bluuebunny/crossref_metadata_2025 huggingface dataset:
COVID‐19 multisystem inflammatory syndrome in three teenagers with confirmed SARS‐CoV‐2 infection
Authors: Ng Khuen Foong , Kothari Trishul , Bandi Srini , Bird Paul William , Goyal Kanika , Zoha Mohammad , Rai Vinayak , Tang Julian Wei‐Tze
Published: June 2020

Coronavirus disease 2019 (COVID‐19) is generally a relatively mild illness in children. An emerging disease entity coined as pediatric inflammatory multisystem syndrome temporally associated with SARS‐CoV‐2 (PIMS‐TS) has been reported recently, but is very rare and only affects a very small minority of children. Here we describe the clinical presentations and outcomes of three teenagers with serologically‐confirmed SARS‐CoV‐2 infection admitted to a pediatric intensive care unit for PIMS‐TS. Although their initial presentations were very similar, their COVID‐19‐related disease varied in severity.
Long‐term variability and trends in meteorological droughts in Western Europe (1851–2018)
Authors: Vicente‐Serrano Sergio M. , Domínguez‐Castro Fernando , Murphy Conor , Hannaford Jamie , Reig Fergus , Peña‐Angulo Dhais , Tramblay Yves , Trigo Ricardo M. , Mac Donald Neil , Luna M. Yolanda , Mc Carthy Mark , Van der Schrier Gerard , Turco Marco , Camuffo Dario , Noguera Ivan , García‐Herrera Ricardo , Becherini Francesca , Della Valle Antonio , Tomas‐Burguera Miquel , El Kenawy Ahmed
Published: June 2020

We analysed long‐term variability and trends in meteorological droughts across Western Europe using the Standardized Precipitation Index (SPI). Precipitation data from 199 stations spanning the period 1851–2018 were employed, following homogenisation, to derive SPI‐3 and SPI‐12 series for each station, together with indices on drought duration and severity. Results reveal a general absence of statistically significant long‐term trends in the study domain, with the exception of significant trends at some stations, generally covering short periods. The largest decreasing trends in SPI‐3 (i.e., increasing drought conditions) were found for summer in the British and Irish Isles. In general, drought episodes experienced in the last two or three decades have precedents during the last 170·years, emphasizing the importance of long records for assessing change. The main characteristic of drought variability in Western Europe is its strong spatial diversity, with regions exhibiting a homogeneous temporal evolution. Notably, the temporal variability of drought in Western Europe is more dominant than long‐term trends. This suggests that long‐term drought trends cannot be confirmed in Western Europe using precipitation records alone. This study provides a long‐term regional assessment of drought variability in Western Europe, which can contribute to better understanding of regional climate change during the past two centuries.
The impact of COVID‐19 on franchising in emerging markets: An example from Brazil
Authors: Bretas Vanessa Pilla Galetti , Alon Ilan
Published: June 2020

The outbreak of COVID‐19, the disease caused by the SARS‐CoV‐2 virus, has had significant economic, political, and social consequences worldwide. The franchising sector, consisting mostly of retail and service businesses, is an example of an industry that has been deeply affected. The experiences of franchising stakeholders in Brazil highlight the strengths of the franchising model in such situations. This investigation, based on primary data from webinars with food service, education, retail, and business‐to‐business service companies in Brazil, coupled with reports from commercial and franchising entities, reveals how the COVID‐19 outbreak has affected the franchising sector. It illustrates the measures that were taken, the negotiations that take place between suppliers and landlords, the adaptation of business models, the effects on franchisor‐franchisee relationships, and the impact the pandemic has had on relationships with customers. The strategies adopted by Brazilian franchisors and franchisees suggest lessons for other franchising companies in similar situations, such as those in developing and emerging economies.
In vivo test of a radiography‐based navigation system for control of derotational osteotomies
Authors: Grünwald Leonard , Schröter Steffen , Windolf Markus , Gueorguiev Boyko , Richards Geoff , Buschbaum Jan
Published: June 2020

Malalignment of the femur is a frequently encountered problem in orthopaedics entailing manifold consequences for the affected patients. Corrective osteotomies, necessary to restore the physiological and anatomical relationships, face great challenges due to no existing reliable gold standard for intraoperative control of torsional malalignment. The aim of this study was to test a novel radiography‐based navigation tool for control of derotational osteotomies in a clinical environment. In a first—and preliminary—case‐controlled study on 12 patients (level 3 of evidence), the achieved torsional correction measured with implementation of the navigation tool was compared with measurements from pre‐ and postoperative computed tomography (CT) scans.

The navigation tool was able to acquire and process all relevant data and capture possible malrotation during surgery with only little deviations of 1.61° ± 0.86° (mean ± standard deviation) from the measurements based on CT scans. Next, the system will be used to assist surgeons for more precise treatment avoiding maltorsion after derotational osteotomies.
Summer precipitation for the England and Wales region, 1201–2000 ce, from stable oxygen isotopes in oak tree rings
Authors: Loader Neil J. , Young Giles H. F. , McCarroll Danny , Davies Darren , Miles Daniel , Bronk Ramsey Christopher
Published: June 2020

Oxygen isotope ratios from oak tree rings are used to extend the May–August precipitation totals of the England and Wales precipitation series back to 1201 ce. The agreement between instrumental and reconstructed values is unusually strong, with more than half of the variance explained and standard verification tests passed. The stability of this relationship is confirmed using split‐period calibration and verification. This allows the reconstruction to be variance‐scaled to the full length of the instrumental series back to 1766. Direct comparison with historical reports of very wet and dry summers show good agreement. Near‐constant replication, with a minimum of 10 timbers sourced from historic buildings across central southern England ensures signal strength does not change over time. Summers during the late 20th century appear anomalously dry and those of the 21st century very close to the pre‐20th century average with no evidence in the record of prolonged ‘megadroughts’ across England and Wales.
Yacón (Smallanthus sonchifolius) prevented inflammation, oxidative stress, and intestinal alterations in an animal model of colorectal carcinogenesis
Authors: Verediano Thaísa A , Viana Mirelle L , das Graças Vaz Tostes Maria , de Oliveira Daniela S , de Carvalho Nunes Louisiane , Costa Neuza MB
Published: June 2020

