bluuebunny/crossref_metadata_2025 huggingface dataset:
Off‐label use of prescription analgesics among hospitalized children in the United States
Authors: Carmack Mary , Berde Charles , Monuteaux Michael C. , Manzi Shannon , Bourgeois Florence T.
Published: February 2020

Purpose

Analgesics are the most frequently administered medications among hospitalized children. However, current analgesic prescribing patterns have not been well defined among hospitalized children. In addition, it is unknown what proportion of prescription analgesics is approved for use in children and what proportion is used “off‐label.”

Methods

Nationally representative data from 52 tertiary care children's hospitals in the Pediatric Health Information System were queried to determine prescribing rates of analgesic medications. We analyzed hospitalizations for children <18 years occurring between 1 April 2010 and 30 June 2018. Food and Drug Administration (FDA) drug labels were reviewed for pediatric information, and prescriptions were classified as on‐ or off‐label based on age, route, and formulation.

Results

Among 4.9 million hospitalizations, 1.8 million (37.6%, 95% confidence interval [CI] = 37.6‐37.7) were associated with use of a prescription analgesic. Overall, 36.7% (95% CI = 36.7‐36.7) of hospitalizations included off‐label analgesic therapy, with 26.4% (95% CI = 26.4‐26.5) associated with two or more off‐label analgesics. Off‐label analgesic use was higher among hospitalizations in the intensive care unit (61.5%) or with an operating room procedure (92.8%). Rates of off‐label prescribing increased with age, peaking at 50.5% for adolescents. Prescription analgesics administered most frequently were morphine, fentanyl, and ketorolac, with off‐label use occurring in 24.5%, 23.1%, and 11.3% of hospitalizations, respectively.

Conclusions

Over a third of pediatric hospitalizations were associated with the administration of prescription analgesics that have not been labeled for use in children. Our findings highlight the critical need to ensure that safe and effective analgesics are developed for children and that pediatric labeling is expanded for existing analgesics to inform treatment decisions.
iTRAQ‐Based Proteomics Reveals that the Tomato ms1035 Gene Causes Male Sterility through Compromising Fat Acid Metabolism
Authors: Wang Baike , Li Ning , Wang Juan , Huang Shaoyong , Tang Yaping , Yang Shengbao , Yang Tao , Wang Qiang , Yu Qinghui , Gao Jie
Published: February 2020

So far, over 50 spontaneous male sterile mutants of tomato have been described and most of them are categorized as genetic male sterility. To date, the mechanism of tomato genetic male sterility remained unclear. In this study, differential proteomic analysis is performed between genetic male sterile line (2‐517), which carries the male sterility (ms1035) gene, and its wild‐type (VF‐11) using isobaric tags for relative and absolute quantification‐based strategy. A total of 8272 proteins are quantified in the 2–517 and VF‐11 lines at the floral bud and florescence stages. These proteins are involved in different cellular and metabolic processes, which express obvious functional tendencies toward the hydroxylation of the ω‐carbon in fatty acids, the tricarboxylic acid cycle, the glycolytic, and pentose phosphate pathways. Based on the results, a protein network explaining the mechanisms of tomato genetic male sterility is proposed, finding the compromising fat acid metabolism may cause the male sterility. These results are confirmed by parallel reaction monitoring, quantitative Real‐time PCR (qRT‐PCR), and physiological assays. Taken together, these results provide new insights into the metabolic pathway of anther abortion induced by ms1035 and offer useful clues to identify the crucial proteins involved in genetic male sterility in tomato.
Fluid Volume Management in Prosthesis Users: Augmenting Panel Release with Pin Release
Authors: McLean Jake B. , Larsen Brian G. , Weathersby Ethan J. , Carter,BS Ryan V. , Allyn Katheryn J. , Garbini Joseph L. , Sanders Joan E.
Published: February 2020

Background

Management of fluid in the limbs is a challenge faced by people with disabilities. In prosthetics, a means for transtibial prosthesis users to stabilize their residual limb fluid volume during the day may improve socket fit.

Objective

To determine if releasing the panels and locking pin of a cabled‐panel adjustable socket during socket release significantly improved limb fluid volume recovery and retention over releasing the panels alone.

Design

Repeated‐measures experiment to assess the effects on limb fluid volume retention.

Setting

Participants were tested in a laboratory setting while walking on a treadmill.

Intervention

Release of a locking pin tether during sitting as a limb volume accommodation strategy.

Main Outcome Measure

Percent limb fluid volume retention for panel and pin release compared with panel release alone at 2 minutes (short term) and 50 minutes (long term) after subsequent activity. Limb fluid volume was monitored using bioimpedance analysis.

Results

Median percent limb fluid volume retention for the panel and pin release was significantly greater than panel release alone for both anterior and posterior regions for the long term (P = .0499 and .0096, respectively) but not the short term (P = .0712 and .1580, respectively).

Conclusion

Augmenting panel release with pin release may be an effective accommodation strategy for prosthesis users with transtibial amputation to better retain limb fluid volume.
The influence of monomer chemistry on radical formation and secondary reactions during electron‐beam polymerization
Authors: Thiher Nicole L. K. , Schissel Sage M. , Jessop Julie L. P.
Published: February 2020

The vast majority of industrial electron‐beam (EB) polymerizations are initiated via radical mechanism. Because radicals drive EB polymerization, understanding their formation and secondary reactions can provide insight into polymerization kinetics and property development. Primary and initiating radicals were quantified by measuring
G(R•) and
G(M•), respectively, for various acrylate and methacrylate monomers. Monomer chemistry was shown to impact primary radical formation; however, increased primary radical concentration did not necessarily correlate to increased conversion. Despite exhibiting high values of
G(R•), methacrylates achieved very little conversion and had
G(M•) values near zero. Acrylates achieved much higher
G(M•) values and rates of polymerization compared to their methacrylate counterparts. Additionally, the efficiency of primary radicals converting to initiating radicals,
f(M•), for each acrylate monomer was shown to be a good predictor of the amount of gel fraction formed during polymerization. Understanding radical formation and secondary radical reactions can help guide the structure/processing conditions/properties relationships that are currently underdeveloped for EB reactions.
Graphdiyne: A Brilliant Hole Accumulator for Stable and Efficient Planar Perovskite Solar Cells
Authors: Zhang Jianjun , Tian Jiawu , Fan Jiajie , Yu Jiaguo , Ho Wingkei
Published: February 2020

