bluuebunny/crossref_metadata_2025 huggingface dataset:
Copulas‐based risk analysis for inter‐seasonal combinations of wet and dry conditions under a changing climate
Authors: Fang Wei , Huang Shengzhi , Huang Guohe , Huang Qiang , Wang Hao , Wang Lu , Zhang Ying , Li Pei , Ma Lan
Published: November 2018

Abrupt transitions between droughts and floods present greater challenges to water resource management than independent drought or flood events. It is therefore of significant importance to further include drought–flood transitions in the risk analysis of water‐related hazards under a changing climate. This study more generally evaluates the risks of combinations of dry and wet conditions between adjacent seasons. First, dry and wet conditions are monitored by the standardized precipitation index (SPI). Then, a copula‐based framework is proposed for the deviation of joint return periods of dryness–wetness combinations at different severity levels. In addition, SPI series trend detection is conducted using the Mann–Kendall test to analyse the temporal–spatial changes in dry and wet conditions. Wavelet analysis is applied to investigating correlations of dry and wet conditions with climate variability signals, which may provide predictive signals for dryness–wetness combinations. The results of a case study in the Pearl River basin (PRB), China over the period of 1960–2015 indicate that (a) the flood season (from July to October) tends towards dryness and there are wetting trends in the late autumn and winter; (b) as the joint return period is considered the proxy for the risk of dryness–wetness combination, shorter joint return periods remind a higher risk of suffering from abrupt dryness–wetness transitions in the spring–summer and summer–autumn, as well as the more frequent occurrence of continued dryness/wetness in the autumn–winter and winter–spring; (c) the western and eastern PRB are separately characterized by intensified and reduced risks of the most frequent combinations under a changing climate; and (d) El Niño–Southern Oscillation events, the Pacific Decadal Oscillation and sunspot activities have a close association with dry and wet conditions in the PRB. The study provides a supplement for the current risk map and may benefit the early warning and mitigation of water‐related hazards.
Evaluation of a large ensemble regional climate modelling system for extreme weather events analysis over Bangladesh
Authors: Rimi Ruksana H. , Haustein Karsten , Barbour Emily J. , Jones Richard G. , Sparrow Sarah N. , Allen Myles R.
Published: November 2018

Potential increases in the risk of extreme weather events under climate change can have significant socio‐economic impacts at regional levels. These impacts are likely to be particularly high in South Asia where Bangladesh is one of the most vulnerable countries. Regional climate models (RCMs) are valuable tools for studying weather and climate at finer spatial scales than are typically available in global climate models. Quantitative assessment of the likely changes in the risk of extreme events occurring requires very large ensemble simulations due to their rarity. The weather@home setup within theclimateprediction.netdistributed computing project is capable of providing the necessary very large ensembles at regionally higher resolution, but has only been evaluated over the South Asia region for its representation of seasonal climatological and monthly means. Here, we evaluate how realistically the HadAM3P‐HadRM3P model setup of weather@home can reproduce the observed patterns of temperature and rainfall in Bangladesh with focus on the modelled extreme events. Using very large ensembles of regional simulations, we find that there are substantial spatial and temporal variations in rainfall and temperature biases compared with observations. These are highest in the pre‐monsoon, which are largely caused by timing issues in the model. Modelled mean monsoon and post‐monsoon temperatures are in good agreement with observations, whereas there is a dry bias in the modelled mean monsoon rainfall. The rainfall bias varies both spatially and with the data set used for comparison. Despite of these biases, the model‐simulated temperature and rainfall extremes in summer monsoon over Bangladesh are approximately representative of the observed ones. At the wettest parts of northeast Bangladesh, rainfall extremes are underestimated compared to GPCC and APHRODITE but are within the range of CPC observations. Therefore, the weather@home RCM, HadRM3P may provide a sufficiently reliable tool for studying the extreme weather events in Bangladesh.
Vitamin C Administration to the Critically Ill: A Systematic Review and Meta‐Analysis
Authors: Langlois Pascal L. , Manzanares William , Adhikari Neill K. J. , Lamontagne François , Stoppe Christian , Hill Aileen , Heyland Daren K.
Published: November 2018

Vitamin C, an enzyme cofactor and antioxidant, could hasten the resolution of inflammation, oxidative stress, and microvascular dysfunction. While observational studies have demonstrated that critical illness is associated with low levels of vitamin C, randomized controlled trials (RCTs) of vitamin C, alone or in combination with other antioxidants, have yielded contradicting results. We searched MEDLINE, EMBASE, CINAHL, and the Cochrane Central Register of Controlled Trials (inception to December 2017) for RCTs comparing vitamin C, by enteral or parenteral routes, with placebo or none, in intensive care unit (ICU) patients. Two independent reviewers assessed study eligibility without language restrictions and abstracted data. Overall mortality was the primary outcome; secondary outcomes were incident infections, ICU length of stay (LOS), hospital LOS, and duration of mechanical ventilation (MV). We prespecified 5 subgroups hypothesized to benefit more from vitamin C. Eleven randomized trials were included. When 9 RCTs (n = 1322) reporting mortality were pooled, vitamin C was not associated with reduced risk of mortality (risk ratio [RR] 0.72, 95% confidence interval [CI]: 0.43–1.20, P = .21). No effect was found on infections, ICU or hospital LOS, or duration of MV. In multiple subgroup comparison, no statistically significant subgroup effects were observed. However, we did observe a tendency towards a mortality reduction (RR 0.21; 95% CI: 0.04–1.05; P = .06) when intravenous high‐dose vitamin C monotherapy was administered. Current evidence does not support supplementing critically ill patients with vitamin C. A moderately large treatment effect may exist, but further studies, particularly of monotherapy administration, are warranted.
Nitrogen isotope (δ15N) patterns for amino acids in lemur bones are inconsistent with aridity driving megafaunal extinction in south‐western Madagascar
Authors: Hixon Sean W. , Elliott Smith Emma A. , Crowley Brooke E. , Perry George H. , Randrianasy Jeannot , Ranaivoarisoa Jean Freddy , Kennett Douglas J. , Newsome Seth D.
Published: November 2018

