Characteristic Components Research Articles

Structure-directed bioengineering the lid1 of cold-adapted Pseudomonas sp. TB11 esterase to boost catalytic capacity

Structure-guided bioengineering enzymes has been an efficient strategy to obtain biocatalyst with desirable properties. In this study, the cold-adapted esterase from Pseudomonas sp. (CPE) was optimized through bioinformatic-based structured-guided bioengineering on lid1 region. Substitutions of non-conserved Q55 led to noticeable increase in hydrolysis without sacrificing enzyme thermostability, activating effects of Ca2+ and organic solvents. Compared to the wild type, both of Q55V and Q55N among the constructed variants exhibited about a 2.0-fold and 6.5-fold higher hydrolytic activity toward short-chain and long-chain substrates, respectively. In contrast, lid swapping with the lid of Thermomyces lanuginosus lipase reduced the activity and thermostability of CPE. Catalytic kinetics revealed that substitution of Q55 with Y, V, N and R enhanced the substrate affinity of CPE. Hydrolysis by Q55V remarkedly enriched the characteristic flavor components of single cream. The study sheds light on structure-guided bioengineering of lid tailoring cold-adapted esterases with desired catalytic performance to meet the demand from biotechnological applications.

Exploring the effect of mold fermentation on the taste and flavor properties of traditional Japanese smoked-dried bonito (katsuobushi)

The present study aimed to investigate the differences in the physicochemical properties, taste characteristics, and flavor compounds of Katsuobushi, a traditional Japanese smoked-dried bonito product, including Arabushi (unfermented) and Karebushi (mold-fermented), as well as the effects of surface fermentation on the internal, middle, and external of Karebushi products. The findings showed that mold fermentation could be an effective method for improving the color characteristics of Katsuobushi. Karebushi possessed the highest content of flavorful amino acids and nucleotides, which synergistically enhanced the level of umami taste profiles. Notably, the EUC value of the exterior (12.51 g MSG/100 g) is significantly higher than that of the interior (8.81 g MSG/100 g), which means that the surface fermentation imparts a stronger umami taste to the exterior. In addition, the abundance of organic acids in the Karebushi helped to improve the umami and sweet tastes. The electronic nose and fingerprint profiles revealed that Karebushi was found to have higher types and contents of flavor compounds than Arabushi. 3-Methyl-1-butanol, 2,5-dimethylpyrazine, and α-pinene are the characteristic volatile aroma components of Karebushi, contributing to the exceptional malty, nutty, and roasted aroma. This study may be conducive to a better understanding of the effect of mold surface fermentation on the flavor characteristics of Katsuobushi, and provide a theoretical basis for the development of appropriate start cultures.

A cleavable chimeric peptide with targeting and killing domains enhances LPS neutralization and antibacterial properties against multi-drug resistant E. coli

Pathogenic Escherichia coli is one of the most common causes of diarrhea diseases and its characteristic component of the outer membrane-lipopolysaccharide (LPS) is a major inducer of sepsis. Few drugs have been proven to kill bacteria and simultaneously neutralize LPS toxicity. Here, the chimeric peptides-R7, A7 and G7 were generated by connecting LBP14 (LPS-targeting domain) with L7 (killing domain) via different linkers to improve antibacterial and anti-inflammatory activities. Compared to parent LBP14-RKRR and L7, the antibacterial activity of R7 with a cleavable “RKRR” linker and the “LBP14-RKRR + L7” cocktail against Escherichia coli, Salmonella typhimurium and Staphylococcus aureus was increased by 2 ~ 4-fold. Both A7 and G7 with non-cleavable linkers almost lost antibacterial activity. The ability of R7 to neutralize LPS was markedly higher than that of LBP14-RKRR and L7. In vivo, R7 could be cleaved by furin in a time-dependent manner, and release L7 and LBP14-RKRR in serum. In vivo, R7 can enhance mouse survival more effectively than L7 and alleviate lung injuries by selective inhibition of the NF-κB signaling pathways and promoting higher IAP activity. It suggests that R7 may be promising dual-function candidates as antibacterial and anti-endotoxin agents.

