bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and Performance of Antibacterial Polyvinyl Alcohol/Polyethylene Glycol/Chitosan Hydrogels Containing Silver Chloride Nanoparticles via One-step Method
Authors: Li Gang , Zhang Daohai , Qin Shuhao
Published: July 2019

Silver nano-particles (AgNPs)-filled antibacterial materials have been widely employed in the fields of biology and biomedicine. However, AgNPs have shown obvious cytotoxicity. Hence it is more reasonable to use silver chloride nanoparticles (AgCl NPs) to prepare antibacterial materials due to the slow release of silver ions created by AgCl NPs formed in the chitosan. In this experiment, a useful antibacterial hydrogel for skin repairation was prepared by exploring the relationship between AgCl NPs and cytotoxicity. It is worth noting that the crosslinked network structure was successfully obtained in an antibacterial AgCl/PVA (Polyvinyl alcohol)/PEG (Polyethylene glycol)/CS (Chitosan) hydrogel materials by the hydrothermal method. In detail, the dynamic particle size distribution of AgCl NPs was relatively uniform, which is analyzed by a dynamic light scattering (DLS). The internal structure of the lyophilized hydrogel showed obvious porous structure, indicating that the hydrogel had high water content. The result of X-ray photoelectron spectroscopy (XPS) confirmed the existence of a silver element. The release concentration of silver ions was analyzed by inductively coupled plasma (ICP) to study the effect of silver ions release concentration on the antibacterial activity and cytotoxicity of hydrogel. The results show that the lower concentration of silver ions can make the hydrogel have good antibacterial activity and low cytotoxicity. The bacteriostatic rate of the antibacterial hydrogel was over 90%. Simultaneously, the mechanical properties test shows that the hydrogel has good mechanical properties, which can be widely used as an antibacterial material.
Liposomal Vitamin D3 as an Anti-aging Agent for the Skin
Authors: Bi Ye , Xia Hongxi , Li Lianlian , Lee Robert J. , Xie Jing , Liu Zongyu , Qiu Zhidong , Teng Lesheng
Published: July 2019

Vitamin D3 is an effective skin protective substance to prevent photoaging. Liposomes were used as a carrier to deliver vitamin D3 to improve the stability and to enhance the treatment effect of vitamin D3. The stability of vitamin D3 liposomes, average cumulative penetration, and retention of vitamin D3 in the skin were then evaluated and compared with free vitamin D3. Finally, the treatment effect of vitamin D3 liposomes in a rat photoaging model was appraised and Haematoxylin-Eosin (H&E) staining was used to assess the histology changes of the skin after vitamin D3 liposome treatment. The results indicated that liposomes could significantly improve the stability of vitamin D3. The average skin retention of vitamin D3 liposomes was 1.65 times that of the vitamin D3 solution. Vitamin D3 liposomes could repair the surface morphology of skin in the photoaging model and promote the production of new collagen fibers. Vitamin D3 liposomes as a potential skin care agent could significantly improve skin appearance and repair damage in the histology of photoaging.
Flame Retardancy and Toughness of Poly(Lactic Acid)/GNR/SiAHP Composites
Authors: Wu Ningjing , Yu Jihang , Lang Wenchao , Ma Xiaobing , Yang Yue
Published: July 2019

A novel flame-retardant and toughened bio-based poly(lactic acid) (PLA)/glycidyl methacrylate-grafted natural rubber (GNR) composite was fabricated by sequentially dynamical vulcanizing and reactive melt-blending. The surface modification of aluminum hypophosphite (AHP) enhanced the interfacial compatibility between the modified aluminum hypophosphite by silane (SiAHP) and PLA/GNR matrix and the charring ability of the PLA/GNR/SiAHP composites to a certain extent, and the toughness and flame retardancy of the PLA/GNR/SiAHP composites were slightly higher than those of PLA/GNR/AHP composites, respectively. The notched impact strength and elongation of the PLA composite with 20 wt. %GNR and 18 wt.% SiAHP were 13.1 kJ/m2 and 72%, approximately 385% and 17 fold higher than those of PLA, respectively, and its limiting oxygen index increased to 26.5% and a UL-94 V-0 rating was achieved. Notedly, the very serious melt-dripping characteristics of PLA during combustion was completely suppressed. The peak heat release rate and total heat release values of the PLA/GNR/SiAHP composites dramatically reduced, and the char yield obviously increased with an increasing SiAHP content in the cone calorimeter test. The good flame retardancy of the PLA/GNR/SiAHP composites was suggested to be the result of a synergistic effect involving gaseous and condensed phase flame-retardant mechanisms. The high-performance flame-retardant PLA/GNR/SiAHP composites have great potential application as replacements for petroleum-based polymers in the automotive interior and building fields.
Characteristics, Compression, and Buffering Performance of Pomelo-Like Hierarchical Capsules Containing Shear Thickening Fluid
Authors: Li Ting-Ting , Huo Junli , Liu Xing , Wang Hongyang , Shiu Bing-Chiuan , Lou Ching-Wen , Lin Jia-Horng
Published: July 2019

