bluuebunny/crossref_metadata_2025 huggingface dataset:
Vegetarian Diets and Medical Expenditure in Taiwan—A Matched Cohort Study
Authors: Lin Chin-Lon , Wang Jen-Hung , Chang Chia-Chen , Chiu Tina H.T. , Lin Ming-Nan
Published: November 2019

Vegetarian diets and lifestyle have been shown to reduce the risk of many chronic non-communicable diseases, which now accounts for the major global burden of diseases. We aimed to determine the contribution of vegetarian diets and lifestyle to the actual direct medical cost in a population-based study. Through linkage to the National Health Insurance Research Database of Taiwan, we compared the health care utilization and medical expenditure of 2166 vegetarians and 4332 age-sex-matched omnivores recruited from the Buddhist Tzu Chi Foundation. Diet and lifestyle questionnaires were self-administered and prospectively collected. We used the general linear model to estimate the 5-year average medical expenditure in vegetarians versus omnivores while adjusting for age, sex, education, exercise habits, smoking, and alcohol drinking. Medical expenses related to non-diet associated lifestyle factors (smoking, alcohol drinking, active community volunteering, and religious emotional support) were estimated through a comparison with the published population medical cost data standardized to match the age and sex characteristics of the cohort. Tzu Chi vegetarians had significantly lower outpatient visits. This translated into 13% lower outpatient (p = 0.007) and 15% lower total medical expenditures (p = 0.008) when compared with the Tzu Chi omnivores, who had an additional 10% lower medical expenditure when compared with the general population. No difference in dental visits and expenses were found between diet groups. Vegetarian diets are associated with significantly lower medical care expenditure and could be an effective strategy to alleviate the medical–economic burden in selected populations.
Baicalein as a Potential Inhibitor against BACE1 and AChE: Mechanistic Comprehension through In Vitro and Computational Approaches
Authors: Han Jin , Ji Yeongseon , Youn Kumju , Lim GyuTae , Lee Jinhyuk , Kim Dong Hyun , Jun Mira
Published: November 2019

One of the major neurodegenerative features of Alzheimer’s disease (AD) is the presence of neurotoxic amyloid plaques composed of amyloid beta peptide (Aβ). β-Secretase (BACE1) and acetylcholinesterase (AChE), which promote Aβ fibril formation, have become attractive therapeutic targets for AD. P-glycoprotein (P-gp), the major efflux pump of the blood-brain barrier (BBB), plays a critical role in limiting therapeutic molecules. In pursuit of discovering a natural anti-AD candidate, the bioactivity, physicochemical, drug-likeness, and molecular docking properties of baicalein, a major compound from Scutellaria baicalensis, was investigated. Baicalein exhibited strong BACE1 and AChE inhibitory properties (IC50 23.71 ± 1.91 µM and 45.95 ± 3.44 µM, respectively) and reacted in non-competitive and competitive manners with substrates, respectively. in Silico docking analysis was in full agreement with the in vitro results, demonstrating that the compound exhibited powerful binding interaction with target enzymes. Particularly, three continuous hydroxyl groups on the A ring demonstrated strong H-bond binding properties. It is also noteworthy that baicalein complied with all requirements of Lipinski’s rule of five by its optimal physicochemical properties for both oral bioavailability and blood–brain barrier permeability. Overall, the present study strongly demonstrated the possibility of baicalein having in vivo pharmacological efficacy for specific targets in the prevention and/or treatment of AD.
Impaired Glucose Tolerance is Associated with Enhanced Platelet-Monocyte Aggregation in Short-Term High-Fat Diet-Fed Mice
Authors: Mkandla Zibusiso , Mutize Tinashe , Dludla Phiwayinkosi V. , Nkambule Bongani B.
Published: November 2019

High-fat diet (HFD) feeding is known to induce metabolic dysregulation, however, less is known on its impact in promoting the hypercoagulable state. This current study aimed to evaluate platelet-monocyte aggregate (PMA) formation following short-term HFD feeding. This is particularly important for understanding the link between inflammation and the hypercoagulable state during the early onset of metabolic dysregulation. To explore such a hypothesis, mice were fed a HFD for 8 weeks, with body weights as well as insulin and blood glucose levels monitored on a weekly basis during this period. Basal hematological measurements were determined and the levels of spontaneous peripheral blood PMAs were assessed using whole blood flow cytometry. The results showed that although there were no significant differences in body weights, mice on HFD displayed impaired glucose tolerance and markedly raised insulin levels. These metabolic abnormalities were accompanied by elevated baseline PMA levels as an indication of hypercoagulation. Importantly, it was evident that baseline levels of monocytes, measured using the CD14 monocyte marker, were significantly decreased in HFD-fed mice when compared to controls. In summary, the current evidence shows that in addition to causing glucose intolerance, such as that identified in a prediabetic state, HFD-feeding can promote undesirable hypercoagulation, the major consequence implicated in the development of cardiovascular complications.
Association between Nutrients and Visceral Fat in Healthy Japanese Adults: A 2-Year Longitudinal Study Brief Title: Micronutrients Associated with Visceral Fat Accumulation
Authors: Ozato Naoki , Saito Shinichiro , Yamaguchi Tohru , Katashima Mitsuhiro , Tokuda Itoyo , Sawada Kaori , Katsuragi Yoshihisa , Imoto Seiya , Ihara Kazushige , Nakaji Shigeyuki
Published: November 2019