Most endemic species with body masses >10 kg on Madagascar went extinct within the past 1000 years. The extent to which human predation, anthropogenic landscape transformation and aridification may separately or together explain this extinction pattern remains controversial. We present nitrogen isotope (δ15N) values of individual amino acids preserved in bones from now‐extinct Pachylemur insignis and extant Propithecus verreauxi from two subfossil sites in south‐western Madagascar: Tsirave and Taolambiby. The amino acid‐specific approach allows us to identify environmental signals that are otherwise difficult to recognize in bulk collagen δ15N values. Specifically, we use the δ15N values of source amino acids (phenylalanine and lysine) as a proxy for habitat aridity between ca. 4000 years ago and present and the spacing of δ15N values between trophic and source amino acids to quantify trophic levels for these two lemur species. Despite paleoenvironmental evidence for lowering water tables and the expansion of relatively arid savanna between 4000 and 1000 years ago, our isotope data suggest that these lemurs did not live in increasingly arid habitats and did not change their trophic level. Together, our results support the hypothesis that aridity alone did not play a major role in late Holocene megafaunal extinctions in south‐western Madagascar.
Abrupt rise in the contribution of CH4‐derived carbon to benthic secondary production of a shallow hemiboreal/boreal lake
Authors: Belle Simon , Tõnno Ilmar , Stivrins Normunds , Freiberg Rene , Veski Siim
Published: November 2018

Understanding long‐term carbon flows through aquatic food webs is essential to assess impact of climatic and environmental changes on lake ecosystems. We reconstructed temporal changes in carbon sources fuelling chironomid biomass in a small and shallow hemiboreal/boreal lake over the last 11 000 years. Results were compared with temporal dynamics of known potential controlling factors: summer air temperature, human activities, phytoplankton assemblages and organic matter composition. We report an abrupt rise in the contribution of methane‐derived carbon to chironomid biomass. However, this sudden increase was not the consequence of drastic changes in the composition of sedimentary organic matter, mean air temperature, lake trophic state or human activities in the catchment area. Our results suggest that shallowing of the lake caused by sedimentary infilling processes was a possible driver of the expansion of anoxic zones, enhancing CH4 cycling in lake sediments. However, complementary studies are needed to better understand the mechanisms by which lake shallowing could affect carbon flows to aquatic consumers, and then better assess the natural dynamics of past carbon processing in the benthic food web of shallow lakes.
Evaluating sulfates and nitrates as enemies of the recent constructions: Spectroscopic and thermodynamical study
Authors: Morillas Héctor , Upasen Settakorn , Maguregui Maite , Marcaida Iker , Gallego‐Cartagena Euler , Oliveira Marcos L.S. , Silva Luis F.O.
Published: November 2018

Salt crystallization is one of the major problems currently faced by the field of architecture and construction. Its effects are devastating to the extent that they may even lead to loss of material. Although many innovative and resistant materials have been developed in the last years, in most of the constructions, salt crystallization is a persistent problem. Salts crystallizations are formed by the dissolution and subsequent precipitation of the soluble salts present in the material itself or due to the formation of new ones because of the reaction between original components of the building materials with salts coming from infiltration waters or with acid aerosols present in the atmosphere. Among others, some of the most common salts that can crystallize in the building materials are nitrates and sulfates. Both of them are soluble compounds, which can mobilize throughout the material easily, reprecipitate, and generate volume changes responsible for fissures, fractures, and even the loss of building material. In this work, a specific study of salts crystallizations in a recent construction erected in 2013 in Amorebieta (Basque Country, North of Spain) using a different kind of materials has been studied. The materials affected by salts are joint mortars, which in a first step were characterized by X‐ray diffraction and Raman microscopy to determine the mineralogical composition. In a second step, a soluble salts tests by ion chromatography was applied to approach quantitatively the impact of the salts. Finally, in a third step, the reactions that give rise to the decay products (thenardite, nitrocalcite, and/or epsomite mainly) were proposed and confirmed through a thermodynamic modelling.
High‐quality direct‐view display combining multiple integral 3D images
Authors: Okaichi Naoto , Kawakita Masahiro , Sasaki Hisayuki , Watanabe Hayato , Mishina Tomoyuki
Published: November 2018

