44 research outputs found

    Evaluation of Suitability for Green Tea Processing of Different Tea Cultivars Based on Multivariate Statistical Analysis

    Get PDF
    Principal component analysis (PCA) and multiple linear regression analysis (MLRA) were used to analyze and investigate the suitability of green tea for tea tree varieties in different tea cultivars. The fresh leaves of 63 tea cultivars planted in the same garden were processed into roasted green tea by the same method. The sensory and major physicochemical qualities (tea polyphenols, free amino acids, water extracts and chlorophyll) and the color (L*, a* and b*) of green tea were analyzed. To evaluate the suitability of the tested cultivars for green tea processing and its major influential factors, the data obtained were analyzed by PCA and MLRA. The results showed that the coefficient of variation (CV) of chlorophyll content in different cultivars was the highest (26.7%), followed by tea a* value (22.2%), sensory score for tea infusion color (17.1%) and sensory score for tea color (16.2%). A significant correlation was found between the polyphenol content of green tea and its color, tea infusion color and the color of infused tea leaves; between the chlorophyll content, |a*| and b* values of green tea and its color; between the chlorophyll content and |a*| value of green tea and the color of infused tea leaves; and between the |a*| and b* values of green tea and tea infusion color (P < 0.01). The PCA results showed that the contribution rate of the first five principal components (PCs) was 76.895%, and that of the first principal component was 31.918%, mainly pointing to the color quality. According to the evaluation model constructed based on the first five PCs, the top 10 cultivars were Zhongcha 108, Wuniuzao, Pingyangtezao, Mengshan 9, Soubeizhong, Fudingdabai, Jiukeng 16, Fudingdahao, Maolv, and Longjing 43. Using MLRA, the regression function between overall sensory score (Y) and |a*| value (x) was obtained as Y = 68.668 + 5.174x (R2 = 0.313) (P < 0.001). The top 10 varieties determined from this equation were highly consistent with the results of PCA, indicating that a* value is an important indicator for the evaluation of the suitability of tea cultivars for green tea processing

    A repeating fast radio burst associated with a persistent radio source

    Get PDF
    The dispersive sweep of fast radio bursts (FRBs) has been used to probe the ionized baryon content of the intergalactic medium1, which is assumed to dominate the total extragalactic dispersion. Although the host-galaxy contributions to the dispersion measure appear to be small for most FRBs2, in at least one case there is evidence for an extreme magneto-ionic local environment3,4 and a compact persistent radio source5. Here we report the detection and localization of the repeating FRB 20190520B, which is co-located with a compact, persistent radio source and associated with a dwarf host galaxy of high specific-star-formation rate at a redshift of 0.241 ± 0.001. The estimated host-galaxy dispersion measure of approximately 903−111+72 parsecs per cubic centimetre, which is nearly an order of magnitude higher than the average of FRB host galaxies2,6, far exceeds the dispersion-measure contribution of the intergalactic medium. Caution is thus warranted in inferring redshifts for FRBs without accurate host-galaxy identifications

    Human immunodeficiency virus type-1 infection inhibits autophagy

    Full text link
    Job file for the creation/design of stained glass from either the Charles J. Connick Studio (1912-1945) or the Charles J. Connick Associates studio (1945-1986). The job file contains a job number, location information, date of completion, size, contact information, price, and a description of the project. This particular job file contains information on a job located at: Framingham, Massachusetts. Grace Congregational Church

    Control Protocol and Self-adaptive Mechanism for Live Virtual Machine Migration over XIA

    No full text
    Part 3: Virtualization and Cloud Computing TechnologiesInternational audienceFIA (Future Internet Architecture) is supported by US NSF for future Internet designing. XIA is one of the projects which comply with clean slate concept thoroughly. Meanwhile, virtual machine migration technique is crucial in cloud computing. As a network application, VM migration should also be supported in XIA. This paper is an experimental study aims at verifying the feasibility of VM migration over XIA. We primarily present intra-AD (Administrative Domain) and inter-AD VM migration with KVM instances. The procedure is achieved by a migration control protocol which is suitable for the characters of XIA architecture. Moreover, an elementary self-adaptive mechanism is introduced to maintain VM connectivity and connection states. It is also beneficial for VM migration in TCP/IP network. Evaluation results show that our solution well supports live VM migration in XIA and all the communications leading to VM can be kept uninterrupted after migration

    The association between bullous pemphigoid and cognitive outcomes in middle-aged and older adults: A systematic review and meta-analysis.

