TS-240A缓蚀阻垢剂在闭路循环水系统中的应用

西安惠大公司闭路循环水系统存在着严重的腐蚀问题,根据闭路系统的特点,并在大量的试验基础上开发出了环境友好型缓蚀阻垢剂TS-240A.TS-240A以钼酸盐为主剂,复配膦羧酸以及多元分散剂等其他药剂,经过近两年来在西安惠大公司的闭路循环水系统现场应用,证明该药剂具有较好的缓蚀阻垢效果.     

Serial combination drying processes: A measure to improve quality of dried carrot disks and to reduce drying time

Conventional drying processes like hot air-drying (HAD), freeze-drying (FD) and microwave vacuum drying (MVD) have specific advantages and disadvantages concerning product quality and drying time. Recent studies have shown that serial combinations of these processes can lead to better product quality (water content, color, hardness, rehydration, volume, and ingredient retention) and favorable process parameters (shorter time, less energy consumption). However, little is known about the timing of the changeover point between the different processes. In this study, we investigated the development of quality parameters (volume retention, rehydration properties) during FD, HAD, and MVD either as a single or as a serial combination process with varying changeover point. Therefore, carrot disks were processed in a modular drying processor to different final relative moisture contents. On this basis, recommendations were derived for certain combinations of drying processes to achieve desired product quality parameters, partially with shorter drying times.     

A pH-sensitive micelle for codelivery of siRNA and doxorubicin to hepatoma cells

Aiming to effectively codeliver chemotherapeutic drugs (DOX) and siRNA (BCL-2 siRNA) into tumor cells, well-defined triblock copolymers composed of hydrophilic and hydrophobic blocks were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. The poly(ethylene glycol) (PEG) macroRAFT agent and two pH-sensitive monomers (2-(diethylamino)ethyl methacrylate, DEA and 2-(dimethylamino)ethyl methacrylate, DMA) were used for synthesizing the copolymers consisting of pH-sensitive PDEA, PDMA and PEG blocks. At pH 10, the copolymer in aqueous solution self-assembled into a micelle with hydrophobic core consisting of PDEA and PDMA for doxorubicin (DOX) encapsulation, owing to the deprotonation of the side tertiary amino groups. At neutral pH, the hydrophobic core became porous and positively charged to allow siRNA complexation due to PDMA solubilization (the pK_a of PDMA is around 8.0). Inside the acidic lysosomal compartments, PDEA was protonated and thus became hydrophilic to result in rapid release of DOX. Moreover, existence of two pH-sensitive blocks PDMA and PDEA endowed the copolymer with proton buffering effect that facilitated lysosomal escape of nanocomplex and siRNA release inside cells. Our results showed that the two codelivered therapeutic agents acted synergistically on the human hepatic carcinoma HepG2 cells to induce apoptosis in a highly effective manner.     

缓蚀阻垢剂GD-310A在热电厂循环冷却水系统中的应用

根据热电厂循环冷却水的水质特点,通过静态阻垢试验、旋转挂片腐蚀试验和动态模拟试验筛选出GD-310A缓蚀阻垢剂。试验及应用结果表明,该药剂具有优良的缓蚀阻垢性能。     

Gestational Exposure to Bisphenol A Affects Testicular Morphology,Germ Cell Associations,and Functions of Spermatogonial Stem Cells in Male Offspring

Exposure to bisphenol A (BPA) in the gestational period damages the reproductive health of offspring; detailed evidence regarding BPA-induced damage in testicular germ cells of offspring is still limited. In this study, pregnant mice (F0) were gavaged with three BPA doses (50 μg, 5 mg, and 50 mg/kg body weight (bw)/day; tolerable daily intake (TDI), no-observed-adverse-effect-level (NOAEL), and lowest-observed-adverse-effect level (LOAEL), respectively) on embryonic days 7 to 14, followed by investigation of the transgenerational effects of such exposure in male offspring. We observed that the NOAEL- and LOAEL-exposed F1 offspring had abnormalities in anogenital distance, nipple retention, and pubertal onset (days), together with differences in seminiferous epithelial stages and testis morphology. These effects were eradicated in the next F2 and F3 generations. Moreover, there was an alteration in the ratio of germ cell population and the apoptosis rate in germ cells increased in F1 offspring at the LOAEL dose. However, the total number of spermatogonia remained unchanged. Finally, a reduction in the stemness properties of spermatogonial stem cells in F1 offspring was observed upon LOAEL exposure. Therefore, we provide evidence of BPA-induced disruption of physiology and functions in male germ cells during the gestational period. This may lead to several reproductive health issues and infertility in offspring.     

