bluuebunny/crossref_metadata_2025 huggingface dataset:
Macrophage ABHD5 promotes colorectal cancer growth by suppressing spermidine production by SRM
Authors: Miao Hongming , Ou Juanjuan , Peng Yuan , Zhang Xuan , Chen Yujuan , Hao Lijun , Xie Ganfeng , Wang Zhe , Pang Xueli , Ruan Zhihua , Li Jianjun , Yu Liqing , Xue Bingzhong , Shi Hang , Shi Chunmeng , Liang Houjie
Published: May 2016

Metabolic reprogramming in stromal cells plays an essential role in regulating tumour growth. The metabolic activities of tumour-associated macrophages (TAMs) in colorectal cancer (CRC) are incompletely characterized. Here, we identify TAM-derived factors and their roles in the development of CRC. We demonstrate that ABHD5, a lipolytic co-activator, is ectopically expressed in CRC-associated macrophages. We demonstrate in vitro and in mouse models that macrophage ABHD5 potentiates growth of CRC cells. Mechanistically, ABHD5 suppresses spermidine synthase (SRM)-dependent spermidine production in macrophages by inhibiting the reactive oxygen species-dependent expression of C/EBPɛ, which activates transcription of the srm gene. Notably, macrophage-specific ABHD5 transgene-induced CRC growth in mice can be prevented by an additional SRM transgene in macrophages. Altogether, our results show that the lipolytic factor ABHD5 suppresses SRM-dependent spermidine production in TAMs and potentiates the growth of CRC. The ABHD5/SRM/spermidine axis in TAMs might represent a potential target for therapy.
Structural evaluations and temperature dependent photoluminescence characterizations of Eu3+-activated SrZrO3 hollow spheres for luminescence thermometry applications
Authors: Das Subrata , Som Sudipta , Yang Che-Yuan , Chavhan Sudam , Lu Chung-Hsin
Published: May 2016

This research is focused on the temperature sensing ability of perovskite SrZrO3:Eu3+ hollow spheres synthesized via the sol-gel method followed by heating. The Rietveld refinement indicated that the precursors annealed at 1100 °C were crystallized to form orthorhombic SrZrO3. SrZrO3 particles exhibited non-agglomerated hollow spherical morphology with an average particle size of 300 nm. The UV-excited photoluminescence spectrum of SrZrO3:Eu3+ consisted of two regions. One region was associated with SrZrO3 trap emission, and the other one was related to the emission of Eu3+ ions. The intensity ratio of the emission of Eu3+ ions to the host emission (FIR) and the emission lifetime of Eu3+ ions were measured in the temperature range of 300–550 K. The sensitivity obtained via the lifetime method was 7.3× lower than that measured via the FIR. Within the optimum temperature range of 300–460 K, the as-estimated sensor sensitivity was increased from 0.0013 to 0.028 K−1. With a further increase in temperatures, the sensitivity started to decline. A maximum relative sensitivity was estimated to be 2.22%K−1 at 460 K. The resolutions in both methods were below 1K in the above temperature range. The results indicated the suitability of SrZrO3:Eu3+ for the distinct high temperature sensing applications.
Pressure-induced magnetic transitions with change of the orbital configuration in dimerised systems
Authors: Korotin Dmitry M. , Anisimov Vladimir I. , Streltsov Sergey V.
Published: May 2016

We suggest a possible scenario for magnetic transition under pressure in dimerised systems where electrons are localised on molecular orbitals. The mechanism of transition is not related with competition between kinetic energy and on-site Coulomb repulsion as in Mott-Hubbard systems, or between crystal-field splitting and intra-atomic exchange as in classical atomic spin-state transitions. Instead, it is driven by the change of bonding-antibonding splitting on part of the molecular orbitals. In the magnetic systems with few half-filled molecular orbitals external pressure may result in increase of the bonding-antibonding splitting and localise all electrons on low-lying molecular orbitals suppressing net magnetic moment of the system. We give examples of the systems, where this or inverse transition may occur and by means of ab initio band structure calculations predict that it can be observed in α−MoCl4 at pressure P ~ 11 GPa.
In-Water and Neat Batch and Continuous-Flow Direct Esterification and Transesterification by a Porous Polymeric Acid Catalyst
Authors: Baek Heeyoel , Minakawa Maki , Yamada Yoichi M. A. , Han Jin Wook , Uozumi Yasuhiro
Published: May 2016

A porous phenolsulphonic acid—formaldehyde resin (PAFR) was developed. The heterogeneous catalyst PAFR was applied to the esterification of carboxylic acids and alcohols, affording the carboxylic acid esters in a yield of up to 95% where water was not removed from the reaction mixture. Surprisingly, the esterification in water as a solvent proceeded to afford the desired esters in high yield. PAFR provided the corresponding esters in higher yield than other homogeneous and heterogeneous catalysts. The transesterification of alcohols and esters was also investigated by using PAFR, giving the corresponding esters. PAFR was applied to the batch-wise and continuous-flow production of biodiesel fuel FAME. The PAFR-packed flow reactor that was developed for the synthesis of carboxylic acids and FAME worked for four days without loss of its catalytic activity.
First-principles calculated decomposition pathways for LiBH4 nanoclusters
Authors: Huang Zhi-Quan , Chen Wei-Chih , Chuang Feng-Chuan , Majzoub Eric H. , Ozoliņš Vidvuds
Published: May 2016

