477 research outputs found
The fast light of CsI(Na) crystals
The responds of different common alkali halide crystals to alpha-rays and
gamma-rays are tested in our research. It is found that only CsI(Na) crystals
have significantly different waveforms between alpha and gamma scintillations,
while others have not this phenomena. It is suggested that the fast light of
CsI(Na) crystals arises from the recombination of free electrons with
self-trapped holes of the host crystal CsI. Self-absorption limits the emission
of fast light of CsI(Tl) and NaI(Tl) crystals.Comment: 5 pages, 11 figures Submit to Chinese Physics
Antioxidant and antidiabetic properties of Chinese and Indian bitter melons (Momordica charantia L.)
Bitter melon (Momordica charantia L.) has been used for anti-diabetes treatment for decades. Indian and Chinese bitter melons (BM) are two commonly produced cultivars in the US market. This study has comparatively evaluated the effects of two processing methods (fresh and freeze-drying) on Chinese and Indian BM by measuring their bioactivity in terms of total phenolic content (TPC), total triterpene content (TTC), antioxidant activity, and antidiabetic properties using the DPPH free radical scavenging and reducing power assays, and the α-amylase and α-glucosidase inhibition assays. The TPC (GAE mg/g dw) in freeze-dried BM were 6.03 and 6.09, and in fresh BM were 4.81 and 4.83 for Indian and Chinese BM, respectively. The TTC (OAE mg/g dw) in Indian BM were 7.25 and 5.63, and in Chinese BM were 5.88 and 3.87 for fresh and freeze-dried samples, respectively. TPC and TTC in the freeze-dried BM samples were significantly higher than that in the fresh ones (p \u3c 0.05). The DPPH IC50 of India BM was significantly lower than that of Chinese BM (p \u3c 0.05). All BM samples ranged from 9.18 to 18.6 mg/ml. The reducing power was significantly different between Indian and Chinese BM (p \u3c 0.01) for fresh samples, but after freeze-drying, there was no detectable difference in reducing power (p ≥ 0.05). The Indian BM showed a significantly stronger α-glucosidase inhibition effect as compared to the Chinese BM. TTC was positively correlated with reducing power (p \u3c 0.05). TPC was negatively correlated with α-amylase inhibition efficiency (p \u3c 0.05)
jaw-1D: a gain-of-function mutation responsive to paramutation-like induction of epigenetic silencing
The Arabidopsis thaliana gain-of-function T-DNA insertion mutant jaw-1D produces miR319A, a microRNA that represses genes encoding CIN-like TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTORs (TCPs), a family of transcription factors that play key roles in leaf morphogenesis. In this study, we show that jaw-1D is responsive to paramutation-like epigenetic silencing. A genetic cross of jaw-1D with the polycomb gene mutant curly leaf-29 (clf-29) leads to attenuation of the jaw-1D mutant plant phenotype. This induced mutation, jaw-1D*, was associated with down-regulation of miR319A, was heritable independently from clf-29, and displayed paramutation-like non-Mendelian inheritance. Down-regulation of miR319A in jaw-1D* was linked to elevated levels of histone H3 lysine 9 dimethylation and DNA methylation at the CaMV35S enhancer located within the activation-tagging T-DNA of the jaw-1D locus. Examination of 21 independent T-DNA insertion mutant lines revealed that 11 could attenuate the jaw-1D mutant phenotype in a similar way to the paramutation induced by clf-29. These paramutagenic mutant lines shared the common feature that their T-DNA insertion was present as multi-copy tandem repeats and contained high levels of CG and CHG methylation. Our results provide important insights into paramutation-like epigenetic silencing, and caution against the use of jaw-1D in genetic interaction studies
Linking PHYTOCHROME-INTERACTING FACTOR to Histone Modification in Plant Shade Avoidance
