The cis-epoxysuccinate hydrolase (CESH) from Rhizobium strain BK-20 is the key enzyme for L(+)-tartaric acid production. To establish a highly efficient and stable production process, we first optimized the enzyme production from Rhizobium strain BK-20, and then developed an immobilized cell-culture process for sustained production of L(+)-tartaric acid. The enzyme activity of free cells reached (3 498.0 +/- 142.6) U/g, and increased by 643% after optimization. The enzyme activity of immobilized cells reached (2 817.2 +/- 226.7) U/g, under the optimal condition with sodium alginate as carrier, cell concentration at 10% (W/V) and gel concentration at 1.5% (W/V). The immobilized cells preserved high enzyme activity and normal structure after 10 repeated batches. The conversion rate of the substrate was more than 98%, indicating its excellent production stability.
Alginates ; chemistry ; Cells, Immobilized ; Glucuronic Acid ; chemistry ; Hexuronic Acids ; chemistry ; Hydrolases ; metabolism ; Rhizobium ; enzymology ; metabolism ; Tartrates ; metabolism

Objective To explore the impact of psychological intervention on response and defense style of AIDS patients.Methods 88 AIDS patients were selected and investigated using medical response (MCMQ) and defense style (DSQ) survey,the scores before and after psychological intervention were compared.Results Mental health problems included fear,afraid,pessimism and worry,the response style included face,avoid,yield.Scores showed significant difference before and after intervention among patients choosing immature-type,mature-type and cover-up defense styles.Conclusions Psychological intervention can promote rehabilitation and health of AIDS patients as well as improve their life quality and prevent disease relapse.

Objective: To observe the effects of moxibustion pretreatment on the protein expressions of epidermal growth factor receptor (EGFR), phosphorylation extracellular signal-regulated kinase 1/2 (p-ERK1/2) and activated protein-1 (AP-1), the key factors of extracellular signal-regulated kinase signaling transduction pathway in gastric tissue of rats with stress-induced gastric mucosal damage, and to discuss the mechanisms of moxibustion therapy in promoting the restoration of damaged gastric mucosa.
Methods: Thirty Sprague-Dawley (SD) rats were randomly divided into a normal group, a model group, and a moxibustion group using the random digits table, 10 in each group. Except the rats in the normal group, rats in the other two groups were used to make stress-induced gastric mucosal damage model using restraint and cold stress. Before modeling, rats in the moxibustion group were alternately treated with moxibustion at Zusanli (ST 36) and Zhongwan (CV 12), or Pishu (BL 20) and Weishu (BL 21), once a day, for a total of 8 d. Histological changes of gastric mucosa were observed under the light microscopy, the expression of gastric tissue p-ERK1/2 was detected by immunohistochemistry assay, and the protein levels of EGFR and AP-1 were measured by Western blots.
Results: Compared with rats in the normal group, gastric mucosal damage was more serious, and protein expressions of gastric tissue EGFR, p-ERK1/2 and AP-1 increased in the model group (P<0.01,P<0.05,P<0.05). Compared with rats in the model group, gastric mucosal damage was milder, and protein expressions of gastric tissue EGFR, p-ERK1/2 and AP-1 increased in the moxibustion group (allP<0.01).
Conclusion:Moxibustion at Zusanli (ST 36), Zhongwan (CV 12), Pishu (BL 20) and Weishu (BL 21) couldincrease EGFR, p-ERK1/2 and AP-1 expression levels in gastric tissue of stress-induced gastric mucosal damage rats, maintain the information transfer function of ERK signaling transduction pathway, and promote restoration of gastric mucosal damage.

Objective: To study the correlation of occupation musculoskeletal disease (OMD) and safety behavior in assembly line workers. Methods: Selected assembly line workers of 3 manufacturing factory in Pacity as the objects of this study by judgement sampling. Questionnaires were used for messages collection including the general sociodemographic characteristic, OMD condition, occupational safety behaviors. Results: This study shows that, 826 OMD workers were found that the annual prevalence was 38.03%. The scores of work posture, handling habits, health habit in OMD group was lower than non-OMD group (P<0.01) but personal protection behavior was higher than non-OMD group (P<0.01) . Test of binary logistic regression revealed that age, workage, work posture, handling habits were the factors of OMD (P<0.01) . Conclusion Safety behaviors were the potent factors of OMD that work posture and handling habits should be broadcast.

