Anti-aggregation colorimetric sensing of cysteine using silver nanoparticles in the presence of Pb2.

Using silver nitrate as the silver source and sodium borohydride as the reducing agent, we synthesized negatively charged silver nanoparticles (AgNPs). Subsequently, the AgNPs solution was mixed with positively charged lead ions, resulting in AgNPs aggregation via electrostatic interactions. This led to a color change in the solution from yellow to purple and eventually to blue-green. Our study focused on a colorimetric method that exhibited high selectivity and sensitivity in detecting cysteine using AgNPs-Pb2+ as a sensing probe. Upon the introduction of cysteine to the AgNPs-Pb2+ system, the absorbance of AgNPs increased at 396 nm and decreased at 520 nm. The formation of a complex between cysteine and lead ions prevented the aggregation of silver nanoparticles, enabling the colorimetric detection of cysteine. The relationship between the concentration of ΔA396/A520 and cysteine showed linearity within the range of 0.01 to 0.1 µM; the regression equation of the calibration curve is ΔA396/A520 = 9.0005c - 0.0557 (c: µM), with an R2 value of 0.9997. The detection limit was found to be 3.8 nM (S/N = 3). This method demonstrated exceptional selectivity and sensitivity for cysteine and was effectively used for the determination of cysteine in urine. Our findings offer a new perspective for the future advancement of anti-aggregation silver nanocolorimetry.

Differential Privacy Preservation for Continuous Release of Real-Time Location Data.

Continuous real-time location data is very important in the big data era, but the privacy issues involved is also a considerable topic. It is not only necessary to protect the location privacy at each release moment, but also have to consider the impact of data correlation. Correlated Laplace Mechanism (CLM) is a sophisticated method to implement differential privacy on correlated time series. This paper aims to solve the key problems of applying CLM in continuous location release. Based on the finding that the location increment is approximately stationary in many scenarios, a location correlation estimation method based on the location increment is proposed to solve the problem of nonstationary location data correlation estimation; an adaptive adjustment model for the CLM filter based on parameter quantization idea (QCLM) as well as its effective implementation named QCLM-Lowpass utilizing the lowpass spectral characteristics of location data series is proposed to solve the problem of output deviations due to the undesired transient response of the CLM filter in time-varying environments. Extensive simulations and real data experiments validate the effectiveness of the proposed approach and show that the privacy scheme based on QCLM-Lowpass can offer a better balance between the ability to resist correlation-based attacks and data availability.

Genome-Wide Analysis of TCP Transcription Factors and Their Expression Pattern Analysis of Rose Plants (Rosa chinensis).

The plant-specific transcription factor TEOSINTE BRANCHED, CYCLOIDEA, AND PROLIFERATING CELL FACTOR (TCP) gene family plays vital roles in various biological processes, including growth and development, hormone signaling, and stress responses. However, there is a limited amount of information regarding the TCP gene family in roses (Rosa sp.). In this study, we identified 18 TCP genes in the rose genome, which were further classified into two subgroups (Group A and Group B) via phylogenetic analysis. Comprehensive characterization of these TCP genes was performed, including gene structure, motif composition, chromosomal location, and expression profiles. Synteny analysis revealed that a few TCP genes are involved in segmental duplication events, indicating that these genes played an important role in the expansion of the TCP gene family in roses. This suggests that segmental duplication events have caused the evolution of the TCP gene family and may have generated new functions. Our study provides an insight into the evolutionary and functional characteristics of the TCP gene family in roses and lays a foundation for the future exploration of the regulatory mechanisms of TCP genes in plant growth and development.

Insights into chloroplast genome structure, intraspecific variation, and phylogeny of Cyclamen species (Myrsinoideae).

Species from the flowering plant genus Cyclamen are popular amongst consumers. In particular Cyclamen persicum Mill. has been significantly used commercially, and certain small flowering species such as Cyclamen hederifolium and Cyclamen coum are gradually growing in popularity in the potted flower market. Here, the chloroplast genomes of nine Cyclamen samples including four Cyclamen species and five varieties of C. hederifolium were sequenced for genome structure comparison, White green septal striped leaves related gene screening and DNA molecular markers were developed for phylogenetic analysis. In comparing Cyclamen species' chloroplast genomes, gene content and gene order were found to be highly similar with the length of genomes ranging from 151,626 to 153,058 bp. The chloroplast genome of Cyclamen has 128 genes, including 84 protein-coding genes, 36 transfer RNA genes, and 8 ribosomal RNA genes. Based on intraspecific variation, seven hotspots, including three genes and four intergenic regions, were identified as variable markers for downstream species delimitation and interspecific relationship analyses. Moreover, a phylogenetic tree constructed with complete chloroplast genomes, revealed that Cyclamen are monophyletic with Lysimachia as the closest neighbor. Phylogenetic analyses of the 14 Cyclamen species with the seven variable regions showed five distinct clades within this genus. The highly supported topologies showed these seven regions may be used as candidate DNA barcode sequences to distinguish Cyclamen species. White green septal striped leaves is common in C. hederifolium, however the molecular mechanism of this has not yet been described. Here, we find that the intergenic region rps4-trnT-UGU seems related to white green septal striped leaves.

