bluuebunny/crossref_metadata_2025 huggingface dataset:
Source-receptor relationships for speciated atmospheric mercury at the remote experimental lakes area, Northwestern Ontario, Canada
Authors: Cheng I. , Zhang L. , Blanchard P. , Graydon J. A. , Louis V. L. St.
Published: December 2011

Abstract. Source-receptor relationships for speciated atmospheric mercury measured at the Experimental Lakes Area (ELA), Northwestern Ontario, Canada were investigated using various receptor-based approaches. The data used in this study include gaseous elemental mercury (GEM), mercury bound to fine airborne particles (< 2.5 μm) (PHg), reactive gaseous mercury (RGM), major inorganic ions, sulphur dioxide, nitric acid gas, ozone, and meteorological variables, all of which were measured between May 2005 and December 2006. The source origins identified were related to transport of industrial and combustion emissions (associated with elevated GEM), photochemical production of RGM (associated with elevated RGM), road-salt particles with adsorption of gaseous Hg (associated with elevated PHg and RGM), crustal/soil emissions, and background pollution. Back trajectory modelling illustrated that a remote site, like the ELA, is affected by distant Hg point sources in Canada and the United States. The sources identified from correlation analysis, principal components analysis and K-means cluster analysis were generally consistent. The discrepancies between the K-means and Hierarchical cluster analysis were the clusters related to transport of industrial/combustion emissions, photochemical production of RGM, and crustal/soil emissions. Although it was possible to assign the clusters to these source origins, the trajectory plots for the Hierarchical clusters were similar to some of the trajectories belonging to several K-means clusters. This likely occurred because the variables indicative of transport of industrial/combustion emissions were elevated in at least two or more of the clusters, which means this Hg source was well-represented in the data.
Climate dependent diatom production is preserved in biogenic Si isotope signatures
Authors: Sun X. , Andersson P. , Humborg C. , Gustafsson B. , Conley D. J. , Crill P. , Mörth C.-M.
Published: December 2011

Abstract. The aim of this study was to reconstruct diatom production in the subarctic northern tip of the Baltic Sea, Bothnian Bay, based on down-core analysis of Si isotopes in biogenic silica (BSi). Dating of the sediment showed that the samples covered the period 1820 to 2000. The sediment core record can be divided into two periods, an unperturbed period from 1820 to 1950 and a second period affected by human activities (from 1950 to 2000). This has been observed elsewhere in the Baltic Sea. The shift in the sediment core record after 1950 is likely caused by large scale damming of rivers. Diatom production was inferred from the Si isotope composition which ranged between δ30Si −0.18‰ and +0.58‰ in BSi, and assuming fractionation patterns due to the Raleigh distillation, the production was shown to be correlated with air and water temperature, which in turn were correlated with the mixed layer (ML) depth. The sedimentary record showed that the deeper ML depth observed in colder years resulted in less production of diatoms. Pelagic investigations in the 1990's have clearly shown that diatom production in the Baltic Sea is controlled by the ML depth. Especially after cold winters and deep water mixing, diatom production was limited and dissolved silicate (DSi) concentrations were not depleted in the water column after the spring bloom. Our method corroborates these findings and offers a new method to estimate diatom production over much longer periods of time in diatom dominated aquatic systems, i.e. a large part of the world's ocean and coastal seas.
Resistance of Platelets in Hypercholesterolemia to Inhibition by Activated Coagulation Factor X
Authors: Kahn Nighat , Khan Bilal , Sinha Asru K.
Published: December 2011

Platelet hyperactivity may be involved in the pathogenesis of both thrombogenesis and hypercholesterolemia. The cholesterol-enriched states may contribute to accelerated development of atherosclerosis. The effect of high cholesterol on platelet activation and on inhibition by coagulation factor Xa, was studiedin vitro. Incubation of normal platelets (n=20) with cholesterol-rich dispersion resulted in a small increase of platelet aggregation (PA) and thromboxaneA2(TXA2) synthesis when compared with platelets incubated with cholesterol-normal dispersion. In hypercholesterolemic patients (n=20), ADP-induced PA andTXA2synthesis showed only small increases over normal controls. Addition of factor Xa (1 unit/mL) prevented the ADP-induced PA and markedly inhibitedTXA2synthesis in normal platelets (1.3±0.2and8.7±2.0pmolTXA2/108platelets, with and without factor Xa, resp.). However, factor Xa failed to significantly suppressTXA2synthesis in cholesterol-incubated normal platelets (9.5±1.4and11.8±1.3pmolTXA2/108platelets, with and without factor Xa; resp.,P=NS) as well as in platelets from patients with hypercholesterolemia (8.6±4.0and10.9±4.9pmolTXA2/108platelets, with and without factor Xa; resp.,P=NS). Exposure of platelets to high cholesterol concentrations,in vitroandin vivo, marginally increased PA andTXA2synthesis but resulted in loss of responsiveness to factor Xa, which could significantly contribute to platelet activation in hypercholesterolemic states.
The Influence of Dust Standards on the Prevalence and Severity of Coal Worker's Pneumoconiosis at Autopsy in the United States of America
Authors: Vallyathan Val , Landsittel Douglas P , Petsonk Edward L , Kahn Jeffrey , Parker John E , Osiowy Karen Tofflemire , Green Francis H.Y
Published: December 2011

Context.—Coal worker's pneumoconiosis is a major occupational lung disease in the United States. The disease is primarily controlled through reducing dust exposure in coal mines using technological improvements and through the establishment of dust standards by regulatory means.

