bluuebunny/crossref_metadata_2025 huggingface dataset:
Marital Status and Outcome of Patients Presenting with Acute Coronary Syndrome: An Observational Report
Authors: Hadi Khafaji Hadi A.R. , Al Habib Khalid , Asaad Nidal , Singh Rajvir , Hersi Ahmad , Falaeh Husam Al , Saif Shukri Al , Al‐Motarreb Ahmed , Almahmeed Wael , Sulaiman Kadhim , Amin Haitham , Al‐Lawati Jawad , Al‐Sagheer Norah Q. , Alsheikh‐Ali Alawi A. , Al Suwaidi Jassim
Published: June 2012

Background & hypothesis:

Data on the clinical characteristics and outcome of patients presenting with acute coronary syndrome (ACS) according to their marital status is not clear.

Methods:

A total of 5334 patients presenting with ACS in 65 hospitals in 6 Middle East countries in the 2nd Gulf Registry of Acute Coronary Events (Gulf RACE‐2) were studied according to their marital status (5024 married, 100 single, and 210 widowed patients).

Result:

When compared to married patients, widowed patients were older and more likely to be female. Widowed patients were more likely to have diabetes mellitus, hypertension, history of heart failure, and peripheral vascular disease and were less likely to be tobacco users when compared to the other groups. Widowed patients were also more likely to present with atypical symptoms and have advanced Killip class. Widowed patients were more likely to present with non‐ST‐elevation myocardial infarction (NSTEMI) when compared to the other 2 groups. Widowed patients were more likely to have heart failure (P = 0.001), cardiogenic shock (P = 0.001), and major bleeding (P = 0.002) when compared to the other groups. No statistically significant difference was observed in regard to duration of hospital stay, door to needle time in STEMI patients, or cardiac arrhythmias between the various groups. Widowed patients had higher in‐hospital, 30‐day, and 1‐year mortality rates (P = 0.001). Marital status was an independent predictor for in‐hospital mortality.

Conclusion:

Widowed marital status was associated with worse cardiovascular risk profile, and worse in‐hospital and 1‐year outcome. Future work should be focused on whether the provision of psychosocial support will result in improved outcomes among this high‐risk group. Clin. Cardiol. 2011 DOI: 10.1002/clc.22034

Gulf RACE is a Gulf Heart Association (GHA) project and was financially supported by the GHA, Sanofi Aventis, and the College of Medicine Research Center at King Khalid University Hospital, King Saud University, and Riyadh, Saudi Arabia.

The authors have no other funding, financial relationships, or conflicts of interest to disclose.
Mechanisms of cytokinesis in budding yeast
Authors: Wloka Carsten , Bi Erfei
Published: June 2012

Cytokinesis is essential for cell proliferation in all domains of life. Because the core components and mechanisms of cytokinesis are conserved from fungi to humans, the budding yeast Saccharomyces cerevisiae has served as an attractive model for studying this fundamental process. Cytokinesis in budding yeast is driven by two interdependent cellular events: actomyosin ring (AMR) constriction and the formation of a chitinous cell wall structure called the primary septum (PS), the functional equivalent of extracellular matrix remodeling during animal cytokinesis. AMR constriction is thought to drive efficient plasma membrane ingression as well as to guide PS formation, whereas PS formation is thought to stabilize the AMR during its constriction. Following the completion of the PS formation, two secondary septa (SS), consisting of glucans and mannoproteins, are synthesized at both sides of the PS. Degradation of the PS and a part of the SS by a chitinase and glucanases then enables cell separation. In this review, we discuss the mechanics of cytokinesis in budding yeast, highlighting its common and unique features as well as the emerging questions. © 2012 Wiley Periodicals, Inc.
Phase 2 study of everolimus monotherapy in patients with nonfunctioning neuroendocrine tumors or pheochromocytomas/paragangliomas
Authors: Oh Do‐Youn , Kim Tae‐Won , Park Young Suk , Shin Sang Joon , Shin Seong Hoon , Song Eun‐Kee , Lee Hyo Jin , Lee Kewn‐wook , Bang Yung‐Jue
Published: June 2012

BACKGROUND:

The current study was conducted to evaluate the efficacy and safety of everolimus in the treatment of patients with nonfunctioning neuroendocrine tumors (NETs) or pheochromocytomas/paragangliomas.

METHODS:

Patients with histologically confirmed nonfunctioning NETs or pheochromocytomas/paragangliomas and with documented disease progression before study enrollment were eligible for the current study. Everolimus was administered daily at a dose of 10 mg for 4 weeks. Response was assessed by Response Evaluation Criteria In Solid Tumors (RECIST; version 1.0) every 8 weeks. The primary endpoint was the 4‐month progression‐free survival rate (PFSR). The hypothesis of the current study was that the 4‐month PFSR would increase from 50% to 65%. Safety was evaluated using the National Cancer Institute's Common Terminology Criteria for Adverse Events (version 3.0).

