bluuebunny/crossref_metadata_2025 huggingface dataset:
Nuclear spin/parity dependent spectroscopy and predissociation dynamics in vOH = 2 ← 0 overtone excited Ne–H2O clusters: Theory and experiment
Authors: Ziemkiewicz Michael P. , Pluetzer Christian , Loreau Jérôme , van der Avoird Ad , Nesbitt David J.
Published: December 2017

Vibrationally state selective overtone spectroscopy and state- and nuclear spin-dependent predissociation dynamics of weakly bound ortho- and para-Ne–H2O complexes (D0(ortho) = 34.66 cm−1 and D0(para) = 31.67 cm−1) are reported, based on near-infrared excitation of van der Waals cluster bands correlating with vOH = 2 ← 0 overtone transitions (|02−〉 and |02+〉) out of the ortho (101) and para (000) internal rotor states of the H2O moiety. Quantum theoretical calculations for nuclear motion on a high level potential energy surface [CCSD(T)/VnZf12 (n = 3, 4)], corrected for basis set superposition error and extrapolated to the complete basis set (CBS) limit, are employed to successfully predict and assign Π–Σ, Σ–Σ, and Σ–Π infrared bands in the spectra, where Σ or Π represent approximate projections of the body-fixed H2O angular momentum along the Ne–H2O internuclear axis. IR-UV pump-probe experimental capabilities permit real-time measurements of the vibrational predissociation dynamics, which indicate facile intramolecular vibrational energy transfer from the H2O vOH = 2 overtone vibrations into the VdWs (van der Waals) dissociation coordinate on the τprediss = 15-25 ns time scale. Whereas all predicted strong transitions in the ortho-Ne–H2O complexes are readily detected and assigned, vibrationally mediated photolysis spectra for the corresponding para-Ne–H2O bands are surprisingly absent despite ab initio predictions of Q-branch intensities with S/N > 20-40. Such behavior signals the presence of highly selective nuclear spin ortho-para predissociation dynamics in the upper state, for which we offer a simple mechanism based on Ne-atom mediated intramolecular vibrational relaxation in the H2O subunit (i.e., |02±〉 → {|01±〉; v2 = 2}), which is confirmed by the ab initio energy level predictions and the nascent OH rotational (N), spin orbit (Π1/2,3/2), and lambda doublet product distributions.
Influence of temperature and wavelength on the switchable photovoltaic response of a BiFe0.95Mn0.05O3 thin film
Authors: Yousfi S. , Bouyanfif H. , El Marssi M.
Published: December 2017

The photovoltaic (PV) response of an epitaxial BiFe0.95Mn0.05O3 thin film grown using pulsed laser deposition has been investigated on a broad range of temperature. The wavelength dependent photovoltaic effect shows the contribution of the manganese doping and the presence of vacancies (Bi and O vacancies). The temperature dependent response of the PV response rules out electromigration and/or Schottky barriers as dominant mechanisms. This is corroborated with the observed switchable photovoltaic effect that can be explained either by the depolarizing field or by the bulk photovoltaic effect. In addition, the PV response shows a strong correlation with the low temperature polaronic-like conduction mechanism, and a high open circuit voltage (2.5 V) is detected in the investigated vertical capacitive geometry.
Thermal strain measurement of EAST tungsten divertor component with bare fiber Bragg grating sensors
Authors: Wang Xingli , Wang Wanjing , Wang Jichao , Wei Ran , Sun Zhaoxuan , Li Qiang , Xie Chunyi , Luo Guang-Nan
Published: December 2017

Fiber Bragg Gratings (FBGs) have been widely used in the sensor field to monitor temperature and strain. However, the weak mechanical property of optical fibers and insufficient heat-resistant property of general optic-fiber sensors have prevented it from being widely used, such as in some extreme engineering situations. In this work, a bare FBG sensor system had been introduced to measure thermal strain of an Experimental Advanced Superconducting Tokamak tungsten divertor component under baking condition. This strain measurement system had withstood as high temperature as 210 °C and finished the measurement experiment successfully. Meaningful measurement results had been obtained and analyzed, which showed the applicability of such a bare fiber grating sensor system and as well contributed to studying on tungsten divertor’s thermal strain conditions.
Trotter’s limit formula for the Schrödinger equation with singular potential
Authors: Nathanson Ekaterina S. , Jørgensen Palle E. T.
Published: December 2017

We discuss the Schrödinger equation with singular potentials. Our focus is non-relativistic Schrödinger operators H with scalar potentials V defined on Rd, hence covering such quantum systems as atoms, molecules, and subatomic particles whether free, bound, or localized. By a “singular potential” V, we refer to the case when the corresponding Schrödinger operators H, with their natural minimal domain in L2(Rd), are not essentially self-adjoint. Since V is assumed real valued, the corresponding Hermitian symmetric operator H commutes with the conjugation in L2(Rd), and so (by von Neumann’s theorem), H has deficiency indices (n, n). The case of singular potentials V refers to when n > 0. Hence, by von Neumann’s theory, we know the full variety of all the self-adjoint extensions. Since the Trotter formula is restricted to the case when n = 0, and here n > 0, two questions arise: (i) existence of the Trotter limit and (ii) the nature of this limit. We answer (i) affirmatively. Our answer to (ii) is that when n > 0, the Trotter limit is a strongly continuous contraction semigroup; so it is not time-reversible.
Metabolic versatility of a novel N2‐fixing Alphaproteobacterium isolated from a marine oxygen minimum zone
Authors: Martínez‐Pérez Clara , Mohr Wiebke , Schwedt Anne , Dürschlag Julia , Callbeck Cameron M. , Schunck Harald , Dekaezemacker Julien , Buckner Caroline R. T. , Lavik Gaute , Fuchs Bernhard M. , Kuypers Marcel M. M.
Published: December 2017

