bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring the Effect of Iron Metal-Organic Framework Particles in Polylactic Acid Membranes for the Azeotropic Separation of Organic/Organic Mixtures by Pervaporation
Authors: Msahel Asma , Galiano Francesco , Pilloni Martina , Russo Francesca , Hafiane Amor , Castro-Muñoz Roberto , Kumar Vijay Bhooshan , Gedanken Aharon , Ennas Guido , Porat Ze’ev , Scano Alessandra , Hamouda Sofiane Ben , Figoli Alberto
Published: January 2021

A microporous carboxylate metal-organic framework MIL-100 Fe was prepared as submicron particles by microwave-assisted hydrothermal synthesis (Fe-MOF-MW). This product was explored, for the first time, for the preparation of polylactic acid (PLA) mixed matrix membranes. The produced MOF was characterised by powder X-ray diffraction (PXRD), environmental scanning electron microscopy (ESEM) as well as by thermogravimetric analysis (TGA) and nitrogen adsorption/desorption. The effect of different Fe-MOF-MW concentrations (0.1 and 0.5 wt%) on the membrane properties and performance were evaluated. These membranes were used in the pervaporation process for the separation of methanol/methyl tert-butyl-ether mixtures at the azeotropic point. The influence of the feed temperature and vacuum pressure on the membrane performance was evaluated and the results were compared with PLA pristine membranes. Moreover, the produced membranes have been characterised in terms of morphology, MOF dispersion in the polymeric membrane matrix, wettability, thickness, mechanical resistance and swelling propensity. The presence of Fe-MOF-MW was found to have a beneficial effect in improving the selectivity of mixed matrix membranes towards methanol at both concentrations. The highest selectivity was obtained for the PLA membranes embedded with 0.5 wt% of Fe-MOF-MW and tested at the temperature of 25 °C and vacuum pressure of 0.09 mbar.
Polysulfone–Polyvinyl Pyrrolidone Blend Polymer Composite Membranes for Batik Industrial Wastewater Treatment
Authors: Febriasari Arifina , Huriya  , Ananto Annisa Hasna , Suhartini Meri , Kartohardjono Sutrasno
Published: January 2021

Batik wastewater, in general, is colored and has high concentrations of BOD (biological oxygen demand), COD (chemical oxygen demand), and dissolved and suspended solids. Polysulfone (PSf)-based membranes with the addition of polyvinyl pyrrolidone (PVP) were prepared to treat batik industrial wastewater. PSf/PVP membranes were prepared using the phase inversion method with N-methyl-2 pyrrolidone (NMP) as the solvent. Based on the membrane characterization through FESEM, water contact angle, porosity, and mechanical tests showed a phenomenon where the addition of PVP provided thermodynamic and kinetic effects on membrane formation, thereby affecting porosity, thickness, and hydrophilicity of the membranes. The study aims to observe the effect of adding PVP on polysulfone membrane permeability and antifouling performance on a laboratory scale through the ultrafiltration (UF) process. With the addition of PVP, the operational pressure of the polysulfone membrane was reduced compared to that without PVP. Based on the membrane filtration results, the highest removal efficiencies of COD, TDS (total dissolved solid), and conductivity achieved in the study were 80.4, 84.6, and 83.6%, respectively, on the PSf/PVP 0.35 membrane operated at 4 bar. Moreover, the highest color removal efficiency was 85.73% on the PSf/PVP 0.25 operated at 5 bar. The antifouling performance was identified by calculating the value of total, reversible, and irreversible membrane fouling, wherein in this study, the membrane with the best antifouling performance was PSf/PVP 0.25.
Quantitative Evaluations of Hydrogen Diffusivity in V-X (X = Cr, Al, Pd) Alloy Membranes Based on Hydrogen Chemical Potential
Authors: Suzuki Asuka , Yukawa Hiroshi
Published: January 2021

Vanadium (V) has higher hydrogen permeability than Pd-based alloy membranes but exhibits poor resistance to hydrogen-induced embrittlement. The alloy elements are added to reduce hydrogen solubility and prevent hydrogen-induced embrittlement. To enhance hydrogen permeability, the alloy elements which improve hydrogen diffusivity in V are more suitable. In the present study, hydrogen diffusivity in V-Cr, V-Al, and V-Pd alloy membranes was investigated in view of the hydrogen chemical potential and compared with the previously reported results of V-Fe alloy membranes. The additions of Cr and Fe to V improved the mobility of hydrogen atoms. In contrast, those of Al and Pd decreased hydrogen diffusivity. The first principle calculations revealed that the hydrogen atoms cannot occupy the first-nearest neighbor T sites (T1 sites) of Al and Pd in the V crystal lattice. These blocking effects will be a dominant contributor to decreasing hydrogen diffusivity by the additions of Al and Pd. For V-based alloy membranes, Fe and Cr are more suitable alloy elements compared with Al and Pd in view of hydrogen diffusivity.
Acknowledgment to Reviewers of Membranes in 2020
Authors:   Membranes Editorial Office
Published: January 2021

Peer review is the driving force of journal development, and reviewers are gatekeepers who ensure that Membranes maintains its standards for the high quality of its published papers [...]
Sidewall Slope Control of InP Via Holes for 3D Integration
Authors: Lee Jongwon , Roh Kilsun , Lim Sung-Kyu , Kim Youngsu
Published: January 2021

