Immunological properties of low molecular-weight proteins binding heavy metals in rat kidney and liver

Two homogenous fractions of hepatic metallothioneins ((Cd,Zn) MT-1 and (Cd,Zn) MT-2) and renal metal binding proteins ((Bi,Cu) BP-1 and (Bi,Cu) BP-2) were isolated from rats exposed to heavy metals and specific antisera to them were produced in rabbits.These antisera were tested by immunodiffusion and immunoelectrophoresis for their ability to bind different fractions of hepatic Cd,Zn -metallothionein and renal (Bi,Cu)-, (Hg,Cu)- and (Cd,Cu)-binding proteins. It was found that anti (Bi,Cu) BP antisera did not cross-react with hepatic (Cd,Zn) MT-1 and (Cd,Zn) MT-2. Strong immunological cross-reactions were detected between anti (Bi,Cu) BP antisera and individual forms of (Cd,Cu)-, (Hg,Cu)- and (Bi,Cu)-binding proteins isolated from rat kidneys.     

Bi PAP呼吸机无创通气联合氧气驱动雾化吸入对慢阻肺合并呼吸衰竭的疗效

摘要 目的：研究Bi PAP呼吸机无创通气以及氧气驱动雾化吸入联用对慢性阻塞性肺疾病（慢阻肺）合并呼吸衰竭的疗效。方法：选择2016年12月～2018年12月我院的121例慢阻肺合并呼吸衰竭患者,随机分为两组。对照组采用Bi PAP呼吸机无创通气疗法,观察组联合氧气驱动雾化吸入布氨溴索和地奈德混悬液。比较两组的呼吸频率、血气指标和心率;血清肺表面活性相关蛋白D(Pulmonary surfactant related protein,SP-D)以及部活化调节趋化因子(PARC/CCL18)水平、肺功能。结果：观察组的有效率明显高于对照组(P<0.05);治疗后,两组的呼吸频率、血气指标和心率明显改善(P<0.05),且观察组的呼吸频率、血气指标和心率明显优于对照组(P<0.05);治疗后,两组的血清PARC/CCL18 以及SP-D水平均明显降低(P<0.05),且观察组的血清PARC/CCL18 以及SP-D水平明显低于对照组(P<0.05);治疗后,两组的FEV₁%、呼吸困难指数以及FEV₁/FVC明显改善(P<0.05),且观察组的FEV₁%、呼吸困难指数以及FEV₁/FVC明显优于对照组(P<0.05)。结论：Bi PAP呼吸机无创通气以及氧气驱动雾化吸入联用能改善慢阻肺合并呼吸衰竭的血气指标、生命体征和肺功能,降低血清 PARC/CCL18 以及SP-D水平。     

Synthesis and evaluation of a bifunctional chelate for development of Bi(III)-labeled radioimmunoconjugates

A new bifunctional ligand C-DEPA was designed and synthesized as a component for antibody-targeted radiation therapy (radioimmunotherapy, RIT) of cancer. C-DEPA was conjugated to a tumor targeting antibody, trastuzumab, and the corresponding C-DEPA-trastuzumab conjugate was evaluated for radiolabeling kinetics with ^205/6Bi. C-DEPA-trastuzumab conjugate rapidly bound ^205/6Bi, and ^205/6Bi-C-DEPA-trastuzumab conjugate was stable in human serum for 72 h. The in vitro radiolabeling kinetics and serum stability data suggest that C-DEPA is a potential chelate for preclinical RIT applications using ²¹²Bi and ²¹³Bi.     

Controllable extracellular biosynthesis of bismuth sulfide nanostructure by sulfate‐reducing bacteria in water–oil two‐phase system

Due to strong hydrolysis of Bi³⁺ as precursor in aqueous media, there are no reports on biosynthesis of bismuth sulfide (Bi₂S₃) nanomaterials. In this work, the water–oil two‐phase system was used to biosynthesize the Bi₂S₃ nanomaterials based on the coupling reaction of biological reduction and chemical precipitation process for the first time. The results showed that the water–oil two‐phase system successfully eliminated hydrolysis of the Bi³⁺ and controllably and extracellularly fabricated the Bi₂S₃ crystal with high purity. The nanorods with diameter of about 100 nm and length of about 1.0 μm were attained under high dose of lactic acid and SO₄^2?; while low dose obtained the nanobundles consisted of nanoneedles with tip diameter of 10–20 nm and length of about 5.0–10.0 μm. The Bi₂S₃ nanorods as photocatalyst almost completely degraded methylene blue from solution within 12 h; whereas the Bi₂S₃ nanobundles removed about 87% of the dye. The amount of the Bi₂S₃ nanorods decreased by 48% due to photocorrosion, whereas 52% with the nanobundles. The Bi₂S₃ nanorods had relatively higher photocatalysis activity and slightly stronger photocorrosion resistance than the Bi₂S₃ nanobundles. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:960–966, 2014     

用细菌/杆状病毒系统在昆虫细胞中表达GFP与HCV抗原融合蛋白

用细菌／杆状病毒（Ｂａｃ－ｔｏ－Ｂａｃ）系统在昆虫细胞中高效表达了绿色荧光蛋白（ＧＦＰ）与ＨＣＶ抗原的双功能融合蛋白,经ＥＬＩＳＡ测定和荧光显微镜观查证实,表达产物既能发射易于检测的绿色荧光,又具有ＨＣＶ的抗原活性,实现了用绿色荧光蛋白等分子标记抗原,为免疫诊断新方法的建立打下了理论基础．     