This paper proposes a method for combining multiple integral three‐dimensional (3D) images using direct‐view displays to obtain high‐quality results. A multi‐image combining optical system (MICOS) is used to enlarge and combine multiple integral 3D images without gaps. An optical design with a simple lens configuration that does not require a diffuser plate prevents the deterioration in resolution resulting from lens arrangement errors and the diffuser plate. An experiment was performed to compare a previously developed method with the proposed method, and the latter showed a significant improvement in image quality. A method for expanding the effective viewing angle of the proposed optical design was also developed, and its effectiveness was confirmed experimentally. A prototype device of the proposed optical design was constructed using a high‐density organic light‐emitting diode (OLED) panel with 8K resolution and 1058 ppi pixel density to achieve 311 (H) × 175 (V) elemental images, a viewing angle of 20.6° in both the horizontal and vertical directions, and a display size of 9.1 in. In addition, the proposed optical design enabled making device considerably thinner, ie, with a thickness of only 47 mm.
Endoscopic endonasal resection of adenoid cystic carcinoma of the sinonasal tract and skull base
Authors: Volpi Luca , Bignami Maurizio , Lepera Davide , Karligkiotis Apostolos , Pistochini Andrea , Ottini Giorgia , Grigioni Elena , Lombardi Davide , Nicolai Piero , Castelnuovo Paolo
Published: November 2018

Objectives

Adenoid cystic carcinoma (ACC) is a locally aggressive salivary gland malignancy prone to perineural invasion and local recurrences. In the literature, few data exist to guide treatment when this tumor involves the paranasal sinuses and skull base. We report our experience in the management of sinonasal adenoid cystic carcinoma through an endoscopic endonasal approach.

Methods

Retrospective analysis of patients affected by sinonasal ACC treated through an endoscopic endonasal approach from 1997 to 2015, managed at the Universities of Varese and Brescia, Italy.

Results

Thirty‐four patients were included in the analysis. The ethmoid sinus (55.9%), nasal septum (17.7%), maxillary sinus (11.7%), and sphenoid sinus (5.9%) were the primary tumor sites encountered. Twenty patients (58.8%) presented with T3 or T4, without any systemic spreading. Twenty‐nine patients underwent endoscopic transnasal resection, whereas the involvement of the anterior skull base in five cases required a transnasal endoscopic craniectomy. Overall, 20 of 34 (58.8%) patients received some form of adjuvant radiotherapy. The follow‐up ranged from 12 to 202 months (mean of 73.2 months). The 5‐year overall, disease‐specific, and recurrence‐free survival rates were 86.5% ± 7.39%, 86.5% ± 7.39%, and 71.8% ± 8.67%, respectively.

Conclusions

The endoscopic approach is safe and effective for selected sinonasal ACC, reducing the comorbidities of the external approaches while producing similar oncological results. High T‐stage, grade III histology, positive surgical margins, and perineural infiltration all have an important negative prognostic value.

Level of Evidence

4 Laryngoscope, 129:1071–1077, 2019
Nimodipine improves vocal fold and facial motion recovery after injury: A systematic review and meta‐analysis
Authors: Lin R. Jun , Klein‐Fedyshin Michele , Rosen Clark A.
Published: November 2018

Introduction

Nimodipine is a calcium channel blocker that has been used to treat hypertension and vasospasm. Emerging evidence in the literature suggests that it is neuroprotective by reducing cellular apoptosis after neuronal injury and promoting axonal sprouting at the nodes of Ranvier.

Objectives

To conduct a systematic review of the usage of nimodipine in cranial nerve injury and to perform a meta‐analysis to estimate the efficacy of nimodipine on functional recovery of the injured cranial nerves.

Methods

Literature search was performed in eight databases using preferred reporting items for systematic reviews and meta analyses (PRISMA) guidelines. Human studies that used nimodipine as a monotherapy for treating cranial nerve injury were included for review. Cranial nerve function recovery was the primary outcome measure.

Results

672 records were screened and 58 full texts in English were assessed. Nine studies were included in the final review. 5 of these, including 110 participants who received nimodipine for either recurrent laryngeal nerve or facial nerve injury and 556 controls, were used for meta‐analysis. Nimodipine significantly increased the odds of vocal fold motion recovery (odds ratio [OR] 13.73, 95% confidence interval [CI] 6.21, 30.38, P < .01), and the odds of facial motion recovery (OR 2.78, 95% CI 1.20, 6.44, P = .02). Overall, nimodipine‐treated patients had significantly higher odds of recovering vocal fold or facial motion compared with controls (OR 6.09, 95% CI 3.41, 10.87, P < .01).

Conclusion

Existing evidence supports the positive effect of nimodipine on vocal fold and facial motion recovery after injury. Future research should focus on randomized clinical trials comparing recovery rates between nimodipine‐ and placebo‐treated groups. Laryngoscope, 129:943–951, 2019
Out of tragedy comes closer ties between Florida providers, schools
Authors: Enos Gary
Published: November 2018

One aftereffect of the tragedy that unfolded at Marjory Stoneman Douglas High School in Parkland, Florida, last February is being seen in a more formalized relationship between local school districts in the state and members of the mental health provider community. MHW spoke last week with representatives of both entities as such a partnership grows in Lee County, which includes the cities of Fort Myers and Cape Coral in the state's southwest region.
RAND: Youth MH community engagement campaign succeeds
Authors: Canady Valerie A.
Published: November 2018

Recognizing that many people in need of mental health treatment don't receive it, Los Angeles County mental health officials launched a youth‐targeted social media campaign with an emphasis on empowering youth and increasing awareness of seeking mental health care.
Tobacco use at lowest level, still high for people with MI
Authors: Canady Valerie A.
Published: November 2018