The N2‐fixing (diazotrophic) community in marine ecosystems is dominated by non‐cyanobacterial microorganisms. Yet, very little is known about their identity, function and ecological relevance due to a lack of cultured representatives. Here we report a novel heterotrophic diazotroph isolated from the oxygen minimum zone (OMZ) off Peru. The new species belongs to the genus Sagittula (Rhodobacteraceae, Alphaproteobacteria) and its capability to fix N2 was confirmed in laboratory experiments. Genome sequencing revealed that it is a strict heterotroph with a high versatility in substrate utilization and energy acquisition mechanisms. Pathways for sulfide oxidation and nitrite reduction to nitrous oxide are encoded in the genome and might explain the presence throughout the Peruvian OMZ. The genome further indicates that this novel organism could be in direct interaction with other microbes or particles. NanoSIMS analyses were used to compare the metabolic potential of S. castanea with single‐cell activity in situ; however, N2 fixation by this diazotroph could not be detected at the isolation site. While the biogeochemical impact of S. castanea is yet to be resolved, its abundance and widespread distribution suggests that its potential to contribute to the marine N input could be significant at a larger geographical scale.
Perioperative albumin ratio is associated with post‐operative pancreatic fistula
Authors: Gruppo Mario , Angriman Imerio , Martella Bruno , Spolverato Ylenia C. , Zingales Francesca , Bardini Romeo
Published: December 2017

Background

Despite improvements in surgical techniques and perioperative management, post‐operative pancreatic fistula (POPF) remains a serious complication after pancreaticoduodenectomy (PD). The aim of this study was to evaluate the role of perioperative clinical variables of patients, including albumin level, in predicting pancreatic fistula.

Methods

A total of 86 patients underwent PD for pancreas cancer between 2011 and 2017 at our institution. We prospectively investigated the relation between patient's characteristics and the incidence of clinically relevant (CR)‐POPF. Perioperative albumin ratio was defined as post‐operative day 1 (POD1) albumin level/preoperative albumin level.

Results

A total of 23 patients (26.7%) developed CR‐POPF. At univariate analysis POPF correlated with soft pancreas (P = 0.045), low POD1 albumin (P = 0.02), POD1 and POD3 amylase levels in drainage fluid (P = 0.003 and P = 0.014, respectively) and perioperative albumin ratio (0.58 ± 0.10 versus 0.69 ± 0.12 in patients without POPF; P = 0.003). No significant correlations with POPF were demonstrated for surgical time, serum amylase levels and preoperative albumin levels. At multivariate analysis POD3 amylase level in drainage fluid and perioperative albumin ratio were the only significant independent parameters (P = 0.027 and P = 0.047, respectively).

Conclusions

Perioperative albumin ratio can predict POPF after PD.
Factors influencing lymph node skip metastasis in colorectal cancer: a retrospective study
Authors: Bao Feng , Deng Zhi‐gang , Wang Dong , Xian‐yu Jian‐bo , Li Guo‐qiang , Xiang Chun‐hua , Xiang Rong‐chao , Zhi Xing
Published: December 2017

Background

The risk factors for lymph node skip metastasis (LNSM) have not been thoroughly clarified in patients with advanced colorectal cancer (CRC). This study aimed to identify the risk factors for LNSM in CRC patients who underwent laparoscopic radical resection with D3 lymphadenectomy.

Methods

This retrospective cohort study included a total of 167 consecutive patients who underwent laparoscopic radical resection with D3 lymphadenectomy for CRC between April 2005 and June 2017. The patients were sorted into the LNSM‐positive (skip+ group) and LNSM‐negative (skip− group) groups. Logistic regression was used to identify the risk factors for LNSM.

Results

Compared with the skip− group, the frequency of tumour size <5 cm, pT1‐2 stage, and pN1 stage were significantly higher in the skip+ group (tumour size <5 cm: 68.8 versus 46.7%, P = 0.025; pT1‐2 stage: 18.8 versus 4.4%, P = 0.012; pN1 stage: 78.1 versus 57.0%, P = 0.028), respectively. Multivariate logistic regression analysis revealed that pT1‐2 stage (odds ratio (OR) = 4.3, 95% confidence interval (CI): 1.1–16.6, P = 0.034) and pN1 stage (OR = 2.6, 95% CI: 1.1–6.8, P = 0.047) were independent risk factors for LNSM.

Conclusions

pT1‐2 stage and pN1 stage are significantly associated with LNSM. Radical D3 lymphadenectomy should remain standard practice for CRC.
Clinical pathway improves implementation of evidence‐based strategies for the management of androgen deprivation therapy‐induced side effects in men with prostate cancer
Authors: Bultijnck Renée , Van de Caveye Inge , Rammant Elke , Everaert Sofie , Lumen Nicolaas , Decaestecker Karel , Fonteyne Valérie , Deforche Benedicte , Ost Piet
Published: December 2017

Objectives

To assess the effects of a prostate cancer (PCa) clinical pathway on the implementation of evidence‐based strategies for the management of androgen deprivation therapy (ADT)‐induced side effects.

Patients and Methods

A clinical pathway was introduced at hospital level in 2015. The pathway consists of evidence‐based strategies for the management ofADT‐induced side effects. All patients withPCa receivingADTfor >6 months were eligible to enter the clinical pathway. Data on recommended evidence‐based strategies were retrospectively extracted from the electronic health records of all eligible patients in the year before (2014) and the year of implementation of the pathway (2015). Descriptive statistics were used for patient characteristics. The chi‐squared test (or Fisher's exact test) and Mann–WhitneyU‐test were used to compare results in the control group with those in the intervention group.

