Nucleases is an important enzyme widely used in biotechnology. A codon optimized nuclease gene (SNU) from Northern Shrimps was inserted into pPICZα A vector, and expressed extracellularly in strain SMD1168H. On the basis of multi-copy recombinant strain, we further optimized the expression condition and characterized SNU. SNU was highly expressed and stable after 1% methanol induction for 72 h, yield reached 1.4×10⁵ U/mL. SDS-PAGE electrophoresis demonstrated that this is a N-linked glycoprotein of 50 kDa. It was purified by one step DEAE Sephadex chromatography to the purity of about 15 mg/L with a specific activity of 6.291×10⁶ U/mg. Functional analysis on the nuclease activity indicated that it was stimulated by bivalent iron, such as Ca²⁺, Mn²⁺, Co²⁺ and Mg²⁺, but inhibited by Zn²⁺, Cu²⁺ and high salt. Meanwhile, it was irreversibly inactivated at 70 ℃ for 10 min.
Animals ; Codon ; Electrophoresis, Polyacrylamide Gel ; Endonucleases ; biosynthesis ; Glycoproteins ; Hot Temperature ; Penaeidae ; enzymology ; Pichia ; metabolism ; Recombinant Proteins ; biosynthesis

Objective:To analyze the clinical curative effect of protective sleep nursing on neonatal hyperbilirubinemia.Methods:Eight neonates with hyperbilirubinemia who were admitted from April 2019 to August 2019 were enrolled. They were divided into control group (40 cases) and observation group (40 cases) by random digits table method. Both groups were given routine nursing. On basis of control group, observation group was given protective sleep nursing. The clinical effect, sleep time, discomfort reactions and nursing satisfaction were compared between the two groups.Results:After nursing, the sleep time, crying time and bilirubin level were (18.67 ± 1.45) h/d, (0.82 ± 0.12) h/d, (191.58 ± 12.74) μmol/L in the observation group, and (17.63 ± 1.33) h/d, (1.05 ± 0.15) h/d, (202.42 ± 13.08) μmol/L in the control group, there were significant differences between the two groups ( t values were 3.343, 7.573, 3.755, P<0.05). The duration and regression time of jaundice were (5.26±1.24), (8.70±2.12) d in the observation group, and (7.14±1.18), (12.95±2.31) d in the control group, there were significant differences between the two groups ( t values were 6.946, 8.573, P<0.05). The good rate of sleep quality, incidence rates of vomiting, skin damage and needle falling out, and nursing satisfaction rate were 90.00%(36/40), 7.50%(3/40), 5.00%(2/40), 10.00%(4/40), 100.00%(40/40) in the observation group, and 72.50% (29/40), 27.50%(11/40), 22.50%(9/40), 32.50%(13/40), 87.50%(35/40) in the control group, there were significant differences between the two groups ( χ2 values were 4.021-6.050, P<0.05). Conclusions:The application of protective sleep nursing in treatment of neonatal hyperbilirubinemia can effectively prolong their sleep time, improve their sleep quality, which is conducive to improving their symptoms, reducing discomfort reactions.And satisfaction of their family members is relatively higher.

ObjectiveTo analyze the mental health status and its influencing factors in middle school students under the regular prevention and control of COVID-19， so as to provide references for the intervention and management of their mental health problems. MethodsFrom March 7 to 21， 2021， a stratified random sampling method was used to select 19 352 students from 17 schools in 3 districts and 9 counties of Linyi City， Shandong Province. Basic data were collected through a self-designed questionnaire. All students completed the Symptom Checklist 90 （SCL-90） to assess their mental health status. Then the factors affecting the mental health status of middle school students were screened using independent sample t-test， one-way ANOVA test and multiple stepwise regression analysis. Results① A total of 6 350 （32.81%） middle school students were found to have mental health problems. ② Each SCL-90 factor score and total average score yielded statistical difference among middle school students of different genders， relationships with classmate， closeness to friends， concerns about the epidemic， and pressure exerted by schoolwork （P<0.01）. Each SCL-90 factor score and total average score of middle school students were significant different in terms of the hours of smartphone usage for recreation per day， sleep duration per night in hours and exercise frequency （P<0.01）. ③ Multiple stepwise regression analysis denoted that female gender， poor relationship with classmate， no close friend and long hours of smartphone usage for recreation were the risk factors for mental health of middle school students （β=0.096， 0.183， 0.064， 0.232， P<0.01）. ConclusionThe prevalence rate of mild mental health problems is quite high among middle school students under the regular epidemic prevention and control. Additionally， female gender， poor relationship with classmate， no close friend and long hours of smartphone usage for recreation have a negative impact on middle school students' mental health.

Chimeric antigen receptor T (CAR-T) cell therapy is a novel cellular immunotherapy that is widely used to treat hematological malignancies, including acute leukemia, lymphoma, and multiple myeloma. Despite its remarkable clinical effects, this therapy has side effects that cannot be underestimated. Cytokine release syndrome (CRS) is one of the most clinically important and potentially life-threatening toxicities. This syndrome is a systemic immune storm that involves the mass cytokines releasing by activated immune cells. This phenomenon causes multisystem damages and sometimes even death. In this study, we reported the management of a patient with recurrent and refractory multiple myeloma and three patients with acute lymphocytic leukemia who suffered CRS during CAR-T treatment. The early application of tocilizumab, an anti-IL-6 receptor antibody, according to toxicity grading and clinical manifestation is recommended especially for patients who suffer continuous hyperpyrexia, hypotensive shock, acute respiratory failure, and whose CRS toxicities deteriorated rapidly. Moreover, low doses of dexamethasone (5-10 mg/day) were used for refractory CRS not responding to tocilizumab. The effective management of the toxicities associated with CRS will bring additional survival opportunities and improve the quality of life for patients with cancer.