Lipase is a kind of widely used hydrolase.Surface display is an efficient method of highthroughput screening for protein engineering of lipase.Besides,lipase displaying on surface of microorganism has many advantages,such as higher stability against high temperature and organic solvent,compared with free lipase,so the host strain displaying lipase can be used as wholecell biocatalyst,which has some advantages compared with traditional immobilization of lipase.There are three kinds of host strain for displaying lipase:phage,bacteria and yeast.The surface display of lipase in the three display systems were systematically discribed,and their current uses and possible trends in the future were discussed also.

Objective To investigate the effects of ovariectomy and cholesterol rich diet on the change of estrogen receptor content of vascular endothelial cells and hearts of female rats. Methods The receptor binding assay (RBA) was adopted to measure the content of estrogen receptors, and the serum levels of estradiol and lipids were measured. Results The content of ER was much lower in hearts and VEC of ovariectomy〔(0.51?0.09) fmol/mg pro,(6.73 ? 0.52) fmol/106 cell〕and cholesterol rich rats〔(0.97?0.12) fmol/mg pro,(9.15 ?0.53) fmol/106 cell〕than pseudo-operation rats 〔(2.08?0.15) fmol/mg pro ,(17.66?1.26) fmol/106 cell , P

A PP plastic film for food packaging (0. 1 mm) was prepared by adding two antioxidants of 2,6-di-tert-butyl-4-methyl-phenol(BHT) and pentaerythritol tetrakis ( 3-( 3, 5-di-tert-butyl-4-hydroxyphenyl ) propionate)(Irganox 1010) with different concentrations into polypropylene (PP) resin, then mixing extrusion granulate by the double screw plastic extruder and hot pressing the film at 190℃. The migration amount of the two antioxidants in food simulants (95% ethanol) was determined by high performance liquid chromatography (HPLC) with diode array detector (PDA) (detection wavelength is 282 nm). The migration of BHT was detected and Irganox 1010 was not detected. Based on the large amount of experimental data, the migration model was fitted by a software, then the migration model of antioxidant BHT was established, the applicability of the two migration model was compared with the actual data. The results showed that the fitting degree ( R2 ) of Weibull model to the actual migration result was greater than 0. 99 and better than Piringer model. It was found that there was a mathematical relationship as τ≈12. 2 ( L2/D) between parameters of Weibull model and Piringer model.

Purpose The diagnosis, treatment and prognosis of benign and malignant biliary stricture are significantly different. This study aims to evaluate the quantitative analysis of biliary structures using magnetic resonance cholangiopancreatography (MRCP) combined with dynamic contrast enhanced CT (DCE-CT).Materials and Methods The quantitative parameters of MRCP and DCE-CT imaging data from 27 patients with benign biliary stricture (benign group) and 30 patients with malignant biliary stricture (malignant group) were retrospectively analyzed. The wall thickness, stricture length and diameter, proximal ductal dilatation and degree of enhancement in two groups were compared, and its correlation was analyzed to evaluate the accuracy of MRCP and DCE-CT.Results There were significant differences in wall thickness [(3.2±2.0) mmvs (2.1±0.6) mm], stricture length [(15.8±8.1) mmvs (9.5±6.5) mm] and diameter [0 mmvs (2.0±0.9) mm], proximal ductal dilatation and the degree of enhancement [(12.7±3.6) mmvs (9.3±2.7) mm] between the two groups (t=2.825, 3.270, 4.025,P<0.001;Z=-3.909,P<0.001). Multivariable stepwise regression analysis showed that the wall thickness and diameter, and the CT HU in portal venous and equilibrium phases combined with CT plain scanning were significant predictors of malignant biliary strictures (t=-6.424-2.309,P<0.05). The sensitivity, specificity, inter-modality agreement and Youden index of MRCP and DCE-CT in diagnosing 57 patients with biliary stricture were 96.67%, 100.00%, 98.25% and 0.97, respectively; with statistical significance in predicting benign and malignant biliary stricture (AUC=0.994,P<0.001).Conclusion Using MRCP and DCE-CT, the wall thickness and diameter of the stricture, and the difference in CT HU in portal venous and equilibrium phases combined with CT plain scanning are valuable in differential diagnosis of benign and malignant biliary stricture.