Objective.—To determine if dust standards established in the US Federal Coal Mine Health and Safety Act of 1969 have reduced the prevalence and severity of coal worker's pneumoconiosis.

Design.—The study population included materials from 6103 deceased coal miners submitted to the National Coal Workers' Autopsy Study from 1971 through 1996. Type and severity of coal worker's pneumoconiosis were classified using standardized diagnostic criteria.

Results.—Among miners who worked exclusively prior to the 1969 dust standard, 82.6% had coal macules, 46.3% coal nodules, 28.2% silicotic nodules, and 10.3% progressive massive fibrosis. Lower prevalences were noted among miners exposed exclusively to post-1970 dust levels: 58.8% had coal macules, 15.0% coal nodules, 8.0% silicotic nodules, and 1.2% progressive massive fibrosis. The differences in prevalence were highly significant (P < .001) for all types of pneumoconiosis, including progressive massive fibrosis, after adjustment for age, years of mining, and smoking status.

Conclusions.—The study confirms a beneficial impact of the first 25 years of the dust standard established by the 1969 act on the prevalence and severity of coal worker's pneumoconiosis in US coal miners. However, pneumoconiosis continues to occur among miners who have worked entirely within the contemporary standard, suggesting a need for further reductions in exposure to respirable coal mine dust.
Squamous Lesions of the Ovary
Authors: Mahe Etienne , Sur Monalisa
Published: December 2011

The ovary shows an innate potential for markedly variable histogenesis, including squamous differentiation. Although not uncommon, squamous differentiation in ovarian lesions can be present in several diagnostic contexts, both benign and malignant. We present a review of the literature pertaining to squamous lesions of the ovary. In particular, we summarize the relevant clinical features, workup, gross findings and histopathologic features, differential diagnosis, treatment, and prognostic features of both the common and rare squamous entities found in the ovary.
Numerical Fidelity of Endoscopic Biopsy Fragments in the Processing Sequence of a University Surgical Pathology Laboratory
Authors: Owens Scott R , Wiehagen Luke , Simmons Christopher , Sikorova Alena , Stewart William , Kelly Susan , Nestler Richard , Yousem Samuel A
Published: December 2011

Context.—Diagnostic specimens in surgical pathology are, in general, becoming smaller and smaller, as minimally invasive surgical procedures are used to obtain representative tissue. Conservation and effective utilization of small biopsy tissue is therefore crucial in the pathology laboratory.

Objective.—To identify potential areas where biopsy tissue may be lost in the course of processing in our university-based laboratory.

Design.—We followed 2934 endoscopic biopsy samples as they moved through our grossing area and histology laboratory by documenting the number of fragments inked and placed within tissue paper at the time of gross assessment, the number of fragments found in each cassette after processing and subsequently embedded in paraffin, and the number of pieces of tissue present on glass slides after staining.

Results.—In 805 (27.4%) cases, the number of fragments of tissue noted on glass slides containing 2 levels of the paraffin block differed from the number submitted in the tissue cassette. Of these, most (137, 17%) differed between the number of fragments embedded in paraffin and those identified on glass slides. Loss of tissue fragments occurred in only 7.2% of cases, while 26.3% had gains in tissue fragments.

Conclusions.—Recognition of type(s) and source(s) of variation in biopsy fragment numbers is important in quality control and in the overall practical management of a histology laboratory.
A Strategy for Optimizing Staffing to Improve the Timeliness of Inpatient Phlebotomy Collections
Authors: Morrison Aileen P , Tanasijevic Milenko J , Torrence-Hill Joi N , Goonan Ellen M , Gustafson Michael L , Melanson Stacy E.F
Published: December 2011

Context.—The timely availability of inpatient test results is a key to physician satisfaction with the clinical laboratory, and in an institution with a phlebotomy service may depend on the timeliness of blood collections. In response to safety reports filed for delayed phlebotomy collections, we applied Lean principles to the inpatient phlebotomy service at our institution. Our goal was to improve service without using additional resources by optimizing our staffing model.

Objective.—To evaluate the effect of a new phlebotomy staffing model on the timeliness of inpatient phlebotomy collections.

Design.—We compared the median time of morning blood collections and average number of safety reports filed for delayed phlebotomy collections during a 6-month preimplementation period and 5-month postimplementation period.

Results.—The median time of morning collections was 17 minutes earlier after implementation (7:42 am preimplementation; interquartile range, 6:27–8:48 am; versus 7:25 am postimplementation; interquartile range, 6:20–8:26 am). The frequency of safety reports filed for delayed collections decreased 80% from 10.6 per 30 days to 2.2 per 30 days.

