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Cutinase can degrade aliphatic and aromatic polyesters, as well as polyethylene terephthalate. Lack of commercially available cutinase calls for development of cost-effective production of efficient cutinase. In this study, eight cutinase genes were cloned from Sclerotinia sclerotiorum. The most active gene SsCut-52 was obtained by PCR combined with RT-PCR, expressed in Escherichia coli BL21 and purified by Ni-NTA affinity chromatography to study its characteristics and pathogenicity. Sscut-52 had a total length of 768 bp and 17 signal peptides at the N terminals. Phylogenetic analysis showed that its amino acid sequence had the highest homology with Botrytis keratinase cutinase and was closely related to Rutstroemia cutinase. Sscut-52 was highly expressed during the process of infecting plants by Sclerotinia sclerotiorum. Moreover, the expression level of Sscut-52 was higher than those of other cutinase genes in the process of sclerotia formation from mycelium. The heterologously expressed cutinase existed in the form of inclusion body. The renatured SsCut-52 was active at pH 4.0-10.0, and mostly active at pH 6.0, with a specific activity of 3.45 U/mg achieved. The optimum temperature of SsCut-52 was 20-30 ℃, and less than 60% of the activity could be retained at temperatures higher than 50 ℃. Plant leaf infection showed that SsCut-52 may promote the infection of Banlangen leaves by Sclerotinia sclerotiorum.
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Ascomycota/genetics , Carboxylic Ester Hydrolases , Cloning, Molecular , PhylogenyABSTRACT
Objective To establish a neural network model based on enhanced CT for distinguishing ISUP grade of clear cell renal cell carcinoma (ccRCC). Methods We collected 131 cases of ccRCC, with 92 cases of low ISUP grade and 39 cases of high ISUP grade. Patients were divided into training set and validation set according to 5:5 stratified sampling. The enhanced CT images of each ccRCC patient were evaluated by the radiologist. Recursive feature elimination (RFE) was used to reduce the dimension of patients' general features and enhanced CT features, which was used for neural network modeling and validation. Results Patients' general features and enhanced CT features were verified by RFE method and then reduced to 14 features. The top 5 features were growth pattern, necrosis, enlargement of lymph nodes, tumor size and capsule. The AUC of the neural network model based on these 5 features in training set was 0.8844 (95%CI: 0.8062-0.9626), sensitivity was 89.47% and specificity was 82.61%; and those in validation set were 0.7924 (95%CI: 0.6567-0.9280), 75.00% and 86.96%, respectively. Conclusion The neural network model of ccRCC ISUP grade based on enhanced CT has relatively high diagnostic efficiency.
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Objective A predictive model of WHO/ISUP grading of renal clear cell carcinoma was constructed based on CT radiomics.Methods The clinical data of 104 patients with ccRCC confirmed by operation or biopsy from March 2014 to December 2018 in the Mfiliated Hospital of Shaanxi University of Traditional Chinese Medicine were retrospectively analyzed.There were 70 males and 34 females,and the age was 61.2 ± 11.7 years.The patients were randomly divided into development cohort (73 cases) and validation cohort (31 cases) by stratified sampling according to 7∶3 ratio.According to the WHO/ISUP pathological grading criteria of renal cancer in 2016,Ⅰ and Ⅱ were defined as low-grade group,Ⅲ and Ⅳ were defined as high-grade group.The radiomics features of ccRCC were calculated in cortical phase images of CT enhanced scanning.LASSO regression was used to reduce the radiomics feature dimensionality in the training group,and to establish radiomics risk scores.The binary logistic regression was used to build the prediction model,which was used in the validation group.Bootstrap method was used to validate the model of training and validation group.AUC,sensitivity and specificity were calculated respectively.Hosmer-Lemeshow goodness-of-fit test was used to evaluate model calibration degree.Results After dimensionality reduction,the radiomics risk score of ccRCC was established.The low and high-level risk scores of the training group were-2.49 ± 1.73 and 1.23 ± 2.17,with significant difference (t =-7.785,P ＜ 0.01).The binary logistic regression multivariate analysis showed that the radiomics risk score was an independent risk factor in identifying low or high-grade ccRCC with odds ratio of (OR =3.576,95％ CI 1.964 ～ 6.513).The predictive model was Y =1/[1 + exp(-Z)],Z =1.274 × radiomics risk score + 0.072.The AUC of radiomics risk score in training group was 0.940 (95％ CI 0.883-0.998) with 95.5％ sensitivity and 88.2％ specificity after internal verification by Bootstrap method,and good Hosmer-Lemeshow goodness-of-fit test (x2 =4.463,P ＞ 0.05).The low and high-level risk scores of the Validation group were-2.27 ± 2.02 and 0.82 ± 2.08,with significant difference (t =-3.832,P ＜ 0.01).The AUC in validation group was 0.859(95％ CI 0.723-0.995) with 77.8％ sensitivity and 81.8％ specificity,and with good Hosmer-Lemeshow goodness-of-fit test (x2 =14.554,P =0.068) as well.Conclusions The prediction model based on CT radiomics has high accuracy in predicting high or low grade of ccRCC.
