bluuebunny/crossref_metadata_2025 huggingface dataset:
The cytokine secretion profile of mesenchymal stromal cells is determined by surface structure of the microenvironment
Authors: Leuning Daniëlle G. , Beijer Nick R. M. , du Fossé Nadia A. , Vermeulen Steven , Lievers Ellen , van Kooten Cees , Rabelink Ton J. , Boer Jan de
Published: May 2018

Mesenchymal stromal cells (MSC) secrete factors that contribute to organ homeostasis and repair in a tissue specific manner. For instance, kidney perivascular mesenchymal stromal cells (kPSCs) can facilitate renal epithelial repair through secretion of hepatocyte growth factor (HGF) while the secretome of bone marrow MSCs gives rise to immunosuppression. Stromal cells function in a complex 3-dimensional (3D) connective tissue architecture that induces conformational adaptation. Here we tested the hypothesis that surface topography and associated cell adaptations dictate stromal cell function through tuning of the cytokines released. To this end, we cultured human bone marrow and kidney perivascular stromal cells in the TopoWell plate, a custom-fabricated multi-well plate containing 76 unique bioactive surface topographies. Using fluorescent imaging, we observed profound changes in cell shape, accompanied by major quantitative changes in the secretory capacity of the MSCs. The cytokine secretion profile was closely related to cell morphology and was stromal cell type specific. Our data demonstrate that stromal cell function is determined by microenvironment structure and can be manipulated in an engineered setting. Our data also have implications for the clinical manufacturing of mesenchymal stromal cell therapy, where surface topography during bioreactor expansion should be taken into account to preserve therapeutic properties.
Ion–ion interactions in the denatured state contribute to the stabilization of CutA1 proteins
Authors: Yutani Katsuhide , Matsuura Yoshinori , Naitow Hisashi , Joti Yasumasa
Published: May 2018

In order to elucidate features of the denatured state ensembles that exist in equilibrium with the native state under physiological conditions, we performed 1.4-μs molecular dynamics (MD) simulations at 400 K and 450 K using the monomer subunits of three CutA1 mutants from Escherichia coli: an SH-free mutant (Ec0SH) with denaturation temperature (Td) = 85.6 °C, a hydrophobic mutant (Ec0VV) with Td = 113.3 °C, and an ionic mutant (Ec0VV_6) with Td = 136.8 °C. The occupancy of salt bridges by the six substituted charged residues in Ec0VV_6 was 140.1% at 300 K and 89.5% at 450 K, indicating that even in the denatured state, salt bridge occupancy was high, approximately 60% of that at 300 K. From these results, we can infer that proteins from hyperthermophiles with a high ratio of charged residues are stabilized by a decrease in conformational entropy due to ion–ion interactions in the denatured state. The mechanism must be comparable to the stabilization conferred by disulfide bonds within a protein. This suggests that introduction of charged residues, to promote formation of salt bridges in the denatured state, would be a simple way to rationally design stability-enhanced mutants.
Elevated plasma lipoprotein(a) levels were associated with increased risk of cardiovascular events in Chinese patients with stable coronary artery disease
Authors: Dai Wen , Long Junke , Cheng Ying , Chen Yaqin , Zhao Shuiping
Published: May 2018

Recent studies have suggested that lipoprotein(a) [Lp(a)] is associated with cardiovascular disease (CVD). However, the contribution of Lp(a) to residual risk of CVD has not been determined in Chinese populations. We conducted a prospective study to evaluate the association between Lp(a) and the risk of major adverse cardiovascular events (MACEs) in patients with stable coronary artery disease (CAD) who received optimal medication treatment (OMT). The study enrolled 1602 patients with stable CAD from 5 hospitals in China. The baseline clinical characteristics and follow-up MACE data for the patients were recorded. Coronary lesion severity was assessed by the Gensini scoring system. All-cause death, non-fatal myocardial infarction, non-fatal stroke and unplanned coronary revascularization were considered MACEs. We found that plasma Lp(a) levels were positively associated with coronary lesion severity at baseline (p < 0.001). During a mean follow-up period of 39.6 months, 166 (10.4%) patients suffered MACEs. There were significant differences in the adjusted event-free survival rates among the Lp(a) quartile subgroups (p = 0.034). The hazard ratio for MACEs was 1.291 (95% confidence interval: 1.091–1.527, p = 0.003) per standardized deviation in the log-transformed Lp(a) level after adjustment for traditional cardiovascular risk factors. Therefore, Lp(a) was an independent predictor of MACEs in Chinese patients with stable CAD who received OMT.
Hypothermia broadens the therapeutic time window of mesenchymal stem cell transplantation for severe neonatal hypoxic ischemic encephalopathy
Authors: Ahn So Yoon , Chang Yun Sil , Sung Dong Kyung , Sung Se In , Park Won Soon
Published: May 2018

Recently, we have demonstrated that concurrent hypothermia and mesenchymal stem cells (MSCs) transplantation synergistically improved severe neonatal hypoxic ischemic encephalopathy (HIE). The current study was designed to determine whether hypothermia could extend the therapeutic time window of MSC transplantation for severe neonatal HIE. To induce HIE, newborn rat pups were exposed to 8% oxygen for 2 h following unilateral carotid artery ligation on postnatal day (P) 7. After approving severe HIE involving >50% of the ipsilateral hemisphere volume, hypothermia (32 °C) for 2 days was started. MSCs were transplanted 2 days after HIE modeling. Follow-up brain MRI, sensorimotor function tests, assessment of inflammatory cytokines in the cerebrospinal fluid (CSF), and histological evaluation of peri-infarction area were performed. HIE induced progressively increasing brain infarction area over time, increased cell death, reactive gliosis and brain inflammation, and impaired sensorimotor function. All these damages observed in severe HIE showed better, robust improvement with a combination treatment of hypothermia and delayed MSC transplantation than with either stand-alone therapy. Hypothermia itself did not significantly reduce brain injury, but broadened the therapeutic time window of MSC transplantation for severe newborn HIE.
Conserved and non-conserved characteristics of porcine glial cell line-derived neurotrophic factor expressed in the testis
Authors: Kakiuchi Kazue , Taniguchi Kazumi , Kubota Hiroshi
Published: May 2018