Conclusion.—Reallocating staff to match the pattern of demand for phlebotomy collections throughout the day represents a strategy for improving the performance of an inpatient phlebotomy service.
Phenolic Contents and Antioxidants Activities in Jamman Fruit (Eugenia jambolana) Products
Authors: Sheikh Saghir Ahmed , Shahnawaz Muhammad , Nizamani Shafi Muhammad , Bhanger Muhammad Iqbal , Ahmed Ejaz
Published: December 2011

In this study, total phenolic contents and antioxidant activity were determined in various products made from two cultivars of jamman fruit (Eugenia jambolana) i.e. improved (V1) and indigenous (V2). Five products were made from each cultivar such as jam, squash, ready-to-drink juice, pulp powder and seed powder. Fruit cultivars were endogenous to the typical region of Sindh-Pakistan. Total phenolic contents were analyzed by Folin-Ciocalteu colorimetric method, whereas, the total antioxidant activity was analyzed by using the 2, 2-diphenil-1-picrylhydrazyl radical scavenging capacity (DPPH) assays. The highest total phenolic contents and antioxidants were observed in freeze dried seed powder while the lowest contents were found in squash.
Detection of Outliers in Bioequivalence Studies Data Analysis with Williams Design
Authors: Rasheed A. , Junaid S. , Ahmad T.
Published: December 2011

Background: Drug Regulatory agencies all over the world generally discourage exclusion of outliers in a BE (BE) study; on the other hand in routine bio-statistical work we take these into the account. If the decision rules for identifying the outliers are clearly mentioned before the start of the study and laid down in protocol by the responsible biostatistician in collaboration with clinicians, the problem of outliers can be dealt smartly without jeopardizing the whole study for redoing. The purpose of this article is to introduce procedure for reliably detecting outlier subject(s) with Williams design.

Experimental: Literature review reveals many different methods for the detection of outlier values in BE studies; most of them are for BE of two treatments. For BE studies with more than two treatments use of Williams design seems imperative; but inclusion and deletion of outlying subjects may lead to profound effect on conclusion of BE which in turn may be dangerous for the health. The suggested method is an adjustment to a previously introduced method using exploratory data analysis technique such as principle component analysis and Andrews curves.
Cellular Trafficking and Subcellular Interactions of Cationic Gene Delivery Nanomaterials
Authors: Barar Jaleh , Omidi Yadollah
Published: December 2011

Various cationic nanobiomaterials have been widely used as gene delivery nanosystems (GDNSs) in vitro and in vivo. Various cellular machineries are involved in trafficking of GDNSs, whose surface functional moieties and architectural properties confer great potential to interact with cell membranes and subcellular biomolecules. It appears such intrinsic inadvertent biological functionalities may impact the outcome of the biomedical applications of these nanobiomaterials. Various advanced materials used as GDNSs may display selective phenotypic effects in target cells/tissues as a result of initiation of various signaling pathways perhaps due to its cellular interactions with plasma cell membranes and/or intracellular compartments including genetic materials. Thus, better understanding about cellular/molecular impacts of GDNSs may maximize their clinical outcomes and accordingly minimize their inevitable undesired consequences. The main focus of this review is based on the cellular trafficking and interactions of cationic gene delivery nanobiomaterials with target cells or subcellular compartments.
Photodependent release from poly(vinyl alcohol)/epoxypropoxy coumarin hydrogels
Authors: Lee Mi Sun , Kim Jin‐Chul
Published: December 2011

To obtain a photoresponsive hydrogel, poly(vinyl alcohol) (PVA) having coumarin residue as a pending group was crosslinked by photodimerizing the coumarin pendants. PVA having coumarin pendants was prepared by reacting the polymer with epoxypropoxy coumarin (EPC) in a strong alkali condition with EPC/PVA molar ratio of 200/1. According to the 1H NMR spectrum of PVA‐EPC conjugate, the molar ratio of EPC residue to PVA was about 4.3/1, indicating that EPC was attached to PVA every 444 repeating units of vinyl alcohol. An aqueous solution of PVA‐EPC (5%, w/v) became a semi‐solid hydrogel by the irradiation of a light (λ = 365 nm; 400 W) for 1 hr. The dimerization degree of EPC residues of the hydrogel decreased and increased in a periodical manner under the cyclic irradiation between two UV lights (λ = 365 nm and λ = 254 nm). The release of 5(6)‐carboxyfluorescein (CF) from PVA‐EPC hydrogel was significantly enhanced by the 5 min‐irradiation of λ = 254 nm (6 W), possibly due to the photodedimerization of EPC residues of the hydrogel. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
ChemInform Abstract: Two‐Dimensional Nanocrystals Produced by Exfoliation of Ti3AlC2.
Authors: Naguib Michael , Kurtoglu Murat , Presser Volker , Lu Jun , Niu Junjie , Heon Min , Hultman Lars , Gogotsi Yury , Barsoum Michel W.
Published: December 2011

Treatment of Ti3AlC2 powders in HF (2 h) results in exfoliation and formation of two‐dimensional Ti3C2 layers with OH and/or F surface groups and conical scrolls.
Quasikristalle: Stoffe mit besonderer Struktur
Authors: Welter Kira
Published: December 2011

Der Chemie‐Nobelpreis des Jahres 2011 geht an den israelischen Wissenschaftler Dan Shechtman für die Entdeckung der Quasikristalle – außergewöhnliche Materialien mit einer Struktur, die es nach früherer Überzeugung eigentlich gar nicht geben dürfte. In solchen Feststoffen sind die Atome oder Moleküle in Mustern angeordnet, die regelmäßig erscheinen, aber sich niemals wiederholen. Da dieser einzigartige Aufbau zunächst als unmöglich galt, musste der diesjährige Nobelpreisträger vor seiner verdienten Anerkennung einen harten Kampf führen. Zu seinen schärfsten Kritikern gehörte kein geringerer als der zweifache Nobelpreisträger Linus Pauling. Doch schließlich mussten die Wissenschaftler ihre Definition von Kristallen überdenken.
A new approach for assessing offshore piles subjected to cyclic axial loading
Authors: Seidel Marc , Coronel Maria Carmen
Published: December 2011

A new requirement of the BSH (Bundesamt für Seeschifffahrt und Hydrographie, the regulatory authority for offshore wind farms in Germany), is the assessment of the effect of cyclic loading on the capacity of foundations supporting offshore wind turbines. There are few practical design methods until now. This paper presents a new approach for assessing offshore piles subjected to cyclic axial loading, which combines two known methods, the approach for static loading as developed by the Imperial College of London (termed ICP approach) and a load‐transfer‐approach as incorporated in software “RATZ” for cyclic loading. Results using this method are compared against tests performed for the Health & Safety Executive (HSE) in Dunkirk and very good agreement is found.