In this study, a double-walled and pomelo-like hierarchical shear thickening fluid (STF) is successfully encapsulated using the simple and environment-friendly calcium alginate encapsulation technique by instilling STF into sodium alginate (SA) and crosslinking by calcium chloride solution. The encapsulated STF has a pomelo-like structure with a shell thickness of 2.9 μm and core pores with a size of 21.43 μm. The effect of the size of STF capsules (2.10, 1.89, 1.86, 1.83, 1.73, and 1.63 mm) is explored in terms of thermal stability, swelling capacity, mechanical property, and release performance. The buffering performance of different sizes of STF-containing capsules is also investigated. The pomelo-like STF capsules can withstand a processing temperature of 250 °C. With a decrease in particle size, the compression strain energy slowly increases first and then rapidly enhances. The kinetic release of pomelo-like STF capsules conforms to Fickian diffusion. STF-containing capsules with a diameter of 1.83 mm present the greatest thermal stability, the highest STF amount, the maximum swelling coefficient, and the fastest kinetic diffusion. STF-containing capsules also have an improved buffering performance in PU foam. This capsule has the best comprehensive performance and can adapt to diversified applications, such as personnel armor and other protective sports equipment.
Mechanical and Static Stab Resistant Properties of Hybrid-Fabric Fibrous Planks: Manufacturing Process of Nonwoven Fabrics Made of Recycled Fibers
Authors: Chuang Yu-Chun , Bao Limin , Lin Mei-Chen , Lou Ching-Wen , Lin TingAn
Published: July 2019

With the development of technology, fibers and textiles are no longer exclusive for the use of clothing and decoration. Protective products made of high-strength and high-modulus fibers have been commonly used in different fields. When exceeding the service life, the protective products also need to be replaced. This study proposes a highly efficient recycling and manufacturing design to create more added values for the waste materials. With a premise of minimized damage to fibers, the recycled selvage made of high strength PET fibers are reclaimed to yield high performance staple fibers at a low production cost. A large amount of recycled fibers are made into matrices with an attempt to decrease the consumption of new materials, while the combination of diverse plain woven fabrics reinforces hybrid-fabric fibrous planks. First, with the aid of machines, recycled high strength PET fibers are processed into staple fibers. Using a nonwoven process, low melting point polyester (LMPET) fibers and PET staple fibers are made into PET matrices. Next, the matrices and different woven fabrics are combined in order to form hybrid-fabric fibrous planks. The test results indicate that both of the PET matrices and fibrous planks have good mechanical properties. In particular, the fibrous planks yield diverse stab resistances from nonwoven and woven fabrics, and thus have greater stab performance.
Anomaly Detection in Hyperspectral Imagery Based on Low-Rank Representation Incorporating a Spatial Constraint
Authors: Tan Kun , Hou Zengfu , Ma Donglei , Chen Yu , Du Qian
Published: July 2019

Hyperspectral imagery contains abundant spectral information. Each band contains some specific characteristics closely related to target objects. Therefore, using these characteristics, hyperspectral imagery can be used for anomaly detection. Recently, with the development of compressed sensing, low-rank-representation-based methods have been applied to hyperspectral anomaly detection. In this study, novel low-rank representation methods were developed for anomaly detection from hyperspectral images based on the assumption that hyperspectral pixels can be effectively decomposed into a low-rank component (for background) and a sparse component (for anomalies). In order to improve detection performance, we imposed a spatial constraint on the low-rank representation coefficients, and single or multiple local window strategies was applied to smooth the coefficients. Experiments on both simulated and real hyperspectral datasets demonstrated that the proposed approaches can effectively improve hyperspectral anomaly detection performance.
Mid-season Crop Classification Using Dual-, Compact-, and Full-Polarization in Preparation for the Radarsat Constellation Mission (RCM)
Authors: Mahdianpari Masoud , Mohammadimanesh Fariba , McNairn Heather , Davidson Andrew , Rezaee Mohammad , Salehi Bahram , Homayouni Saeid
Published: July 2019

Despite recent research on the potential of dual- (DP) and full-polarimetry (FP) Synthetic Aperture Radar (SAR) data for crop mapping, the capability of compact polarimetry (CP) SAR data has not yet been thoroughly investigated. This is of particular concern, given the availability of such data from RADARSAT Constellation Mission (RCM) shortly. Previous studies have illustrated potential for accurate crop mapping using DP and FP SAR features, yet what contribution each feature makes to the model accuracy is not well investigated. Accordingly, this study examined the potential of the early- to mid-season (i.e., May to July) RADARSAT-2 SAR images for crop mapping in an agricultural region in Manitoba, Canada. Various classification scenarios were defined based on the extracted features from FP SAR data, as well as simulated DP and CP SAR data at two different noise floors. Both overall and individual class accuracies were compared for multi-temporal, multi-polarization SAR data using the pixel- and object-based random forest (RF) classification schemes. The late July C-band SAR observation was the most useful data for crop mapping, but the accuracy of single-date image classification was insufficient. Polarimetric decomposition features extracted from CP and FP SAR data produced relatively equal or slightly better classification accuracies compared to the SAR backscattering intensity features. The RF variable importance analysis revealed features that were sensitive to depolarization due to the volume scattering are the most important FP and CP SAR data. Synergistic use of all features resulted in a marginal improvement in overall classification accuracies, given that several extracted features were highly correlated. A reduction of highly correlated features based on integrating the Spearman correlation coefficient and the RF variable importance analyses boosted the accuracy of crop classification. In particular, overall accuracies of 88.23%, 82.12%, and 77.35% were achieved using the optimized features of FP, CP, and DP SAR data, respectively, using the object-based RF algorithm.
Monitoring Green Infrastructure for Natural Water Retention Using Copernicus Global Land Products
Authors: Taramelli Andrea , Lissoni Michele , Piedelobo Laura , Schiavon Emma , Valentini Emiliana , Nguyen Xuan Alessandra , González-Aguilera Diego
Published: July 2019