Traditional carbon materials have demonstrated immense potential in perovskite solar cells (PSCs) owing to their superior electrical properties and environmental stability. Graphdiyne (GDY), as an emerging carbon allotrope, features uniformly distributed pores, endless design flexibility, and unique electronic character compared with traditional carbon materials. Herein, graphdiyne is introduced into the upper part of the perovskite (CH3NH3PbI3) layer by utilizing a GDY‐containing antisolvent during the one‐step synthesis of perovskite. Intriguingly, GDY plays an essential role in hole accumulation and transportation because of its higher Fermi level than perovskite. As a result, the automatic separation of photogenerated carriers inside the perovskite film is achieved. Furthermore, the Schottky barrier formed on the interface between perovskite and GDY guarantees the unidirectional hole transport from perovskite to GDY, thereby benefiting further extraction to the hole transport layer. Consequently, GDY‐modified perovskite‐based planar PSCs exhibit a boosted Jsc of 24.21 mA cm−2 and up to 19.6% power conversion efficiency owing to the increased efficient light utilization and charge extraction. The device with GDY modification exhibits less than 10% shrinkage after a month in ambience. Overall, this work demonstrates an easy method for the utilization of GDY to boost the charge extraction and environmental stability in PSCs.
Coupled effects of sustained compressive loading and freeze–thaw cycles on water penetration into concrete
Authors: Bao Jiuwen , Xue Shanbin , Zhang Peng , Dai Zhengzheng , Cui Yifei
Published: February 2020

The combined action of sustained loading and freeze–thaw cycles (FTCs) plays an important role in the durability and service life of concrete exposed to the cold coastal area. Water transport is a primary factor closely pertaining to freeze–thaw damage in concrete, and the microcracks induced by sustained loading could provide a flow path to facilitate water penetration into concrete. This paper presents the results of an experimental investigation on water penetration behavior of ordinary and air‐entrained concrete (OC and AC) subjected to sustained compressive loading and FTCs. Aiming at the combined effects of low compressive stress ratio and FTCs on water transport, a series of water absorption and permeability experiments with the stress ratio of 0, 0.3, and 0.5 after various FTCs were conducted. The relative dynamic elastic modulus and mass loss were afterwards measured to characterize the frost damage within concrete. The experimental results indicated that the sustained compressive loading and frost action have significant influences on capillary water absorption and permeability for the OC and AC specimens. Both the initial coefficient of capillary absorption and water permeability coefficient increase with the increase of FTCs, while they initially decrease and later increase with the increase of compressive stress ratio.
Secondary metabolites from the aerial parts of Buddleja macrostachya Benth
Authors: Hien Truong Thi Thu , Quang Tran Hong , Nhiem Nguyen Xuan , Phi Vu Phuong , Van Dong Le , Dung Hoang Viet , Trung Do Minh , Tram Le Huyen , Van Kiem Phan
Published: February 2020

Phytochemical investigation of the aerial parts of Buddleja macrostachyaresulted in the isolation of seven compounds, including 6‐α‐L‐(2′′‐caffeoyl)rhamnopyranosylcatalpol (1), 6‐α‐L‐(4′′‐O‐trans‐p‐coumaroyl)rhamnopyranosylcatalpol (2), apigenin (3), acacetin‐7‐O‐α‐L‐rhamnopyranosyl‐(1→6)‐β‐D‐glucopyranoside (4), mimengoside C (5), buddlejasaponin Ia(6), and buddejasaponin I (7). Their chemical structures were identified based on 1D, 2D NMR, and MS spectroscopic analysis and comparison with the reported data in literature. This is the first time to report the isolation of 6‐α‐L‐(2′′‐caffeoyl)rhamnopyranosylcatalpol and 6‐α‐L‐(4′′‐O‐trans‐p‐coumaroyl)rhamnopyranosylcatalpol from the genus Buddleja.
Synthesis and structure of two platinum(II) complexes bearing N‐heterocyclic carbene and dimethyl sulfoxide
Authors: Van Thong Pham , Thom Do Thi , Chi Nguyen Thi Thanh
Published: February 2020

The reactions of cis‐[PtCl2(DMSO)2] (1) with either 1,3‐dibenzylimidazolium chloride (Bn2‐imy·HCl) or 1,3‐dibenzylbenzimidazolium chloride (Bn2‐bimy·HCl) in the presence of a base (Ag2O/ Na2CO3/ CH3COONa) afforded two mixed monocarbene‐dimethyl sulfoxide (DMSO) complexes, namely cis‐[PtCl2(DMSO)(Bn2‐imy)] (2) and cis‐[PtCl2(DMSO)(Bn2‐bimy)] (3), with the high yields. The structures of 1÷3 were elucidated by Pt analysis, EDX, IR and 1H NMR spectra. The results show that the DMSO in 1÷3 coordinates with Pt(II) via the S atom, the deprotonated azolium salt is bound up with Pt(II) via the C atom (NCHN) and occupies cis‐position in comparison with the DMSO in 2 and 3.
Synthesis and characterization of HA/β‐TCP bioceramic powder
Authors: Vuong Bui Xuan
Published: February 2020

The main goal of this study is to elaborate and evaluate the physicochemical properties of the synthetic biphasic calcium phosphate (BCP) powder: a combined mixture of hydroxyapatite (HA): Ca10(PO4)6(OH)2 and beta‐tricalcium phosphate (β‐TCP): Ca3(PO4)2. The BCP mixture has two advantages: high bioactivity (HA) and rapid biodegradation (β‐TCP). The obtained powders of BCP were prepared by precipitate method. XRD analysisconfirmed that the synthetic materials were comprised of both HA and β‐TCP crystalline phases. SEM images showed that the small particles of HA attached on bigger particles of β‐TCP in the structure morphology of BCP. The in‐vitro experiment was carried out in static condition by soaking of a series of 50 mg BCP powders in 100 ml simulated body fluid (SBF) solution at different periods of soaking time. The microstructure and chemical bonds after soaking were studied by XRD and SEM methods. The obtained results confirmed the bioactivity of synthetic BCP material by the formation of a new apatite layer on its surface.
Optimization of the synthesis of amidoamine‐based surfactant
Authors: Hung Bui Duy , Binh Pham Thi Nam , Ha Vu Thi Thu , Thang Duong Quang
Published: February 2020

