bluuebunny/crossref_metadata_2025 huggingface dataset:
Reducing and Total Sugar Content in Onion During Storage in the Republic of Macedonia
Authors: Bogevska Zvezda , Agic Rukie , Popsimonova Gordana , Davitkovska Margarita , Iljovski Igor
Published: January 2017

In Macedonia, sweet onion landrace ‘buchinska arshlama’ is traditionally stored during winter period from October until April. The objective of this research was to determine the content of reducing sugar and total sugar in onion bulbs during storage period in a traditional way and in cold rooms. Every month, samples were taken for chemical analysis. The results were statistically processed and tested with t-test. The average reducing sugar content in onion stored in a traditional way was 4.8%, while the average reducing sugar content in onion stored in cold rooms was 4.6%. The average total sugar content in onion stored in a traditional way was 6.0%, while the average total sugar content in onion stored in a cold room was 5.6%. These results showed that onion `buchinska arshlama` can be successfully stored in a traditional way until the beginning of February or longer in cold rooms.
Assessment of Fishery Products Consumption Behavior: the Case of Turkey
Authors: Yilmaz İbrahim , Yilmaz Serpil , Olguner M. Tunca
Published: January 2017

From the early history of humanity until today, fish and other fishery products have always been involved in human diet. The intake of a sufficient number of proteins has been enabled through high-quality fish meat containing a significant quantity of essential amino acids as well as omega-3 fatty acids. According to the studies, 150 grams of fish, meets the needs of a 50-60% of daily protein intake for an adult. A large part of fishery production in Turkey (86%), is consumed fresh. Turkey, within the scope of Common Fisheries Policy is trying to harmonize fisheries with the EU. A failure to update the 1380 coded Fisheries Law and rapid issuing of EU compatible regulations, safe food for consumers, high quality products along the year for processing industry and marketers, as well as the inability to ensure sustainable price development for the producers, prevent the success of the sector. The aim of this study was to determine the consumption behavior when taking fishery products in terms of food safety, reliability, product quality as well as the level of income and education.
Using the Volta phase plate with defocus for cryo-EM single particle analysis
Authors: Danev Radostin , Tegunov Dimitry , Baumeister Wolfgang
Published: January 2017

Previously, we reported an in-focus data acquisition method for cryo-EM single-particle analysis with the Volta phase plate (Danev and Baumeister, 2016). Here, we extend the technique to include a small amount of defocus which enables contrast transfer function measurement and correction. This hybrid approach simplifies the experiment and increases the data acquisition speed. It also removes the resolution limit inherent to the in-focus method thus allowing 3D reconstructions with resolutions better than 3 Å.
Combinatorial Evolution of Biomimetic Magnetite Nanoparticles
Authors: Lenders Jos J. M. , Bawazer Lukmaan A. , Green David C. , Zope Harshal R. , Bomans Paul H. H. , de With Gijsbertus , Kros Alexander , Meldrum Fiona C. , Sommerdijk Nico A. J. M.
Published: January 2017

Inspired by Nature's capacity to synthesize well‐defined inorganic nanostructures, such as the magnetite particles produced by magnetotactic bacteria, genetic algorithms are employed to combinatorially optimize the aqueous synthesis of magnetite (Fe3O4) nanoparticles through the action of copolypeptide additives. An automated dispensing system is used to prepare and rapidly screen hundreds of mineralization reactions with randomized conditions, varying ferrous iron, base, oxidant, and polypeptide chemistry. Optimization over multiple generations allows identification of conditions under which the copolypeptides promote magnetite formation where this does not occur in their absence. It is found that nanoparticle size, size distribution, and shape can be tuned by the concentrations and compositions of the copolypeptides, and that the reaction pH is the most important factor in controlling the crystalline phase. This approach should be broadly applicable to the syntheses of solid‐state materials and represents a valuable strategy for extending biomimetic mineralization to the production of technological materials.
Toughness and Fracture Properties in Nacre‐Mimetic Clay/Polymer Nanocomposites
Authors: Morits Maria , Verho Tuukka , Sorvari Juhana , Liljeström Ville , Kostiainen Mauri A. , Gröschel André H. , Ikkala Olli
Published: January 2017

Nacre inspires researchers by combining stiffness with toughness by its unique microstructure of aligned aragonite platelets. This brick‐and‐mortar structure of reinforcing platelets separated with thin organic matrix has been replicated in numerous mimics that can be divided into two categories: microcomposites with aligned metal oxide microplatelets in polymer matrix, and nanocomposites with self‐assembled nanoplatelets—usually clay or graphene oxide—and polymer. While microcomposites have shown exceptional fracture toughness, current fabrication methods have limited nacre‐mimetic nanocomposites to thin films where fracture properties remained unexplored. Yet, fracture resistance is the defining property of nacre, therefore centrally important in any mimic. Furthermore, to make use of these properties in applications, bulk materials are required. Here, up to centimeter‐thick nacre‐mimetic clay/polymer nanocomposites are produced by the lamination of self‐assembled films. The aligned clay nanoplatelets are separated by poly(vinyl alcohol) matrix, with 106–107 nanoplatelets on top of each other in the bulk plates. Fracture testing shows crack deflection and a fracture toughness of 3.4 MPa m1/2, not far from nacre. Flexural tests show high stiffness (25 GPa) and strength (220 MPa) that, despite the hydrophilic constituents, are not substantially affected by exposure to humidity.
Multi‐Scale Microstructural Thermoelectric Materials: Transport Behavior, Non‐Equilibrium Preparation, and Applications
Authors: Su Xianli , Wei Ping , Li Han , Liu Wei , Yan Yonggao , Li Peng , Su Chuqi , Xie Changjun , Zhao Wenyu , Zhai Pengcheng , Zhang Qingjie , Tang Xinfeng , Uher Ctirad
Published: January 2017

