bluuebunny/crossref_metadata_2025 huggingface dataset:
Oligo(ethylene glycol)/alkyl‐modified Chromophore Assemblies for Photon Upconversion in Water
Authors: Haruki Rena , Kouno Hironori , Hosoyamada Masanori , Ogawa Taku , Yanai Nobuhiro , Kimizuka Nobuo
Published: January 2019

Molecular self‐assembly is a powerful means to construct nanoscale materials with advanced photophysical properties. Although the protection of the photo‐excited states from oxygen quenching is a critical issue, it still has been in an early phase of development. In this work, we demonstrate that a simple and typical molecular design for aqueous supramolecular assembly, modification of the chromophoric unit with hydrophilic oligo(ethylene glycol) chains and hydrophobic alkyl chains, is effective to avoid oxygen quenching of triplet–triplet annihilation‐based photon upconversion (TTA‐UC). While a TTA‐UC emission is completely quenched when the donor and acceptor are molecularly dispersed in chloroform, their aqueous co‐assemblies exhibit a clear upconverted emission in air‐saturated water even under extremely low chromophore concentrations down to 40 μm. The generalization of this nano‐encapsulation approach offers new functions and applications using oxygen‐sensitive species for supramolecular chemistry.
A Photostable AIEgen for Specific and Real‐time Monitoring of Lysosomal Processes
Authors: Zhang Weijie , Zhou Fan , Wang Zhiming , Zhao Zujin , Qin Anjun , Tang Ben Zhong
Published: January 2019

Lysosomes are recognized as advanced organelles involved in many cellular processes and are also considered as crucial regulators of cell homeostasis. The current strategies for monitoring activities of lysosomes exhibit some limitations. Herein, we synthesized a novel fluorescent probe named 2M‐DPAS with AIE characteristics, which was proved to have significant advantages of good biocompatibility, high selectivity, bright emission and excellent photostability. Based on those, 2M‐DPAS can be used to continuously monitor the dynamic changes of lysosomes, including autophagy and mitophagy, as well as to track the process of endocytosis of macromolecules in lysosomes, which are of benefit to better know about the lysosomes‐related diseases.
Impact of FRET between Molecular Aggregates and Quantum Dots
Authors: Maity Partha , Gayathri Thumuganti , Singh Surya Prakash , Ghosh Hirendra N.
Published: January 2019

Energy transfer has been employed in third‐generation solar cells for the conversion of light into electrical energy. Long‐range nonradiative energy transfer from semiconductor quantum dots (QDs) to fluorophores has been demonstrated by using CdS QDs and thiophene−BODIPY (boron dipyrromethene, abbreviated as TG2). TG2 shows a broad photoluminescence (PL) spectrum, which varies with concentration. At very low concentrations, monomeric units are present; then, upon increasing the concentration, these monomers form a mixed (J‐/H‐)aggregated state. Energy transfer between the CdS QDs and TG2 was confirmed by separately investigating the interactions between CdS and the monomer of TG2 and between CdS and the aggregated states of TG2. Size‐dependent PL quenching confirmed that nonradiative Förster resonance energy transfer (FRET) from photoexcited CdS QDs to the J‐aggregate state of TG2 was the major energy‐relaxation channel, which occurred on the timescale of hundreds of fs. These results have broad applications in the field of light harvesting based on the assembly of molecular aggregates.
An A‐D‐A′‐D‐A Conjugated Molecule Entailing Diazapentalene Unit for an n‐Type Organic Semiconductor
Authors: Lin Gaobo , Wang Lingna , Yang Yizhou , Liu Zitong , Zhang Guanxin , Zhang Deqing
Published: January 2019

Conjugated molecules with low lying LUMO levels are demanding for the development of air stable n‐type organic semiconductors. In this paper, we report a new A‐D‐A′‐D‐A conjugated molecule (DAPDCV) entailing diazapentalene (DAP) and dicyanovinylene groups as electron accepting units. Both theoretical and electrochemical studies manifest that the incorporation of DAP unit in the conjugated molecule can effectively lower the LUMO energy level. Accordingly, thin film of DAPDCV shows n‐type semiconducting behavior with electron mobility up to 0.16 cm2⋅V−1⋅s−1 after thermal annealing under N2 atmosphere. Moreover, thin film of DAPDCV also shows stable n‐type transporting property in air with mobility reaching 0.078 cm2⋅V−1⋅s−1.
Au–Ag Nanoflower Catalysts with Clean Surfaces for Alcohol Oxidation
Authors: Imura Yoshiro , Akiyama Ryota , Furukawa Shinya , Kan Ryota , Morita‐Imura Clara , Komatsu Takayuki , Kawai Takeshi
Published: January 2019

Shape‐controlled metal nanocrystals, such as nanowires and nanoflowers, are attractive owing to their potentially novel catalytic properties and bimetallic nanocrystals composed of two distinct metals are expected to act as highly active catalysts. However, their catalytic activities are limited because of the capping agents adsorbed on the metal surfaces, which are necessary for the preparation and dispersion of these nanocrystals in solvents. Therefore, the preparation of bimetallic shape‐controlled noble metal nanocrystals with clean surfaces, devoid of almost all capping agents, are expected to have high catalytic activity. Herein, we report the preparation of bimetallic Au–Ag nanoflowers using melamine as the capping agent. The bimetallic Au–Ag nanoflowers with a clean surface were subsequently obtained by a support and extraction method. The bimetallic nanoflowers with a clean surface were then used for the aerobic oxidation of 1‐phenylethyl alcohol and they exhibited high rates for the formation of acetophenone compared to Au nanoflowers and spherical nanoparticles with almost the same size and Au/Ag ratio. We also show that Au–Ag nanoflowers containing only 1 % Ag (Au99–Ag1NFs) exhibit the highest rate of acetophenone formation among Au–Ag nanoflowers with different Au/Ag ratios owing to an increase in the electron density of the Au atoms that act as active sites for the oxidation of 1‐phenylethyl alcohol.
Removal of Oil Spills through a Self‐Propelled Smart Device
Authors: Ju Guannan , Yang Xiao , Li Lin , Cheng Mengjiao , Shi Feng
Published: January 2019

