bluuebunny/crossref_metadata_2025 huggingface dataset:
Tris(2,2′‐bipyridine)ruthenium Derivatives with Multiple Viologen Acceptors: Quadratic Dependence of Photocatalytic H2 Evolution Rate on the Local Concentration of the Acceptor Site
Authors: Kitamoto Kyoji , Sakai Ken
Published: July 2016

Three Ru(bpy)32+ derivatives tethered to multiple viologen acceptors, [Ru(bpy)2(4,4′‐MV2)]6+, [Ru(bpy)2(4,4′‐MV4)]10+, and [Ru(bpy)(4,4′‐MV4)2]18+ [bpy=2,2′‐bipyridine, 4,4′‐MV2=4‐ethoxycarbonyl‐4′‐(N‐G1‐carbamoyl)‐2,2′‐bipyridine, and 4,4′‐MV4=4,4′‐bis(N‐G1‐carbamoyl)‐2,2′‐bipyridine, where G1=Asp(NHG2)‐NHG2 and G2=‐(CH2)2‐N+C5H4‐C5H4N+‐CH3] were prepared as “photo‐charge separators (PCSs)”. Photoirradiation of these complexes in the presence of a sacrificial electron donor (EDTA) results in storage of electrons per PCS values of 1.3, 2.7, and 4.6, respectively. Their applications in the photochemical H2 evolution from water in the presence of a colloidal Pt H2‐evolving catalyst were investigated, and are discussed along with those reported for [Ru(bpy)2(5,5′‐MV4)]10+, [Ru(4,4′‐MV4)3]26+, and [Ru(5,5′‐MV4)3]26+ (Inorg. Chem. Front. 2016, 3, 671–680). The PCSs with high dimerization constants (Kd=105–106 m−1) are superior in driving H2 evolution at pH 5.0, whereas those with lower Kd values (103–104 m−1) are superior at pH 7.0, where Kd=[(MV+)2]/[MV+.]2. The (MV+)2 site can drive H2 evolution only at pH 5.0 as a result of its 0.15 eV lower driving force for H2 evolution relative to MV+., whereas the PCSs with lower Kd values exhibit higher performance at pH 7.0 owing to the higher population of free MV+.. Importantly, the rate of electron charging over the PCSs is linear to the apparent H2 evolution rate, and shows an intriguing quadratic dependence on the number of MV2+ units per PCS.
Tuning of the Electronic Levels of Oligothiophene–Naphthalimide Assemblies by Chemical Modification
Authors: de la Peña Alejandro , Arrechea‐Marcos Iratxe , Mancheño María J. , Ruiz Delgado M. Carmen , López Navarrete J. Teodomiro , Segura José L. , Ponce Ortiz Rocío
Published: July 2016

Inversion of the connections of amidine linkers combined with controlled oligothiophene chain catenation in oligothiophene–naphthalimide assemblies provides an efficient method to tune the HOMO and LUMO values in this type of assemblies. This modification also suppresses the intramolecular charge transfer (ICT) band normally found in this type of derivatives, also delocalizing the frontier molecular orbitals over the whole conjugated skeleton. The resultant assemblies were used in the fabrication of field‐effect transistors, which showed well‐balanced ambipolar transport.
Photoelectrochemical CO2 Reduction by a Molecular Cobalt(II) Catalyst on Planar and Nanostructured Si Surfaces
Authors: He Da , Jin Tong , Li Wei , Pantovich Sebastian , Wang Dunwei , Li Gonghu
Published: July 2016

In the presence of a molecular CoII catalyst, CO2 reduction occurred at much less negative potentials on Si photoelectrodes than on an Au electrode. The addition of 1 % H2O significantly improved the performance of the CoII catalyst. Photovoltages of 580 and 320 mV were obtained on Si nanowires and a planar Si photoelectrode, respectively. This difference likely originated from the fact that the multifaceted Si nanowires are better in light harvesting and charge transfer than the planar Si surface.
Comparative study between physicochemical characterization of biochar and metal organic frameworks (MOFs) as gas adsorbents
Authors: Bamdad Hanieh , Hawboldt Kelly
Published: July 2016

In this study, biochar produced from three different woody biomasses, softwood (shaving, bark (Balsam fir)), and hardwood (Ash wood), are compared in terms of chemical and physical properties. The biochar was produced via fast pyrolysis at 450 °C in a 4 kg/h capacity auger reactor. The produced biochars were characterized for elemental composition, surface area, morphology, proximate analysis, and thermal properties. The biochars were compared with a Metal Organic Framework (MOF) with respect to properties key to adsorbent applications. All biochars were basic (pH 8.9–10.7), while MOFs were acidic. The morphologies of biochar and MOF‐5 differ in pore size, chemistry, and structure. Biochar has higher carbon content and more aromatic functional groups than MOFs, which could play an important role for adsorption of acidic gases from natural/produced gas.
Prognostic nomogram for refining the prognostication of the proposed 8th edition of the AJCC/UICC staging system for nasopharyngeal cancer in the era of intensity‐modulated radiotherapy
Authors: Pan Jian Ji , Ng Wai Tong , Zong Jing Feng , Lee Sarah W. M. , Choi Horace C. W. , Chan Lucy L. K. , Lin Shao Jun , Guo Qiao Juan , Sze Henry C. K. , Chen Yun Bin , Xiao You Ping , Kan Wai Kuen , O'Sullivan Brian , Xu Wei , Le Quynh Thu , Glastonbury Christine M. , Colevas A. Dimitrios , Weber Randal S. , Lydiatt William , Shah Jatin P. , Lee Anne W. M.
Published: July 2016

BACKGROUND

The objective of this study was to develop a nomogram for refining prognostication for patients with nondisseminated nasopharyngeal cancer (NPC) staged with the proposed 8th edition of the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) staging system.