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Objective@#A predictive model of WHO/ISUP grading of renal clear cell carcinoma was constructed based on CT radiomics.@*Methods@#The clinical data of 104 patients with ccRCC confirmed by operation or biopsy from March 2014 to December 2018 in the Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine were retrospectively analyzed. There were 70 males and 34 females, and the age was 61.2±11.7 years. The patients were randomly divided into development cohort (73 cases) and validation cohort (31 cases) by stratified sampling according to 7∶3 ratio. According to the WHO/ISUP pathological grading criteria of renal cancer in 2016, Ⅰ and Ⅱ were defined as low-grade group, Ⅲ and Ⅳ were defined as high-grade group. The radiomics features of ccRCC were calculated in cortical phase images of CT enhanced scanning. LASSO regression was used to reduce the radiomics feature dimensionality in the training group, and to establish radiomics risk scores. The binary logistic regression was used to build the prediction model, which was used in the validation group. Bootstrap method was used to validate the model of training and validation group. AUC, sensitivity and specificity were calculated respectively. Hosmer-Lemeshow goodness-of-fit test was used to evaluate model calibration degree.@*Results@#After dimensionality reduction, the radiomics risk score of ccRCC was established. The low and high-level risk scores of the training group were -2.49±1.73 and 1.23±2.17, with significant difference (t=-7.785, P < 0.01). The binary logistic regression multivariate analysis showed that the radiomics risk score was an independent risk factor in identifying low or high-grade ccRCC with odds ratio of (OR=3.576, 95%CI 1.964~6.513). The predictive model was Y=1/[1+ exp(-Z)], Z=1.274×radiomics risk score+ 0.072. The AUC of radiomics risk score in training group was 0.940 (95%CI 0.883-0.998) with 95.5% sensitivity and 88.2% specificity after internal verification by Bootstrap method, and good Hosmer-Lemeshow goodness-of-fit test (χ2=4.463, P>0.05). The low and high-level risk scores of the Validation group were -2.27±2.02 and 0.82±2.08, with significant difference (t=-3.832, P<0.01). The AUC in validation group was 0.859(95%CI 0.723-0.995) with 77.8% sensitivity and 81.8% specificity, and with good Hosmer-Lemeshow goodness-of-fit test (χ2=14.554, P=0.068) as well.@*Conclusions@#The prediction model based on CT radiomics has high accuracy in predicting high or low grade of ccRCC.