Oil/water separation through superhydrophobic/superoleophilic materials has attracted considerable interest over the past decades; however, dealing with oil spills on broad waters through an active way remains a challenge. Herein, we report a self‐propelled smart device driven by the decomposition of hydrogen peroxide that can spontaneously move on the water surface and collect floating oil droplets inside with superhydrophobic and superoleophilic properties. Moreover, the self‐propelled smart device exhibits excellent stability and high efficiency for oil/water separation. We believe this study may provide a promising strategy for fabricating smart aquatic devices that have potential applications in water remediation.
Intramolecular Metal⋅⋅⋅π‐Arene Interactions in Neutral and Cationic Main Group Compounds
Authors: Schwamm Ryan J. , Fitchett Christopher M. , Coles Martyn P.
Published: January 2019

The role of intramolecular metal⋅⋅⋅π‐arene interactions has been investigated in the solid‐state structures of a series of main group compounds supported by the bulky amide ligands, [N(tBuAr≠)(SiR3)]− (tBuAr≠=2,6‐(CHPh2)2‐4‐tBuC6H2, R=Me, Ph). The lithium and potassium amide salts showed different patterns of solvation and demonstrated that the SiPh3 substituent is able to be involved in stabilizing the electrophilic metal. These group 1 metal compounds served as ligand transfer reagents to access a series of bismuth(III) halides. Chloride extraction from Bi(N{tBuAr≠}{SiPh3})Cl2 using AlCl3 afforded the 1:1 salt [Bi(N{tBuAr≠}{SiPh3})Cl][AlCl4]. This was accompanied by a significant rearrangement of the stabilizing π‐arene contacts in the solid‐state. Attempted preparation of the corresponding tetraphenylborate salt resulted in phenyl‐transfer and generation of the neutral Bi(N{tBuAr≠}{SiPh3})(Ph)Cl.
Neutral and Negatively Charged Phosphate Modifications Altering Thermal Stability, Kinetics of Formation and Monovalent Ion Dependence of DNA G‐Quadruplexes
Authors: Su Yongdong , Fujii Hirofumi , Burakova Ekaterina A. , Chelobanov Boris P. , Fujii Masayuki , Stetsenko Dmitry A. , Filichev Vyacheslav V.
Published: January 2019

The effect of phosphate group modifications on formation and properties of G‐quadruplexes (G4s) has not been investigated in detail. Here, we evaluated the structural, thermodynamic and kinetic properties of the parallel G‐quadruplexes formed by oligodeoxynucleotides d(G4T), d(TG4T) and d(TG5T), in which all phosphates were replaced with N‐methanesulfonyl (mesyl) phosphoramidate or phosphoryl guanidine groups resulting in either negatively charged or neutral DNA sequences, respectively. We established that all modified sequences were able to form G‐quadruplexes of parallel topology; however, the presence of modifications led to a decrease in thermal stability relative to unmodified G4s. In contrast to negatively charged G4s, assembly of neutral G4 DNA species was faster in the presence of sodium ions than potassium ions, and was independent of the salt concentration used. Formation of mixed G4s composed of both native and neutral G‐rich strands has been detected using native gel electrophoresis, size‐exclusion chromatography and ESI‐MS. In summary, our results indicate that the phosphate modifications studied are compatible with G‐quadruplex formation, which could be used for the design of biologically active compounds.
Guest Solvent‐dependence of the Nanomechanical Response in Substituted Dihydropyrimidinone Crystals
Authors: Bhandary Subhrajyoti , Rani Gulshan , Mangalampalli S. R. N. Kiran , Rao G. B. Dharma , Ramamurty Upadrasta , Chopra Deepak
Published: January 2019

The nanomechanical responses of two crystalline phases of a dihydropyrimidine analogue (1) were similar irrespective of the presence (or absence) of the guest solvent. In contrast, the mechanical responses of two differently solvated forms of the second related (2) crystals were significantly different. These contrasting behaviors are rationalized in terms of intermolecular interactions and energy distributions.
Feasibility and efficiency of concurrent chemoradiotherapy with a single agent or double agents vs radiotherapy alone for elderly patients with esophageal squamous cell carcinoma: Experience of two centers
Authors: Huang Chunyue , Zhu Yujia , Li Qiwen , Zhang Wenwen , Liu Hui , Zhang Weijun , Hu Yonghong , Yuan Yawei , Liu Mengzhong
Published: January 2019

The incidence of elderly patients with esophageal cancer (OC) is increasing as the population ages. Until now, the treatment strategy in these patients has been unclear. The aim of our study was to assess the efficiency and tolerance of treatment with radiotherapy alone (RT alone), single‐agent‐based concurrent chemoradiotherapy (CCRT‐1), or double‐agent‐based concurrent chemoradiotherapy (CCRT‐2) in elderly patients (≥65 years) with OC. A total of 271 patients with OC aged 65 years or older were included in this study. The median overall survival (OS), median progression‐free survival (PFS), overall response rate (ORR), disease control rate (DCR), and treatment‐related toxicities were assessed. The median OS time for all patients was 23.6 ± 2.3 months, with 2‐year survival rates of 48.0 ± 3.0%. The median PFS time was 13.6 ± 1.3 months with the 2‐year PFS rate was 33.0 ± 4.0%. Among patients who received CCRT‐1, better OS, and PFS were found in patients who received docetaxel than in patients received fluorouracil and platinum. In a subgroup analysis, 118 patients who underwent RT alone had a median OS time of 15.6 ± 1.9 months and median PFS time of 10.4 ± 0.9 months. The median OS time of patients who received CCRT‐1 was 28.8 ± 10.1 months compared with 27.8 ± 2.5 months for the patients treated with CCRT‐2 (P = 0.537). The similar results were observed for median PFS, with 16.5 ± 3.2 months in the CCRT‐1 group and 17.0 ± 2.0 months in the CCRT‐2 group (P = 0.321). Grade ≥3 leukocytopenia and grade ≥2 weight loss during treatment occurred in 40.6% and 17.9% of patients, respectively, in the CCRT‐2 group, which was higher than that observed in the CCRT‐1 group. Our results suggested that CCRT could be considered as an acceptable treatment for elderly patients with OC. The CCRT‐1 group presented with a lower incidence of treatment toxicities but comparable survival outcomes, compared to the CCRT‐2 group. Docetaxel was superior to fluorouracil and platinum in terms of OS.
Tumor‐infiltrating CD8+ T‐cell density is an independent prognostic marker for oral squamous cell carcinoma
Authors: Shimizu Shota , Hiratsuka Hiroyoshi , Koike Kazushige , Tsuchihashi Kei , Sonoda Tomoko , Ogi Kazuhiro , Miyakawa Akira , Kobayashi Junichi , Kaneko Takeshi , Igarashi Tomohiro , Hasegawa Tadashi , Miyazaki Akihiro
Published: January 2019