BACKGROUND

Yacón (Smallanthus sonchifolius) roots store carbohydrate in the form of prebiotic fructooligosaccharides (FOS), which improve intestinal health. Yacon has the potential to prevent the intestinal barrier alterations associated with colorectal cancer (CRC). This study aimed to investigate the preventive effects of yacón flour (YF) on alterations promoted by CRC induced by 1,2‐dimethylhydrazine in rats.

RESULTS

CRC increased tumor necrosis factor alpha levels (group CY = 10.2 ± 0.72; group C = 9.6 ± 1.0; group Y = 5.8 ± 0.54; group S = 5.95 ± 0.6 pg mL−1) and short‐chain fatty acid production, and decreased total antioxidant capacity (group CY = 4.7 ± 0.72; group C = 3.3 ± 0.3; group Y = 4.1 ± 0.47; group S = 6.7 ± 0.78 U mL−1). Furthermore, YF treatment reduced intraluminal pH (group CY = 6.45 ± 0.47; group C = 7.65 ± 0.44; group Y = 6.75 ± 0.46; group S = 8.13 ± 0.2), lactulose/mannitol ratio, tumor necrosis factor‐alpha (TNF‐α)/interleukin (IL)‐10 ratio, and increased secretory immunoglobulin A (group CY = 9.48 ± 1.46; group C = 10.95 ± 3.87; group Y = 15.95 ± 7.36; group S = 9.19 ± 1.52), but did not affect IL‐10, IL‐12, and TNF‐α levels nor the IL‐12/IL‐10 ratio.

CONCLUSION

YF as a source of fructooligosaccharides may help to maintain the integrity of intestinal health, which is altered in induced CRC in rats. © 2020 Society of Chemical Industry
Optimization of pectinase‐assisted extraction of Annona muricata L. juice and the effect of liquefaction on its pectin structure
Authors: Makebe Calister Wingang , Desobgo Zangue Steve Carly , Ambindei Wilson Agwanande , Billu Abraham , Nso Emmanuel Jong , Nisha P
Published: June 2020

BACKGROUND

Soursop (Annona muricata L.) is an underutilized tropical and subtropical fruit with high nutritional and therapeutic benefits. This fruit is faced with enormous post‐harvest losses due to its high perishability. This work was aimed to optimize the pectinase‐assisted extraction conditions of soursop juice using Doehlert design and to study the effect of pectinase on its pectin structure.

RESULTS

The predicted models were validated for all the responses studied and the regression coefficients ranged from 0.905 to 0.987 (P ≤ 0.05). An incubation time of 172 min, enzyme concentration of 0.04% (w/w) and incubation temperature at 42.9 °C were found to be the optimal conditions for soursop juice extraction, which resulted in 75.20%, 3.74, 7.35 °Brix, 87.06%T, and 0.44% MAE for soursop juice yield (%), pH, total soluble solids (TSS) (°Brix), clarity (%T) and titratable acidity (% malic acid equivalent, MAE), respectively. Morphologically, untreated soursop pulp presented a non‐uniform spherical surface; enzyme hydrolyzed soursop exhibited ruptured and wrinkled surface; meanwhile for the different pectin obtained, untreated soursop pectin depicted porous surface and enzyme hydrolyzed soursop pectin showed whirling rough surface. Fourier‐transform infrared (FTIR) confirmed the presence of similar chemical group stretching and vibrations in commercial pectin and soursop pectin.

CONCLUSION

Under the optimum conditions, the numerical predictions were similar to the experimental data obtained, thus confirming the validity of the models. Application of enzyme treatment caused the breakdown of pectin structure as illustrated by scanning electron microscopy (SEM) and FTIR analyses.
Fluoride uptake and translocation in food crops grown in fluoride‐rich soils
Authors: Rizzu Margherita , Tanda Alberto , Canu Linda , Masawe Khairia , Mtei Kelvin , Deroma Mario A , Roggero Pier P , Seddaiu Giovanna
Published: June 2020

BACKGROUND

The East African Rift Valley (EARV) area is characterized by an intense volcanic activity, which largely influences the nature of soils, ground and surface waters causing a transfer of fluoride from volcanic emissions to the environment. Field experiments were conducted in fluorine‐contaminated areas of Ngarenanyuki (Arumeru district) in north Tanzania. In order to evaluate the potential fluoride exposure from diet and the related health risk for the local population, the content of fluoride in soil and plant tissues was assessed, focusing on the edible portions (leaves, fruits or seeds) of the main cultivated and consumed food crops in the area.

RESULTS

Average fluoride contents of 8.0, 11.4, 11.3 and 14.2 mg kg−1 of dry matter were observed respectively for maize (Zea mays L.), tomato (Lycopersicon esculentum Mill.), bean (Phaseolus vulgaris L.) and kale (Brassica sp. pl.) edible parts. The cumulative estimated average daily dose (EADD) ranged from 0.026 to 0.165 mg F d−1 kg−1 among different rural population groups and considering two different hypotheses of absorption fraction (75% or 100%), i.e. the amount of fluoride that is absorbed during the digestion process. The associated hazard index (HI) values varied from 0.43 to 2.75.

