bluuebunny/crossref_metadata_2025 huggingface dataset:
Solid Phase Extraction of Trace Amounts of Praseodymium Using Transcarpathian Clinoptilolite
Authors: Stashkiv Olha , Vasylechko Volodymyr , Gryshchouk Galyna , Patsay Ihor
Published: February 2019

Sorptive properties of the Transcarpathian clinoptilolite towards Pr(III) were studied under dynamic conditions. The sorption capacity of clinoptilolite under optimal conditions (sorbent grain diameter of 0.20–0.31 mm; pH 9.0, temperature of preliminary precalcination of 350 °C, and flow rate of the Pr(III) salt solution with the concentration of 1.0 μg·mL−1 through the sorbent of 5 mL·min−1) was equal to 47.5 mg·g−1. The best desorbent of Pr from the clinoptilolite was the 1 M solution of KCl acidified with HCl to a pH value of 3.0. The method of Pr(III) trace amounts preconcentration in a solid phase extraction mode with further determination of this REE via spectrophotometric technique was developed. The linearity of the proposed method was evaluated in the range of 2–100 ng·mL−1 with detection limit of 0.7 ng·mL−1.
Towards a Model Based Sensor Measurement Variance Input for Extended Kalman Filter State Estimation
Authors: Pointon Harry A. G. , McLoughlin Benjamin J. , Matthews Christian , Bezombes Frederic A.
Published: February 2019

In this paper, we present an alternate method for the generation and implementation of the sensor measurement variance used in an Extended Kalman Filter (EKF). Furthermore, it demonstrates the limitations of a conventional EKF implementation and postulates an alternate form for representing the sensor measurement variance by extending and improving the characterisation methodology presented in the previous work. As presented in earlier work, the use of surveying grade optical measurement instruments allows for a more effective characterisation of Ultra-Wide Band (UWB) localisation sensors; however, in cluttered environments, the sensor measurement variance will change, making this method not robust. To compensate for the noisier readings, an EKF using a model based sensor measurement variance was developed. This approach allows for a more accurate representation of the sensor measurement variance and leads to a more robust state estimation system. Simulations were run using synthetic data in order to test the effectiveness of the EKF against the originally developed EKF; next, the new EKF was compared to the original EKF using real world data. The new EKF was shown to function much more stably and consistently in less ideal environments for UWB deployment than the previous version.
Fluid Inclusions at the Plavica Au-Ag-Cu Telescoped Porphyry–Epithermal System, Former Yugoslavian Republic of Macedonia (FYROM)
Authors: Melfos Vasilios , Voudouris Panagiotis , Serafimovski Todor , Tasev Goran
Published: February 2019

The Plavica Au-Ag-Cu porphyry and high sulfidation (HS) epithermal deposit is located at the Kratovo–Zlatovo volcanic field in Eastern Former Yugoslavian Republic of Macedonia. In this study, new fluid inclusions data provide additional evidence of the presence of a porphyry style mineralization which is associated with an overlain HS epithermal deposit. The Oligocene–Miocene magmatic rocks have a calc–alkaline to high-K calc–alkaline affinity and consist of sub-volcanic intrusions and volcanic rocks. Previous studies distinguished four alteration types: (a) Sericitic, (b) advanced argillic, (c) silicification, and (d) propylitic alteration. Fluid inclusions showed an early magmatic brine in porphyry style veins with high salinity (33–57 wt% NaCl equiv.), which coexists with a vapor rich fluid with lower salinity (14–20 wt% NaCl equiv.), at temperatures 380–500 °C, under boiling conditions. At shallower depths, the fluid inclusions demonstrate various HS–epithermal deposits which were formed by moderate to low salinity (3–14 wt% NaCl equiv.) hydrothermal fluids at lower temperatures from 200 to 300 °C.
Improved Rainfall Prediction Using Combined Pre-Processing Methods and Feed-Forward Neural Networks
Authors: Tran Anh Duong , Duc Dang Thanh , Pham Van Song
Published: February 2019

Rainfall prediction is a fundamental process in providing inputs for climate impact studies and hydrological process assessments. Rainfall events are, however, a complicated phenomenon and continues to be a challenge in forecasting. This paper introduces novel hybrid models for monthly rainfall prediction in which we combined two pre-processing methods (Seasonal Decomposition and Discrete Wavelet Transform) and two feed-forward neural networks (Artificial Neural Network and Seasonal Artificial Neural Network). In detail, observed monthly rainfall time series at the Ca Mau hydrological station in Vietnam were decomposed by using the two pre-processing data methods applied to five sub-signals at four levels by wavelet analysis, and three sub-sets by seasonal decomposition. After that, the processed data were used to feed the feed-forward Neural Network (ANN) and Seasonal Artificial Neural Network (SANN) rainfall prediction models. For model evaluations, the anticipated models were compared with the traditional Genetic Algorithm and Simulated Annealing algorithm (GA-SA) supported by Autoregressive Moving Average (ARMA) and Autoregressive Integrated Moving Average (ARIMA). Results showed both the wavelet transform and seasonal decomposition methods combined with the SANN model could satisfactorily simulate non-stationary and non-linear time series-related problems such as rainfall prediction, but wavelet transform along with SANN provided the most accurately predicted monthly rainfall.
Micropulse Laser Treatment of Retinal Diseases
Authors: Gawęcki Maciej
Published: February 2019

