bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of mycolic acid deficiency on cells of Corynebacterium glutamicum ATCC13869
Authors: Gao Yunfei , Hu Xiaoqing , Wang Jianli , Li Huazhong , Wang Xiaoyuan
Published: October 2017

Mycolic acid (MA) plays important role in Corynebacterium glutamicum, but the key enzymes in the biosynthetic pathway of MA in C. glutamicum ATCC13869 have not been characterized. Since the locus BBD29_RS14045 in C. glutamicum ATCC13869 shows high similarity to the gene Cgl2871, which encodes Pks13, the key enzyme for synthesizing MA in C. glutamicum ATCC13032, it was deleted, resulting in the mutant WG001. Compared with the wild‐type ATCC13869, MA was not synthesized in WG001, but more phosphatidylglycerol and phosphatidylinositol containing longer unsaturated fatty acids were produced. WG001 cells also show hindered cell growth and defective cell separation when compared with ATCC13869 cells. Transcriptomic analysis shows that many genes relevant to the pathways of fatty acids, inositol, phospholipids, cell wall, and cell division were significantly regulated in WG001 cells when compared with ATCC13869 cells. This study demonstrates that the locus BBD29_RS14045 encodes a key enzyme that plays important role for synthesizing MA in C. glutamicum ATCC13869.
Large‐scale purification of high purity α1‐antitrypsin from Cohn Fraction IV with virus inactivation by solvent/detergent and dry‐heat treatment
Authors: Huangfu Chaoji , Zhang Jinchao , Ma Yuyuan , Jia Junting , Li Jingxuan , Lv Maomin , Ma Xiaowei , Zhao Xiong , Zhang Jingang
Published: October 2017

α1‐Antitrypsin (AAT) is widely used to treat patients with congenital AAT deficiency. Cohn Fraction IV (Cohn F IV) is normally discarded during the manufacturing process of albumin but contains approximately 33% of plasma AAT. We established a new process for large‐scale purification of AAT from it. liquid chromatography‐electrospray ionization‐tandem mass spectrometry and high‐performance liquid chromatography were applied for qualitative identification and composition analysis, respectively. Stabilizers were optimized for AAT activity protection during lyophilization and dry‐heat. Virus inactivation by dry‐heat and solvent/detergent (S/D) was validated on a range of viruses. AAT with purity of 95.54%, specific activity of 3,938.5 IU/mg, and yield of 26.79%, was achieved. More than 95% activity was reserved after S/D. More than 96% activity was obtained after lyophilization or dry‐heat. After S/D, pseudorabies virus (PRV) and vesicular stomatitis virus (VSV) were inactivated below detectable level within 1 H. Virus titer reductions of more than 5.50 log10 and 5.38 log10 were achieved for PRV and VSV, respectively. Porcine parvovirus and encephalomyocarditis virus were inactivated by 3.17 log10 and 5.88 log10 reduction after dry‐heat. The advantages of this process, including suitability for large‐scale production, high purity, better utilization of human plasma, viral safety, commercial and inexpensive chromatography medium, may facilitate its further application.
Synthesis and characterization of KCe(PO3)4 doped with some lanthanide activators
Authors: Bhonsule Sharmila U. , Wankhede Sangeeta P. , Moharil Sanjiv V.
Published: October 2017

KCe(PO3)4 doped with Dy3+,Tb3+,Yb3+and Nd3+ phosphors were synthesized by a solid state diffusion method. The prepared samples were characterized by X‐ray diffraction and photoluminescence. KCe(PO3)4 exhibits emission in ultraviolet (UV) region which indicates weak Ce3+–Ce3+ interaction. The Ce3+–Ce3+energy transfer is not efficient. In light of this, energy transfer from Ce3+ to other lanthanides like Dy3+, Tb3+,Yb3+ and Nd3+ is rather surprising.
Development of a Potential Protein Display Platform in Corynebacterium glutamicum Using Mycolic Acid Layer Protein, NCgl1337, as an Anchoring Motif
Authors: Choi Jae Woong , Yim Sung Sun , Jeong Ki Jun
Published: October 2017

In the cell surface display, the choice of host cell and anchoring motif are the most crucial for the efficient display of passenger proteins. Corynebacterium glutamicum has mycolic acid layer in outer membrane and the use of protein in the mycolic acid layer as an anchoring motif can provide a potential platform for surface display in C. glutamicum. All 19 mycolic acid layer proteins of C. glutamicum are analyzed, and two proteins, NCgl0535 and NCgl1337, which have a signal peptide and predicted O‐mycoloylation site, are selected as anchoring motifs candidates. Among them, NCgl1337, which shows better expression with higher display efficiency, is chosen as a potential anchoring motif. Two forms of the NCgl1337 anchoring motif, a full‐length (1–324 amino acids) and a short‐length (1–50 amino acids) containing only signal peptide and O‐mycoloylation site, are constructed and their abilities for surface display are examined using two protein models, endoxylanase from Streptomyces coelicolor and α‐amylase from Streptococcus bovis. For both model proteins, the short‐length NCgl1337 anchoring motif exhibits higher yield of protein display on the surface of C. glutamicum than the full‐length NCgl1337. Finally, with C. glutamicum displaying α‐amylase, a batch fermentation is performed for the production of l‐lysine from starch degradation, and a production of l‐lysine as high as 10.8 ± 0.92 g L−1 was achieved after 18 h of culture.
Bifunctional Catalysis for the Conversion of Synthesis Gas to Olefins and Aromatics
Authors: Weber J. Lennart , Dugulan Iulian , de Jongh Petra E. , de Jong Krijn P.
Published: October 2017

