bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancement in Evaporative Effectiveness of an Evaporative Tubular Heat Dissipator Using Experimental Design Approach
Authors:   Rajneesh , Kumar Raj
Published: September 2014

An experimental investigation of evaporative effectiveness and mass transfer coefficient on a bundle of tubes of an evaporative tubular heat dissipator is presented. Based on the experiments, correlations of evaporative effectiveness and mass transfer coefficient are derived using multiple regression analysis. A statistical model is developed to correlate the operating variables using design of experiment approach by selecting central composite design of a response surface methodology. Results shown in this article indicate that as the cooling film flow rate increases, evaporative effectiveness and mass transfer coefficient increases provided that the air flow rate is constant which is flowing from underneath the tubes of the evaporative tubular heat dissipator. Derived correlations are helpful in improvement of the design of heat transfer devices and many other engineering applications. Consideration of relative humidity of upstreaming air as one of the operating variables leads to the contribution to heat and mass transfer study of evaporative tubular heat dissipators in the present investigation.
Lie Group Analysis and Numerical Solutions for Magnetoconvective Slip Flow along a Moving Chemically Reacting Radiating Plate in Porous Media with Variable Mass Diffusivity
Authors: Uddin Md. Jashim , Khan W. A. , Ismail Ahmad Izani
Published: September 2014

A numerical investigation of magnetoconvective boundary layer slip flow along a nonisothermal continuously moving permeable nonlinear radiating plate in Darcian porous media is reported. The concentration dependent mass diffusivity, viscous dissipation, Joule heating, and chemical reaction are taken into account. A Lie group of transformation is applied to the governing transport equations and boundary condition to find the corresponding similarity equations. Furthermore, the similarity equations with the relevant boundary conditions are solved numerically using the Runge‐Kutta‐Fehlberg fourth‐fifth order numerical method. Numerical results for the dimensionless velocity, temperature, and concentration distributions as well as friction factor, local Nusselt, and local Sherwood numbers are discussed for various controlling parameters. It is found that that the dimensionless concentration increases whilst the rate of mass transfer decreases with the mass diffusivity parameter. An excellent correlation is found between the present results and published results. The study finds applications in the polymer industry and metallurgy.
Simulating streamflow on regulated rivers using characteristic reservoir storage patterns derived from synthetic remote sensing data
Authors: Yoon Yeosang , Beighley Edward
Published: September 2014

This study presents a method to estimate streamflow in rivers regulated by lakes or reservoirs using synthetic satellite remote sensing data. To illustrate the approach, the new reservoir routing method is integrated into the Hillslope River Routing model, and a case study is presented for the highly regulated river in the Cumberland River basin (46,400 km2). The study period is April–May 2000, which contains a significant flood event that occurred in 1–2 May 2000. The model is shown to capture storage/release characterises in eight reservoirs with a mean normalized root mean square error (NRMSE) of 20% for entire simulation period and 27% for the May flood event. These errors are 69 and 75%, respectively, less than the NRMSE if reservoirs are not included in the model. Given the limitations of satellite missions, the impacts of the revisit cycles and operational periods are quantified. We used 26 observation sets of satellite altimetry over Cumberland River basin that are generated by considering both repeat cycles and satellite operation periods. For the revisit cycles, increasing the interval of repeat cycle leads to a corresponding increase of mean NRMSE from 27 to 59% as a result of sampling fewer flood events and smoothing of the change in storage signal as a result of longer intervals between visits. For the operation periods, the impact of data periods is limited because of the strong seasonal pattern of reservoir operations. Overall, the results suggest that the generalized routing model derived from reservoir stage observations can be used to simulate reservoir operating conditions, which can be used in forecasting hydrologic impacts of land cover or climate change. Copyright © 2014 John Wiley & Sons, Ltd.
Improving cervical cancer screening attendance in Finland
Authors: Virtanen Anni , Anttila Ahti , Luostarinen Tapio , Malila Nea , Nieminen Pekka
Published: September 2014

High attendance is essential to cervical cancer screening results. Attendance in the Finnish program is currently at 70%, but extensive opportunistic screening occurs beside the organized. A shift from opportunistic to organized screening is imperative to optimize the costs and impact of screening and minimize potential harms. We evaluated the effect of reminder letters (1st reminder) and self‐sampling test (2nd reminder) on program attendance. The study population consisted of 31,053 screening invitees in 31 Finnish municipalities. 8,284 non‐attendees after one invitation received a reminder letter and 4,536 further non‐attendees were offered a self‐sampling option. Socioeconomic factors related to participation were clarified by combining screening data to data from Statistics Finland. Reminder letters increased participation from 72.6% (95% CI 72.1, 73.1) to 79.2% (95% CI 78.8, 79.7) and self‐sampling further to 82.2% (95% CI 81.8, 82.7). Reminder letters with scheduled appointments resulted in higher increase than open invitations (10 vs. 6%). Screening of original non‐attendees increased the yield of CIN3+ lesions by 24%. Non‐attendance was associated with young age, immigrant background, lower education level and having never been married. We showed that a total attendance of well over 80% can be achieved within an organized program when the invitational protocol is carefully arranged.
Reduction of classroom noise levels using group contingencies
Authors: Ring Brandon M. , Sigurdsson Sigurdur O. , Eubanks Sean L. , Silverman Kenneth
Published: September 2014

