Dear Editor,Local recurrence and cervical lymph node metastases are major causes of mortality in patients with head and neck squamous cell carcinoma(HNSCC).To date,none of the proposed strategies for predicting outcom...Dear Editor,Local recurrence and cervical lymph node metastases are major causes of mortality in patients with head and neck squamous cell carcinoma(HNSCC).To date,none of the proposed strategies for predicting outcomes in this disease have proven fully effective,and a comprehensive physical examination remains the primary method for early detection and monitoring of HNSCC.展开更多
With recent advances in biotechnology, genome-wide association study （GWAS） has been widely used to identify genetic variants that underlie human complex diseases and traits. In case-control GWAS, typical statistica...With recent advances in biotechnology, genome-wide association study （GWAS） has been widely used to identify genetic variants that underlie human complex diseases and traits. In case-control GWAS, typical statistical strategy is traditional logistical regression （LR） based on single-locus analysis. However, such a single-locus analysis leads to the well-known multiplicity problem, with a risk of inflating type I error and reducing power. Dimension reduction-based techniques, such as principal component-based logistic regression （PC-LR）, partial least squares-based logistic regression （PLS-LR）, have recently gained much attention in the analysis of high dimensional genomic data. However, the perfor- mance of these methods is still not clear, especially in GWAS. We conducted simulations and real data application to compare the type I error and power of PC-LR, PLS-LR and LR applicable to GWAS within a defined single nucleotide polymorphism （SNP） set region. We found that PC-LR and PLS can reasonably control type I error under null hypothesis. On contrast, LR, which is corrected by Bonferroni method, was more conserved in all simulation settings. In particular, we found that PC-LR and PLS-LR had comparable power and they both outperformed LR, especially when the causal SNP was in high linkage disequilibrium with genotyped ones and with a small effective size in simulation. Based on SNP set analysis, we applied all three methods to analyze non-small cell lung cancer GWAS data.展开更多
Somatosensory evoked potentials(SEPs)have been widely used to assess neurological function in clinical practice.A good understanding of the association between SEP signals and neurological function is helpful for prec...Somatosensory evoked potentials(SEPs)have been widely used to assess neurological function in clinical practice.A good understanding of the association between SEP signals and neurological function is helpful for precise diagnosis of impairment location.Previous studies on SEPs have been reported in animal models.However,few studies have reported the relationships between SEP waveforms in animals and those in humans.In this study,we collected normal SEP waveforms and decomposed them into specific time–frequency components(TFCs).Our results showed three stable TFC distribution regions in intact goats and rats and in humans.After we induced spinal cord injury in the animal models,a greater number of small TFC distribution regions were observed in the injured goat and rat groups than in the normal group.Moreover,there were significant correlations(P<0.05)and linear relationships between the main SEP TFCs of the human group and those of the goat and rat groups.A stable TFC distribution of SEP components was observed in the human,goat and rat groups,and the TFC distribution modes were similar between the three groups.Results in various animal models in this study could be translated to future clinical studies based on SEP TFC analysis.Human studies were approved by the Institutional Review Board of the University of Hong Kong/Hospital Authority Hong Kong West Cluster(approval No.UM 05-312 T/975)on December 5,2005.Rat experiments were approved by the Committee on the Use of Live Animals in Teaching and Research of Li Ka Shing Faculty of Medicine of the University of Hong Kong(approval No.CULART 2912-12)on January 28,2013.Goat experiments were approved by the Animal Ethics Committee of Affiliated Hospital of Guangdong Medical University(approval No.GDY2002132)on March 5,2018.展开更多
