Immunomodulatory effects of hydatid antigens on mesenchymal stem cells: gene expression alterations and functional consequences.

Background: Cystic echinococcosis, caused by the larval stage of Echinococcus granulosus, remains a global health challenge. Mesenchymal stem cells (MSCs) are renowned for their regenerative and immunomodulatory properties. Given the parasite's mode of establishment, we postulate that MSCs likely play a pivotal role in the interaction between the parasite and the host. This study aims to explore the response of MSCs to antigens derived from Echinococcus granulosus, the etiological agent of hydatid disease, with the hypothesis that exposure to these antigens may alter MSC function and impact the host's immune response to the parasite. Methods: MSCs were isolated from mouse bone marrow and co-cultured with ESPs, HCF, or pLL antigens. We conducted high-throughput sequencing to examine changes in the MSCs' mRNA expression profile. Additionally, cell cycle, migration, and secretory functions were assessed using various assays, including CCK8, flow cytometry, real-time PCR, Western blot, and ELISA. Results: Our analysis revealed that hydatid antigens significantly modulate the mRNA expression of genes related to cytokine and chemokine activity, impacting MSC proliferation, migration, and cytokine secretion. Specifically, there was a downregulation of chemokines (MCP-1, CXCL1) and pro-inflammatory cytokines (IL-6, NOS2/NO), alongside an upregulation of anti-inflammatory mediators (COX2/PGE2). Furthermore, all antigens reduced MSC migration, and significant alterations in cellular metabolism-related pathways were observed. Conclusion: Hydatid disease antigens induce a distinct immunomodulatory response in MSCs, characterized by a shift towards an anti-inflammatory phenotype and reduced cell migration. These changes may contribute to the parasite's ability to evade host defenses and persist within the host, highlighting the complex interplay between MSCs and hydatid disease antigens. This study provides valuable insights into the pathophysiology of hydatid disease and may inform the development of novel therapeutic strategies.

A provably lightweight and secure DSSE scheme, with a constant storage cost for a smart device client.

Outsourcing data to remote cloud providers is becoming increasingly popular amongst organizations and individuals. A semi-trusted server uses Searchable Symmetric Encryption (SSE) to keep the search information under acceptable leakage levels whilst searching an encrypted database. A dynamic SSE (DSSE) scheme enables the adding and removing of documents by performing update queries, where some information is leaked to the server each time a record is added or removed. The complexity of structures and cryptographic primitives in most existing DSSE schemes makes them inefficient, in terms of storage, and query requests generate overhead costs on the Smart Device Client (SDC) side. Achieving constant storage cost for SDCs enhances the viability, efficiency, and easy user experience of smart devices, promoting their widespread adoption in various applications while upholding robust privacy and security standards. DSSE schemes must address two important privacy requirements: forward and backward privacy. Due to the increasing number of keywords, the cost of storage on the client side is also increasing at a linear rate. This article introduces an innovative, secure, and lightweight Dynamic Searchable Symmetric Encryption (DSSE) scheme, ensuring Type-II backward and forward privacy without incurring ongoing storage costs and high-cost query generation for the SDC. The proposed scheme, based on an inverted index structure, merges the hash table with linked nodes, linking encrypted keywords in all hash tables. Achieving a one-time O(1) storage cost without keyword counters on the SDC side, the scheme enhances security by generating a fresh key for each update. Experimental results show low-cost query generation on the SDC side (6,460 nanoseconds), making it compatible with resource-limited devices. The scheme outperforms existing ones, reducing server-side search costs significantly.

Exploration of altered miRNA expression and function in MSC-derived extracellular vesicles in response to hydatid antigen stimulation.