The therapeutic workplace is an employment‐based abstinence reinforcement intervention for unemployed drug users where trainees receive on‐the‐job employment skills training in a classroom setting. The study is an extension of prior therapeutic workplace research, which suggested that trainees frequently violated noise standards. Participants received real‐time graphed feedback of noise levels and had the opportunity to earn monetary group reinforcement for maintaining a low number of noise violations. Results suggested that feedback and monetary reinforcement reduced the number of noise violations.
Protective effects of ascorbic acid against the genetic and epigenetic alterations induced by 3,5‐dimethylaminophenol in AA8 cells
Authors: Chao Ming‐Wei , Erkekoglu Pınar , Tseng Chia‐Yi , Ye Wenjie , Trudel Laura J. , Skipper Paul L. , Tannenbaum Steven R. , Wogan Gerald N.
Published: September 2014

Exposure to monocyclic aromatic alkylanilines (MAAs), namely 2,6‐dimethylaniline (2,6‐DMA), 3,5‐dimethylaniline (3,5‐DMA) and 3‐ethylaniline (3‐EA), was significantly and independently associated with bladder cancer incidence. 3,5‐DMAP (3,5‐dimethylaminophenol), a metabolite of 3,5‐DMA, was shown to induce an imbalance in cytotoxicity cellular antioxidant/oxidant status, and DNA damage in mammalian cell lines. This study was designed to evaluate the protective effect of ascorbic acid (Asc) against the cytotoxicity, reactive oxygen species (ROS) production, genotoxicity and epigenetic changes induced by 3,5‐DMAP in AA8 Chinese Hamster Ovary (CHO) cells. In different cellular fractions, 3,5‐DMAP caused alterations in the enzyme activities orchestrating a cellular antioxidant balance, decreases in reduced glutathione levels and a cellular redox ratio as well as increases in lipid peroxidation and protein oxidation. We also suggest that the cellular stress caused by this particular alkylaniline leads to both genetic (Aprt mutagenesis) and epigenetic changes in histones 3 and 4 (H3 and H4). This may further cause molecular events triggering different pathological conditions and eventually cancer. In both cytoplasm and nucleus, Asc provided increases in 3,5‐DMAP‐reduced glutathione levels and cellular redox ratio and decreases in the lipid peroxidation and protein oxidation. Asc was also found to be protective against the genotoxic and epigenetic effects initiated by 3,5‐DMAP. In addition, Asc supplied protection against the cell cycle (G1 phase) arrest induced by this particular alkylaniline metabolite. Copyright © 2014 John Wiley & Sons, Ltd.
Hydrophobic sodium fluoride‐based nanocrystals doped with lanthanide ions: assessment of in vitro toxicity to human blood lymphocytes and phagocytes
Authors: Sojka Bartlomiej , Kuricova Miroslava , Liskova Aurelia , Bartusova Maria , Banski Mateusz , Misiewicz Jan , Dusinska Maria , Horvathova Mira , Jahnova Eva , Ilavska Silvia , Szabova Michaela , Rollerova Eva , Podhorodecki Artur , Tulinska Jana
Published: September 2014

In vitro immunotoxicity of hydrophobic sodium fluoride‐based nanocrystals (NCs) doped with lanthanide ions was examined in this study. Although there is already a significant amount of optical and structural data on NaYF4 NCs, data on safety assessment are missing. Therefore, peripheral whole blood from human volunteers was used to evaluate the effect of 25 and 30 nm hydrophobic NaYF4 NCs dissolved in cyclohexane (CH) on lymphocytes, and of 10 nm NaYF4 NCs on phagocytes. In the concentration range 0.12–75 µg cm−2 (0.17–106 µg ml−1), both 25 and 30nm NaYF4 NCs did not induce cytotoxicity when measured as incorporation of [3H]‐thymidine into DNA. Assessment of lymphocyte function showed significant suppression of the proliferative activity of T‐lymphocytes and T‐dependent B‐cell response in peripheral blood cultures (n = 7) stimulated in vitro with mitogens phytohemagglutinin (PHA) and pokeweed (PWM) (PHA > PWM). No clear dose–response effect was observed. Phagocytic activity and respiratory burst of leukocytes (n = 5–8) were generally less affected. A dose‐dependent suppression of phagocytic activity of granulocytes in cultures treated with 25 nm NCs was observed (vs. medium control). A decrease in phagocytic activity of monocytes was found in cells exposed to higher doses of 10 and 30 nm NCs. The respiratory burst of phagocytes was significantly decreased by exposure to the middle dose of 30 nm NCs only. In conclusion, our results demonstrate immunotoxic effects of hydrophobic NaYF4 NCs doped with lanthanide ions to lymphocytes and to lesser extent to phagocytes. Further research needs to be done, particularly faze transfer of hydrophobic NCs to hydrophilic ones, to eliminate the solvent effect. Copyright © 2014 John Wiley & Sons, Ltd.
Induction of Complementary Function Reductase Enzymes in Colon Cancer Cells by Dithiole‐3‐thione versus Sodium Selenite
Authors: Erzinger Melanie M. , Bovet Cédric , Uzozie Anuli , Sturla Shana J.
Published: September 2014

