查找使用阿拉丁产品的科研文献

Stability and Population of Radicals in Electrical Trees in Epoxy Resins Based on Electron Paramagnetic Resonance Spectroscopy

Lu Han,Jiaye Xie,Qi Li,Jinliang He

Lignin modification for in-situ cured lignin-maleyl network in semi-crystalline polyamide/lignin shape memory composites

Chen Yang,Tao Shen,Zhuotao Tan,Wei Zhuang,Chenjie Zhu,Ming Li,Hanjie Ying

Lignin-based shape memory polymers (SMPs) have received increasing attention in the context of lignin valorization. This work designed a novel SMP with high content of lignin and high transition temperature (>150 °C) for shape memory. Soda lignin (SL) was first modified with maleic anhydride resulting in a lignin derivative (MAL) as confirmed by FTIR, 31 P NMR, 2D-HSQC and TGA. The modification results in an elevated molecular weight and reduced T g . SMPs were designed based on a penetrating lignin-maleyl network in a crystalline polyamide (PA) matrix, the former serving as the lock for the permanent shape and the latter as the reversible switch. The SMPs were prepared via procedures of solution mixing, film casting and in-situ thermal curing. Rheological study revealed that the precursors can be fully cured at 200 °C within 20 min with the aid of a bismaleimide spacer, which ensures a proper temperature window for curing. Compared to the PA/SL series, the PA/MAL series demonstrated improved mechanical properties and well-integrated interfacial morphologies, which enables efficient shape memory performance. This work provides a proof-of-concept study demonstrating that the design of crosslinked semi-crystalline polyamide/lignin dual-phase composites with modified lignin enables high-transition-temperature shape memory behavior for potential demanding applications such as in aerospace or mining engineering.

Hydrodynamics and liquid–liquid mass transfer in gas–liquid–liquid three-phase flow in a cross microchannel

Jingwei Zhang,Yiwei Zhou,Zhuo Chen,Jianhong Xu

Gas-liquid–liquid three-phase flow in cross microchannels has been widely used in flow chemistry and process intensification. At present, the flow and mass transfer characteristics in this type of channel are not well understood. In this work, the hydrodynamics and liquid–liquid mass transfer characteristics of gas–liquid–liquid three-phase flow were systematically investigated. For the gas–liquid–liquid hydrodynamics, the general regulation laws of bubble and droplet size were obtained by considering the synergistic effect of shearing phases, and the bubble/droplet size prediction model based on the multiphase cooperative behavior was proposed, which could be used in predicting droplet/bubble size in flow systems. For the gas–liquid–liquid mass transfer process, the experimental results showed that the mass transfer coefficient first increased and then decreased with the increase of gas flow rate when the oil phase flow rate was fixed. The semi-empirical prediction formula of the mass transfer coefficient was obtained by considering the vortex strength, the interfacial area and the effective mass transfer area at the same time, which was in good agreement with the experimental results. This work could be the comprehensive study of gas–liquid–liquid three-phase flow and liquid–liquid mass transfer under gas enhancement in a cross microchannel.

Au Catalyzing Control Release NO in vivo and Tumor Growth-Inhibiting Effect in Chemo-Photothermal Combination Therapy

Ying Zhang,Tianfu Zhou,Jian Li,Nuo Xu,Mingze Cai,Hong Zhang,Qinfu Zhao,Siling Wang

DGT method for the in situ measurement of triazines and the desorption kinetics of atrazine in soil

Zheng Siheng,Sheng Feng,Gu Cheng,Li Yanying,Fang Zhou,Luo Jun

Triazines are frequently detected in nature water and agricultural soils worldwide. They are considered harmful to plants, animals, and the human health. In this study, diffusive gradients in thin films (DGT) method was developed for the assessment of several triazines. DGT device was used for the in situ measurement of atrazine in a pesticide factory and obtained reliable data. The atrazine concentrations measured by DGT, and solvent extraction method was in a constant ratio. The DIFS model was coupled with DGT technique to study the desorption kinetics of atrazine in four kinds of different soils. The yellow–brown soil was more inclined to adsorb atrazine than other three soils. 2_D DIFS model was used to obtain the partition coefficient for labile atrazine ( K dl ), the values of the response time ( T c ), and desorption/adsorption rates ( k 1 and k −1 ). The yellow–brown soil has a larger labile pool size, and a faster resupply speed of atrazine. The 1_D DIFS model was used to simulate the profiles of atrazine concentrations in soil solution and solid phase. The results show that the desorption of atrazine in soil was limited by kinetic limitation at short time, and was limited by the solid phase reservoir at long time.