Subthreshold micropulse laser treatment has been intensively used for selected retinal diseases in the last decade; however, the exact mechanism of the action of lasers in the subthreshold micropulse mode is not yet fully understood. This kind of treatment is safe and cheap, and contrary to classic laser photocoagulation, it leaves the retinal cells intact. A modern theory of micropulse laser interaction with retinal tissue and a possible explanation of this mechanism are presented in this review. The authors present all the relevant literature on the application of micropulse lasers in different retinal disorders. The efficacy of this treatment is analyzed on the basis of available studies and then placed in the perspective of other therapeutic methods that are used in retinal diseases.
Clinical Features, Survival and Prognostic Factors of Glycogen-Rich Clear Cell Carcinoma (GRCC) of the Breast in the U.S. Population
Authors: Zhou Zhengqiu , Kinslow Connor J. , Hibshoosh Hanina , Guo Hua , Cheng Simon K. , He Chunyan , Gentry Matthew S. , Sun Ramon C.
Published: February 2019

The World Health Organization (WHO) defines glycogen-rich clear cell carcinoma (GRCC) of the breast as a carcinoma with glycogen accumulation in more than 90% of its tumor cells. Due to the rarity of this disease, its reported survival and clinical associations have been inconsistent due to reliance on case reports and limited case series. As a result, the prognostic implication of this cancer subtype remains unclear. Using the U.S. Surveillance, Epidemiology, and End Results (SEER) program database, we compared the incidence, demographics and prognostic factors of 155 cases of GRCC of the breast to 1,251,584 cases of other (non-GRCC) breast carcinomas. We demonstrate that GRCC is more likely to be identified as high grade, advanced stage, and more likely to have triple negative receptor status. GRCC cases display a poorer prognosis than non-GRCC carcinomas of the breast irrespective of age, AJCC staging, tumor grade, joint hormone receptor/human epidermal growth factor receptor 2 (HER2) status, and treatment. Similar to non-GRCC carcinomas, older age and higher American Joint Committee on Cancer (AJCC)/TNM staging were associated with poorer prognosis for GRCC, while treatment with surgery and radiation were associated with improved survival. Radiation, specifically in the setting of breast-conserving surgery, further improved survival compared to surgery alone. Our study highlights the poorer prognosis associated with glycogen accumulation in breast cancers and hence stresses the importance of identifying this more aggressive tumor type.
Enhancing the Fracture Toughness Properties by Introducing Anchored Nano-Architectures at the Metal–FRP Composite Interface
Authors: Mahendrarajah Ghowsalya , Kandare Everson , Khatibi Akbar A.
Published: February 2019

This paper presents a novel technique for improving aluminium–glass/epoxy composite interfacial bonding through the generation of metallic nano-architectures on the metal surface. Silver nanowires (AgNWs) deposited via solution casting at varying concentrations and annealed at different temperatures in an air atmosphere improved the aluminium-glass/epoxy composite fracture toughness as measured via mode I experiments. For AgNW concentrations of 1 and 3 g/m2 deposited via a single-stage process and annealed at 375 °C, the initiation fracture toughness of the aluminium-glass/epoxy composite improved by 86% and 157%, respectively, relative to the baseline composite without AgNWs. The corresponding steady-state fracture toughness of these nano-modified fibre metal laminates (FMLs) were at least seven times greater than the baseline composite. The FML variant in which AgNWs were deposited at a concentration of 3 g/m2 through a two-stage process followed by annealing at 375 °C and 300 °C, respectively after each deposition, achieved the highest steady-state fracture toughness of all nano-modified composites—a fracture toughness value that was 13 times greater than the baseline composite. Intrinsic and extrinsic toughening mechanisms dictated by the morphology of the silver nano-architectures were found to be responsible for the improved initiation and steady-state fracture toughness in nano-modified FMLs.
A 50.5 ns Wake-Up-Latency 11.2 pJ/Inst Asynchronous Wake-Up Controller in FDSOI 28 nm
Authors: Christmann Jean-Frédéric , Berthier Florent , Coriat David , Miro-Panades Ivan , Guthmuller Eric , Thuries Sébastien , Thonnart Yvain , Makosiej Adam , Debicki Olivier , Heitzmann Frédéric , Valentian Alexandre , Vivet Pascal , Beigné Edith
Published: February 2019

Due to low activity in Internet of Things (IoT) applications, systems tend to leverage low power modes in order to reduce their power consumption. Normally-off computing thus arose, consisting in having turned off most part of a system’s power supply, while dynamically turning on components as the application needs it. As wake up sources may be diverse, simple controllers are integrated to handle smart wake up schemes. Therefore, to prevent overconsumption while transitioning to running mode, fast wake up sequences are required. An asynchronous 16-bit Reduced Instruction Set Computer (RISC) Wake-up Controller (WuC) is proposed demonstrating 50.5 ns@9.2 Million Instructions Per Second (MIPS)@0.6 V wake-up latency, drastically reducing the overall wake-up energy of IoT systems. A clockless implementation of the controller saves the booting time and the power consumption of a clock generator, while providing high robustness to environmental variations such as supply voltage level. The WuC is also able to run simple tasks with a reduced Instruction Set Architecture (ISA) and achieves as low as 11.2 pJ/inst @0.5 V in Fully Depleted Silicon On Insulator (FDSOI) 28 nm.
Clarifying the Response of Gold Return to Financial Indicators: An Empirical Comparative Analysis Using Ordinary Least Squares, Robust and Quantile Regressions
Authors: Miyazaki Takashi
Published: February 2019