We analyze thermodynamic stability and decomposition pathways of LiBH4 nanoclusters using grand-canonical free-energy minimization based on total energies and vibrational frequencies obtained from density-functional theory (DFT) calculations. We consider (LiBH4)n nanoclusters with n = 2 to 12 as reactants, while the possible products include (Li)n, (B)n, (LiB)n, (LiH)n and Li2BnHn; off-stoichiometric LinBnHm (m ≤ 4n) clusters were considered for n = 2, 3 and 6. Cluster ground-state configurations have been predicted using prototype electrostatic ground-state (PEGS) and genetic algorithm (GA) based structural optimizations. Free-energy calculations show hydrogen release pathways markedly differ from those in bulk LiBH4. While experiments have found that the bulk material decomposes into LiH and B, with Li2B12H12 as a kinetically inhibited intermediate phase, (LiBH4)n nanoclusters with n ≤ 12 are predicted to decompose into mixed LinBn clusters via a series of intermediate clusters of LinBnHm (m ≤ 4n). The calculated pressure-composition isotherms and temperature-pressure isobars exhibit sloping plateaus due to finite size effects on reaction thermodynamics. Generally, decomposition temperatures of free-standing clusters are found to increase with decreasing cluster size due to thermodynamic destabilization of reaction products.
Metabolomics Investigation Reveals Metabolite Mediators Associated with Acute Lung Injury and Repair in a Murine Model of Influenza Pneumonia
Authors: Cui Liang , Zheng Dahai , Lee Yie Hou , Chan Tze Khee , Kumar Yadunanda , Ho Wanxing Eugene , Chen Jian Zhu , Tannenbaum Steven R. , Ong Choon Nam
Published: May 2016

Influenza virus infection (IVI) can cause primary viral pneumonia, which may progress to acute lung injury (ALI) and respiratory failure with a potentially fatal outcome. At present, the interactions between host and influenza virus at molecular levels and the underlying mechanisms that give rise to IVI-induced ALI are poorly understood. We conducted a comprehensive mass spectrometry-based metabolic profiling of serum, lung tissue and bronchoalveolar lavage fluid (BALF) from a non-lethal mouse model with influenza A virus at 0, 6, 10, 14, 21 and 28 days post infection (dpi), representing the major stages of IVI. Distinct metabolite signatures were observed in mice sera, lung tissues and BALF, indicating the molecular differences between systematic and localized host responses to IVI. More than 100 differential metabolites were captured in mice sera, lung tissues and BALF, including purines, pyrimidines, acylcarnitines, fatty acids, amino acids, glucocorticoids, sphingolipids, phospholipids, etc. Many of these metabolites belonged to pulmonary surfactants, indicating IVI-induced aberrations of the pulmonary surfactant system might play an important role in the etiology of respiratory failure and repair. Our findings revealed dynamic host responses to IVI and various metabolic pathways linked to disease progression, and provided mechanistic insights into IVI-induced ALI and repair process.
TRPV1 is crucial for proinflammatory STAT3 signaling and thermoregulation-associated pathways in the brain during inflammation
Authors: Yoshida Ayaka , Furube Eriko , Mannari Tetsuya , Takayama Yasunori , Kittaka Hiroki , Tominaga Makoto , Miyata Seiji
Published: May 2016

Transient receptor potential vanilloid receptor 1 (TRPV1) is a non-selective cation channel that is stimulated by heat (>43 °C), mechanical/osmotic stimuli, and low pH. The importance of TRPV1 in inflammatory responses has been demonstrated, whereas its participation in brains remains unclear. In the present study, the intracerebroventricular (icv) administration of the TRPV1 agonist resiniferatoxin (RTX) induced the activation of signal transducer and activator of transcription 3 (STAT3) in circumventricular organs (CVOs) and thermoregulation-associated brain regions with a similar patttern to the peripheral and icv administration of lipopolysaccharide (LPS). With the peripheral and icv LPS stimuli, STAT3 activation was significantly lower in Trpv1−/− mice than in Trpv1+/+ mice. The icv administration of RTX induced transient hypothermia, whereas that of the TRPV1 antagonist capsazepine enhanced the magnitude and period of LPS-induced hyperthermia. These results indicate that TRPV1 is important for activating proinflammatory STAT3 signaling and thermoregulation-associated brain pathways in the brain.
Paneth Cell in Adenomas of the Distal Colorectum Is Inversely Associated with Synchronous Advanced Adenoma and Carcinoma
Authors: Mahon Megan , Xu Jie , Yi Xianghua , Liu Xiuli , Gao Nan , Zhang Lanjing
Published: May 2016

Recent studies have linked appearance of Paneth cells in colorectal adenomas to adenoma burden and male gender. However, the clinical importance of Paneth cells’ associations with synchronous advanced adenoma (AA) and colorectal carcinoma (CRC) is currently unclear. We performed a comprehensive case-control study using 1,900 colorectal adenomas including 785 from females and 1,115 from males. We prospectively reviewed and recorded Paneth cell status in the colorectal adenomas consecutively collected between February 2014 and June 2015. Multivariable logistic regression analyses revealed that, in contrast to the adenomas without Paneth cells, the Paneth cell-containing adenomas at distal colorectum were inversely associated with presence of a synchronous AA or CRC (odds ratio [OR] 0.39, P = 0.046), whereas no statistical significance was reached for Paneth cell-containing proximal colorectal adenomas (P = 0.33). Synchronous AA and CRC were significantly associated with older age (60 + versus <60 years, OR 1.60, P = 0.002), male gender (OR 1.42, P = 0.021) and a history of AA or CRC (OR 2.31, P < 0.001). However, synchronous CRC was not associated with Paneth cell status, or a history of AA or CRC. Paneth cell presence in the adenomas of distal colorectum may be a negative indicator for synchronous AA and CRC and seems to warrant further studies.
Long-term expression of miRNA for RNA interference using a novel vector system based on a negative-strand RNA virus
Authors: Honda Tomoyuki , Yamamoto Yusuke , Daito Takuji , Matsumoto Yusuke , Makino Akiko , Tomonaga Keizo
Published: May 2016