High visceral fat area (VFA) is a stronger predictor of cardiovascular disease and overall mortality than body mass index or waist circumference. VFA may be decreased by proper dietary habits. Although previous epidemiologic studies demonstrated an association between nutritional components or foodstuffs and VFA, only the associations of a few nutrients, such as dietary fiber and calcium, are reported. We performed a comprehensive 2-year longitudinal study in more than 624 healthy people and analyzed 33 micronutrients to investigate nutrients that contribute to changes in visceral fat. Our analyses revealed that “macronutrients” and “micronutrients” were “mutual confounders”. Therefore, when evaluating the association between VFA and micronutrients, associations were adjusted by macronutrients. The ingestion of 7 nutrients: soluble dietary fiber, manganese, potassium, magnesium, vitamin K, folic acid, and pantothenic acid, which are abundant components in vegetable diets, was significantly inversely correlated with a change in VFA. Additionally, a change in the ingestion of one nutrient, monounsaturated fat, was significantly positively correlated with a change in VFA. These associations were independent of body mass index and waist circumference. Thus, a predominantly vegetable diet may decrease VFA. In addition, adjusting the intake of macronutrients might help to clarify the association of micronutrients with VFA.
Reply to “Letter to the Editor Re: Scott S.N., et al. Nutrients 2019, 11(5), 1022”
Authors: Scott Sam N. , Anderson Lorraine , Morton James P. , Wagenmakers Anton J. M. , Riddell Michael C.
Published: November 2019

We appreciate the interest and comments from Dr [...]
Evolution of H5-Type Avian Influenza A Virus Towards Mammalian Tropism in Egypt, 2014 to 2015
Authors: Mahmoud Sara Hussein , Mostafa Ahmed , El-Shesheny Rabeh , Seddik Mohamed Zakaraia , Khalafalla Galal , Shehata Mahmoud , Kandeil Ahmed , Pleschka Stephan , Kayali Ghazi , Webby Richard , Veljkovic Veljko , Ali Mohamed Ahmed
Published: November 2019

Highly pathogenic avian influenza viruses (HPAIV) of the H5-subtype have circulated continuously in Egypt since 2006, resulting in numerous poultry outbreaks and considerable sporadic human infections. The extensive circulation and wide spread of these viruses in domestic poultry have resulted in various evolutionary changes with a dramatic impact on viral transmission ability to contact mammals including humans. The transmitted viruses are either (1) adapted well enough in their avian hosts to readily infect mammals, or (2) adapted in the new mammalian hosts to improve their fitness. In both cases, avian influenza viruses (AIVs) acquire various host-specific adaptations. These adaptive variations are not all well-known or thoroughly characterized. In this study, a phylogenetic algorithm based on the informational spectrum method, designated hereafter as ISM, was applied to analyze the affinity of H5-type HA proteins of Egyptian AIV isolates (2006–2015) towards human-type cell receptors. To characterize AIV H5-HA proteins displaying high ISM values reflecting an increased tendency of the HA towards human-type receptors, recombinant IV expressing monobasic, low pathogenic (LP) H5-HA versions in the background of the human influenza virus A/PR/8/1934(H1N1) (LP 7+1), were generated. These viruses were compared with a LP 7+1 expressing a monobasic H5-HA from a human origin virus isolate (human LP-7271), for their receptor binding specificity (ISM), in vitro replication efficiency and in vivo pathogenicity in mammals. Interestingly, using ISM analysis, we identified a LP 7+1 virus (LP-S10739C) expressing the monobasic H5-HA of AIV A/Chicken/Egypt/S10739C/2015(H5N1) that showed high affinity towards human-type receptors. This in silico prediction was reflected by a higher in vitro replication efficiency in mammalian cell cultures and a higher virulence in mice as compared with LP-7271. Sequence comparison between the LP-S10739C and the LP-7271 H5-HA, revealed distinct amino acid changes. Their contribution to the increased mammalian receptor propensity of LP-S10739C demands further investigation to better deduce the molecular determinant behind the reported high morbidity of 2014 to 2015 HPAI H5N1 virus in humans in Egypt. This study provides insights into the evolution of Egyptian H5 HPAIVs and highlights the need to identify the viral evolution in order to recognize emerging AIV with the potential to threaten human and animal populations.
Micelle-Forming Block Copolymers Tailored for Inhibition of P-gp-Mediated Multidrug Resistance: Structure to Activity Relationship
Authors: Braunová Alena , Kaňa Martin , Kudláčová Júlia , Kostka Libor , Bouček Jan , Betka Jan , Šírová Milada , Etrych Tomáš
Published: November 2019

Multidrug resistance (MDR) is often caused by the overexpression of efflux pumps, such as ABC transporters, in particular, P-glycoprotein (P-gp). Here, we investigate the di- and tri- block amphiphilic polymer systems based on polypropylene glycol (PPO) and copolymers of (N-(2-hydroxypropyl)methacrylamide) (PHPMA) as potential macromolecular inhibitors of P-gp, and concurrently, carriers of drugs, passively targeting solid tumors by the enhanced permeability and retention (EPR) effect. Interestingly, there were significant differences between the effects of di- and tri- block polymer-based micelles, with the former being significantly more thermodynamically stable and showing much higher P-gp inhibition ability. The presence of Boc-protected hydrazide groups or the Boc-deprotection method did not affect the physico-chemical or biological properties of the block copolymers. Moreover, diblock polymer micelles could be loaded with free PPO containing 5–40 wt % of free PPO, which showed increased P-gp inhibition in comparison to the unloaded micelles. Loaded polymer micelles containing more than 20 wt % free PPO showed a significant increase in toxicity; thus, loaded diblock polymer micelles containing 5–15 wt % free PPO are potential candidates for in vitro and in vivo application as potent MDR inhibitors and drug carriers.
Folate Receptor-Targeting and Reactive Oxygen Species-Responsive Liposomal Formulation of Methotrexate for Treatment of Rheumatoid Arthritis
Authors: Chen Minglei , Daddy J.C. Kambere Amerigos , Su Zhigui , Guissi Nida El Islem , Xiao Yanyu , Zong Li , Ping Qineng
Published: November 2019