Background

The presence of tumor‐infiltrating lymphocytes (TILs) is associated with improved survival in head and neck squamous cell carcinoma. However, the prognostic value of TILs remains unclear in oral squamous cell carcinoma (OSCC).

Methods

We evaluated the associations between tumor‐infiltrating CD8+ T‐cell density and survival in five distinct compartments in 139 OSCC cases.

Results

There was a significant association between increased tumor‐infiltrating CD8+ T cells and their distribution. High parenchymal CD8+ T‐cell density at the invading tumor edge was associated with improved overall survival (OS) and disease‐specific survival (DSS; P < 0.01 and P < 0.01, respectively). High stromal CD8+ T‐cell density at the tumor periphery was also associated with improved recurrence‐free survival (RFS; P < 0.01). Cox regression analysis revealed that high stromal CD8+ T‐cell density at the tumor periphery and high parenchymal CD8+ T‐cell density at the invading edge were independent prognostic makers (hazard ratio: 0.38 and 0.19, 95% confidence interval, 0.18‐0.80 and 0.05‐0.72, P = 0.01 and 0.01, respectively) for RFS and OS, respectively.

Conclusions

Assessment of CD8+ T cells at the parenchyma of the invading edge and peripheral stroma provides an indicator of tumor recurrence and prognosis.
“Not just another meta‐analysis”: Sources of heterogeneity in psychosocial treatment effect on cancer survival
Authors: Mirosevic Spela , Jo Booil , Kraemer Helena C. , Ershadi Mona , Neri Eric , Spiegel David
Published: January 2019

Background

Currently, there are eight meta‐analyses that address the question whether psychosocial intervention can prolong survival with widely disparate conclusions. One reason for inconsistent findings may be the methods by which previous meta‐analyses were conducted.

Methods

Databases were searched to identify valid randomized controlled trials that compared psychosocial intervention with usual care. Hazard ratios (HRs) and their confidence intervals were pooled to estimate the strength of the treatment effect on survival time, and z‐tests were performed to assess possible heterogeneity of effect sizes associated with different patient and treatment characteristics.

Results

Twelve trials involving 2439 cancer patients that met screening criteria were included. The overall effect favored the treatment group with a HR of 0.71 (95% Cl 0.58‐0.88; P = 0.002). An effect size favoring treatment group was observed in studies sampling lower vs higher percentage of married patients’ (NNT = 4.3 vs NNT = 15.4), when Cognitive‐Behavioral Therapy was applied at early vs late cancer stage (NNT = 2.3 vs NNT = −28.6), and among patients’ older vs younger than 50 (NNT = 4.2 vs NNT = −20.5).

Conclusions

Psychosocial interventions may have an important effect on survival. Reviewed interventions appear to be more effective in unmarried patients, patients who are older, and those with an early cancer stage who attend CBT. Limitations of previous meta‐analysis are discussed.
The prognostic impact of programmed cell death 1 and its ligand and the correlation with epithelial‐mesenchymal transition in thymic carcinoma
Authors: Funaki Soichiro , Shintani Yasushi , Fukui Eriko , Yamamoto Yoko , Kanzaki Ryu , Ose Naoko , Kanou Takashi , Minami Masato , Mori Eiichi , Okumura Meinoshin
Published: January 2019

Background

The significance of epithelial‐mesenchymal transition (EMT) and immune checkpoint proteins in thymic carcinoma remains unknown. We examined the clinical significance of EMT, tumor‐infiltrating lymphocytes expressing the immune checkpoint protein, programmed cell death 1 (PD‐1 + TILs), and the expression of PD‐1 ligand 1 (PD‐L1) in thymic carcinoma (TC). We also investigated the relationships between these immune checkpoint proteins and the EMT status and examined the impact of induction chemotherapy on patients with tumors that express these proteins.

Methods

The relationship between PD‐1 + TILs/PD‐L1 and clinicopathological findings including EMT was investigated by immunohistochemistry (IHC) of surgically resected samples from 43 patients with TC. In 15 patients receiving induction therapy (IT), those factors were compared before and after IT.

Results

With IHC, 26 cases (60.5%) were positive for PD‐L1, and 19 cases were positive for PD‐1 + TILs (44.2%). The disease‐free survival rate in patients showing EMT and who were PD‐1/PD‐L1 positive was significantly worse compared to negative cases (EMT; P = 0.0095, PD‐1; P = 0.001, PD‐L1; P = 0.0037). We found a significant relationship between PD‐L1 and EMT status (P = 0.01). In patients who received IT, PD‐L1 increased, and the change was strongly correlated with EMT status (P = 0.01).

Conclusion

Epithelial‐mesenchymal transition, PD‐L1, and PD‐1 + TILs have prognostic impact, and PD‐L1 is correlated with EMT status. PD‐L1 expression after IT was significantly higher compared to before IT and was correlated with the EMT change. Thus, PD‐L1 may be upregulated during EMT, and anti‐PD‐1/PD‐L1 immunotherapy may provide reliable treatment of TC in combination with chemotherapy.
Next‐generation sequencing in precision oncology: Patient understanding and expectations
Authors: Roberts J. Scott , Gornick Michele C. , Le Lan Q. , Bartnik Natalie J. , Zikmund-Fisher Brian J. , Chinnaiyan Arul M. ,   for the MI‐ONCOSEQ Study team
Published: January 2019

Background

Implementation of precision oncology interventions poses several challenges to informed consent and patient education. This study assessed cancer patients’ understanding, expectations, and outcomes regarding participation in research examining the impact of matched tumor and germline sequencing on their clinical care.

