bluuebunny/crossref_metadata_2025 huggingface dataset:
Photofunctionality in Porphyrin‐Hybridized Bis(dipyrrinato)zinc(II) Complex Micro‐ and Nanosheets
Authors: Sakamoto Ryota , Yagi Toshiki , Hoshiko Ken , Kusaka Shinpei , Matsuoka Ryota , Maeda Hiroaki , Liu Zheng , Liu Qian , Wong Wai‐Yeung , Nishihara Hiroshi
Published: February 2017

New bis(dipyrrinato)zinc(II) complex micro‐ and nanosheets containing zinc(II) porphyrin (N2) are synthesized. A liquid/liquid interface method between dipyrrin porphyrin ligand L2 and zinc acetate produces N2 with a large domain size. N2 can be layered quantitatively onto a flat substrate by a modified Langmuir–Schäfer method. N2 deposited on a SnO2 electrode functions as a photoanode for a photoelectric conversion system. The photoresponse of N2 covers the whole visible wavelength range (400–650 nm), with a maximum quantum efficiency of more than twice that of a bis(dipyrrinato)zinc(II) complex nanosheet without porphyrin.
Parametric investigation of polymethacrylate monolith synthesis and stability via thermogravimetric characterisation
Authors: Acquah Caleb , Danquah Michael K. , Moy Charles K. S. , Anwar Mahmood , Ongkudon Clarence M.
Published: February 2017

Polymethacrylate monoliths are synthetic adsorbents with macroporous and mesoporous interconnected channels that can be engineered to target the hydrodynamic features of a wide range of molecular species. However, rigorous study into the effect of synthesis conditions on their thermal stability is limited. This work attempts to characterise the influence of key synthesis process variables on the stability of polymethacrylate monoliths using thermogravimetric analysis at a heating rate of 10 °C/min. Experimental results showed that the thermal stability of polymethacrylate monoliths increased with decreasing polymerisation temperature from 85 to 65 °C. Increasing the total porogen (P) to monomer (M) ratio increased the thermal stability of the monolith by >62% and >50% for P40/M60–P60/M40 and P60/M40–P80/M20, respectively. The impact of the initiator concentration, monomer variation, biporogen ratio, washing and activation of the monoliths was investigated. Nuclear magnetic resonance analyses conducted confirmed the hydrolysis of epoxy moieties on the monolith. © 2017 Curtin University of Technology and John Wiley & Sons, Ltd.
Speckle observations with PISCO in Merate (Italy): XV
Authors: Prieur J.‐L. , Scardia M. , Pansecchi L. , Argyle R. W. , Zanutta A. , Aristidi E.
Published: February 2017

We present relative astrometric measurements of visual binaries, made in 2014 with the speckle camera Pupil Interferometry Speckle camera and COronagraph (PISCO) at the 102‐cm Zeiss telescope of Brera Astronomical Observatory, in Merate. Our observing list contains orbital couples as well as binaries whose motion is still uncertain. We obtained 224 new measurements of 218 visual binary stars, with angular separations in the range 0′′.15–10′′, and an average accuracy of 0′′.015. The mean error on the position angles is 0°.5. Most of the position angles were determined without the usual 180° ambiguity with the application of triple‐correlation techniques and/or by inspection of the long integration files. We complete this data with the results of a study of the multiple system ADS 6993 with PISCO during the period 2004–2014 and propose a new method to resolve part of the 180‐degree ambiguity with the autocorrelations only. We then present new revised orbits for ADS 671, 1615, 1709, 5447, 10075, and 12447, partly derived from PISCO observations. The corresponding estimated values for the masses of those systems are compatible with the spectral types.
Influence of vasomodulators and tumor transplantation on the disposition of 5‐fluorouracil after application to the liver surface in rats
Authors: Kodama Yukinobu , Horishita Miyuki , Tokunaga Ayako , Miyamoto Hirotaka , Fumoto Shintaro , Sasaki Hitoshi , Nakamura Junzo , Nishida Koyo
Published: February 2017

This study investigated the effect of epinephrine (a vasoconstrictor) and hydralazine (a vasodilator) on the hepatic disposition of 5‐fluorouracil (5‐FU) after application to the surface of the liver in rats. Normal livers were compared with a Walker 256 carcinoma cell tumor model. A cylindrical diffusion cell was attached to the liver surface. 5‐Fluorouracil was added into the diffusion cell in combination with vasomodulators or after pretreatment with epinephrine. After selected treatment times, the 5‐FU concentrations were assayed at three sites in the excised livers. The 5‐FU concentration in the region under the cell attachment site (site 1) was significantly higher after concomitant application of 5‐FU and epinephrine, compared with 5‐FU alone, and increased in an epinephrine dose‐dependent manner. On the other hand, preferential distribution of 5‐FU at site 1 was not seen when applied in combination with hydralazine. After 10 min of epinephrine pretreatment, the concentration of 5‐FU at site 1 was approximately two times higher than that for the control. Furthermore, the 5‐FU concentration at site 1 of the tumor model was greatly increased compared with the normal liver. These results suggest that application of epinephrine to the liver surface might enhance the accumulation of 5‐FU at the desired target site.
Configuration‐dependent variability of the effect of an electric field on the plasma glucocorticoid level in immobilized mice
Authors: Hori Takuya , Inoue Noboru , Suzuki Hiroshi , Harakawa Shinji
Published: February 2017