RNA interference (RNAi) has emerged as a promising technique for gene therapy. However, the safe and long-term expression of small RNA molecules is a major concern for the application of RNAi therapies in vivo. Borna disease virus (BDV), a non-segmented, negative-strand RNA virus, establishes a persistent infection without obvious cytopathic effects. Unique among animal non-retroviral RNA viruses, BDV persistently establishes a long-lasting persistent infection in the nucleus. These features make BDV ideal for RNA virus vector persistently expressing small RNAs. Here, we demonstrated that the recombinant BDV (rBDV) containing the miR-155 precursor, rBDV-miR-155, persistently expressed miR-155 and efficiently silenced its target gene. The stem region of the miR-155 precursor in rBDV-miR-155 was replaceable by any miRNA sequences of interest and that such rBDVs efficiently silence the expression of target genes. Collectively, BDV vector would be a novel RNA virus vector enabling the long-term expression of miRNAs for RNAi therapies.
Reduced tonic inhibition after stroke promotes motor performance and epileptic seizures
Authors: Jaenisch Nadine , Liebmann Lutz , Guenther Madlen , Hübner Christian A. , Frahm Christiane , Witte Otto W.
Published: May 2016

Stroke survivors often recover from motor deficits, either spontaneously or with the support of rehabilitative training. Since tonic GABAergic inhibition controls network excitability, it may be involved in recovery. Middle cerebral artery occlusion in rodents reduces tonic GABAergic inhibition in the structurally intact motor cortex (M1). Transcript and protein abundance of the extrasynaptic GABAA-receptor complex α4β3δ are concurrently reduced (δ-GABAARs). In vivo and in vitro analyses show that stroke-induced glutamate release activates NMDA receptors, thereby reducing KCC2 transporters and down-regulates δ-GABAARs. Functionally, this is associated with improved motor performance on the RotaRod, a test in which mice are forced to move in a similar manner to rehabilitative training sessions. As an adverse side effect, decreased tonic inhibition facilitates post-stroke epileptic seizures. Our data imply that early and sometimes surprisingly fast recovery following stroke is supported by homeostatic, endogenous plasticity of extrasynaptic GABAA receptors.
Triazole resistance mediated by mutations of a conserved active site tyrosine in fungal lanosterol 14α-demethylase
Authors: Sagatova Alia A. , Keniya Mikhail V. , Wilson Rajni K. , Sabherwal Manya , Tyndall Joel D. A. , Monk Brian C.
Published: May 2016

Emergence of fungal strains showing resistance to triazole drugs can make treatment of fungal disease problematic. Triazole resistance can arise due to single mutations in the drug target lanosterol 14α-demethylase (Erg11p/CYP51). We have determined how commonly occurring single site mutations in pathogenic fungi affect triazole binding using Saccharomyces cerevisiae Erg11p (ScErg11p) as a target surrogate. The mutations Y140F/H were introduced into full-length hexahistidine-tagged ScErg11p. Phenotypes and high-resolution X-ray crystal structures were determined for the mutant enzymes complexed with short-tailed (fluconazole and voriconazole) or long-tailed (itraconazole and posaconazole) triazoles and wild type enzyme complexed with voriconazole. The mutations disrupted a water-mediated hydrogen bond network involved in binding of short-tailed triazoles, which contain a tertiary hydroxyl not present in long-tailed triazoles. This appears to be the mechanism by which resistance to these short chain azoles occurs. Understanding how these mutations affect drug affinity will aid the design of azoles that overcome resistance.
Ferromagnetism controlled by electric field in tilted phosphorene nanoribbon
Authors: Farooq M. Umar , Hashmi Arqum , Hong Jisang
Published: May 2016

Study on phosphorene nanoribbon was mostly focused on zigzag and armchair structures and no ferromagnetic ground state was observed in these systems. Here, we investigated the magnetic property of tilted black phosphorene nanoribbons (TPNRs) affected by an external electric field. We also studied the edge passivation effect on the magnetism and thermal stability of the nanoribbons. The pure TPNR displayed an edge magnetic state, but it disappeared in the edge reconstructed TPNR due to the self-passivation. In addition, we found that the bare TPNR was mechanically unstable because an imaginary vibration mode was obtained. However, the imaginary vibration mode disappeared in the edge passivated TPNRs. No edge magnetism was observed in hydrogen and fluorine passivated TPRNs. In contrast, the oxygen passivated TPNR was more stable than the pure TPNR and the edge-to-edge antiferromagntic (AFM) ground state was obtained. We found that the magnetic ground state could be tuned by the electric field from antiferromagnetic (AFM) to ferromagnetic (FM) ground state. Interestingly, the oxygen passivated TPNR displayed a half-metallic state at a proper electric field in both FM and AFM states. This finding may provoke an intriguing issue for potential spintronics application using the phosphorene nanoribbons.
Curly arrows meet electron density transfers in chemical reaction mechanisms: from electron localization function (ELF) analysis to valence-shell electron-pair repulsion (VSEPR) inspired interpretation
Authors: Andrés Juan , Berski Sławomir , Silvi Bernard
Published: May 2016

The displacement of the nuclei along the reaction path provides an explanatory interpretation of the electron density transfers making possible to understand chemical reactions.
Thermoelectric high-entropy alloys with low lattice thermal conductivity
Authors: Fan Z. , Wang H. , Wu Y. , Liu X. J. , Lu Z. P.
Published: May 2016

Reducing lattice thermal conductivity is one of the most effective routes for improving the performance of thermoelectric materials.
Stabilization of a Zn(ii) hydrosulfido complex utilizing a hydrogen-bond accepting ligand
Authors: Hartle Matthew D. , Delgado Mayra , Gilbertson John D. , Pluth Michael D.
Published: May 2016