Seedlessness has always been a valuable quality characteristic of edible grape varieties.Although the production of seedless grapes has been ongoing for decades,the genetic complexity of seedless grapes is not yet ful...Seedlessness has always been a valuable quality characteristic of edible grape varieties.Although the production of seedless grapes has been ongoing for decades,the genetic complexity of seedless grapes is not yet fully understood.Therefore,determining the genetic mechanisms and key regulatory genes of seedless grapes is of great significance for seedless grape breeding and meeting market demands.The emergence of high-throughput analysis software offers greater possibilities for mining genes related to plant organ development.Specifically,to mine a greater number of candidate genes related to grape seed traits,this study used the seed trait parameters analyzed by Tomato Analyzer as the target trait and then used a genome-wide association study(GWAS)to mine candidate genes.In the two-year analysis using principal component analysis(PCA),we extracted five principal components with a cumulative contribution rate of 96.586%.The cumulative contribution rate for component 1 reached 87.352%.Correlation analysis revealed correlation coefficients ranging from 0.54 to 0.98 among the seven basic traits.The GWAS results indicated that 370 SNP loci were significantly correlated with seed traits.These SNP loci were distributed on 18 chromosomes,except for chromosome 4,with most SNP loci distributed on chromosome 18.Based on the physical location of single nucleotide polymorphism(SNP)markers significantly associated with seed-related traits in the grape reference genome,candidate genes are screened within the range of linkage disequilibrium(LD)attenuation distance,both upstream and downstream of the significant SNP loci.These candidate genes were mainly transcription factor-related genes(VvMADS4 and VvMADS5),ubiquitin ligase-related genes(E3 ubiquitin ligase BIG BROTHER),serine/threonine protein kinase-related genes,and carbohydrate metabolism-related genes(Sucrose Synthase 2)and simultaneously controlled multiple(at least two or more)seed traits.These results indicate that seed traits are jointly regulated by some genes involved in seed morphology regulation.In this work,we identified new gene loci related to grape seed traits.Identifying molecular markers closely related to these seed traits is of great significance for breeding seedless grape varieties.展开更多
Association analysis provides an opportunity to find genetic variants underlying complex traits. A principal components regression （PCR）-based approach was shown to outperform some competing approaches. However, a l...Association analysis provides an opportunity to find genetic variants underlying complex traits. A principal components regression （PCR）-based approach was shown to outperform some competing approaches. However, a limitation of this method is that the principal components （PCs） selected from single nucleotide polyrnorphisms （SNPs） may be unrelated to the phenotype. In this article, we investigate the theoretical properties of such a method in more detail. We first derive the exact power function of the test based on PCR, and hence clarify the relationship between the test power and the degrees of freedom （DF）. Next, we extend the PCR test to a general weighted PCs test, which provides a unified framework for understanding the properties of some related statistics. We then compare the performance of these tests. We also introduce several data-driven adaptive alternatives to overcome difficulties in the PCR approach. Finally, we illustrate our results using simulations based on real genotype data. Simulation study shows the risk of using the unsupervised rule to determine the number of PCs, and demonstrates that there is no single uniformly powerful method for detecting genetic variants.展开更多
In recent years, the antibacterial and anti-inflammatory effects of the Labiatae plants have been widely recognized, and have been used in clinical practice, and their anti-tumor effects are also very significant, and...In recent years, the antibacterial and anti-inflammatory effects of the Labiatae plants have been widely recognized, and have been used in clinical practice, and their anti-tumor effects are also very significant, and receiving more and more attention. At present, malignant tumors are still the first killer threatening human health. Because of the long-term use of chemical anti-tumor drugs with certain drug resistance and obvious side effects, finding high-efficiency anti-tumor active ingredients from natural plants and Chinese herbal medicines has become a hot spot in the field of pharmacy. Literature survey indicates that the active ingredients in Labiatae plants have anti-tumor effects. Therefore, this paper summarized and discussed the anti-tumor types, mechanisms and active components of the Labiatae plants, so as to provide a basis and reference for the development of new anti-tumor drugs or preparations.展开更多