We recently reported that an immobilization stress‐induced increase in glucocorticoid (GC) level was suppressed in mice exposed to an electric field (EF) of 50 Hz in a kV/m‐dependent manner. In this study, we investigated the reproducibility of the suppressive effect induced by EF exposure by varying the voltage and distance between the electrodes (0.5 kV/50 mm, 1 kV/100 mm, 2 kV/200 mm) and comparing the effects on the plasma GC level. In addition, the effect of mice being in contact with the lower electrode or not was compared at 1 kV/100 mm. Immobilization‐induced GC levels were significantly decreased in mice exposed to an EF at 1 kV/100 mm for 60 min (P < 0.01), but not in mice exposed to 0.5 kV/50 mm or 2 kV/200 mm. Furthermore, the suppressive effect of the 1 kV/100 mm EF was canceled when a polypropylene sheet (0.1 mm thick) was placed between the animal and lower electrode. Our findings corroborated that an EF of 10 kV/m inhibits stress‐induced changes in the endocrine system in mice and demonstrated that this effect depends on the configuration of the EF exposure system, even when the EF strength remains the same. Bioelectromagnetics. 38:265–271, 2017. © 2017 Wiley Periodicals, Inc.
Effects of local vibration and pulsed electromagnetic field on bone fracture: A comparative study
Authors: Bilgin Hakkı Murat , Çelik Ferhat , Gem Mehmet , Akpolat Veysi , Yıldız İsmail , Ekinci Aysun , Özerdem Mehmet Siraç , Tunik Selçuk
Published: February 2017

The effectiveness of various therapeutic methods on bone fracture has been demonstrated in several studies. In the present study, we tried to evaluate the effect of local low‐magnitude, high‐frequency vibration (LMHFV) on rat tibia fracture in comparison with pulsed electromagnetic fields (PEMF) during the healing process. Mid‐diaphysis tibiae fractures were induced in 30 Sprague‐Dawley rats. The rats were assigned into groups such as control (CONT), LMHFV (15 min/day, 7 days/week), and PEMF (3.5 h/day, 7 days/week) for a three‐week treatment. Nothing was applied to control group. Radiographs, serum osteocalcin levels, and stereological bone analyses of the three groups were compared. The X‐rays of tibiae were taken 21 days after the end of the healing process. PEMF and LMHFV groups had more callus formation when compared to CONT group; however, the difference was not statistically significant (P = 0.375). Serum osteocalcin levels were elevated in the experimental groups compared to CONT (P ≤ 0.001). Stereological tests also showed higher osteogenic results in experimental groups, especially in LMHFV group. The results of the present study suggest that application of direct local LMHFV on fracture has promoted bone formation, showing great potential in improving fracture outcome. Bioelectromagnetics. 38:339–348, 2017. © 2017 Wiley Periodicals, Inc.
Radiofrequency exposure near an attocell as part of an ultra‐high density access network
Authors: Thielens Arno , Vermeeren Günter , Caytan Olivier , Torfs Guy , Demeester Piet , Bauwelinck Johan , Rogier Hendrik , Martens Luc , Joseph Wout
Published: February 2017

In the future, wireless radiofrequency (RF) telecommunications networks will provide users with gigabit‐per‐second data rates. Therefore, these networks are evolving toward hybrid networks, which will include commonly used macro‐ and microcells in combination with local ultra‐high density access networks consisting of so‐called attocells. The use of attocells requires a proper compliance assessment of exposure to RF electromagnetic radiation. This paper presents, for the first time, such a compliance assessment of an attocell operating at 3.5 GHz with an input power of 1 mW, based on both root‐mean‐squared electric field strength (Erms) and peak 10 g‐averaged specific absorption rate (SAR10g) values. The Erms values near the attocell were determined using finite‐difference time‐domain (FDTD) simulations and measurements by a tri‐axial probe. They were compared to the International Commission on Non‐Ionizing Radiation Protection's (ICNIRP) reference levels. All measured and simulated Erms values above the attocell were below 5.9 V/m and lower than reference levels. The SAR10g values were measured in a homogeneous phantom, which resulted in an SAR10g of 9.7 mW/kg, and used FDTD simulations, which resulted in an SAR10g of 7.2 mW/kg. FDTD simulations of realistic exposure situations were executed using a heterogeneous phantom, which yielded SAR10g values lower than 2.8 mW/kg. The studied dosimetric quantities were in compliance with ICNIRP guidelines when the attocell was fed an input power <1 mW. The deployment of attocells is thus a feasible solution for providing broadband data transmission without drastically increasing personal RF exposure. Bioelectromagnetics. 38:295–306, 2017. © 2017 Wiley Periodicals, Inc.
Anchored Fe3O4 Nanoparticles on rGO Nanosheets as High‐Power Negative Electrodes for Aqueous Batteries
Authors: Sanchez Jaime S. , Pendashteh Afshin , Palma Jesus , Anderson Marc , Marcilla Rebeca
Published: February 2017

