Objective To develop a method for determination of mercury in blood by atomic fluorescence spectrometry. Methods Using a thiourea extraction method, the mercury in blood is determined by atomic fluorescence spectrometry. Results The linearity of calibration curve of mercury was in the concentration of 0.000-10.00 ?g/L. The detection limit was 0.06 ?g/L. The recovery rates were 95.5%-100.3%.The RSDs were 4.1%-4.5%. Conclusion The method has the advantages of simple operation, high sensitivity, good repeatability and is applicable to the determination of mercury in blood.

AIM: To evaluate the effect of the chosen incision on corneal astigmatism after implantable collamer lens ( ICL) surgery.
METHODS:The study included 195 eyes of 102 patients, and all eyes were randomly divided into two groups: the chosen incision group ( Group A, 97 eyes) and temporal corneal incision ( Group B, 98 eyes ) . Before the operation, and 1wk, 1mo and 3mo after the operation, each patient was examined with corneal topography to observe the changes of corneal astigmatism.
RESULTS: Preoperative corneal astigmatisms were (1-26±0. 35) D in group A and (1. 28±0. 38) D in group B, thus there was no statistically significant difference ( P>0-05). One week postoperatively, the astigmatism were (0.93±0.29)D in group A and (1.32±0.33)D in group B. One month postoperatively, the astigmatism were (0. 85±0.16)D in group A and (1.27±0.18)D in group B. Three months postoperatively, the astigmatism were ( 0. 80±0-13)D in group A and (1. 25±0. 20) D in group B. The differences between the two groups were statistically significant (P<0. 01).
CONCLUSION: The chosen incision can reduce postoperative astigmatism to a certain extent after ICL surgery.

Objective ST-T complex change, which represents the ventricle repolarization phase, is the main clinical indicator in detecting myocardial ischemia (MI) based on electrocardiogram (ECG) signals.However, its feature point location is not accurate due to interferences. In this paper, a new approach about myocardial ischemia analysis was proposed based on QRS complex. Methods QRS complex, representing the ventricle depolarization process, was used to analyze myocardial ischemia, and some parameters were extracted synthetically in time domain. Then they were used for statistical analysis of myocardial ischemia states and non-myocardial ischemia states. Results Five parameters had significant differences after verification of Non-MI signals in MIT-BIH database and MI signals in long-term ST database (LTST) and they were: QRS upward and downward slopes, transient heart rate, R angle and Q angle in a triangle QRS. Conclusion Five parameters extracted from QRS complex had significant differences. The proposed method provides an important basis for myocardial ischemia detection.

A patient was treated by multiple dental implants,the implanted 6 was adjucent to impacted 8 .Immediately after implanta-tion,4 month and 3 year after implantation the distace between 8 and 6 implant central line was 4.4,3.2 and 2.5 mm,the angle between 8 long axis and 6 implant central line was 42.3°,45.5°and 50.3°.Then 8 was extracted.

Objective To investigate the effect of ionizing radiation on the expression of transcription factor STAT3 target genes in the pulmonary adenocarcinoma cell line A549.Methods The expressions of VEGF,Bcl-2 and Survivin in A549 cells with or without STAT3 inhibition were detected by RT-PCR and/or Western blot 24 h after 2 or 4 Gy of γ-ray irradiation.Results After γ-ray irradiation with 2 or 4 Gy,the expression of VEGF and Survivin increased significantly.However,the expression of Bcl-2 was not affected by γ-ray irradiation.Furthermore,the increased expression of VEGF and Survivin induced by radiation was found to be inhibited after radiation-induced activation of STAT3 was blocked by AG490 inhibiter.Conclusions γ-ray irradiation could up-regulate the expression of Survivin and VEGF via activating STAT3.The increase of Survivin might partly inhibit the radiation-induced apoptosis of A549 cells,and the up-regulation of VEGF might contribute to the tumor angiogenesis.

AIM:To investigate the roles of feeder cells ln stratification of murine corneal epithelial cells and build an ideal method to engineer stratified epithelial sheet.METHODS:Using contact feeder culture,separated feeder culture,compound feeder culture and culture without feeder cells by Air-lifting method in Transwell chamber culture system,tissue engineered corneal epithelium was reconstructed.Corneal sheets were stained with hematoxylin and eosin(HE)for histological observation.The expression of p63 and keratin 19(K19)and involucrin(IVL)was investigated by immunocytochemistry analysis.RESULTS:Stratification was limited to three to four layers in the contact feeder group,whereas separate feeder sheets were slightly more stratified.The compound feeder group produced a stratified epithelium with five to seven layers of cells.The group without 3T3 feeder cells formed only two to three layers of cells.Immunostaining images in the compound feeder group showed expression of progenitor markers p63 and K19 in the basal and suprabasal layer,as well as differentiation marker involucrin in all layers.CONCLUSION:The remarkable stratification as well as the Iimbal phenotype makes the compound feeder system a candidate tool for cultivating transplantable epithelial sheets.