RESULTS:

A total of 34 patients were enrolled. Of these, 27 patients had nonfunctioning NETs, 5 had pheochromocytomas, and 2 had paragangliomas. The 4‐month PFSR was 78%. Partial response (PR) was observed in 3 patients. Twenty‐eight patients had stable disease (SD) and 2 patients developed progressive disease (PD). The response rate (RR) and overall disease control rate (DCR) were 9.0% (95% confidence interval [95% CI], 0%‐18.6%) and 93.9% (95% CI, 85.8%‐100%), respectively. The PFS was 15.3 months (95% CI, 4.6 months‐26.0 months). Of the patients with nonfunctioning NETs, 3 achieved a PR and 23 had SD (RR, 11.1%; DCR, 100%); the PFS was 17.1 months (95% CI, 11.1 months‐23.0 months) and the 4‐month PFSR was 90.0%. Twenty‐one patients (80.8%) demonstrated tumor shrinkage. In 7 patients with pheochromocytomas/paragangliomas, 5 achieved SD, and 2 developed PD. The PFS was 3.8 months (95% CI, 0.5 months‐7.0 months) and the 4‐month PFSR was 42.9%. Four patients demonstrated tumor shrinkage. The major grade 3/4 adverse events were thrombocytopenia (14.7%), hyperglycemia (5.9%), stomatitis (5.9%), and anemia (5.9%).

CONCLUSIONS:

Everolimus was associated with high therapeutic efficacy and tolerability in patients with nonfunctioning NETs, and demonstrated modest efficacy in patients with pheochromocytomas/paragangliomas. Cancer 2012. © 2012 American Cancer Society.
Incorporating information regarding preimplantation genetic diagnosis into discussions concerning testing and risk management for BRCA1/2 mutations
Authors: Hurley Karen , Rubin Lisa R. , Werner‐Lin Allison , Sagi Michal , Kemel Yelena , Stern Rikki , Phillips Aliza , Cholst Ina , Kauff Noah , Offit Kenneth
Published: June 2012

BACKGROUND:

Studies have shown that BRCA1/2 mutation carriers are interested in learning about reproductive options such as preimplantation genetic diagnosis (PGD) to prevent passing their risk onto their children. However, attitudes vary widely, and the procedure raises complex ethical and psychosocial issues. This complexity, plus the highly technical nature of PGD, makes it difficult to integrate PGD information into genetic counseling sessions that already cover probabilistic, emotionally charged risk information.

METHODS:

A total of 33 carriers of the BRCA1/2 mutation who were of reproductive age and had previously undergone genetic counseling viewed a tutorial regarding PGD and were interviewed concerning their attitudes toward PGD and preferences about how to include PGD information in genetic counseling.

RESULTS:

The majority of participants preferred to be briefly informed of the availability of PGD information, and to receive written materials regarding PGD, but with the option of deferring detailed discussion if they already believed themselves to be overloaded or perceived that PGD was not immediately relevant to their risk management and/or childbearing plans. For some individuals, the stress of testing temporarily interfered with information processing, producing states of cognitive avoidance (“in a fog,” or “tuning out”). Some preferred to discuss PGD with a physician with whom they had an ongoing relationship (eg, obstetrician/gynecologist, primary care provider, or oncologist).

CONCLUSIONS:

Providers offering cancer genetic testing may consider indicating the availability of PGD information to their patients, while attending to the patients' level of interest and ability to absorb information. Research is needed to link patient responses to information overload with psychosocial outcomes (eg, distress, and quality of decision‐making). Continuing medical education is needed to support providers in facilitating informed decisions regarding PGD. Cancer 2012. © 2012 American Cancer Society.
Prognostic value of the Follicular Lymphoma International Prognostic Index score in marginal zone lymphoma
Authors: Heilgeist Andreas , McClanahan Fabienne , Ho Anthony D. , Witzens‐Harig Mathias
Published: June 2012

BACKGROUND:

In marginal zone lymphoma (MZL), clinical and follow‐up data on large cohorts of patients are difficult to obtain. The objective of this single‐center, retrospective analysis of a large cohort of 144 patients with MZL was to elucidate the role of prognostic markers, treatments, and outcomes in this disease.

METHODS:

In total, 144 patients were identified who were diagnosed with MZL at the authors' institution between 2003 and 2010. Data on clinical parameters, treatments, response, and survival were analyzed. In addition, the validity of the International Prognostic Index (IPI) and Follicular Lymphoma International Prognostic Index (FLIPI) prognostic scores were tested in patients with MZL.

RESULTS:

Among 144 patients with MZL, 96 patients (67%) had extralymph node (extranodal) MZL, 32 patients (22%) had lymph node (nodal) MZL, and 16 patients (11%) had splenic MZL. The 5‐year progression‐free survival rate was 82% in the nodal MZL group, 88% in the extranodal MZL group, and 74% in the splenic MZL group and did not different between the 3 groups (P = .60). The 5‐year overall survival rate was excellent in all 3 MZL groups (nodal MZL, 89%; extranodal MZL, 92%; splenic MZL, 82%; P = .46). In our cohort, the FLIPI score was a significant prognostic marker: The 5‐year progression‐free survival rate for patients who had FLIPI scores of 0 to 2 (low or intermediate risk) was excellent at 92%, whereas it was only 62% for patients who had FLIPI scores of 3 to 5 (poor risk; P = .003). Similarly, the 5‐year overall survival rate for patients who had FLIPI scores of 0 to 2 was 95%, whereas it was only 62% for patients who had FLIPI scores of 3 to 5 (P = .0009).

