Depressive symptoms and its multifaceted associated factors among young men who have sex with men facing the dual threats of COVID-19 and mpox in China.

INTRODUCTION: The COVID-19 pandemic has significantly impacted the mental health of human beings since 2020, especially the young people and the pre-existing marginalized groups such as men who have sex with men (MSM). During the COVID-19 pandemic, the multi-country outbreak of mpox in 2022 additionally posed a significant stress on the most-affected communities (i.e., MSM). This study investigated the level of depressive symptoms and its multifaceted associated factors among Chinese young men who have sex with men (YMSM) in this unique period. METHODS: In September 2022, a large-scale cross-sectional survey was conducted among YMSM aged 18-29 years across six representative provinces in China. Hierarchical regression analysis was performed to test the various types of associated factors of depressive symptoms. RESULTS: Among the 2493 participants, 65.6 % (n = 1638) reported mild to severe depressive symptoms. The hierarchical regression analysis identified that depressive symptoms was significantly positively associated with unemployment, having substance use in the past 6 months, a higher level of MSM self-stigma, incompletion of COVID-19 vaccination, greater mpox risk perception, and presence of mpox related-like symptoms. LIMITATIONS: This study used the facility-based sampling method to recruit the participants, which may lead to selection bias. CONCLUSIONS: Chinese YMSM faced significant mental health challenges during the concurrent epidemics of COVID-19 and mpox, which was associated with their socio-economic status, risk behaviors, stigma, and multiple diseases-related variables. Proactive measures may hold promise as effective strategies for mitigating mental distress among marginalized groups during public health crises.

[Stable integration sites in Saccharomyces cerevisiae: identification and application in the biosynthesis of valencene].

Valencene, a high-value sesquiterpene with a citrus aroma, is widely employed in the food and cosmetic fields and the industrial synthesis of nootkatone. In this study, 16 genomic loci in the intergenic regions (IGRs) of Saccharomyces cerevisiae were identified. A Ypet expression cassette was successfully integrated into various genomic loci by CRISPR-Cas9, with an impressive integration success rate of 87.50% and exhibiting expression variations of up to 1.91-fold depending on the insertion site. The study demonstrates that the positional effect exhibits relative stability in gene expression, and is essentially unaffected by changes in promoters and reporter genes. Furthermore, a high-expression element combination, PTDH3-TPRC1, was selected. The iterative integration of the valencene synthase gene VSm from Callitropsis nootkatensis at the selected loci increased the valencene yield to 254.67 mg/L. Overexpression of key genes tHMG1-ERG20 with multiple copies increased the valencene yield by 93.49%. The engineered strain L-13 achieved the valencene yield of 9 530.18 mg/L by two-stage fed-batch fermentation in a 3 L fermenter. This yield represents a nearly 100-fold increase compared with that of the starting strain, highlighting the significant potential of the screened genomic loci in optimizing valencene production.

Injury Mortality of Children and Adolescents Aged 0-19 Years - China, 2010-2021.

Introduction: To examine the recent trends in child injury mortality in China. Methods: Injury mortality data of 2010-2021 for children and adolescents aged 0-19 years were from the China Health Statistics Yearbook. Injury mortality disparities across urban vs. rural locations, gender, and age groups were scrutinized. Annual percent change (APC), average annual percent change (AAPC), and their 95% confidence intervals (95% CI) were estiamted usimg Joinpoint regression models. Results: The age-standardized injury mortality significantly dropped from 21.87 to 9.41 per 100,000 population among children and youth aged 0-19 years during 2010-2021, with an AAPC of -6.7% (95% CI: -8.2%, -5.2%). The urban-rural disparity and gender gap in injury mortality reduced gradually. In 2021, drowning and road traffic crashes were the top two causes of child injury deaths, explaing 31.1% and 27.9% of total injury deaths, respectively. Suffocation accounted for 62.3% of injury deaths among infants younger than a year. Alarmingly, the suicide mortality rate rose from 2.16 to 3.42 per 100,000 population between 2010 and 2021 among teenagers aged 15-19 years. Subgroup analyses yielded similar results. Conclusions: During 2010-2021, the injury mortality decreased significantly among Chinese children and adolescents, and the responding urban-rural disparities narrowed.

Behavioral Intention of Receiving Monkeypox Vaccination and Undergoing Monkeypox Testing and the Associated Factors Among Young Men Who Have Sex With Men in China: Large Cross-Sectional Study.