Background: Hydatid disease is caused by Echinococcus parasites and can affect various tissues and organs in the body. The disease is characterized by the presence of hydatid cysts, which contain specific antigens that interact with the host's immune system. Mesenchymal stem cells (MSCs) are pluripotent stem cells that can regulate immunity through the secretion of extracellular vesicles (EVs) containing microRNAs (miRNAs). Methods: In this study, hydatid antigens were isolated from sheep livers and mice peritoneal cavities. MSCs derived from mouse bone marrow were treated with different hydatid antigens, and EVs were isolated and characterized from the conditioned medium of MSCs. Small RNA library construction, miRNA target prediction, and differential expression analysis were conducted to identify differentially expressed miRNAs. Functional enrichment and network construction were performed to explore the biological functions of the target genes. Real-time PCR and Western blotting were used for miRNA and gene expression verification, while ELISA assays quantified TNF, IL-1, IL-6, IL-4, and IL-10 levels in cell supernatants. Results: The study successfully isolated hydatid antigens and characterized MSC-derived EVs, demonstrating the impact of antigen concentration on MSC viability. Key differentially expressed miRNAs, such as miR-146a and miR-9-5p, were identified, with functional analyses revealing significant pathways like Endocytosis and MAPK signaling associated with these miRNAs' target genes. The miRNA-HUB gene regulatory network identified crucial miRNAs and HUB genes, such as Traf1 and Tnf, indicating roles in immune modulation and osteogenic differentiation. Protein-protein interaction (PPI) network analysis highlighted central HUB genes like Akt1 and Bcl2. ALP activity assays confirmed the influence of antigens on osteogenic differentiation, with reduced ALP activity observed. Expression analysis validated altered miRNA and chemokine expression post-antigen stimulation, with ELISA analysis showing a significant reduction in CXCL1 expression in response to antigen exposure. Conclusion: This study provides insights into the role of MSC-derived EVs in regulating parasite immunity. The findings suggest that hydatid antigens can modulate the expression of miRNAs in MSC-derived EVs, leading to changes in chemokine expression and osteogenic capacity. These findings contribute to a better understanding of the immunomodulatory mechanisms involved in hydatid disease and provide potential therapeutic targets for the development of new treatment strategies.

The transcription factor MYB1 activates DGAT2 transcription to promote triacylglycerol accumulation in sacha inchi (Plukenetia volubilis L.) leaves under heat stress.

Triacylglycerol (TAG) accumulation is frequently triggered in vegetative tissues experiencing heat stress, which may increases plant basal plant thermo-tolerance by sequestering the toxic lipid intermediates that contribute to membrane damage or cell death under stress conditions. However, stress-responsive TAG biosynthesis and the underlying regulatory mechanisms are not fully understood. Here, we investigated the lipidomic and transcriptomic landscape under heat stress in the leaves of sacha inchi (Plukenetia volubilis L.), an important oilseed crop in tropical regions. Under heat stress (45 °C), the content of polyunsaturated TAGs (e.g., TAG18:2 and TAG18:3) and total TAGs were significantly higher, while those of unsaturated sterol esters, including ZyE 28:4, SiE 18:2 and SiE 18:3, were dramatically lower. Transcriptome analysis showed that the expression of PvDGAT2-2, encoding a type II diacylglycerol acyltransferase (DGAT) that is critical for TAG biosynthesis, was substantially induced under heat stress. We confirmed the function of PvDGAT2-2 in TAG production by complementing a yeast mutant defective in TAG biosynthesis. Importantly, we also identified the heat-induced transcription factor PvMYB1 as an upstream activator of PvDGAT2-2 transcription. Our findings on the molecular mechanism leading to TAG biosynthesis in leaves exposed to heat stress have implications for improving the biotechnological production of TAGs in vegetative tissues, offering an alternative to seeds.

Ofloxacin weakened treatment performance of rural domestic sewage in an aerobic biofilm system by affecting biofilm resistance, bacterial community, and functional genes.

Ofloxacin (OFL) is a typical fluoroquinolone antibiotic widely detected in rural domestic sewage, however, its effects on the performance of aerobic biofilm systems during sewage treatment process remain poorly understood. We carried out an aerobic biofilm experiment to explore how the OFL with different concentrations affects the pollutant removal efficiency of rural domestic sewage. Results demonstrated that the OFL negatively affected pollutant removal in aerobic biofilm systems. High OFL levels resulted in a decrease in removal efficiency: 9.33% for chemical oxygen demand (COD), 18.57% for ammonium (NH4+-N), and 8.49% for total phosphorus (TP) after 35 days. The findings related to the chemical and biological properties of the biofilm revealed that the OFL exposure triggered oxidative stress and SOS responses, decreased the live cell number and extracellular polymeric substance content of biofilm, and altered bacterial community composition. More specifically, the relative abundance of key genera linked to COD (e.g., Rhodobacter), NH4+-N (e.g., Nitrosomonas), and TP (e.g., Dechlorimonas) removal was decreased. Such the OFL-induced decrease of these genera might result in the down-regulation of carbon degradation (amyA), ammonia oxidation (hao), and phosphorus adsorption (ppx) functional genes. The conventional pollutants (COD, NH4+-N, and TP) removal was directly affected by biofilm resistance, functional genes, and bacterial community under OFL exposure, and the bacterial community played a more dominant role based on partial least-squares path model analysis. These findings will provide valuable insights into understanding how antibiotics impact the performance of aerobic biofilm systems during rural domestic sewage treatment.

