bluuebunny/crossref_metadata_2025 huggingface dataset:
Increasing motor neuron excitability to treat weakness in sepsis
Authors: Nardelli Paul , Powers Randall , Cope Tim C. , Rich Mark M.
Published: November 2017

Objective

Weakness induced by critical illness (intensive care unit acquired weakness) is a major cause of disability in patients and is currently untreatable. We recently identified a defect in repetitive firing of lower motor neurons as a novel contributor to intensive care unit acquired weakness. To develop therapy for intensive care unit acquired weakness, it was necessary to determine the mechanism underlying the defect in repetitive firing.

Methods

Both computer simulation and in vivo dynamic voltage clamp of spinal motor neurons in septic rats were employed to explore potential mechanisms underlying defective repetitive firing.

Results

Our results suggest alteration in subthreshold voltage‐activated currents might be the mechanism underlying defective repetitive firing. It has been shown previously that pharmacologic activation of serotonin receptors on motor neurons increases motor neuron excitability, in part by enhancing subthreshold voltage‐activated inward currents. Administration of a U.S. Food and Drug Administration–approved serotonin agonist (lorcaserin) to septic rats greatly improved repetitive firing and motor unit force generation.

Interpretation

Our findings suggest activation of serotonin receptors with lorcaserin may provide the first ever therapy for intensive care unit acquired weakness in patients. Ann Neurol 2017;82:961–971
Clinical and genetic findings in children with central nervous system arteriovenous fistulas
Authors: Saliou Guillaume , Eyries Mélanie , Iacobucci Marta , Knebel Jean‐François , Waill Marie‐Christine , Coulet Florence , Ozanne Augustin , Soubrier Florent
Published: November 2017

Objective

To assess the spectrum of genetic anomalies in a cohort of children presenting at least one cerebral or spinal pial arteriovenous fistula (AVF), and to describe their clinical characteristics.

Methods

From 1988 to 2016, all consecutive patients with at least one cerebral or spinal pial AVF were screened for genetic disease. All patients aged <18 years were included. Symptoms associated with AVF were recorded: heart failure, neurological deficit/seizure, and hemorrhage. The outcome was assessed using the modified Rankin Scale and school performance in children with cerebral AVF and the American Spinal Injury Association impairment scale in children with spinal AVF.

Results

Forty‐three children were included. Twenty‐five children were male and 18 were female. A germline mutation was identified in 23 probands (53.5 ± 14.9%): 8 in ENG (34.8 ± 14.2%), 1 in ACVRL1 (4.3 ± 6%) leading to a diagnosis of HHT, and 14 in RASA1 (60.9 ± 14.4%) leading to a diagnosis of capillary malformation/arteriovenous malformation type 1. No EphB4 gene mutation was identified. HHT patients presented a significantly lower rate of heart failure at diagnosis (p = 0.047). A trend toward an increased bleeding rate at presentation was observed in HHT (p = 0.069) and an increased rate of giant venous pouch in children in whom no mutation was identified (p = 0.097). Finally, an association with RASA1 mutation was observed in children with associated skin capillary hemangioma (p <  0001).

Interpretation

These results highlight the importance of genetic testing in this setting in view of the high frequency of gene mutations in pediatric cerebrospinal AVFs, and show the predominance of RASA1 over HHT mutations. Ann Neurol 2017;82:972–980
Enantioselective Synthesis ofN,S‐Acetals by an Oxidative Pummerer‐Type Transformation using Phase‐Transfer Catalysis
Authors: Biswas Souvagya , Kubota Koji , Orlandi Manuel , Turberg Mathias , Miles Dillon H. , Sigman Matthew S. , Toste F. Dean
Published: November 2017

Reported is the first enantioselective oxidative Pummerer‐type transformation using phase‐transfer catalysis to deliver enantioenriched sulfur‐bearing heterocycles. This reaction includes the direct oxidation of sulfides to a thionium intermediate, followed by an asymmetric intramolecular nucleophilic addition to form chiral cyclicN,S‐acetals with moderate to high enantioselectivites. Deuterium‐labelling experiments were performed to identify the stereodiscrimination step of this process. Further analysis of the reaction transition states, by means of multidimensional correlations and DFT calculations, highlight the existence of a set of weak noncovalent interactions between the catalyst and substrate that govern the enantioselectivity of the reaction.
Intramolecular Acetyl Transfer to Olefins by Catalytic C−C Bond Activation of Unstrained Ketones
Authors: Rong Zi‐Qiang , Lim Hee Nam , Dong Guangbin
Published: November 2017

A rhodium‐catalyzed intramolecular acetyl‐group transfer has been achieved through a “cut and sew” process. The challenge arises from the existence of different competitive pathways. Preliminary success has been achieved with unstrained enones that contain a biaryl linker. The use of an electron‐rich N‐heterocycilc carbene (NHC) ligand is effective to inhibit undesired β‐hydrogen elimination. Various 9,10‐dihydrophenanthrene derivatives can be prepared with excellent functional‐group compatibility. The 13C‐labelling study suggests that the reaction begins with cleavage of the unstrained C−C bond, followed by migratory insertion and reductive elimination.
Basic Remarks on Acidity
Authors: Himmel Daniel , Radtke Valentin , Butschke Burkhard , Krossing Ingo
Published: November 2017