Shade avoidance syndrome (SAS) allows a plant grown in a densely populated environment to maximize opportunities to access to sunlight. Although it is well established that SAS is accompanied by gene expression changes, the underlying molecular mechanism needs to be elucidated. Here, we identify the H3K4me3/H3K36me3-binding proteins, Morf Related Gene (MRG) group proteins MRG1 and MRG2, as positive regulators of shade-induced hypocotyl elongation in Arabidopsis (Arabidopsis thaliana). MRG2 binds PHYTOCHROME-INTERACTING FACTOR7 (PIF7) and regulates the expression of several common downstream target genes, including YUCCA8 and IAA19 involved in the auxin biosynthesis or response pathway and PRE1 involved in brassinosteroid regulation of cell elongation. In response to shade, PIF7 and MRG2 are enriched at the promoter and gene-body regions and are necessary for increase of histone H4 and H3 acetylation to promote target gene expression. Our study uncovers a mechanism in which the shade-responsive factor PIF7 recruits MRG1/MRG2 that binds H3K4me3/H3K36me3 and brings histone-acetylases to induce histone acetylations to promote expression of shade responsive genes, providing thus a molecular mechanistic link coupling the environmental light to epigenetic modification in regulation of hypocotyl elongation in plant SAS
Silencing miR-146a-5p protects against injury-induced osteoarthritis in mice
Osteoarthritis (OA), the most prevalent joint disease and the leading cause of disability, remains an incurable disease largely because the etiology and pathogenesis underlying this degenerative process are poorly understood. Low-grade inflammation within joints is a well-established factor that disturbs joint homeostasis and leads to an imbalance between anabolic and catabolic processes in articular cartilage; however, the complexity of the network between inflammatory factors that often involves positive and negative feedback loops makes current anti-cytokine therapy ineffective. MicroRNAs (miRNAs) have emerged as key regulators to control inflammation, and aberrant miRNAs expression has recently been linked to OA pathophysiology. In the present study, we characterized transcriptomic profiles of miRNAs in primary murine articular chondrocytes in response to a proinflammatory cytokine, IL-1β, and identifie
The mediating role of metabolites between gut microbiome and Hirschsprung disease: a bidirectional two-step Mendelian randomization study
BackgroundGut microbiome (GM) was observed to be associated with the incidence of Hirschsprung disease (HD). However, the effect and mechanism of GM in HD is still unclear. To investigate the relationship between GM and HD and the effect of metabolites as mediators, a bidirectional two-step Mendelian randomization (MR) study was conducted.MethodsThe study selected instrument variables (IVs) from summary-level genome-wide association studies (GWAS). The MiBioGen consortium provided the GWAS data for GM, while the GWAS data for metabolites and HD were obtained from the GWAS Catalog consortium. Two-sample MR analyses were performed to estimate bidirectional correlations between IVs associated with GM and HD. Then, genetic variants related to 1,400 metabolite traits were selected for further mediation analyses using the Product method.ResultsThis study found that seven genus bacteria had a significant causal relationship with the incidence of HD but not vice versa. 27 metabolite traits were significantly correlated with HD. After combining the significant results, three significant GM-metabolites-HD lines have been identified. In the Peptococcus-Stearoyl sphingomyelin (d18:1/18:0)-HD line, the Stearoyl sphingomyelin (d18:1/18:0) levels showed a mediation proportion of 14.5%, while in the Peptococcus-lysine-HD line, the lysine levels had a mediation proportion of 12.9%. Additionally, in the Roseburia-X-21733-HD line, the X-21733 levels played a mediation proportion of 23.5%.ConclusionOur MR study indicates a protective effect of Peptococcus on HD risk that is partially mediated through serum levels of stearoyl sphingomyelin (d18:1/18:0) and lysine, and a risk effect of Roseburia on HD that is partially mediated by X-21733 levels. These findings could serve as novel biomarkers and therapeutic targets for HD
Role of OCT4 in cisplatin treatment of testicular embryonal carcinoma
Purpose: To determine the role of embryonal transcription factor OCT4 in cisplatin treatment of testicular embryonal carcinoma.Methods: In vitro assays were employed to assess the effect of cisplatin treatment on testicular embryonal carcinoma cell lines under OCT4 silencing. Following treatment with 500 ng/μL cisplatin, MTT assay was used to examine cell proliferation of 2012-EP and 833K-E cells with or without OCT silencing, while wound healing assay was used to examine cell migration ability. Transwell assay and crystal violet staining were employed to measure cell invasive capacity, whereas the distribution pattern of cell cycle was assessed by flow cytometry. The expression levels of several critical components in tumorigenicity related pathways