bluuebunny/crossref_metadata_2025 huggingface dataset:
High‐Internal‐Phase Pickering Emulsions Stabilized Solely by Peanut‐Protein‐Isolate Microgel Particles with Multiple Potential Applications
Authors: Jiao Bo , Shi Aimin , Wang Qiang , Binks Bernard P.
Published: May 2018

High‐internal‐phase Pickering emulsions have various applications in materials science. However, the biocompatibility and biodegradability of inorganic or synthetic stabilizers limit their applications. Herein, we describe high‐internal‐phase Pickering emulsions with 87 % edible oil or 88 % n‐hexane in water stabilized by peanut‐protein‐isolate microgel particles. These dispersed phase fractions are the highest in all known food‐grade Pickering emulsions. The protein‐based microgel particles are in different aggregate states depending on the pH value. The emulsions can be utilized for multiple potential applications simply by changing the internal‐phase composition. A substitute for partially hydrogenated vegetable oils is obtained when the internal phase is an edible oil. If the internal phase is n‐hexane, the emulsion can be used as a template to produce porous materials, which are advantageous for tissue engineering.
A Structural View on Medicinal Chemistry Strategies against Drug Resistance
Authors: Agnello Stefano , Brand Michael , Chellat Mathieu F. , Gazzola Silvia , Riedl Rainer
Published: May 2018

The natural phenomenon of drug resistance is a widespread issue that hampers the performance of drugs in many major clinical indications. Antibacterial and antifungal drugs are affected, as well as compounds for the treatment of cancer, viral infections, or parasitic diseases. Despite the very diverse set of biological targets and organisms involved in the development of drug resistance, the underlying molecular mechanisms have been identified to understand the emergence of resistance and to overcome this detrimental process. Detailed structural information on the root causes for drug resistance is nowadays frequently available, so next‐generation drugs can be designed that are anticipated to suffer less from resistance. This knowledge‐based approach is essential for fighting the inevitable occurrence of drug resistance.
The Scaffold Design of Trivalent Chelator Heads Dictates Affinity and Stability for Labeling His‐tagged Proteins in vitro and in Cells
Authors: Gatterdam Karl , Joest Eike F. , Gatterdam Volker , Tampé Robert
Published: May 2018

Small chemical/biological interaction pairs are at the forefront in tracing protein function and interaction at high signal‐to‐background ratios in cellular pathways. However, the optimal design of scaffold, linker, and chelator head still deserve systematic investigation to achieve the highest affinity and kinetic stability for in vitro and especially cellular applications. We report on a library of N‐nitrilotriacetic acid (NTA)‐based multivalent chelator heads (MCHs) built on linear, cyclic, and dendritic scaffolds and compare these with regard to their binding affinity and stability for the labeling of cellular His‐tagged proteins. Furthermore, we describe a new approach for tracing cellular target proteins at picomolar probe concentrations in cells. Finally, we outline fundamental differences between the MCH scaffolds and define a cyclic trisNTA chelator that displays the highest affinity and kinetic stability of all reported reversible, low‐molecular‐weight interaction pairs.
Towards Macroscopic Crystalline 2D Polymers
Authors: Feng Xinliang , Schlüter A. Dieter
Published: May 2018

Periodic and nanoporous monolayer polymers, the structures of which can be viewed as molecular fishing nets, have been classified as 2D polymers. They have been previously synthesized under mild photoirradiation conditions in the interior of layered single crystals of well‐designed monomers, followed by a liquid‐phase exfoliation. While these mild conditions allow for full structure control, the size of 2D polymers obtained cannot exceed that of the crystals from which they are prepared. In this Review, we discuss different concepts currently pursued to prepare macroscopically sized 2D polymers, focusing on syntheses at the air–water and liquid–liquid interfaces. While these interfaces are larger reaction loci than single crystals, sheet‐like polymers obtained at them pose complex and time‐consuming analytical challenges. Some of these challenges are concretely discussed and indicators are provided for identifying the promising cases, enabling to concentrate on them in the future research. Additionally, this Review discusses three representative examples of 2D polymers to provide a state‐of‐the‐art picture of this emerging field of polymer and materials science. Finally, we sketch the range of applications, such as nanomembranes, electronics, optoelectronics, and electrocatalysts for water splitting, that are relevant for these novel organic 2D materials.
The Remarkable Effect of Halogen Substitution on the Membrane Transport of Fluorescent Molecules in Living Cells
Authors: Ungati Harinarayana , Govindaraj Vijayakumar , Mugesh Govindasamy
Published: May 2018

Small‐molecule‐based fluorescent probes have become important tools in biology for sensing and imaging applications. However, the biological applications of many of the fluorescent molecules are hampered by low cellular uptake and high toxicity. In this paper, we show for the first time that the introduction of halogen atoms enhances the cellular uptake of fluorescent molecules and the nature of halogen atoms plays a crucial role in the plasma membrane transport in mammalian cells. The remarkably higher uptake of iodinated compounds compared to that of their chloro or bromo analogues suggests that the strong halogen bonding ability of iodine atoms may play an important role in the membrane transport. This study provides a novel strategy for the transport of fluorescent molecules across the plasma membrane in living cells.
In Situ Cyclization of Native Proteins: Structure‐Based Design of a Bicyclic Enzyme
Authors: Pelay‐Gimeno Marta , Bange Tanja , Hennig Sven , Grossmann Tom N.
Published: May 2018

