Authors:Yun Zhao, Ajay Singh, Seungwook Jang, Anjie Wang, and Dong-Pyo Kim
Plain and N-doped carbonaceous particles are synthesized from biomass resources such as glucose via continuous hydrothermal carbonization (HTC) process at 200 °C and 250 psi for the first time using a microfluidic system in a fast and continuous manner. The continuous HTC is controlled by reaction time (3.7–30 min) and concentration (0–10 wt.%) of ethylenediamine as a nitrogen additive to produce a series of the plain carbonaceous and N-doped carbonaceous particles with size range from 0.8 to 1.2 um. The as-synthesized and the pyrolyzed particles are characterized by various analytical instruments to understand their chemical structures with elemental compositions, morphology of particles, and thermal defunctionalization.
Authors:Qiang Ren, Tianrui Xia, Xian-Gao Quan, Lin Ding, and Hui-Yun Wang
Scutellaria barbata D. Don has been used as a traditional Chinese medicine for antitumor and anti-inflammatory. However, there were just a few investigations about S. barbata D. Don according to bioactivity-directed isolation and online identification for the chemical constituents. In this work, eight compounds were isolated from S. barbata D. Don. The three flavonoids indicated the cytotoxic activity against human leukemic Reh cell lines. In addition, the constituents of S. barbata D. Don were further characterized and identified by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS). The UHPLC- Q-TOF-MS method was in negative ion mode. HPLC separation was performed on a Tosoh TSK gel ODS-100V (4.6 × 150 mm, 3.0 μm) column by gradient elution using water containing 0.3% formic acid and acetonitrile as mobile phase at a flow rate of 0.8 mL min−1. A total of 18 compounds, including 4 phenolic acids and 14 flavonoids were tentatively characterized and identified by means of the retention time, accurate mass, and characteristic fragment ions.
The hydrogenation of biomass-derived ethyl lactate was studied over several ruthenium catalysts (Ru/TiO2, Ru/SiO2, Ru/γ-Al2O3, Ru/NaY and Ru/C), with the intent of developing a simple and additive-free catalytic system. The catalytic performance is dependent on the nature of the support. Ru/SiO2 was found to be an efficient catalyst for the hydrogenation of ethyl lactate to 1,2-propanediol (1,2-PDO). Parametric studies show that the reaction temperature, hydrogen pressure and catalyst amount can significantly influence the catalytic performance. Under optimal reaction conditions (433 K, 5 MPa), high yield of 1,2-PDO (82.1%) was obtained without the introduction of any additives. Form a practical point of view, this study may open the way to a new approach for the production of 1,2-PDO.
Authors:Yun Wang, Jianhong Chen, Yutian Li, Puling Li, Javed Iqbal, Ying Chen, Yinlian Ma, and Cun Zhang
A reliable and rapid high-performance liquid chromatography coupled with diode array detector method (HPLC–DAD) was established and validated to determine eight gingerol simultaneously in the rhizomes of Zingiber offcinale Rosc. The separation of eight compounds (4-hydroxy-3-methoxy-benzenebutanol,3,5-dihydroxy-1-(4-hydroxy-3-methoxyphenyl) decane, 3,5-dihydroxy-1-(3,4-dimethoxyphenyl) decane, 6-gingerol, 8-gingerol, 6-shogaol, 5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-1,4-decadien-3-one, and 10-gingerol) were performed on an Agilent TC(2) C18 (250 mm × 4.6 mm, 5 μm) at 30 °C using acetonitrile (A) and 1% formic acid aqueous solution (B) as the mobile phase with gradient elution (0–10 min, 20%–35% A; 10–28 min, 35%–55% A; 28–35 min, 55%–60% A; 35–55 min, 60%–70% A; 55.01–60 min, 100%–100% A). The detection wavelength was set at 280 nm, and the flow rate was 0.8 mL/min. Validation of the analytical method was performed by linearity, precision, and accuracy test. All compounds were quantified with good linear calibration curves (coefficient of determination R2, >0.9999). The method showed good precision with overall coefficients of variation between 0.56% and 0.84%. The range of recovery was from 95.50% to 104.14% for the analytes. This method was successfully applied to quantify eight gingerols in Z. offcinale Rosc from different regions in China, so it can provide quality assessment for this medicine.
Authors:Shunsen Huang, Xiaoxiong Lai, Ye Xue, Cai Zhang, and Yun Wang
Background and aims
Previous research has established risk factors for problematic smartphone use (PSU), but few studies to date have explored the structure of PSU symptoms. This study capitalizes on network analysis to identify the core symptoms of PSU in a large sample of students.
This research investigated 26,950 grade 4 students (male = 13,271) and 11,687 grade 8 students (male = 5,739) using the smartphone addiction proneness scale (SAPS). The collected data were analyzed using a network analysis method, which can provide centrality indexes to determine the core symptoms of PSU. The two networks from the different groups were compared using a permutation test.
The results indicated that the core symptoms of students' problematic smartphone use were the loss of control and continued excessive use across the two samples.