Hiding scrambled text messages in speech signals using a lightweight hyperchaotic map and conditional LSB mechanism.

This study presents a lightweight, secure audio steganography system for hiding text messages for transmission over the Internet, with the aim of addressing the current problems of high computational cost and insufficient security identified in earlier studies. We propose a two-phase functioning mechanism. Text characters are first transformed into ASCII code and stored in a vector, which is then divided into three sub-vectors. These sub-vectors are scrambled using two low-complexity operations, namely a forward-backward reading technique and an odd-even index. Two scrambling loops are performed, the first on the small sub-vectors the second on the vector as a whole. In the hiding phase, the speech signal samples are divided into 256 blocks using only 200 values per block, and low-complexity quadratic and the Hénon maps are used to hide the speech signal in a random manner. The conditional LSB is applied as a low-complexity algorithm to identify hidden bits, and a special hyperchaotic map algorithm is developed to randomly choose locations. The proposed approach provides good security for a scrambled text message, with high SNR and PSNR, small MSE and PESQ, a SSIM value of close to one (As indicated in Tables 1, 2, 3, and 4), a BER value of close to zero (as shown in table 8), NCC value near +1 (as shown in table 8), and an MOS value of near five (as described in table 6), as well as a low computational hiding cost.

Low complexity smart grid security protocol based on elliptic curve cryptography, biometrics and hamming distance.

The incorporation of information and communication technologies in the power grids has greatly enhanced efficiency in the management of demand-responses. In addition, smart grids have seen considerable minimization in energy consumption and enhancement in power supply quality. However, the transmission of control and consumption information over open public communication channels renders the transmitted messages vulnerable to numerous security and privacy violations. Although many authentication and key agreement protocols have been developed to counter these issues, the achievement of ideal security and privacy levels at optimal performance still remains an uphill task. In this paper, we leverage on Hamming distance, elliptic curve cryptography, smart cards and biometrics to develop an authentication protocol. It is formally analyzed using the Burrows-Abadi-Needham (BAN) logic, which shows strong mutual authentication and session key negotiation. Its semantic security analysis demonstrates its robustness under all the assumptions of the Dolev-Yao (DY) and Canetti- Krawczyk (CK) threat models. From the performance perspective, it is shown to incur communication, storage and computation complexities compared with other related state of the art protocols.

Volatile-compound fingerprinting and discrimination of positional isomers in stamp-pad ink tracing using HS-GC-IMS combined with multivariate statistical analysis.

The rising crime rate associated with document forgery has a significant impact on public safety and social stability. In document fraud cases, determining the origin of a particular stamp-pad ink is the most important objective. In this study, a comprehensive analysis of the volatile compounds in quick-drying stamp-pad inks from six commonly used brands were performed for the first time, utilizing a combination of headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) and multivariate statistical analysis methods. Visual and comparative analysis of the differential volatile components among different stamp-pad ink samples was conducted using fingerprints and volcano plots. A total of 127 volatile compounds were accurately identified, with ketones, esters, alcohols, and aldehydes being the most abundant compounds in the stamp-pad inks. Hierarchical clustering analysis (HCA), including dendrograms and clustering heatmaps, was utilized to explore the correlations between these compounds and the samples. Additionally, the precise identification of positional isomers and functional group isomers of aliphatic compounds was achieved. To achieve accurate discrimination of various stamp-pad ink samples, a multivariate statistical analysis method was utilized to establish a classification model for them. Based on the results obtained from HS-GC-IMS, effective discrimination among different brands of stamp-pad ink samples was achieved through principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). The model exhibited excellent performance, with the fit index of dependent variables (R2Y) and the predictive index of the model (Q2) values of 0.99 and 0.984, respectively. These results provided significant theoretical evidence for the application of HS-GC-IMS as an efficient technique in the analysis of volatile compounds, identification of positional isomers and functional group isomers, as well as tracing the origin of stamp-pad ink and analyzing the formation time of documents.