Glial cell line-derived neurotrophic factor (GDNF) is essential for the self-renewal and proliferation of spermatogonial stem cells (SSCs) in mice, rats, and rabbits. Although the key extrinsic factors essential for spermatogonial proliferation in other mammals have not been determined, GDNF is one of the potential candidates. In this study, we isolated porcine GDNF (pGDNF) cDNAs from neonatal testis and generated recombinant pGDNF to investigate its biological activity on gonocytes/undifferentiated spermatogonia, including SSCs. In porcine testis, long and short forms of GDNF transcripts, the counterparts of pre-(α)pro and pre-(β)pro GDNF identified in humans and rodents, were expressed. The two transcripts encode identical mature proteins. Recombinant pGDNF supported proliferation of murine SSCs in culture, and their stem cell activity was confirmed by a transplantation assay. Subsequently, porcine gonocytes/undifferentiated spermatogonia were cultured with pGDNF; however, pGDNF did not affect their proliferation. Furthermore, GDNF expression was localised to the vascular smooth muscle cells, and its cognate receptor GFRA1 expression was negligible during spermatogonial proliferation in the testes. These results indicate that although pGDNF retains structural similarity with those of other mammals and conserves the biological activity on the self-renewal of murine SSCs, porcine SSCs likely require extrinsic factors other than GDNF for their proliferation.
Adaptation to criticality through organizational invariance in embodied agents
Authors: Aguilera Miguel , Bedia Manuel G.
Published: May 2018

Many biological and cognitive systems do not operate deep within one or other regime of activity. Instead, they are poised at critical points located at phase transitions in their parameter space. The pervasiveness of criticality suggests that there may be general principles inducing this behaviour, yet there is no well-founded theory for understanding how criticality is generated at a wide span of levels and contexts. In order to explore how criticality might emerge from general adaptive mechanisms, we propose a simple learning rule that maintains an internal organizational structure from a specific family of systems at criticality. We implement the mechanism in artificial embodied agents controlled by a neural network maintaining a correlation structure randomly sampled from an Ising model at critical temperature. Agents are evaluated in two classical reinforcement learning scenarios: the Mountain Car and the Acrobot double pendulum. In both cases the neural controller appears to reach a point of criticality, which coincides with a transition point between two regimes of the agent’s behaviour. These results suggest that adaptation to criticality could be used as a general adaptive mechanism in some circumstances, providing an alternative explanation for the pervasive presence of criticality in biological and cognitive systems.
HLA-class II haplotypes and Autism Spectrum Disorders
Authors: Bennabi Meriem , Gaman Alexandru , Delorme Richard , Boukouaci Wahid , Manier Céline , Scheid Isabelle , Si Mohammed Nassima , Bengoufa Djaouida , Charron Dominique , Krishnamoorthy Rajagopal , Leboyer Marion , Tamouza Ryad
Published: May 2018

Infections and autoimmunity are associated with autism spectrum disorders (ASD), with both strongly influenced by the genetic regulation of the human leukocyte antigen (HLA) system. The relationship between ASD and the HLA genetic diversity requires further investigation. Using a case control design, the distribution of HLA class II-DRB1 and DQB1 alleles, genotypes and haplotypes were investigated in ASD patients, versus healthy controls (HC). ASD patients meeting DSM-IV TR criteria and HC (474 and 350 respectively) were genotyped at medium resolution using a Luminex-based SSO technology. Comparisons of genotypes, allele frequencies associated with a haplotype analysis were performed. Results indicate: (i) the HLA-DRB1 *11-DQB1*07 haplotype was more prevalent in ASD patients, versus HC (Pc = 0.001), partially replicating previous data and possibly linking to gastro-intestinal (GI)-related pro-inflammatory processes, given that this haplotype associates with pediatric celiac disorders; (ii) the HLA-DRB1 *17-DQB1*02 haplotype was higher in HC, versus ASD patients (Pc = 0.002), indicating that this is a protective haplotype. Using the Autism Diagnostic Interview to assess clinical dimensions, higher scores on social (Pc = 0.006) and non-verbal functioning (Pc = 0.004) associated with the DRB1 *11 DQB1*07 haplotype. Our results support HLA involvement in ASD, with possible relevance to GI and gut-brain axis dysregulation.
Maternal supraphysiological hypercholesterolemia associates with endothelial dysfunction of the placental microvasculature
Authors: Fuenzalida Bárbara , Sobrevia Bastián , Cantin Claudette , Carvajal Lorena , Salsoso Rocío , Gutiérrez Jaime , Contreras-Duarte Susana , Sobrevia Luis , Leiva Andrea
Published: May 2018