Ein neuer Ansatz für die Bemessung axial‐zyklisch belasteter Pfähle von Offshore‐Konstruktionen. Es ist eine Anforderung des BSH, dass die Wirkung zyklischer Belastung auf die Tragfähigkeit von Fundamenten von Offshore‐Windenergieanlagen beurteilt wird. Bisher sind praktisch anwendbare Bemessungsmethoden selten. In diesem Beitrag wird ein neuer Ansatz vorgestellt, der zwei bekannte Methoden kombiniert, die ICP‐Methode für die statische Belastung und ein Ansatz über Last‐Verschiebungskurven für zyklische Belastung. Ergebnisse, die mit dieser Methode erzielt werden, werden mit Versuchen verglichen, die für die HSE in Dünkirchen durchgeführt wurden, und eine sehr gute Übereinstimmung wird festgestellt.
Infiltrating monocytes versus resident kupffer cells: Do alternatively activated macrophages need to be targeted alternatively?
Authors: Tacke Frank , Kurts Christian , Kowdley Kris , McCaughan Geoffrey , Trautwein Christian
Published: December 2011

A defining feature of inflammation is the accumulation of innate immune cells in the tissue that are thought to be recruited from the blood. We reveal that a distinct process exists in which tissue macrophages undergo rapid in situ proliferation in order to increase population density. This inflammatory mechanism occurred during T helper 2 (TH2)-related pathologies under the control of the archetypal TH2 cytokine interleukin-4 (IL-4) and was a fundamental component of TH2 inflammation because exogenous IL-4 was sufficient to drive accumulation of tissue macrophages through self-renewal. Thus, expansion of innate cells necessary for pathogen control or wound repair can occur without recruitment of potentially tissue-destructive inflammatory cells. (Hepatology 2011)
Enhancing agricultural productivity and rural incomes through sustainable use of natural resources in the Semi Arid Tropics
Authors: Wani Suhas P , Dixin Yin , Li Zhong , Dar William D , Chander Girish
Published: December 2011

BACKGROUND: A participatory watershed management approach is one of the tested, sustainable and eco‐friendly options to upgrade rain‐fed agriculture to meet growing food demand along with additional multiple benefits in terms of improving livelihoods, addressing equity issues and biodiversity concerns.

RESULTS: Watershed interventions at study sites in Thailand (Tad Fa and Wang Chai) and India (Kothapally) effectively reduced runoff and the associated soil loss. Such interventions at Xiaoxincun (China) and Wang Chai improved groundwater recharging and availability. Enhanced productive transpiration increased rainwater use efficiency for crop production by 13–29% at Xiaoxincun; 13–160% at Lucheba (China), 32–37% at Tad Fa and 23–46% at Wang Chai and by two to five times at Kothapally. Watershed interventions increased significantly the additional net returns from crop production as compared with the pre‐watershed intervention period. Increased water availability opened up options for crop diversification with high‐value crops, including increased forage production and boosted livestock‐based livelihoods.

CONCLUSION: In dryland tropics, integrated watershed management approach enabled farmers to diversify the systems along with increasing agricultural productivity through increased water availability, while conserving the natural resource base. Household incomes increased substantially, leading to improved living and building the resilience of the community and natural resources. Copyright © 2011 Society of Chemical Industry
A Novel Generalized 3D‐QSAR Model of Camptothecin Analogs
Authors: Bacilieri Magdalena , Paoletta Silvia , Basili Serena , Fanton Marco , Moro Stefano
Published: December 2011

In the present paper, we are interested to explore if the application of docking‐driven conformational analysis could increase the goodness of 3D‐QSAR statistical models, as alternative approach to a conventional ligand‐based conformer generation. In particular, we have selected as peculiar key‐study an ensemble of Camptothecin (CPT) analogs classified as human DNA Topoisomerase I (Top1) selective inhibitors. The CPT analogs dataset has been recently analyzed by Hansch and Verma using a classical 2D‐QSAR study.
Identification and Application of Antitarget Activity Hotspots to Guide Compound Optimization
Authors: Hessler Gerhard , Matter Hans , Schmidt Friedemann , Giegerich Clemens , Wang Li‐hsing , Güssregen Stefan , Baringhaus Karl‐Heinz
Published: December 2011