This is the first demonstration of sidewall slope control of InP via holes with an etch depth of more than 10 μm for 3D integration. The process for the InP via holes utilizes a common SiO2 layer as an InP etch mask and conventional inductively coupled plasma (ICP) etcher operated at room temperature and simple gas mixtures of Cl2/Ar for InP dry etch. Sidewall slope of InP via holes is controlled within the range of 80 to 90 degrees by changing the ICP power in the ICP etcher and adopting a dry-etched SiO2 layer with a sidewall slope of 70 degrees. Furthermore, the sidewall slope control of the InP via holes in a wide range of 36 to 69 degrees is possible by changing the RF power in the etcher and introducing a wet-etched SiO2 layer with a small sidewall slope of 2 degrees; this wide slope control is due to the change of InP-to-SiO2 selectivity with RF power.
Long-Term Human Hematopoietic Stem Cell Culture in Microdroplets
Authors: Carreras Pilar , González Itziar , Gallardo Miguel , Ortiz-Ruiz Alejandra , Morales Maria Luz , Encinas Jessica , Martínez-López Joaquín
Published: January 2021

We previously reported a new approach for micromanipulation and encapsulation of human stem cells using a droplet-based microfluidic device. This approach demonstrated the possibility of encapsulating and culturing difficult-to-preserve primary human hematopoietic stem cells using an engineered double-layered bead composed by an inner layer of alginate and an outer layer of Puramatrix. We also demonstrated the maintenance and expansion of Multiple Myeloma cells in this construction. Here, the presented microfluidic technique is applied to construct a 3D biomimetic model to recapitulate the human hematopoietic stem cell niche using double-layered hydrogel beads cultured in 10% FBS culture medium. In this model, the long-term maintenance of the number of cells and expansion of hHSCS encapsulated in the proposed structures was observed. Additionally, a phenotypic characterization of the human hematopoietic stem cells generated in the presented biomimetic model was performed in order to assess their long-term stemness maintenance. Results indicate that the ex vivo cultured human CD34+ cells from bone marrow were viable, maintained, and expanded over a time span of eight weeks. This novel long-term stem cell culture methodology could represent a novel breakthrough to improve Hematopoietic Progenitor cell Transplant (HPT) as well as a novel tool for further study of the biochemical and biophysical factors influencing stem cell behavior. This technology opens a myriad of new applications as a universal stem cell niche model potentially able to expand other types of cells.
Modeling and Compensation for Asymmetrical and Dynamic Hysteresis of Piezoelectric Actuators Using a Dynamic Delay Prandtl–Ishlinskii Model
Authors: Wang Wen , Han Fuming , Chen Zhanfeng , Wang Ruijin , Wang Chuanyong , Lu Keqing , Wang Jiahui , Ju Bingfeng
Published: January 2021

Piezoelectric actuators are widely used in micro- and nano-manufacturing and precision machining due to their superior performance. However, there are complex hysteresis nonlinear phenomena in piezoelectric actuators. In particular, the inherent hysteresis can be affected by the input frequency, and it sometimes exhibits asymmetrical characteristic. The existing dynamic hysteresis model is inaccurate in describing hysteresis of piezoelectric actuators at high frequency. In this paper, a Dynamic Delay Prandtl–Ishlinskii (DDPI) model is proposed to describe the asymmetrical and dynamic characteristics of piezoelectric actuators. First, the shape of the Delay Play operator is discussed under two delay coefficients. Then, the accuracy of the DDPI model is verified by experiments. Next, to compensate the asymmetrical and dynamic hysteresis, the compensator is designed based on the Inverse Dynamic Delay Prandtl–Ishlinskii (IDDPI) model. The effectiveness of the inverse compensator was verified by experiments. The results show that the DDPI model can accurately describe the asymmetrical and dynamic hysteresis, and the compensator can effectively suppress the hysteresis of the piezoelectric actuator. This research will be beneficial to extend the application of piezoelectric actuators.
Utilization of a Gas-Sensing System to Discriminate Smell and to Monitor Fermentation during the Manufacture of Oolong Tea Leaves
Authors: Tseng Ting-Shiang , Hsiao Mei-Hui , Chen Po-An , Lin Shu-Yen , Chiu Shih-Wen , Yao Da-Jeng
Published: January 2021

The operational duration of shaking tea leaves is a critical factor in the manufacture of oolong tea; this duration influences the formation of its flavor and fragrance. The current method to control the duration of fermentation relies on the olfactory sense of tea masters; they monitor the entire process through their olfactory sense, and their experience decides the duration of shaking and setting. Because of this human factor and olfactory fatigue, it is difficult to define an optimum duration of shaking and setting; an inappropriate duration of shaking and setting deteriorates the quality of the tea. In this study, we used metal-oxide-semiconductor gas sensors to establish an electronic nose (E-nose) system and tested its feasibility. This research was divided into two experiments: distinguishing samples at various stages and an on-line experiment. The samples of tea leaves at various stages exhibited large differences in the level of grassy smell. From the experience of practitioners and from previous research, the samples could be categorized into three groups: before the first shaking (BS1), before the shaking group, and after the shaking group. We input the experimental results into a linear discriminant analysis to decrease the dimensions and to classify the samples into various groups. The results show that the smell can also be categorized into three groups. After distinguishing the samples with large differences, we conducted an on-line experiment in a tea factory and tried to monitor the smell variation during the manufacturing process. The results from the E-nose were similar to those of the sense of practitioners, which means that an E-nose has the possibility to replace the sensory function of practitioners in the future.
Micropatterning of Substrates for the Culture of Cell Networks by Stencil-Assisted Additive Nanofabrication
Authors: Previdi Anita , Piazzoni Claudio , Borghi Francesca , Schulte Carsten , Lorenzelli Leandro , Giacomozzi Flavio , Bucciarelli Alessio , Malgaroli Antonio , Lamanna Jacopo , Moro Andrea , Racchetti Gabriella , Podestà Alessandro , Lenardi Cristina , Milani Paolo
Published: January 2021