Maternal physiological or supraphysiological hypercholesterolemia (MPH, MSPH) occurs during pregnancy. MSPH is associated with foetal endothelial dysfunction and atherosclerosis. However, the potential effects of MSPH on placental microvasculature are unknown. The aim of this study was to determine whether MSPH alters endothelial function in the placental microvasculature both ex vivo in venules and arterioles from the placental villi and in vitro in primary cultures of placental microvascular endothelial cells (hPMEC). Total cholesterol < 280 mg/dL indicated MPH, and total cholesterol ≥280 mg/dL indicated MSPH. The maximal relaxation to histamine, calcitonin gene-related peptide and adenosine was reduced in MSPH venule and arteriole rings. In hPMEC from MSPH placentas, nitric oxide synthase (NOS) activity and L-arginine transport were reduced without changes in arginase activity or the protein levels of endothelial NOS (eNOS), human cationic amino acid 1 (hCAT-1), hCAT-2A/B or arginase II compared with hPMEC from MPH placentas. In addition, it was shown that adenosine acts as a vasodilator of the placental microvasculature and that NOS is active in hPMEC. We conclude that MSPH alters placental microvascular endothelial function via a NOS/L-arginine imbalance. This work also reinforces the concept that placental endothelial cells from the macro- and microvasculature respond differentially to the same pathological condition.
Discovery of a novel IL-15 based protein with improved developability and efficacy for cancer immunotherapy
Authors: Hu Qiyue , Ye Xin , Qu Xiangdong , Cui Dongbing , Zhang Lei , Xu Zhibin , Wan Hong , Zhang Lianshan , Tao Weikang
Published: May 2018

Interleukin-15 (IL-15) can promote both innate and adaptive immune reactions by stimulating CD8+/CD4+ T cells and natural killer cells (NK) while showing no effect in activating T-regulatory (Treg) cells or inducing activation-associated death among effector T cells and NK cells. Thus, IL-15 is considered as one of the most promising molecules for antitumor immune therapy. To improve the drug-like properties of natural IL-15, we create an IL-15-based molecule, named P22339, with the following characteristics: 1) building a complex of IL-15 and the Sushi domain of IL-15 receptor α chain to enhance the agonist activity of IL-15 via transpresentation; 2) through a rational structure-based design, creating a disulfide bond linking the IL-15/Sushi domain complex with an IgG1 Fc to augment its half-life. P22339 demonstrates excellent developability, pharmacokinetic and pharmacodynamic properties as well as antitumor efficacy in both in vitro assessments and in vivo studies. It significantly suppresses tumor growth and metastasis in rodent models, and activates T effector cells and NK cells in cynomolgus monkey. Overall, these data suggest that P22339 has a great potential for cancer immunotherapy.
Potassium-rich brine deposit in Lop Nor basin, Xinjiang, China
Authors: Sun Ming-guang , Ma Li-chun
Published: May 2018

Lop Nor potash deposit is the largest sulfate-type liquid potassium salt deposit in China, consisting of three areas: Xinqing platform, Luobei depression, and Tenglong platform. In this study, the geological background, basin structure, and fracture system of the deposit, along with the brine storage size of the three ore bodies are introduced in detail, using underground brine elevation models of the mining areas. We collected 91 samples of brine from long-term observation boreholes in the Lop Nor ore district, and analyzed their ion contents. The KCl content of the brine varies from 1% to 1.45% and that of B2O3 varies from 1900 to 4500 mg/L, which are higher than the cut-off for Chinese industrial mining grades. The spatial distributions of KCl and B2O3 contents in different ore beds were plotted, and the distributions of different grades of K+ and B3+ were revealed.
Low factor XIII levels after intravenous thrombolysis predict short-term mortality in ischemic stroke patients
Authors: Székely Edina Gabriella , Czuriga-Kovács Katalin Réka , Bereczky Zsuzsanna , Katona Éva , Mezei Zoltán András , Nagy Attila , Tóth Noémi Klára , Berényi Ervin , Muszbek László , Csiba László , Bagoly Zsuzsa
Published: May 2018

In this observational study we investigated whether levels of factor XIII (FXIII) and its major polymorphisms affect the outcome of thrombolysis by recombinant tissue plasminogen activator (rtPA) in acute ischemic stroke (AIS) patients. Study cohort included 132 consecutive AIS patients undergoing i.v. thrombolysis within 4.5 h of symptom onset. Blood samples taken on admission, immediately after and 24 h after therapy were analyzed for FXIII activity and antigen levels. FXIII-A p.Val34Leu, p.Tyr204Phe, FXIII-B p.His95Arg and intron K(IVS11 + 144) polymorphisms were genotyped. Neurological deficit was assessed using the National Institutes of Health Stroke Scale. Intracranial hemorrhage was classified according to ECASSII criteria. Long-term functional outcome was defined at 3 months post-event by the modified Rankin scale. FXIII levels showed a gradual decrease immediately after thrombolysis and 24 h later, which was not related to therapy-associated bleeding. In a multiple logistic regression model, a FXIII level in the lowest quartile 24 h post-lysis proved to be an independent predictor of mortality by 14 days post-event (OR:4.95, 95% CI:1.31–18.68, p < 0.05). No association was found between the investigated FXIII polymorphisms and therapeutic outcomes. In conclusion, our findings indicate that FXIII levels 24 h after thrombolysis might help to identify patients at increased risk for short-term mortality.
Carvacrol and linalool co-loaded in β-cyclodextrin-grafted chitosan nanoparticles as sustainable biopesticide aiming pest control
Authors: Campos Estefânia V. R. , Proença Patrícia L. F. , Oliveira Jhones L. , Pereira Anderson E. S. , de Morais Ribeiro Lígia Nunes , Fernandes Fabrício O. , Gonçalves Kelly C. , Polanczyk Ricardo A. , Pasquoto-Stigliani Tatiane , Lima Renata , Melville Cirano C. , Della Vechia Jaqueline F. , Andrade Daniel J. , Fraceto Leonardo F.
Published: May 2018

