184 research outputs found
Phytochromes are Involved in Elongation of Seminal Roots and Accumulation of Dry substances in Rice Seedlings
Abstract: Phytochromes have been reported to play important roles in seedling de-etiolation and flowering in rice. To identify the roles of phytochromes in regulating root growth and accumulation of dry substances, the lengths of seminal roots and dry weights of seedlings were measured in wild type as well as phytochrome A (phyA) and phytochrome B (phyB) mutants grown under different conditions. When the whole seedlings were exposed to white light, the elongation of the seminal roots was significantly photoinhibited in the wild type, whereas this inhibitory effect was clearly reduced in the phyA and phyB mutants. When the roots of the seedlings were blocked from white light, the phyA and phyB mutants exhibited significantly longer seminal roots than the wild type. These results suggest that both the root-localized and shoot-localized phyA and phyB are involved in the photoinhibition of seminal root elongation in rice seedlings. By measuring the dry weights of roots and shoots, it is revealed that phyB positively regulates the accumulation of dry substances in shoots. Moreover, we reveal that phyA plays the reverse effects on the accumulation of dry substances in roots and shoots in rice seedlings
CROP: Conservative Reward for Model-based Offline Policy Optimization
Offline reinforcement learning (RL) aims to optimize policy using collected
data without online interactions. Model-based approaches are particularly
appealing for addressing offline RL challenges due to their capability to
mitigate the limitations of offline data through data generation using models.
Prior research has demonstrated that introducing conservatism into the model or
Q-function during policy optimization can effectively alleviate the prevalent
distribution drift problem in offline RL. However, the investigation into the
impacts of conservatism in reward estimation is still lacking. This paper
proposes a novel model-based offline RL algorithm, Conservative Reward for
model-based Offline Policy optimization (CROP), which conservatively estimates
the reward in model training. To achieve a conservative reward estimation, CROP
simultaneously minimizes the estimation error and the reward of random actions.
Theoretical analysis shows that this conservative reward mechanism leads to a
conservative policy evaluation and helps mitigate distribution drift.
Experiments on D4RL benchmarks showcase that the performance of CROP is
comparable to the state-of-the-art baselines. Notably, CROP establishes an
innovative connection between offline and online RL, highlighting that offline
RL problems can be tackled by adopting online RL techniques to the empirical
Markov decision process trained with a conservative reward. The source code is
available with https://github.com/G0K0URURI/CROP.git
Aqueous Extract of Clerodendranthus spicatus
Clerodendranthus spicatus (Thunb.) C.Y.Wu (CS) is commonly used to treat kidney diseases in traditional Chinese medicine for its prominent anti-inflammatory effect and nourishing function to kidneys. In this study, aqueous extract of CS was assessed for its protective effect on UV-induced skin damage of mice. The chemical compositions of CS aqueous extract were determined by HPLC-ESI-MS/MS, in which 10 components were identified. During the experimental period, CS (0.9, 1.8, and 3.6 g/mL) was externally applied to shaved dorsal skins of mice prior to UV irradiation, daily for ten weeks. The results presented that CS (3.6 g/mL) apparently improved photodamaged skin appearance such as erythema, edema, and coarseness. The abnormal epidermal thickening was significantly reduced, and the dermal structures became more complete. The underlying protective mechanisms were associated with improving antioxidant enzymes activities including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px), downregulating inflammatory cytokines (IL-1β, IL-6, TNF-α, COX-2, and PGE2) expressions, recovering collagen density, and reducing matrix metalloproteinases productions. Sun protection factor of CS (3.6 g/mL) was 16.21±0.03. Our findings for the first time demonstrated that CS had therapeutic effect on the photoaged skin. The results indicated that CS is a potential agent for photoprotective cosmetics
Non-canonical Bromodomain within DNA-PKcs Promotes DNA Damage Response and Radioresistance through Recognizing an IR-Induced Acetyl-Lysine on H2AX
Regulatory mechanisms underlying γH2AX induction and the associated cell fate decision during DNA damage response (DDR) remain obscure. Here, we discover a bromodomain (BRD)-like module in DNA-PKcs (DNA-PKcs-BRD) that specifically recognizes H2AX acetyl-lysine 5 (K5ac) for sequential induction of γH2AX and concurrent cell fate decision(s). First, top-down mass spectrometry of radiation-phenotypic, full-length H2AX revealed a radiation-inducible, K5ac-dependent induction of γH2AX. Combined approaches of sequence-structure modeling/docking, site-directed mutagenesis, and biochemical experiments illustrated that through docking on H2AX K5ac, this non-canonical BRD determines not only the H2AX-targeting activity of DNA-PKcs but also the over-activation of DNA-PKcs in radioresistant tumor cells, whereas a Kac antagonist, JQ1, was able to bind to DNA-PKcs-BRD, leading to re-sensitization of tumor cells to radiation. This study elucidates the mechanism underlying the H2AX-dependent regulation of DNA-PKcs in ionizing radiation-induced, differential DDR, and derives an unconventional, non-catalytic domain target in DNA-PKs for overcoming resistance during cancer radiotherapy