Nature-based solutions are increasingly relevant tools for spatial and environmental planning, climate change adaptation (CCA), and disaster risk reduction (DRR). For this reason, a wide range of institutions, governments, and financial bodies are currently promoting the use of green infrastructure (GI) as an alternative or a complement to traditional grey infrastructure. A considerable amount of research already certifies the benefits and multi-functionality of GI: natural water retention measures (NWRMs), as GIs related specifically to the water sector are also known, are, for instance, a key instrument for the prevention and mitigation of extreme phenomena, such as floods and droughts. However, there are persisting difficulties in locating and identifying GI and one of the most promising solutions to this issue, the use of satellite-based data products, is hampered by a lack of well-grounded knowledge, experiences, and tools. To bridge this gap, we performed a review of the Copernicus Global Land Service (CGLS) products, which consist of freely-available bio-geophysical indices covering the globe at mid-to-low spatial resolutions. Specifically, we focused on vegetation and energy indices, examining previous research works that made use of them and evaluating their current quality, aiming to define their potential for studying GI and especially NWRMs related to agriculture, forest, and hydro-morphology. NWRM benefits are also considered in the analysis, namely: (i) NWRM biophysical impacts (BPs), (ii) ecosystem services delivered by NWRMs (ESs), and (iii) policy objectives (POs) expressed by European Directives that NWRMs can help to achieve. The results of this study are meant to assist GI users in employing CGLS products and ease their decision-making process. Based on previous research experiences and the quality of the currently available versions, this analysis provides useful tools to identify which indices can be used to study several types of NWRMs, assess their benefits, and prioritize the most suitable ones.
Identification and Compensation Technique of Non-Uniform Temperature Field for Lamb Wave-and Multiple Sensors-Based Damage Detection
Authors: Sun Hu , Yi Junyan , Xu Yu , Wang Yishou , Qing Xinlin
Published: July 2019

Lamb wave-based damage detection for large-scale composites is one of the most prosperous structural health monitoring technologies for aircraft structures. However, the temperature has a significant effect on the amplitude and phase of the Lamb wave signal so that temperature compensation is always the focus problem. Especially, it is difficult to identify the damage in the aircraft structures when the temperature is not uniform. In this paper, a compensation method for Lamb wave-based damage detection within a non-uniform temperature field is proposed. Hilbert transform and Levenberg-Marquardt optimization algorithm are developed to extract the amplitude and phase variation caused by the change of temperature, which is used to establish a data-driven model for reconstructing the reference signal at a certain temperature. In the temperature compensation process, the current Lamb wave signal of each exciting-sensing path under the estimated structural condition is substituted into the data-driven model to identify an interpolated initial temperature field, which is further processed by an outlier removing algorithm to eliminate the effect of damage and get the actual non-uniform temperature field. Temperature compensation can be achieved by reconstructing the reference signals within the identified non-uniform temperature field, which are used to compare with the current acquired signals for damage imaging. Both simulation and experiment were conducted to verify the feasibility and effectiveness of the proposed non-uniform temperature field identification and compensation technique for Lamb wave-based structural health monitoring.
An Aeromagnetic Compensation Method Based on a Multimodel for Mitigating Multicollinearity
Authors: Zhao Guanyi , Han Qi , Peng Xiang , Zou Pengyi , Wang Haidong , Du Changping , Wang He , Tong Xiaojun , Li Qiong , Guo Hong
Published: July 2019

Aeromagnetic surveys play an important role in geophysical exploration and many other fields. In many applications, magnetometers are installed aboard an aircraft to survey large areas. Due to its composition, an aircraft has its own magnetic field, which degrades the reliability of the measurements, and thus a technique (named aeromagnetic compensation) that reduces the magnetic interference field effect is required. Commonly, based on the Tolles–Lawson model, this issue is solved as a linear regression problem. However, multicollinearity, which refers to the case when more than two model variables are highly linearly related, creates accuracy problems when estimating the model coefficients. The analysis in this study indicates that the variables that cause multicollinearity are related to the flight heading. To take this point into account, a multimodel compensation method is proposed. By selecting the variables that contribute less to the multicollinearity, different sub-models are built to describe the magnetic interference of the aircraft when flying in different orientations. This method restricts the impact of multicollinearity and improves the reliability of the measurements. Compared with the existing methods, the proposed method reduces the interference field more effectively, which is verified by a set of airborne tests.
Transmission of Still Images Using Low-Complexity Analog Joint Source-Channel Coding
Authors: Balsa Jose , Domínguez-Bolaño Tomás , Fresnedo Óscar , García-Naya José A. , Castedo Luis
Published: July 2019

An analog joint source-channel coding (JSCC) system designed for the transmission of still images is proposed and its performance is compared to that of two digital alternatives which differ in the source encoding operation: Joint Photographic Experts Group (JPEG) and JPEG without entropy coding (JPEGw/oEC), respectively, both relying on an optimized channel encoder–modulator tandem. Apart from a visual comparison, the figures of merit considered in the assessment are the structural similarity (SSIM) index and the time required to transmit an image through additive white Gaussian noise (AWGN) and Rayleigh channels. This work shows that the proposed analog system exhibits a performance similar to that of the digital scheme based on JPEG compression with a noticeable better visual degradation to the human eye, a lower computational complexity, and a negligible delay. These results confirm the suitability of analog JSCC for the transmission of still images in scenarios with severe constraints on power consumption, computational capabilities, and for real-time applications. For these reasons the proposed system is a good candidate for surveillance systems, low-constrained devices, Internet of things (IoT) applications, etc.
Using Recurrent Neural Networks to Compare Movement Patterns in ADHD and Normally Developing Children Based on Acceleration Signals from the Wrist and Ankle
Authors: Muñoz-Organero Mario , Powell Lauren , Heller Ben , Harpin Val , Parker Jack
Published: July 2019