Pesticides are the main tactics for pest control because they reduce the pest population very fast and their efficiency does not depend on abiotic factors. However, the indiscriminate use of these substances can speed up the development of resistant populations and causing environmental contamination. Therefore, alternative methods of pest control are sought, such as the use of botanical compounds. Nanoencapsulation of volatile compounds has been shown to be an important tool that can be used to overcome the lack of stability of these compounds. In this work, we describe the preparation and characterization of chitosan nanoparticles functionalized with β-cyclodextrin containing carvacrol and linalool. The toxicity and biological activity were evaluated. Decreases of toxicity were observed when the compounds were nanoencapsulated. The nanoparticles presented insecticidal activity against the speciesHelicoverpa armigera(corn earworm) andTetranychus urticae(spider mite). In addition, repellent activity and reduction in oviposition were observed for the mites.
Highly reproducible alkali metal doping system for organic crystals through enhanced diffusion of alkali metal by secondary thermal activation
Authors: Lee Jinho , Park Chibeom , Song Intek , Koo Jin Young , Yoon Taekyung , Kim Jun Sung , Choi Hee Cheul
Published: May 2018

In this paper, we report an efficient alkali metal doping system for organic single crystals. Our system employs an enhanced diffusion method for the introduction of alkali metal into organic single crystals by controlling the sample temperature to induce secondary thermal activation. Using this system, we achieved intercalation of potassium into picene single crystals with closed packed crystal structures. Using optical microscopy and Raman spectroscopy, we confirmed that the resulting samples were uniformly doped and became K2picene single crystal, while only parts of the crystal are doped and transformed into K2picene without secondary thermal activation. Moreover, using a customized electrical measurement system, the insulator-to-semiconductor transition of picene single crystals upon doping was confirmed by in situ electrical conductivity and ex situ temperature-dependent resistivity measurements. X-ray diffraction studies showed that potassium atoms were intercalated between molecular layers of picene, and doped samples did not show any KH- nor KOH-related peaks, indicating that picene molecules are retained without structural decomposition. During recent decades, tremendous efforts have been exerted to develop high-performance organic semiconductors and superconductors, whereas as little attention has been devoted to doped organic crystals. Our method will enable efficient alkali metal doping of organic crystals and will be a resource for future systematic studies on the electrical property changes of these organic crystals upon doping.
JDP2 overexpression provokes cardiac dysfunction in mice
Authors: Heger Jacqueline , Bornbaum Julia , Würfel Alona , Hill Christian , Brockmann Nils , Gáspár Renáta , Pálóczi János , Varga Zoltán V. , Sárközy Márta , Bencsik Péter , Csont Tamás , Török Szilvia , Kojonazarov Baktybek , Schermuly Ralph Theo , Böngler Kerstin , Parahuleva Mariana , Ferdinandy Peter , Schulz Rainer , Euler Gerhild
Published: May 2018

The transcriptional regulator JDP2 (Jun dimerization protein 2) has been identified as a prognostic marker for patients to develop heart failure after myocardial infarction. We now performed in vivo studies on JDP2-overexpressing mice, to clarify the impact of JDP2 on heart failure progression. Therefore, during birth up to the age of 4 weeks cardiac-specific JDP2 overexpression was prevented by doxycycline feeding in transgenic mice. Then, JDP2 overexpression was started. Already after 1 week, cardiac function, determined by echocardiography, decreased which was also resembled on the cardiomyocyte level. After 5 weeks blood pressure declined, ejection fraction and cardiac output was reduced and left ventricular dilatation developed. Heart weight/body weight, and mRNA expression of ANP, inflammatory marker genes, collagen and fibronectin increased. Collagen 1 protein expression increased, and fibrosis developed. As an additional sign of elevated extracellular matrix remodeling, matrix metalloproteinase 2 activity increased in JDP2 mice. Thus, JDP2 overexpression is deleterious to heart function in vivo. It can be concluded that JDP2 overexpression provokes cardiac dysfunction in adult mice that is accompanied by hypertrophy and fibrosis. Thus, induction of JDP2 is a maladaptive response contributing to heart failure development.
Quantum Cascade Laser-Based Infrared Microscopy for Label-Free and Automated Cancer Classification in Tissue Sections
Authors: Kuepper Claus , Kallenbach-Thieltges Angela , Juette Hendrik , Tannapfel Andrea , Großerueschkamp Frederik , Gerwert Klaus
Published: May 2018

A feasibility study using a quantum cascade laser-based infrared microscope for the rapid and label-free classification of colorectal cancer tissues is presented. Infrared imaging is a reliable, robust, automated, and operator-independent tissue classification method that has been used for differential classification of tissue thin sections identifying tumorous regions. However, long acquisition time by the so far used FT-IR-based microscopes hampered the clinical translation of this technique. Here, the used quantum cascade laser-based microscope provides now infrared images for precise tissue classification within few minutes. We analyzed 110 patients with UICC-Stage II and III colorectal cancer, showing 96% sensitivity and 100% specificity of this label-free method as compared to histopathology, the gold standard in routine clinical diagnostics. The main hurdle for the clinical translation of IR-Imaging is overcome now by the short acquisition time for high quality diagnostic images, which is in the same time range as frozen sections by pathologists.
Vector polymorphic beam
Authors: Rodrigo José A. , Alieva Tatiana
Published: May 2018

A scalar polymorphic beam is designed with independent control of its intensity and phase along a strongly focused laser curve of arbitrary shape. This kind of beam has been found crucial in the creation of freestyle laser traps able to confine and drive the motion of micro/nano-particles along reconfigurable 3D trajectories in real time. Here, we present and experimentally prove the concept of vector polymorphic beam adding the benefit of independent design of the light polarization along arbitrary curves. In particular, we consider polarization shaped tangential and orthogonal to the curve that are of high interest in optical manipulation and laser micromachining. The vector polymorphic beam is described by a surprisingly simple closed-form expression and can be easily generated by using a computer generated hologram.
Click chemistry-based core–shell molecularly imprinted polymers for the determination of pyrimethamine in fish and plasma samples
Authors: Huang Shuyi , Guo Manli , Tan Lei , Tan Jiean , Wu Jinyi , Tang Youwen , Liang Yong
Published: May 2018