Multifunctional nanomedicines with active targeting and stimuli-responsive drug release function utilizing pathophysiological features of the disease are regarded as an effective strategy for treatment of rheumatoid arthritis (RA). Under the inflammatory environment of RA, activated macrophages revealed increased expression of folate receptor and elevated intracellular reactive oxygen species (ROS) level. In this study, we successfully conjugated folate to polyethylene glycol 100 monostearate as film-forming material and further prepared methotrexate (MTX) and catalase (CAT) co-encapsulated liposomes, herein, shortened to FOL-MTX&CAT-L, that could actively target to activated macrophages. Thereafter, elevated intracellular hydrogen peroxide, the main source of ROS, diffused into liposomes and encapsulated CAT catalyzed the decomposition of hydrogen peroxide into oxygen and water. Continuous oxygen-generation inside liposomes would eventually disorganize its structure and release the encapsulated MTX. We characterized the in vitro drug release, cellular uptake and cytotoxicity studies as well as in vivo pharmacokinetics, biodistribution, therapeutic efficacy and safety studies of FOL-MTX&CAT-L. In vitro results revealed that FOL-MTX&CAT-L possessed sufficient ROS-sensitive drug release, displayed an improved cellular uptake through folate-mediated endocytosis and exhibited a higher cytotoxic effect on activated RAW264.7 cells. Moreover, in vivo results showed prolonged blood circulation time of PEGylated liposomes, enhanced accumulation of MTX in inflamed joints of collagen-induced arthritis (CIA) mice, reinforced therapeutic efficacy and minimal toxicity toward major organs. These results imply that FOL-MTX&CAT-L may be used as an effective nanomedicine system for RA treatment.
Conjugation of Amisulpride, an Anti-Psychotic Agent, with 5-Aminosalicylic Acid via an Azo Bond Yields an Orally Active Mutual Prodrug against Rat Colitis
Authors: Kim Wooseong , Kim Dayoon , Jeong Seongkeun , Ju Sanghyun , Lee Hanju , Kim Soojin , Yoo Jin-Wook , Yoon In-Soo , Jung Yunjin
Published: November 2019

Amisulpride (ASP), an anti-psychotic agent, is a pharmacologically equivalent to sulpiride (SP). Because SP demonstrates anti-ulcer and anti-colitic activities, ASP with an aniline moiety was azo-coupled to salicylic acid to generate 5-(aminoethanoylsulfamoyl)-N-[(1-ethylpyrrolidin-2-yl)methyl]-2-methoxybenzamide (ASP-azo-ASA), with the expectation that it would act as a colon-specific mutual prodrug against colitis. Following a 24 h incubation, approximately 80% of ASP-azo-ASA was cleaved to form ASP and 5-aminosalicylic acid (5-ASA) in the cecal contents, whereas it remained stable in the small intestinal contents. Oral gavage of ASP-azo-ASA (oral ASP-azo-ASA) delivered 5-ASA to the cecum to levels comparable with those observed for sulfasalazine (SSZ; clinical colon-specific prodrug of 5-ASA) and without detectable concentrations of ASP in the blood, indicating efficient colonic delivery. Oral ASP-azo-ASA ameliorated 2, 4-dinitrobenzenesulfonic acid hydrate (DNBS)-induced colitis in rats more effectively than oral SSZ. Additionally, oral ASP-azo-ASA lowered the levels of inflammatory mediators in the inflamed distal colon more effectively than oral SSZ. Combined treatment with 5-ASA and ASP via the rectal route more effectively reversed colonic damage and inflammation than treatment with 5-ASA or ASP alone, confirming the mutual anti-colitic actions of 5-ASA and ASP. In conclusion, ASP-azo-ASA is an orally active mutual prodrug against rat colitis with limited systemic absorption of ASP.
A Stepwise Pharmacist-Led Medication Review Service in Interdisciplinary Teams in Rural Nursing Homes
Authors: Halvorsen Kjell H. , Stadeløkken Torunn , Garcia Beate H.
Published: November 2019