CONCLUSIONS:

The FLIPI score had strong prognostic value in patients with MZL. Patients who have low‐risk or intermediate‐risk FLIPI scores have an excellent prognosis, whereas patients with poor‐risk FLIPI scores are candidates for novel treatment approaches. Cancer 2013. © 2012 American Cancer Society.
Meningeal‐like organization of neural tissues in calanoid copepods (Crustacea)
Authors: Mercier Frederic , Weatherby Tina M. , Hartline Daniel K.
Published: June 2012

Meninges, the connective tissue of the vertebrate central nervous system (CNS), have not been recognized in invertebrates. We describe the ultrastructure of the adult brain, antennules, and cord in five marine copepods: Calanus finmarchicus, Gaussia princeps, Bestiolina similis, Labidocera madurae, and Euchaeta rimana. In all of these locations we identified cell types with characteristics of the typical cells of vertebrate meninges and of their peripheral nervous system (PNS) connective tissue counterpart: fibroblasts, having flattened twisting processes with labyrinthine cavities communicating with the extracellular space, and macrophages, containing prominent lysosomes, well‐developed endoplasmic reticulum, Golgi apparatus, and indented heterochromatin. The vertebrate distinction between electron‐dense cells in the most external connective tissues (dura mater and epineurium) versus electron‐lucent cells in the more internal connective tissues (pia‐arachnoid and endoneurium‐perineurium) was also found in the copepod CNS and PNS. Similar to the vertebrate organization, electron‐dense cell networks penetrated from the outer layer (subcuticle) to surround inner substructures of the copepod nervous systems, and electron‐lucent networks penetrated deeply from the brain and nerve surfaces to form intertwined associations with neural cells. Moreover, the association of these cells with basement membranes, glycocalyx, and fibrils of collagen in copepods conforms to a meningeal organization. The primary deviation from the vertebrate ultrastructural organization was the often tight investment of axons by the meningeal‐like cells, with an intercalated basement membrane. Together, these data suggest that the tissues investing the copepod nervous system possess an organization that is analogous in many respects to that of vertebrate meninges. J. Comp. Neurol. 521:760–790, 2013. © 2012 Wiley Periodicals, Inc.
Edge‐Localized Mode Control and Transport Generated by Externally Applied Magnetic Perturbations
Authors: Joseph I.
Published: June 2012

This article reviews the subject of edge localized mode (ELM) control using externally applied magnetic perturbations and proposes theoretical mechanisms that may be responsible for the induced transport changes. The first question that must be addressed is: what is the structure of magnetic field within the plasma? Although initial hypotheses focused on the possibility of the creation of a region of stochastic field lines at the tokamak edge, drift magnetohydrodynamics theory predicts that magnetic reconnection is strongly suppressed over the region of the pedestal with steep gradients and fast perpendicular rotation. Reconnection can only occur near the location where the perpendicular electron velocity vanishes, and hence the electron impedance nearly vanishes, or near the foot of the pedestal, where the plasma is sufficiently cold and resistive. The next question that must be addressed is: which processes are responsible for the observed transport changes, nonlinearity, turbulence, or stochasticity? Over the pedestal region where ions and electrons rotate in opposite directions relative to the perturbation, the quasilinear Lorentz force decelerates the electron fluid and accelerates the ion fluid. The quasilinear magnetic flutter flux is proportional to the force and produces an outward convective transport that can be significant. Over the pedestal region where the E × B flow and the electrons rotate in opposite directions relative to the perturbation, magnetic islands with a width on the order of the ion gyroradius can directly radiate drift waves. In addition, the combination of quasilinear electron transport and ion viscous transport can lead to a large net particle flux. Since there are many transport mechanisms that may be active simultaneously, it is important to determine which physical mechanisms are responsible for ELM control and to predict the scaling to future devices (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
3D Blob Modelling with BOUT++
Authors: Angus J. R. , Umansky M. , Krasheninnikov S. I.
Published: June 2012

Plasma blobs found in the edge region of tokamaks are important to understand because they contribute to a large amount of the plasma particle transport in the SOL (scrape off layer). Most of the work to date is limited to 2D theory and simulations by ignoring the variation of blob parameters along the magnetic field line. 3D effects are examined in the electrostatic limit in this paper using the code BOUT++ by allowing for the variation of blob density and potential along the field line. It is demonstrated that the 3D variation of these parameters can lead to a Boltzmann potential relation that will cause the blob to spin and induce turbulent motion via unstable drift waves (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transport of Neutrals in Scrape‐Off Layer Plasmas: Autoregressive Beta Process to Describe Plasma Density and Temperature Fluctuations
Authors: Mekkaoui A. , Marandet Y. , Rosato J. , Capes H. , Stamm R. , Koubiti M. , Reiter D.
Published: June 2012

Improving the description of the far scrape‐off layer (SOL) in current edge code suites such as SOLPS is the subject of current efforts, given the importance of main chamber plasma wall interactions (first wall recycling and sputtering) in the design and operation of tokamaks. One of the specific features of the far SOL is the large amplitude of turbulent fluctuations. Neutral particles (atom and molecules) are affected by these fluctuations through the rates of atomic physics processes. In accordance with experimentally measured PDF (probability density function) for both the plasma density and temperature fluctuations, ne and Te are modeled using a Beta PDF. Space and time correlations are accounted for by using an autogressive process. The effects of fluctuations on the neutral atoms penetration depth, as well as on the beryllium sputtering yield are discussed (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Development of Coupled IMPGYRO‐SOLPS Codes for Analyzing Tokamak Plasmas with Tungsten Impurities
Authors: Toma M. , Bonnin X. , Hoshino K. , Hatayama A. , Schneider R. , Coster D.
Published: June 2012

