bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractMethylhexahydrophthalic 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

AbstractPolyalthia 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

AbstractFrom 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

AbstractAn 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

AbstractDuring 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

AbstractThe 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

AbstractIn 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

AbstractTwo 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

AbstractSix 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

AbstractFrom 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

AbstractIn 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

AbstractUsing 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

AbstractThe 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

AbstractAdvanced 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

AbstractThe 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

AbstractChemical 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

AbstractDilated 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

AbstractWe 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

Abstract
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.