Increased tolerance of enzymes towards thermal and chemical stress is required for many applications and can be achieved by macrocyclization of the enzyme resulting in the stabilizing of its tertiary structure. Thus far, macrocyclization approaches utilize a very limited structural diversity, which complicates the design process. Herein, we report an approach that enables cyclization through the installation of modular crosslinks into native proteins composed entirely of proteinogenic amino acids. Our stabilization procedure involves the introduction of three surface‐exposed cysteine residues, which are reacted with a triselectrophile, resulting in the in situ cyclization of the protein (INCYPRO). A bicyclic version of sortase A was designed that exhibits increased tolerance towards thermal as well as chemical denaturation, and proved to be efficient in protein labeling under denaturing conditions. In addition, we applied INCYPRO to the KIX domain, resulting in up to 24 °C increased thermal stability.
High‐Frequency Fe–H Vibrations in a Bridging Hydride Complex Characterized by NRVS and DFT
Authors: Pelmenschikov Vladimir , Gee Leland B. , Wang Hongxin , MacLeod K. Cory , McWilliams Sean F. , Skubi Kazimer L. , Cramer Stephen P. , Holland Patrick L.
Published: May 2018

High‐spin iron species with bridging hydrides have been detected in species trapped during nitrogenase catalysis, but there are few general methods of evaluating Fe−H bonds in high‐spin multinuclear iron systems. An 57Fe nuclear resonance vibrational spectroscopy (NRVS) study on an Fe(μ‐H)2Fe model complex reveals Fe−H stretching vibrations for bridging hydrides at frequencies greater than 1200 cm−1. These isotope‐sensitive vibrational bands are not evident in infrared (IR) spectra, showing the power of NRVS for identifying hydrides in this high‐spin iron system. Complementary density functional theory (DFT) calculations elucidate the normal modes of the rhomboidal iron hydride core.
Adsorption characteristics and kinetics of synthesized anionic surfactant and polymeric surfactant on sand surface for application in enhanced oil recovery
Authors: Saxena Neha , Kumar Sudhir , Mandal Ajay
Published: May 2018

The adsorption behaviour of aqueous solutions of anionic surfactant and polymeric surfactant derived from Jatropha oil onto sand surface was investigated in connection of their application in enhanced oil recovery. The loss of surfactant by adsorption on reservoir rock must be premeditated for proper design of injected surfactant slugs in a chemical enhanced oil recovery. The sand particles used in the present study as representative of reservoir rock were characterized by Fourier transform infrared and energy‐dispersive X‐ray analyses. Adsorption properties were studied as a function of time and concentration for both surfactant and polymeric surfactant. The equilibrium adsorption data were fitted with the Langmuir, Freundlich, Temkin, and Redlich–Peterson isotherm models. Thermodynamic studies revealed that the adsorption of surfactant and polymeric surfactant were spontaneous in sand–aqueous system. The kinetics of adsorption was explained using different equations, namely, the Lagergren first‐order equation, the pseudo second‐order equation, and the intraparticle diffusion equation. The kinetic parameters in each model were identified and measured in order to explain adsorption dynamics.
Numerical study of phase split characteristics of slug flow at a branching micro‐T‐junction
Authors: Dong Jianxin , Zhang Xubin , Wang Fumin , Lv Guojun , Wu Botao , Cai Wangfeng
Published: May 2018

The phase split behavior of air–water slug flow at branching micro‐T‐junctions was studied by the volume of fluid model. The effects of velocity, surface tension, and viscosity on phase split results have been tested by slug units of fixed length. The split of a gas bubble at the T‐junction shows obstructing and nonobstructing modes. Through comparison, we found that the appearance of tunnels changes the driving force of bubble breakup from upstream pressure to viscous shearing force. Split features are influenced by the length of slug unit and the flow ratio in the obstructing mode. Nevertheless, the viscous force and surface tension should not be slighted for nonobstructing mode. Moreover, tendency of the flow maldistribution of nonobstructing mode is more pronounced with higher velocity and smaller surface tension. The liquid slug length has a negligible effect on the split results of gas phase. Thus, the results of two‐phase split could be obtained from the gas split ratio solely. Pattern diagram for the transition between the 2 modes was proposed. Eventually, the importance of the length information of slug unit was also verified by the predictive model of phase split that formulated with the regression analysis of numerical data.
DinCH and ESBO actual migration from PVC infusion tubings used in an oncopediatric unit
Authors: Tortolano Lionel , Matmati Houssem , Bourhis Matthieu , Manerlax Katia , Lemare François , Saunier Johanna , Yagoubi Najet
Published: May 2018

Plasticizer leaching from poly(vinyl chloride) (PVC) tubing is a well‐studied phenomenon and is a real issue in medical care today. The present study focuses on the release of two plasticizers 1,2‐cyclohexane dicarboxylic acid diisononyl ester (DINCH) (primary) and epoxidized soy bean oil (ESBO) (secondary) from PVC extension tubings used in an oncopediatric unit. The release of plasticizers is calculated by comparison to unused tubings with the same batch number. Both the DINCH and ESBO ratio diminishes in used versus new extension tubings. The loss of plasticizers has not been related to the presence of a specific drug. Our results confirm the leaching of classic plasticizers like the DINCH and of secondary plasticizers like the ESBO from tubings in real life. It confirms too the existence of a complex phenomenon in which exchanges between drugs, lipids, PVC matrices, and the administration sequences can change the global release of plasticizers. Considering all the variables involved in real‐life data, the in vitro testing appears to be the most efficient way to confirm these observations. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46649.
Degradation and residues of indoxacarb enantiomers in rice plants, rice hulls and brown rice using enriched S‐indoxacarb formulation and enantiopure formulation
Authors: Shi Lihong , Gui Ting , Zhao Shan , Xu Jin , Wang Fei , Sui Changling , Zhang Yuping , Hu Deyu
Published: May 2018