Inclusion of a hydrogen bond accepting motif in the secondary coordination sphere of a pyridinediimine ligand enables formation of a stable Zn–SH adduct. We report here reversible coordination of HS− to Zn(didpa)Cl2 to form [Zn(didpa)Cl2SH]−, which is stabilized by an intramolecular hydrogen bond.
A photodegradable hexaaza-pentacene molecule for selective dispersion of large-diameter semiconducting carbon nanotubes
Authors: Han Jie , Ji Qiyan , Li Hongbo , Li Gang , Qiu Song , Li Hai-Bei , Zhang Qichun , Jin Hehua , Li Qingwen , Zhang Jin
Published: May 2016

4HP exhibits high selectivity for large-diameter s-SWCNTs.
Chloride anion transporters inhibit growth of methicillin-resistant Staphylococcus aureus (MRSA) in vitro
Authors: Share Andrew I. , Patel Khushali , Nativi Cristina , Cho Eun J. , Francesconi Oscar , Busschaert Nathalie , Gale Philip A. , Roelens Stefano , Sessler Jonathan L.
Published: May 2016

Anion transporters were tested for antimicrobial activity and shown to inhibit the growth of MRSA in vitro.
Spectroscopic observation of nitrogen anions N− in solid matrices
Authors: Boltnev R. E. , Bykhalo I. B. , Krushinskaya I. N. , Pelmenev A. A. , Mao S. , Meraki A. , McColgan P. T. , Lee D. M. , Khmelenko V. V.
Published: May 2016

Analysis of old and recent experiments on thermoluminescence of cryocrystals and nanoclusters of N2, Ne, Ar, and Kr containing stabilized nitrogen atoms suggests that the so-called γ-line may correspond to the bound–bound transition 1D–3P of nitrogen anions N− formed in solids by the association of delocalized electrons and metastable nitrogen atoms N(2D).
Methylation of aromatic amines and imines using formic acid over a heterogeneous Pt/C catalyst
Authors: Zhu Lei , Wang Lian-Sheng , Li Bojie , Li Wei , Fu Boqiao
Published: May 2016

Methylation of anilines and aromatic imines has been achieved by using a heterogeneous Pt/C catalyst with formic acid in the presence of a hydrosilane reductant.
Germylenes and stannylenes stabilized within N2PE rings (E = Ge or Sn): combined experimental and theoretical study
Authors: Vrána Jan , Ketkov Sergey , Jambor Roman , Růžička Aleš , Lyčka Antonín , Dostál Libor
Published: May 2016

Bis(amino)phosphanes were shown to be excellent easily accessible precursors for the preparation of a variety of tetrylenes that significantly differ in their structures.
The oxygen reduction reaction at the three-phase boundary: nanoelectrodes modified with Ag nanoclusters
Authors: Clausmeyer Jan , Botz Alexander , Öhl Denis , Schuhmann Wolfgang
Published: May 2016

Silver nanoclusters are deposited on bifunctional Θ-shaped nanoelectrodes consisting of a carbon nanoelectrode combined with a hollow nanopipette. The Θ-nanoelectrodes are used as model systems to study interfacial mass transport in gas diffusion electrodes and in particular oxygen-depolarized cathodes (ODC) for the oxygen reduction reaction (ORR) in chlor-alkali electrolysers. By local delivery of O2 gas to the electroactive Ag nanoclusters through the adjacent nanopipette, enhanced currents for the ORR at the Ag nanoparticles are recorded which are not accountable when considering the low solubility and slow diffusion of O2 in highly alkaline media. Instead, local oversaturation of O2 leads to current enhancement at the Ag nanoclusters. Due to the intrinsic high mass transport rates at the nanometric electrodes accompanied by local delivery of reactants, the method generally allows to study electrochemical reactions at single nanoparticles beyond the limitations induced by slow diffusion and low reactant concentration. Kinetic and mechanistic information, for instance derived from Tafel slopes, can be obtained from kinetic regimes not accessible to standard techniques.
Pneumatic-aided micro-molding for flexible fabrication of homogeneous and heterogeneous cell-laden microgels
Authors: Ma Chao , Tian Chang , Zhao Lei , Wang Jinyi
Published: May 2016

We describe a pneumatic-aided micro-molding (PAM) strategy to prepare various cell-laden microgels with homogeneous/heterogeneous cell types and different hydrogels.
Influence of supramolecular encapsulation of camptothecin by cucurbit[7]uril: reduced toxicity and preserved anti-cancer activity
Authors: Yang Xue , Wang Ziyi , Niu Yanan , Chen Xiuping , Lee Simon M. Y. , Wang Ruibing
Published: May 2016

Encapsulation of camptothecin by cucurbit[7]uril significantly inhibited the systemic toxicities of the free drug, while maintaining its antitumor/anti-angiogenic activities.
Dispersion forces acting between silica particles across water: influence of nanoscale roughness
Authors: Valmacco Valentina , Elzbieciak-Wodka Magdalena , Besnard Céline , Maroni Plinio , Trefalt Gregor , Borkovec Michal
Published: May 2016

Differences in nanoscale roughness lead to variations in the strength of dispersion forces of more than an order of magnitude.
New diphenyl diselenides o-substituted by an O(S,Se)-caranyl skeleton – synthesis and application in asymmetric reactions
Authors: Ścianowski Jacek , Pacuła Agata J. , Zielińska-Błajet Mariola , Wojtczak Andrzej
Published: May 2016