This Review provides a unified view on Brønsted acidity. For this purpose, a brief overview of the concepts acidity, acid strengths, and pH value is given, including problems, proposed solutions, and the use of the pHabs/
scale as a unifying concept. Thereafter, some examples of the accessibility and application of unified pHabs values are given. The Review is rounded off with the analogy of acid‐base chemistry to redox chemistry with the introduction of the unified redox scale peabs. The combination of pHabs and peabs values in the protoelectric potential map (PPM), as elaborated in ongoing studies on the thermochemistry of single ions, provides a means to classify and to compare all possible acid‐base/redox reactions in a medium‐independent and, thus, unified fashion.
The Long‐Term Stability of KO2 in K‐O2 Batteries
Authors: Xiao Neng , Rooney Ryan T. , Gewirth Andrew A. , Wu Yiying
Published: November 2017

The rechargeable K‐O2 battery is recognized as a promising energy storage solution owing to its large energy density, low overpotential, and high coulombic efficiency based on the single‐electron redox chemistry of potassium superoxide. However, the reactivity and long‐term stability of potassium superoxide remains ambiguous in K‐O2 batteries. Parasitic reactions are explored and the use of ion chromatography to quantify trace amounts of side products is demonstrated. Both quantitative titrations and differential electrochemical mass spectrometry confirm the highly reversible single‐electron transfer process, with 98 % capacity attributed to the formation and decomposition of KO2. In contrast to the Na‐O2 counterparts, remarkable shelf‐life is demonstrated for K‐O2 batteries owing to the thermodynamic and kinetic stability of KO2, which prevents the spontaneous disproportionation to peroxide. This work sheds light on the reversible electrochemical process of K++e−+O2↔KO2.
A Sterically Constrained Tricyclic PC3 Phosphine: Coordination Behavior and Insertion of Chalcogen Atoms into P−C Bonds
Authors: Hentschel Anne , Brand Alexander , Wegener Philipp , Uhl Werner
Published: November 2017

A tricyclic phosphine has been generated that has a rigid molecular backbone with the P atoms exclusively bound to C(sp2) atoms as well as a very large Tolman angle and buried volume. It is an interesting new ligand in coordination chemistry (Au, Pd complexes) and shows unusual insertion reactions into its endocyclic P−C bonds facilitated by its inherent molecular strain.
Design of a novel optical sensor for determination of trace amounts of copper by UV–visible spectrophotometry in real samples
Authors: Pourbasheer Eslam , Morsali Somayeh , Azari Zhila , Karimi Mohammad Ali , Ganjali Mohammad Reza
Published: November 2017

A new optical chemical sensor is established for sensitive and selective spectrophotometric detection of copper based on the immobilization of 3‐(2‐methyl‐2,3‐dihydro‐1,3‐benzothiezol‐2‐yl)‐2H‐chromen‐2‐one on a triacetylcellulose membrane. Copper ions react with the immobilized ligand and cause an increase in the absorption of the membrane at 550 nm in universal buffer solution at pH = 6. The effects of pH, indicator concentration and reaction time on the immobilization of the ligand were studied. This optode exhibits a linear range of 7.0 × 10−7 to 1 × 10−4 mol l−1 of copper ion concentration with a limit of detection of 3.0 × 10−7 mol l−1. The response time of the newly designed optode is within 3 min. The effect of different possible interfering species was investigated and it was found that the sensor has very good selectivity. The proposed sensor benefits from advantages such as low cost, high stability, low detection limit, fast response time, reproducibility, relatively long lifetime, and good selectivity for Cu2+ ion determination among a large number of alkali, alkaline earth, transition and heavy metal ions. The sensor can readily be regenerated with thiourea solution and its response is reversible and reproducible (relative standard deviation < 1.4%). The proposed optode was applied successfully for the determination of Cu(II) in various samples.
Axial base‐controlled catalytic activity, oxidative stability and product selectivity of water‐insoluble manganese and iron porphyrins for oxidation of styrenes in water under green conditions
Authors: Zakavi Saeed , Hashemi‐Amiri Akbar , Asadi Fatemeh
Published: November 2017

A series of water‐insoluble iron(III) and manganese(III) porphyrins, FeT(2‐CH3)PPCl, FeT(4‐OCH3)PPCl, FeT(2‐Cl)PPCl, FeTPPCl, MnT(2‐CH3)PPOAc, MnT(4‐OCH3)PPOAc, MnT(2‐Cl)PPOAc and MnTPPOAc, in the presence of imidazole (ImH), F−, Cl−, Br− and acetate were used as catalysts for the aqueous‐phase heterogeneous oxidation of styrenes to the corresponding epoxides and aldehydes with sodium periodate. Also, the effect of various reaction parameters such as reaction time, molar ratio of catalyst to axial base, type of axial base, molar ratio of olefin to oxidant and nature of metal centre on the activity and oxidative stability of the catalysts and the product selectivity was investigated. Higher catalytic activities were found for the iron complexes. Interestingly, the selectivity towards the formation of epoxide and aldehyde (or acetophenone) was significantly influenced by the type of axial base. Furthermore, Br− and ImH were found to be the most efficient co‐catalysts for the oxidation of olefins performed in the presence of the manganese and iron porphyrins, respectively. The optimized molar ratio of catalyst to axial base was different for various axial bases. Also, the order of co‐catalyst activity of the axial bases obtained in aqueous medium was different from that reported for organic solvents. The use of a convenient axial base under optimum reaction catalyst to co‐catalyst molar ratio in the presence of the manganese porphyrin gave the oxidative products with a conversion of ca 100% in a reaction time of less than 3 h. However, the catalytic activity of the iron porphyrins could not be effectively improved by increasing the catalyst to co‐catalyst molar ratio.
Gemini quaternary ammonium salt cationic surfactant‐assisted hydrothermal synthesis: An effective way to tune the textural properties of zeolite and the acidity of Beta molecular sieves
Authors: Wang Shiyao , Zheng Ziliang , He Bo , Sun Chen , Li Xing , Wu Xu , An Xia , Xie Xianmei
Published: November 2017