A chiral liquid chromatography–tandem high resolution mass spectroscopic method was developed for the analysis of indoxacarb enantiomers in rice plants, rice hulls and brown rice. Chiral separation of two enantiomers was carried out on a Superchiral S‐OD column maintained at 20°C and eluted with 0.3 mL/min methanol. Samples were extracted by acetonitrile solution with ultrasound and cleansed by dispersive solid‐phase extraction of 50 mg of primary secondary amine and 50 mg of C18. This method was successfully used to study the degradation and residues of two enantiomers with enriched S‐indoxacarb (2.33S/1R) and pure S‐indoxacarb in rice plants. The half‐lives of R‐indoxacarb and S‐indoxacarb were 4.20–4.33 and 3.45–3.57 days in rice plants during the degradation of enriched S‐indoxacarb in Guizhou and Hunan, respectively, whereas the half‐lives of pure S‐indoxacarb were 2.68 and 3.69 days in Guizhou and Hunan, respectively. The results indicated that preferential S‐indoxacarb degradation occurred and that enantiomeric transformation was absent in the total experiment periods of pure S‐indoxacarb in rice plants. The final residue concentrations of indoxacarb enantiomers in brown rice were significantly less than those in rice plants and rice hulls in the same rice field after applying indoxacarb SC and indoxacarb EC.
How industry peers improve your sustainable development? The role of listed firms in environmental strategies
Authors: Yang Xue , Wang Yuandi , Hu Die , Gao Yongqiang
Published: May 2018

Factors driving firms to become more sustainable have been widely investigated in the literature on environmental strategy, but some important horizontal factors are still missing, such as influence from peers in the same industry. Drawing on signaling theory and expectancy theory, we complement existing studies by highlighting the role of listed firms in raising other firms' awareness and motivation of adopting environmental strategies, while taking the moderating capability factor into account. By setting our study in the context of listed and nonlisted private‐owned enterprises in China, the empirical analysis of 1,391 nonlisted firms indicates that the number of listed firms in an industry has positive effects on both reactive and proactive environmental strategies of nonlisted firms. The superior performance of these listed peers motivates nonlisted firms to adopt a proactive environmental strategy but constraints the reactive one. These effects are further strengthened by the relative scale of a nonlisted firm.
Pathway analysis of genetic variants in folate‐mediated one‐carbon metabolism‐related genes and survival in a prospectively followed cohort of colorectal cancer patients
Authors: Ose Jennifer , Botma Akke , Balavarca Yesilda , Buck Katharina , Scherer Dominique , Habermann Nina , Beyerle Jolantha , Pfütze Katrin , Seibold Petra , Kap Elisabeth J. , Benner Axel , Jansen Lina , Butterbach Katja , Hoffmeister Michael , Brenner Hermann , Ulrich Alexis , Schneider Martin , Chang‐Claude Jenny , Burwinkel Barbara , Ulrich Cornelia M.
Published: May 2018

Folate‐mediated one‐carbon metabolism (FOCM) is a key pathway essential for nucleotide synthesis, DNA methylation, and repair. This pathway is a critical target for 5‐fluorouracil (5‐FU), which is predominantly used for colorectal cancer (CRC) treatment. A comprehensive assessment of polymorphisms in FOCM‐related genes and their association with prognosis has not yet been performed. Within 1,739 CRC cases aged ≥30 years diagnosed from 2003 to 2007 (DACHS study), we investigated 397 single nucleotide polymorphisms (SNPs) and 50 candidates in 48 FOCM‐related genes for associations with overall‐ (OS) and disease‐free survival (DFS) using multiple Cox regression (adjusted for age, sex, stage, grade, BMI, and alcohol). We investigated effect modification by 5‐FU‐based chemotherapy and assessed pathway‐specific effects. Correction for multiple testing was performed using false discovery rates (FDR). After a median follow‐up time of 5.0 years, 585 patients were deceased. For one candidate SNP in MTHFR and two in TYMS, we observed significant inverse associations with OS (MTHFR: rs1801133, C677T: HRhet = 0.81, 95% CI: 0.67–0.97; TYMS: rs1001761: HRhet = 0.82, 95% CI: 0.68–0.99 and rs2847149: HRhet = 0.82, 95% CI: 0.68–0.99). After FDR correction, one polymorphism in paraoxonase 1 (PON1; rs3917538) was significantly associated with OS (HRhet = 1.28, 95% CI: 1.07–1.53; HRhzv = 2.02, 95% CI:1.46–2.80; HRlogAdd = 1.31, pFDR = 0.01). Adjusted pathway analyses showed significant associations for pyrimidine biosynthesis (P = 0.04) and fluorouracil drug metabolism (P < 0.01) with significant gene–chemotherapy interactions, including PON1 rs3917538. This study supports the concept that FOCM‐related genes could be associated with CRC survival and may modify effects of 5‐FU‐based chemotherapy in genes in pyrimidine and fluorouracil metabolism, which are relevant targets for therapeutic response and prognosis in CRC. These results require confirmation in additional clinical studies.
SNAI2 and TWIST1 in lymph node progression in early stages of NSCLC patients
Authors: Emprou Camille , Le Van Quyen Pauline , Jégu Jérémie , Prim Nathalie , Weingertner Noëlle , Guérin Eric , Pencreach Erwan , Legrain Michèle , Voegeli Anne‐Claire , Leduc Charlotte , Mennecier Bertrand , Falcoz Pierre‐Emmanuel , Olland Anne , Santelmo Nicolas , Quoix Elisabeth , Massard Gilbert , Guenot Dominique , Chenard Marie‐Pierre , Beau‐Faller Michèle
Published: May 2018