Results

In total, 126 patients were included in the control group and 132 patients in the intervention group. Baseline patient characteristics were well balanced. After implementation of the pathway, metabolic, bone and cardiac risk assessment screenings were more frequently applied in the intervention group (metabolic 46% vs 4%; bone 58% vs 10%; cardiac 61% vs 16%;P< 0.001). Advice on strategies preventingADT‐induced side effects was more frequently provided in the intervention group (exercise 62% vs 11%; nutrition 58% vs 10%; psycho‐education 54% vs 13%;P< 0.001).

Conclusion

A clinical pathway for patients withPCa improved the implementation of evidence‐based strategies for the management ofADT‐induced side effects. A clinical pathway could serve as a method to bridge the gap between evidence‐based guidelines and daily clinical practice.
Downregulation of lncRNA CASC2 facilitates osteosarcoma growth and invasion through miR‐181a
Authors: Ba Zhiwen , Gu Lili , Hao Songnan , Wang Xiaofang , Cheng Zhenping , Nie Guangchen
Published: December 2017

Objectives

Long non‐coding RNA cancer susceptibility candidate 2 (CASC2) is a novel lncRNA and has been indicated as playing tumour suppressor gene in several tumours. However, the role of CASC2 in osteosarcoma is still uncovered.

Materials and methods

The CASC2 and miR‐181a expressions were measured via qRT‐PCR. CCK‐8 assay and colony formation assay were performed to determine the cell growth, and transwell assay was performed to assess the cell invasion.

Results

We showed that CASC2 expression was downregulated in osteosarcoma samples and cell lines. Moreover, we showed that downregulated expression of CASC2 was correlated with advanced TNM stage. Furthermore, overexpression of CASC2 inhibited osteosarcoma cell proliferation, colony formation, and invasion. In addition, we indicated that ectopic expression of CASC2 suppressed miR‐181a expression and enhanced the expression of Ras association domain family member 6 (RASSF6), PTEN and ATM in osteosarcoma cell, which were the direct target gene of miR‐181a. Moreover, we indicated that RASSF6 expression was downregulated in osteosarcoma samples and cell lines and downregulated expression of RASSF6 was correlated with advanced TNM stage. We found that the expression of RASSF6 was positively correlated with the expression of CASC2 in osteosarcoma tissues. Ectopic expression of CASC2 suppressed the osteosarcoma cell proliferation, colony formation and invasion through regulating RASSF6 expression.

Conclusions

Our data illuminated that CASC2 acted as a tumour suppressor in osteosarcoma progression.
Current clinical algorithms for predicting common bile duct stones have only moderate accuracy
Authors: Ebrahim Mohamed , Sorensen Lars T. , Jorgensen Lars N. , Kalaitzakis Evangelos
Published: December 2017

Background and Aim

A risk‐stratified approach for selecting patients likely to harbor common bile duct (CBD) stones to proceed directly to endoscopic or surgical stone clearance, rather than undergo less invasive testing, has been proposed. We assessed the performance of three clinical algorithms used to predict CBD stones.

Methods

All patients undergoing first‐time endoscopic retrograde cholangiopancreatography (ERCP) in 2011–2012 as a result of suspected CBD stones were enrolled prospectively in a clinical database. Data such as imaging test findings and liver function tests (LFTs) were collected 48 h prior to and on the day of ERCP. Patients were stratified into different risk groups for harboring CBD stones according to three clinical algorithms using imaging and laboratory data. Findings on ERCP were used as gold standard. Performance characteristics of each algorithm were separately calculated for each time point of LFT assessment.

Results

Overall, 186 patients were analyzed, 75% of whom presented CBD stones on ERCP. Proportion of patients categorized as high‐risk for harboring CBD stones varied among the three algorithms (67% vs 73% vs 56%). Also, the algorithms showed only moderate, albeit comparable, accuracy for predicting the presence of CBD stones (0.65, 95% confidence interval [CI] 0.62–0.68 vs 0.68, 95% CI 0.63–0.67 vs 0.59, 95% CI 0.57–0.61). Similar results were obtained when performance characteristics were recalculated using LFT from 48 h prior to ERCP (data not shown).

Conclusion

Three diagnostic algorithms commonly used for predicting CBD stones have comparable but only moderate accuracy. Further research is warranted to improve risk stratification of patients with suspected CBD stones.
High‐performance serial block‐face SEM of nonconductive biological samples enabled by focal gas injection‐based charge compensation
Authors: DEERINCK T.J. , SHONE T.M. , BUSHONG E.A. , RAMACHANDRA R. , PELTIER S.T. , ELLISMAN M.H.
Published: December 2017

A longstanding limitation of imaging with serial block‐face scanning electron microscopy is specimen surface charging. This charging is largely due to the difficulties in making biological specimens and the resins in which they are embedded sufficiently conductive. Local accumulation of charge on the specimen surface can result in poor image quality and distortions. Even minor charging can lead to misalignments between sequential images of the block‐face due to image jitter. Typically, variable‐pressure SEM is used to reduce specimen charging, but this results in a significant reduction to spatial resolution, signal‐to‐noise ratio and overall image quality. Here we show the development and application of a simple system that effectively mitigates specimen charging by using focal gas injection of nitrogen over the sample block‐face during imaging. A standard gas injection valve is paired with a precisely positioned but retractable application nozzle, which is mechanically coupled to the reciprocating action of the serial block‐face ultramicrotome. This system enables the application of nitrogen gas precisely over the block‐face during imaging while allowing the specimen chamber to be maintained under high vacuum to maximise achievable SEM image resolution. The action of the ultramicrotome drives the nozzle retraction, automatically moving it away from the specimen area during the cutting cycle of the knife. The device described was added to a Gatan 3View system with minimal modifications, allowing high‐resolution block‐face imaging of even the most charge prone of epoxy‐embedded biological samples.
Ceratocorys mariaovidiorum sp. nov. (Gonyaulacales), a new dinoflagellate species previously reported as Protoceratium reticulatum
Authors: Salgado Pablo , Fraga Santiago , Rodríguez Francisco , Riobó Pilar , Bravo Isabel
Published: December 2017