酵母多糖-角鲨烯复合佐剂对甲型肝炎和乙型肝炎抗原诱导小鼠体液免疫应答的增强作用

目的探讨酵母多糖-角鲨烯复合佐剂对甲型肝炎(简称甲肝)和乙型肝炎(简称乙肝)抗原诱导小鼠体液免疫应答的增强作用,并对皮下和鼻腔接种的免疫效果进行比较。方法将酵母多糖与角鲨烯按一定比例混合,制成复合佐剂,将不同剂量的复合佐剂与HBsAg混合,并设生理盐水对照组、HBsAg对照组、铝佐剂对照组和酵母多糖对照组,均经皮下免疫ICR小鼠1次,分别于免疫后2、4、8、16周,采用ELISA法检测小鼠血清中抗HBsAg IgG抗体水平,筛选复合佐剂的最佳免疫剂量。以复合佐剂的最佳免疫剂量与甲肝抗原混合,并设生理盐水对照组、甲肝抗原对照组、铝佐剂对照组和酵母多糖对照组,均经皮下免疫ICR小鼠1次,分别于免疫后2、4、8周检测小鼠血清中抗甲肝抗原IgG抗体水平。以复合佐剂最佳免疫剂量分别与HBsAg和甲肝抗原混合,并设生理盐水对照组、HBsAg对照组和甲肝抗原对照组,经鼻腔免疫ICR小鼠,共免疫3次,间隔2周,分别于末次免疫后4、8周检测小鼠血清中抗HBsAg和甲肝抗原IgG抗体水平。在试验期间,对小鼠的健康状况进行观察,并对小鼠的心脏、肝脏、脾脏、肺脏、肾脏组织进行病理分析。结果酵母多糖-角鲨烯复合佐剂对HBsAg的最佳免疫剂量为2 mg酵母多糖+8μl角鲨烯,该组抗体水平明显高于铝佐剂对照组和酵母多糖对照组(P<0.05);复合佐剂对甲肝抗原也有较好的体液免疫增强作用,抗体水平显著高于铝佐剂对照组和酵母多糖对照组(P<0.05);复合佐剂通过鼻腔免疫,对HBsAg和甲肝抗原的体液免疫应答也有增强作用,但效果不如皮下免疫,甲肝抗原鼻腔免疫效果优于HBsAg(P<0.05)。在试验期内,小鼠均未出现异常反应,各器官均未发生病变。结论酵母多糖-角鲨烯复合佐剂能显著增强甲肝和HBsAg抗原对小鼠的体液免疫应答,免疫效果优于铝佐剂;皮下免疫效果优于鼻腔免疫;在免疫剂量范围内,复合佐剂安全性良好。     

A combination of Ag/alumina and Ag modified ZSM-5 to remove NOx and CO during lean conditions

Single and bi-metallic silver modified ZSM-5 catalysts were synthesized using different methods of preparation, characterized by several techniques and tested in simulated diesel conditions. Additionally the catalytic behaviour of the most active catalyst, containing 5 wt.% Ag and prepared by impregnation (5Ag(Imp)-H-ZSM-5), was studied over a broad temperature range with two reducing agents (octane and propene). To correlate the catalytic activity of the prepared catalysts with preparation parameters the materials were characterized by XRD, SEM, N₂-physisorption, octane/propene-TPD, EPR and ICP techniques. A dual bed system consisting of Ag/alumina and the most active zeolitic material (5Ag(Imp)-H-ZSM-5) was shown not only to substantially enhance the activity of Ag/alumina in the low temperature region, but also to completely oxidize the CO and unburned hydrocarbons.     