Considering only about one third of the world's energy consumption is effectively utilized for functional uses, and the remaining is dissipated as waste heat, thermoelectric (TE) materials, which offer a direct and clean thermal‐to‐electric conversion pathway, have generated a tremendous worldwide interest. The last two decades have witnessed a remarkable development in TE materials. This Review summarizes the efforts devoted to the study of non‐equilibrium synthesis of TE materials with multi‐scale structures, their transport behavior, and areas of applications. Studies that work towards the ultimate goal of developing highly efficient TE materials possessing multi‐scale architectures are highlighted, encompassing the optimization of TE performance via engineering the structures with different dimensional aspects spanning from the atomic and molecular scales, to nanometer sizes, and to the mesoscale. In consideration of the practical applications of high‐performance TE materials, the non‐equilibrium approaches offer a fast and controllable fabrication of multi‐scale microstructures, and their scale up to industrial‐size manufacturing is emphasized here. Finally, the design of two integrated power generating TE systems are described—a solar thermoelectric‐photovoltaic hybrid system and a vehicle waste heat harvesting system—that represent perhaps the most important applications of thermoelectricity in the energy conversion area.
Amino Acids and Peptide‐Based Supramolecular Hydrogels for Three‐Dimensional Cell Culture
Authors: Dou Xiao‐Qiu , Feng Chuan‐Liang
Published: January 2017

Supramolecular hydrogels assembled from amino acids and peptide‐derived hydrogelators have shown great potential as biomimetic three‐dimensional (3D) extracellular matrices because of their merits over conventional polymeric hydrogels, such as non‐covalent or physical interactions, controllable self‐assembly, and biocompatibility. These merits enable hydrogels to be made not only by using external stimuli, but also under physiological conditions by rationally designing gelator structures, as well as in situ encapsulation of cells into hydrogels for 3D culture. This review will assess current progress in the preparation of amino acids and peptide‐based hydrogels under various kinds of external stimuli, and in situ encapsulation of cells into the hydrogels, with a focus on understanding the associations between their structures, properties, and functions during cell culture, and the remaining challenges in this field. The amino acids and peptide‐based hydrogelators with rationally designed structures have promising applications in the fields of regenerative medicine, tissue engineering, and pre‐clinical evaluation.
The Catalytic Mechanism of the Class C Radical S‐Adenosylmethionine Methyltransferase NosN
Authors: Ding Wei , Li Yongzhen , Zhao Junfeng , Ji Xinjian , Mo Tianlu , Qianzhu Haocheng , Tu Tao , Deng Zixin , Yu Yi , Chen Fener , Zhang Qi
Published: January 2017

S‐Adenosylmethionine (SAM) is one of the most common co‐substrates in enzyme‐catalyzed methylation reactions. Most SAM‐dependent reactions proceed through an SN2 mechanism, whereas a subset of them involves radical intermediates for methylating non‐nucleophilic substrates. Herein, we report the characterization and mechanistic investigation of NosN, a class C radical SAM methyltransferase involved in the biosynthesis of the thiopeptide antibiotic nosiheptide. We show that, in contrast to all known SAM‐dependent methyltransferases, NosN does not produce S‐adenosylhomocysteine (SAH) as a co‐product. Instead, NosN converts SAM into 5′‐methylthioadenosine as a direct methyl donor, employing a radical‐based mechanism for methylation and releasing 5′‐thioadenosine as a co‐product. A series of biochemical and computational studies allowed us to propose a comprehensive mechanism for NosN catalysis, which represents a new paradigm for enzyme‐catalyzed methylation reactions.
Preferential Carbon Monoxide Oxidation over Copper‐Based Catalysts under In Situ Ball Milling
Authors: Eckert Rene , Felderhoff Michael , Schüth Ferdi
Published: January 2017

In situ ball milling of solid catalysts is a promising yet almost unexplored concept for boosting catalytic performance. The continuous preferential oxidation of CO (CO‐PROX) under in situ ball milling of Cu‐based catalysts such as Cu/Cr2O3 is presented. At temperatures as low as −40 °C, considerable activity and more than 95 % selectivity were achieved. A negative apparent activation energy was observed, which is attributed to the mechanically induced generation and subsequent thermal healing of short‐lived surface defects. In situ ball milling at sub‐zero temperatures resulted in an increase of the CO oxidation rate by roughly 4 orders of magnitude. This drastic and highly selective enhancement of CO oxidation showcases the potential of in situ ball milling in heterogeneous catalysis.
Enantioselective Synthesis of Chiral Oxime Ethers: Desymmetrization and Dynamic Kinetic Resolution of Substituted Cyclohexanones
Authors: Nimmagadda Sri Krishna , Mallojjala Sharath Chandra , Woztas Lukasz , Wheeler Steven E. , Antilla Jon C.
Published: January 2017

