduplications are rapidly emerging in the wake of increased utilization of high‐resolution methods for the detection of genomic copy number variants (CNVs). Due to their recent discovery, the complete phenotypic characterization of these syndromes is still in progress. For practicing clinicians, this unprecedented molecular diagnostic capability has in many cases outpaced our ability to convey conclusive information regarding these conditions to patients and family members. In particular, genomic microduplication syndromes are frequently associated with variable phenotypes and incomplete penetrance, leading to difficulty in counseling regarding the potential future consequences of a given microduplication. In this review, we have attempted to provide an initial set of recommendations for the management of patients with recurrent microduplication syndromes. We summarize the clinical information for microduplications of 14 different genomic regions and provide a framework for clinical evaluation and anticipatory guidance in these conditions. It is our expectation that these preliminary guidelines will be revised further for each microduplication syndrome as more information becomes available. © 2010 Wiley‐Liss, Inc.
Introductory comments on special section—Genomic microduplications: When adding may equal subtracting
Authors: Bacino Carlos A. , Cheung Sau‐Wai
Published: April 2010

The clinical implementation of array‐based comparative genomic hybridization (aCGH) has allowed detection of copy number variations (CNVs) from megabases in size to those involving only a single exon. One major challenge that followed the clinical implementation of array CGH technology has been the interpretation of CNVs whose clinical significance can be elusive. The copy number gains resulting from genomic rearrangements are often more difficult to interpret than the copy number losses. Some of the CNV gains can be pathogenic, while others can be unrelated to disease since CNVs are often polymorphic in the normal population. The challenge faced by clinicians is how to differentiate between the disease causing CNVs and the nonpathogenic polymorphisms. Therefore, it is critical to systematically collect phenotypic information associated with CNVs and deposit it in searchable and publicly accessible databases. © 2010 Wiley‐Liss, Inc.
Long‐term field studies: positive impacts and unintended consequences
Authors: Strier Karen B.
Published: April 2010

Long‐term field studies of wild primates can have far‐reaching impacts that transcend their contributions to science. These impacts can benefit not only the study animals, study areas, and local human communities, but they can also have unintended, potentially negative consequences. Examples of some of the positive impacts from the Northern Muriqui Project of Caratinga, in Minas Gerais, Brazil, include contributions to conservation efforts on behalf of this critically endangered species, capacity building through the training of Brazilian students, and employment opportunities for local people through our collaboration with a locally administered NGO that is facilitating ecotourism, education, and reforestation programs. Some concerns about unintended consequences of the research include the effects of our trails and trail traffic on surrounding vegetation and other aspects of the environmental “footprints” that both long‐term researchers and short‐term visitors may leave. In addition, although precautions against potential health risks from routine exposure to human observers are now standard protocol, little is known about the other ways in which our long‐term research presence can affect the primates' experiences or alter their perceptions of their social and ecological environments. Risk analysis, which weighs both the positive and negative impacts can provide useful perspectives for addressing the ethical considerations that can arise during long‐term field studies. Am. J. Primatol. 72:772–778, 2010. © 2010 Wiley‐Liss, Inc.
Residual tumor cells are unique cellular targets in glioblastoma
Authors: Glas Martin , Rath Barbara H. , Simon Matthias , Reinartz Roman , Schramme Anja , Trageser Daniel , Eisenreich Ramona , Leinhaas Anke , Keller Mihaela , Schildhaus Hans‐Ulrich , Garbe Stephan , Steinfarz Barbara , Pietsch Torsten , Steindler Dennis A. , Schramm Johannes , Herrlinger Ulrich , Brüstle Oliver , Scheffler Björn
Published: April 2010

Residual tumor cells remain beyond the margins of every glioblastoma (GBM) resection. Their resistance to postsurgical therapy is considered a major driving force of mortality, but their biology remains largely uncharacterized. In this study, residual tumor cells were derived via experimental biopsy of the resection margin after standard neurosurgery for direct comparison with samples from the routinely resected tumor tissue. In vitro analysis of proliferation, invasion, stem cell qualities, GBM‐typical antigens, genotypes, and in vitro drug and irradiation challenge studies revealed these cells as unique entities. Our findings suggest a need for characterization of residual tumor cells to optimize diagnosis and treatment of GBM. ANN NEUROL 2010;68:264–269
Higher 25‐hydroxyvitamin D is associated with lower relapse risk in multiple sclerosis
Authors: Simpson Steve , Taylor Bruce , Blizzard Leigh , Ponsonby Anne‐Louise , Pittas Fotini , Tremlett Helen , Dwyer Terence , Gies Peter , van der Mei Ingrid
Published: April 2010

Objective

A protective association between higher vitamin D levels and the onset of multiple sclerosis (MS) has been demonstrated; however, its role in modulating MS clinical course has been little studied. We investigated whether higher levels of serum 25‐hydroxyvitamin D (25‐OH‐D) were associated with a lower risk of relapses in people with MS.