The complete plastome sequence of Heuchera micrantha Douglas ex Lindl. (Saxifragaceae), an ornamental plant.

The perennial herb Heuchera micrantha (Saxifragaceae) is a popular ornamental plant. However, the plastome sequence of H. micrantha has not been reported yet. Here, we assembled the complete plastome of H. micrantha using Illumina high-throughput pair-end sequencing. The plastome is a circular DNA molecule of 155,469 bp, comprising a pair of inverted repeat (IR, 25,654 bp) regions, a small single copy (SSC, 18,050 bp) region, and a large single copy (LSC, 86,111 bp) region. It encodes 129 genes, of which 84 are protein-coding genes, 37 are transfer RNAs, and eight are rRNAs. The total GC content is 37.8%. Phylogenetic analysis shows that H. micrantha, together with three other Heuchera species is clustered with Tiarella cordifolia. This complete plastome is beneficial for future genetic research on the Heuchera group.

Characterization of the complete chloroplast genome of the Helleborus atrorubens Waldst. & Kit. (Ranunculaceae).

Helleborus atrorubens is an economically important perennial garden plant with medicinal value. Here, we sequenced the complete chloroplast genome of H. atrorubens. The results revealed the chloroplast genome to be 166,695 bp in length. It possesses a typical quadripartite structure containing one large single copy (LSC) region (84994 bp), one small single copy (SSC) region (17,825 bp), and a pair of inverted repeat (IR) regions (31938 bp). This chloroplast genome encoded 130 genes, out of which 85 code for proteins, 37 for transfer RNAs, and 8 for ribosomal RNAs. Simple sequence repeat (SSR) markers and the top variable coding regions were identified. Our study lays a foundation for further research, such as species differentiation and phylogenetic reconstruction of the Helleborus genus.

The Chromosome-Scale Assembly of the Curcuma alismatifolia Genome Provides Insight Into Anthocyanin and Terpenoid Biosynthesis.

Curcuma alismatifolia, a bulbous flower known for its showy bracts, is widely used around the world as a cut flower, potted, and garden plant. Besides its ornamental value, this species is rich in terpenoid metabolites and could serve as a resource for essential oils. Here, we report a chromosome-level genome assembly of C. alismatifolia and describe its biosynthetic pathways for anthocyanins and terpenoids. This high-quality, assembled genome size is 991.3 Mb with a scaffold N50 value of 56.7 Mb. Evolutionary analysis of the genome suggests that C. alismatifolia diverged from Zingiber officinale about 9.7 million years ago, after it underwent a whole-genome duplication. Transcriptome analysis was performed on bracts at five developmental stages. Nine highly expressed genes were identified, encoding for six enzymes downstream of the anthocyanin biosynthetic pathway. Of these, one gene encoding F3'5'H might be a key node in the regulation of bract color formation. Co-expression network analysis showed that MYB, bHLH, NAC, and ERF transcription factors collectively regulated color formation in the bracts. Characterization of terpenoid biosynthesis genes revealed their dispersal and tandem duplications, both of which contributed greatly to the increase in the number of terpene synthase genes in C. alismatifolia, especially to species-specific expansion of sesquiterpene synthase genes. This work facilitates understanding of genetic basis of anthocyanin and terpenoid biosynthesis and could accelerate the selective breeding of C. alismatifolia varieties with higher ornamental and medicinal value.

Detection of Ag+ ions via an anti-aggregation mechanism using unmodified gold nanoparticles in the presence of thiamazole.