Methods

A total of 297 patients (mean age: 59 years; 50% female; 96% white) with refractory, metastatic cancer were surveyed, including 217 who completed surveys both before and after undergoing integrated whole exome and transcriptome sequencing as part of a larger clinical research study.

Results

At baseline, the vast majority of patients expected to receive several potential direct benefits from study participation, including written reports of sequencing findings (88%), greater understanding of the causes of their cancer (74%), and participation in clinical trials for which sequencing results would make them eligible (84%). In most cases, these benefits were not realized by study completion. Despite explanations from study personnel to the contrary, most participants (67%‐76%) presumed that incidental germline sequencing findings relevant to noncancerous health conditions (eg, diabetes) would automatically be disclosed to them. Patients reported low levels of concern about study risks at baseline and low levels of regret about study participation at follow‐up.

Conclusions

Findings suggest that cancer patients participating in precision oncology intervention research have largely unfulfilled expectations of direct benefits related to their study participation. Increased focus on patient education to supplement the informed consent process may help manage patients’ expectations regarding the extent and likelihood of benefits received as a result of undergoing genomic sequencing.
Toxicity and Sublethal Effects of Phthalides Analogs to Rhyzopertha dominica
Authors: Farias Elizeu S. , Araújo Tamíris A. , Resende Gabriela C. , Campos Júlia N. D. , Pimentel Mirian F. , Alvarenga Elson S. , Picanço Marcelo C.
Published: January 2019

Phthalides and their precursors have demonstrated a large variety of biological activities. Eighteen phthalides were synthesized and tested on the stored grain pest Rhyzopertha dominica. In the screening bioassay, compounds rac‐(2R,2aS,4R,4aS,6aR,6bS,7R)‐7‐bromohexahydro‐2,4‐methano‐1,6‐dioxacyclopenta[cd]pentalen‐5(2H)‐one (15) and rac‐(3R,3aR,4R,7S,7aS)‐3‐(propan‐2‐yloxy)hexahydro‐4,7‐methano‐2‐benzofuran‐1(3H)‐one (17) showed mortality similar to the commercial insecticide, Bifenthrin® (≥90 %). The time (LT50) and dose (LD50) necessary to kill 50 % of the R. dominica population were determined for the most efficacious phthalides 15 and 17. Compound 15 presented the lowest LD50 (1.97 μg g−1), being four times more toxic than Bifenthrin® (LD50=9.11 μg g−1). Both compounds presented an LT50 value equal to 24 h. When applied at a sublethal dose, both phthalides (especially compound 15), reduced the emergence of the first progeny of R. dominica. These findings highlight the potential of phthalides 15 and 17 as precursors for the development of insecticides for R. dominica control.
Prospection of Enzyme Modulators in Aqueous and Ethanolic Extracts of Lippia sidoides Leaves: Genotoxicity, Digestion, Inflammation, and Hemostasis
Authors: Aparecida Braga Mariana , Silva de Abreu Tatiane , Cardoso Trento Marcus Vinicius , Henrique Andrade Machado Gustavo , Lopes Silva Pereira Luciana , Assaid Simão Anderson , Marcussi Silvana
Published: January 2019

The aqueous and ethanolic extracts of Lippia sidoides Cham. were chemically characterized and tested for their action on enzymes involved in processes such as inflammation, blood coagulation, and digestion. Both extracts potentiated the activity of phospholipases A2 present in the venom of Bothrops atrox in 12 % and completely inhibited the hemolysis induced by B. jararacussu and B. moojeni venoms in the proportions between 1 : 0.5 and 1 : 5 (venom/extracts (w/w)). They inhibited the thrombolysis induced by B. moojeni (10 to 25 %), potentiated the thrombolysis induced by the Lachesis muta muta venom (30 to 80 %), prolonged the coagulation time induced by B. moojeni and L. muta muta venoms, and presented antigenotoxic action. Both extracts reduced the activity of α‐glycosidases, the aqueous extract inhibited lipases, and the ethanolic extract inhibited α‐amylases. The results demonstrate the modulatory action of the extracts on proteases, phospholipases, and digestive enzymes. In addition, the rich phenolic composition of these extracts highlights their potential for nutraceutical use.
Chromane Enantiomers from the Flower Buds of Tussilago farfara L. and Assignments of Their Absolute Configurations
Authors: Sun Jia , Yu Jin‐Hai , Zhang Jun‐Sheng , Song Xiu‐Qing , Bao Jie , Zhang Hua
Published: January 2019

Fourteen chromane derivatives of seven pairs of enantiomers (1–14) have been obtained from the ethanolic extract of the flower buds of Tussilago farfara L. Their structures with absolute configurations have been elucidated by detailed spectroscopic analyses, chemical methods, and particularly comparison of experimental ECD spectra with theoretically computed ones. Biological evaluations revealed that they did not show cytoprotective, antimicrobial, and α‐glucosidase inhibitory activities.
Hidden Specificities in Enzyme Catalysis: Structural Basis of Substrate Structure‐Selectivity Relationship of a Ketoreductase
Authors: Häckh Matthias , Lucas Xavier , Marolt Marija , Leadlay Peter F. , Müller Michael , Günther Stefan , Lüdeke Steffen
Published: January 2019