Pterodon emarginatus Seed Preparations: Antiradical Activity, Chemical Characterization, and In Silico ADMET Parameters of β-caryophyllene and Farnesol.

The study of medicinal plants and their active compounds is relevant to maintaining knowledge of traditional medicine and to the development of new drugs of natural origin with lower environmental impact. From the seeds of the Brazilian plant Pterodon emarginatus, six different preparations were obtained: essential oil (EO), ethanol extract (EthE) prepared using the traditional method, and four extracts using solvents at different polarities, such as n-hexane, chloroform, ethyl acetate, and methanol (HexE, ChlE, EtAE, and MetE). Chemical characterization was carried out with gas chromatography, allowing the identification of several terpenoids as characteristic components. The two sesquiterpenes β-caryophyllene and farnesol were identified in all preparations of Pterodon emarginatus, and their amounts were also evaluated. Furthermore, the total flavonoid and phenolic contents of the extracts were assessed. Successively, the antiradical activity with DPPH and ORAC assays and the influence on cell proliferation by the MTT test on the human colorectal adenocarcinoma (HT-29) cell line of the preparations and the two compounds were evaluated. Lastly, an in silico study of adsorption, distribution, metabolism, excretion, and toxicity (ADMET) showed that β-caryophyllene and farnesol could be suitable candidates for development as drugs. The set of data obtained highlights the potential medicinal use of Pterodon emarginatus seeds and supports further studies of both plant preparations and isolated compounds, β-caryophyllene and farnesol, for their potential use in disease with free radical involvement as age-related chronic disorders.

Proanthocyanidins from Chinese Bayberry (Myrica rubra Sieb. et Zucc.) Leaves Effectively Inhibit the Formation of Biogenic Amines in the Brewing Soy Sauce

Biogenic amines are a group of metabolites generated in the process of soy sauce brewing, which can result in severe negative impacts on human health at high concentrations. In this study, we innovatively proposed natural extracts (0.1 wt%), of proanthocyanidins, from Chinese bayberry (Myrica rubra Sieb. et Zucc.) leaves to alternate commercial additives (0.1 wt%), i.e., sodium benzoate and potassium sorbate, for lowering the harmful biogenic amine formation during the fermentation of soy sauce. HPLC results showed that natural extracts from Chinese bayberry leaves could effectively decrease the content of cadaverine, putrescine, histamine, tyramine, phenylethylamine, and agmatine (p < 0.05). In contrast to the inhibitory influence exhibited by commercial sodium benzoate and potassium sorbate, extracts from bayberry leaves can maintain spermidine, spermine, and tryptamine at certain concentrations. Furthermore, both sodium benzoate and potassium sorbate significantly reduced the production of ammonium salt and characteristic components (p < 0.05), like soluble saltless solids, total nitrogen, and amino acid nitrogen, during the 40-day fermentation of soy sauce, whereas proanthocyanidins extracted from Chinese bayberry leaves slightly inhibited the content of ammonium salt. Thus, we can conclude that, while inhibiting the biogenic amine and ammonium salt production, extracts from Chinese bayberry leaves facilitate or maintain the production of characteristic indicators compared to commercial sodium benzoate and potassium sorbate. Taken together, natural extracts from Chinese bayberry leaves can be considered a natural additive to significantly improve the quality of traditional brewing soy sauce.

