bluuebunny/crossref_metadata_2025 huggingface dataset:
Social Factors and Mortality from NASH in Canada
Authors: Leenaars Antoon A , Lester David
Published: August 2007

The NASH categories (Natural, Accident, Suicide, Homicide) used on death certificates are known to obscure many of the psychological dimensions of death. Although there are many studies of death certificates of the extent to which suicide may be misclassified as accidental or natural deaths, and a few studies comparing individuals who commit suicides to accidental death victims, this topic is often neglected at a sociological level. This analysis of the NASH modes of death examines if these deaths differ from a sociological perspective. Specifically, rates of divorce, marriage, birth, and unemployment were correlated with deaths of natural causes (stomach cancer, cirrhosis of the liver), accidents (motor vehicle accident), suicide, and homicide. The results suggest that the sociological associations with some causes of death (i. e., cirrhosis of the liver, suicide and, homicide) have a similar social pattern but are different from others (i. e., motor vehicle accidents and stomach cancer). Although there are problems of interpretation at a sociological level, it is suggested that the social epidemiology of death may be obscured by the NASH classification. Recent suggestions on terminology and taxonomy by the International Academy for Suicide Research (IASR) are offered as one step towards addressing this issue.
Suicide, Euthanasia and AIDS
Authors: Mishara Brian L.
Published: August 2007

This article critically reviews research on suicide, AIDS, and HIV seropositivity. Studies indicate that men with a diagnosis of AIDS or HIV seropositivity have up to 36 times greater risk of suicide than men without the diagnosis. Yet few studies controlled for independent risk factors such as premorbid or comorbid psychiatric syndromes. Also, control groups may not be appropriate, little data are available on women, and explanations of suicidal dynamics are mostly speculative. After a look at the research on the desire for euthanasia and assisted suicide with other illnesses, the author suggests alternative hypotheses concerning suicidality, the desire for euthanasia, and AIDS.
Suicidal Ideation in Sudanese Women
Authors: Goldney Robert D , Harris Lillian Craig , Badri Alia , Michael Sara , Fisher Laura
Published: August 2007

A literature review indicated that suicidal behavior in Sudan was very infrequent. However, an assessment of suicidal ideation in two Sudanese groups of women demonstrated high levels, particularly in women in a displaced-persons area. In addition, the recent establishment of a Befrienders International volunteer service allowed anecdotal evidence of substantial suicidal behavior to be collated. These findings highlight the need for further professional and volunteer assistance with continuing evaluation and research concerning programs for this vulnerable population.
Using Rational Suicide as an Intervention to Prevent Irrational Suicide
Authors: Werth James L
Published: August 2007

This paper sets forth the idea that using the concept of, and criteria for, rational suicide can be a clinically useful intervention even with people who may be irrational in their suicidality. Case examples are used to illustrate ways in which reviewing the criteria may help move a person away from an impulsive decision to suicide.
P and S velocity structure of the crust and the upper mantle beneath central Java from local tomography inversion
Authors: Koulakov I. , Bohm M. , Asch G. , Lühr B.‐G. , Manzanares A. , Brotopuspito K. S. , Fauzi Pak , Purbawinata M. A. , Puspito N. T. , Ratdomopurbo A. , Kopp H. , Rabbel W. , Shevkunova E.
Published: August 2007

Here we present the results of local source tomographic inversion beneath central Java. The data set was collected by a temporary seismic network. More than 100 stations were operated for almost half a year. About 13,000 P and S arrival times from 292 events were used to obtain three‐dimensional (3‐D) Vp, Vs, and Vp/Vs models of the crust and the mantle wedge beneath central Java. Source location and determination of the 3‐D velocity models were performed simultaneously based on a new iterative tomographic algorithm, LOTOS‐06. Final event locations clearly image the shape of the subduction zone beneath central Java. The dipping angle of the slab increases gradually from almost horizontal to about 70°. A double seismic zone is observed in the slab between 80 and 150 km depth. The most striking feature of the resulting P and S models is a pronounced low‐velocity anomaly in the crust, just north of the volcanic arc (Merapi‐Lawu anomaly (MLA)). An algorithm for estimation of the amplitude value, which is presented in the paper, shows that the difference between the fore arc and MLA velocities at a depth of 10 km reaches 30% and 36% in P and S models, respectively. The value of the Vp/Vs ratio inside the MLA is more than 1.9. This shows a probable high content of fluids and partial melts within the crust. In the upper mantle we observe an inclined low‐velocity anomaly which links the cluster of seismicity at 100 km depth with MLA. This anomaly might reflect ascending paths of fluids released from the slab. The reliability of all these patterns was tested thoroughly.
Generation mechanism of quasidecadal variability of upper ocean heat content in the equatorial Pacific Ocean
Authors: Hasegawa Takuya , Yasuda Tamaki , Hanawa Kimio
Published: August 2007