In this study, lauryl amidoamine was synthesized by reaction of methyl laurate with ethylendiamine. The reaction conditions were optimized using Modde 5.0 software. According to the results, the optimum molar ratio of ethylenediamine to methyl laurate, reaction temperature and reaction time were 2,135°C and 3.8 h, respectively. The actual experimental yield was 96.69 % under the optimum condition, which compared well with the maximum predicted value of 97.22 %. The synthesis of coconut amidoamine from coconut methyl esters had yield 95.73 % under the same conditions. Size of water in diesel oil 0.05S emulsion using coconut amidoamine as an emulsifier of 147 nm was obtained.
Chemical constituents of Boehmeria holosericea Blume (Urticaceae)
Authors: Ai Doan Thi Thuy , Van Trinh Thi Thanh , Huong Doan Thi Mai , Litaudon Marc , Tram Le Huyen , Van Cuong Pham
Published: February 2020

From fruits of Boehmeriaholosericea, six compounds 1‐6 were isolated by various chromatographic methods. Their structures were elucidated by extensive spectroscopic analysis, including ESI‐MS,1D NMR, 2D NMR spectra, they are identified as ruspolinone (1), benzyl β‐D‐glucoside (2), 3,4‐dimethoxyacetophenone (3), adenine (4), adenosine (5) and uridine (6). All the compounds were obtained for the first time from Boehmeria genus.
Study of the adsorption of 2,4‐dichlorophenoxyacetic acid from the aqueous solution onto carbon nanotubes
Authors: Hue Hoang Kim , Anh Lam Vinh , Thiep To Van
Published: February 2020

The adsorption of 2,4‐dichlorophenoxyacetic acid (2,4‐D) from the aqueous solution on carbon nanotubes (CNTs‐TC) was investigated in the concentration range from 52.248 to 205.672 mg L‐1. The results indicated that carbon nanotubes exhibited the highest 2,4‐D uptake capacity of 84.034 mg g‐1 at 283 K. Freundlich isotherm model showed a better fit with obtained adsorption data than Langmuir and Temkin isothermal models. The adsorption performance of 2,4‐D onto CNTs‐TC fitted the pseudo‐second‐order model and apparent equilibrium was reached within 50 minutes. The overall rate process appeared to be influenced by both external mass transfer and intra‐particle diffusion, but mainly governed by intra‐particle diffusion. The activation energy of adsorption was determined to be 6.4514 kcal.mol‐1. The calculated thermodynamic parameters showed adsorption of 2,4‐D onto CNTs‐TC was exothermic and spontaneous.
Secondary metabolites from the marine‐derived fungus Paraconiothyrium sp. VK‐13
Authors: Quang Tran Hong , Nhiem Nguyen Xuan , Tai Bui Huu , Yen Pham Hai , Dung Duong Thi , Ngan Nguyen Thi Thanh , Le Tuan Anh Hoang , Van Minh Chau , Van Kiem Phan
Published: February 2020

Chemical investigation of a fermentation culture of the marine endophytic fungus Paraconiothyrium sp. VK‐13 resulted in the isolation of five compounds, including a new phenolic compound, 1‐(2,5‐dihydroxyphenyl)‐1‐oxobutan‐3‐yl acetate (1) and four known metabolites, 1‐(2,5‐dihydroxyphenyl)‐2‐buten‐1‐one (2), 3,7‐dimethyl‐1,8‐dihydroxy‐6‐methoxyisochroman (3), modiolides A (4) and B (5). Their chemical structures were identified based on 1D, 2D NMR, and MS spectroscopic analysis and comparison with the data reported previously in the literature. All the isolated compounds were reported for the first time from the genus Paraconiothyrium.
Effects of the ease of separation index (ESI) and feed composition on the selection of distillation configuration
Authors: Dung Nguyen Trung , Thai Vu Hong
Published: February 2020

Distillation process consumes the energy in chemical industry. To reduce the consumption, divided wall column (DWC) has been known to be suitable for multicomponent separation and be able to save both energy and capital cost compared to conventional distillation column. However, due to more operation parameters than traditional distillation, design method, control and operation of the DWC are more complicated. In this paper, firstly, a conceptual design of a DWC system is proposed. The method based on shortcut methods of Fenske, Underwood, Gilliland and Kirbride, which can rapidly determine structural and operational parameters of the DWC. Secondly, to compare the energy of use between DWC and conventional column, three ternary mixtures are studied with different values of the ease of separation index (ESI) and feed compositions. The results show that the energy consumption of the DWC system is more efficient than the traditional distillation column but it is not always the best arrangement in the multicomponent separation process. The selecting depended on both ESI value and feed composition of a mixture. Based on the comparison, a distillation boundary of ternary diagram is drawn to make a proper choice for the best configuration.
Introduction of Co3O4 to MnO2/activated carbon for high performance electrode materials toward electrochemical capacitor application
Authors: Van Khu Le , Thuy Luong Thi Thu , Chi Ngo Kim
Published: February 2020

Cobalt oxide has been chosen for incorporating with MnO2/activated carbon (AC) material. The samples were characterized by means of X‐ray diffraction (XRD), transmission electron microscopy (TEM), and isothermal adsorption – desorption of N2 at 77.35 K (BET). The results showed that the CoMn/AC samples are amorphous and covered by homogeneous, dispersed oxide particles. The BET surface area and pore volume are up to 2826 m2/g and 1.7441 cm3/g, respectively. The electrochemical characterization was performed using cyclic voltammetry and galvanostatic charge/discharge test in 6.0 M KOH electrolyte. CoMn/AC electrode incorporated with 1.5 % Co3O4 exhibited higher specific capacitance than other percentages, reached 358 F/g at a scan rate of 5 mV/s and 1159 F/g at specific current density of 0.5 A/g. The enhanced capacitance is attributed to the combination of two charge storage mechanism: electrical double layer capacitor and pseudo‐capacitor.
Studying on the adsorption of chromium(VI) on polyaniline modified with activated tea residue
Authors: Ha Tran Thi , Quan Vo An , Hop Nguyen Quang , Thuy Tran Minh , Ngoc Nguyen Thi , Que Le Xuan
Published: February 2020

