Studies on Androgen Receptor mRNA expression in Pancreas,Hypothalamus and Ovary of Androgen Sterilized Rats

Objective To investigate the androgen receptor （AR） mRNA expression in pancreas, hypothalamus and ovary of androgen sterilized rats （ASR）.Methods ASR model was established by subcutaneous injection of testosterone propionate to SD female rats at the age of 9 days. Around the age of 106 days （proestrus）, all rats were killed, serum Δ4-andronestedione （Δ 4-A）, total testosterone （TT）, free testosterone （FT）, insulin （Ins） and C-peptide （C-P） were measured by radioimmunoassay （RIA）. Total RNA in pancreas, hypothalamus and ovary were extracted and the amount of AR mRNA was quantitatedly analyzed by RT-PCR with single base mutant template as inner standard. Results Serum concentrations of Δ4-A, TT, FT, Ins and C-P in ASR model rats were significantly higher than those in control group （P〈0.05, P〈0.01）. The expression of AR mRNA in pancreas, hypothalamus and ovary increased significantly （P〈0. 05, P〈0.01） of model rats as compared with control group. Conclusion The elevated serum androgen levels in ASR model could enhance the expression of AR mRNA levels in pancreas, hypothalamus and ovary, which further induce hyperinsulinemia and anovulation.

Spatial phylogenetics of the Chinese angiosperm flora provides insights into endemism and conservation

The flora of China is well known for its high diversity and endemism. Identifying centers of endemism and designating conservation priorities are essential goals for biodiversity studies.However, there is no comprehensive study from a rigorous phylogenetic perspective to understand patterns of diversity and endemism and to guide biodiversity conservation in China. We conducted a spatial phylogenetic analysis of the Chinese angiosperm flora at the generic level to identify centers of neo-and paleoendemism. Our results indicate that:(i) themajority of grid cells in China with significantly high phylogenetic endemism(PE) were located in the mountainous regions;(ii) four of the nine centers of endemism recognized, located in northern and western China, were recognized for the first time;(iii) arid and semiarid regions in Northwest China were commonly linked to significant PE, consistent with other spatial phylogenetic studies worldwide;and(iv) six highpriority conservation gaps were detected by overlaying the boundaries of China’s nature reserves on all significant PE cells. Overall, we conclude that the mountains of southern and northern China contain both paleo-endemics(ancient relictual lineages) and neo-endemics(recently diverged lineages). The areas we highlight as conservation priorities are important for broad-scale planning, especially in the context of evolutionary history preservation.

Electroanalytical method for determination of shikonin based on the enhancement effect of cyclodextrin functionalized carbon nanotubes

A simple and sensitive electroanalytical method for determination of shikonin, a widely used antitumoral agent, using β-cyclodextrin-functionalized multiwalled carbon nanotubes composite modified glassy carbon electrodes （MWCNTs/β-CD/GCE） was presented. CDs are water-soluble and environmentally friendly and can improve the dispersibility of MWCNTs/βCD functional materials, which was confirmed by SEM. The electrochemical behaviors of shikonin on different electrodes were investigated by cyclic voltammetry （CV） and differential pulse voltammograms （DPVs）. The results demonstrated that the redox peak currents of shikonin obtained at MWCNTs/fl-CD/GCE were much higher than those at the βCD/GCE and MWCNTs/GCE, which can be attributed to the combination of the excellent electrocatalytic properties of MWCNTs and the molecular recognition ability of βCD. At MWCNTs/ βCD/GCE, the response current exhibits a linear range from 5.0 nmol/L to 10.0 μmol/L with a detection limit of 1.0nmol/L （S/N=3）. As a practical application, the proposed method was applied to quantitatively determine shikoninin urine samples with satisfying results.

POLY(THIOPHENE-3-ACETIC ACID)-PALLADIUM NANOPARTICLE COMPOSITE MODIFIED ELECTRODES FOR SUPERSENSITIVE DETERMINATION OF HYDRAZINE

A promising electrochemical sensor was fabricated by electrodeposition of Pd nanoparticles （PdNPs） on poly（thiophene-3-acetic acid） （PTAA）-modified glassy carbon electrode （GCE）, forming a PdNPs/PTAA composites-modified GCE （PdNPs/PTAA/GCE）. Scanning electron microscope （SEM） and electrochemical techniques were used for the characterization of these composites. It was found that the PdNPs/PTAA layer was very uniform. ]Electrochemical experiments showed that this proposed PdNPs/PTAA composites-modified electrode exhibited excellent electrocatalytic activity towards the oxidation of hydrazine. Under the optimum conditions, the proposed sensor can be applied to the quantification of hydrazine with a wide linear range from 8.0 × 10-9 mol/L to 1.0 × 10-5 mol/L with a low detection limit of 2.67 × 10-9 mol/L. The experiment results also showed that the sensor exhibited good reproducibility and long-term stability, as well as high selectivity with no interference from other potential competing species.