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1.
Talanta ; 278: 126416, 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38924989

ABSTRACT

The non-thermal and thermal effects on aroma of sea buckthorn juice have rarely been investigated. In this study, 57 odor compounds were identified in fresh sea buckthorn juice (FSBJ), high pressure processing sea buckthorn juice (HSBJ), and pasteurized sea buckthorn juice (PSBJ), including 29 esters, 8 aldehydes, 1 ketone, 5 alcohols, 5 acids, 6 terpenoids, and 3 others. Ethyl 2-methylbutanoate, ethyl 3-methylbutanoate, ethyl hexanoate, and ethyl 2-hydroxy-3-methylbutanoate with flavor dilution factors ranging from 729 to 59,049 contributed to the fruity odors of FSBJ and HSBJ. Besides, the formation of off-odor compounds including hexanal, nonanal, furfural, 3-methylbutanoic acid, and dimethyl disulfide with odor activity values ≥ 1, imparts fatty, roasted, sweaty, and cooked odor in PSBJ. The variations of vitamin C and reducing sugar are significantly associated with changes in odor-active compounds during pasteurized processing. These findings provide new insights that high pressure processing minimizes the adverse effects of pasteurization.

2.
Plants (Basel) ; 13(12)2024 Jun 18.
Article in English | MEDLINE | ID: mdl-38931118

ABSTRACT

There are obvious differences in quality between different varieties of the same plant, and it is not clear whether they can be effectively distinguished from each other from a bacterial point of view. In this study, 44 tea tree varieties (Camellia sinensis) were used to analyze the rhizosphere soil bacterial community using high-throughput sequencing technology, and five types of machine deep learning were used for modeling to obtain characteristic microorganisms that can effectively differentiate different varieties, and validation was performed. The relationship between characteristic microorganisms, soil nutrient transformation, and tea quality formation was further analyzed. It was found that 44 tea tree varieties were classified into two groups (group A and group B) and the characteristic bacteria that distinguished them came from 23 genera. Secondly, the content of rhizosphere soil available nutrients (available nitrogen, available phosphorus, and available potassium) and tea quality indexes (tea polyphenols, theanine, and caffeine) was significantly higher in group A than in group B. The classification result based on both was consistent with the above bacteria. This study provides a new insight and research methodology into the main reasons for the formation of quality differences among different varieties of the same plant.

3.
Plants (Basel) ; 13(10)2024 May 08.
Article in English | MEDLINE | ID: mdl-38794362

ABSTRACT

Aviation mutagenesis is a breeding method for the rapid selection of superior plant varieties. In this study, rhizosphere soil chemical indexes, soil enzyme activities, and soil metabolites were measured in Dahongpao tea trees with aviation mutagenesis (TM) and without aviation mutagenesis (CK). The main soil metabolites distinguishing TM and CK and their relationships with soil chemical indexes and soil enzyme activities were analyzed and obtained. The results showed that there was no significant change in the rhizosphere soils' pH of TM tea trees compared to CK (p = 0.91), while all other chemical indexes of TM were significantly higher than CK (p < 0.05). In addition, the activities of enzymes related to soil nutrient cycling such as urease, protease, sucrase, acid phosphatase and cellulase, and enzymes related to soil antioxidants such as superoxide dismutase, catalase, peroxidase, and polyphenol oxidase were significantly increased (p < 0.05) in the rhizosphere soils of TM tea trees compared to CK. Soil metabolite analysis showed that the main soil metabolites distinguishing CK from TM were carbohydrates, nitrogen compounds, and amines. Of these, carbohydrates and nitrogen compounds were significantly positively correlated with soil chemical indexes and soil enzymes, whereas amine was significantly negatively correlated with soil chemical indexes such as organic matter, total nitrogen, total potassium, available nitrogen, available phosphorus; amine showed significant negative correlation with soil enzymes such as catalase, peroxidase, polyphenol oxidase, and urease. It can be seen that aviation mutagenesis is conducive to improving the ability of tea tree rhizosphere aggregation and transformation of soil nutrients, increasing the total amount of soil nutrients and the content of available nutrients, which is more conducive to promoting the uptake of nutrients by the tea tree, and thus promoting the growth of the tea tree.