This paper demonstrates the development and validation of a high-performance liquid chromatography (HPLC) method for the determination of pyrimethamine in fish and plasma samples using core–shell molecularly imprinted polymers (MIPs).
Two dominant self-assembly pathways to a Pd3L6 double-walled triangle
Authors: Tateishi Tomoki , Kai Shumpei , Sasaki Yuya , Kojima Tatsuo , Takahashi Satoshi , Hiraoka Shuichi
Published: May 2018

A Pd(ii)-linked double-walled triangle is assembled through the growth of single-walled chain-like intermediates followed by the macrocyclization and the formation of double-walls.
Electron injection study of photoexcitation effects on supported subnanometer Pt clusters for CO2 photoreduction
Authors: Yang Chi-Ta , Wood Brandon C. , Bhethanabotla Venkat R. , Joseph Babu
Published: May 2018

Upon the injection of electrons, supported Pt clusters stabilize the adsorption of bent-form CO2 species and facilitate the formation of CO2− anions.
Reactivity of a dearomatised pincer CoIIBr complex with PNCNHC donors: alkylation and Si–H bond activation via metal–ligand cooperation
Authors: Simler Thomas , Choua Sylvie , Danopoulos Andreas A. , Braunstein Pierre
Published: May 2018

Whereas [Co(CyP*NaCNHC)Br] (1) with dearomatised pincer CyP*NaCNHC affords the CoII–alkyl complex 3, uncommon silane reduction yields the CoI complex 4.
Incorporation of tocopherol-rich extracts from mushroom mycelia into yogurt
Authors: Bouzgarrou Chaima , Amara Khira , Reis Filipa S. , Barreira João C. M. , Skhiri Fethia , Chatti Noureddine , Martins Anabela , Barros Lillian , Ferreira Isabel C. F. R.
Published: May 2018

The tocopherol extract from Ganoderma lucidum proved to be the most suitable choice as a new functionalizing agent to be incorporated in yogurt.
Fermented goat milk consumption improves iron status and evokes inflammatory signalling during anemia recovery
Authors: López-Aliaga Inmaculada , García-Pedro José D. , Moreno-Fernandez Jorge , Alférez Mª José M. , López-Frías Magdalena , Díaz-Castro Javier
Published: May 2018

In spite of the crucial role of the inflammatory state under anemic conditions, to date, no studies have directly tested the modulation of cytokines during iron overload.
On-line pseudo-stationary magnetic solid-phase extraction using magnetic cation exchange microparticles and its application to the determination of strontium
Authors: Ayala Alejandro , Takagai Yoshitaka
Published: May 2018

An on-line magnetic solid-phase extraction system was developed for Sr determination.
UV photochemical vapor generation–nitrogen microwave induced plasma optical emission spectrometric determination of nickel
Authors: Li Mengtian , Deng Yujia , Jiang Xiaoming , Hou Xiandeng
Published: May 2018

Photochemical vapor generation was utilized for gaseous sample introduction into a nitrogen microwave induced plasma optical emission spectrometer in order to enhance the analytical performance.
Correction: design, synthesis and evaluation of cinnamic acid ester derivatives as mushroom tyrosinase inhibitors
Authors: Sheng Zhaojun , Ge Siyuan , Xu Ximing , Zhang Yan , Wu Panpan , Zhang Kun , Xu Xuetao , Li Chen , Zhao Denggao , Tang Xiaowen
Published: May 2018

Correction for ‘Design, synthesis and evaluation of cinnamic acid ester derivatives as mushroom tyrosinase inhibitors’ by Zhaojun Sheng et al., Med. Chem. Commun., 2018, DOI: 10.1039/c8md00099a.
An ionic liquid gel: a heterogeneous catalyst for Erlenmeyer–Plochl and Henry reactions
Authors: Jagadale Megha , Naikwade Altafhusen , Salunkhe Rajashri , Rajmane Mohan , Rashinkar Gajanan
Published: May 2018

Agar gel entrapped [Bmim]OH has been prepared and employed as an efficient heterogeneous catalyst for the synthesis of β-nitro alcohols and azlactones.
Functionalized 2D nanomaterials with switchable binding to investigate graphene–bacteria interactions
Authors: Tan Kok H. , Sattari Shabnam , Donskyi Ievgen S. , Cuellar-Camacho Jose L. , Cheng Chong , Schwibbert Karin , Lippitz Andreas , Unger Wolfgang E. S. , Gorbushina Anna , Adeli Mohsen , Haag Rainer
Published: May 2018

Graphene and its derivatives have recently attracted much attention for sensing and deactivating pathogens.
Chelation-assisted C–N cross-coupling of phosphinamides and aryl boronic acids with copper powder at room temperature
Authors: Peng Yao , Lei Jian , Qiu Renhua , Peng Lingteng , Au Chak-Tong , Yin Shuang-Feng
Published: May 2018

A protocol for the chelation-assisted C–N cross-coupling of phosphinamides and aryl boronic acids with copper powder under an oxygen atmosphere is reported.
The secondary structures of PEG-functionalized random copolymers derived from (R)- and (S)- families of alkyne polycarbodiimides
Authors: Kulikov Oleg V. , Siriwardane Dumindika A. , Budhathoki-Uprety Januka , McCandless Gregory T. , Mahmood Samsuddin F. , Novak Bruce M.
Published: May 2018

Macromolecular micelles: a hydrophobic polyamidine backbone surrounded by hydrophilic PEG chains.
The influence of NCE− (E = S, Se, BH3) ligands on the temperature of spin crossover in a family of iron(ii) mononuclear complexes
Authors: Fei Bin , Chen Xiu Qin , Cai You De , Fang Jing-Kun , Tong Ming Liang , Tucek Jiri , Bao Xin
Published: May 2018