METHODS

Consecutive patients who had been investigated with magnetic resonance imaging, staged with the proposed 8th edition of the AJCC/UICC staging system, and irradiated with intensity‐modulated radiotherapy from June 2005 to December 2010 were analyzed. A cohort of 1197 patients treated at Fujian Provincial Cancer Hospital was used as the training set, and the results were validated with 412 patients from Pamela Youde Nethersole Eastern Hospital. Cox regression analyses were performed to identify significant prognostic factors for developing a nomogram to predict overall survival (OS). The discriminative ability was assessed with the concordance index (c‐index). A recursive partitioning algorithm was applied to the survival scores of the combined set to categorize the patients into 3 risk groups.

RESULTS

A multivariate analysis showed that age, gross primary tumor volume, and lactate dehydrogenase were independent prognostic factors for OS in addition to the stage group. The OS nomogram based on all these factors had a statistically higher bias‐corrected c‐index than prognostication based on the stage group alone (0.712 vs 0.622, P <.01). These results were consistent for both the training cohort and the validation cohort. Patients with <135 points were categorized as low‐risk, patients with 135 to <160 points were categorized as intermediate‐risk, and patients with ≥160 points were categorized as high‐risk. Their 5‐year OS rates were 92%, 84%, and 58%, respectively.

CONCLUSIONS

The proposed nomogram could improve prognostication in comparison with the TNM stage group. This could aid in risk stratification for individual NPC patients. Cancer 2016;122:3307–3315. © 2016 American Cancer Society.
Heteroepitaxial Growth of Well‐Dispersed Co3O4 Nanocatalysts on Porous ZnO Nanoplates via Successive Hydrothermal Deposition
Authors: Feng Zhenyu , Bao Wenya , Xu Xiaohong , Ma Xicheng , Zhan Jinhua , Yin Yadong
Published: July 2016

We report a unique successive hydrothermal deposition method for the heteroepitaxial growth of well‐dispersed crystalline Co3O4 nanoparticles on single‐crystalline porous ZnO nanoplates toward a Co3O4/ZnO nanocomposite catalyst. The specific heteroepitaxial crystal faces between Co3O4 and ZnO limit the size of Co3O4 particles to be approximately 5 nm and allow the exposure of more active sites. The intermediate of hydrozincite [Zn5(CO3)2(OH)6] plays a role as template in creating porous ZnO nanoplates and oriented Co3O4 grains via thermal decomposition process. The active exposure of the catalyst is probed by CO oxidation. The nanocomposite exhibits significantly enhanced catalytic efficiency towards CO oxidation at temperatures ranging from 30 to 115 °C, in comparison with a homogeneous Co3O4 sample and one‐step Co/ZnO products.
Tuning Gold Nanoparticle Aggregation through the Inhibition of Acid Phosphatase Bioactivity: A Plasmonic Sensor for Light‐Up Visual Detection of Arsenate (AsV)
Authors: Zhang Jia , Zhang Chuan‐Ling , Yu Shu‐Hong
Published: July 2016

A plasmonic biosensor for arsenate has been developed which uses gold nanoparticles (AuNPs) as the signal reporter and in which the biocatalytic activity of acid phosphatase (AcP) is modified by the target ion. The enzyme catalyzes the hydrolysis of negatively charged adenosine 5′‐monophosphate (AMP) to neutral adenosine, causing appreciable aggregation of AuNPs and then visible color change of the solution from red to blue. The presence of arsenate (AsV), as a molecular analogue of phosphate, can effectively interfere with the bioactivity of AcP by competitive inhibition, and so the hydrolysis process is slowed down. This is reflected by the change in the solution color from blue to red with increasing concentrations of AsV. In contrast to AuNP‐based sensors for arsenic (basically AsIII) that employ the strong interaction between AsIII‐specific molecules and AsIII, this sensor adopts a different sensing principle and is the first visible sensor for specifically AsV specifically using AuNPs. Finally the practical assay of AsV in groundwater and lake water was performed with satisfactory results, suggesting this approach can be used for quantification of AsV levels in real water samples.
Disease introduction is associated with a phase transition in bighorn sheep demographics
Authors: Manlove Kezia , Cassirer E. Frances , Cross Paul C. , Plowright Raina K. , Hudson Peter J.
Published: July 2016

Ecological theory suggests that pathogens are capable of regulating or limiting host population dynamics, and this relationship has been empirically established in several settings. However, although studies of childhood diseases were integral to the development of disease ecology, few studies show population limitation by a disease affecting juveniles. Here, we present empirical evidence that disease in lambs constrains population growth in bighorn sheep (Ovis canadensis) based on 45 years of population‐level and 18 years of individual‐level monitoring across 12 populations. While populations generally increased (λ = 1.11) prior to disease introduction, most of these same populations experienced an abrupt change in trajectory at the time of disease invasion, usually followed by stagnant‐to‐declining growth rates (λ = 0.98) over the next 20 years. Disease‐induced juvenile mortality imposed strong constraints on population growth that were not observed prior to disease introduction, even as adult survival returned to pre‐invasion levels. Simulations suggested that models including persistent disease‐induced mortality in juveniles qualitatively matched observed population trajectories, whereas models that only incorporated all‐age disease events did not. We use these results to argue that pathogen persistence may pose a lasting, but under‐recognized, threat to host populations, particularly in cases where clinical disease manifests primarily in juveniles.
Nonlinear disruption of ecological interactions in response to nitrogen deposition
Authors: Ochoa‐Hueso Raúl
Published: July 2016