A convenient methodology for the synthesis of optically active diselenides and selenides functionalized with terpenyl moieties and their applications in the selenenylation of alkenes, and Tsuji–Trost and Henry reactions are presented.
Design, synthesis and in vitro splicing inhibition of desmethyl and carba-derivatives of herboxidiene
Authors: Ghosh Arun K. , Lv Kai , Ma Nianchun , Cárdenas Emilio L. , Effenberger Kerstin A. , Jurica Melissa S.
Published: May 2016

Enantioselective syntheses of the desmethyl and carba-derivatives of herboxidiene and their biological evaluation in splicing assay are reported.
Directed electrostatic activation in enantioselective organocatalytic cyclopropanation reactions: a computational study
Authors: Georgieva Miglena K. , Duarte Filipe J. S. , Santos A. Gil
Published: May 2016

This study allows the proposal of new mechanistic concepts that considerably change and improve our understanding of the reaction pathway.
Synthesis of furo[3,2-c]coumarin derivatives using visible-light-promoted radical alkyne insertion with bromocoumarins
Authors: Zhou Hui , Deng Xinzhao , Ma Zhenjun , Zhang Aihua , Qin Qixue , Tan Ren Xiang , Yu Shouyun
Published: May 2016

Heterocyclic framework furo[3,2-c]coumarins were constructed using a visible-light promoted photoredox neutral coupling of 3-bromo-4-hydroxycoumarins with commercially available alkynes.
The assignment of the configuration for α-hydroxy acid esters using a CEC strategy
Authors: Peng Ruixue , Lin Lili , Zhang Yuheng , Wu Wangbin , Lu Yan , Liu Xiaohua , Feng Xiaoming
Published: May 2016

A simple and efficient 1H NMR method for determining the absolute configuration of chiral α-hydroxy acid esters using a CEC strategy with a chiral N,N′-dioxide-scandium(iii) complex was developed.
Thermoresponsive polymers based on ring-opening metathesis polymerization
Authors: Zhao Yuming , Zhang Ke
Published: May 2016

A library of thermoresponsive polymers were developed with hydrophobic polynorbornene backbones and hydrophilic N-alkyl-amide/imide side groups, whose thermoresponsive behaviour in water could be conveniently tuned in a wide temperature range.
PGMA-based supramolecular hyperbranched polycations for gene delivery
Authors: Qi Miao , Duan Shun , Yu Bingran , Yao Hao , Tian Wei , Xu Fu-Jian
Published: May 2016

PGMA-based supramolecular hyperbranched polycations were synthesized for effective gene delivery.
n-Type phosphorus-doped nanocrystalline diamond: electrochemical and in situ Raman spectroelectrochemical study
Authors: Vlčková Živcová Z. , Frank O. , Drijkoningen S. , Haenen K. , Mortet V. , Kavan L.
Published: May 2016

Electrochemical and in situ Raman spectroelectrochemical characterization of n-type phosphorus-doped nanocrystalline diamond (P-NCD) is carried out.
Construction of highly sensitive surface-enhanced Raman scattering (SERS) nanosensor aimed for the testing of glucose in urine
Authors: Sun Dan , Qi Guohua , Xu Shuping , Xu Weiqing
Published: May 2016

A facile, highly sensitive “turn on” SERS nanosensor for the detection of glucose in urine has been developed based on the aggregation of the 4-mercaptophenylboronic acid decorated silver nanoparticles in the specific bonding to glucose.
Tailoring the lasing modes in CH3NH3PbBr3 perovskite microplates via micro-manipulation
Authors: Liu Shuai , Sun Wenzhao , Gu Zhiyuan , Wang Kaiyang , Zhang Nan , Xiao Shumin , Song Qinghai
Published: May 2016

Laser emissions from perovskite microplates have been intensively studied recently.
Synthesis and high cycle performance of Li2ZnTi3O8/C anode material promoted by asphalt as a carbon precursor
Authors: Ren Yurong , Lu Peng , Huang Xiaobing , Ding Jianning , Wang Haiyan
Published: May 2016

A carbon layer (ca. 3 nm) formed on the surface of Li2ZnTi3O8 nanoparticles (ca. 30 nm) which is favorable to improve the electronic conductivity and lithium ion diffusion, resulting in improved rate capability and cycling performance.
Photon energy transfer by quantum dots in organic–inorganic hybrid solar cells through FRET
Authors: Han Yong Woon , Lee Eui Jin , Joo Jinwhan , Park Jongnam , Sung Tae Hyun , Moon Doo Kyung
Published: May 2016

Organic–inorganic hybrid solar cells were fabricated with InP QDs (5 wt%) in a BHJ active layer (PTB7 + PC71BM).
Ligand-directed rapid formation of ultralong ZnO nanowires by oriented attachment for UV photodetectors
Authors: Wang Jing , Li Xian , Teng Changjiu , Xia Yi , Xu Jianlong , Xie Dan , Xiang Lan , Komarneni Sridhar
Published: May 2016

Ultralong ZnO nanowires with lengths of 20–80 μm and aspect ratios of 200–500 were synthesized within 15 minutes via a low-temperature hydrothermal method.
Domains of STIP1 responsible for regulating PrPC-dependent amyloid-β oligomer toxicity
Authors: Maciejewski Andrzej , Ostapchenko Valeriy G. , Beraldo Flavio H. , Prado Vania F. , Prado Marco A.M. , Choy Wing-Yiu
Published: May 2016