Objective:To evaluate the value of the crescent sign for predicting the invasiveness of lung adenocarcinoma presenting as pure ground-glass nodule (pGGN).Methods:The clinical, pathological and imaging data of 316 patients (320 pGGNs) confirmed lung adenocarcinoma by surgery and pathology from July 2013 to June 2018 in the First Affiliated Hospital of Wenzhou Medical University were retrospectively analyzed. All pGGNs were divided into preinvasive group (148 pGGNs) and invasive group (172 pGGNs) according to histopathology. Logistic regression analysis was used to determine the risk factors for invasiveness of pGGN, and the ROC curve analysis was performed on each risk factor.Results:Crescent sign was found in 24 cases (16.2%) in the preinvasive group and 49 (28.5%) in the invasive group, and the difference between the two groups was statistically significant (χ2=6.804 ,P=0.009).There were statistically significant differences in patient′s age, lesion size, shape, lobulation sign, and vascular stretch sign between the two groups ( P<0.05). The ROC curve showed that with the lesion size 10.5 mm as the optimal cut off value, the sensitivity for differential diagnosis of preinvasive and invasive lesions was 65.7%, the specificity was 61.5%, and the area under the curve was 0.666. Logistic regression analysis showed that maximum diameter of the lesion ≥10.5 mm, irregular shape, crescent sign and vascular stretch were independent risk factors of invasiveness of pGGN, and the OR value (95%CI) were 3.192 (1.981-5.144), 3.672 (1.545-8.725), 1.972 (1.104-3.521), and 2.026 (1.087-3.777), respectively. A logistic model was established based on the above four independent risk factors, and the area under curve was 0.711 (95%CI 0.655-0.768). Conclusion:Crescent sign can effectively reflect the invasiveness of pGGN. Maximum diameter of the lesion ≥10.5 mm, irregular shape, crescent sign and vascular stretch sign are independent risk factors of invasiveness of pGGN.

Objective To analyze crossed cerebellar diaschisis(CCD) after subacute phase of spontaneous cerebral hemorrhage(SPSCH)and it's relevant factors with whole-brain CT perfusion(CTP) imaging. Methods Eighty-six patients diagnosed with unilateral SPSCH by CT were prospectively enrolled in our study from July 2015 to October 2016. Whole-brain CTP was performed in each patient.Cerebral blood flow(CBF), cerebral blood volume(CBV), mean transit time(MTT)and time-to-peak(TTP) inipsilateral and contralateral cerebellum were manually measured.The asymmetric indexs(AIs) were also calculated. Moreover, the volume of hematoma, the maximumarea of peri-hematomahypoperfusionin CBF and clinical factors(age, gender, time intervals from symptom onset)were analyzed,and NIHSS scores were used to evaluate the neurological status before patient admission, inspection, and discharge.CCD was rated positive when a unilateral supratentorial hematomawas appeared and an accompanying perfusion decrease was showed in the contralateral cerebellum on at least two sequential slices of CTP maps.All the individuals were divided into two groups including CCD-positive groupand CCD-negative group. The perfusion parameters (CBF, CBV, MTT, and TTP)between the contralateral and ipsilateral cerebellum were analyzed by the two-tailed paired t-test in CCD-positive group. The differences in the perfusion and clinical variables between the two groups were analyzed by the independent sample t-test and the Chi-squared test. Therelationships between the AI values and clinical or radiologic variables were assessed with Pearson correlation test. Results We found 35 CCD positive cases and 51 negative cases in the 86 patients.In CCD-positive groups, the perfusion values of cerebellumipsilateral and contralateral to the hematomawere as follows:CBF were (40.88±11.23) vs. (33.91±9.96) ml·100 g-1·min-1, CBV were (3.30±1.18) vs. (2.75±1.13) ml/100 g and TTP were (22.09±3.98) vs. (22.88±4.15) s, respectively, and there was statistical significance (t=10.231,8.223,-2.883,P<0.05).In CCD positive group, CBF, CBV, TTP, and MTT of the contralateral cerebellar hemisphere was changed in 35, 32, 26, and 16 cases,respectively.The AI value of CBF(AICBF)in CCD-positive group was (17.10±9.10)%, which was higher than that in the negative group (-0.95±17.01)%, there was statistical significance(t=6.367,P<0.05).The AI value of CBV(AICBV)was (17.43 ± 11.65)% in CCD-positive group, also significantly higher than that in negative group which was (1.55±21.06)%(t=4.477, P<0.05). No statistical difference(P>0.05)was found in hematoma location,hematoma volume, supratentorialhypoperfusion area and NIHSS scores(at admission, inspection)between CCD-positive and negative groups.The AICBF and AITTP showed linear correlation with time intervals in CCD-positive patients(P<0.05). Conclusions CCD is a common phenomenon in patients with SPSCH.Of all the perfusion parameters,CBF abnormalities are more common.The severity of CCD has a certain correlation with time intervals.There is no significant correlation between CCD and the clinical or radiological data(age, NIHSS scores,hematoma volume, and supratentorial hypoperfusion area).