We investigate the relationship between oceanic and atmospheric anomaly fields in the tropical Pacific on the quasidecadal (QD; 10 to 18 years) scale is explored. It is suggested that the anomalous wind stress curl in the tropical South Pacific can generate the equatorial upper ocean heat content (OHC) anomalies on the QD scale via the Sverdrup transport resembling that of the recharge‐discharge oscillator model for the dynamics of El Niño‐Southern Oscillation (ENSO). The results also show that the wind stress curl anomalies in the tropical South Pacific are accompanied by ENSO‐like, QD‐scale anomaly patterns of the sea level pressure and sea surface temperature. Furthermore, the results indicate that the equatorial QD‐scale OHC anomalies can also be generated by the ENSO‐like propagations of the OHC anomalies in the tropical North and South Pacific. This study presents a systematic linkage between the ENSO‐like, QD‐scale OHC propagation in the tropical North and South Pacific, the Sverdrup transport variation in the tropical South Pacific, and the ENSO‐like, QD‐scale SST and SLP anomalies in the tropical Pacific.
Multimodel projections of stratospheric ozone in the 21st century
Authors: Eyring V. , Waugh D. W. , Bodeker G. E. , Cordero E. , Akiyoshi H. , Austin J. , Beagley S. R. , Boville B. A. , Braesicke P. , Brühl C. , Butchart N. , Chipperfield M. P. , Dameris M. , Deckert R. , Deushi M. , Frith S. M. , Garcia R. R. , Gettelman A. , Giorgetta M. A. , Kinnison D. E. , Mancini E. , Manzini E. , Marsh D. R. , Matthes S. , Nagashima T. , Newman P. A. , Nielsen J. E. , Pawson S. , Pitari G. , Plummer D. A. , Rozanov E. , Schraner M. , Scinocca J. F. , Semeniuk K. , Shepherd T. G. , Shibata K. , Steil B. , Stolarski R. S. , Tian W. , Yoshiki M.
Published: August 2007

Simulations from eleven coupled chemistry‐climate models (CCMs) employing nearly identical forcings have been used to project the evolution of stratospheric ozone throughout the 21st century. The model‐to‐model agreement in projected temperature trends is good, and all CCMs predict continued, global mean cooling of the stratosphere over the next 5 decades, increasing from around 0.25 K/decade at 50 hPa to around 1 K/decade at 1 hPa under the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) A1B scenario. In general, the simulated ozone evolution is mainly determined by decreases in halogen concentrations and continued cooling of the global stratosphere due to increases in greenhouse gases (GHGs). Column ozone is projected to increase as stratospheric halogen concentrations return to 1980s levels. Because of ozone increases in the middle and upper stratosphere due to GHG‐induced cooling, total ozone averaged over midlatitudes, outside the polar regions, and globally, is projected to increase to 1980 values between 2035 and 2050 and before lower‐stratospheric halogen amounts decrease to 1980 values. In the polar regions the CCMs simulate small temperature trends in the first and second half of the 21st century in midwinter. Differences in stratospheric inorganic chlorine (Cly) among the CCMs are key to diagnosing the intermodel differences in simulated ozone recovery, in particular in the Antarctic. It is found that there are substantial quantitative differences in the simulated Cly, with the October mean Antarctic Cly peak value varying from less than 2 ppb to over 3.5 ppb in the CCMs, and the date at which the Cly returns to 1980 values varying from before 2030 to after 2050. There is a similar variation in the timing of recovery of Antarctic springtime column ozone back to 1980 values. As most models underestimate peak Cly near 2000, ozone recovery in the Antarctic could occur even later, between 2060 and 2070. In the Arctic the column ozone increase in spring does not follow halogen decreases as closely as in the Antarctic, reaching 1980 values before Arctic halogen amounts decrease to 1980 values and before the Antarctic. None of the CCMs predict future large decreases in the Arctic column ozone. By 2100, total column ozone is projected to be substantially above 1980 values in all regions except in the tropics.
A wind tunnel simulation of the effects of stoss slope on the lee airflow pattern over a two‐dimensional transverse dune
Authors: Dong Zhibao , Qian Guangqiang , Luo Wanyin , Wang Hongtao
Published: August 2007

Secondary airflow plays an important role in dune formation and development. The lee airflow pattern over transverse dunes is important in determining the shape, alignment, and spacing of dunes and is influenced significantly by the lee slope angle. In this paper we present the results of scaled wind tunnel simulations of the effects of stoss slope on the mean lee airflow patterns of transverse dunes. The leeward velocity field was measured nonintrusively using particle image velocimetry to assess the airflow pattern. We found that the flow separated over the dunes with a leeward angle close to the slip face angle of natural transverse dunes and was insensitive to stoss angle. Separation cells were characterized by a back eddy. Reattachment distance, height, area, and aspect ratio were used to characterize the separation cell. The first three parameters increased with increasing stoss angle for angles less than 15° but remained constant or decreased slightly with angles greater than 15°. On the basis of the leeward velocity profiles, six flow regions corresponding to those in previous models were recognized. These regions are initially bounded by kinks but gradually transition downwind and merge to recover a uniform velocity profile after a significant distance. We suggest that the separation cell is most developed when the angle of stoss slope reaches 15°, but the significance of this angle in the evolution of transverse dunes needs further exploration.
Evidence for late Pleistocene thinning of Siple Dome, West Antarctica
Authors: Price S. F. , Conway H. , Waddington E. D.
Published: August 2007

We use a two‐dimensional, full‐stress, thermomechanical flow band model to investigate late Pleistocene and Holocene histories of ice thickness and ice flow at Siple Dome in West Antarctica. Measurements obtained from an ice core and borehole near the ice divide and measurements of radar‐detected internal stratigraphy are used as targets for modeling. Models that account for the climate history (accumulation rate and temperature) alone yield a poor match to observations; histories of ice dynamics (ice thickness, ice divide location, and ice flow enhancement) also need to be included. Our favored model includes 350 m of thinning at Siple Dome between 15,000 and 14,000 years ago, onset of divide flow 3000 years ago, ongoing divide migration starting 2500 years ago, and evolution of ice fabric over the past 30,000 years. The timing of thinning is earlier than that inferred from geologic evidence from the margins but is coincident with a 20 m rise in global sea level about 14,500 years ago (meltwater pulse 1A). This opens the possibility that thinning was a result of increased activity of the ice streams in the late Pleistocene, forced by meltwater pulse 1A. The contribution to meltwater pulse 1A as a result of this thinning was likely small.
Surfactant properties of atmospheric and model humic‐like substances (HULIS)
Authors: Taraniuk Ilya , Graber Ellen R. , Kostinski Alex , Rudich Yinon
Published: August 2007