Background: The provision of responsible medication therapy to old nursing home residents with comorbidities is a difficult task and requires extensive knowledge about optimal pharmacotherapy for different conditions. We describe a stepwise pharmacist-led medication review service in combination with an interdisciplinary team collaboration in order to identify, resolve, and prevent medication related problems (MRPs). Methods: The service included residents from four rural Norwegian nursing homes during August 2016–January 2017. All residents were eligible if they (or next of kin) supplied oral consent. The interdisciplinary medication review service comprised four steps: (1) patient and medication history taking; (2) systematic medication review; (3) interdisciplinary case conference; and (4) follow-up of pharmaceutical care plan. The pharmacist collected information about previous and present medication use, and clinical and laboratory values necessary for the medication review. The nurses collected information about possible symptoms related to adverse drug reactions. The pharmacist conducted the medication reviews, identified medication-related problems (MRPs) which were discussed at case conferences with the responsible physician and the responsible nurses. The main outcome measures were number and types of MRPs, percentage agreement between pharmacists and physicians and factors associated with MRPs. Results: The service was delivered for 151 (94%) nursing home residents. The pharmacist identified 675 MRPs in 146 (97%) medication lists (mean 4.0, SD 2.6, range 0–13). The MRPs most frequently identified concerned ‘unnecessary drug’ (22%), ‘too high dosage’ (17%) and ‘drug interactions’ (16%). The physicians agreed upon 64% of the pharmacist recommendations, and action was taken immediately for 32% of these. We identified no association between the number of MRPs and sex (p = 0.485), but between the number of MRPs, and the number of medications and the individual nursing homes. Conclusion: The pharmacist-led medication review service in the nursing homes was highly successfully piloted with many solved and prevented MRPs in interdisciplinary collaboration between the pharmacist, physicians, and nurses. Implementation of this service as a standard in all four nursing homes seems necessary and feasible. If such a service is implemented, effects related to patient outcomes, interdisciplinary collaboration, and health economy should be studied.
Optical Image Encryption System Using Several Tilted Planes
Authors: Vilardy O. Juan M. , Jimenez Carlos J. , Torres M. Cesar O.
Published: November 2019

A well-known technique for optical image encryption is the double random phase encoding (DRPE) technique, which uses two random phase masks (RPMs), one RPM at the input plane of the encryption system and the other RPM at the Fourier plane of the optical system, in order to obtain the encrypted image. In this work, we propose to use tilted planes for the Fourier and the output planes of the optical DRPE encryption system with the purpose of adding two new security keys, which are the angles of the tilted planes. The optical diffraction on a tilted plane is computed using the angular spectrum of plane waves and the coordinate rotation in the Fourier domain. The tilted distributions at the intermediate and output planes of the optical DRPE encryption system are the second RPM and the encrypted image, respectively. The angles of the tilted planes allow improvement to the security of the encrypted image. We perform several numerical simulations with the purpose of demonstrating the validity and feasibility of the proposed image encryption system.
Preparation and Performance of Silica/ESBR Nanocomposites Modified by Bio-Based Dibutyl Itaconate
Authors: Ji Haijun , Yang Hui , Li Liwei , Zhou Xinxin , Yin Lan , Zhang Liqun , Wang Runguo
Published: November 2019

Ester-functionalized styrene-butadiene rubber (dibutyl itaconate-styrene-butadiene rubber) (D-ESBR) was synthesized by low-temperature emulsion polymerization using dibutyl itaconate (DBI) as a modified monomer containing ester groups. Nonpetroleum-based silica with hydroxy groups was used as a filler to enhance the D-ESBR, which can provide excellent mechanical properties, low rolling resistance, and high wet skid resistance. During the preparation of the silica/D-ESBR nanocomposites, a hydrogen-bonding interface was formed between the hydroxy groups on the surface of silica and the ester groups in the D-ESBR macromolecules. As the content of ester groups in the D-ESBR increases, the dispersion of silica in the nanocomposites is gradually improved, which was verified by rubber process analyzer (RPA) and scanning electron microscopy (SEM). Overall mechanical properties of the silica/D-ESBR modified with 5 wt % DBI were improved and became superior to that of the non-modified nanocomposite. Compared with the non-modified silica/D-ESBR, the DBI modified silica/D-ESBR exhibited a lower tan δ value at 60 °C and comparable tan δ value at 0 °C, indicating that the DBI modified silica/D-ESBR had lower rolling resistance without sacrificing wet skid resistance.
Functional Metal Organic Framework/SiO2 Nanocomposites: From Versatile Synthesis to Advanced Applications
Authors: Ma Mengyu , Lu Liangyu , Li Hongwei , Xiong Yuzhu , Dong Fuping
Published: November 2019

Metal organic frameworks (MOFs), also called porous coordination polymers, have attracted extensive attention as molecular-level organic-inorganic hybrid supramolecular solid materials bridged by metal ions/clusters and organic ligands. Given their advantages, such as their high specific surface area, high porosity, and open active metal sites, MOFs offer great potential for gas storage, adsorption, catalysis, pollute removal, and biomedicine. However, the relatively weak stability and poor mechanical property of most MOFs have limited the practical application of such materials. Recently, the combination of MOFs with inorganic materials has been found to provide a possible strategy to solve such limitations. Silica, which has excellent chemical stability and mechanical properties, shows great advantages in compounding with MOFs to improve their properties and performance. It not only provides structured support for MOF materials but also improves the stability of materials through hydrophobic interaction or covalent bonding. This review summarizes the fabrication strategy, structural characteristics, and applications of MOF/silica composites, focusing on their application in chromatographic column separation, catalysis, biomedicine, and adsorption. The challenges of the application of MOF/SiO2 composites are addressed, and future developments are prospected.
Selection of Immiscible Polymer Blends Filled with Carbon Nanotubes for Heating Applications
Authors: Marischal Louis , Cayla Aurélie , Lemort Guillaume , Campagne Christine , Devaux Éric
Published: November 2019