Lymph node metastasis is an important prognosis factor in non‐small cell lung cancer (NSCLC) patients. The aim of this study was to investigate the role of epithelial to mesenchymal transition (EMT) in lymph node progression in the early stages of NSCLC. We studied a retrospective cohort of 160 consecutive surgically treated NSCLC patients with available frozen tumor samples for expression of EMT markers (CDH1, CTNNB1, CDH2, and VIMENTIN), inducers (TGFB1, c‐MET, and CAIX), and transcription factors (EMT‐TF: SNAI1, SNAI2, ZEB1, TWIST1, and TWIST2). Partial EMT was more frequent in N1‐2 (N+) vs N0 patients (P < .01). TGFB1 (P = .02) as well as SNAI2 (P < .01) and TWIST1 (P = .04) were the most differentially expressed genes in N+ tumors. In this group, ZEB1 was correlated with all EMT inducers and other EMT‐TFs were overexpressed depending on the inducers. CAIX was an independent prognostic factor for overall survival (IC 95% HR: 1.10‐5.14, P = .03). Partial EMT is involved in lymph node progression of NSCLC patients and depends on the TGFβ pathway. EMT‐TFs are differentially expressed depending on EMT inducers. CAIX might be a relevant prognostic marker in early stage NSCLC.
Overactivated neddylation pathway in human hepatocellular carcinoma
Authors: Yu Jian , Huang Wei‐long , Xu Qing‐guo , Zhang Ling , Sun Shu‐han , Zhou Wei‐ping , Yang Fu
Published: May 2018

Dysregulation of the neddylation pathway is related to various cancers. However, the specific role of the neddylation pathway in human hepatocellular carcinoma (HCC) remains largely unclear. In this study, the neddylation pathway in HCC and adjacent noncancerous liver (ANL) tissues was evaluated by immunohistochemistry (IHC), Western blotting, and qRT‐PCR (quantitative real‐time polymerase chain reaction). The results showed that the entire neddylation pathway, including NEDD8 (the IHC staining of NEDD8 represents the global‐protein neddylation), E1 NEDD8‐activating enzymes (NAE1 and UBA3), E2 NEDD8‐conjugating enzymes (UBE2F and UBE2M), E3 NEDD8‐ligases (MDM2, RBX1 and RNF7), and deneddylation enzymes (COPS5, UCHL1 and USP21), was overactivated in HCC. Furthermore, the upregulation of NEDD8 in HCC was correlated with aggressive characteristics and was an independent risk factor for overall survival (OS) and recurrence‐free survival (RFS) in patients with HCC after hepatectomy. The upregulation of NAE1, UBE2M, and UCHL1 in HCC was associated with aggressive characteristics and poor OS and RFS in patients with HCC after hepatectomy. In conclusion, our research reveals that the entire neddylation pathway is overactivated in HCC and associated with clinical characteristics and prognosis of patients with HCC.
Corn, potato, and wrinkled pea starches with heat–moisture treatment: Structure and digestibility
Authors: Shi Miaomiao , Gao Qunyu , Liu Yanqi
Published: May 2018

Background and objectives

Starches from corn, potato, and wrinkled pea were heat treated at 100 and 120°C for 12 hr at a moisture content of 25% to produce slowly digestible starches. The effect of heat–moisture treatment (HMT) on structure and digestibility of those starches was investigated.

Findings

Changes in morphological aspects could be found in corn and pea starches after HMT treatment, potato starch retained its granular appearance with only some slight breakage of granules. For the HMT‐treated starches, the intensity of birefringence slightly decreased and the polarized cross also still existed. All the HMT starches showed the increasing To, Tp, and Tc and the decreasing enthalpy. The X‐ray diffraction pattern of potato and pea starches was shifted from B‐ or C‐type to A‐type by HMT, and corn starch changed to A + V‐ type. Compared with native starch, the relative crystallinity of starches decreased, and the degree of gelatinization of all starches was greater than that of their counterparts. After HMT, RDS and SDS contents of potato and pea starches (except corn starch) increased compared with their native counterparts, whereas RS content of all three starches was decreased. Compared with native starch, the digestibility of starches after HMT had a certain degree of increase.

Conclusions

Heat–moisture treatment had different effects on the granules morphology of different starch. The HMT samples exhibited greater To, Tp, and Tc values than those of the native counterparts with regard to the three starch types. The crystal structure and crystal pattern were transformed to the A‐type by HMT. Corn starch was easier to gelatinize than potato starch and pea starch after HMT, which could be the lower amylose content of corn starch and a smaller proportion of long chain. With the increase of HMT temperature, the starch sample RDS and SDS contents increased and RS decreased.

Significance and novelty

Corn starch was easier to gelatinize than potato starch and pea starch after HMT. With the increase in HMT temperature, the starch sample RDS and SDS contents increased and RS decreased.
Nutritional composition, bioactive compounds, and diabetic enzyme inhibition capacity of three varieties of buckwheat in Japan
Authors: Tien Nguyen Ngoc Thanh , Trinh Le Ngoc Dang , Inoue Naoto , Morita Naofumi , Hung Pham Van
Published: May 2018

Background and objectives

Buckwheat (Fagopyrum esculentum) is a source of nutrients whose total content relies on various factors such as genotype, environmental stresses, and developmental phase. The objective of this study was to investigate chemical composition, nutritional values (amino acid and fatty acid composition), bioactive compounds (total phenolic and flavonoid contents, antioxidant), and diabetic enzyme inhibition capacity of a tetraploid Tartary buckwheat “Shinano kurotsubu” cultivated in Japan as compared to other kinds of buckwheat varieties including a common buckwheat and a Tartary buckwheat “Hokkai T8.”

