ICP-MS测定化妆品中硼

目的 建立化妆品中硼的电感耦合等离子体-质谱检测方法.方法 以硝酸-过氧化氢体系微波消解处理样品;以Sc作为内标元素,电感耦合等离子体-质谱法测定(射频功率1000w,雾化器流速1.00 L/min,透镜电压6.0 V,进样速度26 r/min).结果 方法线性范围为0～500 μg/L,按取样1.00 g定容至50.0 ml计算,方法检出限可达151μg/kg;相对标准偏差为3.7％,加标回收率在99.0％～102％.结论 方法灵敏度高、操作简便,用于化妆品中硼的测定,结果满意.     

Boron nitride nanosheets modified with zinc oxide nanoparticles as novel fillers of dental resin composite

ObjectiveThe purpose of this study was to synthesize boron nitride nanosheets modified with zinc oxide nanoparticles (BNNSs/ZnO) and incorporate them as a novel inorganic filler to get an antibacterial dental resin composite.MethodsThe BNNSs/ZnO nanocomposites were synthesized via the hydrothermal method and characterized by Field Emission Scanning Electron Microscope (FESEM), Transmission Electron Microscopy (TEM), Energy Dispersive Spectrometer (EDS), X-ray Diffraction (XRD) and Fourier Transform-Infrared (FTIR) Spectroscopy. The BNNSs/ZnO or BNNSs were added into the experimental dental composite with different proportions, respectively. The mechanical and physical properties of the modified dental composite were evaluated. Their antibacterial activities were also assessed by quantitative analysis using Streptococcus mutans (S. mutans).ResultsThe BNNSs/ZnO nanocomposites were successfully synthesized, and the growth of ZnO nanoparticles (ZnO NPs) on boron nitride nanosheets was confirmed. The flexural strength (FS), flexural modulus (FM) and the compressive strength (CS) of all modified resin composites showed no change compared to the control group. The curing depth, degree of conversion, water absorption and solubility of the modified composites were still within the clinical requirement. The antibacterial rates of the modified composites were significantly increased compared to the control group, which can reach 98 % when 0.5 % BNNSs/ZnO was added.SignificanceThe modified dental resin composite with novel BNNSs or BNNSs/ZnO fillers shows significantly high antibacterial activity with suitable physicochemical and mechanical properties.     

The influence of NH3-attaching on the NMR and NQR parameters in the (6,0) zigzag single-walled BPNTs: a density functional study

The structural properties, NMR and NQR parameters in the pristine and NH₃-attached (6,0) zigzag BPNTs model were calculated using DFT methods in order to evaluate the influence of NH₃-attached on the (6,0) zigzag BPNTs for the first time. Geometry optimizations were carried out at the BLYP, B3LYP/6-31G^* levels of theory using the Gaussian 03 program suites. The chemical shielding (CS) parameters for the sites of various ¹¹B and ³¹P atoms and quadrupole coupling constant (C_Q), and asymmetry parameter (η_Q) at the sites of various ¹¹B nuclei were calculated in the pristine and the NH₃-attached (6,0) zigzag BPNTs model. The values of dipole moments detect notable changes due to direct effect of the NH₃-attached on the BPNTs; however, the tip diameters are slightly significant changed in comparison to the pristine models and the gap energies of the NH₃-attached BPNT do not detect any changes in comparison to the pristine model. For the NH₃-attached BPNT, the NMR values for the ¹¹B₁₄ atom which is directly bonded to the NH₃ molecule and the ³¹P atoms that directly bonded to the ¹¹B₁₄ atom in the BPNT are significantly changed. CS^I parameters of the atoms are increased whereas CS^A parameters of the atoms are decreased. The NQR results showed that in BPNTs, the B atoms at the edges of nanotubes play dominant roles in determining the electronic behaviors of BPNTs and the average value of C_Q (¹¹B) and η_Q for the NH₃-attached (6,0) zigzag BPNTs is further in comparison to the pristine model.     