Attention deficit and hyperactivity disorder (ADHD) is a neurodevelopmental condition that affects, among other things, the movement patterns of children suffering it. Inattention, hyperactivity and impulsive behaviors, major symptoms characterizing ADHD, result not only in differences in the activity levels but also in the activity patterns themselves. This paper proposes and trains a Recurrent Neural Network (RNN) to characterize the moment patterns for normally developing children and uses the trained RNN in order to assess differences in the movement patterns from children with ADHD. Each child is monitored for 24 consecutive hours, in a normal school day, wearing 4 tri-axial accelerometers (one at each wrist and ankle). The results for both medicated and non-medicated children with ADHD, and for different activity levels are presented. While the movement patterns for non-medicated ADHD diagnosed participants showed higher differences as compared to those of normally developing participants, those differences were only statistically significant for medium intensity movements. On the other hand, the medicated ADHD participants showed statistically different behavior for low intensity movements.
Motion Segmentation Based on Model Selection in Permutation Space for RGB Sensors
Authors: Zhao Xi , Qin Qianqing , Luo Bin
Published: July 2019

Motion segmentation is aimed at segmenting the feature point trajectories belonging to independently moving objects. Using the affine camera model, the motion segmentation problem can be viewed as a subspace clustering problem—clustering the data points drawn from a union of low-dimensional subspaces. In this paper, we propose a solution for motion segmentation that uses a multi-model fitting technique. We propose a data grouping method and a model selection strategy for obtaining more distinguishable data point permutation preferences, which significantly improves the clustering. We perform extensive testing on the Hopkins 155 dataset, and two real-world datasets. The experimental results illustrate that the proposed method can deal with incomplete trajectories and the perspective effect, comparing favorably with the current state of the art.
Synthesis of Ni-Co Hydroxide Nanosheets Constructed Hollow Cubes for Electrochemical Glucose Determination
Authors: Sun Fengchao , Wang Shutao , Wang Yuqi , Zhang Jingtong , Yu Xinping , Zhou Yan , Zhang Jun
Published: July 2019

Hierarchical Ni-Co double transition metal hydroxide nanosheets have been explored as an effective strategy for the design of nonenzymatic glucose sensors. Ni-Co hydroxide nanosheets constructed hollow cubes were successfully synthesized by using Cu2O cubes as templates and subsequently etched by Na2S2O3 to achieve a hollow cubic structure. The molar ratio between Ni and Co was tuned by varying the precursor ratio of NiCl2 and CoCl2. It was observed by transmission electron microscopy (TEM) that the increasing Ni precursor resulted in particle morphology, and the increasing ratio of the Co precursor resulted in more lamellar morphology. The sample with the composition of Ni0.7Co0.3(OH)2 displayed the best performance for glucose sensing with high selectivity (1541 μA mM–1 cm–2), low detection limit (3.42 µM with S/N = 3), and reasonable selectivity. Similar strategies could be applied for the design of other electrode materials with high efficiency for nonenzymatic glucose determination.
Application of the Enzymatic Electrochemical Biosensors for Monitoring Non-Competitive Inhibition of Enzyme Activity by Heavy Metals
Authors: Ashrafi Amir M. , Sýs Milan , Sedláčková Eliška , Shaaban Farag Amir , Adam Vojtěch , Přibyl Jan , Richtera Lukáš
Published: July 2019

The inhibition effect of the selected heavy metals (Ag+, Cd2+, Cu2+, and Hg2+) on glucose oxidase (GOx) enzyme from Aspergillus niger (EC 1.1.3.4.) was studied using a new amperometric biosensor with an electrochemical transducer based on a glassy carbon electrode (GCE) covered with a thin layer of multi-wall carbon nanotubes (MWCNTs) incorporated with ruthenium(IV) oxide as a redox mediator. Direct adsorption of multi-wall carbon nanotubes (MWCNTs) and subsequent covering with Nafion® layer was used for immobilization of Gox. The analytical figures of merit of the developed glucose (Glc) biosensor are sufficient for determination of Glc in body fluids in clinical analysis. From all tested heavy metals, mercury(II) has the highest inhibition effect. However, it is necessary to remember that cadmium and silver ions also significantly inhibit the catalytic activity of Gox. Therefore, the development of Gox biosensors for selective indirect determination of each heavy metal still represents a challenge in the field of bioelectroanalysis. It can be concluded that amperometric biosensors, differing in the utilized enzyme, could find their application in the toxicity studies of various poisons.
Empowering Citizens through Perceptual Sensing of Urban Environmental and Health Data Following a Participative Citizen Science Approach
Authors: Ottaviano Manuel , Beltrán-Jaunsarás María Eugenia , Teriús-Padrón José Gabriel , García-Betances Rebeca I. , González-Martínez Sergio , Cea Gloria , Vera Cecilia , Cabrera-Umpiérrez María Fernanda , Arredondo Waldmeyer María Teresa
Published: July 2019

The growth of the urban population together with a high concentration of air pollution have important health impacts on citizens who are exposed to them, causing serious risks of the development and evolution of different chronic diseases. This paper presents the design and development of a novel participatory citizen science-based application and data ecosystem model. These developments are imperative and scientifically designed to gather and process perceptual sensing of urban, environmental, and health data. This data acquisition approach allows citizens to gather and generate environment- and health-related data through mobile devices. The sum of all citizens’ data will continuously enrich and increase the volumes of data coming from the city sensors and sources across geographical locations. These scientifically generated data, coupled with data from the city sensors and sources, will enable specialized predictive analytic solutions to empower citizens with urban, environmental, and health recommendations, while enabling new data-driven policies. Although it is difficult for citizens to relate their personal behaviour to large-scale problems such as climate change, pollution, or public health, the developed ecosystem provides the necessary tools to enable a greener and healthier lifestyle, improve quality of life, and contribute towards a more sustainable local environment.
Urbanization and Management of the Catchment Retention in the Aspect of Operation of Storm Overflow: A Probabilistic Approach
Authors: Szeląg Bartosz , Cienciała Agnieszka , Sobura Szymon , Studziński Jan , García Juan T.
Published: July 2019