For the purpose of a consistent treatment of tungsten impurity together with background plasma, coupling of the IMPGYRO and SOLPS codes has been undertaken. The fluid part of SOLPS transfers the background plasma data to the IMPGYRO kinetic impurity code, while IMPGYRO transfers the effect of tungsten impurities to SOLPS as particle, momentum and energy source/sink terms. An initial test calculation has been performed under a simple model for impurity generation. The impurity content in the system reaches a quasi‐steady state in the coupled calculation. The temporal history of the simulation shows that an initial impurity generation results in a relatively large radiation loss and plasma cooling. The cooler plasma suppresses further impurity generation, leading to a quasi‐steady state in the coupled calculation (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of the Bohm Criterion for Two‐Ion‐Species Plasmas Using PARASOL
Authors: Azuma S. , Fukuyama A. , Takizuka T.
Published: June 2012

In SOL‐divertor plasmas, a condition on the plasma flow velocity, called the Bohm criterion, is required for the formation of a stable sheath in front of a divertor plate. While, for a single‐ion species, the usual analytical procedure gives the criterion as a unique solution for the incident ion flow velocity, for two‐ion‐species plasmas the procedure results in a relation between the ion flow velocities. We carried out full particle simulations with a one‐dimensional particle code PARASOL, and clarified in detail the dependence of the condition for two‐ion‐species plasmas on collisionality and ions mass (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Plasma Convection Near the Magnetic Null of a Snowflake Divertor During an ELM Event
Authors: Ryutov D.D. , Cohen R.H. , Rognlien T.D. , Umansky M.V.
Published: June 2012

A snowflake magnetic configuration is created in a tokamak when the poloidal magnetic field and its first spatial derivatives become zero at a certain point. The separatrix then acquires a characteristic hexagonal shape reminiscent of a snowflake. We study new features of the plasma macroscopic equilibrium and stability in the vicinity of the snowflake null. We note that, compared to the standard X‐point divertor, the zone of weak poloidal magnetic field is much larger. The weak poloidal field leads to development of intense plasma convection over the expanded area around the null‐point during the ejection phase of an edge localized mode (ELM) event when the plasma pressure in the scrape‐off layer increases compared to its inter‐ELM value. Intense convection may lead to a roughly‐equal splitting of the heat flux between the 4 snowflake divertor legs and to a broadening of the plasma wetted area in each leg, thereby mitigating damage to divertor plates (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Divertor Design through Shape Optimization
Authors: Dekeyser W. , Reiter D. , Baelmans M.
Published: June 2012

Due to the conflicting requirements, complex physical processes and large number of design variables, divertor design for next step fusion reactors is a challenging problem, often relying on large numbers of computationally expensive numerical simulations. In this paper, we attempt to partially automate the design process by solving an appropriate shape optimization problem. Design requirements are incorporated in a cost functional which measures the performance of a certain design. By means of changes in the divertor shape, which in turn lead to changes in the plasma state, this cost functional can be minimized. Using advanced adjoint methods, optimal solutions are computed very efficiently. The approach is illustrated by designing divertor targets for optimal power load spreading, using a simplified edge plasma model (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Weaknesses and improvements of an efficient certificateless signature scheme without using bilinear pairings
Authors: Tsai Jia‐Lun , Lo Nai‐Wei , Wu Tzong‐Chen
Published: June 2012

The certificateless signature (CLS) scheme is a special signature scheme that solves the key escrow problem in identity‐based signature schemes. In CLS schemes, the private key is generated cooperatively by the key generator center (KGC) and signer, such that a malicious KGC cannot masquerade as the signer and sign a message. He et al. in 2011 proposed an efficient CLS scheme without using bilinear pairings. However, we discovered that the CLS scheme by He et al. cannot resist a strong type 2 adversary if this adversary replaces the master public key of the KGC. This work proposes an improved scheme that overcomes this weakness. Copyright © 2012 John Wiley & Sons, Ltd.
Boulders as building blocks: improving habitat and river connectivity for stream fish
Authors: Branco Paulo , Boavida Isabel , Santos José Maria , Pinheiro António , Ferreira Maria Teresa
Published: June 2012

Fragmentation of freshwater systems is one of the more common human‐induced impacts on the environment, and one of the most dramatic because it leads to disconnections among riverine habitats, severely affecting fish populations. To counter this form of ecological abuse, there has been a significant increase of the number of restoration actions. This work approached stream restoration from a holistic point of view, combining habitat modelling with laboratory experimental research. A 2D hydrodynamic model was used to test the increase in weighted usable area (WUA) created by different boulder placement (BP) scenarios in a disturbed site, with a widespread potamodromous cyprinid fish – the Iberian barbel (Luciobarbus bocagei) – as the target species. This was complemented by experimental trials in a full‐scale experimental fishway with different bottom substrata arrangements, in order to assess the effects of boulders on barbel movements. Results show that instream BP increases WUA for barbel and facilitates fishway negotiation. The findings reflect the importance of placing instream boulders in fragmented systems in order to enhance suitable habitat area and river connectivity. However, BP must be specifically designed for each case and should always be preceded by a comprehensive study for each site and target fish species. Copyright © 2012 John Wiley & Sons, Ltd.
Indium‐Mediated Addition of γ‐Substituted Allylic Halides to N‐Aryl α‐Imino Esters: Diastereoselective Production of β,β′‐Disubstituted α‐Amino Acid Derivatives with Two Contiguous Stereocenters
Authors: Aslam Nayyar Ahmad , Rajkumar Vadla , Reddy Chennakesava , Yasuda Makoto , Baba Akio , Babu Srinivasarao Arulananda
Published: June 2012