CONCLUSIONS

Considering the dietary habits of the local population, the outcomes of the present study suggest that the investigated crops can substantially contribute to fluoride related diseases, especially in earlier ages. © 2020 Society of Chemical Industry
Identification of lipophilic components in Citri Reticulatae Pericarpium cultivars by supercritical CO2 fluid extraction with ultra‐high‐performance liquid chromatography–Q Exactive Orbitrap tandem mass spectrometry
Authors: Zheng Guodong , Liu Mengshi , Chao Yingxin , Yang Yuhua , Zhang Dedong , Tao Yiwen , Zhang Jianye , Zeng Caifang , Wei Minyan
Published: June 2020

To systematically identify the lipophilic constituents of Citri Reticulatae Pericarpium from different cultivars, supercritical CO2 fluid extraction and ultra‐high‐performance liquid chromatography–Q Exactive Orbitrap tandem mass spectrometry were integrated for the component analysis of 18 batches of Citri Reticulatae Pericarpium from 12 cultivars for the first time. A total of 57 components from the supercritical CO2 fluid extracts were demonstrably or tentatively identified by the obtained parent peaks, fragment peaks, and retention times. In total, two flavonoids, six organic acids, nine coumarins, three aldehydes, seven esters, three terpenes, one limonoid, and five other compounds were detected for the first time; notably, coumarin components have not yet been reported in Citri Reticulatae Pericarpium. Furthermore, the extract constituents differed between cultivars. In particular, organic acids were more abundant in Citrus reticulata “Chachi” than in other cultivars, and pterostilbene was exclusively found in Citrus reticulata “Yichangju”. The results showed that a greater variety of compounds in Citri Reticulatae Pericarpium could be extracted by supercritical CO2 fluid extraction and detected by ultra‐high‐performance liquid chromatography–Q Exactive Orbitrap tandem mass spectrometry. This study provides a more scientific basis for further analysis of the pharmacological activity and quality of Citri Reticulatae Pericarpium components from different cultivars.
Practical Guide for Identification of Internal Carotid Artery During Endoscopic Nasopharyngectomy
Authors: Battaglia Paolo , Eesa Mohamed , Pietrobon Giacomo , Karligkiotis Apostolos , Castelnuovo Paolo , Turri‐Zanoni Mario
Published: June 2020

View Supplementary Video 1 Laryngoscope, 2020
Closed Total Laryngectomy During the COVID‐19 Pandemic Disease
Authors: De Seta Daniele , Marrosu Valeria , Russo Francesca Y. , Carta Filippo , Puxeddu Roberto
Published: June 2020

View Video S1
Dissipative Kerr Solitons in a III‐V Microresonator
Authors: Moille Gregory , Chang Lin , Xie Weiqiang , Rao Ashutosh , Lu Xiyuan , Davanço Marcelo , Bowers John E. , Srinivasan Kartik
Published: June 2020

Stable microresonator Kerr soliton frequency combs in a III‐V platform (AlGaAs on SiO2) are demonstrated through quenching of thermorefractive effects by cryogenic cooling to temperatures between 4 and 20 K. This cooling reduces the resonator's thermorefractive coefficient, whose room‐temperature value is an order of magnitude larger than that of other microcomb platforms like Si3N4, SiO2, and AlN, by more than two orders of magnitude, and makes soliton states adiabatically accessible. Realizing such phase‐stable soliton operation is critical for applications that fully exploit the ultra‐high effective nonlinearity and high optical quality factors exhibited by this platform.
Photo‐ and pH‐Responsive Polycarbonate Block Copolymer Prodrug Nanomicelles for Controlled Release of Doxorubicin
Authors: Kalva Nagendra , Uthaman Saji , Augustine Rimesh , Jeon Su Hyeon , Huh Kang Moo , Park In‐Kyu , Kim Il
Published: June 2020

Photo/pH dual‐responsive amphiphilic diblock copolymers with alkyne functionalized pendant o‐nitrobenzyl ester group are synthesized using poly(ethylene glycol) as a macroinitiator. The pendant alkynes are functionalized as aldehyde groups by the azide‐alkyne Huisgen cycloaddition. The anticancer drug doxorubicin (DOX) molecules are then covalently conjugated through acid‐sensitive Schiff‐base linkage. The resultant prodrug copolymers self‐assemble into nanomicelles in aqueous solution. The prodrug nanomicelles have a well‐defined morphology with an average size of 20–40 nm. The dual‐stimuli are applied individually or simultaneously to study the release behavior of DOX. Under UV light irradiation, nanomicelles are disassembled due to the ONB ester photocleavage. The light‐controlled DOX release behavior is demonstrated using fluorescence spectroscopy. Due to the pH‐sensitive imine linkage the DOX molecules are released rapidly from the nanomicelles at the acidic pH of 5.0, whereas only minimal amount of DOX molecules is released at the pH of 7.4. The DOX release rate is tunable by applying the dual‐stimuli simultaneously. In vitro studies against colon cancer cells demonstrate that the nanomicelles show the efficient cellular uptake and the intracellular DOX release, indicating that the newly designed copolymers with dual‐stimuli‐response have significant potential applications as a smart nanomedicine against cancer.
Cell‐Laden Hydrogels for Multikingdom 3D Printing
Authors: Johnston Trevor G. , Fillman Jacob P. , Priks Hans , Butelmann Tobias , Tamm Tarmo , Kumar Rahul , Lahtvee Petri‐Jaan , Nelson Alshakim
Published: June 2020