4.
Foods ; 13(10)2024 May 16.
Article in English | MEDLINE | ID: mdl-38790849

ABSTRACT

The quality of the Dahongpao mother tree (Camellia sinensis) remains a mystery to this day. In this study, for the first time, the differences between the Dahongpao mother tree (MD) and Dahongpao cuttings (PD), in terms of odor characteristics and taste characteristics were analyzed by metabomics. The results showed that MD had stronger floral, fruity, green, and woody odor characteristics than PD, and that the contributions were mainly from dihydromyrcenol, methyl salicylate, 2-isobutylpyrazine, 1,6-dihydrocarveol, gamma-terpineol, and linalyl acetate. Further, fresh and brisk taste and mellowness taste characteristics of MD were significantly higher than PD, with contributions mainly from amino acids and derivatives and organic acids. Secondly, bitterness taste characteristics of PD were significantly higher than MD, with contributions from phenolic acids, flavones, and flavonols. This study preliminarily unraveled the legend of the superior quality of the Dahongpao mother tree, and also provided an important reference for the breeding of tea-tree cuttings.

5.
Molecules ; 29(7)2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38611780

ABSTRACT

This study investigates the synthesis of mesophase pitch using low-cost fluid catalytic cracking (FCC) slurry and waste fluid asphaltene (WFA) as raw materials through the co-carbonization method. The resulting mesophase pitch product and its formation mechanism were thoroughly analyzed. Various characterization techniques, including polarizing microscopy, softening point measurement, Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), were employed to characterize and analyze the properties and structure of the mesophase pitch. The experimental results demonstrate that the optimal optical texture of the mesophase product is achieved under specific reaction conditions, including a temperature of 420 °C, pressure of 1 MPa, reaction time of 6 h, and the addition of 2% asphaltene. It was observed that a small amount of asphaltene contributes to the formation of mesophase pitch spheres, facilitating the development of the mesophase. However, excessive content of asphaltene may cover the surface of the mesophase spheres, impeding the contact between them and consequently compromising the optical texture of the mesophase pitch product. Furthermore, the inclusion of asphaltene promotes polymerization reactions in the system, leading to an increase in the average molecular weight of the mesophase pitch. Notably, when the amount of asphaltene added is 2%, the mesophase pitch demonstrates the lowest ID/IG value, indicating superior molecular orientation and larger graphite-like microcrystals. Additionally, researchers found that at this asphaltene concentration, the mesophase pitch exhibits the highest degree of order, as evidenced by the maximum diffraction angle (2θ) and stacking height (Lc) values, and the minimum d002 value. Moreover, the addition of asphaltene enhances the yield and aromaticity of the mesophase pitch and significantly improves the thermal stability of the resulting product.

6.
Comput Biol Med ; 174: 108463, 2024 May.
Article in English | MEDLINE | ID: mdl-38640634

ABSTRACT

Medical image fusion can provide doctors with more detailed data and thus improve the accuracy of disease diagnosis. In recent years, deep learning has been widely used in the field of medical image fusion. The traditional method of medical image fusion is to operate by superimposing and other methods of pixels. The introduction of deep learning methods has improved the effectiveness of medical image fusion. However, these methods still have problems such as edge blurring and information redundancy. In this paper, we propose a deep learning network model based on Transformer and an improved DenseNet network module integration that can be applied to medical images and solve the above problems. At the same time, the method can be moved to natural images. The use of Transformer and dense concatenation enhances the feature extraction capability of the method by limiting the feature loss which reduces the risk of edge blurring. We compared several representative traditional methods and more advanced deep learning methods with this method. The experimental results show that the Transformer and the improved DenseNet network module have a strong capability of feature extraction. The method yields good results both in terms of visual quality and objective image evaluation metrics.


Subject(s)
Deep Learning , Humans , Image Processing, Computer-Assisted/methods , Algorithms , Image Interpretation, Computer-Assisted/methods , Neural Networks, Computer
7.
Foods ; 13(6)2024 Mar 20.
Article in English | MEDLINE | ID: mdl-38540936

ABSTRACT

Aviation mutagenesis is a fast and efficient breeding method. In this study, we analyzed the effect of aviation mutagenesis on volatile compounds and odor characteristics in Dahongpao fresh leaves and gross tea for the first time. The results showed that aviation mutagenesis significantly increased the total volatile compounds of Dahongpao fresh leaves and gross tea. Aviation mutagenesis most critically significantly increased the content of beta-myrcene in Dahongpao fresh leaves, prompting its conversion to beta-pinene, cubebol, beta-phellandrene, zingiberene, (Z,Z)-3,6-nonadienal, and 6-pentyloxan-2-one after processing, which in turn enhanced the fruity, green, spicy, and woody odor characteristics of the gross tea. This study provided a reference for further exploration of aviation mutagenic breeding of Camellia sinensis.