The fabrication of in vitro neuronal cell networks where cells are chemically or electrically connected to form functional circuits with useful properties is of great interest. Standard cell culture substrates provide ensembles of cells that scarcely reproduce physiological structures since their spatial organization and connectivity cannot be controlled. Supersonic Cluster Beam Deposition (SCBD) has been used as an effective additive method for the large-scale fabrication of interfaces with extracellular matrix-mimicking surface nanotopography and reproducible morphological properties for cell culture. Due to the high collimation of SCBD, it is possible to exploit stencil masks for the fabrication of patterned films and reproduce features as small as tens of micrometers. Here, we present a protocol to fabricate micropatterned cell culture substrates based on the deposition of nanostructured cluster-assembled zirconia films by stencil-assisted SCBD. The effectiveness of this approach is demonstrated by the fabrication of micrometric patterns able to confine primary astrocytes. Calcium waves propagating in the astrocyte networks are shown.
Development of a CMOS-Compatible Carbon Nanotube Array Transfer Method
Authors: Siah Chun Fei , Lum Lucas Yu Xiang , Wang Jianxiong , Goh Simon Chun Kiat , Tan Chong Wei , Hu Liangxing , Coquet Philippe , Li Hong , Tan Chuan Seng , Tay Beng Kang
Published: January 2021

Carbon nanotubes (CNTs) have, over the years, been used in research as a promising material in electronics as a thermal interface material and as interconnects amongst other applications. However, there exist several issues preventing the widespread integration of CNTs onto device applications, e.g., high growth temperature and interfacial resistance. To overcome these issues, a complementary metal oxide semiconductor (CMOS)-compatible CNT array transfer method that electrically connects the CNT arrays to target device substrates was developed. The method separates the CNT growth and preparation steps from the target substrate. Utilizing an alignment tool with the capabilities of thermocompression enables a highly accurate transfer of CNT arrays onto designated areas with desired patterns. With this transfer process as a starting point, improvement pointers are also discussed in this paper to further improve the quality of the transferred CNTs.
Recent Advances in Three-Dimensional Multicellular Spheroid Culture and Future Development
Authors: Shen Honglin , Cai Shuxiang , Wu Chuanxiang , Yang Wenguang , Yu Haibo , Liu Lianqing
Published: January 2021

Three-dimensional multicellular spheroids (MCSs) have received extensive attention in the field of biomedicine due to their ability to simulate the structure and function of tissues in vivo more accurately than traditional in vitro two-dimensional models and to simulate cell–cell and cell extracellular matrix (ECM) interactions. It has become an important in vitro three-dimensional model for tumor research, high-throughput drug screening, tissue engineering, and basic biology research. In the review, we first summarize methods for MCSs generation and their respective advantages and disadvantages and highlight the advances of hydrogel and microfluidic systems in the generation of spheroids. Then, we look at the application of MCSs in cancer research and other aspects. Finally, we discuss the development direction and prospects of MCSs
Inertial Microfluidics-Based Separation of Microalgae Using a Contraction–Expansion Array Microchannel
Authors: Kim Ga-Yeong , Son Jaejung , Han Jong-In , Park Je-Kyun
Published: January 2021

Microalgae separation technology is essential for both executing laboratory-based fundamental studies and ensuring the quality of the final algal products. However, the conventional microalgae separation technology of micropipetting requires highly skilled operators and several months of repeated separation to obtain a microalgal single strain. This study therefore aimed at utilizing microfluidic cell sorting technology for the simple and effective separation of microalgae. Microalgae are characterized by their various morphologies with a wide range of sizes. In this study, a contraction–expansion array microchannel, which utilizes these unique properties of microalgae, was specifically employed for the size-based separation of microalgae. At Reynolds number of 9, two model algal cells, Chlorella vulgaris (C. vulgaris) and Haematococcus pluvialis (H. pluvialis), were successfully separated without showing any sign of cell damage, yielding a purity of 97.9% for C. vulgaris and 94.9% for H. pluvialis. The result supported that the inertia-based separation technology could be a powerful alternative to the labor-intensive and time-consuming conventional microalgae separation technologies.
Parallel Recordings of Transmembrane hERG Channel Currents Based on Solvent-Free Lipid Bilayer Microarray
Authors: Miyata Ryusuke , Tadaki Daisuke , Yamaura Daichi , Araki Shun , Sato Madoka , Komiya Maki , Ma Teng , Yamamoto Hideaki , Niwano Michio , Hirano-Iwata Ayumi
Published: January 2021

The reconstitution of ion-channel proteins in artificially formed bilayer lipid membranes (BLMs) forms a well-defined system for the functional analysis of ion channels and screening of the effects of drugs that act on these proteins. To improve the efficiency of the BLM reconstitution system, we report on a microarray of stable solvent-free BLMs formed in microfabricated silicon (Si) chips, where micro-apertures with well-defined nano- and micro-tapered edges were fabricated. Sixteen micro-wells were manufactured in a chamber made of Teflon®, and the Si chips were individually embedded in the respective wells as a recording site. Typically, 11 to 16 BLMs were simultaneously formed with an average BLM number of 13.1, which corresponded to a formation probability of 82%. Parallel recordings of ion-channel activities from multiple BLMs were successfully demonstrated using the human ether-a-go-go-related gene (hERG) potassium channel, of which the relation to arrhythmic side effects following drug treatment is well recognized.
Adjunct Culture of Non-Starter Lactic Acid Bacteria for the Production of Provola Dei Nebrodi PDO Cheese: In Vitro Screening and Pilot-Scale Cheese-Making
Authors: Randazzo Cinzia Lucia , Liotta Luigi , Angelis Maria De , Celano Giuseppe , Russo Nunziatina , Hoorde Koenraad Van , Chiofalo Vincenzo , Pino Alessandra , Caggia Cinzia
Published: January 2021