While cigarette smoking has reached the lowest level ever recorded among U.S. adults, according to researchers of new data published by the Centers for Disease Control and Prevention (CDC), the use of any tobacco product was higher among adults with serious psychological distress.
Construction of high‐energy solutions for the supercritical biharmonic Schrödinger equation
Authors: Gan Lu
Published: November 2018

We consider the problem Δ2u = V(x)up + ϵ in
with u,Δu→0 as |x|→ + ∞, where
, N ≥ 5, V is a positive continuous potential. Our aim is to construct high‐energy solutions for this equation by applying the finite‐dimensional reduction method and the penalization method.
Technical Note: More accurate and efficient segmentation of organs‐at‐risk in radiotherapy with convolutional neural networks cascades
Authors: Men Kuo , Geng Huaizhi , Cheng Chingyun , Zhong Haoyu , Huang Mi , Fan Yong , Plastaras John P. , Lin Alexander , Xiao Ying
Published: November 2018

Purpose

Manual delineation of organs‐at‐risk (OARs) in radiotherapy is both time‐consuming and subjective. Automated and more accurate segmentation is of the utmost importance in clinical application. The purpose of this study is to further improve the segmentation accuracy and efficiency with a novel network named convolutional neural networks (CNN) Cascades.

Methods

CNN Cascades was a two‐step, coarse‐to‐fine approach that consisted of a simple region detector (SRD) and a fine segmentation unit (FSU). The SRD first used a relative shallow network to define the region of interest (ROI) where the organ was located, and then, the FSU took the smaller ROI as input and adopted a deep network for fine segmentation. The imaging data (14,651 slices) of 100 head‐and‐neck patients with segmentations were used for this study. The performance was compared with the state‐of‐the‐art single CNN in terms of accuracy with metrics of Dice similarity coefficient (DSC) and Hausdorff distance (HD) values.

Results

The proposed CNN Cascades outperformed the single CNN on accuracy for each OAR. Similarly, for the average of all OARs, it was also the best with mean DSC of 0.90 (SRD: 0.86, FSU: 0.87, and U‐Net: 0.85) and the mean HD of 3.0 mm (SRD: 4.0, FSU: 3.6, and U‐Net: 4.4). Meanwhile, the CNN Cascades reduced the mean segmentation time per patient by 48% (FSU) and 5% (U‐Net), respectively.

Conclusions

The proposed two‐step network demonstrated superior performance by reducing the input region. This potentially can be an effective segmentation method that provides accurate and consistent delineation with reduced clinician interventions for clinical applications as well as for quality assurance of a multicenter clinical trial.
Protein Provision in Critically Ill Adults Requiring Enteral Nutrition: Are Guidelines Being Met?
Authors: Mitchell Alexandra , Clemente Rowan , Downer Claire , Greer Frances , Allan Kaylee , Collinson Avril , Taylor Stephen
Published: November 2018

Background

In a previous audit, 81% of enteral protein prescriptions failed to meet protein guidelines. To address this, a very high‐protein enteral formula and protein supplements were introduced, and protein prescriptions were adjusted to account for nonnutrition energy sources displacing enteral formula. This follow‐up audit compared protein provision in critically ill adults requiring exclusive enteral nutrition (EN), first, with local and international guidelines, and second, after changes to practice, with the previous audit in the same intensive care unit (ICU).

Methods

Data were collected from 106 adults consecutively admitted to the ICU of a U.K. tertiary hospital and requiring exclusive EN ≥3 days. Protein targets based on local guidelines (1.25, 1.5, or 2.0 g/kg/d), nutrition prescription, and delivery were recorded for 24 hours between days 1–3, 5–7, 8–10, and 18–20 post‐ICU admission.

Results

The proportion of day 1–3 protein prescriptions meeting protein targets increased from 19% in 2015 to 69% in 2017 (P < .0005, φ = 0.50). The median percentage of protein target delivered was lower than prescribed (79% vs 103%; (P < .0005; r = 0.53) and EN delivery only met the target of 22% of patients. The proportion of protein prescriptions meeting protein targets was similar for days 1–3 (69%), 5–7 (71%), and 8–10 (68%), but increased slightly by days 18–20 (74%). The proportion of patients for which EN delivery met protein targets increased with the number of days post‐ICU admission (22%, 26%, 37%, and 53% for days 1–3, 5–7, 8–10, and 18–20, respectively).

Conclusion

The proportion of protein prescriptions meeting guideline targets was higher after changes to practice.
A systematic mixed methods review: Recovering from a hip fracture in a health promoting perspective
Authors: Lind Johanne , Mahler Marianne
Published: November 2018

Aim

To describe and interpret how older adults who have returned home to recover from a hip fracture cope with life in a health promoting perspective.

Design

Data were collected through the search in seven electronic databases during 2014. Inclusion criteria were peer reviewed, empirical studies. The keywords were hip fracture, coping, empowerment, self‐efficacy, elderly, frail elderly, oldest old. Seventeen papers published 1991–2014 were eligible for inclusion. Analysis of the qualitative and quantitative papers was conducted separately guided by the key words coping, empowerment and self‐efficacy. Due to diversity of studies, a meta‐analysis was not performed. The findings were reported in a narrative synthesis.