Enzymes often convert both physiological and non‐physiological substrates with high stereoselectivity; yet, for some enzymes, opposite product chirality is observed. A possible explanation is the existence of hidden specificities becoming apparent when non‐physiological substrates confer different substrate–enzyme interactions than the physiological substrate. To test this hypothesis, a series of α‐methylated β‐keto esters were converted with Tyl‐KR1, a ketoreductase from polyketide synthesis in Streptomyces fradiae. The conversions of six substrates with different physicochemical properties exhibited enantioselectivities ranging from 84 % ee for R,R to 84 % ee for S,S, yet high and uniform diastereoselectivity (anti, d.r.>9:1). The exchange of a single atom, namely an oxygen ester instead of a thioester, led to almost complete loss of enantioselectivity (<5 % ee). An additional S,S‐selective binding mode as a hidden specificity in Tyl‐KR1 has been identified through molecular modeling and site‐directed mutagenesis.
Congenital fistula of the fourth branchial arch: Report of case with long‐lasting misdiagnosis
Authors: Stadler Thomas M. , Morand Grégoire B. , Schmid Stephan , Broglie Martina A.
Published: January 2019

Key Clinical Message

Fourth branchial arch anomalies are extremely rare. The anatomic course of the fourth branchial arch fistula usually determines the delay in diagnosis. High clinical suspicion should be given to reoccurring neck infections in infants and young adults. Diagnosis is obtained by direct laryngoscopy.
Cobalt Nanoparticles Embedded in N‐Doped Porous Carbon Derived from Bimetallic Zeolitic Imidazolate Frameworks for One‐Pot Selective Oxidative Depolymerization of Lignin
Authors: Sun Kangkang , Chen Shujie , Zhang Jiawei , Lu Guo‐Ping , Cai Chun
Published: January 2019

Cobalt nanoparticles embedded in N‐doped porous carbon (Co@CN) were prepared by the pyrolysis of bimetallic zeolitic imidazolate frameworks (BMZIFs) based on ZIF‐8 and ZIF‐67. The catalyst shows excellent catalytic efficiency in one‐pot selective oxidative cleavage of different linkages like β‐O‐4, a‐O‐4 and β‐1 in organosolv lignin and lignin model compounds in the presence of oxygen (ambient pressure) under mild conditions (383 K). Compared with traditional supported catalyst, the catalyst gives a highly hollow structure, which favored the adsorption of substrates and oxygen. The uniform cobalt nanoparticles surrounded by N‐doped graphitic structures and the strong electron transfer from graphitic nitrogen to Co NPs make it hard to be oxidized prior to use and higher catalytic reactivity. Moreover, the catalyst can be easily recovered by magnetic force after the reaction, and reused after reduction for five times without an obvious change in yields.
Manganese‐Catalyzed C−H Olefination Reactions
Authors: Hu Yuanyuan , Wang Congyang
Published: January 2019

Olefins are essential building blocks in organic synthesis, the access to which from simple C−H substrates through catalysis of transition metals, in particular the earth's abundant ones meets the requirements of green and sustainable chemistry. Manganese‐catalyzed C−H olefination reactions have emerged as an efficient approach to olefins in recent years, complementary to traditional olefin synthesis. Varieties of alkynes, alkenes, allenes as well as alcohols are successfully applied to the Mn‐catalyzed reactions with C−H substrates, providing multisubstituted olefins bearing varied functional groups. This minireview presents great progresses newly achieved on manganese‐catalyzed C−H olefination reactions.
Vis‐NIR Light‐Responsive Photocatalytic Activity of C3N4−Ag−Ag2O Heterojunction‐Decorated Carbon‐fiber Cloth as Efficient Filter‐Membrane‐Shaped Photocatalyst
Authors: Shen Xiaofeng , Zhang Yan , Duoerkun Gumila , Shi Zhun , Liu Jianshe , Chen Zhigang , Keung Wong Po , Zhang Lisha
Published: January 2019

C3N4‐decorated carbon‐fiber (CF) cloth has been demonstrated to be a filter‐membrane‐shaped photocatalyst for degrading flowing wastewater, but it can be excited only by visible light (λ<450 nm). To extend the photoresponse range to NIR region, herein we have designed and prepared C3N4−Ag−Ag2O heterojunctions on CF cloth. The growth of C3N4 nanosheets (thickness: 20–30 nm) on CF cloth is realized by a thermal condensation method, and then Ag/Ag2O nanoparticles (10–20 nm) are deposited on CF/C3N4 cloth by a chemical precipitation method. CF/C3N4/Ag/Ag2O cloth exhibits excellent flexibility and strong photoabsorption in a broad Vis‐NIR region (400–1400 nm), wider than CF/C3N4 (absorption edge: 450 nm). Under the irradiation of 808 nm or 980 nm laser, CF/C3N4/Ag/Ag2O cloth can remove 83 %/41 % AO7 and 72 %/38 % 4‐CP in 140 min respectively, significantly higher than those (33 %/13 % AO7 and 31 %/10 % 4‐CP) by CF/Ag/Ag2O cloth and those (3 %/1 % AO7 and 0 %/1 % 4‐CP) by CF/C3N4 cloth. Interestingly, when CF/C3N4/Ag/Ag2O cloth is used as the filter‐membrane to photo‐degrade the flowing wastewater (AO7, 20 mg L−1, rate: 1.5 L h−1), the removal efficiency of AO7 reaches up 97 % after 8 grade reactors. Therefore, CF/C3N4/Ag/Ag2O cloth can be used as an efficient filter‐membrane‐shaped photocatalyst with NIR photoresponse.
Hierarchical Zn‐Doped CoO Nanoflowers for Electrocatalytic Oxygen Evolution Reaction
Authors: Huo Meiling , Yang Zhiyuan , Yang Chenxi , Gao Zhong , Qi Jing , Liang Zuozhong , Liu Kaiqiang , Chen Heyin , Zheng Haoquan , Cao Rui
Published: January 2019

Hierarchical Zn‐doped CoO nanoflowers have been prepared using their hydroxides as precursors. The nanoflowers are assembled by dozens of 2D nanoplates. Each nanoplate is formed by numerous Zn‐doped CoO nanoparticles. Zn‐doped CoO catalyst is highly efficient for electrocatalytic water oxidation with a low overpotential (η=293 mV at j=10 mA cm−2) and long‐term stability, which is comparable to the commercial RuO2 catalysts in alkaline media. The 3D hierarchical structure provides abundant surface catalytic sites, while the density functional theory (DFT) calculations show that the Zn doping is also beneficial for the enhanced oxygen evolution reaction (OER) activities. This series of novel hierarchical porous nanoflowers is a promising anode material for water oxidation.
Review on Metal Sulphide‐based Z‐scheme Photocatalysts
Authors: Di Tingmin , Xu Quanlong , Ho WingKei , Tang Hua , Xiang Quanjun , Yu Jiaguo
Published: January 2019