Cellular induction of reductase enzymes can alter the susceptibility of cells toward drugs and chemicals. In this study, we compared the capacity of a single dose of sodium selenite and 3H‐1,2‐dithiole‐3‐thione (D3T) to influence the drug‐relevant reducing capacity of HT29 cells over time, and defined the protein‐specific contribution to this activity on the basis of selected reaction monitoring mass spectrometry. Thioredoxin reductase 1 (TrxR1) protein levels and activity were inducible up to 2.2‐fold by selenium. In contrast, selenium had only a minor influence on prostaglandin reductase 1 (PTGR1) and NAD(P)H:quinone oxidoreductase 1 (NQO1) activity and protein levels. D3T, a strong Nrf2 inducer, induced all the reductases and additionally increased the cytotoxicity of hydroxymethylacylfulvene, a bioreductive DNA‐alkylating drug. The data and experimental approaches allow one to define induction potency for reductase enzymes PTGR1, TrxR1, and NQO1 in HT29 cells and link these to changes in drug cytotoxicity.
Impact of HIV‐1 infection on herpes simplex virus type 2 genetic variability among co‐infected individuals
Authors: Abrão Emiliana P. , Burrel Sonia , Désiré Nathalie , Bonnafous Pascale , Godet Angélique , Caumes Eric , Agut Henri , Boutolleau David
Published: September 2014

Herpes simplex virus type 2 (HSV‐2) is the most common cause of genital ulcer disease worldwide. While the contribution of HSV‐2 to acquisition and course of human immunodeficiency virus (HIV) infection has been well described, less attention has been paid to the impact of HIV infection on the variability and the pathophysiology of HSV‐2 infection. The goal of the present study was to characterize genotypically and phenotypically HSV‐2 strains isolated from 12 patients infected by HIV‐1 and from 12 HIV‐negative patients. Replication capacity analyses were carried out in Vero cells and full‐length nucleotide sequences were determined for glycoproteins B (gB), D (gD), G (gG), thymidine kinase (TK), and DNA polymerase (POL) HSV‐2 genes. Sequence alignments and phylogenetic trees were performed. No significant differences were found in terms of replication capacity. The interstrain nucleotide identities of the 3 glycoprotein genes (gB, gC, and gG) ranged from 99.5% to 100% among the 24 HSV‐2 strains. The phylogenetic analysis showed no clustering of HSV‐2 strains when correlating to the HIV status of the patients. A lower variability was observed for the functional proteins TK and DNA polymerase (98.9% to 100% identity). Genetic analysis of TK evidenced mutations related to acyclovir‐resistance in two HSV‐2 strains. No specific differences regarding replication capacity and gene sequence were found when comparing HSV‐2 strains isolated from patients infected with HIV‐1 and HIV‐negative patients, suggesting that the virological properties of HSV‐2 infection are not influenced by HIV‐1 infection among co‐infected patients. J. Med. Virol. 87:357–365, 2015. © 2014 Wiley Periodicals, Inc.
Clinical Significance of Middle Turbinate Lateralization After Endoscopic Sinus Surgery
Authors: Bassiouni Ahmed , Chen Philip G. , Naidoo Yuresh , Wormald Peter‐John
Published: September 2014

Objectives/Hypothesis

To investigate the clinical significance of middle turbinate lateralization (MTL) occurrence postendoscopic sinus surgery (ESS) for chronic rhinosinusitis, namely, association with postoperative symptoms and eventual need for undergoing revision surgery.

Study Design

Retrospective chart review of consecutive postoperative follow‐up appointments (November 2009–May 2011) for patients who had had full‐house ESS (post hoc analysis).

Methods

Endoscopic video recordings were reviewed by a blinded reviewer to determine occurrence of MTL (any portion of the middle turbinate touching the lateral nasal wall). Postoperative symptom questionnaires using the Adelaide scoring system were collected. Records were reviewed to determine the need for revision surgeries during follow‐up.

Results

A total of 151 patients had follow‐up with video endoscopy from 2009 to 2011. No statistically significant association between MTL and symptoms was found (P > .05). Of the patients with MTL, 21% required revision versus 9% in those who had no MTL (P = .07). Log‐rank test showed that there was a statistically significant difference between the revision surgery survival curves for the MTL and no‐MTL groups (P = .03). Controlling for the inability to examine the frontal sinus, the difference between the two survival functions increased (P = .005).

Conclusions

MTL was not associated with patient‐reported symptoms, but may be associated with a more rapid need for future revision surgery. We hypothesize that this effect is related to interference with the frontal sinus.

Level of Evidence

4. Laryngoscope, 125:36–41, 2015
Molecular interaction originating from polar functional group in lubricants and its relationship with their traction property under elastohydrodynamic lubrication
Authors: Takiwatari Koji , Nanao Hidetaka , Hoshi Yasushi , Mori Shigeyuki
Published: September 2014

The correlation between molecular interaction and traction properties was investigated using a traction tester and in situ observation of elastohydrodynamic lubrication film with a micro‐Fourier transform infrared spectrometer. The sample oils used were polypropylene glycols (PPGs) with the end‐group of alcohol or ether and a synthetic hydrocarbon oil, poly‐α‐olefin. From the traction tests, it was found that the traction coefficient of PPG was sensitive to the end‐group. PPG with alcohol as the end‐group showed a higher traction coefficient than that with the ether group. In situ observation with a micro‐Fourier transform infrared was performed in order to investigate the molecular interaction of the lubricant oil. It was found that the hydrogen bonding of hydroxyl groups in PPG was strengthened by high pressure in the Hertzian contact region. These results suggest that the rheological properties in the elastohydrodynamic lubrication contact region were affected by the strengthened hydrogen bonding. Copyright © 2014 John Wiley & Sons, Ltd.
Tracer Diffusion in Heterogeneous Polymer Networks
Authors: Di Lorenzo Fany , Seiffert Sebastian
Published: September 2014