Studies on chemical profiling and pharmacokinetics of traditional Chinese medicine Formula Kang Shuai Lao Pian

Kang Shuai Lao Pian (KSLP) is a traditional Chinese medicine (TCM) preparation used to delay aging. However, due to the lack of research on the chemical composition and pharmacokinetic behavior of KSLP, its material basis and in vivo components with high exposure remain ambiguous. The UPLC/Q-Orbitrap-MS/MS was performed to identify the preliminary chemical profile of KSLP. A total of 138 compounds, including ginsenosides, phenylethanol glycosides, iridoids, alkaloids, ionones and others, were identified in accordance with their retention times, accurate masses and characteristic MS/MS fragment patterns. Moreover, considering the active components and characteristic components of KSLP, the extraction process of KSLP was optimized, and the quantitative analysis by UPLC/QQQ-MS/MS of 13 compounds in KSLP was established. The method was stable and sensitive, and could be used for the quality control of KSLP. Then, the pharmacokinetic study was carried out by further refining the components of KSLP. Besides, quantitative method for 6 compounds in rat plasma was validated and developed by UPLC/QQQ-MS/MS. The established approach was successfully applied to characterize the pharmacokinetic features of components in KSLP and it was found that the absorption and elimination of ginsenosides in KSLP was slow. Altogether, this study laid a solid foundation and provided theoretical guidance for further clarification of bioactive components of KSLP.

Characteristic Components and Authenticity Evaluation of Chinese Honeys from Three Different Botanical Sources.

We aimed to identify the characteristic phytochemicals of safflower, Chinese sumac, and bauhinia honeys to assess their authenticity. We discovered syringaldehyde, riboflavin, lumiflavin, lumichrome, rhusin [(1E,4E)-1,5-diphenylpenta-1,4-dien-3-one-O-cinnamoyl oxime], bitterin {4-hydroxy-4-[3-(1-hydroxyethyl) oxiran-2-yl]-3,5,5-trimethylcyclohex-2-en-1-one}, and unedone as characteristic phytochemicals of these three types of honeys. The average contents of syringaldehyde, riboflavin, lumiflavin, or lumichrome in safflower honey were 41.20, 5.24, 24.72, and 36.72 mg/kg; lumiflavin, lumichrome, and rhusin in Chinese sumac honey were 39.66, 40.55, and 2.65 mg/kg; bitterin, unedone, and lumichrome in bauhinia honey were 8.42, 26.33, and 8.68 mg/kg, respectively. To our knowledge, the simultaneous presence of riboflavin, lumichrome, and lumiflavin in honey is a novel finding responsible for the bright-yellow color of honey. Also, it is the first time that lumiflavin, rhusin, and bitterin have been reported in honey. We effectively distinguish pure honeys from adulterations, based on characteristic components and high-performance liquid chromatography fingerprints; thus, we seem to provide intrinsic markers and reliable assessment criteria to assess honey authenticity.

Co‐culture relationship between Zygosaccharomyces rouxii and Candida versatilis and its effect on the flavour of soy sauce

SummaryZygosaccharomyces rouxii and Candida versatilis are important flavour‐producing yeasts in soy sauce fermentation. In the present study, the interaction between Z. rouxii and C. versatilis co‐cultures in YPD and raw soy sauce medium was investigated and applied to soy sauce fermentation. The concentration of Z. rouxii in the co‐culture was 0.47 times that in the mono‐culture. This observation suggested that C. versatilis inhibited the growth of Z. rouxii, likely attributed to various factors, including the production of acids and heat‐ and protease‐sensitive substances by C. versatilis. Furthermore, we examined the physicochemical properties and characteristic volatile flavour components of soy sauce by adding varying ratios of Z. rouxii and C. versatilis at different stages of fermentation. The results showed that mixed fermentation of Z. rouxii and C. versatilis enhanced the total nitrogen, amino acid nitrogen, 4‐hydroxy‐2(5)‐ethyl‐5(2)‐methyl‐3(2H)‐furanone, and volatile compounds in soy sauce compared to single‐strain fermentation. Additionally, optimal soy sauce results were obtained when yeasts were added on day 45, with an inoculation ratio of 1:1. In conclusion, during the moromi fermentation stage, the appropriate selection of the inoculation ratio and time for Z. rouxii and C. versatilis addition can effectively enhance the physicochemical properties and flavour attributes of soy sauce.

