Optimization and simplification of optical systems represent a milestone in advancing the development of handheld and portable laser-induced breakdown spectroscopy(LIBS)systems towards smaller,more integrated forms.Th...Optimization and simplification of optical systems represent a milestone in advancing the development of handheld and portable laser-induced breakdown spectroscopy(LIBS)systems towards smaller,more integrated forms.This research,for the first time,conducted a comprehensive optimization design and comparative analysis of three compact LIBS system optical paths:the paraxial optical path(OP),the off-axis OP,and the reflective OP.The differences in spectral intensity and stability among these paths were revealed,providing a scientific basis for selecting the optimal OP for LIBS systems.The research found that the paraxial OP excels in spectral performance and quantitative analysis accuracy,making it the preferred choice for compact LIBS systems.Specifically,the paraxial OP significantly enhances spectral intensity,achieving a 6 times improvement over the off-axis OP and an even more remarkable 150 times increase compared to the reflective OP,greatly enhancing detection sensitivity.Additionally,the relative standard deviation,spectral stability index,maintains a consistently low level,ranging from 10.9%to 13.4%,significantly outperforming the other two OPs and ensuring the reliability of analytical results.In the field of quantitative analysis,the paraxial OP also demonstrates higher accuracy,precision,and sensitivity,comparing to other OPs.The quantitative analysis models for Si,Cu,and Ti elements exhibit excellent fitting,providing users with high-quality quantitative analysis results that are of great significance for applications in material science,environmental monitoring,industrial inspection,and other fields.In summary,this study not only confirms the enormous application potential of the paraxial OP in compact LIBS systems but also provides valuable practical experience and theoretical support for the miniaturization and integration of LIBS systems.Looking ahead,with continuous technological advancements,the design of the paraxial OP is expected to further propel the widespread adoption of LIBS technology in portable,on-site detection applications.展开更多
One-dimensional Cd S@TiO_2 core-shell heterostructures were fabricated via the hydrolysis of tetrabutyl titanate(TBT) on preformed Cd S nanowires. The as-prepared products were characterized by X-ray diffraction, tran...One-dimensional Cd S@TiO_2 core-shell heterostructures were fabricated via the hydrolysis of tetrabutyl titanate(TBT) on preformed Cd S nanowires. The as-prepared products were characterized by X-ray diffraction, transmission electron microscopy, selected area electron diffraction and diffuse reflectance spectroscopy techniques. Results demonstrated that the hydrolysis of TBT had a great influence on the morphology of the coated TiO_2 shell, resulting in the formation of TiO_2 nanoparticles and nanolayer-modified Cd S@TiO_2 heterostructures. Degradation of methylene blue using Cd S@TiO_2 core-shell heterostructures as photocatalysts under visible light irradiation was investigated. Comparative photocatalytic tests showed that the TiO_2 nanoparticles-modified heterostructure exhibited a superior activity due to the passivity of photogenerated charge carriers.展开更多
Prediction systems are an important aspect of intelligent decisions.In engineering practice,the complex system structure and the external environment cause many uncertain factors in the model,which influence the model...Prediction systems are an important aspect of intelligent decisions.In engineering practice,the complex system structure and the external environment cause many uncertain factors in the model,which influence the modeling accuracy of the model.The belief rule base(BRB)can implement nonlinear modeling and express a variety of uncertain information,including fuzziness,ignorance,randomness,etc.However,the BRB system also has two main problems:Firstly,modeling methods based on expert knowledge make it difficult to guarantee the model’s accuracy.Secondly,interpretability is not considered in the optimization process of current research,resulting in the destruction of the interpretability of BRB.To balance the accuracy and interpretability of the model,a self-growth belief rule basewith interpretability constraints(SBRB-I)is proposed.The reasoning process of the SBRB-I model is based on the evidence reasoning(ER)approach.Moreover,the self-growth learning strategy ensures effective cooperation between the datadriven model and the expert system.A case study showed that the accuracy and interpretability of the model could be guaranteed.The SBRB-I model has good application prospects in prediction systems.展开更多
The broken efficiency of cell wall and the release amount of Pichia pastoris intracellular protein under different cell breaking conditions were investigated in this paper. The results showed that broken efficiency us...The broken efficiency of cell wall and the release amount of Pichia pastoris intracellular protein under different cell breaking conditions were investigated in this paper. The results showed that broken efficiency using hot alkali combined with high-pressure homogenizing method was higher than that of enzyme hydrolysis, hot alkali treatment and high-pressure homogenation, respectively. Suspended medium had little effect on the broken efficiency of yeast cell, but had significant effect on the protein release yield. The results indicated that optimal condition for intracellular proteins extraction was 30% (wet weight, w/v) of yeast cells suspend in 50 mM phosphate buffer (pH 10.0), water bathed at 60?C for 2 hours, homogenized twice at 100 MPa pressure. The broken efficiency of Pichia pastoris cell could reach 87.6% and the protein yield was 35.48 g per 100 g cells.展开更多
