Determination of Pb (Lead), Cd (Cadmium), Cr (Chromium), Cu (Copper), and Ni (Nickel) in Chinese tea with high-resolution continuum source graphite furnace atomic absorption spectrometry

AbstractThe contents of lead, cadmium, chromium, copper, and nickel were determined in 25 tea samples from China, including green, yellow, white, oolong, black, Pu'er, and jasmine tea products, using high-resolution continuum source graphite furnace atomic absorption spectrometry. The methods used for sample preparation, digestion, and quantificational analysis were established, generating satisfactory analytical precisions (represented by relative standard deviations ranging from 0.6% to 2.5%) and recoveries (98.91–101.32%). The lead contents in tea leaves were 0.48–10.57 mg/kg, and 80% of these values were below the maximum values stated by the guidelines in China. The contents of cadmium and chromium ranged from 0.01 mg/kg to 0.39 mg/kg and from 0.27 mg/kg to 2.45 mg/kg, respectively, remaining in compliance with the limits stipulated by China's Ministry of Agriculture. The copper contents were 7.73–63.71 mg/kg; only 64% of these values complied with the standards stipulated by the Ministry of Agriculture. The nickel contents ranged from 2.70 mg/kg to 13.41 mg/kg. Consequently, more attention must be paid to the risks of heavy metal contamination in tea. The quantitative method established in this work lays a foundation for preventing heavy metal toxicity in human from drinking tea and will help establish regulations to control the contents of heavy metals in tea

Effect of compounds on the purification and antibody preparation of the extracellular domain fragment of the receptor CD163

<p>Abstract</p> <p>Background</p> <p>Porcine reproductive and respiratory syndrome virus (PRRSV) has been acknowledged as one of the most important agents affecting swine. The scavenger receptor CD163 is one of the important entry mediators for PRRSV.</p> <p>Results</p> <p>The tD4 and tD5 CD163 genes were amplified, and the PCR products were cloned into pET-28a(+) (designated pET-28a-tD4 and pET-28a-tD5, respectively). The plasmids pET-28a-tD4 and pET-28a-tD5 were then transformed into the <it>E. coli </it>BL21 (DE3) strain and expressed by adding 1 mmol/L of isopropyl-beta-D-thiogalactopyranoside. The proteins were highly expressed in the supernatant from the tD4- and tD5-producing cells that were incubated with a binding buffer containing the following compounds: β-mercaptoethanol, urea, Tween 20, glycerol, and SDS, while they were rarely expressed in the supernatant from the tD4- and tD5-producing cells that were incubated with binding buffer without the compounds. The tD4 and tD5 proteins were purified, and BALB/c mice were immunized with the purified proteins. Western blotting analysis showed that the tD4 and tD5 proteins were capable of reacting with tD5 antibodies; the titer of both the tD4 and tD5 antiserums was 1:160 against the tD5 protein, as shown by ELISA.</p> <p>Conclusions</p> <p>These studies provide a new way for the purification of proteins expressed in inclusion bodies and the preparation of the corresponding antibodies.</p

The Litsea genome and the evolution of the laurel family

The laurel family within the Magnoliids has attracted attentions owing to its scents, variable inflorescences, and controversial phylogenetic position. Here, we present a chromosome-level assembly of the Litsea cubeba genome, together with low-coverage genomic and transcriptomic data for many other Lauraceae. Phylogenomic analyses show phylogenetic discordance at the position of Magnoliids, suggesting incomplete lineage sorting during the divergence of monocots, eudicots, and Magnoliids. An ancient whole-genome duplication (WGD) event occurred just before the divergence of Laurales and Magnoliales; subsequently, independent WGDs occurred almost simultaneously in the three Lauralean lineages. The phylogenetic relationships within Lauraceae correspond to the divergence of inflorescences, as evidenced by the phylogeny of FUWA, a conserved gene involved in determining panicle architecture in Lauraceae. Monoterpene synthases responsible for production of specific volatile compounds in Lauraceae are functionally verified. Our work sheds light on the evolution of the Lauraceae, the genetic basis for floral evolution and specific scents

Electroacupuncture for relieving itching in atopic eczema: study protocol for a multicenter, randomized, sham-controlled trial

BackgroundAtopic eczema (AE) is a common atopic inflammatory skin disease affecting 2.1–4.9% of the population in different countries. Pruritus, one of the most burdensome symptoms, is often underestimated for the problems it can cause, creating a vicious loop of itching, scratching, and lichenification. Therefore, further research into practical and safe treatments that relieve itchy symptoms and enhance skin protection is key to overcoming AE. Acupuncture, with or without electrical stimulation, is one of the most commonly used therapeutic measures to treat AE. This trial aimed to objectively evaluate the efficacy and safety of the electroacupuncture (EA) antipruritic technique in AE pruritus and obtain high-level clinical evidence for the popularization and application of EA for AE.Methods and analysisThis multicenter, single-blinded, randomized controlled trial is planned to transpire from April 15, 2023, to June 30, 2025. We will recruit 132 participants with AE (44 per group). Participants will be assigned randomly to three equal-sized groups: EA, sham electroacupuncture, and sham acupuncture. Treatment will be administered three times a week during the 2-week intervention phase. The primary outcome measure is the Visual Analog Scale, with a numeric rating scale to evaluate pruritus. Secondary outcome measures include the Eczema Area and Severity Index and Dermatology Life Quality Index. Other outcome measures include physical examination, serum IgE, and safety evaluation. The number, nature, and severity of adverse events will be carefully recorded.Trial registrationClinicalTrials.gov, 22Y11922200. Registered 3 September 2022, https://register.clinicaltrials.gov

Wolfberry genomes and the evolution of Lycium (Solanaceae)

AbstractWolfberry Lycium, an economically important genus of the Solanaceae family, contains approximately 80 species and shows a fragmented distribution pattern among the Northern and Southern Hemispheres. Although several herbaceous species of Solanaceae have been subjected to genome sequencing, thus far, no genome sequences of woody representatives have been available. Here, we sequenced the genomes of 13 perennial woody species of Lycium, with a focus on Lycium barbarum. Integration with other genomes provides clear evidence supporting a whole-genome triplication (WGT) event shared by all hitherto sequenced solanaceous plants, which occurred shortly after the divergence of Solanaceae and Convolvulaceae. We identified new gene families and gene family expansions and contractions that first appeared in Solanaceae. Based on the identification of self-incompatibility related-gene families, we inferred that hybridization hotspots are enriched for genes that might be functioning in gametophytic self-incompatibility pathways in wolfberry. Extremely low expression of LOCULE NUBER (LC) and COLORLESS NON-RIPENING (CNR) orthologous genes during Lycium fruit development and ripening processes suggests functional diversification of these two genes between Lycium and tomato. The existence of additional flowering locus C-like MADS-box genes might correlate with the perennial flowering cycle of Lycium. Differential gene expression involved in the lignin biosynthetic pathway between Lycium and tomato likely illustrates woody and herbaceous differentiation. We also provide evidence that Lycium migrated from Africa into Asia, and subsequently from Asia into North America. Our results provide functional insights into Solanaceae origins, evolution and diversification.</jats:p