Discussion and conclusions
These findings suggest that loss of control is a key feature of problematic smartphone use. The results also provide some evidence relevant to previous research from the perspective of network analysis and some suggestions for future treatment or prevention of students' problematic smartphone use.
Authors:Shunsen Huang, Xiaoxiong Lai, Yajun Li, Yuhan Luo, and Yun Wang
Background and aims
To understand the interaction between problematic smartphone use (PSU) and related influencing factors (individual variables, family environment, and school environment) and to determine the most influential factors affecting the use of smartphones by juveniles to implement effective interventions in the future.
A total of 3,442 children and adolescents (3,248 actual participants (males = 1,638, average age = 12.27 ± 2.36)) were included in the study. This study measured juveniles’ PSU and its influencing factors: individual variables (4 factors), family environments (13 factors), and school environments (5 factors). This study employed a network analysis approach for data assessment.
This study found that there were several central influencing factors (such as self-control ability, loss of control, parent-child relationship, and peer attitudes towards smartphone use) and bridge factors (such as peer attitudes towards smartphone use, peer pressure for smartphone use, and fear of missing out).
Discussion and conclusions
Juveniles’ PSU included several core symptoms and critical influencing factors. Intervention based on these factors may be effective, timely, and inexpensive.
Recently, it was reported that the toxicity of copper particles increases with the decrease of the particle size on a mass
basis. To understand this phenomenon, inductively coupled plasma mass spectrometry (ICP-MS) techniques and in vitro chemical
studies were carried out to explore how they produce toxicity in vivo. The results suggest that when the sizes of particles
become small and down to a nanoscale, copper becomes extremely reactive in a simulative intracorporeal environment. The nanosized
copper particles consume the hydrogen ions in stomach more quickly than micron ones. These processes further convert the copper
nanoparticles into cupric ions whose toxicity is very high in vivo.
Nanosized copper particles are widely used in fields of lubricants, polymers/plastic, metallic coating and ink. Recently,
we found that copper particles in different sizes can lead to different toxicological effects. To clarify the target organs
of copper particles of different sizes, the inductively coupled plasma mass spectroscopy (ICP-MS) was employed to evaluate
the distribution of copper in different organs of mice after a single dose oral exposure. The results suggest that the main
target organs for copper nanoparticles are kidney, liver and blood. Liver is the main damaged organ.
Using microcalorimetry, the characteristic metabolic heat flow power-time curves of S. aureus growth affected by Ursodesoxycholic acid and Hyodeoxycholic acid were measured at 37 °C. The thermal-kinetic parameters such as, growth rate constant k, the maximum power output (Pm), the time corresponding to the maximum power output (tp), total heat-production Qt, half inhibitory concentration of the drugs (IC50) were calculated from the growth curves. For both HDCA and UDCA, with the increasing of concentration, k, Pm, and Qt decreased, meanwhile, k–c fit a linear equation, tp was prolonged correspondingly. Principle component analysis, the results indicated tp might be the main parameter in evaluating the antibacterial activity of HDCA and UDCA in microcalorimetric method. Combining with tp and IC50, the results revealed that the differences and trends of antibacterial activity of these bile acid derivatives were: HDCA > UDCA. Structure-activity relationship (SAR) analysis showed that the α-OH at C-3 and C-6 position at equal pace on the steroid nucleus enhanced the hydrophilicity of HDCA, which led to a stronger antibacterial effect than UDCA. In this study, a useful tool was provided to accurately evaluate the antibacterial effects of bile acid derivatives. The thermolysis curve recorded by microcalorimetry could provide a lot of kinetic and thermodynamic information for the study of growth process of living microbial, which could be helpful in the screening of high efficacy antibacterial agents.
Authors:Yong He, Rui Ding, Hang Liu, Xiao Wang, Jing-Li Xu, Man Feng, Yu-Rong Chen, Chuan-Min Qi, Cheng Peng, Zhao-Hui Zhu, Yong-Hong Dang, Ming Wang, and Yun-Chuan Ma
As degradation product of Antineoplaston A10 in vivo, phenylacetyl glutamine showed antitumor activities. According to literatures,
we designed and radiosynthesized a phenylacetyl glutamine derivative, which was achieved under a mild reaction condition.
Evaluations in vitro and in vivo were performed on tumor bearing mice. Excitingly, the radiochemical purity of (S)-2-((S)-2-(4-(3-fluoropropyl)benzamido)-3-phenylpropanamido)pentanedioic
acid ([18F]FBPPA) was 98%, and besides the best radiochemical yield was up to 46%. T/Bl (Tumor/Blood) and T/M (Tumor/Muscle) ratios
of [18F]FBPPA at 60 min post injection were 2.33 and 3.51. Meanwhile, it showed satisfied stability in vitro and in vivo, compared
with 2-[18F]fluorodeoxyglucose ([18F]FDG). Although [18F]FBPPA deserved further studies to make optimizations on its structure, the results revealed it might become a potential
PET imaging agent for detecting tumors.