Objective: To study the epidemiological characteristics and related factors of dyslipidemia among adult residents in Xinjiang Uygur Autonomous Region (Xinjiang) in 2013-2014. Methods: A total of 4 120 adult residents consisting of Han and Uygur group aged over 18 years old were selected by using a stratified cluster random sampling method in 8 counties of Xinjiang from 2013 to 2014. The related factors of dyslipidemia were collected by questionnaire and physical measurement. The total cholesterol, triglyceride, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol were detected by enzyme method. Factors associated with dyslipidemia were analyzed by chi-squared test and a multivariate unconditioned logistic regression model adjusted for gender, urban or rural area, age-group, body mass index (BMI), central obesity, smoking, drinking, education attainment, diabetes mellitus and hypertension. Results: The prevalence of dyslipidemia was 45.00% (1 854 cases). The prevalence of dyslipidemia was higher in Uygur group (47.80% (977/2 044)) than that in Han group (42.24% (877/2 076)) (χ²=12.84, P<0.001). The analysis showed that dyslipidemia was related with gender (OR=0.41, 95%CI: 0.33-0.51), urban area (OR=0.54, 95%CI: 0.39-0.76), BMI (overweight group (OR=1.52, 95%CI: 1.18-1.96); obesity group (OR=2.20, 95%CI: 1.64-2.96)), central obesity (OR=1.66, 95%CI: 1.29-2.14) and diabetes mellitus (OR=1.49, 95%CI: 1.06-2.11) in Uygur group. The analysis also showed that dyslipidemia was related with BMI (overweight group (OR=1.72, 95%CI: 1.32-2.25), obesity group (OR=2.60, 95%CI: 1.85-3.64)), central obesity (OR=1.45, 95%CI: 1.13-1.87), smoking (OR=1.46, 95%CI: 1.09-1.95), diabetes mellitus (OR=1.77, 95%CI: 1.38-2.25) and hypertension (OR=1.62, 95%CI: 1.31-2.00) in Han group. Conclusions The prevalence of dyslipidemia in Xinjiang was higher than the national average prevalence. The prevalence of dyslipidemia in Uygur group was significantly higher than that in Han group. The gender, living area, BMI, central obesity and diabetes mellitus were risk factors of dyslipidemia in Uygur group, and BMI, central obesity, smoking, diabetes mellitus and hypertension were risk factors of dyslipidemia in Han group in Xinjiang.

Objective:To investigate therapeutic effect of cisplatin sequential recombinant human vascular endostatin thoracic perfusion in treatment of malignant pleural effusion.Methods:A total of 80 patients with malignant pleural effusion in Maoming People's Hospital from January 2018 to February 2021 were enrolled, and all patients were divided into 2 groups according to the random number table methods, each group with 40 cases. The control group was treated with small-bore catheter minimally invasive drainage combined with cisplatin thoracic perfusion, and the study group was treated with small-bore catheter minimally invasive drainage combined with cisplatin sequential recombinant human vascular endostatin thoracic perfusion. And then the clinical efficacy, expressions of vascular endothelial growth factor (VEGF) expression, pain degree and adverse reactions were compared of both groups.Results:The treatment efficacy rate of the study group was higher than that of the control group [90% (36/40) vs. 75% (30/40)], and the difference was statistically significant ( χ2 = 5.04, P < 0.05). After treatment, the level of VEGF in pleural fluid and serum of the study group was lower than that of the control group [(304±106) pg/ml vs. (598±159) pg/ml,(103±43) pg/ml vs. (189±49) pg/ml], and the difference was statistically significant ( t = 6.62, P < 0.001; t = 6.23, P < 0.001). After treatment, the visual analogue scale (VAS) score of the study group was lower than that of the control group [(3.7±0.3) scores vs. (4.4±0.7) scores], and the difference was statistically significant ( t = 2.10, P < 0.05). The incidence of adverse reactions including stethalgia, fever, nausea and vomiting in both groups had no statistically significant differences (all P > 0.05). Conclusions:Cisplatin sequential recombinant human vascular endostatin thoracic perfusion combined with small-bore catheter minimally invasive drainage can effectively ameliorate clinical symptoms, inhibit the expression of VEGF, and alleviate pain degree with no serious adverse reactions in patients with malignant pleural effusion.