A study on carbon coating to silicon and electrochemical characteristics of Si-C/Li cells

The aim of this paper is to study the electrochemical behavior of Si-C material synthesized by heating a mixture of silicon and polyvinylidene fluoride (PVDF) in the ratios of 5, 20, and 50 wt%. The particle size of the synthesized material was found to be increased with increase in the PVDF ratio. The coexistence of silicon with carbon was confirmed from the XRD analysis. A field emission scanning electron microscope (FESEM) study performed with the material proved the improvement in coating efficiency with increase in the PVDF ratio. Coin cells of the type 2025 were made by using the synthesized material, and the electrochemical properties were studied. An electrode was prepared by using the developed Si-C material. Si-C|Li cells were made with this electrode. A charge|discharge test was performed for 20 cycles at 0.1 C hour rate. Initial charge and discharge capacities of Si-C material derived from 20 wt% of PVDF was found to be 1,830 and 526 mAh|g, respectively. Initial charge/discharge characteristics of the electrode were analyzed. The level of reversible specific capacity was about 216mAh/g at Si-C material derived from 20 wt% of PVDF, initial intercalation efficiency (IIE), intercalation efficiency at initial charge/discharge, was 68%. Surface irreversible specific capacity was 31 mAh/g, and average specific resistance was 2.6 ohm * g.     

A 2-dimensional small-angle X-ray scattering study of the microphase-separated morphology exhibited by thermoplastic polyurethanes and its response to deformation

The morphological behaviour of poly(ether-urethane)s undergoing deformation was studied using two-dimensional small-angle X-ray scattering (2D-SAXS). The data was analysed using the Zernike-Prins and Percus-Yevick models, which fitted the data well and indicated morphologies composed of discrete, elongated hard segment (HS) microdomains. Although the formulations contained relatively large HS weight fractions, relatively low volume fractions of scattering bodies were indicated, which implied limited segmental de-mixing. Possible explanations for this were discussed.Curve-fitting the 2D-SAXS data for deformation experiments using the Zernike-Prins model, indicated that HS microdomains initially became aligned with the applied strain and subsequently fragmented. This suggested a morphological basis for the observed mechanical properties of these materials, which will be explored in more detail, in subsequent publications.     

A novel flow field with controllable pressure gradient to enhance mass transport and water removal of PEM fuel cells

An easily machined novel flow field with controllable pressure gradient across adjacent channels was designed and a two dimensional, across-the-channel, two-phase model was developed to study the gas transport and water removal of the novel configuration. The effect of channel-rib width ratio, GDL thickness and pressure gradient on the profiles of oxygen concentration and water saturation within the GDL were investigated. Special attention was paid to the mechanisms of the promoted mass transport and water removal rates under a pressure gradient. The model was validated by experiments with various channel-rib ratios and GDL thicknesses at different operating pressure. The results revealed that, oxygen concentration was increased, and the water saturation was reduced under the rib with a pressure gradient generated across the adjacent channels. The optimal pressure gradient is between 0.1 to 0.2 atm for the studied channel geometry and configuration. The mechanisms of the improved cell performance were elucidated.     

A combined computational fluid dynamics (CFD) and experimental approach to quantify the adhesion force of bacterial cells attached to a plane surface

A three‐dimensional model is developed to study the laminar shear flow past a bacterial cell attached to a plane surface. The induced hydrodynamic forces and torque exerted on the cell are computed to clarify the prevailing mechanisms involved in the detachment of model bacteria. Results are discussed in terms of drag and torque magnitude as a function of the angles defining the orientation of the cell. It is shown that reorientation and rolling of spheroid‐shaped cells are favored. It is also confirmed that rod‐shaped cells would tend to lie on the surface and become aligned with the flow. The model is used to quantify the adhesion force of spheroid Bacillus cereus spores to stainless steel, deduced from previously described experiments in a shear stress flow chamber. The magnitude of the predicted adhesion force is close to that obtained using atomic force microscopy under similar experimental conditions. © 2012 American Institute of Chemical Engineers AIChE J, 2012     