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Objective To compare the effect on image quality of low-dose upper abdominal CT reconstructed with the new version of model-based iterative reconstruction (MBIRn) focused on low-contrast resolution (MBIRNR40),conventional model-based iterative reconstruction (MBIRc),adaptive statistical iterative reconstruction (ASIR) and routine-dose CT reconstructed with filtered back projection (FBP).Methods Water plantom at rest was scanned with CT,and spatial resolution and density resolution were compared among FBP,ASIR,MBIRc,and MBIRNR40.Sixty patients with 2 times CT in the upper abdomen within a year were enrolled.The initial examination was acquired at a standard radiation dose (noise index [NI] of 10 HU) and reconstructed with the conventional FBP algorithm.The follow-up scan was acquired at a lowdose (NI=20 HU) and reconstructed with the standard ASIR,MBIRc and MBIRNR40.All images were obtained with 0.625 mm slice thickness.CT values and noise of fat,muscle as well as the liver and kidney parenchyma were measured and CNR of liver and kidney parenchyma using the fat SD as background image noise were calculated.Two radiologists independently graded images for noise,sharpness of details of structures and lesion.The quantitative image quality scores of different reconstructions were analyzed with one-way ANOVA using FBP reconstruction as reference of standard.The degree of interobserver consistency was evaluated using Kappa test.Results The phantom study revealed the highest spatial resolution with MBIRc and highest density resolution with MBIRNR40 among all reconstructions.The dose-length product and radiation dose for the first inspection was (93.18 ± 41.21) mGy · cm,(1.40 ± 0.62) mSv,respectively,and were (368.03 ± 146.25)mGy · cm,(5.52 ± 2.19)mSv for the second inspection,representing an approximate overall dose reduction of 74.68％ and 74.64％.The mean image noise of muscle and fat for MBIRNR40 was significantly lower than that of MBIR,ASIR and FBP(P＜0.05).The mean CNR values of liver and spleen for MBIRNR40 were significantly higher than that of ASIR,MBIRc and FBP (P＜0.05).Two radiologists had a good subjective score consistency.Low-dose MBIRNR40 subjective image noise was the lowest,showing the most detailed on the upper abdominal detail structure and lesion edge,better than MBIRc,MBIRc was superior to routine-dose FBP,low dose ASIR was worst,the difference was statistically significant (P＜0.05).Conclusion With 75％ dose reduction in upper abdominal CT,the MBIRNR40 can provide well objective and subjective image quality than MBIRc and ASIR40,and the routine-dose FBP.
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Objective To assess image quality of adaptive statistical iterative reconstruction (ASIR),conventional modelbased iterative reconstruction (MBIRc) and a new lung-specific setting (MBIRRP20 and MBIRNR40) from the new version of model-based iterative reconstruction (MBIRn) in submillisievert chest CT comparing with ASIR in standard-dose.Methods Two chest CT examinations were performed with standard-dose and low-dose in 30 patients.Low-dose CT images were reconstructed with ASIR,MBIRc and MBIRn,while standard-dose CT images were reconstructed with ASIR only.Objective image noise and SNR were measured on the same part from the back muscle and subcutaneous fat which located at the level of thoracic entry,trachea carina and hepatic portal.Image quality of lung,mediastinum and upper abdomen structures were evaluated on a 5-point scale.The results were compared with one-way ANOVA and Wilcoxon signed-rank tests.Results The effective dose equivalent for standard-dose CT was (3.01 ± 1.89) mSv,compared with (0.88 ± 0.83) mSv for low dose CT,which decreased by 70.76％.The mean image noise for low-dose MBIRNR40 was significantly lower than that of conventional-dose ASIR,low-dose ASIR and MBIRc (P＜0.05).The mean SNR for low-dose MRIRNR40 was significant ly higher than that of conventional dose ASIR,low-dose ASIR and MBIRc (P＜0.05).The subjective image noise score was significantly lower than that of ASIR and MBIRc,and the score of sharpness of details of the structures score for low dose MBIRn was significantly better than that of the ASIR and MBIRc (P＜0.05).Conclusion MBIRNR40 can significantly reduce image noise and improve SNR compared to ASIR and MBIRc in low-dose,even better than ASIR in standard dose,which reduce radiation dose by about 70％.In low-dose,MBIRPP20 can well display lung structures,and MBIRNR40 can display mediastinal and the upper abdominal structures.
