No abstract is provided for this article.
To investigate the residual status of antibiotics in fresh and raw milk from Zhenjiang market and provide basis for strengthening control of the quality of milk products,TTC(2,3,5-triphenyltetrazolium chloride)(GB4789.27-2003) was applied to determine the antibiotic residues in fresh and raw milk.The decision criteria is that the industry standard of antibiotics should not be detected from the qualified milk issued by the Ministry of Agriculture in September 2001.The positive rate of antibiotic residues in raw milk was 5.86% in keeping free-roaming farmers;the positive rate of antibiotic residues in fresh milk was 4.67% in market.In the baged and cased of fresh milk samples,the detecting rates were 4.41% and 4.79%,respectively.The results of the investigation indicated that the residual antibliotics in fresh and raw milk still existed in Zhenjiang.It was suggested that the work for monitoring the quality of milk products should be strengthened in addition to that effective measures are taken for reducing the quantity of residual antibiotics in the fresh and raw milk as well as to reduce the harm of antibiotic residues to the people.
As the carpooling has become prevailing in China, private cars and net about cars occupy the most of carpooling market. However, the current operation of taxipooling is the owner-led mode and unreasonable. To prosper the market of taxi, enhance utilization of taxi resource, and relieve the urban traffic congestion, this paper analyzes the demand of taxipooling. The demand is estimated in terms of three aspects: customer, taxi drivers, and traffic environment and resource, by using data of the current operation situation of different cities in China. Furthermore, based on the system of prevalent net about cars and the operation characters of taxi, this paper studies the regulation, organization, and fare distribution model of taxipooling.
Arbutin, a glycoside, is derived from the leaves of several plants, including wheat, pear, and bearberry plants, and has a significant role in the treatment of melanoma, cystitis, and cough. Here, we aimed to modify Yarrowia lipolytica to produce arbutin. To construct the arbutin synthetic pathway in Y. lipolytica, three genes (chorismate pyruvate-lyase (UbiC), 4-hydroxybenzoate 1-hydroxylase (MNX1), and hydroquinone glucosyltransferase (AS)) were codon-optimized and heterologously expressed. To maximize arbutin production, seven arbutin-biosynthesis molecular targets were overexpressed, and we found that the individual strengthening of DHS1 and DHS2 led to an 8.9- and 7.8-fold improvement in arbutin yield, respectively. Through optimization, a maximum arbutin titer of 8.6 ± 0.7 g/L was achieved using the finally engineered strain, po1f-At09. Overall, this is the first report of heterologous arbutin synthesis in Y. lipolytica at a high titer. Furthermore, this work opens a possibility for the overproduction of shikimate pathway derivatives in Y. lipolytica.
There are circumstances where tumors can only be partially resected. Therefore, multimodality therapy targeting post-operative residuals is important. Here, we show that bioorthogonal click chemistry enables targeted delivery to heterogeneous tumors, but its utility against tumor post-debulking is ineffective due to platelet cloaks that shield tumor cells from bioorthogonal pairing. We further discover tumor-infiltrating platelet levels respond to local pH changes. Elucidating this pH-platelet linkage, we design an injectable hydrogel for resection cavity implantation that simultaneously azido-tags tumor cells and inhibit their catalysis to acidify surrounding milieu. Unlike transient buffering, tumor acidification blockade sustains pH normalization, leading to durable platelet reduction. This reinstates bioorthogonal targeting of dibenzyl cyclooctyne-modified nanoparticles, thereby enhancing photodynamic ablation of residuals while amplifying systemic antitumor immunity. Concurrently, platelet/pH normalization interrupts metastasis cascade from invasion to circulation to colonization. Overall, attenuating tumor pH-platelet linkage unlocks bioorthogonal chemistry as a potential option for adjuvant therapy after tumor debulking.
Species of Craterellus (Hydnaceae, Cantharellales) in China are investigated on the basis of morphological and molecular phylogenetic analyses of DNA sequences from nuc 28S rDNA D1-D2 domains (28S) and nuc rDNA internal transcribed spacer ITS1-5.8S-ITS2 region. Five species are recognized in China, of which three of them are described as new, viz. C. fulviceps , C. minor , and C. parvopullus , while two of them are previously described taxa, viz. C. aureus , and C. lutescens . A key to the known Chinese taxa of the genus is also provided.