Feasibility evaluation of neutron capture therapy for hepatocellular carcinoma using selective enhancement of boron accumulation in tumour with intra-arterial administration of boron-entrapped water-in-oil-in-water emulsion

Introduction

Hepatocellular carcinoma (HCC) is one of the most difficult to cure with surgery, chemotherapy, or other combinational therapies. In the treatment of HCC, only 30% patients can be operated due to complication of liver cirrhosis or multiple intrahepatic tumours. Tumour cell destruction in boron neutron-capture therapy (BNCT) is due to the nuclear reaction between ¹⁰B atoms and thermal neutrons, so it is necessary to accumulate a sufficient quantity of ¹⁰B atoms in tumour cells for effective tumour cell destruction by BNCT. Water-in-oil-in-water (WOW) emulsion has been used as the carrier of anti-cancer agents on intra-arterial injections in clinical. In this study, we prepared ¹⁰BSH entrapped WOW emulsion by double emulsifying technique using iodized poppy-seed oil (IPSO), ¹⁰BSH and surfactant, for selective intra-arterial infusion to HCC, and performed simulations of the irradiation in order to calculate the dose delivered to the patients.

Materials and methods

WOW emulsion was administrated with intra-arterial injections via proper hepatic artery on VX-2 rabbit hepatic tumour models. We simulated the irradiation of epithermal neutron and calculated the dose delivered to the tissues with JAEA computational dosimetry system (JCDS) at JRR4 reactor of Japan Atomic Research Institute, using the CT scans of a HCC patient.

Results and discussions

The ¹⁰B concentrations in VX-2 tumour obtained by delivery with WOW emulsion were superior to those by conventional IPSO mix emulsion. According to the rabbit model, the boron concentrations (ppm) in tumour, normal liver tissue, and blood are 61.7, 4.3, and 0.1, respectively. The results of the simulations show that normal liver biologically weighted dose is restricted to 4.9 Gy-Eq (CBE; liver tumour: 2.5, normal liver: 0.94); the maximum, minimum, and mean tumour weighted dose are 43.1, 7.3, and 21.8 Gy-Eq, respectively, in 40 min irradiation. In this study, we show that ¹⁰B entrapped WOW emulsion could be applied to novel intra-arterial boron delivery carrier for BNCT, and we show the possibility to apply BNCT to HCC. We can irradiate tumours as selectively and safety as possible, reducing the effects on neighbouring healthy tissues.     

运用免疫荧光法检测温热对于硼化合物细胞微分布影响

目的硼中子俘获疗法(BNCT)的有效性主要取决于硼-10元素在肿瘤细胞内的聚集。目前的硼检测手段仅限于分析肿瘤组织中硼的平均浓度,不能准确地评价硼化合物(BPA)在组织中的详细分布。先前研究证实温热处理可以提高放疗疗效,本研究通过免疫荧光法检测温热是否对BPA细胞内的微分布有影响。方法通过免疫荧光法分析硼化合物在肿瘤细胞中的分布以及温热对BPA分布的影响。在体外对人肺癌细胞株A549和人头颈部鳞状细胞癌细胞株SAS进行培养,并且加入BPA共培养1h。另外,A549细胞经温热处理1h后,利用抗BPA抗体通过免疫荧光法进行检测。免疫荧光强度通过图像分析软件进行分析。结果检测发现BPA主要聚集于细胞核周围,BPA免疫荧光的强度随着培养基中BPA浓度的增加而增强。尽管在26μg/ml浓度和13μg/ml浓度时,细胞免疫荧光的平均强度相近,但直方图分析发现26μg/ml时细胞主要向高荧光强度区域移动。经温热处理后,BPA在细胞中的分布没有明显增加。结论本研究利用免疫荧光法对BPA在细胞内的分布进行了分析,以上结果暗示温热对肿瘤细胞硼摄取的影响可能主要需要通过改善肿瘤循环、增加肿瘤内BPA的输送来实现。     

硼中子俘获治疗(BNCT)及剂量测量方法

目的 通过描述硼中子俘获治疗(BNCT)剂量测量方法的现状,探讨其剂量测量中的关键问题和解决方案。方法 通过广泛调研BNCT的发展、基本原理、剂量组成以及当前硼中子俘获治疗过程中的剂量测量方法,研究BNCT剂量测量中的关键问题。结果 剂量监测是保证BNCT治疗质量的关键环节。可采用累积或实时测量的方法分别测量出热中子、超热中子和γ的剂量。结论 用于硼中子俘获治疗的辐射场是n-γ的混合场,BNCT剂量测量的难点是混合辐射场中热中子、超热中子和γ剂量的甄别技术。     