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Objective To evaluate the effectiveness and safety of flexible ureteroscopy lithotripsy (FURL) combined with holmium laser for the concurrent treatment of bilateral upper ureteral tract calculi.Methods The clinical data in 43 patients with bilateral upper ureteral tract calculi concurrently treated by FURL combined with holmium laser in our hospital from September 2014 to November 2016 were retrospectively analyzed.All cases conducted CT scanning before operation.The flexible ureteroscope was intraoperatively placed and the lithotripsy was conducted by using 200 μm optical fiber at a power of 0.8-1.0 J/10-20Hz,which was coordinated by reticular basket.After lithotripsy,bilateral urethral stents were placed.KUB or CT was re-examined on postoperative 1 d.The cases of residual stone were performed KUB again after removing urethral stent after 4-6 weeks.Results All cases were successfully placed the flexible ureteroscope by one time.The mean operation time was (101.5±37.2) min and the overall stone-free rate (SFR) was 81.4 ％ (35/43).SFR was 100％ in the patients with the stone burden less than 30 mm and 63.2％ in the patients with the stone burden ≥30 mm,the difference was statistically significant(P＜0.05).One case appeared fever (39.5 ℃) after operation,1 case developed subcapsular renal hematoma and no other severe complications occurred.Conclusion FURL combined with holmium laser is an effective means to concurrently treating bilateral upper ureteral calculi,especially for the patients with stone burden ＜30 mm,which has higher stone clearance rate with good safety.
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Objective To assess image quality of adaptive statistical iterative reconstruction (ASIR),conventional modelbased iterative reconstruction (MBIRc) and a new lung-specific setting (MBIRRP20 and MBIRNR40) from the new version of model-based iterative reconstruction (MBIRn) in submillisievert chest CT comparing with ASIR in standard-dose.Methods Two chest CT examinations were performed with standard-dose and low-dose in 30 patients.Low-dose CT images were reconstructed with ASIR,MBIRc and MBIRn,while standard-dose CT images were reconstructed with ASIR only.Objective image noise and SNR were measured on the same part from the back muscle and subcutaneous fat which located at the level of thoracic entry,trachea carina and hepatic portal.Image quality of lung,mediastinum and upper abdomen structures were evaluated on a 5-point scale.The results were compared with one-way ANOVA and Wilcoxon signed-rank tests.Results The effective dose equivalent for standard-dose CT was (3.01 ± 1.89) mSv,compared with (0.88 ± 0.83) mSv for low dose CT,which decreased by 70.76％.The mean image noise for low-dose MBIRNR40 was significantly lower than that of conventional-dose ASIR,low-dose ASIR and MBIRc (P＜0.05).The mean SNR for low-dose MRIRNR40 was significant ly higher than that of conventional dose ASIR,low-dose ASIR and MBIRc (P＜0.05).The subjective image noise score was significantly lower than that of ASIR and MBIRc,and the score of sharpness of details of the structures score for low dose MBIRn was significantly better than that of the ASIR and MBIRc (P＜0.05).Conclusion MBIRNR40 can significantly reduce image noise and improve SNR compared to ASIR and MBIRc in low-dose,even better than ASIR in standard dose,which reduce radiation dose by about 70％.In low-dose,MBIRPP20 can well display lung structures,and MBIRNR40 can display mediastinal and the upper abdominal structures.
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Objective To evaluate the effectiveness and safety of flexible ureteroscopy lithotripsy (FURL) combined with holmium laser for the concurrent treatment of bilateral upper ureteral tract calculi.Methods The clinical data in 43 patients with bilateral upper ureteral tract calculi concurrently treated by FURL combined with holmium laser in our hospital from September 2014 to November 2016 were retrospectively analyzed.All cases conducted CT scanning before operation.The flexible ureteroscope was intraoperatively placed and the lithotripsy was conducted by using 200 μm optical fiber at a power of 0.8-1.0 J/10-20Hz,which was coordinated by reticular basket.After lithotripsy,bilateral urethral stents were placed.KUB or CT was re-examined on postoperative 1 d.The cases of residual stone were performed KUB again after removing urethral stent after 4-6 weeks.Results All cases were successfully placed the flexible ureteroscope by one time.The mean operation time was (101.5±37.2) min and the overall stone-free rate (SFR) was 81.4 ％ (35/43).SFR was 100％ in the patients with the stone burden less than 30 mm and 63.2％ in the patients with the stone burden ≥30 mm,the difference was statistically significant(P＜0.05).One case appeared fever (39.5 ℃) after operation,1 case developed subcapsular renal hematoma and no other severe complications occurred.Conclusion FURL combined with holmium laser is an effective means to concurrently treating bilateral upper ureteral calculi,especially for the patients with stone burden ＜30 mm,which has higher stone clearance rate with good safety.