BACKGROUND: The worldwide human monkeypox (mpox) outbreak in 2022 mainly affected men who have sex with men (MSM). In China, young men who have sex with men (YMSM) were at a potential high risk of mpox infection due to their sexual activeness and the eased COVID-19 restrictions at the end of 2022. OBJECTIVE: This study aimed to investigate the behavioral intention of receiving mpox vaccination and undergoing mpox testing in 4 different scenarios and explore their associations with background and behavioral theory-related factors among Chinese YMSM. METHODS: An online cross-sectional survey was conducted among YMSM aged 18-29 years from 6 representative provinces of China in September 2022. Participants recruited (recruitment rate=2918/4342, 67.2%) were asked to self-administer an anonymous questionnaire designed based on prior knowledge about mpox and classic health behavior theories. Data on the participants' background, mpox knowledge and cognition, mpox vaccination and testing cognition, and the behavioral intention of receiving mpox vaccination and undergoing mpox testing were collected. Descriptive analysis and univariate and multivariate linear regressions were performed. Geodetector was used to measure the stratified heterogeneity of behavioral intention. RESULTS: A total of 2493 YMSM with a mean age of 24.6 (SD 2.9) years were included. The prevalence of having a behavioral intention of receiving mpox vaccination ranged from 66.2% to 88.4% by scenario, varying in epidemic status and cost. The prevalence of having an mpox testing intention was above 90% in all scenarios regardless of the presence of symptoms and the cost. The positive factors related to vaccination intention included mpox knowledge (ba=0.060, 95% CI 0.016-0.103), perceived susceptibility of mpox (ba=0.091, 95% CI 0.035-0.146), perceived severity of mpox (ba=0.230, 95% CI 0.164-0.296), emotional distress caused by mpox (ba=0.270, 95% CI 0.160-0.380), perceived benefits of mpox vaccination (ba=0.455, 95% CI 0.411-0.498), self-efficacy of mpox vaccination (ba=0.586, 95% CI 0.504-0.668), and having 1 male sex partner (ba=0.452, 95% CI 0.098-0.806), while the negative factor was perceived barriers to vaccination (ba=-0.056, 95% CI -0.090 to -0.022). The positive factors related to testing intention were perceived severity of mpox (ba=0.283, 95% CI 0.241-0.325), perceived benefits of mpox testing (ba=0.679, 95% CI 0.636-0.721), self-efficacy of mpox testing (ba=0.195, 95% CI 0.146-0.245), having 1 male sex partner (ba=0.290, 95% CI 0.070-0.510), and having in-person gatherings with MSM (ba=0.219, 95% CI 0.072-0.366), while the negative factor was emotional distress caused by mpox (ba=-0.069, 95% CI -0.137 to -0.001). CONCLUSIONS: Among Chinese YMSM, the intention of undergoing mpox testing is optimal, while the mpox vaccination intention has room for improvement. A future national response should raise YMSM's mpox knowledge, disseminate updated information about mpox and preventive measures, improve preventive service accessibility and privacy, and provide advice on positively coping with the associated emotional distress.

Behavioral intentions of self-isolation and informing close contacts after developing mpox-related symptoms among young men who have sex with men in China.

The 2022 multi-country mpox outbreak raised public concern globally. Self-isolation and informing close contacts after developing mpox-related symptoms are critical measures in controlling the outbreak. This study investigated behavioral intentions of self-isolation and informing close contacts after developing mpox-related symptoms and associated factors among young men who have sex with men (YMSM) aged 18-29 years in China. The cross-sectional study was conducted among 2493 YMSM in six provincial regions in China from September 10th to 30th, 2022. Descriptive and logistic analyses were applied, using the intentions of self-isolation and informing close contacts after developing mpox-related symptoms as binary outcomes. The mean age of the participants was 24.6 (SD = 2.9) years. The prevalence of having intentions of self-isolation and informing close contacts after developing mpox-related symptoms was 88.6% (95% CI: 87.3%-89.9%) and 84.9% (95% CI: 83.5%-86.3%). Participants who were employed (adjusted odds ratio (AOR) = 1.474, 95% CI: 1.035-2.097; AOR = 1.371, 95% CI:1.002, 1.876), had higher mpox knowledge scores (AOR = 1.474, 95% CI: 1.035-2.097; AOR = 1.371, 95% CI: 1.002-1.876), and had higher perceived threats of mpox (AOR = 1.079, 95% CI: 1.030-1.130; AOR = 1.045, 95% CI: 1.002-1.090) were more likely to intend to self-isolate and inform close contacts. Participants who had MSM in-person gatherings in the past 6 months were more likely to intend to self-isolate (AOR = 1.392, 95% CI: 1.066-1.208). Participants with higher depression scores (AOR = 0.968, 95% CI: 0.948-0.989) and self-stigma (AOR = 0.975, 95% CI: 0.954-0.997) were less likely to intend to self-isolate and inform close contacts, respectively. Self-isolation and informing close contacts when developing disease-related symptoms are acceptable measures in response to mpox in China. Strengthening targeted risk communication and self-efficacy, raising disease knowledge, providing mental support, and reducing stigma toward the affected community are warranted.