The temperature of spin crossover was systematically tuned by replacing the NCE− (E = S, Se, BH3) co-ligands in a family of mononuclear complexes.
Controllable fabrication of bio-bar codes for dendritically amplified sensing of human T-lymphotropic viruses
Authors: Wang Li-juan , Ren Ming , Liang Li , Zhang Chun-yang
Published: May 2018

We demonstrate for the first time the controllable fabrication of bio-bar codes for dendritically amplified sensing of low-abundant HTLV-II DNA.
Mechanical properties of bulk graphene oxide/poly(acrylic acid)/poly(ethylenimine) ternary polyelectrolyte complex
Authors: Duan Yipin , Wang Chao , Zhao Mengmeng , Vogt Bryan D. , Zacharia Nicole S.
Published: May 2018

Ternary complexes formed in a single pot process through mixing of cationic (branched polyethylenimine, BPEI) and anionic (graphene oxide, GO, and poly(acrylic acid), PAA) aqueous solutions exhibit superior mechanical performance in comparison to binary analogs.
Adding refractory 5d transition metal W into PtCo system: an advanced ternary alloy for efficient oxygen reduction reaction
Authors: Wu Yijun , Zhao Yige , Liu Jingjun , Wang Feng
Published: May 2018

Schematic diagram of the Pt–Co–W catalyst with remarkably enhanced ORR activity compared to Pt/C catalysts.
Triple layered core–shell ZVI@carbon@polyaniline composite enhanced electron utilization in Cr(vi) reduction
Authors: Gong Kedong , Hu Qian , Xiao Yangyi , Cheng Xiang , Liu Hu , Wang Ning , Qiu Bin , Guo Zhanhu
Published: May 2018

PANI and carbon layers in the ZVI@C@PANI enhanced H+capture and electron utilization in the Cr(vi) reduction for an enhanced Cr(vi) removal performance.
Electronic transport properties of heterojunction devices constructed by single-wall Fe2Si and carbon nanotubes
Authors: Dai Xinyue , Zhang Lishu , Li Jie , Wang Zhichao , Li Hui
Published: May 2018

The electronic structures of the armchair Fe2Si nanotubes are calculated by using the SGGA+U method.
Estimation and compensation methods of time delay and phase offset in hybrid filter bank DACs
Authors: Yang Xing , Wang Houjun , Liu Ke
Published: May 2018

This Letter studies the non‐ideal analogue filters performance, time delay and phase offset in hybrid filter bank (HFB) DACs. After compensating the non‐ideal filters performance using a digital signal, a linear phase function containing time delay and phase was deduced based on the auto‐power spectrum of the HFB DAC output in the overlapped frequency band. ‘Three‐point’ method was used to simultaneously estimate these two errors by unwrapping the phase affected the principal value interval of the inverse trigonometric function. These two errors were compensated by the digital pre‐distortion technique. Finally, simulation results were provided to verify the effectiveness of this proposed method.
Multiphysics modelling approach to microwave heating of cerium oxide particles in diverse packing situations
Authors: Hammoud Hussein , Valdivieso François , Vaucher Sébastien
Published: May 2018

In this work, a single‐mode resonant microwave cavity (2.45 GHz) is loaded with spherical particles. A weakly coupled electromagnetic (EM)–thermal solver is used iteratively to determine how the microscopic geometry (local curvatures between the particles, grain size and neck size) modifies the EM field, and in turn the thermal field in the particles and also to quantify the microwave effect for an experimental process. The modelling is performed with the conformal finite element solver COMSOL Multiphysics. Moreover, this study will show that the electric field norm increases for one spherical particle of ceria with different sizes and consequently the temperature increases. In addition, the electric field and heating behaviour have been studied in the case of three particles with different neck sizes. Finally, the effect of the configuration versus the E‐field direction has been studied for three particles and has a significant result.
The XXL Survey
Authors: Guglielmo V. , Poggianti B. M. , Vulcani B. , Moretti A. , Fritz J. , Gastaldello F. , Adami C. , Caretta C. A. , Willis J. , Koulouridis E. , Ramos Ceja M. E. , Giles P. , Baldry I. , Birkinshaw M. , Bongiorno A. , Brown M. , Chiappetti L. , Driver S. , Elyiv A. , Evrard A. , Grootes M. , Guennou L. , Hopkins A. , Horellou C. , Iovino A. , Maurogordato S. , Owers M. , Pacaud F. , Paltani S. , Pierre M. , Plionis M. , Ponman T. , Robotham A. , Sadibekova T. , Smolčić V. , Tuffs R. , Vignali C.
Published: May 2018

Context. Superclusters form from the largest enhancements in the primordial density perturbation field and extend for tens of Mpc, tracing the large-scale structure of the Universe. X-ray detections and systematic characterisations of superclusters and the properties of their galaxies have only been possible in the last few years.

Aims. We characterise XLSSsC N01, a rich supercluster at z ~ 0.3 detected in the XXL Survey, composed of X-ray clusters of different virial masses and X-ray luminosities. As one of the first studies on this topic, we investigate the stellar populations of galaxies in different environments in the supercluster region.

Methods. We study a magnitude-limited (r ≤ 20) and a mass-limited sample (log(M*∕M⊙) ≥ 10.8) of galaxies in the virialised region and in the outskirts of 11 XLSSsC N01 clusters, in high-density field regions, and in the low-density field. We compute the stellar population properties of galaxies using spectral energy distribution (SED) and spectral fitting techniques, and study the dependence of star formation rates (SFR), colours, and stellar ages on environment.