8.
Medicine (Baltimore) ; 103(3): e36934, 2024 Jan 19.
Article in English | MEDLINE | ID: mdl-38241549

ABSTRACT

To estimate the safety and effectiveness of endoscopic nasal dacryocystorhinostomy in the remedy of chronic dacryocystitis. The clinical data of 105 subjects with chronic dacryocystitis enrolled into our hospital were analyzed retrospectively. The subjects were distinguished into nasal endoscopic group (endoscopic dacryocystorhinostomy; i.e., 51 cases) according to their surgical methods and external-route group (external-route dacryocystorhinostomy; i.e., 54 cases). The therapeutic effect, lacrimal gland secretion function, tear film stability, degree of epiphora, lacrimal passage patency, complications, and recurrence rate were contrasted between the 2 groups. The nasal endoscopic group exhibited a higher effective remedy rate (98.04%) compared with the external-route group (83.33%). Three months postoperation, both groups showed improvements in lacrimal gland secretion function and tear film stability, with the nasal endoscopic group demonstrating more significant enhancement in lacrimal gland secretion function than the external-route group. Six months postoperation, a reduction in the degree of epiphora was observed in both groups, with the nasal endoscopic group displaying a more pronounced decrease in epiphora severity and a higher lacrimal passage patency rate than the external-route group. Furthermore, the nasal endoscopic group experienced lower incidences of postoperative complications and recurrence rates. Endoscopic dacryocystorhinostomy is safe and effective in the remedy of chronic dacryocystitis.


Subject(s)
Dacryocystitis , Dacryocystorhinostomy , Lacrimal Apparatus Diseases , Nasolacrimal Duct , Humans , Dacryocystorhinostomy/adverse effects , Dacryocystorhinostomy/methods , Retrospective Studies , Dacryocystitis/surgery , Nose , Lacrimal Apparatus Diseases/surgery , Endoscopy/methods , Nasolacrimal Duct/surgery , Treatment Outcome
9.
Adv Mater ; : e2310040, 2024 Jan 30.
Article in English | MEDLINE | ID: mdl-38291858

ABSTRACT

Digital Light Processing (DLP) is a vat photopolymerization-based 3D printing technology that fabricates parts typically made of chemically crosslinked polymers. The rapidly growing DLP market has an increasing demand for polymer raw materials, along with growing environmental concerns. Therefore, circular DLP printing with a closed-loop recyclable ink is of great importance for sustainability. The low-ceiling temperature alkyl-substituted δ-valerolactone (VL) is an industrially accessible biorenewable feedstock for developing recyclable polymers. In this work, acrylate-functionalized poly(δ-valerolactone) (PVLA), synthesized through the ring-opening transesterification polymerization of VL, is used as a platform photoprecursor to improve the chemical circularity in DLP printing. A small portion of photocurable reactive diluent (RD) turns the unprintable PVLA into DLP printable ink. Various photocurable monomers can serve as RDs to modulate the properties of printed structures for applications like sacrificial molds, soft actuators, sensors, etc. The intrinsic depolymerizability of PVLA is well preserved, regardless of whether the printed polymer is a thermoplastic or thermoset. The recovery yield of virgin quality VL monomer is 93% through direct bulk thermolysis of the printed structures. This work proposes the utilization of depolymerizable photoprecursors and highlights the feasibility of biorenewable VL as a versatile material platform toward circular DLP printing.

10.
BMC Cancer ; 24(1): 64, 2024 Jan 12.
Article in English | MEDLINE | ID: mdl-38216964

ABSTRACT

BACKGROUND: Cancer associated fibroblasts (CAFs) can remodel tumor microenvironment by secreting exosomes. This study aimed to investigate the role of exosomes derived from cancer-associated fibroblasts in colorectal cancer (CRC) progression. METHODS: Circular RNA (circRNA) array was used to identify differentially expressed circRNAs in exosomes from normal fibroblasts (NFs) and CAFs, and confirmed one differentially expressed circRNA circ_0067557 by real-time PCR. The effect of circ_0067557 on proliferation, metastasis, chemoresistance and apoptosis was verified by wound heal, tranwell, CCK8, sphere-forming and flow cytometry assay. RESULTS: Circ_0067557 expression in exosomes from CAFs was higher than those from NFs. CAF-derived exosomes promoted the proliferation, migration, invasion and chemoresistance of CRC cells while suppressed apoptosis. Silencing of circ_0067557 inhibited malignant phenotypes of CRC cells by targeting Lin28A and Lin28B. Moreover, CAF-derived exosomes enhanced the growth of CRC xenograft tumors. CONCLUSION: Circ_0067557/Lin28A and Lin28B signal axis may be a potential therapy target for CRC.


