bluuebunny/crossref_metadata_2025 huggingface dataset:
Disturbances in Melatonin, Cortisol and Core Body Temperature Rhythms after Major Surgery
Authors: Gögenur Ismail , Ocak Ubbat , Altunpinar Ömer , Middleton Benita , Skene Debra J. , Rosenberg Jacob
Published: December 2006

Background

It has been suggested that circadian rhythm disturbances are present after major surgery and that this may play a role in the development of postoperative sleep disturbances, fatigue, cognitive dysfunction and cardiovascular morbidity. The objective of this study was to examine the profile of melatonin, cortisol and core body temperature rhythms before and after major surgery.

Methods

Blood samples (melatonin and cortisol) and core body temperature readings were collected every hour in the 24‐h period prior to surgery and the 48 h after surgery from 11 patients undergoing major abdominal surgery. All patients had private rooms. Light exposure was controlled and monitored. Phase markers [50% dim light melatonin onset (DLMO 50%) and offset (DLMOff 50%), cortisol and core body temperature acrophase] for the three circadian rhythm profiles were calculated before and after surgery. The correlation between the melatonin rhythm and time of surgery, duration of surgery and opioid use was examined.

Results

A median delay in the onset of melatonin was seen on the first postoperative day [median DLMO 50% 22:46 hours (range: 21:15–01:08 hours) on the preoperative day compared with 23:54 hours (range: 19:09–02:46 hours) on the first postoperative day; P ≤ 0.05]. A significant positive correlation existed between the duration of surgery and the time of melatonin onset (r = 0.67, P ≤ 0.05). There was a significantly reduced basal secretion of melatonin immediately after surgery, with a subsequent significant increase in maximum melatonin values on the second postoperative night. A median delay of up to 4 h was seen in the timing of the peak of the temperature rhythm on the second postoperative day. Both cortisol secretion and core body temperature were increased after surgery and did not return to preoperative values in the 48 h of the postoperative study period. No significant correlation between opioid dose and the basal or maximum melatonin levels or the time of melatonin onset was found.

Conclusion

We found disturbances in three circadian markers after major surgery. The clinical consequences of postoperative circadian disturbances should be investigated further in the future.
Utility of Once‐Daily Dose of Low‐Molecular‐Weight Heparin to Prevent Venous Thromboembolism in Multisystem Trauma Patients
Authors: Cothren C. Clay , Smith Wade R. , Moore Ernest E. , Morgan Steven J.
Published: December 2006

Introduction

Venous thromboembolism is a preventable cause of death in the severely injured patient. Low‐molecular‐weight heparins (LMWHs) have been recommended as effective, safe prophylactic agents. However, LMWH use remains controversial in patients at risk for bleeding, those with traumatic brain injury, and those undergoing multiple invasive or operative procedures. We hypothesized that a protocol utilizing once‐daily LMWH prophylaxis in high‐risk trauma patients, regardless of the need for invasive procedures, is feasible, safe, and effective.

Methods

From August 1998 to August 2000, all patients admitted to our American College of Surgeons‐verified Level I trauma facility following injury were evaluated for deep venous thrombosis (DVT) risk and prospectively followed. Patients at high risk for DVT, including those with stable intracranial injuries, were placed on our institutional protocol and prospectively followed. Patients on the protocol received daily injections of the LMWH, dalteparin; DVT screening was performed with duplex ultrasonography within 48 hours of admission and after 7 to 10 days after injury. Regimen compliance, bleeding complications, DVT rates, and pulmonary embolus (PE) rates were analyzed.

Results

During the 2‐year study period, 6247 trauma patients were admitted; 743 were considered at high risk for DVT. Most of the patients were men (72%), with a mean age of 38.7 years (range 15–89 years) and a mean injury severity score (ISS) of 19.5. Compliance with the daily regimen was maintained in 74% of patients. DVT was detected in 3.9% and PE in 0.8%. The wound complications rate was 2.7%, and the need for unexplained transfusions was 3%. There were no exacerbations of head injury following dalteparin initiation due to bleeding. There were 16 patient deaths; none was caused by PE or late hemorrhage.

Conclusions

Once‐daily dosing of prophylactic LMWH dalteparin is feasible, safe, and effective in high‐risk trauma patients. Our protocol allows one to “operate through” systemic prophylaxis and ensures timely prophylaxis for brain‐injured and multisystem trauma patients.
Intraperitoneal Polypropylene Mesh Hernia Repair Complicates Subsequent Abdominal Surgery
Authors: Halm J. A. , de Wall L. L. , Steyerberg E. W. , Jeekel J. , Lange J. F.
Published: December 2006

Background

Prosthetic incisional hernia repair (PIHR) is superior to primary closure in preventing hernia recurrence. Serious complications have been associated with the use of prosthetic material. Complications of subsequent surgical interventions after prior PIHR in relation to its anatomical position were the objectives of this study.

Patients and Methods

Patients who underwent subsequent laparotomy/laparoscopy after PIHR between January 1992 and February 2005 at our institution were evaluated. Intraperitoneal and preperitoneal mesh was related to complication rates after subsequent surgical interventions.

Results

Sixty‐six of 335 patients underwent re‐laparotomy after PIHR. The perioperative course was complicated in 76% (30/39) of procedures with intraperitoneal placed grafts compared to 29% (8/27) of interventions with preperitoneally positioned meshes (P < 0.001). Small bowel resections were necessary in 21% of the intraperitoneal group (8/39) versus 0% in the preperitoneal group. Surgical site infection rates were higher in the intraperitoneal group (10/39, 26%, versus 1/27, 4%). Enterocutaneous fistula formation was rare and occurred in two patients after subsequent laparotomy (5%).