This paper presents the concepts of a probabilistic model for storm overflow discharges, in which arbitrary dynamics of the catchment urbanization were included in the assumed period covered by calculations. This model is composed of three components. The first constitutes the classification model for the forecast of storm overflow discharges, in which its operation was related to rainfall characteristics, catchment retention, as well as the degree of imperviousness. The second component is a synthetic precipitation generator, serving for the simulation of long-term observation series. The third component of the model includes the functions of dynamic changes in the methods of the catchment development. It allows for the simulation of changes in the extent of imperviousness of the catchment in the long-term perspective. This is an important advantage of the model, because it gives the possibility of forecasting (dynamic control) of catchment retention, accounting for the quantitative criteria and their potential changes in the long-term perspective in relation to the number of storm overflows. Analyses carried out in the research revealed that the empirical coefficients included in the logit model have a physical interpretation, which makes it possible to apply the obtained model to other catchments. The paper also shows the use of the prepared probabilistic model for rational catchment management, with respect to the forecasted number of storm overflow discharges in the long-term and short-term perspective. The model given in the work can be also applied to the design and monitoring of catchment retention in such a way that in the progressive climatic changes and urbanization of the catchment, the number of storm overflow discharges remains within the established range.
Optimal Incentive Contract for Sales Team with Loss Aversion Preference
Authors: Li Chao , Cheng Si-Jie , Cheng Peng-Fei
Published: July 2019

When manufacturing enterprises employ sales team (or multiple salesmen) to sell products, there is asymmetric information such as the ability and efforts salesmen. Enterprises can use contracts to incentivize salesmen to work hard to maximize their profits. Assuming that market demand is sensitive to effort, and the salesman can exploit the market by increasing effort, a multi-agent model is established for the case of symmetrical information and asymmetrical information, in which the sales team has a loss aversion preference. In this multi-agent model, the agents’ utility function is non-concave and cannot be solved by traditional methods. We use a backward stochastic differential equation (BSDE) to represent agents’ contract through the martingale representation theorem and use the stochastic optimal control and matrix method to obtain the explicit solution of the optimal contract. Based on the conclusions of the research, an empirical analysis is made on the sales team of an enterprise.
A Bifunctional Adsorber Particle for the Removal of Hydrophobic Uremic Toxins from Whole Blood of Renal Failure Patients
Authors: Sternkopf Marieke , Thoröe-Boveleth Sven , Beck Tobias , Oleschko Kirsten , Erlenkötter Ansgar , Tschulena Ulrich , Steppan Sonja , Speer Thimoteus , Goettsch Claudia , Jankowski Vera , Jankowski Joachim , Noels Heidi ,   The European Uremic Toxin Work Group-EUTox
Published: July 2019

Hydrophobic uremic toxins accumulate in patients with chronic kidney disease, contributing to a highly increased cardiovascular risk. The clearance of these uremic toxins using current hemodialysis techniques is limited due to their hydrophobicity and their high binding affinity to plasma proteins. Adsorber techniques may be an appropriate alternative to increase hydrophobic uremic toxin removal. We developed an extracorporeal, whole-blood bifunctional adsorber particle consisting of a porous, activated charcoal core with a hydrophilic polyvinylpyrrolidone surface coating. The adsorption capacity was quantified using analytical chromatography after perfusion of the particles with an albumin solution or blood, each containing mixtures of hydrophobic uremic toxins. A time-dependent increase in hydrophobic uremic toxin adsorption was depicted and all toxins showed a high binding affinity to the adsorber particles. Further, the particle showed a sufficient hemocompatibility without significant effects on complement component 5a, thrombin-antithrombin III complex, or thrombocyte concentration in blood in vitro, although leukocyte counts were slightly reduced. In conclusion, the bifunctional adsorber particle with cross-linked polyvinylpyrrolidone coating showed a high adsorption capacity without adverse effects on hemocompatibility in vitro. Thus, it may be an interesting candidate for further in vivo studies with the aim to increase the efficiency of conventional dialysis techniques.
Hydrogeochemical Model Supporting the Remediation Strategy of a Highly Contaminated Industrial Site
Authors: Ciampi Paolo , Esposito Carlo , Petrangeli Papini Marco
Published: July 2019

Delineation and understanding the geology and the hydrogeology of a contaminated site, considering its chemical and its biological aspects, are fundamental requirements for successful environmental remediation. The aim of this research is to provide some evidence about the effectiveness of a hydrogeochemical geodatabase to facilitate the integrated management, representation and analysis of heterogeneous data, enabling the appropriate selection, design and optimization of an effective remediation strategy. This study investigates a new technology for the remediation of a dense non-aqueous phase liquid aged source zone, with the aim of enhancing in situ bioremediation by coupling groundwater circulation wells with a continuous production system of electron donors. The technology was verified through a pilot test carried out at an industrial site highly contaminated by chlorinated aliphatic hydrocarbons. The multidisciplinary conceptual model confirmed a complex hydrogeological situation, with the occurrence of active residual sources in low permeability layers. The pilot test results clearly demonstrate a significant mobilization of contaminants from the low permeability zone, and the possibility of favoring the in situ natural attenuation mechanisms based upon biological reductive dechlorination. Different information related to the hydrogeochemical sphere must be integrated and taken into consideration when developing a reliable remediation strategy for contaminated sites.
Pengaruh Pemberian Aromatherapi Jahe Terhadap Mual Muntah Pada Ibu Hamil Trimester I
Authors: Kurnia Herni
Published: July 2019