In this study, I apply a quantile regression model to investigate how gold returns respond to changes in various financial indicators. The model quantifies the asymmetric response of gold return in the tails of the distribution based on weekly data over the past 30 years. I conducted a statistical test that allows for multiple structural changes and find that the relationship between gold return and some key financial indicators changed three times throughout the sample period. According to my empirical analysis of the whole sample period, I find that: (1) the gold return rises significantly if stock returns fall sharply; (2) it rises as the stock market volatility increases; (3) it also rises when general financial market conditions tighten; (4) gold and crude oil prices generally move toward the same direction; and (5) gold and the US dollar have an almost constant negative correlation. Looking at each sample period, (1) and (2) are remarkable in the period covering the global financial crisis (GFC), suggesting that investors divested from stocks as a risky asset. On the other hand, (3) is a phenomenon observed during the sample period after the GFC, suggesting that it reflects investors’ behavior of flight to quality.
The Evolving Common Law Jurisprudence Combatting the Threat of Terrorism in the United Kingdom, United States, and Canada
Authors: Simeon James C.
Published: February 2019

Terrorism is a concept that defies a simple and straightforward legal definition. Therefore, it is not surprising to find that there is no Comprehensive Convention on Terrorism with a universally accepted definition of what constitutes “terrorism.” Consequently, States have devised their own definitions of what constitutes terrorism that are typically found in their criminal law. This raises the fundamental question of whether there is a convergence or divergence in jurisprudential trends on what constitutes terrorism among States? Presumably, a convergence in jurisprudential trends is more likely to contribute to combatting the threat of terrorism at the international and national levels. Accordingly, this article comparatively analyzes the definition of terrorism in three common law jurisdictions: the United Kingdom, the United States, and Canada. It finds that although there are a number of similarities in the definition of terrorism in these three States, they have significantly different definitions of what constitutes terrorism. The UK definition, ostensibly, has the broadest definition of terrorism of the three States. The US has, undoubtedly, the most unique, with separate definitions for “international terrorism” and “domestic terrorism.” Additionally, Canada has the most international definition of terrorism, drawing on 13 functional terrorism Conventions to define offenses such as hijacking, hostage taking, and bombing, etc. The second part of the article comparatively analyzes seven of the leading Supreme Court cases on terrorism in these three States. From the ratio or rationes decidendi in each of these cases, it draws out the twelve legal principles that underlie these judgements and finds that they are similar and overall consistent. The conclusion reached is that there is, at least in these three common law jurisdictions, an apparent convergence in jurisprudential trends in the law of terrorism. This augurs well for the development and emergence of a common definition of what constitutes terrorism at the international and transnational levels, as well as more rigorous and effective counter-terrorism laws and policies within and across States.
Guidelines and Benchmarks for Deployment of Deep Learning Models on Smartphones as Real-Time Apps
Authors: Sehgal Abhishek , Kehtarnavaz Nasser
Published: February 2019

Deep learning solutions are being increasingly used in mobile applications. Although there are many open-source software tools for the development of deep learning solutions, there are no guidelines in one place in a unified manner for using these tools toward real-time deployment of these solutions on smartphones. From the variety of available deep learning tools, the most suited ones are used in this paper to enable real-time deployment of deep learning inference networks on smartphones. A uniform flow of implementation is devised for both Android and iOS smartphones. The advantage of using multi-threading to achieve or improve real-time throughputs is also showcased. A benchmarking framework consisting of accuracy, CPU/GPU consumption, and real-time throughput is considered for validation purposes. The developed deployment approach allows deep learning models to be turned into real-time smartphone apps with ease based on publicly available deep learning and smartphone software tools. This approach is applied to six popular or representative convolutional neural network models, and the validation results based on the benchmarking metrics are reported.
Use of Complementary and Alternative Medicine by Patients with Irritable Bowel Syndrome According to the Roma IV Criteria: A Single-Center Italian Survey
Authors: Larussa Tiziana , Rossi Marianna , Suraci Evelina , Marasco Raffaella , Imeneo Maria , Abenavoli Ludovico , Luzza Francesco
Published: February 2019

Aim: This study was conducted to evaluate the impact of complementary and alternative medicine (CAM) in patients with irritable bowel syndrome (IBS) as assessed by the Rome IV criteria. Methods: Consecutive patients referring for IBS were re-evaluated according to the Rome IV criteria. Demographic features and characteristics potentially associated with the use of CAM were collected. A validated, self-administered, survey questionnaire dealing with CAM and patients’ level of knowledge, motivation, perception, and information seeking-behavior toward the use of CAM was analyzed. Multivariate logistic regression analysis was performed in order to identify predictors of CAM use among participants. Results: Among 156 patients claiming IBS, 137 (88%) met the Rome IV criteria, and 62 of them (45%) were CAM users. Biologically based therapy was the most chosen CAM (78%). Significant risk factors (adjusted odds ratio, 95% confidence interval) for the use of CAM were female gender (7.22, 2.31–22.51), a higher BMI (1.16, 1.02–1.33), and a good knowledge of CAM (4.46, 1.73–11.45), while having children was a protective factor (0.25, 0.07–0.95). Only 19% of patients used CAM due to medical advice and over half (51%) thought it was a “more natural” approach. Although a minority of patients (16%) had full satisfaction from CAM, 81% of users would repeat the CAM experience for their IBS symptoms. Conclusions: The widespread use of CAM in IBS, the patients’ belief in its safety, and their willingness to re-use it suggest that knowledge of health-care providers and patient education should be improved.
Common Variations in Prothrombotic Genes and Susceptibility to Ischemic Stroke in Young Patients: A Case-Control Study in Southeast Iran
Authors: Hashemi Seyed Mehdi , Ramroodi Nourollah , Amiri Fard Hamed , Talebian Sahar , Haghighi Rohani Maryam , Rezaei Mahnaz , Noora Mehrangiz , Salimi Saeedeh
Published: February 2019