Living materials are created through the embedding of live, whole cells into a matrix that can house and sustain the viability of the encapsulated cells. Through the immobilization of these cells, their bioactivity can be harnessed for applications such as bioreactors for the production of high‐value chemicals. While the interest in living materials is growing, many existing materials lack robust structure and are difficult to pattern. Furthermore, many living materials employ only one type of microorganism, or microbial consortia with little control over the arrangement of the various cell types. In this work, a Pluronic F127‐based hydrogel system is characterized for the encapsulation of algae, yeast, and bacteria to create living materials. This hydrogel system is also demonstrated to be an excellent material for additive manufacturing in the form of direct write 3D‐printing to spatially arrange the cells within a single printed construct. These living materials allow for the development of incredibly complex, immobilized consortia, and the results detailed herein further enhance the understanding of how cells behave within living material matrices. The utilization of these materials allows for interesting applications of multikingdom microbial cultures in immobilized bioreactor or biosensing technologies.
Nanoscopic Characterization of Stearic Acid Release from Bovine Serum Albumin Hydrogels
Authors: Sanaeifar Niuosha , Mäder Karsten , Hinderberger Dariush
Published: June 2020

The release behavior of 16‐doxyl stearic acid (16‐DSA) from hydrogels made from bovine serum albumin (BSA) is characterized. 16‐DSA serves as a model tracer molecule for amphiphilic drugs. Various hydrogel preparation procedures are tested and the fatty acid release from the different gels is compared in detail. These comparisons reach from the macroscopic level, the viscoelastic behavior via rheological characterization to changes on the nanoscopic level concerning the secondary structure of the protein during gelation through infrared (ATR‐IR) spectroscopy. 16‐DSA‐BSA interaction via continuous wave electron paramagnetic resonance (CW EPR) spectroscopy in addition gives a nanoscopic view of small molecule–hydrogel interaction. The combined effects of fatty acid concentration, hydrogel incubation time, and gelation procedures on release behavior are studied via CW EPR spectroscopy and dynamic light scattering (DLS) measurements, which provide deep insight on the interaction of 16‐DSA with BSA hydrogels and the nature and size of the released components, respectively. It is found that the release rate of the fatty acid from BSA hydrogels depends on and can thus be tuned through its loading percentage, duration of hydrogel formation and the type of gelation methods. All of the results confirm the potential of these gels as delivery hosts in pharmaceutical applications allowing the sustained release of drug.
The Effect of Polymer Dots During Mammalian Early Embryo Development and Their Biocompatibility on Maternal Health
Authors: Zhang Juxiang , Teng Fei , Tang Shiyi , Zhang Yufan , Guo Yixiao , Li Jingru , Li Yuqiao , Zhang Chunfu , Xiong Liqin
Published: June 2020

Conjugated polymer dots have excellent fluorescence properties in terms of their structural diversity and functional design, showing broad application prospects in the fields of biological imaging and biosensing. Polymer dots contain no heavy metals and are thought to be of low toxicity and good biocompatibility. Therefore, systematic studies on their potential toxicity are needed. Herein, the biocompatibility of poly[(9,9‐dioctylfluorenyl‐2,7diyl)‐co‐(1,4‐benzo‐{2,1′,3}‐thiadiazole)],10% benzothiadiazole(y) (PFBT) and poly[2‐methoxy‐5‐(2‐ethylhexyloxy)‐1,4‐phenylenevinylene] (MEH‐PPV) polymer dots on early embryo development as well as maternal health is studied in detail. The results show that prepared polymer dots are dose‐dependently toxic to preimplantation embryos, and low‐dose polymer dots can be used for cell labeling of early embryos without affecting the normal development of embryos into blastocysts. In addition, the in vivo distribution data show that the polymer dots accumulate mainly in the maternal liver, spleen, kidney, placenta, ovary, and lymph nodes of the pregnant mice. Histopathological examination and blood biochemical tests demonstrate that exposure of the maternal body to polymer dots at a dosage of 14 µg g−1 does not affect the normal function of the maternal organs and early fetal development. The research provides a safe basis for the wide application of polymer dots.
Wound Healing Attributes of Polyelectrolyte Multilayers Prepared with Multi‐l‐arginyl‐poly‐l‐aspartate Pairing with Hyaluronic Acid and γ‐Polyglutamic Acid
Authors: Uddin Zeeshan , Fang Tsuei‐Yun , Siao Jyun‐Yin , Tseng Wen‐Chi
Published: June 2020

Biodegradable multi‐l‐arginyl‐poly‐l‐aspartate (MAPA), more commonly cyanophycin, prepared with recombinant Escherichia coli contains a polyaspartate backbone with lysine and arginine as side chains. Two assemblies of polyelectrolyte multilayers (PEMs) are fabricated at three different concentration ratios of insoluble MAPA (iMAPA) with hyaluronic acid (iMAPA/HA) and with γ‐polyglutamic acid (iMAPA/γ‐PGA), respectively, utilizing a layer‐by‐layer approach. Both films with iMAPA and its counterpart, HA or γ‐PGA, as the terminal layer are prepared to assess the effect on film roughness, cell growth, and cell migration. iMAPA incorporation is higher for a higher concentration of the anionic polymer due to better charge interaction. The iMAPA/HA films when compared to iMAPA/γ‐PGA multilayers show least roughness. The growth rates of L929 fibroblast cells on the PEMs are similar to those on glass substrate, with no supplementary effect of the terminal layer. However, the migration rates of L929 cells increase for all PEMs. γ‐PGA incorporated films impart 50% enhancement to the cell migration after 12 h of culture as compared to the untreated glass, and the smooth films containing HA display a maximum 82% improvement. The results present the use of iMAPA to construct a new layer‐by‐layer system of polyelectrolyte biopolymers with a potential application in wound dressing.
Controllable Superlubricity System of Polyalkylene Glycol Aqueous Solutions under Various Applied Conditions
Authors: Liu Wenrui , Wang Hongdong , Liu Yuhong , Zhang Caixia , Luo Jianbin
Published: June 2020