Global environmental change (GEC) is affecting species interactions and causing a rapid decline in biodiversity. In this study, I present a new Ecosystem Disruption Index to quantify the impacts of simulated nitrogen (N) deposition (0, 10, 20, and 50 kg N·ha−1·yr−1 + 6–7 kg N·ha−1·yr−1 background) on abiotic and biotic ecological interactions. This comparative index is based on pairwise linear and quadratic regression matrices. These matrices, calculated at the N treatment level, were constructed using a range of abiotic and biotic ecosystem constituents: soil pH, shrub cover, and the first component of several separate principal component analyses using soil fertility data (total carbon and N) and community data (annual plants, microorganisms, biocrusts, edaphic fauna) for a total of seven ecosystem constituents. Four years of N fertilization in a semiarid shrubland completely disrupted the network of ecological interactions, with a greater proportional increase in ecosystem disruption at low N addition levels. Biotic interactions, particularly those involving microbes, shrubs, and edaphic fauna, were more prone to be lost in response to N, whereas interactions involving soil properties were more resilient. In contrast, edaphic fauna was the only group directly affected by N addition, with mites and collembolans increasing their abundance with up to 20 kg N·ha−1·yr−1 and then decreasing, which supports the idea of higher‐trophic‐level organisms being more sensitive to disturbance due to more complex links with other ecosystem constituents. Future experimental studies evaluating the impacts of N deposition, and possibly other GEC drivers, on biodiversity and biotic and abiotic interactions may be able to explain results more effectively in the context of ecological networks as a key feature of ecosystem sensitivity.
Enantioselective Cascade Reaction of α‐Cyano Ketones and Isatylidene Malononitriles: Asymmetric Construction of Spiro[4H‐pyran‐oxindoles]
Authors: Xie Jin , Xing Wei‐Long , Sha Feng , Wu Xin‐Yan
Published: July 2016

α‐Cyano ketones have been employed for the first time as Michael donors in the construction of chiral spiro compounds. By using only 2 mol‐% of a chiral multifunctional organocatalyst, chiral spiro[4H‐pyran‐oxindole] derivatives were prepared in yields of 97–99 % with enantioselectivities of 76–97 % ee. This method provides a new approach to the synthesis of chiral spirocyclic oxindoles.
Investigation of Electrochemical Oxidation of Methanol at a Carbon Paste Electrode Modified with Ni(II)‐BS Complex and Reduced Graphene Oxide Nano Sheets
Authors: Mousavi Zeinab , Benvidi Ali , Jahanbani Shahriar , Mazloum‐Ardakani Mohammad , Vafazadeh Rasoul , Zare Hamid R.
Published: July 2016

In the present research, the electro oxidation of methanol was investigated by different electrochemical methods at a carbon paste electrode (CPE) modified with bis(salicylaldehyde)‐nickel(II)‐dihydrate complex (Ni(II)‐BS) and reduced graphene oxide (RGO) (which named Ni(II)‐BS/RGO/CPE) in an alkaline solution. This modified electrode showed very efficient activity for oxidation of methanol. It was found that methanol was oxidized by NiOOH groups generated by further electrochemical oxidation of nickel (II) hydroxide on the surface of the modified electrode. The rate constant and electron transfer coefficient were calculated to be 2.18 s−1 and 0.4, respectively. The anodic peak currents revealed a linear dependency with the square root of scan rate. This behaviour is the characteristic of a diffusion controlled process, so the diffusion coefficient of methanol was found to be 1.16×10−5 cm2 s−1 and the number of transferred electron was calculated to be 1. Moreover, differential pulse voltammetry (DPV) investigations showed that the peak current values were proportional to the concentration of methanol in two linear ranges. The obtained linear ranges were from 0.5 to 100.0 µM (R2=0.991) and 400.0 to 1300.0 µM (R2=0.992), and the detection limit was found to be 0.19 µM for methanol determination. Generally, the Ni(II)‐BS/RGO/CPE sensor was used for determination of methanol in an industrial ethanol solution containing 4.0 % methanol.
Redox Processes of Guanine Moieties in DNA Heptamers Related to Hydrogen Evolution
Authors: Triskova Iveta , Fiala Radovan , Trnkova Libuse
Published: July 2016

The paper is focused on the electrochemical investigation of DNA heptamers d(GCXXXGC) with different central triplets of nucleotides (XXX=GAA, AAA, CCC, GGG). On a hanging mercury electrode (HMDE), the reduction peaks of adenine (A) and cytosine (C) moieties are detectable, but those of guanine (G) moieties are covered by an intensive current of hydrogen evolution. Because cyclic voltammetry allows us to monitor only the oxidation processes of the G reduced species, the effect of hydrogen evolution reaction (HER) was studied by means of these anodic signals. For different vertex potentials (from −1.60 V to −1.85 V) and a different number of cycles (1–5), all heptamers in buffered solutions (pH 5.8) were tested and double‐peak G oxidation signals (GI and GII) evaluated. The different structures of the heptamers in solutions are confirmed by NMR spectra. Both the impact of hydrogen evolution into the production of 7,8‐dihydroguanine moieties forming together with hydrogen in negative potentials and the catalytic effect of heptamers on hydrogen evolution are discussed.
The rs6983267 SNP and long non‐coding RNA CARLo‐5 are associated with endometrial carcinoma
Authors: Zhao Xiwa , Wei Xurui , Zhao Lianmei , Shi Li , Cheng Jianxin , Kang Shan , Zhang Hui , Zhang Jun , Li Li , Zhang Haibo , Zhao Wei
Published: July 2016