Soluble oligomers of amyloid-beta peptide (AβO) transmit neurotoxic signals through the cellular prion protein (PrPC) in Alzheimer's disease (AD). Secreted stress-inducible phosphoprotein 1 (STIP1), an Hsp70 and Hsp90 cochaperone, inhibits AβO binding to PrPC and protects neurons from AβO-induced cell death. Here, we investigated the molecular interactions between AβO and STIP1 binding to PrPC and their effect on neuronal cell death. We showed that residues located in a short region of PrP (90–110) mediate AβO binding and we narrowed the major interaction in this site to amino acids 91–100. In contrast, multiple binding sites on STIP1 (DP1, TPR1 and TPR2A) contribute to PrP binding. DP1 bound the N-terminal of PrP (residues 23–95), whereas TPR1 and TPR2A showed binding to the C-terminal of PrP (residues 90–231). Importantly, only TPR1 and TPR2A directly inhibit both AβO binding to PrP and cell death. Furthermore, our structural studies reveal that TPR1 and TPR2A bind to PrP through distinct regions. The TPR2A interface was shown to be much more extensive and to partially overlap with the Hsp90 binding site. Our data show the possibility of a PrP, STIP1 and Hsp90 ternary complex, which may influence AβO-mediated cell death.
Actinin-1 binds to the C-terminus of A2B adenosine receptor (A2BAR) and enhances A2BAR cell-surface expression
Authors: Sun Ying , Hu Wenbao , Yu Xiaojie , Liu Zhengzhao , Tarran Robert , Ravid Katya , Huang Pingbo
Published: May 2016

A2BAR (A2B adenosine receptor) has been implicated in several physiological conditions, such as allergic or inflammatory disorders, vasodilation, cell growth and epithelial electrolyte secretion. For mediating the protein–protein interactions of A2BAR, the receptor's C-terminus is recognized to be crucial. In the present study, we unexpectedly found that two point mutations in the A2BAR C-terminus (F297A and R298A) drastically impaired the expression of A2BAR protein by accelerating its degradation. Thus we tested the hypothesis that these two point mutations disrupt A2BAR's interaction with a protein essential for A2BAR stability. Our results show that both mutations disrupted the interaction of A2BAR with actinin-1, an actin-associated protein. Furthermore, actinin-1 binding stabilized the global and cell-surface expression of A2BAR. By contrast, actinin-4, another non-muscle actinin isoform, did not bind to A2BAR. Thus our findings reveal a previously unidentified regulatory mechanism of A2BAR abundance.
An asparagine residue mediates intramolecular communication in nucleotide-regulated pyrophosphatase
Authors: Anashkin Viktor A. , Salminen Anu , Vorobjeva Natalia N. , Lahti Reijo , Baykov Alexander A.
Published: May 2016

Many prokaryotic soluble PPases (pyrophosphatases) contain a pair of regulatory adenine nucleotide-binding CBS (cystathionine β-synthase) domains that act as ‘internal inhibitors’ whose effect is modulated by nucleotide binding. Although such regulatory domains are found in important enzymes and transporters, the underlying regulatory mechanism has only begun to come into focus. We reported previously that CBS domains bind nucleotides co-operatively and induce positive kinetic co-operativity (non-Michaelian behaviour) in CBS-PPases (CBS domain-containing PPases). In the present study, we demonstrate that a homodimeric ehPPase (Ethanoligenens harbinense PPase) containing an inherent mutation in an otherwise conserved asparagine residue in a loop near the active site exhibits non-co-operative hydrolysis kinetics. A similar N312S substitution in ‘co-operative’ dhPPase (Desulfitobacterium hafniense PPase) abolished kinetic co-operativity while causing only minor effects on nucleotide-binding affinity and co-operativity. However, the substitution reversed the effect of diadenosine tetraphosphate, abolishing kinetic co-operativity in wild-type dhPPase, but restoring it in the variant dhPPase. A reverse serine-to-asparagine replacement restored kinetic co-operativity in ehPPase. Molecular dynamics simulations revealed that the asparagine substitution resulted in a change in the hydrogen-bonding pattern around the asparagine residue and the subunit interface, allowing greater flexibility at the subunit interface without a marked effect on the overall structure. These findings identify this asparagine residue as lying at the ‘crossroads’ of information paths connecting catalytic and regulatory domains within a subunit and catalytic sites between subunits.
Wideband balun bandpass filter explored for a balanced dipole antenna with high selectivity
Authors: Zhang Gang , Wang Jianpeng , Wu Wen
Published: May 2016

A novel microstrip wideband balun bandpass filter (BPF) is presented for development of a balanced dipole antenna with wide operating band and high frequency selectivity. By utilising the standing‐wave property of current distribution along a half‐wavelength (λ/2) open‐ended microstrip line, out‐of‐phase signals are ideally obtained at two output ports of a balun. Meanwhile, proper coupling topologies between the open‐circuited λ/2 microstrip transmission line and the quadruple‐mode resonators are selected to achieve a balun BPF with both characteristics of balanced performance and wideband filtering properties. A balun BPF operating at 1.65 GHz with 32% fractional bandwidth is at first designed. The derived results not only exhibit good performance with 0.49 dB amplitude imbalance and 7.2° phase imbalance, but also achieve high selectivity relying on two transmission zeros. Next, this balun BPF is integrated with a balanced dipole antenna with a flat shape towards wideband and high‐selective radiation. Both simulated and measured results achieve higher than 10 dB return loss and 2.4 dBi radiation gain over a band of 1.4–1.9 GHz.
Source‐switched charge pump with reverse leakage compensation technique for spur reduction of wideband PLL
Authors: Zhang Zhao , Yang Jincheng , Liu Liyuan , Feng Peng , Liu Jian , Wu Nanjian
Published: May 2016