Axially chiral cyclohexylidene oxime ethers exhibit unique chirality because of the restricted rotation of C=N. The first catalytic enantioselective synthesis of novel axially chiral cyclohexylidene oximes has been developed by catalytic desymmetrization of 4‐substituted cyclohexanones with O‐arylhydroxylamines and is catalyzed by a chiral BINOL‐derived strontium phosphate with excellent yields and good enantioselectivities. In addition, chiral BINOL‐derived phosphoric acid catalyzed dynamic kinetic resolution of α‐substituted cyclohexanones has been performed and yields versatile intermediates in high yields and enantioselectivities.
Glycerol‐plasticized spirulina–poly(vinyl alcohol) films with improved mechanical performance
Authors: Shi Bo , Liang Liang , Yang Hui , Zhang Liming , He Fuan
Published: January 2017

Spirulina–poly(vinyl alcohol) (PVA)–glycerol (SPG) films with improved mechanical performance, especially tensile strength (TS) and the elongation at break (EAB), are fabricated by a casting method. The integrity, color, solubility, microstructure, thermal properties, tensile strength, and compatibility of the SPG films are assessed. SPG films became smooth, homogeneous, and flexible after plasticizing with glycerol. The presence of PVA and hydrogen bonding of PVA with glycerol and spirulina protein improves the water resistance of SPG films by decreasing water absorption of spirulina protein and decreasing water diffusion through the films. The amount of carbonaceous residues decreases from 31% to 14% because of the co‐pyrolysis of spirulina, PVA, and glycerol. TS increases from 2.5 to 26 Mpa and modulus from 53 to 610 Mpa with increasing PVA content. Glycerol enhances film flexibility and EAB up to 50%. Spirulina can be composited with hydrophilic polymers to fabricate compatible, processable and thermally recyclable films with desirable mechanical performance. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44842.
Synthesis and swelling property of the starch‐based macroporous superabsorbent
Authors: Meng Yeqiao , Ye Lin
Published: January 2017

The starch‐based macroporous superabsorbent polymer (St‐MP SAP) was synthesized by graft copolymerization of acrylic acid (AA)/2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid (AMPS) onto cassava starch through free radical polymerization method by using sodium bicarbonate (SHC) as porogen. The monomer conversion kinetics was investigated to determine the suitable time of adding SHC so as to produce large numbers of stable and uniform pores inside the SAP. Introduction of SHC led to the formation of increasing pores and loose structure in St‐MP SAP, the decrease of shear storage modulus (G′). With increasing SHC content, the size of the macro pores increased and the wall thickness decreased, and a large number of micropores can be observed on the pore walls. Meanwhile the equilibrium swelling ratio of St‐MP SAP first increased and then decreased, and reached maximum as high as 1878 g/g and 119 g/g in distilled water and NaCl aqueous solution respectively for the sample with presence of 0.8 wt % SHC. Furthermore, the swelling rate constant (k) increased monotonously and fast swelling was presented. The macro and micropore structure in St‐MP SAP enabled water to flow by capillary effect with much fewer obstructions, and the specific surface area increased, with the result that more hydrophilic groups can get in touch with water molecules rapidly. By introduction of SHC, the water molecules which can form hydrogen bonds with St‐MP SAP molecules decreased, resulting in the decrease of the binding capacity of water molecules and water retention property. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44855.
Adaptive Impulsive Observers for a Class of Switched Nonlinear Systems with Unknown Parameter
Authors: Li Jinghan , Ma Ruicheng , Dimirovski Georgi M.
Published: January 2017

This work investigates and solves the design of adaptive impulsive observers for a class of uncertain switched nonlinear systems with unknown parameter. Sufficient conditions are derived for designing such observers for each subsystem to reconstruct asymptotically and update system states in real time. The state observer is represented in terms of impulsive differential equations. The parameter estimation law is modelled by an impulse‐free, time‐varying differential equation associated with the impulse time sequence in order to determine when the observer estimated state is updated. The asymptotic convergence to zero of the observation errors is established by applying the method of multiple time‐varying Lyapunov functions. Sufficient conditions are derived that guarantee the convergence of parameter estimation. An example of switched Lorenz system along with numeric and simulation results is presented to demonstrate the effectiveness of the proposed method.
Distinct profiles of social skill in adults with autism spectrum disorder and schizophrenia
Authors: Morrison Kerrianne E. , Pinkham Amy E. , Penn David L. , Kelsven Skylar , Ludwig Kelsey , Sasson Noah J.
Published: January 2017