with or without OCT silencing were determined by Western-blot analysis.Results: Cisplatin enhanced OCT4-silenced cell viability at all concentration (p < 0.01) when compared to control cells. Upon treatment with 500 ng/μL cisplatin, OCT4-silenced cells showed 2- to 3-fold enhancement in cell proliferation (p < 0.001), 2-fold increase in cell migration capacity (p < 0.001), and about 1.5-fold enhancement in invasive capacity (p < 0.001) when compared to control cells. In addition, OCT4 silencing upregulated the expression level of the proteins involved in cell proliferation, cell mobility, cancer metastasis and cell cycle control.Conclusion: The results suggest that OCT4 may serve as a therapeutic target for testicular embryonal carcinoma treatment in combination with cisplatin by modulating OCT4 expression level. This physiological evidence indicates that OCT4 downregulation contributes to cisplatin resistance in chemotherapy and subsequent disease relapse.Keywords: OCT4, Cisplatin resistance, Testicular embryonal carcinoma, Chemotherap
A fingerprint based crypto-biometric system for secure communication
To ensure the secure transmission of data, cryptography is treated as the
most effective solution. Cryptographic key is an important entity in this
procedure. In general, randomly generated cryptographic key (of 256 bits) is
difficult to remember. However, such a key needs to be stored in a protected
place or transported through a shared communication line which, in fact, poses
another threat to security. As an alternative, researchers advocate the
generation of cryptographic key using the biometric traits of both sender and
receiver during the sessions of communication, thus avoiding key storing and at
the same time without compromising the strength in security. Nevertheless, the
biometric-based cryptographic key generation possesses few concerns such as
privacy of biometrics, sharing of biometric data between both communicating
users (i.e., sender and receiver), and generating revocable key from
irrevocable biometric. This work addresses the above-mentioned concerns.
In this work, a framework for secure communication between two users using
fingerprint based crypto-biometric system has been proposed. For this,
Diffie-Hellman (DH) algorithm is used to generate public keys from private keys
of both sender and receiver which are shared and further used to produce a
symmetric cryptographic key at both ends. In this approach, revocable key for
symmetric cryptography is generated from irrevocable fingerprint. The biometric
data is neither stored nor shared which ensures the security of biometric data,
and perfect forward secrecy is achieved using session keys. This work also
ensures the long-term security of messages communicated between two users.
Based on the experimental evaluation over four datasets of FVC2002 and NIST
special database, the proposed framework is privacy-preserving and could be
utilized onto real access control systems.Comment: 29 single column pages, 8 figure
Paucatalinone A from Paulownia Catalpifolia Gong Tong Elicits mitochondrial-mediated cancer cell death to combat osteosarcoma
As the global cancer burden escalates, the search for alternative therapies becomes increasingly vital. Natural products, particularly plant-derived compounds, have emerged as promising alternatives to conventional cancer treatments due to their diverse bioactivities and favorable biosafety profiles. Here, we investigate Paucatalinone A, a newly discovered geranylated flavanone derived from the fruit of Paulownia Catalpifolia Gong Tong, notable for its significant anti-cancer properties. We revealed the capability of Paucatalinone A to induce apoptosis in osteosarcoma cells and deciphered its underlying mechanisms. Our findings demonstrate that Paucatalinone A substantially augments apoptosis, inhibits cell proliferation, and demonstrates a pronounced anti-tumor effect in a murine model of osteosarcoma. Mechanistically, Paucatalinone A disrupts calcium homeostasis and exacerbates intracellular reactive oxygen species accumulation, leading to mitochondrial impairment, cytoskeletal collapse, and caspase-dependent apoptotic cell death. This study underscores the potential of Paucatalinone A in initiating apoptosis in cancer cells and highlights the therapeutic efficacy of plant-derived agents in treating osteosarcoma, offering a viable approach for managing other intractable cancers
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