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لقاء في القرية العالمية = An encounter in the global village : قصص مختارة من المؤتمر الدولي الرابع عشر للقصة القصيرة
هذا الكتاب يحتوي على قصص مختارة من المؤتمر الدولي الرابع عشر للقصة القصيرة وهذا اللقاء الذي نظم من قبل جمعية دراسة القصص القصيرة الإنجليزية (أس أس أس أس إي) وهي جمعية عالمية أنشئت في الولايات المتحدة عام 1992 وينعقد كل عامين ويعتبر اللقاء العالمي الوحيد الذي يركز بشكل خاص على دراسات القصة القصيرة أما القصص المشاركة في اللقاء فهي مكتوبة من قبل 29 كاتبا ينتمون إلى عشرة دول هي الصين وتايوان والهند والولايات المتحدة وكندا ونيوزلندا وفرنسا وإيرلندا والنمسا وسنغافورا وجامايكا.
BOOK
Circularly polarized luminescence in chiral orientationally ordered soft matter systems
Circularly polarized luminescent (CPL) materials have received significant attention in the field of fundamental science recently. These materials offer substantial advancement of technological applications, such as optical data storage, displays, and quantum communication. Various strategies have been proposed in self‐assembled materials consisting of inorganic, organic, and hybrid systems, particularly in the chiral orientationally ordered soft matter systems (e.g., chiral liquid crystals (LCs) and LC polymers). However, developing scientific approaches to achieve the pronounced and steerable circularly polarized light emission remains challenging. Herein, we present a comprehensive review on the recent development of CPL materials based on chiral LCs, including thermotropic LCs (cholesteric LCs and bent‐core LCs), lyotropic LCs (nanocellulose LCs and polyacetylene‐based LCs), and LC polymers (cholesteric LC‐based polymers, helical nanofibers, and helical network). In addition, the fundamental mechanisms, design principles, and potential applications based on these chiral LCs and LC polymers in soft matter systems are systematically reviewed. This review summarizes with a prospect on the latent challenges, which can strengthen our understanding of the basic principles of CPL in chiral orientationally ordered soft matter systems and provide a new insight into the progress in several fields, such as chemistry, materials science, optics, electronics, and biology. Representative chiral liquid crystals (LCs) with characteristics of circularly polarized luminescence, including cholesteric LCs, bent‐core LCs, lyotropic LCs, and LC polymers.
Journal Article
SlMYC2 mediates stomatal movement in response to drought stress by repressing SlCHS1 expression
Drought stress limits plant development and reproduction. Multiple mechanisms in plants are activated to respond to stress. The MYC2 transcription factor is a core regulator of the jasmonate (JA) pathway and plays a vital role in the crosstalk between abscisic acid (ABA) and JA. In this study, we found that SlMYC2 responded to drought stress and regulated stomatal aperture in tomato ( Solanum lycopersicum ). Overexpression of SlMYC2 repressed SlCHS1 expression and decreased the flavonol content, increased the reactive oxygen species (ROS) content in guard cells and promoted the accumulation of JA and ABA in leaves. Additionally, silencing the SlCHS1 gene produced a phenotype that was similar to that of the MYC2- overexpressing ( MYC2 -OE) strain, especially in terms of stomatal dynamics and ROS levels. Finally, we confirmed that SlMYC2 directly repressed the expression of SlCHS1 . Our study revealed that SlMYC2 drove stomatal closure by modulating the accumulation of flavonol and the JA and ABA contents, helping us decipher the mechanism of stomatal movement under drought stress.
Journal Article
Excited-State-Altering Ratiometric Fluorescent Probes for the Response of β-Galactosidase in Senescent Cells
β-galactosidase (β-Gal) has emerged as a pivotal biomarker for the comprehensive investigation of diseases associated with cellular senescence. The development of a fluorescent sensor is of considerable importance for precisely detecting the activity and spatial distribution of β-Gal. In this study, we developed two excited-state-altering responsive fluorescent sensors (TF1 and TF2) for ratiometric detection of β-Gal. Two TCF dyes, composed of tricyanofuran (TCF) and naphthol units, feature electron “pull–push” systems and are quenched fluorescence by β-Gal. Upon β-Gal hydrolysis, a significant ratiometric shift in absorption from ca. 475 nm to 630 nm is observed, accompanied by the emergence of a fluorescence signal at ca. 660 nm. The enzyme-responsive optical red-shifts are attributed to the excited-state transition from intramolecular charge transfer (ICT) state to local excited (LE) state, which was confirmed by density functional theory (DFT) calculations. Both fluorescent sensors display exceptional sensitivity and selectivity for the response of β-Gal in PBS solution and are capable of tracking β-Gal within senescent A549 cells. This study introduces a framework for developing multimodal optical probes by systematically modulating excited-state properties, demonstrating their utility in senescence studies, diagnostic assay design, and therapeutic assessment.