In many application fields, such as medicine or sports, heating textiles use electrically conductive multifilaments. This multifilament can be developed from conductive polymer composites (CPC), which are blends of an insulating polymer filled with electrically conductive particles. However, this multifilament must have filler content above the percolation threshold, which leads to an increase of the viscosity and problems during the melt spinning process. Immiscible blends between two polymers (one being a CPC) can be used to allow the reduction of the global filler content if each polymer is co-continuous with a selective localization of the fillers in only one polymer. In this study, three immiscible blends were developed between polypropylene, polyethylene terephthalate, or polyamide 6 and a filled polycaprolactone with carbon nanotubes. The morphology of each blend at different ratios was studied using models of co-continuity and prediction of fillers localization according to viscosity, interfacial energy, elastic modulus, and loss factor of each polymer. This theoretical approach was compared to experimental values to find out differences between methods. The electrical properties (electrical conductivity and Joule effect) were also studied. The co-continuity, the selective localization in the polycaprolactone, and the Joule effect were only exhibited by the polypropylene/filled polycaprolactone 50/50 wt.%.
Synthesis of a Novel Linear α, ω-Di (Chloro Phosphoramide) Polydimethylsiloxane and Its Applications in Improving Flame-Retardant and Water-Repellent Properties of Cotton Fabrics
Authors: Dong Chaohong , Sun Ling , Ma Xingbo , Lu Zhou , He Pengshuang , Zhu Ping
Published: November 2019

A novel linear α, ω-di (chloro phosphoramide)-terminated polydimethylsiloxane (CPN-PDMS) was successfully synthesized and utilized as a formaldehyde-free water-repellent and flame-retardant for cotton fabrics. The flame retardancy of treated cotton fabrics was estimated by limiting oxygen index (LOI) test, vertical flammability test, and cone calorimetry test. The cotton fabrics treated with 350 g/L CPN-PDMS obtained excellent flame retardancy with an LOI value of 30.6% and the char length was only 4.3 cm. Combustion residues were studied using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) analysis. Results show that CPN-PDMS can effectively enhance water repellency and fire resistance of cotton fabrics. Furthermore, the breaking strength test and the whiteness test strongly prove that the tensile strength and whiteness of the treated cotton fabrics were slightly lower than that of the pure cotton fabrics. The wash stability test showed that after 30 laundering cycles, the treated cotton fabrics still had an LOI value of 28.5% and a water-repellent effect of grade 80, indicating that CPN-PDMS was an excellent washing durability additive. In summary, these property enhancements of treated cotton fabrics were attributed to the synergistic effect of silicon-phosphorus-nitrogen elements in CPN-PDMS.
Nanofiller Dispersion, Morphology, Mechanical Behavior, and Electrical Properties of Nanostructured Styrene-Butadiene-Based Triblock Copolymer/CNT Composites
Authors: Staudinger Ulrike , Satapathy Bhabani K. , Jehnichen Dieter
Published: November 2019

A nanostructured linear triblock copolymer based on styrene and butadiene with lamellar morphology is filled with multiwalled carbon nanotubes (MWCNTs) of up to 1 wt% by melt compounding. This study deals with the dispersability of the MWCNTs within the nanostructured matrix and its consequent impact on block copolymer (BCP) morphology, deformation behavior, and the electrical conductivity of composites. By adjusting the processing parameters during melt mixing, the dispersion of the MWCNTs within the BCP matrix are optimized. In this study, the morphology and glass transition temperatures (Tg) of the hard and soft phase are not significantly influenced by the incorporation of MWCNTs. However, processing-induced orientation effects of the BCP structure are reduced by the addition of MWCNT accompanied by a decrease in lamella size. The stress-strain behavior of the triblock copolymer/MWCNT composites indicate higher Young’s modulus and pronounced yield point while retaining high ductility (strain at break ~ 400%). At a MWCNT content of 1 wt%, the nanocomposites are electrically conductive, exhibiting a volume resistivity below 3 × 103 Ω·cm. Accordingly, the study offers approaches for the development of mechanically flexible functional materials while maintaining a remarkable structural property profile.
Core-Shell Structure Design of Hollow Mesoporous Silica Nanospheres Based on Thermo-Sensitive PNIPAM and pH-Responsive Catechol-Fe3+ Complex
Authors: Peng Weili , Zhang Zeping , Rong Minzhi , Zhang Mingqiu
Published: November 2019

A kind of core-shell hybrid nanoparticle comprised of a hollow mesoporous silica nanoparticles (HMS) core and a copolymer shell bearing N-(3,4-dihydroxyphenethyl) methacrylamide (DMA) and N-isopropylacrylamide (NIPAM) as responsive moieties was prepared. Moreover, the factors that could impact the surface morphology and hierarchical porous structure were discussed. In the presence of Fe3+, catechol-Fe3+ complexes were formed to achieve pH-responsive polymer shell, combining with thermal-sensitiveness of poly(N-isopropylacrylamide). Doxorubicin (DOX) was applied as a model drug and the behaviors of its loading/release behaviors were investigated to prove the idea. The results exhibited a significant drug loading capacity of 8.6% and embed efficiency of 94.6% under 1 mg ml–1 DOX/PBS solution. In fact, the loading capacity of drug can be easily improved to as high as 28.0% by increasing the DOX concentration. The vitro cytotoxicity assay also indicated that the as-prepared nanoparticles have no significant cytotoxicity on RAW 264.7 cells. The in vitro experiment showed that the cumulative release of DOX was obviously dependent on the temperature and pH values. This pH/temperature-sensitive hollow mesoporous silica nanosphere is expected to have potential applications in controlled drug release.
Smart Microneedles with Porous Polymer Coatings for pH-Responsive Drug Delivery
Authors: Ullah Asad , Khan Haroon , Choi Hye Jin , Kim Gyu Man
Published: November 2019