NAD- and NADP-dependent mitochondrially targeted methylenetetrahydrofolate dehydrogenase-cyclohydrolases can rescue mthfd2 null fibroblasts

Mouse fibroblasts in which the mthfd2 gene encoding mitochondrial NAD-dependent methylenetetrahydrofolate dehydrogenase-cyclohydrolase (NMDMC) was previously inactivated were infected with retroviral expression constructs of dehydrogenase/cyclohydrolase cDNA. Cellular fractionation confirmed that the expressed proteins were properly targeted to the mitochondria. Expression of the NAD-dependent methylenetetrahydrofolate dehydrogenase-cyclohydrolase enzyme in mitochondria corrected the glycine auxotrophy of the null mutant cells. A construct in which the cyclohydrolase activity of NMDMC was inactivated by point mutation also rescued the glycine auxotrophy, although poorly. This suggests that the cyclohydrolase activity is also required to ensure optimal production of 10-formyltetrahydrofolate. The expression of the NADP-dependent methylenetetrahydrofolate dehydrogenase-cyclohydrolase-synthetase in the mitochondria also reversed the glycine requirement of the null cells demonstrating that the use of the NAD cofactor is not absolutely essential to maintain the flux of one-carbon metabolites. All rescued cells demonstrated a decrease in the ratio of incorporation of exogenous formate to serine in standardized radiolabeling studies. This ratio, which is approximately 2.5 for nmdmc(-/-) cells and 0.3 for the wild type cells under the conditions used, is a qualitative indicator of the ability of the mitochondria of the cells to generate formate.     

Synergistical Enhancement of Thermoelectric Properties in n‐Type Bi2O2Se by Carrier Engineering and Hierarchical Microstructure

Oxygen‐containing compounds are promising thermoelectric (TE) materials for their chemical and thermal stability. As compared with the high‐performance p‐type counterparts (e.g., ZT ≈1.5 for BiCuSeO), the enhancement of the TE performance of n‐type oxygen‐containing materials remains challenging due to their mediocre electrical conductivity and high thermal conductivity. Here, n‐type layered Bi₂O₂Se is reported as a potential TE material, of which the thermal conductivity and electrical transport properties can be effectively tuned via carrier engineering and hierarchical microstructure. By selective modification of insulating [Bi₂O₂]²⁺ layers with Ta dopant, carrier concentration can be increased by four orders of magnitude (from 10¹⁵ to 10¹⁹ cm^?3) while relatively high carrier mobility can be maintained, thus greatly enhancing the power factors (≈451.5 µW K^?2 m^?1). Meanwhile, the hierarchical microstructure can be induced by Ta doping, and the phonon scattering can be strengthened by atomic point defects, nanodots of 5–10 nm and grains of sub‐micrometer level, which progressively suppresses the lattice thermal conductivity. Accordingly, the ZT value of Bi_1.90Ta_0.10O₂Se reaches 0.36 at 773 K, a ≈350% improvement in comparison with that of the pristine Bi₂O₂Se. The average ZT value of 0.30 from 500 to 823 K is outstanding among n‐type oxygen‐containing TE materials. This work provides a desirable way for enhancing the ZT values in oxygen‐containing compounds.     

Synthesis,structure and density functional theory calculations of a novel photoluminescent trisarylborane–bismuth(III) complex

A novel trisarylborane–Bi(III) complex, tris(4‐(dimesitylboryl)phenyl)bismuthine [Bi(PhBMes₂)₃], in which (Ph = phenyl, and Mes = mesityl), was synthesized via the reaction of bismuth (III) chloride (BiCl₃) with three equivalents of lithiated (4‐bromophenyl)‐ dimesitylborane [BrPhBMes₂]. The new trisarylbismuthine was characterized by elemental analysis, ultraviolet–visible (UV–vis) spectroscopy, and NMR (¹H and ¹³C) spectroscopy. The molecular structure of Bi(PhBMes₂)₃ in the solid state was determined using single‐crystal X‐ray diffraction analysis, which showed short intermolecular C–H···H–C contact. The complex is a fluorescent emitter (λ_max = 395 nm) at room temperature and a phosphorescent emitter (λ_max = 423 nm) at 77 K, which displayed a long lifetime of 495 ms. The UV–vis transitions were investigated using density function theory (DFT) and time‐dependent (TD)‐DFT calculations. Natural bond orbital analysis showed that the bismuth (III) center was mainly Lewis acidic in nature.     

Kinetic model for synthesis of fructosyl-stevioside using suspended β-fructofuranosidase

The synthesis experiments of fructosyl-stevioside were conducted under the various conditions of the initial concentrations of the substrates and the enzyme. The transfructosylation of stevioside with sucrose and the hydrolyses of sucrose and fructosyl-stevioside simultaneously occurred. The fructosyl-stevioside synthesis was inhibited by the side products, glucose and fructose. A kinetic model was constructed by considering the Ping-Pong Bi Bi mechanism for the transfructosylation, the apparent Ordered Uni Bi mechanism for the hydrolysis and the competitive inhibition by the side products. The model constants were estimated by fitting the model equations with the experimental results for the sucrose hydrolysis and the fructosyl-stevioside synthesis. The model can predict not only the appropriate conditions to efficiently synthesize the fructosyl-stevioside, but also the reaction time giving the maximum conversion.