ABSTRAK: Kehamilan merupakan pertumbuhan dan perkembangan janin intrauterin mulai sejak konsepsi dan berakhir sampai permulaan persalinan. Kehamilan menimbulkan perubahan-perubahan fisiologi yang terjadi di seluruh sistem organ, sebagian besar perubahan pada tubuh ibu kebanyakan disebabkan oleh kerja hormonal. Perubahan yang terjadi pada ibu hamil dapat menimbulkan ketidaknyamanan dalam kehamilan, salah satunya adalah mual muntah. Berdasarkan hasil penelitian 50-90% wanita hamil mengalami mual pada trimester pertama. Penanganan mual muntah selama masa kehamilan dapat dilakukan melalui tindakan farmakologi maupun non farmakologi. Salah satu terapi non farmakologi yaitu dengan aromaterapi Jahe. Tujuan penelitian ini adalah untuk mengetahui Pengaruh pemberian Aromatherapi Jahe Terhadap Mual Muntah Pada Ibu Hamil Trimester I. Desain penelitan quasy experiment, dengan jenis rancangan pre -post test control group design. Penelitian ini dilakukan di Wilayah Kerja Puskesmas Purbaratu Kota Tasikmalaya Tahun 2019. Sampel dipilih secara purposive sampling dan didapatkan jumlah sampel 36 responden. Hasil penelitian Sebagian besar responden tidak mengalami mual muntah setelah diberikan aromaterapi jahe yaitu sebanyak  12 orang (66.7%) dan hasil uji Mann Whitney bahwa pada kelompok perlakuan diperoleh nilai p<0,05 dengan demikian terdapat pengaruh pemberian aromaterapi jahe terhadap mual muntah pada ibu hamil trimester I di Wilayah Kerja Puskesmas Purbaratu Kota Tasikmalaya.

ABSTRAK: Kehamilan merupakan pertumbuhan dan perkembangan janin intrauterin mulai sejak konsepsi dan berakhir sampai permulaan persalinan. Kehamilan menimbulkan perubahan-perubahan fisiologi yang terjadi di seluruh sistem organ, sebagian besar perubahan pada tubuh ibu kebanyakan disebabkan oleh kerja hormonal. Perubahan yang terjadi pada ibu hamil dapat menimbulkan ketidaknyamanan dalam kehamilan, salah satunya adalah mual muntah. Berdasarkan hasil penelitian 50-90% wanita hamil mengalami mual pada trimester pertama. Penanganan mual muntah selama masa kehamilan dapat dilakukan melalui tindakan farmakologi maupun non farmakologi. Salah satu terapi non farmakologi yaitu dengan aromaterapi Jahe. Tujuan penelitian ini adalah untuk mengetahui Pengaruh pemberian Aromatherapi Jahe Terhadap Mual Muntah Pada Ibu Hamil Trimester I. Desain penelitan quasy experiment, dengan jenis rancangan pre -post test control group design. Penelitian ini dilakukan di Wilayah Kerja Puskesmas Purbaratu Kota Tasikmalaya Tahun 2019. Sampel dipilih secara purposive sampling dan didapatkan jumlah sampel 36 responden. Hasil penelitian Sebagian besar responden tidak mengalami mual muntah setelah diberikan aromaterapi jahe yaitu sebanyak  12 orang (66.7%) dan hasil uji Mann Whitney bahwa pada kelompok perlakuan diperoleh nilai p<0,05 dengan demikian terdapat pengaruh pemberian aromaterapi jahe terhadap mual muntah pada ibu hamil trimester I di Wilayah Kerja Puskesmas Purbaratu Kota Tasikmalaya.
Construction de mosaïques pour l'analyse des textures subpolyédriques
Authors: Grolier Jacques , Hucher Monique
Published: July 2019

Packing polyhedra into geometric models is a useful approach to the description of sub-polyhedric rock textures. When a packed aggregate of polyhedra is cut, a mosaic of individual polygons is obtained. Crystallographic concepts, enabling to predict what kinds of mosaics are obtained along any section plane in the polyhedral aggregate, are introduced. Thus, the shape (regular or irregular), the number of sides of the polygons in a given mosaic and likewise, the pattern of a mosaic — whether the mosaics made up of polygons of one type only, or a mixture of several types — can be determined by crystallographic operations. A few mosaics, obtained when packed aggregates of tetrakaidecahedra, rhombododecahedra, and cube-rhombododecahedra are cut along preferred planes of orientation, are presented. Geometric models are compared to the textural pattern of a few rocks, ceramics and metals. The frequency distribution of the mosaic types obtained by cutting across packed aggregates of tetrakaidecahedra is looked into it. Lastly, the spatial random distribution of two, and also the three mineral phases in the aggregate is graphically illustrated.
La mélonjosephite Ca Fe2+Fe3+(PO4)2(OH), une nouvelle espèce minérale
Authors: Fransolet André-Mathieu
Published: July 2019