This work demonstrates a simple approach for coating a porous polymer layer on stainless-steel (SS) microneedles characterized by a pH-responsive formulation for self-regulated drug delivery. For many drug-delivery applications, the release of therapeutic agents in an acidic microenvironment is desirable. Acid-sensitive polymers and hydrogels were extensively explored, but easily prepared polymeric microcarriers that combine acid sensitivity and biodegradability are rare. Here, we describe a simple and robust method of coating a porous polymer layer on SS microneedles (MNs) that release a model drug (lidocaine) in a pH-responsive fashion. It was constructed by packing the model drug and a pH-sensitive component (sodium bicarbonate) into the pores of the polymer layer. When this acid-sensitive formulation was exposed to the acidic microenvironment, the consequent reaction of protons (H+) with sodium bicarbonate (NaHCO3) yielded CO2. This effect generated pressure inside the pores of the coating and ruptured the thin polymer membrane, thereby releasing the encapsulated drug. Scanning electron micrographs showed that the pH-sensitive porous polymer-coated MNs exposed to phosphate-buffered saline (PBS) at pH 7.4 were characterized by closed pores. However, MNs exposed to PBS at pH 5.5 consisted of open pores and the thin membrane burst. The in vitro studies demonstrated the pH sensitivity of the drug release from porous polymer-coated MNs. Negligible release was observed for MNs in receiving media at pH 7.4. In contrast, significant release occurred when the MNs were exposed to acidic conditions (pH 5.5). Additionally, comparable results were obtained for drug release in vitro in porcine skin and in PBS. This revealed that our developed pH-responsive porous polymer-coated MNs could potentially be used for the controlled release of drug formulations in an acidic environment. Moreover, the stimuli-responsive drug carriers will enable on-demand controlled release profiles that may enhance therapeutic effectiveness and reduce systemic toxicity.
A Calculation Model of the Dimensionless Productivity Index Based on Non-Piston Leading Edge Propulsion Theory in Multiple Oilfield Development Phases
Authors: Huang Bin , Liang Qiaoyue , Fu Cheng , He Chunbai , Song Kaoping , Liu Jinzi
Published: November 2019

The dimensionless productivity index is an important indicator for measuring the oil production capacity of oilfields. The traditional calculation method of the dimensionless productivity index is not suitable for the continuous multiple development phases of oilfields. In this study, based on Darcy’s Law and the theory of non-piston leading edge propulsion, we considered the influence of capillary pressure and derived a differential equation for leading edge propulsion distance. We established a calculation model of the dimensionless productivity index that is suitable for the multiple development phases of oilfields, including water flooding, polymer flooding, and binary compound flooding. The model was applied to the W block of the JZ9-3 oilfield, and the calculation results of the model were compared with the actual statistical results. The results show that the calculation error rates of the dimensionless productivity index in three phases of oilfield development are 4.67%, 17.65%, and 18.50%, respectively, and the average error rate is 10.38% in the overall development phase. The dimensionless productivity index curve shows a trend of first rising, then falling, and finally stabilizing when the pore volume number is included. This calculation model expands the field application scope of the theoretical dimensionless productivity index, which is convenient for application in oilfields, and improves the efficiency of the comprehensive evaluation of oilfields during multiple development phases.
Experimental and Numerical Analysis of a Sustainable Farming Compartment with Evaporative Cooling System
Authors: Mousavi M. Sina , Mirfendereski Siamak , Park Jae Sung , Eun Jongwan
Published: November 2019

The United Arab Emirates (UAE) relies on groundwater as well as desalinated water which are very expensive and energy-concentrated. Despite the lack of water resources, only 54% of wastewater was recycled in the UAE in 2016. In this study, a Sustainable Farming Compartment (SFC) with an evaporative cooling system is investigated as an alternative to reusing wastewater and the optimal design is identified experimentally and numerically. First, the applicability of the SFC was examined to reduce the ambient temperature in the system. A prototype SFC was tested in the environmentally constrained laboratory and field site considering an extreme climate condition (with high temperature and humidity) in Abu Dhabi to evaluate the temperature drop and humidity change of the SFC. The experimental results showed that the temperature of the SFC significantly decreases by 7–15 °C when the initial relative humidity is 50%. For validation, an energy modeling using dynamic numerical simulations was performed that shows statistically good agreement with the experimental results. Based on the parametric studies of the system components, the optimal cooling performance of the system in terms of locations of inlet and outlet, the variation of Reynolds number was evaluated. The study suggested an optimized design for the SFC with an evaporative cooling system.
Feature Extraction Method for Hydraulic Pump Fault Signal Based on Improved Empirical Wavelet Transform
Authors: Zheng Zhi , Wang Zhijun , Zhu Yong , Tang Shengnan , Wang Baozhong
Published: November 2019