Subject(s)
Cancer-Associated Fibroblasts , Colorectal Neoplasms , Exosomes , MicroRNAs , Humans , Cancer-Associated Fibroblasts/metabolism , Carcinogenesis/metabolism , Cell Line, Tumor , Cell Proliferation/genetics , Cell Transformation, Neoplastic/metabolism , Colorectal Neoplasms/pathology , Drug Resistance, Neoplasm/genetics , Exosomes/genetics , Exosomes/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , RNA, Circular/genetics , RNA, Circular/metabolism , Tumor Microenvironment/genetics , Animals
11.
J Food Sci ; 89(1): 81-95, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37983847

ABSTRACT

Shaking and tumbling are extremely important for the formation of the special flavor of Wuyi rock tea. In this study, we analyzed the effects of different shaking and tumbling degrees on the quality index content of tea leaves and determined changes in gene expression in tea leaves using RNA sequencing technology. On this basis, the correlation between gene expression intensities in tea leaves and tea quality index content was analyzed. The results showed that heavy shaking and tumbling (MW3) increased gene expression of metabolic pathways, biosynthesis of secondary metabolites, starch and sucrose metabolism, biosynthesis of amino acids, glycine, serine, and threonine metabolism, alpha-linolenic acid metabolism pathways and decreased gene expression of flavonoid biosynthesis, carbon fixation in photosynthetic organisms, phenylpropanoid biosynthesis, and plant hormone signal transduction pathways in tea leaves, which in turn increased the content of caffeine, soluble sugar, amino acid and decreased the content of flavone, tea polyphenol, catechin component in tea leaves; the opposite was true for light shaking and tumbling. Second, this study found that MW3 was more beneficial in improving the mellowness, sweetness, and fresh and brisk taste of tea leaves and reducing the bitterness of tea leaves. This study provides some references to guide the processing of Wuyi rock tea with different flavors. PRACTICAL APPLICATION: Heavy shaking and tumbling was more beneficial in improving the mellowness, sweetness, and fresh and brisk taste of tea leaves and reducing the bitterness of tea leaves. Therefore, the degree of shaking and tumbling in Wuyi production can be appropriately improved to produce high-quality tea and improve the economic benefits of tea.


Subject(s)
Camellia sinensis , Tea , Tea/chemistry , Camellia sinensis/chemistry , Caffeine/analysis , Gene Expression Profiling , Polyphenols/analysis , Plant Leaves/chemistry
12.
Front Plant Sci ; 14: 1288444, 2023.
Article in English | MEDLINE | ID: mdl-38155858

ABSTRACT

Continuous planting has a severe impact on the growth of Casuarina equisetifolia. In this study, the effects of three different long-term monocultures (one, two and three replanting) on the physicochemical indexes, microbial functional diversity, and soil metabolomics were analyzed in C. equisetifolia rhizosphere soil. The results showed that rhizosphere soil organic matter content, cation exchange capacity, total and available nitrogen, total and available phosphorus, and total and available potassium contents significantly decreased with the increasing number of continuous plantings. The evaluation of microbial functional diversity revealed a reduction in the number of soil microorganisms that rely on carbohydrates for carbon sources and an increase in soil microorganisms that used phenolic acid, carboxylic acid, fatty acid, and amines as carbon sources. Soil metabolomics analysis showed a significant decrease in soil carbohydrate content and a significant accumulation of autotoxic acid, amine, and lipid in the C. equisetifolia rhizosphere soil. Consequently, the growth of C. equisetifolia could hinder total nutrient content and their availability. Thus, valuable insights for managing the cultivation of C. equisetifolia and soil remediation were provided.

13.
Sensors (Basel) ; 23(24)2023 Dec 08.
Article in English | MEDLINE | ID: mdl-38139555

ABSTRACT

A sinkhole attack is characterized by low difficulty to launch, high destructive power, and difficulty to detect and defend. It is a common attack mode for wireless sensor networks. This paper proposes a sinkhole attack detection and defense strategy integrating SPA and Jaya algorithms in wireless sensor networks (WSNs). Then, combined with the SPA trust model, the trust values of suspicious nodes were calculated, and the attack nodes were detected. The Jaya algorithm was adopted to avoid the attacked area so that nodes can find the route to communicate with the real Sink, and attack nodes are isolated in the network to improve the capabilities of network directional defense. The simulation results show that the improved detection algorithm can effectively detect malicious nodes in the network, and the defense strategy implemented in the attacked area can improve the packet delivery rate, reduce network delay and energy consumption, and improve the security and reliability of wireless sensor networks.

