bluuebunny/crossref_metadata_2025 huggingface dataset:
Ru (III) Schiff‐base complex anchored on nanosilica as an efficient and retrievable catalyst for hydration of nitriles
Authors: Sultana Samim , Borah Geetika , Gogoi Pradip K.
Published: November 2018

Transition metal catalyzed hydration of nitriles is an attractive methodology for amide synthesis, and hence recently attracted wide attention. It is one of the significant organic transformations as amides play a vital role in biological, pharmaceutical and industrial applications. In this work, we report the synthesis of a new solid supported Ru (III) Schiff base complex, Ru@imine‐nanoSiO2immobilized on nanosilica obtained from rice husk. The complex was characterized by FTIR, powder X‐ray diffraction, BET surface area measurement, UV–vis, SEM–EDX, TEM, ESR, X‐ray photoelectron spectroscopy and ICP‐AES analysis. Using Ru@imine‐nanoSiO2as the catalyst, the hydration of nitriles ini‐PrOH at 40 °C was studied which resulted in good isolated yields (60–99%). The catalyst can be recycled and reused up to 5thcycle without any loss in activity. The products were characterized by FTIR, GC–MS and1H‐NMR spectroscopy and compared with authentic samples.
Cu (II) tyrosinate complexes containing methyl substituted phenanthrolines: Synthesis, X‐ray crystal structures, biomolecular interactions, antioxidant activity, ROS generation and cytotoxicity
Authors: İnci Duygu , Aydın Rahmiye , Vatan Özgür , Huriyet Huzeyfe , Zorlu Yunus , Çoşut Bünyemin , Çinkılıç Nilüfer
Published: November 2018

In this paper, three new copper (II) complexes, [Cu(4‐mphen)(tyr)(H2O)]ClO4 (1), [Cu(5‐mphen)(tyr)(H2O)]ClO4·1.5H2O (2) and [Cu (tmphen)(tyr)(NO3)]0.5H2O (3) (4‐mphen: 4‐methyl‐1,10‐phenanthroline, 5‐mphen: 5‐methyl‐1,10‐phenanthroline, tmphen: 3,4,7,8‐tetramethyl‐1,10‐phenanthroline and tyr: L‐tyrosine), were synthesized and characterized using elemental analyses, FT‐IR, ESI‐MS, cyclic voltammetry and single‐crystal X‐ray diffraction. It was found that the complexes adopt a distorted five‐coordinate square pyramidal geometry. The interaction of the three complexes with calf thymus DNA was also investigated using UV–visible absorption spectra, ethidium bromide and Hoechst 33258 displacement assay and thermal denaturation. The DNA cleavage activity of the complexes, monitored using gel electrophoresis, showed significant damage of the pUC19 plasmid DNA. Binding activity of bovine serum albumin (BSA) reveals that these complexes can strongly quench the fluorescence of BSA through a static quenching mechanism. The results suggested that interaction of the complexes with DNA occurred through a partial intercalation into the minor grooves of DNA. In addition, interaction of the complexes with bovine serum albumin quenched the fluorescence emission of the tryptophan residues of the protein binding constants and thermodynamic parameters were obtained from the fluorescence quenching experiments at different temperatures. Free radical scavenging activities of the complexes were determined by various in vitro assays such as 1,1‐diphenyl‐2‐picryl‐hydrazyl free radicals (DPPH˙) and H2O2 scavenging methods. In addition, the cytotoxicity of these complexes in vitro on tumor cell lines (Caco‐2 and MCF‐7) was examined by XTT and showed better antitumor effect on the tested cells. ROS (reactive oxygen species) and comet experiments are consistent with each other and these complexes lead to DNA damage via the production of ROS. The effect of the hydrophobic properties of the synthesized complexes on DNA and BSA binding activities were discussed.
MIL‐53(Fe) Metal–Organic Frameworks (MOFs) as an Efficient and Reusable Catalyst for the One‐Pot Four‐Component Synthesis of Pyrano[2,3‐c]‐pyrazoles
Authors: Ghasemzadeh Mohammad Ali , Mirhosseini‐Eshkevari Boshra , Abdollahi‐Basir Mohammad Hossein
Published: November 2018

A novel and simple approach for the efficient and rapid synthesis of pyrano[2,3‐c]‐pyrazoleshas been accomplished via the four‐component condensation reaction of malononitrile, hydrazine hydrate, ethyl acetoacetate, and substituted aldehydes using MIL‐53(Fe) metal–organic framework (MOF) as a catalyst in ethanol at room temperature. Recycling studies have shown that the MIL‐53(Fe) can be readily recovered and reused six times without significant loss of its activity. The present protocol offers the advantages including short reaction times, simple workup, high yields, elimination of toxic solvents, no chromatographic purification and recoverability of the catalyst. Also, the catalyst was fully characterized by SEM, EDX, FT‐IR, XRD, TGA and TEM analysis.
Biomimetic Synthesis of Ag2Se Quantum Dots with Enhanced Photothermal Properties and as “Gatekeepers” to Cap Mesoporous Silica Nanoparticles for Chemo–Photothermal Therapy
Authors: Li Xianglong , Liu Zexiu , Luo Kai , Yin Xiuhui , Lin Xucong , Zhu Chunling
Published: November 2018