Methods

We conducted a prospective cohort study of 145 participants with relapsing‐remitting MS from 2002 to 2005. Serum 25‐OH‐D levels were measured biannually, and the hazard of relapse was assessed using survival analysis.

Results

There was an inverse linear relationship between 25‐OH‐D levels and the hazard of relapse over the subsequent 6 months, with hazard ratio (HR) 0.91 (95% confidence interval [CI]: 0.85–0.97) per 10nmol/l increase in 25‐OH‐D level (p= 0.006). When variation due to timing of blood collection was removed by estimating 25‐OH‐D at the start of each season, this association persisted, with HR 0.90 (95% CI, 0.83–0.98) per 10nmol/l increase (p= 0.016). Taking into account the biological half‐life of 25‐OH‐D, we estimated 25‐OH‐D at monthly intervals, resulting in a slightly enhanced association, with HR 0.88 (95% CI, 0.82–0.95) per 10nmol/l increase (p= 0.001). Adjusting for potential confounders did not alter these findings.

Interpretation

In this prospective population‐based cohort study, in a cohort largely on immunomodulatory therapy, higher 25‐OH‐D levels were associated with a reduced hazard of relapse. This occurred in a dose‐dependent linear fashion, with each 10nmol/l increase in 25‐OH‐D resulting in up to a 12% reduction in risk of relapse. Clinically, raising 25‐OH‐D levels by 50nmol/l could halve the hazard of a relapse. ANN NEUROL 2010;68:193–203
Strong signature of the active Sun in 100 years of terrestrial insolation data
Authors: Weber W.
Published: April 2010

Terrestrial solar irradiance data of the Smithsonian Astrophysical Observatory from 1905 to 1954 and of Mauna Loa Observatory from 1958 to 2008 are analyzed. The analysis shows that, with changing solar activity, the atmosphere modifies the solar irradiance on the percentage level, in all likelihood via cosmic ray intensity variations produced by the active sun. The analysis strongly suggests that cosmic rays cause a large part of the atmospheric aerosols. These aerosols show specific absorption and scattering properties due to an inner structure of hydrated ionic centers, most probably of O2‐ and O2+ produced by the cosmic rays.
Zeolithe mit sehr großen Poren als Bindeglied zwischen mikro‐ und mesoporösen Strukturen
Authors: Jiang Jiuxing , Yu Jihong , Corma Avelino
Published: April 2010

In diesem Aufsatz wird untersucht, welche Bedingungen für die Synthese von Zeolithen mit niedriger Gerüstdichte und sehr großen Poren erforderlich sind. Korrelationen zwischen der Gerüststabilität und geometrischen und topologischen Deskriptoren werden vorgestellt, wobei vor allem der Einfluss des Synthesemechanismus, des strukturdirigierenden Reagens, der Gerüstatome und der Gelkonzentration betrachtet wird. Ebenfalls diskutiert werden die katalytischen und Adsorptionseigenschaften von Zeolithen mit sehr großen Poren, z. B. dem erst kürzlich entdeckten chiralen mesoporösen ITQ‐37. Schließlich werden Strategien für die gezielte Synthese von Zeolithen mit Porengrößen und ‐formen vorgeschlagen, die diesen bestimmte katalytische und Adsorptionseigenschaften verleihen sollen.
Extra‐Large‐Pore Zeolites: Bridging the Gap between Micro and Mesoporous Structures
Authors: Jiang Jiuxing , Yu Jihong , Corma Avelino
Published: April 2010

