Carbamate pesticides, a new type of broad-spectrum pesticides for controlling pests, mites, and weeds, are developed to address the shortcomings of organochlorine and organophosphorus pesticides. Their widespread use and slow degradation have led to environmental pollution, causing damage to ecosystems and human health. Managing pesticide residues is a pressing issue in the current environmental protection. This study aims to investigate the expression of SyEst870, a member of the SGNH/GDSL hydrolase family in Sphingobium yanoikuyae, in a prokaryotic system and evaluate the ability of the recombinant protein to degrade carbamate pesticides. The prokaryotic expression vector pET-32a-SyEst870 was constructed and transformed into the Escherichia coli BL21 for heterologous expression. The purified protein was studied in terms of enzyme activity and effects of temperature, pH, and metal ions on the enzyme activity, with p-nitrophenol acetate as the substrate and based on the standard curve of p-nitrophenol. LC-MS (liquid chromatography-mass spectrometry) was employed to examine the degradation effects of SyEst870 on carbaryl, metolcarb, and isoprocarb. GC-MS (gas chromatography-mass spectrometry) was employed to detect the degradation products of SyEst870 for the three pesticides. The soluble protein SyEst870 was successfully obtained through the heterologous expression in Escherichia coli, which yielded an enzyme with the activity of 677.5 U after affinity chromatography. SyEst870 exhibited degradation rates of 82.34%, 84.43%, and 92.87% for carbaryl, metolcarb, and isoprocarb, respectively, at an initial concentration of 100 mg/L within 24 h at 30 ℃ and pH 7.0. The primary degradation products of carbaryl were identified as α-naphthol and methyl isocyanate. Metolcarb was mainly degraded into m-cresol and methyl isocyanate, and isoprocarb was mainly degraded into 2-isopropylphenol and methyl isocyanate. Compared with the half-life of carbamate pesticides in the natural environment, which ranges from a few days to several weeks, the recombinant protein SyEst870 can rapidly eliminate the residues of carbamate pesticides. This study lays a foundation for addressing pesticide residues in the environment and in fruits and vegetables.
Escherichia coli/metabolism* ; Sphingomonadaceae/genetics* ; Recombinant Proteins/metabolism* ; Biodegradation, Environmental ; Esterases/metabolism* ; Pesticides/isolation & purification* ; Carbamates/isolation & purification*

OBJECTIVE：To study the prepar ation technology of gastric floating tablets of Schisandra chinensis total lignans （SCTL），and evaluate the quality of prepared tablets. METHODS ：Based on single factor test ，the orthogonal experiment was conducted to optimize the formulation of SCTL gastric floating tablets with the contents of hydroxypropylmethylcellulose （HPMC） K15M，NaHCO3 and microcrystalline cellulose as the factors ，using starting time ，holding time and cumulative release rate of gastric floating tablets as evaluation indexes. The properties ，weight difference ，floatability and accumulative release rate of the prepared SCTL gastric floating tablets were determined. The gastric floating tablets were qualitatively identified by TLC ，and the contents of schisandrin A and total lignans were determined by HPLC and UV spectrophotometry. RESULTS ：The optimal formulation of SCTL gastric floating tablets was made up of 23％ SCTL extract ，20％ HPMC K 15M，40％ microcrystalline cellulose，15％ sodium bicarbonate ，1％ octadecyl alcohol and 1％ polyvinylpyrrolidone. The results of detection of this preparation were in line with the related provisions of “0101 tablet”stated in 2015 edition of Chinese Pharmacopoeia （part Ⅳ）. TLC indicated that the chromatogram of the test sample showed the main spots of same color as the corresponding positions of the chromatogram of schizandrol A control ，Schisandra chinensis reference substance and raw material ，while the negative control has no interference. Content determination results shows that the average content of schizandrol A and total lignans in SCTL gastric floating tablets is 3.187，19.617 mg. It was preliminarily formulated that the content limitation of schizandrol A in one tablet should not be less than 2.50 mg，and the content of total lignans （calculated by schizandrol A ）should not be less than 15.50 mg. CONCLUSIONS：The preparation technology of SCTL gastric floating tablets is stable ，feasible and controllable in quality.

