荷钆硬脂酰壳寡糖的制备及其在胰腺癌成像中的应用

目的 制备荷钆硬脂酰壳寡糖（COSSA-DTPA-Gd）,评价其胶束性质、细胞毒性、体外弛豫率和在胰腺肿瘤中的MR成像效果。方法 利用酰化反应合成硬脂酰壳寡糖,再枝接螯合剂DTPA并与Gd³⁺螯合得到最终产物。采用电镜和激光粒度仪等测定产物胶束性质;噻唑蓝法测定产物细胞毒性;在MR上测定体外弛豫率,评估其在原位胰腺肿瘤成像强化中的效果。结果 合成的COSSA-DTPA-Gd在水中可自发形成胶束,临界胶束浓度为（5.12±0.43）μg/ml,外观近似球形,粒径（58.3±5.7）nm,带正电荷,含钆量为330.31 μmol/g。产物的细胞毒性与市售对比剂马根维显相似（P>0.05）,24 h内细胞存活率>85%。COSSA-DTPA-Gd的体外纵向弛豫率为8.23 mM^-1·s^-1,静注后对胰腺肿瘤的成像效果优于马根维显,肿瘤周边首先强化,肿瘤内部渐进性强化。结论 COSSA-DTPA-Gd胶束对比剂对胰腺肿瘤具有良好的成像效果。     

Preparation and evaluation of a melt pelletised paracetamol/stearic acid sustained release delivery system.

The potential of a sustained release formulation for paracetamol produced by melt pelletisation was investigated. The chosen formulation was based on the combination of stearic acid as a melting binder and anhydrous lactose as a filler. After determination of the size distribution, the pellet characterisation included scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), specific surface area and true density determination. Hence, the in vitro release from every single size fraction (2000, 1250, 800, 630, <630 microm) was evaluated and the release mechanism was analysed with the help of an appropriate mathematical model. The results of drug content and superficial atomic composition were found to be constant in all pellets size fractions, attesting the ability of melt pelletisation in a high shear mixer to form a product with homogeneous composition. The mathematical model is built on the hypotheses that drug diffusion and solid drug dissolution in the release environment are the key phenomena affecting drug release kinetics. Smaller classes apart (particles are not perfectly spherical), the comparison between model best fitting and experimental data indicated the reasonability of these hypotheses. Moreover, model reliability is proved by its ability of predicting drug release from a known mixture of the above mentioned particles classes.     

甘油标准物质的研制

目的 研制浓度适宜、便于保存和使用的甘油水溶液标准物质.方法 参照一级标准物质技术规范(JJG 1006-1994)及有关技术文件,制备适当浓度的甘油水溶液,HPLC法进行均匀性和稳定性检验,滴定法测定该溶液的甘油含量.结果 (1)甘油溶液均匀性检验:3次测量结果的x-±s分别为1.297 5±0.014 3、1.302 0±0.008 9、1.313 7±0.007 8,经方差分析,差异无统计学意义(F=11.462,P=0.166),说明甘油溶液分装均匀.(2)4℃保存至少稳定4年,定值为0.103 6 g/g,不确定度为0.000 4 g/g.结论 研制的甘油标准物质符合国家一级标准技术要求.已于2006年5月被国家质量监督检验检疫总局批准为国家一级标准物质(GBW 09149).     

Theoretical and experimental study on theophylline release from stearic acid cylindrical delivery systems.

The purpose of this study is to evaluate the possibility of developing a cylindrical sustained-release dosage form for theophylline directly by means of a ram extrusion process. In particular, the formulations contained: stearic acid as a low melting binder, monohydrate lactose and polyethylene glycol 6000 as hydrophilic fillers. The influence of type and percentage of the components was studied considering different parameters such as the time required for 50% of the drug release (t50%)and the drug diffusion coefficient in the delivery system. The choice of the different formulations to be tested is carried out employing an axial design with constraint domains. The limits of each component were fixed on the basis of preliminary trials. The analysis of the t50% values revealed that the release kinetics is mainly affected by stearic acid and theophylline content, whilst lactose effect is almost negligible. A substantial correspondence between the experimental results and the analysis of the drug release kinetics performed by means of an ad hoc developed mathematical model was found. The proposed mathematical model allows to conclude that wherever the release mechanism is initially ruled by dissolution, then diffusion plays the most important role.     