A source‐switched charge pump (SSCP) with reverse leakage compensation technique is proposed to reduce spur level of wideband PLL induced by the reverse sub‐threshold leakage of the charge pump. This technique can set the source–drain voltage of current‐source N‐type MOS (NMOS)/P‐type MOS to be close to zero at off‐state of the charge pump and thus reduce the reverse leakage. Compared with the conventional SSCP, only one NMOS capacitor, two CMOS switches and two inverters are added in the proposed charge pump. So, there is negligible extra power and extra area cost. A 0.7–1.6 GHz PLL is designed with the conventional and the proposed charge pumps in 65 nm CMOS process. Simulation results show the proposed SSCP can reduce orders of the magnitude of the reverse leakage without the penalty of current matching, compared with the conventional charge pump. The PLL with the proposed charge pump achieves up to 28 dB spur level reduction.
Humidity assay for studying plant-pathogen interactions in miniature controlled discrete humidity environments with good throughput
Authors: Xu Zhen , Jiang Huawei , Sahu Binod Bihari , Kambakam Sekhar , Singh Prashant , Wang Xinran , Wang Qiugu , Bhattacharyya Madan K. , Dong Liang
Published: May 2016

This paper reports a highly economical and accessible approach to generate different discrete relative humidity conditions in spatially separated wells of a modified multi-well plate for humidity assay of plant-pathogen interactions with good throughput. We demonstrated that a discrete humidity gradient could be formed within a few minutes and maintained over a period of a few days inside the device. The device consisted of a freeway channel in the top layer, multiple compartmented wells in the bottom layer, a water source, and a drying agent source. The combinational effects of evaporation, diffusion, and convection were synergized to establish the stable discrete humidity gradient. The device was employed to study visible and molecular disease phenotypes of soybean in responses to infection by Phytophthora sojae, an oomycete pathogen, under a set of humidity conditions, with two near-isogenic soybean lines, Williams and Williams 82, that differ for a Phytophthora resistance gene (Rps1-k). Our result showed that at 63% relative humidity, the transcript level of the defense gene GmPR1 was at minimum in the susceptible soybean line Williams and at maximal level in the resistant line Williams 82 following P. sojae CC5C infection. In addition, we investigated the effects of environmental temperature, dimensional and geometrical parameters, and other configurational factors on the ability of the device to generate miniature humidity environments. This work represents an exploratory effort to economically and efficiently manipulate humidity environments in a space-limited device and shows a great potential to facilitate humidity assay of plant seed germination and development, pathogen growth, and plant-pathogen interactions. Since the proposed device can be easily made, modified, and operated, it is believed that this present humidity manipulation technology will benefit many laboratories in the area of seed science, plant pathology, and plant-microbe biology, where humidity is an important factor that influences plant disease infection, establishment, and development.
Positive direct current corona discharges in single wire-duct electrostatic precipitators
Authors: Yehia Ashraf , Abdel-Fattah E. , Mizuno Akira
Published: May 2016

This paper is aimed to study the characteristics of the positive dc corona discharges in single wire-duct electrostatic precipitators. Therefore, the corona discharges were formed inside dry air fed single wire-duct reactor under positive dc voltage at the normal atmospheric conditions. The corona current-voltage characteristics curves have been measured in parallel with the ozone concentration generated inside the reactor under different discharge conditions. The corona current-voltage characteristics curves have agreed with a semi empirical equation derived from the previous studies. The experimental results of the ozone concentration generated inside the reactor were formulated in the form of an empirical equation included the different parameters that were studied experimentally. The obtained equations are valid to expect both the current-voltage characteristics curves and the corresponding ozone concentration that generates with the positive dc corona discharges inside single wire-duct electrostatic precipitators under any operating conditions in the same range of the present study.
Dielectric relaxation of alkyl chains in graphite oxide and n-alkylammonium halides
Authors: Ai Xiaoqian , Tian Yuchen , Gu Min , Yu Ji , Tang Tong B.
Published: May 2016

The dynamic of n-alkylammonium halides and n-alkylammonium cations (n = 12, 14, 16, 18) intercalated in graphite oxide (GO) have been investigated with complex impedance spectroscopy. X-ray diffraction, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, elemental analysis and thermogravimetry served to characterize the materials. The intercalated alkylammonium cations distributes as monolayers (when n = 12, 14 or 16) or bilayers (when n = 18), with their long axis parallel to GO layers, and with cations of headgroups bonded ionically to C-O- groups of GO; backbones of the confined molecules remain free. All halides and intercalation compounds suffer dielectric loss at low temperature. Arrhenius plots of the thermal dependence of the loss peaks, which are asymmetric, produce apparent activation energies that rise with increasing n. Ngai’s correlated-state model helps to correct for effects of dipole-dipole interaction, leading to virtually identical values for actual activation energy of 110 meV ± 5%; the values are also almost the same as the barrier energy for internal rotation in the alkyl macromolecule. We conclude that the relaxation of the alkylammonium cations arises not from C3 reorientation of the CH3 at its headgroup, but from small-angle wobbling around its major axis, an intrinsic motion.
Solution processable organic/inorganic hybrid ultraviolet photovoltaic detector
Authors: Guo Xiaopeng , Tang Libin , Xiang Jinzhong , Ji Rongbin , Zhang Kai , Lai Sin Ki , Zhao Jun , Kong Jincheng , Lau Shu Ping
Published: May 2016

Ultraviolet (UV) photodetector is a kind of important optoelectronic device which can be widely used in scientific and engineering fields including astronomical research, environmental monitoring, forest-fire prevention, medical analysis, and missile approach warning etc. The development of UV detector is hindered by the acquirement of stable p-type materials, which makes it difficult to realize large array, low-power consumption UV focal plane array (FPA) detector. Here, we provide a novel structure (Al/Poly(9,9-di-n-octylfuorenyl-2,7-diyl)(PFO)/ZnO/ITO) to demonstrate the UV photovoltaic (PV) response. A rather smooth surface (RMS roughness: 0.28 nm) may be reached by solution process, which sheds light on the development of large-array, light-weight and low-cost UV FPA detectors.
Integrated transcriptomics and metabolomics reveal induction of hierarchies of resistance genes in potato against late blight
Authors: Yogendra Kalenahalli N. , Kushalappa Ajjamada C.
Published: May 2016