Surface‐active organics such as humic‐like substances (HULIS) are abundant in aerosol particles and can lower the surface tension of cloud droplets forming on secondary organic and biomass burning aerosols. How fast is the diffusion of these species, relative to the time scale of cloud droplet growth? Here we report surface tension measurements of solutions containing HULIS extracted from smoke and pollution aerosol particles as well those of molecular weight‐fractionated aquatic fulvic acids. Diffusion coefficients are estimated based on the Gibbs adsorption isotherms. The results suggest that HULIS diffusion to the surface of forming droplets is typically more rapid than the time scale of droplet growth so that cloud microphysical properties are affected.
Modeling studies of NO‐γ emissions of sprites
Authors: Liu Ningyu , Pasko Victor P.
Published: August 2007

Motivated by observations of NO‐γ emissions: NO(A2Σ+) → NO(X2Πr) + hν from streamer discharges in laboratory experiments, we develop a model to study these emissions associated with streamer discharges in air at different pressures. The modeling results indicate that the NO(A2Σ+) species in sprite streamers at 70 km altitude are mostly produced by interaction of N2(A3Σu+) metastable species with high‐density ambient NO(X2Πr) molecules. Analysis of the production and loss mechanisms for the upper excited states leading to NO‐γ and N2 LBH emissions demonstrates that the total intensity of NO‐γ emissions associated with sprites is substantially weaker than that of the N2 LBH emissions. The same conclusion can be drawn for elves following similar analysis. It is demonstrated that the presented modeling approach and analysis are consistent with prior knowledge on NO‐γ emissions from aurora, indicating that to observe the NO‐γ emissions from aurora, the ambient NO density must be highly enhanced in the auroral region.
A 900‐year (600 to 1500 A.D.) record of the Indian summer monsoon precipitation from the core monsoon zone of India
Authors: Sinha Ashish , Cannariato Kevin G. , Stott Lowell D. , Cheng Hai , Edwards R. Lawrence , Yadava Madhusudan G. , Ramesh R. , Singh Indra B.
Published: August 2007

We present a near‐annually resolved record of the Indian summer monsoon (ISM) rainfall variations for the core monsoon region of India that spans from 600 to 1500 A.D. from a 230Th‐dated stalagmite oxygen isotope record from Dandak Cave. Our rainfall reconstruction, which spans the Medieval Warm Period (MWP) and the earliest portion of the Little Ice Age (LIA), indicates that the short instrumental record of ISM underestimates the magnitude of monsoon rainfall variability. Periods of severe drought, lasting decades, occurred during the 14th and mid 15th centuries and coincided with several of India's most devastating famines.
Electrical conductivity of the lower‐mantle ferropericlase across the electronic spin transition
Authors: Lin Jung‐Fu , Weir Samuel T. , Jackson Damon D. , Evans William J. , Vohra Yogesh K. , Qiu Wei , Yoo Choong‐Shik
Published: August 2007

Electrical conductivity of the lower‐mantle ferropericlase‐(Mg0.75,Fe0.25)O has been studied using designer diamond anvils to pressures over one megabar and temperatures up to 500 K. The electrical conductivity of (Mg0.75,Fe0.25)O gradually rises by an order of magnitude up to 50 GPa but decreases by a factor of approximately three between 50 to 70 GPa. This decrease in the electrical conductivity is attributed to the isosymmetric high‐spin to low‐spin transition of iron in ferropericlase. That is, the electronic spin transition of iron results in a decrease in the mobility and/or density of the charge transfer carriers in the low‐spin ferropericlase. The activation energy of the low‐spin ferropericlase is 0.27 eV at 101 GPa, consistent with the small polaron conduction (electronic hopping, charge transfer). Our results indicate that low‐spin ferropericlase exhibits lower electrical conductivity than high‐spin ferropericlase, which needs to be considered in future geomagnetic models for the lower mantle.
Alkylation of prohibitin by cyclohexylphenyl‐chloroethyl urea on an aspartyl residue is associated with cell cycle G1 arrest in B16 cells
Authors: Bouchon B , Papon J , Communal Y , Madelmont J‐C , Degoul F
Published: August 2007

Background and purpose:

Phenyl‐chloroethyl ureas (CEUs) are a class of anticancer drugs that mainly react with proteins. Two molecules of this family, cyclohexylphenyl‐chloroethyl urea (CCEU) and iodophenyl‐chloroethyl urea (ICEU) induced G1/S and G2/M cell cycle blocks, respectively. We hypothesised that these observations were linked to a differential protein alkylation pattern.

Experimental approach:

Proteins from B16 cells incubated with [14C‐urea]‐CCEU and [125I]‐ICEU were compared by 2D‐analyses followed by MALDI‐TOF identification of modified proteins and characterisation of the CCEU binding. Protein expression was investigated by Western blot analyses and cell cycle data were obtained by flow cytometry.

Key results:

Several proteins (PDIA1, PDIA3, PDIA6, TRX, VDAC2) were alkylated by both ICEU and CCEU but β‐tubulin and prohibitin (PHB) were specifically alkylated by either ICEU or CCEU respectively. Specific alkylation of these two proteins might explain the observed difference in B16 cell cycle arrest in G2 and G1 phases respectively. Mass spectrometry studies on the alkylated prohibitin localised the modified peptide and identified Asp‐40 as the target for CCEU. This alkylation induced an increased cellular content of PHB that should contribute to the accumulation of cells in G1 phase.