Findings

The protein content of the tetraploid Tartary buckwheat groats (14.14%) was significantly higher than that of the common or Tartary buckwheat groats (p < 0.05). However, the tetraploid Tartary buckwheat groats had lower lipid and ash contents as compared to the Tartary buckwheat groats. Amino acid composition and total amounts of unsaturated fatty acids of the tetraploid Tartary buckwheat were somewhat similar to those of the Tartary buckwheat. The tetraploid Tartary buckwheat was also found to have high total phenolic, total flavonoid, rutin, and quercetin contents, high antioxidant and diabetic enzyme inhibition capacities similar to the Tartary buckwheat.

Conclusions

The tetraploid Tartary buckwheat was found to be a good source of nutrients and functional components and could be used for food processing.

Significance and novelty

Recently, a new buckwheat variety named tetraploid Tartary buckwheat (var. “Shinano kurotsubu”) was successfully developed, and this variety is of more benefit for the milling process because of larger grain and more easily dehulled as compared to the Tartary buckwheat. This is the first report on the nutritional composition, bioactive compounds, and diabetic enzyme inhibition capacity of this buckwheat variety.
Snapshot in surgery: How do you approach this 12‐year‐old girl?
Authors: Bustos Roberto , Gheza Federico , Masrur Mario
Published: May 2018

Key Clinical Message

This case open questions about the dimensional limit for a laparoscopic treatment of a giant bezoar. A minimally invasive option should be considered every time a gastric obstruction is suspected, particularly for psychiatric patients, for whom a short hospital stay can be greatly beneficial.
Complete necrosis of graft ureter following renal transplant in a patient with primary antiphospholipid syndrome: A case report
Authors: Fernando Manoj Hilary , Jayarajah Umesh , Rubakan Donald , Fonseka Ruwan , Goonewardena Serozsha
Published: May 2018

Key Clinical Message

Complete necrosis of the graft ureter is a rare but serious complication following kidney transplant. In a patient with antiphospholipid syndrome, a combination of factors such as arterial thromboembolism, hematoma formation, and surgical collateral damage can cause ischemia of the graft ureter. Preoperative optimization of disease activity and coagulation with meticulous preservation of ureteric perfusion may help in prevention.
3D Graphene Network Encapsulating Mesoporous ZnS Nanospheres as High‐Performance Anode Material in Sodium‐Ion Batteries
Authors: Hu Liang , Hu Xiang , Lin Zhoubin , Wen Zhenhai
Published: May 2018

The front cover artwork is provided by the group of Zhenhai Wen from the Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences (China). The image shows the hybrid structure of rGO enwrapping ZnS nanospheres can effectively restrict volume expansion and promote the cycling stability of sodium‐ion batteries. Read the full text of the Article at 10.1002/celc.201800412.
Can Heterocyclic γ‐Peptides Provide Polyfunctional Platforms for Synthetic Glycocluster Construction?
Authors: Simon Matthieu , Ali Lamiaa M. A. , El Cheikh Khaled , Aguesseau Julie , Gary‐Bobo Magali , Garcia Marcel , Morère Alain , Maillard Ludovic T.
Published: May 2018

Sugars play key roles in many molecular and cellular communication processes involving a family of proteins named lectins. The low affinity associated with sugar recognition is generally counterbalanced by the multivalent nature of the interaction. While many polyglycosylated architectures have been described, only a few studies focused on the impact of topology variations of the multivalent structures on the interaction with lectin proteins. One major interest of our group concerns the design of new highly predictable and stable molecular pseudo‐peptide architectures for therapeutic applications. In such a context, we described a class of constrained heterocyclic γ‐amino acids built around a thiazole ring, named ATCs. ATC oligomers are helical molecules resulting from the formation of a highly stable C9 hydrogen‐bonding pattern. Following our program, we herein address the potential of ATC oligomers as tunable scaffolds for the development of original multivalent glycoclusters.
Highly Enantioselective Kinetic Resolution of Michael Adducts through N‐Heterocyclic Carbene Catalysis: An Efficient Asymmetric Route to Cyclohexenes
Authors: Chen Xiang‐Yu , Li Sun , Liu Qiang , Kumar Mukesh , Peuronen Anssi , Rissanen Kari , Enders Dieter
Published: May 2018

A highly efficient strategy for the kinetic resolution of Michael adducts was realized using a chiral N‐heterocyclic carbene catalyst. The kinetic resolution provides a new convenient route to single diastereomers of cyclohexenes and Michael adducts in good yields with high enantiomeric excesses (up to 99 % ee with a selectivity factor of up to 458). This “two flies with one swat” concept allows the synthesis of these two synthetically valuable compound classes at the same time by a single transformation.
Nanostructured Catalyst for Fischer–Tropsch Synthesis
Authors: Gao Wa , Zhu Qingshan , Ma Ding
Published: May 2018