The diffusion of linear polymer chains in swollen polymer networks is studied with different extents of spatial heterogeneity of their crosslinking density. Structural heterogeneity is imparted to these gels by photo‐crosslinking of polymer precursor chains in semidilute solution, which comprise either just one batch of precursors, yielding gels with just a little spatial heterogeneity, or mixtures of two different batches of precursors, one with high and one with low degree of functionalization with crosslinkable moieties, yielding gels with more pronounced heterogeneity. In addition, heterogeneous gels are also prepared from crosslinkable precursor chains and defined fractions of pre‐crosslinked microgel particles that serve as doped‐in nanometer‐scale domains of high local crosslinking density. The resulting gels are probed by static light scattering and shear rheology, and the self‐diffusion of fluorescent linear tracer chains within the gels is studied by fluorescence recovery after photobleaching. The outcome of these investigations is that spatial heterogeneity of a given crosslinking density in swollen polymer networks decreases their ability to store mechanical deformation energy, but has no marked impact on the above‐micrometer‐scale diffusivity of linear tracer chains.

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Reversibly Dispersible/Collectable Metal‐Organic Frameworks Prepared by Grafting Thermally Responsive and Switchable Polymers
Authors: Liu Heyang , Zhu He , Zhu Shiping
Published: September 2014

A reversibly dispersible/collectable metal‐organic framework (MOF) system has been developed. The MOF particles were modified by grafting the thermally switchable copolymers of 2‐(2‐methoxyethoxy)ethyl methacrylate and oligo(ethylene glycol) methacrylate through a surface‐initiated atom transfer radical polymerization (SI‐ATRP) approach. The resulted MOF materials preserved their original framework structure and could be readily dispersed in water at room temperature to form stable dispersions. The dispersed MOF particles could also be re‐collected by heating the dispersions to above the lower critical solution temperature (LCST) of the grafted copolymer. The dispersion and collection processes were reversible.
Breath Figures of Nanoscale Bricks: A Universal Method for Creating Hierarchic Porous Materials from Inorganic Nanoparticles Stabilized with Mussel‐Inspired Copolymers
Authors: Saito Yuta , Shimomura Masatsugu , Yabu Hiroshi
Published: September 2014

High‐performance catalysts and photovoltaics are required for building an environmentally sustainable society. Because catalytic and photovoltaic reactions occur at the interfaces between reactants and surfaces, the chemical, physical, and structural properties of interfaces have been the focus of much research. To improve the performance of these materials further, inorganic porous materials with hierarchic porous architectures have been fabricated. The breath figure technique allows preparing porous films by using water droplets as templates. In this study, a valuable preparation method for hierarchic porous inorganic materials is shown. Hierarchic porous materials are prepared from surface‐coated inorganic nanoparticles with amphiphilic copolymers having catechol moieties followed by sintering. Micron‐scale pores are prepared by using water droplets as templates, and nanoscale pores are formed between the nanoparticles. The fabrication method allows the preparation of hierarchic porous films from inorganic nanoparticles of various shapes and materials.

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Sleep Attacks in Patients With Parkinson's Disease on Dopaminergic Medications: A Systematic Review
Authors: Yeung Eugene Y.H. , Cavanna Andrea E.
Published: September 2014

Dopaminergic medications are used as first‐line treatment for Parkinson's disease (PD). In 1999, a case series was published describing 9 patients who took dopamine agonists (pramipexole or ropinirole) and experienced sudden irresistible sleep attacks. Sleep attacks have subsequently been reported with other dopaminergic medications, including levodopa. Because these symptoms might not be rare and can affect health‐related quality of life, we set out to review the prevalence and clinical characteristics of sleep attacks in patients with PD on dopaminergic medications. We conducted a systematic literature review using the terms parkinson* AND dopamine* AND narcolep* OR sleep attack in multiple databases (PubMed, Embase, and PsycINFO). The systematic literature review yielded 23 relevant articles, including nine case reports or case series and 14 original studies. According to the pooled data from the five studies reporting prevalence figures (n = 10,084), sleep attacks occur in 13.0% of patients with PD on dopaminergic medications. Our analysis failed to show significant differences in the Epworth Sleepiness scores between patients with and without sleep attacks (mean difference: 2.92; 95% confidence interval: −0.47–6.31). The I2 value of 76% indicated high heterogeneity among the studies. Sleep attacks are not a rare occurrence in patients with PD on dopamine agonist treatment. We found conflicting results on whether sleep attacks in PD resemble narcolepsy. The pathophysiology of these symptoms might be related to dopamine D2 and D4 receptor gene polymorphisms. The most effective management strategies were dose reduction and discontinuation of the offending drugs.
How Do I Examine Nonmotor Aspects of Parkinson's Disease? What Not to Miss and What to Ignore?
Authors: Todorova Antoniya , Martin Anne , Chaudhuri K. Ray
Published: September 2014

Nonmotor symptoms (NMS) of Parkinson's disease are a wide range of symptoms that occur well before the onset of the motor syndrome and are present right until the end of life. NMS could be classified to several types and broadly belong to dopaminergic, nondopaminergic, drug‐induced subgroups and those related to motor response fluctuations. NMS are relatively under‐recognized in clinical practice and can be rapidly assessed in the clinic by asking patients to complete the Non‐Motor Symptoms Questionnaire (which can be downloaded from http://www.movementdisorders.org/MDS/Education/Rating-Scales/Rating-Scales-By-Disorder.htm) while they are waiting to be seen. The consultation thereafter can cover the important aspects of the symptoms that have been declared by the patient in addition to the management of the motor symptoms.
Unilateral NMR investigation of multifunctional treatments on stones based on colloidal inorganic and organic nanoparticles
Authors: Di Tullio Valeria , Cocca Mariacristina , Avolio Roberto , Gentile Gennaro , Proietti Noemi , Ragni Pietro , Errico Maria Emanuela , Capitani Donatella , Avella Maurizio
Published: September 2014