Conclusions

Re‐laparotomy after PIHR with polypropylene meshes are associated with more preoperative and postoperative complications when the mesh is placed intraperitoneally. Therefore 0intraperitoneal positioning of polypropylene mesh at incisional hernia repair should be avoided if possible.
Synthesis and properties of bis(sodium sulfonated ester) types of cleavable surfactants derived from 1‐O‐alkylglycerols
Authors: Ono Daisuke , Yamamura Shingo , Nakamura Masaki , Takeda Tokuji
Published: December 2006

Novel sulfonated ester types of cleavable surfactants were easily prepared by acid‐catalyzed esterification of 1‐O‐alkylglycerols with bromocarboxylic acids, followed by the Strecker reaction. These surfactants have good solubility in water. Though this series of cleavable surfactants are divalent in type, they show good micelle formation and the ability to lower surface tension. The solubility of these surfactants in hard water was more than 10 times higher than sodium 1‐dodecanesulfonate. They decompose quickly and completely in 0.5 M NaOD. Their biodegradabilities were higher or almost the same as that of sodium 1‐dodecanesulfonate.
Stability of sodium hypochlorite in the presence of aqueous flavoring essence
Authors: Zhu Zheng‐Lin
Published: December 2006

The stability of NaOCl in the presence of aqueous flavoring essences (lemon, mint, osmanthus flowers, pineapple, and vanilla) at 40±1°C was studied. Data from determination of OCl− showed: (i) The stability of NaOCl solution decreased in the presence of essences in the order: mint> lemon and osmanthus flowers>pineapple>vanilla (P<0.01); (ii) OCl− loss with the addition of lemon after incubation for 15 d was significantly greater in solutions with initial pH of 13.50 compared with those initially at pH 12.50 (P<0.01); and (iii) OCl− loss was not significantly influenced by the difference in initial pH value with or without the addition of other essences.
The reductase steps of the type II fatty acid synthase as antimicrobial targets
Authors: Zhang Yong‐Mei , Lu Ying‐Jie , Rock Charles O.
Published: December 2006

The increasing of multidrug resistance of clinically important pathogens calls for the development of novel antibiotics with unexploited cellular targets. FA biosynthesis in bacteria is catalyzed by a group of highly conserved proteins known as the type II FA synthase (FAS II) system. Bacteria FAS II organization is distinct from its mammalian counterpart; thus the FAS II pathway offers several unique steps for selective inhibition by antibacterial agents. Some known antibiotics that target the FAS II system include triclosan, isoniazid, and thiolactomycin. Recent years have seen remarkable progress in the understanding of the genetics, biochemistry, and regulation of the FAS II system with the availability of the complete geome, sequence for many bacteria. Crystal structures of the FAS II pathway enzymes have been determined for not only the Escherichia coli model system but also other gram‐netative and gram‐positive pathogens. The protein structures have greatly facilitated structure‐based design of novel inhibitors and the improvement of existing antibacterial agents. This review discusses new developments in the discovery of inhibitors that specifically target the two reductase steps of the FAS II system, β‐ketoacyl‐acyl carrier potein (ACP) reductase and enoyl‐ACP reductase.
Functions of peroxisome proliferator‐activated receptors (PPAR) in skin homeostasis
Authors: Di‐Poï Nicolas , Michalik Liliane , Desvergne Béatrice , Wahli Walter
Published: December 2006

The peroxisome proliferator‐activated receptors (PPAR) are ligand‐activated transcription factors that belong to the nuclear hormone receptor family. Three isotypes (PPARα, PPARβ or δ, and PPARγ) with distinct tissue distributions and cellular functions have been found in vertebrates. All three PPAR isotypes are expressed in rodent and human skin. They were initially investigated for a possible function in the establishment of the permeability barrier in skin because of their known function in lipid metabolism in other cell types. In vitro studies using specific PPAR agonists and in vivo gene disruption approaches in mice indeed suggest an important contribution of PPARα in the formation of the epidermal barrier and in sebocyte differentiation. The PPARγ isotype plays a role in stimulating sebocyte development and lipogenesis, but does not appear to contribute to epidermal tissue differentiation. The third isotype, PPARβ, regulates the late stages of sebaceous cell differentiation, and is the most effective isotype in stimulating lipid production in these cells, both in rodents and in humans. In addition, PPARβ activation has pro‐differentiating effects in kera‐tinocytes under normal and inflammatory conditions. Finally, preliminary studies also point to a potential role of PPAR in hair follicle growth and in melanocyte differentiation. By their diverse biological effects on cell proliferation and differentiation in the skin, PPAR agonists or antagonists may offer interesting oppotunities for the treatment of various skin disorders characterized by inflammation, cell hyperproliferation, and aberrant differentiation.
Cytochrome c release is required for phosphatidylserine peroxidation during fas‐triggered apoptosis in lung epithelial A549 cells
Authors: Jiang Jianfei , Kini Vidisha , Belikova Natalia , Serinkan Behice F. , Borisenko Grigory G. , Tyurina Yulia Y. , Tyurin Vladimir A. , Kagan Valerian E.
Published: December 2006