Objective To explore the continuous improvement to reduce the suctioning pediatrics lumen instruments return-cleaning rate of the first time washing, improve work efficiency and reduce the cost by applying root cause analysis. Methods Using causal analysis of fishbone diagram to analysis and verify the main reason of leading to high lumen instruments return-cleaning rate. According to the three terminal factors of continuous quality improvement, quality control group was set up, lumen instruments cleaning quality control standards was made, water flow mode of lumen instruments cleaning was changed, selected the appropriate cleaning tools and real picture show, synchronize quality control measures of publishing the quality and safety board. Compared before and after return-cleaning rate of three different detection methods and the different parts of the same suction lumen instruments. Results Before carrying out eye-measurement, cotton swab to wipe, ATP bioluminescence back washing rate was 0.89% (2/225), 7.11%(16/225), 27.11%(61/225), respectively after implementation of 0, 0.44%(1/226), 3.98%(9/226), visual observation before and after the return rate of washing was no statistically significant difference (χ2=2.018, P>0.05);Cotton swab to wipe, ATP bioluminescence back washing rate difference was statistically significant (χ2=13.820, 45.999, P<0.01). The lumen instruments total return-washing rate was decreased from 35.11% (79/225) to 4.42% (10/226). Among them, the return- washing rate of the inside surface of lumen instruments was decreased from 32.89% (74/225) to the 3.10% (7/226) and the difference was statistically significant(χ2=67.028, 67.915,P<0.01). By contraries, the thread interface and the outside surface of lumen instruments return- cleaning rate before and after the implementation has no statistical significance (P>0.05). Conclusions ATP bioluminescence assay has fine effects to detect the return-washing rate of the inner wall of the lumen instruments. The Root Cause Analysis method significantly reduced the return-washing rate of the inside surface of the suction lumen instruments, improve the efficiency, save the medical cost and reduce the hospital infection.

Objective: RET/PTC gene rearrangement can lead to aberrant activation of tyrosine kinase receptors, which is a common mutation in papillary thyroid carcinoma (PTC). This study focuses on the association of RET/PTC rearrangements with PTC clinical factors. Methods: From January 2011 to December 2013, a total of 114 patients with PTC were enrolled in this study. Clinicopathological parameters, lifestyle, and thyroid hormone levels were collected. RET/PTC rearrangements were detected by TaqMan PCR and verified by Sanger sequencing.Data were analyzed with SPSS software, including chi-square test, Fisher′s exact test, Mann-Whitney U test, Student′s t-test, and Logistic regression. Results: RET/PTC rearrangements were not found in all paracancerous normal thyroid tissues, and were detected in 23.68% (27/114) of PTC. Further analysis revealed no correlation between RET/PTC rearrangement and thyroid function, clinicopathologic parameters, and lifestyle in the total PTC group or in the subgroup of patients with concomitant diseases (including Hashimoto′s thyroiditis and nodular goiter). But in the subgroup of PTC without concomitant disease, RET/PTC rearrangement was associated with tumor multifocal (P=0.018), and RET/PTC-positive PTC patients had an increased risk of tumor multifocal (OR=5.57, 95% CI 1.39-22.33). It was also found that RET/PTC rearrangement was associated with an abnormal increase in TSH level of one month after surgery (P= 0.037). Conclusion Nodular goiter and Hashimoto ′s thyroiditis may be a confounding factor in PTC. RET/PTC rearrangement may play an important role in the occurrence of thyroid carcinoma multifocal after exclusion of this confounding factor.

Objective To improve the cleaning quality of reusable medical instruments continuously through root cause analysis,reduce healthcare-associated infection(HAI)and the wear and tear of instruments.Methods The major factors influencing the cleaning quality of instruments were analyzed and clarified by fishbone diagram,contin-uous quality improvement was carried out based on 5 terminal factors,the rate of rusting,stain,repeated cleaning, damage,and clinical department satisfaction before and after the implementation of continuous improvement were compared.Results The qualified rate of instrument clean increased from 94.24% before implementing measures to 97.60% after implementing measures,the rate of rusting,stain,repeated cleaning,damage decreased from 3.39%, 2.37%,5.76%,and 2.08% to 1 .55%,0.85%,2.40%,and 0.48% respectively,there were significant difference among different groups(all P <0.001 );the score of satisfaction rate to central sterile supply department elevated from(93.87±3.87)before implementing measures to (98.08 ±0.59)after implementing measures(t =6.80,P <0.001).Conclusion Root cause analysis is important in improving cleaning quality of reusable instruments continu-ously,as well as reducing HAI and the wear and tear of instrument,it can save medical cost.