Fe3O4 nanoparticles were anchored on GO nanosheets and evaluated as negative electrode materials for high‐performance aqueous batteries. The prepared samples were characterized by using XRD, Raman spectroscopy, TGA, and TEM. The energy‐storage behavior of the samples was investigated by testing high‐mass‐loaded (ca. 8.5 mg ⋅ cm−2) Fe3O4−rGO electrodes with different electrochemical techniques, including cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. The nanocomposites showed better electrochemical storage properties than pure Fe3O4 nanoparticles and rGO nanosheets, suggesting superior performance through synergistic effects. Accordingly, the Fe3O4−rGO nanocomposite with an optimized composition of [60 : 40] showed a maximum capacity of 402 C ⋅ g−1 (111.6 mA ⋅ h ⋅ g−1) and superior rate capability (ca. 40 % capacity retention with a 20‐fold increase in scan rate) compared to the pure oxide. To further evaluate the applicability of the Fe3O4−rGO nanocomposite, aqueous batteries based on the Fe3O4−rGO [60 : 40] nanocomposite as negative electrodes and NiCoMnO4 as positive electrodes were assembled and examined by using various electrochemical techniques. Fe3O4−rGO//NiCoMnO4 cells demonstrated a maximum specific energy of 26 Wh ⋅ kg−1 and a maximum specific power of 6.8 kW ⋅ kg−1, with a desirable rate capability. All of the obtained results suggest the Fe3O4−rGO nanocomposite as a promising negative electrode material for high‐power aqueous batteries.
On the Way to a Trisanionic {Cu3O2} Core for Oxidase Catalysis: Evidence of an Asymmetric Trinuclear Precursor Stabilized by Perfluoropinacolate Ligands
Authors: Hannigan Steven F. , Arnoff Amanda I. , Neville Sarah E. , Lum June S. , Golen James A. , Rheingold Arnold L. , Orth Nicole , Ivanović‐Burmazović Ivana , Liebhäuser Patricia , Rösener Thomas , Stanek Julia , Hoffmann Alexander , Herres‐Pawlis Sonja , Doerrer Linda H.
Published: February 2017

CuI complexes of the form K[(R3P)Cu(pinF)], in which (pinF)2− is the bidentate, oxygen‐donating ligand perfluoropinacolate, were synthesized and characterized. Low‐temperature oxygenation of the K[(R3P)Cu(pinF)(PR3)] species resulted in a trisanionic bis(μ3‐oxo) trinuclear copper(II,II,III) core characterized by UV/Vis spectroscopy (λmax [nm] = 330, 535, 630), cryospray‐ionization mass spectrometry, and X‐band electron paramagnetic resonance spectroscopy (derivative resonance at 3300 G, Δms=2 at 1500 G). The kinetic behavior of the trimeric {Cu3O2} species was quantified by stopped‐flow spectroscopy and the associated electronic structures were investigated by DFT calculations. An asymmetric {Cu3O2} species, AsTpinF, which bears a structure similar to multicopper oxidases, forms prior to full formation of the symmetric trinuclear core, SyTpinF. The trimer catalytically oxidizes para‐hydroquinone to benzoquinone (a form of oxidase chemistry).
Visible and Near‐IR Emissions from k2N‐ and k3N‐Terpyridine Rhenium(I) Assemblies Obtained by an [n×1] Head‐to‐Tail Bonding Strategy
Authors: Laramée‐Milette Baptiste , Zaccheroni Nelsi , Palomba Francesco , Hanan Garry S.
Published: February 2017

An [n×1] head‐to‐tail bonding strategy has been used for the synthesis of ReI metallacycles. From a k3N‐dicarbonyl precursor, a single discrete [4×1] square assembly was isolated and characterized, whereas a k2N‐tricarbonyl precursor led to two major species, a square and a [3×1] triangular assembly. Solid‐state X‐ray diffraction study has confirmed the high angular distortion (71° to 96°) of the k2N precursors. The electrochemical reversibility of the triangular (5) and square (6, 7) assemblies is increased with respect to that of their precursors. Photophysical investigation has confirmed pronounced red‐shifts in the emissions of the k3N‐dicarbonyl species 4 (935 nm) and 7 (980 nm), as confirmed by density functional theory (DFT) and time‐dependent DFT (TD‐DFT) calculations.
Synthesis of Ester‐ and Phosphonate‐Functionalized AuI–Imidazolylidene Chlorides through the Isonitrile Route
Authors: Wurm Thomas , Hornung Julius , O'Neill Matthew , Rudolph Matthias , Rominger Frank , Hashmi A. Stephen K.
Published: February 2017

Starting from DMSAuCl, isonitriles and functionalized propargylammonium salts in the presence of simple trimethylamine as auxiliary base, unsymmetrically substituted ester‐ and phosphonate‐functionalized AuI–imidazolylidene complexes were synthesized in an easy‐to‐use modular one‐pot template synthesis. In the course of the reaction, after the initial nucleophilic addition of the amine to the gold(I)‐activated isonitrile, a Michael addition closes the N‐heterocyclic carbene (NHC) ring. Then the remaining double bond migrates into the NHC ring, evidently a more stable position than the initial exocyclic double bond. These functional groups attached to the back bone of the NHC ligands represent ideal handles for a further modification of the system, for example an attachment to larger assemblies or heterogenization by an attachment to surfaces are conceivable.
ZONAL DIFFERENCES IN THERMOSPHERIC AIR DENSITIES AT MID‐LATITUDES
Authors: Hui WANG , Ke‐Deng ZHANG , Xin Wan
Published: February 2017

This study investigated longitudinal differences in the thermospheric air mass density (ρ) during the solar minimum period from 2007 to 2009 at magnetic mid‐latitudes. Both observations by CHAMP satellite and model simulations using the Global Ionosphere‐Thermosphere Model were analyzed. It was found that ρ exhibited wave‐1 structure in its longitudinal profile (i.e., one peak and one trough), which was almost 180° out of phase between the two hemispheres. The phase of the wave changed with the local time, exhibiting a clear diurnal variation. The value of ρ exhibited few longitudinal variations in the eastern part of the northern hemisphere, where the electron density showed some longitudinal differences. The reason for this was that the variation in the electron density was too slight to affect ρ in the Europe‐Asia sector via ion drag. As confirmed by the simulation, the longitudinal difference in ρ was reduced by almost 40%∼50% in terms of the maximum value of the peak‐trough difference when ion drag was negligible. Thus, both the model and the observations confirmed the important role of ion drag in the longitudinal structure of neutral density. This study further indicated the obvious longitudinal difference in the solar heating at magnetic mid‐latitudes. The peak‐to‐trough difference in the solar zenith angle could reach 20°∼30°. The non‐uniformity of solar irradiation heating could be another cause of the longitudinal structure of the air mass density.
THE 3D TRANSIENT ELECTROMAGNETIC FORWARD MODELING OF VOLCANOGENIC MASSIVE SULFIDE ORE DEPOSITS
Authors: Rui‐Xue LI , He WANG , Zhen‐Zhu XI , Xia LONG , Hai‐Tao HOU , Yuan‐Yuan LIU , Huan JIANG
Published: February 2017