Objective:To explore the relationship between metabolic acidosis and cardiac valve calcification in maintenance hemodialysis (MHD) patients in the Pearl River Delta Region.Methods:Patients on MHD greater than 3 months who were treated in 10 blood purification centers in the Pearl River Delta Region from July 1 to September 30, 2019 were selected for this multicenter cross-sectional study. Based on a Doppler ultrasound, MHD patients were further divided into non-valve calcification group and valve calcification group. The demographics data, frequency of dialysis, blood pressure, single pool Kt/V(spKt/V), dialysis medications and laboratory data were collected and compared. Spearman correlation analysis was used to analyze the correlation between serum carbon dioxide combining power (CO 2CP) and cardiac valve calcification. Multivariate logistic regression model was used to analyze the influencing factors of cardiac valve calcification. Results:A total of 664 MHD patients were included in this study, with age of (57.0±14.2) years old and dialysis age of 43.0 (22.3, 71.7) months, including 395 males (59.5%) and 269 females (40.5%). Among them, there were 119 patients (17.9%) with diabetes and 186 patients (28.0%) with dialysis 2 times per week. There were 329 patients (49.5%) in the valve calcification group, and 335 patients (50.5%) in the non-valve calcification group. Compared to those in non-valve calcification group, valve calcification group had longer duration of dialysis, higher proportion of patients with dialysis 2 times per week, higher levels of diastolic blood pressure, fasting blood glucose, intact parathyroid hormone and ferritin, higher proportion of patients with blood CO 2CP<19 mmol/L (median CO 2CP), higher proportion of patients on usage of calcium channel blocker, angiotensin converting enzyme inhibitor/angiotensin receptor blocker, α-receptor blocker, β-receptor blocker, calcitriol and lanthanum carbonate (all P<0.05), while the levels of spKt/V, hemoglobin, serum CO 2CP, corrected calcium, blood phosphorus, blood alkaline phosphatase, albumin, total cholesterol, triacylglycerol, low-density lipoprotein, high-density lipoprotein, transferrin saturation, and the proportion of patients on usage of sevelamer and cinacalcet were lower (all P<0.05). Spearman analysis showed significant negative correlation between serum CO 2CP and valve calcification ( rs=-0.697, P<0.001). Multivariate logistic regression analysis showed that dialysis performed twice a week ( OR=2.789, 95% CI 1.232-6.305, P=0.014), blood total cholesterol ( OR=1.449, 95% CI 1.014-2.071, P=0.042), CO 2CP<19 mmol/L ( OR=22.412, 95% CI 10.640-47.210, P<0.001) were the influencing factor of valve calcification in MHD patients. Conclusions:MHD patients with cardiac valve calcification have significant acid loading. Metabolic acidosis is an independent influencing factor for cardiac valve calcification in MHD patients.

{L-End}Objective To analyze sound pressure level and spectrum characteristics of noise from various equipment in noise-related worksites in wooden furniture enterprises in Zhongshan City. {L-End}Methods A total of 107 wooden furniture enterprises with equipment sound pressure levels ≥85.0 dB(A) were selected as the research subjects using the judgment sampling method. Individual noise meters were used to detect the sound level and spectrum of equipment in noise-related worksites. Cluster analysis was used to analyze the noise spectrum characteristics of each noise equipment. {L-End}Results The incidence of sound pressure level exceeding the national standard of occupational exposure limits for noise in workplace among the research subjects was 60.4% (365/604). The equipment with the highest sound pressure level was the sliding table saw (rough shape cutting position) at 101.4 dB(A), while the lowest was the sanding machine (grinding position) at 85.0 dB(A). The clustering analysis results showed that the noise spectrum characteristics of nail guns, sliding table saw, edge banders, spray guns, and drilling machines were similar, with the highest sound pressure level of 4 000.0 Hz, mainly concentrating in the high-frequency. The noise spectrum characteristics of punching machines, sanding machine, lathes, and engraving machines were similar, with the highest sound pressure level ranging from 500.0 to 1 000.0 Hz, mainly concentrating in the mid-frequency. The noise spectrum characteristics of drilling machines, planers, hot press machines, and mortise and tenon machines were similar, with the highest sound pressure level ranging from 500.0 to 1 000.0 Hz, mainly concentrating in the mid- and high-frequency. The sound pressure level of the mixer reached its peak at 8 000.0 Hz, demonstrating a wide frequency domain characteristic of sound pressure level with the presence of low-, mid- and high-frequencies. {L-End}Conclusion The noise-exposed hazards of wooden furniture enterprises are relatively serious, and the spectral characteristics of the equipment with noise are distinct. It is recommended to implement targeted noise reduction measures and personal hearing protection based on the specific spectrum characteristics of equipment noise.