Oxidation of phosphatidylserine (PtdSer) has been shown to play a pivotal role in signaling during cell apoptosis and subsequent recognition of apoptotic cells by phagocytes. However, the redox catalytic mechanisms involved in selective PtdSer oxidation during apoptosis remain poorly understood. here we employed anti‐Fas antibody CH‐11‐treated A549 cells as a physiologically relevant model to investigate the involvement of PtdSer oxidation and its potential mechanism during apoptosis. We demonstrated that ligation of CH‐11 with its cognate receptor initiated execution of apoptotic program in interferon gamma‐pretreated A549 cells as evidenced by activation of caspase and DNA fragmentation. A significant increase of cytochrome c (cyt c) content in the cytosol as early as 2 h after CH‐11 exposure was detected indicating that Fas‐induced apoptosis in A549 cells proceeds via extrinsic type II pathway and includes mitochondrial signaling. PtdSer was selectively oxidized 3 h after anti‐Fas triggering while two more abundant phospholipids—phosphatidylcholine (PtdCho) and phosphatidylethanolamine (PtdEtn)—and the major intracellular antioxidant, glutathione, remained nonoxidized. A pan‐caspase inhibitor, z‐VAD, fully blocked cyt c release and oxidation of PtdSer in Fas‐treated A549 cells. On the other hand, z‐DQMD, a caspase‐3 inhibitor, completely inhibited caspase‐3 activity but did not fully block caspase‐8 activation and release of cyt c. Importantly, z‐DQMD failed to protect PtdSer from oxidation. In addition, in a model system, we demonstrated that peroxidase activity of cyt c was greatly enhanced in the presence of dioleoylphosphatidylserine containing liposomes by monitoring oxidation of 2′,7′‐dichlorodihydrofluorescein to 2′,7′‐dichlorofluorescein. We further showed that peroxidase activity of cyt c catalyzed oxidation of 1‐palmitoyl‐2‐arachidonoyl‐3‐glycero‐phosphoserine using a newly developed HPLC assay. MS analysis of 1‐palmitoyl‐2‐arachidonoyl‐3‐glycero‐phosphoserine revealed that in addition to its mono‐ and dihydroperoxides, several different PtdSer oxidation products can be formed. Overall, we concluded that cyt c acts as a catalyst of PtdSer oxidation during Fas‐triggered A549 cell apoptosis.
Synthetically Lethal Interactions Involving Loss of the Yeast ERG24: The Sterol C‐14 Reductase Gene
Authors: Shah Alam Bhuiyan M. , Eckstein James , Barbuch Robert , Bard Martin
Published: December 2006

ERG2 and ERG24 are yeast sterol biosynthetic genes which are targets of morpholine antifungal compounds. ERG2 and ERG24 encode the C‐8 sterol isomerase and the C‐14 reductase, respectively. ERG2 is regarded as a non‐essential gene but the viability of ERG24 depends on genetic background, type of medium, and CaCl2 concentration. We demonstrate that erg2 and erg24 mutants are viable in the deletion consortium background but are lethal when combined in the same haploid strain. The erg2erg24 double mutant can be suppressed by mutations in the sphingolipid gene ELO3 but not ELO2. Suppression occurs on rich medium but not on synthetic complete medium. We also demonstrate that the suppressed elo3erg2erg24 does not have a sterol composition markedly different from that of erg24. Further genetic analysis indicates that erg24 combined with mutations in erg6 or erg28 is synthetically lethal but when combined with mutations in erg3 is weakly viable. These results suggest that novel sterol intermediates probably contribute to the synthetic lethality observed in this investigation.
Practical Syntheses of Triacylglycerol Regioisomers Containing Long‐chain Polyunsaturated Fatty Acids
Authors: Fraser Benjamin H. , Perlmutter Patrick , Wijesundera Chakra
Published: December 2006

Docosahexaenoic acid (DHA, 22:6n‐3) is known to protect against a range of degenerative disease conditions and aid in the development of eye and brain function in infants. In dietary lipids DHA is found primarily in the triacylglycerol (TAG) form. However, the effects of the positional distribution of DHA in TAG on lipid functional properties such as bioactivity and oxidative stability are not clearly understood. Studies on this subject for the most part are limited by a lack of regioisomerically pure TAG model compounds containing DHA or similar long‐chain (LC)‐polyunsaturated fatty acids (PUFA). This paper reports on the development of a practical procedure, based on chemical and enzymatic reactions, for the syntheses of regioisomerically enriched, symmetrical and unsymmetrical TAG isomers containing two palmitic acid and one of linoleic acid, linolenic acid, or DHA. 1,3‐Selective acylation of glycerol with vinyl esters of fatty acids catalyzed by Candida antarctica lipase and direct coupling with fatty acids in the presence of the coupling agents 1‐(3‐dimethylaminopropyl)‐3‐ethylcarbodiimide hydrochloride and 4‐dimethylaminopyridine furnished 1,3‐dihexadecanoyl‐2‐docosahexaenoyl glycerol and its unsymmetrical isomer 1,2‐dihexadecanoyl‐3‐docosahexaenoyl glycerol in 99 and 60% yield, respectively. Critical to the success of the unsymmetrical TAG synthesis is the demonstration that PUFA‐containing glycerol acetonides can readily survive appropriately tailored acid‐catalyzed conditions. In this way, sufficient quantities of highly regioisomerically enriched PUFA‐containing unsymmetrical monoacylglycerols (MAG) and TAG have now become routinely accessible. The methods are amenable to scale‐up and could be adopted for regioenriched synthesis of a wide range of TAG.
Moisture Removal Substantially Improves the Efficiency of in Situ Biodiesel Production from Soybeans
Authors: Haas Michael J. , Scott Karen M.
Published: December 2006