The conditions required to produce zeolites with low framework density and extra‐large pores are discussed. Correlations between framework stability and geometrical and topological descriptors are presented. An attempt has been made to rationalize the synthesis of extra‐large‐pore zeolites in terms of the synthesis mechanism, the directing effect of the organic structure directing agent (OSDA), the framework atoms, and the gel concentration. Extra‐large‐pore zeolites, including the recently discovered chiral mesoporous ITQ‐37, are described and their catalytic and adsorption properties discussed. Finally, strategies are presented for the preparation of extra‐large‐pore zeolites with different pore topologies that can fulfill pre‐established catalytic and adsorption targets.
Electrospun ultrafine composite fibers from organic‐soluble chitosan and poly(ethylene oxide)
Authors: Chang Wenkai , Ma Guiping , Yang Dongzhi , Su Dandan , Song Guoqiang , Nie Jun
Published: April 2010

The ultrafine composite fibers had been successfully achieved by electrospinning of chloroform solutions of octadecyl chitosan (O‐CS) and poly(ethylene oxide) (PEO). The ultrafine composite fibers membranes were subjected to detailed analysis by Fourier‐transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and water contact angle (WCA). The FTIR results confirmed that ultrafine composite fibers contained the two polymers. The SEM images showed that the morphology and diameter of the composite fibers were mainly affected by the weight ratio of O‐CS/PEO, the electric field strength, and the collection distance. The WCA data demonstrated that the composite fibers membranes performed a quite hydrophobic character. The special morphology of neck and porous structure was observed experimentally during electrospinning. The neck structure was due to the fibers elongated in the direction of stretching through the electric field, and the porous structure was decided by the competition between the phase separation and the fast evaporation rate of chloroform. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis, spectral, thermal, and chelation potentials of polymeric hydrazone based on 2,4‐dihydroxy benzophenone
Authors: Sankar R. , Vijayalakshmi S. , Rajagopan S. , Kaliyappan T.
Published: April 2010

A chelating polymer, poly(2,4‐dihydroxy benzophenone hydrazone–formaldehyde) [poly(DHBPH–F)], was synthesized by the polycondensation of 2,4‐dihydroxy benzophenone hydrazone with formaldehyde in the presence of oxalic acid as a catalyst. Poly(DHBPH–F) was characterized by Fourier transform infrared and 1H‐NMR spectral data. The molecular weight of the polymer was determined by gel permeation chromatography. Polychelates were obtained when the dimethylformamide solution of the polymer containing a few drops of ammonia was treated with an aqueous solution of metal ions. Elemental analysis of the polychelates indicated that the metal–ligand ratio was 1 : 2. The IR spectra of the polymer–metal complexes suggested that the metals were coordinated through the oxygen of the phenolicOH group and the nitrogen of the azomethine group. The electron paramagnetic resonance and magnetic moment data indicated a square planar configuration for Cu(II) chelate and an octahedral structure for Ni(II) chelate. The thermogravimetric analysis, differential scanning calorimetry, and X‐ray diffraction data indicated that the incorporation of the metal ions significantly enhanced the degree of crystallinity. The polymerization initiation, electrical conductivity, and catalytic activity of the polychelates are discussed. Heavy‐metal ions [viz., Cu(II) and Ni(II)] were removed with this formaldehyde resin, and the metal‐ion uptake efficiency at different pH's, the nature and concentration of the electrolyte, and the reusability of the resin were also studied. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis, characterizations, and mechanical properties of structurally modified poly(vinyl alcohol)
Authors: Anbarasan R. , Pandiarajaguru R. , Prabhu R. , Dhanalakshmi V. , Jayalakshmi A. , Dhanalakshmi B. , Nisha S. Ulfath , Gandhi S. , Jayalakshmi T.
Published: April 2010

Poly(vinyl alcohol) (PVA) was structurally modified with two different types of chemicals under nitrogen atmosphere in the presence of Sb2O3 as a catalyst at 80°C in an aqueous medium. An FTIR and NMR spectrum confirmed the structural modification of PVA. DSC and TGA counseled the thermal properties of structurally modified PVA. Urea modified PVA exhibited higher mechanical strength than the pristine PVA. The FTIR‐relative intensities of olefin formation and ketone formation were increased with the increase of weight of water. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Fabrication of electrospun eggshell membrane nanofibers by treatment with catechin
Authors: Kang Jian , Kotaki Masaya , Okubayashi Satoko , Sukigara Sachiko
Published: April 2010