Chelation‐controlled Barbier‐type indium‐mediated addition of γ‐substituted allylic halides to N‐aryl (including N‐PMP) α‐imino‐ and N‐acylhydrazono esters and highly diastereoselective tailoring of functionalized γ,δ‐unsaturated β,β′‐disubstituted N‐aryl α‐amino acid derivatives, bearing two contiguous stereocenters is reported. Further N‐allylation of the resulting γ,δ‐unsaturated β,β′‐disubstituted N‐aryl amino acid derivatives followed by ring closing metathesis (RCM) led to the synthesis of 2,3‐disubstituted N‐aryltetrahydropyridine derivatives bearing two contiguous stereocenters. The stereochemistry of the key products was unequivocally established from X‐ray structure analyses.
Fluorinated Carbohydrates as Lectin Ligands: Biorelevant Sensors with Capacity to Monitor Anomer Affinity in 19F‐NMR‐Based Inhibitor Screening
Authors: André Sabine , Cañada F. Javier , Shiao Tze Chieh , Largartera Laura , Diercks Tammo , Bergeron‐Brlek Milan , el Biari Khouzaima , Papadopoulos Alex , Ribeiro Joao P. , Touaibia Mohamed , Solís Dolores , Menéndez Margarita , Jiménez‐Barbero Jesús , Roy René , Gabius Hans‐Joachim
Published: June 2012

Our recent description of pulse sequences for the intramolecular relay of 1H polarization to the 19F reporter of a carbohydrate ligand after saturation transfer from a cognate lectin prompted us to test the applicability of this technique for inhibitor screening. By strategically combining synthetic organic chemistry and cell assays with 19F‐NMR‐based competition experiments, we document the validity of this approach. Two mannose‐specific leguminous agglutinins as receptors, the α‐methyl derivative of 2‐deoxy‐2‐fluoro‐D‐mannopyranoside as sensor and synthetic mannosides selected to represent different inhibitory capacities were used to establish a test panel. Signal amplitudes were found to vary among the two related lectins, and their precipitation by glycodendrimers enabled inherent limits to be set. The obtained experimental basis was then broadened by assaying a galactopyranoside‐binding plant toxin, using 6‐deoxy‐6‐fluoro‐D‐galactopyranose as a sensor molecule. The easy identification of the two anomeric signals by 19F NMR spectroscopy enabled ready detection of the preference of this lectin for the α‐anomer and allowed the two individual inhibition profiles to be deduced. These 19F NMR spectroscopic data were in accord with the activities of inhibitors used to protect cells from toxicity. Our results therefore provide an experimental basis for 19F‐NMR‐based inhibitor screening.
On the Use of Carbon Nanotubes to Promote the Electricity Generation During Sulfate Removal
Authors: Bai Lu , Deng Liu , Liu Ling , Yong Daming , Yu Dengbin , Dong Shaojun
Published: June 2012

Carbon nanotubes (CNTs) were explored as a promoter in electron transfer during sulfate removal. The results of a potentiostatic method, cyclic voltammetry, and electrochemical impedance spectroscopy demonstrated that the CNTs modified electrode exhibited better performance (e.g. 13‐fold increase of the electricity generation) than that of bare electrodes. Due to the large specific surface area, excellent conductivity, and good biocompatibility, CNTs not only accelerated the electron transfer between electrode and biofilm, but also provided a suitable microbial environment for sulfate‐reducing bacteria immobilization. Thus, the CNTs modified electrode has great potential to be used in a high‐power microbial fuel cell for sulfate removal.
Trivalent copper chelate‐luminol chemiluminescence system for highly sensitive CE detection of dopamine in biological sample after clean‐up using SPE
Authors: Wang Lin , Liu Ying , Xie Haoyue , Fu Zhifeng
Published: June 2012

A transition metal chelate unstable at a high oxidation state, diperiodatocuprate (III) (K5[Cu(HIO6)2], DPC), was synthesized and applied in the luminol‐based chemiluminescence (CL) system for highly sensitive CE end‐column detection of dopamine (DA). This method was based on the fact that DA enhanced the CL emission resulting from the reaction between luminol and DPC in alkaline medium. The DPC‐luminol‐DA CL system showed very intensive emission and very fast kinetic characteristics, thus resulting in a high sensitivity in flow‐through detection mode for CE. Under optimal conditions, the linear range was 1.0 × 10−8–5.0 × 10−5 g/mL (R2 = 0.9984) with a limit of detection of 6.0 × 10−9 g/mL (S/N = 3). The RSDs of the peak height and the migration time were about 4.2 and 2.4% for a standard sample at 3.0 × 10−6 g/mL (n = 5), respectively. The presented method has been successfully used for the determination of DA in commercial preparation and human urine samples after clean‐up using SPE.
Electrophoresis for the analysis of heparin purity and quality
Authors: Volpi Nicola , Maccari Francesca , Suwan Jiraporn , Linhardt Robert J.
Published: June 2012