The optimization of a lead structure to a development candidate often requires removal of undesirable antitarget activities. To this end, we have developed an approach to extract antitarget activity hotspots from larger databases and to transfer this knowledge onto novel chemical series. These antitarget activity hotspots will be captured as pairs of informative molecules, which are chemically closely related, but differ significantly in biological activity. We illustrate the application of antitarget activity hotspots as informative compound pairs for the optimization of side effects in lead structures for relevant antitargets in pharmaceutical research. The use for prospective design requires establishing a structural link between known antitarget hotspot pairs and a new lead structure: we employ 3D‐based similarity comparison for this task. The entire workflow serves as idea generator in early optimization. The feasibility of this approach is demonstrated in several optimization problems related to hERG inhibition, and CYP3A4 inhibition. Several structural examples demonstrate the ability of the 3D‐shape searching to identify related scaffolds and the usefulness of the antitarget hotspot information to guide optimization by modulating the undesirable antitarget activity. Such a concept based on the analysis of local similarities and the transfer to 3D‐related series is especially promising in those cases, where the construction of antitarget QSAR models fails to detect local SAR trends for guiding the next optimization cycle.
The effect of hydroxyspiro‐orthocarbonates on the cationic photopolymerization of an epoxy resin and on the mechanical properties of the final polymer
Authors: Ortiz Ricardo Acosta , Savage Gomez Amy Grace , Duarte María Lydia Berlanga , Sangermano Marco
Published: December 2011

It is well known that bicyclic compounds like spiro‐orthocarbonates (SOCs) have the ability to reduce or eliminate the shrinkage produced during polymerization. In the work reported, four different SOCs were prepared, two of them with one and two hydroxyl groups, respectively, another with two alkoxy groups and one reference compound without substituents. It was found that the SOCs with hydroxyl groups increased the photopolymerization rate and conversion of an epoxycycloaliphatic monomer, while the compound with butoxy groups had an antagonistic effect, reducing both photopolymerization rate and conversion, due to the basic character of the ether groups. The reference compound did not display accelerating effects but it did increase slightly the conversion. Dynamic mechanical analysis revealed that the SOC with two hydroxyl groups increased the values of storage modulus of the obtained polymer in comparison with the polymer from pristine monomer. This may be due to the multifunctionality of this compound that induced a higher level of crosslinking, while the SOC with one hydroxyl group had the opposite effect, decreasing the viscoelastic property values of the polymer due to chain‐transfer reactions originated by the hydroxyl groups. The SOC with two hydroxyl groups was the more efficient of the studied compounds in reducing the shrinkage of the cured polyether. Copyright © 2011 Society of Chemical Industry
Meteorology, Topography and Snowpack Conditions causing Two Extreme Mid‐Winter Slush and Wet Slab Avalanche Periods in High Arctic Maritime Svalbard
Authors: Eckerstorfer M. , Christiansen H. H.
Published: December 2011

Mid‐winter wet avalanche cycles in High Arctic Svalbard occurred during January 2010 and March 2011, allowing studies of slush and wet slab avalanche deposits. Both cycles represented extreme events in magnitude and frequency and were caused by the passage of low‐pressure atmospheric systems with positive air temperatures, high wind speeds and 100‐year record monthly rainfall. Slush avalanches were confined to river‐cut gorges, with low starting‐zone inclinations, and deposits consisting of flow lobes and levées. Wet slab avalanches were not confined topographically, started anywhere on open mountain slopes and displayed tongue‐shaped debris deposits. During both of the two wet avalanche periods analysed, snowpack conditions favoured the release of slush avalanches, as the snowpack consisted of a coarse‐grained middle section above a water‐impermeable ice layer. Such snowpack conditions are typical for central Svalbard. The resulting slush and wet slab avalanches were extreme in their size and runout distances, crossing frequently used snowmobile tracks at 20 locations and posing a threat to traffic and infrastructure. Four additional potential large‐scale slush avalanche periods were identified from analysis of the meteorological record from Longyearbyen (1912–2011). They cluster in the mid to early 1990s, with comparable meteorological conditions to the January 2010 and March 2011 wet avalanche cycles. It is concluded that the frequency and duration of low‐pressure weather systems are the dominant controls on wet snow avalanches, and that mean snow season air temperature (October–May) is of little importance. Copyright © 2011 John Wiley & Sons, Ltd.
Semiconductor nanorod layers aligned through mechanical rubbing
Authors: Amit Yorai , Faust Adam , Lieberman Itai , Yedidya Lior , Banin Uri
Published: December 2011

Large‐scale lateral alignment of nanorods (NRs) is of interest for manifestation of their anistropic properties including polarized emission and directional electrical transport. This study investigates the utility of mechanical rubbing for macroscopic scale alignment of colloidal semiconductor NRs. CdSe/CdS seeded‐rods, exhibiting linearly polarized emission, are aligned by mechanical rubbing of a spin‐coated glass substrate. The dragging force exerted by the rubbing fibers results in deflection and reorientation of the NRs along the rubbing direction. The rubbed samples were characterized by various methods including absorption, polarized emission, optical fluorescence microscopy, atomic force microscopy, and ultra‐high resolution scanning electron microscopy. The emission polarization contrast ratio (CR), defined as the ratio between emission intensities parallel and perpendicular to the rubbing direction, was used to characterize the rods alignment. The effects of substrate treatments on the CR were studied, showing that partially hydrophobic surface provides optimal conditions for alignment. Excess organic ligands added to the deposited NR solution strongly affect the extent of alignment. This was studied for a series of NR samples of different dimensions and an optimal additive ratio of ∼3 ligand molecules per 1 nm2 NR surface area was found to yield the highest CR. Average CR values of 3.5 were detected over the entire 6 cm2 substrate area, with local values exceeding 4.5. While samples of rubbed spherical quantum dots and spin‐coated films of NRs show no emission polarization, the emission intensity from rubbed NR samples is polarized obeying Malus' law (wherein, the intensity is proportional to cos2(θ)). Mechanical rubbing, well known for its use in LC devices, may be considered as a method for large‐scale alignment of NRs on substrates.
Adverse Outcomes in Patients with Postoperative Ascites after Liver Resection for Hepatocellular Carcinoma
Authors: Chan Kun‐Ming , Lee Chen‐Fang , Wu Ting‐Jung , Chou Hong‐Shiue , Yu Ming‐Chin , Lee Wei‐Chen , Chen Miin‐Fu
Published: December 2011