Background and Objective: Evidence indicates that genetic factors may be involved in the risk of ischemic stroke (IS). The aim of this study was to assess the effect of genetic polymorphisms located in exons or untranslated regions of MTHFR as well as FV genes on ischemic stroke. Materials and Methods: In this case-control study, 106 patients with IS and 157 healthy volunteers (age <50 years) were genotyped for MTHFR C677T, A1298C, C2572A and C4869G, FVL, and prothrombin G20210A polymorphisms. Results: The MTHFR 677CT genotype was more frequent in patients and increased risk of IS with Odds Ratio = 1.9. The MTHFR A1298C and C2572A polymorphisms were not associated with IS in dominant and recessive models. Our findings showed a significant decrease in the MTHFR 4869CG genotype in IS patients, and this variant was associated with a decreased risk of IS in the dominant model. The CAAT haplotype was associated with increased risk, and the GAAC haplotype was associated with decreased risk of IS compared to other haplotypes. There was no relation between FVL G1691A polymorphism and IS risk. Conclusions: The present study showed that the MTHFR 677CT genotype was more frequent and the MTHFR 4869CG genotype was less frequent in young IS patients.
IL33/ST2 Axis in Diabetic Kidney Disease: A Literature Review
Authors: Tonacci Alessandro , Quattrocchi Paolina , Gangemi Sebastiano
Published: February 2019

Interleukin-33 (IL-33) is a cytokine belonging to the IL-1 family, playing a role in inflammatory, infectious and autoimmune diseases and expressed in the cellular nucleus in several tissues. High levels of IL-33 are expressed in epithelial barrier tissues and endothelial barriers. ST2 is a receptor for IL-33, expressed selectively on a subset of Th2 cells, mediating some of their functions. The IL-33/ST2 axis plays an important role in several acute and chronic inflammatory diseases, including asthma and rheumatoid arthritis. Different disorders are related to the activity of IL-33, ST2, or their axis, including cardiovascular disease or renal disturbances. Therefore, in the present work, a literature review was conducted, covering the period from 1 January 2000 to 30 November 2018, in PubMed, ScienceDirect, and Google Scholar database, to assess the involvement of the IL-33/ST2 axis in diabetic kidney disease. 6 articles directly dealing with the argument were identified, highlighting a clear link between IL-33/ST2 axis and diabetic kidney disease or related nephropathy. Overall, the involvement of ST2 seems to be more predictive than IL-33, especially in investigating the deterioration of kidney function; however, both compounds are pivotal in the field of renal diseases. Future studies are required to confirm the scientific evidences on larger and more heterogeneous cohorts.
Antibacterial Properties of Polysulfone Membranes Blended with Arabic Gum
Authors: Sabri Souhir , Najjar Ahmad , Manawi Yehia , Eltai Nahla , Al-Thani Asma , Atieh Muataz , Kochkodan Viktor
Published: February 2019

Polysulfone (PS) membranes blended with different loadings of arabic gum (AG) were synthesized using phase inversion method and the antibacterial properties of the synthesized membranes were tested using a number Gram-negative (Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacterial species. It was shown that AG addition to the dope polymer solutions essentially changed porous structure, hydrophilicity and zeta potential of the cast PS/AG membranes. These changes were due to the amphiphilic properties of AG macromolecules that contained negatively charged hydrophilic residues. A pronounced decrease in bacterial attachment was seen in the field emission scanning electron microscopy (FESEM) images for PS/AG membrane samples compared to both commercial (Microdyn-Nadir) and bare PS (without AG) membranes. AG loading dependent trend was observed where the prevention of bacterial colonization on the membrane surface was strongest at the highest (7 wt. %) AG loading in the casting solution. Possible mechanisms for the prevention of bacterial colonization were discussed. Significantly, the inhibition of bacterial attachment and growth on PS/AG membranes was observed for both Gram-positive and Gram-negative bacterial models, rendering these novel membranes with strong biofouling resistance attractive for water treatment applications.
Effect of Surface Treatment of Multi-Directionally Forged (MDF) Titanium Implant on Bone Response
Authors: Suzuki Ginga , Hirota Masatsugu , Hoshi Noriyuki , Kimoto Katsuhiko , Miura Hiromi , Yoshinari Masao , Hayakawa Tohru , Ohkubo Chikahiro
Published: February 2019