Fischer–Tropsch synthesis (FTS) is a heterogeneous catalytic process for the production of fuels or chemicals from synthesis gas (CO + H2), which can be derived from nonpetroleum feedstocks such as natural gas, coal, or biomass. Co, Ru, Fe and Ni are all active in FTS, but only cheaper Fe and Co based catalysts are used in industry because the price of Ru is relatively high. However, the industrial Fe‐ and Co‐ based FTS catalysts normally work at a relatively high temperature range of 493—623 K in order to get a reasonable space time yield. Moreover, the product selectivity of FTS is governed by the law of polymerization, i.e., a so‐called Anderson‐Schulz‐Flory distribution holds, which restricts its industrial application. In this account, we highlight some of our progress toward the design/fabrication of nanostructured Fe, Co and Ru catalysts to improve FTS activity at the low temperature and to change the product selectivity and confine the product distribution into a certain range.
Optimizing colorectal cancer screening by race and sex: Microsimulation analysis II to inform the American Cancer Society colorectal cancer screening guideline
Authors: Meester Reinier G. S. , Peterse Elisabeth F. P. , Knudsen Amy B. , de Weerdt Anne C. , Chen Jennifer C. , Lietz Anna P. , Dwyer Andrea , Ahnen Dennis J. , Siegel Rebecca L. , Smith Robert A. , Zauber Ann G. , Lansdorp‐Vogelaar Iris
Published: May 2018

BACKGROUND

Colorectal cancer (CRC) risk varies by race and sex. This study, 1 of 2 microsimulation analyses to inform the 2018 American Cancer Society CRC screening guideline, explored the influence of race and sex on optimal CRC screening strategies.

METHODS

Two Cancer Intervention and Surveillance Modeling Network microsimulation models, informed by US incidence data, were used to evaluate a variety of screening methods, ages to start and stop, and intervals for 4 demographic subgroups (black and white males and females) under 2 scenarios for the projected lifetime CRC risk for 40‐year‐olds: 1) assuming that risk had remained stable since the early screening era and 2) assuming that risk had increased proportionally to observed incidence trends under the age of 40 years. Model‐based screening recommendations were based on the predicted level of benefit (life‐years gained) and burden (required number of colonoscopies), the incremental burden‐to‐benefit ratio, and the relative efficiency in comparison with strategies with similar burdens.

RESULTS

When lifetime CRC risk was assumed to be stable over time, the models differed in the recommended age to start screening for whites (45 vs 50 years) but consistently recommended screening from the age of 45 years for blacks. When CRC risk was assumed to be increased, the models recommended starting at the age of 45 years, regardless of race and sex. Strategies recommended under both scenarios included colonoscopy every 10 or 15 years, annual fecal immunochemical testing, and computed tomographic colonography every 5 years through the age of 75 years.

CONCLUSIONS

Microsimulation modeling suggests that CRC screening should be considered from the age of 45 years for blacks and for whites if the lifetime risk has increased proportionally to the incidence for younger adults. Cancer 2018;124:2974‐85. © 2018 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.
A Two‐Photon Pumped Supramolecular Upconversion Microresonator
Authors: Ravi Jada , Venkatakrishnarao Dasari , Sahoo Chakradhar , Naraharisetty Sri Ram Gopal , Mitetelo Nikolai , Ezhov Alexander A. , Mamonov Evgeniy , Murzina Tatiana , Chandrasekar Rajadurai
Published: May 2018

A two‐photon pumped non‐linear optical (NLO) Fabry‐Pèrot (F‐P) type organic micro‐crystal resonator useful for a myriad of upconversion‐based light technologies is presented. The resonator is parallelepiped‐shaped and composed of a self‐assembled donor‐acceptor‐donor type molecule namely, 9,9,9”,9”‐tetramethyl‐9H,9’H,9”H‐[2, 2’:7,2”‐terfluoren]‐9’‐one (TTO). X‐ray crystal structure of an orange‐yellow TTO micro‐crystal reveals C−H⋅⋅⋅O type weak intermolecular hydrogen bond between the oxygen atom of the fluorenone unit and fluorine hydrogen atom. For one‐ and two‐photon excitation the micro‐crystals exhibit F‐P type modes in their photoluminescence signal. The fundamental frequency‐dependent NLO intensity shows a continuous increase as the fundamental wavelength is decreasing down to 770 nm. The two‐photon luminescence signals from these micro‐resonators are several orders of magnitude higher than the thin films of similar thickness.
Efficient dense matrix‐vector multiplication on GPU
Authors: He Guixia , Gao Jiaquan , Wang Jun
Published: May 2018

Given that the dense matrix‐vector multiplication (Ax or ATx) is of great importance in scientific computations, how to accelerate it is investigated on the graphics processing unit (GPU) in this paper. We present a warp‐based implementation of Ax on the GPU, called GEMV‐Adaptive, and a thread‐based implementation of ATx on the GPU, called GEMV‐T‐Adaptive. For our proposed GEMV‐Adaptive and GEMV‐T‐Adaptive, there are the following novelties: (1) an adaptive warp allocation strategy for GEMV‐Adaptive is proposed to assign the optimal warp number for each matrix row, (2) an adaptive thread allocation strategy for GEMV‐T‐Adaptive is designed to assign the optimal thread number to each matrix row, and (3) several optimization schemes are formulated. Experimental results show that the proposed GEMV‐Adaptive and GEMV‐T‐Adaptive mitigate the performance fluctuations of the implementations in the CUBLAS library, always have high performance, and outperform the most recently proposed GEMV and GEMV‐T kernels by Gao et al, respectively, for all test matrices.
TCNQ Physisorption on the Topological Insulator Bi2Se3
Authors: Pia Ada Della , Lisi Simone , Luca Oreste De , Warr Daniel A. , Lawrence J. , Otrokov Mikhail M. , Aliev Ziya S. , Chulkov Evgueni V. , Agostino Raffaele G. , Arnau Andrés , Papagno Marco , Costantini Giovanni
Published: May 2018