Preparation and characterization of lauric acid–stearic acid/expanded perlite as a composite phase change material

Rapid energy consumption stimulates the development of energy-saving materials. In this work, the L–S eutectic mixture used as a PCM was compounded with EP via vacuum adsorption to synthesize LS/EP CPCM. The maximum mass adsorption rate of EP on L–S is determined to be 70% via leakage experiments. The microscopic morphology, chemical, and crystal structure were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD), respectively. The phase change properties were measured by differential scanning calorimetry (DSC). The melting temperature of LS/EP is 37.79 °C, with a latent heat of 126.05 J g⁻¹, and it has a crystallinity of over 90%. The thermal decomposition was evaluated by TGA. The initial decomposition temperature is 132.20 °C for LS/EP. In addition, the results of accelerated phase change cycling experiments showed that LS/EP CPCM has good reliability.

(1) The maximum mass adsorption rate of EP on L–S is 70%. (2) The melting temperature of LS/EP is 37.79 °C, with latent heat of 126.05 J g⁻¹, and it has a crystallinity of over 90%. (3) LS/EP CPCM has good thermal stability and reliability.     

Model-based temperature control for improving lactic acid production from glycerol

To maximize the final lactic acid productivity and concentration, temperature control was optimized using a mathematical modelling approach. A kinetic model, including cell growth, product formation and substrate consumption equations, was proposed to describe the lactic acid production process by Escherichia coli AC-521 with glycerol as the substrate. By constructing four functions, the temperature effect was introduced on the fermentation process, where four parameters (X_max, μ_max, Y_ps and β) were observed to be significantly affected by the temperature. For the convenience of application, the temperature control strategies were simplified by dividing the whole fermentation process into several units. In each unit, the temperature was controlled constantly. Based on the model, the optimal temperature for each unit was determined to maximize the final lactate productivity. This temperature control strategy can be effectively applied in batch and fed-batch cultures, and the verified experimental evaluation showed a good correlation with the model data. Under improved temperature control conditions, a maximal lactic acid concentration of 90.4 g L⁻¹ was obtained after 80 h of fed-batch fermentation, giving a productivity of 1.13 g L⁻¹ h⁻¹, which is 1.2 times more than that in the conventional constant temperature during the cultivation course.

With model-based temperature control, yield of lactic acid obtained was higher than that obtained in the conventional process with a constant temperature.     

A highly efficient rod-like-CeO2-supported palladium catalyst for the oxidative carbonylation of glycerol to glycerol carbonate

A rod-like-CeO₂-supported Pd catalyst (Pd/CeO₂-r) was prepared using two-step hydrothermal impregnation and used in the oxidative carbonylation of glycerol to produce glycerol carbonate. The characterization results showed that the Pd was highly dispersed on the surface of the CeO₂-r, and metallic Pd was the main species in the catalyst. The Pd/CeO₂-r exhibited good catalytic performance for the oxidative carbonylation of glycerol. Under optimized reaction conditions, the glycerol conversion and glycerol carbonate selectivity were 93% and 98%, respectively, and turnover frequency was 1240 h⁻¹. However, because of the leaching of Pd and the growth of Pd particles, the catalyst was gradually deactivated throughout reuse.

Pd/CeO₂-r was prepared by a two-step hydrothermal-impregnation method for oxidative carbonylation of glycerol. It exhibited high activity, and glycerol conversion was 93% and glycerol carbonate selectivity was 98% with a TOF of 1240 h⁻¹ under optimized conditions.     

血清总胆固醇、总甘油、游离甘油和甘油三酯标准物质的研制

目的 研制与临床标本基质相似的血清总胆固醇(TC)、总甘油(TTG)、游离甘油(FG)和甘油三酯(TG)标准物质.方法 按国家标准物质技术规范的要求,制备4种血脂浓度的健康人新鲜混合血清,用酶法测定TC检测均匀性,用HPLC法检测稳定性并定值,评估不确定度.结果 4种血清均匀性检验数据方差分析P值分别为0.339、0.212、0.275、0.196(均＞0.05),说明均匀性良好;稳定性研究结果显示4种血清TC和TG在-20℃保存至少可稳定4年;4种血清的标准值和不确定度TC分别为(5.110±0.064)mmol/L、(4.761±0.062)mmol/L、(3.941±0.050)mmol/L和(3.158±0.041)mmol/L;TTG分别为(2.212±0.043)mmol/L、(1.679±0.033)mmol/L、(1.275±0.027)mmol/L和(1.067±0.023)mmol/L;FG分别为(0.142±0.005)mmol/L、(0.149±0.004)mmol/L、(0.146±0.003)mmol/L和(0.122±0.003)mmol/L;TG分别为(2.069±0.043)mmol/L、(1.530±0.033)mmol/L、(1.129±0.027)mmol/L和(0.945±0.023)mmol/L.结论 研制的血清总胆固醇、总甘油、游离甘油和甘油三酯标准物质均匀性和稳定性良好,定值可靠,已被国家质量监督检验检疫总局发布为国家一级标准物质(GBW 09145、GBW 09146、GBW 09147、GBW 09148).     