Rare earth elements (REEs), especially heavy rare earth elements (HREEs), are in demand for their current and emerging applications in advanced technologies. Here we perform computer-driven micro-mapping at the millim...Rare earth elements (REEs), especially heavy rare earth elements (HREEs), are in demand for their current and emerging applications in advanced technologies. Here we perform computer-driven micro-mapping at the millimeter scale of the minerals that comprise Round Top Mountain, in west Texas, USA. This large rhyolite deposit is enriched in HREEs and such other critical elements as Li, Be, and U. Electron probe microanalysis of 2 × 2 mm areas of thin sections of the rhyolite produced individual maps of 16 elements. These were superimposed to generate a 16-element composition at each pixel. Principal components analysis of elements at each pixel identified the specific mineral at that site. The pixels were then relabeled as the appropriate minerals, thereby producing a single mineral map. The overall mineral composition of the 7 studied samples compared favorably with prior analyses of the Round Top deposit available in the literature. Likewise the range of porosity in the maps was consistent with that of previous direct measurements by water saturation. This new statistical and GIS-based technique provides a robust and unbiased approach to electron microprobe mapping. The study further showed that the high-value yttrofluorite grains exhibited little tendency to cluster with other late-stage trace minerals and that the samples extended the previously documented overall homogeneity of the deposit at field scale to this microscopic scale.展开更多
Conventional neuroimaging techniques cannot truly reflect the change of regional cerebral blood flow in patients with carpal tunnel syndrome.Pseudo-continuous arterial spinning labeling(pCASL)as an efficient non-invas...Conventional neuroimaging techniques cannot truly reflect the change of regional cerebral blood flow in patients with carpal tunnel syndrome.Pseudo-continuous arterial spinning labeling(pCASL)as an efficient non-invasive neuroimaging technique can be applied to directly quantify the neuronal activities of individual brain regions that show the persistent symptoms owing to its better spatial resolution and increased signal-to-noise ratio.Therefore,this prospective observational study was conducted in 27 eligible female carpal tunnel syndrome,aged 57.7±6.51 years.Psychometric tests,nerve conduction studies and pCASL neuroimaging assessment were performed.The results showed that the relevant activated brain regions in the cortical,subcrotical,and cerebral regions were correlated with numbness,pain,functionality,median nerve status and motor amplitude of median nerve(K=21–2849,r=–0.77–0.76,P<0.05).There was a tendency of pain processing which shifted from the nociceptive circuitry to the emotional and cognitive one during the process of chronic pain caused by carpal tunnel syndrome.It suggests the necessity of addressing the ignored cognitive or emotional state when managing patients with carpal tunnel syndrome.Approval for this study was obtained from the Institutional Review Board of The University of Hong Kong/Hospital Authority Hong Kong West,China(HKU/HA HKW IRB,approval No.UW17-129)on April 11,2017.This study was registered in Clinical Trial Registry of The University of Hong Kong,China(registration number:HKUCTR-2220)on April 24,2017.展开更多