In an effort to reduce the production cost of biodiesel, we previously described an approach termed “in situ transesterification” wherein the transesterification of a vegetable oil occurred directly in its raw agricultural material. In that method, substantial quantities of reagents were required to achieve high‐efficiency transesterification. Here we report that by drying the substrate a marked reduction in the reagent requirements was achieved. Reaction conditions for maximum fatty acid methyl ester (FAME) production were identified using statistical experimental design methods. In 16‐h reactions with 5 g of flakes (2.6% moisture) and 18 mL of 0.10 N NaOH in methanol, 97% theoretical maximum transesterification was achieved. For dry flakes, optimal transesterification was achieved in 10 h in reactions containing 5 g of flakes and 12 mL of 0.10 N NaOH in methanol. This represented a 60% reduction in methanol and a 56% reduction in NaOH use compared with the transesterification of full‐moisture flakes. Under these conditions the degree of transesterification was 100% of the theoretical maximum. The transesterification of 20 kg of flakes with a moisture content of 0.8% was conducted under optimal reaction conditions. Both triacylglycerols (TAG) and phosphoacylglycerols (PL) were transesterified to high degrees, with an overall efficiency of 97.3% of the maximum theoretical efficiency. PL were not detected in the flakes following transesterification, and the amount of remaining unreacted TAG was only 1.0% of that input. Following washes with water, 0.5 M NaCl, and dilute NaOH, the recovered FAME met the ASTM specifications for biodiesel. The tocopherol levels of the FAME exceeded by 76% those of a representative commercial biodiesel. Soy flakes retained 97% of their protein following in situ transesterification.
A simple method for re-dilatation of an acute tracheostoma stenosis
Authors: Soo G , Tong M C F
Published: December 2006

Tracheostomy or laryngectomy stomas may sometimes re-stenose, resulting in respiratory distress for the patient unless the stoma is rapidly re-dilated and an adequate airway re-established.

This article describes a simple and effective method for the acute re-dilatation of a tracheostoma stenosis, using an aural speculum, prior to the insertion of a patent airway tube. This technique has been successfully used in our department since 1995 and, in our experience, causes significantly less distress to our patients when compared with other means employed previously.
GPS interfrequency biases and total electron content errors in ionospheric imaging over Europe
Authors: Dear Richard M. , Mitchell Cathryn N.
Published: December 2006

Measurements from the Global Positioning System (GPS) satellites provide a valuable source of information about the ionosphere in the form of integrations of electron concentration. The slant total electron content (TEC) through the ionosphere can be estimated for specific satellite‐to‐ground paths using the two GPS frequencies and knowledge of the dispersive properties of the ionosphere. However, these TEC values are in error because of the interfrequency biases of the satellites and receivers. In order to assess the accuracy of TEC in the ionospheric images, the determination of interfrequency biases must be studied. This paper addresses the determination of the magnitudes of these biases for individual GPS satellites paired with GPS receivers in Europe using the ionospheric imaging tool Multi‐instrument Data Analysis System (MIDAS). This is done so that the accuracy of the TEC in the ionospheric images can be assessed. A simulation study was undertaken to verify the approach, then experimental results were compared with independent values of the biases calculated by the Center for Orbit Determination in Europe. Experimental results reveal that changes in the biases can be related directly to documented changes in receiver hardware. They allow an estimate of the receiver biases and hence the error in TEC estimation using GPS data.
Submarine Fernandina: Magmatism at the leading edge of the Galápagos hot spot
Authors: Geist Dennis J. , Fornari Daniel J. , Kurz Mark D. , Harpp Karen S. , Adam Soule S. , Perfit Michael R. , Koleszar Alison M.
Published: December 2006

New multibeam and side‐scan sonar surveys of Fernandina volcano and the geochemistry of lavas provide clues to the structural and magmatic development of Galápagos volcanoes. Submarine Fernandina has three well‐developed rift zones, whereas the subaerial edifice has circumferential fissures associated with a large summit caldera and diffuse radial fissures on the lower slopes. Rift zone development is controlled by changes in deviatoric stresses with increasing distance from the caldera. Large lava flows are present on the gently sloping and deep seafloor west of Fernandina. Fernandina's submarine lavas are petrographically more diverse than the subaerial suite and include picrites. Most submarine glasses are similar in composition to aphyric subaerially erupted lavas, however. These rocks are termed the “normal” series and are believed to result from cooling and crystallization in the subcaldera magma system, which buffers the magmas both thermally and chemically. These normal‐series magmas are extruded laterally through the flanks of the volcano, where they scavenge and disaggregate olivine‐gabbro mush to produce picritic lavas. A suite of lavas recovered from the terminus of the SW submarine rift and terraces to the south comprises evolved basalts and icelandites with MgO = 3.1 to 5.0 wt.%. This “evolved series” is believed to form by fractional crystallization at 3 to 5 kb, involving extensive crystallization of clinopyroxene and titanomagnetite in addition to plagioclase. “High‐K” lavas were recovered from the southwest rift and are attributed to hybridization between normal‐series basalt and evolved‐series magma. The geochemical and structural findings are used to develop an evolutionary model for the construction of the Galápagos Platform and better understand the petrogenesis of the erupted lavas. The earliest stage is represented by the deep‐water lava flows, which over time construct a broad submarine platform. The deep‐water lavas originate from the subcaldera plumbing system of the adjacent volcano. After construction of the platform, eruptions focus to a point source, building an island with rift zones extending away from the adjacent, buttressing volcanoes. Most rift zone magmas intrude laterally from the subcaldera magma chamber, although a few evolve by crystallization in the upper mantle and deep crust.
Chemical aging and the hydrophobic‐to‐hydrophilic conversion of carbonaceous aerosol
Authors: Petters Markus D. , Prenni Anthony J. , Kreidenweis Sonia M. , DeMott Paul J. , Matsunaga Aiko , Lim Yong B. , Ziemann Paul J.
Published: December 2006