The transient electromagnetic forward modeling of volcanogenic massive sulfide (VMS) ore deposits is to calculate the eddy currents electromagnetic response of a three dimensional body in the full space of deep‐sea environment. We simulated the three dimensional transient electromagnetic response of the VMS deposits using full‐domain vector finite element method. The ore body was discretized with brick rectangular elements. The finite element equation was deduced in frequency domain by employing Galerkin procedure, and the conversion to time domain was by inverse Fourier transform. We confirmed the validity of the full‐domain vector finite element algorithm by comparing simulated results with analytical solutions of double half‐space model. The results have a good agreement with each other, which indicates that the vector finite element method is capable of solving whole space problem. In order to demonstrate the ability of the numerical method in calculating the response of VMS deposits containing complex boundary conditions, we compared vector finite element solution of a three dimensional electrical model with physical experiment results according to electromagnetic physical scale modeling rules. The comparison suggests that for the complex electromagnetic boundary of seawater, ore body and country rocks, the transient electromagnetic response of VMS deposits calculated by full‐domain vector finite element method has same features with the physical scale modeling result. The vector finite element method is simple and its results are precise with obvious and clear anomaly response.
Copper Catalyzed Iodosulfenylation of Styrenes by Dual C—H Oxidative Functionalization
Authors: Liu Yurong , Hu Bolun , Zhang Xingguo
Published: February 2017

A new method for the synthesis of β‐iodoalkenyl sulfides via copper catalyzed difunctionalization of styrenes is described. The method allows the formation of two chemical bonds, a C—I bond and a C—S bond, in a single reaction. Using alkenes in place of alkynes to synthesize β‐iodoalkenyl sulfides is a significant advantage of this methodology for both synthetic and medicinal chemistry.
The rotation of mouse myoblast nuclei is dependent on substrate elasticity
Authors: Hickey Ryan , Pelling Andrew E.
Published: February 2017

The complex interplay of biochemical signaling and mechanical traction forces regulate the position of cellular nuclei. Although the phenomenon of nuclear rotation has been observed for many years, the influence of substrate elasticity was unknown. We discovered another layer of complexity to this phenomenon: nuclear rotation is dependent on substrate elasticity. Nuclear rotation is drastically reduced on physiologically relevant stiffnesses. Here, we studied nuclear rotation in mouse C2C12 myoblasts cultured on soft substrates designed to mimic resting tissue (∼26 kPa) and on hard glass substrates. We examined the roles of the actin and microtubule cytoskeleton on the presence and dynamics of nuclear rotation in these two different microenvironments. We demonstrated the clear dependence of nuclear rotation dynamics on matrix stiffness. These results will have important implications for the design of future studies of nuclear rotation and our understanding of the phenomenon as a whole. Unnaturally, hard substrates do not only fail to mimic the in vivo microenvironment, but can also induce cellular processes that would not normally occur in the natural cellular environment.
Quantification of familial risk of nasopharyngeal carcinoma in a high‐incidence area
Authors: Liu Zhiwei , Chang Ellen T. , Liu Qing , Cai Yonglin , Zhang Zhe , Chen Guomin , Huang Qi‐Hong , Xie Shang‐Hang , Cao Su‐Mei , Shao Jian‐Yong , Jia Wei‐Hua , Zheng Yuming , Liao Jian , Chen Yufeng , Lin Longde , Liang Liming , Ernberg Ingemar , Vaughan Thomas L. , Adami Hans‐Olov , Huang Guangwu , Zeng Yi , Zeng Yi‐Xin , Ye Weimin
Published: February 2017

BACKGROUND

To the authors' knowledge, no studies to date have explored familial risks of nasopharyngeal carcinoma (NPC) in detail and quantified its lifetime risk in high‐incidence populations.

METHODS

The authors conducted a population‐based case‐control study of 2499 NPC cases and 2576 controls randomly selected in southern China from 2010 through 2014. Unconditional logistic regression was used to estimate multivariable‐adjusted odds ratios (ORs) with 95% confidence intervals (95% CIs) associated with a family history of NPC. In addition, the authors compiled a reconstructed cohort comprising 40,781 first‐degree relatives of cases and controls to calculate the lifetime cumulative risk of NPC.

RESULTS

Individuals with a first‐degree family history of NPC were found to be at a >4‐fold risk of NPC (OR, 4.6; 95% CI, 3.5‐6.1) compared with those without such a history, but had no excess risk of other malignancies. The excess risk was higher for a maternal than a paternal history and was slightly stronger for a sibling compared with a parental history, and for a sororal than a fraternal history. Among relatives of cases, the cumulative risk of NPC up to age 74 years was 3.7% (95% CI, 3.3%‐4.2%), whereas that among relatives of controls was 0.9% (95% CI, 0.7%‐1.2%). Cumulative risk was higher in siblings than in parents among relatives of cases, whereas no such difference was noted among relatives of controls.