Overlapping social impairments in Autism Spectrum Disorder (ASD) and Schizophrenia (SCZ) contributed to decades of diagnostic confusion that continues to this day in some clinical settings. The current study provides the first direct and detailed comparison of social behavior in the two disorders by identifying profiles of social skill in adults with ASD (n = 54), SCZ (n = 54), and typically developing (TD) controls (n = 56) during a real‐world social interaction. ASD and SCZ groups exhibited poorer social skill, both overall and on most discrete abilities, relative to the TD group. Direct comparison of ASD to SCZ revealed distinct behavioral profiles, with ASD uniquely characterized by fewer interactive behaviors, and SCZ characterized by greater impaired gaze and flat/inappropriate affective responses. Additionally, IQ was associated with both overall social skill and many discrete social skills in SCZ, but was largely unrelated to social skill in ASD. These results indicate that overlapping social deficits in ASD and SCZ are comprised of both shared and distinct social skill impairments. The largest distinctions—reduced social reciprocity but better expressivity in ASD relative to SCZ, and a greater role of IQ in social skill for SCZ than ASD—highlight disorder‐specific features that can improve etiological understanding, diagnostic differentiation, and treatment strategies. Autism Res 2017, 10: 878–887. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.
Whole‐cell Escherichia coli lactate biosensor for monitoring mammalian cell cultures during biopharmaceutical production
Authors: Goers Lisa , Ainsworth Catherine , Goey Cher Hui , Kontoravdi Cleo , Freemont Paul S. , Polizzi Karen M.
Published: January 2017

Many high‐value added recombinant proteins, such as therapeutic glycoproteins, are produced using mammalian cell cultures. In order to optimize the productivity of these cultures it is important to monitor cellular metabolism, for example the utilization of nutrients and the accumulation of metabolic waste products. One metabolic waste product of interest is lactic acid (lactate), overaccumulation of which can decrease cellular growth and protein production. Current methods for the detection of lactate are limited in terms of cost, sensitivity, and robustness. Therefore, we developed a whole‐cell Escherichia coli lactate biosensor based on the lldPRD operon and successfully used it to monitor lactate concentration in mammalian cell cultures. Using real samples and analytical validation we demonstrate that our biosensor can be used for absolute quantification of metabolites in complex samples with high accuracy, sensitivity, and robustness. Importantly, our whole‐cell biosensor was able to detect lactate at concentrations more than two orders of magnitude lower than the industry standard method, making it useful for monitoring lactate concentrations in early phase culture. Given the importance of lactate in a variety of both industrial and clinical contexts we anticipate that our whole‐cell biosensor can be used to address a range of interesting biological questions. It also serves as a blueprint for how to capitalize on the wealth of genetic operons for metabolite sensing available in nature for the development of other whole‐cell biosensors. Biotechnol. Bioeng. 2017;114: 1290–1300. © 2017 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc.
Kinetic insights into ϵ‐caprolactone synthesis: Improvement of an enzymatic cascade reaction
Authors: Scherkus Christian , Schmidt Sandy , Bornscheuer Uwe T. , Gröger Harald , Kara Selin , Liese Andreas
Published: January 2017

A computational approach for the simulation and prediction of a linear three‐step enzymatic cascade for the synthesis of ϵ‐caprolactone (ECL) coupling an alcohol dehydrogenase (ADH), a cyclohexanone monooxygenase (CHMO), and a lipase for the subsequent hydrolysis of ECL to 6‐hydroxyhexanoic acid (6‐HHA). A kinetic model was developed with an accuracy of prediction for a fed‐batch mode of 37% for substrate cyclohexanol (CHL), 90% for ECL, and >99% for the final product 6‐HHA. Due to a severe inhibition of the CHMO by CHL, a batch synthesis was shown to be less efficient than a fed‐batch approach. In the fed‐batch synthesis, full conversion of 100 mM CHL was 28% faster with an analytical yield of 98% compared to 49% in case of the batch synthesis. The lipase‐catalyzed hydrolysis of ECL to 6‐HHA circumvents the inhibition of the CHMO by ECL enabling a 24% higher product concentration of 6‐HHA compared to ECL in case of the fed‐batch synthesis without lipase. Biotechnol. Bioeng. 2017;114: 1215–1221. © 2017 Wiley Periodicals, Inc.
Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for peritoneal metastases of colorectal origin
Authors: Kok N F M , de Hingh I H J T
Published: January 2017

Weak evidence base for clinical trials
Deep sedation Vs. general anesthesia in 232 patients undergoing percutaneous mitral valve repair using the MitraClip® system
Authors: Horn Patrick , Hellhammer Katharina , Minier Michael , Stenzel Monika A. , Veulemans Verena , Rassaf Tienush , Luedike Peter , Pohl Julia , Balzer Jan , Zeus Tobias , Kelm Malte , Westenfeld Ralf
Published: January 2017

Objectives

To investigate in a series of 232 patients whether the MitraClip® procedure can be performed safely using deep sedation (DS) without general anesthesia (GA).

Background

Transcatheter mitral valve repair using the MitraClip® system is a safe and effective therapy for severe mitral regurgitation (MR) in patients who are at high operative risk or are unsuitable for surgery. For these patients, avoidance of GA might be beneficial.

Methods

Between 2011 and 2015, we performed 232 MitraClip® procedures for the treatment of severe MR. Of those, 76 procedures were performed using GA, while the remaining 156 procedures were performed using DS.

Results

Age, logistic EuroScore, severity of MR, left and right ventricular function, and renal function did not differ between the groups. The primary combined safety endpoint, which was defined as the occurrence of major adverse cardiac and cerebrovascular events, conversion to surgery, major vascular complications or pneumonia, did not differ between MitraClip® procedures performed using GA and MitraClip® procedures performed using DS. Intraprocedural conversion to GA was required in 2% of the patients in the DS group. There were no differences in procedural success or clinical outcome between the groups at the 3‐month follow‐up. Preparation time in the catheterization laboratory and intensive care unit (ICU) stay were shorter in the DS group compared to the GA group.