Effects of dietary stearic acid on plasma cholesterol levels.

Dietary advice based on saturated versus unsaturated fatty acids for the purpose of controlling the plasma cholesterol level has for many years plagued the American public with unpalatable diets that are difficult to adhere to. Stearic acid, an 18-carbon saturated fatty acid, does not share the hypercholesterolemic effect of other saturated fatty acids and may be the key to more palatable diets for the cholesterol-conscious dieter in the future.     

硬脂酸石蜡混合液替代二甲苯透明剂制片的探讨

我科采用硬脂酸石蜡混合液替代二甲苯透明剂作为脱水剂和石蜡间的中介剂，已有近10年的时间，经反复摸索实践取得满意的制片效果，现介绍如下。     

Preparation of calcium carbonate microrods from the gypsum scale layer of evaporation equipment

The difficult-to-remove CaSO₄ scale layer attached to an evaporator wall is a major problem in related industries. How to efficiently remove the CaSO₄ scale layer and convert it into fine chemicals with high added value, so as to turn waste into treasure, is a current research hotspot. In this study, a CaSO₄ scale layer was removed by 15 min rotary washing via a phase transfer route. Further, using the eluted calcium gluconate solution as a raw material and polyethylene glycol as the crystal control agent, CaCO₃ was prepared by a CO₂ carbonization method. The preparation conditions of CaCO₃ were optimized by single factor experiments, and the phase and morphology of the prepared samples were characterized by XRD and FESEM. The results show that the optimized conditions are as follows: reaction temperature 80 °C, reaction time 1 h, polyethylene glycol addition 3%, and a stirring rate of 400 rpm. The samples prepared under these conditions are pure-phase calcite-type CaCO₃ microrods with lengths of 1–2 μm and diameters of 300–500 nm.

The difficult-to-remove CaSO₄ scale layer attached to an evaporator wall is a major problem in related industries.     

Preparation and properties of capric acid–stearic acid-based ternary phase change materials

Two kinds of CA–SA-based ternary phase change materials (PCMs), namely, capric acid–stearic acid–palmitic acid (CA–SA–PA) and capric acid–stearic acid–octadecanol (CA–SA–OD), were prepared by the melting–blending method. By the step cooling curve method, the optimum mass ratio of the two PCMs were determined to be CA : SA : PA = 77.4 : 8.6 : 14.0 and CA : SA : OD = 81.9 : 9.1 : 9.0, and the crystallization temperatures were 19.20 °C and 23.90 °C, respectively. The phase transition temperatures as measured by DSC were 18.60 °C and 24.82 °C, and the latent heat of phase transition were 129.15 J g⁻¹ and 161.74 J g⁻¹, respectively. The results are in good agreement with those measured by the step cooling curve method. The chemical and crystalline properties of the two PCMs were analyzed by FT-IR and XRD. It was found that CA–SA is combined with PA or OD by physical action, and the components have good compatibility and form a good eutectic structure. In addition, the results of heat storage and heat release experiments and the 500 times of accelerated melting–solidification cycling test showed that the two kinds of PCMs have good heat resistance and thermal reliability. Therefore, the prepared CA–SA–PA and CA–SA–OD have good performance and great application potential in building energy saving and solar energy utilization.

Two kinds of CA–SA-based ternary phase change materials (PCMs), namely, capric acid–stearic acid–palmitic acid (CA–SA–PA) and capric acid–stearic acid–octadecanol (CA–SA–OD), were prepared by the melting–blending method.     

Topological investigation of the reaction mechanism of glycerol carbonate decomposition by bond evolution theory

The reaction mechanisms of the decomposition of glycerol carbonate have been investigated at the density functional theory level within the bond evolution theory. The four reaction pathways yield to 3-hydroxypropanal (TS1), glycidol (TS2a and TS2b), and 4-methylene-1,3-dioxolan-2-one (TS3). The study reveals non-concerted processes with the same number (four) of structural stability domains for each reaction pathway. For the two decarboxylation mechanisms, the two first steps are similar. They correspond to the cleavage of two single CO bonds to the detriment of the increased population of the lone pairs of two O atoms. These are followed, along TS1, by the transformation of a CO single bond into a double bond together with a proton transfer to create a CH bond. For TS2a and TS2b, the last step is a cyclization by CO bond formation. For the TS3 pathway, the first stage consists in the cleavage of a CH bond and the transfer of its electron population to both a proton and a C atom, the second step corresponds to the formation of an OH bond, and the last one describes the formation of a CC double bond. Moreover, the analysis of the energies, enthalpies, and free enthalpies of reaction and of activation leads to the conclusion that 3-hydroxypropanal is both the thermodynamic and kinetic product, independent of the method of calculation.