Semiconductor‐based Z‐scheme heterojunction photocatalysts have received considerable attention for solar energy conversion and environmental purification due to their spatially separated reduction and oxidation sites, effective separation and transportation of photo‐excited charge carriers and strong redox ability. With their wide visible‐light responsive range and high photocatalytic activity, metal sulphide is an important material in developing photocatalysts. This review summarizes and highlights recent research progress in sulphide‐based direct Z‐scheme photocatalysts, followed by analysis on the limitations over all‐solid‐state Z‐scheme photocatalyst. Furthermore, the applications and characterization methods of sulphide‐based direct Z‐scheme photocatalyst are summarized. Finally, the challenges and perspectives of sulphide‐based Z‐scheme photocatalyst are discussed.
All Fiber Based Electrochemical Capacitor towards Wearable AC Line Filters with Outstanding Rate Capability
Authors: Gao Kaifei , Wang Siliang , Liu Weijie , Yue Yang , Rao Jiangyu , Su Jun , Li Luying , Zhang Zhi , Liu Nishuang , Xiong Lun , Gao Yihua
Published: January 2019

Due to their high spatial utilization, excellent flexibility and good adaptability, fiber‐shaped devices have promising potential for applications in wearable electronics. However, the fiberization process of the component with alternate current (AC) line filtering function is still far from being satisfactory, since it is difficult to arrange an ordered structure in a fiber shape in large‐scale manufacturing. This leads to a slow frequency response. Herein, a weavable fiber‐shaped electrochemical capacitor (SC) for AC line filtering is made of reduced graphene oxide (rGO) fibers with a highly oriented porous structure by wet‐spinning method. The highly consistent orientations of the rich pores greatly improve the ionic accessible sites, ion mobility and the electron transport pathways. As a result, the all‐fiber‐based SC revealing a high rate performance (500 V s−1) and a fast frequency response (RC time constant ∼0.241 ms, phase angle ∼−80°) is successfully applied to filter ±1.5 V AC to 1.04 V direct current (DC). Notably, the highly flexible SC exhibits an outstanding consistency during the performance test at bending and folding states. This work shows a potential substitution for aluminium electrolytic capacitors (AEC) towards wearable electronic.
Cyanohydridoborate Anions: Synthesis, Salts, and Low‐Viscosity Ionic Liquids
Authors: Bischoff Lisa A. , Drisch Michael , Kerpen Christoph , Hennig Philipp T. , Landmann Johannes , Sprenger Jan A. P. , Bertermann Rüdiger , Grüne Matthias , Yuan Qinqin , Warneke Jonas , Wang Xue‐Bin , Ignat'ev Nikolai V. , Finze Maik
Published: January 2019

High‐yield syntheses up to molar scales for salts of [BH(CN)3]− (2) and [BH2(CN)2]− (3) starting from commercially available Na[BH4] (Na5), Na[BH3(CN)] (Na4), BCl3, (CH3)3SiCN, and KCN were developed. Direct conversion of Na5 into K2 was accomplished with (CH3)3SiCN and (CH3)3SiCl as a catalyst in an autoclave. Alternatively, Na5 is converted into Na[BH{OC(O)R}3] (R=alkyl) that is more reactive towards (CH3)3SiCN and thus provides an easy access to salts of 2. Some reaction intermediates were identified, for example, Na[BH(CN){OC(O)Et}2] (Na7 b) and Na[BH(CN)2{OC(O)Et}] (Na8 b). A third entry to 2 and 3 uses ether adducts of BHCl2 or BH2Cl such as the commercial 1,4‐dioxane adducts that react with KCN and (CH3)3SiCN. Alkali metal salts of 2 and 3 are convenient starting materials for organic salts, especially for low viscosity ionic liquids (ILs). [EMIm]3 has the lowest viscosity and highest conductivity with 10.2 mPa s and 32.6 mS cm−1 at 20 °C known for non‐protic ILs. The ILs are thermally, chemically, and electrochemically robust. These properties are crucial for applications in electrochemical devices, for example, dye‐sensitized solar cells (Grätzel cells).
New Casbanes and the First trans‐Cyclopropane seco‐Casbane from the Australian Rainforest Plant Croton insularis
Authors: Maslovskaya Lidiya A. , Savchenko Andrei I. , Pierce Carly J. , Boyle Glen M. , Gordon Victoria A. , Reddell Paul W. , Parsons Peter G. , Williams Craig M.
Published: January 2019

Investigation of the Australian rainforest plant Croton insularis revealed seven new cis‐, two new trans‐cyclopropane casbanes, and the first trans‐cyclopropane seco‐casbane. The relative configuration of the cyclopropane moiety for all compounds (EBC‐182, 217, 218, 220, 343, 357, 358, 361, 365, 373; EBC=EcoBiotics Compound) was assigned using 13C NMR data. Comparison of the experimental electronic circular dichroism (ECD) spectra with the theoretical curves, calculated by TD‐DFT at the B3LYP/6‐31+G**//B3LYP/6‐31+G** level, in conjunction with NOE data afforded the absolute configuration. EBC‐180, 181 and 220 displayed potent activity against cervical carcinoma (HeLa cells).
Ensemble Effects in the Temperature‐Dependent Photoluminescence of Silicon Nanocrystals
Authors: Jakob Matthias , Javadi Morteza , Veinot Jonathan G. C. , Meldrum Al , Kartouzian Aras , Heiz Ulrich
Published: January 2019