Objective: The aim of the study was to investigate the pregnancy outcomes and possible influencing factors concerning complicated monochorionic (MC) multiple pregnancies undergoing selective fetal reduction using radi...Objective: The aim of the study was to investigate the pregnancy outcomes and possible influencing factors concerning complicated monochorionic (MC) multiple pregnancies undergoing selective fetal reduction using radiofrequency ablation (RFA).Methods: This retrospective cohort study included 54 women with complicated MC multiple pregnancy who underwent selective fetal reduction using RFA at the Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region from January 2015 to March 2020. According to the indications for RFA, the 54 women were divided into three groups: complex complications (n = 30), structural anomalies (n = 18), and triplet pregnancy (n = 6). According to the gestational age for RFA, all patients were divided into three groups: 16-19+6 weeks (n = 17), 20-23+6 weeks (n = 17), and 24-26+6 weeks (n = 20). We analyzed the pregnancy outcomes (including the overall survival rate (OSR), gestational age at delivery, birth weight of newborns) and postoperative complications such as miscarriage, and intrauterine fetal death (IUFD) according to the indications and gestational age of reduction by using suitable statistical testing.Results: The OSR was 83.3% (45/54). The mean ± standard deviation (SD) of gestation at the time of reduction was 21.6 ± 3.2 weeks. The GA at delivery was 34.0(32.0,37.5) weeks. The mean ±SD of newborns’ birth weight was 2118 ± 685 g. The overall rates of miscarriage, PROM, and IUFD were 9.3% (5/54), 7.4% (4/54), and 7.4% (4/54), respectively. According to the indications for reduction, the OSR for complex complications, structural anomalies, and triplet pregnancy groups were 83.3% (25/30), 83.3% (15/18), and 83.3% (5/6), respectively. Statistically significant differences were only found in the mean birth weight among the three groups (P < 0.05). No significant difference was found in the rate of miscarriage, and mean gestation at delivery among the three groups (P > 0.05). In the group with complex complications, the OSR of twin-to-twin transfusion syndrome, selective intrauterine growth restriction, twin reversed arterial perfusion sequence, and twin anemia polycythemia sequence were 66.7% (6/9), 93.3% (14/15), 80.0% (4/5), and 100.0% (1/1), respectively, with no significant difference among these groups (P > 0.05). According to the gestational age of reduction, the OSRs among the three groups were 82.4% (14/17), 76.5% (13/17), and 90.0% (18/20), respectively, and the rate of miscarriage, IUFD, and mean gestation age at delivery among these groups showed no significant difference (P > 0.05).Conclusion: Selective fetal reduction by RFA is an important treatment method for complicated MC multiple pregnancy, although it may lead to complications like miscarriage, and IUFD. The indication of reduction seems to affect the pregnancy outcome. An optimal treatment plan should be selected according to the patient’s conditions in clinical practice.展开更多
Objective:To build a reference fetal growth chart for the Chinese population based on fetal ultrasound measurements.Methods:This was a multicenter,population-based retrospective cohort study.Longitudinal ultrasound me...Objective:To build a reference fetal growth chart for the Chinese population based on fetal ultrasound measurements.Methods:This was a multicenter,population-based retrospective cohort study.Longitudinal ultrasound measurement data were collected from 24 hospitals in 18 provinces of China from 1st September through 31st October of 2019.The estimated fetal weight(EFW)was calculated based on head circumference,abdominal circumference,and femur length using Hadlock formula 3.Fetal growth curves were estimated using a two-level linear regression model with cubic splines.All participants were divided into two groups:the northern group(n=5829)and the southern group(n=3246)based on the geographical division of China and male fetus group(n=4775)and female fetus group(n=4300)based on fetal gender.The EFW was compared by fetal gender and geographical group.All statistical models were adjusted for maternal sociodemographic characteristics.Results:A total of 9075 participants with 31,700 ultrasound measurement records were included in this study.Male fetuses demonstrated significantly larger EFW compared to female ones starting at 16 weeks of gestation and extending to delivery(global testP<0.01).The overall geographic difference in EFW was significant(global testP=0.03),and week-specific comparisons showed that the northern group had a greater EFW starting at 15 weeks of gestation and extending to 29 weeks of gestation,although this difference did not extend to the time of delivery.TheZ-score of EFW confirmed that our Chinese fetal growth charts differed from previously published standards.Conclusion:This study provides EFW and ultrasound biometric reference measurements for Chinese fetuses and reveals differences from other fetal growth charts.The chart is worth promoting in more regions of China but should be tested prudently before use.展开更多
基金financially supported by National Natural Science Foundation of China (Nos.62305392 and 62305123)Independent Research and Development Project of Naval Engineering University (No.2023504050)the Nursery Plan Project of Navel University of Engineering (2022)。