The present study aimed at selecting non-starter lactic acid bacteria strains, with desirable technological and enzymatic activities, suitable as adjunct culture for the Provola dei Nebrodi cheese production. One hundred and twenty-one lactic acid bacteria, isolated from traditional Provola dei Nebrodi cheese samples, were genetically identified by Rep-PCR genomic fingerprinting, using the (GTG)5-primer, and by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS). Twenty-seven strains, included in the qualified presumption of safety (QPS) list, were tested for technological and proteinase/peptidase activities. Results showed that technological features and flavour formation abilities were strain-dependent. Among the selected strains, Lacticaseibacillus paracasei PN 76 and Limosilactobacillus fermentum PN 101 were used as adjunct culture in pilot-scale cheese-making trials. Data revealed that adjunct cultures positively affected the flavour development of cheese, starting from 30 days of ripening, contributing to the formation of key flavour compounds. The volatile organic compound profiles of experimental cheeses was significantly different from those generated in the controls, suggesting that the selected adjunct strains were able to accelerate the flavour development, contributing to a unique profile of Provola dei Nebrodi cheese.
Tracing the Trophic Plasticity of the Coral–Dinoflagellate Symbiosis Using Amino Acid Compound-Specific Stable Isotope Analysis
Authors: Ferrier-Pagès Christine , Martinez Stephane , Grover Renaud , Cybulski Jonathan , Shemesh Eli , Tchernov Dan
Published: January 2021

The association between corals and photosynthetic dinoflagellates is one of the most well-known nutritional symbioses, but nowadays it is threatened by global changes. Nutritional exchanges are critical to understanding the performance of this symbiosis under stress conditions. Here, compound-specific δ15N and δ13C values of amino acids (δ15NAA and δ13CAA) were assessed in autotrophic, mixotrophic and heterotrophic holobionts as diagnostic tools to follow nutritional interactions between the partners. Contrary to what was expected, heterotrophy was mainly traced through the δ15N of the symbiont’s amino acids (AAs), suggesting that symbionts directly profit from host heterotrophy. The trophic index (TP) ranged from 1.1 to 2.3 from autotrophic to heterotrophic symbionts. In addition, changes in TP across conditions were more significant in the symbionts than in the host. The similar δ13C-AAs signatures of host and symbionts further suggests that symbiont-derived photosynthates are the main source of carbon for AAs synthesis. Symbionts, therefore, appear to be a key component in the AAs biosynthetic pathways, and might, via this obligatory function, play an essential role in the capacity of corals to withstand environmental stress. These novel findings highlight important aspects of the nutritional exchanges in the coral–dinoflagellates symbiosis. In addition, they feature δ15NAA as a useful tool for studies regarding the nutritional exchanges within the coral–symbiodiniaceae symbiosis.
Comparative Genomics of Marine Bacteria from a Historically Defined Plastic Biodegradation Consortium with the Capacity to Biodegrade Polyhydroxyalkanoates
Authors: de Vogel Fons A. , Schlundt Cathleen , Stote Robert E. , Ratto Jo Ann , Amaral-Zettler Linda A.
Published: January 2021

Biodegradable and compostable plastics are getting more attention as the environmental impacts of fossil-fuel-based plastics are revealed. Microbes can consume these plastics and biodegrade them within weeks to months under the proper conditions. The biobased polyhydroxyalkanoate (PHA) polymer family is an attractive alternative due to its physicochemical properties and biodegradability in soil, aquatic, and composting environments. Standard test methods are available for biodegradation that employ either natural inocula or defined communities, the latter being preferred for standardization and comparability. The original marine biodegradation standard test method ASTM D6691 employed such a defined consortium for testing PHA biodegradation. However, the taxonomic composition and metabolic potential of this consortium have never been confirmed using DNA sequencing technologies. To this end, we revived available members of this consortium and determined their phylogenetic placement, genomic sequence content, and metabolic potential. The revived members belonged to the Bacillaceae, Rhodobacteraceae, and Vibrionaceae families. Using a comparative genomics approach, we found all the necessary enzymes for both PHA production and utilization in most of the members. In a clearing-zone assay, three isolates also showed extracellular depolymerase activity. However, we did not find classical PHA depolymerases, but identified two potentially new extracellular depolymerases that resemble triacylglycerol lipases.
Interactions between Anaerobic Fungi and Methanogens in the Rumen and Their Biotechnological Potential in Biogas Production from Lignocellulosic Materials
Authors: Li Yuqi , Meng Zhenxiang , Xu Yao , Shi Qicheng , Ma Yuping , Aung Min , Cheng Yanfen , Zhu Weiyun
Published: January 2021

Anaerobic fungi in the digestive tract of herbivores are one of the critical types of fiber-degrading microorganisms present in the rumen. They degrade lignocellulosic materials using unique rhizoid structures and a diverse range of fiber-degrading enzymes, producing metabolic products such as H2/CO2, formate, lactate, acetate, and ethanol. Methanogens in the rumen utilize some of these products (e.g., H2 and formate) to produce methane. An investigation of the interactions between anaerobic fungi and methanogens is helpful as it provides valuable insight into the microbial interactions within the rumen. During the last few decades, research has demonstrated that anaerobic fungi stimulate the growth of methanogens and maintain methanogenic diversity. Meanwhile, methanogens increase the fiber-degrading capability of anaerobic fungi and stimulate metabolic pathways in the fungal hydrogenosome. The ability of co-cultures of anaerobic fungi and methanogens to degrade fiber and produce methane could potentially be a valuable method for the degradation of lignocellulosic materials and methane production.
Fungal Endophytes as Efficient Sources of Plant-Derived Bioactive Compounds and Their Prospective Applications in Natural Product Drug Discovery: Insights, Avenues, and Challenges
Authors: Singh Archana , Singh Dheeraj K. , Kharwar Ravindra N. , White James F. , Gond Surendra K.
Published: January 2021