It has been recently demonstrated that the superlubricity behavior of polyalkylene glycol (PAG) aqueous solutions can be achieved in a wide variety of applied conditions. However, certain parameters are expected to be adjusted further to achieve a more controllable superlubricity system. Herein, it is demonstrated that an ultralow friction coefficient can be obtained by concentrated PAG aqueous solutions (80 wt% HB‐260) as the contact pressure becomes relatively low (37 MPa). Meanwhile, the superlubricity state can be adjusted in a timely manner by adjusting the relative sliding speed. Here, the viscosity of the PAG aqueous solution (determined by its concentration and molecular weight) and applied conditions, including contact pressure and relative sliding speed, are considered as critical parameters influencing the lubricating performance. According to the theoretical analysis, the superlubricity state is confirmed and a fitted superlubricity region is proposed, which provides a comprehensive guide for achieving controllable superlubricity in the future.
Design and Preparation of Tertiary Amine Modified Polyurethane Acrylate Oligomer with Co‐Initiation/Polymerization Bifunctions for Photo‐Curable Inkjet Printing of Textiles
Authors: Meng Yiding , Sun Guangdong , Huang Yi , Wang Chenglong , Wang Lili , Fan Qinguo , Shao Jianzhong
Published: June 2020

In order to resolve the conflict issues existing in currently available polyurethane acrylate (PUA) oligomers for photo‐curable inkjet printing of textile, and to avoid the safety problems caused by the immigration of small molecule amine co‐initiator, a series of tertiary amine modified PUA oligomers are delicately designed and synthesized. The chemical structures of the synthesized PUA oligomers are confirmed by FTIR and 1H‐NMR analyses. The optimized PUA oligomer/hydroxyethyl acrylate based polymerization system show a low viscosity, high storage stability and good compatibility with various functional segments. Furthermore, the modified PUA oligomer acts as both the photopolymerization constituent and the macromolecular co‐initiator assisting to achieve high photopolymerization rate and conversion rate, and avoiding the disadvantages caused by the migration of small amine co‐initiators. Benefitting from the semi‐IPN formed by this polymerization system with suitable crosslinking density and phase separation degree, a soft, strong and flexible cured film is obtained. The high photo‐reactivity with low viscosity of the polymerization system and the good flexibility with high strength of the resultant photo‐cured film ensures the applications of the modified PUA oligomer, and the printed fabrics achieve 4 grade of colorfastness with improved handle properties, as well as brilliant color and fine patterns.
High‐Performance Flexible Pressure and Temperature Sensors with Complex Leather Structure
Authors: Abodurexiti Ayinuer , Yang Congcong , Maimaitiyiming Xieraili
Published: June 2020

The ability of the skin to be pressure‐sensitive has prompted scientists to develop materials and equipment to simulate this function. Recently, flexible and stretchable artificial electronic skin has received increasing attention with its unique ability to detect subtle pressure changes. Pressure sensing is one of the key functions of electronic skin devices. Here, a stretchy and highly sensitive pressure sensor is developed that used a polydimethylsiloxane (PDMS) film with leather composite layer as flexible part. These features enable the sensor to accurately detect a variety of human activities, such as small finger movements and bending, pulse and so on. The sensor is found to have a good sensing signal for temperature. This feature provides great promise for sensors to detect temperature.
Layered Double Hydroxide/Polymer Supramolecule with Different Structures for Leather Multiperformance Intensification
Authors: Ma Jianzhong , Yang Na , Gao Dangge , Jia Lu , Yang Xiaoyan
Published: June 2020

LDH/P supramolecule with exfoliated and intercalated structure by exfoliation/adsorption and in situ polymerization method is prepared, respectively. Afterward, the LDH/polymer supramolecule with exfoliated (LDH/P‐E, exfoliation/adsorption) and intercalated (LDH/P‐I, in situ polymerization) and partial exfoliated and partial intercalated (LDH/P‐B, physical blending, reported in the previous work) is used in leather tanning and retanning process to evaluate the structure–activity relationship between LDH/P and leather application performance. LDH/P supramolecule with exfoliated structure shows the best intensification ability to most of the leather performances, and the sequence of intensification ability of LDH/P is LDH/P‐E > LDH/P‐B > LDH/P‐I. This is related to the size and penetration property of LDH/P. For the leather performance intensification, the positively charged LDH layers can promote the absorption of negatively charged leather chemicals, and thus the dyeing and softness of leather can be intensified. The nanolayered structure of LDH filled between leather gaps can play a toughening and block effect, and thus the physical and mechanical strength, thickening rate, and the inhibition of volatilization of small organic molecule property of leather can be intensified. Furthermore, the reduction of chemical oxygen demand value of dyeing waste water is also an evidence that the LDH/P is an environmental retanning auxiliary.
Highly Stretchable, Compressible, Resilient, and Equilibrium Swelling Hydrogels with Elastic Nano Junctions
Authors: Zhu Liangyu , Zhang Xinlei , Shao Zengwu , Guo Mingyu
Published: June 2020

In this work, a flexible and polymerizable polyurethane‐urea (PUU) nanoparticle is used for the first time to prepare hydrogels showing highly stretchable, compressible, and resilient properties in their equilibrium swelling state. The PUU nanoparticles are prepared by reported interfacial polycondensation of O/W nanoemulsions followed by surface modification with acrylate groups. The hydrogels are prepared by simple free‐radical copolymerization of acrylamide and the polymerizable PUU nanoparticles. These PUU nanoparticles are expected to act as polyfunctional nanocrosslinkers and elastic junctions of the hydrogel’s network. The obtained hydrogels show high water containing character (94–97 wt%) in their equilibrium swelling state. The equilibrium swelling hydrogels can still be stretched and compressed up to 430–1170% and 95%, respectively, without fracture. Furthermore, cyclic tensile tests with a maximum strain of 500% or 700% show that the resilience of these equilibrium swelling hydrogels is as high as 95–97%. This work provides a new strategy and some new insights into the fabrication of fully swelling hydrogels with both extraordinary ductility and resilience, which is of critical importance for many of their practical applications.
Polyethylenimine‐Based Shape Memory Polyurethane with Low Transition Temperature and Excellent Memory Performance
Authors: Garg Hema , Mohanty Jayashree , Gupta Priyanka , Das Apurba , Tripathi Bijay P. , Kumar Bipin
Published: June 2020

