For optimization of production processes and product quality,often knowledge of the factors influencing the process outcome is compulsory.Thus,process analytical technology(PAT)that allows deeper insight into the proc...For optimization of production processes and product quality,often knowledge of the factors influencing the process outcome is compulsory.Thus,process analytical technology(PAT)that allows deeper insight into the process and results in a mathematical description of the process behavior as a simple function based on the most important process factors can help to achieve higher production efficiency and quality.The present study aims at characterizing a well-known industrial process,the transesterification reaction of rapeseed oil with methanol to produce fatty acid methyl esters(FAME)for usage as biodiesel in a continuous micro reactor set-up.To this end,a design of experiment approach is applied,where the effects of two process factors,the molar ratio and the total flow rate of the reactants,are investigated.The optimized process target response is the FAME mass fraction in the purified nonpolar phase of the product as a measure of reaction yield.The quantification is performed using attenuated total reflection infrared spectroscopy in combination with partial least squares regression.The data retrieved during the conduction of the DoE experimental plan were used for statistical analysis.A non-linear model indicating a synergistic interaction between the studied factors describes the reactor behavior with a high coefficient of determination(R^(2))of 0.9608.Thus,we applied a PAT approach to generate further insight into this established industrial process.展开更多
BACKGROUND After an esophagectomy, the stomach is most commonly used to restore continuity of the upper gastrointestinal tract. These esophago-gastric anastomoses are prone to serious complications such as leakage ass...BACKGROUND After an esophagectomy, the stomach is most commonly used to restore continuity of the upper gastrointestinal tract. These esophago-gastric anastomoses are prone to serious complications such as leakage associated with high morbidity and mortality. Graft perfusion is considered to be an important predictor for anastomotic integrity. Based on the current literature we believe Indocyanine green fluorescence angiography(ICGA) is an easy assessment tool for gastric tube(GT) perfusion, and it might predict anastomotic leakage(AL).AIM To evaluate feasibility and effectiveness of ICGA in GT perfusion assessment and as a predictor of AL.METHODS This study was designed according to the PRISMA guidelines and registered in the PROSPERO database. PubMed and EMBASE were independently searched by 2 reviewers for studies presenting data on intraoperative ICGA GT perfusion assessment during esophago-gastric reconstruction after esophagectomy.Relevant outcomes such as feasibility, complications, intraoperative surgical changes based on ICGA findings, quantification attempts, anatomical data and the impact of ICGA on postoperative anastomotic complications, were collected by 2 independent researchers. The quality of the included articles was assessed based on the Methodological Index for Non-Randomized Studies. The 19 included studies presented data on 1192 esophagectomy patients, in 758 patients ICGA was used perioperative to guide esophageal reconstruction.RESULTS The 19 included studies for qualitative analyses all described ICGA as a safe and easy method to evaluate gastric graft perfusion. AL occurred in 13.8% of the entire cohort, 10% in the ICG guided group and 20.6% in the control group(P <0.001). When poorly perfused cases are excluded from the analyses, the difference in AL was even larger(AL well-perfused group 6.3% vs control group 20.5%, P <0.001). The AL rate in the group with an altered surgical plan based on the ICG image was 6.5%, similar to the well perfused group(6.3%) and significantly less than the poorly perfused group(47.8%)(P < 0.001), suggesting that the technique is able to identify and alter a potential bad outcome.CONCLUSION ICGA is a safe, feasible and promising method for perfusion assessment. The lower AL rate in the well perfused group suggest that a good fluorescent signal predicts a good outcome.展开更多