14.
Front Plant Sci ; 14: 1324184, 2023.
Article in English | MEDLINE | ID: mdl-38126014

ABSTRACT

Casuarina equisetifolia (C. equisetifolia) is an economically important forest tree species, often cultivated in continuous monoculture as a coastal protection forest. Continuous planting has gradually affected growth and severely restricted the sustainable development of the C. equisetifolia industry. In this study, we analyzed the effects of continuous planting on C. equisetifolia growth and explored the rhizosphere soil microecological mechanism from a metagenomic perspective. The results showed that continuous planting resulted in dwarfing, shorter root length, and reduced C. equisetifolia seedling root system. Metagenomics analysis showed that 10 key characteristic microorganisms, mainly Actinoallomurus, Actinomadura, and Mycobacterium, were responsible for continuously planted C. equisetifolia trees. Quantitative analysis showed that the number of microorganisms in these three genera decreased significantly with the increase of continuous planting. Gene function analysis showed that continuous planting led to the weakening of the environmental information processing-signal transduction ability of soil characteristic microorganisms, and the decrease of C. equisetifolia trees against stress. Reduced capacity for metabolism, genetic information processing-replication and repair resulted in reduced microbial propagation and reduced microbial quantity in the rhizosphere soil of C. equisetifolia trees. Secondly, amino acid metabolism, carbohydrate metabolism, glycan biosynthesis and metabolism, lipid metabolism, metabolism of cofactors and vitamins were all significantly reduced, resulting in a decrease in the ability of the soil to synthesize and metabolize carbon and nitrogen. These reduced capacities further led to reduced soil microbial quantity, microbial carbon and nitrogen, microbial respiration intensity, reduced soil enzyme nutrient cycling and resistance-related enzyme activities, a significant reduction in available nutrient content of rhizosphere soils, a reduction in the ion exchange capacity, and an impediment to C. equisetifolia growth. This study provides an important basis for the management of continuously planted C. equisetifolia plantations.

15.
J Org Chem ; 88(24): 17511-17520, 2023 Dec 15.
Article in English | MEDLINE | ID: mdl-38018775

ABSTRACT

Despite the widespread applications of sulfoximines, green and efficient access to functionalized sulfoximines remains a challenge. By employing an electrochemical strategy, we describe an approach for the construction of N-aroylsulfoximines, which features a broad substrate scope, mild reaction conditions, safety on a gram scale, and no need for an external oxidant and transition metal catalysts.

16.
Front Plant Sci ; 14: 1266026, 2023.
Article in English | MEDLINE | ID: mdl-38034585

ABSTRACT

Soil acidification is very likely to affect the growth of tea trees and reduce tea yield. In this study, we analyzed the effects of soils with different pH on the physiological characteristics of tea leaves and determined the multi-element content and hormone metabolomes of tea leaves by ICP-MS and LC-MS/MS, based on which we further analyzed their interaction. The results showed that increasing soil pH (3.29~5.32) was beneficial to increase the available nutrient content of the rhizosphere soil of tea tree, improve the antioxidant enzyme activity and photosynthesis capacity of tea tree leaves, and promote the growth of tea tree. Orthogonal partial least squares discriminant analysis (OPLS-DA) and bubble characteristics analysis were used to screen key elements and hormones for the effect of pH on tea leaves, which were further analyzed by redundancy analysis (RDA) and interaction network. The results showed that an increase in soil pH (3.29~5.32) favored the accumulation of seven key elements (C, K, Ca, Mg, Mn, P, S) in tea tree leaves, which in turn promoted the synthesis of six key hormones (salicylic acid, salicylic acid 2-O-ß-glucoside, tryptamine, 2-oxindole-3-acetic acid, indole-3-acetic acid, trans-zeatin-O-glucoside). It can be seen that the increase in soil pH (3.29~5.32) enhanced the resistance of the tea tree itself, improved the photosynthesis ability of the tea tree, and effectively promoted the growth of the tea tree.