The conversion of synthesis gas (a mixture of hydrogen and carbon monoxide) to value‐added chemicals has attracted significant attention in the past few years. Strong emphasis has been placed on enabling a process that allows the production of short olefins from synthesis gas, which can be derived from coal, biomass, or natural gas. Here, we introduce bifunctional catalysis to tailor the selectivity towards aromatics next to olefins by combining an iron‐based Fischer–Tropsch to olefins catalyst with the acid function of a zeolite. Olefins were formed from synthesis gas on an iron‐based catalyst and partly converted to aromatics on the acid sites of the zeolite. Surprisingly, this aromatization did not follow the pathway of hydrogen transfer, whereby three paraffin molecules are produced for every aromatic molecule formed, which allowed us to obtain carbon selectivity towards chemicals (sum of lower olefins and aromatics) of 70–80 % at 1 bar reaction pressure. Increasing the partial pressure of hydrogen led to substantial hydrogenation of olefins towards paraffins.
Production of Higher Hydrocarbons from CO2 over Nanosized Iron Catalysts
Authors: Pour Ali Nakhaei , Housaindokht Mohammad Reza , Asil Ali Garmroodi
Published: October 2017

The effects of the particle size of a Fe/Cu/K catalyst on CO and CO2 hydrogenation reactions as well as the variation of crucial factors such as surface area and basicity, reduction, carburization, and catalytic behavior of precipitated Fe/Cu/K catalysts were evaluated. Hematite nanoparticle catalysts with various surface tensions were produced by homogeneous precipitation in alcohol/water solvents. The basicity of the K‐promoted iron catalyst was higher in iron catalysts with lower particle size. The increase in K‐basic sites at the surface of catalysts with smaller particle size was attributed to their higher surface areas. Elevation of catalyst basicity led to considerably stronger dissociative CO adsorption. Shifting the oxygen removal pattern to lower temperature was the consequence of faster nucleation of FeCx crystallites on promoted surface oxides. CO2 hydrogenation can occur in two distinct direct and indirect routes via the Fischer‐Tropsch mechanism.
Preparation of Pillar[5]arene‐Based [2]Rotaxanes by a Stopper‐Exchange Strategy
Authors: Nierengarten Iwona , Meichsner Eric , Holler Michel , Pieper Pauline , Deschenaux Robert , Delavaux‐Nicot Béatrice , Nierengarten Jean‐François
Published: October 2017

A pillar[5]arene‐containing rotaxane building block bearing exchangeable stoppers has been prepared in multigram scale quantities with high yields from the reaction of 2,4‐dinitrophenol (DNP) with the inclusion complex resulting from the association of dodecanedioyl chloride with 1,4‐diethoxypillar[5]arene. Stopper exchange reactions have been achieved by treatment of the resulting DNP diester with various amines through an addition–elimination mechanism preventing the unthreading of the axle component during the reaction and thus preserving the [2]rotaxane structures. The resulting diamide [2]rotaxane derivatives have thus been obtained in good to excellent yields. Importantly, [2]rotaxanes difficult or impossible to prepare by direct introduction of the two stoppers in a single synthetic step are now easily available.
An Exfoliated 2D Egyptian Blue Nanosheet for Highly Selective Enrichment of Multi‐phosphorylated Peptides in Mass Spectrometric Analysis
Authors: Yang Shi‐Shu , Yu Hai‐Xia , Wang Zi‐Zhen , Liu Hai‐Long , Zhang Hao , Yu Xizhong , Shang Wenbin , Chen Gui‐Quan , Gu Zhi‐Yuan
Published: October 2017

Phosphopeptide enrichment is essential for the phosphoprotein profiling, due to the low abundance in complex biological samples. Moreover, selective binding of multi‐phosphopeptides over mono‐phosphopeptides is rarely established, but strongly needed in real sample analysis, especially for the investigation of cell behaviors with the multisite phosphorylation cascades. Here two‐dimensional (2D) nanosheets were synthesized of Egyptian blue (CaCuSi4O10), the well‐known ancient pigment, and its analogues (SrCuSi4O10 and BaCuSi4O10), which were employed in the enrichment of phosphopeptides for the first time. Surprisingly, the 2D CaCuSi4O10 nanosheet was highly selective towards multi‐phosphopeptides without enriching the mono‐phosphorylated peptides in a wide range of acidic conditions or buffer compositions. Meanwhile, the SrCuSi4O10 and BaCuSi4O10 nanosheet analogues do not exhibit this unique selectivity. Moreover, the ultrathin and well‐defined 2D morphology, with abundant CaII, of Egyptian blue nanosheet was applied in cortical samples of forebrain specific PDK1 conditional knockout mice and their age‐matched littermate controls, that are associated with Alzheimer's disease. The as‐prepared 2D CaCuSi4O10 nanosheet not only showed specific selectivity, but also exhibited high sensitivity (detection limit of 4×10−7 m).
Construction of Large‐Area Uniform Graphdiyne Film for High‐Performance Lithium‐Ion Batteries
Authors: He Jianjiang , Bao Kaijing , Cui Weiwei , Yu Jiaojiao , Huang Changshui , Shen Xiangyan , Cui Zili , Wang Ning
Published: October 2017