Teacher-student complementary sample contrastive distillation.

Knowledge distillation (KD) is a widely adopted model compression technique for improving the performance of compact student models, by utilizing the "dark knowledge" of a large teacher model. However, previous studies have not adequately investigated the effectiveness of supervision from the teacher model, and overconfident predictions in the student model may degrade its performance. In this work, we propose a novel framework, Teacher-Student Complementary Sample Contrastive Distillation (TSCSCD), that alleviate these challenges. TSCSCD consists of three key components: Contrastive Sample Hardness (CSH), Supervision Signal Correction (SSC), and Student Self-Learning (SSL). Specifically, CSH evaluates the teacher's supervision for each sample by comparing the predictions of two compact models, one distilled from the teacher and the other trained from scratch. SSC corrects weak supervision according to CSH, while SSL employs integrated learning among multi-classifiers to regularize overconfident predictions. Extensive experiments on four real-world datasets demonstrate that TSCSCD outperforms recent state-of-the-art knowledge distillation techniques.

Mechanism of aroma enhancement methods in accelerating Congou black tea acidification subjected to room temperature storage.

Acidification of aroma-enhanced black tea during storage was studied. UPLC-Q-TOF/MS (Ultra Performance Liquid Chromatography and Quadrupole-Time of Flight Mass Spectrometer) and HPLC (High-Performance Liquid Chromatography) analysis of non-volatile substances and organic acids revealed a decrease of soluble sugars and amino acids in aroma-enhanced black tea, while an increase in organic acids such as oxalic acid, malic acid and quinic acid. Further in vitro experiments indicated that the acidification of aroma-enhanced tea during storage can be attributed to decomposition of sugars and amino acids by heating, oxidation of aromatic aldehydes. Meanwhile, the amino acids, catechins, soluble sugars and flavonoids that constitute the taste of black tea are further reduced, changing the taste composition of tea infusion and further increasing its acidity. This study revealed the reasons for black tea acidification during aroma enhancement and storage and provided a theoretical basis for improving black tea quality.

Study on color, aroma, and taste formation mechanism of large-leaf yellow tea during an innovative manufacturing process.

This study used samples processed with an innovative manufacturing process to explore the dynamic changes of large-leaf yellow tea (LYT) in color, aroma, and taste substances, and the quality components were most significantly affected in the stages of first pile-yellowing (FP) and over-fired drying (TD). In this process, the moisture and temperature conditions caused chlorophyll degradation, Maillard reactions, caramelization reactions, and isomerization of phenolic substances, forming the quality of LYT. Specifically, chlorophyll degradation favored the formation of color quality; the taste quality was determined by the content of soluble sugars, amino acids, catechins, etc.; the aroma quality was dependent on the content changes of alcohols and aldehydes, as well as the increase of sweet and roasting aroma substances in the third drying stage. Additionally, twelve key aroma components, including linalool, (E)-ß-ionone, 2,3-diethyl-5-methyl-pyrazine, etc., were identified as contributors to revealing LYT rice crust-like and sweet aroma formation mechanism.

The key aroma components of steamed green tea decoded by sensomics and their changes under different withering degree.