CONCLUSIONS

Individuals with a family history of NPC have a substantially higher risk of NPC. These relative and cumulative risk estimates can guide the development of strategies for early detection and clinical consultation in populations with a high incidence of NPC. Cancer 2017;123:2716‐25. © 2017 American Cancer Society.
In Situ Electroluminescence Color Tuning by Thermal Deprotonation Suitable for Thermal Sensors and Anti‐fraud Labels
Authors: Giovanella Umberto , Cariati Elena , Lucenti Elena , Pasini Mariacecilia , Galeotti Francesco , Botta Chiara
Published: February 2017

A novel and versatile approach to tune photoluminescence and electroluminescence by in situ controlled thermal deprotonation is presented. This methodology, based on a single organic π‐conjugated material (pyrene derivative), allows the manufacturing of organic light‐emitting diode (OLED) prototypes by solution methods with controlled tunable emission ranging from the orange (protonated form of the dye) to the blue (pristine or deprotonated form). While several protonation/deprotonation cycles can be performed on thin films, for the devices only one cycle is possible so that their use as anti‐fraud labels can be envisaged. OLEDs exhibit daylight visible brightness of 150 cd m−2 and device lifetime exceeding 30 hours of continuous operation. Thanks to the simplicity of both material design and device fabrication our approach opens new perspectives in the wide field of thermal sensors for customer care or risk perception.
Ligature‐associated bacterial profiles are linked to type 2 diabetes mellitus in a rat model and influenced by antibody treatment against TNF‐α or RAGE
Authors: Grauballe M.B. , Belstrøm D. , Østergaard J.A. , Paster B.J. , Schou S. , Flyvbjerg A. , Holmstrup P.
Published: February 2017

There is a bidirectional relationship between periodontal disease (PD) and type 2 diabetes mellitus (T2D). T2D may lead to ecological perturbations in the oral environment, which may facilitate an altered microbiota. However, previous studies have been inconclusive in determining the effect of T2D on oral bacterial profiles. Therefore, we aimed to evaluate the influence of T2D on the ligature‐associated bacterial profile in a diabetic rat model with PD and investigated the impact of blocking inflammatory pathways with antibodies targeting either Tumor Necrosis Factor α (TNF‐α) or the receptor of advanced glycation end‐products (RAGE). A total of 62 Zucker obese rats (45 T2D) and 17 lean (non‐T2D) were divided into 4 treatment groups; lean with PD, obese with PD, obese with PD and anti‐TNF‐α treatment, and obese with PD with anti‐RAGE treatment. Periodontal disease was ligature induced. Ligature‐associated bacterial profiles were analyzed using Human Oral Microbe Identification Microarray (HOMIM). Ligature‐associated bacterial profiles differed between lean and obese rats. Furthermore, treatment with antibodies against TNF‐α or RAGE had an impact on subgingival bacterial profiles. T2D phenotypes are associated with different ligature‐associated bacterial profiles and influenced by treatment with antibodies against TNF‐α or RAGE.
Acinar cell cystadenoma: A challenging cytology diagnosis, facilitated by moray® micro‐forceps biopsy
Authors: Chen Athena L. , Misdraji Joseph , Brugge William R. , Ferrone Cristina R. , Pitman Martha B.
Published: February 2017

Acinar cell cystadenoma is a rare, benign cystic lesion of the pancreas. There have been only a few retrospective reports on its cytological features. We present the first case of acinar cell cystadenoma in a 65‐year‐old woman, diagnosed pre‐operatively by pancreatic cyst fluid cytology and Moray® micro‐forceps biopsy. We emphasize possible diagnostic pitfalls of acinar cell cystadenoma cyst fluid cytology and suggest useful morphologic, immunohistochemical, and other clues to aid in diagnosis. Diagn. Cytopathol. 2017;45:557–560. © 2017 Wiley Periodicals, Inc.
Specific gravity of woody tissue from lowland Neotropical plants: differences among forest types
Authors: Casas Luisa Fernanda , Aldana Ana María , Henao‐Diaz Francisco , Villanueva Boris , Stevenson Pablo R.
Published: February 2017

Wood density, or more precisely, wood specific gravity, is an important parameter when estimating aboveground biomass, which has become a central tool for the management and conservation of forests around the world. When using biomass allometric equations for tropical forests, researchers are often required to assume phylogenetic trait conservatism, which allows us to assign genus‐ and family‐level wood specific gravity mean values, to many woody species. The lack of information on this trait for many Neotropical plant species has led to an imprecise estimation of the biomass stored in Neotropical forests. The data presented here has information of woody tissue specific gravity from 2,602 individual stems for 386 species, including trees, lianas, and hemi‐epiphytes of lowland tropical forests in Colombia. This data set was produced by us collecting wood cores from woody species in five localities in the Orinoco and Magdalena Basins in Colombia. We found lower mean specific gravity values in várzea than in terra firme and igapó.
A Facile Strategy for the Preparation of Highly Mesoporous γ‐Alumina
Authors: Sachse Alexander , Gérardin Corine , Delahay Gérard , Belamie Emmanuel , Kostov Krassimir L. , Alonso Bruno
Published: February 2017

A new, rapid, and very facile strategy for the large‐scale preparation of highly porous γ‐Al2O3 was developed. Defined γ‐alumina microparticles with a narrow mesopore‐size distribution, specific surface area of 400 m2 g–1, and a pore volume of 0.65 mL g–1 were obtained by merely employing an aqueous aluminum chloride solution.
In vivo detection of lateral–ventral tier nigral degeneration in Parkinson's disease
Authors: Huddleston Daniel E. , Langley Jason , Sedlacik Jan , Boelmans Kai , Factor Stewart A. , Hu Xiaoping P.
Published: February 2017