Large‐area graphdiyne film is constructed by heat treatment, including thermally induced evaporation and a cross‐coupling reaction process. The growth mechanism is proposed based on the observation and characterization that the heating temperature plays an important role in the evaporation of oligomers and in triggering the thermal cross‐coupling reaction, whereas the heating duration mainly determines the execution of the thermal cross‐coupling reaction. By controlling the heat‐treatment process, a graphdiyne film with uniform morphology and good conductivity is obtained. The improved GDY film based electrodes deliver good interfacial contact and more lithium storage sites; thus leading to superior electrochemical performance. A reversible capacity of 901 mAh g−1 is achieved. Specifically, the electrodes exhibit excellent rate performance, with which a capacity of 430 mAh g−1 is maintained at a rate as high as 5 A g−1. These advantages mean that the uniform graphdiyne film is a good candidate for the fabrication of a flexible and high‐capacity electrode material.
High‐grade urothelial carcinoma in urine cytology with jet black and smooth or glassy chromatin
Authors: Renshaw Andrew A. , Gould Edwin W.
Published: October 2017

BACKGROUND

Some high‐grade urothelial carcinomas (UCs) in urine cytology can have jet black, smooth, or glassy chromatin, but to the authors' knowledge, the incidence and criteria for diagnosis are not well described. The current study was performed to define the incidence and appearance of high‐grade UC in urine cytology in cytospin preparations with jet black and smooth or glassy chromatin.

METHODS

Cytospin preparations from 331 cases with biopsy follow‐up (230 benign/low‐grade UCs and 101 malignant UCs) were reviewed.

RESULTS

Cases with malignant cells with jet black and smooth or glassy chromatin were identified in a total of 60 cases (59.4% of all malignancies). These comprised 18 carcinoma in situ cases, 28 high‐grade papillary UCs, 8 invasive UCs, 3 squamous cell carcinomas, 2 adenocarcinomas, and 1 melanoma. Of the 93 high‐grade UCs, 51 (54.8%) had cells with either jet black and smooth or glassy chromatin. These cells were the only type of malignant cell in 6 of 101 cases (5.9%). All cases had at least 50 cells with jet black nuclei. Nuclei with jet black and smooth chromatin often were smaller than normal urothelial cells, often but not always elongate, had irregular nuclear outlines including pointed areas, and usually were accompanied by necrosis. Cells with glassy chromatin often were larger than normal urothelial cells, had rounder but still irregular nuclei, and also had frequent necrosis.

CONCLUSIONS

Malignant urothelial cells in urine cytology with jet black chromatin are common and can be diagnosed as “positive for malignancy” based on their irregular nuclear outline, increased cellularity (≥50 abnormal cells), and frequent necrosis. Cancer Cytopathol 2018;126:64‐8. © 2017 American Cancer Society.
Heterogeneity of Clinical Trials for Antihypertensive Drugs in Japan: Exploratory Analysis of Confirmatory Phase III Trials Used for Marketing Approval
Authors: Kaneko Reina , Sano Kota , Ono Shunsuke
Published: October 2017

The results of pivotal trials, which provide a rationale for marketing approval decisions for new drugs, are considered for various comparative purposes in postmarketing analyses. Using meta‐regression analysis of 91 randomized controlled trials of 61 approved antihypertensive drugs in Japan, we show that mean baseline blood pressure (BP) of each arm was associated with predetermined entry criteria (EC), age, and trial start year (TSY). BP changes following treatment were associated with EC, subject characteristics (e.g., age, complications, baseline BP), study design (e.g., concomitant drug use), and TSY. Effect sizes were generally larger in trials for the first and second drugs in the same class than in trials for follow‐on drugs. Results of pivotal trials may vary depending on many factors, suggesting possible challenges associated with the comparison of these results indirectly. Due to the heterogeneity in pivotal trials, caution should be exercised when comparing approved drugs and conducting meta‐analyses retrospectively.
Reliability challenge for impedance network‐based DC‐DC boost converters
Authors: Haji‐Esmaeili Mohammad Mehdi , Babaei Ebrahim
Published: October 2017

In this paper, reliability evaluation is proposed for some of the most famous impedance network‐based DC‐DC boost converters. Markov reliability approach is used to evaluate the reliability of the converters. Also, some other factors such as components' failure rates, reliability functions, and mean time to failures are introduced and evaluated. Detailed explanations for the evaluation methods of the mentioned factors are also provided in the context of the paper. In addition to the mathematical analysis, numerical calculations are also done through the simulation results of the converters. Simulations are done in PSCAD/EMTDC. Finally, a numerical and graphical reliability comparison is provided for the mentioned converters. The purpose of this paper is to give a comprehensive reliability evaluation and comparison for some of the most popular impedance network‐based DC‐DC converters. In addition, this paper gives a detailed reliability analysis that can be used in reliability assessment of all types of power electronic converters, so it can help the researchers to consider reliability calculations into their designing.
The influence of grasping habits and object orientation on motor planning in children and adults
Authors: Jovanovic Bianca , Schwarzer Gudrun
Published: October 2017

We investigated the influence of habitual grasp strategies and object orientation on motor planning in 3‐year‐olds and 4‐ to 5‐year‐old children and adults. Participants were required to rotate different vertically oriented objects around 180°. Usually, adults perform this task by grasping objects with an awkward grip (thumb and index finger pointing downward) at the beginning of the movement, in order to finish it with a comfortable hand position. This pattern corresponds to the well‐known end‐state comfort effect (ESC) in grasp planning. The presented objects were associated with different habitual grasp orientations that either corresponded with the grasp direction required to reach end‐state comfort (downward) or implied a contrary grasp orientation (upward). Additionally, they were presented either in their usual, canonical orientation (e.g., shovel with the blade oriented downward versus cup with its opening oriented upward) or upside down. As dependent variable we analyzed the number of grips conforming to the end‐state comfort principle (ESC score) realized in each object type and orientation condition. The number of grips conforming to ESC strongly increased with age. In addition, the extent to which end‐state comfort was considered was influenced by the actual orientation of the objects’ functional parts. Thus, in all age‐groups the ESC score was highest when the functional parts of the objects were oriented downward (shovel presented canonically with blade pointing downward, cup presented upside down) and corresponded to the hand orientation needed to realize ESC.
Pitfalls and Limitations in Group 6 Triamidophosphane Chemistry: Cage‐Closure Restrictions in Square‐Pyramidal Nitrido Complexes and Degradation via Spiro‐[4.4]‐λ5‐Amidophosphorane Formation
Authors: Sietzen Malte , Batke Sonja , Merz Lukas , Wadepohl Hubert , Ballmann Joachim
Published: October 2017