Emission characteristics, environmental impacts and health risk assessment of volatile organic compounds from the typical chemical industry in China

To study the volatile organic compounds (VOCs) emission characteristics of industrial enterprises in China, 6 typical chemical industries in Yuncheng City were selected as research objects, including the modern coal chemical industry (MCC), pharmaceutical industry (PM), pesticide industry (PE), coking industry (CO) and organic chemical industry (OC). The chemical composition of 91 VOCs was quantitatively analyzed. The results showed that the emission concentration of VOCs in the chemical industry ranged from 1.16 to 155.59 mg/m3. Alkanes were the main emission components of MCC (62.0%), PE (55.1%), and OC (58.5%). Alkenes (46.5%) were important components of PM, followed by alkanes (23.8%) and oxygenated volatile organic compounds (OVOCs) (21.2%). Halocarbons (8.6%-71.1%), OVOCs (9.7%-37.6%) and alkanes (11.2%-27.0%) were characteristic components of CO. The largest contributor to OFP was alkenes (0.6%-81.7%), followed by alkanes (9.3%-45.9%), and the lowest one was alkyne (0%-0.5%). Aromatics (66.9%-85.4%) were the largest contributing components to SOA generation, followed by alkanes (2.6%-28.5%), and the lowest one was alkenes (0%-4.1%). Ethylene and BTEX were the key active species in various chemical industries. The human health risk assessment showed workers long-term exposed to the air in the chemical industrial zone had a high cancer and non-cancer risk during work, and BTEX and dichloromethane were the largest contributors.

The Adsorption Mechanisms of SF6-Decomposed Species on Tc- and Ru-Embedded Phthalocyanine Surfaces: A Density Functional Theory Study.

Designing high-performance materials for the detection or removal of toxic decomposition gases of sulfur hexafluoride is crucial for both environmental monitoring and human health preservation. Based on first-principles calculations, the adsorption performance and gas-sensing properties of unsubstituted phthalocyanine (H2Pc) and H2Pc doped with 4d transition metal atoms (TM = Tc and Ru) towards five characteristic decomposition components (HF, H2S, SO2, SOF2, and SO2F2) were simulated. The findings indicate that both the TcPc and RuPc monolayers are thermodynamically and dynamically stable. The analysis of the adsorption energy indicates that H2S, SO2, SOF2, and SO2F2 underwent chemisorption on the TcPc monolayer. Conversely, the HF molecules were physisorbed through interactions with H atoms. The chemical adsorption of H2S, SO2, and SOF2 occurred on the RuPc monolayer, while the physical adsorption of HF and SO2F2 molecules was observed. Moreover, the microcosmic mechanism of the gas-adsorbent interaction was elucidated by analyzing the charge density differences, electron density distributions, Hirshfeld charges, and density of states. The TcPc and RuPc monolayers exhibited excellent sensitivity towards H2S, SO2, and SOF2, as evidenced by the substantial alterations in the band gaps and work functions of the TcPc and RuPc nanosheets. Our calculations hold significant value for exploring the potential chemical sensing applications of TcPc and RuPc monolayers in gas sensing, with a specific focus on detecting sulfur hexafluoride.

Comparative study on chemical components of Gannan navel orange in different maturity stages based on UPLC-QTOF-MS metabolomics

Metabolites changes during fruit growth are currently being studied intensively. In this experiment, Ultra-high performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry was used to identify metabolites during the growing phase of navel oranges. A total of 63 metabolites were identified, and monitored changes in amino acid content. Principal component analysis and Partial least-squares-discriminate analysis were used to construct a cluster analysis model among navel orange metabolites. Among the 19 differential metabolites, flavonoids were the main metabolic markers during the growth of navel oranges. Correlation cluster analysis was used to fit the correlation between the characteristic components, and it was found that many flavonoids were highly correlated. Finally, combined with Kyoto Encyclopedia of Genes and Genomes enrichment analysis, the key metabolic pathway was identified as flavonoid synthesis. The α-glucosidase inhibition experiment showed that with the growth of navel orange, the inhibition rate of the metabolites to α-glucosidase activity decreased continuously. This study provides a necessary basis for exploring the metabolic mechanism of navel orange growth.