Novel hierarchical Beta zeolites have been successfully synthesized via a one‐pot dual‐templates strategy utilizing gemini organic surfactant and tetraethylammonium hydroxide (TEAOH)through hydrothermal process. The influence of several parameters on the formation of hierarchical Beta zeolite, the change in acidity and a possible growth scheme were systematically investigated. The physicochemical properties of these catalysts were characterized by PXRD, BET, SEM, HRTEM SAED, TG and NH3‐TPD techniques, and the performance as acid catalysts was verified using the transformation of EtOH as a model reaction. On one hand, WAXRD data indicated that decreasing the temperature of synthesis and increasing amounts of C12‐6‐12 in the process of synthesis resulted in lower crystallinity of Beta zeolites due to the BEA nuclei formation and crystal growth constrained by C12‐6‐12. On the other hand, SAXRD and HRTEM data evidenced that C12‐6‐12 initially generated a pseudo‐ordered mesoporous phase which was then partially occupied by the zeolite. After a period of ~96 h for crystallization, the hierarchy zeolite possessing 765.7 m2·g‐1 of Brunauer‐Emmett‐Tellerarea, and average mesopore size distribution of 3.51 nm can be synthesized, and its microporous structure has a good crystallinity and lower amounts of acid sites than that of the microporous Beta one. Furthermore, the as‐obtained hierarchical zeolite displayed lower deactivation rate mainly due to the less coke formation on the surface of catalyst. It is expected to develop more considerable potential application value for the hierarchical Beta zeolite structure in the near future.
Green synthesis and characterization of silver nanoparticles by Allium cepa L. to produce silver nano‐coated fabric and their antimicrobial evaluation
Authors: Sharma Prashansa , Pant Suman , Rai Shambhavi , Yadav Renu Bala , Sharma Swapnil , Dave Vivek
Published: November 2017

This research work was proposed to study the antimicrobial activity of the silver nanocoated fabric with the purpose of producing good dressing and clothing material. We synthesized simple, ecofriendly, cost‐effective and sustainable silver nanoparticles by using the aqueous extract of Allium cepa L. Here, A. cepa L. acts as a good reducing and capping agent that produced stable silver nanoparticles having particle size of range 36 ± 1 to 98 ± 2 nm, Poly dispersiblity index 0.234 ± 0.61 to 1.023 ± 0.33 and Zeta potential ‐12 ± 1.5 mV to ‐26 ± 1.2 mV. The effect of temperature and extract volume used was considered for optimization of synthetic procedure. The nanocoated fabric was characterized for morphological study, size (using transmission electron microscopy (TEM) and field emission scanning electron microscopy (FE‐SEM) and zeta‐potential (Zeta Potentiometer). The presence of functional groups were observed by using attenuated total reflection‐Fourier transform infrared (ATR‐FTIR) and Raman spectroscopy. The crystallinity and structural property of the synthesized silver nanoparticles were studied in terms of Powder X‐ray diffraction (PXRD). An IC50 value and zone of inhibition was studied which demonstrate that the silver nanocoated fabric have an excellent antibacterial property against Gram‐negative (Escherichia coli) and Gram‐positive (Staphylococcus aureus) bacteria. Further nanocoated fabric material was washed (with function of time 0, 10, 25, and 50 laundry cycles) and still retained their anti‐bacterial activity towards both strain. Initially there was 52 μg/ml of silver nanoparticles on the cotton fabric but after 50 laundry cycle in 500 ml of distilled water the fabric showed 92% efficiency against gram positive and 90% efficacy toward gram negative bacteria. It was found that 4.16 μg/ml nano particles leached in case of S. Aureus and 5.2 μg/mL silver nanoparticles leached in case of E. coli. Nanocoated fabric material synthesized using green synthesis was found to be economical with good resistance to washing.
A innovative switchable polarity solvent, based on 1,8‐diazabicyclo‐[5.4.0]‐ undec‐7‐ene and decanol was prepared for enrichment of aluminum in biological sample prior to analysis by flame atomic absorption spectrometry
Authors: Arain Mariam S. , Kazi Tasneem G. , Afridi Hassan I. , Khan Naeemullah , Ali Jamshed
Published: November 2017

A novel switchable solvent (SS) extraction methodology has been used for the enrichment of aluminium (Al) in acid‐digested blood samples of patients with neurological disorders before proceeding to flame atomic absorption spectrometry. 1,8‐Diazabicyclo[5.4.0]undec‐7‐ene and decanol in combination made a SS which reversibly changes from hydrophobic (nonpolar) to hydrophilic (polar) according to switch‐on and switch‐off phenomena in aqueous medium by exposure to anti‐solvent trigger (CO2). The SS polar micro‐emulsion was switched on by bubbling CO2, and switched off by heating from 40 to 70°C with exposure to N2 gas. The changes obtained in the structure and physical properties of the SS due to switching from lower polarity to higher polarity were investigated using Fourier transform infrared spectroscopic analysis. The SS was effectively analysed as an extractive medium for hydrophobic chelate of Al with 3,5,7,2,4‐pentahydroxyflavone (morin) and extracted in SS. Then hydrophobic enriched Al‐morin‐SS was treated with 1.0 M HNO3 and CO2 purging at various time intervals, switch to a miscible polar hydrophilic monophase state. The SS was easily recycled up to six times for further enrichment process. For the developed method, various parameters were optimized such as pH, volume of chelating reagent, CO2 purging time and pressure, and rate of heating. Under favourable conditions, enhancement factor and limit of detection were observed as 25 and 0.47 μg l−1, respectively, for 10 ml of samples/standards solution. The accuracy of the developed method was determined using certified reference material (SRM 3101a), with a standard addition procedure. The method was used for the pre‐concentration of Al in blood samples of patients with neurological disorders.
A new approach for the optimization of nonsharp distillation superstructures
Authors: Pirhoushyaran T. , Shafiei S.
Published: November 2017

