In this study, high-throughput promoter screening was employed to optimize the heterologous expression of Mesorhizobium loti carbonic anhydrase (MlCA) in order to reduce the costs associated with carbon capture and storage (CCS). To simplify the complexity of traditional vectors, a fusion protein expression system was constructed using superfolder green fluorescent protein (sfGFP) and MlCA. The synthetic promoter library in Escherichia coli was utilized for efficient one-step screening. Based on fluorescence intensity on agar plates, a total of 143 monoclonal colonies were identified, forming a library with varying expression levels. The top four recombinants with the highest fluorescence intensity were selected, among which MlCA driven by the promoter 342042/+ exhibited the highest enzymatic activity, with a specific activity of the 34.6 Wilbur-Anderson units (WAU)/mg. Optimization experiments revealed that MlCA exhibited the best performance when cultured for 4 days under pH 7.0 and 40 ℃ conditions. The Michaelis constant (K_m·hdy) and maximum reaction rate (V_max·hdy) for CO₂ hydration were determined to be 62.46 mmol/L and 0.164 mmol/(s·L), respectively. For esterase hydrolysis, MlCA showed the K_m and V_max of 639.8 mmol/L and 0.035 mmol/(s·L), respectively. MlCA accelerated the CO₂ hydration process, promoting CO₂ mineralized into CaCO₃ within 9 min at low pH and room temperature conditions. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses confirmed that the precipitated product was calcite. This study provides a low-cost and environmentally friendly alternative for future CCS applications.
Carbonic Anhydrases/biosynthesis* ; Promoter Regions, Genetic/genetics* ; Escherichia coli/metabolism* ; Carbon Sequestration ; Carbon Dioxide/metabolism* ; Green Fluorescent Proteins/metabolism*

Humans ; Asthma/drug therapy* ; Biological Therapy

Objective To evaluate the reliability of serum catecholamine concentrations in reflecting the depth of dexmedetomidine-based general anesthesia.Methods Forty patients,aged 30-45 yr,of American Society of Anesthesiologists physical status Ⅰ-Ⅱ,undergoing elective laparoscopic hysterectomy under general anesthesia,were divided into 2 groups (n =20 each) using a random number table:dexmedetomidine-based general anesthesia group (group Ⅰ) and general anesthesia group (group Ⅱ).Dexmedetomidine was intravenously infused as a loading bolus of 1 μg/kg over 10 min before induction of anesthesia,followed by an infusion of 0.5 μg · kg-1 · h-1 until 30 min before the end of operation in group Ⅰ.The equal volume of normal saline was given instead of dexmedetomidine in group Ⅱ.Anesthesia was induced with iv midazolam 0.05 mg/kg,propofol 1 mg/kg,cisatracurium 0.15 mg/kg and sufentanil 0.4 μg/kg.Anesthesia was maintained with iv infusion of remifentanil 0.1-0.3 μg · kg-1 · min 1,1％-2％ sevoflurane inhalation and intermittent iv boluses of cisatracurium.Before administration of dexmedetomidine,at the end of administration of the loading dose,at the end of intubation,at the end of skin incision,after establishment of pneumoperitoneum and at the end of operation (T0-5),venous blood samples were taken from the peripheral vein for determination of concentrations of epinephrine (E) and norepinephrine (NE) in serum (by enzyme-linked immunosorbent assay).Results Compared with group Ⅱ],the serum NE and E concentrations were significantly decreased at T1-4 in group Ⅰ (P＜0.05).Compared with the baseline at T0,the serum NE and E concentrations were significantly decreased at T1 in group Ⅰ,and increased at T2-4 in group Ⅱ (P＜0.05).Conclusion The serum catecholamine concentration produces poor reliability in reflecting the depth of dexmedetomidine-based general anesthesia,and thus it is not a suitable monitoring index.

Objective To integrative the effect of ulinastatin on postoperative cognitive function in elderly gastric cancer surger-y.Methods Two hundred elderly patients with gastric cancer surgery were randomly divided into observed group (100 cases)and control group (100 cases).Patients in observed group received the intravenous drip of ulinastatin before and after the surgery,while others only received the intravenous drip of physiological saline before and after the surgery.Results The urine output of observed group was (441.7±78.5)mL,which was significantly lower than that in control group as the result was (613.2±81.2)mL(P <0.05).After the treatment,the score of MMSE,visual regeneration and association learning in both observed group and control group were significantly lower than that before the treatment(P <0.05).The scores of MMSE,visual regeneration and association learning in observed group were 24.4±1.5,9.7±1.7 and 12.4±1.8,which were significantly higher than that in control group as the scores were 21.1±1.0,8.7±1.5 and 11.3±1.7 (P <0.05).The level of S100βin serum of observed group at the end of sur-gery,1 day and 3 day after the surgery were (0.099±0.024)μg/L,(0.074±0.026)μg/L and (0.061±0.022)μg/L,which were significantly lower than that in control group as the results were (0.138±0.042)μg/L,(0.110±0.034)μg/L and (0.075±0.031)μg/L (P < 0.05).Conclusion Ulinastatin can not only improve the postoperative cognitive dysfunction in elderly patients with postoperative,but can also reduce the level of S100βin serum.It provides brain protection for patients.

A label-free electrochemical immunosensor using hollow structure nanomaterials based on its ordered porous and big surface area was designed. Au nanocage, with good conductivity, catalysis, and biocompatibility, was prepared and modified on the surface of glassy carbon electrode with graphene to immobilize antibody of microcystin directly. In the absence of microcystin, biosensor can obtain high current response signal of electrochemical probe ( [ Fe( CN) 6 ] 3-/4-. When microcystin was combined with its antibody specifically, the charge density and mass transfer resistance on the surface of electrode increased, resulting in a decrease of the corresponding peak current of [ Fe ( CN ) 6 ] 3-/4-. This change was in proportion to the concentration of microcystin indirectly. Experiment conditions such as cultivation time of antigen and concentration of antibody were optimized. The results showed wide linear range of 0. 05 μg/L-1. 0 mg/L and the detection limit of 0. 017 ng/mL. This sensor has good stability and simple production procedure. This sensor provides a new and simple means for the ultrasensitive determination of microcystins in real water samples.

Objective To study the expression of P73 and its relationship with expression of Survivin in colon carcinoma. Methods The expression of P73 and Survivin was studied by immunohistochemical technique in 46 cases of colon carcinoma and 12 cases of normal colon mucosa. Results The P73 expression rate of colon carcinoma was significant higher than that of normal colon mucosa(χ2 = 13.42, P ＜0.01 ). Overexpression of P73 was related to the pathological grade and Dukes stage ( ( χ2 = 8.01, P ＜0.01 ), and it was closely related to lymphatic metastasis of colon carcinoma( P ＜0.01 ). There was a positive relation between P73 and Survivin( rs =0.487, P ＜0.01 ). Conclusions The expression of P73 was closely associated with Survivin in colon carcinoma. The results suggested that the overexpression of P73 and Survivin was involved in the tumorigenesis and development of colon carcinoma and P73 and Survivin might be used as a new tumor marker in metastasis and prognosis of colon carcinoma.