The benzylene‐linked triaminophosphanes P(C6H4‐o‐CH2NHXyl)3 ([A]H3) and P(CH2C6H4‐o‐NHPh)3 ([B]H3) react with (Me2N)3Mo≡N to afford the square‐pyramidal nitrido complexes 1 and 2, each comprising one residual dimethylamido moiety and one uncoordinated ligand sidearm. Only the [A]‐coordinated complex 1 was found to eliminate the remaining dimethylamido ligand on heating. Instead of the closed‐cage molybdenum(VI) nitrido complex [A]Mo≡N, cyclometalated molybdaziridine 3 was isolated, as the syn alignment of the uncoordinated sidearm and nitrido ligand in 1 inhibits a productive cage‐closure reaction. By using [NPN]‐coordinated model complexes, analogous syn arrangements were found not only for molybdenum, but also for the related tungsten nitrido complexes and the group 5 imides. Attempts to access the closed‐cage MoVI nitrido comlex [A]Mo≡N by transmetalation between [A]Sn(nBu) (9) and (tBuO)3Mo≡N led to the formation of spiro‐[4.4]‐λ5‐amidophosphorane 10. These results contrast with the findings made for azatranes and methylene‐linked exo‐P‐configured triamidophosphane complexes.
Selective Generation of (1H‐1,2,4‐Triazol‐1‐yl)methyl Carbanion and Condensation with Carbonyl Compounds
Authors: Lassalas Pierrik , Claraz Aurélie , Tran Gaël , Vors Jean‐Pierre , Tsuchiya Tomoki , Coqueron Pierre‐Yves , Cossy Janine
Published: October 2017

2‐(1H‐1,2,4‐Triazol‐1‐yl)ethanols have received significant interest in agricultural and medicinal chemistry owing to their herbicidal and antifungal activities. To develop a versatile method to access these substituted triazoles, we explored the generation of the (1H‐1,2,4‐triazol‐1‐yl)methyl carbanion and its condensation with carbonyl compounds. By judicious choice of a suitable anion precursor (tributylstannyl group) or a stabilizing anion group (phenylsulfanyl or phenylsulfinyl group), a wide range of aldehydes and ketones reacted with the carbanions to give a large diversity of 2‐(1H‐1,2,4‐triazol‐1‐yl)ethanols in good yields.
Using RAPD and ISSR Molecular Markers to Analyze the Genetic Diversity of Rose scented Pelargonium Populations
Authors: Yi Qing‐yuan , Yi Shao‐wen , Qin Tai‐feng , Li Cheng‐yun
Published: October 2017

In the field, the chemical constituents of the essential oil of Pelargonium graveolens cutting (diploid) and polyploid seedlings are the same, but the principal components of geraniol, geranyl formate, and linalool in polyploid plants are remarkably higher than those of cutting seedlings. The contents of citronellol, citronellyl formate, and rose oxide are significantly lower in polyploid seedlings than in cutting seedlings. ISSR and RAPD molecular markers were used to analyze P. graveolens in two different genetic populations and to compare the genetic background of differences between cutting and polyploid seedlings. The genomic DNA of 60 cutting and polyploid seedlings was extracted for PCR amplification by using 3 ISSR primers and 11 RAPD primers for random sampling from adjacent cultivated fields. Among the primers, ISSR‐25 primer detected the highest diversity of the loci. Seven loci of variation were found in the two populations. The variation rates detected using 3 ISSR primers were 13.3% and 6.7% for the cutting and polyploid populations, respectively. Genetic polymorphisms in P. graveolens genome with mutation rates of 11.7% and 3.3% were respectively determined in cutting and polyploid seedlings by using 3 RAPD primers (B11, P4, and R19). Both types of molecular markers also revealed the mutation in cutting and polyploid seedlings. Results demonstrated that a genetic difference can be observed by the molecular markers, although no evident phenotypic difference exists in cutting and polyploid seedlings in fields. The trend of these molecular markers is consistent, that is, individual genetic differences in cutting seedlings are greater than those in polyploid seedlings. These results suggested that polyploid seedlings in a population are relative uniform and applicable to production.
Case report of treatment with a sigmoid neovagina for a patient with vesicovaginal fistula and gynatresia
Authors: Sunday‐Adeoye Ileogben , Eni Uche E. , Ekwedigwe Kenneth C. , Daniyan Babafemi A.C. , Abodunrin Olusola N. , Isikhuemen Maradona E. , Eliboh Monday O. , Uguru Sunday M.
Published: October 2017

A patient experienced severe gynatresia 11 months after vesicovaginal fistula repair. A sigmoid neovagina was included in the surgical repair.
Predictors of intimate partner violence among pregnant women
Authors: Lee Sunghee , Lee Eunyoung
Published: October 2017

Objective

To identify predictive factors of intimate partner violence (IPV) among pregnant women.

Methods

In a cross‐sectional study, 250 pregnant, married women attending three women's hospitals in South Korea for prenatal care were enrolled between July 1 and August 31, 2016. The women answered structured questionnaires assessing conflict negotiation coping, social support, and IPV, which was measured by 18 questions in three domains: psychological, physical, and sexual violence. Participants who reported experience in response to more than one question were deemed to have encountered IPV. Binomial logistic regression analysis was used to investigate predictive factors of IPV.