Conclusions and implications:

This study reinforces our findings that CEUs alkylate proteins through an ester linkage with an acidic amino acid and shows that PHB alkylation contributes to G1/S arrest in CCEU treated B16 cells. Modification of PHB status and/or activity is an open route for new cancer therapeutics.

British Journal of Pharmacology (2007) 152, 449–455; doi:10.1038/sj.bjp.0707415; published online 20 August 2007
The molecular mechanism of the inhibition by licofelone of the biosynthesis of 5‐lipoxygenase products
Authors: Fischer L , Hornig M , Pergola C , Meindl N , Franke L , Tanrikulu Y , Dodt G , Schneider G , Steinhilber D , Werz O
Published: August 2007

Background and purpose:

Licofelone is a dual inhibitor of the cyclooxygenase and 5‐lipoxygenase (5‐LO) pathway, and has been developed for the treatment of inflammatory diseases. Here, we investigated the molecular mechanisms underlying the inhibition by licofelone of the formation of 5‐LO products.

Experimental approach:

The efficacy of licofelone to inhibit the formation of 5‐LO products was analysed in human isolated polymorphonuclear leukocytes (PMNL) or transfected HeLa cells, as well as in cell‐free assays using respective cell homogenates or purified recombinant 5‐LO. Moreover, the effects of licofelone on the subcellular redistribution of 5‐LO were studied.

Key results:

Licofelone potently blocked synthesis of 5‐LO products in Ca2+‐ionophore‐activated PMNL (IC50=1.7 μM) but was a weak inhibitor of 5‐LO activity in cell‐free assays (IC50≫10 μ
M). The structures of licofelone and MK‐886, an inhibitor of the 5‐LO‐activating protein (FLAP), were superimposable. The potencies of both licofelone and MK‐886 in ionophore‐activated PMNL were impaired upon increasing the concentration of arachidonic acid, or under conditions where 5‐LO product formation was evoked by genotoxic, oxidative or hyperosmotic stress. Furthermore, licofelone prevented nuclear redistribution of 5‐LO in ionophore‐activated PMNL, as had been observed for FLAP inhibitors. Finally, licofelone as well as MK‐886 caused only moderate inhibition of the synthesis of 5‐LO products in HeLa cells, unless FLAP was co‐transfected.

Conclusions and implications:

Our data suggest that the potent inhibition of the biosynthesis of 5‐LO products by licofelone requires an intact cellular environment and appears to be due to interference with FLAP.

British Journal of Pharmacology (2007) 152, 471–480; doi:10.1038/sj.bjp.0707416; published online 20 August 2007
Endocannabinoids and the haematological system
Authors: Randall M D
Published: August 2007

Endocannabinoids are blood borne and may also be secreted by the endothelium. Accordingly, there has been interest in the interactions between (endo)cannabinoids and blood cells. There is certainly evidence that (endo)cannabinoids may promote platelet activation, indicating that they may be thrombogenic. Platelets are involved both in the metabolism and release of endocannabinoids, and so it is possible that their circulating levels may be regulated by platelets. This process is altered in disease states such that platelet‐derived endocannabinoids contribute towards hypotension in cardiovascular shock. Not only may endocannabinoids regulate platelet function and possibly lead to thrombogenesis, but they may also influence haematopoiesis. Given these emerging roles, the aim of this review is to examine the interactions between cannabinoids and blood.

British Journal of Pharmacology (2007) 152, 671–675; doi:10.1038/sj.bjp.0707420; published online 20 August 2007
Role and regulation of acylethanolamides in energy balance: focus on adipocytes and β‐cells
Authors: Matias I , Gonthier M‐P , Petrosino S , Docimo L , Capasso R , Hoareau L , Monteleone P , Roche R , Izzo A A , Di Marzo V
Published: August 2007

The endocannabinoid, arachidonoylethanolamide (AEA), and the peroxisome proliferator‐activated receptor (PPAR)‐α ligand, oleylethanolamide (OEA) produce opposite effects on lipogenesis. The regulation of OEA and its anti‐inflammatory congener, palmitoylethanolamide (PEA), in adipocytes and pancreatic β‐cells has not been investigated. We report here the results of studies on acylethanolamide regulation in these cells during obesity and hyperglycaemia, and provide an overview of acylethanolamide role in metabolic control. We analysed by liquid chromatography‐mass spectrometry OEA and PEA levels in: 1) mouse 3T3F442A adipocytes during insulin‐induced differentiation, 2) rat insulinoma RIN m5F β‐cells kept in ‘low’ or ‘high’ glucose, 3) adipose tissue and pancreas of mice with high fat diet‐induced obesity (DIO), and 4) in visceral fat or blood of obese or type 2 diabetes (T2D) patients. In adipocytes, OEA levels remain unchanged during differentiation, whereas those of PEA decrease significantly, and are under the negative control of both leptin and PPAR‐γ. PEA is significantly downregulated in subcutaneous adipose tissue of DIO mice. In RIN m5F insulinoma β‐cells, OEA and PEA levels are inhibited by ‘very high’ glucose, this effect being enhanced by insulin, whereas in cells kept for 24 h in ‘high’ glucose, they are stimulated by both glucose and insulin. Elevated OEA and PEA levels are found in the blood of T2D patients. Reduced PEA levels in hypertrophic adipocytes might play a role in obesity‐related pro‐inflammatory states. In β‐cells and human blood, OEA and PEA are down‐ or up‐regulated under conditions of transient or chronic hyperglycaemia, respectively.