Background

Postoperative ascites (POA) is a common complication after liver resection (LR). The aim of the present study was to identify the risk factors for developing POA and to evaluate its clinical significance in the prognosis of patients with hepatocellular carcinoma (HCC).

Methods

We performed a retrospective analysis of data obtained from 651 patients who underwent LR for the treatment of HCC between January 2001 and July 2005. The patients selected for the study were categorized and analyzed on the basis of the presence or absence of POA.

Results

Overall, 166 (25.5%) patients developed POA. A multivariate logistic regression analysis identified that five significant factors—cirrhotic liver, high indocyanine green retention, portal hypertension, hypoalbuminemia, and extent of LR—were associated with the development of POA. The recurrence‐free survival and overall survival of patients with POA were significantly lower than those of patients without POA. The 5‐year recurrence‐free survival rates of patients with intractable POA over those of patients without POA were 31.7% versus 36.1%, and the corresponding 5‐year overall survival rates were 17.4% versus 57.0%. The relative risk of mortality within 1 year in patients with POA was 2.4 times (95% confidence interval, 1.76–3.27; p < 0.001) higher than that in patients without POA.

Conclusions

A nomogram for predicting the probability of POA after LR for HCC was constructed on the basis of the identified risk factors, which may be used for risk‐stratifying patients who may or may not benefit from surgical resection. Because patients with POA after LR show a high incidence of HCC recurrence and mortality risk, those with intractable ascites should be considered for prompt liver transplantation.
Potential risk factors for the reactivation of the replication of hepatitis B and C viruses after transcatheter arterial chemoembolization of hepatocellular carcinoma
Authors: Lin Chia‐I. , Lin Zu‐Yau , Hsieh Ming‐Yen , Huang Chung‐Feng , Chen Su‐Hwei , Chuang Wan‐Long
Published: December 2011

The purpose of this study was to investigate the potential risk factors for the reactivation of the replication of hepatitis B virus (HBV) and hepatitis C virus (HCV) after transcatheter arterial chemoembolization (TACE) of hepatocellular carcinoma. Forty‐four hepatocellular carcinoma patients treated by TACE using epirubicin plus mitomycin C were studied. Serum HBV DNA (n = 17) and HCV RNA (n = 27) levels were measured 1 day before and 3 months after TACE. Plasma concentrations of chemotherapeutic agents were determined at 1 hour and 72 hours after TACE. A total of 29 patients (n = 13 for chronic hepatitis Band n = 16 for chronic hepatitis C) showed significant changes of the viral loads after TACE. Patients with increased viral loads after TACE were older (p = 0.041), had higher incidence of pre‐TACE white blood cell counts being less than normal limit (p = 0.023), and had higher plasma mitomycin C concentrations (p = 0.039) than those in patients with decreased viral loads. Analysis by multiple logistic regressions using age, decreased or normal pre‐TACE white blood cell counts, mitomycin C concentrations >3.95 ng/mL adopted by receiver operating characteristic curve (p = 0.037), and epirubicin concentrations have shown that decreased pre‐TACE white blood cell counts was the only significant factor associated with increased viral loads after TACE (p = 0.048). In conclusion, patients with decreased pre‐TACE white blood cell counts have a potential risk for the reactivation of the replication of HBV or HCV after TACE.
Structure and stability of hollow vortex equilibria
Authors: Llewellyn Smith Stefan G. , Crowdy Darren G.
Published: December 2011

This paper considers the structure and linear stability of two-dimensional hollow vortex equilibria. Equilibrium solutions for a single hollow vortex in linear and nonlinear straining flows are derived in analytical form using free streamline theory. The linear stability properties of this solution class are then determined numerically and a new type of resonance-induced displacement instability is identified. It is found to be a consequence of the fact that one of the shape distortion modes of a circular hollow vortex has the same frequency as one of the modes corresponding to displacement of the vortex centroid. The instability is observed in the case of an isolated hollow vortex situated in straining flow of order three. We also revisit the hollow vortex row solution due to Baker, Saffman & Sheffield (J. Fluid Mech., vol. 74, 1976, p. 1469), and since it is currently lacking in the literature, we present a full linear stability analysis of this solution using Floquet analysis.
A large foodborne outbreak of norovirus in diners at a restaurant in England between January and February 2009
Authors: SMITH A. J. , McCARTHY N. , SALDANA L. , IHEKWEAZU C. , McPHEDRAN K. , ADAK G. K. , ITURRIZA-GÓMARA M. , BICKLER G. , O'MOORE É.
Published: December 2011