The objective of this study was to measure neuromelanin‐sensitive MRI contrast changes in the lateral‐ventral tier of substantia nigra pars compacta in Parkinson's disease (PD). Histopathological studies of PD have demonstrated both massive loss of melanized dopamine neurons and iron accumulation in the substantia nigra pars compacta. Neurodegeneration is most profound in the lateral‐ventral tier of this structure. We have previously shown in both healthy controls and individuals with PD that neuromelanin‐sensitive MRI and iron‐sensitive MRI contrast regions in substantia nigra overlap. This overlap region is located in the lateral‐ventral tier. Exploiting this area of contrast overlap for region of interest selection, we developed a semi‐automated image processing approach to characterize the lateral‐ventral tier in MRI data. Here we apply this approach to measure magnetization transfer contrast, which corresponds to local neuromelanin density, in both the lateral‐ventral tier and the entire pars compacta in 22 PD patients and 19 controls. Significant contrast reductions were seen in PD in both the entire pars compacta (P = 0.009) and in its lateral‐ventral tier (P = 0.0002); in PD contrast was significantly lower in the lateral‐ventral tier than in the entire pars compacta (P = 0.0008). These findings are the first in vivo evidence of the selective vulnerability of this nigral subregion in PD, and this approach may be developed for high impact biomarker applications. Hum Brain Mapp 38:2627–2634, 2017. © 2017 Wiley Periodicals, Inc.
Nonalcoholic fatty liver disease‐related cirrhosis is commonly unrecognized and associated with hepatocellular carcinoma
Authors: Bertot Luis C. , Jeffrey Gary P. , Wallace Michael , MacQuillan Gerry , Garas George , Ching Helena L. , Adams Leon A.
Published: February 2017

Determination of cirrhosis in nonalcoholic fatty liver disease (NAFLD) is important as it alters prognosis and management. We aimed to examine whether cirrhosis was diagnosed incidentally or intentionally in patients with NAFLD. We reviewed 100 patients with NAFLD cirrhosis to determine mode of cirrhosis diagnosis (incidental or by intent), severity of liver disease at diagnosis, diagnostician, and previous clinical imaging or laboratory evidence of unrecognized cirrhosis. The majority (66/100) of patients with NAFLD cirrhosis were diagnosed incidentally, with the majority of these (74%) diagnosed with NAFLD simultaneously. Those with incidental cirrhosis diagnoses had more deranged platelet and international normalized ratio levels (P < 0.05) and were more likely to have concomitant hepatocellular carcinoma (HCC) (12% versus 0%, P < 0.05). Incidental cirrhosis was diagnosed following imaging (32%) or liver tests (26%) performed for reasons unrelated to liver disease, following unexpected endoscopic finding of varices (21%) or an unexpected surgical finding (14%). Diagnoses by intent were predominantly made by gastroenterologists/hepatologists, whereas general practitioners, surgeons, and physicians tended to diagnose cirrhosis incidentally (P < 0.001). The majority of patients diagnosed incidentally (n = 48/66, 73%) had previous thrombocytopenia, splenomegaly, or high noninvasive fibrosis scores. Following diagnosis, patients diagnosed incidentally were less likely to undergo HCC screening. Conclusion: The majority of patients with NAFLD cirrhosis are diagnosed incidentally. These patients are more likely to have advanced liver disease and HCC. Increased awareness of screening for cirrhosis is needed in patients with NAFLD. (Hepatology Communications 2017;1:53–60)
Gut microbial composition can differentially regulate bile acid synthesis in humanized mice
Authors: Kang Dae Joong , Hylemon Phillip B , Gillevet Patrick M , Sartor R. Balfour , Betrapally Naga S. , Kakiyama Genta , Sikaroodi Masoumeh , Takei Hajime , Nittono Hiroshi , Zhou Huiping , Pandak William M. , Yang Jing , Jiao Chunhua , Li Xiaojiaoyang , Lippman H. Robert , Heuman Douglas M. , Bajaj Jasmohan S.
Published: February 2017

We previously reported that alcohol drinkers with and without cirrhosis showed a significant increase in fecal bile acid secretion compared to nondrinkers. We hypothesized this may be due to activation by alcohol of hepatic cyclic adenosine monophosphate responsive element‐binding protein 3‐like protein 3 (CREBH), which induces cholesterol 7α‐hydroxylase (Cyp7a1). Alternatively, the gut microbiota composition in the absence of alcohol might increase bile acid synthesis by up‐regulating Cyp7a1. To test this hypothesis, we humanized germ‐free (GF) mice with stool from healthy human subjects (Ctrl‐Hum), human subjects with cirrhosis (Cirr‐Hum), and human subjects with cirrhosis and active alcoholism (Alc‐Hum). All animals were fed a normal chow diet, and none demonstrated cirrhosis. Both hepatic Cyp7a1 and sterol 12α‐hydroxylase (Cyp8b1) messenger RNA (mRNA) levels were significantly induced in the Alc‐Hum and Ctrl‐Hum mice but not in the Cirr‐Hum mice or GF mice. Liver bile acid concentration was correspondingly increased in the Alc‐Hum mice despite fibroblast growth factor 15, fibroblast growth receptor 4, and small heterodimer partner mRNA levels being significantly induced in the large bowel and liver of the Ctrl‐Hum mice and Alc‐Hum mice but not in the Cirr‐Hum mice or GF mice. This suggests that the normal pathways of Cyp7a1 repression were activated in the Alc‐Hum mice and Ctrl‐Hum mice. CREBH mRNA was significantly induced only in the Ctrl‐Hum mice and Alc‐Hum mice, possibly indicating that the gut microbiota up‐regulate CREBH and induce bile acid synthesis genes. Analysis of stool bile acids showed that the microbiota of the Cirr‐Hum and Alc‐Hum mice had a greater ability to deconjugate and 7α‐dehydroxylate primary bile acids compared to the microbiota of the Cirr‐Hum mice. 16S ribosomal RNA gene sequencing of the gut microbiota showed that the relative abundance of taxa that 7‐α dehydroxylate primary bile acids was higher in the Ctrl‐Hum and Alc‐Hum groups. Conclusion: The composition of gut microbiota influences the regulation of the rate‐limiting enzymes in bile acid synthesis in the liver. (Hepatology Communications 2017;1:61–70)
Hippocampal‐cortical contributions to strategic exploration during perceptual discrimination
Authors: Voss Joel L. , Cohen Neal J.
Published: February 2017