Conclusion

The MitraClip® implantation performed using DS is as safe and effective as MitraClip® implantation performed using GA. © 2017 Wiley Periodicals, Inc.
Circulatory support using the impella device in fontan patients with systemic ventricular dysfunction: A multicenter experience
Authors: Morray Brian H. , Dimas Vivian V. , Lim Scott , Balzer David T. , Parekh Dhaval R. , Van Mieghem Nicolas M. , Ewert Peter , Kim Dennis W. , Justino Henri , McElhinney Doff B. , Jones Thomas K.
Published: January 2017

Background

There are limited mechanical circulatory support options for patients with single ventricle (SV) anatomy. This is a multicenter, retrospective study of the Impella pump to support the systemic ventricle in a cohort of SV patients with Fontan circulation.

Methods

Patients with SV anatomy supported with an Impella device from 2012 to 2015 were included. Demographic information, indication for support, adverse events and short‐term outcome data were collected.

Results

Ten patients were included. The median age and weight at implant was 26 years (4‐38 years) and 64 kg (15–102 kg). Indications for support were systemic ventricular failure with cardiogenic shock (n = 8) or high‐risk electrophysiology (EP) procedures (n = 2). The median duration of support was 49 hr (2.7–264 hr). Support was discontinued for ventricular recovery in five patients, transition to another device in two patients, completion of EP procedure in two patients and death in one patient. Survival to hospital discharge was 80%. Adverse events occurred in 4 patients. There were two cases of hemolysis, one case of increasing aortic valve insufficiency with implant and one asymptomatic access site thrombus. There were no bleeding or thromboembolic events.

Conclusions

Impella devices can provide temporary support for the systemic ventricle in SV patients as a bridge to recovery or additional device. Procedural survival and adverse event profiles are favorable. © 2017 Wiley Periodicals, Inc.
Spatial Distribution of the Vanadium Atomic Species in MoVTeO and MoVTeNbO Oxide Catalysts as Revealed by High‐Angle Annular Dark‐Field Scanning Transmission Electron Microscopy
Authors: Epicier Thierry , Aouine Mimoun , Nguyen Thi Thao , Millet Jean‐Marc M.
Published: January 2017

High‐angle annular dark‐field scanning transmission electron microscopy (STEM–HAADF) was used to characterize a light‐alkane mild‐oxidation catalyst corresponding to two different MoVTe(Nb)O M1 phases. For that purpose a semiautomatic integration routine was developed, which allows the analysis of several hundred atomic columns with a normalization procedure to quantitatively determine the vanadium content of mixed (V, Mo) crystallographic sites with a low statistical variability. The obtained results were compared with data previously obtained on other M1 phases with different compositions. The comparison showed that the V distribution over the sites was not strongly influenced by the presence or absence of niobium, the method of synthesis used, and the nature of the Te or Sb cations in the hexagonal channels, but depended mainly on the total V content of the phases. Extrapolation to low V content enabled a discussion on the possible location of the vanadium active sites.
Physicochemical Processes Occurring inside Clusters Consisting of FCC Catalyst Particles
Authors: Shi Xiaogang , Wu Yingya , Wang Min , Lv Linying , Gao Jinsen , Lan Xingying
Published: January 2017

Three‐dimensional computational fluid dynamics simulations were performed to study gas flow, heat transfer, and catalytic reactions of vacuum gas oil inside spherical and ellipsoidal clusters consisting of fluid catalytic cracking catalyst particles. Simulation results with respect to gas flow inside the cluster and convective heat transfer between the gas and catalyst particle agreed well with results from the literature. Simulation results indicated that the gas stayed longer and had a higher temperature inside the cluster than that in the main stream, which intensified secondary reactions of gasoline species in the gas. At a higher cluster porosity, it was predicted that the gas could flow through the cluster with lower resistance and that secondary reactions lessened.
Volumetric Mass Transfer Coefficient in Fermenters: Scale‐up Study in Viscous Liquids
Authors: Petříček Radim , Labík Libor , Moucha Tomáš , Rejl František Jonáš , Valenz Lukáš , Haidl Jan
Published: January 2017

In the design of mechanically agitated fermenters, the volumetric mass transfer coefficient kLa often becomes the key parameter. In case of viscous liquids, kLa prediction based on literature correlations suffers from a wide distribution. The aim is to provide reliable kLa correlations based on a large experimental data set obtained using the dynamic pressure method, the physical correctness of which was verified earlier. Multiple‐impeller fermenters of two scales were used. The impeller tip speed, rather than the power input, revealed to be the proper term for prediction of kLa. When the impeller power number is used, kLa values for various impeller types can be predicted by a common correlation which, based on a wide range of operational conditions, can be applied in the design.
Location and Network Planning for Modular Container Plants in the Process Industry
Authors: Clausen Uwe , Langkau Sven , Goedicke Ina , Lier Stefan
Published: January 2017