Steamed green tea has a long history and unique aroma, but little is known about its key aroma components. In this study, 173 volatiles in steamed green tea were identified using solvent-assisted flavor evaporation and headspace-solid phase microextraction plus two chromatographic columns of different polarities. Aroma extract dilution analysis revealed 48 highly aroma-active compounds with flavor dilution factors 64-1024. Internal standards were used to calculate odorant active value (OAV), and 11 OAV > 1 key aroma compounds were determined. Omission test identified eight substances, including dimethyl sulfide, (E)-ß-ionone, cis-jasmone, linalool, nonanal, heptanal, isovaleraldehyde and (Z)-3-hexenol, as the key aroma active compounds of steamed green tea. With the increase of withering degree, the content of these substances increased first and then decreased except for heptanal and cis-jasmone. Moreover, the water content of 62 % was suggested to be an appropriate withering degree during the processing of steamed green tea.

Green Production of a High-value Mosquito Insecticide of Nootkatone from Seaweed Hydrolysates.

Nootkatone is a type of valuable sesquiterpene that is widely used in food, cosmetics, fragrance, and other fields. The industry is faced with a major challenge due to the high expenses associated with plant-extracted nootkatone. We have developed a fermentation process for valencene production using seaweed hydrolysate as a carbon source via engineered Saccharomyces cerevisiae. Reduced-pressure distillation purified valencene was used as a substrate, and a yeast strain carrying HPO/AtCPR1 and ADH genes was constructed for whole-cell catalysis. After biotransformation at 25 °C for 3 h, a high yield of 73% for nootkatone production was obtained. Further, simple rotary evaporation was used to obtain nootkatone with a high purity of 97.4%. Mosquito-repellent testing showed that 1% nootkatone has a mosquito-repellent effect lasting up to 6 h, which is comparable to the 20% N,N-diethyl-meta-toluamide (DEET) effect. This study provided practical experience for developing third-generation biomass resources, generating new ideas for green manufacturing of valuable chemical products, and serving as a reference for creating efficient and eco-friendly mosquito repellents.

Electron-beam writing of a relaxor ferroelectric polymer for multiplexing information storage and encryption.

To meet the strong demand for high-level encryption security, several efforts have been focused on developing new encryption techniques with high density and data security. Herein we employed a template-free electron beam lithography (EBL) technique to write various nanopatterns on poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (P(VDF-TrFE-CTFE)) films and applied it to electron-beam/electric multiplexing memory. Furthermore, electron beams can arbitrarily tailor down the domain structure evolutions and dipole directions, as proved by a combination of AFM-IR and PFM. Finally, our devices could function concurrently as an electron-beam write-only-memory (EB-WOM) and FeRAM, where the information could be encoded with the metastable phase evolutions from the ferroelectric phase to the paraelectric phase and variable bi-level ferroelectric signals. Our systematic study provides an inspiring idea for the design of information encryption devices with high-security requirements in flexible electronic fields.

Non-targeted metabolomics characterization of flavor formation of Lichuan black tea processed from different cultivars in Enshi.

Nine tea cultivars planted in Enshi were selected and processed into "Lichuan black tea". Sensory evaluation showed that cultivar had the greatest influence on taste and aroma quality, including sweetness, umami and concentration of taste, as well as sweet and floral fragrances of aroma. The non-volatile and volatile components were identified by UPLC-Q-TOF/MS and GC-MS, and PCA analysis showed good separation between cultivars, which could cause the difference in quality. Baiyaqilan, Meizhan and Echa 10 had a floral aroma, with obvious difference in their aromatic composition from other cultivars. Moreover, Echa 10 also had a strong sweet aroma. The key aroma components in Echa 10 (with the largest cultivation area) were further investigated by GC-O-MS combined with odor activity value (OAV) analysis, included ß-damascenone, phenylethylaldehyde, nonenal, geraniol, linalool, jasmonone, (E)-2-nonenal, ß-cyclocitral, (E)-ß-ocimene, methyl salicylate, ß-ionone, 2,6,10,10-tetramethyl-1-oxaspiro[4.5]dec-6-ene, citral, ß-myrcene, nerol, phenethyl alcohol, benzaldehyde, hexanal, nonanoic acid, and jasmin lactone.

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, ß-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 ß-damascenone in the former two samples. Additionally, excessive OAV increase of fatty aldehydes in F8H masked its similar floral and fruity aroma.

Mpox risk perception and associated factors among Chinese young men who have sex with men: Results from a large cross-sectional survey.