Ag2Se quantum dots (QDs) with near‐infrared (NIR) fluorescence have been widely utilized in NIR fluorescence imaging in vivo because of their narrow bulk band gap and excellent biocompatibility. However, most of synthesis methods for Ag2Se QDs are expensive and the reactants are toxic. Herein, a new protein‐templated biomimetic synthesis approach is proposed for the preparation of Ag2Se QDs by employing bovine serum albumin (BSA) as a template and dispersant. The BSA‐templated Ag2Se QDs (Ag2Se@BSA QDs) showed NIR fluorescence with high fluorescence quantum yield (≈21.2 %), excellent biocompatibility and good dispersibility in different media. Moreover, the obtained Ag2Se@BSA QDs exhibited remarkable photothermal conversion (≈27.8 %), which could be used in photothermal therapy. As a model application in biomedicine, the Ag2Se@BSA QDs were used as “gatekeepers” to cap mesoporous silica nanoparticles (MSNs) by means of electrostatic interaction. By taking the advantages of NIR fluorescence and photothermal property of Ag2Se@BSA QDs, the obtained MSN‐DOX‐Ag2Se nanoparticles (MDA NPs) were employed as a nanoplatform for combined chemo‐photothermal therapy. Compared with free DOX and MDA NPs without NIR laser, the laser‐treated MDA NPs exhibited lower cell viability in vitro, implying that Ag2Se@BSA QDs are highly promising photothermal agents and the MDA NPs are potential carriers for chemo–photothermal therapy.
Design of Fractional‐Order Backstepping Sliding Mode Control for Quadrotor UAV
Authors: Shi Xiaoyu , Cheng Yuhua , Yin Chun , Dadras Sara , Huang Xuegang
Published: November 2018

This paper derives a nonlinear translational and rotational dynamic model of the quadrotor UAV. An original fractional‐order backstepping sliding mode control method for a typical quadrotor UAV is presented. The new approach can decrease the chattering phenomenon and increase the robustness of control strategy. The strongly coupled characteristics of the under‐actuated system are sought by the virtual controllers. The feasibility for different track trajectories are verified using MATLAB. The new control method can not only track the expected trajectory very well but also has a better robustness for different complex trajectory under disturbances, as the simulation results demonstrate.
A Robust Control Scheme Based on Sliding Mode Observer to Drive a Knee‐Exoskeleton
Authors: Mefoued Saber , Belkhiat Djamel Eddine Chouaib
Published: November 2018

In this paper, a robust control scheme to drive a knee‐exoskeleton has been designed to assist people with limited knee movement. Dynamic modeling and parameter identification of the “subject's lower limb‐exoskeleton” has been performed and a sliding mode observer (SMO) developed and integrated in the system's closed loop to provide velocity. Lyapunov's theory allows demonstration of the stability of the system. Experimental tests have been performed with the aid of five voluntary subjects, in sitting position, and during flexion/extension of the knee joint. The performance of the proposed control scheme is compared with those obtained using the classical proportional integrator derivative (PID) controller. These tests track the desired position and velocity trajectories with small tracking errors and evaluate the system's stability and system's robustness against the subject's parameters, variations, and external disturbances.
Antioxidant and reactive oxygen species scavenging properties of cellular albumin in HepG2 cells is mediated by the glutathione redox system
Authors: Seidkhani‐Nahal Ali , Allameh Abdolamir , Soleimani Masoud
Published: November 2018

This study was carried out to examine the role of intracellular albumin in the modulation of oxidative damage induced by glutathione modifiers in HepG2 cells. Also, the relationship of albumin synthesis with oxidative stress factors including antioxidants was studied. HepG2 cell culture was supplemented with glutathione modifiers; L‐Buthionine‐sulfoximine (BSO; 0.1 and 1.0 mM) or N‐acetyl cysteine (NAC; 1 and 10 mM) and the cell viability and changes in reduced glutathione (GSH), oxidized glutathione (GSSG), reactive oxygen species (ROS), catalase, and superoxide dismutase were measured. Besides, albumin expression at protein and mRNA levels was determined in cells pretreated with BSO or NAC. Kinetic studies showed that albumin expression in HepG2 cells is correlated with GSH and GSSG levels. Changes in albumin expression at protein and mRNA levels reached their maximum (19% and 55%, respectively) in the cells 6 H after NAC treatments. A substantial decrease in intracellular albumin due to BSO (27%) was associated with a significant increase in the generation of cellular ROS (17%). In contrast, increased albumin synthesis (intracellular and secretory) was associated with inhibition in cellular ROS. Overall data may suggest that albumin expression in coordination with the glutathione redox system is part of the antioxidant defense mechanism in liver cells.
Understanding the participation of GREM1 polymorphisms in nonsyndromic cleft lip with or without cleft palate in the Brazilian population
Authors: Viena Camila Sane , Machado Renato Assis , Persuhn Darlene Camati , Martelli‐Júnior Hercílio , Medrado Alena Peixoto , Coletta Ricardo D. , Reis Silvia R. A.
Published: November 2018

Background

GREM1, which encodes Gremlin 1, an antagonist of bone morphogenic proteins with effects on proliferation and apoptosis, has been considered a candidate gene for nonsyndromic cleft lip with or without cleft palate (NSCL±P). In this study, we investigated potential associations of single nucleotide polymorphisms (SNP) in GREM1 and NSCL±P risk in the Brazilian population. Additionally, SNP‐SNP interactions of GREM1 with previously reported rs1880646 variant in NTN1 (netrin 1), a gene also responsible for apoptotic phenotypes were verified.

Methods

Applying Taqman allelic discrimination assays, we evaluated the variants rs16969681, rs16969816, rs16969862, and rs1258763 in 325 case‐parent trios and in 1,588 isolated samples in a case‐control study. Allelic and genotypic analyses, as well as interaction tests assessing gene‐environmental factor (GxE) and SNP‐SNP interaction with rs1880646 variant in NTN1, were performed based on logistic regression analysis adjusted for the effects of gender and genomic ancestry proportions.