Flexible shape memory polyurethanes (SMPUs) are the favorable candidates as a coating or substrate for wearable smart textiles, electronics, and biomedical applications. However, conventional SMPUs (e.g., 1,4 butanediol (BDO)‐based) are not suitable in these applications due to high rigidity, poor mechanical properties, low shape recovery, and high transition temperature. Herein, a polyethylenimine (PEI)‐based SMPU with low transition temperature and tailored properties are reported. The synthesized SMPU are characterized, and their properties are compared with BDO‐SMPUs. The chemical structure of PEI is explored to improve thermal and mechanical properties and to assess their effect on shape memory behavior. The bulky nature of PEI plays a critical role in lowering transition temperature and introduces flexibility in the structure at room temperature. A drop in Young's modulus is found from 13.6 MPa in BDO‐SMPU to 6.2 MPa in PEI‐SMPU. Simultaneously, tensile strength is increased from 3.77 MPa in BDO‐SMPU to 11.85 MPa in PEI‐SMPU. Owing to the improved mechanical properties in PEI‐SMPU, 100% shape recovery is observed, which displays a reproducible trend in ten repetitive cycles due to the presence of reversible physical crosslinks. Therefore, it is envisioned that this can serve as a potential shape memory material in smart wearable technologies.
Materialistic cues make us miserable: A meta‐analysis of the experimental evidence for the effects of materialism on individual and societal well‐being
Authors: Moldes Olaya , Ku Lisbeth
Published: June 2020

Consumer‐oriented societies are awash with materialistic messages that link happiness and success to wealth and consumption. However, despite extensive research evidence that dispositional materialistic orientations are correlated with lower well‐being, the effects of materialistic cues on the well‐being of individuals and social groups have not been examined. The present research meta‐analytically reviews the experimental evidence for the causal effects of materialism on two dimensions of well‐being: (a) individual and (b) societal. We included 27 independent studies that met the inclusion criteria of priming materialism and measuring well‐being (N = 3,649), containing a total of 62 effect sizes. Multilevel modeling revealed that materialism has an effect on both individual (δ = −0.39) and societal well‐being (δ = −0.41), suggesting that materialistic cuescauselower well‐being. Moderation effects suggested that materialistic cues might have a higher effect on interpersonal well‐being than on self‐evaluation indicators. We discuss the limitations of the current evidence, highlight the research gaps and underdeveloped areas, and provide recommendations such as minimum sample size for future experimental work, since the advancement of this area will help us to gain a better understanding of the impact of consumer‐oriented societies on the well‐being of individuals and social groups.
Study of Crystallinity Index and Thermal Properties of Sweet Sorghum Fiber after Pressurized‐Cooker Treatment
Authors: Ismojo  , Hadiwibowo Rangga , Yuanita Evana , Kustiyah Elvi , Chalid Mochamad
Published: June 2020

The main purpose of the research is to investigate the effect of thermal treatment through commercial pressure cooker (5, 25, and 60 min) on thermal and crystallinity properties of stalk sweet sorghum fibres. Crystallinity index and thermal stability of the fibers have been studied by using X‐ray diffraction (XRD) and simultaneous thermal analysis (STA) characterization, respectively, compared to untreated fibers. The result of this study shows that this treatment increased crystallinity index and thermal stability properties of the fibers. This result also shows that sorghum fiber can be used for a reinforcement candidate in thermoplastic matrix.
Optimization of Standard Indonesian Rubber 20 and Ethylene Propylene Diene Monomer Blending for Ship Launcher Application
Authors: Hidayat Ade S. , Jayatin  , Arti Dewi K. , Gumilar Muhammad D. , Susanto Herri , Larasati Amelia , Pratiwi Ulfa
Published: June 2020

Indonesia is one of the largest natural rubber producers in the world. However, the utilization of natural rubber is still not optimal, even though with a touch of technology, natural rubber can be utilized to create technical products that have high added value. One of the rubber products is rubber airbag. The purpose of this research is to know the effect of variations of natural rubber type Standard Indonesian Rubber (SIR) 20 and ethylene propylene diene monomer (EPDM) rubber composition processed with auxiliary chemicals on the quality of mechanical properties of rubber airbag product which is considered quite optimal. Rubber compound is made from the mixture of natural rubber SIR 20 and synthetic rubber EPDM with variation of SIR 20/EPDM ratio A) 100/0; B) 90/10; C) 80/20; D) 0/100 phr. Rubber compound is made with kneader machine and open mill. Then its mechanical properties are tested in accordance with the target technical specifications to be achieved. Testing is done both before and after its immersion in sea water at 95 °C for 29 days. Test results both before and after immersion in sea water shows that the composition of natural rubber and EPDM has significant effect on mechanical properties and chemical structure of rubber compound vulcanizate. The optimum rubber compound formula for rubber airbag is sample A with 100 phr of SIR 20 composition with excellent mechanical properties of tensile strength, hardness, rebound resilience, and abrasion resistance.
Viscoelastic Behavior and Thermal Stability of Poly(Lactic Acid) Bio‐Composite Filled with Micro‐Graphite
Authors: Kaavessina Mujtahid , Distantina Sperisa , Shohih Esa Nur , Lomi Henry Alvin Sebastian , Pratiwi Betha Putri , Chafid Achmad
Published: June 2020