Results. For r ≤ 20, the fraction of star-forming/blue galaxies, computed either from the specific-SFR (sSFR) or rest-frame colour, shows depletion within the cluster virial radii, where the number of galaxies with log (sSFR/ yr−1) > −12 and with (g − r)restframe < 0.6 is lower than in the field. For log(M*∕M⊙) ≥ 10.8, no trends with environment emerge, as massive galaxies are mostly already passive in all environments. No differences among low- and high-density field members and cluster members emerge in the sSFR-mass relation in the mass-complete regime. Finally, the luminosity-weighted age–mass relation of the passive populations within cluster virial radii show signatures of recent environmental quenching.

Conclusions. The study of luminous and massive galaxies in this supercluster shows that while environment has a prominent role in determining the fractions of star-forming/blue galaxies, its effects on the star formation activity in star-forming galaxies are negligible.
Deep secrets of intermediate-mass giants and supergiants
Authors: Smiljanic R. , Donati P. , Bragaglia A. , Lemasle B. , Romano D.
Published: May 2018

Context. Recent observational results have demonstrated an increase in the surface Na abundance that correlates with stellar mass for red giants between 2 and 3M⊙. This trend supports evolutionary mixing processes as the explanation for Na overabundances seen in some red giants. In this same mass range, the surface Al abundance was shown to be constant.

Aims. Our main aim was to extend the investigation of the Na and Al surface abundances to giants more massive than 3M⊙. We sought to establish accurately whether the Na abundances keep increasing with stellar mass or a plateau is reached. In addition, we investigated whether mixing can affect the surface abundance of Al in giants more massive than 3M⊙.

Methods. We obtained new high-resolution spectra of 20 giants in the field of 10 open clusters; 17 of these stars were found to be members of 9 clusters. The giants have masses between 2.5M⊙and 5.6M⊙. A model atmosphere analysis was performed and abundances of up to 22 elements were derived using equivalent widths. Additionally, abundances of C, N, and O were determined using spectrum synthesis. The abundances of Na and Al were corrected for non-local thermodynamic equilibrium (non-LTE) effects. Moreover, to extend the mass range of our sample, we collected from the literature high-quality C, N, O, and Na abundances of 32 Galactic Cepheids with accurate masses in the range between 3M⊙and 14M⊙.

Results. The surface abundances of C, N, O, Na, and Al were compared to predictions of stellar evolution models with and without the inclusion of rotation-induced mixing. The surface abundances of most giants and Cepheids of the sample can be explained by models without rotation. For giants above Ȉ2.5M⊙, the Na abundances reach a plateau level of about [Na/Fe] ~ 0.20–0.25 dex (in non-LTE). This is true for both Cepheids and giants in open clusters. Regarding Al, the non-LTE [Al/Fe] ratios are mostly close to solar and suggest that Al is not affected by the first dredge-up up to ~5.0M⊙. Our results support previous works that found models with rotation to overestimate the mixing effects in intermediate-mass stars.
The central velocity dispersion of the Milky Way bulge
Authors: Valenti E. , Zoccali M. , Mucciarelli A. , Gonzalez O. A. , Surot F. , Minniti D. , Rejkuba M. , Pasquini L. , Fiorentino G. , Bono G. , Rich R. M. , Soto M.
Published: May 2018

Context. Current spectroscopic and photometric surveys are providing a comprehensive view of the Milky Way bulge stellar population properties with unprecedented accuracy. This in turn allows us to explore the correlation between kinematics and stellar density distribution, crucial to constrain the models of Galactic bulge formation.

Aims. The Giraffe Inner Bulge Survey (GIBS) revealed the presence of a velocity dispersion peak in the central few degrees of the Galaxy by consistently measuring high velocity dispersion in the three central most fields. Due to the suboptimal distribution of these fields, all being at negative latitudes and close to each other, the shape and extension of the sigma peak is poorly constrained. In this study we address this by adding new observations distributed more uniformly and in particular including fields at positive latitudes that were missing in GIBS.

Methods. Observations with Multi Unit Spectroscopic Explorer (MUSE) were collected in four fields at (l, b) = (0°, +2°), (0°, −2°), (+1°, −1°), and (−1°, +2°). Individual stellar spectra were extracted for a number of stars comprised between ~500 and ~1200, depending on the seeing and the exposure time. Velocity measurements are done by cross-correlating observed stellar spectra in the CaT region with a synthetic template, and velocity errors are obtained through Monte Carlo simulations, cross-correlating synthetic spectra with a range of different metallicities and different noise characteristics.

Results. We measure the central velocity dispersion peak within a projected distance from the Galactic center of ~280 pc, reaching σVGC ~ 140 km s−1 at b = −1°. This is in agreement with the results obtained previously by GIBS at negative longitude. The central sigma peak is symmetric with respect to the Galactic plane, with a longitude extension at least as narrow as predicted by GIBS. As a result of the Monte Carlo simulations we present analytical equations for the radial velocity measurement error as a function of metallicity and signal-to-noise ratio for giant and dwarf stars.
Comparison of Constructive Interference in Steady-State and T1-Weighted MRI Sequence at Detecting Pituitary Adenomas in Cushing's Disease Patients
Authors: Lang Min , Habboub Ghaith , Moon Doksu , Bandyopadhyay Abin , Silva Danilo , Kennedy Laurence , Kshettry Varun , Recinos Pablo
Published: May 2018

Background T1-weighted magnetic resonance imaging (MRI) remains the standard pituitary imaging sequence. However, up to 50% of pituitary adenomas are missed with standard imaging in Cushing's disease (CD) patients. Utility of other imaging sequences needs be explored.

Objective To compare a T2-gradient echo sequence, constructive interference in steady state (CISS), with a contrast-enhanced (CE) T1-weighted sequence, volume-interpolated breath-hold examination (VIBE), in the detection of pituitary adenomas in CD patients.