In this study, the Cr(VI) adsorption on modified polyaniline materials (MPM) was investigated. The MPM was produced by polymerization of aniline in 1 M H2SO4solution with the presence of activated tea residue. The tea residue samples have been activated by 0.5 KOH or H3PO4 (85 %) solution. The absorption of the Cr(VI) ions on the MPM was studied in this paperby means of infrared (IR) spectroscopy, scanning electron microscopy (SEM) and atomic adsorption spectrometer (AAS) in order to get a preliminary assessment of Cr(VI) adsorption efficiency. The experiment results shown that the applied MPM has good Cr(VI) adsorption capacity, the appropriate pH range for the adsorption process is 5.5÷7.5. The MPM after synthesis process is stable and easy to store and to apply for treatment of heavy metals in waste water.
Cyclopeptides from marine actinomycete Streptomyces sp. G261
Authors: Danh Cao Duc , Dao Phi Thi , Huong Doan Thi Mai , Thach Tran Dang , Anh Nguyen Mai , Minh Le Thi Hong , Anh Tran Tuan , Van Cuong Pham
Published: February 2020

According to the results from our screening program, the EtOAc extract of a Streptomyces sp. (strain G261) collected in Cu Lao Cham – Quang Nam showed antimicrobial activity against Enterococcus faecalis, Bacillus cereus, Pseudomonas aeruginosa and Candida albicans. Seven secondary metabolites Cyclo‐(Leu‐Pro) (1), Cyclo‐(Pro‐Gly) (2), Cyclo‐(Pro‐Ala) (3), Cyclo‐(Leu‐Tyr) (4), Cyclo‐(Pro‐Tyr) (5), and Cyclo‐trans‐4‐OH‐(Pro‐Phe) (6) were isolated from the cultures broth of Streptomyces (strain G261). Their structures were determined by MS and 2D NMR spectroscopic analysis, as well as by comparison with reported data in literature.
Release of chondroitin sulfate form the chicken keel cartilage by protamex hydrolysis
Authors: Le Vien Nguyen Thi , Van Thien Phu Luu , Phuong Nguyen Thi Thanh , Hanh Tran Thi Hong , Dao Dong Thi Anh
Published: February 2020

Glycosaminoglycan (GAGs) is one kind of mucopolysaccharide, the natural biocompound can be extracted from cartilage of sharks, pigs, cows, chickens, etc. It contains chondroitin‐4‐sulphate, chondroitin‐6‐sulphate, heparansulphate, dermatansulphate, keratan sulphate, and hyaluronic acid, links with protein chains and thus are called proteoglycan. Chondroitin‐4‐sulfate (CS), the highest proportion in GAGs of poultry cartilage, is using as a supplement of functional food for preventing and supporting treatment of arthritis and eye tissues. Therefore, it is necessary to release the CS from chicken cartilage that is abundant by‐products of poultry processing. In this study, the hydrolysis conditions by protamex of chicken cartilage were investigated. The variables such as: pH, protamex content, incubation temperature, and hydrolysis time were optimized. The results of the analysis of variance (ANOVA) shown that the variables actively affected CS content. The optimal conditions of hydrolysis were pH of 5.81, ratio of enzyme per substances of 0.85 % w/wprotein, temperature of 54.63°C and hydrolysis time of 204 minutes, GAGs content reached 25.28 %. Analysis by HPLC revealed CS content 17.69 % dry matter of raw material
Preliminary study on the chemical constituents of the leaves of Macaranga balansae Gagnep.
Authors: Thang Pham Toan , Dung Nguyen Anh , Giap Tran Huu , Oanh Vu Thi Kim , Hang Nguyen Thi Minh , Huong Tran Thu , Thanh Le Nguyen , Huong Doan Thi Mai , Van Cuong Pham
Published: February 2020

Macaranga balansae Gagnep., locally known as “Ba soi lông tơ” or “Mã rạng balansa”, is a tree endemic to Vietnam, found at central provinces. Its ethyl acetate extract was showed cytotoxic activity against TG1 cancer cell line. In this paper, we report the preliminary study on the chemical constituents of the leaves of M. balansae. Seven known compounds including lupeol (1), phytol (2), isophytol (3), sitostenone (4), sitoindoside I (5), gallic acid (6) and methyl gallate (7) were isolated from the ethyl acetate extract of the leaves of M. balansae. Their chemical structures were identified by NMR, MS spectra and in comparison with the reported literatures.
Effects of reaction parameters on photodegradation of caffeine over hierarchical flower‐like ZnO nanostructure
Authors: Mai Le Thi , Hoai Luu Thi , Tuan Vu Anh
Published: February 2020

In this paper, the flower‐like ZnO nanostructure was prepared by hydrothermal method. As‐synthesized sample was characterized by XRD, SEM, and N2 adsorption/desorption isotherm. The photocatalytic performance of ZnO was evaluated by degradation of caffeine under UV irradiation. The effects of various reaction parameters such as catalyst dosage, pH of solution, and caffeine concentration on degradation of caffeine were investigated. The results showed that 3 g/L of ZnO could completely degrade 5 mg/L of caffeine under neutral or desired alkaline medium within 120 min. In addition, the impacts of inorganic ions (cation and anion) on degradation process were also studied. Flower‐like ZnO also exhibited the good degradation efficiency of some popular organic dyes in wastewater such as methyl orange, congo red, tartrazine, nile blue and janus green B. The reaction kinetic of photodegradation of caffeine was studied by first kinetic model.
Synthesis and biological activities of organoaluminum steroids
Authors: Dzhemilev Usein M. , D'Yakonov Vladimir A. , Tuktarova Regina A. , Gloriozova Tatyana A. , Dzhemileva Lilya U. , Terent'Ev Alexander O. , Dembitsky Valery M.
Published: February 2020