The single nucleotide polymorphism (SNP) rs6983267 and cancer‐associated region long non‐coding RNA (CARLo‐5) are associated with various human cancers. This study aimed to investigate the expression of CARLo‐5 in endometrial carcinoma (EC) and its relationship with clinicopathological features and patient survival. The association of the rs6983267 SNP with EC risk and its involvement in the regulation of CARLo‐5 expression in EC were investigated. The rs6983267 SNP was genotyped by polymerase chain reaction (PCR) and ligase detection reaction in 543 EC patients and 584 controls. The expression of CARLo‐5 in 108 EC tissues and 66 normal endometrial tissues (NETs) was determined using quantitative real‐time PCR. The genotype and allele distributions of the rs6983267 SNP differed significantly between patients and controls. There was a significant correlation between the rs6983267 genotypes and lymph node metastasis of EC patients (P = 0.026). CARLo‐5 expression was significantly higher in EC tissues than in NETs (P < 0.001) and significantly associated with FIGO stage (P = 0.029) and lymph node metastasis (P = 0.030). Patients with high CARLo‐5 expression had significantly shorter overall survival than those with low CARLo‐5 expression (P = 0.003). The rs6983267 genotype was significantly correlated with CARLo‐5 expression (P < 0.05). In conclusion, CARLo‐5 was identified as a pro‐oncogenic lncRNA that may play an important role in EC progression and represent a prognostic marker for EC. The expression of CARLo‐5 was significantly correlated with the rs6983267 genotype associated with increased susceptibility to EC. Environ. Mol. Mutagen. 57:508–515, 2016. © 2016 Wiley Periodicals, Inc.
Temporal variation in circulating concentrations of organochlorine pollutants in a pelagic seabird breeding in the high Arctic
Authors: Bustnes Jan O. , Bårdsen Bård-Jørgen , Moe Børge , Herzke Dorte , Hanssen Sveinn A. , Sagerup Kjetil , Bech Claus , Nordstad Tore , Chastel Olivier , Tartu Sabrina , Gabrielsen Geir Wing
Published: July 2016

The present study explored short-term temporal variations in circulating concentrations of 3 legacy organochlorines with different physicochemical properties (polychlorinated biphenyl 153 [PCB-153], p,p′-dichlorodiphenyldichloroethylene [DDE], and hexachlorobenzene [HCB]) in breeding kittiwakes (Rissa tridactyla) in a colony in Svalbard (78°N), Norwegian Arctic. Concentrations were measured in blood of a large number (n = 412–521 blood samples, depending on the data analyses) of prebreeding, incubating, and chick-rearing birds over a period of 5 yr (2007–2011). The PCB-153 concentrations were equal in male and female blood in the prebreeding period, whereas females had significantly lower concentrations during incubation and chick rearing, probably because of their ability to eliminate organochlorines through egg laying. A similar temporal pattern was observed with DDE, although the lower concentrations in incubating females were not significant. Males and females had similar concentrations of HCB over all reproductive stages. The concentrations of all 3 compounds varied greatly between years. The concentrations of PCB-153 tended to decline over the study period, whereas concentrations of HCB showed an increasing trend, especially among chick-rearing males late in the season. Concentrations of PCB-153 increased approximately 2.5 times from the prebreeding to the chick-rearing period, concurrent with mobilization of body lipids (reduced body mass). A similar, but less pronounced trend was found for HCB. For DDE, however, kittiwakes had the highest concentrations in the prebreeding period, suggesting relatively high exposure in their winter areas. The present study documented large variations in circulating concentrations of legacy organochlorines among and within breeding seasons in kittiwakes, but the alterations within seasons were relatively consistent from year to year. Environ Toxicol Chem 2017;36:442–448. © 2016 SETAC
Reconstructing Early Neolithic Paleogeography: EMI‐Based Subsurface Modeling and Chronological Modeling of Holocene Peat below the Lower Scheldt Floodplain in NW Belgium
Authors: Verhegge Jeroen , Saey Timothy , Van Meirvenne Marc , Missiaen Tine , Crombé Philippe
Published: July 2016

Well‐preserved prehistoric landscapes and sites have been found, buried deeply below the Holocene peat or floodplain deposits of “Waasland Scheldt polders.” During the mid‐to‐late Holocene, Late Weichselian (river) dunes within the floodplain and river flanks were favored locations for Final Early Neolithic occupation. Available living space was determined by the dune topography and elevation of the peat at that time. Therefore, an elevation model of the peat base was created using multireceiver electromagnetic induction (EMI) survey data. Electrical conductivity data of a dune were collected and 1D inverted within a three‐layered soil model with variable electrical conductivity of the top layer and variable depth to the base of the middle layer (i.e., the peat). The modeled peat base depth was calibrated and validated, and eventually replaced by depth data from coring and cone penetration measurements wherever depth modeling from inverting the EMI measurements proved inaccurate. Using the resulting peat base elevation model, a paleogeographic map at the time of the modeled end date of Mesolithic–Neolithic transitional Swifterbant Culture sites nearby was created by chronologically modeling the peat elevation at that time. The developed paleogeographic mapping methodology can be used for subsequent archaeological prospection by core sampling or to contextualize excavated sites.
Toward the integration of Omics data in epidemiological studies: still a “long and winding road”
Authors: López de Maturana Evangelina , Pineda Sílvia , Brand Angela , Van Steen Kristel , Malats Núria
Published: July 2016