The family Ceratocoryaceae includes the genera Ceratocorys, Protoceratium, and Schuettiella, whose phylogenetic relationships are poorly known. Here, the new non‐yessotoxin‐producing species of the genus Ceratocorys, Ceratocorys mariaovidiorum sp. nov., previously reported as the toxic Protoceratium reticulatum, is described from examinations by light and scanning electron microscopy, molecular phylogeny, and toxin analyses. The species description is made from culture samples of strains CCMP1740 and CCMP404 from USA waters. Ceratocorys mariaovidiorum is globular and has thick and strongly reticulated plates with one pore within each reticule, just like P. reticulatum, but the key difference between the two species is the presence of five precingular plates in C. mariaovidiorum instead of six as in P. reticulatum. The thecal plate formula is Po, 4′, 0a, 5″, 6c, ~7s, 5‴, 0p, 2′′′′. The apical pore plate is oval with a λ‐shaped pore. The first apical plate is narrow with a ventral pore on the right anterior side; it contacts the apical pore plate and its contact with the anterior sulcal plate is slight or absent. The fourth precingular plate of other Gonyaulacales is absent. Ceratocorys mariaovidiorum may have small spines on the second antapical plate. A phylogenetic study based on internal transcribed spacer/5.8SrDNA supports the morphological classification of C. mariaovidiorum as a new species of Ceratocorys and in a different clade from P. reticulatum.
The Regulatory Role of the Oral Commensal Streptococcus mitis on Human Monocytes
Authors: Engen S. A. , Schreurs O. , Petersen F. , Blix I. J. S. , Bækkevold E. S. , Schenck K.
Published: December 2017

Streptococcus mitis colonizes all niches of the human oral cavity from early infancy and throughout life. Monocytes patrol blood vessels, lymphoid and non‐lymphoid tissues and migrate into infected tissue where they participate in the inflammatory cascade and immune regulation. Here, we studied the effect of S. mitis on monocytes. Transcriptome analysis of monocytes exposed to S. mitis (SmMo) revealed increased transcription of chemotactic factors (CCL2, CCL3, CCL20, CXCL1, CXCL2) and cytokines (IL1A, IL1B, IL6, IL23, IL36G, TNF), indicating that S. mitis may trigger recruitment of leucocytes and initiate inflammation. Increased transcription in SmMo of IL1B, IL6 and IL23 indicated that S. mitis may participate in the induction of Th17 responses and agreed with our earlier findings of S. mitis‐mediated memory Th17 reactivity. Furthermore, S. mitis inhibited tetanus toxoid‐specific CD4 T cell proliferation. This can be due to the increased secretion of IL‐10 and expression of PD‐L1 that was observed in SmMo. PGE2 can modulate IL‐10 and PD‐L1 expression, concomitant with that of CCR7, IL‐12 and IL‐23 that also were changed. This, along with increased SmMo transcription of PTGS2 (COX2) and PTGER4 (EP4), pointed to a role of PGE2. Measurement of PGE2 secretion by SmMo showed indeed a marked increase, and chemical inhibition of PGE2 production lowered the PD‐L1 expression on SmMo. In conclusion, our findings show that S. mitis may trigger immune modulation by recruiting immune cells to the site of infection, while at the same time dampening the severity of the response through expression of IL‐10, PGE2 and PD‐L1.
3,6-Dichlorosalicylate Catabolism Is Initiated by the DsmABC Cytochrome P450 Monooxygenase System in Rhizorhabdus dicambivorans Ndbn-20
Authors: Li Na , Yao Li , He Qin , Qiu Jiguo , Cheng Dan , Ding Derong , Tao Qing , He Jian , Jiang Jiandong
Published: December 2017

The degradation of the herbicide dicamba is initiated by demethylation to form 3,6-dichlorosalicylate (3,6-DCSA) in
Rhizorhabdus
dicambivorans
Ndbn-20. In the present study, a 3,6-DCSA degradation-deficient mutant, Ndbn-20m, was screened. A cluster,
dsmR1DABCEFGR2
, was lost in this mutant. The cluster consisted of nine genes, all of which were apparently induced by 3,6-DCSA. DsmA shared 30 to 36% identity with the monooxygenase components of reported three-component cytochrome P450 systems and formed a monophyletic branch in the phylogenetic tree. DsmB and DsmC were most closely related to the reported [2Fe-2S] ferredoxin and ferredoxin reductase, respectively. The disruption of
dsmA
in strain Ndbn-20 resulted in inactive 3,6-DCSA degradation. When
dsmABC
, but not
dsmA
alone, was introduced into mutant Ndbn-20m and
Sphingobium quisquiliarum
DC-2 (which is unable to degrade salicylate and its derivatives), they acquired the ability to hydroxylate 3,6-DCSA. Single-crystal X-ray diffraction demonstrated that the DsmABC-catalyzed hydroxylation occurred at the C-5 position of 3,6-DCSA, generating 3,6-dichlorogentisate (3,6-DCGA). In addition, DsmD shared 51% identity with GtdA (a gentisate and 3,6-DCGA 1,2-dioxygenase) from
Sphingomonas
sp. strain RW5. However, unlike GtdA, the purified DsmD catalyzed the cleavage of gentisate and 3-chlorogentisate but not 6-chlorogentisate or 3,6-DCGA
in vitro
. Based on the bioinformatic analysis and gene function studies, a possible catabolic pathway of dicamba in
R. dicambivorans
Ndbn-20 was proposed.