This review presents the synthesis of organoaluminum steroids (OAS) using catalytic cycloalumination of vinylcholestane and/or allylcholestane derivatives with Et3Al catalyzed by Cp2ZrCl2 which gives aluminacyclopentanes in a yield of about 90 %. Biological activity of synthesized organoaluminum steroids was determined with an aid of PASS program. Organoaluminum steroids showed antiprotozoal, antihypercholesterolemic, and antieczematic activity with a certainty from 78 to 92 %.
Flavonoids and other compounds from Vitex limonifolia
Authors: Thoa Nguyen Thi Kim , Ban Ninh Khac , Trang Do Thi , Linh Tran My , Giang Vu Huong , Nhiem Nguyen Xuan , Van Kiem Phan
Published: February 2020

Using combined chromatographic methods, three flavonoids, 5,4′‐dihydroxy‐3,7‐dimethoxyflavone (1), vitecetin (2), 5,4′‐dihydroxy‐7,3′‐dimethoxyflavone (3), a lignan, verrucosin (4), and a γ‐pyrone glycoside, maltol O‐β‐D‐glucopyranoside (5) were isolated from the methanol extract of the leaves of Vitex limonifolia. Their structures were identified on the basis of spectroscopic evidence and comparison with those reported in the literature. Compounds 1 and 3‐5 were reported from Vitex genus for the first time.
Study on the curing reaction of epoxidized rubber seed oil for eco‐friendly composite application
Authors: Thuy Nguyen Thi , Liem Nguyen Thanh , Duc Vu Minh
Published: February 2020

Methylhexahydrophthalic anhydride (MHHPA) was used as a hot curing agent for epoxidizing rubber seed oil (ERSO and ERSOe) with the presence of methylimidazole (NMI) catalyst. The effect of MHHPA, NMI, glycerol content and temperature on hardening process was studied through the peak exothermic temperature of the curing reaction. Moreover, differential scanning calorimetry analysis (DSC) was used to calculate a curing degree versus reaction time. The obtained optimal conditions (the molar ratio of epoxide group to MHHPA: 1.05/1; the content of NMI and glycerol: 3 wt% and 1.5 wt% of total weight of the resin and MHHPA; curing temperature of 140 and 160°C for ERSOe and ERSO matrix, respectively) were used for manufacturing the eco‐friendly composites. The results showed that this study could open up the new pathway of replacing a petroleum–derived hazardous unsaturated polyester resin with the eco‐friendly epoxidized rubber seed oil in manufacturing the composite.
Megastigmanes and flavones from Polyalthia thorelii collected in Nam Dong, Thua Thien Hue
Authors: Cuong Le Canh Viet , Lien Le Thi , Nhi Nguyen Phuc Khanh , Ha Tran Phuong , Tuan Do Thanh , Hoa Khong Thi , Oanh Nguyen Thi Kim , Anh Le Tuan , Anh Hoang Le Tuan
Published: February 2020

Polyalthia thorelii (Pierre) Fin. ex Gagnep. has been used as a traditional medicine for the treatment of stomachache. The present study describes the isolation and structural elucidation of five compounds from the methanol extract of the aerial parts of P. thorelii. Their structures were identified as: grasshoper ketone (1), ampelopsisionoside (2), (6S,9S)‐roseoside (3), quercetin‐3‐rutinoside (4), and quercetin‐3‐O‐β‐D‐glucopyranoside (5) by spectroscopic analyses and comparison with the data reported in the literature. To the best of our knowledge, compounds 1 and 3 were isolated from genus Polyalthia and remain compounds were isolated from P. thorelii for the first time.
Phenolic and lignan compounds from Stixis suaveolens
Authors: Anh Ngo Quoc , Yen Tran Thi , Hang Nguyen Thuy , Anh Duong Hong , Viet Pham Hung , Hoang Nguyen Huy , Van Doan Vu , Van Kiem Phan
Published: February 2020

From the leaves of Stixis suaveolens (Roxb.), ten compounds were isolated and elucidated chemical structures by using combined methods. Their structures were identified as (±)‐5‐methoxylariciresinol(1), (7S, 8R, 8R՛)‐5,5՛‐dimethoxylariciresinol (2), (+)‐dehydrodiconiferyl alcohol (3), (+)‐dehydrodiconiferyl alcohol‐4‐O‐β‐D‐glucoside (4), (7R,8R)‐threo‐guaiacylglycerol‐8‐O‐4՛‐sinapyl ether 7‐O‐β‐D‐glucopyranoside (5), 3‐hydroxy‐2{4‐[(1E)‐3‐hydroxyprop‐1‐en‐1‐yl]‐2 methoxyphenoxy}propyl β‐D‐glucopyranoside (6), coniferin (7), syringin (8), Z‐coniferin (9), and dihydrosyringin (10) by comparison of their NMR, MS data with those of published literature.
Quantification of lutein from Marigold flower (Tagetes erecta L.) petals by liquid chromatography – tandem mass spectrometry method
Authors: Nguyet Nguyen Thi Minh , Ha Vu Thi Thu , Binh Nguyen Thanh , Dang Nguyen Minh , Bay Nguyen Thi
Published: February 2020

An attempt was made to develop a liquid chromatography–tandem mass spectrometric (LC‐MS/MS) method which is rapid, sensitive and validated for the qualitative and quantitative analysis of lutein from the Marigold petals. Linearity, specificity, sensitivity, precision, accuracy, and analyte stability were evaluated. Two multiple reaction‐monitoring (MRM) transitions for each analyte were observed: 568.01 > 104.53 and 568.01 > 118.60 for lutein. The retention time of the substance was 3.22 minutes. In this study, an excellent linearity was obtained with correlation coefficient, R, higher than 0.999. The limit of detection (LOD) and limit of quantification (LOQ) were 0.0078 and 0.0240 ng/mL, respectively. This paper is one of the few studies on these subjects and represents the first application of advanced LC‐MS/MS technology.
Viscosine: A new microbial flavonoid from marine‐derived, Streptomyces sp. RMS518F
Authors: Selim Rehab M. , Shaaban Mohamed , Hamdy Abdelhamid Aly , Abou Zeid Azza A. , Ata Athar
Published: February 2020