The Value of Radiological Imaging in Assessing Extrarenal Fat and Renal Vein Invasion in Renal Cell Carcinoma.

Renal cell carcinoma with extrarenal fat (perinephric or renal sinus fat) and renal vein invasion is the main evidence for the T3a stage according to the American Joint Committee on Cancer tumor-node-metastasis (TNM) staging system. Extrarenal fat invasion of renal cell carcinoma is defined as the presence of perinephric fat invasion or renal sinus fat invasion. Renal vein invasion is defined as the presence of main or segmental (branch) renal vein invasion. Accurate assessment of extrarenal fat and renal vein invasion is crucial for urologists to adopt the optimal therapeutic schedule, including radical nephrectomy or nephron-sparing treatments. Currently, imaging is still the most widely used means of examination for diagnosis and staging of renal cell carcinoma, especially multidetector computed tomography (MDCT). Therefore, we have, herein, summarized the latest progress and the future direction regarding imaging for assessing perinephric or renal sinus fat and renal vein invasion of renal cell carcinoma to assist clinical treatment selection and patient risk stratification.

Clonal Propagation and Assessment of Biomass Production and Saponin Content of Elite Accessions of Wild Paris polyphylla var. yunnanensis.

Paris polyphylla var. yunnanensis is an endangered medicinal plant endemic to China with great economic importance for the pharmaceutical industry. Two significant barriers to its commercial development are the long duration of its seed germination and the frequency of interspecific hybridization. We developed a method for clonal propagation of Paris polyphylla var. yunnanensis and successfully applied it to selected elite wild plants, which could become cultivar candidates based on their biomass production and saponin content. In comparison to the traditional method, somatic embryogenesis produced an average of 63 somatic embryos per gram of callus in just six weeks, saving 12 to 15 months in plantlet production. The produced in vitro plantlets were strong and healthy and 94% survived transplanting to soil. Using this method, four candidate cultivars with diverse morphologies and geographic origins were clonally reproduced from selected elite wild accessions. In comparison to those obtained with the traditional P. polyphylla propagation technique, they accumulated higher biomass and polyphyllin levels in rhizomes plus adventitious roots during a five-year period. In conclusion, somatic embryogenesis-based methods offer an alternate approach for the rapid and scaled-up production of P. polyphylla, as well as opening up species conservation options.

Health risks posed by environmental benzophenone-type ultraviolet filters (BP-UVFs): An investigation into the binding of BP-UVFs to trypsin and their adverse effects.

Benzophenone-type ultraviolet filters (BP-UVFs) are ubiquitous in the environment, and people frequently ingest them via food chain and drinking water. However, there is no clear information about whether BP-UVFs are detrimental to human health. Herein, experiments using multi-spectroscopy revealed typical BP-UVFs, i.e., benzophenone (BP), 2-hydroxybenzophenone (2-OHBP), 4-hydroxybenzophenone (4-OHBP), 2,2'-dihydroxybenzophenone (2,2'-OHBP), 2,4-dihydroxybenzophenone (2,4-OHBP), 4,4'-dihydroxybenzophenone (4,4'-OHBP), 2,4,4'-trihydroxybenzophenone (2,4,4'-OHBP), 2,2',4,4'-tetraphydroxybenzophenone (2,2',4,4'-OHBP), 2-hydroxy-4-methoxybenzophenone (2-OH-4-MeOBP) and 2,2'-dihydroxy-4-methoxybenzophenone (2,2'-OH-4-MeOBP), could bind to the active site of trypsin with different binding constants (2.69 × 104-1.07 × 106 L/mol), cause structural abnormalities and inhibit the enzymatic activity in varying degrees, indicating that the BP-UVFs ingestion poses a risk to human health. In contrast to previous research, this study systematically analysed the binding mechanism using an innovative combination of molecular docking and advanced quantum chemistry calculations, including molecular dynamics simulations, energy calculations, etc. The results revealed that most amino acids that make up trypsin have a greater positive electrostatic surface potential (ESP). Therefore, the greater the area and distribution of negative ESP in a particular BP-UVFs, the more easily it will bind to trypsin. This provides new insight into the binding of pollutants to proteins. This study suggests a need for better monitoring and control of environmental BP-UVFs.