IMPORTANCE
Dicamba is widely used to control a variety of broadleaf weeds and is a promising target herbicide for the engineering of herbicide-resistant crops. The catabolism of dicamba has thus received increasing attention. Bacteria mineralize dicamba initially via demethylation, generating 3,6-dichlorosalicylate. However, the catabolism of 3,6-dichlorosalicylate remains unknown. In this study, we cloned a gene cluster,
dsmR1DABCEFGR2
, involved in 3,6-dichlorosalicylate degradation from
R. dicambivorans
Ndbn-20, demonstrated that the cytochrome P450 monooxygenase system DsmABC was responsible for the 5-hydroxylation of 3,6-dichlorosalicylate, and proposed a dicamba catabolic pathway. This study provides a basis to elucidate the catabolism of dicamba and has benefits for the ecotoxicological study of dicamba. Furthermore, the hydroxylation of salicylate has been previously reported to be catalyzed by single-component flavoprotein or three-component Rieske non-heme iron oxygenase, whereas DsmABC was the only cytochrome P450 monooxygenase system hydroxylating salicylate and its methyl- or chloro-substituted derivatives.
UTILIZAÇÃO DE RAIOS X NA AVALIAÇÃO DA MORFOLOGIA INTERNA DE SEMENTES DE SORGO
Authors: JAVORSKI MAICON , CICERO SILVIO MOURE
Published: December 2017

A utilização de raios X em sementes constitui-se em uma técnica eficiente na avaliação da morfologia interna de sementes de diversas espécies; trata-se de um método rápido, preciso e não destrutivo. Assim, a presente pesquisa teve o objetivo avaliar a morfologia interna das sementes de sorgo, por meio de raios X, e relacioná-la com a germinação. Para tanto foram utilizadas sementes do híbrido 50A70, representado por dez lotes. As sementes radiografadas foram submetidas ao teste de germinação de modo a relacionar a morfologia interna das sementes com as respectivas plântulas normais, anormais ou sementes mortas. Concluiu-se que o teste de raios X é eficiente na identificação de danos por deterioração de tecidos, danos mecânicos, danos por malformação e danos por insetos, possibilitando estabelecer a relação entre o dano observado e o prejuízo causado para a germinação.
Observational Study of an Unusual Cataclysmic Binary 2MASS J16211735+4412541*
Authors: Zola S. , Szkody P. , Ciprini S. , Verrecchia F. , Debski B. , Ogloza W. , Drozdz M. , Reichart D. , Caton D. B. , Hoette V. L.
Published: December 2017

We present results from an observational campaign on the close binary system 2MASS J16211735+4412541 and a preliminary model based on the photometric data gathered during the quiescent and outburst levels. The modeling, done with the Wilson–Devinney code and its improvements, failed to reproduce the observational properties of the system. A secondary minimum obtained within the stellar model that is too shallow, as well as the evidence provided by the spectroscopic observations performed at outburst and quiescence, point toward an accretion disk surrounding one component, likely a white dwarf, as the cause of the outburst. Using a simple disk model, we modeled the observed multicolor light curves taken two (2016 August) and eight (2017 March) months after the outburst. We obtained a reasonable fit to the 2016 August light curves but those from 2017 March cannot be explained with the same parameters. We conclude that J1621 is an eclipsing cataclysmic binary, with an accretion disk still present almost a year after outburst, and not a contact-type system as previously classified. The binary is seen at an inclination of about 84° and there is evidence of changing accretion rates and disk parameters as a result of the outburst. Our results indicate that more cataclysmic variables may be hidden among contact binaries.
Understanding the Links among the Magnetic Fields, Filament, Bipolar Bubble, and Star Formation in RCW 57A Using NIR Polarimetry
Authors: Eswaraiah Chakali , Lai Shih-Ping , Chen Wen-Ping , Pandey A. K. , Tamura M. , Maheswar G. , Sharma S. , Wang Jia-Wei , Nishiyama S. , Nakajima Y. , Kwon Jungmi , Purcell R. , Magalhães A. M.
Published: December 2017

The influence of magnetic fields (B-fields) on the formation and evolution of bipolar bubbles, due to the expanding ionization fronts (I-fronts) driven by the H ii regions that are formed and embedded in filamentary molecular clouds, has not been well-studied yet. In addition to the anisotropic expansion of I-fronts into a filament, B-fields are expected to introduce an additional anisotropic pressure, which might favor the expansion and propagation of I-fronts forming a bipolar bubble. We present results based on near-infrared polarimetric observations toward the central ∼8′ × 8′ area of the star-forming region RCW 57A, which hosts an H ii region, a filament, and a bipolar bubble. Polarization measurements of 178 reddened background stars, out of the 919 detected sources in the JHK

s
bands, reveal B-fields that thread perpendicularly to the filament long axis. The B-fields exhibit an hourglass morphology that closely follows the structure of the bipolar bubble. The mean B-field strength, estimated using the Chandrasekhar–Fermi method (CF method), is 91 ± 8 μG. B-field pressure dominates over turbulent and thermal pressures. Thermal pressure might act in the same orientation as the B-fields to accelerate the expansion of those I-fronts. The observed morphological correspondence among the B-fields, filament, and bipolar bubble demonstrate that the B-fields are important to the cloud contraction that formed the filament, to the gravitational collapse and star formation in it, and in feedback processes. The last one includes the formation and evolution of mid-infrared bubbles by means of B-field supported propagation and expansion of I-fronts. These may shed light on preexisting conditions favoring the formation of the massive stellar cluster in RCW 57A.
Deep HST Imaging in 47 Tucanae: A Global Dynamical Model
Authors: Heyl J. , Caiazzo I. , Richer H. , Anderson J. , Kalirai J. , Parada J.
Published: December 2017