Poly(lactic acid) or PLA bio‐composite is prepared by filling with micro‐graphite via solution blending. The micro‐graphite loading is varied from 0–15 wt%. The objectives of this research are to investigate the influence of micro‐graphite loading on PLA bio‐composite, on the viscoelasticity and thermal stability. The viscoelasticity behavior exhibits a considerable dependence on the melt properties of the PLA/micro‐graphite bio‐composites on the percentage micro‐graphite. The complex viscosity |η*|, storage modulus (G’), and loss modulus (G″) tend to improve with increasing micro‐graphite loading. Thermogravimetric analyses indicate that the micro‐graphite slightly stabilizes the PLA. The decomposition reaction is shifted to a higher temperature in the range 7–9 °C. This reaction leads to the loss of volatile byproducts, which occur at temperatures higher than 310 °C. It means far from the melt processing conditions. The differential scanning calorimetry thermogram shows that the glass transition temperature (Tg) and the melting temperature are close to that of neat PLA with changes only around 2–4 °C.
Preparation of Alginate/Nanocellulose Nanocomposite for Protein Adsorption
Authors: Piluharto Bambang , Salamah Ummu , Indarti Dwi
Published: June 2020

The aim of this study is to prepare alginate‐based nanocomposite for protein adsorption. Nanocomposite is prepared by dissolving alginate in the nanocellulose (NC) suspension and injected in calcium chloride bath to form alginate/NC beads. Herein, nanocellulose contents are used as a variable to study protein adsorption behavior. Protein adsorption is studied by batch method. Parameters of adsorption including effect of pH and isotherm adsorption are investigated. The results show that the optimum pH value for protein adsorption is 4 for all compositions of nanocomposites. Based on the equilibrium data for adsorption isotherm, it is shown that Langmuir isotherm model is better than Freundlich model for all compositions of alginate/NC composites. Increasing maximum adsorption capacity of alginate/NC nanocomposite was influenced slightly by nanocellulose content.
Molecular Weight, Degree of Deacetylation, and Acute Oral Toxicity Evaluation of Irradiated and Nonirradiated Chitosan Using Mice
Authors: Darwis Darmawan , Pangerteni Dewi Sekar , Abbas Basril , Puspitasari Tita , Nuryanthi Nunung , Nurrochmad Arief , Airin Claude Mona
Published: June 2020

Chitosan has been used as antimicrobial, anti‐fungal, anti‐virus, antioxidant, and anti‐cancer agent. As a new biomaterial, chitosan will be required to undergo certain toxicity tests for biocompatibility and safety assessment; one of the requirements is acute toxicity. In this study, nonirradiated and irradiated chitosan is used. The MW of chitosan is analyzed using GPC. The degree of deacetylation (DD) is measured by FTIR. OECD Guideline for Testing of Chemicals No 423 is used for evaluation of acute oral toxicity tests of nonirradiated and irradiated chitosan using mice with body weight (BW) ranging from 20 to 30 g. During 14 days after the dosing of chitosan, there are daily observations of toxic symptoms, death of test animals, changes in weight gain, and manifestations of toxic effects of individual animals. The results show that nonirradiated and irradiated chitosan with 75 kGy have an average MW of 276.0 and 90.0 kDa, respectively. Chitosan has a DD of 92%, which is increased by 4% at 75 kGy irradiation dose. Administration of nonirradiated and irradiated chitosan with a concentration of 300 mg/kg BW and continuous following with 2000 mg/kg BW show no toxic symptoms or death of mice test animals, LD50 > 5000 mg/kg. It is concluded that nonirradiated and irradiated chitosan with 75 kGy are categorized as practically nontoxic with LD50 > 5000 mg/kg. The dose up to a test limit of 5000 mg/kg BW is estimated to be equivalent to the dose of 38.79 mg (≈ 38.79 g) in humans (70 kg).
Synthesis and Application of Bacterial Cellulose‐co‐(poly)acrylamide as an Adsorbent for Cu and Pb Metal Ions
Authors: Oktaviani Oktaviani , Puspitasari Tita , Pangerteni Dewi Sekar , Nuryanthi Nunung , Syahputra Akhmad Rasyid
Published: June 2020

The bacterial cellulose‐co‐polyacrylamide (BC‐PAAM) is successfully synthesized by radiation‐induced graft polymerization using gamma rays with the simultaneous technique. The optimum irradiation dose applied is 50 kGy and the mass ratio among acrylamide (AAm) and bacterial cellulose (BC) is 1:4. The sorption of aqueous Cu and Pb onto BC‐PAAM is investigated in the relation of pH 3 and 5. The heavy metal ions are applied as single during adsorption study. The sorption uptake of the metal ions by BC‐PAAM shows that the adsorption capacity is higher at pH of 5 compared to the adsorption capacity of pH 3, both for Cu and Pb metal ions. The adsorption capacity obtained in the condition of pH 5 is 20.88 and 81.79 mg g−1 for Cu and Pb, respectively. While the adsorption efficiency in pH 5 is 29.54% (for Cu) and 92.76% (for Pb). The adsorbent (before and after metal ions uptake) is characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry.
Preparation of Chitosan Hydrogel with Malonic Acid Crosslinker as Soil Conditioner for Soybean Plant (Glycine max L. merril)
Authors: Ritonga Halimahtussaddiyah , Nurdin Muhammad , Ramadhan L. O. A. N. , Salsabila Wd. Syafitri , Si S. , Rembon Fransiskus S.
Published: June 2020