Primary and secondary prevention can highly benefit a personalized medicine approach through the accurate discrimination of individuals at high risk of developing a specific disease from those at moderate and low risk. To this end precise risk prediction models need to be built. This endeavor requires a precise characterization of the individual exposome, genome, and phenome. Massive molecular omics data representing the different layers of the biological processes of the host and the nonhost will enable to build more accurate risk prediction models. Epidemiologists aim to integrate omics data along with important information coming from other sources (questionnaires, candidate markers) that has been proved to be relevant in the discrimination risk assessment of complex diseases. However, the integrative models in large‐scale epidemiologic research are still in their infancy and they face numerous challenges, some of them at the analytical stage. So far, there are a small number of studies that have integrated more than two omics data sets, and the inclusion of non‐omics data in the same models is still missing in most of studies. In this contribution, we aim at approaching the omics and non‐omics data integration from the epidemiology scope by considering the “massive” inclusion of variables in the risk assessment and predictive models. We also provide already available examples of integrative contributions in the field, propose analytical strategies that allow considering both omics and non‐omics data in the models, and finally review the challenges imbedding this type of research.
Targeting DDR2 in head and neck squamous cell carcinoma with dasatinib
Authors: von Mässenhausen Anne , Sanders Christine , Brägelmann Johannes , Konantz Martina , Queisser Angela , Vogel Wenzel , Kristiansen Glen , Duensing Stefan , Schröck Andreas , Bootz Friedrich , Brossart Peter , Kirfel Jutta , Lengerke Claudia , Perner Sven
Published: July 2016

Squamous cell carcinoma of the head and neck (HNSCC) is the tenth most common tumor entity in men worldwide. Nevertheless therapeutic options are mostly limited to surgery and radio‐chemotherapy resulting in 5‐year survival rates of around 50%. Therefore new therapeutic options are urgently needed. During the last years, targeting of receptor tyrosine kinases has emerged as a promising strategy that can complement standard therapeutical approaches. Here, we aimed at investigating if the receptor tyrosine kinase DDR2 is a targetable structure in HNSCC. DDR2 expression was assessed on a large HNSCC cohort (554 patients) including primary tumors, lymph node metastases and recurrences and normal mucosa as control. Subsequently, DDR2 was stably overexpressed in two different cell lines (FaDu and HSC‐3) using lentiviral technology. Different tumorigenic properties such as proliferation, migration, invasion, adhesion and anchorage independent growth were assessed with and without dasatinib treatment usingin‐vitrocell models andin‐vivozebrafish xenografts. DDR2 was overexpressed in all tumor tissues when compared to normal mucosa. DDR2 overexpression led to increased migration, invasion, adhesion and anchorage independent growth whereas proliferation remained unaltered. Upon dasatinib treatment migration, invasion and adhesion could be inhibitedin‐vitroandin‐vivowhereas proliferation was unchanged. Our data suggest treatment with dasatinib as a promising new therapeutic option for patients suffering from DDR2 overexpressing HNSCC. Since dasatinib is already FDA‐approved we propose to test this drug in clinical trials so that patients could directly benefit from this new treatment option.
Preparation of Compound I in P450cam: The Prototypical P450
Authors: Yosca Timothy H. , Green Michael T.
Published: July 2016

Cytochrome P450cam occupies a central position in the heme monooxygenase landscape. For many years, P450cam has served as a prototype for understanding structure and function in bacterial, fungal, microsomal, and plant P450s. The enzyme is believed to function through a highly reactive iron(IV)oxo radical species called compound I. While the first glimpses of compound I were observed in P450cam over thirty years ago, subsequent attempts to prepare the intermediate for further characterizations have proven unsuccessful. Given that the initial reports provided great promise, the nature of the subsequent failures has been extremely puzzling. Here we detail the preparation of compound I in P450cam. Using insights gained from previous investigations, we have obtained the intermediate in ∼ 45 % yield, allowing characterizations by UV/Visible, Mössbauer, and EPR spectroscopies. This report provides a missing piece of the monooxygenase landscape, verifying the existence of compound I in the most studied P450.
Inverse SORS for detecting a low Raman‐active turbid sample placed inside a highly Raman‐active diffusely scattering matrix – A feasibility study
Authors: Khan Khan Mohd. , Dutta Surjendu B. , Krishna Hemant , Majumder Shovan K.
Published: July 2016

The broad range of applications of spatially‐offset Raman spectroscopy (SORS) were found to involve samples having only marginal differences in Raman cross‐sections between the surface and subsurface targets. We report the results of a feasibility study to evaluate the potential of the approach to identify the presence of a very low Raman‐active turbid sample placed inside a highly Raman‐active diffusely scattering matrix. Paraffin sandwiched tissue blocks prepared by embedding slices of chicken muscle tissue into solid paraffin blocks were employed as representative samples for the study. It was found that in contrast to the several millimetres of probing depth reported in the earlier applications, the Raman signatures of tissue were best recovered when it was located beneath the surface of the paraffin block at a depth of around a millimetre, beyond which the quality of recovery was increasingly poorer. However, the probing depth could be further increased by increasing the thickness of the embedded tissue sections. The results clearly suggest that though the probing depth achievable under the current condition is less than that found in previous applications, nevertheless it is sufficient for various other applications that would not require probing as deep as was required earlier.