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[Abstraet] Purpose To explore the application of noise reduction settings among modelbased iterative reconstruction (MBIRn) on decreasing radiation dose in CTA through experimental study.Materials and Methods Spectral CT was used to scan vessel model which could accommodate 8 tubes under static condition under 120 kVp fixed tube voltage at 10 mA,50 mA,150 mA and 600 mA.The tubes were filled with purified water,1,2,5,10,20 and 30 mgI/ml solutions and 30 mgCa/ml solution.Algorithms of FBP (standard),ASIR40 (combined by 40％ ASIR and FBP),MBIRc and MBIRn with optimized spatial resolution setting as MBIRRP20,MBIRstnd (standard setting),and MBIRNR40 (noise reduction setting) were adopted for original scanning data to reconstruct images of 0.625 mm slice thickness for contrastive analysis.Three fixed layers were chosen and regions of interest were placed on central tube and surrounding ester matrix,and CT value and standard variation (SD) were measured to represent noise.Noise reduction setting MBIRNR40 and solution noise of other reconstruction algorithm images were calculated and compared and average value of contrast noise ratio (CNR) was compared.Results Compared to FBP under different tube currents,ASIR40,MBIRc,MBIRRP20,MBIRstnd and MBIRNR40 reduce noise and increase CNR at different levels.Average noise of MBIRNR40 was the lowest (reduced by 78.33％) and CNR the highest (increased by 241.74％),making it superior to other reconstruction algorithm images (P＜0.05).Meanwhile,the lower the radiation dose was,the more obvious its advantage was.Reconstruction image noise of MBIRNR40 at 10 mA was close to that of FBP and ASIR40 at 600 mA.CNR was obvious greater than that of FBP and ASIR40 at other tube voltage.Conclusion Reconstruction algorithms of MBIRc,MBIRn and ASIR can help enhance CTA image quality and reduce radiation dose.Noise reduction setting MBIRNR40 from MBIRn has the lowest noise and greatest CNR.The lower the radiation dose is,the more obvious its advantage is.
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Purpose To explore the correlation between normal pancreas and abdominal aorta in the peak enhancement (PE) and the shift time at the peak by applying the multislices spiral CT perfusion imaging.Materials and Methods Prospectively analyzed 62 patients who received enhancement CT examination for the superior or the middle abdomen,underwent optimum level CT perfusion imaging after plain scanning.These data were processed on a Vitreal 2.0 worker-station by using Toshiba body software package.The time-density curves (TDC) of the normal pancreas and the abdominal aorta were drawn,the PE and the shift time of PE were recorded and their correlation was analyzed.Results Compared with abdominal aorta,the mean value of PE of the normal pancreas was lower,and the difference was statistically significant [(111.94± 14.42)HU vs (351.83 ± 74.93)HU,P＜0.05],the mean difference was (246.10± 65.86)HU.Compared with abdominal aorta,the mean shift times of PE of the normal pancreas was latter,and the difference was statistically significant [(37.56±6.90) s vs (30.82±6.73) s,P＜0.05],the mean difference was (6.54±2.97)s.The PE and shift time of PE of the normal pancreas were positively and linearly correlated with that of abdominal aorta (r=0.438,r=0.379).Conclusion The PE of the normal pancreas is not synchronous with that of the abdominal aorta.The shift time of the former is usually 6～8 seconds slower than that of the latter.This provides a basis to find the PE of the normal pancreas in enhanced scan.