Results

Overall, 85 (34.0%) participants had experienced IPV. Likelihood of IPV was linked with younger age (adjusted odds ratio [aOR] 0.90, 95% confidence interval [CI] 0.83–0.94; P=0.012), unemployment (aOR 1.98, 95% CI 1.07–3.70; P=0.031), and graduate school education (aOR 7.32, 95% CI 1.68–31.84; P=0.008). The likelihood of IPV increased as the social support score decreased (aOR 0.92, 95% CI 0.88–0.95; P<0.001).

Conclusion

Efforts to screen for IPV and to intervene to reduce the impact of such violence on pregnant women's delivery outcomes should be a maternal health priority in South Korea.
Mechanisms of toxicity associated with six tyrosine kinase inhibitors in human hepatocyte cell lines
Authors: Mingard Cécile , Paech Franziska , Bouitbir Jamal , Krähenbühl Stephan
Published: October 2017

Tyrosine kinase inhibitors have revolutionized the treatment of certain cancers. They are usually well tolerated, but can cause adverse reactions including liver injury. Currently, mechanisms of hepatotoxicity associated with tyrosine kinase inhibitors are only partially clarified. We therefore aimed at investigating the toxicity of regorafenib, sorafenib, ponatinib, crizotinib, dasatinib and pazopanib on HepG2 and partially on HepaRG cells. Regorafenib and sorafenib strongly inhibited oxidative metabolism (measured by the Seahorse‐XF24 analyzer) and glycolysis, decreased the mitochondrial membrane potential and induced apoptosis and/or necrosis of HepG2 cells at concentrations similar to steady‐state plasma concentrations in humans. In HepaRG cells, pretreatment with rifampicin decreased membrane toxicity (measured as adenylate kinase release) and dissipation of adenosine triphosphate stores, indicating that toxicity was associated mainly with the parent drugs. Ponatinib strongly impaired oxidative metabolism but only weakly glycolysis, and induced apoptosis of HepG2 cells at concentrations higher than steady‐state plasma concentrations in humans. Crizotinib and dasatinib did not significantly affect mitochondrial functions and inhibited glycolysis only weakly, but induced apoptosis of HepG2 cells. Pazopanib was associated with a weak increase in mitochondrial reactive oxygen species accumulation and inhibition of glycolysis without being cytotoxic. In conclusion, regorafenib and sorafenib are strong mitochondrial toxicants and inhibitors of glycolysis at clinically relevant concentrations. Ponatinib affects mitochondria and glycolysis at higher concentrations than reached in plasma (but possibly in liver), whereas crizotinib, dasatinib and pazopanib showed no relevant toxicity. Mitochondrial toxicity and inhibition of glycolysis most likely explain hepatotoxicity associated with regorafenib, sorafenib and possibly pazopanib, but not for the other compounds investigated.
Deep eutectic solvents: designer fluids for chemical processes
Authors: Wazeer Irfan , Hayyan Maan , Hadj‐Kali Mohamed K
Published: October 2017

The increasing demand for multi‐task green solvents has spurred the development of next‐generation liquid media such as deep eutectic solvents (DESs), which have recently attracted increased attention. DESs are mixtures of salts and complexing agents, having freezing points lower than those of starting individual components. Similarly to ionic liquids, DESs exhibit distinctive properties such as chemical and thermal stability, biodegradability, non‐flammability, and cost effectiveness. These features account for their wide range of applications, e.g. as extractants, reactants, catalysts, reaction media, additives, and lubricants. This review summarizes the recent research efforts directed at exploring the potential applications of DESs in various chemical processes. With the rapid publication of reports on this new generation of solvents, other roles also are expected to be seen sooner or later. © 2017 Society of Chemical Industry
A review of methods for comparing treatments evaluated in studies that form disconnected networks of evidence
Authors: Stevens John W. , Fletcher Christine , Downey Gerald , Sutton Anthea
Published: October 2017

A network meta‐analysis allows a simultaneous comparison between treatments evaluated in randomised controlled trials that share at least one treatment with at least one other study. Estimates of treatment effects may be required for treatments across disconnected networks of evidence, which requires a different statistical approach and modelling assumptions to account for imbalances in prognostic variables and treatment effect modifiers between studies. In this paper, we review and discuss methods for comparing treatments evaluated in studies that form disconnected networks of evidence. Several methods have been proposed but assessing which are appropriate often depends on the clinical context as well as the availability of data. Most methods account for sampling variation but do not always account for others sources of uncertainty. We suggest that further research is required to assess the properties of methods and the use of approaches that allow the incorporation of external information to reflect parameter and structural uncertainty.
Effects of Posidonia oceanica banquettes on intake, digestibility, nitrogen balance and metabolic profiles in sheep
Authors: Castillo Cristina , Hernández Joaquín , Sotillo Mesanza Juan , Gutiérrez Cándido , Montes Ana M , Mantecón Ángel Ruiz
Published: October 2017

BACKGROUND

The marine plant Posidonia oceanica (L.) (PO) has been demonstrated in goats to be a source of fibre. The aim of the present study was to assess the effects of introducing this marine plant as a substitute for barley straw in the feed of mature ewes, assessing the effects of its addition on intake, digestibility and ruminal fermentation and on the ewes' metabolic profiles (energy and protein). PO was used at 75 g day−1 per ewe (15% of the total forage), 150 g day−1 per ewe (30% of the total forage) and 300 g day−1 per ewe (60% of the total forage).