20-Hydroxyecdysone and Receptor Interplay in the Regulation of Hemolymph Glucose Level in Honeybee (Apis mellifera) Larvae

Jing Yu,Hongfang Wang,Wenfeng Chen,Hongyu Song,Ying Wang,Zhenguo Liu,Baohua Xu

The hormone 20-hydroxyecdysone (20E) and the ecdysone receptors (ECR and USP) play critical roles in the growth and metabolism of insects, including honeybees. In this study, we investigated the effect of 20E on the growth and development of honeybee larvae by rearing them in vitro and found reduced food consumption and small-sized pupae with increasing levels of 20E. A liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based analysis of widely targeted metabolomics was used to examine the changes in the metabolites after an exogenous 20E application to honeybee larvae and the underlying mechanisms. A total of 374 different metabolites were detected between the control group and the 20E treatment group, covering 12 subclasses. The most significant changes occurred in 7-day-old larvae, where some monosaccharides, such as D-Glucose and UDP-galactose, were significantly upregulated. In addition, some metabolic pathways, such as glycolysis/gluconeogenesis and galactose metabolism, were affected by the 20E treatment, suggesting that the 20E treatment disrupts the metabolic homeostasis of honeybee larvae hemolymph and that the response of honeybee larvae to the 20E treatment is dynamic and contains many complex pathways. Many genes involved in carbohydrate metabolism, including genes of the glycolysis and glycogen synthesis pathways, were downregulated during molting and pupation after the 20E treatment. In contrast, the expression levels of the genes related to gluconeogenesis and glycogenolysis were significantly increased, which directly or indirectly upregulated glucose levels in the hemolymph, whereas RNA interference with the 20E receptor EcR-USP had an opposite effect to that of the 20E treatment. Taken together, 20E plays a critical role in the changes in carbohydrate metabolism during metamorphosis.Keywords:20-hydroxyecdysone;metabolomics;hemolymph;glucose;ecdysone receptors

All-in-one device for mapping the interactive effects of photodynamic therapy dosimetry in tumor gaseous microenvironment

Shu Zhang,Yuewu Li,Rui Dong,Weitao Li,Zhiyu Qian,Yamin Yang

Photodynamic therapy (PDT) elicits cell death , vascular damage , or/and anti-tumor host immune response upon activating the administered photosensitive drug by an appropriate light source. Because PDT is heavily dependent on tissue oxygen (O 2 ) in essence, the concentration-dependent impact of O 2 on tailoring cellular response to PDT remains an in-depth investigation. As a multifaceted modality, optimal combinations of photosensitizer (PS) concentration, light dose, and O 2 delivery are critical to achieve ideal therapeutic outcomes. We herein present a fully integrated all-in-one device for the in vitro assessment of PDT efficacy synchronizing the quantitative control of three PDT disciplines simultaneously, aiming at 1) identifying the influence of varying gaseous microenvironments on PDT; and 2) determining the contribution of each PDT factor and estimating the strength of their synergic effect. The gas-gradient-generating unit for contactless headspace O 2 delivery and spatial light control filtering layer in our device could either work as a stand-alone module or combine to screen a range of experimental PDT parameters. By sweeping a total of 128 conditions over four 5-aminolevulinic acid (5-ALA) concentrations, four light dosages, and eight O 2 levels in one single experiment, we determined the main effects of the three key PDT agents and highlighted the interactive effect between 5-ALA and light after full-factorial statistical analysis. Our device is not only a versatile tool for predicting PDT efficacy during the translational study but also provides valuable multidimensional information for the interrelation between key PDT factors, which may expedite clinical PDT dosimetry and furnish new insights for the fundamental understanding of photobiological processes.