Optimum processing conditions for the electrospinning of water‐soluble eggshell membrane (S‐ESM) were investigated. Two biocompatible polymers, poly(ethylene oxide) (PEO) and poly(vinyl alcohol) (PVA), were used to improve the processability of S‐ESM for electrospinning in aqueous media. Uniform nanofibers with average diameters of 240 and 335 nm were successfully electrospun for blend ratios at S‐ESM/PEO = 95 : 5 and S‐ESM/PVA = 60 : 40 with a solutes concentration of 20 and 18 wt %, respectively. Insoluble S‐ESM/PEO and S‐ESM/PVA fibers were achieved after treatment with catechin and required no toxic or synthetic additives. FTIR spectra indicated that the hydrogen bond formed between S‐ESM and catechin was the main interaction that improved the insolubility of S‐ESM/PEO and S‐ESM/PVA nanofibers in water. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Dynamic processes of the photoinduced birefringence of two novel azobenzene‐functionalized polymers
Authors: Pei Songhao , Chen Xingbo , Jiang Zhenhua , Peng Weixian
Published: April 2010

The growth and decay processes of optically induced birefringence in two novel azobenzene compounds [one was a hyperbranched poly(aryl ether) containing azobenzene groups, and the other was a hydrogen‐bonded complex] were studied. The temperature dependence of the birefringence signal was investigated. The curves for the buildup and decay of birefringence fit well to biexponential functions. The dependence of the fitting parameters on the temperature is also discussed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Intrinsic brain connectivity in fibromyalgia is associated with chronic pain intensity
Authors: Napadow Vitaly , LaCount Lauren , Park Kyungmo , As‐Sanie Sawsan , Clauw Daniel J. , Harris Richard E.
Published: April 2010

Objective

Fibromyalgia (FM) is considered to be the prototypical central chronic pain syndrome and is associated with widespread pain that fluctuates spontaneously. Multiple studies have demonstrated altered brain activity in these patients. The objective of this study was to investigate the degree of connectivity between multiple brain networks in patients with FM, as well as how activity in these networks correlates with the level of spontaneous pain.

Methods

Resting‐state functional magnetic resonance imaging (FMRI) data from 18 patients with FM and 18 age‐matched healthy control subjects were analyzed using dual‐regression independent components analysis, which is a data‐driven approach for the identification of independent brain networks. Intrinsic, or resting‐state, connectivity was evaluated in multiple brain networks: the default mode network (DMN), the executive attention network (EAN), and the medial visual network (MVN), with the MVN serving as a negative control. Spontaneous pain levels were also analyzed for covariance with intrinsic connectivity.

Results

Patients with FM had greater connectivity within the DMN and right EAN (corrected P [Pcorr] < 0.05 versus controls), and greater connectivity between the DMN and the insular cortex, which is a brain region known to process evoked pain. Furthermore, greater intensity of spontaneous pain at the time of the FMRI scan correlated with greater intrinsic connectivity between the insula and both the DMN and right EAN (Pcorr < 0.05).

Conclusion

These findings indicate that resting brain activity within multiple networks is associated with spontaneous clinical pain in patients with FM. These findings may also have broader implications for how subjective experiences such as pain arise from a complex interplay among multiple brain networks.
Colored timed Petri nets for modeling and analysis of cluser tools
Authors: Wu NaiQi , Zhou MengChu
Published: April 2010

In this paper, a colored timed resource‐oriented Petri net (CTROPN) is developed to model the cluster tools in semiconductor fabrication. It is structurally simple and concise, since each module in a cluster tool corresponds to a unique place in CTROPN. It is also powerful in modeling the qualitative and temporal behavior of the cluster tools with a single‐blade or dual‐blade robot. The initial transient behavior, steady‐state behavior and the final transient behavior can all be investigated through a single model. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Krämerbrücke in Erfurt — Bauwerksgeschichte und Instandsetzung der Gewölbetragkonstruktion in den Jahren 1985/86
Authors: Vockrodt Hans‐Jörg
Published: April 2010

Brücken zu bauen und instandzuhalten war zu allen Zeiten eine Herausforderung für Baumeister, Ingenieure und Architekten. Der vorliegende Beitrag soll nach einem kurzen Blick auf die Geschichte des Brückenbaus im Allgemeinen und die der Krämerbrücke im Speziellen, die grundhafte Instandsetzung der Gewölbetragkonstruktion in den Jahren 1985/86 in Erinnerung bringen, ohne die die Krämerbrücke aus dem heutigen Stadtbild sicherlich bereits verschwunden wäre.