RESULTS

Substitution of 15% of the forage with PO has no negative consequences on dry matter intake, final live weight and metabolic status in mature ewes; in addition, PO may improve the animal's nitrogen utilisation. The upper limit of substitution was 30%, where only few changes were noted without metabolic consequences. Substitution of 60% impaired performance and affects tissue functions in the animal's body.

CONCLUSION

Moderate quantities of barley straw (between 75 and 150 g day−1 per ewe) can be replaced by PO in feed rations for mature ewes. © 2017 Society of Chemical Industry
Simultaneous determination of niacin and pyridoxine at trace levels by using diode array high‐performance liquid chromatography and liquid chromatography with quadrupole time‐of‐flight tandem mass spectrometry
Authors: Sel Sabriye , Öztürk Er Elif , Bakırdere Sezgin
Published: October 2017

A highly sensitive and simple diode‐array high‐performance liquid chromatography and liquid chromatography with quadrupole time‐of‐flight tandem mass spectrometry method was developed for the simultaneous determination of niacin and pyridoxine in pharmaceutical drugs, tap water, and wastewater samples. To determine the in vivo behavior of niacin and pyridoxine, analytes were subjected to simulated gastric conditions. The calibration plots of the diode‐array high‐performance liquid chromatography and liquid chromatography with quadrupole time‐of‐flight tandem mass spectrometry method showed good linearity over a wide concentration range with close to 1.0 correlation coefficients for both analytes. The limit of detection/limit of quantitation values for liquid chromatography quadrupole time‐of‐flight tandem mass spectrometry analysis were 1.98/6.59 and 1.3/4.4 μg/L for niacin and pyridoxine, respectively, while limit of detection/limit of quantitation values for niacin and pyridoxine in high‐performance liquid chromatography analysis were 3.7/12.3 and 5.7/18.9 μg/L, respectively. Recovery studies were also performed to show the applicability of the developed methods, and percentage recovery values were found to be 90–105% in tap water and 94–97% in wastewater for both analytes. The method was also successfully applied for the qualitative and quantitative determination of niacin and pyridoxine in drug samples.
Mobile phase effects on the retention on polar columns with special attention to the dual hydrophilic interaction–reversed‐phase liquid chromatography mechanism, a review
Authors: Jandera Pavel , Hájek Tomáš
Published: October 2017

Hydrophilic interaction liquid chromatography on polar columns in aqueous–organic mobile phases has become increasingly popular for the separation of many biologically important compounds in chemical, environmental, food, toxicological, and other samples. In spite of many new applications appearing in literature, the retention mechanism is still controversial. This review addresses recent progress in understanding of the retention models in hydrophilic interaction liquid chromatography. The main attention is focused on the role of water, both adsorbed by the column and contained in the bulk mobile phase. Further, the theoretical retention models in the isocratic and gradient elution modes are discussed. The dual hydrophilic interaction liquid chromatography reversed‐phase retention mechanism on polar columns is treated in detail, especially with respect to the practical use in one‐ and two‐dimensional liquid chromatography separations.
Kinetic Studies on SNAr Reactions of Substituted Benzofurazan Derivatives: Quantification of the Electrophilic Reactivities and Effect of Amine Nature on Reaction Mechanism
Authors: Raissi H. , Jamaoui I. , Goumont R. , Boubaker T.
Published: October 2017

Kinetics of the nucleophilic aromatic substitution reactions of 7‐L‐4‐nitrobenzofurazans 1 (1a: L = Cl and 1b: L = OCH3) and secondary cyclic amines (morpholine, piperidine, and pyrolidine) 2a–c have been measured in acetonitrile solution at 20°C. The derived values of second‐order rate constants (k1) have been employed to determine the electrophilicity parameters E for both benzofurazans 1a and 1b according to the linear free enthalpy relationship: log k (20°C) = sN(E + N) (Eq. ). The second‐order rate constants for reactions of benzofurazans 1 with a series of 4‐X‐substituted anilines 3a–d (X = OH, OCH3, CH3, and H) have also been measured in MeCN and found to agree within a factor of 0.14–50 with those calculated by Eq. from the electrophilicity parameters E measured in this work and the known nucleophile‐specific parameters N and sN of anilines 3. On the other hand, the reactions of these benzofurazans 1 with anilines 3 exhibit linear Brønsted‐type plots with βnuc = 1.27 for 1a and 1.01 for 1b, which are considerably greater than those (0.57 for 1a and 0.62 for 1b) obtained with the secondary cyclic amines 2. These high values of βnuc have been interpreted in terms of a single electron transfer mechanism. Secondary evidence for the validity of this mechanism is provided by the agreement between the rate constants, k1, for substitution of benzofurazans 1 by the anilines 3 and their oxidation potentials E°.
Power‐Law Kinetic Models for Synthesis of Ammonia Borane
Authors: Özgür Derya Öncel , Özkan Göksel
Published: October 2017

In the past few years, there have been increasing numbers of studies for the production and dehydrogenation of ammonia borane (NH3BH3, AB), which has become a significant hydrogen storage material. However, kinetic model studies based on the synthesis of AB in the literature have not been encountered, though there are many kinetic modeling studies on dehydrogenation of AB (Akbayrak et al., Appl Catal B 2016, 198, 162–170; Choi et al., Phys Chem Chem Phys 2014, 16(17), 7959–7968; Esteruelas et al., Inorg Chem 2016, 55(14), 7176–7181; Park et al., Int J Hydrogen Energy 2015, 40(46), 16316–16322; Rakap, Appl Catal B 2015, 163, 129–134; Tonbul et al., Int J Hydrogen Energy 2016, 41(26), 11154–11162; Zhang et al., Int J Hydrogen Energy 2016, 41(39), 17208–17215). The paper describes the development of a kinetic model for synthesis of ammonia borane by using borohydride (NaBH4) and ammonium salt (NH4)2SO4. The synthesis of AB experiments was carried out at different temperature ranges between 25 and 50°C, different inlet molar ratios (NaBH4/(NH4)2SO4 = 1–4), and different molarities with respect to NaBH4 (0.11–0.67 M NaBH4). After the parametric experiments were conducted, empirical power law was evaluated for the synthesis reaction. The power‐law model represented the trends of the kinetics of the synthesis reaction and was reproduced as .
Development of alkaline electrochemical characteristics demonstrates soil formation in bauxite residue undergoing natural rehabilitation
Authors: Kong Xiangfeng , Tian Tao , Xue Shengguo , Hartley William , Huang Longbin , Wu Chuan , Li Chuxuan
Published: October 2017

