Objective To explore the detection rate and major risk factors of nodular thyroid diseases among adults.Methods A total of 35 495 adults who carried out health checkup during January 1st,2009 and December 31th,2010 in our center were assessed for the occurance of nodular thyroid diseases and the size and number of thyroid nodules by age and gender.Chi-square test,rank sum test and Chi-square trend test were used for data analysis.Results The total detection rate of nodular thyroid diseases was 33.87％ (female vs male:41.76％ vs 29.68％).The prevalence of single thyroid nodule was decreased with age,as opposed to multi-thyroid nodules.Single thyroid nodule was more commonly seen in males,which was reversed in multi-thyroid nodules.Small,middle and large thyroid nodules were found in 77.49％,18.19％ and 4.32％ males or 72.57％,21.59％ and 5.84％ females,respectively.Moreover,thyroid cancer was detected in 0.4‰ of those with nodular thyroid diseases.Conclusions The detection rate of nodular thyroid diseases among adult health checkup receivers was higher,which calls on the needs of intensive monitor and effective prevention of the condition.

The low expression rate of exogenous genes in cyanobacteria is one of the bottlenecks of cyanobacteria genetic engineering. The T7 RNA polymerase expression system has achieved the efficient expression of exogenous genes in Escherichia coli. Cyanobacteria and E. coli are both Gram-negative bacteria with high genetic homology. The construction of T7 RNA polymerase expression system in cyanobacteria may improve the expression of foreign genes. In order to construct the T7 RNA polymerase expression system in Anabaena sp. PCC 7120, methods such as overlapping extension PCR and digestion-ligation technique were used to construct a site-specific integration vector pEASY-T1-F1-TacT7RNAPCmR-F2 and a shuttle expression vector pRL-T7-hG-CSF. The site-specific integration vector is capable of expressing T7 RNA polymerase, and the shuttle expression vector expresses hG-CSF driven by the T7 promoter. Then we introduced the site-specific integration vector into the wild type cyanobacteria by electroporation and transferred the shuttle expression vector into the site-integrated transgenic cyanobacteria by triparental conjugative transfer. In the end, we identified the presence of foreign genes in cyanobacteria by PCR, tested the transcription level of foreign genes in cyanobacteria by RT-PCR, and detected the protein expression of foreign genes in cyanobacteria by Western blotting. The two vectors were successfully constructed, the T7 RNA polymerase gene and hG-CSF gene were transferred into cyanobacteria well, and both genes were also expressed in cyanobacteria. In summary, the T7 RNA polymerase expression system was successfully constructed in cyanobacteria, and the expression rate of hG-CSF gene was doubled than the traditional cyanobacteria expression systems. This expression system will provide a better tool for the application of cyanobacteria genetic engineering and will promote the development of cyanobacteria as a chassis cell in the fields of synthetic biology in the future.
Anabaena/genetics* ; Cloning, Molecular ; DNA-Directed RNA Polymerases ; Escherichia coli/genetics* ; Gene Expression ; Mercury ; Plasmids ; Viral Proteins