Multi-directional forging (MDFing) of titanium drastically improved its mechanical properties due to the evolution of an ultrafine-grained structure. Forging strain was repeatedly applied while changing the forging axis during MDFing. Of note is the decreased elastic modulus of MDFed titanium (MDF-Ti) as compared to conventional coarse-grained pure Ti (Ti). In the present study, we evaluated bone’s response toward surface-treated MDF-Ti after implantation into the extraction sockets of rat maxillary molars. As surface treatments, acid (Acid, sulfuric acid at 120 °C for 75 s), alkali without post-heat (Alkali, NaOH at 60 °C for 24 h), and alkali with post-heat (Alkali-heat, subsequent heating at 600 °C for 1 h) treatments were employed. The presence of minute nanoscale dimples in the microscale dimples to form regular fractal structures on MDF-Ti surfaces was observed after Acid treatments. Structures of sponge-like porous networks after Alkali treatments and submicron fiber networks after Alkali-heat treatment were produced on the surfaces of both Ti and MDF-Ti. Surface-treated specimens were superhydrophilic. More crystal deposition was clearly observed on each surface-treated specimen after immersion in simulated body fluid for both Ti and MDF-Ti. The bone-to-implant contact (BIC) ratios of the Acid and Alkali-heat specimens were significantly higher than those of the untreated control (p < 0.05). Moreover, Acid and Alkali-heat treatment for MDF-Ti caused significantly greater BICs than that for Ti (p < 0.05). In conclusion, Acid or Alkali-heat treatment of MDF-Ti is useful for improving bone response.
Metabolomics Approaches for the Diagnosis and Understanding of Kidney Diseases
Authors: Abbiss Hayley , Maker Garth L. , Trengove Robert D.
Published: February 2019

Diseases of the kidney are difficult to diagnose and treat. This review summarises the definition, cause, epidemiology and treatment of some of these diseases including chronic kidney disease, diabetic nephropathy, acute kidney injury, kidney cancer, kidney transplantation and polycystic kidney diseases. Numerous studies have adopted a metabolomics approach to uncover new small molecule biomarkers of kidney diseases to improve specificity and sensitivity of diagnosis and to uncover biochemical mechanisms that may elucidate the cause and progression of these diseases. This work includes a description of mass spectrometry-based metabolomics approaches, including some of the currently available tools, and emphasises findings from metabolomics studies of kidney diseases. We have included a varied selection of studies (disease, model, sample number, analytical platform) and focused on metabolites which were commonly reported as discriminating features between kidney disease and a control. These metabolites are likely to be robust indicators of kidney disease processes, and therefore potential biomarkers, warranting further investigation.
Incorporation of Geometallurgical Attributes and Geological Uncertainty into Long-Term Open-Pit Mine Planning
Authors: Morales Nelson , Seguel Sebastián , Cáceres Alejandro , Jélvez Enrique , Alarcón Maximiliano
Published: February 2019

Long-term open-pit mine planning is a critical stage of a mining project that seeks to establish the best strategy for extracting mineral resources, based on the assumption of several economic, geological and operational parameters. Conventionally, during this process it is common to use deterministic resource models to estimate in situ ore grades and to assume average values for geometallurgical variables. These assumptions cause risks that may negatively impact on the planned production and finally on the project value. This paper addresses the long-term planning of an open-pit mine considering (i) the incorporation of geometallurgical models given by equiprobable scenarios that allow for the assessing of the spatial variability and the uncertainty of the mineral deposit, and (ii) the use of stochastic integer programming model for risk analysis in direct block scheduling, considering the scenarios simultaneously. The methodology comprises two stages: pit optimization to generate initial ultimate pit limit per scenario and then to define a single ultimate pit based on reliability, and stochastic life-of-mine production scheduling to define block extraction sequences within the reliability ultimate pit to maximize the expected discounted value and minimize the total cost of production objective deviations. To evaluate the effect of the geometallurgical information, both stages consider different optimization strategies that depend on the economic model to be used and the type of processing constraints established in the scheduling. The results show that geometallurgical data with their associated uncertainties can change the decisions regarding pit limits and production schedule and, consequently, to impact the financial outcomes.
Distribution and Risk Assessment of Heavy Metals in Sediment from Bohai Bay, China
Authors: Liu Baolin , Zhang Wensi , Chi Guangxi
Published: February 2019

Sediment core and porewater samples from the Western coastal tidal flat in Bohai Bay, China, were collected for meals and physical-chemical properties analysis. The vertical distribution characteristics of eight metals along the core was investigated based on 137Cs and 210Pb radionuclide dating. The chemical fractions of six metals (Cu, Pb, Zn, Ni, Mn and Cd) were also measured based on the modified European Community Bureau of Reference (BCR) sequential extraction procedures to better understand the mobility and bioavailability of these metals in the sediment. In addition, geoaccumulation index (Igeo) and risk assessment code (RAC) are used to assess risk status of these metals in the environment. 210Pb measurement indicates a sedimentation rate of about −1.87 cm∙year−1. The metals Cu, Zn, Pb and Ni show similar vertical distributions throughout the core, while Mn and Cd show different distribution patterns. Ni, Cu, Pb and Zn are strongly associated with the residual fraction while Mn and Cd are dominant in the acid-soluble fraction. According to the estimated diffusive fluxes, the Zn ions were the most mobilized, followed by Cu, Ni, Pb, and to a lesser extent Cd. The result of Igeo shows that Ni in sediments does not reflect any pollution, and Cu, Pb and Zn are in a level from unpolluted to modest polluted throughout the core. Mn and Cd have obvious anthropogenic sources. Based on the RAC, Cd and Mn pose a high to very high risk to the local environment, respectively, due to the significant percentage of exchangeable fraction. Clay content is significantly positively correlated with Ni, Cu, Al and Fe, and Cu, Pb, Zn and Ni might originate from the same sources or be influenced by similar geochemical processes. River runoff and atmospheric deposition are important sources for heavy metals, and since 1998, domestic sewage discharge might have had an important influence on the source of heavy metals (except for Cd and Mn).
Graphene-Based Nanocomposites for Neural Tissue Engineering
Authors: Bei Ho Pan , Yang Yuhe , Zhang Qiang , Tian Yu , Luo Xiaoming , Yang Mo , Zhao Xin
Published: February 2019