The sensitivity of aerosol radiative properties (i.e., scattering coefficient, extinction coefficient, single scatter albedo, and asymmetry factor) and radiation transmission to aerosol composition, size distributions...The sensitivity of aerosol radiative properties (i.e., scattering coefficient, extinction coefficient, single scatter albedo, and asymmetry factor) and radiation transmission to aerosol composition, size distributions, and relative humidity (RH) is examined in this paper. Mie calculations and radiation calculations using a tropospheric visible radiation model are performed. The aerosol systems considered include inorganic and organic ions (e.g., Cl-, Br-, , , Na+, , K+, Ca2+, Mg2+, HCOO-, CH3COO-, CH3CH2COO-, CH3COCOO-, OOCCOO2-, MSA1-), and (2) water-insoluble inorganic and organic compounds e.g., (black carbon, n-alkanes, SiO2, Al2O3, Fe2O3 and other organic compounds). The partial molar refraction method and the volume-average method are used to calculate the real and imaginary parts of refractive index of real aerosols, respectively. The sensitivity simulations show that extinction coefficient increases by 70% when RH varies from 0 to 80%. Both extinction coefficient and asymmetry factor increase by ~48% when real part varies from 1.40 to 1.65. Scattering coefficient and single scattering albedo decrease by 18% and 24%, respectively, when the imaginary part varies from –0.005 to –0.1. Scattering and extinction coefficients increase by factors of 118 and 123, respectively, when the geometric mean radius varies from 0.05 to 0.3 ?m. Scattering and extinction coefficients and asymmetry factor increase by factors of 389, 334, and 5.4, respectively, when geometric standard deviation varies from 1.2 to 3.0. The sensitivity simulations using a tropospheric visible radiation model show that the radiation transmission is very sensitive to the change in geometric mean radius and standard deviation;other factors are insignificant.展开更多
目的建立通肠清胰合剂的HPLC指纹图谱,并对5种成分进行含量测定。方法采用Agilent ZORBAX SB?C_(18)色谱柱(250 mm×4.6 mm,5μm),以乙腈?p H 5.0磷酸盐缓冲液为流动相,梯度洗脱,检测波长为230 nm和250 nm,流速为1.0 m L/min,柱温...目的建立通肠清胰合剂的HPLC指纹图谱,并对5种成分进行含量测定。方法采用Agilent ZORBAX SB?C_(18)色谱柱(250 mm×4.6 mm,5μm),以乙腈?p H 5.0磷酸盐缓冲液为流动相,梯度洗脱,检测波长为230 nm和250 nm,流速为1.0 m L/min,柱温为30℃,进样量为10μL。通过中药色谱指纹图谱相似度评价系统(2012版)建立10个批次的通肠清胰合剂HPLC指纹图谱,同时进行相似度评价。结合软件SPSS 27.0、Origin Pro 2024b进行聚类分析和主成分分析。结果黄芩苷、芍药苷、大黄酸、厚朴酚、和厚朴酚分别在一定浓度范围内线性关系良好(r≥0.9998),平均回收率和RSD分别在96.39%~97.96%、1.54%~2.37%(n=6)之间。10批通肠清胰合剂指纹图谱显示存在12个共有峰,相似度为0.984~1.000。10批样品可聚为3类,其中S1~S7为第一类,S10为第二类,S8和S9为第三类。指认了5个成分,分别为大黄酸、芍药苷、黄芩苷、厚朴酚、和厚朴酚。结论本研究所建立的通肠清胰合剂HPLC指纹图谱及成分含量测定方法准确可靠、重复性强,为通肠清胰合剂的质量控制提供了科学依据。展开更多
文摘Dear Editor,Local recurrence and cervical lymph node metastases are major causes of mortality in patients with head and neck squamous cell carcinoma(HNSCC).To date,none of the proposed strategies for predicting outcomes in this disease have proven fully effective,and a comprehensive physical examination remains the primary method for early detection and monitoring of HNSCC.
基金founded by the National Natural Science Foundation of China(81202283,81473070,81373102 and81202267)Key Grant of Natural Science Foundation of the Jiangsu Higher Education Institutions of China(10KJA330034 and11KJA330001)+1 种基金the Research Fund for the Doctoral Program of Higher Education of China(20113234110002)the Priority Academic Program for the Development of Jiangsu Higher Education Institutions(Public Health and Preventive Medicine)
文摘With recent advances in biotechnology, genome-wide association study （GWAS） has been widely used to identify genetic variants that underlie human complex diseases and traits. In case-control GWAS, typical statistical strategy is traditional logistical regression （LR） based on single-locus analysis. However, such a single-locus analysis leads to the well-known multiplicity problem, with a risk of inflating type I error and reducing power. Dimension reduction-based techniques, such as principal component-based logistic regression （PC-LR）, partial least squares-based logistic regression （PLS-LR）, have recently gained much attention in the analysis of high dimensional genomic data. However, the perfor- mance of these methods is still not clear, especially in GWAS. We conducted simulations and real data application to compare the type I error and power of PC-LR, PLS-LR and LR applicable to GWAS within a defined single nucleotide polymorphism （SNP） set region. We found that PC-LR and PLS can reasonably control type I error under null hypothesis. On contrast, LR, which is corrected by Bonferroni method, was more conserved in all simulation settings. In particular, we found that PC-LR and PLS-LR had comparable power and they both outperformed LR, especially when the causal SNP was in high linkage disequilibrium with genotyped ones and with a small effective size in simulation. Based on SNP set analysis, we applied all three methods to analyze non-small cell lung cancer GWAS data.