Design Retrospective analysis of CD patients who underwent endoscopic transsphenoidal pituitary adenomectomy at our institution.

Patients and Measurement Twelve patients were included in the study. Two neuroradiologists, who were blinded to the patients' clinical and surgical findings, independently reviewed the CE-VIBE and CISS images. Localization of pituitary adenoma from imaging was compared with intraoperative localization.

Results The averaged sensitivity of detecting pituitary adenoma in CD patients was not significantly different between CE-VIBE sequence (63%) and CISS sequence (54%). The positive predictive value was 75% (Observer A) and 100% (Observer B) with CE-VIBE sequence, and 64% (Observer A) and 100% (Observer B) with CISS sequence. In two patients, pituitary adenoma was easily localized with CISS sequence but hard to detect with CE-VIBE sequence. In two other patients, the adenoma was much better delineated on CE-VIBE sequence.

Conclusion In our series, the addition of CISS sequence to T1-weighted MRI imaging protocols improved the detection of pituitary adenomas in CD patients. CISS sequence may be a useful adjunct to T1-weighted pituitary MRI protocols and an appropriate alternative for patients with gadolinium contraindications.
Risk Factors for Umbilical Cord Prolapse at the Time of Artificial Rupture of Membranes
Authors: Kawakita Tetsuya , Huang Chun-Chih , Landy Helain
Published: May 2018

Objective The aim of the study was to examine the association between cervical exam at the time of artificial rupture of membranes (AROM) and cord prolapse.

Study Design We conducted a retrospective cohort study using the data from the Consortium on Safe Labor. We included women with cephalic presentation and singleton pregnancies at ≥ 23 weeks' gestation who underwent AROM during the course of labor. Multivariable logistic regression was used to calculate the adjusted odds ratio (aOR) with 95% confidence interval (95% CI), controlling for prespecified covariates.

Results Of 57,204 women who underwent AROM, cord prolapse occurred in 113 (0.2%). Compared with dilation 6 to 10 cm + station ≥ 0 at the time of AROM, <6 cm + any station and 6–10 cm + station ≤ −3 were associated with increased risks of cord prolapse (<6 cm + station ≤ −3 [aOR, 2.29; 95% CI, 1.02–5.40]; <6 cm + station −2.5 to −0.5 [aOR, 2.34; 95% CI, 1.23–4.97]; <6 cm + station ≥ 0 [aOR, 3.31; 95% CI, 1.39–8.09]; and 6–10 cm + station ≤ −3 [aOR, 5.47; 95% CI, 1.35–17.48]).

Conclusion Cervical dilation < 6 cm with any station and 6 to 10 cm with station ≤ −3 were associated with a higher risk of cord prolapse.
An advanced robust method for speed control of switched reluctance motor
Authors: Zhang Chao , Ming Zhengfeng , Su Zhanping , Cai Zhuang
Published: May 2018

This paper presents an advanced robust controller for the speed system of a switched reluctance motor (SRM) in the presence of nonlinearities, speed ripple, and external disturbances. It proposes that the adaptive fuzzy control is applied to regulate the motor speed in the outer loop, and the detector is used to obtain rotor detection in the inner loop. The new fuzzy logic tuning rules are achieved from the experience of the operator and the knowledge of the specialist. The fuzzy parameters are automatically adjusted online according to the error and its change of speed in the transient period. The designed detector can obtain the rotor’s position accurately in each phase module. Furthermore, a series of contrastive simulations are completed between the proposed controller and proportion integration differentiation controller including low speed, medium speed, and high speed. Simulations show that the proposed robust controller enables the system reduced by at least 3% in overshoot, 6% in rise time, and 20% in setting time, respectively, and especially under external disturbances. Moreover, an actual SRM control system is constructed at 220 V 370 W. The experiment results further prove that the proposed robust controller has excellent dynamic performance and strong robustness.
Coalescence induced dislocation reduction in selectively grown lattice-mismatched heteroepitaxy: Theoretical prediction and experimental verification
Authors: Yako Motoki , Ishikawa Yasuhiko , Wada Kazumi
Published: May 2018

A method for reduction of threading dislocation density (TDD) in lattice-mismatched heteroepitaxy is proposed, and the reduction is experimentally verified for Ge on Si. Flat-top epitaxial layers are formed through coalescences of non-planar selectively grown epitaxial layers, and enable the TDD reduction in terms of image force. Numerical calculations and experiments for Ge on Si verify the TDD reduction by this method. The method should be applicable to not only Ge on Si but also other lattice-mismatched heteroepitaxy such as III-V on Si.
Separating light absorption layer from channel in ZnO vertical nanorod arrays based photodetectors for high-performance image sensors
Authors: Ma Yang , Wu Congjun , Xu Zhihao , Wang Fei , Wang Min
Published: May 2018

Photoconductor arrays with both high responsivity and large ON/OFF ratios are of great importance for the application of image sensors. Herein, a ZnO vertical nanorod array based photoconductor with a light absorption layer separated from the device channel has been designed, in which the photo-generated carriers along the axial ZnO nanorods drive to the external electrodes through nanorod-nanorod junctions in the dense layer at the bottom. This design allows us to enhance the photocurrent with unchanged dark current by increasing the ratio between the ZnO nanorod length and the thickness of the dense layer to achieve both high responsivity and large ON/OFF ratios. As a result, the as-fabricated devices possess a high responsivity of 1.3 × 105 A/W, a high ON/OFF ratio of 790, a high detectivity of 1.3 × 1013 Jones, and a low detectable light intensity of 1 μW/cm2. More importantly, the developed approach enables the integration of ZnO vertical nanorod array based photodetectors as image sensors with uniform device-to-device performance.