Laboratory experiments simulating chemical aging of carbonaceous aerosol by atmospheric oxidants demonstrate that oxidative processing increases their ability to activate as cloud droplets. A microphysical model shows, however, that the measured increase in hygroscopicity is insufficient to lead to efficient wet scavenging for sub‐100 nm particles that are typically emitted from combustion sources. The absence of an efficient atmospheric oxidation pathway for hydrophobic‐to‐hydrophilic conversion suggests that the fate of carbonaceous aerosol is instead controlled by its interaction with more hydrophilic species such as sulfates, nitrates, and secondary organic aerosol, leading to longer lifetimes, higher burdens, and greater contributions to climate forcing in the free troposphere than are currently estimated.
Observation of sub‐inertial internal tides in McMurdo Sound, Antarctica
Authors: Albrecht N. , Vennell R. , Williams M. , Stevens C. , Langhorne P. , Leonard G. , Haskell T.
Published: December 2006

McMurdo Sound, Antarctica, at 78°S is poleward of the critical latitudes for both diurnal and semi‐diurnal internal tides, which are, respectively, 30°S and 75°S. Yet fieldwork during April 2003 and November 2004 observed energy at both frequencies. High temporal resolution density profiles in April 2003 and mooring observations at 240 m depth in November 2004 show a diurnal internal tide with displacements of up to 12 m. The horizontal decay length scales for diurnal evanescent internal tides indicate that they were locally generated. The November 2004 mooring observations also show a semi‐diurnal tide with displacements up to 12 m, although some of the energy in these waves could be baroclinic inertial motion, which has a similar frequency at this latitude. The semi‐diurnal internal waves have a larger decay length scale than the diurnal internal waves, so are not necessarily locally generated.
The SO2 camera: A simple, fast and cheap method for ground‐based imaging of SO2 in volcanic plumes
Authors: Mori Toshiya , Burton Mike
Published: December 2006

SO2 flux is widely monitored on active volcanoes as it gives a window into the hidden, subsurface magma dynamics. We present here a new approach to SO2 flux monitoring using ultraviolet imaging of the volcanic plume through carefully chosen filters to produce images of SO2 column amount. The SO2 camera heralds a breakthrough in both our ability to measure SO2 flux at unprecedented frequencies (2 Hz) and at unprecedented accuracy, thanks to the application of correlation techniques to determine wind speed directly from the images and the ability to measure the whole profile simultaneously. In this paper we detail the commercially available pieces required to construct the SO2 camera, introduce a retrieval scheme to determine SO2 amounts from the images and present results from a field campaign in November 2005 on Sakurajima volcano, Japan.
Magnetotail variations associated with substorm expansion onsets for storm time and nonstorm time
Authors: Miyashita Y. , Kamide Y. , Miyoshi Y. , Machida S. , Liou K. , Mukai T. , Saito Y. , Meng C.‐I. , Parks G. K.
Published: December 2006

We have statistically studied magnetotail variations associated with expansion onsets for storm and nonstorm time substorms, using Geotail data. Here storm time was defined as Sym‐H ≤ −30 nT. It was found that there are no qualitative differences in magnetotail variations between these two types of substorms, although the energy accumulation and the dipolarization tend to be more significant during storm time substorms. The statistical results evidently show that the magnetic reconnection and the dipolarization do occur in the magnetotail around onset for both types of substorms, suggesting that storm and nonstorm time substorms are caused by the same mechanism.
Role of carbon monoxide in electrically induced non‐adrenergic, non‐cholinergic relaxations in the guinea‐pig isolated whole trachea
Authors: Dellabianca A , Sacchi M , Anselmi L , De Amici E , Cervio E , Agazzi A , Tonini S , Sternini C , Tonini M , Candura S M
Published: December 2006

Background and purpose:

Nitric oxide (NO) and vasoactive intestinal peptide (VIP) are considered transmitters of non‐adrenergic, non‐cholinergic (NANC) relaxations in guinea‐pig trachea, whereas the role of carbon monoxide (CO) is unknown. This study was designed to assess the participation of CO, and to investigate the localization of haem oxygenase‐2 (HO‐2), the CO‐producing enzyme, in tracheal neurons.

Experimental approach:

NANC responses to electrical field stimulation (EFS) at 3 and 10 Hz were evaluated in epithelium‐free whole tracheal segments as intraluminal pressure changes. Drugs used were: L‐nitroarginine methyl ester (L‐NAME, 100 μ
M) to inhibit NO synthase (NOS), α‐chymotrypsin (2 U ml−1) to inactivate VIP, zinc protoporphyrin‐IX (ZnPP‐IX, 10 μM) to inhibit HO‐2, and 1H‐[1,2,4]oxadiazolo[4,3‐a]quinoxalin‐1‐one (ODQ, 10 μM), a soluble guanylyl cyclase inhibitor. For immunohistochemistry, tissues were exposed to antibodies to PGP 9.5, a general neuronal marker, HO‐2 and NOS, and processed with an indirect immunofluorescence method.