    No full text
    BackgroundBullous pemphigoid (BP) is a rare autoimmune skin condition that causes large fluid-filled blisters on the skin, especially in older adults. BP has been linked to various diseases and medications, but its association with cognitive outcomes is unclear.MethodsWe conducted a systematic review and meta-analysis of studies investigating the association between BP and cognitive outcomes, such as all-cause dementia, Alzheimer's disease, and vascular dementia in middle-aged and older adults. We searched PubMed, Embase, and Web of Science databases for relevant studies published up to March 2023. We included studies that reported odds ratios (ORs) or hazard ratios (HRs) with 95% confidence intervals (CIs) for the association between BP and cognitive outcomes. We pooled the ORs, or HRs using random-effects models and performed subgroup and sensitivity analyses to explore potential sources of heterogeneity.ResultsThe study selection process identified 13 studies for inclusion in the analysis, 11 studied arms of which used a case-control design and 7 studied arms of which used a cohort design. The studies were conducted primarily in Europe, with a few from Asia and the United States. The meta-analysis found that BP was associated with higher odds of all-cause dementia in middle-aged and older participants in both cohort studies(HR = 1.41,95% CI: 1.20-1.66, P = 0.000) and case-control (OR = 4.25, 95% CI, 2.73-6.61; P = 0.000). The study found no significant publication bias in the included studies. The meta-regression analyses identified some subgroups associated with significantly reported odds ratios in case-control association analysis, including Europe, BP diagnosed based on clinical, histology, immunofluorescence, and both adjustment status of NO and YES.ConclusionsOur meta-analysis suggests that BP is associated with an increased risk of all-cause dementia in middle-aged and older adults. Further studies are needed to elucidate the underlying mechanisms and causal relationship between BP and cognitive outcomes

    Microstructure and Tensile Properties of the Mg-6Zn-4Al-<i>x</i>Sn Die Cast Magnesium Alloy

    No full text
    The effect of various Sn contents (1&#8315;2 wt. %) on the microstructure, age hardening response, and tensile and casting properties of the high-pressure die cast Mg-6Zn-4Al alloy were studied. All as-cast alloys consisted of &#945;-Mg and icosahedral quasi-crystalline phase; and the addition of 2% Sn caused the formation of Mg2Sn phases. Dendrite structure and eutectic phases were observably refined by Sn addition. The hot tearing susceptibility of the die cast Mg-6Zn-4Al alloy prominently decreased with increasing Sn addition. During T6 heat treatment, Sn addition did not obviously affect the time to reach peak hardness, but significantly enhanced the age hardening response and improved the strength of alloys under peak-aged conditions. Compared to single aging, double aging resulted in the higher density of finer &#946;1&#8242; and &#946;2&#8242; precipitates. The double aged Mg-6Zn-4Al-1Sn alloy offered the optimum tensile properties among all conditions. The yield strength, ultimate tensile strength, and elongation were 209 MPa, 305 MPa, and 4.3%, respectively

    The pharmacological mechanism of β-elemene in the treatment of esophageal cancer revealed by network pharmacology and experimental verification

    No full text
    Abstract The study aimed to investigate the mechanism of action of β-elemene (ELE) in the treatment of esophageal cancer (EC). In this study, public databases were used to predict related targets in ELE and EC. The network analysis was performed to identify key targets of ELE in EC treatment. Further, bioinformatics and DAVID databases were used for GO and KEGG enrichment analysis, respectively. Ultimately, molecular docking and in vitro cell experiments were conducted to validate the results of network pharmacology enrichment. As a result, 34 candidate targets for ELE in the treatment of EC were obtained, and five key targets (STAT3, EGFR, CTNNB1, BCL2L1 and CASP9) were identified. GO functional annotation yielded 2200 GO entries (p < 0.05). KEGG signaling pathway enrichment analysis screened 100 pathways (p < 0.05). Molecular docking results showed that ELE had similar affinity with five key targets. In vitro experiments showed that the expressions of STAT3, EGFR and BCL2L1 were significantly decreased, and the expression of CASP9 in the ELE intervention group was significantly increased compared with that in the control group. All in all, ELE may play a key role in the treatment of EC by regulating the expression of STAT3, EGFR, BCL2L1 and CASP9