17.
J Transl Med ; 21(1): 794, 2023 11 08.
Article in English | MEDLINE | ID: mdl-37940972

ABSTRACT

The occurrence and progression of tumors can be established through a complex interplay among tumor cells undergoing epithelial-mesenchymal transition (EMT), invasive factors and immune cells. In this study, we employed single-cell RNA sequencing (scRNA-seq) and spatially resolved transcriptomics (ST) to evaluate the pseudotime trajectory and spatial interactive relationship between EMT-invasive malignant tumors and immune cells in primary colorectal cancer (CRC) tissues at different stages (stage I/II and stage III with tumor deposit). Our research characterized the spatiotemporal relationship among different invasive tumor programs by constructing pseudotime endpoint-EMT-invasion tumor programs (EMTPs) located at the edge of ST, utilizing evolution trajectory analysis integrated with EMT-invasion genes. Strikingly, the invasive and expansive process of tumors undergoes remarkable spatial reprogramming of regulatory and immunosuppressive cells, such as myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs), regulatory T cells (Treg), and exhausted T cells (Tex). These EMTP-adjacent cell are linked to EMT-related invasion genes, especially the C-X-C motif ligand 1 (CXCL1) and CXCL8 genes that are important for CRC prognosis. Interestingly, the EMTPs in stage I mainly produce an inflammatory margin invasive niche, while the EMTPs in stage III tissues likely produce a hypoxic pre-invasive niche. Our data demonstrate the crucial role of regulatory and immunosuppressive cells in tumor formation and progression of CRC. This study provides a framework to delineate the spatiotemporal invasive niche in CRC samples.


Subject(s)
Colorectal Neoplasms , Epithelial-Mesenchymal Transition , Humans , Epithelial-Mesenchymal Transition/genetics , Colorectal Neoplasms/pathology , Prognosis , Biomarkers, Tumor/genetics , Cell Line, Tumor , Tumor Microenvironment
18.
Front Plant Sci ; 14: 1235687, 2023.
Article in English | MEDLINE | ID: mdl-37780509

ABSTRACT

Withering is very important to the quality of Wuyi rock tea. In this study, transcriptomics and metabolomics were used to analyze the effects of different withering methods on tea quality formation. The results showed that sunlight withering (SW) was most beneficial in increasing the gene expression of ubiquinone and other terpenoid-quinone biosynthesis (ko00130), pyruvate metabolism (ko00620), starch and sucrose metabolism (ko00500), and tryptophan metabolism (ko00380) pathways, and increasing the content of nucleotides and derivatives, terpenoids, organic acids and lipids, thus enhancing the mellowness, fresh and brisk taste and aroma of tea. Withering trough withering (WW) was most beneficial in increasing the gene expression of glutathione metabolism (ko00480), phenylpropanoid biosynthesis (ko00940) pathways, increasing the content of phenolic acids and flavonoids, thus enhancing tea bitterness. A comprehensive evaluation of the metabolite content and taste characteristics of tea leaves showed SW to be the best quality and charcoal fire withering (FW) to be the worst quality. This study provided an important basis for guiding the processing of Wuyi rock tea with different flavors.

19.
Org Lett ; 25(41): 7529-7534, 2023 Oct 20.
Article in English | MEDLINE | ID: mdl-37819202

ABSTRACT

The electrochemical synthesis of N-aroylsulfoximines features the use of tetra-n-butylammonium iodide (TBAI) as the medium and a broad substrate scope, thus affording a wide range of N-aroylated sulfoximines in moderate to good yields. The advantages of this electrochemical strategy are augmented by mild reaction conditions that are external oxidant-free, ligand-free, and easy to scale up to gram scale. Both the control experiments and the mechanistic studies revealed that the whole electrochemical process proceeded through a palladium (II/IV/II) catalytic cycle.

20.
Opt Lett ; 48(20): 5201-5204, 2023 Oct 15.
Article in English | MEDLINE | ID: mdl-37831827

ABSTRACT

We experimentally demonstrate a novel and practical timing detector based on a double-pass acousto-optic frequency shifter. With time and frequency multiplexing, for the first time to our knowledge, a balanced detection is realized using only a single photodiode, which greatly decreases the excess electronic noise during photodetection. With a total input optical power of 1.4 mW (0.35 mW per pulse train), an almost shot-noise-limited detection floor of 28.3 zs/√Hz is achieved, and the timing jitter integrated from 1 kHz to 1 MHz is reduced from 99.0 as (without eliminating the photodetector electronic noise) to only 30.4 as. Even with an input power of 50 µW per pulse train, 221.4 zs/√Hz detection floor and 268.0 as integrated timing jitter at [1 kHz and 1 MHz] are still maintained. This timing detector provides a powerful tool for high-precision metrology, ultra-long-distance ranging, and large-scale timing synchronization.

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