Objective:To explore the feasibility of CT angiography (CTA) in investigating vascular dilatation of anterior choroidal artery (AChA) and posterior communicating artery (PComA) in patients with Moyamoya syndrome (MMS).Methods:From July 2017 to July 2018, the clinical and imaging data of MMS patients with brain CTA and DSA performed were analyzed retrospectively. According to DSA results, 71 MMS patients were divided into unilateral MMS group (20 cases, 20 hemispheres) and bilateral MMS group (51 cases, 102 hemispheres). There were 20 cases in unilateral MMS group, 10 males and 10 females, with an average age of (45±9) years; 51 cases in bilateral MMS group, 24 males and 27 females, with an average age of (44±12) years. The hemispheres were divided into dilated group and non-dilated group according to the dilatation of AChA or PComA. Kappa analysis was used to evaluate the consistency of two inspection methods to judge the expansion of AChA. The lumen diameters of PComA, P1 and P2 segments of posterior cerebral artery were measured on CTA images, and the ratio of PComA/P1 and PComA/P2 were calculated. The repeatability of CTA measures was evaluated by intra-group correlation coefficient. Independent sample t-test was used to compare CTA measurement results between PComA dilated group and non-dilated group, and ROC curve was drawn to calculate the best threshold for diagnosis of PComA expansion. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of CTA measures were calculated. Results:The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of CTA diagnosis of AChA expansion inunilateral MMS were all 100.00%. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of CTA diagnosis of AChA expansionin bilateral MMS were 90.00%, 93.90%, 93.14%, 78.26% and 97.47%. Compared with DSA, there was no significant difference in the diagnostic performance of AChA expansion between single and bilateral MMS diagnosed by CTA ( P>0.05). The two methods had strong consistency (Kappa value was 1.00 and 0.79 respectively, P<0.01). A total of 46 patients (69 cerebral hemispheres) were included in the evaluation of PComA. PComA/P1 (1.09±0.41) and PComA/P2 (0.86±0.13) in the dilated group were significantly higher than those in the non-dilated group (0.71±0.21 for PComA/P1 and 0.75±0.23 for PComA/P2). The differences were statistically significant ( t=-4.59, -2.50, P<0.05). The best threshold in diagnosing PComA expansion was 0.87 (PComA/P1) and 0.76 (PComA/P2), and the sensitivity, specificity, accuracy, positive predictive value and negative predictive value were 84.62%, 83.33%, 84.06%, 86.84%, 80.65% and 79.49%, 60.00%, 71.01%, 72.09% and 69.23%, respectively. Compared with DSA, the Kappa value of CTA measures in diagnosis of PComA expansion was 0.68 (PComA/P1) and 0.40 (PComA/P2), respectively, and the difference was statistically significant ( P<0.05). Conclusions:CTA has a strong consistency with DSA in evaluating the AChA expansion in MMS. When the PComA/P1 ratio on CTA is greater than 0.87, it can be used as the diagnosis criterion for PComA expansion.

Yarrowia lipolytica lipase Lip2 (YlLip2) is an important industrial enzyme with many potential applications. To alleviate the dissolved oxygen (DO) limitation and improve YlLip2 production during high-cell density fermentation, the YlLip2 gene lip2 and Vitreoscilla hemoglobin (VHb) gene vgb were co-expressed in Pichiapastoris under the control of AOX1 and PsADH2 promoter, respectively. The PsADH2 promoter from Pichia stipitis could be activated under oxygen limitation. The SDS-PAGE and CO-difference spectrum analysis indicated that VHb and YlLip2 had successfully co-expressed in recombinant strains. Compared with the control cells (VHb-, GS115/9Klip2), the expression levels of YlLip2 in VHb-expressing cells (VHb+, GS115/9Klip2-pZPVT) under oxygen limitation were improved 25% in shake-flask culture and 83% in a 10 L fermentor. Moreover, the VHb+ cells displayed higher biomass than VHb- cells at lower DO levels in a 10 L fermentor. In this study, we also achieved a VHb-expressing clone harboring multicopy lip2 gene (GS115/9Klip2-pZPVTlip2 49#), which showed the maximum lipolytic activity of 33 900 U/mL in a 10 L fermentor under lower DO conditions. Therefore, it can be seen that expression of VHb with PsADH2 promoter in P. pastoris combined with increasing copies of lip2 gene is an effective strategy to improve YlLip2 production.
Bacterial Proteins ; biosynthesis ; genetics ; Fermentation ; Fungal Proteins ; biosynthesis ; genetics ; Lipase ; biosynthesis ; genetics ; Oxygen ; analysis ; pharmacology ; Pichia ; metabolism ; Protein Engineering ; Recombinant Proteins ; biosynthesis ; genetics ; Truncated Hemoglobins ; biosynthesis ; genetics