Impact of accelerator-based boron neutron capture therapy (AB-BNCT) on the treatment of multiple liver tumors and malignant pleural mesothelioma

Background and purpose

To confirm the feasibility of accelerator-based BNCT (AB-BNCT) for treatment of multiple liver tumors and malignant pleural mesothelioma (MPM), we compared dose distribution and irradiation time between AB-BNCT and reactor-based BNCT (RB-BNCT).

Material and methods

We constructed treatment plans for AB-BNCT and RB-BNCT of four multiple liver tumors and six MPM. The neutron beam data on RB-BNCT were those from the research reactor at Kyoto University Research Reactor Institute (KURRI). The irradiation time and dose-volume histogram data were assessed for each BNCT system.

Results

In BNCT for multiple liver tumors, when the 5 Gy-Eq dose was delivered as the mean dose to the healthy liver tissues, the mean dose delivered to the liver tumors by AB-BNCT and RB-BNCT was 68.1 and 65.1 Gy-Eq, respectively. In BNCT for MPM, when the mean lung dose to the normal ipsilateral lung was 5 Gy-Eq, the mean dose delivered to the MPM tumor by AB-BNCT and RB-BNCT was 20.2 and 19.9 Gy-Eq, respectively. Dose distribution analysis revealed that AB-BNCT is superior to RB-BNCT for treatment of deep-seated tumors.

Conclusions

The feasibility of the AB-BNCT system constructed at our institute was confirmed from a clinical viewpoint in BNCT for multiple liver tumors and MPM.     

等离子喷涂B4C涂层的抗辐射性能研究

目的 研究用等离子技术喷涂的碳化硼(B4C)涂层的抗辐射能力.方法 将0.1 mm厚度B4C涂在16号锰钢上,研究它对加速器产生的6、10、15 MV高能射线,6、9、12、15 MeV高能电子线,60Co γ线和快中子辐射的防护作用.同时将0.1 mm B4C涂在纸板上,研究它对深部X线机的X线辐射的防护作用.结果 等离子喷涂制备B4C涂层对高能X线和60Co γ线没有防护作用.对电子线有一定防护作用,且随深度的增加有增大趋势,但作用不大.对快中子有较大防护作用.对深部X线机X线有防护作用,防护能力较强.0.1 mm厚的涂层就可带来15%的衰减.结论 用等离子技术喷涂的B4C涂层可在医学领域用来防护千伏级射线.     

Comparison of cardioprotective effects of labeled and unlabeled oleanoic acids with new BOPIM dye on primary neonatal rat cardiomyocytes following hypoxia/reoxygenation injury

BackgroundIt is well known that fluorescent labeling has recently become a major research tool in molecular and cellular biology for demonstrating therapeutic mechanisms and metabolic pathways. However, few studies have reported the use of fluorescent labeling of natural products.MethodsWe recently explored the boron 2-(2′-pyridyl) imidazole (BOPIM) derivative analogs, which are highly fluorescent, non-aggregated, and nontoxic. In the present study, the natural product oleanolic acid (OA) was functionalized and labeled with BOPIM, thus yielding a highly fluorescent probe, the comparison of cardioprotective effects of labeled and unlabeled OAs with BOPIM on primary neonatal rat cardiomyocytes with hypoxia/reoxygenation (H/R) injury were investigated.ResultsPretreatment with OA and BOPIM-OA significantly prevented the H/R induced cell death in primary neonatal rat cardiomyocytes. However, BOPIM exhibited no improvements on the H/R injury cardiomyocytes, and which were similar to those of the H/R group. The results of comparison of cardioprotective effects between labeled and unlabeled OAs with BOPIM showed that introducing the BOPIM chromophore did not make a difference with H/R injury cardiomyocytes.ConclusionBOPIM chromophore is a suitable probe for investigating the pharmacological mechanisms of natural products.