硼对鸡肉铜铁锌锰含量的影响

目的 :探讨硼对鸡肉铜、铁、锌、锰含量的影响。方法 :选择 1日龄固始鸡 30 0羽 ,随机分成 4个组 ,分别在饮水中添加硼 (以硼酸作为硼源 ) 0、10 0、2 0 0和 4 0 0mg/L。测定 2 1、2 8、35和 4 2日龄时鸡肉中的铜、铁、锌、锰含量。结果 :各组鸡肉铜含量在 0 5 2～ 0 74 μg/g(湿重 )之间 ;锰含量在 0 31～ 0 4 6 μg/ g(湿重 )之间 ;日龄和组间差异均不显著 (P >0 .0 5 ) ;鸡肉铁含量在 6 2 3～ 10 4 1μg/ g(湿重 )之间 ,锌含量在 9 98～ 19 76 μg/ g(湿重 )之间 ,两者均于第 35和 4 2日龄时显著高于对照组 (P <0 0 5 )。结论 :说明硼对鸡肉中铜、锰含量没有影响 ,适量的硼 (10 0mg/L)能显著提高鸡肉中铁和锌的含量。     

硼中子俘获疗法诱导SHG44胶质瘤细胞凋亡

目的 探讨硼中子俘获疗法(BNCT)是否抑制人脑胶质瘤细胞SHG44增殖及其作用机制。方法 BNCT作用后,应用四甲基偶氮唑蓝比色法检测SHG44细胞的增殖抑制,采用光镜、电镜、荧光显微镜观察细胞的形态学变化。应用流式细胞仪检测SHG44细胞的凋亡率,以Western blot检测细胞表达Bcl-2、Bax蛋白的变化。结果 BNCT对SHG44细胞的增殖抑制作用呈剂量依赖性。BNCT 4和8 Gy后48 h流式细胞仪检测凋亡率分别为63.2%和88.3%。BNCT作用后,Bax蛋白表达增高,Bcl-2蛋白表达下降。结论 BNCT对胶质瘤细胞SHG44具有明显的增殖抑制及诱导凋亡作用,并使Bax蛋白表达上调、Bcl-2蛋白表达下调。     

Biodistribution of the boron carriers boronophenylalanine (BPA) and/or decahydrodecaborate (GB-10) for Boron Neutron Capture Therapy (BNCT) in an experimental model of lung metastases

BNCT was proposed for the treatment of diffuse, non-resectable tumors in the lung. We performed boron biodistribution studies with 5 administration protocols employing the boron carriers BPA and/or GB-10 in an experimental model of disseminated lung metastases in rats. All 5 protocols were non-toxic and showed preferential tumor boron uptake versus lung. Absolute tumor boron concentration values were therapeutically useful (25–76 ppm) for 3 protocols. Dosimetric calculations indicate that BNCT at RA-3 would be potentially therapeutic without exceeding radiotolerance in the lung.     

Critical review,with an optimistic outlook,on Boron Neutron Capture Therapy (BNCT)

The first BNCT trials took place in the USA in the early 1960's, yet BNCT is still far from mainstream medicine. Nonetheless, in recent years, reported results in the treatment of head and neck cancer and recurrent glioma, coupled with the progress in developing linear accelerators specifically for BNCT applications, have given some optimism to the future of BNCT. This article provides a brief reminder on the ups and downs of the history of BNCT and supports the view that controlled and prospective clinical trials with a modern design will make BNCT an evidence-based treatment modality within the coming decade.     

Boron intake and prostate cancer risk

Introduction Experimental studies suggest that boron may prevent prostate cancer. Only one small epidemiological study has been conducted of boron, which found that those in the highest quartile of boron intake had less than half the risk of prostate cancer versus those in the lowest quartile. Methods We evaluated the association between boron intake and prostate cancer within the VITamins And Lifestyle (VITAL) cohort. A total of 35,244 men completed the baseline supplement and food frequency questionnaire (FFQ) in 2000–2002. A boron database was constructed from published sources to estimate boron intake from the FFQ and from multivitamins. A total of 832 men developed prostate cancer from baseline to 31 December 2004. Results Dietary boron intake and total boron intake from diet plus multivitamins were not associated with prostate cancer risk. The hazard ratio of prostate cancer for those in the highest versus lowest quartile of total boron intake was 1.17 (95% CI 0.85, 1.61). This risk did not vary by prostate cancer stage or Gleason score. Furthermore, none of the foods high in boron content was associated with a decreased risk of prostate cancer. Discussion This cohort study provides no evidence for a preventive role of boron intake on prostate cancer. Since few studies exist on this topic, future research is needed to better elucidate any role that boron may play in the prevention of prostate cancer.     