Multi-epoch observations with the Advanced Camera Survey and WFC3 on the Hubble Space Telescope provide a unique and comprehensive probe of stellar dynamics within 47 Tucanae. We confront analytic models of the globular cluster with the observed stellar proper motions that probe along the main sequence from just above 0.8–0.1M
⊙ as well as white dwarfs younger than 1 Gyr. One field lies just beyond the half-light radius where dynamical models (e.g., lowered Maxwellian distributions) make robust predictions for the stellar proper motions. The observed proper motions in this outer field show evidence for anisotropy in the velocity distribution as well as skewness; the latter is evidence of rotation. The measured velocity dispersions and surface brightness distributions agree in detail with a rotating anisotropic model of the stellar distribution function with mild dependence of the proper-motion dispersion on mass. However, the best-fitting models underpredict the rotation and skewness of the stellar velocities. In the second field, centered on the core of the cluster, the mass segregation in proper motion is much stronger. Nevertheless the model developed in the outer field can be extended inward by taking this mass segregation into account in a heuristic fashion. The proper motions of the main-sequence stars yield a mass estimate of the cluster of

at a distance of 4.7 kpc. By comparing the proper motions of a sample of giant and subgiant stars with the observed radial velocities we estimate the distance to the cluster kinematically to be 4.29 ± 0.47 kpc.
Systematic Analysis of the Effects of Mode Conversion on Thermal Radiation from Neutron Stars
Authors: Yatabe Akihiro , Yamada Shoichi
Published: December 2017

In this paper, we systematically calculate the polarization in soft X-rays emitted from magnetized neutron stars, which are expected to be observed by next-generation X-ray satellites. Magnetars are one of the targets for these observations. This is because thermal radiation is normally observed in the soft X-ray band, and it is thought to be linearly polarized because of different opacities for two polarization modes of photons in the magnetized atmosphere of neutron stars and the dielectric properties of the vacuum in strong magnetic fields. In their study, Taverna et al. illustrated how strong magnetic fields influence the behavior of the polarization observables for radiation propagating in vacuo without addressing a precise, physical emission model. In this paper, we pay attention to the conversion of photon polarization modes that can occur in the presence of an atmospheric layer above the neutron star surface, computing the polarization angle and fraction and systematically changing the magnetic field strength, radii of the emission region, temperature, mass, and radii of the neutron stars. We confirmed that if plasma is present, the effects of mode conversion cannot be neglected when the magnetic field is relatively weak,

.  Our results indicate that strongly magnetized (

) neutron stars are suitable to detect polarizations, but not-so-strongly magnetized (

) neutron stars will be the ones to confirm the mode conversion.
3‐D Modeling of Irregular Volcanic Sources Using Sparsity‐Promoting Inversions of Geodetic Data and Boundary Element Method
Authors: Zhai Guang , Shirzaei Manoochehr
Published: December 2017

Geodetic observations of surface deformation associated with volcanic activities can be used to constrain volcanic source parameters and their kinematics. Simple analytical models, such as point and spherical sources, are widely used to model deformation data. The inherent nature of oversimplified model geometries makes them unable to explain fine details of surface deformation. Current nonparametric, geometry‐free inversion approaches resolve the distributed volume change, assuming it varies smoothly in space, which may detect artificial volume change outside magmatic source regions. To obtain a physically meaningful representation of an irregular volcanic source, we devise a new sparsity‐promoting modeling scheme assuming active magma bodies are well‐localized melt accumulations, namely, outliers in the background crust. First, surface deformation data are inverted using a hybridL1‐ andL2‐norm regularization scheme to solve for sparse volume change distributions. Next, a boundary element method is implemented to solve for the displacement discontinuity distribution of the reservoir, which satisfies a uniform pressure boundary condition. The inversion approach is thoroughly validated using benchmark and synthetic tests, of which the results show that source dimension, depth, and shape can be recovered appropriately. We apply this modeling scheme to deformation observed at Kilauea summit for periods of uplift and subsidence leading to and following the 2007 Father's Day event. We find that the magmatic source geometries for these periods are statistically distinct, which may be an indicator that magma is released from isolated compartments due to large differential pressure leading to the rift intrusion.
Evaluation of the Runoff and River Routing Schemes in the Community Land Model of the Yellow River Basin
Authors: Sheng Mingyang , Lei Huimin , Jiao Yang , Yang Dawen
Published: December 2017

Runoff and river routing schemes play important roles in land surface models (LSMs) because they regulate the soil moisture, heat flux, and vegetation dynamics of land surface processes and account for the carbon and nutrient transport in river channels. However, these schemes are often simplistic and conceptual. Hence, in this study, we focused on (1) evaluating these schemes in the Community Land Model (CLM) and (2) altering the model representations using physically based schemes based on a study of the Yellow River basin. For runoff simulation, CLM exhibits limitations in water‐limited areas, especially areas with aridity index values greater than 2. Additionally, CLM greatly overestimates runoff, and produces negative Nash‐Sutcliffe efficiency (NSE) coefficients, few quick flow variations, high quick flow index values, and large root mean square errors of total water storage. These issues were greatly improved by implementing schemes of physically based overland flow, lateral soil water flow, and interchange between groundwater and river water. Furthermore, for the river routing scheme, the use of 1‐D kinematic wave routing improved previously unrealistic aspects of the flood hydrographs (e.g., incorrect flood peak values and times) of the original CLM. Moreover, compared with using the grid element‐based river routing approach in CLM, the computational costs were reduced by up to 45% by implementing the flow interval element method. Finally, our results indicate that parameter calibration in CLM minimally improved the simulation performance in water‐limited areas, while physically based schemes generated better results.
Characterization of Moist Processes Associated With Changes in the Propagation of the MJO With Increasing CO2
Authors: Adames Ángel F. , Kim Daehyun , Sobel Adam H. , Del Genio Anthony , Wu Jingbo
Published: December 2017