The adulteration of raw heparin with oversulfated chondroitin sulfate (OSCS) in 2007–2008 produced a global crisis resulting in extensive revisions to the pharmacopeia monographs and prompting the FDA to recommend the development of additional methods for the analysis of heparin purity. As a consequence, a wide variety of innovative analytical approaches have been developed for the quality assurance and purity of unfractionated and low‐molecular‐weight heparins. This review discusses recent developments in electrophoresis techniques available for the sensitive separation, detection, and partial structural characterization of heparin contaminants. In particular, this review summarizes recent publications on heparin quality and related impurity analysis using electrophoretic separations such as capillary electrophoresis (CE) of intact polysaccharides and hexosamines derived from their acidic hydrolysis, and polyacrylamide gel electrophoresis (PAGE) for the separation of heparin samples without and in the presence of its relatively specific depolymerization process with nitrous acid treatment.
Identification of fentanyl derivatives at trace levels with nonaqueous capillary electrophoresis‐electrospray‐tandem mass spectrometry (MSn, n = 2, 3): Analytical method and forensic applications
Authors: Rittgen Jan , Pütz Michael , Zimmermann Ralf
Published: June 2012

The identification of fentanyl derivatives at trace levels employing capillary electrophoresis coupled to electrospray ionization tandem mass spectrometry (CE‐ESI‐MSn, n = 2, 3) is presented. The studied synthetic opioid fentanyl and its derivatives have an exceeding analgesic potency which can be up to 8000 times higher that of morphine. Apart from their therapeutical applications, there is an abuse of them in the drug scene as a heroin substitute. The identification of these opioids at trace levels is of further significant forensic interest with respect to recent seizures of clandestine fentanyl laboratories in Germany. In this work, a nonaqueous capillary electrophoresis (NACE)‐ESI‐MSn procedure was developed for the separation and identification of six fentanyl derivatives including fentanyl, cis‐ and trans‐methylfentanyl, sufentanil, alfentanil, and carfentanil. Their fragmentation pattern in MSn experiments were investigated as well as the influence of the sheath‐liquid mixture and the influence of the inside diameter of the fused silica capillary on the peak shape and the signal to noise ratio. Method validation included determination of the detection limits (about 1–2 nmol/L) and the repeatability of migration time (at most 0.07% relative standard deviation). The NACE‐MS procedure was successfully applied for the analysis of real samples from seizures in illegal fentanyl laboratories.
Nonaqueous capillary electrophoresis–mass spectrometry: A versatile, straightforward tool for the analysis of alkaloids from psychoactive plant extracts
Authors: Posch Tjorben Nils , Martin Nathalie , Pütz Michael , Huhn Carolin
Published: June 2012

In this study we show that a nonaqueous capillary electrophoresis mass spectrometry (NACE‐MS) method carefully optimized by a design of experiment can be applied to a very large number of alkaloids in different plant extracts. It is possible to characterize the pattern of the psychoactive alkaloids in several plant samples and preparations thereof, each presenting different challenges in their analysis. The method is shown to be able to separate structurally closely related substances, diastereomers and further isobaric compounds, to separate members of different alkaloid classes within one run and to tolerate significant matrix load. A comparison with methods presented in the literature reveals that a near‐generic NACE‐MS method for the fast profiling of alkaloids in forensically relevant plant samples has been developed.
Separation of enantiomers of norephedrine by capillary electrophoresis using cyclodextrins as chiral selectors: Comparative CE and NMR studies
Authors: Lomsadze Ketevan , Vega Elena Domínguez , Salgado Antonio , Crego Antonio L. , Scriba Gerhard K.E. , Marina Maria Luisa , Chankvetadze Bezhan
Published: June 2012

In this study, the enantiomer migration order (EMO) of norephedrine (NEP) in the presence of various CDs was investigated by CE. NMR and CE techniques were used to analyze the mechanism of the chiral recognition between NEP enantiomers and four CDs, i.e., native α‐CD, β‐CD, heptakis(2,3‐di‐O‐acetyl‐6‐O‐sulfo)‐β‐CD (HDAS‐β‐CD), and heptakis(2,3‐di‐O‐methyl‐6‐O‐sulfo)‐β‐CD (HDMS‐β‐CD). EMO was reversed in the presence of α‐CD and β‐CD, although only minor differences in the structures of the complexes formed between NEP and these CDs could be derived from rotating frame nuclear Overhauser experiments (ROESY). The complexes between the enantiomers of NEP and the sulfated CDs, HDMS‐β‐CD, and HDAS‐β‐CD, were substantially different. However, EMO of NEP was identical in the presence of these CDs. HDAS‐β‐CD proved to be the most suitable chiral selector for the CE enantioseparation of NEP.
Microchip capillary electrophoresis instrumentation for in situ analysis in the search for extraterrestrial life
Authors: Mora Maria F. , Stockton Amanda M. , Willis Peter A.
Published: June 2012