Are Zhuzi contentious? A rhetorical investigation of speech/word radicals in ancient Chinese texts

Abstract In communication, rhetors are inclined to employ contentious rhetorical modes designed to win or compete. Consequently, noncontentious rhetorical modes, such as invitational rhetoric, are underappreciated. This study fosters a better understanding of the rationale and possibility of noncontentious rhetorical modes rooted in texts by traditional Chinese intellectuals. We identify, classify, and interpret indigenous terms identified with speech/word radicals in nine Chinese philosophical classics across five major schools of thought in ancient China using a corpus-driven approach and key concepts of rhetorical studies to delineate the pattern, components, and modes of ancient Chinese rhetoric. The results show that (1) characters with speech/word radicals in ancient Chinese texts follow a pattern between rank and frequency; (2) basic components of rhetorical acts in ancient China can be described based on these terms, and characteristic rhetorical components are identified upon similarities and differences among five schools of thought; and (3) studying rhetorical modes of ancient Chinese rhetoric with speech/word radicals reveals that intellectuals in ancient China adopted both the contentious modes and the noncontentious modes of rhetoric. This study also demonstrates the possibility of studying semantic radicals in texts through digital methods to delineate ancient Chinese rhetoric.

Metabolomics and electronic tongue reveal the effects of different storage years on metabolites and taste quality of Oolong Tea

Oolong tea have better richness, sweetness and throat after a certain time of storage. These variations in taste and quality are closely related to changes in the composition of oolong tea during storage, however, the metabolic profiles of oolong tea during storage have not been reported so far. Therefore, we evaluated the differences in taste quality of oolong tea in four storage years (1991, 2001, 2011 and 2021) by using electronic tongue technology, and the results showed that the bitterness, astringency and richness of oolong tea are significantly reduced during storage, but the acidity have the opposite trend, while the sweetness did not trend, with the least sweetness in 2011 and no difference in sweetness in the rest of the years. We further explored the metabolites contributing to the differences in taste quality of Dancong tea in four storage years (1991, 2001, 2011 and 2021) using metabolomics technique and the results showed that a total of 1245 metabolites were detected, of which nine were taste characteristic components of Aged Dancong tea. Dancong tea mainly increased azelaic acid, suberic acid, 2-hydroxyphenylacetic acid and other sour characteristic components in aged tea by regulating phenylalanine metabolism, metabolic pathways, and pyrimidine metabolism and mainly decreased benzamide, propyl 4-hydroxybenzoate, pyrrole-2-carboxylic acid and other bitterness and astringency characteristic components by regulating arginine and proline metabolism, flavonoid biosynthesis, biosynthesis of secondary metabolites, which enhanced the sour and umami of aged tea and reduced its bitterness and astringency. This study provides theoretical support for the quality of aged oolong tea, with a view to providing guidance for the storage of oolong tea.

Classification of Chinese traditional cereal vinegars and antioxidant property predication by fluorescence spectroscopy.

In this work, a rapid and accurate strategy for classification of Chinese traditional cereal vinegars (CTCV) and antioxidant property predication was proposed by using the combination fluorescence spectroscopy and machine learning. Three characteristic fluorescent components were extracted by parallel factor analysis (PARAFAC), which have correlations greater than 0.8 with antioxidant activity of CTCV obtained by Pearson correlation analysis. Machine learning methods, including linear discriminant analysis (LDA), partial least squares-discriminant analysis (PLS-DA) and N-way partial least squares discriminant analysis (N-PLS-DA), were used for the classification of different types of CTCV, and the correct classification rates was higher than 97%. The antioxidant property of CTCV were further quantified by using optimized variable-weighted least-squares support vector machine based on particle swarm optimization (PSO-VWLS-SVM). The proposed strategy provides a basis for further research on antioxidant active ingredients and antioxidant mechanisms of CTCV, and enable the continued exploration and application of CTCV from different types.