文摘Optimization and simplification of optical systems represent a milestone in advancing the development of handheld and portable laser-induced breakdown spectroscopy(LIBS)systems towards smaller,more integrated forms.This research,for the first time,conducted a comprehensive optimization design and comparative analysis of three compact LIBS system optical paths:the paraxial optical path(OP),the off-axis OP,and the reflective OP.The differences in spectral intensity and stability among these paths were revealed,providing a scientific basis for selecting the optimal OP for LIBS systems.The research found that the paraxial OP excels in spectral performance and quantitative analysis accuracy,making it the preferred choice for compact LIBS systems.Specifically,the paraxial OP significantly enhances spectral intensity,achieving a 6 times improvement over the off-axis OP and an even more remarkable 150 times increase compared to the reflective OP,greatly enhancing detection sensitivity.Additionally,the relative standard deviation,spectral stability index,maintains a consistently low level,ranging from 10.9%to 13.4%,significantly outperforming the other two OPs and ensuring the reliability of analytical results.In the field of quantitative analysis,the paraxial OP also demonstrates higher accuracy,precision,and sensitivity,comparing to other OPs.The quantitative analysis models for Si,Cu,and Ti elements exhibit excellent fitting,providing users with high-quality quantitative analysis results that are of great significance for applications in material science,environmental monitoring,industrial inspection,and other fields.In summary,this study not only confirms the enormous application potential of the paraxial OP in compact LIBS systems but also provides valuable practical experience and theoretical support for the miniaturization and integration of LIBS systems.Looking ahead,with continuous technological advancements,the design of the paraxial OP is expected to further propel the widespread adoption of LIBS technology in portable,on-site detection applications.
基金financial support Independent Innovation Foundation of Shandong University(IIFSDU-2009JQ011)
文摘One-dimensional Cd S@TiO_2 core-shell heterostructures were fabricated via the hydrolysis of tetrabutyl titanate(TBT) on preformed Cd S nanowires. The as-prepared products were characterized by X-ray diffraction, transmission electron microscopy, selected area electron diffraction and diffuse reflectance spectroscopy techniques. Results demonstrated that the hydrolysis of TBT had a great influence on the morphology of the coated TiO_2 shell, resulting in the formation of TiO_2 nanoparticles and nanolayer-modified Cd S@TiO_2 heterostructures. Degradation of methylene blue using Cd S@TiO_2 core-shell heterostructures as photocatalysts under visible light irradiation was investigated. Comparative photocatalytic tests showed that the TiO_2 nanoparticles-modified heterostructure exhibited a superior activity due to the passivity of photogenerated charge carriers.
基金This work was supported in part by the Postdoctoral Science Foundation of China under Grant No.2020M683736in part by the Natural Science Foundation of Heilongjiang Province of China under Grant No.LH2021F038+2 种基金in part by the innovation practice project of college students in Heilongjiang Province under Grant Nos.202010231009,202110231024,and 202110231155in part by the basic scientific research business expenses scientific research projects of provincial universities in Heilongjiang Province Grant Nos.XJGZ2021001in part by the Education and teaching reform program of 2021 in Heilongjiang Province under Grant No.SJGY20210457.
文摘Prediction systems are an important aspect of intelligent decisions.In engineering practice,the complex system structure and the external environment cause many uncertain factors in the model,which influence the modeling accuracy of the model.The belief rule base(BRB)can implement nonlinear modeling and express a variety of uncertain information,including fuzziness,ignorance,randomness,etc.However,the BRB system also has two main problems:Firstly,modeling methods based on expert knowledge make it difficult to guarantee the model’s accuracy.Secondly,interpretability is not considered in the optimization process of current research,resulting in the destruction of the interpretability of BRB.To balance the accuracy and interpretability of the model,a self-growth belief rule basewith interpretability constraints(SBRB-I)is proposed.The reasoning process of the SBRB-I model is based on the evidence reasoning(ER)approach.Moreover,the self-growth learning strategy ensures effective cooperation between the datadriven model and the expert system.A case study showed that the accuracy and interpretability of the model could be guaranteed.The SBRB-I model has good application prospects in prediction systems.
文摘The broken efficiency of cell wall and the release amount of Pichia pastoris intracellular protein under different cell breaking conditions were investigated in this paper. The results showed that broken efficiency using hot alkali combined with high-pressure homogenizing method was higher than that of enzyme hydrolysis, hot alkali treatment and high-pressure homogenation, respectively. Suspended medium had little effect on the broken efficiency of yeast cell, but had significant effect on the protein release yield. The results indicated that optimal condition for intracellular proteins extraction was 30% (wet weight, w/v) of yeast cells suspend in 50 mM phosphate buffer (pH 10.0), water bathed at 60?C for 2 hours, homogenized twice at 100 MPa pressure. The broken efficiency of Pichia pastoris cell could reach 87.6% and the protein yield was 35.48 g per 100 g cells.