An outbreak of gastroenteritis affected at least 240 persons who had eaten at a gourmet restaurant over a period of 7 weeks in 2009 in England. Epidemiological, microbiological, and environmental studies were conducted. The case-control study demonstrated increased risk of illness in those who ate from a special ‘tasting menu’ and in particular an oyster, passion fruit jelly and lavender dish (odds ratio 7·0, 95% confidence interval 1·1–45·2). Ten diners and six staff members had laboratory-confirmed norovirus infection. Diners were infected with multiple norovirus strains belonging to genogroups I and II, a pattern characteristic of molluscan shellfish-associated outbreaks. The ongoing risk from dining at the restaurant may have been due to persistent contamination of the oyster supply alone or in combination with further spread via infected food handlers or the restaurant environment. Delayed notification of the outbreak to public health authorities may have contributed to outbreak size and duration.
The Kuroshio nutrient stream and its temporal variation in the East China Sea
Authors: Guo Xinyu , Zhu Xiao‐Hua , Wu Qing‐Song , Huang Daji
Published: December 2011

Using in situ data from 88 cruises from 1987 to 2009 in the East China Sea, downstream nutrient flux (the product of velocity and nutrient concentration) and nutrient transport (integration of flux over a section) by Kuroshio were examined. The presence of a maximum nutrient flux core in the middle layer was confirmed. Seasonal variation in the nutrient flux was not significant and was much smaller than interannual variations. The change in the Kuroshio speed and current structure were major causes for interannual variations in the nutrient flux. The downstream nitrate transport by the Kuroshio in the East China Sea had a mean value of 170.8 kmol s−1 and a standard deviation of 41.6 kmol s−1. The mean seasonal nitrate transport ranged between about 161 and 177 kmol s−1 and the absolute interannual variation from about 100 to 280 kmol s−1. The phosphate flux and phosphate transport can be approximately estimated by the ratio (13.64) of nitrate concentration to phosphate concentration. The nitrate concentration in the middle and bottom layers across the Kuroshio in the East China Sea was found to increase significantly over the 23 year period, and especially after 2004 but not at ratios with oxygen that suggest increased remineralization of organic matter. The nutrient transport, however, did not increase significantly because increases in the surface layer were offset by decreases in the middle and bottom layers caused by reduction in velocity in the density ranges of 26.0 to 27.2 σθ below the Kuroshio.
Oxidative stress in the haematopoietic niche regulates the cellular immune response in Drosophila
Authors: Sinenko Sergey A , Shim Jiwon , Banerjee Utpal
Published: December 2011

Oxidative stress induced by high levels of reactive oxygen species (ROS) is associated with the development of different pathological conditions, including cancers and autoimmune diseases. We analysed whether oxidatively challenged tissue can have systemic effects on the development of cellular immune responses using Drosophila as a model system. Indeed, the haematopoietic niche that normally maintains blood progenitors can sense oxidative stress and regulate the cellular immune response. Pathogen infection induces ROS in the niche cells, resulting in the secretion of an epidermal growth factor‐like cytokine signal that leads to the differentiation of specialized cells involved in innate immune responses.
The return of the phage
Authors: Hunter Philip
Published: December 2011

Phages have been used to treat infectious diseases since their discovery nearly a century ago. Modern sequencing and genetic engineering technologies now enable researchers to vastly expand the use of phages as general drug delivery vehicles.
Denitrification likely catalyzed by endobionts in an allogromiid foraminifer
Authors: Bernhard Joan M , Edgcomb Virginia P , Casciotti Karen L , McIlvin Matthew R , Beaudoin David J
Published: December 2011

Nitrogen can be a limiting macronutrient for carbon uptake by the marine biosphere. The process of denitrification (conversion of nitrate to gaseous compounds, including N2 (nitrogen gas)) removes bioavailable nitrogen, particularly in marine sediments, making it a key factor in the marine nitrogen budget. Benthic foraminifera reportedly perform complete denitrification, a process previously considered nearly exclusively performed by bacteria and archaea. If the ability to denitrify is widespread among these diverse and abundant protists, a paradigm shift is required for biogeochemistry and marine microbial ecology. However, to date, the mechanisms of foraminiferal denitrification are unclear, and it is possible that the ability to perform complete denitrification is because of the symbiont metabolism in some foraminiferal species. Using sequence analysis and GeneFISH, we show that for a symbiont-bearing foraminifer, the potential for denitrification resides in the endobionts. Results also identify the endobionts as denitrifying pseudomonads and show that the allogromiid accumulates nitrate intracellularly, presumably for use in denitrification. Endobionts have been observed within many foraminiferal species, and in the case of associations with denitrifying bacteria, may provide fitness for survival in anoxic conditions. These associations may have been a driving force for early foraminiferal diversification, which is thought to have occurred in the Neoproterozoic era when anoxia was widespread.
Electronic structure of silicon oxynitride: Ab-initio and experimental study, comparison with silicon nitride
Authors: Nekrashevich S. S. , Gritsenko V. A.
Published: December 2011

Amorphous silicon oxide SiO2, silicon nitride Si3N4, and silicon oxynitride SiOxNy are three key dielectrics in silicon devices. Implementation of nitrided oxide (oxynitride SiOxNy) as a gate dielectric in metal-oxide-semiconductor field effect transistors has been shown to significantly improve the reliability and lifetime of devices. Also, amorphous oxynitride is used as a tunnel dielectric in nonvolatile flash memory devices. The present paper is devoted to the experimental and theoretical study of silicon oxynitride electronic structure. The ionic formula of crystalline Si2N2O is deduced from the first principles. Effective masses of charge carriers in Si2N2O are calculated and compared with experimental data on tunnel injection in amorphous SiNxOy samples. Also experimental x-ray absorption and emission spectra are compared with the theoretically calculated ones.
Quantum cutting mechanism in Tb3+-Yb3+ co-doped oxyfluoride glass
Authors: Duan Qianqian , Qin Feng , Wang Dan , Xu Wei , Cheng Jianmin , Zhang Zhiguo , Cao Wenwu
Published: December 2011