Consolidation and protection are among the most important treatments usually carried out in conservation of stone artifacts and monuments. In this paper, portable unilateral NMR and conventional techniques were used for investigating new multifunctional treatments based on tetraethoxysilane, silica, and polytetrafluoroethylene nanoparticles. The study was carried out on a very complex and heterogeneous porous stone such as tuff. NMR study allowed to obtain detailed information on the penetration depth of treatments, the hydrophobic effect, and changes in the open porosity caused by treatments. Physical and chemical inhomogeneities between the impregnated layers of tuff and the layers underneath were also detected. The average pores radius and pores interconnection obtained from NMR diffusion measurements were used for the first time to compare effects of different consolidating and/or protective treatments on stone. Because unilateral NMR technique is neither destructive nor invasive, investigation of treatments can be also carried out and optimized directly on buildings and monuments of interest for Cultural Heritage. Copyright © 2014 John Wiley & Sons, Ltd.
Stereochemical behavior of geminal and vicinal 77Se–13C spin–spin coupling constants studied at the SOPPA(CC2) level taking into account relativistic corrections
Authors: Rusakov Yury Yu. , Krivdin Leonid B.
Published: September 2014

A systematic theoretical study of geminal and vicinal 77Se–13C spin–spin coupling constants in the series of the open‐chain selenides and selenium‐containing heterocycles revealed that relativistic effects play an essential role in the selenium–carbon coupling mechanism, especially when the coupling pathway includes a triple bond, contributing to about 10–15% of their total values and noticeably improving the agreement of the calculated couplings with experiment. Both geminal and vicinal 77Se–13C spin–spin coupling constants show marked stereochemical behavior as documented by their calculated dihedral angle dependence that could be used as a practical guide in stereochemical studies of organoselenium compounds. Copyright © 2014 John Wiley & Sons, Ltd.
Zitieren: warum und wie?
Authors: Böhme Uwe , Tesch Silke
Published: September 2014

Autoren sind verpflichtet, vorangegangene Arbeiten aufzulisten. Die Techniken und Standards des wissenschaftlichen Zitierens sind jedoch sehr unterschiedlich.
Hydrofunktionalisierung mit unüblicher Regioselektivität
Authors: Gulder Tanja , Gulder Tobias A. M.
Published: September 2014

Die Photoredoxkatalyse mit sichtbarem Licht ist ein neues Werkzeug, um die übliche Markownikow‐Selektivität bei der Hydrofunktionalisierung umzukehren.
Lernpfade gestalten, analysieren und neue Wege beschreiten
Authors: Pietrusky Stefan , Schuhen Katrin
Published: September 2014

Das onlinebasierte Lern‐ und Lehrsystem Crosslinkedlab unterstützt Unterricht und Lehre in der Chemie. Die individuell anpassbare Software hilft Studenten, mit der heutigen Informationsfülle zurecht zu kommen. Eine neue Erweiterung macht unter anderem Reaktionsmechanismen leichter verständlich und vernetzt Theorie und Praxis naturwissenschaftlichen Arbeitens.
Gesichertes Wissen der Chemie
Authors: Bauner Mareike
Published: September 2014

Chemiker greifen zum Römpp, wenn sie nach Fachinformationen suchen. Das Lexikon bietet webbasiert und mit neuer Oberfläche mehr als 65 000 Stichwörter von Amphetamin bis Zink‐Recycling.
Chinas Energiemix wandelt sich
Authors: Schmid Rolf
Published: September 2014

Die chinesische Regierung hat sich vorgenommen, mehr Energie bereit zu stellen und die Energiekosten zu senken. Gleichzeitig will sie gegen die Luftverschmutzung vorgehen und den CO2‐Ausstoß verringern.
“Zweimal eindeutig ja”
Authors: Bengs Holger
Published: September 2014

Medikamentenentwicklung braucht neue Impulse, damit sie schnell geht. Über Open Innovation und Auftragsforschung spricht Jochen Maas, der Sanofi‐Geschäftsführer für Forschung und Entwicklung in Deutschland.
Pferd oder Rind?
Authors: von Bargen Christoph , Humpf Hans‐Ulrich , Brockmeyer Jens
Published: September 2014

Zur Qualitätssicherung bei Lebensmitteln gehört der Nachweis, ob die Angaben des Herstellers über die Inhalte stimmen. Targeted Proteomics liefert bei tierischen Produkten Authentizitätsnachweise: Die neue Methode zeigt an, von welcher Tierart die Proteine in einem Fleischgericht stammen.
Chemische Identität einzelner Partikel
Authors: Huck‐Jones Deborah , Hessemann Renate
Published: September 2014

Probleme der Pulvercharakterisierung, bei denen Größe und Form der Partikel alleine nicht genügend Informationen liefern, löst die Kombination aus Bildanalyse und Ramanspektroskopie. Zwei Beispiele sind Drogenfahndung und Zementproduktion.
Der Weg in den Beruf
Authors: Plasa Tim
Published: September 2014

Chemiker finden schneller eine Stelle als Biologen, verdienen als Berufseinsteiger aber weniger als Chemieingenieure. Dies sind einige der Ergebnisse einer Absolventenbefragung. Nach wie vor gilt Chemikern der Bachelorabschluss nicht als berufsqualifizierend, und die wenigen, die mit dem Bachelor ins Berufsleben starten, fühlen sich oft überfordert.
Key parameters in determining energy generated by CPV modules
Authors: Kurtz Sarah , Muller Matthew , Jordan Dirk , Ghosal Kanchan , Fisher Brent , Verlinden Pierre , Hashimoto Jun , Riley Daniel
Published: September 2014