During the search for bioactive metabolites from marine sediment derived‐actinomycetes, a new microbial flavonoid 6‐hydroxykaempferol‐3,6‐dimethyl ether, viscosine (1) was isolated from the marine sediment derived‐actinobacteria RMS518F strain. Structure of the compound (1) was determined by 1D‐ and 2D‐NMR (1 and 2‐Dimensional Nuclear Magnetic Resonance), mass spectrometry and comparison of these data with literature. Taxonomically, the strain was characterized as Streptomyces carpaticus on the bases of 16S rRNA gene sequence. Biologically, compound (1) exhibited moderate antimicrobial activity against the Gram‐positive bacteria, Staphylococcus aureus ATCC6538‐P; Bacillus cereus ATCC11778 and Saccharomyces cerevisiae ATCC9080 yeast. Compound (1)was also significantly active against the human colon carcinoma cell line (HCT‐116) and the hepatocellular carcinoma cell line (Hep G2) with IC50 values of 73.4 and 62.8 μg/mL, respectively compared with the antineoplastic drug (Doxorubicin) (37.6 and 21.6 μg/mL), while no activity has been noticed against the human breast cancer cell line (MCF‐7).
Simultaneous determination of arsenic and mercury in water at trace levels by differential pulse anodic stripping voltammetry using a simple gold disk electrode
Authors: Dang Vu Hai , Yen Pham Thi Hai , Phong Pham Hong , Duy Pham Khac , Ha Vu Thi Thu
Published: February 2020

The conventional gold disk electrode was applied for simultaneous determination of As(III) and Hg(II) in the media of KCl 0.1 M + HCl 0.1 M. The optimal accumulation time, the repeatability of the electrode and calibration curves were determined by DPASV technique. The electrode works stably with RSD 4.01 % and 2.98 % for As(III) and Hg(II) respectively and showed a wide linearity in the concentration range of 1‐60 μg/L of both heavy metal ions. The obtained LODs were 0.096 ppb for Hg(II) and 0. 307 ppb for As(III) with 420 s of accumulation time in case of simultaneous analysis.
Protein tyrosine phosphatase 1B inhibitory activities of compounds isolated from Polygonum cuspidatum
Authors: Luyen Le Hong , Quan Pham Minh , Hung Nguyen Phi
Published: February 2020

In the search for new natural PTP1B inhibitory compounds from medicinal plants, two 9,10‐anthraquinones were isolated and structurally identified as physcion (1) and emodin (2) from the alcoholic extract of the root of Polygonum cuspidatum. Chemical structures of these isolates were identified by interpretation of spectroscopic data (1H, 13C NMR and MS) as well as comparing with reported literatures. Compounds 1–2 possessed inhibitory activity on PTP1B enzyme with IC50 values of 26.1 ± 0.7 and 13.3 ± 0.4 μM, respectively. Ursolic acid was used as positive control showing an IC50 value of 3.5 ± 0.2 μM in this assay. This result reveals that these 9,10‐anthraquinones might be considered as new natural compounds for development of antidiabetic agents.
Theoretical study on the adsorption of benzylpenicillin molecule onto vermiculite surface
Authors: Tri Nguyen Ngoc , Trung Nguyen Tien
Published: February 2020

Two stable configurationss (P1 and P2) formed by interaction of benzylpenicillin molecule with vermiculite surface are obtained on the potential energy surface. The adsorption energies of P1 and P2 complexes are significantly negative at ca. ‐58 and ‐47 kcal.mol‐1, respectively. The adhesion of benzylpenicillin on vermiculite surface is favorable via > C=O···Mg interactions and O‐H···O hydrogen bonds between ‐COOH group of the molecule with Mg2+ and O2‐ ions on the surface. Notably, the benzylpenicilline molecule is adsorbed favorably onto vermiculite surface at Mg2+ site binding to O2‐ ions in ‐SiO3 group as compared to that in ‐AlO3 group. It is found that stability of P1 and P2 is contributed by both >C=O···Mg and O‐H···O interactions. Remarkably, the electron density transfer from the surface to the molecule is slightly stronger than that from molecule to surface. Calculated results indicate that the adsorption of benzylpenicillin on vermiculite surface is regarded as a strong chemisorption process.
Roles of H2O to hydrogen bonds, structure and strength of complexes of CH3CHS and H2O
Authors: Cuc Nguyen Thi Thanh , Dai Ho Quoc , Nhung Nguyen Thi Ai , Hung Nguyen Phi , Trung Nguyen Tien
Published: February 2020

Six stable geometrical structures of the interaction between CH3CHS and H2O were observed on potential energy surface at the MP2/ aug‐cc‐pVDZ level of theory. Interaction energies corrected by both ZPE and BSSE for all the complexes at the MP2/aug‐cc‐pVTZ//MP2/aug‐cc‐pVDZ high level of theory range from ‐12.0 to ‐61.4 kJ.mol‐1. When adding water molecule to CH3CHS, stability of interacting system and cooperative capacity of complexes are increased. In general, the strength of complexes is contributed by O–H∙∙∙O/S and C–H∙∙∙O hydrogen bonds, and their stability decreases in the order of O–H∙∙∙O > O–H∙∙∙S > C–H∙∙∙O. Interestingly, a larger contraction and a stronger increase of stretching frequency of Csp2–H bond as compared to Csp3–H bond are observed following complexation although the Csp2–H∙∙∙O H‐bonds are stronger than the Csp3–H∙∙∙O counterparts. This detective result is mainly determined by a decrease in the electron density of the σ*(C − H) orbital.
Flavonoids from the stem barks of Swintonia griffithii Kurz (Anacadiaceae) and their tyrosinase inhibitory activities
Authors: Phu Dang Hoang , Tho Le Huu , Truong Do Van Nhat , Hai Nguyen Xuan , Mai Nguyen Thi Thanh , Nhan Nguyen Trung
Published: February 2020