La mélonjosephite se présente en masses très finement fibreuses, de couleur vert foncé. Orthorhombique avec a = 9,548 Å ; b = 10,847 Å et c = 6,380 Å ; Z = 4, d[calc.] = 3,61 ; d[mes] = 3,65 ; les raies les plus intenses du diffractogramme de poudre sont : 5,42 (90), 3.185 (30), 3,049 (100), 2,912 (40), 2,710 (90), 2,624 (60), 2,383 (30), 2,187 (35) Å. Il existe un clivage (?) transversal imparfait. Dureté inférieure à 5. Biaxe négatif ; nv = 1,720, nm = 1,770 et ng = 1,800, 2 V : 80-85° ; dispersion forte. X (nv) = c et Z (ng) = b ; pléochroïque : X brun foncé, presque opaque, Y brun verdâtre, Z jaune or à légèrement verdâtre. Le minéral est facilement dissout par HCl. Analyse chimique : P₂O₅ = 39,96 ; Fe₂O₃ = 21,81 ; Al₂O₃ = 0,17 ; FeO = 17,39 ; MgO = 1,18 ; MnO = 0,44 ; CaO = 14,99, Na₂O = 0,48 ; Li₂O = 0,07 ; H₂O⁺ = 2,50, insol. 0,97 (total = 99,96 %) correspondant à Ca (Fe²⁺, Mg) Fe³⁺ (PO₄)₂ (OH). Le spectre infrarouge est donné et brièvement discuté. Le minéral est à rapprocher de la dufrénite ou de la rockbridgéite. Nommée en l'honneur de J. Mélon. Les échantillons types sont déposés au Musée de l'Institut de Minéralogie, Université de Liège (Belgique).
Corrélations hydrogéochimiques de certains oligoéléments des eaux thermales azotées
Authors: Pentcheva E. N.
Published: July 2019

Hydrogeochemical correlations are studied which deal with trace-elements that characterise alkaline thermal waters releasing nitrogen. Both correlation coefficients and equations are examined ; they have been obtained by computer by means of the least squares method and regression analysis.

Some explanations and interpretations are proposed, directly in relation to possible migration forms.
La géomicrobiologie et la biominéralurgie
Authors: Goñi Juan C. , Greffard J. , Gugalski T. , Leleu Michel
Published: July 2019

This article is a review of main applications of microbiology to geochemistry and ore dressing.

We show, using examples from our works and from foreign works, what the study of certain kind of micro-organism brings to the understanding of low temperature geochemical processes and what are the hopes of industrial applications.

The silicates alteration, the oxidation of iron and manganese, the oxidation of iron and sulfur, the reduction of sulfates are the main areas which lead to problems like : the formation of manganese nodules, the formation of biosynthetic sulfide, the fight against pollution, the biolixiviation of sulfides.
Le volcanisme tertiaire des monts du Forez (Massif central français) : basanites à analcime, à leucite et néphélinites à mélilite
Authors: Hernandez Jean
Published: July 2019

The oligocene-miocene volcanics of the Forez region include : melilite nephelinites, leucite and analcite basanites, limburgites and basanitoids.

On the basis of twenty new analysis, it is suggested that nephelinites and basanites form two groups of distinct origin ; the variations in alkali content cannot explain alone the presence of analcite or leucite.

The alumina content of several salites indicates a high temperature and low pressure of cristallisation. The origin of the lavas is to be sought for in the upper mantle, low pressure fractionation being probably of minor importance.
La brassite, MgHAsO4 • 4H2O, une nouvelle espèce minérale
Authors: Fontan François , Orliac Marcel , Permingeat François , Pierrot Roland , Stahl Réjane
Published: July 2019

The study of artificial crystals allows a complete description of a new-mineral species, observed as early as 1958, under the shape of crusts and white, cryptocristalline and pulverulent coatings, on specimens from various origins : Jachymov (Bohemia) (type-deposit), Bieber (Saxony), Neurode (Silesia) and Wittichen (Baden). The name of brassite is in honour of Réjane Brasse. Brassite is orthorhombic Pbca a = 7.472, b = 10.891, c = 16.585 Å, Z = 8, dmes. = 2.28, dₓ =  2.326. Main powder diagram lines : 4.97(10) 4.14(6) 3.88(5) 3.45(5) 3.20(8) 3.07(7) 2.32(5). Artificial crystals are colourless, tabular on (001), which is an excellent cleavage, rectangular and bevel edged by : (011) (021) and (102). Biaxial (+), 2V very large, ng = 1.562 on c, nm = 1.546 on a, nv = 1.531 on b. The chemical analysis of the Jachymov brassite corresponds well to the MgHAsO₄ • 4H₂O composition of the artificial product. Thermic analysis show that deshydration begins at 85° C and leads to the formation of a hemihydrate at around 135° C, then to the pyroarseniate at a temperature as high as 250° C with exothermic crystallization at around 570° C. The roesslerite deshydrates itself spontaneously into brassite, which remains stable in normal laboratory conditions. This type of formation certainly occurs in nature, but on the other hand, the direct crystallization of brassite seems to be exceptional, perhaps because of the abundance of carbonates increasing the pH of solutions in deposits rich in arsenic. Type material will be preservated at the Ecole nationale supérieure des mines de Paris.
Les malachites cobaltifères du Shaba méridional (Zaïre)
Authors: Deliens Michel , Oosterbosch Robert , Verbeek Théodore
Published: July 2019

Les malachites cobaltifères se présentent en sphérulites ou en encroûtements mamelonnés verts, beiges ou bruns. On distingue deux groupes ; le premier est constitué de minéraux vert foncé à vert olive, renfermant moins de 6,5 % de cobalt ; les propriétés optiques et les spectres de rayons X sont voisins de ceux de la malachite. Le second groupe est constitué de minéraux beiges à bruns renfermant de 14 à 18,5 % de cobalt ; le spectre de rayons X diffère sensiblement de celui de la malachite par l'apparition de raies intenses à d = 2,95 Å et 2,59 Å et par la disparition des raies fortes de la malachite d = 2,854 Å et 2,777 Å. Il semble exister un hiatus entre ces deux groupes.
The iron content of ferromagnesian silicates and oxides as a function of the oxygen distribution in the Earth's mantle
Authors: Khitarov N. I. , Kuskov O. L.
Published: July 2019