In general, the optimization problem of the separation of a multicomponent feed stream into two or more multicomponent products with the use of nonsharp distillation columns is an MINLP with a nonlinear objective function. Due to the high number of variables and the high degree of nonlinearity, the presentation of a comprehensive and simple three‐phase approach was considered to solve the Mixed Integer Nonlinear Programming (MINLP) using the combination of mathematical and stochastic methods. In the method, the variables are classified into two groups: A set of variables are optimized by genetic algorithm as a stochastic algorithm; doing so converts MINLP to Linear Programming (LP), and the remaining variables are managed by solving an LP problem for known values of the former set by a regular and quick mathematical method such as simplex search. One advantage of this study is that it extracts some essential relationships between the first set of variables by the mathematical operations on the nonlinear constraints of the main problem as these variables are not optimized altogether; instead, some of them are optimized and the rest are obtained with the assistance of those relationships. Thus, the optimization workload (in both parts of GA and LP problem) is very low and the best structure can be obtained in a very short time (less than 2 min). Also, the study applies the lowest reduction on the main superstructure than previous works and therefore, the generalization of the problem is further preserved. Three published examples are used to verify the proposed method.
Experimental studies on coal water slurries prepared from coal gasification wastewater
Authors: Li Dedi , Liu Jianzhong , Wang Jinqian , Bai Qingcheng , Cheng Jun , Cen Kefa
Published: November 2017

Coal gasification wastewater (CGW) contains high concentrations of pollutants and varying chemical components and thus is difficult to treat. CGW slurry (CGWS), which is prepared by blending coal, CGW, and additives, is a new wastewater utilization technology that can be used to efficiently and conveniently treat CGW. This work mainly investigated the slurryability, rheology, stability, and combustion properties of CGWS prepared from Shenhua and Yima coals. Results showed that (a) the maximum solid loading of CGWS was slightly lower than that of ordinary coal–water slurry (CWS), but CGWS exhibited better pseudoplastic rheology and stability than CWS; moreover, increasing the solid loading of CGWS resulted in an increasingly pseudoplastic trend and enhanced stability; (b) CGW strengthened the combustion capacity of coke and CGWS demonstrating better ignition, burning, and burnout properties than CWS. These findings suggest that the use of CGWS technology in CGW treatment is beneficial economically and environmentally.
Pre‐Zika descriptive epidemiology of microcephaly in Texas, 2008–2012
Authors: Hoyt Adrienne T. , Canfield Mark A. , Langlois Peter H. , Waller Dorothy K. , Agopian A. J. , Shumate Charles J. , Hall Noemi B. , Marengo Lisa K. , Ethen Mary K. , Scheuerle Angela E.
Published: November 2017

Background

There are limited population‐based studies on microcephaly. We characterized the epidemiology of microcephaly in Texas during a 5‐year period (2008–2012), prior to the Zika epidemic in the Western hemisphere (2015). The associations of suspected risk factors were compared across four clearly defined case groups.

Methods

Data from the Texas Birth Defects Registry were used to calculate the prevalence of congenital microcephaly and crude and adjusted prevalence ratios using Poisson regression. Twelve maternal and infant factors were assessed across case groups, which included total (explained + unexplained), explained (e.g., syndromic), unexplained, and severe unexplained microcephaly (head circumference <3rd percentile).

Results

The birth prevalence for total and total severe microcephaly were 14.7 and 4.8 per 10,000 livebirths, respectively. For explained and unexplained cases, significantly elevated risks were noted for mothers who were older (35+), less educated (≤12 years), diabetic (pre‐pregnancy or gestational), or had a preterm delivery. Unlike explained cases, however, mothers who were non‐White or smoked had an increased risk for unexplained microcephaly. Furthermore, young maternal age (<20), multiparity, and higher BMI reduced the risk for unexplained microcephaly. For severe unexplained cases, the risk profile was similar to that for all unexplained cases—with the exception of null associations noted for diabetes and birth year.

Conclusions

We found that risk patterns for microcephaly varied across case groupings. Risk factors included maternal race/ethnicity, age, and smoking during pregnancy. Among severe unexplained cases, notable positive associations were seen among mothers who were non‐Hispanic Black or less educated, while inverse associations were noted for obesity.
The JUPITER registry: One‐year outcomes of transapical aortic valve implantation using a second generation transcatheter heart valve for aortic regurgitation
Authors: Silaschi Miriam , Conradi Lenard , Wendler Olaf , Schlingloff Friederike , Kappert Utz , Rastan Ardawan J , Baumbach Hardy , Holzhey David , Eichinger Walter , Bader Ralf , Treede Hendrik
Published: November 2017

Objectives

We present 1‐year outcomes of the post‐market registry of a next‐generation transcatheter heart valve used for aortic regurgitation (AR).