Environmental health risks induced by interaction between phthalic acid esters (PAEs) and biological macromolecules: A review.

As a kind of compounds abused in industry productions, phthalic acid esters (PAEs) cause serious problems in natural environment. PAEs pollution has penetrated into environmental media and human food chain. This review consolidates the updated information to assess the occurrence and distribution of PAEs in each transmission section. It is found that micrograms per kilogram of PAEs are exposed to humans through daily diets. After entering the human body, PAEs often undergo the metabolic process of hydrolysis to monoesters phthalates and conjugation process. Unfortunately, in the process of systemic circulation, PAEs will interact with biological macromolecules in vivo under the action of non-covalent binding, which is also the essence of biological toxicity. The interactions usually operate in the following pathways: (a) competitive binding; (b) functional interference; and (c) abnormal signal transduction. While the non-covalent binding forces mainly contain hydrophobic interaction, hydrogen bond, electrostatic interaction, and π interaction. As a typical endocrine disruptor, the health risks of PAEs often start with endocrine disorder, further leading to metabolic disruption, reproductive disorders, and nerve injury. Besides, genotoxicity and carcinogenicity are also attributed to the interaction between PAEs and genetic materials. This review also pointed out that the molecular mechanism study on biological toxicity of PAEs are deficient. Future toxicological research should pay more attention to the intermolecular interactions. This will be beneficial for evaluating and predicting the biological toxicity of pollutants at molecular scale.

Safety of benzophenone-type UV filters: A mini review focusing on carcinogenicity, reproductive and developmental toxicity.

Consumer products containing benzophenone-type ultraviolet (UV) filters (BPs) have been widely accepted by the public, resulting in the widely existence of various BPs in the human body and environment. In recent years, more and more evidences show that BPs are endocrine disruptors. In view of the continuous exposure risk of BPs and their endocrine disrupting characteristics, the carcinogenicity of BPs and their effects on reproduction and development are of particular concern. However, due to the wide varieties of BPs and the scattered toxicity studies on BPs, people have a limited understanding on the safety of BPs. Therefore, this paper systematically reviews the carcinogenicity, reproductive and developmental toxicity of BPs in order to expand people's knowledge on the health risks of BPs and screen for more safe BPs. Although existing toxicological studies are insufficient, it can be determined that BPs have different potentials for carcinogenicity, and reproductive and developmental toxicity. Among those BPs, 2-hydroxyl-4-methoxyl benzophenone needs to be used with caution due to its adverse effects on cancer cell proliferation and migration, reproductive ability, sex differentiation, neurodevelopment, and so on. It is worth noting that functional group substitutions significantly affect the interaction between BPs and biomolecules such as DNA, cancer cells, and seminal fluid, resulting in different levels of toxicity. In short, it is very necessary to evaluate the carcinogenicity, reproductive and developmental toxicity of BPs, which is of great significance for establishing reasonable BPs content standards in cosmetics, water quality treatment standards for BPs, and so on.

The binding mechanism of benzophenone-type UV filters and human serum albumin: The role of site, number, and type of functional group substitutions.

Benzophenone-type UV filters (BPs) are common in natural aquatic environments. They can cause endocrine disruption or other adverse effects once they enter the human body via the food chain or drinking water. The primary cause of BPs accumulation and toxicity is the transport of BPs into the human body. Functional group substitutions can have a significant impact on the interactions of BPs and transporters, resulting in a variety of impact effects. Therefore, we explored the interaction between human serum albumin (HSA, a typical transporter) and ten typical BPs [benzophenone (BP1), 2-hydroxybenzophenone (BP2), 4-hydroxybenzophenone (BP3), 2,2'-dihydroxybenzophenone (BP4), 2,4-dihydroxybenzophenone (BP5), 4,4'-dihydroxybenzophenone (BP6), 2,4,4'-trihydroxybenzophenone (BP7), 2,2',4,4'-tetrahydroxybenzophenone (BP8), 2-hydroxy-4-methoxybenzophenone (BP9), and 2,2'-dihydroxy-4-methoxybenzophenone (BP10)] to study the role of functional group substitutions in binding. The results showed that BPs could bind to HSA at site 2, with binding constants ranging from 2.01 × 103 to 4.57 × 105 L/mol. Compared to BP1, hydroxyl and methoxy substitutions enhanced the BPs-HSA binding. The combined effect of the number and site of hydroxyl substitution at BPs determined the binding strength between BPs and HSA. It was more accessible to bind HSA when BPs were substituted with para-hydroxyl (4-hydroxyl) groups than with ortho-hydroxyl (2-hydroxyl) groups. Moreover, the additional para-methoxy (4-methoxy) group increased the BP-HSA binding strength by approximately 47 times under the same hydroxyl substitution conditions. Theoretical calculations revealed that functional group substitutions increased the intermolecular binding force by increasing the negative electrostatic potential surface area of BPs, which significantly increased the electrostatic and dispersion forces between the BPs and HSA. This BPs-HSA binding decreased the α-helix of HSA and influenced the ratio of other secondary structures, including ß-sheet, ß-turn, and random coil of HSA. This study provides a theoretical and experimental foundation for understanding the human health risks associated with BPs.