The hippocampus is crucial for long‐term memory; its involvement in short‐term or immediate expressions of memory is more controversial. Rodent hippocampus has been implicated in an expression of memory that occurs on‐line during exploration termed “vicarious trial‐and‐error” (VTE) behavior. VTE occurs when rodents iteratively explore options during perceptual discrimination or at choice points. It is strategic in that it accelerates learning and improves later memory. VTE has been associated with activity of rodent hippocampal neurons, and lesions of hippocampus disrupt VTE and associated learning and memory advantages. Analogous findings of VTE in humans would support the role of hippocampus in active use of short‐term memory to guide strategic behavior. We therefore measured VTE using eye‐movement tracking during perceptual discrimination and identified relevant neural correlates with functional magnetic resonance imaging. A difficult perceptual‐discrimination task was used that required visual information to be maintained during a several second trial, but with no long‐term memory component. VTE accelerated discrimination. Neural correlates of VTE included robust activity of hippocampus and activity of a network of medial prefrontal and lateral parietal regions involved in memory‐guided behavior. This VTE‐related activity was distinct from activity associated with simply viewing visual stimuli and making eye movements during the discrimination task, which occurred in regions frequently associated with visual processing and eye‐movement control. Subjects were mostly unaware of performing VTE, thus further distancing VTE from explicit long‐term memory processing. These findings bridge the rodent and human literatures on neural substrates of memory‐guided behavior, and provide further support for the role of hippocampus and a hippocampal‐centered network of cortical regions in the immediate use of memory in on‐line processing and the guidance of behavior.
Hippocampal neural activity reflects the economy of choices during goal‐directed navigation
Authors: Tryon Valerie L. , Penner Marsha R. , Heide Shawn W. , King Hunter O. , Larkin Joshua , Mizumori Sheri J. Y.
Published: February 2017

Distinguishing spatial contexts is likely essential for the well‐known role of the hippocampus in episodic memory. We studied whether types of hippocampal neural organization thought to underlie context discrimination are impacted by learned economic considerations of choice behavior. Hippocampal place cells and theta activity were recorded as rats performed a maze‐based probability discounting task that involved choosing between a small certain reward or a large probabilistic reward. Different spatial distributions of place fields were observed in response to changes in probability, the outcome of the rats' choice, and whether or not rats were free to make that choice. The degree to which the reward location was represented by place cells scaled with the expected probability of rewards. Theta power increased around the goal location also in proportion to the expected probability of signaled rewards. Furthermore, theta power dynamically varied as specific econometric information was obtained “on the fly” during task performance. Such an economic perspective of memory processing by hippocampal place cells expands our view of the nature of context memories retrieved by hippocampus during adaptive navigation.
Effect of on‐site training on the accuracy of blood loss estimation in a simulated obstetrics environment
Authors: Mbachu Ikechukwu I. , Udigwe Gerald O. , Ezeama Chukwuemeka O. , Eleje George U. , Eke Ahizechukwu C.
Published: February 2017

Objective

To determine the effect of on‐site training on the accuracy of blood loss estimation in a simulated obstetrics environment.

Methods

In a tertiary hospital in Nigeria, clinical scenarios were created in April 2013 using known blood volumes in an objective structured clinical examination fashion. Doctors and nurses who worked in the obstetrics unit observed and recorded the blood volume at different clinical stations (first study stage). Subsequently, the actual amount of blood was revealed, followed by on‐site training on the volume capacities of the study instruments. Three weeks later, the second stage of the study was performed like the first stage but using different amounts of blood for all stations. The differences in the mean errors of blood loss estimation between the two stages were determined.

Results

The analysis included 144 healthcare providers who completed both stages of the study. There were significant differences in the mean error of blood loss estimation before and after the training session for the following stations: delivery bed (P<0.001), sanitary pad 1 (P=0.001), sanitary pad 2 (P=0.001), delivery pad (P=0.001), floor (P<0.001), and laparotomy pad (P=0.001).