British Journal of Pharmacology (2007) 152, 676–690; doi:10.1038/sj.bjp.0707424; published online 20 August 2007
Roflumilast inhibits leukocyte‐endothelial cell interactions, expression of adhesion molecules and microvascular permeability
Authors: Sanz M‐J , Cortijo J , Taha M A , Cerdá‐Nicolás M , Schatton E , Burgbacher B , Klar J , Tenor H , Schudt C , Issekutz A C , Hatzelmann A , Morcillo E J
Published: August 2007

Background and purpose:

The present study addressed the effects of the investigational PDE4 inhibitor roflumilast on leukocyte‐endothelial cell interactions and endothelial permeabilityin vivoandin vitro.

Experimental approach:

In vivo, intravital video‐microscopy was used to determine effects of roflumilast p.o. on leukocyte‐endothelial cell interactions and microvascular permeability in rat mesenteric venules.In vitro, the effects of roflumilast N‐oxide, the active metabolite of roflumilast in humans, and other PDE4 inhibitors on neutrophil adhesion to tumour necrosis factorα(TNFα)‐activated human umbilical vein endothelial cells (HUVEC), E‐selectin expression and thrombin‐induced endothelial permeability was evaluated. Flow cytometry was used to determine the effect of roflumilast onN‐formyl‐methionyl‐leucyl‐phenylalanine (fMLP)‐induced CD11b upregulation on human neutrophils.

Key results:

In vivo, roflumilast, given 1 h before lipopolysaccharide (LPS), dose‐dependently reduced leukocyte‐endothelial cell interactions in rat mesenteric postcapillary venules. It also diminished histamine‐induced microvascular permeability. Immunohistochemical analyses revealed that roflumilast prevented LPS‐induced endothelial P‐ and E‐selectin expression.In vitro, roflumilast N‐oxide concentration‐dependently suppressed neutrophil adhesion to TNFα‐activated HUVEC and CD11b expression on fMLP‐stimulated neutrophils. It also reduced TNFα‐induced E‐selectin expression on HUVEC, when PDE3 activity was blocked. HUVEC permeability elicited by thrombin was concentration‐dependently suppressed by roflumilast N‐oxide. While roflumilast N‐oxide was as potent as roflumilast at inhibiting stimulated endothelial cell and neutrophil functions, both compounds were significantly more potent than the structurally unrelated PDE4 inhibitors, rolipram or cilomilast.

Conclusions and implications:

These findings further support earlier observations on the inhibition of inflammatory cell influx and protein extravasation by roflumilastin vivo.

British Journal of Pharmacology(2007)152, 481–492; doi:10.1038/sj.bjp.0707428; published online 20 August 2007
Characterization of 4‐(2‐hydroxyphenyl)‐1‐[2′‐[N‐(2″‐pyridinyl)‐p‐fluorobenzamido]ethyl]piperazine (p‐DMPPF) as a new potent 5‐HT1Aantagonist
Authors: Defraiteur C , Plenevaux A , Scuvée‐Moreau J , Rouchet N , Goblet D , Luxen A , Seutin V
Published: August 2007

Background and purpose:

The identification of potent and selective radioligands for the mapping of 5‐HT receptors is interesting both for clinical and experimental research. The aim of this study was to compare the potency of a new putative 5‐HT1Areceptor antagonist,p‐DMPPF, (4‐(2‐hydroxyphenyl)‐1‐[2′‐[N‐(2′′‐pyridinyl)‐p‐fluorobenzamido]ethyl]piperazine) with that of the well‐known 5‐HT1Aantagonists, WAY‐100635 (N‐[2‐[4‐(2‐methoxyphenyl)‐1‐piperazinyl]‐ethyl]‐N‐(2‐pyridinyl) cyclohexanecarboxamide) and its fluorobenzoyl analogue,p‐MPPF (4‐(2‐methoxyphenyl)‐1‐[2′‐[N‐(2″‐pyridinyl)‐p‐fluorobenzamido]ethyl]piperazine).

Experimental approach:

Single cell extracellular recordings of dorsal raphe (DR) neurones were performed in rat brain slices. The potency of each compound at antagonizing the effect of the 5‐HT1Aagonist, 8‐OH‐DPAT [8‐hydroxy‐2‐(di‐n‐propylamino)‐tetraline], was quantified using the Schild equation. The pharmacological profile ofp‐DMPPF was defined using competition binding assays.

Key results:

Consistently with a 5‐HT1Areceptor antagonist profile, incubation of slices with an equimolar (10 nM) concentration of each compound markedly reduced the inhibitory effect of 8‐OH‐DPAT on the firing rate of DR neurones, causing a significant rightward shift in its concentration‐response curve. The rank order of potency of the antagonists was WAY‐100635>p‐DMPPFp‐MPPF. The sensitivity of DR neurones to the inhibitory effect of 8‐OH‐DPAT was found to be heterogeneous. The binding experiments demonstrated thatp‐DMPPF is highly selective for 5‐HT1Areceptors, with aKivalue of 7 nM on these receptors.

Conclusions and implications:

The potency of the new compound,p‐DMPPF, as a 5‐HT1Aantagonist is similar to that ofp‐MPPF in our electrophysiological assay. Its selectivity towards 5‐HT1Areceptors makes it a good candidate for clinical development.