Late blight caused by Phytophthora infestans is a devastating disease affecting potato production worldwide. The quantitative resistance is durable, but the underlying molecular and biochemical mechanisms are poorly understood, limiting its application in breeding. Integrated transcriptomics and metabolomics approach was used for the first time to study the hierarchies of molecular events occurring, following inoculation of resistant and susceptible potato genotypes with P. infestans. RNA sequencing revealed a total of 4216 genes that were differentially expressed in the resistant than in the susceptible genotype. Genes that were highly expressed and associated with their biosynthetic metabolites that were highly accumulated, through metabolic pathway regulation, were selected. Quantitative real-time PCR was performed to confirm the RNA-seq expression levels. The induced leucine-rich repeat receptor-like kinases (LRR-RLKs) are considered to be involved in pathogen recognition. These receptor genes are considered to trigger downstream oxidative burst, phytohormone signalling-related genes, and transcription factors that regulated the resistance genes to produce resistance related metabolites to suppress the pathogen infection. It was noted that several resistance genes in metabolic pathways related to phenylpropanoids, flavonoids, alkaloids and terpenoid biosynthesis were strongly induced in the resistant genotypes. The pathway specific gene induction provided key insights into the metabolic reprogramming of induced defence responses in resistant genotypes.
Microstructures of magnetically assisted dual-phase steel resistance spot welds
Authors: Li Y. B. , Li D. L. , David S. A. , Lim Y. C. , Feng Z.
Published: May 2016

Traditional spot welds and magnetically assisted spot welds were made in 2.25 mm thick galvanised dual-phase steel, and the weld microstructures were compared. The magnetically assisted weld nugget had a ‘dog bone’ shape, and it had an increased diameter, which indicates a larger load-bearing area that will improve mechanical performance. The fusion zone of the magnetically assisted welds had a finer and less-directional grain structure than the conventional welds, which would improve weld strength, plastic strains, and ductility. Both types of welds contained an unusual soft zone very close to the fusion zone that is thought to be an integral part of the fusion zone. The soft zone of the magnetically assisted welds was wider than the conventional welds.
Differential Time Course of Microstructural White Matter in Patients With Psychotic Disorder and Individuals at Risk: A 3-Year Follow-up Study
Authors: Domen Patrick , Peeters Sanne , Michielse Stijn , Gronenschild Ed , Viechtbauer Wolfgang , Roebroeck Alard , Os Jim van , Marcelis Machteld ,   for Genetic Risk and Outcome of Psychosis (G.R.O.U.P.)
Published: May 2016

Background

Although widespread reduced white matter (WM) integrity is a consistent finding in cross-sectional diffusion tensor imaging (DTI) studies of schizophrenia, little is known about the course of these alterations. This study examined to what degree microstructural WM alterations display differential trajectories over time as a function of level of psychosis liability.

Methods

Two DTI scans with a 3-year time interval were acquired from 159 participants (55 patients with a psychotic disorder, 55 nonpsychotic siblings and 49 healthy controls) and processed with tract-based spatial statistics. The mean fractional anisotropy (FA) change over time was calculated. Main effects of group, as well as group × region interactions in the model of FA change were examined with multilevel (mixed-effects) models.

Results

Siblings revealed a significant mean FA decrease over time compared to controls (B = −0.004, P = .04), resulting in a significant sibling-control difference at follow-up (B = −0.007, P = .03). Patients did not show a significant change over time, but their mean FA was lower than controls both at baseline and at follow-up. A significant group × region interaction (χ2 = 105.4, P = .01) revealed group differences in FA change in the right cingulum, left posterior thalamic radiation, right retrolenticular part of the internal capsule, and the right posterior corona radiata.

Conclusion

Whole brain mean FA remained stable over a 3-year period in patients with psychotic disorder and declined over time in nonaffected siblings, so that at follow-up both groups had lower FA with respect to controls. The results suggest that liability for psychosis may involve a process of WM alterations.
Coached Peer Review: Developing the Next Generation of Authors
Authors: Sidalak Daniel , Purdy Eve , Luckett-Gatopoulos S. , Murray Heather , Thoma Brent , Chan Teresa M.
Published: May 2016

Problem

Publishing in academic journals is challenging for learners. Those who pass the initial stages of internal review by an editor often find the anonymous peer review process harsh. Academic blogs offer alternate avenues for publishing medical education material. Many blogs, however, lack a peer review process, which some consumers argue compromises the quality of materials published.

Approach

CanadiEM (formerly BoringEM) is an academic educational emergency medicine blog dedicated to publishing high-quality materials produced by learners (i.e., residents and medical students). The editorial team has designed and implemented a collaborative “coached peer review” process that comprises an open exchange among the learner–author, editors, and reviewers. The goal of this process is to facilitate the publication of high-quality academic materials by learner–authors while providing focused feedback to help them develop academic writing skills.

Outcomes

The authors of this Innovation Report surveyed (February–June 2015) their blog’s learner–authors and external expert “staff” reviewers who had participated in coached peer review for their reactions to the process. The survey results revealed that participants viewed the process positively compared with both traditional journal peer review and academic blog publication processes. Participants found the process friendly, easy, efficient, and transparent. Learner–authors also reported increased confidence in their published material. These outcomes met the goals of coached peer review.

Next Steps

CanadiEM aims to inspire continued participation in, exposure to, and high-quality production of academic writing by promoting the adoption of coached peer review for online educational resources produced by learners.