Enhancement in adsorption potential of microplastics in sewage sludge for metal pollutants after the wastewater treatment process

Xiaowei Li,Qingqing Mei,Lubei Chen,Hongyuan Zhang,Bin Dong,Xiaohu Dai,Chiquan He,John Zhou

Microplastics (MPs) as new pollutants of environmental concern have been widely detected in sewage sludge , and may act as significant vectors for metal pollutants due to their adsorption property. Our findings show that Cd, Pb, and Co, but not Ni, contents in sewage sludge are lower than that of corresponding metal irons adsorbed on sludge-based MPs, indicating that the MPs accumulate such metal pollutants as Cd in the sludge samples. In contrast to virgin MPs, sludge-based MPs are one order of magnitude higher adsorption capacity for Cd, which reaches up to 2.523 mg g −1 , implying that there is a considerable enhancement in adsorption potential of the MPs for metals after the wastewater treatment process . SEM analysis shows that sludge-based MPs have rougher and more porous surface than virgin MPs, and FTIR spectra reveal that functional groups such as C O and O H are found on sludge-based MPs. Further, two-dimensional FTIR correlation spectroscopy indicates that C O and N H functional groups play a vital role in the process that sludge-based MPs adsorb Cd, which are not found in virgin MPs. The results imply that increased adsorption potentials of the sludge-based MPs to Cd are attributed to changes in the MP physicochemical properties during wastewater treatment process. In addition, such factors as pH value, and sludge inorganic and organic components also have an effect on the MP adsorption to Cd. Principal component analysis shows that the MPs could be divided into three categories, i.e. polyamide, rubbery MPs (polyethylene and polypropylene) and glassy MPs (polyvinyl chloride and polystyrene). Their adsorption potentials to Cd follow the decreasing order: polyamide > rubbery MPs > glassy MPs. In summary, these findings indicate that MPs may exert an important influence on fate and transport of metal pollutants during sewage sludge treatment process, which deserves to be further concerned.

Role of ionic liquids in the efficient transfer of lithium by Cyanex 923 in solvent extraction system

Li Cui,Kun Jiang,Junfeng Wang,Kun Dong,Xiangping Zhang,Fangqin Cheng

The solvent extraction of Li + by Cyanex 923 was investigated upon the addition of different imidazolium-based ionic liquids (ILs). The results showed 1-hydroxylethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([HOEmim][NTf 2 ]) can improve the extraction of Li + most effectively. The fundamental mechanism is that [HOEmim][NTf 2 ] can remarkably enhance the coordination ability of Cyanex 923 to Li + to form more stable and hydrophobic ion-pair species [Li(Cyanex 923) n ][NTf 2 ] ( n max = 3) resulting from the electrostatic interaction and typical hydrogen bonding of IL, and thus facilitating the transfer of Li + into organic phase. This work has revealed the transfer mechanism of Li + in a solvent extraction system comprising of IL and neural ligand. The knowledge of the coordination environment of Li + in the presence of IL also gives us a new insight into the separation of 6 Li/ 7 Li. The disadvantage of this process is the loss of IL. However, this study provides guidance for the design of better IL-based systems for the separation of metal ions.

Gender difference in hepatic toxicity of titanium dioxide nanoparticles after subchronic oral exposure in Sprague-Dawley rats

Zhangjian Chen,Di Zhou,Shupei Zhou,Guang Jia

Existing literature pointed out that the liver may be the target organ of toxicity induced by titanium dioxide nanoparticles (TiO 2 NPs) via oral exposure. Gender differences in health effects widely exist and relevant toxicological research is important for safety assessment. To explore the gender susceptibility of TiO 2 NP-induced hepatic toxicity and the underlying mechanism, we examined female and male Sprague-Dawley rats administrated with TiO 2 NPs orally at doses of 0, 2, 10 and 50 mg/kg body weight per day for 90 days. The serum biochemical indicators and liver pathological observation were used to assess hepatic toxicity. We found significant hepatic toxicity could be induced by subchronic oral exposure to TiO 2 NPs, which was more obvious and severe in female rats. No accumulation of TiO 2 NPs in the liver was observed, indicating that hepatic toxicity may not be caused through direct pathways. Oxidized glutathione, lipid peroxidation products increased significantly and reduced glutathione decreased significantly in the liver of rats in repeated TiO 2 NP-exposed groups. Hematological parameters of white blood cells and inflammatory cytokines in serum including interleukin 1α, interleukin 4 and tumor necrosis factor also increased significantly. Indirect pathways through initiating oxidative stress and inflammatory responses were suggested as the possible mechanism of the hepatic toxicity in this experiment. The higher sensitivity to redox homeostasis imbalance and inflammation of female rats may be the main reason for gender differences. Our research suggested that gender should be a susceptible factor for identifying and monitoring long-term oral toxicity of TiO 2 NPs.