Key results:

α‐Chymotrypsin did not affect NANC relaxations. ODQ inhibited NANC responses by about 60%, a value similar to that obtained by combining L‐NAME and ZnPP‐IX. The combination of ODQ, L‐NAME and ZnPP‐IX reduced the responses by 90%. Subpopulations of HO‐2 positive neurons containing NOS were detected in tracheal sections.

Conclusions and Implications:

In the guinea‐pig trachea, NANC inhibitory responses at 3 and 10 Hz use NO and CO as main transmitters. Their participation is revealed following inhibition of NOS, HO‐2 and soluble guanylyl cyclase. The involvement of CO as a relaxing transmitter paves the way for novel therapeutic approaches in the treatment of airway obstruction.

British Journal of Pharmacology (2007) 150, 220–226. doi:10.1038/sj.bjp.0706968
ω‐3 Polyunsaturated fatty acids (PUFAs or fish oils) and atrial fibrillation
Authors: Opthof T , Den Ruijter H M
Published: December 2006

British Journal of Pharmacology (2007) 150, 258–260. doi:10.1038/sj.bjp.0706978
The influence of external factors on the corrosion resistance of high temperature superconductor thin films against moisture
Authors: Murugesan M. , Obara H. , Yamasaki H. , Kosaka S.
Published: December 2006

High temperature superconductor (HTS) thin films have been systematically investigated for their corrosion resistance against moisture by studying the role of external factors such as temperature (T), relative humidity (RH), and the type of substrates in the corrosion. In general, (i) the corrosion is progressed monotonously with increasing T as well as RH, (ii) a threshold level of water vapor is needed to cause degradation, and (iii) between T and RH, the influence of T is more dominant. HTS films on SrTiO3 and CeO2 buffered sapphire (cbs) substrates showed better corrosion stability and a low rate of degradation in the critical current density as compared to that of the film grown on MgO substrate. Between DyBa2Cu3Oz (DBCO) and YBa2Cu3Oz, the former is reproducibly found to have many fold higher corrosion resistance against moisture. This observed enhancement in the corrosion resistance in DBCO could be explained by the improved microstructure in the films and the better lattice matching with the substrate. Thus, the dual advantage of DBCO/cbs films, i.e., the enhanced corrosion stability of DBCO and the appropriate dielectric properties of sapphire, can be readily exploited for the use of DBCO/cbs films in the microwave and power devices.
Irradiation behavior of SrTiO3 at temperatures close to the critical temperature for amorphization
Authors: Zhang Y. , Wang C. M. , Engelhard M. H. , Weber W. J.
Published: December 2006

Damage accumulation on both the Sr and Ti sublattices in strontium titanate (SrTiO3) has been investigated under 1.0MeV Au+ irradiation at 360 and 400K, close to the critical temperature for amorphization (∼370K). Under irradiation at 360K, the relative disorder on both sublattices follows a nonlinear dependence on ion dose. Amorphization starts from the damage peak region (at a depth of 60nm) and grows toward the surface and into the bulk. At 400K, the evolution of point defects to extended defects occurs as ion fluence increases. The disorder initially peaks at a depth of 60nm, saturates at a disorder level of ∼0.75, and then decreases with further irradiation. At an ion fluence of 6.0×1015cm−2, an amorphous layer of ∼10nm thickness is formed at the sample surface. After annealing at 375K for 1h, the buried amorphous layer formed during irradiation at 360K is recrystallized with planar defects and dislocation loops. However, the surface amorphous layer formed at 400K irradiation remains amorphous, and fewer defects are observed in the irradiated region. Irradiation-enhanced recrystallization due to high flux electron energy deposition is observed.
Determination of the texturing gradient in ex situ MgB2∕Fe tapes examined by x-ray diffraction and its effects on the pinning force
Authors: Senatore Carmine , Lezza Paola , Flükiger René
Published: December 2006

We found that the reduced pinning forces of ex situ MgB2∕Fe monofilamentary tapes do not scale with temperature if the external magnetic field is applied parallel to the tape surface. A model is proposed to explain the behavior of the volume pinning forces in parallel and perpendicular orientations of the magnetic field, accounting for the observed texturing gradient between the center of the filament and the MgB2∕Fe interface. The degree of texturing of the sample, as determined by x-ray diffraction, is confirmed by modeling the pinning force in parallel field as the superposition of two components, the first one due to a highly textured region on the external part of the filament and the latter due to a low texturing region in the core.
Tunnel magnetoresistance and robust room temperature exchange bias with multiferroic BiFeO3 epitaxial thin films
Authors: Béa H. , Bibes M. , Cherifi S. , Nolting F. , Warot-Fonrose B. , Fusil S. , Herranz G. , Deranlot C. , Jacquet E. , Bouzehouane K. , Barthélémy A.
Published: December 2006

The authors report on the functionalization of multiferroic BiFeO3 epitaxial films for spintronics. A first example is provided by the use of ultrathin layers of BiFeO3 as tunnel barriers in magnetic tunnel junctions with La2∕3Sr1∕3MnO3 and Co electrodes. In such structures, a positive tunnel magnetoresistance up to 30% is obtained at low temperature. A second example is the exploitation of the antiferromagnetic spin structure of a BiFeO3 film to induce a sizable (∼60Oe) exchange bias on a ferromagnetic film of CoFeB at room temperature. Remarkably, the exchange bias effect is robust upon magnetic field cycling, with no indications of training.
Multisegmented one-dimensional hybrid structures of carbon nanotubes and metal nanowires
Authors: Ou Fung Suong , Shaijumon M. M. , Ci Lijie , Benicewicz Derek , Vajtai Robert , Ajayan P. M.
Published: December 2006