We identify the key inputs and measurement data needed for accurate energy rating of concentrator photovoltaic (CPV) modules based on field observations of multiple CPV modules. Acceptance angle is shown to correlate with the observed module‐level performance ratio (PR) for the modules studied. Using power ratings based on concentrator standard test conditions, PRs between 90% and 95% were observed during the summers with up to ~10% lower PRs during the winters. A module fabricated by Semprius showed 94% ±0.7% PR over almost 2 years with seasonal variation in PR of less than 1% showing how a module with relatively large acceptance angle may show very consistent average efficiency (calculated from the energy generated relative to the energy available), potentially simplifying energy ratings. The application of the results for translation of energy rating from one location to another is discussed, concluding that most of the translation differences may be correlated with temperature differences between sites with the largest variation happening when optical efficiency depends on temperature. Copyright © 2014 John Wiley & Sons, Ltd.
Physical and structural basis for polymorphism in amyloid fibrils
Authors: Tycko Robert
Published: September 2014

As our understanding of the molecular structures of amyloid fibrils has matured over the past 15 years, it has become clear that, while amyloid fibrils do have well‐defined molecular structures, their molecular structures are not uniquely determined by the amino acid sequences of their constituent peptides and proteins. Self‐propagating molecular‐level polymorphism is a common phenomenon. This article reviews current information about amyloid fibril structures, variations in molecular structures that underlie amyloid polymorphism, and physical considerations that explain the development and persistence of amyloid polymorphism. Much of this information has been obtained through solid state nuclear magnetic resonance measurements. The biological significance of amyloid polymorphism is also discussed briefly. Although this article focuses primarily on studies of fibrils formed by amyloid‐β peptides, the same principles apply to many amyloid‐forming peptides and proteins.
Passive charge state control of nitrogen‐vacancy centres in diamond using phosphorous and boron doping
Authors: Groot‐Berning Karin , Raatz Nicole , Dobrinets Inga , Lesik Margarita , Spinicelli Piernicola , Tallaire Alexandre , Achard Jocelyn , Jacques Vincent , Roch Jean‐François , Zaitsev Alexander M. , Meijer Jan , Pezzagna Sébastien
Published: September 2014

The control and stabilisation of the charge state of nitrogen‐vacancy centres in diamond is an important issue for the achievement of reliable processing of spin‐based quantum information. The effect of phosphorous and boron doping of diamond on the charge state of nitrogen‐vacancy (NV) centres is shown here. Ensembles of NV centres are produced at a depth of 60 nm in ultrapure diamond by implantation of nitrogen ions. Overlapping with the NV ensembles, donor and acceptor doped regions of different doping levels are prepared by ion implantation of phosphorus and boron followed by annealing in vacuum at 1500 °C. We show how the charge state of NV centres is controlled by the presence of phosphorous or boron atoms in their neighbourhood. For the lowest doping level, spectral measurements on the ensemble of NV centres reveal a higher amount of NV0 in the case of boron and a higher amount of NV− in the case of phosphorus, as compared with undoped regions. This behaviour is strengthened when the doping level is increased. Interestingly, the charge state control of native silicon‐vacancy centres is also evidenced. Finally, we discuss the role of the surface termination of diamond on the average charge state of the NV ensemble (still dominant even at a depth of 60 nm) and confirm that the surface 2D‐hole‐gas (H‐termination) can be compensated by nitrogen itself.
High‐pressure optical study of bromine‐doped single‐walled carbon nanotube films
Authors: Strauch J. , Anis B. , Kuntscher C. A.
Published: September 2014

We present a high‐pressure optical spectroscopy study on single‐walled carbon nanotubes (SWCNTs) doped with bromine using nitrogen as pressure transmitting medium. Bromine‐doped SWCNTs (Br‐SWCNTs) with different doping levels were prepared by the gas phase method and characterized by optical and Raman spectroscopy. The absorption and Raman spectra clearly reveal the effects of charge doping by bromine. Like for pristine SWCNTs, the absorption bands of Br‐SWCNTs show a red shift under pressure. Anomalies in the pressure‐induced relative frequency shift indicate structural changes in the nanotubes. The results are compared with those for empty nanotubes.
Generating highly nonlinear resilient Boolean functions resistance against algebraic and fast algebraic attacks
Authors: Yang Jun‐Po , Zhang Wei‐Guo
Published: September 2014

Boolean functions play an important role in the design of stream ciphers. In this paper, a simulated annealing algorithm is designed to obtain Boolean functions satisfying all the needed criteria: high nonlinearity, 1‐resiliency, optimal algebraic degree, optimal (or suboptimal) algebraic immunity, and good immunity to fast algebraic attacks. These functions provide a good trade‐off among the criteria to resist the known cryptanalytic techniques. Copyright © 2014 John Wiley & Sons, Ltd.
Dissimilar Metal Active Gas Welding of TWIP and DP Steel Sheets
Authors: Russo Spena Pasquale , Matteis Paolo , Scavino Giorgio
Published: September 2014