Journal Article
Cellular Toxicity and Immunological Effects of Carbon-based Nanomaterials
Background
Carbon nanomaterials are a growing family of materials featuring unique physicochemical properties, and their widespread application is accompanied by increasing human exposure.
Main body
Considerable efforts have been made to characterize the potential toxicity of carbon nanomaterials in vitro and in vivo. Many studies have reported various toxicology profiles of carbon nanomaterials. The different results of the cytotoxicity of the carbon-based materials might be related to the differences in the physicochemical properties or structures of carbon nanomaterials, types of target cells and methods of particle dispersion,
etc.
The reported cytotoxicity effects mainly included reactive oxygen species generation, DNA damage, lysosomal damage, mitochondrial dysfunction and eventual cell death via apoptosis or necrosis. Despite the cellular toxicity, the immunological effects of the carbon-based nanomaterials, such as the pulmonary macrophage activation and inflammation induced by carbon nanomaterials, have been thoroughly studied. The roles of carbon nanomaterials in activating different immune cells or inducing immunosuppression have also been addressed.
Conclusion: Here, we provide a review of the latest research findings on the toxicological profiles of carbon-based nanomaterials, highlighting both the cellular toxicities and immunological effects of carbon nanomaterials. This review provides information on the overall status, trends, and research needs for toxicological studies of carbon nanomaterials.
Journal Article
Flexible Formation of Nanoparticles: Selectively Self-Assembling with Glycoclusters to Form Nano-Photosensitizers for Multipurpose Bioimaging and Photodynamic Therapy
The smart construction of nano-photosensitizers (PSs) is significant for multipurpose applications, such as bioimaging, efficient photodynamic anti-tumor or anti-bacterial studies. This work reports a flexible self-assembling strategy for the construction of nano-PSs, in which PSs spontaneously form amorphous aggregates for killing bacteria, or self-assemble with tetraphenylethene (TPE) based glycoclusters (TPE-Glc4) to construct glyco-dots for cell imaging and photodynamic anti-tumor studies. Tricyanofuran (TCF) and TPE units were bridged with furan or thiophene moiety to construct two PSs (1 and 2) with NIR fluorescence in monomers, and a performance of the aggregation-induced generation of reactive oxygen species (AIG-ROS) in an aggregated state. Compared to the large amorphous aggregates (2-a), TPE-based glycoclusters encapsulated with PS form glyco-dots (2-Glc) that exhibit a smaller and more homogeneous hydrated size of approximately 40 nm, as well as enhanced water-solubility and biocompatibility. TPE-glycoclusters facilitate the cellular uptake of 2 into HepG2 cells, therefore enhancing the NIR fluorescence imaging signal and photodynamic therapy. Meanwhile, 2-a exhibits satisfied phototoxicity against Escherichia coli. This work highlights the flexible self-assembly of nano-PSs for multifunctional bioapplications.
Journal Article
A membrane‐associated NAC transcription factor OsNTL3 is involved in thermotolerance in rice
Summary Heat stress induces misfolded protein accumulation in endoplasmic reticulum (ER), which initiates the unfolded protein response (UPR) in plants. Previous work has demonstrated the important role of a rice ER membrane‐associated transcription factor OsbZIP74 (also known as OsbZIP50) in UPR. However, how OsbZIP74 and other membrane‐associated transcription factors are involved in heat stress tolerance in rice is not reported. In the current study, we discovered that OsNTL3 is required for heat stress tolerance in rice. OsNTL3 is constitutively expressed and up‐regulated by heat and ER stresses. OsNTL3 encodes a NAC transcription factor with a predicted C‐terminal transmembrane domain. GFP‐OsNTL3 relocates from plasma membrane to nucleus in response to heat stress and ER stress inducers. Loss‐of‐function mutation of OsNTL3 confers heat sensitivity while inducible expression of the truncated form of OsNTL3 without the transmembrane domain increases heat tolerance in rice seedlings. RNA‐Seq analysis revealed that OsNTL3 regulates the expression of genes involved in ER protein folding and other processes. Interestingly, OsNTL3 directly binds to OsbZIP74 promoter and regulates its expression in response to heat stress. In turn, up‐regulation of OsNTL3 by heat stress is dependent on OsbZIP74. Thus, our work reveals the important role of OsNTL3 in thermotolerance, and a regulatory circuit mediated by OsbZIP74 and OsNTL3 in communications among ER, plasma membrane and nucleus under heat stress conditions.