The processes that lead to changes in the propagation and maintenance of the Madden‐Julian Oscillation (MJO) as a response to increasing CO2are examined by analyzing moist static energy budget of the MJO in a series of NASA GISS model simulations. It is found changes in MJO propagation is dominated by several key processes. Horizontal moisture advection, a key process for MJO propagation, is found to enhance predominantly due to an increase in the mean horizontal moisture gradients. The terms that determine the strength of the advecting wind anomalies, the MJO horizontal scale and the dry static stability, are found to exhibit opposing trends that largely cancel out. Furthermore, reduced sensitivity of precipitation to changes in column moisture, i.e., a lengthening in the convective moisture adjustment time scale, also opposes enhanced propagation. The dispersion relationship of Adames and Kim, which accounts for all these processes, predicts an acceleration of the MJO at a rate of ∼3.5% K−1, which is consistent with the actual phase speed changes in the simulation. For the processes that contribute to MJO maintenance, it is found that damping by vertical MSE advection is reduced due to the increasing vertical moisture gradient. This weaker damping is nearly canceled by weaker maintenance by cloud‐radiative feedbacks, yielding the growth rate from the linear moisture mode theory nearly unchanged with the warming. Furthermore, the estimated growth rates are found to be a small, negative values, suggesting that the MJO in the simulation is a weakly damped mode.
Comparison of a new nanoform of the photosensitizer chlorin e6, based on plant phospholipids, with its free form
Authors: Kostryukova Lyubov V. , Prozorovskiy Vladimir N. , Medvedeva Natalya V. , Ipatova Olga M.
Published: December 2017

Photodynamic therapy is an advanced method of treating cancer and various benign diseases, including infections. It uses light‐activated molecules [photosensitizers (PSs)] to generate reactive oxygen species (ROS) when irradiated with light of a specific wavelength. This study examined the photophysical and photosensitizing activity of the PS chlorin e6 incorporated in a delivery system based on plant phospholipids. This new nanoform of chlorin e6 comprised particles with a diameter of 18.4 ± 2.5 nm and zeta potential of −34.6 ± 3.0 mV. Incorporation of chlorin e6 in phospholipid nanoparticles was observed to cause a bathochromic shift of Q‐band absorption maximum by 14 nm without an absorption change in the range of the Soret band. Fluorescence intensity of chlorin e6 embedded in the phospholipid nanoparticles increased 1.7‐fold. Chlorin e6 in phospholipid nanoparticles, when irradiated, was able to generate ROS as shown by oxidation of polyunsaturated fatty acids of the phospholipid matrix of the delivery system and reduced l‐glutathione. In vivo it was demonstrated that the new nanoform of chlorin e6 provides more accumulation of PSs in tumor tissue than its free form. Moreover, its accumulation in the skin was lower and its elimination from the skin almost five times faster than when administered in free form. The observed differences of this new nanoform of chlorin e6 should lead to enhancement of antitumor efficacy and a decrease in phototoxicity.
Synaptic Suppression Triplet‐STDP Learning Rule Realized in Second‐Order Memristors
Authors: Yang Rui , Huang He‐Ming , Hong Qing‐Hui , Yin Xue‐Bing , Tan Zheng‐Hua , Shi Tuo , Zhou Ya‐Xiong , Miao Xiang‐Shui , Wang Xiao‐Ping , Mi Shao‐Bo , Jia Chun‐Lin , Guo Xin
Published: December 2017

The synaptic weight modification depends not only on interval of the pre‐/postspike pairs according to spike‐timing dependent plasticity (classical pair‐STDP), but also on the timing of the preceding spike (triplet‐STDP). Triplet‐STDP reflects the unavoidable interaction of spike pairs in natural spike trains through the short‐term suppression effect of preceding spikes. Second‐order memristors with one state variable possessing short‐term dynamics work in a way similar to the biological system. In this work, the suppression triplet‐STDP learning rule is faithfully demonstrated by experiments and simulations using second‐order memristors. Furthermore, a leaky‐integrate‐and‐fire (LIF) neuron is simulated using a circuit constructed with second‐order memristors. Taking the advantage of the LIF neuron, various neuromimetic dynamic processes, including local graded potential leaking out, postsynaptic impulse generation and backpropagation, and synaptic weight modification according to the suppression triplet‐STDP rule, are realized. The realized weight‐dependent pair‐ and triplet‐STDP rules are clearly in line with findings in biology. The physically realized triplet‐STDP rule is powerful in developing direction and speed selectivity for complex pattern recognition and tracking tasks. These scalable artificial synapses and neurons realized in second‐order memristors can intrinsically capture the neuromimetic dynamic processes; they are the promising building blocks for constructing brain‐inspired computation systems.
Electrochemically Inert g‐C3N4 Promotes Water Oxidation Catalysis
Authors: Chen Yaping , Zhou Qian , Zhao Guoqiang , Yu Zhenwei , Wang Xiaolin , Dou Shi Xue , Sun Wenping
Published: December 2017