The application of mobile production units enables the production close to the customers or the raw materials source. The choice of location depends on the demand and requirements of the customers and their geographical distribution. Therefore, economic and qualitative evaluation criteria have to be considered. A method to develop a modular production network, validated in a case study, is presented in this paper.
Tracking Live‐Cell Response to Hexavalent Chromium Toxicity by using Scanning Electrochemical Microscopy
Authors: Henderson Jeffrey D. , Filice Fraser P. , Li Michelle S. M. , Ding Zhifeng
Published: January 2017

The effects of exposure to toxic heavy metals, such as chromium, are of interest in scientific research, owing to its association with oxidative stress, cytotoxicity, and carcinogenicity. This study aims to explore the effects of Cr (VI) on live cell responses. Herein, scanning electrochemical microscopy (SECM) is employed by using depth scan imaging and feedback mode to monitor the membrane permeability of single live human bladder cancer (T24) cells following 1 h incubations with Cr (VI) stimuli. By using membrane‐permeable and impermeable redox mediators, ferrocenemethanol and ferrocenecarboxylic acid, respectively, SECM depth scans yield both electrochemical and topographic information. This provides insights into the relative changes in membrane homeostasis with increased exposure to Cr (VI). Here, SECM has shown great power in determining membrane response to Cr (VI) exposure. Dependent on the level of exposure, transition between three distinct trends was observed. At low incubation concentrations of Cr (VI), the cell membrane permeability coefficients were relatively unaffected. With moderate increases in Cr (VI) concentrations, membrane permeability coefficients of the incubated cells were observed to decrease. Finally, with the higher incubation concentrations, membrane permeability coefficients were found to increase toward values similar to control cells. The Cr (VI) toxicity was further investigated by means of a MTT cell viability study, which exhibited a similar decreasing trend to the cell membrane permeability. These findings further demonstrate the strength of SECM as a bioanalytical technique for monitoring cellular homeostasis.
Synthesis of High‐Purity Imidazolium Tetrafluoroborates and Bis(oxalato)borates
Authors: Schmitz Paulo , Jakelski Rene , Jalkanen Kirsi , Winter Martin , Bieker Peter
Published: January 2017

The synthesis and purification of imidazolium‐based ionic liquids (ILs) with boron‐containing anions is reported. The scope was the optimization of the meta thesis reaction and on the purification of the synthesized ILs. It was possible to reduce the reaction and purification times, to avoid the use of acetonitrile as processing solvent, and to increase the yield compared to the known procedure for [BOB]− anion‐containing ILs. Furthermore, to the best of our knowledge the flashpoints of the ILs could be determined for the first time by the continuously closed‐cup flashpoint (CCCFP) method.
Halogen and Hydrogen Bonding between (N‐Halogeno)‐succinimides and Pyridine Derivatives in Solution, the Solid State and In Silico
Authors: Stilinović Vladimir , Horvat Gordan , Hrenar Tomica , Nemec Vinko , Cinčić Dominik
Published: January 2017

A study of strong halogen bonding within three series of halogen‐bonded complexes, derived from seven para‐substituted pyridine derivatives and three N‐halosuccinimides (iodo, bromo and chloro), has been undertaken with the aid of single‐crystal diffraction, solution complexation and computational methods. The halogen bond was compared with the hydrogen bond in an equivalent series based on succinimide. The halogen‐bond energies are in the range −60 to −20 kJ mol−1 and change regularly with pyridine basicity and the Lewis acidity of the halogen. The halogen‐bond energies correlate linearly with the product of charges on the contact atoms, which indicates a predominantly electrostatic interaction. The binding enthalpies in solution are around 19 kJ mol−1 less negative due to solvation effects. The optimised geometries of the complexes in the gas phase are comparable to those of the solid‐state structures, and the effects of the supramolecular surroundings in the latter are discussed. The bond energies for the hydrogen‐bonded series are intermediate between the halogen‐bond energies of iodine and bromine, although there are specific differences in the geometries of the halogen‐ and hydrogen‐bonded complexes.
Tandem Oxidative C−H Amination and Iodization to Synthesize Difunctional Atropoisomeric P‐Stereogenic Phosphinamides
Authors: Ma Yan‐Na , Zhang Xi , Yang Shang‐dong
Published: January 2017

An efficient metal‐free tandem intramolecular oxidative C−H amination and iodization of phosphinamide was performed and a series of new phosphorus heterocyclic compounds was obtained. This method provides a concise and highly valuable pathway for the synthesis of difunctional atropoisomeric P‐stereogenic phosphinamides.
Conversion of ground tire rubber to lead ions adsorbents by chemical modification
Authors: Wang Shaobo , Liao Huiwei , Deng Qiulin , Guo Wenjie , Zeng Zhuo
Published: January 2017

Thermal‐chemical treatment of waste rubber tires as an adsorbent has attracted considerable attention in the last few years. However, the main drawback associated with such tire‐derived adsorbents is their pyrolysis process of preparation, which consumes more energy and does harm to the environment. In this work, modified ground tire rubber was prepared merely by chemical treatment and used for the removal of Pb2+ from aqueous solution. The surface chemical property of ground tire rubber was changed through the reaction with bromine, followed by a lysine reaction to develop the carboxylic and amino groups on the rubber. The modified ground tire rubber was characterized by FTIR, SEM, LDPSA, and X‐ray diffraction. Experimental parameters, such as pH, adsorbent dosage, and contact time on the removal of Pb2+ from aqueous solution were investigated. Under optimal conditions, the modified ground tire rubber presents an excellent removal efficiency of 92 % with an adsorbent dosage of 1.0 g/L. Additionally, the adsorption kinetic behaviour of the process was discussed and the pseudo‐second‐order model was found to fit well to the experimental data.
Hysterectomy‐corrected cervical cancer mortality rates reveal a larger racial disparity in the United States
Authors: Beavis Anna L. , Gravitt Patti E. , Rositch Anne F.
Published: January 2017

BACKGROUND

The objectives of this study were to determine the age‐standardized and age‐specific annual US cervical cancer mortality rates after correction for the prevalence of hysterectomy and to evaluate disparities by age and race.