Graphene has made significant contributions to neural tissue engineering due to its electrical conductivity, biocompatibility, mechanical strength, and high surface area. However, it demonstrates a lack of biological and chemical cues. Also, it may cause potential damage to the host body, limiting its achievement of efficient construction of neural tissues. Recently, there has been an increasing number of studies showing that combining graphene with other materials to form nano-composites can provide exceptional platforms for both stimulating neural stem cell adhesion, proliferation, differentiation and neural regeneration. This suggests that graphene nanocomposites are greatly beneficial in neural regenerative medicine. In this mini review, we will discuss the application of graphene nanocomposites in neural tissue engineering and their limitations, through their effect on neural stem cell differentiation and constructs for neural regeneration.
Profiling Volatile Constituents of Homemade Preserved Foods Prepared in Early 1950s South Dakota (USA) Using Solid-Phase Microextraction (SPME) with Gas Chromatography–Mass Spectrometry (GC-MS) Determination
Authors: Leinen Lucas J. , Swenson Vaille A. , Juntunen Hope L. , McKay Scott E. , O’Hanlon Samantha M. , Videau Patrick , Gaylor Michael O.
Published: February 2019

An essential dimension of food tasting (i.e., flavor) is olfactory stimulation by volatile organic compounds (VOCs) emitted therefrom. Here, we developed a novel analytical method based on solid-phase microextraction (SPME) sampling in argon-filled gas sampling bags with direct gas chromatography–mass spectrometry (GC-MS) determination to profile the volatile constituents of 31 homemade preserves prepared in South Dakota (USA) during the period 1950–1953. Volatile profiles varied considerably, but generally decreased in detected compounds, complexity, and intensity over three successive 2-h SPME sampling periods. Volatile profiles were generally predominated by aldehydes, alcohols, esters, ketones, and organic acids, with terpenoids constituting much of the pickled cucumber volatiles. Bisphenol-A (BPA) was also serendipitously detected and then quantified in 29 samples, at levels ranging from 3.4 to 19.2 μg/kg, within the range of levels known to induce endocrine disruption effects. Absence of BPA in two samples was attributed to their lids lacking plastic liners. As the timing of their preparation coincides with the beginning of BPA incorporation into consumer products, these jars may be some of the first BPA-containing products in the USA. To the best of our knowledge, this is the first effort to characterize BPA in and volatile profiles of rare historical foods with SPME.
Short-Term Neonatal Oral Administration of Oleanolic Acid Protects against Fructose-Induced Oxidative Stress in the Skeletal Muscles of Suckling Rats
Authors: Nyakudya Trevor Tapiwa , Isaiah Simon , Ayeleso Ademola , Ndhlala Ashwell Rungano , Mukwevho Emmanuel , Erlwanger Kennedy Honey
Published: February 2019

Nutritional manipulations in the neonatal period are associated with the development of negative or positive health outcomes later in life. Excessive fructose consumption has been attributed to the increase in the global prevalence of metabolic syndrome (MetS) and the development of oxidative stress. Oleanolic acid (OA) has anti-diabetic and anti-obesity effects. We investigated the protective potential of orally administering OA in the neonatal period, to prevent fructose-induced oxidative stress, adverse health outcomes and maturation of the gastrointestinal tract (GIT) in suckling rats. Seven-day old Sprague-Dawley rats (N = 30) were gavaged daily with 10 mL/kg of: distilled water (DW), oleanolic acid (OA; 60 mg/kg), high fructose solution (HF; 20% w/v), or OAHF for 7 days. On day 14, tissue samples were collected to determine clinical health profiles, hepatic lipid content, and activity of anti-oxidant enzymes. Furthermore, biomarkers of oxidative stress and anti-oxidant capacity in the skeletal muscles were assessed. The gastrointestinal tract (GIT) morphometry was measured. Rats in all groups grew over the 7-day treatment period. There were no significant differences in the terminal body masses, GIT morphometry, surrogate markers of general health, liver lipid content across all treatment groups (p < 0.05). Neonatal fructose administration decreased the activity of catalase, depleted GSH and increased lipid peroxidation. However, the level of GSH and catalase activity were improved by neonatal OA treatment. Short-term oral OA administration during the critical developmental period protects against fructose-induced oxidative stress without adverse effects on health outcomes associated with MetS or precocious development of the GIT in suckling male and female rats.
Triboluminescence of Centrosymmetric Lanthanide β-Diketonate Complexes with Aggregation-Induced Emission
Authors: Wong Ho-Yin , Chan Wesley Ting Kwok , Law Ga-Lai
Published: February 2019