Results

The risk alleles of all SNP were undertransmitted in NSCL±P trios, though the case‐control analysis confirmed only the association with rs16969862 alleles (OR: 0.78, 95% CI: 0.63–0.96, p = .02). The GxE interaction analysis revealed a significant interaction between maternal environmental contact with agrotoxics and rs16969816 (OR: 0.25, 95% CI: 0.08–0.74, p = .01), and pairwise interaction test with NTN1 rs1880646 yielded significant p values in the 1,000 permutation test for rs16969681, rs16969816, and rs16969862.

Conclusion

The GREM1 is involved in the etiology of NSCL±P in the Brazilian population and reveal that the interaction between GREM1 and NTN1 may be related with the pathogenesis of this common craniofacial malformation.
An evaluation of the single‐session interview‐informed synthesized contingency analysis
Authors: Jessel Joshua , Hanley Gregory P. , Ghaemmaghami Mahshid , Metras Rachel
Published: November 2018

Functional analysis can often be a lengthy process requiring time and resources not readily available to practitioners working with children who exhibit severe problem behavior. The interview‐informed synthesized contingency analysis (IISCA) was recently developed as an alternative functional analysis format that improved analytic efficiency by requiring only 25 min to conduct. Furthermore, a within‐session analysis of the first test session of the entire IISCA could reduce the process to as little as a single 5‐min session. We extended this previous research by conducting what was termed the single‐session IISCA with three boys who exhibited severe problem behavior. A function‐based treatment package, including reinforcement thinning, informed by the results of the single‐session IISCA nearly eliminated problem behavior for all three participants. We suggest that the single‐session IISCA could be a viable alternative to other functional analysis formats when time is limited.
Photophysics and photodynamics of Pyronin Y in n‐alcohols
Authors: Beşer Burcu Meryem , Onganer Yavuz , Arik Mustafa
Published: November 2018

The photophysical properties and photodynamics of Pyronin Y (PyY) dye compound in seven polar protic solvents (n‐alcohols) were examined as a function of temperature by using UV–visible, steady‐state and time‐resolved fluorescence spectroscopy techniques. To understand dye–solvent interactions, photophysical parameters including Stokes’ shifts, fluorescence quantum yields and fluorescence lifetimes were determined. To examine the effect of solvent polarity, the difference between the ground state dipole moment and the excited state dipole moment was determined. For this purpose, the multiple regression analysis and the Kamlet–Taft technique were used. Moreover, photodynamic parameters, rotational relaxation times and steady‐state anisotropy were calculated. The result showed that the specific interactions of PyY with the solvent molecules take place through hydrogen bonding. As the hydrocarbon chain of the alcohols gets longer, photophysical parameters diminish, probably because of weaker hydrogen bonding. Furthermore, it was found out that the dipole moment of excited states (μe) is higher than that of the ground state (μg). In addition, Brownian motions increased with the increasing temperature that weakened the fluorescence character of PyY. It was also revealed that the rotation of PyY increased with a prolonged hydrocarbon chain of alcohol series, due to the lesser extent of hydrogen bonding.
Dissipation behavior of chlorpyrifos residues and risk assessment in sugarcane fields
Authors: Wang Haiping , Zheng Liguo , Yu Wanting , Cao Xiaomin , Yang Renbin
Published: November 2018

As chlorpyrifos is used globally to control pests in sugarcane fields, analysis of its residues on food crops is essential to assess product safety for humans. In this study, chlorpyrifos content in sugarcane plants, soil and juice was determined using a gas chromatography with an electron capture detector. The limit of quantification was 0.01 mg/kg for plant and soil, and 0.01 mg/L for juice. The degradation and residual risk in sugarcane fields after applying chlorpyrifos to two sample sites (Changsha and Danzhou, China) were assessed. Chlorpyrifos concentrations in plants and soil decreased rapidly over time, reaching a degradation rate ranging from 98.82 to 99.25% on day 35. The half‐life of chlorpyrifos in both plants and soil was only 5.97–6.12 days. Regardless of application dosage (standard or high) at a pre‐harvest interval of 60 days, chlorpyrifos was undetectable in the harvested sugarcane. Risk assessment indicated that chlorpyrifos residue in sugarcane did not pose a health risk to humans.
National Cancer Database report of nonmetastatic esophageal small cell carcinoma
Authors: Verma Vivek , Sleightholm Richard L. , Fang Penny , Ryckman Jeffrey M. , Lin Chi
Published: November 2018

Background

Esophageal small cell carcinoma (ESCC) is a rare malignancy for which there is no consensus management approach. This is the largest known analysis of nonmetastatic ESCC patients to date, evaluating national practice patterns and outcomes of surgical‐based therapy vs chemoradiotherapy (CRT) vs chemotherapy alone.

Methods

The National Cancer Data Base was queried for esophageal cancer patients with histologically confirmed nonmetastatic ESCC. Univariable and multivariable logistic regression ascertained factors associated with receipt of surgical‐based management. Kaplan‐Meier analysis evaluated overall survival (OS) and the log‐rank test is used to compare OS between groups; Cox univariate and multivariate analyses determined variables associated with OS.

Results

Altogether, 323 patients were analyzed; 64 (20%) patients underwent surgical‐based therapy, 211 (65%) CRT, and 48 (15%) chemotherapy alone. On multivariable analysis, no single factor significantly predicted for administration of surgery. Despite no OS differences between the surgery‐based (median OS 21 months) and CRT arms (18 months), both were superior to CT alone (10 months) (P < 0.001). Among other factors, receiving any local therapy independently predicted for higher OS over chemotherapy alone on Cox multivariate analysis (P < 0.001).