Improving myopia awareness via school-based myopia prevention health education among Chinese students
AIM: To investigate the myopia awareness level, knowledge, attitude, and skills at baseline and to implement and evaluate the efficacy of myopia prevention health education among Chinese students. METHODS: A total of 1000 middle school students from 2 middle schools were invited to participate in the study, and myopia prevention health education was conducted. The students were assessed at baseline, followed by a survey. The efficacy of health education was evaluated using the self-comparison method pre- and post-health education. RESULTS: The study included 957 and 850 pre- and post-health education participants, respectively. The baseline knowledge of all respondents on myopic symptoms (87.5%), myopia is a risk of eyes (72.9%), myopia prevention (91.3%), myopia increases with age (86.7%), performing periodic eye examinations (92.8%), and one first, one foot, and one inch (84.8%) significantly increased after health education (P<0.001 for all). However, the percentage of students who still did not think it necessary to take breaks after 30-40min of continuous near work was 27.0%. The opinion that “myopia can be cured” was still present in 38.3%. CONCLUSION: Implementing school-based myopia prevention health education improves knowledge, attitudes, and skills regarding myopia among Chinese middle school students
Curcumin’s Metabolites, Tetrahydrocurcumin and Octahydrocurcumin, Possess Superior Anti-inflammatory Effects in vivo Through Suppression of TAK1-NF-κB Pathway
Curcumin (CUR), a promising naturally occurring dietary compound, is commonly recognized as the potential anti-inflammatory agent. While the application of CUR was hampered by its low stability and poor systemic bioavailability, it has been suggested that the biological activities of CUR are intimately related to its metabolites. In the current investigation, we aimed to comparatively explore the anti-inflammatory effects of tetrahydrocurcumin (THC), octahydrocurcumin (OHC), and CUR, and to elucidate the underlying action mechanisms on experimental mice models of acute inflammation, i.e., xylene-induced ear edema, acetic acid-induced vascular permeability, and carrageenan-induced paw edema. The results showed that THC and OHC exerted significant and dose-dependent inhibitions on the formation of ear edema induced by xylene and paw edema provoked by carrageenan and inhibited the Evans blue dye leakage in peritoneal cavity elicited by acetic acid. Moreover, THC and OHC treatments were more effective than CUR in selectively inhibiting the expression of cyclooxygenase 2 (COX-2) and suppressing nuclear factor-κB (NF-κB) pathways via transforming growth factor β activated kinase-1 (TAK1) inactivation in the carrageenan-induced mouse paw edema model
An Analysis of the Sensitivity of Proteogenomic Mapping of Somatic Mutations and Novel Splicing Events in Cancer
Improvements in mass spectrometry (MS)-based peptide sequencing provide a new opportunity to determine whether polymorphisms, mutations, and splice variants identified in cancer cells are translated. Herein, we apply a proteogenomic data integration tool (QUILTS) to illustrate protein variant discovery using whole genome, whole transcriptome, and global proteome datasets generated from a pair of luminal and basal-like breast-cancer-patient-derived xenografts (PDX). The sensitivity of proteogenomic analysis for singe nucleotide variant (SNV) expression and novel splice junction (NSJ) detection was probed using multiple MS/MS sample process replicates defined here as an independent tandem MS experiment using identical sample material. Despite analysis of over 30 sample process replicates, only about 10% of SNVs (somatic and germline) detected by both DNA and RNA sequencing were observed as peptides. An even smaller proportion of peptides corresponding to NSJ observed by RNA sequencing were detected (<0.1%). Peptides mapping to DNA-detected SNVs without a detectable mRNA transcript were also observed, suggesting that transcriptome coverage was incomplete (∼80%). In contrast to germline variants, somatic variants were less likely to be detected at the peptide level in the basal-like tumor than in the luminal tumor, raising the possibility of differential translation or protein degradation effects. In conclusion, this large-scale proteogenomic integration allowed us to determine the degree to which mutations are translated and identify gaps in sequence coverage, thereby benchmarking current technology and progress toward whole cancer proteome and transcriptome analysis
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