British Journal of Pharmacology(2007)152, 952–958; doi:10.1038/sj.bjp.0707431; published online 20 August 2007
Novel approaches to developing new antibiotics for bacterial infections
Authors: Coates A R M , Hu Y
Published: August 2007

Antibiotics are an essential part of modern medicine. The emergence of antibiotic‐resistant mutants among bacteria is seemingly inevitable, and results, within a few decades, in decreased efficacy and withdrawal of the antibiotic from widespread usage. The traditional answer to this problem has been to introduce new antibiotics that kill the resistant mutants. Unfortunately, after more than 50 years of success, the pharmaceutical industry is now producing too few antibiotics, particularly against Gram‐negative organisms, to replace antibiotics that are no longer effective for many types of infection. This paper reviews possible new ways to discover novel antibiotics. The genomics route has proven to be target rich, but has not led to the introduction of a marketed antibiotic as yet. Non‐culturable bacteria may be an alternative source of new antibiotics. Bacteriophages have been shown to be antibacterial in animals, and may find use in specific infectious diseases. Developing new antibiotics that target non‐multiplying bacteria is another approach that may lead to drugs that reduce the emergence of antibiotic resistance and increase patient compliance by shortening the duration of antibiotic therapy. These new discovery routes have given rise to compounds that are in preclinical development, but, with one exception, have not yet entered clinical trials. For the time being, the majority of new antibiotics that reach the marketplace are likely to be structural analogues of existing families of antibiotics or new compounds, both natural and non‐natural which are screened in a conventional way against live multiplying bacteria.

British Journal of Pharmacology(2007)152, 1147–1154; doi:10.1038/sj.bjp.0707432; published online 20 August 2007
Optical limitations in thin-film low-band-gap polymer/fullerene bulk heterojunction devices
Authors: Persson Nils-Krister , Wang Xiangjun , Inganäs Olle
Published: August 2007

Photovoltaic devices from the low-band-gap alternating copolymer APFO-Green1, blended with the fullerene derivative BTPF70 as electron acceptor, show a pronounced variation of the external quantum efficiency with varying thickness. Device simulation, based on ellipsometric characterization, reveals that this behavior is to be expected and valid also for most low-band-gap polymers and that it can be explained by optical interference. Requirements for materials suitable for wide spectral coverage in thin-film organic solar cells are delineated. Furthermore, the internal quantum efficiency is calculated to be ≈0.4.
Interactions and dynamics in Li+Li2 ultracold collisions
Authors: Cvitaš Marko T. , Soldán Pavel , Hutson Jeremy M. , Honvault Pascal , Launay Jean-Michel
Published: August 2007

A potential energy surface for the lowest quartet electronic state (A′4) of lithium trimer is developed and used to study spin-polarized Li+Li2 collisions at ultralow kinetic energies. The potential energy surface allows barrierless atom exchange reactions. Elastic and inelastic cross sections are calculated for collisions involving a variety of rovibrational states of Li2. Inelastic collisions are responsible for trap loss in molecule production experiments. Isotope effects and the sensitivity of the results to details of the potential energy surface are investigated. It is found that for vibrationally excited states, the cross sections are only quite weakly dependent on details of the potential energy surface.
General biorthogonal projected bases as applied to second-order Møller-Plesset perturbation theory
Authors: Weijo Ville , Manninen Pekka , Jørgensen Poul , Christiansen Ove , Olsen Jeppe
Published: August 2007

With low-order scaling correlated wave function theories in mind, we present second quantization formalism as well as biorthonormalization procedures for general—singular or nonsingular—bases. Of particular interest are the so-called projected atomic orbital bases, which are obtained from a set of atom-centered functions and feature a separation of occupied and virtual spaces. We demonstrate the formalism by deriving and implementing second-order Møller-Plesset perturbation theory in it, and discuss the convergence and preconditioning of the iterative amplitude equations in detail.
The water-oxygen dimer: First-principles calculation of an extrapolated potential energy surface and second virial coefficients
Authors: Wheatley Richard J. , Harvey Allan H.
Published: August 2007

The systematic intermolecular potential extrapolation routine (SIMPER) is applied to the water-oxygen complex to obtain a five-dimensional potential energy surface. This is the first application of SIMPER to open-shell molecules, and it is the first use, in this context, of asymptotic dispersion energy coefficients calculated using the unrestricted time-dependent coupled-cluster method. The potential energy surface is extrapolated to the complete basis set limit, fitted as a function of intermolecular geometry, and used to calculate (mixed) second virial coefficients, which significantly extend the range of the available experimental data.
Π
1
←
X
Σ
+
1
band systems of jet-cooled ScCo and YCo
Authors: Nagarajan Ramya , Morse Michael D.
Published: August 2007

Rotationally resolved resonant two-photon ionization (R2PI) spectra of ScCo and YCo are reported. The measured spectra reveal that these molecules possess ground electronic states of Σ+1 symmetry, as previously found in the isoelectronic Cr2 and CrMo molecules. The ground state rotational constants for ScCo and YCo are B0″=0.20131(22)cm−1 and B0″=0.12096(10)cm−1, corresponding to ground state bond lengths of r0″=1.8121(10)Å and r0″=1.9830(8)Å, respectively. A single electronic band system, assigned as a Π1←XΣ+1 transition, has been identified in both molecules. In ScCo, the Π1 state is characterized by T0=15428.8, ωe′=246.7, and ωe′xe′=0.73cm−1. In YCo, the Π1 state has T0=13951.3, ωe′=231.3, and ωe′xe′=2.27cm−1. For YCo, hot bands originating from levels up to v″=3 are observed, allowing the ground state vibrational constants ωe″=369.8, ωe″xe″=1.47, and ΔG1∕2″=365.7cm−1 to be deduced. The bond energy of ScCo has been measured as 2.45eV from the onset of predissociation in a congested vibronic spectrum. A comparison of the chemical bonding in these molecules to related molecules is presented.
Tight-binding molecular dynamics study of the role of defects on carbon nanotube moduli and failure
Authors: Haskins Richard W. , Maier Robert S. , Ebeling Robert M. , Marsh Charles P. , Majure Dustin L. , Bednar Anthony J. , Welch Charles R. , Barker Bruce C. , Wu David T.
Published: August 2007