Unveiling Weyl-related optical responses in semiconducting tellurium by mid-infrared circular photogalvanic effect.

Elemental tellurium, conventionally recognized as a narrow bandgap semiconductor, has recently aroused research interests for exploiting Weyl physics. Chirality is a unique feature of Weyl cones and can support helicity-dependent photocurrent generation, known as circular photogalvanic effect. Here, we report circular photogalvanic effect with opposite signs at two different mid-infrared wavelengths which provides evidence of Weyl-related optical responses. These two different wavelengths correspond to two critical transitions relating to the bands of different Weyl cones and the sign of circular photogalvanic effect is determined by the chirality selection rules within certain Weyl cone and between two different Weyl cones. Further experimental evidences confirm the observed response is an intrinsic second-order process. With flexibly tunable bandgap and Fermi level, tellurium is established as an ideal semiconducting material to manipulate and explore chirality-related Weyl physics in both conduction and valence bands. These results are also directly applicable to helicity-sensitive optoelectronics devices.

Direct Light Orbital Angular Momentum Detection in Mid-Infrared Based on the Type-II Weyl Semimetal TaIrTe4.

The direct photocurrent detection capability of light orbital angular momentum (OAM) has recently been realized with topological Weyl semimetals, but it is limited to the near-infrared wavelength range. The extension of the direct OAM detection capability to the mid-infrared band, which is a wave band that plays an important role in a vast range of applications, has not yet been realized. This is because the photocurrent responses of most photodetectors are neither sensitive to the phase information nor efficient in the mid-infrared region. In this study, a photodetector based on the type-II Weyl semimetal tantalum iridium telluride (TaIrTe4 ) is designed with peculiar electrode geometries to directly detect the topological charge of the OAM using the orbital photogalvanic effect (OPGE). The results indicate that the helical phase gradient of light can be distinguished by a current winding around the optical beam axis, with a magnitude proportional to its quantized OAM mode number. The topologically enhanced responses in the mid-infrared region of TaIrTe4 further help overcome the low responsivity issues and finally render direct OAM detection capability. This study enables on-chip-integrated OAM detection, and thus OAM-sensitive focal plane arrays in the mid-infrared region.

Establishing Tetraploid Embryogenic Cell Lines of Magnolia officinalis to Facilitate Tetraploid Plantlet Production and Phenotyping.

The production of synthetic polyploids for plant breeding is compromised by high levels of mixoploids and low numbers of solid polyploid regenerants during in vitro induction. Somatic embryogenesis could potentially contribute to the maximization of solid polyploid production due to the single cell origin of regenerants. In the present study, a novel procedure for establishing homogeneous tetraploid embryogenic cell lines in Magnolia officinalis has been established. Embryogenic cell aggregate (ECA) about 100-200 µm across, and consisting of dozens of cells, regenerated into a single colony of new ECAs and somatic embryos following colchicine treatment. Histological analysis indicated that the few cells that survived some colchicine regimes still regenerated to form a colony. In some colonies, 100% tetraploid somatic embryos were obtained without mixoploid formation. New granular ECA from single colonies with 100% tetraploid somatic embryos were isolated and cultured individually to proliferate into cell lines. These cell lines were confirmed to be homogeneous tetraploid by flow cytometry. Many tetraploid somatic embryos and plantlets were differentiated from these cell lines and the stability of ploidy level through the somatic embryogenesis process was confirmed by flow cytometry and chromosome counting. The establishment of homogeneous polyploid cell lines, which were presumed to represent individual polyploidization events, might expand the phenotypic variations of the same duplicated genome and create novel breeding opportunities using newly generated polyploid plantlets.