The search for signs of life on extraterrestrial planetary bodies is among NASA's top priorities in Solar System exploration. The associated pursuit of organics and biomolecules as evidence of past or present life demands in situ investigations of planetary bodies for which sample return missions are neither practical nor affordable. These in situ studies require instrumentation capable of sensitive chemical analyses of complex mixtures including a broad range of organic molecules. Instrumentation must also be capable of autonomous operation aboard a robotically controlled vehicle that collects data and transmits it back to Earth. Microchip capillary electrophoresis (μCE) coupled to laser‐induced fluorescence (LIF) detection provides this required sensitivity and targets a wide range of relevant organics while offering low mass, volume, and power requirements. Thus, this technology would be ideally suited for in situ studies of astrobiology targets, such as Mars, Europa, Enceladus, and Titan. In this review, we introduce the characteristics of these planetary bodies that make them compelling destinations for extraterrestrial astrobiological studies, and the principal groups of organics of interest associated with each. And although the technology we describe here was first developed specifically for proposed studies of Mars, by summarizing its evolution over the past decade, we demonstrate how μCE‐LIF instrumentation has become an ideal candidate for missions of exploration to all of these nearby worlds in our Solar System.
Ammonia (NH3) emissions during drying of untreated and dewatered biogas digestate in a hybrid waste‐heat/solar dryer
Authors: Maurer Claudia , Müller Joachim
Published: June 2012

Digestate from the biogas digestion process contains high amounts of water and nitrogen, which can lead to over‐fertilization problems in regions with intensive livestock farming due to a surplus of ammonium, which contributes to the global warming effects. The best option to reduce the water content as well as to concentrate the nitrogen is to dry digestate; however, volatile nitrogen present in the digestate has the tendency to be emitted. Therefore, the objective of this study was to investigate the emissions of untreated and dewatered digestate during the drying process and to determine the nitrogen loss of the drying product by calculating the loss over time by the emissions and compare it with initial and final ammonium content made by chemical analysis. The drying procedure was performed in a hybrid waste‐heat/solar dryer. Ammonia rate was measured continuously during drying by Fourier transform infrared spectroscopy. Untreated digestate showed higher cumulative emissions of ammonia () than dewatered material () due to lower water content and shorter drying time. Emissions from the filtrate may still be an issue, which should be addressed in future studies.
Repeatability of a laboratory batch method to determine the specific biogas and methane yields
Authors: Mittweg Greta , Oechsner Hans , Hahn Volker , Lemmer Andreas , Reinhardt‐Hanisch Annett
Published: June 2012

To evaluate the potential of a substrate to form biogas, it is essential to have a fast and accurate method to determine the specific biogas yield (SBY) and specific methane yield (SMY). The objectives of this study were to assess the repeatability of the Hohenheim Biogas Yield Test (HBT) and to assess the influence of sample withdrawal and preparation on the determined SBY and SMY. Samples of dried maize whole plant material, maize cob, and power fodder, with up to six different treatments for preparation, were analyzed for their SBY and SMY using a discontinuous fermentation assay. Further, chemical composition of the whole plant sample was examined and different calculation models were used to predict SMY. The HBT showed a strong repeatability and a high precision for SMY. Two of the tested chemical composition models showed a satisfactory performance compared to the mean of the measured methane values. Significant effects caused by different sample treatments could be observed.
Nonlinear analysis of out‐of‐plane masonry façades: full dynamic versus pushover methods by rigid body and spring model
Authors: Casolo Siro , Uva Giuseppina
Published: June 2012

The paper proposes a systematic comparison between two methods of analysis that are well established in the field of earthquake engineering: nonlinear dynamic analysis and nonlinear static procedure (NSP), applied to the out‐of‐plane seismic response of two masonry façades representative of many ancient Italian churches. The comparison is based on extensive numerical analyses, which focus on the flexural and torsional mechanisms, while the in‐plane damage mechanisms and the possible detachment between the façade and the lateral walls because of a poor connection have been presently disregarded. The computations, both in the static and in the dynamic field, are based on a rigid body and spring model specifically implemented for this issue, computationally efficient and equipped with a realistic model of damage and hysteresis at the mesoscale. An innovative aspect of this study is the heuristic modelling of three‐wythe masonry, to include some typical texture effects on the macroscale nonlinear response. For each façade, two different masonry textures were considered, performing extensive dynamic analyses that offered a detailed overview about the performance under earthquakes of different intensities. In parallel, NSP and the classical N2‐based seismic assessment were applied. A critical discussion and comparison of the results of the two methods is presented to rationally appraise limits and opportunities. In particular, flexural and twisting out‐of‐plane mechanisms were clearly appraised in the dynamic field, whereas NSPs were not always able to describe the collapse, because they missed the partial failures determined by higher vibration modes, as could be expected. Copyright © 2012 John Wiley & Sons, Ltd.
Snow cornice dynamics as a control on plateau edge erosion in central Svalbard
Authors: Eckerstorfer Markus , Christiansen Hanne H. , Vogel Stephan , Rubensdotter Lena
Published: June 2012