基金supported by the National Natural Science Foundation of China,No.81871768(to YH)the Natural Science Foundation of Tianjin of China,No.18JCYBJC29600(to HYC)High Level-Hospital Program,Health Commission of Guangdong Province of China,No.HKUSZH201902011(to YH).
文摘Somatosensory evoked potentials(SEPs)have been widely used to assess neurological function in clinical practice.A good understanding of the association between SEP signals and neurological function is helpful for precise diagnosis of impairment location.Previous studies on SEPs have been reported in animal models.However,few studies have reported the relationships between SEP waveforms in animals and those in humans.In this study,we collected normal SEP waveforms and decomposed them into specific time–frequency components(TFCs).Our results showed three stable TFC distribution regions in intact goats and rats and in humans.After we induced spinal cord injury in the animal models,a greater number of small TFC distribution regions were observed in the injured goat and rat groups than in the normal group.Moreover,there were significant correlations(P<0.05)and linear relationships between the main SEP TFCs of the human group and those of the goat and rat groups.A stable TFC distribution of SEP components was observed in the human,goat and rat groups,and the TFC distribution modes were similar between the three groups.Results in various animal models in this study could be translated to future clinical studies based on SEP TFC analysis.Human studies were approved by the Institutional Review Board of the University of Hong Kong/Hospital Authority Hong Kong West Cluster(approval No.UM 05-312 T/975)on December 5,2005.Rat experiments were approved by the Committee on the Use of Live Animals in Teaching and Research of Li Ka Shing Faculty of Medicine of the University of Hong Kong(approval No.CULART 2912-12)on January 28,2013.Goat experiments were approved by the Animal Ethics Committee of Affiliated Hospital of Guangdong Medical University(approval No.GDY2002132)on March 5,2018.
基金supported by grants from the Basic Research Business Fees for Public Welfare in Xinjiang Autonomous Region(Mining candidate genes related to grape seed traits based on GWAS,KY2023028)the Xinjiang Uygur Autonomous Region Tianchi Talent-Young Doctor for Chuan Zhang(Revealing the domestication history of Xinjiang native grape varieties and genetic analysis of important agronomic traits)the Xinjiang Academy of Agricultural Sciences Youth Science and Technology Backbone Innovation Ability Training Project(xjnkq-2023006).
文摘Seedlessness has always been a valuable quality characteristic of edible grape varieties.Although the production of seedless grapes has been ongoing for decades,the genetic complexity of seedless grapes is not yet fully understood.Therefore,determining the genetic mechanisms and key regulatory genes of seedless grapes is of great significance for seedless grape breeding and meeting market demands.The emergence of high-throughput analysis software offers greater possibilities for mining genes related to plant organ development.Specifically,to mine a greater number of candidate genes related to grape seed traits,this study used the seed trait parameters analyzed by Tomato Analyzer as the target trait and then used a genome-wide association study(GWAS)to mine candidate genes.In the two-year analysis using principal component analysis(PCA),we extracted five principal components with a cumulative contribution rate of 96.586%.The cumulative contribution rate for component 1 reached 87.352%.Correlation analysis revealed correlation coefficients ranging from 0.54 to 0.98 among the seven basic traits.The GWAS results indicated that 370 SNP loci were significantly correlated with seed traits.These SNP loci were distributed on 18 chromosomes,except for chromosome 4,with most SNP loci distributed on chromosome 18.Based on the physical location of single nucleotide polymorphism(SNP)markers significantly associated with seed-related traits in the grape reference genome,candidate genes are screened within the range of linkage disequilibrium(LD)attenuation distance,both upstream and downstream of the significant SNP loci.These candidate genes were mainly transcription factor-related genes(VvMADS4 and VvMADS5),ubiquitin ligase-related genes(E3 ubiquitin ligase BIG BROTHER),serine/threonine protein kinase-related genes,and carbohydrate metabolism-related genes(Sucrose Synthase 2)and simultaneously controlled multiple(at least two or more)seed traits.These results indicate that seed traits are jointly regulated by some genes involved in seed morphology regulation.In this work,we identified new gene loci related to grape seed traits.Identifying molecular markers closely related to these seed traits is of great significance for breeding seedless grape varieties.