Multisegmented one-dimensional hybrid structures of carbon nanotubes and metal nanowires were fabricated using the alumina templates. Metal nanowires are first grown inside part of the nanochannel using electrodeposition technique, which is followed by the growth of carbon nanotubes using chemical vapor deposition. Well-adhered interfaces formed between the carbon nanotubes and the metal nanowires. The hybrid structure reported here results in nanoscale metal contact with carbon nanotube and will provide a solution to problem of using carbon nanotubes in interconnects. Nanotube-nanowire interfaces for different metals have also been examined and are characterized using scanning electron microscopy and transmission electron microscopy.
Quantum key distribution at 1550nm with twin superconducting single-photon detectors
Authors: Hadfield Robert H. , Habif Jonathan L. , Schlafer John , Schwall Robert E. , Nam Sae Woo
Published: December 2006

The authors report on the full implementation of a superconducting detector technology in a fiber-based quantum key distribution (QKD) link. Nanowire-based superconducting single-photon detectors (SSPDs) offer infrared single-photon detection with low dark counts, low jitter, and short recovery times. These detectors are highly promising candidates for future high key rate QKD links operating at 1550nm. The authors use twin SSPDs to perform the BB84 protocol in a 1550nm fiber-based QKD link clocked at 3.3MHz. They exchange secure key over a distance of 42.5km in telecom fiber and demonstrate that secure key can be transmitted over a total link loss exceeding 12dB.
In situ identification of the metastable phase during solidification from the undercooled YFeO3 melt by fast x-ray diffractometry at 250Hz
Authors: Nagashio K. , Kuribayashi K. , Vijaya Kumar M. S. , Niwata K. , Hibiya T. , Mizuno A. , Watanabe M. , Katayama Y.
Published: December 2006

A time-resolved x-ray diffraction (XRD) experiment at 250Hz using a synchrotron radiation source was carried out during the containerless solidification of ReFeO3 (Re=Y and Lu) in order to identify the metastable phase in situ. The metastable phase solidified primarily from the undercooled YFeO3 melt finally transformed to the stable orthorhombic YFeO3 phase during the short period of recalescence (∼0.035s). Although the metastable phase could not be detected in the as-solidified sample by the powder XRD, the in situ diffraction pattern of the metastable phase in the YFeO3 system was consistent with that of the metastable hexagonal LuFeO3 phase.
Rearrangements in the Furan Series. IV. The Reaction Between Furan-2-Carbaldehyde and Aniline
Authors: Lewis KG , Mulquiney CE
Published: December 2006

It has been shown that reaction of furan-2-carbaldehyde with three or four molecules of aniline gives rise to a substance assigned as 4- phenyl-1,6-di( phenylamino )-7-phenylimino-3a,4,4a,7,7a,7b-hexahydro-1H-dicyclopenta [ b,d ]pyrrol-2(3H)-one rather than the simple anil previously proposed. The use of an excess of furan-2-carbaldehyde gives not furoin anil but a compound of polymeric structure.
Self‐determination, stage of readiness to change for exercise, and frequency of physical activity in young people
Authors: Daley Amanda J. , Duda Joan L.
Published: December 2006

Grounded in self‐determination theory (Deci & Ryan, 1985) and the transtheoretical model (Prochaska & DiClemente, 1983), the aim of this study was to examine the relationship between exercise regulations varying in self‐determination with stage of readiness to change for exercise and physical activity patterns in university students. A cross‐sectional survey design was used. The sample consisted of 409 (158 men, 251 women) university undergraduates aged 18–30 years. Participants completed the Behavioural Regulations in Exercise Questionnaire‐2, the visual analogue stage of change for exercise ladder, and a physical activity questionnaire. Linear discriminant function analyses revealed that men and women at the early stages were less self‐determined in the regulation of their exercise behaviour than those at the later stages of change. Additionally, men and women who were more self‐determined reported being more physically active over the previous 3 months. These results suggest that self‐determination may have an important role to play in the adoption and maintenance of health‐promoting behaviours in young adults.
The relationships between hamstring flexibility, lumbar flexion, and low back pain in rowers
Authors: Stutchfield Ben M. , Coleman Simon
Published: December 2006

In this study, we examined the relationships between low back pain, hamstring flexibility, and lumbar flexion in rowers. Twenty‐six male university rowers participated. Hamstring flexibility was assessed using an adjusted straight leg raise technique, and lumbar flexion was assessed via a distraction of skin marks protocol while long sitting. A questionnaire ascertained rowing details and low back pain characteristics. Low back pain was highly prevalent. No association was observed between low back pain and hamstring flexibility, or between hamstring flexibility and lumbar flexion. Sufferers of low back pain showed reduced lumbar flexion (P=0.03; 95% confidence interval = − 3.7 to −0.2). Results obtained using the adjusted straight leg raise technique suggested that low back pain was not associated with hamstring inflexibility, which suggests that increasing hamstring flexibility for rehabilitation or prevention of low back pain in rowers might not be necessary.
Positive and Negative Generation Effects in Source Monitoring
Authors: Riefer David M. , Chien Yuchin , Reimer Jason F.
Published: December 2006