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Genipin crosslinker releasing sutures for improving the mechanical/repair strength of damaged connective tissue
Authors: Sundararaj Sharath , Slusarewicz Paul , Brown Matt , Hedman Thomas
Published: July 2016

The most common mode of surgical repair of ruptured tendons and ligaments involves the use of sutures for reattachment. However, there is a high incidence of rerupture and repair failure due to pulling out of the suture material from the damaged connective tissue. The main goal of this research was to achieve a localized delivery of crosslinking agent genipin (GP) from rapid‐release biodegradable coatings on sutures, for strengthening the repair of ruptured connective tissue. Our hypothesis is that GP released from the suture coating will lead to exogenous crosslinking of native connective tissue resulting in beneficial effects on clinically relevant mechanical parameters such as tear resistance, tissue strength, and energy required to rupture the tissue (toughness). Sutures were successfully coated with a biodegradable polymer layer loaded with the crosslinking agent genipin, without compromising the mechanical properties of the suture. The rapid‐release of genipin was achieved under both in vitro and ex vivo conditions. Exogenous crosslinking using these genipin releasing sutures was demonstrated using equine tendons. The tendons treated with genipin releasing sutures showed significant improvement in failure load, energy required for pull‐out failure, and stiffness. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2199–2205, 2017.
1H MR spectroscopy in cervical carcinoma using external phase array body coil at 3.0 Tesla: Prediction of poor prognostic human papillomavirus genotypes
Authors: Lin Gigin , Lai Chyong‐Huey , Tsai Shang‐Yueh , Lin Yu‐Chun , Huang Yu‐Ting , Wu Ren‐Chin , Yang Lan‐Yan , Lu Hsin‐Ying , Chao Angel , Wang Chiun‐Chieh , Ng Koon‐Kwan , Ng Shu‐Hang , Chou Hung‐Hsueh , Yen Tzu‐Chen , Hung Ji‐Hong
Published: July 2016

Purpose

To assess the clinical value of proton (1H) MR spectroscopy in cervical carcinomas, in the prediction of poor prognostic human papillomavirus (HPV) genotypes as well as persistent disease following concurrent chemoradiotherapy (CCRT).

Materials and Methods

1H MR spectroscopy using external phase array coil was performed in 52 consecutive cervical cancer patients at 3 Tesla (T). Poor prognostic HPV genotypes (alpha‐7 species or absence of HPV infection) and persistent cervical carcinoma after CCRT were recorded. Statistical significance was calculated with the Mann‐Whitney two‐sided nonparametric test and areas under the receiver operating characteristics curve (AUC) analysis.

Results

A 4.3‐fold (P = 0.032) increased level of methyl resonance at 0.9 ppm was found in the poor prognostic HPV genotypes, mainly attributed to the presence of HPV18, with a sensitivity of 75%, a specificity of 81%, and an AUC of 0.76. Poor prognostic HPV genotypes were more frequently observed in patients with adeno‐/adenosquamous carcinoma (Chi‐square, P < 0.0001). In prediction of the four patients with persistent disease after CCRT, elevated methyl resonance demonstrated a sensitivity of 100%, a specificity of 74%, and an AUC of 0.82.

Conclusion

1H MR spectroscopy at 3T can be used to depict the elevated lipid resonance levels in cervical carcinomas, as well as help to predict the poor prognostic HPV genotypes and persistent disease following CCRT. Further large studies with longer follow up times are warranted to validate our initial findings.

Level of Evidence: 1

J. Magn. Reson. Imaging 2017;45:899–907.
Epstein–Barr virus strains and variations: Geographic or disease‐specific variants?
Authors: Neves Marco , Marinho‐Dias Joana , Ribeiro Joana , Sousa Hugo
Published: July 2016

The Epstein–Barr Virus (EBV) is associated with the development of several diseases, including infectious mononucleosis (IM), Burkitt's Lymphoma (BL), Nasopharyngeal Carcinoma, and other neoplasias. The publication of EBV genome 1984 led to several studies regarding the identification of different viral strains. Currently, EBV is divided into EBV type 1 (B95‐8 strain) and EBV type 2 (AG876 strain), also known as type A and type B, which have been distinguished based upon genetic differences in the Epstein–Barr nuclear antigens (EBNAs) sequence. Several other EBV strains have been described in the past 10 years considering variations on EBV genome, and many have attempted to clarify if these variations are ethnic or geographically correlated, or if they are disease related. Indeed, there is an increasing interest to describe possible specific disease associations, with emphasis on different malignancies. These studies aim to clarify if these variations are ethnic or geographically correlated, or if they are disease related, thus being important to characterize the epidemiologic genetic distribution of EBV strains on our population. Here, we review the current knowledge on the different EBV strains and variants and its association with different diseases.J. Med. Virol. 89:373–387, 2017.© 2016 Wiley Periodicals, Inc.
Prevalence and risk factors of HCV infection in a metropolitan area in southern Italy: Tail of a cohort infected in past decades
Authors: Morisco Filomena , Loperto Ilaria , Stroffolini Tommaso , Lombardo Flavia Lucia , Cossiga Valentina , Guarino Maria , De Feo Alessia , Caporaso Nicola
Published: July 2016

Data on the prevalence of HCV infection in Italy are often outdated and from non‐urban populations. This study assessed the prevalence and risk factors for HCV infection in a large metropolitan area in southern Italy. A random 1:3 systematic sample of the adult general population of Naples was selected from three general practitioner patient registers in three different city districts. Socioeconomic indicators and risk factors for HCV infection were collected. Anti‐HCV and HCV‐RNA assays were performed. Logistic regression analysis was used to identify independent predictors of HCV infection. Of 1,500 randomly selected subjects, 1,315 (87.7%) participated in the study. Forty subjects (3.0%; 95%CI: 2.1–4.0) were anti‐HCV‐positive, with HCV‐RNA detected by PCR in 31 (77.5%) of these. Anti‐HCV prevalence increased with age, peaking (8.2%) in people born during the years 1945–1955. It was 1.7% in people residing in the better socioeconomic districts; but 5.7% in those residing in the district with lower socioeconomic status (P < 0.01). In multivariate analysis, age ≥60 years (OR 2.8, 95%CI: 1.3–6.1) and lower educational level (OR 3.6; 95%CI: 1.4–9.3), which is a proxy of low socioeconomic status, were the only independent predictors of the likelihood of anti‐HCV positivity. Overall, 22.5% of anti‐HCV positive subjects were previously unaware of their status. In the large city of Naples, infection with HCV is most common in people aged older than 60 years. Differences in socioeconomic conditions have played an important role in the spread of this infection. HCV positive subjects born during the years 1945–1955 are those who may benefit, to a greater extent, to be identified in order to receive the new effective therapy. J. Med. Virol. 89:291–297, 2017. © 2016 Wiley Periodicals, Inc.
Early global radiation measurements: a review
Authors: Stanhill Gerald , Achiman Ori
Published: July 2016