In this work the temperature‐dependent photoluminescence of alkyl‐capped silicon nanocrystals with mean diameters of between 3 and 9 nm has been investigated. The nanocrystals were characterized extensively by FTIR, TEM, powder XRD, and X‐ray photoelectron spectroscopy prior to low‐temperature and time‐resolved photoluminescence spectroscopy experiments. The photoluminescence (PL) properties were evaluated in the temperature range of 41–300 K. We found that the well‐known temperature‐dependent blueshift of the PL maximum decreases with increasing nanocrystal diameter and eventually becomes a redshift for nanocrystal diameters larger than 6 nm. This implies that the observed shifts cannot be explained solely by band‐gap widening, as is commonly assumed. We propose that the luminescence of drop‐cast silicon nanocrystals is affected by particle ensemble effects, which can explain the otherwise surprising temperature dependence of the luminescence peak.
Direct Measurement of Through‐Bond Effects in Molecular Multivalent Interactions
Authors: Feng Xueyan , Yu Chanchan , Feng Feng , Lu Pan , Chai Yahong , Li Qilong , Zhang Di , Wang Xiuyu , Yao Li
Published: January 2019

Multivalent interactions occur throughout biology, and have a number of characteristics that monovalent interactions do not. However, it remains challenging to directly measure the binding force of molecular multivalent interactions and identify the mechanism of interactions. In this study, the specific interaction between bivalent aptamer and thrombin has been measured directly and quantitatively by force‐induced remnant magnetization spectroscopy to investigate the binding force and through‐bond effects of the multivalent interactions. The measured differential binding forces enable through‐bond effects in thrombin–aptamer complexes to be identified, where aptamer binding at exosite II produces visible effects on their binding at exosite I and vice versa. This method might be suitable for practical applications in the design of high‐performance ligands.
A Fluorescence Light‐Up Silver Nanocluster Beacon Modulated by Metal Ions and Its Application in Telomerase‐Activity Detection
Authors: Peng Manshu , Na Na , Ouyang Jin
Published: January 2019

DNA‐templated silver nanoclusters (DNA‐AgNCs) have been extensively studied in recent years. The enhancement of fluorescence emission from DNA‐AgNCs is still being explored. Herein, a study on the fluorescence enhancement of DNA‐AgNCs induced by metal ions is reported. The enhancement is greatly dependent on the primary sequence and secondary structure of the DNA strands. Thus, a label‐free AgNCs‐based molecular beacon (MB) was explored for the detection of telomerase activity. Nonfluorescent MB‐AgNCs in phosphate buffer emit dramatic red fluorescence when Mg2+ is introduced, whereas Mg2+ has a limited effect on the weak fluorescence of DNA‐AgNCs when the hairpin structure of MB is opened. Telomerase primer can be elongated by telomerase, which results in unfolding of MB in a strand‐displacement reaction. On the basis of the different brightnesses of AgNCs produced by the two DNA templates, telomerase activity can be detected. The MB‐AgNCs sensing platform provides a simple and low‐cost method to detect telomerase activity and shows great potential in the construction of cost‐effective probes for biomolecular detection.
Oxygen‐Deficient Dumbbell‐Shaped Anatase TiO2−x Mesocrystals with Nearly 100 % Exposed {101} Facets: Synthesis, Growth Mechanism, and Photocatalytic Performance
Authors: Li Yongjun , Ye Xiaozhou , Cao Shengxin , Yang Chujing , Wang Yun , Ye Jianfeng
Published: January 2019

The development of hierarchical TiO2 superstructures with new morphologies and intriguing photoelectric properties for utilizing solar energy is known to be an effective approach to alleviate the serious problems of environmental pollution. Herein, unique oxygen‐deficient dumbbell‐shaped anatase TiO2−x mesocrystals (DTMCs) enclosed by nearly 100 % {101} facets were readily synthesized by mesoscale transformation in TiCl3/acetic acid (HAc) mixed solution, followed by calcination under vacuum. These mesocrystals exhibited much higher photoreactivity toward removing the model pollutants methyl orange and CrVI than truncated tetragonal bipyramidal anatase nanocrystals (TNCs), anatase mesocrystals built from truncated tetragonal bipyramidal anatase nanocrystals (TTMCs), and anatase mesocrystals constructed by anatase nanocrystals with nearly 100 % exposed {101} facets (TMCs), revealing that both the oxidation and reduction abilities of anatase TiO2 were simultaneously enhanced upon fabricating an oxygen‐deficient mesocrystalline architecture with about 100 % exposed {101} facets. Further characterization illustrated that such an enhancement of photoreactivity was mainly due to the strengthened light absorption, boosted charge carrier separation, and nearly 100 % exposed {101} facets of the oxygen‐deficient dumbbell‐shaped anatase mesocrystals. This work will be useful for guiding the synthesis of oxygen‐deficient ordered superstructures of metal oxides with desired morphologies and exposed facets for promising applications in environmental remediation.
Selective Carbanion–Pyridine Coordination of a Reactive P,N Ligand to RhI
Authors: Devillard Marc , Ehlers Andreas , Siegler Maxime A. , van der Vlugt Jarl Ivar
Published: January 2019

Ligands with reactive carbon sites in the periphery of a metal center have emerged as a powerful approach for metal–ligand bond activation. These reactive carbon sites are commonly generated by deprotonation strategies. Carbon–silicon bond cleavage is a potential alternative to access such constructs. Herein, the monodesilylation of bis‐silyl‐substituted P,N scaffold PNSi2 in the coordination sphere of [RhI(Cl)(CO)(PNSi2)] (1) with sodium azide is disclosed. This affords a unique dinucleating anionic κ2‐C,N‐κ1‐P ligand with a carbanionic methine carbon atom directly bound to rhodium as part of a four‐membered Rh‐N‐C‐C rhodacycle. This dimer undergoes meta‐pyridine C−H activation facilitated by weak bases, which leads to a desymmetrization of the system and provides a σ,π‐bridging 3‐pyridyl fragment bound to RhI. The facile Si−C cleavage strategy may pave the way to studying the reactivity and functionalization of a variety of κ2‐C,N‐coordinated pyridine scaffolds for selective transformations.
Nanowire‐Templated Synthesis of FeNx‐Decorated Carbon Nanotubes as Highly Efficient, Universal‐pH, Oxygen Reduction Reaction Catalysts
Authors: Li Yanqiang , Huang Huiyong , Chen Siru , Wang Chao , Ma Tingli
Published: January 2019