Rapid detection of multi-indicator components of classical famous formula Zhuru Decoction concentration process based on fusion CNN-LSTM hybrid model with the near-infrared spectrum

Traditional Chinese Medicine (TCM) is a collective term for the medicines of all ethnic groups in China, including Han Chinese and ethnic minority medicines, reflecting the Chinese people's understanding of life, health and disease, and is a system of medicine with a long historical tradition and unique theories and technical methods. Due to the nonlinearity, large hysteresis, and strong interference in the concentration process used in the production of traditional Chinese medicine, it is challenging to use just one conventional control method to achieve the desired control effect. The majority of traditional quality control methods used in processing the samples will result in the loss of the active ingredient and in the detection of impurities. Monitoring of multiple critical quality attributes (CQAs) is crucial for the overall process of the index ingredient. In this study, based on the above background, fast and nondestructive near-infrared spectroscopy (NIRS) technique incorporating convolutional neural network (CNN) and long-short-term memory network (LSTM) was utilized to construct a quantitative model based on the seven characteristic components, puerarin, 3′-hydroxy puerarin, 3′-methoxy puerarin, puerarin apigenin, daidzin, glycyrrhizin and glycyrrhizic acid, during the concentration process. The results showed that the relative mean error (MAPE) values of the different components ranged from 0.7% to 2.8% and R2 from 0.981 to 0.992 based on the proposed CNN-LSTM model. The results showed that the combined model of near-infrared spectroscopy fused with convolutional neural network (CNN) and long-short-term memory network (LSTM) was feasible for accurate and rapid monitoring of the concentration of the classic famous prescription Zhuru Decoction (ZRD) during the decoction process and that the method could provide a reference value for rapid nondestructive testing of traditional Chinese medicine compound formulas.

Carbon market price prediction based on sequence decomposition-reconstruction-dimensionality reduction and improved deep learning model

Identifying carbon market price signals and accurately predicting carbon prices is of great significance in the development of carbon markets and carbon trading management. In this study, a fast ensemble empirical mode decomposition (FEEMD) method was used to analyze the fluctuation patterns of carbon market prices and obtain their characteristic components. Then the characteristic components of carbon prices were reconstructed using sample entropy theory (SRSE), and a partial autocorrelation analysis (PACF) technique was used to screen the data points exerting large impacts on carbon market prices. The FEEMD-SRSE-PACF-ILSTM hybrid model constructed. The main innovation points are as follows: The FEEMD is proposed to solves the common modal aliasing problem during carbon price decomposition and improves the efficiency of the carbon price sequence decomposition; the sample entropy theory and partial autocorrelation analysis methods are applied to reconstruct the characteristic components of carbon prices; the LSTM neural network model was optimized by the grey wolf algorithm to enhance its stability and adaptability. The analyzed price changes of large regional carbon markets in China, the European Union, and the United States can be effectively used to predict prices in the carbon market and guide its participants towards low-carbon investment and trading.

Characterizing and Decoding the Effects of Different Fermentation Levels on Key Aroma Substances of Congou Black Tea by Sensomics.

Fermentation is the key technology for black tea aroma formation. The key aroma substances of black tea at different fermentation stages (unfermented (WDY), underfermented (F1H), fully fermented (F4H), and overfermented (F8H)) were characterized by the methodology of Sensomics. Aroma extract dilution analysis was performed on volatile fractions extracted by using solvent-assisted flavor evaporation and solid-phase microextraction, yielding 93 odor-active areas. Internal standard method plus stable isotope dilution analysis was used for quantitative analysis. The omission experiment identified 23 aroma substances. Further reduction and addition experiments revealed phenylacetaldehyde, (E,E)-2,4-heptadienal, geraniol, linalool, β-damascenone, 2-methylbutyraldehyde, dimethyl sulfide, and isovaleraldehyde with odor activity values (OAV) > 100 as the characteristic aroma components of F4H and also as the main contributors to aroma differences between different fermentation degrees. The green odor of (E,E)-2,4-heptadienal was highlighted in WDY and F1H relative to that in F4H due to the lower contribution of phenylacetaldehyde and β-damascenone in the former two samples. Additionally, excessive OAV increase of fatty aldehydes in F8H masked its similar floral and fruity aroma.