Background

Transcatheter aortic valve replacement (TAVR) is routine in high‐risk patients with aortic stenosis but is not recommended for AR. The JenaValve™ (JenaValve Technology GmbH, Munich, Germany) overcomes technical challenges in AR patients through a leaflet clipping mechanism.

Methods

The JenaValve EvalUation of Long Term Performance and Safety In PaTients with SEvere Aortic Stenosis oR Aortic Insufficiency (JUPITER) Registry is a European study to evaluate safety and effectiveness of this THV. From 2012‐2015, 30 patients with AR were enrolled.

Results

Mean age was 74.4 ± 9.3 years. Procedural success was 96.7% (29/30). One patient was converted to open surgery. No annular rupture or coronary ostia obstruction occurred. Mortality at 30 days was 10.0% (3/30). Combined safety endpoint was met in 13.3% (4/30). Paravalvular regurgitation was not present/trivial in 84.6% (22/26) and mild in 15.4% (4/26). Rate of permanent pacemaker implantation was 3.8% (1/26). One‐year Kaplan‐Meier survival was 79.9%, one‐year combined efficacy was 73.1% (19/30). No further strokes were observed during 1 year of follow‐up.

Conclusions

The JenaValve overcomes technical challenges of TAVR in AR through a clipping mechanism. We report satisfactory outcomes of a multicenter registry using the JenaValve for predominant AR, as rate of THV embolization, residual AR and permanent pacemaker implantation was low. One‐year results using the JenaValve for AR encourage its use for this indication.
Comparison of left atrial pressure monitoring with dedicated catheter versus steerable guiding catheter during transcatheter mitral valve repair
Authors: Eleid Mackram F. , Reeder Guy S. , Rihal Charanjit S.
Published: November 2017

Objective

The objective of this study was to determine the accuracy of left atrial pressure (LAP) measurement through the manufacturer provided steerable guiding catheter (SGC) during transcatheter mitral valve repair (TMVR).

Background

LAP measurement during TMVR has been shown to be associated with clinical improvement when measured through a dedicated catheter.

Methods

Simultaneous LAP was performed in consecutive patients using an independent fluid‐filled 4F multipurpose catheter and compared to LAP waveforms measured through the manufacturer‐provided MitraClip SGC during TMVR (Abbott, Santa Clara, CA).

Results

Mean age of 10 consecutive subjects with primary mitral regurgitation undergoing TMVR was 83 ± 3 years (60% female). Left atrial v wave and mean pressures through the dedicated catheter were 42 ± 7 and 24 ± 3 mmHg vs. 35 ± 7 and 23 ± 3 mmHg through the SGC (P < 0.001 and P = 0.23, respectively). Mean differences in v wave and mean LAP were 8 ± 4 and 1.0 ± 2.4 mmHg (percent difference 19 and 3%), respectively. SGC waveform overdamping was observed in all cases.

Conclusions

Left atrial v wave pressure measurement through a dedicated catheter with sideholes during TMVR has superior accuracy compared to the manufacturer provided SGC, which results in waveform overdamping and a significant underestimation of v wave pressure. These data have important implications for clinical practice.
Fulminant hemolysis in glucose‐6‐phosphate dehydrogenase deficiency
Authors: Moiz Bushra , Ali Sidra Asad
Published: November 2017

Key Clinical Message

Glucose‐6‐phosphate dehydrogenase (G6PD) deficiency is an X‐linked disorder affecting some 400 million people worldwide. Though clinically silent, it may result in hemolysis on oxidative stress induced by drugs or infections. Viral hepatitis A with coexisting G6PD deficiency can be devastating associated with severe hemolysis, anemia, renal failure, and hepatic encephalopathy.
Power Generation from Coke Oven Gas Using Chemical Looping Combustion: Thermodynamic Simulation
Authors: Luo Ming , Wang Chao , Yi Yang , Liu Ke , Cai Jianjun , Wang Qian
Published: November 2017

A chemical looping combustion (CLC) combined cycle with coke oven gas as fuel and NiO/NiAl2O4 as an oxygen carrier is proposed. The system was simulated by Aspen Plus® and the oxygen carrier circulation ratio was calculated. The effects of key operational temperatures and different gas turbines on the system performance were investigated. Under optimized conditions, a high CO2 capture efficiency could be achieved. To capture CO2 thoroughly, the PG6561B gas turbine can be employed, allowing for nearly 100 % CO2 capture efficiency.
Aromatic Compounds from Lignin Liquefaction over ZSM‐5 Catalysts in Supercritical Ethanol
Authors: Fan Di , Xie Xinan , Li Yan , Li Lu , Sun Jiao
Published: November 2017

A systematic research about the liquefaction of alkali lignin in supercritical ethanol using ZSM‐5 zeolite catalysts is reported, which includes the synergistic effect of temperature, catalytic content, and reaction time on product yield and distribution. Fourier transform infrared and gas chromatography‐mass spectrometry analysis were carried out to evaluate the compositions of bio‐oil and solid residue. Under moderate condition, maximum conversion and yield of bio‐oil were satisfactorily high. With the help of ZSM‐5 catalyst, lignin could be successfully converted into aromatic compounds.
The Mutation in the Single‐Crystal Structural Transformation Process, Induced by the Combined Stimuli of Temperature and Solvent
Authors: Zhang Chuanlei , Li Yanle , Xu Heng , Ma Jing , Zheng Hegen
Published: November 2017