It is of increasing importance to develop highly active and economical oxygen reduction reaction (ORR) electrocatalysts, which have great significance for the large‐scale implementation of various energy conversion systems, including metal–air batteries and fuel cells. Herein, a novel method to synthesize FeNx‐decorated carbon nanotubes as a high‐efficiency ORR catalyst, by utilizing ZnO nanowires as a sacrificial template and a Fe–polydopamine complex as metal and carbon sources, is reported. The obtained catalyst shows great potential for replacing Pt/C as the ORR catalyst under various pH conditions, from alkaline to acidic electrolytes. The high conductivity, large surface area of the carbon nanotube, and highly active FeNx species contributed greatly to the high performance of the catalyst. The work presented herein paves a new way for the synthesis of 1D porous nanomaterials for a broad range of energy‐related applications.
Towards the Design of Optically Active Thiophene S‐Oxides using Quantum Chemistry
Authors: Verlinden Steven , Woller Tatiana , De Proft Frank , Verniest Guido , Alonso Mercedes
Published: January 2019

The importance of axially chiral biaryls has risen steeply in the recent decades. This structural motif proved to be successful in catalytic asymmetric synthesis and the configuration of the biaryl axis is decisive for the biological activity. A new approach for the atroposelective synthesis of biaryls would be through a cycloaddition between an enantiopure phenyl‐substituted thiophene S‐oxide and an alkyne. Importantly, the chiral center of the thiophene S‐oxide needs to be stable enough to avoid pyramidal inversion during the cycloaddition. Considering that the racemization of thiophene monoxides has been scarcely investigated so far, we perform a thorough quantum chemical study on the inversion barriers of a large number of chiral thiophene S‐oxide derivatives. Our main goal is to identify substitution patterns leading to stable atropisomers at room temperature. Appealingly, the role of stereoelectronic effects and the position of the substituents as well as the importance of aromaticity on the pyramidal inversion barrier are elucidated for the first time.
Metal–Organic Frameworks Harness Cu Chelating and Photooxidation Against Amyloid β Aggregation in Vivo
Authors: Yu Dongqin , Guan Yijia , Bai Fuquan , Du Zhi , Gao Nan , Ren Jinsong , Qu Xiaogang
Published: January 2019

Recently, photooxygenation of amyloid β (Aβ) has emerged as an effective way to inhibit Aβ aggregation in Alzheimer's disease (AD) treatment. However, their further application has been highly obstructed by self‐aggregation, no metal chelating ability, and poor protein‐enrichment capacity. Herein, porphyrinic metal–organic frameworks (PMOFs) are utilized as a superior CuII chelating and photooxidation agent for inhibiting Aβ aggregation. We selected only four classical kinds of POMFs (Zr–MOF, Al–MOF, Ni–MOF, Hf–MOF) for further investigation in our study, which are stable in physiological conditions and exhibit excellent biocompatibility. Among them, Hf–MOF was the most efficient Aβ photooxidant. A possible explanation about the difference in capacity of 1O2 generation of these four PMOFs has been provided according to the experimental results and DFT calculations. Furthermore, Hf–MOFs are modified with Aβ‐targeting peptide, LPFFD. This can not only enhance Hf–MOFs targeting cellular Aβ to decrease Aβ‐induced cytotoxicity, but also improve Aβ photooxidation in the complicated living environment. More intriguingly, in vivo studies indicate that the well‐designed LPFFD modified Hf–MOFs can decrease Aβ‐induced neurotoxicity and extend the longevity of the commonly used transgenic AD model Caenorhabditis elegans CL2006. Our work may open a new avenue for using MOFs as neurotoxic‐metal‐chelating and photo‐therapeutic agents for AD treatment.
Synthesis of Polycyclic and Cage Siloxanes by Hydrolysis and Intramolecular Condensation of Alkoxysilylated Cyclosiloxanes
Authors: Sugiyama Tomoaki , Shiba Hiroya , Yoshikawa Masashi , Wada Hiroaki , Shimojima Atsushi , Kuroda Kazuyuki
Published: January 2019

The controlled synthesis of oligosiloxanes with well‐defined structures is important for the bottom‐up design of siloxane‐based nanomaterials. This work reports the synthesis of various polycyclic and cage siloxanes by the hydrolysis and intramolecular condensation of monocyclic tetra‐ and hexasiloxanes functionalized with various alkoxysilyl groups. An investigation of monoalkoxysilylated cyclosiloxanes revealed that intramolecular condensation occurred preferentially between adjacent alkoxysilyl groups to form new tetrasiloxane rings. The study of dialkoxy‐ and trialkoxysilylated cyclotetrasiloxanes revealed multistep intramolecular condensation reactions to form cubic octasiloxanes in relatively high yields. Unlike conventional methods starting from organosilane monomers, intramolecular condensation enables the introduction of different organic substituents in controlled arrangements. So‐called Janus cubes have been successfully obtained, that is, Ph4R4Si8O12, in which R=Me, OSiMe3, and OSiMe2Vi (Vi=vinyl). These findings will enable the creation of siloxane‐based materials with diverse functions.
Assembly of the Entire Carbon Backbone of a Stereoisomer of the Antitumor Marine Natural Product Hemicalide
Authors: Lecourt Camille , Dhambri Sabrina , Yamani Khalil , Boissonnat Guillaume , Specklin Simon , Fleury Etienne , Hammad Karim , Auclair Eric , Sablé Serge , Grondin Antonio , Arimondo Paola B. , Sautel François , Massiot Georges , Meyer Christophe , Cossy Janine , Sorin Geoffroy , Lannou Marie‐Isabelle , Ardisson Janick
Published: January 2019

A strategy for the assembly of the entire carbon backbone of a stereoisomer of the antitumor marine natural product hemicalide has been investigated. The devised convergent approach relies on Horner–Wadsworth–Emmons and Julia–Kocienski olefination reactions for the construction of the C6=C7 and C34=C35 double bonds, respectively, an aldol reaction to create the C27−C28 bond, and a Suzuki–Miyaura cross‐coupling as the endgame to form the C15−C16 bond.