Measurements of global radiation Eg↓ made in the first half of the 20th century are reviewed. The thermoelectric pyranometers used to measure Eg↓ in the United States, Western Europe and Russia are described and the published sources of data available up to and including the 1957 International Geophysical Year are documented together with the few analyses of this data which have been reported. Two 100‐year‐long series measured at Potsdam, Germany and Washington, DC in the United States are presented to illustrate the potential value of the early measurements in understanding the changes in Eg↓ which have occurred in the last 60 years.
How many RCM ensemble members provide confidence in the impact of land‐use land cover change?
Authors: Laux Patrick , Nguyen Phuong N. B. , Cullmann Johannes , Van Tan Phan , Kunstmann Harald
Published: July 2016

Regional climate models (RCMs) include both terrestrial and atmospheric compartments and thereby allow studying land–atmosphere feedback, in particular, the impact of land‐use land cover driven by biogeophysical processes on regional climate. In this study, a method is developed to separate the signals from the noise in RCM simulations of the effects of changes in land use, using perturbed initial boundary conditions (PICs). We want to know how many ensemble members are required to identify robust and statistically significant land‐use land cover change (LULCC) effects from RCM LULCC studies. The method is applied to a case study of urbanization and deforestation, for which LULCC scenarios are implemented in the RCM Weather Research and Forecasting (WRF). Based on WRF ensemble simulations with PICs for 2010, the signal‐to‐noise ratio (SNR) is used to identify areas with pronounced effect of an LULCC or, rather, the parametrization of the land‐use classes. While in the urbanization scenarios clear and statistically significant signals are found for air temperature and for both latent‐ and sensible heat (SNR values up to 24), the effects are less pronounced for precipitation, and for deforestation in general (SNR values < 1). For the case study of urbanization and precipitation, the impact of the ensemble size is studied in order to derive robust conclusions about the effects of LULCC on precipitation. We conclude that single RCM realizations of different land‐use representations are not sufficient to derive LULCC‐induced signals, particularly not for precipitation. Small ensemble sizes led to concluding there were significant LULCC‐induced precipitation signals, but these disappeared when the ensemble size was increased. Our regional analysis suggests the need for ensemble sizes well above 10 for precipitation.
Carotenoids in fresh and processed tomato (Solanum lycopersicum) fruits protect cells from oxidative stress injury
Authors: Del Giudice Rita , Petruk Ganna , Raiola Assunta , Barone Amalia , Monti Daria Maria , Rigano Maria Manuela
Published: July 2016

BACKGROUND

Lipophilic antioxidants in tomato (Solanum lycopersicum) fruits exert important functions in reducing the risk of human diseases. Here the effect of thermal processing on the antioxidant activity of lipophilic extracts from the commercial tomato hybrid ‘Zebrino’ was analysed. Carotenoid content and lipophilic antioxidant activity were determined and the ability of tomato extracts in rescuing cells from oxidative stress was assessed.

RESULTS

Lipophilic antioxidant activity was completely retained after heat treatment and extracts were able to mitigate the detrimental effect induced by oxidative stress on different cell lines. Lycopene alone was able to rescue cells from oxidative stress, even if to a lower extent compared with tomato extracts. These results were probably due to the synergistic effect of tomato compounds in protecting cells from oxidative stress injury.

CONCLUSION

The current study provides valuable insights into the health effect of the dietary carotenoids present in fresh and processed tomato fruits. © 2016 Society of Chemical Industry
Kinetics of Ge(IV) Extraction Using a Microstructured Membrane Contactor
Authors: Willersinn Stefan , Bart Hans‐Jörg
Published: July 2016

For hydrometallurgical metal extraction, the mass transfer by diffusion is additionally coupled with a chemical reaction of the metal ion with the extractant molecule, usually at the interface. Consequently, the kinetics is either limited by diffusion or chemical reaction (or both, respectively, in a mixed regime). Conventional methods for determining the extraction kinetics often lead to a misinterpretation, especially for fast reactions, and an isolated view of the interfacial reaction is restricted. With a new microcontactor setup, it is possible to perform a comprehensive kinetic analysis with very low sample volumes compared to established methods. Additionally, it is possible to quantify all individual mass transfer resistances and identify the extraction regime with the developed mass transfer model. The chemical reaction part is investigated isolated, to derive rate laws and kinetic constants. The methodology is discussed for the extraction of Ge(IV) from aqueous solutions with the two extractants 5,8‐diethyl‐7‐hydroxydodecan‐6‐oxime (LIX 63) and 7‐(4‐ethyl‐1‐methyloctyl)‐8‐hydroxyquinoline (Kelex 100). It was found that the extraction with LIX 63 is reaction limited and with Kelex 100 the reaction resistance is in the same order of magnitude as the diffusion resistances. The obtained results provide fundamental kinetic data for the design of solvent extraction equipment.
Hepatic encephalopathy expands the predictivity of model for end‐stage liver disease in liver transplant setting: Evidence by means of 2 independent cohorts
Authors: Lucidi Cristina , Ginanni Corradini Stefano , Abraldes Juan G. , Merli Manuela , Tandon Puneeta , Ferri Flaminia , Parlati Lucia , Lattanzi Barbara , Poli Edoardo , Di Gregorio Vincenza , Farcomeni Alessio , Riggio Oliviero
Published: July 2016