Alterations in Nonvolatile Components of Tea (Camellia sinensis) Induced by Insect Feeding under Field Conditions

Tea leaf components are affected by environmental factors such as insect feeding, and metabolites have been studied using specific insect and tea leaf model systems. However, in gardens, tea leaves are eaten by various insects. Because the components of tea may affect human health, the effect of insect damage on metabolites needs to be clarified. The aim of this study was to investigate the effects of insect feeding on the nonvolatile components of tea in a field experiment. Furthermore, we determined the effects of insect damage on the composition of black tea products. Tea leaves were sampled from insect-attacked and moderately insect-attacked areas. Catechins were quantified by ultra-performance liquid chromatography. Tea leaves were analyzed by ultra-performance liquid chromatography–mass spectrometry, followed by orthogonal partial least squares-discriminant analysis and molecular networking analysis. The nonvolatile components in insect-attacked leaves were significantly affected. The amounts of gallate-type catechins in highly attacked leaves were approximately 1.2 times higher than in moderately attacked leaves. Furthermore, highly attacked leaves had increased levels of afzelechin gallate, procyanidins, and hydrolyzable tannins. These results varied with previous reports that used model systems with specific insects. In addition, some of these compounds were also detected as characteristic components in black tea from highly attacked leaves.

Comparative proteomic analysis of edible bird’s nest from different origins

Edible bird’s nest (EBN) mainly made of saliva that secreted by a variety of swiftlets is a kind of precious traditional Chinese medicine. EBNs from different biological and geographical origins exhibit varieties in morphology, material composition, nutritive value and commercial value. Here, we collected four different EBN samples from Huaiji, China (Grass EBN), Nha Trang, Vietnam (Imperial EBN) and East Kalimantan, Indonesia (White EBN and Feather EBN) respectively, and applied label-free quantitative MS-based proteomics technique to identify its protein composition. First, phylogenetic analysis was performed based on cytb gene to identify its biological origin. Second, a total of 37 proteins of EBNs were identified, among which there were six common proteins that detected in all samples and exhibited relatively higher content. Gene ontology analysis revealed the possible function of EBN proteins, and principal component analysis and hierarchical clustering analysis based on 37 proteins were performed to compare the difference of various EBNs. In summary, our study deciphered the common and characteristic protein components of EBNs of different origins and described their possible functions by GO enrichment analysis, which helps to establish an objective and reliable quality evaluation system.

Influence of tritium distribution in aluminum and iron for shape of the beta-ray induced X-ray spectrum

Beta-ray induced X-ray spectrometry (BIXS) is commonly used for qualitative measurement of tritium in solids. We considered that BIXS could also be used quantitatively to determine the depth of tritium in solids. To determine the change in the shape of the BIX spectrum with tritium depth, spectra in aluminum and iron were calculated using the Monte Carlo simulation code (Galet-BIXS). The spectral shape was determined by the relative fractions of the characteristic X-ray components and bremsstrahlung. It was changed with the tritium depth, even when the number of tritium decay events was held constant in the simulations. Specifically, the spectral shape gave information about the tritium depth. However, the accuracy of the estimated tritium depth depended not only on the elements that interact with the beta particles but also on the tritium depth. In some cases, the tritium depth could not be evaluated from the BIX spectra. For example, the spectral shape for aluminum in helium was kept up to 10 µm deep of the tritium depth. When the atmosphere was replaced from helium to argon, the spectral shape was changed with the tritium depth up to 10 µm. Nevertheless, our method allows quantitative analysis of tritium in solids based on the BIX spectrum in most cases. We believe that the Monte Carlo simulation of the BIX spectrum is crucial to the further development to determine the tritium depth in solids.