Conclusion

Periodic education by simulation using clinical scenarios could improve the accuracy of visual blood loss estimation.
Anin vitroinvestigation of the marked impact of dendritic cell interactions with bone grafts
Authors: Zhang Lili , Ke Jin , Wang Yulan , Yang Shuang , Miron Richard J. , Zhang Yufeng
Published: February 2017

The immune response to bone biomaterials plays a critical role during early inflammation and biomaterial‐induced osteogenesis. Dendritic cells (DCs) possess a significant impact during immune responses to biomaterials. While conventional strategies to evaluate the osteogenic potential of bone substitute materials focus mainly on osteoblast differentiation. Therefore the present study was to investigate the interactions DCs to porous β‐tricalcium phosphate (β‐TCP) to investigate whether DCs participate in the material‐coordinated osteogenic process. DC maturation and function were investigated by detecting the expression of cell surface markers and inflammatory cytokines by RT‐PCR. DCs seeded on β‐TCP showed a decrease in co‐stimulatory molecules (CD86 and CD40) and pro‐inflammatory gene IFN‐γ but an increase in anti‐inflammatory genes including IL‐1ra, IL‐4, and IL‐10, as well as TGF‐β1. Thereafter, conditioned media was harvested from DCs seeded on standard tissue culture plastic and β‐TCP to be utilized with osteoblast cell cultures. It was found that conditioned media from DCs seeded on β‐TCP markedly promoted osteoblast differentiation by increasing the expression of osteogenic genes RUNX2, ALP, OCN as well as increased ALP activity and alizarin red stainingin vitro. In conclusion, the findings from the present study point to the potential crucial role of DCs in biomaterial‐induced osteogenesis. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1703–1711, 2017.
Stabilization of activated fragments by shell‐wise construction of an embedding environment
Authors: Krausbeck Florian , Sobez Jan‐Grimo , Reiher Markus
Published: February 2017

An activated fragment which is structurally unstable when considered isolated can be stabilized through binding to a suitable molecular environment; for instance, to a transition‐metal fragment. The metal fragment may be designed in a shell‐wise build‐up of a surrounding molecular environment. However, adding more and more atoms in a consecutive fashion soon leads to a combinatorial explosion of structures, which is unfeasible to handle without automation. Here, we present a fully automated and parallelized framework that constructs such an embedding environment atom‐wise. Molecular realizations of such an environment are constructed based on simple heuristic rules intended to screen a sufficiently large portion of the possible compound space and are then subsequently optimized by electronic structure methods. (Constrained‐optimized) structures are then evaluated with respect to a scoring function, for which we choose here the concept of gradient‐driven molecule construction. This concept searches for structure modifications that reduce the forces on all atoms. We develop and analyze our approach at the example of CO2 activation by reproducing a known compound and mapping out possible alternative structures and their effect on the stabilization of a (bent) CO2 ligand. For all generated structures, the nuclear gradient on the activated fragment and its coordination energy are evaluated to steer the design process. © 2017 Wiley Periodicals, Inc.
Mentor suitability and mentoring relationship quality: Lessons from the Glasgow Intergenerational Mentoring Network
Authors: McArthur Katie , Wilson Alastair , Hunter Katie
Published: February 2017

Inequality in educational attainment is a serious and increasing problem in Scotland and the rest of the United Kingdom, and youth mentoring is gaining popularity as an intervention to address this issue. However, evidence for the effectiveness of mentoring is weak, and research suggests that a large proportion of mentoring relationships end prematurely, which can be harmful to young people. This article draws on data from the Glasgow Intergenerational Mentoring Network, an ongoing research and development project facilitating mentoring for secondary school pupils in socially disadvantaged areas, employing retired professionals as volunteer mentors. Case material is presented to discuss the nature of mentoring and the role of the mentor. This article conceptualizes volunteer mentors as relational experts, relational learners, and nonrelational mentors. The implications of these categories are discussed in terms of recruitment, training, and support of mentors, to facilitate ethical and effective mentoring relationships.
Phase‐contrast MR flow imaging: A tool to determine hepatic hemodynamics in rats with a healthy, fibrotic, or cirrhotic liver
Authors: Schaffner Denise , von Elverfeldt Dominik , Deibert Peter , Lazaro Adhara , Merfort Irmgard , Lutz Lisa , Neubauer Jakob , Baumstark Manfred W. , Kreisel Wolfgang , Reichardt Wilfried
Published: February 2017

Purpose

To test a magnetic resonance (MR) scanning protocol as a noninvasive tool to determine hepatic hemodynamics and to assess the degree of liver fibrosis in an animal model of liver fibrosis and cirrhosis.

Materials and Methods

Fifty‐four male Wistar rats were studied. Thirty‐nine received thioacetamide (TAA) in their drinking water for either 12 or 16 weeks. MR measurements were performed using flow‐sensitive 2D phase‐contrast MRI and a 9.4T preclinical scanner. The following hemodynamic parameters were investigated: portal cross‐sectional area, mean portal flow velocity, and portal and aortic flow volume rate. Therefore, rats (n = 46) were divided into three groups: CON (control, n = 13), FIB (fibrosis, n = 25), and CIR (cirrhosis, n = 8). Furthermore, the degree of liver fibrosis was assessed by a self‐established MR score and verified by a standardized histological score (n = 48).

Results

Portal and aortic flow parameters could be reliably detected. A significant decrease in portal flow velocity was found in FIB (FIB vs. CON: –21%, P = 0.006 and CIR vs. CON: –17%, P = 0.105) and in portal flow volume rate in FIB and CIR (FIB vs. CON: –20%, P = 0.009 and CIR vs. CON: –25%, P = 0.024). If the histological score is taken as standard, the self‐established MR score enabled discrimination between healthy and diseased livers (sensitivity to identify diseased livers: 89% and specificity to identify healthy livers: 100%).

Conclusion

This MR scanning protocol presents a noninvasive tool to determine hepatic hemodynamics in healthy and diseased rats.

Level of Evidence: 2

Technical Efficacy: Stage 1

J. Magn. Reson. Imaging 2017;46:1526–1534.