Research is mixed as to whether self-generation improves memory for the source of information. We propose the hypothesis that positive generation effects (better source memory for self-generated information) occur in reality-monitoring paradigms, while negative generation effects (better source memory for externally presented information) tend to occur in external source-monitoring paradigms. This hypothesis was tested in an experiment in which participants read or generated words, followed by a memory test for the source of each word (read or generated) and the word's colour. Meiser and Bröder's (2002) multinomial model for crossed source dimensions was used to analyse the data, showing that source memory for generation (reality monitoring) was superior for the generated words, while source memory for word colour (external source monitoring) was superior for the read words. The model also revealed the influence of strong response biases in the data, demonstrating the usefulness of formal modelling when examining generation effects in source monitoring.
Prognostic Value of Portal Pressure at the Time of Kasai Operation in Patients With Biliary Atresia
Authors: Duché Matthieu , Fabre Monique , Kretzschmar Benno , Serinet Marie‐Odile , Gauthier Frédéric , Chardot Christophe
Published: December 2006

Aim:

To examine the prognostic value of portal pressure at the time of Kasai operation in patients with biliary atresia (BA).

Patients and Methods:

All 127 patients with BA, born between 1991 and 1996, who underwent a Kasai operation in Bicêtre Hospital were studied. Intraoperatively, the umbilical vein was catheterised and a portal pressure index (PPI), defined by the height of the physiologic saline column above the liver surface level, was measured. Overall patient survival, survival with native liver (SNL) and, in patients living with their native liver, survival without significant portal hypertension (SwsPHT) were calculated by Kaplan‐Meier method and compared by univariate and multivariate analyses.

Results:

Measurement of PPI was successful in 113/127 patients (89%) without complication. Median PPI was 15 cm (range, 5–35). Portal pressure index was positively correlated with age at surgery and histological severity of liver fibrosis. Ten‐year overall patient survival was 78.2%; 10‐year SNL was 35.7%. In patients living with their native liver, 5‐ and 10‐year SwsPHT were 65.3% and 43.6%, respectively. Portal pressure index >15 cm, complete extrahepatic BA and polysplenia were independently associated with a worse SNL. Portal pressure index >15 cm and the absence of postoperative normalisation of bilirubin were independently associated with a worse SwsPHT.

Conclusion:

Biliary atresia patients with elevated portal pressure at the time of Kasai operation have lower chances of success of this procedure and a higher risk of developing portal hypertension, even if bilirubin levels normalise after the operation. Measurement of PPI was simple and safe and better predicted the postoperative outcome than did the histological scores of liver fibrosis.
Characteristics of Inflammatory Bowel Disease With Onset During the First Year of Life
Authors: Ruemmele Frank M , El Khoury Maurice G , Talbotec Cécile , Maurage Chantal , Mougenot Jean‐François , Schmitz Jacques , Goulet Olivier
Published: December 2006

Background:

Inflammatory bowel disease (IBD) is recognized in young children, however, only rare data on onset and evolution are available in children younger than 1 year. In the present clinical study, we aimed to analyze characteristics and clinical course of children with very early onset IBD. We were particularly interested in the relationship between bacterial infections and the use of antibiotics before the onset of IBD.

Patients and Methods:

The IBD database of Necker‐Enfants‐Malades‐Hospital was screened for patients with IBD with disease onset during the first year of life and a follow‐up of at least 2.5 years. Ten patients were identified during the period 1996–2002.

Results:

All patients presented with rectal bleeding and had colonic involvement. Four patients had definitive diagnosis of Crohn disease; ulcerative or indeterminate colitis was seen in 2 and 4 children, respectively. Five of the patients had a positive history of neonatal or early‐onset bacterial infection with use of antibiotics before onset of IBD, 4 patients were still breastfed and 3 just weaned when GI symptoms started. Seven patients had a severe onset of disease requiring bowel rest, parenteral nutrition and steroid medication, followed by azathioprine or cyclosporine medication. Surgery was necessary in 3 of 10 patients. Disease relapses were frequent and observed in 8 of 10 children.

Discussion:

Very early onset IBD may reflect a subgroup of patients characterized by a particular sensitivity to modifications of the intestinal flora. Neonatal IBD was most often severe in presentation and evolution.
Enterobius vermicularis and Colitis in Children
Authors: Jardine Michelle , Kokai George K , Dalzell A Mark
Published: December 2006

Objectives:

We observed a cohort of children presenting with rectal bleeding that were identified as having Enterobius vermicularis at colonoscopy and questioned the reliability of conventional diagnostic methods of identifying E. vermicularis.

Patients and Methods:

The study was retrospective in nature and subjects were investigated by colonoscopy between May 1997 and December 1999. Patients were identified as having E. vermicularis infestation by direct visualisation of the adult worms at colonoscopy. Patients were treated with mebendazole and a record of their clinical response documented.

Results:

A total of 180 colonoscopic examinations were performed during the study period. E. vermicularis was identified macroscopically in 31 cases (17.2%). The symptom profile of patients with E. vermicularis were abdominal pain, 19 of 26 (73%); rectal bleeding, 16 of 26 (62%); chronic diarrhoea, 13 of 26 (50%) and weight loss, 11 of 26 (42%). Ova cysts and parasites were identified in none of the saline swabs analysed in 20 patients. Sellotape testing was performed in only 4 patients and was negative in all. Of the 26 children, 21 (81%) demonstrated histopathological features of nonspecific colitis. There was clinical resolution of symptoms in 19 of 23 patients.

Conclusions:

We suggest that in patients with symptoms suggestive of inflammatory bowel disease, E. vermicularis infestation must be excluded as a common cause of nonspecific colitis. We also suggest that diagnostic tests such as saline swabs and Sellotape testing may be lacking in sensitivity.