Topological insulators are promising candidates for spintronic applications due to their topologically protected, spin‐momentum locked and gapless surface states. The breaking of the time‐reversal symmetry after the introduction of magnetic impurities, such as 3d transition metal atoms embedded in two‐dimensional molecular networks, could lead to several phenomena interesting for device fabrication. The first step towards the fabrication of metal‐organic coordination networks on the surface of a topological insulator is to investigate the adsorption of the pure molecular layer, which is the aim of this study. Here, the effect of the deposition of the electron acceptor 7,7,8,8‐tetracyanoquinodimethane (TCNQ) molecules on the surface of a prototypical topological insulator, bismuth selenide (Bi2Se3), is investigated. Scanning tunneling microscope images at low‐temperature reveal the formation of a highly ordered two‐dimensional molecular network. The essentially unperturbed electronic structure of the topological insulator observed by photoemission spectroscopy measurements demonstrates a negligible charge transfer between the molecular layer and the substrate. Density functional theory calculations confirm the picture of a weakly interacting adsorbed molecular layer. These results reveal significant potential of TCNQ for the realization of metal‐organic coordination networks on the topological insulator surface.
PN sequence blind estimation in multiuser DS‐CDMA systems with multipath channels based on successive subspace scheme
Authors: Mirzadeh Sarcheshmeh Hossein , Khaleghi Bizaki Hossein , Alizadeh Sajjad
Published: May 2018

In this paper, we proposed a new method based on expanding subspace algorithm and finite alphabet characteristics, for blind estimation of the users' spreading sequences in the multiuser direct sequence code division multiple access system in the presence of the multipath channels. In the proposed scheme, we show that the estimation of the users' overall channels in the direct sequence code division multiple access system is equivalent to the impulse response estimation of the multi‐input multi‐output finite impulse response channels. Our proposed approach is based on the successive estimation of the columns of the equivalent multi‐input multi‐output finite impulse response channels from the lowest degree columns to the highest degree ones. Accordingly, each user's overall channel that is the convolution of the original multipath channel and the spreading sequence is estimated. Then we extract PN sequences from the overall channel using finite alphabet characteristics of the spreading sequence chips for each user. According to simulation results, our proposed scheme outperforms the conventional methods in that it does not require symbol synchronization and does not have channel constraints (for example, AWGN and single user system) in the multipath channels.
Biodiversity‐ecosystem functioning relationships in a long‐term non‐weeded field experiment
Authors: Veen G. F. , van der Putten Wim H. , Bezemer T. Martijn
Published: May 2018

Many grassland biodiversity experiments show a positive relationship between biodiversity and ecosystem functioning, however, in most of these experiments plant communities are established by sowing and natural colonization is prevented by selective weeding of non‐sown species. During ecosystem restoration, for example on abandoned fields, plant communities start on bare soil, and diversity is often manipulated in a single sowing event. How such initial plant diversity manipulations influence plant biodiversity development and ecosystem functioning is not well understood. We examined how relationships between taxonomic and functional diversity, biomass production and stability develop over 16 yr in non‐weeded plots sown with 15 species, four species, or that were not sown. We found that sown plant communities become functionally similar to unsown, naturally colonized plant communities. However, initial sowing treatments had long‐lasting effects on species composition and taxonomic diversity. We found only few relationships between biomass production, or stability in biomass production, and functional or taxonomic diversity, and the ones we observed were negative. In addition, the cover of dominant plant species was positively related to biomass production and stability. We conclude that effects of introducing plant species at the start of secondary succession can persist for a long time, and that in secondary succession communities with natural plant species dynamics diversity–functioning relationships can be weak or negative. Moreover, our findings indicate that in systems where natural colonization of species is allowed effects of plant dominance may underlie diversity–functioning relationships.
Geographic variation in the sensitivity of an herbivore‐induced seaweed defense
Authors: Jones Emily , Long Jeremy D.
Published: May 2018

Intraspecific variation in primary producer induced defenses may affect how these defenses contribute to population and community regulation. For instance, inducible defenses may play larger roles in primary producer populations that are sensitive to low levels of grazing than populations that only respond to high levels of grazing. Although the incidence of herbivore‐induced defenses is well documented, and there are examples of geographic variation in these defenses, we have limited knowledge of the factors that affect sensitivity to grazing (i.e., the minimum grazer density needed to elicit these responses) within and among populations. Filling this gap is necessary to understand the importance of these defenses under different conditions. To address whether the sensitivity of seaweed induced defenses varies geographically, we exposed Northern and Southern California populations of the seaweed Silvetia compressa to five densities of the snail Tegula funebralis, under ambient, regional environmental conditions. Southern seaweeds required high levels of grazing to induce defenses, while all levels of herbivory decreased Northern seaweed palatability. To better understand these different responses to low levels of grazing, we conducted common garden experiments to directly test the roles of experimental environment and herbivore source. Consistent with initial experiments, Northern Silvetia responded to low levels of grazing, regardless of environmental conditions, while Southern Silvetia never responded to low levels of grazing, even after being acclimated to Northern environmental conditions for 24 d. Additionally, Southern Silvetia did not respond to grazing by Northern snails, suggesting that herbivore source did not explain this geographic pattern in inducible seaweed defenses. Together, these observations suggest that the seaweed source explains this geographic pattern in sensitivity. Trade‐offs with constitutive defenses did not help explain this pattern, as Southern Silvetia had weaker constitutive defenses than Northern seaweeds. This may be due to a combination of low grazing pressure and low predictability of attack in the South. Thus, population variation in sensitivity may be due to long‐term differences in environmental histories, resulting in local adaptation or legacy effects from exposure to local conditions. Overall, our results indicate that these herbivore‐induced responses may be more important in Northern Silvetia populations than Southern ones.
Validation of U.S. mortality prediction models for hospitalized heart failure in the United Kingdom and Japan
Authors: Nagai Toshiyuki , Sundaram Varun , Shoaib Ahmad , Shiraishi Yasuyuki , Kohsaka Shun , Rothnie Kieran J. , Piper Susan , McDonagh Theresa A. , Hardman Suzanna M.C. , Goda Ayumi , Mizuno Atsushi , Sawano Mitsuaki , Rigby Alan S. , Quint Jennifer K. , Yoshikawa Tsutomu , Clark Andrew L. , Anzai Toshihisa , Cleland John G.F.
Published: May 2018