AIM:To investigate how to design personalized cataract surgery programs to achieve surgical correction of preoperative corneal astigmatism with surgical astigmatism under the guidance of corneal topography, improve postoperative visual quality and reduce the cost of treatment.
METHODS: Totally 202 cases ( 226 eyes ) cataract patients were divided into randomized treatment group and individualized treatment group. According to the method and location of the incision, randomized treatment group were divided into 8 groups. Surgical astigmatism after different incision were calculated with the use of preoperative and postoperative corneal astigmatism through vector analysis method. Individualized treatment groups were designed personably for surgical method with reference of every surgically induced astigmatism, the surgical method chooses the type of surgical incision based on close link between preoperative corneal astigmatism and surgically induced astigmatism, and the incision was located in the steep meridian. The postoperative corneal astigmatism of individualized treatment group was observed.
RESULTS: Postoperative corneal astigmatism of individualized treatment group were lower than that of 3.0mm clear corneal tunnel incision in the randomized treatment group, there were statistically significance difference, while with 3. 0mm sclera tunnel incision group there were no statistically significance difference. After 55. 8% of patients with the use of individualized surgical plan could undergo the operation of extracapsular cataract extraction with relatively low cost and rigid intraocular lens implantation, the per capita cost of treatment could be reduced.
CONCLUSION: Personalized cataract surgery programs are designed to achieve surgical correction of preoperative corneal astigmatism under the use of corneal topography, improve postoperative visual quality and reduce the cost of treatment.

The sfa1 gene encoded a bifunctional enzyme with the activities of both alcohol dehydrogenase and glutathione-dependent formaldehyde dehydrogenase in Saccharomyces cerevisiae.The gene disruption cassette produced by PCR using the same long oligonucleotides which comprise 19 or 22 nucleotides complementary to sequences in the templates(pUG6 and pUG66 marker plasmid)at 3' end and 45 nucleotides at 5' end that annealed to sites upstream or downstream of the genomic target sequence to be deleted.After two linear disruption cassettes with a Cre/loxP mediated marker were transformed into the cells of Saccharomyces cerevisiae YS-1,the positive transformants were checked by PCR to correct the integration of the cassette and concurrent deletion of the chromosomal target sequence.Once correctly integrated into the genome,the select marker can be efficiently rescued by transformating the plasmid pSH47 into YS-1 and inducing the Cre expression with a Cre/loxP-mediated marker removal procedure.The expression of the Cre recombinase finally resulted in the removal of the marker gene,leaving behind a single loxP site at the chromosomal locus.The diploid mutant YS-1-sfa1 was generated,which could enhance the output of ethanol with 8.0% by shaking culture in flask compared with the original strain YS-1.

Objective To explore the effect of prevention and treatment on steroid-induced osteonecrosis of mice femoral head(ONFH) treated with metformin. Methods Thirty-six Kunming mice were randomly divided into three groups (n = 12):A (Control Group), B (Model Group)and C (Prevention Group). For producing ONFH mice models, did the intraperitoneal injection of horse serum (10 mL/kg) to B and C firstly. After two weeks, continuing the intraperitoneal injection of horse serum (5 mL/kg) again with the prednisolone intramuscularly [45 mL/(kg· day), totally for 5 days]. Meanwhile, feeding normal saline 10 mL/(kg·day) to B and feeding metformin hydrochloride [0.2 g/(kg·day)] to C. For A, mice were only given normal saline intramuscularly and intragastrically in equal quantity at the same time. The contents of serum cholesterol (TC), triglycerid (TG), plasma von willebrand factor (VWF) and plasminogen activator inhibitor 1 (PAI-1) were determined at the 2nd, 4th and 6th week after treatment. The micewere sacrificed at 2nd, 4th, and 6th weekafter treatment, and femoral heads were harvested to do histopathology analysis. Results The appearance and shape of the femoral head and the surface of cartilages were normal. The percentage of empty osteocyte lacunae in B was significantly higher than that in C (P < 0.05), there was no significant difference between A and C (P>0.05). TC and TG contents in C were significantly lower than that in B in 2th、4th、6th weeek(P<0.05), and higher than that in A(P<0.05). VWF and PAI-1 level in C were significantly lower than that in B at 2nd and 4th week (P<0.05), but there were no statistical significance at 6th week. there were no statistical significance for the comparison between A and C. Conclusion Metformin can prevent steroid-induced ONFH by improving hyperlipemia, hypercoagulability and hypofibrinolysis, then effectively prevent osteonecrosis.