Results

Recovery is an individual process of regaining health. It is important to include the person's resources and own goals in life. Physical training must be combined with psychosocial interventions to promote personal engagement and health.
The development of an interest group system in a constrained democracy: Montenegro
Authors: Komar Olivera
Published: November 2018

This article is the first comprehensive examination of Montenegro's interest group system. This system is a product of a combination of traditional influences and recent developments. The major traditional influences are a closed, patriarchal society with strong family and kinship relations, and a nonparticipatory political culture. These combined with over a quarter century of dominance by the ex‐communist party have been major impediments to the growth of interest group activity. Despite this, significant developments have occurred in the establishment of new interests and their activities, much of this made possible by the strong presence of various elements of the international community. Nevertheless, Montenegro has a bifurcated interest group system in which a small elite dominates interest group activity, while, for the most part, the mass of society do not participate in political advocacy.
Cyantraniliprole seed treatment efficiency against Agrotis ipsilon (Lepidoptera: Noctuidae) and residue concentrations in corn plants and soil
Authors: Zhang Zhengqun , Xu Chunmei , Ding Jinfeng , Zhao Yunhe , Lin Jin , Liu Feng , Mu Wei
Published: November 2018

BACKGROUND

The black cutworm Agrotis ipsilon is the most destructive early season insect pest of corn. In this study, the control efficiency of cyantraniliprole seed treatment against A. ipsilon was evaluated, and the residual concentrations of cyantraniliprole and its metabolite J9Z38 in the stalks of corn seedlings and soil were investigated.

RESULTS

Plant pot experiments showed that A. ipsilon larval mortality was greater than 92% and that the percentage of corn seedlings damaged by A. ipsilon was less than 24% when corn seeds were treated with cyantraniliprole at 2 and 4 g AI kg−1 seed. Cyantraniliprole seed treatment at a dosage of 2 g AI kg−1 seed significantly reduced A. ipsilon infestation compared to chlorantraniliprole and clothianidin seed treatments in corn fields. Cyantraniliprole seed treatment resulted in more persistent control efficiency of A. ipsilon in spring than in summer. Cyantraniliprole and J9Z38 residues in corn stalks and soil degraded more slowly in the spring than in the summer.

CONCLUSION

Cyantraniliprole used as a seed treatment can protect corn plants from A. ipsilon infestations throughout the seedling stage. The high biological activity of cyantraniliprole was consistent with the residue levels of cyantraniliprole in the corn stalks and soil. © 2018 Society of Chemical Industry
Optimizing aphid biocontrol with the predator Aphidoletes aphidimyza, based on biology and ecology
Authors: Boulanger François‐Xavier , Jandricic Sarah , Bolckmans Karel , Wäckers Felix L , Pekas Apostolos
Published: November 2018

Aphidoletes aphidimyza is one of the most important predators used in the augmentative biological control of aphids, key pests of many crops worldwide. Adult females are very efficient in locating aphid infestations over a relatively long range, up to 45 m, and deposit eggs near or within aphid colonies. The predatory larvae are aphid generalists preying on several agriculturally important aphid species. The successful use of this biocontrol agent in agricultural systems depends on several biotic and abiotic factors. Among biotic factors, aphid species, plant structure, interspecific competition and intraguild predation may significantly impact the predator´s population dynamics. Key abiotic conditions include day lengths (above a critical threshold to prevent diapause), availability of mating sites in the crop, temperature (above 15 °C to enable egg laying), air relative humidity (above 70%) and availability of pupation sites. Although several successes have been reported in open field crops with naturally occurring or released populations, commercial releases are primarily used in protected crops. Optimized emergence boxes combining provisioning of food sources for the adults, integration with the technological advances that occurred in the greenhouse environment lately, insights into the nutritional ecology in open field crops and exploration of the genetic variability are proposed as future directions to improve adoption and efficacy of A. aphidimyza in crop protection. © 2018 Society of Chemical Industry
Electrical Properties and Thermal Expansion Characteristics of (1–x)Ba0.948Ca0.05Er0.002Ti0.94Zr0.06O3–(x)Pr Lead‐Free Piezoelectric Ceramics Sintered at a Low‐Temperature
Authors: Tian Yongshang , Cao Lijia , Li Shuiyun , Fu Shiying , Chen Zhijia , Ji Xiang , Jing Qiangshan
Published: November 2018

(1 − x)Ba0.948Ca0.05Er0.002Ti0.94Zr0.06O3–(x)Pr (x = 0–0.75 mol%) ceramics are sintered at 1240 °C by conventional solid‐state reaction method using the as‐synthesized nanoparticles, which are prepared by a modified Pechini method. The structural, morphological, electrical, and thermal expansion properties as a function of varying x are systematically investigated. All samples feature rhombohedral phase, and their lattice parameters are accurately calculated by Rietveld refinement software. Volume of oxygen vacancies initially decreases and then increases with increasing x, leading to diversified electrical properties. Deteriorated electrical properties of the ceramics with excessive x are attributed to the increment of defect complexes with a large volume of oxygen vacancies. The coefficient of thermal expansion values of the ceramics that is influenced by phase evolution and structure defects under different temperature ranges are studied. The respective optimal electrical properties, that is, d33 = 186 pC N−1 and kp = 27.2% are obtained at x = 0.30 mol%. This research is believed to be insightful to practical application of the lead‐free multifunctional electron components.
Symmetry lowering by cage doping in spherical superatoms: Evaluation of electronic and optical properties of 18‐electron W@Au12Ptn (n = 0‐4) superatomic clusters from relativistic DFT calculations
Authors: Gam Franck , Arratia‐Perez Ramiro , Kahlal Samia , Saillard Jean‐Yves , Muñoz‐Castro Alvaro
Published: November 2018