From the stem barks of Swintonia griffithii, six flavonoids: (–)‐naringenin (1), (–)‐eriodictyol (2), (+)‐taxifolin (3), (–)‐butin (4), (–)‐fustin (5), and 3′,4′,7‐trihydroxyflavone (6) were isolated. Their structures were determined based on the spectroscopic interpretation and compared with those of reported data. In the tyrosinase inhibitory activity test, (+)‐taxifolin (3) and 3′,4′,7‐trihydroxyflavone (6) exhibited potent effect with the IC50 values of 20.9 and 56.7 μM, respectively.
Using calculations of the electronically excited states for investigation of fluorescent sensors: A review
Authors: Van Bay Mai , Hien Nguyen Khoa , Quy Phan Tu , Nam Pham Cam , Van Dang Ung , Quang Duong Tuan
Published: February 2020

In this review, the calculations of the electronically excited states were introduced as the recent outstanding applications of quantum chemical calculations for developing the fluorescent sensors. The applications of the ground state and excited state optimized geometry‐based calculations for the absorption and fluorescence properties have been introduced along with their advantages and limitations.
Chemical constituents from the soft coral Sinularia digitata
Authors: Huong Nguyen Thi , Ngoc Ninh Thi , Hanh Tran Thi Hong , Quang Tran Hong , Cuong Nguyen Xuan , Nam Nguyen Hoai , Van Minh Chau
Published: February 2020

Using various chromatographic separations, six known compounds namely (1R*,2E,4R*,7E,10S*,11S*,12R*)‐10,18‐diacetoxy‐dolabella‐2,7‐dien‐6‐one (1), emblide (2), sarcophine (3), (3R)‐4‐[(2R,4S)‐4‐acetoxy‐2‐hydoxy‐2,6,6‐trimethylcyclohexylidene‐3‐en‐2‐one (4), 3β‐hydroxypregna‐5,16‐dien‐20‐one (5), and 3β‐hydroxyandrost‐5‐en‐17‐one (6) were isolated from a methanol extract of the Vietnamese soft coral Sinularia digitata. The structural elucidation was confirmed by extensive analysis of the 1D and 2D NMR spectroscopic data as well as comparison of them with the reported values.
Acute and subchronic oral toxicity assessment of calcium hydroxyapatite‐alginate in animals
Authors: Hanh Nguyen Thi , Bich Phan Thi Ngoc , Thao Hoang Thi Thanh
Published: February 2020

The purpose of this study is assessment of acute and subchronic toxicity of HA‐Alg prepared to be used as calcium supplement. Acute toxicity studies wereconducted in Swiss mice, the results showed that preparedHA‐Alg is non‐acute toxic (LD50 greater than 5000 mg/kg). Subchronic toxicity was evaluated in rabbits of both sexes by repeated oral administration using a gavage for 28 consecutivedays. The estimation of general conditions and behaviors including body weight, fur, food consumption and water intake, bowel movement, morbidity, mortality have been carried out. Data of blood hematological, serum biochemical parameters and pathomorphological exploration revealed no statistically significant differences amongrabbitstreated with HA‐Alg(dosesof 60 mg/kgb.w./day and 180 mg/kgb.w./day) and the control group.
Kinetic modeling of degradation for alizarin yellow R by the activated persulfate by Fe0 (ZVI) under UV light
Authors: Binh Nguyen Thanh , Khue Do Ngoc , Van Chung Tran , Hoa Nguyen Thanh , Quang Doan Song
Published: February 2020

Advanced oxidation processes (AOPs) based on persulfate activated by zero valent iron (ZVI) were used to remove azo dyes in water. Activated persulfate generate to strong free radicals SO4‐• (E0 = 2.6 V) and HO• (E0 = 2.8 V). The UV light was used to improve the efficiency of this activated persulfate. This study focused on determining a kinetic model, reaction rate constants and concentrations of SO4‐• and HO• in processes of persulfate activated by ZVI with or without UV light to degrade alizarin yellow R (AY). By using both experimental resultsand data analysis using the developed pseudo‐first‐order kinetic model, the reaction rate constants for the reaction of AY at pH 4.5 were determined to be 6.98 × 10‐4 s‐1 and 1.38 × 10‐3 s‐1 in condition without UV light and with UV light, respectively. The concentrations of SO4‐•, HO• at 30 minutes of the process were 9.41 × 10‐4 mM, 4.12 × 10‐7 mM without UV and 8.58 × 10‐4 mM, 8.10 × 10‐7 mM with UV, respectively.
Evaluation of DNA polymerase inhibitory activities of depsidones, depsides and diaryl ethers from the Vietnamese lichen Rimelia clavulifera
Authors: Duy Le Hoang , Takenaka Yukiko , Mizushina Yoshiyuki , Tanahashi Takao
Published: February 2020

The Vietnamese lichen Rimelia clavulifera of the family Parmeliaceae was chemically investigated to isolate fourteen known compounds. The inhibitory activities of the isolated lichen substances against mammalian DNA polymerases and human cancer cell growth were assessed. β‐Collatolic acid exhibited inhibitory activities against mammalian DNA polymerases α, β, and κ with IC50 values 9.8 ± 0.6, 8.8 ± 0.5, 19.5 ± 1.1 μM, respectively and showed cytotoxic effects against the HeLa cell line with an IC50 value of 22.2 ± 2.4 μM.
Chemical constituents of Ficus consociata Blume (Moraceae)
Authors: Dat Huynh Ngoc , Tien Le Hoang Thuy , Dung Nguyen Thi My , Van Kieu Nguyen , Huy Duong Thuc , Tuyet Nguyen Thi Anh , Phung Nguyen Kim Phi
Published: February 2020

Chemical investigation of the ethyl acetate extract of Ficus consociata leaves, collected at Bien Hoa city, Dong Nai province, led to the isolation and structural elucidation of seven compounds, including luteolin (1), cirsiliol (2), isoquercetin (3), quercetin 3‐O‐α‐L‐arabinopyranoside (4), nikotoflorin (5), hesperidin (6) and (2E,4E,1'S,2'R,4'S,6'R)‐dihydrophaseic acid (7). Their chemical structures were elucidated by a combination of electronic circular dichroism (ECD) experiments and spectroscopic data (HR‐MS, 1D, 2D NMR) analysis, and comparison with those reported in the literature. Although, these compounds were already known in other species, but this is the first report on chemical constituents of F. consociata.
A study of the corrections to factorization in $$ {\overline{B}}^0\to {D}^{\ast +}\omega {\pi}^{-} $$
Authors: Eidelman S.I. , Kardapoltsev L.V. , Matvienko D.V.
Published: February 2020