Aims

Prognostic models for hospitalized heart failure (HHF) were developed predominantly for patients of European origin in the United States of America; it is unclear whether they perform similarly in other health care systems or for different ethnicities. We sought to validate published prediction models for HHF in the United Kingdom (UK) and Japan.

Methods and results

Patients in the UK (n =894) and Japan (n =3158) were prospectively enrolled and were similar in terms of sex (∼60% men) and median age (∼77 years). Models predicted that British patients would have a higher mortality than Japanese, which was indeed true both for in‐hospital (4.8% vs. 2.5%) and 180‐day (20.7% vs. 9.5%) mortality. The model c‐statistics for the published/derivation (range 0.70–0.76) and Japanese (range 0.75–0.77) cohorts were similar and higher than for the UK (0.62–0.75) but models consistently overestimated mortality in Japan. For in‐hospital mortality, the OPTIMIZE‐HF model performed best, providing similar discrimination in published/derivation, UK and Japanese cohorts [c‐indices: 0.75 (0.74–0.77); 0.75 (0.68–0.81); and 0.77 (0.70–0.83), respectively], and least overestimated mortality in Japan. For 180‐day mortality, the c‐statistics for the ASCEND‐HF model were similar in published/derivation (0.70) and UK [0.69 (0.64–0.74)] cohorts but higher in Japan [0.75 (0.71–0.79)]; calibration was good in the UK but again overestimated mortality in Japan.

Conclusion

Calibration of published prediction models appears moderately accurate and unbiased when applied to British patients but consistently overestimates mortality in Japan. Identifying the reason why patients in Japan have a better than predicted prognosis is of great interest.
A Concise and Efficient Route to Electron‐Accepting 2,2′‐[2,2′‐Arenediylbis(11‐oxoanthra[1,2‐b]thiophene‐6‐ylidene)]dipropanedinitriles
Authors: Baranov Denis S. , Uvarov Mikhail N. , Kazantsev Maxim S. , Glebov Evgeni M. , Nevostruev Danil A. , Mostovich Evgeny A. , Antonova Olga V. , Kulik Leonid V.
Published: May 2018

A concise organolithium‐free route to build electron‐accepting molecules consisting of two 2‐(11‐oxoanthra[1,2‐b]thiophen‐6‐ylidene)propanedinitrile units connected by functionalized π‐conjugated linkers was developed. Annulation of two thiophene rings in one step was achieved through chemoselective cyclocondensation of a bis(ethynylanthraquinone) substrate with sodium sulfide. Finally, electron‐accepting dicyanomethylene moieties were introduced by Knoevenagel condensation with malodinitrile. The synthesized 2,2′‐[2,2′‐arenediylbis(11‐oxoanthra[1,2‐b]thiophene‐6‐ylidene)]dipropanedinitriles were studied by UV/Vis and fluorescence spectroscopy, cyclic voltammetry, and DFT calculations. The acceptor properties of these compounds were confirmed by efficient light‐induced electron transfer in their blend with a donor polymer, poly(3‐hexylthiophene‐2,5‐diyl), detected by electron paramagnetic resonance spectroscopy.
Structural Assignment of Fluorocyclobutenes by 19F NMR Spectroscopy – Comparison of Calculated 19F NMR Shielding Constants with Experimental 19F NMR Shifts
Authors: Kučnirová Kateřina , Šimůnek Ondřej , Rybáčková Markéta , Kvíčala Jaroslav
Published: May 2018

Although the optimized reduction of perfluorocyclobutene with LiAlH4 gave a quantitative yield of the target 3,3,4,4‐tetrafluorocyclobut‐1‐ene, unoptimized reductions led to complex inseparable mixtures of fluorocyclobutenes. These mixtures showed highly complex 19F NMR spectra, the assignment of which was quite tedious. Hence, we accomplished a series of single‐reference computations of the 19F NMR magnetic shieldings of the corresponding fluorine atoms. Surprisingly, various DFT approaches, including both traditional and advanced functionals, gave highly diverse results with poor correlations between the experimental and computed 19F chemical shifts, and the individual fluorocyclobutenes could not be identified. In contrast, the domain‐based local pair natural orbital coupled clusters (DLPNO‐CCSD) method, developed recently as a part of the ORCA computational package, gave shielding values that enabled the assignment of all structures observed, albeit with some systematic errors. Slightly better magnetic shielding values were obtained by a simple Hartree–Fock (HF) method with a specially tailored IGLO‐III basis set. The method developed was successfully employed for the assignment of the 19F NMR shifts of unknown fluorocyclobutenes.