Conclusions

This study of a large, contemporary national database demonstrates that most ESCC is treated with CRT in the United States; adding local therapy to systemic therapy may be beneficial to these patients, although individualized multidisciplinary management is still recommended.
Lactate dehydrogenase A: A key player in carcinogenesis and potential target in cancer therapy
Authors: Feng Yangbo , Xiong Yanlu , Qiao Tianyun , Li Xiaofei , Jia Lintao , Han Yong
Published: November 2018

Elevated glycolysis remains a universal and primary character of cancer metabolism, which deeply depends on dysregulated metabolic enzymes. Lactate dehydrogenase A (LDHA) facilitates glycolytic process by converting pyruvate to lactate. Numerous researches demonstrate LDHA has an aberrantly high expression in multiple cancers, which is associated with malignant progression. In this review, we summarized LDHA function in cancer research. First, we gave an introduction of structure, location, and basic function of LDHA. Following, we discussed the transcription and activation mode of LDHA. Further, we focused on the function of LDHA in cancer bio‐characteristics. Later, we discussed the clinical practice of LDHA in cancer prevention and treatment. What we discussed gives a precise insight into LDHA especially in cancer research, which will contribute to exploring cancer pathogenesis and its handling measures.
Lewis Acid Catalysis of Nb2O5 for Reactions of Carboxylic Acid Derivatives in the Presence of Basic Inhibitors
Authors: Siddiki S. M. A. Hakim , Rashed Md. Nurnobi , Ali Md. Ayub , Toyao Takashi , Hirunsit Pussana , Ehara Masahiro , Shimizu Ken‐ichi
Published: November 2018

This review focuses on catalytic applications of niobium pentoxide (Nb2O5) and niobic acid (Nb2O5 ⋅ nH2O). These materials serve as heterogeneous acid catalysts that show excellent activity and selectivity for various types of reactions including hydrations, dehydrations, and oxidations. Most recently, they have been used for dehydration reactions of polyols and nucleophilic substitution reactions of carboxylic acid derivatives. A special focus is placed on the latter reactions, where superficial Nb5+ cations act as Lewis‐acidic sites that activate oxygen‐containing functional groups of substrates even in the presence of basic inhibitors such as water or amines. This unique behavior of Nb‐oxide‐based catalysts is a consequence of their Lewis acidity, which is characterized by their ability to simultaneously activate C=O bonds but not to engage in strong competitive adsorption of base molecules. Both experimental and theoretical investigations are presented in order to assess the characteristic features of the Nb‐oxide‐based catalysts together with their structural features.
Tungsten Catalyst Incorporating a Well‐Defined Tetracoordinated Aluminum Surface Ligand for Selective Metathesis of Propane, [(≡Si−O−Si≡)(≡Si−O−)2Al−O−W(≡CtBu) (H)2]
Authors: Werghi Baraa , Bendjeriou‐Sedjerari Anissa , Jedidi Abdesslem , Morlanes Natalia , Abou‐Hamad Edy , Bhatte Kushal , Guan Erjia , Ma Tao , Aguilar‐Tapia Antonio , Ould‐Chikh Samy , Cavallo Luigi , Gates Bruce C. , Basset Jean‐Marie
Published: November 2018

A well‐defined aluminium‐bound hydroxyl group on the surface of mesoporous SBA‐15, [(≡Si−O−Si≡) (≡Si−O)2 Al−OH], 3 was obtained by reacting di‐isopropyl aluminium hydride with SBA‐15 treated at 700 °C. The resulting surface [(≡Si−O−Si≡) (≡Si−O) 2 Al (isobutyl) fragment undergoes β‐H elimination at 400 °C leading to [(≡Si−O−Si≡)(≡Si−O−)2Al−O) Al−H]. Further oxidation of this Al‐hydride with N2O leads to 3. This acidic support was used to create a well‐defined surface organo‐tungsten fragment [(≡Si−O−Si≡)(≡Si−O−)2Al−O−W(≡CtBu)(CH2tBu)2] by reacting 3 with W(≡C‐tBu)(CH2‐tBu)3. A further reaction with hydrogen under mild conditions afforded the tungsten carbyne bis‐hydride [(≡Si−O−Si≡)(≡Si−O−)2Al−O−W(H)2(≡C‐tBu)]. The performance of each of the W‐supported catalysts was assessed for propane metathesis in a flow reactor at 150 °C. [(≡Si−O−Si≡)(≡Si−O−)2 Al−O−W(≡CtBu)(H)2] was found to be a single‐site catalyst, giving the highest turnover number (TON=800) and the highest reported selectivity for butane (45 %) vs. ethane (32 %) known for oxide‐supported tungsten complex catalysts (with the supports being silica, silica‐alumina, and alumina). The results demonstrate that modification of the oxide ligands on silica via the creation of Al Lewis acid center as an anchoring site for organometallic complexes opens up new catalytic properties, markedly enhancing the catalytic performance of supported organo‐tungsten species.
Comparison of Oil‐in‐Water Emulsion between Ultrasonic Irradiation and Mechanical Stirring
Authors: Sumitomo Syunsuke , Ueta Miharu , Uddin M. Azhar , Kato Yoshiei
Published: November 2018

To compare oil‐in‐water emulsification behaviors between ultrasonic irradiation and impeller stirring, experiments and calculation by mathematical models were performed. For ultrasonic irradiation, the peak diameter of dispersed oil droplets decreased with an increase in input power and reductions in ultrasonic frequency, ratio of dispersed volume, and interfacial tension. For mechanical stirring, it declined with higher mechanical rotation speed. The results calculated by the mathematical models approximately agreed with the experiments. Ultrasonic irradiation was better than mechanical stirring by an impeller for producing a fine emulsion at higher supplied energy rate into liquid, whereas the tendency was inverse for a rough emulsion at lower input energy rate.
Development of a Split Bipolar Electrode System for Electrochemical Fluorination of Triphenylmethane
Authors: Miyamoto Kazuhiro , Nishiyama Hiroki , Tomita Ikuyoshi , Inagi Shinsuke
Published: November 2018

