A new carbazole-based phenanthrenyl ruthenium complex as sensitizer for a dye-sensitized solar cell

Three new amphiphilic ruthenium complexes (Ru-1, Ru-2 and Ru-3) based on phenanthrenyl derivatives have been synthesized and used as photosensitizers for dye-sensitized solar cells (DSSCs). The ruthenium complex Ru-1 containing a carbazole group showed especially improved photophysical properties (red-shifted metal-to-ligand charge-transfer transition absorptions and enhanced molar extinction coefficients) and interesting electrochemical properties, resulting in its improved open circuit potential and high overall light-to-electric power conversion efficiency of 5.3% (AM1.5, 75 mW/cm²). These facts indicate that the carbazole-based phenanthrenyl ruthenium complex is a promising candidate for improving the conversion efficiency of dye-sensitized solar cells.     

A new study of cell disruption to release recombinant thermostable enzyme from Escherichia coli by thermolysis

Extraction of intracellular protein from Escherichia coli is traditionally achieved by mechanical, chemical or enzymatic disruption technology. In this study, a novel thermolysis method was used to disrupt E. coli cells to release a recombinant thermostable esterase. We found that heat treatment of E. coli was highly effective to destroy the integrity of bacterial cell walls and release the recombinant hyperthermophilic esterase at temperatures above 60 degrees C. The effects of temperature, pH and cell concentration on the efficiency of cell disruption were examined. The most effective temperature for cell disruption was at 80 degrees C. The pH and cell concentration had only minor effect on the release of the hyperthermophilic esterase. In addition, we found that the hyperthermophilic esterase could be purified at the early stage of the thermolysis, which is a major advantage of the thermolysis method. Finally, a comparison between thermolysis and traditional methods for the disruption of cells and the release of the thermostable enzyme was made.     

Developmental expression of CagMdkb during gibel carp embryogenesis

Midkine (Mdk) genes have been revealed to have different expression patterns in vertebrates and therefore, additional studies on Mdk expression patterns are required in more species. In this study, CagMdkb has been cloned and characterized from a SMART cDNA library of 10-somite stage embryos of Carassius auratus gibelio. Its full length cDNA is 1091 bp and encodes a sequence of 147 amino acids, which shows 97.3% identity to zebrafish Mdkb on the amino acid level. RT-PCR analysis reveals that CagMdkb is first transcribed in gastrula embryos and maintains a relatively stable expression level during subsequent embryogenesis. Western blot analysis reveals a 19 kDa maternal CagMdkb protein band and the zygotic CagMdkb protein is expressed from gastrula stage. At around 10 somite stage, the 19 kDa CagMdkb is processed to another protein band of about 17 kDa, which might be the secreted form with the 21-residue signal peptide removed. With immunofluorescence analysis, maternal CagMdkb protein was found to be localized in each blastamere cell of early embryos. The zygotic CagMdkb positive fluorescence signal was detected from a pair of large neurons at 18-somite stage. At the later stages, CagMdkb protein was also extended to numerous small neurons in the forebrain, midbrain and hindbrain, as well as to nerve fibers in the spinal cord. Co-localization with 3A10 antibody revealed CagMdkb immunoreactivity on developing Mauthner neurons, a member of reticulospinal neurons. In addition, ectopic expression of CagMdkb in early embryos of gibel carp and zebrafish suppressed head formation and CagMdkb function was found to depend on secretory activity. All these findings indicate that CagMdkb plays an important role in neural development during gibel carp embryogenesis and there is functional conservation of Mdkb in fish head formation.     

Cholera toxin B protein in transgenic tomato fruit induces systemic immune response in mice

Cholera toxin B (CTB) subunit is a well-characterized antigen against cholera. Transgenic plants can offer an inexpensive and safe source of edible CTB vaccine and may be one of the best candidates for the production of plant vaccines. The present study aimed to develop transgenic tomato expressing CTB protein, especially in the ripening tomato fruit under the control of the tomato fruit-specific E8 promoter by using Agrobacterium-mediated transformation. Transgenic plants were selected using PCR and Southern blot analysis. Exogenous protein extracted from leaf, stem, and fruit tissues of transgenic plants was detected by ELISA and Western blot analysis, showing specific expression in the ripening fruit, with the highest amount of CTB protein being 0.081% of total soluble protein. Gavage of mice with ripe transgenic tomato fruits induced both serum and mucosal CTB specific antibodies. These results demonstrate the immunogenicity of the CTB protein in transgenic tomato and provide a considerable basis for exploring the utilization of CTB in the development of tomato-based edible vaccine against cholera. The rCTB antigen resulted in much lower antibody titers than an equal amount of exgenous CTB in trangenic fruits, suggesting the protective effect of the fibrous tissue of the fruit to the exogenous CTB protein against the degradation of protease in the digestive tracts of mice. Xiao-Ling Jiang and Zhu-Mei He contributed equally to this work.     