Attempts to expand the versatility of well defined clusters are a relevant issue in the design of building blocks for functional nanostructures. Here, we investigate the plausible formation of related structures from the emblematic highly symmetrical 18‐e [W@Au12] cluster. The calculated [W@Au12Ptn] series, with n = 0, 1, 2, 3, and 4, show cohesion energies, HOMO‐LUMO gap, adiabatic electron affinities (AEAs) and adiabatic ionization potentials (AIPs), indicating a relative stability to the parent cluster [W@Au12] experimentally characterized, where clusters with n = 1 and n = 4 are suggested as the most stable with respect to oxidation. The resulting symmetry lowering away from the high icosahedral symmetry upon adding Pt atoms induces a sizable splitting of the frontiers shells, which in turn effectively modify the properties of the calculated clusters, as observed from calculated optical properties. The estimated absorption spectra show an interesting broadening effect of the absorption peaks, which appears as a useful approach for further design of broad black absorbers, which are able to absorb light in a wider range, with potential capabilities to enhance the efficiency of thin film solar cells and photocatalysis processes, among other applications.
Methyl sulfates as methoxy isotopic reference materials for δ13C and δ2H measurements
Authors: Greule Markus , Moossen Heiko , Geilmann Heike , Brand Willi A. , Keppler Frank
Published: November 2018

Rationale

Stable hydrogen and carbon isotope ratios of methoxy groups (OCH3) of plant organic matter have many potential applications in biogeochemical, atmospheric and food research. So far, most of the analyses of plant methoxy groups by isotope ratio mass spectrometry have employed liquid iodomethane (CH3I) as the reference material to normalise stable isotope measurements of these moieties to isotope–δ scales. However, comparisons of measurements of stable hydrogen and carbon isotopes of plant methoxy groups are still hindered by the lack of suitable reference materials.

Methods

We have investigated two methyl sulfate salts (HUBG1 and HUBG2), which exclusively contain carbon and hydrogen from one methoxy group, for their suitability as methoxy reference materials. Firstly, the stable hydrogen and carbon isotope values of the bulk compounds were calibrated against international reference substances by high‐temperature conversion‐ and elemental analyser isotope ratio mass spectrometry (HTC‐ and EA‐IRMS). In a second step these values were compared with values obtained by measurements using gas chromatography/isotope ratio mass spectrometry (GC/IRMS) where prior to analysis the methoxy groups were converted into gaseous iodomethane.

Results

The 2H‐ and 13C isotopic abundances of HUBG1 measured by HTC‐ and EA‐IRMS and expressed as δ‐values on the usual international scales are −144.5 ± 1.2 mUr (n = 30) and −50.31 ± 0.16 mUr (n = 14), respectively. For HUBG2 we obtained −102.0 ± 1.3 mUr (n = 32) and +1.60 ± 0.12 mUr (n = 16). Furthermore, the values obtained by GC/IRMS were in good agreement with the HTC‐ and EA‐IRMS values.

Conclusions

We suggest that both methyl sulfates are suitable reference materials for normalisation of isotope measurements of carbon of plant methoxy groups to isotope–δ scales and for inter‐laboratory calibration. For stable hydrogen isotope measurements, we suggest that in addition to HUBG1 and HUBG2 additional reference materials are required to cover the full range of plant methoxy groups reported so far.
Context‐aware hybrid satellite‐terrestrial broadband access
Authors: Ekmekcioglu Erhan , Evans Barry , Kondoz Ahmet , Thompson Paul , Ottavj Luc , Gamberini Fabrice , Watts Simon
Published: November 2018

One of the key performance targets on the European Commission's Digital Agenda is to provide at least 30‐Mbit/s broadband coverage to all European households by 2020. The deployment of existing terrestrial technologies will not be able to satisfy the requirements in the most difficult‐to‐serve locations, either due to a lack of coverage in areas where the revenue potential for terrestrial service providers is too low or due to technological limitations that diminish the available throughput in rural environments. In this paper, we investigate a hybrid broadband system combining satellite and terrestrial access networks. The system design and the key building blocks of the intelligent routing entities (referred to as intelligent gateways) are presented. To justify the hybrid broadband system's performance subjectively, lab trials have been performed with an integrated multiple access network emulator and a variety of typical multimedia applications that have varying requirements. The results of the lab trials suggest that the quality of experience is consistently improved thanks to the utilisation of intelligent gateway devices, when compared with using a single access network at a time.
Eco‐Friendly Production of 5‐Hydroxymethylfurfural from Sucrose Using Commercially Available Dihydric Phosphate as a Catalyst
Authors: Ma Hao , Liao Chunyan , Yang Ping , Qiao Yanhui , Li Ning , Teng Junjiang
Published: November 2018