To overcome the problem of electrochemical fluorination methods using a large amount of supporting electrolytes and fluorine sources, we employed a split bipolar electrode (s‐BPE) system, in which electrode reactions occur in a low concentration of supporting electrolyte and electricity is monitored. We optimized the electrochemical parameters for the s‐BPE system using a U‐shaped electrochemical cell and investigated the electrochemical fluorination of triphenylmethane as a model substrate in the presence of potassium fluoride (KF) or cesium fluoride (CsF) as a supporting electrolyte and a fluorine source dissolved by the help of poly(ethylene glycol) (PEG) additive. The fluorination of triphenylphoshine was also examined under the optimized conditions.
Spectroscopic Determination of the Electronic Structure of a Uranium Single‐Ion Magnet
Authors: Coutinho Joana T. , Perfetti Mauro , Baldoví José J. , Antunes Maria A. , Hallmen Philipp P. , Bamberger Heiko , Crassee Iris , Orlita Milan , Almeida Manuel , van Slageren Joris , Pereira Laura C. J.
Published: November 2018

Early actinide ions have large spin‐orbit couplings and crystal field interactions, leading to large anisotropies. The success in using actinides as single‐molecule magnets has so far been modest, underlining the need for rational strategies. Indeed, the electronic structure of actinide single‐molecule magnets and its relation to their magnetic properties remains largely unexplored. A uranium(III) single‐molecule magnet, [UIII{SiMe2NPh}3‐tacn)(OPPh3)] (tacn=1,4,7‐triazacyclononane), has been investigated by means of a combination of magnetic, spectroscopic and theoretical methods to elucidate the origin of its static and dynamic magnetic properties.
Enantioselective C2‐Alkylation of Indoles through a Redox‐Relay Heck Reaction of 2‐Indole Triflates
Authors: Race Nicholas J. , Yuan Qianjia , Sigman Matthew S.
Published: November 2018

A palladium‐catalyzed enantioselective redox‐relay Heck reaction of 2‐indole triflates and disubstituted alkenes is reported. This process combines readily available indole triflates with a variety of alkenes to afford a range of indole derivatives bearing a stereocenter adjacent to C2. Enantioselectivity is achieved through use of a simple pyridine‐oxazoline ligand. Tuning the electronics of the indole, through judicious choice of N‐protecting group, is required to ensure selective β‐hydride elimination away from the indole core. Utility of this method is highlighted in a modular formal synthesis of an S1P1 agonist precursor developed by Merck.
Transition‐Metal‐Free Three‐Component Radical 1,2‐Amidoalkynylation of Unactivated Alkenes
Authors: Jiang Heng , Studer Armido
Published: November 2018

A transition‐metal‐free radical 1,2‐amidoalkynylation of unactivated alkenes is presented. α‐Amido‐oxy acids were used as amidyl radical precursors, which were oxidized by an organic photoredox catalyst (4CzlPN). The electrophilic N‐radicals chemoselectively reacted with various aliphatic alkenes and the adduct radicals were then trapped by ethynylbenziodoxolone (EBX) reagents to eventually provide the amidoalkynylation products. These transformations, which were conducted under practical and mild conditions, showed high functional group tolerance and broad substrate scope. Mechanistic studies supported the radical nature of these cascades.
Crystallization at ACHEMA 2018
Authors: Temmel Erik , Eicke Matthias Johannes
Published: November 2018

Die zunehmende Digitalisierung eröffnet spannende Möglichkeiten neuartige Prozesse zu realisieren, aber auch alte Prozesse wie die Kristallisation noch besser zu verstehen und damit effizienter zu betreiben. Eine notwendige Voraussetzung sind geeignete Messmethoden. Dazu zählen zum einen die Überwachung von Prozessströmen sowie die Verfolgung der Triebkräfte, aber auch Möglichkeiten, die Zusammensetzung verschiedener Phasen zu bestimmen. Auf einige Methoden, die maßgeblich zum besseren Prozessverständnis beitragen, wird in diesem Beitrag eingegangen. Zudem werden neue Entwicklungen aus den Bereichen Miniaturisierung und kontinuierliche Fahrweisen sowie ein innovatives Verfahren zur quasi‐kontinuierlichen Filtration und Trocknung kristallinen Materials vorgestellt.
Design, Synthesis, and Biological Evaluation of Polyaminocarboxylate Ligand‐Based Theranostic Conjugates for Antibody‐Targeted Cancer Therapy and Near‐Infrared Optical Imaging
Authors: Ren Siyuan , Sun Xiang , Wang Haixing , Nguyen Trung Hai , Sadeghipour Negar , Xu Xiaochun , Kang Chi Soo , Liu Yujie , Xu Hua , Wu Ningjie , Chen Yanda , Tichauer Kenneth , Minh David D. L. , Chong Hyun‐Soon
Published: November 2018