Fungal endophytes are well-established sources of biologically active natural compounds with many producing pharmacologically valuable specific plant-derived products. This review details typical plant-derived medicinal compounds of several classes, including alkaloids, coumarins, flavonoids, glycosides, lignans, phenylpropanoids, quinones, saponins, terpenoids, and xanthones that are produced by endophytic fungi. This review covers the studies carried out since the first report of taxol biosynthesis by endophytic Taxomyces andreanae in 1993 up to mid-2020. The article also highlights the prospects of endophyte-dependent biosynthesis of such plant-derived pharmacologically active compounds and the bottlenecks in the commercialization of this novel approach in the area of drug discovery. After recent updates in the field of ‘omics’ and ‘one strain many compounds’ (OSMAC) approach, fungal endophytes have emerged as strong unconventional source of such prized products.
Impact of Antibiotics Associated with the Development of Toxic Epidermal Necrolysis on Early and Late-Onset Infectious Complications
Authors: Lipovy Bretislav , Holoubek Jakub , Hanslianova Marketa , Cvanova Michaela , Klein Leo , Grossova Ivana , Zajicek Robert , Bukovcan Peter , Koller Jan , Baran Matus , Lengyel Peter , Eimer Lukas , Jandova Marie , Kostal Milan , Brychta Pavel , Borilova Linhartova Petra
Published: January 2021

Toxic epidermal necrolysis (TEN) is a rare disease, which predominantly manifests as damage to the skin and mucosa. Antibiotics count among the most common triggers of this hypersensitive reaction. Patients with TEN are highly susceptible to infectious complications due to the loss of protective barriers and immunosuppressant therapy. The aim of this study was to investigate the potential relationship between antibiotics used before the development of TEN and early and late-onset infectious complications in TEN patients. In this European multicentric retrospective study (Central European Lyell syndrome: therapeutic evaluation (CELESTE)), records showed that 18 patients with TEN used antibiotics (mostly aminopenicillins) before the disease development (group 1), while in 21 patients, TEN was triggered by another factor (group 2). The incidence of late-onset infectious complications (5 or more days after the transfer to the hospital) caused by Gram-positive bacteria (especially by Enterococcus faecalis/faecium) was significantly higher in group 1 than in group 2 (82.4% vs. 35.0%, p = 0.007/pcorr = 0.014) while no statistically significant difference was observed between groups of patients with infection caused by Gram-negative bacteria, yeasts, and filamentous fungi (p > 0.05). Patients with post-antibiotic development of TEN are critically predisposed to late-onset infectious complications caused by Gram-positive bacteria, which may result from the dissemination of these bacteria from the primary focus.
3D Geological Model of the Touro Cu Deposit, A World-Class Mafic-Siliciclastic VMS Deposit in the NW of the Iberian Peninsula
Authors: Arias Mónica , Nuñez Pablo , Arias Daniel , Gumiel Pablo , Castañón Cesar , Fuertes-Blanco Jorge , Martin-Izard Agustin
Published: January 2021

The Touro volcanogenic massive sulfide (VMS) deposit is located in the NW of the Iberian Variscan massif in the Galicia-Trás-os-Montes Zone, an amalgamation of several allochthonous terrains. The Órdenes complex is the most extensive of the allochthone complexes, and amphibolites and paragneisses host the deposit, characterized as being massive or semimassive (stringers) sulfides, mostly made up of pyrrhotite and chalcopyrite. The total resources are 103 Mt, containing 0.41% copper. A 3D model of the different orebodies and host rocks was generated using data from 1090 drill core logs. The model revealed that the structure of the area is a N–S-trending antiform. The orebodies crop out in the limbs and in the hinge zone. The mineralized structures are mostly tabular, up to 100 m in thickness and subhorizontal. Based on the petrography, geochemistry and the 3D model, the Touro deposit is classified as a VMS of the mafic-siliciclastic type formed in an Ordovician back-arc setting, which was buried and metamorphosed in Middle Devonian.
Complex Characteristic of Zircon from Granitoids of the Verkhneurmiysky Massif (Amur Region)
Authors: Machevariani Maria M. , Alekseenko Alexey V. , Bech Jaume
Published: January 2021

The study presents a complex characteristic of zircon from the Verkhneurmiysky intrusive series with Li-F granites. A wide range of morphological and chemical properties of zircon allowed us to obtain new information on the formation and alteration of zircon from biotite and zinnwaldite granitoids and to determine its features, which contribute to the correct definition of Li-F granites formed directly before the tin mineralization. The reviled trends of zircon morphology and composition evolution in the Verkhneurmiysky granites series are: the high-temperature morphotypes are followed by low-temperature ones with more complicated internal structure with secondary alteration zones, mineral inclusions, pores, and cracks; the increasing concentration of volatile (H2O, F), large ion lithophile (Cs, Sr), high field strength (Hf, Nb) and rare-earth elements with decreasing crystallization temperatures and the determining role of the fluid phase (predominantly, F) in the trace element accumulation. The composition of zircon cores in biotite and zinnwaldite granites is very similar. However, the zircon rims from zinnwaldite granites are much more enriched in trace elements compared to those from biotite granites. The first study of zircon from the Verkhneurmiysky granitoids provides new data on the formation and alteration conditions of granitoids, including zinnwaldite ones.
Effects of High Proportion Unground Sea Sand Ore on the Preparation Process and Reduction Performance of Oxidized Pellets
Authors: Cheng Gong-jin , Xing Zhen-xing , Yang He , Xue Xiang-xin
Published: January 2021