Krämer Bridge in Erfurt — History of the structure and restoration of the arch supports in 1985/86. Building and repairing bridges has always been a challenge for builders, engineers and architects. This report is designed to provide a glimpse of the history of bridge building in general and that of the Krämer Bridge in particular and recall the fundamental repair work on the arch supports that took place in 1985/86. Without this work, the Krämer Bridge would certainly have disappeared from the current cityscape.
International trends of Down syndrome 1993–2004: Births in relation to maternal age and terminations of pregnancies
Authors: Cocchi Guido , Gualdi Silvia , Bower Caroline , Halliday Jane , Jonsson Björn , Myrelid Åsa , Mastroiacovo Pierpaolo , Amar Emmanuelle , Bakker Marian K. , Correa Andrea , Doray Berenice , Melve Kari Klungsør , Koshnood Babak , Landau Daniella , Mutchinick Osvaldo M. , Pierini Anna , Ritvanen Anukka , Ruddock Vera , Scarano Giocchino , Sibbald Barbara , Sípek Antonin , Tenconi Romano , Tucker Dave , Annerén Göran
Published: April 2010

BACKGROUND:

The aim of this study was to examine trends of Down syndrome (DS) in relation to maternal age and termination of pregnancies (ToP) in 20 registries of the International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR).

METHODS:

Trends of births with DS (live‐born and stillborn), ToP with DS, and maternal age (percentage of mothers older than 35 years) were examined by year over a 12‐year period (1993–2004). The total mean number of births covered was 1550,000 annually.

RESULTS:

The mean percentage of mothers older than 35 years of age increased from 10.9% in 1993 to 18.8% in 2004. However, a variation among the different registers from 4–8% to 20–25% of mothers >35 years of age was found. The total mean prevalence of DS (still births, live births, and ToP) increased from 13.1 to 18.2/10,000 births between 1993 and 2004. The total mean prevalence of DS births remained stable at 8.3/10,000 births, balanced by a great increase of ToP. In the registers from France, Italy, and the Czech Republic, a decrease of DS births and a great increase of ToP was observed. The number of DS births remained high or even increased in Canada Alberta, and Norway during the study period.

CONCLUSIONS:

Although an increase in older mothers was observed in most registers, the prevalence of DS births remained stable in most registers as a result of increasing use of prenatal diagnostic procedures and ToP with DS. Birth Defects Research (Part A), 2010. © 2010 Wiley‐Liss, Inc.
Advanced features of whole body sectioned images: Virtual Chinese Human
Authors: Tang Lei , Chung Min Suk , Liu Qian , Shin Dong Sun
Published: April 2010

Serially sectioned images of whole cadavers have become available through the work of four projects: the Visible Human Project, the Visible Korean, the Chinese Visible Human, and the Virtual Chinese Human (VCH). For the VCH, new techniques and equipment were developed and applied to two female and two male cadavers to overcome some of the limitations noted in previous studies. In this article on the VCH, the procedures described are those used on a male cadaver. The cadaver was young with little to no pathology; there were no flat back artifacts because the cadaver was frozen and embedded in the upright position. Sectioned images (intervals, 0.2 mm) were of exceptional quality and resolution (0.1 mm‐sized pixels). Several specific structures were outlined (intervals, 0.6 mm) to acquire segmented images, from which surface models were constructed. The VCH data are to be distributed worldwide and are expected to encourage other investigators to produce useful three‐dimensional images and develop interactive simulation programs for clinical practice. Clin. Anat. 23:523–529, 2010. © 2010 Wiley‐Liss, Inc.
Probing the Electronic Effect of Carbon Nanotubes in Catalysis: NH3 Synthesis with Ru Nanoparticles
Authors: Guo Shujing , Pan Xiulian , Gao Haili , Yang Zhiqiang , Zhao Jijun , Bao Xinhe
Published: April 2010

Carbon nanotubes (CNTs) have been shown to modify some properties of nanomaterials and to modify chemical reactions confined inside their channels, which are formed by curved graphene layers. Here we studied ammonia synthesis over Ru as a probe reaction to understand the effect of the electron structure of CNTs on the confined metal particles and their catalytic activity. The catalyst with Ru nanoparticles dispersed almost exclusively on the exterior nanotube surface exhibits a higher activity than the CNT‐confined Ru, although both have a similar metal particle size. Characterization with TEM, N2 physisorption, H2 chemisorption, temperature‐programmed reduction, CO adsorption microcalorimetry, and first‐principles calculations suggests that the outside Ru exhibits a higher electron density than the inside Ru. As a result, the dissociative adsorption of N2, which is an electrophilic process and the rate‐determining step of ammonia synthesis, is more facile over the outside Ru than that over the inside one.