In the last years, TWIP steels have been proposed for the fabrication of car‐body components, due to their excellent combination of strength and toughness. However, a widespread usage of these steels for such applications is conditional on the employment of dissimilar welding with other automotive high‐strength steel grades. In this study, dissimilar butt weld seams of TWIP and Dual Phase steel sheets fabricated by metal active gas welding are examined. The microstructural and mechanical characterization of the welded joints were carried out by optical metallography, microhardness, tensile testing, and fractographic examination. The heat affected zone on the TWIP side was fully austenitic and the only detectable effect was grain coarsening; on the dual phase side new martensite formed close to the fusion zone, while ferrite, and tempered martensite occurred away from the fusion zone. The welded tensile specimens exhibit a plastic behavior influenced by the TWIP steel, even though with more limited tensile strengths and elongation at fractures. The tensile specimens predominantly broke within the weld seams, with the fractures surfaces being ductile.
Numerische Simulation von Verbundstützen im Brandfall
Authors: Mensinger Martin , Hahn Andreas , Zhang Canghai
Published: September 2014

Die weltweit verbreiteten, und teilweise auf recht vereinfachten Ansätzen basierenden Bemessungsverfahren für Verbundstützen im Brandfall, geben Anlass zu einem genauen Vergleich an konkreten Beispielen. Im Folgenden wird auf die numerische Untersuchung einer Verbundstütze mit ANSYS Workbench [1] eingegangen. Die Validierung stützt sich dabei hauptsächlich auf externe Versuchsergebnisse von Romero und Espinos [12]. Abschließend werden die numerischen Ergebnisse des kalibrierten FE‐Modells mit Handrechenergebnissen auf Basis allgemein gültiger Verfahren und Normen, wie z. B. die hierzulande gültige DIN EN 1994‐1‐2 [16], verglichen.

Numerical simulation of composite columns in case of fire. The design procedures used worldwide for composite columns in case of fire with partially simplified approaches provide impetus to an exact comparison on tangible examples. The numerical analysis of a composite column with ANSYS Workbench [1] is described in detail in this paper. The validation mainly relies on external test results of Romero and Espinos [12]. Finally, the numerical results are compared with generally applicable procedures, such as in DIN EN 1994‐1‐2 [16] which is the currently valid standard in Germany.
Robustness of steel‐concrete flooring systems – An experimental assessment
Authors: Zandonini Riccardo , Baldassino Nadia , Freddi Fabio
Published: September 2014

Recently, the interest in the mitigation of the damages caused by accidental events increased significantly. The knowledge of loads transfer mechanisms from the damaged to the undamaged part of the structure is the key for developing adequate design strategies. Despite the potential important role of flooring systems, research of this subject is still limited. A European Research Project aims at achieving an insight into the case of steel‐concrete composite frames with solid concrete slabs. Two geometrically different 3D composite sub‐frames are subjected to the loss of an internal column. The sub‐frames are a full‐scale portion of 5 stories 3D frames. Equivalence between the sub‐frames and the full‐frames required a series of careful numerical analysis, which enabled definition of the boundary restraints of the specimens and of the loading sequence in the test. The present paper illustrates these preparatory studies and gives some preliminary information about the outcomes of the first test.

Robustheit von Verbunddecken – Eine experimentelle Bewertung. In den letzten Jahren ist das Interesse an der Begrenzung von durch Unfälle bedingten Schäden gewachsen. Die Kenntnis der Lastübertragungsmechanismen von den beschädigten zu den unbeschädigten Tragwerksteilen ist der Schlüssel zur Entwicklung geeigneter Bemessungskonzepte. Trotz der wichtigen Erkenntnis über den Einfluss der Deckenwirkung stehen keine ausreichenden Forschungsergebnisse zu dieser Thematik zur Verfügung. In einem europäischen Forschungsprojekt werden Tragsysteme aus Verbundrahmen mit Stahlbetonplatten untersucht. Dabei werden zwei geometrisch unterschiedliche 3D‐Versuchsrahmen auf die extreme Annahme eines Stützenausfalls untersucht. Die Versuchsrahmen sind vollmaßstäblich ausgebildet und repräsentieren den unteren Teil des Rahmentragwerks eines fünfstöckigen Gebäudes. Die Auflagerbedingungen und die Belastungssequenzen der Versuchsrahmen wurden durch zahlreiche numerische Untersuchungen ermittelt, um denjenigen des Rahmensystems vom Gebäude zu entsprechen. Der vorliegende Beitrag zeigt diese Vorstudien und berichtet über einige experimentelle Ergebnisse aus dem ersten Versuch.
Gestaltung und Berechnung von Stahlkonstruktionen für Nachlaufinstallationen von Tunnelbohrmaschinen
Authors: Baumann Hans Jörg , Blümel Steffen , Kälin Andreas
Published: September 2014

Nachlaufinstallationen von Tunnelbohrmaschinen werden grundsätzlich aus Stahl hergestellt. Die Berechnung und konstruktive Gestaltung erfolgt analog den Konstruktionen des Stahlhochbaus auf der Grundlage der EN 1993 oder entsprechender nationaler Normenwerke. Bei der Planung derartiger temporärer und bewegter Bauwerke sind jedoch eine Vielzahl von spezifischen konstruktiven Anforderungen aus der Nutzung und diverse statische Anforderungen hinsichtlich der Beanspruchung sowie der Modellbildung zu berücksichtigen. In diesem Aufsatz werden einige dieser Anforderungen vorgestellt und Lösungsvarianten für die Ausbildung des Tragsystems aufgezeigt.