An eco‐friendly catalytic system consisted of dihydric phosphate (H2PO4—) catalyst and a methyl isobutyl ketone (MIBK)/H2O biphasic solvent has been constructed to produce 5‐hydroxymethylfurfural (HMF) from sucrose, a cheaper and more widely available feedstock than fructose. The effects of reaction conditions, viz., catalyst dosage, reaction temperature, and reaction time, on this dehydration reaction have been investigated systematically, affording more than 70% of HMF yield under the optimum conditions. This environmentally friendly system is also broadly substrate‐tolerant, high concentration of sucrose (86%), scalable catalytic system (scaled up 10 times), and sugarcane juice also give 62.5%, 70.1%, and 70.7% of HMF yield, respectively. Moreover, the function of H2PO4— containing system for isomerization of glucose into fructose has been confirmed; and the dehydration reaction has been proposed to proceed through the catalytic hydrolysis of sucrose into glucose and fructose by protons (H+), followed by the isomerization of glucose into fructose by hydrogen phosphate ions (HPO42−), and the dehydration of fructose into HMF by protons (H+), which are all from the dissociation of H2PO4— ions. Readily available and eco‐friendly catalyst, abundantly available feedstock, and simple reaction conditions could mark this process promising for HMF production in industry.
Selective Colorimetric Detection of Fe (III) Using Metallochromic Tannin‐Impregnated Silica Strips
Authors: Khattab Tawfik A. , Fouda Moustafa M. G. , Allam Ahmed A. , Othman Sarah I. , Bin‐Jumah May , Al‐Harbi Hanan M. , Rehan Mohamed
Published: November 2018

A solid state sensor tool used for determination of ferric ions (Fe+3) in an aqueous medium was developed using the environmental friendly tannin polyphenolic biomolecule as spectroscopic probe and silica plates as a host strip. The colorimetric recognition of the analyte is based on a tanna‐activated silica dipstick with a determination limit in the ppm level. The best detection of Fe (III) was accomplished in a pH range from 3.2 to 8.8. The metallochromic tannin‐impregnated silica diagnostic tool provided an instant color alteration from yellow to dark purple upon immersion in an aqueous environment of ferric cation as was demonstrated by the coloration measurements. This color shift is proportionally correlated with increasing the ferric concentration. Both qualitative and quantitative studies were performed. The sensor demonstrated high selectivity to Fe (III), while no color change was monitored for other metals. The recognition mechanism of ferric occurs via tannic (polyphenolic)‐Fe (III) polydentate complex creation. Different spectroscopic techniques, including scanning electron microscope, energy dispersive X‐ray spectroscopy as well as elemental mapping were utilized to characterize the tannic‐Fe (III) complex formation on the silica dipstick.
Exploring Reaction Mechanisms for the Reduction of NO Molecules over Al‐ or Si‐Anchored Graphene Oxide: A Metal‐Free Approach
Authors: Esrafili Mehdi D.
Published: November 2018

Using periodic density functional theory calculations, the catalytic reduction of NO molecules is studied over a Al‐ or Si‐anchored graphene oxide (GO). It is found that the epoxy groups over GO could trap the Al or Si atom with a large adsorption energy and high diffusion barrier. Both “direct dissociation” and “dimer” mechanisms are studied for the reduction of NO molecules to N2O over these surfaces. According to our results, the NO reduction over Al or Si anchored GO proceeds through a dimer mechanism, due to its low activation energy. Moreover, the dimer mechanism should be more favorable than the direct dissociation since the adsorption energy of the (NO)2 dimer is found to be larger than that of a single NO monomer. Besides, the Si‐anchored GO exhibits higher catalytic activity than the Al‐anchored one. We hope that results of present study provide a valuable guidance on design graphene‐based single‐atom catalysts to remove toxic NO molecules.
A Facile Iron‐Catalyzed Coupling of N‐Activated Benzyl Amines with 1,3‐Dicarbonyl Compounds through C‐N Bond Cleavage
Authors: Paul Dipankar , Chatterjee Paresh N.
Published: November 2018

Benzylation of 1,3‐dicarbonyl compounds using benzyl amines is considered to be a challenging endeavour. In the method presented here, FeCl3 is utilized as an efficient catalyst for the benzylation of 1,3‐dicarbonyl compounds through C−N bond cleavage of N‐activated benzyl amines. Several electron‐withdrawing groups were examined for activating the amino functionality of the benzyl amine. The method furnishes very good yields of the coupling products for a wide range of N‐activated benzyl amines and 1,3‐dicarbonyl compounds. Inexpensiveness, easy availability and low toxicity of the catalyst in addition to mild reaction conditions impart great value to this method for its use in organic synthesis.
Aerobic Oxidation of Benzylic Hydrocarbons by Iron‐Based Metal Organic Framework as Solid Heterogeneous Catalyst
Authors: Nagarjun Nagarathinam , Dhakshinamoorthy Amarajothi
Published: November 2018

In the present work, the aerobic oxidation of indan is reported using Fe(BTC) (BTC: 1,3,5‐benzenetricarboxylate) as solid heterogeneous catalyst and tetrabutylammonium bromide (TBAB) as an additive under mild reaction conditions. Although aerobic oxidation of indane has been reported earlier using MOFs as heterogeneous catalysts, these methods require higher reaction temperature and catalytic amounts of radical initiator. Therefore, this study aims to report the aerobic oxidation of indan employing Fe(BTC) as catalyst without the need of initiators under mild reaction temperature. The catalytic data reveal that the indan conversion reaches to 18% with 97% selectivity of indanol at 80 °C in acetonitrile as solvent. Furthermore, the catalyst stability is surveyed by performing reusability experiments and observing no decay in its activity. On other hand, comparison of fresh with three times reused Fe(BTC) samples by powder X‐ray diffraction (XRD) and scanning electron microscope (SEM) indicates that the crystallinity and morphology of the reused sample, respectively is retained during the course of the reaction. Finally, two times reused Fe(BTC) exhibits similar electron spin resonance (ESR) pattern with that of fresh Fe(BTC), suggesting no changes in the oxidation state of iron.
Facile Fabrication of Unimpeded and Stable Graphene Oxide Coating on Reverse Osmosis Membrane for Dual‐Functional Protection
Authors: Hu Ruirui , Wang Chen , Liu Xu , He Yijia , Zhao Guoke , Zhu Hongwei
Published: November 2018