Anaerobic digestion of biomasses originates different products, the most abundant of which are methane and carbon dioxide. During this process, a 60-70% organic matter reduction occurs and the final product, the diges...Anaerobic digestion of biomasses originates different products, the most abundant of which are methane and carbon dioxide. During this process, a 60-70% organic matter reduction occurs and the final product, the digestate, is charac- terized by high biological stability and high contents of recalcitrant organic molecules and nutrients. In the present work digestates obtained by different mixture of biomasses in a full-scale co-digestion plant operating in Italy were characterized as whole samples without any pre-treatment or extraction by means of Fourier transform infrared spec- troscopy and fluorescence spectroscopy in the synchronous-scan mode and results were compared to those obtained on the single fresh substrates. Biomasses considered were: beef cattle slurry, maize or sorghum silage, agro-industrial residues, olive residues and olive mill wastewater. These substrates exhibited typical spectra related to their different chemical composition. Results obtained on digestates provided evidence of distinctive characteristic of the final product as a function of the different composition of the biomasses loaded into the digestion plant. We concluded that FTIR and fluorescence spectra of digestates produced in a real co-digestion plant “inherit” the main spectroscopic features of the organic wastes from which they are produced. Spectroscopic techniques used in this work succeeded in qualitatively characterizing and differentiating digestates obtained from biomasses of different chemical composition.展开更多
目的利用拉曼光谱与中红外光谱的数据融合技术实现对食用酒精乙醇浓度(酒精度)的快速定量检测。方法首先,分别采集不同浓度食用酒精水溶液的拉曼光谱与中红外光谱。其次,采用多元散射校正(multiplicative scatter correction,MSC)、卷...目的利用拉曼光谱与中红外光谱的数据融合技术实现对食用酒精乙醇浓度(酒精度)的快速定量检测。方法首先,分别采集不同浓度食用酒精水溶液的拉曼光谱与中红外光谱。其次,采用多元散射校正(multiplicative scatter correction,MSC)、卷积平滑(Savitzky-Golay,S-G)、一阶求导的方法对原始数据进行预处理。然后,基于自举软缩减法(bootstrapping soft shrinkage,BOSS)和无信息变量消除算法(uninformative variable elimination,UVE)分别对预处理后的光谱数据进行特征提取,并利用X-Y距离样本集划分法(sample set partitioning based on joint X-Y distance,SPXY)将光谱数据划分为校正集和预测集。最后,建立基于拉曼光谱-中红外光谱数据融合的偏最小二乘回归(partial least squares regression,PLSR)食用酒精乙醇浓度预测模型,并利用麻雀搜寻算法优化的混合核极限学习机算法(sparrow search algorithm-optimized hybrid kernel extreme learning machine,SSA-HKELM)提升预测性能,实现对不同浓度食用酒精的快速、准确定量检测。结果与拉曼光谱数据、中红外光谱数据以及中红外与拉曼光谱的数据层融合构建的预测模型相比,中红外光谱与拉曼光谱特征层融合数据构建的预测模型具有更好的预测性能。其中,最优模型的校正集均方根误差(root mean squared error of calibration set,RMSEC)为0.98314,校正集决定系数(R_(c)^(2))为0.99634,预测集均方根误差(root mean squared error of prediction set,RMSEP)为1.03256,预测集决定系数(R_(p)^(2))为0.99036。结论中红外光谱与拉曼光谱特征层融合预测模型可以实现对不同浓度食用酒精的高效定量检测,为食用酒精的质量检测提供了有效的理论支持与技术保障。展开更多
文摘For optimization of production processes and product quality,often knowledge of the factors influencing the process outcome is compulsory.Thus,process analytical technology(PAT)that allows deeper insight into the process and results in a mathematical description of the process behavior as a simple function based on the most important process factors can help to achieve higher production efficiency and quality.The present study aims at characterizing a well-known industrial process,the transesterification reaction of rapeseed oil with methanol to produce fatty acid methyl esters(FAME)for usage as biodiesel in a continuous micro reactor set-up.To this end,a design of experiment approach is applied,where the effects of two process factors,the molar ratio and the total flow rate of the reactants,are investigated.The optimized process target response is the FAME mass fraction in the purified nonpolar phase of the product as a measure of reaction yield.The quantification is performed using attenuated total reflection infrared spectroscopy in combination with partial least squares regression.The data retrieved during the conduction of the DoE experimental plan were used for statistical analysis.A non-linear model indicating a synergistic interaction between the studied factors describes the reactor behavior with a high coefficient of determination(R^(2))of 0.9608.Thus,we applied a PAT approach to generate further insight into this established industrial process.