Identification of a putative oocyte-specific small nuclear ribonucleoprotein polypeptide C in gibel carp

Previous studies have demonstrated that germinal vesicle of amphibian oocyte contains small nuclear ribonucleoprotein polypeptide C (SNRPC). In this study, a putative member of SNRPC was identified from Carassius auratus gibelio oocyte cDNA library. Its full-length cDNA has an open reading frame of 201 nt for encoding a peptide of 66 aa, a short 5'-UTR of 19 nt and a long 3'-UTR of 347 nt including a polyadenylation signal and poly- (A) tail, and the deduced amino acid sequence has 47% identity with the C-terminal of the zebrafish small nuclear ribonucleoprotein polypeptide C. Western blot analysis revealed its oocyte-specific expression. Immunofluorescence localization indicated that its gene product localized to numerous nucleoli within the oocytes and showed dynamic changes with the nucleoli during oocyte maturation. RT-PCR and Western blot analysis further revealed its constant presence in the oocytes and in the embryos until hatching. The data suggested that the newly identified CagOSNRPC might be a nucleolar protein.     

Morphogenesis of Pistillate Flowers of Cercidiphyllum japonicum(Cercidiphyllaceae)

Floral morphogenesis and the development of Cercidiphyllum japonicum Sieb.et Zucc.were observed by scanning electronmicroscopy(SEM).The results showed that the pistillate inflorescences were congested spikes with the flowers arrangedopposite.Great differences between the so-called"bract"and the vegetative leaf were observed both in morphogenesis andmorphology.In morphogenesis,the"bract"primordium is crescent-shaped,truncated at the apex and not conduplicate,has no stipule primordium at the base but does have some inconspicuous teeth in the margin that are not glandular.Theleaf primordium is triangular,cycloidal at the apex,conduplicate,has two stipule primordia at the base,has one gland-toothat the apex occurring at first and some gland-teeth in the margin that occur later.In morphology,the"bract"is also differentto the vegetative leaf in some characteristics that were also illustrated in the present paper.Based on the hypothesis thatthe bract is more similar to the vegetative leaf than the tepal,we considered that the so-called"bract"of C.japonicum mightbe the tepal of the pistillate flower in morphological nature.Therefore,each pistillate flower contains a tepal and a carpel.We did not find any trace of other floral organs in the morphogenesis of the pistillate flower.Therefore we consideredthat the unicarpellate status of extant Cercidiphyllum might be to highly reduce and advance characteristics that make theextant Cercidiphyllum isolated from both fossil Cercidiphyllum-like plants and its extant affinities.     

Hydrogen sulfide plays a potential alternative for the treatment of metabolic disorders of diabetic cardiomyopathy

Molecular and Cellular Biochemistry - Diabetic cardiomyopathy (DCM) is a cardiovascular complication that tends to occur in patients with diabetes, obesity, or insulin resistance, with a higher...     

冻融条件下生物结皮覆盖对土壤饱和导水率的影响

生物结皮(BSC)是广泛分布的地被物,每逢冬春季节,受冻融交替作用影响,结皮土壤的理化性质和水文学特征明显改变且与裸土差异显著,从而影响该地区土壤可蚀性评估和土壤侵蚀防治。采用室内模拟实验,以蓝藻结皮土壤为对象,研究不同冻融交替次数和初始含水量下,土壤三相对温度变化的响应特征并定量分析结皮覆盖土壤在此条件下饱和导水率(Ks)的变化趋势和突变点。结果表明:初始含水量对Ks无显著影响(P>0.05),冻融交替次数对Ks有极显著影响(P<0.01),冻融条件下裸土的平均Ks为1.941 mm/min,结皮覆盖土壤平均Ks为0.325 mm/min,两者具有极显著差异(P<0.01),且随交替次数增加,Ks差异逐渐增大,并在10次时达到最大值为10.13倍。不同冻融含水量下的结皮土壤的Ks在冻融10—20次时趋近,平均值为0.219mm/min。冻融作用显著改变土壤结构,且在冻融7次时土壤结构变化较明显,冻融过程中<0.1 mm的土壤颗粒显著变化。试验条件下,Ks受因子影响程度大小为:冻融交替次数>土壤结构>结皮厚度>结皮容重>下层土壤容重>...