METHODS

Estimates for deaths due to cervical cancer stratified by age, state, year, and race were derived from the National Center for Health Statistics county mortality data (2000‐2012). Equivalently stratified data on the prevalence of hysterectomy for women 20 years old or older from the Behavioral Risk Factor Surveillance System survey were used to remove women who were not at risk from the denominator. Age‐specific and age‐standardized mortality rates were computed, and trends in mortality rates were analyzed with Joinpoint regression.

RESULTS

Age‐standardized rates were higher for both races after correction. For black women, the corrected mortality rate was 10.1 per 100,000 (95% confidence interval [CI], 9.6‐10.6), whereas the uncorrected rate was 5.7 per 100,000 (95% CI, 5.5‐6.0). The corrected rate for white women was 4.7 per 100,000 (95% CI, 4.6‐4.8), whereas the uncorrected rate was 3.2 per 100,000 (95% CI, 3.1‐3.2). Without the correction, the disparity in mortality between races was underestimated by 44%. Black women who were 85 years old or older had the highest corrected rate: 37.2 deaths per 100,000. A trend analysis of corrected rates demonstrated that white women's rates decreased at 0.8% per year, whereas the annual decrease for black women was 3.6% (P < .05).

CONCLUSIONS

A correction for hysterectomy has revealed that cervical cancer mortality rates are underestimated, particularly in black women. The highest rates are seen in the oldest black women, and public health efforts should focus on appropriate screening and adequate treatment in this population. Cancer 2017;123:1044–50. © 2016 American Cancer Society.
One‐Step Simultaneous Exfoliation and Covalent Functionalization of MoS2 by Amino Acid Induced Solution Processes
Authors: Satheeshkumar Elumalai , Bandyopadhyay Arkamita , Sreedhara M. B. , Pati Swapan K. , Rao C. N. R. , Yoshimura Masahiro
Published: January 2017

The covalent functionalization of transition metal dichalcogenides (TMDs) has attracted significant interest because of their novel physicochemical properties for various applications. Herein, we report on amino acid (AA)‐induced solution‐processed simultaneous exfoliation and in situ covalent functionalization of exfoliated molybdenum disulfide (MoS2). Covalent functionalization of MoS2 with AAs was experimentally validated by various spectrochemical characterization and density functional theory calculations. We find that N terminal binding (NH2) of AAs with sulfur defects on exfoliated MoS2 is much more favorable than the C terminal binding (COOH). Notably, the MoS2 flakes have significantly improved biocompatibility with normal intestinal epithelial cell‐6. This exfoliation technique is presented here as general strategy; it is not limited to MoS2 and may apply to exfoliating other MX2 compounds of TMDs.
Effect of Noncovalent Interactions on Vibronic Transitions: An Experimental and Theoretical Study of the C2H⋅⋅⋅CO2 Complex
Authors: Ryazantsev Sergey V. , Tarroni Riccardo , Feldman Vladimir I. , Khriachtchev Leonid
Published: January 2017

We report on the experimental and theoretical infrared spectrum of the C2H⋅⋅⋅CO2 complex. This complex was prepared by UV photolysis of propiolic acid (HC3OOH) in argon and krypton matrices. The experimental bands of C2H in the C2H⋅⋅⋅CO2 complex are blue‐shifted from those of the C2H monomer. The calculations on the C2H⋅⋅⋅CO2 structures were performed at the RMP2/aug‐cc‐pVTZ level. The relative stability of the complex structures was evaluated by using the RCCSD(T)/aug‐cc‐pVQZ level. To simulate the spectrum of the C2H⋅⋅⋅CO2 complex, we developed the theoretical approach used earlier for the C2H monomer. Based on the calculations, the main experimental bands of the C2H⋅⋅⋅CO2 complex are assigned to the most stable parallel structure. Almost all the strong bands predicted by theory (with intensities >30 km mol−1) are observed in the experiment. To our knowledge, it is the first study of the effect of noncovalent interactions on vibronic transitions and the first report on an intermolecular complex of the C2H radical.
Recursive least square–based fast sparse multipath channel estimation
Authors: Chen Yu , Gui Guan
Published: January 2017