L'équilibre des solutions solides des silicates ferromagnésiens et des oxydes avec du fer métallique dans le manteau terrestre, pendant les premiers pas de son évolution, est considéré en fonction de la fugacité d'oxygène, de la pression et de la température. En général, dans des conditions constantes de P et T, la teneur en fer des solutions solides de spinelles et pyroxènes décroît quand diminue la fugacité d'oxygène et simultanément, se forment des silicates plus magnésiens à structures cristallines compactes, ainsi que du fer métallique. La concentration en oxyde ferreux dans le manteau décroît quand la profondeur augmente et peut être nulle à la frontière noyau-manteau. Cependant, l'abondance en fer total dans le manteau ne décroît pas parce qu'il passe des silicates et oxydes au fer métallique, suite aux variations du potentiel chimique de l'oxygène. La formation du noyau terrestre peut probablement s'expliquer par le fractionnement du fer, dû aux variations des potentiels d'oxydo-réduction dans le manteau et à la limite manteau-noyau, et à la différenciation du fer sous hautes pressions.
Substitution, déformation locale de la maille et équilibre de distribution des éléments en traces entre silicates et solution hydrothermale
Authors: Iiyama Jean Toshimichi
Published: July 2019

Présentation d'un modèle thermodynamique de solutions solides pouvant expliquer des comportements particuliers observés lors de la fixation d'éléments en traces remplaçant un élément majeur dans les silicates. Certains types d'écart à l'idéalité des solutions solides ne peuvent pas être expliqués à l'aide d'un modèle qui suppose une distribution parfaitement aléatoire des éléments en traces dans les sites de substitution.

On imagine une déformation locale de la structure autour d'un site substitué. Cette déformation provoque une variation d'entropie différente de celle des solutions idéales. Ce modèle explique qualitativement l'écart très précoce à la loi de Henry souvent observé dans les courbes d'équilibre de distribution d'éléments en traces entre silicates et solution hydrothermale. Il explique également le sens de cette déviation par rapport à la solution idéale.

Comparaison avec les données expérimentales et discussion sur quelques aspects des solutions solides réelles.
Spinodal precipitation in minerals. Review and some new observations
Authors: Christie Olav H. J. , Olsen Arne
Published: July 2019

The theory of spinodal precipitation was applied to oxides in 1965 and to silicates in 1968. Electron microscope investigations have demonstrated that this process takes place in feldspars and pyroxenes. By aid of electron microscopy the composition of the exsolved phases may be studied in more detail. Moiré effects originating from compositional waves of different composition have been observed in andesine. There are indications of spinodal precipitation even in the nepheline-kalsilite system and in amphiboles exemplified by gedrite.
Substitutions multiples dans la série tennantite˗tétraédrite
Authors: Charlat Michel , Lévy Claude
Published: July 2019

L'analyse à la microsonde électronique de 54 échantillons de la série tennantite˗tétraédrite a montré que la plupart d'entre eux sont hétérogènes et composés et domaines de compositions différentes.

Leur composition connue à partir de 160 analyses a permis de préciser leur formule structurale, résumée sous la forme :

(Cu, Ag)₁₀ (Cu, Fe, Zn, Hg)₂ (As, Sb)₄ S₁₃ Ces analyses ont permis d'établir ou de préciser :

1) l'existence d'un treizième atome de S ;

2) la fréquence plus grande des termes riches en Sb ;

3) la présence de Cu dans les « sites de Fe-Zn » ;

4) l'affinité de Cu pour As et Fe et celle de Ag pour Sb et Zn et donc le fait que les substitutions As-Sb, Cu-Ag, Cu-Fe-Zn-Hg, ne sont pas indépendantes.
Stabilité de l'alloclasite et de la cobaltite dans les systèmes Co-As-S et Co-Ni-As-S
Authors: Maurel Colette , Picot Paul
Published: July 2019

Une étude expérimentale dans le système CoS₂-CoAs₂ établit que la cobaltite ne peut admettre dans son réseau une substitution notable du soufre par l'arsenic, quelle que soit la température. Au-dessus de 800° C, pour des compositions plus riches en arsenic que CoAsS, apparaît une phase orthorhombique du type alloclasite. Au-dessous de 800° C, cette phase n'est pas stable, mais peut exister de façon métastable.

Des considérations théoriques, jointes aux observations faites par d'autres auteurs sur la stabilité structurale des composés arséniés de nickel et de cobalt, conduisent à penser qu'une substitution notable du cobalt par le nickel doit stabiliser la structure de la cobaltite pour des teneurs en arsenic plus élevées que dans CoAsS. Corrélativement, la phase orthorhombique serait limitée à des teneurs en soufre plus faibles.

Les résultats expérimentaux obtenus dans le système Co-Ni-As-S sont en bon accord avec ces déductions, de même que les observations faites sur une alloclasite zonée provenant de Bou Azzer (Maroc).
Solid solution in leucite
Authors: MacKenzie William S. , Richardson Diana M. , Wood Bernard J.
Published: July 2019

Experimental study of the solution of KAlSi₃O₈ in leucite at P[H₂O] = 1 kbar indicates that leucites can take up to about 30 wt. % of KAlSi₃O₈ in solid solution. The experimental data are consistent with ideal solution of KAlSi₃O₈ in leucite.

The temperature of equilibration of leucite and sanidine in rocks can be estimated from these data.