Design and analysis of steel structures for back‐up installations of tunnel boring machines. Back‐up installations of tunnel boring machines are generally made of steel structures. The analysis and structural design is analogous to the steel building constructions and has to be done on the basis of EN 1993 or equivalent national standards. However, for such temporary and moving structures a variety of specific design requirements due to use and various static requirements concerning loads and system modelling have to be taken into account. In this paper, some of these requirements as well as solutions for the design will be presented.
Zur Nachhaltigkeit von Stahl‐ und Verbundkonstruktionen bei Büro‐ und Verwaltungsgebäuden – Tragkonstruktionen (Teil 2)
Authors: Stroetmann Richard , Podgorski Christine
Published: September 2014

Der folgende Beitrag zur Nachhaltigkeit von Tragkonstruktionen für Büro‐ und Verwaltungsgebäude ist eine Fortsetzung des Aufsatzes [1]. Dort wurden zunächst eine Übersicht über das AIF‐FOSTA‐Projekt P881 gegeben und die Objektanforderungen an die Tragkonstruktionen sowie Deckensysteme in Stahl‐ und Verbundbauweise beschrieben. Nach einer Übersicht zur Normungssituation und Bewertungssystemen wurde die im Forschungsprojekt angewendete Methodik zur Beurteilung der ökologischen und ökonomischen Qualität von Tragkonstruktionen erläutert. Ferner ging der Beitrag auf Untersuchungen zur Optimierung von Deckensystemen ein. Gegenstand des hier vorliegenden zweiten Teils ist die Querschnittswahl und Bemessung der Gebäudestützen für ständige und vorübergehende Bemessungssituationen sowie für den Brandfall unter Nachhaltigkeitskriterien. Anschließend werden die Ergebnisse aus Parameterstudien zur Optimierung von Tragsystemen mit Unterzugsdecken vorgestellt, in denen die Decken, Trägersysteme und Stützen einbezogen wurden. In einem noch folgenden Beitrag werden dann Flachdeckensysteme und die Anschlüsse thematisiert.

Sustainability of steel and composite structures of office and administration buildings – Structural systems (part 2). The following paper on the sustainability of structural systems of office and administration buildings is a sequel of the article [1]. In that paper, an overview on the AIF FOSTA Project P881 was given and the requirements resulting from the building and structural design as well as slab systems in steel and composite construction were described. After an overview on the standardization situation and assessment systems, the methods used in the research project to assess the environmental and economic performance of structural systems were explained. In addition, the paper discussed studies on the optimization of slab systems. The choice of the cross‐section and the dimensioning of the building columns for persistent and transient design situations as well as for the case of fire considering sustainability criteria are the subject of the second part on the structural systems. Following this, the results of parametric studies to identify the optimal structural systems with downstand beams are presented, in which the slabs, beam systems and columns are included. Slim floor systems and connections are addressed in a remaining paper.
Sleep deprivation induces differential morphological changes in the hippocampus and prefrontal cortex in young and old rats
Authors: Acosta‐peña Eva , Camacho‐Abrego Israel , Melgarejo‐Gutiérrez Montserrat , Flores Gonzalo , Drucker‐Colín René , García‐García Fabio
Published: September 2014

Sleep is a fundamental state necessary for maintenance of physical and neurological homeostasis throughout life. Several studies regarding the functions of sleep have been focused on effects of sleep deprivation on synaptic plasticity at a molecular and electrophysiological level, and only a few studies have studied sleep function from a structural perspective. Moreover, during normal aging, sleep architecture displays some changes that could affect normal development in the elderly. In this study, using a Golgi‐Cox staining followed by Sholl analysis, we evaluate the effects of 24 h of total sleep deprivation on neuronal morphology of pyramidal neurons from Layer III of the prefrontal cortex (PFC) and the dorsal hippocampal CA1 region from male Wistar rats at two different ages (3 and 22 months). We found no differences in total dendritic length and branching length in both analyzed regions after sleep deprivation. Spine density was reduced in the CA1 of young‐adults, and interestingly, sleep deprivation increased spine density in PFC of aged animals. Taken together, our results show that 24 h of total sleep deprivation have different effects on synaptic plasticity and could play a beneficial role in cognition during aging. Synapse 69:15–25, 2015. © 2014 Wiley Periodicals, Inc.
True Reproducibility of UltraSound Techniques (TRUST): systematic review of reliability studies in obstetrics and gynecology
Authors: Coelho Neto M. A. , Roncato P. , Nastri C. O. , Martins W. P.
Published: September 2014

Objectives

To examine the quality of methods used and the accuracy of the interpretation of agreement in existing studies that examine the reliability of ultrasound measurements and judgments in obstetrics and gynecology.

Methods

A systematic search of MEDLINE was performed on 25 March 2014, looking for studies that examined the reliability of ultrasound measurements and judgments in obstetrics and gynecology with evaluation of concordance (CCC) or intraclass (ICC) correlation coefficients or kappa as a main objective.

Results

Seven hundred and thirty‐three records were examined on the basis of their title and abstract, of which 141 full‐text articles were examined completely for eligibility. We excluded 29 studies because they did not report CCC/ICC/kappa, leaving 112 studies that were included in our analysis. Two studies reported both ICC and kappa and were counted twice, therefore, the number used as the denominator in the analyses was 114. Only 16/114 (14.0%) studies were considered to be well designed (independent acquisition and blinded analysis) and to have interpreted the results properly. Most errors occurring in the studies are likely to overestimate the reliability of the method examined.

Conclusions

The vast majority of published studies examined had
important flaws in design, interpretation and/or reporting. Such limitations are important to identify as they might create false confidence in the existing measurements and judgments, jeopardizing clinical practice and future research. Specific guidelines aimed at improving the quality of reproducibility studies that examine ultrasound methods should be encouraged. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.