Rate equations were created to describe cooperative quantum cutting phenomena, which incorporated the interactions between donor Tb3+ and acceptor Yb3+ ions. Two judgment criteria were developed for the excitation power dependence and time-resolved luminescence spectra of donor and acceptor ions, which can be used to verify the proposed mechanism. Under the excitation of a 473 nm continuous wave laser, the emission intensities of Tb3+ and Yb3+ increased linearly with the excitation power. The decay curve of Yb3+ indicated two distinct contributions: the fast decay time of its own lifetime, and the slow decay time representing the lifetime of the 5D4 energy level of Tb3+. The experimental results meet the two judgment criteria, which confirmed the proposed cooperative quantum cutting mechanism in Tb3+-Yb3+ co-doped oxyfluoride glass.
Numerical analysis of a multi-symplectic scheme for the time-domain Maxwell's equations
Authors: Wang Yushun , Jiang Juan , Cai Wenjun
Published: December 2011

In this paper, we analyze qualitative properties of the first multi-symplectic scheme for two-dimensional Maxwell's equations. We prove that the scheme is unconditionally stable and convergent, non-dissipative, and divergence-free. The numerical dispersion relation of the scheme is shown to converge to the exact dispersion relation of the Maxwell equations. We also present some numerical results to confirm our theoretical results.
Forcing mechanisms of dielectric barrier discharge plasma actuators at carrier frequency of 625 Hz
Authors: Kotsonis M. , Ghaemi S.
Published: December 2011

The forcing behavior of a dielectric barrier discharge (DBD) actuator is investigated experimentally using a time-resolved particle image velocimetry (PIV) system in conjunction with a phase shifting technique. The spatio-temporal evolution of the induced flowfield is accurately captured within one high voltage (HV) cycle allowing the calculation of the instantaneous velocity and acceleration. Additional voltage and current measurements provide the power consumption for each case. Four different applied voltage waveform shapes are independently tested, namely, sine, square, positive sawtooth, and negative sawtooth at fixed applied voltage (10 kVpp) and carrier frequency (625 Hz). The instantaneous flowfields reveal the effect of the plasma forcing during the HV cycle. Sine waveform provides large positive forcing during the forward stroke, with minimal but still positive forcing during the backward stroke. Square waveform provides strong and concentrated positive and negative forcing at the beginning of the forward and backward stroke, respectively. Positive sawtooth provides positive but weak forcing during both strokes while the negative sawtooth case produces observable forcing only during the forward stroke. Results indicate the inherent importance of negative ions on the force production mechanisms of DBD’s. Furthermore, the revealed influence of the waveform shape on the force production can provide guidelines for the design of custom asymmetric waveforms for the improvement of the actuator’s performance.
Surface effects on the wrinkling of piezoelectric films on compliant substrates
Authors: Li Yuhang , Fang Bo , Zhang Jiazhong , Song Jizhou
Published: December 2011

The wrinkling of piezoelectric films on compliant substrates suggests new applications that require integration with curvilinear surface of human body for energy harvesting or health monitoring. In this paper, surface effects including surface elasticity, surface piezoelectricity, and residual surface stress on the wrinkling of piezoelectric films are studied. The wavelength, critical wrinkling voltage, and amplitude are obtained analytically. It is shown that surface effects play a significant role on the wrinkling of piezoelectric films when the thickness is on nanoscale. These results are very helpful for designing and controlling of the wrinkling profile in the new piezoelectric applications.
Room temperature mid-infrared surface-emitting photonic crystal laser on silicon
Authors: Weng Binbin , Ma Jiangang , Wei Lai , Li Lin , Qiu Jijun , Xu Jian , Shi Zhisheng
Published: December 2011

We demonstrate a mid-infrared surface-emitting photonic crystal laser on silicon substrate operating at room temperature. The active region consisting of PbSe/PbSrSe multiple quantum wells was grown by molecular beam epitaxy on Si(111) substrate patterned with a photonic crystal (PC) array. The PC array forms a transverse magnetic polarized photonic bandgap at around 2840 cm−1. Under pulsed optical pumping, room temperature multimode lasing emissions were observed at wavelength ∼3.5 μm with estimated threshold peak pumping intensity of 24 kW/cm2. Angular-dependent measurement indicates the lasing is of a Gaussian-like profile with full width at half maximum of 4.66°.
Anisotropy of electron and hole g-factors in (In,Ga)As quantum dots
Authors: Schwan A. , Meiners B.-M. , Greilich A. , Yakovlev D. R. , Bayer M. , Maia A. D. B. , Quivy A. A. , Henriques A. B.
Published: December 2011

The g-factor tensors of electron and hole in self-assembled (In,Ga)As/GaAs quantum dots are studied by time-resolved ellipticity measurements in a three dimensional vector magnet system. Both g-factor tensors show considerable deviations from isotropy. These deviations are much more pronounced for the hole than for the electron and are described by different anisotropy factors, which can even have opposite signs.