We report the design, synthesis, and evaluation of polyaminocarboxylate ligand‐based antibody conjugates for potential application in targeted cancer therapy and near‐infrared (NIR) fluorescence imaging. We synthesized a new polyaminocarboxylate chelate (CAB‐NE3TA) as a potential anticancer agent. CAB‐NE3TA displayed potent inhibitory activities against various cancer cell lines. We then designed a multifunctional theranostic platform (CAB‐NE3TA‐PAN‐IR800) constructed on an epidermal growth factor receptor (EGFR)‐targeted antibody (panitumumab, PAN) labeled with a NIR fluorescent dye. We also built the first atomistic model of the EGFR–PAN complex and loaded it with the cytotoxic CAB‐NE3TA and the NIR dye. The therapeutic (CAB‐NE3TA‐PAN) and theranostic (CAB‐NE3TA‐PAN‐IR800) conjugates were evaluated using an EGFR‐positive A431 (human skin cancer) cell xenograft mouse model. Biodistribution studies using NIR fluorescence imaging demonstrated that the CAB‐NE3TA‐PAN labeled with the IR800 dye selectively targeted the A431 tumors in mice and resulted in prolonged retention in the tumor tissue and displayed excellent clearance in blood and normal organs. The therapeutic conjugate was capable of significantly inhibiting tumor growth, leading to nearly complete disappearance of tumors in the mice. The results of our pilot in vivo studies support further evaluation of the novel ligand‐based therapeutic and theranostic conjugates for targeted iron chelation cancer therapy and imaging applications.
Pregnancy after cancer: Does timing of conception affect infant health?
Authors: Hartnett Kathleen P. , Mertens Ann C. , Kramer Michael R. , Lash Timothy L. , Spencer Jessica B. , Ward Kevin C. , Howards Penelope P.
Published: November 2018

BACKGROUND

The objective of this retrospective cohort study was to determine whether women who conceive soon after treatment for cancer have higher risks of adverse pregnancy outcomes.

METHODS

Vital records data were linked to cancer registry diagnosis and treatment information in 3 US states. Women who conceived their first pregnancy after diagnosis between ages 20 and 45 years with any invasive cancer or ductal carcinoma in situ were eligible. Log‐binomial models were used to compare risks in cancer survivors who conceived in each interval to the risks in matched comparison births to women without cancer.

RESULTS

Women who conceived ≤1 year after starting chemotherapy for any cancer had higher risks of preterm birth than comparison women (chemotherapy alone: relative risk [RR], 1.9; 95% confidence interval [CI], 1.3‐2.7; chemotherapy with radiation: RR, 2.4; 95% CI, 1.6‐3.6); women who conceived ≥1 year after starting chemotherapy without radiation or ≥2 years after chemotherapy with radiation did not. In analyses imputing the treatment end date for breast cancer survivors, those who conceived ≥1 year after finishing chemotherapy with or without radiation had no higher risks than women without cancer. The risk of preterm birth in cervical cancer survivors largely persisted but was somewhat lower in pregnancies conceived after the first year (for pregnancies conceived ≤1 year after diagnosis: RR, 3.5; 95% CI, 2.2‐5.4; for pregnancies conceived >1 year after diagnosis: RR, 2.4; 95% CI, 1.6‐3.5).

CONCLUSIONS

In women who received chemotherapy, the higher risk of preterm birth was limited to those survivors who had short intervals between treatment and conception.Cancer 2018;124:000‐000.
Luminescent and Magnetic Properties of Coordination Polymers Induced by Coordinating Modes of a Bis(oxamate) Ligand
Authors: Ma Li‐Na , Li Xiu‐Yuan , Shi Wen‐Juan , Li Yong‐Zhi , Liu Ge , Hou Lei , Wang Yao‐Yu
Published: November 2018

The reactions of an unexploited N,N′‐5‐carboxyl‐1,3‐phenylenebis(ethyl oxamate) (HEt2L) ligand with different Mn2+ and Cd2+ salts under solvothermal conditions afforded four three‐dimensional (3D) coordination polymers (CPs): [Mn1.5L(H2O)2]⋅H2O (1) [Mn2L(C2O4)0.5(NMP)(H2O)] ⋅ NMP (2), [Cd1.5L(H2O)2.5] ⋅ H2O (3) and [Cd2L(C2O4)0.5(H2O)3] ⋅ H2O (4) (NMP=N‐methyl pyrrolidone). L, generated by the in‐situ hydrolysis of HEt2L, displays four kinds of coordinating modes through oxamate and carboxylate groups as well as different syn‐syn and syn‐trans configurations. The resulting novel (3,4,5)‐, (3,4,6)‐, (4,5)‐ and (4,4,4,5)‐connected topologies for 1–4 were formed. Among them, 1 has interesting 1D metal‐oxamate zigzag chains, 2 contains 1D channels with a free void of 52.5 %, 3 consists of an unprecedented Cd‐oxamate layer, 4 has a novel Cd‐oxamate‐oxalate chain. The antiferromagnetic interactions of 1 and 2 were observed, meanwhile 3 and 4 exhibit solid‐state luminescence with the maximum emission bands at 483 and 479 nm, respectively, under an excitation of 332 nm.
Secure cognitive radio‐based synchronized transmission of 5G signals using massive MIMO‐OFDM‐ES
Authors: P. Deepanramkumar , Karuppiah Marimuthu , Islam SK Hafizul , Obaidat (Fellow of IEEE and Fellow of SCS) Mohammad S.
Published: November 2018

A cognitive radio network (CRN) can address spectrum scarcity issues to achieve higher levels of spectral efficiency. Fifth‐generation (5G) technologies are advanced telecommunication technologies that are built into CRNs. Network performance is enhanced when using a massive multiple input multiple output (MIMO) system that tolerates a large number of users based on the use of multiple antennas. Several previous research works have been conducted on 5G CRNs, although these works have failed to mitigate interference and the peak‐to‐average power ratio (PAPR). In this paper, a 5G CRN with massive MIMO that ensures secure data transmission is developed. Security is ensured via the standardized key–based secrecy method supported by a certificate authority. A CRN fusion centre (FC) plays a vital role in decision making. Fusion centre rotation is applied to mitigate interference. Massive MIMO‐OFDM effective signalling is used to address PAPR problems. The proposed CRN is experimentally modelled using network simulator 3, and its performance is evaluated. Our simulation results reveal improvements in channel capacity, a reduction in the PAPR and bit error rates, and improvements in spectral efficiency.
Adolescent social stress and social context influence the intake of ethanol and sucrose in male rats soon and long after the stress exposures
Authors: Marcolin Marina L. , Hodges Travis E. , Baumbach Jennet L. , McCormick Cheryl M.
Published: November 2018