This research is on the manufacture of chitosan hydrogel crosslinked with malonic acid to be used as a soil conditioner for soybean plant (glycine max L. merrill). The aim of the study is to determine the effect of chitosan composition on malonic acid and the characteristics of hydrogel, and the effect of hydrogel as soil conditioner—its physical and chemical properties and role in soybean plant growth. Hydrogel of chitosan crosslinked malonic acid is carried out through a crosslinking chemical method. The increase in chitosan and malonic acid concentration can increase the swelling degree of hydrogel by 285.32%. Characterization is done using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). FTIR analysis shows changes in the specific absorption between chitosan and chitosan crosslinked malonic acid that occurs in the area of wave number 1080 cm−1 (C─O). SEM analysis shows that the increase in chitosan composition and malonic acid concentration causes the surface structure to be rough, hollow, and irregular. The use of hydrogel on soil conditions of soybean plants at 75th day measurements which give the most significant positive response is chitosan: malonic acid (2.5 g: 2.5%). Moisture value, soil temperature, C‐organic content, absorbed potassium level, and cation exchange capacity (CEC) content are 50%, 27–30 °C, 2%, 20.54 ppm, and 17.74 meq/100 g, respectively. In addition, the effect of hydrogel use on soybean plants result in the plant reaching a maximum height of 93 cm on the 75th day. The chitosan–malonic acid hydrogel has potential as soil conditioner.
Bionanocomposite of Gelatin–ZnO Nanoparticles as Potential Edible Coating for Broiler Chicken Fillet
Authors: Meindrawan Bayu , Putri Saphira , Susanto Clarissa Sarah , Ofe Ofe , Mangindaan Dave , Ayman Azzadin , Kasih Tota Pirdo
Published: June 2020

In this report, edible coating based on polymeric bionanocomposite of gelatin and ZnO nanoparticles to improve the quality of the broiler chicken fillet during storage is explored. With the addition of ZnO nanoparticles of 0.048% w/w in a solution containing 4% gelatin, the fabricated bionanocomposite film decreases the water vapor transfer rate by 27.54%, increases the tensile strength by 61.32%, reduces polymer film elongation by 60%, and inhibits the growth of Staphylococcus aureus and Escherichia coli by more than 90%, compared to control (gelatin coating with 0% ZnO NPs). When applied to broiler chicken fillet stored in room temperature for 8 h, the gelatin–ZnO NPs 0.048% w/w bionanocomposite polymeric edible coating has the lowest weight loss rate of 17%, maintains hardness at around 80 N, stabilizes the pH of the coated chicken at 6, without any indication of rancidity or slime, with total microorganisms (4.23 log CFU mL−1) significantly below the limit set by Indonesian National Standard SNI 01–3924:2009 (5 log CFU mL−1). Based on the results, it can be concluded that the manufactured polymeric gelatin–ZnO bionanocomposite is very promising for edible coating for poultry industries, and open doors for applications in meat or fruit industries.
Study on the Flammability and Thermal Stability of Non Halogen UPR‐Based Fire Retardant Composite through Combination of Carbon Black and Hydroxide Additives
Authors: Arfiana  , Saputra Asep H. , Murti Sri D. S. , Saputra Hens
Published: June 2020

The non‐halogen UPR‐based fire retardant composites are successfully made by combining the hydroxide additives and carbon black. The composites are synthesized by varying the concentration of carbon black (2.5, 5, 7.5, 10 % wt) respectively, at the constant concentration of Al(OH)3 40 % wt, and Mg(OH)2 10 % wt. The flammability of fire retardant composite is studied by using UL‐94 V flammability test to investigate the ignition time, burning time, and time taken to retard the fire. While the thermal stability of composite is characterized by thermal gravimetric analysis. The flammability test result shows that the addition of carbon black at all concentration with the constant concentration of hydroxide additives could improve the fire retardancy of composite by increasing the time to ignition, reducing the burning time, and gave V‐0 flammability rating. Moreover, the utilization of carbon black 2.5 % wt can enhance the thermal stability of composite by increasing the decomposition temperature, decreasing the mass loss rate, and total mass loss. The morphology of the composite before and after the flammability test are also tested to study the changes of the material structure.
Thermal and Morphological Properties of Cellulose Nanofiber from Pseudo‐Stem Fiber of Abaca (Musa Textilis)
Authors: Saragih Sri Wahyuna , Wirjosentono Basuki , Eddyanto  , Meliana Yenny
Published: June 2020

In the current study, cellulose nanofiber (CNF) has been isolated using the steam explosion method. The objective of this research is to determine the thermal and morphological properties of CNF from pseudo‐stem fiber of abaca (Musa textilis). The obtained CNF is isolated using three steps: (1) Isolation of α‐cellulose using alkaline and acid hydrolysis, (2) treatment of obtained α‐cellulose with steam explosion methods in the presence of H2C2O4 11wt%, and (3) homogenization of CNF. The obtained CNF is characterized using Fourier transform infrared (FT‐IR), X‐ray diffraction (XRD), transmission electron microscope (TEM), and thermal analysis (TGA). The FT‐IR spectra of CNF show the presence of typical vibration from ─OH and ─CH3 at 3600–3300 and 2900–2800 cm−1. The TEM image shows the average fiber width of the obtained CNF is about 5.5 nm, which is in the range 2.90–8.32 nm. Based on XRD spectra, the crystallinity of CNF is higher than α‐cellulose. TGA analysis shows α‐cellulose has better thermal stability than raw abaca fiber and CNF. The presence of lignin and hemicellulose plays a big role in the low thermal stability of raw abaca fiber and CNF. This thermal stability is evaluated from the initial decomposition temperature of raw abaca fiber, α‐cellulose, and CNF at 284, 317, and 300 °C.