基金supported by Special fund for Guangxi science and technology base and talent(Gui Ke AD17129016)the Health Department of Guangxi Province Project(Z2016095)。
文摘Objective: The aim of the study was to investigate the pregnancy outcomes and possible influencing factors concerning complicated monochorionic (MC) multiple pregnancies undergoing selective fetal reduction using radiofrequency ablation (RFA).Methods: This retrospective cohort study included 54 women with complicated MC multiple pregnancy who underwent selective fetal reduction using RFA at the Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region from January 2015 to March 2020. According to the indications for RFA, the 54 women were divided into three groups: complex complications (n = 30), structural anomalies (n = 18), and triplet pregnancy (n = 6). According to the gestational age for RFA, all patients were divided into three groups: 16-19+6 weeks (n = 17), 20-23+6 weeks (n = 17), and 24-26+6 weeks (n = 20). We analyzed the pregnancy outcomes (including the overall survival rate (OSR), gestational age at delivery, birth weight of newborns) and postoperative complications such as miscarriage, and intrauterine fetal death (IUFD) according to the indications and gestational age of reduction by using suitable statistical testing.Results: The OSR was 83.3% (45/54). The mean ± standard deviation (SD) of gestation at the time of reduction was 21.6 ± 3.2 weeks. The GA at delivery was 34.0(32.0,37.5) weeks. The mean ±SD of newborns’ birth weight was 2118 ± 685 g. The overall rates of miscarriage, PROM, and IUFD were 9.3% (5/54), 7.4% (4/54), and 7.4% (4/54), respectively. According to the indications for reduction, the OSR for complex complications, structural anomalies, and triplet pregnancy groups were 83.3% (25/30), 83.3% (15/18), and 83.3% (5/6), respectively. Statistically significant differences were only found in the mean birth weight among the three groups (P < 0.05). No significant difference was found in the rate of miscarriage, and mean gestation at delivery among the three groups (P > 0.05). In the group with complex complications, the OSR of twin-to-twin transfusion syndrome, selective intrauterine growth restriction, twin reversed arterial perfusion sequence, and twin anemia polycythemia sequence were 66.7% (6/9), 93.3% (14/15), 80.0% (4/5), and 100.0% (1/1), respectively, with no significant difference among these groups (P > 0.05). According to the gestational age of reduction, the OSRs among the three groups were 82.4% (14/17), 76.5% (13/17), and 90.0% (18/20), respectively, and the rate of miscarriage, IUFD, and mean gestation age at delivery among these groups showed no significant difference (P > 0.05).Conclusion: Selective fetal reduction by RFA is an important treatment method for complicated MC multiple pregnancy, although it may lead to complications like miscarriage, and IUFD. The indication of reduction seems to affect the pregnancy outcome. An optimal treatment plan should be selected according to the patient’s conditions in clinical practice.
基金supported by the National Key R&D Program of China(2018YFC1002900)。
文摘Objective:To build a reference fetal growth chart for the Chinese population based on fetal ultrasound measurements.Methods:This was a multicenter,population-based retrospective cohort study.Longitudinal ultrasound measurement data were collected from 24 hospitals in 18 provinces of China from 1st September through 31st October of 2019.The estimated fetal weight(EFW)was calculated based on head circumference,abdominal circumference,and femur length using Hadlock formula 3.Fetal growth curves were estimated using a two-level linear regression model with cubic splines.All participants were divided into two groups:the northern group(n=5829)and the southern group(n=3246)based on the geographical division of China and male fetus group(n=4775)and female fetus group(n=4300)based on fetal gender.The EFW was compared by fetal gender and geographical group.All statistical models were adjusted for maternal sociodemographic characteristics.Results:A total of 9075 participants with 31,700 ultrasound measurement records were included in this study.Male fetuses demonstrated significantly larger EFW compared to female ones starting at 16 weeks of gestation and extending to delivery(global testP<0.01).The overall geographic difference in EFW was significant(global testP=0.03),and week-specific comparisons showed that the northern group had a greater EFW starting at 15 weeks of gestation and extending to 29 weeks of gestation,although this difference did not extend to the time of delivery.TheZ-score of EFW confirmed that our Chinese fetal growth charts differed from previously published standards.Conclusion:This study provides EFW and ultrasound biometric reference measurements for Chinese fetuses and reveals differences from other fetal growth charts.The chart is worth promoting in more regions of China but should be tested prudently before use.