ELFs of glycerol carbonate and of its kinetic and thermodynamic decomposition product, 3-hydroxypropanal (+CO₂).     

Correction: A lab-on-a-chip for preconcentration of bacteria and nucleic acid extraction

Correction for ‘A lab-on-a-chip for preconcentration of bacteria and nucleic acid extraction’ by M. Hügle et al., RSC Adv., 2018, 8, 20124–20130.

The authors regret that affiliation details for the author Daniel Karthe are missing from the original article. The correct affiliation details are shown here.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

棕榈酸羟基硬脂酸抗代谢性炎症综合征作用机制的研究进展

老年代谢性炎症综合征(MIS)患病率高,患者体内普遍存在糖脂代谢紊乱和胰岛素抵抗,而新型化合物——羟基脂肪酸支链脂肪酸酯(FAHFAs)具有增强胰岛素敏感性和抗炎作用,其中棕榈酸羟基硬脂酸(PAHSA)是含量最高的一种同分异构体。体内PAHSA水平的改变主要受碳水化合物反应元件结合蛋白(CHREBP)的调节,并通过G蛋白偶联受体120(GPR120)发挥生物学效应。本文主要就PAHSA抗MIS的作用机制研究进展作一综述。     

Relationship between the concentrations of plasma phospholipid stearic acid and plasma lipoprotein lipids in healthy men

This study investigated the correlation between the plasma phospholipid (PL) saturated fatty acid (SFA) concentration (as a surrogate marker of SFA intake) and plasma lipid and lipoprotein lipid concentrations in 139 healthy Australian men aged 20-55 years old with widely varying intakes of saturated fat (vegans, n=18; ovolacto vegetarians, n=43; moderate meat eaters, n=60; high meat eaters, n=18). Both the ovolacto vegetarian and vegan groups demonstrated significant decreases in plasma total cholesterol (TC), low-density-lipoprotein cholesterol (LDL-C) and triacylglycerol concentrations compared with both the high-meat-eater and moderate-meat-eater groups. Total SFA and individual SFA [palmitic acid (16:0), stearic acid (18:0) and arachidic acid (20:0)] in the plasma PL were significantly lower in both the ovolacto vegetarian and vegan groups than in both the high- and moderate-meat-eater groups, while myristic acid (14:0) was significantly lower in the vegans than in the high-meat-eaters. Bivariate analysis of the results showed that the plasma PL stearic acid concentration was strongly positively correlated with plasma TC (P<0.0001), LDL-C (P<0.0001) and triacylglycerol (P<0.0001), with r(2) values of 0.655, 0.518 and 0.43 respectively. In multiple linear regression, after controlling for potential confounding factors (such as exercise, dietary group, age, body mass index, plasma PL myristic acid, palmitic acid and arachidic acid, and dietary total fat, saturated fat, cholesterol, carbohydrate and fibre intake), the plasma PL stearic acid concentration was still strongly positively correlated with plasma TC (P<0.0001) and LDL-C (P=0.006) concentrations. Based on the present data, it would seem appropriate for the population to reduce their dietary total SFA intake rather than to replace other SFA with stearic acid.     

Correction of neutropenia with lithium carbonate during the radiation treatment of lymphogranulomatosis patients

The purpose of the investigation was to study the effect of lithium carbonate on the time-course of changes in neutrophil leukocytes of the peripheral blood. Sixty-nine patients afflicted with Hodgkin's disease were entered into the study. Greater preservation of the content of neutrophil leukocytes was attained with the use of lithium carbonate coupled with radiation therapy. At the same time administration of lithium carbonate in the interval between the stages of anticancer treatment brought about an increase in the neutrophil count.     

Correction: A clinical and computational study on anti-obesity effects of hydroxycitric acid

Correction for ‘A clinical and computational study on anti-obesity effects of hydroxycitric acid’ by Manu Tomar et al., RSC Adv., 2019, 9, 18578–18588.

The authors regret that the name of one of the authors (Raghavendra Pralhada Rao) was shown incorrectly in the original article. The corrected author list is as shown above.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.