Despite its documented prognostic relevance, hepatic encephalopathy (HE) is not considered in liver transplantation (LT) due to its possible poor objectivity. To override this problem, we aimed to analyze if an objective diagnosis of HE may confer additional mortality risk beyond MELD. Study and validation cohorts of patients with cirrhosis were considered in Italy and Canada, respectively. Patients were considered to be HE+ if an episode of overt HE was documented in a hospitalization. Of the 486 patients enrolled in Italy, 184 (38%) were HE+. During the 6‐month follow‐up, 77 patients died and 50 underwent transplantation. The 6‐month mortality of HE+ versus HE– patients was significantly higher (P < 0.001). Model for End‐Stage Liver Disease (MELD; subdistribution hazard ratio [sHR], 1.2; 95% confidence interval [CI], 1.1‐1.2; P < 0.001), HE+ (sHR, 3.6; 95% CI, 1.8‐7.1; P < 0.001), and sodium (sHR, 0.9; 95% CI, 0.8‐0.9; P < 0.001) were independent predictors of 6‐month mortality. In HE+ patients, short‐term mortality increased across the entire MELD spectrum (range, 6‐40). The results were unchanged by including or excluding patients with hepatocellular carcinoma or stratifying patients according to HE characteristics. The higher 6‐month mortality of HE+ versus HE– patients was confirmed also in the Canadian cohort (P < 0.001; n = 300, 33% HE+; 33 died, 104 transplanted). A similar and statistically significant C‐index increase derived by the incorporation of HE in MELD was observed both in the Italian (from 0.67 to 0.75) and Canadian (from 0.69 to 0.74) cohorts. A score based on MELD plus 7 points (95% CI, 4‐10) for HE+ patients optimally predicted 6‐month mortality in the 2 cohorts. According to the net reclassification index, by not considering HE, 29% of overall patients were misclassified by MELD score. In conclusion, the incorporation of HE in MELD score might improve the listing and allocation policy in LT. Liver Transplantation 22 1333–1342 2016 AASLD.
Synthesis of pH‐Cleavable dPG‐Amines for Gene Delivery Application
Authors: Dimde Mathias , Steinhilber Dirk , Neumann Falko , Li Yan , Paulus Florian , Ma Nan , Haag Rainer
Published: July 2016

The development of effective nonviral vectors for gene therapy is still a challenge in research, due to the high toxicity of many existing polycationic nanocarriers. In this paper, the development of two pH‐cleavable polyglycerol‐amine‐based nanocarriers is described. The benz­acetal bond represents the pH‐sensitive cleavage site between dendritic polyglycerol (dPG) and glycerol‐based 1,2‐diamines that can complex genetic material. Due to the acid lability of the acetal moiety, the cleavable dPG‐amines are less toxic in vitro. Cell‐mediated degradation results in non‐toxic dPG with low amine functionalization and low molecular weight cleavage products (cp). The genetic material is released because of the loss of multivalent amine groups. Interestingly, the release kinetics at the endosomal pH could be controlled by simple chemical modification of the acetals. In vitro experiments demonstrate the ability of the cleavable dPG‐amine to transfect HeLa cells with GFP‐DNA, which resulted in cell‐compatible cleavage products.

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Photopolymerization of an Epoxy Resin: Conversion and Temperature Dependence of its Refractive Index
Authors: Aloui Faten , Lecamp Laurence , Lebaudy Philippe , Burel Fabrice
Published: July 2016

Obtaining photocomposite materials with predefined optical properties requires a good knowledge of the refractive index evolution of the photopolymerizable media. In this aim, relationships between refractive index and conversion in the course of an epoxy resin photopolymerization are first established due to real time refractometric and infrared spectroscopic techniques. Refractive index value increases with conversion as long as the photocured material is not in glassy state. A shift of the relationship toward lowest refractive index values is observed when the reaction temperature increases. Second, the final photocured materials previously obtained are characterized. It is highlighted that the higher the photocuring temperature, the higher the epoxy conversion but the lower the material density at room temperature. This unusual result can be explained by the evolution of the material thermo‐optic coefficient, dn/dT. Indeed, the higher the conversion, the lower this coefficient.

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The “Grafting‐to” of Well‐Defined Polystyrene on Graphene Oxide via Nitroxide‐Mediated Polymerization
Authors: García‐Valdez Omar , Ledezma‐Rodríguez Raquel , Torres‐Lubian Román , Yate Luis , Saldívar‐Guerra Enrique , Ziolo Ronald F.
Published: July 2016

The grafting of well‐defined polystyrene to graphene oxide (GO) using nitroxide‐mediated polymerization (NMP) is demonstrated by a two‐step reaction. In the first step, GO is functionalized with glycidyl methacrylate (GMA) to yield GO‐GMA. Polystyrene (PS), previously synthesized via SG1‐based NMP, is then grafted to GO‐GMA by a simple reaction between the SG1 end group and the GMA double bond to yield GO‐GMA‐g‐PS. 1H, heteronuclear single‐quantum correlation (HSQC), nuclear magnetic resonance (NMR), X‐ray photoelectron spectroscopy (XPS), Raman, Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), and thermogravimetric analysis (TGA) are consistent with attachment of the GMA group to the GO surface and with polystyrene being grafted to the GO surface to form the GO‐GMA‐g‐PS nanocomposite (NC). GPC analysis shows a number‐average molecular weight of 3330 g mol−1 for the PS with molecular weight dispersity (Ð) of 1.13. Up to 28 mass% of PS has been introduced into the GO NC. The present “grafting‐to” methodology holds promise for the facile and clean synthesis of graphene oxide polymer NCs.

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