基金supported by the National Basic Research Program (973) of China (No. 2004CB117306)the Hi-Tech Research and Development Program (863) of China (No. 2006AA10A102)
文摘Association analysis provides an opportunity to find genetic variants underlying complex traits. A principal components regression （PCR）-based approach was shown to outperform some competing approaches. However, a limitation of this method is that the principal components （PCs） selected from single nucleotide polyrnorphisms （SNPs） may be unrelated to the phenotype. In this article, we investigate the theoretical properties of such a method in more detail. We first derive the exact power function of the test based on PCR, and hence clarify the relationship between the test power and the degrees of freedom （DF）. Next, we extend the PCR test to a general weighted PCs test, which provides a unified framework for understanding the properties of some related statistics. We then compare the performance of these tests. We also introduce several data-driven adaptive alternatives to overcome difficulties in the PCR approach. Finally, we illustrate our results using simulations based on real genotype data. Simulation study shows the risk of using the unsupervised rule to determine the number of PCs, and demonstrates that there is no single uniformly powerful method for detecting genetic variants.
基金Supported by Project of National Natural Science Foundation(81560659)Science and Technology Research Project of Jiangxi Provincial Department of Education(GJJ170722)+2 种基金Traditional Chinese Medicine Science and Technology Program of Jiangxi Provincial Health and Family Planning Commission(2018B139)Young Teacher Training Program for Key Discipline of Jiangxi University of Traditional Chinese Medicine(2017jzzdxk001)Traditional Chinese Medicine First-class Discipline Special Research Fund Project of Jiangxi Province(JXSYLXK-ZHYAO 061)
文摘In recent years, the antibacterial and anti-inflammatory effects of the Labiatae plants have been widely recognized, and have been used in clinical practice, and their anti-tumor effects are also very significant, and receiving more and more attention. At present, malignant tumors are still the first killer threatening human health. Because of the long-term use of chemical anti-tumor drugs with certain drug resistance and obvious side effects, finding high-efficiency anti-tumor active ingredients from natural plants and Chinese herbal medicines has become a hot spot in the field of pharmacy. Literature survey indicates that the active ingredients in Labiatae plants have anti-tumor effects. Therefore, this paper summarized and discussed the anti-tumor types, mechanisms and active components of the Labiatae plants, so as to provide a basis and reference for the development of new anti-tumor drugs or preparations.
文摘Rare earth elements (REEs), especially heavy rare earth elements (HREEs), are in demand for their current and emerging applications in advanced technologies. Here we perform computer-driven micro-mapping at the millimeter scale of the minerals that comprise Round Top Mountain, in west Texas, USA. This large rhyolite deposit is enriched in HREEs and such other critical elements as Li, Be, and U. Electron probe microanalysis of 2 × 2 mm areas of thin sections of the rhyolite produced individual maps of 16 elements. These were superimposed to generate a 16-element composition at each pixel. Principal components analysis of elements at each pixel identified the specific mineral at that site. The pixels were then relabeled as the appropriate minerals, thereby producing a single mineral map. The overall mineral composition of the 7 studied samples compared favorably with prior analyses of the Round Top deposit available in the literature. Likewise the range of porosity in the maps was consistent with that of previous direct measurements by water saturation. This new statistical and GIS-based technique provides a robust and unbiased approach to electron microprobe mapping. The study further showed that the high-value yttrofluorite grains exhibited little tendency to cluster with other late-stage trace minerals and that the samples extended the previously documented overall homogeneity of the deposit at field scale to this microscopic scale.