Functional group substitutions influence the binding of benzophenone-type UV filters with DNA.

As a class of possible carcinogens, benzophenone-type UV filters (BPs) widely exist in natural environments and organisms. The crucial step of the carcinogenic process induced by cancerous toxins is binding with DNA to form adducts. Here, the binding of 10 typical BPs, i.e., benzophenone (BP1), 2-hydroxyl benzophenone (BP2), 4-hydroxyl benzophenone (BP3), 2,2'-dihydroxyl benzophenone (BP4), 2,4-dihydroxyl benzophenone (BP5), 4,4'-dihydroxyl benzophenone (BP6), 2,4,4'-trihydroxyl benzophenone (BP7), 2,2',4,4'-tetrahydroxyl benzophenone (BP8), 2-hydroxyl-4-methoxyl benzophenone (BP9), and 2,2'-dihydroxyl-4-methoxyl benzophenone (BP10), with DNA was tested via fluorescence quenching experiments. Only hydroxyl group-substituted BPs could bind to DNA by groove binding mode, and the quenching constants were 0.93 × 103-5.89 × 103 L/mol. Substituted BPs were preferentially bound to thymine. Circular dichroism analysis confirmed that BPs could affect DNA base stacking but could not transform its B-form. Based on molecular electrostatic surface potential analyses, molecular dynamics simulations, and energy decomposition calculations, it could be found that the site and number of hydroxyl substitution changed the molecular polarity of BPs, thereby affecting the number and strength of hydrogen bonds between BPs and DNA. The hydroxyl substitution at site 2 was more conducive to binding than at site 4. This study is beneficial in comprehending the carcinogenic mechanisms of BPs.

Seed dormancy, germination and storage behavior of Magnolia sinica, a plant species with extremely small populations of Magnoliaceae.

Magnolia sinica is one of the most endangered Magnoliaceae species in China. Seed biology information concerning its long-term ex situ conservation and utilization is insufficient. This study investigated dormancy status, germination requirements and storage behavior of M. sinica. Freshly matured seeds germinated to ca. 86.5% at 25/15 °C but poorly at 30 °C; GA3 and moist chilling promoted germination significantly at 20 °C. Embryos grew at temperatures (alternating or constant) between 20 °C and 25 °C, but not at 5 °C or 30 °C. Our results indicate that M. sinica seeds possibly have non-deep simple morphophysiological dormancy (MPD). Seeds survived desiccation to 9.27% and 4.85% moisture content (MC) as well as a further 6-month storage at -20 °C and in liquid nitrogen, including recovery in vitro as excised embryos. The established protocol ensured that at least 58% of seedlings were obtained after both cold storage and cryopreservation. These results indicate that both conventional seed banking and cryopreservation have potential as long-term ex situ conservation methods, although further optimized approaches are recommended for this critically endangered magnolia species.

Ultrafast photothermoelectric effect in Dirac semimetallic Cd3As2 revealed by terahertz emission.

The thermoelectric effects of topological semimetals have attracted tremendous research interest because many topological semimetals are excellent thermoelectric materials and thermoelectricity serves as one of their most important potential applications. In this work, we reveal the transient photothermoelectric response of Dirac semimetallic Cd3As2, namely the photo-Seebeck effect and photo-Nernst effect, by studying the terahertz (THz) emission from the transient photocurrent induced by these effects. Our excitation polarization and power dependence confirm that the observed THz emission is due to photothermoelectric effect instead of other nonlinear optical effect. Furthermore, when a weak magnetic field (~0.4 T) is applied, the response clearly indicates an order of magnitude enhancement on transient photothermoelectric current generation compared to the photo-Seebeck effect. Such enhancement supports an ambipolar transport nature of the photo-Nernst current generation in Cd3As2. These results highlight the enhancement of thermoelectric performance can be achieved in topological Dirac semimetals based on the Nernst effect, and our transient studies pave the way for thermoelectric devices applicable for high field circumstance when nonequilibrium state matters. The large THz emission due to highly efficient photothermoelectric conversion is comparable to conventional semiconductors through optical rectification and photo-Dember effect.