The mpox outbreak since 2022 had attacked the community of men who have sex with men (MSM) heavily. This large cross-sectional study investigated the levels and associated factors of mpox risk perception among young MSM (YMSM) aged 18-29 years in six provincial regions of China in September 2022. The participants were recruited via facility-based sampling. Mpox risk perception was measured by perceived susceptibility and perceived severity of mpox. Geodetector was used to measure stratified heterogeneity of mpox risk perception. Univariate and multivariable linear regressions were used to examine the factors associated with mpox risk perception. A total of 2493 participants were included with a mean age of 24.6 years. The proportion of perceiving a susceptibility of mpox under different scenarios ranged 3.7%-17.0% and that of perceiving a severity of mpox ranged 81.6%-83.2%. Stratified heterogeneity of perceived susceptibility, perceived severity, and overall perceived risk of mpox were observed in several characteristics such as study sites, monthly income, risk behaviors, and psychosocial factors. Multivariable regression showed the level of mpox risk perception was positively associated with having in-person gathering activities (ba = 0.457, 95% CI: 0.208, 0.705), history of HIV infection (ba = 0.431, 95% CI: 0.028, 0.834), depressive symptoms (ba = 0.069, 95% CI: 0.049, 0.090), and self-stigma to MSM identity (ba = 0.047, 95% CI: 0.024, 0.071). The Chinese YMSM showed a high level of perceived severity of mpox but a low level of perceived susceptibility. It is warranted to strengthen targeted risk communication of mpox, develop comprehensive and unstigmatized health messages, and provide mental health support for YMSM.

IntrinsicNGP: Intrinsic Coordinate based Hash Encoding for Human NeRF.

Recently, many works have been proposed to utilize the neural radiance field for novel view synthesis of human performers. However, most of these methods require hours of training, making them difficult for practical use. To address this challenging problem, we propose IntrinsicNGP, which can train from scratch and achieve high-fidelity results in few minutes with videos of a human performer. To achieve this target, we introduce a continuous and optimizable intrinsic coordinate rather than the original explicit Euclidean coordinate in the hash encoding module of instant-NGP. With this novel intrinsic coordinate, IntrinsicNGP can aggregate inter-frame information for dynamic objects with the help of proxy geometry shapes. Moreover, the results trained with the given rough geometry shapes can be further refined with an optimizable offset field based on the intrinsic coordinate. Extensive experimental results on several datasets demonstrate the effectiveness and efficiency of IntrinsicNGP. We also illustrate our approach's ability to edit the shape of reconstructed subjects.

The aroma characteristics of oolong tea are jointly determined by processing mode and tea cultivars.

This study delved into the aroma characteristics of "Qingxiang" oolong tea, analyzing six different cultivars and their processing modes. The findings showed that both cultivars and processing modes have a significant impact on the oolong tea aroma system. The study identified 18 terpenoid volatiles (VTs), 11 amino-acid-derived volatiles (AADVs), 15 fatty-acid-derived volatiles (FADVs), 3 carotenoid-derived volatiles (CDVs), and 10 other compounds in oolong tea that differentiate it from green and black tea. The turn-over stage was found to be the primary processing stage for oolong tea aroma formation. Molecular sensory analysis revealed that the "fresh" odor attribute is the basis for its aroma, while "floral and fruity" fragrances are its aroma characteristics. The perception of oolong tea as "fresh" and "floral and fruity" is influenced by the interactions of its aroma components. These findings provide a new basis for breed improvement and process enhancement in oolong tea production.

Design and characterization of molecular, crystal and interfacial structures of PVDF-based dielectric nanocomposites for electric energy storage.

PVDF-based polymers with polar covalent bonds are next-generation dielectric materials for electric energy storage applications. Several types of PVDF-based polymers, such as homopolymers, copolymers, terpolymers and tetrapolymers, were synthesized by radical addition reactions, controlled radical polymerizations, chemical modifications or reduction with the monomers of vinylidene fluoride (VDF), tetrafluoroethylene (TFE), trifluoroethylene (TrFE), hexafluoropropylene (HFP) and chlorotrifluoroethylene (CTFE). Owing to rich molecular structures and complicated crystal structures, PVDF-based dielectric polymers can show versatile dielectric polarization properties, including normal ferroelectrics, relaxor ferroelectrics, anti-ferroelectrics and linear dielectrics, which are beneficial for designing polymer films with high capacity and high charge-discharge efficiency for capacitor applications. Furthermore, to satisfy the requirements of practical high-capacity capacitors, the polymer nanocomposite method is another promising strategy to achieve high-capacitance dielectric materials by the addition of high-dielectric ceramic nanoparticles, moderate-dielectric nanoparticles (MgO, and Al2O3), high-insulation nanosheets (BN), etc. It is concluded with the current problems and future perspectives of interfacial engineering, such as core-shell strategies and hierarchical interfaces in polymer-based composite dielectrics for high-energy-density capacitor applications. In addition, an in-depth understanding of the roles of interfaces on the dielectric properties of nanocomposites can be achieved by indirect analysis techniques (theoretical simulation) and direct analysis techniques (scanning probe microscopy). Our systematic discussions on molecular, crystal and interfacial structures provide guidance for designing fluoropolymer-based nanocomposites for high-performance capacitor applications.