文摘Conventional neuroimaging techniques cannot truly reflect the change of regional cerebral blood flow in patients with carpal tunnel syndrome.Pseudo-continuous arterial spinning labeling(pCASL)as an efficient non-invasive neuroimaging technique can be applied to directly quantify the neuronal activities of individual brain regions that show the persistent symptoms owing to its better spatial resolution and increased signal-to-noise ratio.Therefore,this prospective observational study was conducted in 27 eligible female carpal tunnel syndrome,aged 57.7±6.51 years.Psychometric tests,nerve conduction studies and pCASL neuroimaging assessment were performed.The results showed that the relevant activated brain regions in the cortical,subcrotical,and cerebral regions were correlated with numbness,pain,functionality,median nerve status and motor amplitude of median nerve(K=21–2849,r=–0.77–0.76,P<0.05).There was a tendency of pain processing which shifted from the nociceptive circuitry to the emotional and cognitive one during the process of chronic pain caused by carpal tunnel syndrome.It suggests the necessity of addressing the ignored cognitive or emotional state when managing patients with carpal tunnel syndrome.Approval for this study was obtained from the Institutional Review Board of The University of Hong Kong/Hospital Authority Hong Kong West,China(HKU/HA HKW IRB,approval No.UW17-129)on April 11,2017.This study was registered in Clinical Trial Registry of The University of Hong Kong,China(registration number:HKUCTR-2220)on April 24,2017.
文摘The sensitivity of aerosol radiative properties (i.e., scattering coefficient, extinction coefficient, single scatter albedo, and asymmetry factor) and radiation transmission to aerosol composition, size distributions, and relative humidity (RH) is examined in this paper. Mie calculations and radiation calculations using a tropospheric visible radiation model are performed. The aerosol systems considered include inorganic and organic ions (e.g., Cl-, Br-, , , Na+, , K+, Ca2+, Mg2+, HCOO-, CH3COO-, CH3CH2COO-, CH3COCOO-, OOCCOO2-, MSA1-), and (2) water-insoluble inorganic and organic compounds e.g., (black carbon, n-alkanes, SiO2, Al2O3, Fe2O3 and other organic compounds). The partial molar refraction method and the volume-average method are used to calculate the real and imaginary parts of refractive index of real aerosols, respectively. The sensitivity simulations show that extinction coefficient increases by 70% when RH varies from 0 to 80%. Both extinction coefficient and asymmetry factor increase by ~48% when real part varies from 1.40 to 1.65. Scattering coefficient and single scattering albedo decrease by 18% and 24%, respectively, when the imaginary part varies from –0.005 to –0.1. Scattering and extinction coefficients increase by factors of 118 and 123, respectively, when the geometric mean radius varies from 0.05 to 0.3 ?m. Scattering and extinction coefficients and asymmetry factor increase by factors of 389, 334, and 5.4, respectively, when geometric standard deviation varies from 1.2 to 3.0. The sensitivity simulations using a tropospheric visible radiation model show that the radiation transmission is very sensitive to the change in geometric mean radius and standard deviation;other factors are insignificant.
文摘目的建立通肠清胰合剂的HPLC指纹图谱,并对5种成分进行含量测定。方法采用Agilent ZORBAX SB?C_(18)色谱柱(250 mm×4.6 mm,5μm),以乙腈?p H 5.0磷酸盐缓冲液为流动相,梯度洗脱,检测波长为230 nm和250 nm,流速为1.0 m L/min,柱温为30℃,进样量为10μL。通过中药色谱指纹图谱相似度评价系统(2012版)建立10个批次的通肠清胰合剂HPLC指纹图谱,同时进行相似度评价。结合软件SPSS 27.0、Origin Pro 2024b进行聚类分析和主成分分析。结果黄芩苷、芍药苷、大黄酸、厚朴酚、和厚朴酚分别在一定浓度范围内线性关系良好(r≥0.9998),平均回收率和RSD分别在96.39%~97.96%、1.54%~2.37%(n=6)之间。10批通肠清胰合剂指纹图谱显示存在12个共有峰,相似度为0.984~1.000。10批样品可聚为3类,其中S1~S7为第一类,S10为第二类,S8和S9为第三类。指认了5个成分,分别为大黄酸、芍药苷、黄芩苷、厚朴酚、和厚朴酚。结论本研究所建立的通肠清胰合剂HPLC指纹图谱及成分含量测定方法准确可靠、重复性强,为通肠清胰合剂的质量控制提供了科学依据。