Triboluminescence (TL) is a form of light emission induced upon mechanical forces on the material. However, our understanding of this phenomenon is still unclear and more examples are therefore needed in order to elucidate its mechanism. In this work, two types of TL complexes, [Eu(pp-dbm-Cl2)3phen] and [Eu(mm-dbm-Cl2)3phen], which also displays aggregation-induced emission (AIE) were synthesized and investigated for its photo-physical and crystal structural properties. These complexes were crystallized in a centro-symmetric space group P21/n, and remarkably, displayed TL upon grinding that may be due to the presence of extensive π···π, C-H···π and C-H···Cl-C interactions in the close molecular packing of its structure. This rare example deviates from the widely accepted mechanism of TL, hence widening the scope of our understanding in the area.
A Convenient, Rapid, Sensitive, and Reliable Spectrophotometric Assay for Adenylate Kinase Activity
Authors: Song Kai , Wang Yejing , Li Yu , Ding Chaoxiang , Cai Rui , Tao Gang , Zhao Ping , Xia Qingyou , He Huawei
Published: February 2019

Enzymatic activity assays are essential and critical for the study of enzyme kinetics. Adenylate kinase (Adk) plays a fundamental role in cellular energy and nucleotide homeostasis. To date, assays based on different principles have been used for the determination of Adk activity. Here, we show a spectrophotometric analysis technique to determine Adk activity with bromothymol blue as a pH indicator. We analyzed the effects of substrates and the pH indicator on the assay using orthogonal design and then established the most optimal assay for Adk activity. Subsequently, we evaluated the thermostability of Adk and the inhibitory effect of KCl on Adk activity with this assay. Our results show that this assay is simple, rapid, and precise. It shows great potential as an alternative to the conventional Adk activity assay. Our results also suggest that orthogonal design is an effective approach, which is very suitable for the optimization of complex enzyme reaction conditions.
Secondary Metabolites and the Risks of Isaria fumosorosea and Isaria farinosa
Authors: Weng Qunfang , Zhang Xiaofeng , Chen Wei , Hu Qiongbo
Published: February 2019

Isaria fumosorosea and Isaria farinosa are important entomopathogenic fungi with a worldwide distribution and multiple host insects. However, the concerns about the safety risks of myco-pesticides have been attracting the attention of researchers and consumers. Secondary metabolites (SMs), especially the mycotoxins, closely affect the biosafety of Isaria myco-insecticides. In the last forty years, more than seventy SMs were identified and isolated from I. fumosorosea and I. farinose. The SMs of I. fumosorosea include the mycotoxins of non-ribosomal peptides (NRPs) (beauvericin and beauverolides), terpenes (trichocaranes and fumosorinone), lactone compounds (cepharosporolides), acids (dipicolinic acid and oxalic acid), etc. Meanwhile, the NRP mycotoxins (cycloaspeptides) and the terpene compounds (farinosones and militarinones) are the main SMs in I. farinosa. Although several researches reported the two Isaria have promised biosafety, the bioactivities and the safety risks of their SMs have not been studied in detail so far. However, based on existing knowledge, most SMs (i.e., mycotoxins) do not come from Isaria myco-insecticide itself, but are from the host insects infected by Isaria fungi, because only the hosts can provide the conditions for fungal proliferation. Furthermore, the SMs from Isaria fungi have a very limited possibility of entering into environments because many SMs are decomposed in insect cadavers. The biosafety of Isaria myco-insecticides and their SMs/mycotoxins are being monitored. Of course, SMs safety risks of Isaria myco-insecticides need further research.
Therapeutic Approaches of Resveratrol on Endometriosis via Anti-Inflammatory and Anti-Angiogenic Pathways
Authors: Dull Ana-Maria , Moga Marius Alexandru , Dimienescu Oana Gabriela , Sechel Gabriela , Burtea Victoria , Anastasiu Costin Vlad
Published: February 2019

Endometriosis represents a severe gynecological pathology, defined by implantation of endometrial glands and stroma outside the uterine cavity. This pathology affects almost 15% of women during reproductive age and has a wide range of consequences. In affected women, infertility has a 30% rate of prevalence and endometriosis implants increase the risk of ovarian cancer. Despite long periods of studies and investigations, the etiology and pathogenesis of this disease still remain not fully understood. Initially, endometriosis was related to retrograde menstruation, but new theories have been launched, suggesting that chronic inflammation can influence the development of endometriosis because inflammatory mediators have been identified elevated in patients with endometriosis, specifically in the peritoneal fluid. The importance of dietary phytochemicals and their effect on different inflammatory diseases have been highlighted, and nowadays more and more studies are focused on the analysis of nutraceuticals. Resveratrol is a phytoestrogen, a natural polyphenolic compound with antiproliferative and anti-inflammatory actions, found in many dietary sources such as grapes, wine, peanuts, soy, berries, and stilbenes. Resveratrol possesses a significant anti-inflammatory effect via inhibition of prostaglandin synthesis and it has been proved that resveratrol can exhibit apoptosis-inducing activities. From the studies reviewed in this paper, it is clear that the anti-inflammatory effect of this natural compound can contribute to the prevention of endometriosis, this phenolic compound now being considered a new innovative drug in the prevention and treatment of this disease.
Supramolecular Hybrid Material Based on Engineering Porphyrin Hosts for an Efficient Elimination of Lead(II) from Aquatic Medium
Authors: El Abiad Chahrazad , Radi Smaail , Faustino Maria A. F. , Neves M. Graça P. M. S. , Moura Nuno M. M.
Published: February 2019