The New Zealand sea sand ore is a kind of vanadia–titania magnetite formed by erosion in the coastal zone. Because of its coarse particle size, smooth spherical particles, complex chemical composition, it has been added to sinter as an auxiliary material. Based on the principle of optimizing ore blending to strengthen advantages and weaken disadvantages, this paper used New Zealand sea sand raw ore that has not undergone any pretreatment as the main material and prepared it into oxidized pellets using a disc pelletizer and explored the influence of high-proportion unground sea sand ore on the preparation process and reduction performance of oxidized pellets. The influence of unground sea sand ore on the falling strength, compressive strength, reduction swelling index, and reduction degree of pellets was analyzed by the ICPAES, XRF, XRD, SEM-EDS, and other detection methods, and the change laws and influencing factors of oxidized pellets were analyzed. With the increase of the amount of unground sea sand ore used, the falling strength and compressive strength of the green pellets first decreased and then gradually increased, while the compressive strength of the oxidized pellets first increased and then decreased. At the same time, as the amount of sea sand ore used increased, the reduction process of pellets was restricted. The reduction swelling index and the reduction degree index generally show a downward trend. However, the compressive strength of the pellets gradually increased after reduction. Through the research on the pellet-forming performance and reduction properties of unground sea sand ore, it is shown that when the amount of unground sea sand ore used was 40%, it can still be used as raw material for blast furnace ironmaking. Thus, this research provided specific data support for iron and steel enterprises to improve the ratio of unground sea sand ore and reduce production cost.
The Competitive Adsorption of Chromate and Sulfate on Ni-Substituted Magnetite Surfaces: An ATR-FTIR Study
Authors: Lin Xiaoju , Wei Gaoling , Liang Xiaoliang , Liu Jing , Ma Lingya , Zhu Jianxi
Published: January 2021

With similar chemical properties and geometrical configurations, sulfate and chromate display interesting competitive adsorption on mineral surfaces. Although such issues have been investigated on several Fe (hydr)oxide surfaces, e.g., ferrihydrite, goethite and hematite, the competitive adsorption on magnetite surfaces and the constraint mechanism have seldom been studied. This impedes the understanding of the transfer and fate of chromate and sulfate on magnetite surfaces, as magnetite is not only a useful adsorbent but also an efficient reductant to decrease the mobility and toxicity of chromium. In the present study, the geometries of the competitive adsorption of chromate and sulfate on Ni-substituted magnetite surfaces over a pH range of 4–9 were investigated using in situ attenuated total reflectance Fourier transform infrared spectroscopy and two-dimensional correlation analysis. In individual adsorption, nonprotonated monodentate mononuclear (NMM) complexes dominated chromate adsorption, accompanied by a few bidentate binuclear (BB) complexes. For sulfate, NMM complexes and outer-sphere (OS) species predominated under acidic and neutral–alkaline conditions, respectively. The above variation in adsorption configuration resulted in the different adsorption competitiveness between chromate and sulfate at different pH values. Specifically, the NMM complexes of chromate were substituted by NMM sulfate complexes under acidic conditions and vice versa. However, under neutral and alkaline conditions, the OS species of sulfate scarcely affected the adsorption of chromate. The adsorption affinity of chromate and sulfate on Ni-substituted magnetite increased in the following order: OS complex (sulfate) < NMM complexes (chromate) < NMM complexes (sulfate).
Selective Flotation of Elemental Sulfur from Pressure Acid Leaching Residue of Zinc Sulfide
Authors: Liu Guiqing , Jiang Kaixi , Zhang Bangsheng , Dong Zhonglin , Zhang Fan , Wang Fang , Jiang Tao , Xu Bin
Published: January 2021

An efficient flotation process was developed to selectively recover elemental sulfur from a high-sulfur pressure acid leaching residue of zinc sulfide concentrate. The process mineralogy analysis showed that the sulfur content reached 46.21%, and 81.97% of the sulfur existed as elemental sulfur which was the major mineral in the residue and primarily existed as pellet aggregate and biconical euhedral crystal. An elemental sulfur concentrate product with 99.9% of recovery and 83.46% of purity was obtained using the flotation process of one-time blank rougher, two-time agent-added roughers, and two-time cleaners with Z-200 as collector and Na2S + ZnSO4 + Na2SO3 as depressant. The flotation experiment using return water indicated that the cycle use of return water had no adverse effect on the flotation performance of elemental sulfur. The process mineralogy analysis manifested that main minerals in the residue directionally went into the flotation products. Most of elemental sulfur entered the concentrate while other minerals almost completely went into the tailing. Main valuable elements lead, zinc, and silver entered the tailing with sulfides and could be recovered by lead smelting. The proposed process can realize the comprehensive recovery of valuable components in the high-sulfur residue and thus it has wide industrial application prospect.
Flavonoid Glycosides in Brassica Species Respond to UV-B Depending on Exposure Time and Adaptation Time
Authors: Neugart Susanne , Bumke-Vogt Christiane
Published: January 2021

Recently, there have been efforts to use ultraviolet-B radiation (UV-B) as a biotechnological tool in greenhouses. Leafy Brassica species are mainly considered for their ability to synthesize glucosinolates and are valued as baby salads. They also have a remarkable concentration of chemically diverse flavonoid glycosides. In this study, the effect of short-term UV-B radiation at the end of the production cycle was investigated without affecting plant growth. The aim was to verify which exposure and adaptation time was suitable and needs to be further investigated to use UV as a biotechnological tool in greenhouse production of Brassica species. It is possible to modify the flavonoid glycoside profile of leafy Brassica species by increasing compounds that appear to have potentially high antioxidant activity. Exemplarily, the present experiment shows that kaempferol glycosides may be preferred over quercetin glycosides in response to UV-B in Brassica rapa ssp. chinensis, for example, whereas other species appear to prefer quercetin glycosides over kaempferol glycosides, such as Brassica oleracea var. sabellica or Brassica carinata. However, the response to short-term UV-B treatment is species-specific and conclusions on exposure and adaptation time cannot be unified but must be drawn separately for each species.
Natural Materials—Interesting Candidates for Carbon Nanomaterials
Authors: Kumar Arun
Published: January 2021