Membrane fouling and chlorination have remained the greatest threats to durable reverse osmosis (RO) membrane applications. Here, we report a facile technique of high pressure assisted deposition (HPSD) to physically anchor stable graphene oxide (GO) coatings on RO membranes for simultaneous dual‐functional protection against fouling and chlorination without sacrifice of water flux. Thick coatings were directly prepared by HPSD, and a subsequent “skin‐removing” method was used to obtain GO thin coatings with stronger adhesion. The measurement of GO coating thickness was achieved by a “removing‐transferring” method, demonstrating a thickness of 200 and 50 nm for GO thick and thin coatings, respectively. Benefiting from our coating deposition technique of HPSD, 100% of coverage by GO was achieved for both GO coated membranes. The filtration test showed that GO coating was highly permeable to water resulted from the optimized small size of GO sheets (∼200 nm) and the unique water transport properties through GO laminates. The GO thin coating could effectively alleviate the membrane fouling by rendering membrane surface more hydrophilic and smoother, while the thick coating reversely aggravated the fouling due to the more hydrophobic surface. In addition, GO coating could dramatically improve the chlorine stability of RO membrane by impeding the diffusion of reactive chlorine, with a high level of salt rejection after chlorination for GO coated membranes.
A Simple, Mild and Straight forward Route for the Synthesis of α‐Ureidopeptidomimetics Using Cbz‐Protected Amino Acid Esters
Authors: Ramachandra Sagar N. , Srinivasulu C. , Hosamani Basavaprabhu , L Santhosh , Sureshbabu Vommina V.
Published: November 2018

The synthesis of α‐ureidopeptidomimetics employing a simple, mild and straight forward route starting from benzyloxy carbonyl (Cbz‐) protected amino acid esters in presence of 2‐Cl pyridine (2‐chloropyridine) and Tf2O (triflic anhydride) in one‐pot is described. The in situ generated isocyanate intermediates react with amino acid esters to yield the title compounds in good yields (89‐96%) and the protocol proved to be racemization free.
A Novel Self‐Assembled Mitochondria‐Targeting Protein Nanoparticle Acting as Theranostic Platform for Cancer
Authors: Zhu Xin‐Jie , Li Ri‐Fei , Xu Liang , Yin Hui , Chen Long , Yuan Ye , Zhong Wu , Lin Jian
Published: November 2018

Self‐assembled protein nanoparticles have attracted much attention in biomedicine because of their biocompatibility and biodegradability. Protein nanoparticles have become widely utilized as diagnostic or therapeutic agents for various cancers. However, there are no reports that protein nanoparticles can specifically target mitochondria. This targeting is desirable, since mitochondria are critical in the development of cancer cells. In this study, the discovery of a novel self‐assembled metal protein nanoparticle, designated GST‐MT‐3, is reported, which targets the mitochondria of cancer cells within 30 min in vitro and rapidly accumulates in tumors within 1 h in vivo. The nanoparticles chelate cobalt ions [GST‐MT‐3(Co2+)], which induces reactive oxygen species (ROS) production and reduces the mitochondrial membrane potential. These effects lead to antitumor activity in vivo. GST‐MT‐3(Co2+) with covalently conjugated paclitaxel synergistically suppress tumors and prolong survival. Importantly, the effective dosage of paclitaxel is 50‐fold lower than that utilized in standard chemotherapy (0.2 vs 10 mg kg−1). To the best of the authors' knowledge, GST‐MT‐3 is the first reported protein nanoparticle that targets mitochondria. It has the potential to be an excellent platform for combination therapies.
Characterization of hafting adhesives using comprehensive two‐dimensional gas chromatography coupled to time‐of‐flight mass spectrometry
Authors: Perrault Katelynn A. , Dubois Lena M. , Cnuts Dries , Rots Veerle , Focant Jean‐François , Stefanuto Pierre‐Hugues
Published: November 2018

The determination of the presence and the composition of residues from organic materials on archeological objects allows the behavior of our prehistoric ancestors to be better understood. The functional analysis of tools used for daily life activities, such as hunting or hide working, represents an important source of information. However, the chemical characterization of residues from archeological artifacts represents an analytical challenge. On one hand, the residues are made of different natural materials containing hundreds of chemicals. This complexity requires advanced analytical procedures to separate and identify the constituents. On the other hand, the low quantity and the advanced degradation require sensitive and non‐destructive methods. In this study, an approach employing headspace sampling (solid‐phase microextraction) with comprehensive two‐dimensional gas chromatography coupled to high‐resolution‐time‐of‐flight mass spectrometry was developed for the characterization of adhesive residues on simulated archeological artifacts. First, the performance of the analytical system was evaluated on a standard mixture and a pine resin sample. Next, adhesives and adhesives mixtures were analyzed that represented typical compositions that have been witnessed in archaeological applications. This analytical approach is a gateway into new potential for headspace organic residue characterization as a first step of analysis prior to altering residues for additional characterization.