Porphyrins show great promise for future purification demands. This is largely due to their unique features as host binding molecules that can be modified at the synthetic level, and largely improved by their incorporation into inorganic based materials. In this study, we assessed the efficacy of a hybrid material obtained from the immobilization of 5,10,15,20-tetrakis(pentafluorophenyl)-porphyrin on silica surface to remove Pb(II), Cu(II), Cd(II), and Zn(II) ions from water. The new organic-inorganic hybrid adsorbent was fully characterized by adequate techniques and the results show that the hybrid exhibits good chemical and thermal stability. From batch assays, it was evaluated how the efficacy of the hybrid was affected by the pH, contact time, initial metal concentration, and temperature. The adsorption kinetic and isotherms showed to fit the recent developed fractal-like pseudo-second-order model and Langmuir–Freundlich model respectively. The highest adsorption capacities for Pb(II), Cu(II), Cd(II), and Zn(II) ions were 187.36, 125.17, 82.45, and 56.23 mg g−1, respectively, at pH 6.0 and 25 °C. This study also shows that metal cations from real river water samples can be efficient removed in the presence of the new adsorbent material.
Further Probing of Cu2+-Dependent PNAzymes Acting as Artificial RNA Restriction Enzymes
Authors: Luige Olivia , Murtola Merita , Ghidini Alice , Strömberg Roger
Published: February 2019

Peptide nucleic acid (PNA)-neocuproine conjugates have been shown to efficiently catalyse the cleavage of RNA target sequences in the presence of Cu2+ ions in a site-specific manner. These artificial enzymes are designed to force the formation of a bulge in the RNA target, the sequence of which has been shown to be key to the catalytic activity. Here, we present a further investigation into the action of Cu2+-dependent PNAzymes with respect to the dependence on bulge composition in 3- and 4-nucleotide bulge systems. Cu2+-dependent PNAzymes were shown to have a clear preference for 4-nucleotide bulges, as the cleavage of 3-nucleotide bulge-forming RNA sequences was significantly slower, which is illustrated by a shift in the half-lives from approximately 30 min to 24 h. Nonetheless, the nucleotide preferences at different positions in the bulge displayed similar trends in both systems. Moreover, the cleavage site was probed by introducing critical chemical modifications to one of the cleavage site nucleotides of the fastest cleaved 4-nucleotide RNA bulge. Namely, the exclusion of the exocyclic amine of the central adenine and the replacement of the 2′-hydroxyl nucleophile with 2′-H or 2′-OMe substituents in the RNA severely diminished the rate of RNA cleavage by the Cu2+-dependent PNAzyme, giving insight into the mechanism of cleavage. Moreover, the shorter recognition arm of the RNA/PNAzyme complex was modified by extending the PNAzyme by two additional nucleobases. The new PNAzyme was able to efficiently promote the cleavage of RNA when fully hybridised to a longer RNA target and even outperform the previous fastest PNAzyme. The improvement was demonstrated in cleavage studies with stoichiometric amounts of either PNAzyme present, and the extended PNAzyme was also shown to give turnover with a 10-fold excess of the RNA target.
Theaflavin-3,3′-Digallate Suppresses Human Ovarian Carcinoma OVCAR-3 Cells by Regulating the Checkpoint Kinase 2 and p27 kip1 Pathways
Authors: Gao Ying , Yin Junfeng , Tu Youying , Chen Yi Charlie
Published: February 2019

Theaflavin-3,3′-digallate (TF3) is a unique polyphenol in black tea. Epidemiological studies have proved that black tea consumption decreases the incidence rate of ovarian cancer. Our former research demonstrated that TF3 inhibited human ovarian cancer cells. Nevertheless, the roles of checkpoint kinase 2 (Chk2) and p27 kip1 (p27) in TF3-mediated inhibition of human ovarian cancer cells have not yet been investigated. In the current study, TF3 enhanced the phosphorylation of Chk2 to modulate the ratio of pro/anti-apoptotic Bcl-2 family proteins to initiate intrinsic apoptosis in a p53-independent manner and increased the expression of death receptors to activate extrinsic apoptosis in OVCAR-3 human ovarian carcinoma cells. In addition, TF3 up-regulated the expression of p27 to induce G0/G1 cell cycle arrest in OVCAR-3 cells. Our study indicated that Chk2 and p27 were vital anticancer targets of TF3 and provided more evidence that TF3 might be a potent agent to be applied as adjuvant treatment for ovarian cancer.
Bioactivity Profile of the Diterpene Isosteviol and its Derivatives
Authors: Ullah Asad , Munir Sidra , Mabkhot Yahia , Badshah Syed Lal
Published: February 2019

Steviosides, rebaudiosides and their analogues constitute a major class of naturally occurring biologically active diterpene compounds. The wide spectrum of pharmacological activity of this group of compounds has developed an interest among medicinal chemists to synthesize, purify, and analyze more selective and potent isosteviol derivatives. It has potential biological applications and improves the field of medicinal chemistry by designing novel drugs with the ability to cope against resistance developing diseases. The outstanding advancement in the design and synthesis of isosteviol and its derivative has proved its effectiveness and importance in the field of medicinal chemical research. The present review is an effort to integrate recently developed novel drugs syntheses from isosteviol and potentially active pharmacological importance of the isosteviol derivatives covering the recent advances.