Clamping force prediction based on deep spatio-temporal network for machining process of deformable parts.

As an important component of the machining system, the influence of fixtures on the machining deformation of the workpiece cannot be ignored. By controlling the clamping force during the machining process is an effective means to suppress or improve the machining deformation. However, due to the dynamic coupling of part geometry, clamping method, manufacturing process and time-varying cutting forces, it is difficult to obtain accurate clamping forces, which hinders the realization of fixture-based deformation control. In this paper, the variation of clamping force is considered as the response of the joint action of cutting force and other working conditions in spatial and temporal terms, and a clamping force prediction method based on deep spatio-temporal network is proposed. The part geometry model is first parameterized based on voxels, after which the cutting forces are dynamically correlated with the clamping forces in spatial and temporal terms. Then, a convolutional network was designed to capture the spatial correlation between the working conditions such as cutting force and clamping force, and a gated recurrent cell network to capture the temporal correlation to predict the clamping force during machining. Finally, an experiment of milling a cylindrical thin-walled part illustrates the effectiveness of the proposed method.

Structure Design and Working Characteristics Analysis of Direct-Drive Giant Magnetostrictive Injector.

At present, the research of electronically controlled injectors is mostly limited to the non-direct drive structure. Although the research on the direct drive structure is involved, it mostly stays in the conceptual machine or simulation stage. In this paper, based on the direct-drive structure, the giant magnetostrictive material is used as the energy conversion material, the prototype of the direct-drive giant magnetostrictive fuel injector is designed and manufactured, and the experimental test system and AMESim simulation model are built. By means of experiment and simulation, the injection characteristics of Giant magnetostrictive injector (GMI) are tested. It is found that the minimum single injection quantity of GMI is 5.9 mm3 under the condition of 30 MPa rail pressure, which shows high injection accuracy. The experimental results are in good agreement with the simulation results under different driving pulse widths and voltages. When the driving pulse width is not less than 650 µs, the relative errors are all less than 5%, which verifies the effectiveness of the simulation model. The injection performance of GMI is analyzed. The results show that this injector has a stable injection performance, fast response speed (the shortest injection pulse width is about 200 µs), and the injection process can be completed five times in 5 ms.

Study on the Suitability of Tea Cultivars for Processing Oolong Tea from the Perspective of Aroma Based on Olfactory Sensory, Electronic Nose, and GC-MS Data Correlation Analysis.

The oolong tea aroma is shown to consist of cultivar aroma and technical aroma in this study based on the aroma differences between oolong tea products of cultivars of different suitability, as determined by correlation analysis of olfactory, sensory, electronic nose, and GC-MS data. Human senses were significantly affected by the aroma components, which included eight terpene metabolites (ß-Ocimene, (Z)-Furan linalool oxide, linalool, (3E)-4,8-Dimethyl-1,3,7-nonatriene, (E)-Pyranoid linalool oxide, γ-Elemene, Humulene, (Z,E)-α-Farnesene), three carotenoid metabolites (ß-Ionone, (Z)-Geranylacetone and 6-methyl-5-Hepten -2-one), three lipid metabolites ((Z)-3-Hexenyl (Z)-3-hexenoate, Butanoic acid hexyl ester, and (Z)-Jasmone), four amino acid metabolites (Methyl salicylate, Geranyl isovalerate, indole, and Phenylethyl alcohol), and six thermal reaction products (2-Pentylfuran, Octanal, Decanal, (E,E)-2,4-Nonadienal, (Z)-2-Decenal, and (E)-2-Undecenal). Meanwhile, several aroma compounds (such as (E)-Nerolidol and α-Farnesene), mainly comprising the "technical aroma" formed in the processing mode, were noted to be less closely related to cultivar suitability. This study sheds light on the aroma characteristics of different tea cultivars for oolong tea processing.