Social instability stress in adolescent rats (SS; postnatal day 30–45, daily 1 hr isolation +new cage partner) alters behavioural responses to psychostimulants, but differences in voluntary consumption of natural and drug rewards are unknown. SS also is associated with an atypical behavioural repertoire, for example reduced social interactions. Here, we investigated whether SS rats differ from control (CTL) rats in ethanol (EtOH) or sucrose intake in experiments involving different social contexts: alone, in the presence of an unfamiliar peer, in the presence of its cage partner, or in competition against its cage partner. SS rats drank more EtOH than CTL rats irrespective of social context, although the effects were driven primarily by those tested soon after the test procedure rather than weeks later in adulthood. SS and CTL rats did not differ in sucrose intake, except in adulthood under conditions of competition for limited access (SS>CTL). Adolescent rats drank more sucrose than adults, in keeping with evidence that adolescents are more sensitive to natural rewards than adult animals. Overall, adolescent SS modified the reward value of EtOH and sucrose, perhaps through stress/glucocorticoids modifying the development of the mesocorticolimbic system.
Finding events in a continuous world: A developmental account
Authors: Levine Dani , Buchsbaum Daphna , Hirsh‐Pasek Kathy , Golinkoff Roberta M.
Published: November 2018

Event segmentation is a fundamental process of human cognition that organizes the continuous flux of activity into discrete, hierarchical units. The mechanism of event segmentation in infants seems to parallel the mechanism studied in adults, which centers on action predictability. Statistical learning appears to bootstrap infants’ event segmentation by generating action predictions without relying on prior knowledge. Infants’ first‐hand experiences with goal‐directed actions further enhance their prediction of others’ actions. Scaffolds for event segmentation are available in the input, with caregivers providing redundant cues to event boundaries through the use of motionese and acoustic packaging. Research points to the importance of developing event segmentation skills for development in other areas of cognition, including memory, social competence, and language, though more work is needed to capture the directionality of effects. Although event segmentation is a relatively new area of focus in cognition, this process illuminates how children make sense of an ever‐changing world.
Wetland compensation and its impacts on β‐diversity
Authors: Price Edward P. F. , Spyreas Greg , Matthews Jeffrey W.
Published: November 2018

The anthropogenic degradation of natural ecological communities can cause biodiversity loss in the form of biotic homogenization (i.e., reduced β‐diversity). Biodiversity offsetting practices, such as compensatory wetland mitigation, may inadvertently cause biotic homogenization if they produce locally homogenous or regionally recurring communities. The fact that compensation wetlands often resemble degraded wetlands suggests that potential impacts to β‐diversity are likely. Yet, it is unknown how high‐quality, low‐quality (degraded), and compensation wetlands compare in terms of β‐diversity. We compared the β‐diversity of high‐quality, low‐quality, and compensation wetlands at local and regional scales. β‐diversity was quantified as the average distance to group centroids in multivariate space based on pairwise comparisons of community composition. The local spatial structure of β‐diversity was assessed using species turnover across plots. Indicator species analysis was used to describe compositional differences potentially contributing to differences in β‐diversity. Overall, the β‐diversity of compensation sites did not differ from high‐quality or low‐quality natural wetlands. However, compensation wetlands had a high degree of internal turnover along the hydrological gradient, which culminated in homogenous zones in the wettest areas. Compared to high‐quality wetlands, low‐quality wetlands had significantly lower β‐diversity at local scales, but significantly greater β‐diversity at regional scales. Indicator species results showed that compensation wetlands were distinguished by low conservation value species typically found in old fields and waste areas. This analysis also indicated that the invasive grass Phalaris arundinacea was indicative of low‐quality and compensation wetlands. This species is likely contributing to differing patterns of β‐diversity between high‐quality and low‐quality wetlands. These results indicate that conclusions regarding β‐diversity depend on scale and scope of analysis. Particularly, the unique architecture of compensation wetlands makes conclusions regarding within‐site β‐diversity dependent on the observer's position along the hydrological gradient. Additionally, while we conclude that compensation wetlands are not contributing to biotic homogenization at the regional scale, these wetlands are distinct from both high‐quality and low‐quality wetlands in their composition and structure. Therefore, assessments of the overall success of wetland mitigation programs should acknowledge the reality of these differences.
Arylzinc Halides by Silver Catalyzed Zinc Insertion into Aryl Iodides
Authors: Casotti Gianluca , Iuliano Anna , Carpita Adriano
Published: November 2018

A catalytic amount of silver acetate efficiently promotes direct insertion of zinc metal into aryl iodides, having different structure, in ethereal solvent. Electron‐rich substrates also rapidly undergo oxidative metalation. The arylzinc iodides formed give Negishi coupling products under mild reaction conditions to obtain biaryls in high yields. Sensitive functional groups like aldehydes and primary amides are well‐tolerated.
Geraniin Differentially Modulates Chromosome Stability of Colon Cancer and Noncancerous Cells by Oppositely Regulating their Spindle Assembly Checkpoint
Authors: Guo Xihan , Dai Xueqin , Ni Juan , Ma Xiaoling , Xue Jinglun , Wang Xu
Published: November 2018