A 2D coordination polymer containing a free ligand (Lf), fixed by hydrogen bonds, transformed into a 3D metal–organic framework (MOF) in a single‐crystal to single‐crystal fashion. This transformation occurs through the combined stimuli of temperature and solvent. From 50 to 90 °C, a series of changes take place in a gradual form: the Lf is slowly moved to the cobalt center, which is accompanied by a contraction of unit cell and hydrogen bond. When the temperature rises to 95 °C, the hydrogen bond is destroyed, and Lf is suddenly combined with the cobalt ion to form an intricate 3D structure. This mutation process is irreversible and cannot occur just with the stimulus of either temperature or solvent. Notably, even under the combined stimuli, this mutation phenomena is difficult to reproduce when the solvent species and proportions change. DFT calculations were used to try to explain the nature of the phenomenon.
8‐Mercaptoguanine Derivatives as Inhibitors of Dihydropteroate Synthase
Authors: Dennis Matthew L. , Lee Michael D. , Harjani Jitendra R. , Ahmed Mohamed , DeBono Aaron J. , Pitcher Noel P. , Wang Zhong‐Chang , Chhabra Sandeep , Barlow Nicholas , Rahmani Raphaël , Cleary Ben , Dolezal Olan , Hattarki Meghan , Aurelio Luigi , Shonberg Jeremy , Graham Bim , Peat Thomas S. , Baell Jonathan B. , Swarbrick James D.
Published: November 2017

Dihydropteroate synthase (DHPS) is an enzyme of the folate biosynthesis pathway, which catalyzes the formation of 7,8‐dihydropteroate (DHPt) from 6‐hydroxymethyl‐7,8‐dihydropterin pyrophosphate (DHPPP) and para‐aminobenzoic acid (pABA). DHPS is the long‐standing target of the sulfonamide class of antibiotics that compete with pABA. In the wake of sulfa drug resistance, targeting the structurally rigid (and more conserved) pterin site has been proposed as an alternate strategy to inhibit DHPS in wild‐type and sulfa drug resistant strains. Following the work on developing pterin‐site inhibitors of the adjacent enzyme 6‐hydroxymethyl‐7,8‐dihydropterin pyrophosphokinase (HPPK), we now present derivatives of 8‐mercaptoguanine, a fragment that binds weakly within both enzymes, and quantify sub‐μm binding using surface plasmon resonance (SPR) to Escherichia coli DHPS (EcDHPS). Eleven ligand‐bound EcDHPS crystal structures delineate the structure–activity relationship observed providing a structural framework for the rational development of novel, substrate‐envelope‐compliant DHPS inhibitors.
Structure–Activity Relationships for Pt‐Free Metal Phosphide Hydrogen Evolution Electrocatalysts
Authors: Owens‐Baird Bryan , Kolen'ko Yury V. , Kovnir Kirill
Published: November 2017

In the field of renewable energy, the splitting of water into hydrogen and oxygen fuel gases using water electrolysis is a prominent topic. Traditionally, these catalytic processes have been performed by platinum‐group metal catalysts, which are effective at promoting water electrolysis but expensive and rare. The search for an inexpensive and Earth‐abundant catalyst has led to the development of 3d‐transition‐metal phosphides for the hydrogen evolution reaction. These catalysts have shown excellent activity and stability. In this review, we discuss the electronic and crystal structures of bulk and surface of selected Fe, Co, and Ni phosphides, and their relationships to the experimental catalytic activity. The various synthetic protocols towards the state‐of‐the‐art transition metal phosphide electrocatalysts are also discussed.
Selective Preconcentration of Trace Amounts of Cu(II) With Surface‐Imprinted Multiwalled Carbon Nanotubes
Authors: Turan Kübra , Saygili Canlıdinç Rukiye , Kalfa Orhan Murat
Published: November 2017

In this study, a new sorbent is synthesized using surface imprinting technique. Cu(II)‐imprinted multiwalled carbon nanotube sorbent (Cu(II)‐IMWCNT) is used as the solid phase in the solid‐phase extraction method. After the preconcentration procedure, Cu(II) ions are determined by high‐resolution continuum source atomic absorption spectrometry. A total of 0.1 mol L−1 ethylenediaminetetraacetic acid (EDTA) is used to remove Cu(II) ions from the sorbent surface. The optimum experimental conditions for effective preconcentration of Cu(II), parameters such as pH, eluent type and concentration, flow rate, sample volume, sorbent capacity, and selectivity are investigated. The synthesized solid phase is characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The maximum adsorption capacities of Cu(II)‐IMWCNT and non‐imprinted solid phases are 270.3 and 14.3 mg g−1 at pH 5, respectively. Under optimum experimental conditions for Cu(II) ions, the limit of detection is 0.07 μg L−1 and preconcentration factor is 40. In addition, it is determined to be reusable without significant decrease in recovery values up to 100 adsorption–desorption cycles. Cu(II)‐IMWCNT have a high stability. To check the accuracy of the developed method, certified reference materials, and water samples are analyzed with satisfactory analytical results.
Computational predictions of damage propagation preceding dissection of ascending thoracic aortic aneurysms
Authors: Mousavi S. Jamaleddin , Farzaneh Solmaz , Avril Stéphane
Published: November 2017