We performed tight-binding molecular dynamics on single-walled carbon nanotubes with and without a variety of defects to study their effect on the nanotube modulus and failure through bond rupture. For a pristine (5,5) nanotube, Young’s modulus was calculated to be ∼1.1TPa, and brittle rupture occurred at a strain of 17% under quasistatic loading. The predicted modulus is consistent with values from experimentally derived thermal vibration and pull test measurements. The defects studied consist of moving or removing one or two carbon atoms, and correspond to a 1.4% defect density. The occurrence of a Stone-Wales defect does not significantly affect Young’s modulus, but failure occurs at 15% strain. The occurrence of a pair of separated vacancy defects lowers Young’s modulus by ∼160GPa and the critical or rupture strain to 13%. These defects apparently act independently, since one of these defects alone was independently determined to lower Young’s modulus by ∼90GPa, also with a critical strain of 13%. When the pair of vacancy defects adjacent, however, Young’s modulus is lowered by only ∼100GPa, but with a lower critical strain of 11%. In all cases, there is noticeable strain softening, for instance, leading to an ∼250GPa drop in the apparent secant modulus at 10% strain. When a chiral (10,5) nanotube with a vacancy defect was subjected to tensile strain, failure occurred through a continuous spiral-tearing mechanism that maintained a high level of stress (2.5GPa) even as the nanotube unraveled. Since the statistical likelihood of defects occurring near each other increases with nanotube length, these studies may have important implications for interpreting the experimental distribution of moduli and critical strains.
Density functional theory-symmetry adapted perturbation treatment energy decomposition of nucleic acid base pairs taken from DNA crystal geometry
Authors: Sedlák Robert , Jurečka Petr , Hobza Pavel
Published: August 2007

First- and second-order perturbation energies for H-bonded and stacked structures of nucleic acid base pairs in DNA crystal geometries were determined using the density functional theory symmetry adapted perturbation treatment method. Considerably larger stabilization of the former pairs is due to electrostatic and induction energies. Total E(1) energies for both pairs are, however, similar and the same is true for dispersion energy.
Relaxed energy stability analysis on the onset of buoyancy-driven instability in the horizontal porous layer
Authors: Kim Min Chan , Choi Chang Kyun
Published: August 2007

The onset of buoyancy-driven instability in an initially quiescent, isotropic fluid-saturated porous layer is analyzed theoretically. Darcy’s law is employed to examine characteristics of fluid motion under the Boussinesq approximation. The critical condition to mark the onset of convective instability is analyzed based on the relaxed energy method. The predicted critical conditions are compared with the various results based on the conventional energy method and the linear stability theory.
Enhanced Raman scattering from focused surface plasmons
Authors: Bahns J. T. , Imre A. , Vlasko-Vlasov V. K. , Pearson J. , Hiller J. M. , Chen L. H. , Welp U.
Published: August 2007

Surface plasmon polaritons launched at concentric arcs can be focused into a subwavelength wide focal spot of high near-field light intensity. The focused plasmons give rise to enhanced Raman scattering from R6G molecules placed in the focal area. By exploiting the polarization dependence of the focusing the authors establish an enhancement of the Raman signal by a factor of ∼6. The results show that focusing of propagating surface plasmons on flat metal surfaces may be an alternative to localized plasmons on metal nanostructures for achieving enhanced Raman scattering. In particular, a flat metal substrate enables better control over the local electric fields and the placement of analyte molecules, and, therefore, ultimately better fidelity of Raman spectra.
Nonvolatile memory characteristics of nickel-silicon-nitride nanocrystal
Authors: Chen Wei-Ren , Chang Ting-Chang , Liu Po-Tsun , Yeh Jui-Lung , Tu Chun-Hao , Lou Jen-Chung , Yeh Ching-Fa , Chang Chun-Yen
Published: August 2007

The formation of nickel-silicon-nitride nanocrystals by sputtering a comixed target in the argon and nitrogen environment is proposed in this letter. High resolution transmission electron microscope analysis clearly shows the nanocrystals embedded in the silicon nitride and x-ray photoelectron spectroscopy also shows the chemical material analysis of nanocrystals. The memory window of nickel-silicon-nitride nanocrystals enough to define 1 and 0 states is obviously observed, and a good data retention characteristic to get up to 10years is exhibited for the nonvolatile memory application.
Analytic high-order Douglas-Kroll-Hess electric field gradients
Authors: Mastalerz Remigius , Barone Giampaolo , Lindh Roland , Reiher Markus
Published: August 2007

In this work we present a comprehensive study of analytical electric field gradients in hydrogen halides calculated within the high-order Douglas-Kroll-Hess (DKH) scalar-relativistic approach taking picture-change effects analytically into account. We demonstrate the technical feasibility and reliability of a high-order DKH unitary transformation for the property integrals. The convergence behavior of the DKH property expansion is discussed close to the basis set limit and conditions ensuring picture-change-corrected results are determined. Numerical results are presented, which show that the DKH property expansion converges rapidly toward the reference values provided by four-component methods. This shows that in closed-shell cases, the scalar-relativistic DKH(2,2) approach which is of second order in the external potential for both orbitals and property operator yields a remarkable accuracy. As a parameter-dependence-free high-order DKH model, we recommend DKH(4,3). Moreover, the effect of a finite-nucleus model, different parametrization schemes for the unitary matrices, and the reliability of standard basis sets are investigated.
Harmonic analysis of iterated function systems with overlap
Authors: Jorgensen Palle E. T. , Kornelson Keri , Shuman Karen
Published: August 2007