The acylation and phosphorylation pattern of lipid A from Xanthomonas campestris strongly influence its ability to trigger the innate immune response in Arabidopsis

Lipopolysaccharides (LPSs) are major components of the cell surface of Gram-negative bacteria. LPSs comprise a hydrophilic heteropolysaccharide (formed by the core oligosaccharide and the O-specific polysaccharide) that is covalently linked to the glycolipid moiety lipid A, which anchors these macromolecules to the external membrane. LPSs are one of a group of molecules called pathogen-associated molecular patterns (PAMPs) that are indispensable for bacterial growth and viability, and act to trigger innate defense responses in eukaryotes. We have previously shown that LPS from the plant pathogen Xanthomonas campestris pv. campestris (Xcc) can elicit defense responses in the model plant Arabidopsis thaliana. Here we have extended these studies by analysis of the structure and biological activity of LPS from a nonpathogenic Xcc mutant, strain 8530. We show that this Xcc strain is defective in core completion and introduces significant modification in the lipid A region, which involves the degree of acylation and nonstoichiometric substitution of the phosphate groups with phosphoethanolamine. Lipid A that was isolated from Xcc strain 8530 did not have the ability to induce the defense-related gene PR1 in Arabidopsis, or to prevent the hypersensitive response (HR) that is caused by avirulent bacteria as the lipid A from the wild-type could. This suggests that Xcc has the capacity to modify the structure of the lipid A to reduce its activity as a PAMP. We speculate that such effects might occur in wild-type bacteria that are exposed to stresses such as those that might be encountered during plant colonization and disease.     

A novel combination of precursor pyrolysis assisted sintering and rapid sintering for construction of multi-composition coatings to improve ablation resistance of SiOC ceramic modified carbon fiber needled felt preform composites

A double-layer coating composed of MoSi₂–SiO₂–SiC/ZrB₂–MoSi₂–SiC was designed and successfully constructed by a novel combination of precursor pyrolysis assisted sintering and rapid sintering to improve the ablation resistance of SiOC ceramic modified carbon fiber needled felt preform composites (CSs). The ZrB₂–MoSi₂–SiC inner layer coating was in relatively uniform distribution in the zone of 0–3 mm from the surface of CSs through the slurry/precursor infiltration in vacuum and SiOC precursor pyrolysis assisted sintering, which played a predominant role in improving oxidation and ablation resistance and maintaining the morphology of CSs. The MoSi₂–SiO₂–SiC outer layer coating was prepared by the spray and rapid sintering to further protect CSs from high-temperature oxidation. The ablation resistance of CSs coated with double-layer coating was evaluated by an oxygen-acetylene ablation test under the temperature of 1600–1800 °C with different ablation time of 1000 and 1500 s. The results revealed that the mass recession rates increased with the rise of ablation temperature and extension of ablation time, ranging from 0.47 g/(m²·s) to 0.98 g/(m²·s) at 1600–1800 °C for 1000 s and from 0.72 g/(m²·s) to 0.86 g/(m²·s) for 1000–1500 s at 1700 °C, while the linear recession rates showed negative values at 1700 °C due to the formation of oxides, such as SiO₂ and ZrO₂. The ablation mechanism of the double-layer coating was analyzed and found that a SiO₂–ZrO₂–Mo_4.8Si₃C_0.6 oxidation protection barrier would be formed during the ablation process to prevent the oxygen diffusion into the interior CSs, and this study provided a novel and effective way to fabricate high-temperature oxidation protective and ablation resistant coating.     