Boron nitride nanoplatelets as reinforcement material for dental ceramics

ObjectiveThe main goal of this research was to demonstrate the potential value of boron nitride nanoplatelets (BNNPs), which have excellent mechanical properties and biocompatibility, as a suitable reinforcement for dental materials.MethodsThe BNNPs were prepared by exfoliating h-BN via high-energy ball-milling and dispersion on a zirconia matrix. Then the composite powder was consolidated using spark plasma sintering. Fracture toughness, flexural strength and wear resistance were the mechanical properties explored. Agar diffusion-based biocompatibility testing was carried out. Low temperature degradation tests were also performed in a steam environment in an autoclave.ResultsThe BNNPs dispersed zirconia exhibited improved strength (up to 27.3%), and fracture toughness was also increased (up to 37.5%) with the addition of 1–1.5 vol.% BNNPs. Tribological properties were also enhanced by the addition of BNNPs. The cytotoxicity tests confirmed that the BNNPs do not have obvious toxicity. The accelerated low-temperature degradation experiment revealed the barrier properties of the BNNPs, whose addition almost fully inhibited the degradation of the zirconia matrix in a humid environment.SignificanceThe main contribution of this study is the introduction of an advanced material, BNNP, which can be used as a biocompatible reinforcement for dental materials, resulting in enhanced mechanical properties of the system due to its unique structure and extraordinary properties.     

硼中子俘获疗法治疗裸鼠ACHN肾透明细胞癌的疗效观察

目的探讨硼中子俘获疗法(BNCT)治疗ACHN肾透明细胞癌的临床效果。方法建立ACHN肾透明细胞癌的荷瘤裸鼠模型。将荷瘤裸鼠随机分为5组,未注药对照组、未照射对照组、BNCT-I组、BNCT-II组和BNCT-III组,于腹腔注射二羟基硼苯丙氨酸(BPA)2.5 h后进行中子辐射。15 d后观察测量裸鼠肿瘤的大小,评价BNCT的治疗效果。结果辐射治疗后第15天,测得肿瘤体积的平均值分别为:未注药对照组(358.40±18.15)m3,未照射对照组(352.87±23.79)m3,BNCT-I组(277.11±42.33)m3,BNCT-II组(90.04±39.56)m3,BNCT-III组(212.70±52.61)m3。结论 BNCT治疗对ACHN肾透明细胞癌有明显的疗效,其效果与BPA浓度和辐射剂量有关。     

Electrochemical sensing of F− and Cl− with a boronic ester-functionalized polypyrrole

The anodic electropolymerization of pyrrole 3 substituted by a pinacolborane moiety 1 yielded anion-sensitive conjugated polymer films. The effect of different halides (F^?, Cl^? and Br^?) on the voltammetric response of poly(1) was examined in organic and hydro-organic media. Larger effects were observed in CH₂Cl₂ because of a weaker solvation of anions. In this solvent the system corresponding to the doping/undoping of poly(1) was shifted 450 and 175 mV towards less oxidizing potentials in the presence of F^? and Cl^?, respectively. In contrast, the polymer response was unchanged upon the addition of Br^?. These results were consistent with a greater affinity of the immobilized boronic ester groups for F^?, which could be explained by the hardness of the Lewis base.     

Boron neutron capture therapy as a novel modality of radiotherapy for oral cancer: Principle and antitumor effect

Radiotherapy is essential for the treatment of oral cancer, especially in advanced cases. There has been marked progress in this field due to the prevalence of intensity-modified radiation therapy and introduction of particle radiotherapy using protons and carbon-ions. However, these treatments are still non-selective. Boron neutron capture therapy (BNCT) is a unique modality in which neutron beams destroy only boron compound-bearing tumor cells while leaving the surrounding normal tissues intact. Thus, BNCT is a selective form of radiotherapy, if high tumor/normal tissue ratio in boron concentration could be achieved. The principle of BNCT, and the basic study of the mechanism by which BNCT exerts antitumor effects using oral squamous cell carcinoma (SCC) cells and oral SCC xenografts in mice are described.