Snow cornices grow extensively on leeward edges of plateau mountains in central Svalbard. A dominant wind direction, a snowdrift source area and a sharp slope transition largely control the formation of snow cornices in a barren peri‐glacial landscape. Seasonal snow cornice dynamics control bedrock weathering and erosion in sedimentary bedrock on the Gruvefjellet plateau edge in the valley Longyeardalen. Air, snow and ground temperature sensors, as well as automatic time‐lapse cameras on a leeward facing plateau edge were used to study seasonal cornice dynamics. These techniques allowed for monitoring of cornice accretion, deformation and collapse/melting in great detail. The active layer of the top plateau edge is characterized by high moisture content due to rain before freeze‐up in autumn and cornice meltdown during spring thaw. Thus frost weathering there can be very efficient in this otherwise cold and dry environment. Within the first autumn snowstorms, a vertical fully developed cornice was in place (190 cm thick). The backwall surface beneath the thickest part of the cornice remained in the ice segregation ‘frost cracking window’ for almost nine months. Highly weathered rock material from the plateau edge is thus incorporated into the cornice during cornice accretion. Brittle snow deformation leads to the opening of cornice tension cracks between the cornice mass and the snowpack on the plateau. These cracks are a prerequisite for cornice collapses, and often trigger cornice fall avalanches on the slope beneath. In these open cornice tension cracks, weathered rock debris, plucked from the plateau edge, can be visible, demonstrating the erosional property of the cornices. The cornice will either collapse or melt, resulting in suspended sediment transport downslope by cornice fall avalanche or release as rock fall respectively. Therefore, cornices both promote and trigger high weathering rates on Gruvefjellet, and thus control presently the development of the rockwall free faces and the talus cones. Copyright © 2012 John Wiley & Sons, Ltd.
Toxicity of fullerene (C60) to sediment-dwelling invertebrate Chironomus riparius larvae
Authors: Waissi-Leinonen Greta C. , Petersen Elijah J. , Pakarinen Kukka , Akkanen Jarkko , Leppänen Matti T. , Kukkonen Jussi V.K.
Published: June 2012

An environmentally realistic method to test fullerene (C60) toxicity to the benthic organism Chironomus riparius was created by allowing suspended fullerenes to settle down, making a layer on top of the sediment. To test the hypothesis that higher food concentrations will reduce toxic responses, two food concentrations were tested (0.5 and 0.8% Urtica sp.) in sediment containing fullerene masses of 0.36 to 0.55 mg/cm2 using a 10-d chronic test. In the 0.5% food level treatments, there were significant differences in all growth-related endpoints compared with controls. Fewer effects were observed for the higher food treatment. Fullerene agglomerates were observed by electron microscopy in the gut, but no absorption into the gut epithelial cells was detected. In the organisms exposed to fullerenes, microvilli were damaged and were significantly shorter. The potential toxicity of fullerene to C. riparius appears to be caused by morphological changes, inhibiting larval growth. Environ. Toxicol. Chem. 2012; 31: 2108–2116. © 2012 SETAC
The relationship between total cholinesterase activity and mortality in four butterfly species
Authors: Bargar Timothy A.
Published: June 2012

The relationship between total cholinesterase activity (TChE) and mortality in four butterfly species (great southern white [Ascia monuste], common buckeye [Junonia coenia], painted lady [Vanessa cardui], and julia butterflies [Dryas julia]) was investigated. Acute contact toxicity studies were conducted to evaluate the response (median lethal dose [LD50] and TChE) of the four species following exposure to the organophosphate insecticide naled. The LD50 for these butterflies ranged from 2.3 to 7.6 µg/g. The average level of TChE inhibition associated with significant mortality ranged from 26 to 67%, depending on the species. The lower bounds of normal TChE activity (2 standard deviations less than the average TChE for reference butterflies) ranged from 8.4 to 12.3 µM/min/g. As a percentage of the average reference TChE activity for the respective species, the lower bounds were similar to the inhibition levels associated with significant mortality, indicating there was little difference between the dose resulting in significant TChE inhibition and that resulting in mortality. Environ. Toxicol. Chem. 2012; 31: 2124–2129. © 2012 SETAC
Analysis and modelling of YouTube traffic
Authors: Ameigeiras Pablo , Ramos‐Munoz Juan J. , Navarro‐Ortiz Jorge , Lopez‐Soler J.M.
Published: June 2012

YouTube currently accounts for a significant percentage of the Internet's global traffic. Hence, understanding the characteristics of the YouTube traffic generation pattern can provide a significant advantage in predicting user video quality and in enhancing network design. In this paper, we present a characterisation of the traffic generated by YouTube when accessed from a regular PC. On the basis of this characterisation, a YouTube server traffic generation model is proposed, which, for example, can be easily implemented in simulation tools. The derived characterisation and model are based on experimental evaluations of traffic generated by the application layer of YouTube servers. A YouTube server commences the download with an initial burst and later throttles down the generation rate. If the available bandwidth is reduced (e.g. in the presence of network congestion), the server behaves as if the data excess that cannot be transmitted because of the reduced bandwidth were accumulated at a server's buffer, which is later drained if the bandwidth availability is recovered. As we will show, the video clip encoding rate plays a relevant role in determining the traffic generation rate, and therefore, a cumulative density function for the most viewed video clips will be presented. The proposed traffic generation model was implemented in a YouTube emulation server, and the generated synthetic traffic traces were compared with downloads from the original YouTube server. The results show that the relative error between downloads from the emulation server and the original server does not exceed 6% for the 90% of the considered videos. Copyright © 2012 John Wiley & Sons, Ltd.