This review sums up the techniques used for the synthesis of carbon nanotubes (CNTs), carbon nanofibers (CNFs), and carbon nanospheres (CNSs) by employing catalysts of natural origin. Establishing large-scale production and commercial applications of CNTs for a sustainable society is still of high apprehension. In this regard, one of the major factors is the starting materials such as precursors and catalyst sources. However, natural materials contain a minor quantity of metals or metal oxides and could be employed as a catalyst source for the synthesis of CNTs, providing the possibility to replace expensive catalyst sources. A large number of successful studies have been completed so far and confirm that these developed methods for carbon nanomaterials synthesis exhibiting high quality from common natural materials are not only possible but, most importantly, promising and scalable. This review also highlights purification methods and recent promising applications of as-synthesized CNTs.
ANALISIS LOWONGAN PEKERJAAN
Authors: Agustyani Eka Majida , Santoso Ibnu
Published: January 2021

Lowongan kerja seharusnya menyediakan informasi yang dapat membantu para pencari kerja, terutama pencari kerja yang baru saja menyelesaikan pendidikannya karena beberapa dari mereka ada yang tidak memiliki perencanaan karier dan membutuhkan gambaran umum lowongan kerja yang dapat tersedia. Akan tetapi, mereka terkadang justru kebingungan karena lowongan kerja tersebut tidak mencantumkan informasi lengkap. Jobstreet merupakan portal lowongan kerja dengan pengakses terbanyak di Indonesia dan didominasi oleh lowongan kerja dari Provinsi DKI Jakarta. Penelitian ini dilakukan dengan tujuan untuk mendapatkan gambaran umum karakteristik lapangan pekerjaan Jobstreet yang berlokasi di Provinsi DKI Jakarta. Analisis ini dibantu dengan pengelompokkan lowongan kerja dan difokuskan pembahsannya ke latar belakang pendidikan yang paling dicari. Pengelompokkan dilakukan menggunakan metode Hierarchical Agglomerative Clustering dan mendapatkan hasil 5 klaster. Lowongan kerja di Jobstreet banyak mencari pelamar dengan latar belakang pendidikan Sistem Informasi, lulusan S1, dan minimal 1 tahun pengalaman. Perusahaan yang mengiklankan banyak yang bergerak di bidang pelayanan keuangan dan berlokasi di Jakarta Selatan. Lowongan kerja dengan syarat latar belakang pendidikan Sistem Informasi banyak yang berasal dari klaster 2 serta mensyaratkan minimal pendidikan S1 dan 1 tahun pengalaman kerja dengan perusahaan bergerak di bidang Teknik Informatika dan berlokasi di Jakarta Selatan.
KUALITAS UDARA DAN POTENSI TRANSMISI COVID-19 DI PULAU JAWA
Authors: Zulkarnain Rizky , Ramadani Karuniawati Dewi
Published: January 2021

Penularan SARS-CoV-2 di Indonesia semakin mengkhawatirkan. Pandemik COVID-19 tidak hanya berdampak pada individu yang terinfeksi langsung, tetapi juga berimbas kepada para penyintas kolateral, yaitu mereka yang kehidupannya ikut terdisrupsi akibat krisis. Pulau Jawa adalah episentrum penularan COVID-19 di Indonesia. Beberapa studi menunjukkan bahwa kejadian COVID-19 memiliki hubungan yang erat dengan tingginya konsentrasi zat partikulat di udara. Penelitian ini bertujuan untuk mengetahui hubungan antara kualitas udara dan risiko penularan COVID-19 di Pulau Jawa. Kualitas udara diukur dengan konsentrasi NO2, sedangkan risiko penularan COVID-19 direfleksikan oleh Indeks Kewaspadaan COVID-19. Penelitian ini menggunakan empat model untuk melihat pengaruh kadar NO2 terhadap Indeks Kewaspadaan COVID-19, dimana variabel kepadatan penduduk ditambahkan sebagai kontrol. Model-0 adalah model dasar tanpa efek kelompok dan efek spasial. Model-1 adalah pengembangan dari Model-0 dengan menambahkan efek spasial. Model-2 adalah pengembangan dari Model-0 dengan menambahkan efek kelompok. Sedangkan, Model-3 adalah model lengkap dengan efek kelompok dan efek spasial. Hasil analisis menunjukkan bahwa Model-3 adalah model terbaik dalam menjelaskan pengaruh kadar NO2 terhadap Indeks Kewaspadaan COVID-19. Model-3 mampu meningkatkan kinerja model secara substansial. Hasil pengujian mengindikasikan bahwa kadar NO2 berpengaruh positif dan signifikan terhadap Indeks Kewaspadaan COVID-19, setelah efek kelompok dan efek spasial diperhitungkan. Dengan demikian, disimpulkan bahwa semakin tinggi konsentrasi NO2 yang mencerminkan semakin buruk kualitas udara, semakin tinggi pula risiko penularan COVID-19. Hasil ini memiliki implikasi penting untuk strategi pencegahan penyebaran COVID-19, khususnya pada daerah-daerah dengan tingkat pencemaran udara yang tinggi.
PEMANFAATAN METODE WEIGHTED K-NEAREST NEIGHBOR IMPUTATION (WEIGHTED KNNI) UNTUK MENGATASI MISSING DATA
Authors: Fadillah Iman Jihad , Puspita Chaterina Dwi
Published: January 2021