Geraniin has been reported to specifically induce apoptosis in multiple human cancers, but the underlying mechanism is poorly defined. The spindle assembly checkpoint (SAC) is a surveillance system to ensure high‐fidelity chromosome segregation during mitosis. Weakening of SAC to enhance chromosome instability (CIN) can be therapeutic because very high levels of CIN are lethal. In this study, we have investigated the effects of geraniin on the SAC of colorectal cancer HCT116 cells and noncancerous colon epithelial CCD841 cells. We find that treatment of HCT116 cells with geraniin leads to dose‐dependent decrease of cell proliferation, colony formation, and anchorage‐independent growth. Geraniin is found to induce apoptosis in mitotic and postmitotic HCT116 cells. Furthermore, geraniin weakens the SAC function of HCT116 cells by decreasing the transcriptional expression of several SAC kinases (particularly Mad2 and Bub1), which in turn leads to premature anaphase entry, mitotic aberrations, and CIN in HCT116 cells. In contrast, the proliferation of CCD841 cells is slightly inhibited by geraniin. Even more interestingly, geraniin increases the transcriptional expression of several SAC kinases (e.g., Mad1 and BubR1) to strengthen SAC efficiency, which contributes to the reduction of mitotic aberrations and CIN in CCD841 cells. Altogether, our findings reveal that the SAC pathway in human colon cancer and noncancerous cell lineages responses oppositely to geraniin treatment, resulting CIN promotion and suppression, respectively. Specific abrogation of SAC to induce catastrophic CIN in HCT116 cells may account for the selective anticancer action of geraniin.. Environ. Mol. Mutagen. 60:254–268, 2019. © 2018 Wiley Periodicals, Inc.
Hierarchical Ultrafine Ni3V2O8 Nanoparticles Anchored on rGO as High‐Performance Anode Materials for Lithium‐Ion Batteries
Authors: Yang Mingyang , Fu Xuelian , Zhang Jianqiao , Wang Zhenyu , Wang Bingxue , He Liqing , Wu Zhiliang , Cheng Hua , Pan Hui , Lu Zhouguang
Published: November 2018

Ni3V2O8 is a promising anode material for Li‐ion batteries due to its high theoretical capacity that originates from the multivalence of nickel and vanadium. However, its low conductivity results in poor rate performance, and the large volume variation leads to poor stability induced by the inevitable pulverization and aggregation of active materials during cycling. To address these issues, a strategy by anchoring ultrafine Ni3V2O8 nanoparticles on reduced graphene oxide with hierarchical architecture (rGO@Ni3V2O8) is presented. This method is shown to effectively facilitate charge transfer, maintain structural integrity, and accommodate the volume variation during cycling. As a result, the rGO@Ni3V2O8 composite manifests a very stable and high reversible capacity of 1050 mA h g–1 over 200 cycles at a current density of 500 and 900 mA h g–1 after the subsequent 200 cycles at 1 A g–1. Furthermore, excellent rate capability is achieved. More than 45% of the capacity can be retained when the current density is increased from 0.1 to 10 A g–1.
Carbon‐Coated Cu nanoparticles as a Cocatalyst of g‐C3N4 for Enhanced Photocatalytic H2 Evolution Activity under Visible‐Light Irradiation
Authors: Chen Sibo , Yang Siyuan , Sun Xiaolin , He Kelin , Ng Yun Hau , Cai Xin , Zhou Wuyi , Fang Yueping , Zhang Shengsen
Published: November 2018

The photocatalytic H2 evolution is an important technology to solve the energy crisis. The hydrogen evolution rate of the graphite carbon nitride (g‐C3N4) system in triethanolamine solution as sacrificial agent is clearly higher than that in methanol solution. But up to now, most of the Cu nanoparticles as cocatalyst of g‐C3N4 photocatalytic systems for hydrogen evolution are performed in methanol solution because Cu nanoparticles are unstable in triethanolamine solution. Here, carbon‐coated Cu nanoparticles as a cocatalyst of g‐C3N4 composites (Cu@C/g‐C3N4) are prepared by a simple two‐step technology that includes annealing followed by grinding. The compositions, morphology, and optical and photoelectrochemical properties of the composites are characterized by means of physicochemical techniques. The prepared composition is used to generate hydrogen under visible‐light irradiation in triethanolamine solution. The results show that the hydrogen evolution rate of the optimal Cu@C/g‐C3N4 is up to 265.1 μmol g−1 h−1, which is close to the activity of 0.5% Pt/g‐C3N4, and after four repeated reactions, the photocatalytic activity decreases only by ≈15%. The good photocatalytic activity and stability result from Cu nanoparticles increase the transfer efficiency of charge carriers by trapping the photogenerated electrons produced by g‐C3N4 and the protective effect of carbon layer on Cu nanoparticles.
The Synergetic Benefits of Passivation Layer and Catalytic Layer on Hematite for Efficient Water Splitting
Authors: Cheng Xiaoqin , Cao Shiyao , Huan Yahuan , Bai Zhiming , Li Minghua , Wu Hailin , Zhang Ruxiao , Peng Wencai , Ji Zhen , Yan Xiaoqin
Published: November 2018

In photoelectrochemical (PEC) water splitting systems, an overlayer on the surface of the semiconductor has always been pursued with tremendous interest. The multicomponent Fe2O3/FexSn1−xO4/FeOOH photoanode is designed to achieve efficient water splitting. The photocurrent density of Fe2O3/FexSn1−xO4/FeOOH photoanode is 1.70 mA cm−2 at 1.23 V vs reversible hydrogen electrode (RHE), improved by 121.1%, compared with that of the pristine hematite photoanode (0.77 mA cm−2 at 1.23 V vs RHE) under air mass (AM) 1.5 illumination (100 mW cm−2). Detailed characterization is carried out to explore the main factors of photocurrent enhancement. The excellent PEC performance could be attributed to the synergetic benefits of FexSn1−xO4 passivation layer and FeOOH catalyst, which reduce the rate of electron–hole recombination and improve water oxidation reaction kinetics. The results prove a new sight to achieve efficient PEC water splitting.