An iterated function system (IFS) is a system of contractive mappings τi:Y→Y, i=1,…,N (finite), where Y is a complete metric space. Every such IFS has a unique (up to scale) equilibrium measure (also called the Hutchinson measure μ), and we study the Hilbert space L2(μ). In this paper we extend previous work on IFSs without overlap. Our method involves systems of operators generalizing the more familiar Cuntz relations from operator algebra theory and from subband filter operators in signal processing. These Cuntz-like operator systems were used in recent papers on wavelet analysis by Baggett, Jorgensen, Merrill, and Packer [Contemp. Math. 345, 11–25 (2004)], where they serve as a first step to generating wavelet bases of Parseval type (alias normalized tight frames), i.e., wavelet bases with redundancy. Similarly, it was shown in work by Dutkay and Jorgensen [Rev. Mat. Iberoam. 22, 131–180 (2006)] that the iterative operator approach works well for generating wavelets on fractals from IFSs without overlap. But so far the more general and more difficult case of essential overlap has resisted previous attempts at a harmonic analysis and explicit basis constructions, in particular. The operators generating the appropriate Cuntz relations are composition operators, e.g., Fi:f→f∘τi, where (τi) is the given IFS. If the particular IFS is essentially nonoverlapping, it is relatively easy to compute the adjoint operators Si=Fi*, and the Si operators will be isometries in L2(μ) with orthogonal ranges. For the case of essential overlap, we can use the extra terms entering in the computation of the operators Fi* as a “measure” of the essential overlap for the particular IFS we study. Here the adjoint operators Fi* refer to the Hilbert space L2(μ), where μ is the equilibrium measure μ for the given IFS (τi).
Sensor-integrated fluorescent microarray for ultrahigh sensitivity direct-imaging bioassays: Role of a high rejection of excitation light
Authors: Martinelli Lucio , Choumane Houtai , Ha Khoi-Nguyen , Sagarzazu Gabriel , Goutel Carole , Weisbuch Claude , Gacoin Thierry , Benisty Henri
Published: August 2007

Fluorescent microarrays exploit fluorescent labeled targets bound to immobilized biomolecular probes. Their signal-to-noise ratio is limited by the collection aperture in common confocal geometries. Taking advantage of a very high rejection filter deposited onto a silicon arrayed detector (coupled-charge device or complementary metal-oxide semiconductor), it is demonstrated that a highly compact lens-free assay with photon collection of order unity operates with a 30-fold improvement over a conventional (substrate + free-space optics) scheme. Through analysis of improvements over the present demonstrator, a single molecule per pixel sensitivity is predicted.
Three-dimensional structure of CdX (X=Se,Te) nanocrystals by total x-ray diffraction
Authors: Pradhan S. K. , Deng Z. T. , Tang F. , Wang C. , Ren Y. , Moeck P. , Petkov V.
Published: August 2007

The three-dimensional structure of oleic acid-capped CdSe and thiol-capped CdTe nanocrystals used as quantum dots has been determined by total synchrotron radiation x-ray diffraction and atomic pair distribution function analysis. Both CdSe and CdTe are found to exhibit the zinc-blende-type atomic ordering. It is only slightly distorted in CdSe implying the presence of nanosize domains and very heavily distorted in CdTe due to the presence of distinct core-shell regions. The results well demonstrate the great potential of the experimental approach and thus encourage its wider application in quantum dot research.
Enhanced backward wave propagation in evanescent waveguides loaded with split ring resonators
Authors: Carbonell J. , Roglá L. J. , Boria V. E. , Marqués R.
Published: August 2007

This paper reports on the design and experimental characterization of evanescent waveguides loaded with split ring resonators (SRRs) supporting enhanced backward wave propagation. With respect to previous negative refractive index devices based on metallic waveguides, the use of a direct coaxial probe excitation inside an evanescent waveguide drastically improves transmission and reflection characteristics of the periodic structure. Moreover, the addition of metallic windows interleaved between consecutive resonators offers an extra degree of freedom in order to control interresonator couplings, and hence, device parameters like overall transmission, reflection, and bandwidth of the backward wave pass band. A numerical and experimental analysis of different structures overcoming the high loss issue of previously published results is detailed. An experimental validation of the proposed enhancements is done for periodic structures, where no individual tuning of the resonator sections is performed. The proposed technology mainly offers the advantage of miniaturization, and it could be combined in a further step with standard design techniques to provide frequency selective devices.
Measurement of ion energy distributions using a combined energy and mass analyzer
Authors: Walton S. G. , Fernsler R. F. , Leonhardt D.
Published: August 2007

A method is described for measuring ion energy distributions using a commercially available, combined energy analyzer/mass spectrometer. The distributions were measured at an electrode located adjacent to pulsed, electron beam-generated plasmas produced in argon. The method uses energy-dependent tuning and was tested for various plasma conditions. The results indicate an improved collection efficiency of low-energy ions when compared to conventional approaches in measuring ion energy distributions.
Niobium direct detectors for fast and sensitive terahertz spectroscopy
Authors: Reese M. O. , Santavicca D. F. , Prober D. E. , True A. B. , Schmuttenmaer C. A.
Published: August 2007

We report the performance of a niobium hot-electron bolometer designed for laboratory terahertz spectroscopy. The antenna-coupled detector can operate above 4.2K and has fast (subnanosecond) response. Detailed microwave measurements of performance over a wide range of operating conditions were correlated with quantitative terahertz measurements. The maximum responsivity is 4×104V∕W with a noise equivalent power at the detector of 2×10−14W∕Hz1∕2, approaching the intrinsic thermal fluctuation limit for the device. This detector enables a variety of novel laboratory spectroscopy measurements.