Mining and mineral processing industries have generated a large amount of polymineral wastes, causing the destruction and degradation of huge areas of landscapes at extensive geographical locations. Rehabilitation of these mine waste landscapes is critical to social and economic sustainability of mining and metallurgy operations, such as alumina refineries. The Bayer process to refine alumina generates large amounts of highly alkaline bauxite residues that are hazardous to plant growth. Innovative methodologies are urgently needed to address this economic and environmental challenges, one of which is soil formation from bauxite residues. Mineral weathering appears the prerequisite to the initiation of soil formation and development of functional soil properties in bauxite residue disposal areas. The present study investigated natural changes of mineralogy, zeta potential, isoelectric point, surface protonation, active alkaline groups, and associated implications for rehabilitation of the bauxite residue disposal area. Alkaline calcite, hydrogarnet, and sodalite minerals were slowly transformed or dissolved with declining levels over weathering time. Amorphous and semiamorphous minerals also decreased with a corresponding decrease in specific surface area and sorption sites. Zeta potential curve of fresh residue had steeper slope than those of aged residues. The isoelectric point of fresh residue was significantly higher, but those of aged residues were significantly lower, with a significant decrease of isoelectric point with increasing time. These attributes in mineralogy and electrochemical characteristics such as transformation of alkaline minerals, and decreases of surface protonation and active alkaline groups, may be used to help the assessment of soil formation status in the bauxite residues of different age and associated rehabilitation requirements.
Effects of farmed managements in sandy soils on composition and stabilization of soil humic substances
Authors: Martins Gomes Ernane Tarcísio , Berbara Ricardo Luis Louro , Pereira Marcos Gervasio , Urquiaga Segundo Sacramento , Tavares Orlando Carlos Huertas , Assunção Shirlei Almeida , Zonta Everaldo , do Amaral Sobrinho Nelson Moura Brasil , García Andrés Calderín
Published: October 2017

Sandy soils in tropical climates with low organic matter (OM) content result in degradation and fertility loss. It is important to note that humified OM accumulation and stabilization increases soil fertility. This study aimed to characterize humic acids (HAs) in sandy soils on an agroecological farm operating for more than 20 years. The structures of the HA of two Planosols under a grazing (G) and crop rotation (R) management system and of an Acrisol under an agroforestry management system (AFS) were characterized using HA extracted from a local Organosol under cassava monoculture (M) as a structural reference. Lower CHA/CFA ratio in sandy soil reveals a slightly humified OM and higher E4/E6 ratio value in HA confirming lower aromatic structure condensation. The HA in Planosols (R and G) and Acrisols (AFS) are predominantly formed by CAlq‐O,N–, CAlq‐O–, and CAlq‐di‐O structures closely related to the soil physical properties and preserved by interaction with the mineral fraction confirmed by νO‐H, νSi‐O stretching of kaolinite and hematite bands in FTIR spectroscopy. Management and vegetal carbon type (−20.65‰ AFS ‐C3) or (−15.55‰ (G) and −17.82‰ (R) ‐C4) had no effect on HA formation. Evolution of structural change in HA modeled by chemometric analyses showed that more recalcitrant structure characteristic in HA can enhance OM preservation in these sandy soils. This study elucidated the OM stabilization mechanisms of sandy soil HA, their relationship with soil properties and models structural changes for humified OM recovery and preservation, which contribute to increased fertility and agricultural production.
On the Robustness of Forward and Inverse Artificial Neural Networks for the Simulation of Ethylene/1‐Butene Copolymerization
Authors: Charoenpanich Thanutchoke , Anantawaraskul Siripon , Soares João B. P.
Published: October 2017

Forward and inverse artificial neural network (ANN) models are used to describe ethylene/1‐butene copolymerization with a model catalyst having two site types. The forward ANN predicts number and weight average molecular weights, average comonomer content, and polymer yield as a function of a set of polymerization conditions, while the inverse model estimates polymerization conditions needed to produce copolymers with desired microstructures. The forward model is found to be robust and resilient to random noise introduced into the datasets. The inverse model, however, leads to multiple solutions (several polymerization conditions can produce polymers with similar microstructures) and is sensitive to random noise in the data. Although the polymerization conditions estimated from inverse ANN are different from the model data, the estimated polymerization conditions are found to provide similar microstructures even with the random noise.
The definition and measurement of electromagnetic chirality
Authors: Arens Tilo , Hagemann Felix , Hettlich Frank , Kirsch Andreas
Published: October 2017

The notion of electromagnetic chirality, recently introduced in the Physics literature, is investigated in the framework of scattering of time‐harmonic electromagnetic waves by bounded scatterers. This type of chirality is defined as a property of the farfield operator. The relation of this novel notion of chirality to that of geometric chirality of the scatterer is explored. It is shown for several examples of scattering problems that geometric achirality implies electromagnetic achirality. On the other hand, a chiral material law, as for example given by the Drude‐Born‐Fedorov model, yields an electromagnetically chiral scatterer. Electromagnetic chirality also allows the definition of a measure. Scatterers invisible to fields of one helicity turn out to be maximally chiral with respect to this measure. For a certain class of electromagnetically chiral scatterers, we provide numerical calculations of the measure of chirality through solutions of scattering problems computed by a boundary element method.
Technical Note: Correction for the effect of breathing variations in CT pulmonary ventilation imaging
Authors: Yamamoto Tokihiro , Kabus Sven
Published: October 2017

Purpose

The accuracy and precision of computed tomography (CT) pulmonary ventilation imaging with conventional CT scanners are limited by breathing variations. We propose a method to correct for the effect of breathing variations in CT ventilation imaging based on external respiratory signals acquired throughout a scan.