基金"Kom op tegen Kanker"(Stand up to Cancer),the Flemish cancer society
文摘BACKGROUND After an esophagectomy, the stomach is most commonly used to restore continuity of the upper gastrointestinal tract. These esophago-gastric anastomoses are prone to serious complications such as leakage associated with high morbidity and mortality. Graft perfusion is considered to be an important predictor for anastomotic integrity. Based on the current literature we believe Indocyanine green fluorescence angiography(ICGA) is an easy assessment tool for gastric tube(GT) perfusion, and it might predict anastomotic leakage(AL).AIM To evaluate feasibility and effectiveness of ICGA in GT perfusion assessment and as a predictor of AL.METHODS This study was designed according to the PRISMA guidelines and registered in the PROSPERO database. PubMed and EMBASE were independently searched by 2 reviewers for studies presenting data on intraoperative ICGA GT perfusion assessment during esophago-gastric reconstruction after esophagectomy.Relevant outcomes such as feasibility, complications, intraoperative surgical changes based on ICGA findings, quantification attempts, anatomical data and the impact of ICGA on postoperative anastomotic complications, were collected by 2 independent researchers. The quality of the included articles was assessed based on the Methodological Index for Non-Randomized Studies. The 19 included studies presented data on 1192 esophagectomy patients, in 758 patients ICGA was used perioperative to guide esophageal reconstruction.RESULTS The 19 included studies for qualitative analyses all described ICGA as a safe and easy method to evaluate gastric graft perfusion. AL occurred in 13.8% of the entire cohort, 10% in the ICG guided group and 20.6% in the control group(P <0.001). When poorly perfused cases are excluded from the analyses, the difference in AL was even larger(AL well-perfused group 6.3% vs control group 20.5%, P <0.001). The AL rate in the group with an altered surgical plan based on the ICG image was 6.5%, similar to the well perfused group(6.3%) and significantly less than the poorly perfused group(47.8%)(P < 0.001), suggesting that the technique is able to identify and alter a potential bad outcome.CONCLUSION ICGA is a safe, feasible and promising method for perfusion assessment. The lower AL rate in the well perfused group suggest that a good fluorescent signal predicts a good outcome.
文摘Anaerobic digestion of biomasses originates different products, the most abundant of which are methane and carbon dioxide. During this process, a 60-70% organic matter reduction occurs and the final product, the digestate, is charac- terized by high biological stability and high contents of recalcitrant organic molecules and nutrients. In the present work digestates obtained by different mixture of biomasses in a full-scale co-digestion plant operating in Italy were characterized as whole samples without any pre-treatment or extraction by means of Fourier transform infrared spec- troscopy and fluorescence spectroscopy in the synchronous-scan mode and results were compared to those obtained on the single fresh substrates. Biomasses considered were: beef cattle slurry, maize or sorghum silage, agro-industrial residues, olive residues and olive mill wastewater. These substrates exhibited typical spectra related to their different chemical composition. Results obtained on digestates provided evidence of distinctive characteristic of the final product as a function of the different composition of the biomasses loaded into the digestion plant. We concluded that FTIR and fluorescence spectra of digestates produced in a real co-digestion plant “inherit” the main spectroscopic features of the organic wastes from which they are produced. Spectroscopic techniques used in this work succeeded in qualitatively characterizing and differentiating digestates obtained from biomasses of different chemical composition.
文摘目的利用拉曼光谱与中红外光谱的数据融合技术实现对食用酒精乙醇浓度(酒精度)的快速定量检测。方法首先,分别采集不同浓度食用酒精水溶液的拉曼光谱与中红外光谱。其次,采用多元散射校正(multiplicative scatter correction,MSC)、卷积平滑(Savitzky-Golay,S-G)、一阶求导的方法对原始数据进行预处理。然后,基于自举软缩减法(bootstrapping soft shrinkage,BOSS)和无信息变量消除算法(uninformative variable elimination,UVE)分别对预处理后的光谱数据进行特征提取,并利用X-Y距离样本集划分法(sample set partitioning based on joint X-Y distance,SPXY)将光谱数据划分为校正集和预测集。最后,建立基于拉曼光谱-中红外光谱数据融合的偏最小二乘回归(partial least squares regression,PLSR)食用酒精乙醇浓度预测模型,并利用麻雀搜寻算法优化的混合核极限学习机算法(sparrow search algorithm-optimized hybrid kernel extreme learning machine,SSA-HKELM)提升预测性能,实现对不同浓度食用酒精的快速、准确定量检测。结果与拉曼光谱数据、中红外光谱数据以及中红外与拉曼光谱的数据层融合构建的预测模型相比,中红外光谱与拉曼光谱特征层融合数据构建的预测模型具有更好的预测性能。其中,最优模型的校正集均方根误差(root mean squared error of calibration set,RMSEC)为0.98314,校正集决定系数(R_(c)^(2))为0.99634,预测集均方根误差(root mean squared error of prediction set,RMSEP)为1.03256,预测集决定系数(R_(p)^(2))为0.99036。结论中红外光谱与拉曼光谱特征层融合预测模型可以实现对不同浓度食用酒精的高效定量检测,为食用酒精的质量检测提供了有效的理论支持与技术保障。