Abstract

A factorization hypothesis is tested by examining a form factor of the ωπ production in hadronic B0→ D∗±ωπ∓ decays. The form factor is compared to that from available τ -lepton as well as e+e− data using the conserved vector current hypothesis. The difference of normalizations of form factor shapes from B and τ (e+e−) data indicates the important role of the large Nc limit in QCD. Moreover, the growth of the difference between the form factors with the ωπ invariant mass is related to the perturbative QCD corrections of factorization. The current precision of B data does not allow one to find any evidence of corrections to factorization. A promising study could be performed with the Belle II and LHCb data sets.
Kerr-Schild double copy and complex worldlines
Authors: Bah Ibrahima , Dempsey Ross , Weck Peter
Published: February 2020

Abstract

We use the classical double copy to identify a necessary condition for Maxwell theory sources to constitute single copies of Kerr-Schild solutions to Einstein’s equations. In the case of four-dimensional Kerr-Schild spacetimes on Minkowski backgrounds, we extend this condition to a parameterization of the corresponding single copies. These are given by Líenard-Wiechert fields of charges on complex worldlines. This unifies the known instances of the Kerr-Schild double copy black holes on flat four-dimensional backgrounds into a single framework. Furthermore, we use the more generic condition identified to show why the black ring in five dimensions does not admit Kerr-Schild coordinates.
Dilated cardiomyopathies and non-compaction cardiomyopathy
Authors: Hänselmann A. , Veltmann C. , Bauersachs J. , Berliner D.
Published: February 2020

Dilated cardiomyopathy (DCM) is the most common form of cardiomyopathy and one of the most common causes of heart failure. It is characterized by left or biventricular dilation and a reduced systolic function. The causes are manifold and range from myocarditis to alcohol and other toxins, to rheumatological, endocrinological, and metabolic diseases. Peripartum cardiomyopathy is a special form that occurs at the end of or shortly after pregnancy. Genetic mutations can be detected in approximately 30–50% of DCM patients. Owing to the growing possibilities of genetic diagnostics, increasingly more triggering variants and hereditary mechanisms emerge. This is particularly important with regard to risk stratification for patients with variants with an increased risk of arrhythmias. Patient prognosis is determined by the occurrence of heart failure and arrhythmias. In addition to the treatment of the underlying disease or the elimination of triggering harmful toxins, therapy consists in guideline-directed heart failure treatment including drug and device therapy.
ROS-induced oxidative damage in lymphocytes ex vivo/in vitro from healthy individuals and MGUS patients: protection by myricetin bulk and nanoforms
Authors: Akhtar Shabana , Najafzadeh Mojgan , Isreb Mohammad , Newton Lisa , Gopalan Rajendran C. , Anderson Diana
Published: February 2020

We investigated the protective role of myricetin bulk and nanoforms, against reactive oxygen species (ROS)-induced oxidative stress caused by hydrogen peroxide and tertiary-butyl hydro peroxide in lymphocytes in vitro from healthy individuals and those from pre-cancerous patients suffering with monoclonal gammopathy of undetermined significance (MGUS). The change in intracellular reactive oxygen species was measured once cells were treated with myricetin bulk forms and nanoforms with and without either hydrogen peroxide or tertiary-butyl hydro peroxide co-supplementation. The direct and indirect antioxidant activity of myricetin was spectrofluometrically measured using the fluorescent dye 2′,7′-dichlorofluorescin diacetate and using the Comet assay, respectively. Hydrogen peroxide (50 µM) and tertiary-butyl hydro peroxide (300 µM) induced a higher level of reactive oxygen species-related DNA damage and strand breaks. Addition of myricetin nanoform (20 µM) and bulk (10 µM) form could, however, significantly prevent hydrogen peroxide- and tertiary-butyl hydro peroxide-induced oxidative imbalances and the nanoform was more effective. Glutathione levels were also quantified using a non-fluorescent dye. Results suggest that myricetin treatment had no significant effect on the cellular antioxidant enzyme, glutathione. The current study also investigates the effect of myricetin on the induction of double-strand breaks by staining the gamma-H2AX foci immunocytochemically. It was observed that myricetin does not induce double-strand breaks at basal levels rather demonstrated a protective effect.
Enhanced recovery protocol in laparoscopic liver surgery
Authors: Savikko Johanna , Vikatmaa Leena , Hiltunen Anna-Maria , Mallat Noora , Tukiainen Eija , Salonen Sari-Mari , Nordin Arno
Published: February 2020

Introduction

Enhanced recovery protocols (ERP) accelerate recovery and shorten postoperative hospital stay. This increased knowledge of ERPs has also gradually implemented into liver surgery. However, in laparoscopic liver surgery (LLS), the experience of optimized perioperative care protocols is still limited.

Methods

We prospectively studied the implementation of multimodal ERP principles to LLS in the first 100 consecutive patients. Opioid-sparing multimodal pain management was applied together with early mobilization already in the postoperative care unit (PACU). Drains and catheters were avoided and per oral intake was initiated promptly. Primary pain control was achieved with iv NSAIDS, low-dose opioid and corticosteroids. Combination of per oral ibuprofen and long-acting tramadol was routinely administered shortly after operation. The multiprofessional adherence to the protocol was also evaluated.

Results

Investigated LLS was performed during Aug 2016–Apr 2019. Operations were done due to malignancy in 83 (83%) of cases, mostly for colorectal liver metastases (n = 52, 52%). Forty-eight (48%) of the operated patients were female. Median age was 65 years (range 17–91). The American Society of Anaesthesiologists Physical Status (ASA) classification median was three. Median postoperative hospital stay was 2 days (range 1–8 days). More than seventy percent of patients were discharged by the second postoperative day and nearly ninety percent by the third postoperative day. Complications after surgery were few. The new ERP elements were adopted in most of the cases.

Conclusions

ERP was introduced safely and effectively after LLS. The adherence to the ERP was good. Routine discharge 1–2 days after LLS is realistic and achievable.