The present study proposed a novel and highly selective and sensitive method for Ag+ ion detection based on gold nanoparticles (AuNPs) anti-aggregation. Thiamazole can induce AuNPs aggregation due to electrostatic interactions, which result in color transitions in the AuNPs solution from red to blue. However, the presence of Ag+ ions results in the preferential combination of the pyridinic nitrogen of thiamazole with the Ag+ ions. In addition, the Ag+ ions oxidize the sulfhydryl groups(-SH), which inhibit AuNPs aggregation and prompt a color change from blue to red. As a result, the present study established a method for Ag+ ion determination by AuNPs-thiamazole colorimetric probe based on the aforementioned anti-aggregation mechanism. The probe dynamic range was easily tuned via adjustments of the thiamazole amount. The relationship between the Ag+ concentration and AuNPs aggregation was monitored by ultraviolet-visible light (UV-Vis) spectroscopy at a dynamic range of 0.1 nM-9 µM and at a detection limit of 0.042 nM. The river water and tap water recovery analysis validated the successful operation of this colorimetric sensor in environmental monitoring.

The chloroplast genome of the moss Haplocladium microphyllum, first in family Thuidiaceae.

Bryophytes are a highly diverse group containing more than 12,800 species. Haplocladium microphyllum is in a large moss belonging to the family Thuidiaceae. We report the complete chloroplast (124,478 bp) genome sequence of H. microphyllum, it includes a pair of inverted repeat regions (IRs, 9727 bp), one large single-copy (LSC, 86,528 bp) region, and one small single-copy (SSC, 18,496 bp) region. Besides, the complete chloroplast genome contains 134 genes in total, including 88 protein-coding genes, 38 tRNA genes, and eight rRNA genes. Phylogenetic analysis showed that H. microphyllum has the closest relationship with Sanionia uncinata in Amblystegiaceae. Our study lays a foundation for further research like speciation of this species and the phylogeny of the Thuidiaceae family.

The complete chloroplast genome of Plantago fengdouensis (Plantaginaceae): an endemic and Endangered species from China.

This study was the first report about the complete chloroplast genome of Plantago fengdouensis (Plantaginaceae). The circular whole cp genome of P. fengdouensis was in a total length 164,976 bp with the typical quadripartite structure of angiosperms, containing two inverted repeats (IRs) of 38,644 bp separated by a large single-copy (LSC) region and a small single-copy (SSC) region of 82,972 and 4716 bp, respectively. The plastid genome of P. fengdouensis contains 113 genes, including 79 protein-coding genes, 4 ribosomal RNA genes, and 30 transfer RNA genes. The overall GC content of P. fengdouensis plastid genome is 38.0% and the corresponding values in LSC, SSC, and IR regions are 36.6, 30.2, and39.9%, respectively.

Comparative proteomic analysis of Methanothermobacter thermautotrophicus reveals methane formation from H2 and CO2 under different temperature conditions.

The growth of all methanogens is limited to a specific temperature range. However, Methanothermobacter thermautotrophicus can be found in a variety of natural and artificial environments, the temperatures of which sometimes even exceed the temperature growth ranges of thermophiles. As a result, the extent to which methane production and survival are affected by temperature remains unclear. To investigate the mechanisms of methanogenesis that Archaea have evolved to cope with drastic temperature shifts, the responses of Methanothermobacter thermautotrophicus to temperature were investigated under a high temperature growth (71°C) and cold shock (4°C) using Isobaric tags for relative and absolute quantitation (iTRAQ). The results showed that methane formation is decreased and that protein folding and degradation are increased in both high- and low-temperature treatments. In addition, proteins predicted to be involved in processing environmental information processing and in cell membrane/wall/envelope biogenesis may play key roles in affecting methane formation and enhancing the response of M. thermautotrophicus to temperature stress. Analysis of the genomic locations of the genes corresponding to these temperature-dependent proteins predicted that 77 of the genes likely to form 32 gene clusters. Here, we assess the response of M. thermautotrophicus to different temperatures and provide a new level of understanding of methane formation and cellular putative adaptive responses.

Time-dose-mortality data and modeling for the entomopathogenic fungus Aschersonia placenta against the whitefly Bemisia tabaci.

The fungus Aschersonia placenta FJSM was evaluated for control of the sweet potato whitefly, Bemisia tabaci. Bemisia tabaci nymphs (1st-4th instars) on tomato plants in the greenhouse (25-27 °C, 70%-85% relative humidity) were sprayed with suspensions containing 0, 10(4), 10(5), 10(6), 10(7), or 10(8) A. placenta FJSM conidia/mL. Mortality of fungus-treated 1st to 3rd instar nymphs ranged from 93% to 100% but was <25% for 4th instar nymphs; the fungus sporulated from 70% to 80% of the fungus-treated B. tabaci cadavers. LD50 and LD90 values decreased with time after treatment and increased with instar. LT50 values decreased with conidial concentration. The data were then described with time-dose-mortality models. The results indicate that A. placenta FJSM has potential as a mycoinsecticide for control of B. tabaci.