Degradation of emerging contaminants by Co (III) ions in situ generated on anode surface in aqueous solution

Yongzhi Liu,Bin Si,Chun Zhao,Fan Jin,Huaili Zheng,Zhaoyang Wang

Cobalt ion is an environmental contaminant in general. But interestingly, it can also be used to degrade some refractory organic contaminants in water by mediated electrochemical oxidation process (MEOP) based on Co (III). MEOP is a very promising technology , and it can recycling use the mediator ions, Co (III), to degrade refractory organic contaminants in water. However, previous studies for this technology mainly conducted in strong acidic medium, the oxidation ability of this process for emerging contaminants near neutral pH condition was still unclear. Therefore, this study evaluated the emerging contaminants removal and mineralization efficiency of the MEOP-Co (III) around neutral pH, and investigated systematically the influence of series of operating parameters, including initial Co (II) concentration, current density, initial pH, electrolyte, and anions. Results from these studies indicated that the MEOP-Co (III) had a fairly good contaminants removal and mineralization ability for sulfamethoxazole, tetracycline , carbamazepine, diclofenac, and phenol at neutral pH. Besides, no radical was detected in MEOP-Co (III), and the main oxidizing substance was Co (III) ions, which was generated on anode surface. The addition of C O 3 2 − / H C O 3 − could weaken the oxidation ability of MEOP-Co (III), while C l − and P O 4 3 − could enhance the system's oxidation ability. Moreover, a reasonable energy consumption was achieved in MEOP-Co (III), and the highest electric energy per order (EE/O) value was 2.4 kWh·m −3 in this study.

Naringenin Attenuates Myocardial Ischemia-Reperfusion Injury via cGMP-PKGIα Signaling and In Vivo and In Vitro Studies

Li-Ming Yu,Xue Dong,Jian Zhang,Zhi Li,Xiao-Dong Xue,Hong-Jiang Wu,Zhong-Lu Yang,Yang Yang,Hui-Shan Wang

Endoplasmic reticulum (ER) stress and oxidative stress contribute greatly to myocardial ischemia-reperfusion (MI/R) injury. Naringenin, a flavonoid derived from the citrus genus, exerts cardioprotective effects. However, the effects of naringenin on ER stress as well as oxidative stress under MI/R condition and the detailed mechanisms remain poorly defined. This study investigated the protective effect of naringenin on MI/R-injured heart with a focus on cyclic guanosine monophosphate- (cGMP-) dependent protein kinase (PKG) signaling. Sprague-Dawley rats were treated with naringenin (50 mg/kg/d) and subjected to MI/R surgery with or without KT5823 (2 mg/kg, a selective inhibitor of PKG) cotreatment. Cellular experiment was conducted on H9c2 cardiomyoblasts subjected to simulated ischemia-reperfusion treatment. Before the treatment, the cells were incubated with naringenin (80 μmol/L). PKGIα siRNA was employed to inhibit PKG signaling. Our in vivo and in vitro data showed that naringenin effectively improved heart function while it attenuated myocardial apoptosis and infarction. Furthermore, pretreatment with naringenin suppressed MI/R-induced oxidative stress as well as ER stress as evidenced by decreased superoxide generation, myocardial MDA level, gp91phox expression, and phosphorylation of PERK, IRE1α, and EIF2α as well as reduced ATF6 and CHOP. Importantly, naringenin significantly activated myocardial cGMP-PKGIα signaling while inhibition of PKG signaling with KT5823 (in vivo) or siRNA (in vitro) not only abolished these actions but also blunted naringenin’s inhibitory effects against oxidative stress and ER stress. In summary, our study demonstrates that naringenin treatment protects against MI/R injury by reducing oxidative stress and ER stress via cGMP-PKGIα signaling. Its cardioprotective effect deserves further clinical study.