Electrode surface wettability is critically important for heterogeneous electrochemical reactions taking place in aqueous and nonaqueous media. Herein, electrochemically inert g‐C3N4 (GCN) is successfully demonstrated to significantly enhance water oxidation by constructing a superhydrophilic catalyst surface and promoting substantial exposure of active sites. As a proof‐of‐concept application, superhydrophilic GCN/Ni(OH)2 (GCNN) hybrids with monodispersed Ni(OH)2 nanoplates strongly anchored on GCN are synthesized for enhanced water oxidation catalysis. Owing to the superhydrophilicity of functionalized GCN, the surface wettability of GCNN (contact angle 0°) is substantially improved as compared with bare Ni(OH)2 (contact angle 21°). Besides, GCN nanosheets can effectively suppress Ni(OH)2 aggregation to help expose more active sites. Benefiting from the well‐defined catalyst surface, the optimal GCNN hybrid shows significantly enhanced electrochemical performance over bare Ni(OH)2 nanosheets, although GCN is electrochemically inert. In addition, similar catalytic performance promotion resulting from wettability improvement induced by incorporation of hydrophilic GCN is also successfully demonstrated on Co(OH)2. The present results demonstrate that, in addition to developing new catalysts, building efficient surface chemistry is also vital to achieve extraordinary water oxidation performance.
Tuning Electrical Properties of 2D Materials by Self‐Assembled Monolayers
Authors: Lee Wi Hyoung , Park Yeong Don
Published: December 2017

Tuning of electrical properties of 2D materials by self‐assembled monolayers (SAMs) is reviewed in this article. When 2D materials such as graphene and transition metal dichalcogenides (TMDs) are in contact with SAMs, end functional group in SAMs governs dipole moment in SAMs, thereby affecting shift of Fermi level for instantaneous doping of 2D materials. Accordingly, carrier density, work function, and/or field‐effect mobility of 2D materials are changed by the SAMs contact. Recent advances in the SAMs‐induced changes of electrical properties in 2D materials are introduced by considering two types of 2D materials‐SAMs contacts: 1) 2D materials on SAMs and 2) SAMs on 2D materials. 2D materials from graphene to TMDs are fully discussed in the context of SAMs‐induced doping.
Detecting and Tuning the Interactions between Surfactants and Carbon Nanotubes for Their High‐Efficiency Structure Separation
Authors: Zeng Xiang , Yang Dehua , Liu Huaping , Zhou Naigen , Wang Yanchun , Zhou Weiya , Xie Sishen , Kataura Hiromichi
Published: December 2017

The selective interaction is systematically explored between the surfactants (sodium deoxycholate (DOC), sodium dodecyl sulfate (SDS), and sodium cholate (SC)) and the single‐wall carbon nanotubes (SWCNTs) by the gel chromatography technique. The results show that DOC preferentially interacts with small‐diameter semiconducting SWCNTs (S‐SWCNTs), exhibiting the strongest interaction strength for the SWCNTs, and the highest structural selectivity. The surfactant SC shows high selectivity toward the chiral angles of the SWCNTs. Its interaction strength and structural recognition ability are slightly higher than that of SDS but lower than that of DOC. Combining with the proved selectivity of SDS in the adsorption onto the S‐SWCNTs with small CC bond curvature, it is discovered that the synergistic effect of the triple surfactants amplified the interaction difference among the different SWCNTs and the gel, and thus dramatically improved the separation efficiency and structural purity of the SWCNTs, achieving the separation of distinct (n, m) single‐chirality species and their enantiomers in one step. This work not only provides deeper insights into the separation mechanism of SWCNTs with the surfactant sorting techniques, but also has a profound significance in studying the interaction between the SWCNTs and other small molecules.
A Novel Multiple Interface Structure with the Segregation of Dopants in Lead‐Free Ferroelectric (K0.5Na0.5)NbO3 Thin Films
Authors: Li Chao , Wang Lingyan , Chen Wen , Lu Lu , Nan Hu , Wang Dawei , Zhang Yijun , Yang Yaodong , Jia Chun‐Lin
Published: December 2017

Interfaces in oxides are found to possess different properties and can be engineered for modifying local structure and properties of nearby area. In this work, it is reported that the interfaces can be formed in Ba/Zr (BZ)‐doped (K,Na)NbO3 (KNN) thin films by cycles of chemical solution deposition using same precursor solution. In the films, a novel and special cross‐sectional structure is observed with periodic distribution of Ba‐rich and Zr‐rich layers. The Ba‐rich and Zr‐rich layers exhibit different strain, lattice parameters, and crystal structure, leading to an obvious effect on the general ferroelectric properties of the KNN‐based thin films. Moreover, the self‐polarization is also observed, which can be understood to originate from the formed built‐in field by layered distribution of Ba and Zr in the KNN‐BZ thin films.
Flexible WS2@CNFs Membrane Electrode with Outstanding Lithium Storage Performance Derived from Capacitive Behavior
Authors: Wu Chen , Zeng Xiaohui , He Pingge , Chen Libao , Wei Weifeng
Published: December 2017

Flexible electrodes have recently elicited attention due to their potential to be woven into textiles as flexible power supplies for wearable electronic devices. However, contemporary flexible electrodes generally suffer from the limited reaction kinetics and inferior stability. Here, a flexible WS2@CNFs membrane electrode is facilely fabricated via hydrothermal method and subsequent electrospinning to embed WS2 nanosheets into interconnected framework of carbon nanofibers (CNFs). Benefitting from 3D porous architecture and good conductivity of CNFs, WS2@CNFs composites exhibit outstanding cycling stability and rate capability as self‐supported binder‐free anode for lithium‐ion batteries. Especially, WS2@CNFs with 60.3 wt% of WS2 displays a discharge specific capacity as high as 545 mA h g−1 at 0.5 A g−1 after 800 cycles. Even at 2 A g−1, it maintains 62.4% of specific capacity at 0.1 A g−1, and stably cycles back at 0.1 A g−1. Kinetic analysis confirms that the capacitive mechanism is dominant in the Li‐ion storage process, which is derived mainly from the structure evolution from WS2 nanosheets to WS2/W nanoparticles during extended cycling. The reduced nanoparticles also enhance electrochemical activity, conductivity, and reversibility of the conversion reaction, resulting in the increasing capacity with cycles.