    Sustainable ammonia production by non-thermal plasmas: Status, mechanisms, and opportunities

    No full text
    Ammonia is one of our most important industrial chemicals supporting the global food supply as the major crop fertilizer. Moreover, it is increasingly being promoted as a promising carbon-free fuel source, and an energy storage and transportation medium. However, the current approach for ammonia synthesis, known as the Haber-Bosch process, requires large-scale infrastructure preventing the designs of decentralization. The process consumes a large fossil fuel input leading it to be a major source of CO2 emissions. Plasma-enabled ammonia synthesis provides a clean, sustainable and flexible alternative, where the process is driven by the use of plasmas that activate the source gas(es). However, atmospheric plasmas are complex due to their highly reactive environment (energetic electrons, reactive oxygen and nitrogen species, UV photons, electric field effects, and others), resulting in a challenging scientific issue for both plasma researchers and chemical engineers. The review summarizes the current state-of-the-art of plasma-enabled ammonia synthesis, and provides insights into the fundamental physio-chemistry of plasma activation, including the excitation, dissociation and ionization of feedstocks, as well as the underlying mechanisms for the reaction dynamics of reactive species in the highly-reactive plasma environment. Finally, the opportunities and challenges for this plasma-enabled technology are outlined to approach a sustainable and flexible ammonia industry.</p

    Plasma-enabled liquid ethanol conversion for hydrogen production: Discharge characteristics and process control

    No full text
    Recent years have witnessed successful applications of non-thermal plasmas (NTPs) as efficient and flexible tools for direct conversion of liquid alcohols into higher-value energy carriers at mild or even near-room-temperature conditions. Better understanding of the fundamental physical properties of the liquid alcohol discharges is needed for development and optimization of NTP-based applications. Here we investigate the discharge characteristics of a plasma-based liquid ethanol conversion under different process parameters and reveal the general trends of the discharge behavior. Two discharge modes, namely the self-pulsed and direct current (DC) modes, are sustained during the in-liquid discharge. These two modes can be easily interchanged and flexibly controlled by adjusting the processing parameters. The behavior of the bubbles generated during the discharge plays an important role in the transition between the discharge modes. When the discharge is sustained with the diffusion and floating of the bubbles, the DC mode is observed. Otherwise, the discharge develops into the pulse mode. The production rates and composition of the gaseous products are also shown to depend on the discharge modes.</p

    Controlling Energy Transfer in Plasma-Driven Ammonia Synthesis by Adding Helium Gas

    No full text
    Plasma-driven ammonia (NH3) synthesis is regarded as a green complementary to the conventional Haber-Bosch process, especially for decentralized and on-demand production. However, a major challenge remains in reducing its energy cost because a huge amount of energy is consumed but not specifically for exciting, ionizing, and dissociating the feedstock. Therefore, controlling the energy transfer to predominantly generate more reactive species instead of gas heating is crucial to enhancing energy yields in the plasma synthesis of ammonia. Helium (He) is commonly used in atmospheric-pressure gas discharges to assist the generation of stable nonthermal plasmas with reduced breakdown voltages and gas temperatures while enhancing thermal conductivity and diffusion rate. In this work, a simple process based on adding He, which can be recycled and returned to the reactor along with unreacted N2 and H2, has been developed for enhancing NH3 synthesis. Optical emission spectra (OES) show an increased electron density with a significantly enhanced N2+ emission centered at 391.5 nm. With the addition of He, the energy transfer in the plasma is modified, with electron impact leading to the formation of metastable He and He2+ species, which collide with N2 molecules to generate N2+ through Penning ionization and charge transfer, contributing to more efficient N2 activation and NH3 production.</p
    corecore