Methods

The proposed method is based on: (a) calculating voxel‐by‐voxel abdominal surface motion ranges using four‐dimensional (4D) CT image datasets spatiotemporally correlated with external respiratory monitor data, and (b) applying the correction factor, which is defined as the ratio of the overall mean of the abdominal surface motion range in the lungs to that of each voxel, to the CT ventilation value. The performance of the proposed method was investigated by comparing voxel‐wise correlations of the uncorrected and corrected CT ventilation images with single‐photon emission CT (SPECT) ventilation images as a ground truth for nine patients. CT ventilation images were calculated by deformable image registration of the 4D‐CT image datasets, followed by calculation of regional volume changes. A Steiger's Z‐test was used to determine the statistical significance of the difference between the correlations for the uncorrected and corrected CT ventilation images.

Results

The proposed correction method resulted in significant increases (P < 0.05) in the correlation between CT and SPECT ventilation in three patients, trends toward significant increase (P: 0.13–0.18) in two patients, no significant differences in three patients, and a significantly decreased correlation in one patient. The average standard deviation of the abdominal surface motion range in three patients showing significant increases was 0.27 (range 0.10–0.37), which was greater than 0.17 (range 0.07–0.38) in the other six patients.

Conclusions

The proposed method to correct for the effect of breathing variations could be readily implemented and has the potential to improve the accuracy of CT ventilation imaging as demonstrated in a nine‐patient study.
Intramyocellular Lipid Droplet Size Rather Than Total Lipid Content is Related to Insulin Sensitivity After 8 Weeks of Overfeeding
Authors: Covington Jeffrey D. , Johannsen Darcy L. , Coen Paul M. , Burk David H. , Obanda Diana N. , Ebenezer Philip J. , Tam Charmaine S. , Goodpaster Bret H. , Ravussin Eric , Bajpeyi Sudip
Published: October 2017

Objective

Intramyocellular lipid (IMCL) is inversely related to insulin sensitivity in sedentary populations, yet no prospective studies in humans have examined IMCL accumulation with overfeeding.

Methods

Twenty‐nine males were overfed a high‐fat diet (140% caloric intake, 44% from fat) for 8 weeks. Measures of IMCL, whole‐body fat oxidation from a 24‐hour metabolic chamber, muscle protein extracts, and muscle ceramide measures were obtained before and after the intervention.

Results

Eight weeks of overfeeding did not increase overall IMCL. The content of smaller lipid droplets peripherally located in the myofiber decreased, while increases in larger droplets correlated inversely with glucose disposal rate. Overfeeding resulted in inhibition of Akt activity, which correlated with the reductions in smaller, peripherally located lipid droplets and drastic increases in ceramide content. Additionally, peripherally located lipid droplets were associated with more efficient lipid oxidation. Finally, participants who maintained a greater number of smaller, peripherally located lipid droplets displayed a better resistance to weight gain with overfeeding.

Conclusions

These results show that lipid droplet size and location rather than mere IMCL content are important to understanding insulin sensitivity.
Metabolic Benefits of Prior Weight Loss with and without Exercise on Subsequent 6‐Month Weight Regain
Authors: Ryan Alice S. , Serra Monica C. , Goldberg Andrew P.
Published: October 2017

Objective

To determine the 6‐month follow‐up effects after intentional 6‐month weight loss alone (WL) and after weight loss with aerobic exercise (AEX + WL) on body composition, glucose metabolism, and cardiovascular disease risk factors in older postmenopausal women and to identify the mechanisms for weight regain.

Methods

Women (n = 65, BMI > 25 kg/m2) underwent maximal oxygen consumption testing, dual‐energy x‐ray absorptiometry, computed tomography scans, and oral glucose tolerance tests before and after 6 months of AEX + WL or WL and at 12 months ad libitum follow‐up. Insulin sensitivity (M) (hyperinsulinemic‐euglycemic clamp) was measured at baseline and 6 months. Thirty WL and thirty‐five AEX + WL women completed a follow‐up at 12 months.

Results

Similar weight loss was observed (−8%) in both groups from 0 to 6 months. Total fat mass, fat‐free mass, visceral fat area, subcutaneous abdominal and midthigh fat areas, fasting glucose, insulin levels, homeostatic model assessment of insulin resistance (HOMA‐IR), insulin areas under the curve, and triglyceride levels decreased similarly after WL and AEX + WL and remained lower at 12 months than at baseline, despite weight regain at 12 months. Initial M was associated with weight regain (r = −0.40, P < 0.01). Weight regain was related to independent changes in leptin and HOMA‐IR from 6 to 12 months in a multiple regression model (r = 0.77, P < 0.0001).

Conclusions

Reductions in body fat and improvements in insulin sensitivity after AEX + WL and WL were maintained at 12 months despite modest weight regain. Baseline insulin resistance partially predicted the magnitude of weight regain in postmenopausal women.