Journal Article
ISLRWR: A network diffusion algorithm for drug–target interactions prediction
Machine learning techniques and computer-aided methods are now widely used in the pre-discovery tasks of drug discovery, effectively improving the efficiency of drug development and reducing the workload and cost. In this study, we used multi-source heterogeneous network information to build a network model, learn the network topology through multiple network diffusion algorithms, and obtain compressed low-dimensional feature vectors for predicting drug–target interactions (DTIs). We applied the metropolis–hasting random walk (MHRW) algorithm to improve the performance of the random walk with restart (RWR) algorithm, forming the basis by which the self-loop probability of the current node is removed. Additionally, the propagation efficiency of the MHRW was improved using the improved metropolis–hasting random walk (IMRWR) algorithm, facilitating network deep sampling. Finally, we proposed a correction of the transfer probability of the entire network after increasing the self-loop rate of isolated nodes to form the ISLRWR algorithm. Notably, the ISLRWR algorithm improved the area under the receiver operating characteristic curve (AUROC) by 7.53 and 5.72%, and the area under the precision-recall curve (AUPRC) by 5.95 and 4.19% compared to the RWR and MHRW algorithms, respectively, in predicting DTIs performance. Moreover, after excluding the interference of homologous proteins (popular drugs or targets may lead to inflated prediction results), the ISLRWR algorithm still showed a significant performance improvement.
Journal Article
Formation and fluorescent mechanism of red emissive carbon dots from o-phenylenediamine and catechol system
Carbon dots (CDs) as the advancing fluorescent carbon nanomaterial have superior potential and prospective. However, the ambiguous photoluminescence (PL) mechanism and intricate structure-function relationship become the greatest hindrances in the development and applications of CDs. Herein, red emissive CDs were synthesized in high yield from o-phenylenediamine (oPD) and catechol (CAT). The PL mechanism of the CDs is considered as the molecular state fluorophores because 5,14-dihydroquinoxalino[2,3-b] phenazine (DHQP) is separated and exhibits the same PL properties and behavior as the CDs. These include the peak position and shape of the PL emission and PL excitation and the emission dependence on pH and solvent polarity. Both of them display close PL lifetime decays. Based on these, we deduce that DHQP is the fluorophore of the red emissive CDs and the PL mechanism of CDs is similar to DHQP. During the PL emission of CDs, the electron of the molecule state can transfer to CDs. The formation process of DHQP is further confirmed by the reaction intermediates (phthalazine, dimers) and oPD. These findings provide insights into the PL mechanism of this type of CDs and may guide the further development of tunable CDs for tailored properties.The fluorophore source of red emissive oPD&CAT system CDs is the 5,14-dihydroquinoxalino[2,3-b] phenazine (DHQP), formed in the initial reaction stage. Subsequently, the DHQP was connected with carbon core. The excited electrons of the molecular state can transfer into the energy level of CDs, which leads to UV excitation red emissive intensity decreased.
Journal Article
Anti-allergic activity of glycyrrhizic acid on IgE-mediated allergic reaction by regulation of allergy-related immune cells
Glycyrrhizic acid (GA), the major bioactive triterpene glycoside of glycyrrhiza, has been shown to possess a wide range of pharmacological properties, including anti-inflammatory and anti-viral properties. However, few studies have examined the anti-allergic activity and exact mechanism of action of GA. In the present work, the anti-allergic activity and possible mechanisms of action of GA on an immunoglobulin (Ig) E-mediated allergic reaction has been studied using three models of allergic reaction
in vivo
and
in vitro
. Active systemic allergic reaction in Balb/c mice showed that GA can suppress the increased level of IL-4 to restore the immune balance of T
H
1/T
H
2 cells in a dose-dependent manner. Additionally, GA attenuated significantly the B cells producing allergen-specific IgE and IgG
1
partly because of the low levels of T
H
2 cytokines. Both passive cutaneous anaphylaxis
in vivo
and an RBL-2H3 cell-based immunological assay
in vitro
indicated that GA acted as a “mast cell stabilizer”, as it inhibited mast cell degranulation and decreased vascular permeability by inhibiting the expression of Orai1, STIM1 and TRPC1, which blocked extracellular Ca
2+
influxes. The current study suggests that GA may serve as an effective anti-allergic agent derived from food for the prevention and treatment of IgE-mediated allergic reaction.
Journal Article