In the next‐generation wireless communication systems, the broadband signal transmission over wireless channel often incurs the frequency‐selective channel fading behavior and also results in the channel sparse structure, which is supported only by few large coefficients. For the stable wireless propagation to be ensured, linear adaptive channel estimation algorithms, eg, recursive least square and least mean square, have been developed. However, these traditional algorithms are unable to exploit the channel sparsity. Actually, channel estimation performance can be further improved by taking advantage of the sparsity. In this paper, 2 recursive least square–based fast adaptive sparse channel estimation algorithm is proposed by introducing sparse constraints, L1‐norm and L0‐norm, respectively. To improve the flexibility of the proposed algorithms, this paper introduces a regularization parameter selection method to adaptively exploit the channel sparsity. Finally, Monte Carlo–based computer simulations are conducted to validate the effectiveness of the proposed algorithms.
Uncertain future soil carbon dynamics under global change predicted by models constrained by total carbon measurements
Authors: Luo Zhongkui , Wang Enli , Sun Osbert J.
Published: January 2017

Pool‐based carbon (C) models are widely applied to predict soil C dynamics under global change and infer underlying mechanisms. However, it is unclear about the credibility of model‐predicted C pool size, decay rate (k), and/or microbial C use efficiency (e) as only data on bulked total C is usually available for model constraining. Using observing system simulation experiments (OSSE), we constrained a two‐pool model using simulated data sets of total soil C dynamics under topical hypotheses on responses of soil C dynamics to warming and elevated CO2 (i.e., global change scenarios). The results indicated that the model predicted great uncertainties in C pool size, k, and e under all global change scenarios, resulting in the difficulty to correctly infer the presupposed “real” values of those parameters that are used to generate the simulated total soil C for constraining the model. Furthermore, the model using the constrained parameters generated divergent future soil C dynamics. Compared with the predictions using the presupposed real parameters (i.e., the real future C dynamics), the percentage uncertainty in 100‐yr predictions using the constrained parameters was up to 45% depending on global change scenarios and data availability for model‐constraining. Such great uncertainty was mainly due to the high collinearity among the model parameters. Using pool‐based models, we argue that soil C pool size, k, and/or e and their responses to global change have to be estimated explicitly and empirically, rather than through model‐fitting, in order to accurately predict C dynamics and infer underlying mechanisms. The OSSE approach provides a powerful way to identify data requirement for the new generation of model development and test model performance.
Matching seed to site by climate similarity: Techniques to prioritize plant materials development and use in restoration
Authors: Doherty Kyle D. , Butterfield Bradley J. , Wood Troy E.
Published: January 2017

Land management agencies are increasing the use of native plant materials for vegetation treatments to restore ecosystem function and maintain natural ecological integrity. This shift toward the use of natives has highlighted a need to increase the diversity of materials available. A key problem is agreeing on how many, and which, new accessions should be developed. Here we describe new methods that address this problem. Our methods use climate data to calculate a climate similarity index between two points in a defined extent. This index can be used to predict relative performance of available accessions at a target site. In addition, the index can be used in combination with standard cluster analysis algorithms to quantify and maximize climate coverage (mean climate similarity), given a modeled range extent and a specified number of accessions. We demonstrate the utility of this latter feature by applying it to the extents of 11 western North American species with proven or potential use in restoration. First, a species‐specific seed transfer map can be readily generated for a species by predicting performance for accessions currently available; this map can be readily updated to accommodate new accessions. Next, the increase in climate coverage achieved by adding successive accessions can be explored, yielding information that managers can use to balance ecological and economic considerations in determining how many accessions to develop. This approach identifies sampling sites, referred to as climate centers, which contribute unique, complementary, climate coverage to accessions on hand, thus providing explicit sampling guidance for both germplasm preservation and research. We examine how these and other features of our approach add to existing methods used to guide plant materials development and use. Finally, we discuss how these new methods provide a framework that could be used to coordinate native plant materials development, evaluation, and use across agencies, regions, and research groups.
Community assembly in Lake Tanganyika cichlid fish: quantifying the contributions of both niche‐based and neutral processes
Authors: Janzen Thijs , Alzate Adriana , Muschick Moritz , Maan Martine E. , van der Plas Fons , Etienne Rampal S.
Published: January 2017

The cichlid family features some of the most spectacular examples of adaptive radiation. Evolutionary studies have highlighted the importance of both trophic adaptation and sexual selection in cichlid speciation. However, it is poorly understood what processes drive the composition and diversity of local cichlid species assemblages on relatively short, ecological timescales. Here, we investigate the relative importance of niche‐based and neutral processes in determining the composition and diversity of cichlid communities inhabiting various environmental conditions in the littoral zone of Lake Tanganyika, Zambia. We collected data on cichlid abundance, morphometrics, and local environments. We analyzed relationships between mean trait values, community composition, and environmental variation, and used a recently developed modeling technique (STEPCAM) to estimate the contributions of niche‐based and neutral processes to community assembly. Contrary to our expectations, our results show that stochastic processes, and not niche‐based processes, were responsible for the majority of cichlid community assembly. We also found that the relative importance of niche‐based and neutral processes was constant across environments. However, we found significant relationships between environmental variation, community trait means, and community composition. These relationships were caused by niche‐based processes, as they disappeared in simulated, purely neutrally assembled communities. Importantly, these results can potentially reconcile seemingly contrasting findings in the literature about the importance of either niche‐based or neutral‐based processes in community assembly, as we show that significant trait relationships can already be found in nearly (but not completely) neutrally assembled communities; that is, even a small deviation from neutrality can have major effects on community patterns.