Dissections of ascending thoracic aortic aneurysms (ATAAs) cause significant morbidity and mortality worldwide. They occur when a tear in the intima‐media of the aorta permits the penetration of the blood and the subsequent delamination and separation of the wall in 2 layers, forming a false channel. To predict computationally the risk of tear formation, stress analyses should be performed layer‐specifically and they should consider internal or residual stresses that exist in the tissue. In the present paper, we propose a novel layer‐specific damage model based on the constrained mixture theory, which intrinsically takes into account these internal stresses and can predict appropriately the tear formation. The model is implemented in finite‐element commercial software Abaqus coupled with user material subroutine. Its capability is tested by applying it to the simulation of different exemplary situations, going from in vitro bulge inflation experiments on aortic samples to in vivo overpressurizing of patient‐specific ATAAs. The simulations reveal that damage correctly starts from the intimal layer (luminal side) and propagates across the media as a tear but never hits the adventitia. This scenario is typically the first stage of development of an acute dissection, which is predicted for pressures of about 2.5 times the diastolic pressure by the model after calibrating the parameters against experimental data performed on collected ATAA samples. Further validations on a larger cohort of patients should hopefully confirm the potential of the model in predicting patient‐specific damage evolution and possible risk of dissection during aneurysm growth for clinical applications.
Clopidogrel but Not Prasugrel Significantly Inhibits the CYP2C8‐Mediated Metabolism of Montelukast in Humans
Authors: Itkonen Matti K. , Tornio Aleksi , Filppula Anne M. , Neuvonen Mikko , Neuvonen Pertti J. , Niemi Mikko , Backman Janne T.
Published: November 2017

The oxidation of montelukast is mainly mediated by cytochrome P450 (CYP) 2C8, but other mechanisms may contribute to its disposition. In healthy volunteers, we investigated the effects of two widely used P2Y12 inhibitors on montelukast pharmacokinetics. Clopidogrel (300 mg on day 1 and 75 mg on day 2) increased the area under the plasma concentration–time curve (AUC) of montelukast 2.0‐fold (90% confidence interval (CI) 1.72–2.28, P < 0.001) and decreased the M6:montelukast AUC0‐7h ratio to 45% of control (90% CI 40–50%, P < 0.001). Prasugrel (60 mg on day 1 and 10 mg on day 2) had no clinically meaningful effect on montelukast pharmacokinetics. Our results imply that clopidogrel is at least a moderate inhibitor of CYP2C8, but prasugrel is not a clinically relevant CYP2C8 inhibitor. The different interaction potentials of clopidogrel and prasugrel are important to consider when antiplatelet therapy is planned for patients at risk for polypharmacy with CYP2C8 substrates.
Complementary Strategies Toward the Aqueous Processing of High‐Voltage LiNi0.5Mn1.5O4 Lithium‐Ion Cathodes
Authors: Kuenzel Matthias , Bresser Dominic , Diemant Thomas , Carvalho Diogo Vieira , Kim Guk‐Tae , Behm R. Jürgen , Passerini Stefano
Published: November 2017

Increasing the environmental benignity of lithium‐ion batteries is one of the greatest challenges for their large‐scale deployment. Toward this end, we present herein a strategy to enable the aqueous processing of high‐voltage LiNi0.5Mn1.5O4 (LNMO) cathodes, which are considered highly, if not the most, promising for the realization of cobalt‐free next‐generation lithium‐ion cathodes. Combining the addition of phosphoric acid with the cross‐linking of sodium carboxymethyl cellulose by means of citric acid, aqueously processed electrodes with excellent performance are produced. The combined approach offers synergistic benefits, resulting in stable cycling performance and excellent coulombic efficiency (98.96 %) in lithium‐metal cells. Remarkably, this approach can be easily incorporated into standard electrode preparation processes with no additional processing step.
Capacitance‐Assisted Sustainable Electrochemical Carbon Dioxide Mineralisation
Authors: Lamb Katie J. , Dowsett Mark R. , Chatzipanagis Konstantinos , Scullion Zhan Wei , Kröger Roland , Lee James D. , Aguiar Pedro M. , North Michael , Parkin Alison
Published: November 2017

An electrochemical cell comprising a novel dual‐component graphite and Earth‐crust abundant metal anode, a hydrogen producing cathode and an aqueous sodium chloride electrolyte was constructed and used for carbon dioxide mineralisation. Under an atmosphere of 5 % carbon dioxide in nitrogen, the cell exhibited both capacitive and oxidative electrochemistry at the anode. The graphite acted as a supercapacitive reagent concentrator, pumping carbon dioxide into aqueous solution as hydrogen carbonate. Simultaneous oxidation of the anodic metal generated cations, which reacted with the hydrogen carbonate to give mineralised carbon dioxide. Whilst conventional electrochemical carbon dioxide reduction requires hydrogen, this cell generates hydrogen at the cathode. Carbon capture can be achieved in a highly sustainable manner using scrap metal within the anode, seawater as the electrolyte, an industrially relevant gas stream and a solar panel as an effective zero‐carbon energy source.
Prenatal exposure to ketamine in rats: Implications on animal models of schizophrenia
Authors: Coronel‐Oliveros Carlos M. , Pacheco‐Calderón Renny
Published: November 2017