Pada tahun 2020, hampir semua negara di dunia menghadapi wabah COVID-19, termasuk Indonesia. Salah satu dampak yang terjadi karena adanya pandemi COVID-19 adalah terhambatnya kegiatan statistik, seperti tertundanya atau berhentinya pelaksanaan pengumpulan data survei dan sensus serta pengumpulan data lainnya. Sementara itu, untuk memenuhi permintaan dan kebutuhan data selama masa pandemi COVID-19, badan statistik nasional harus tetap melakukan pengumpulan data dan menyediakan data statistik. Oleh sebab itu, badan statistik nasional harus melakukan adaptasi untuk kegiatan proses sensus dan survei yang dilakukan, seperti mencari mode pengumpulan data alternatif, mengurangi ukuran sampel, memodifikasi desain sampel, mengurangi item pertanyaan di kuesioner, atau lainnya. Berdasarkan uraian tersebut, adaptasi kegiatan pengumpulan data sensus/survei yang dilakukan pada masa pandemi COVID-19 akan berpengaruh pada kualitas data yang dihasilkan. Salah satunya adanya missing data. Untuk mengatasi masalah missing data, salah satu metode yang dapat digunakan adalah imputasi data. Salah satu jenis metode imputasi berbasis machine learning yang sering digunakan adalah Weighted K-Nearest Neighbor Imputation (Weighted KNNI). Metode Weighted KNNI memiliki akurasi yang lebih baik dibandingkan kedua metode imputasi lainnya (Unweighted KNNI dan Mean Imputation) pada tiap persentase missing data baik akurasi dari sisi RMSE maupun akurasi dari sisi MAPE. Berdasarkan hasil tersebut yang dilihat dari akurasinya, metode Weighted KNNI dapat digunakan sebagai salah satu solusi untuk menangani ketidaklengkapan data pada masa pandemi COVID19 sekarang ini.
PERBANDINGAN METODE SARIMA DAN METODE TRANSFER PADA PRODUKSI PADI DI KABUPATEN KENDAL
Authors: Yulianto Safa'at , Najib Ahmad Jauharudin
Published: January 2021

Indonesia merupakan negara agraris, artinya pertanian merupakan pemegang peranan penting bagi perekonomian nasional. Berdasarkan data dari Badan Pusat Statistik pada tahun 2017 yang menyatakan pertanian merupakan salah satu sektor yang paling berkonstribusi terhadap perekonomian nasional dengan konstribusi sebesar 13,14 persen. Pada sektor pertanian ini padi merupakan komoditas penghasil produksi terbesar dibanding komoditas lainnya dengan produksi sebesar79 juta ton pada tahun 2016. Sebagai negara dengan jumlah penduduk yang besar maka Indonesia menghadapi tantangan dalam memenuhi kebutuhan padi, namun beralih fungsinya lahan pertanian menjadi non pertanian sangat berpengaruh pada hasil produksi tanaman padi, semakin berkurangnya luas lahan maka semakin berkurang pula produksi padi yang dihasilkan. Tidak terkecuali di Kabupaten Kendal yang memiliki daerah agraris dengan komoditas utama yaitu padi, hasil produksi padi di Kabupaten ini cenderung mengalami penurunan pada tahun 2016 dan 2017. Untuk membantu pemerintah dalam menetapkan kebijakan dalam ketersediaan pangan digunakanlah analisis peramalan. Metode yang paling sering digunakan dalam peramalan adalah metode ARIMA. Metode ini sebenarnya sudah cukup baik, tetapi karena produksi padi juga dipengaruhi oleh luas lahan panen maka diusulkan metode fungsi transfer yang dapat memasukkan variabel luas panen ke dalam model peramalan. Data yang digunakan dalam penelitian ini adalah data produksi padi dan luas panen di Kabupaten Kendal dari bulan Januari 2013 hingga bulan Desember 2017. Hasil pengujian dengan menggunakan metode peramalan fungsi transfer  ini menghasilkan model terbaik
PENGUMPULAN DATA PRODUKTIVITAS TANAMAN PANGAN PADA MASA PANDEMI COVID-19
Authors: Rahmadhani Nialita
Published: January 2021

Mewabahnya Covid-19 telah menimbulkan dampak yang tidak hanya pada dunia kesehatan, namun sektor-sektor lain termasuk sektor pangan dan pertanian juga mendapat pengaruh dari adanya virus tersebut. Dengan adanya peringatan dari Organisasi Pangan dan Pertanian (FAO) mengenai potensi kelangkaan pangan dunia, presiden Joko Widodo menginstruksikan untuk memastikan ketersediaan bahan pokok secara akurat berdasar pada data-data yang valid. Hal ini menjadi tantangan bagi BPS untuk melakukan penyesuain metodologi supaya tetap bisa memenuhi kebutuhan data pangan, salah satunya melalui survei ubinan. Tujuan dari penelitian ini menjelaskan mitigasi dan adaptasi metodologi pelaksanaan survei ubinan, serta menyampaikan evaluasi dampak perubahan tersebut. Data yang digunakan adalah Data Ubinan Subround 1 2019 dan subround 1 2020 yang dikumpulkan oleh BPS. Metode analisis yang digunakan adalah analisis deskriptif dan analisis paired samples t-test. Hasil penelitian menunjukkan bahwa pemasukan data (response rate) komoditas padi pada subround 1 2020 hanya mencapai 65,10%, sebanyak 70,49% petugas tetap menggunakan metode pengukuran dan wawancara, dan tidak ada perbedaan hasil ubinan sebelum pandemi Covid-19 (Subround I 2019) dengan saat pandemi Covid-19 (Subround 1 2020). Dengan demikian, dapat disimpulkan bahwa Metode wawancara tanpa pengukuran bisa menjadi alternatif karena tidak ada perbedaan yang cukup signifikan antara produktivitas padi metode pengukuran dan wawancara dengan metode wawancara tanpa pengukuran.