Design and Engineering of “Green” Nanoemulsions for Enhanced Topical Delivery of Bakuchiol Achieved in a Sustainable Manner: A Novel Eco-Friendly Approach to Bioretinol

In the present work, we establish novel “environmentally-friendly” oil-in-water nanoemulsions to enhance the transdermal delivery of bakuchiol, the so-called “bioretinol” obtained from powdered Psoralea corylifolia seeds via a sustainable process, i.e., using a supercritical fluid extraction approach with pure carbon dioxide (SC-CO₂). According to Green Chemistry principles, five novel formulations were stabilized by “green” hybrid ionic surfactants such as coco-betaine—surfactin molecules obtained from coconut and fermented rapeseed meal. Preliminary optimization studies involving three dispersion stability tests, i.e., centrifugation, heating, and cooling cycles, indicated the most promising candidates for further physicochemical analysis. Finally, nanoemulsion colloidal characterization provided by scattering (dynamic and electrophoretic light scattering as well as backscattering), microscopic (transmission electron and confocal laser scanning microscopy), and spectroscopic (UV–Vis spectroscopy) methods revealed the most stable nanocarrier for transdermal biological investigation. In vitro, topical experiments provided on human skin cell line HaCaT keratinocytes and normal dermal NHDF fibroblasts indicated high cell viability upon treatment of the tested formulation with a final 0.02–0.2 mg/mL bakuchiol concentration. This excellent biocompatibility was confirmed by ex vivo and in vivo tests on animal and human skin tissue. The improved permeability and antiaging potential of the bakuchiol-encapsulated rich extract were observed, indicating that the obtained ecological nanoemulsions are competitive with commercial retinol formulations.     

How to Attain Ultralow Interfacial Tension and Three-Phase Behavior with Surfactant Formulation for Enhanced Oil Recovery: A Review. Part 4: Robustness of the Optimum Formulation Zone Through the Insensibility to Some Variables and the Occurrence of Complex Artifacts

In enhanced oil recovery, not only the low-tension performance, but also the robustness at optimum formulation is an important issue. The fourth part of our review series is dedicated to robustness, defined as the width of the zone exhibiting three-phase behavior around the optimum formulation, whatever the scanned variable. It is first corroborated from a screening of the available data in the literature that the tension minimum is inversely proportional to the square of the three-phase range in the HLD scale. However, since there is still an inaccuracy of about a factor 10 in the tension minimum, some significant improvement can be attained in some cases by increasing the three-phase behavior width in two ways. The first approach consists of finding systems that are insensitive to some formulation variable such as temperature, surfactant mixture composition or concentration, and water-to-oil ratio. The second way is to produce an artifact through which the optimum formulation is produced twice in a scan. If the distance between the two events in the scan is reduced down to be zero, their corresponding three-phase behavior zones merge and result in a wider WIII region with a low tension. Several cases of such events are reported: alkaline scans, anionic-nonionic and anionic-cationic mixture changes, linear change in composition in three-surfactant mixture, partial precipitation from a surfactant mixture in a salinity scan, and excessive partitioning of polyethoxylated nonionics. More complex transitions with three effects in a single scan or three concomitantly scanned variables show even more possibilities in practice.     

A new approach to 3-miktoarm star polymers using a combination of reversible addition-fragmentation chain transfer (RAFT) and ring opening polymerization (ROP) via “Click” chemistry

The synthesis of AB₂-type miktoarm star polymers using a combination of reversible addition-fragmentation chain transfer (RAFT), ring opening polymerization (ROP) and “Click” chemistry was demonstrated in this work. An azide functional RAFT agent was used to polymerize butyl acrylate, polyethylene glycol acrylate and N-isopropylacrylamide monomers. Propargylamine was reacted with glycerine carbonate to obtain a dihydroxy functional alkyne compound which was used for the ring opening polymerization of ?-caprolactone (?-CL) and lactide. The resulting alkyne functional polycaprolactone (PCL) and polylactide (PLA) polymers were reacted with azide functional polymers in the presence of copper bromide (CuBr) catalyst to obtain miktoarm star polymers. The polymers were characterized by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. The star polymers had low polydispersity (∼1.3) with well-defined structures. These polymers have a number of potential applications including crosslinking agents for polyurethane (PU) coatings for biodegradable and fouling release applications.