Schizophrenia is a complex neuropsychiatric disorder characterized by hallucinations, delusions, anhedonia, flat affect and cognitive impairments. The aim of this study was to propose a prenatal treatment with ketamine, a psychedelic drug that acts as a non‐competitive inhibitor of glutamate NMDA receptors, as a neurodevelopmental animal model of schizophrenia. The drug was applied (i.m. 60 mg.kg−1 h−1) in pregnant Sprague–Dawley rats on gestational Day 14. Offspring behavior was studied on pubertal (4 weeks old) and adult (10 weeks old) stages. Also, hippocampal CA1‐CA3 morphology was assessed in adult animals through a Nissl stain. Results showed a disinhibition and hyperactive behavior in pubertal animals exposed to ketamine, followed in adulthood with cognitive impairments, social withdrawal, anxiety, depression, and aggressive‐like behaviors. In the hippocampus, a reduction of the CA3 layer thickness was observed, without changes in cell density. These results strongly suggest a robust link between prenatal pharmacologic manipulation of NMDA receptors and schizophrenia.
Effect of non‐prohibited drugs on the phase II metabolic profile of morphine. An in vitro investigation for doping control purposes
Authors: Ambrosio Gabriella , de la Torre Xavier , Mazzarino Monica , Parr Maria K. , Botrè Francesco
Published: November 2017

The potential consequences of drug‐drug interaction on the strategies adopted by anti‐doping laboratories to report an adverse analytical finding for morphine were investigated. We evaluated in vitro the effects of 14 drugs on the principal metabolic pathways of morphine. The selected drugs are among those most commonly used by the athletes, none of them presently included in the World Anti‐Doping Agency (WADA) Prohibited List. The non‐prohibited drugs included 4 antifungals (fluconazole, itraconazole, ketoconazole, and miconazole), 6 benzodiazepines (alprazolam, bromazepam, clonazepam, lorazepam, lormetazepam, and triazolam), and 4 non‐steroidal anti‐inflammatory drugs (diclofenac, ibuprofen, ketoprofen, and nimesulide). The in vitro assays were based on the use of either human liver microsomes or uridine 5’‐diphospho‐glucuronosyl‐transferases. Morphine and its glucuronides were determined by developed liquid chromatography–mass spectrometry procedure after dilution with an aqueous solution containing their deuterated isotopologues as internal standards. Morphine is mainly excreted as phase II metabolites: about 70% of the parent compound is found to be biotransformed by UGT2B7 to morphine‐3‐glucuronide (6065%) and morphine‐6‐glucuronide (5‐10%). A reduction of the enzymatic activity of the UGT2B7 was recorded in the presence of 9 of the 14 drugs under investigation (ketoconazole, miconazole, itraconazole, diclofenac, ibuprofen, clonazepam, lorazepam, lormetazepam, and triazolam), with a consequent significant reduction of the levels of the glucuronide metabolites. This phenomenon in vivo may affect the rate of the urinary excretion of morphine with the risk of reporting “false negative” results, especially in case of results close to the decision limit value set by WADA.
Turkish graveyards as refuges for orchids against tuber harvest
Authors: Molnár V. Attila , Nagy Timea , Löki Viktor , Süveges Kristóf , Takács Attila , Bódis Judit , Tökölyi Jácint
Published: November 2017

Harvest of orchid tubers for salep production is widespread in southwestern Asia and the Balkans and constitutes a major conservation risk for wild orchid populations. Synanthropic habitats, such as graveyards, are important refuges for orchids and other organisms and could offer protection from salep harvesting because of their special cultural role. However, little is known about the occurrence and factors influencing harvesting of salep in graveyards. During field surveys of 474 graveyards throughout Turkey, we observed 333 graveyards with orchids, 311 graveyards with tuberous orchids, and salep harvest in 14 graveyards. Altogether, 530 individuals of 17 orchid species were collected, representing 9% of the individuals recorded. Harvesting intensity was relatively low, and populations were usually not wholly destroyed. However, some species were clearly more affected than others. Salep harvesting risk of orchid species was significantly associated with flowering time, with early‐flowering species being more affected. A marginally significant positive relationship between harvesting risk and species‐specific tuber size was also detected. Our data suggest that graveyards might offer some protection against salep harvesting in Turkey, but they also show that some orchid taxa are much more affected than others. Overall, our observations add more weight to the conservation value of these special habitats.
Population genomics and geographical parthenogenesis in Japanese harvestmen (Opiliones, Sclerosomatidae, Leiobunum)
Authors: Burns Mercedes , Hedin Marshal , Tsurusaki Nobuo
Published: November 2017

Naturally occurring population variation in reproductive mode presents an opportunity for researchers to test hypotheses regarding the evolution of sex. Asexual reproduction frequently assumes a geographical pattern, in which parthenogenesis‐dominated populations are more broadly dispersed than their sexual conspecifics. We evaluate the geographical distribution of genomic signatures associated with parthenogenesis using nuclear and mitochondrial DNA sequence data from two Japanese harvestman sister taxa, Leiobunum manubriatum and Leiobunum globosum. Asexual reproduction is putatively facultative in these species, and female‐biased localities are common in habitat margins. Past karyotypic and current cytometric work indicates L. globosum is entirely tetraploid, while L. manubriatum may be either diploid or tetraploid. We estimated species phylogeny, genetic differentiation, diversity, and mitonuclear discordance in females collected across the species range in order to identify range expansion toward marginal habitat, potential for hybrid origin, and persistence of asexual lineages. Our results point to northward expansion of a tetraploid ancestor of L. manubriatum and L. globosum, coupled with support for greater male gene flow in southern L. manubriatum localities. Specimens from localities in the Tohoku and Hokkaido regions were indistinct, particularly those of L. globosum, potentially due to little mitochondrial differentiation or haplotypic variation. Although L. manubriatum overlaps with L. globosum across its entire range, L. globosum was reconstructed as monophyletic with strong support using mtDNA, and marginal support with nuclear loci. Ultimately, we find evidence for continued sexual reproduction in both species and describe opportunities to clarify the rate and mechanism of parthenogenesis.