Methyl 3-(4-hydroxyphenyl)propionate (MHPP) is a root exudate that functions as a nitrification inhibitor and as a modulator of the root system architecture (RSA) by inhibiting primary root (PR) elongation and promoting lateral root formation. However, the mechanism underlying MHPP-mediated modulation of the RSA remains unclear. Here, we report that MHPP inhibits PR elongation in Arabidopsis (Arabidopsis thaliana) by elevating the levels of auxin expression and signaling. MHPP induces an increase in auxin levels by up-regulating auxin biosynthesis, altering the expression of auxin carriers, and promoting the degradation of the auxin/indole-3-acetic acid family of transcriptional repressors. We found that MHPP-induced nitric oxide (NO) production promoted reactive oxygen species (ROS) accumulation in root tips. Suppressing the accumulation of NO or ROS alleviated the inhibitory effect of MHPP on PR elongation by weakening auxin responses and perception and by affecting meristematic cell division potential. Genetic analysis supported the phenotype described above. Taken together, our results indicate that MHPP modulates RSA remodeling via the NO/ROS-mediated auxin response pathway in Arabidopsis. Our study also revealed that MHPP significantly induced the accumulation of glucosinolates in roots, suggesting the diverse functions of MHPP in modulating plant growth, development, and stress tolerance in plants.
No abstract is provided for this article.
Aqueous ozone (O3(aq)) solutions were applied to the rockwool substrate of hydroponically cultured tomato and cucumber plants. Single applications of high concentration solutions (0, 5, 10, 15, 20 mg/L), as well as repeated application of lower concentration solutions (0, 2, 4, 6 mg/L), had no impact on leaf area and shoot dry weight accumulation. Repeated O3(aq) applications were also applied to cucumber plants inoculated with Pythium aphanidermatum. Pathogen levels were significantly reduced in all treatments containing O3(aq). The reduction in pathogen numbers did not necessarily affect plant productivity. Key words: Pythium aphanidermatum, irrigation water reuse, oxygenation, tomato, cucumber, rockwool, hydroponics, phytotoxicity.
Main conclusion This study reveals that TRM21 acts as a positive regulator of flavonoid biosynthesis at the translational level in Arabidopsis , impacting both secondary metabolites and genes associated with root hair growth. Abstract TRM (TONNEAU1-recruiting motif) superfamily proteins are reported to be involved in microtubule assembly. However, the functions of this protein family are just beginning to be uncovered. Here, we provide metabolomic and genetic evidence that 1 of the 34 TRM members, TRM21 , positively regulates the biosynthesis of flavonoids at the translational level in Arabidopsis thaliana . A loss-of-function mutation in TRM21 led to root hair growth defects and stunted plant growth, accompanied by significant alterations in secondary metabolites, particularly a marked reduction in flavonoid content. Interestingly, our study revealed that the transcription levels of genes involved in the flavonoid biosynthesis pathway remained unchanged in the trm21 mutants, but there was a significant downregulation in the translation levels of certain genes [ flavanone 3-hydroxylase ( F3H ), dihydroflavonol-4-reductase ( DFR ), anthocyanidin reductase ( ANR ), flavanone 3’-hydroxylase ( F3'H ), flavonol synthase ( FLS ), chalcone synthase ( CHS )]. Additionally, the translation levels of some genes related to root hair growth [ RHO-related GTPases of plant 2 ( ROP2 ), root hair defective 6 ( RHD6 ), root hair defective 2 ( RHD2 )] were also reduced in the trm21 mutants. Taken together, these results indicate that TRM21 functions as a positive regulator of flavonoid biosynthesis at the translational level in Arabidopsis .
Flammulina velutipes, a popular edible mushroom, contains sesquiterpenes with potential health benefits. We characterized 12 sesquiterpene synthases and one P450 enzyme in F. velutipes using Aspergillus oryzae as a heterologous expression system, culminating in the biosynthesis of 16 distinct sesquiterpene compounds. An enzyme encoded by the axeB gene responsible for the synthesis of the spiro [4.5] decane compound axenol was discovered, and the mechanism of spirocycle formation was elucidated through quantum mechanical calculations. Furthermore, we delineated the role of a P450 enzyme colocated with AxeB in producing the novel compound 3-oxo-axenol. Our findings highlight the diverse array of sesquiterpene skeletons and functional groups biosynthesized by these enzymes in F. velutipes and underscore the effectiveness of the A. oryzae system as a heterologous host for expressing genes in the Basidiomycota genome. These insights into the biosynthesis of bioactive compounds in F. velutipes have significant implications for functional food and drug development.