There are many interference components in Fourier amplitude spectrum of a contaminated fault signal, and thus the segment obtained based on the spectrum can lead to serious over-decomposition of empirical wavelet transform (EWT). Aiming to resolve the above problems, a novel method named improved empirical wavelet transform (IEWT) is proposed. Because the power spectrum is less sensitive to the contaminated interference and manifests the presence of fault feature information, IEWT replaces the Fourier amplitude spectrum of EWT with power spectrum in segment acquirement, and threshold processing is also introduced to eliminate the bad influence on the acquirement, and thus the best decomposition result of IEWT can be obtained based on feature energy ratio (FER). The loose slipper fault signal of hydraulic pump is tested and verified. The result demonstrates that the proposed method is superior and can extract the fault feature information accurately.
Drug Leaching Properties of Vancomycin Loaded Mesoporous Hydroxyapatite as Bone Substitutes
Authors: Lett Jayasingh Anita , Sagadevan Suresh , Prabhakar Joseph Joyce , Hamizi Nor Aliya , Badruddin Irfan Anjum , Johan Mohd Rafie , Marlinda Ab Rahman , Abdul Wahab Yasmin , Yunus Khan Tatagar Mohammad , Kamangar Sarfaraz
Published: November 2019

Infections after bone reconstructive surgery become an authentic therapeutic and economic issue when it comes to a modern health care system. In general; infected bone defects are regarded as contraindications for bone grafting. Since the pathogens develop a biofilm on the inner surface of the bone; local delivery of antibiotics becomes more important. The present work focuses on the synthesis of Mesoporous Hydroxyapatite (MPHAP) loaded with drug Vancomycin (Van) and to investigate its loading and leaching ability in phosphate buffer solution (PBS), to be used for post-operative infections. The effect of pore size on MPHAP was analyzed using different fatty acids as organic modifiers. The impacts of various fatty acids chain length on the morphology and pore size were studied. A simple impregnation technique with optimized conditions ensured a high antibiotic loading (up to 0.476 + 0.0135 mg/mL), with a complete in vitro release obtained within 50 h.
Pressure Drop and Cavitation Analysis on Sleeve Regulating Valve
Authors: Qiu Chang , Jiang Cheng-Hang , Zhang Han , Wu Jia-Yi , Jin Zhi-Jiang
Published: November 2019

The sleeve regulating valve is widely used in the pipeline systems of process industries to control fluid flow. When flowing through the sleeve regulating valve, the water is easy to reach cavitation because of the pressure drop in the partial region, which may cause serious damage to pipeline system. In this paper, the pressure drop and cavitation characteristics in the sleeve regulating valve for different pressure differences and valve core displacements are investigated using a multiphase cavitation model. The pressure drop, velocity and vapor volume distribution in the regulating valves are obtained and analyzed. The total vapor volumes are also predicted and compared. The results show that the decrease of the valve core displacement induces the enlargement of the vapor distribution region and the increase of the vapor density. The increase of the pressure difference induces a more serious cavitation. The pressure difference has a slight influence on the cavitation intensity and density in the regulating valve when the valve core displacement is 60 mm. With the decrease of the valve core displacement, the effects of the pressure difference on the cavitation intensity are enhanced. This work is of significance for the cavitation control of the sleeve regulating valves.
Contempt and Labour: An Exploration through Muslim Barbers of South Asia
Authors: Amir Safwan
Published: November 2019

This article explores historical shifts in the ways the Muslim barbers of South Asia are viewed and the intertwined ways they are conceptualised. Tracing various concepts, such as caste identity, and their multiple links to contempt, labour and Islamic ethical discourses and practices, this article demonstrates shifting meanings of these concepts and ways in which the Muslim barbers of Malabar (in southwest India) negotiate religious and social histories as well as status in everyday life. The aim was to link legal and social realms by considering how bodily comportment of barbers and pious Muslims intersect and diverge. Relying on ethnographic fieldwork among Muslim barbers of Malabar and their oral histories, it becomes apparent that status is negotiated in a fluid community where professional contempt, multiple attitudes about modernity and piety crosscut one another to inform local perceptions of themselves or others. This paper seeks to avoid the presentation of a teleology of past to present, binaries distinguishing professionals from quacks, and the pious from the scorned. The argument instead is that opposition between caste/caste-like practices and Islamic ethics is more complex than an essentialised dichotomy would convey.
Assessment of Household Solid Waste Generation and Composition by Building Type in Da Nang, Vietnam
Authors: Vetter-Gindele Jannik , Braun Andreas , Warth Gebhard , Bui Tram Thi Quynh , Bachofer Felix , Eltrop Ludger
Published: November 2019

This study assesses the quantity and composition of household solid waste (HSW) in the City of Da Nang and proposes a transparent and standardised method for its assessment through a combination of very-high-resolution (VHR) satellite imagery, field surveys, questionnaires, and solid waste measurements on the ground. This was carried out in order to identify underutilised resources and to obtain discrete planning values at city level. The procedure proved to be a suitable method for reliable data gathering. To describe HSW generation, 818 valid datasets, subdivided into five building types, and their location were used. The average HSW generation rate was 297 g per capita per day. Within a total of 19 subcategories, organic waste had a share of 62.9%. The specific generation and composition of HSW correlates positively with both the building type and the spatial location within the city. The most HSW (509 g per capita per day), by far, was generated in the ‘villa-type’ building while in the ‘basic-type’ building, this was the least (167 g per capita per day). Taking into account the number of individual buildings, the total HSW generation in Da Nang in 2015 was estimated between 109,844 and 164,455 tonnes per year, which corresponds to about one-third to one-half of the total municipal solid waste.
A Machine Learning Approach to Crater Classification from Topographic Data
Authors: Liu Qiangyi , Cheng Weiming , Yan Guangjian , Zhao Yunliang , Liu Jianzhong
Published: November 2019

Craters contain important information on geological history and have been widely used for dating absolute age and reconstructing impact history. The impact process results in a lot of ejected fragments and these fragments may form secondary craters. Studies on distinguishing primary craters from secondary craters are helpful in improving the accuracy of crater dating. However, previous studies about distinguishing primary craters from secondary craters were either conducted by manual identification or used approaches mainly concerning crater spatial distribution, which are time-consuming or have low accuracy. This paper presents a machine learning approach to distinguish primary craters from secondary craters. First, samples used for training and testing were identified and unified. The whole dataset contained 1032 primary craters and 4041 secondary craters. Then, considering the differences between primary and secondary craters, features mainly related to crater shape, depth, and density were calculated. Finally, a random forest classifier was trained and tested. This approach showed a favorable performance. The accuracy and F1-score for fivefold cross-validation were 0.939 and 0.839, respectively. The proposed machine learning approach enables an automated method of distinguishing primary craters from secondary craters, which results in better performance.
A Decentralized Processing Schema for Efficient and Robust Real-time Multi-GNSS Satellite Clock Estimation
Authors: Jiang Xinyuan , Gu Shengfeng , Li Pan , Ge Maorong , Schuh Harald
Published: November 2019

Real-time multi-GNSS precise point positioning (PPP) requires the support of high-rate satellite clock corrections. Due to the large number of ambiguity parameters, it is difficult to update clocks at high frequency in real-time for a large reference network. With the increasing number of satellites of multi-GNSS constellations and the number of stations, real-time high-rate clock estimation becomes a big challenge. In this contribution, we propose a decentralized clock estimation (DECE) strategy, in which both undifferenced (UD) and epoch-differenced (ED) mode are implemented but run separately in different computers, and their output clocks are combined in another process to generate a unique product. While redundant UD and/or ED processing lines can be run in offsite computers to improve the robustness, processing lines for different networks can also be included to improve the clock quality. The new strategy is realized based on the Position and Navigation Data Analyst (PANDA) software package and is experimentally validated with about 110 real-time stations for clock estimation by comparison of the estimated clocks and the PPP performance applying estimated clocks. The results of the real-time PPP experiment using 12 global stations show that with the greatly improved computational efficiency, 3.14 cm in horizontal and 5.51 cm in vertical can be achieved using the estimated DECE clock.
Bi-Directional Reflectance Factor Determination of the Railroad Valley Playa
Authors: Bruegge Carol J. , Coburn Craig , Elmes Arthur , Helmlinger Mark C. , Kataoka Fumie , Kuester Michele , Kuze Akihiko , Ochoa Tina , Schaaf Crystal , Shiomi Kei , Schwandner Florian M.
Published: November 2019

Vicarious calibration is the determination of an on-orbit sensor’s radiometric response using measurements over test sites such as Railroad Valley (RRV), Nevada. It has the highest accuracy when a remote sensor’s view angle is aligned with that of the surface measurements, namely at a nadir view. For view angles greater than 10°, the dominant error is the uncertainty in the off-nadir correction factor. The factor is largest in the back-scatter principal plane and can reach 20%. The Orbiting-Carbon Observatory has access to a number of datasets to determine this deviation. These include measurements from field instruments such as the Portable Apparatus for Rapid Acquisition of Bidirectional Observation of the Land and Atmosphere (PARABOLA), as well as satellite measurements from Multi-angle Imaging SpectroRadiometer (MISR) and MODerate resolution Imaging Spectroradiometer (MODIS). The correction factor derived from PARABOLA is consistent in time and space to within 2% for view angles as large as 30°. Field spectrometer data show that the correction term is spectrally invariant. For this reason, a time-invariant model of RRV surface reflectance, along with empirically derived coefficients, is sufficient to use in the calibration of off-nadir sensors, provided there has been no recent rainfall. With this off-nadir correction, calibrations can be expected to have uncertainties within 5%.
Examination of Surface Wind Asymmetry in Tropical Cyclones over the Northwest Pacific Ocean Using SMAP Observations
Authors: Sun Ziyao , Zhang Biao , Zhang Jun A. , Perrie William
Published: November 2019

Tropical cyclone (TC) surface wind asymmetry is investigated by using wind data acquired from an L-band passive microwave radiometer onboard the NASA Soil Moisture Active Passive (SMAP) satellite between 2015 and 2017 over the Northwest Pacific (NWP) Ocean. The azimuthal asymmetry degree is defined as the factor by which the maximum surface wind speed is greater than the mean wind speed at the radius of the maximum wind (RMW). We examined storm motion and environmental wind shear effects on the degree of TC surface wind asymmetry under different intensity conditions. Results show that the surface wind asymmetry degree significantly decreases with increasing TC intensity, but increases with increasing TC translation speed, for tropical storm and super typhoon strength TCs; whereas no such relationship is found for typhoon and severe typhoon strength TCs. However, the degree of surface wind asymmetry increases with increasing wind shear magnitude for all TC intensity categories. The relative strength between the storm translation speed and the wind shear magnitude has the potential to affect the location of the maximum wind speed. Moreover, the maximum degree of wind asymmetry is found when the direction of the TC motion is nearly equal to the direction of the wind shear.