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A technique for simultaneous measurement of a 2D bend by using a cantilever-mounted fibre Bragg grating (FBG) is experimentally demonstrated. The value of the two-dimensional deflections is acquired from the central wavelength and chirp bandwidth of the reflection spectrum via the inverse sensitivity matrix. Moreover, an interrogation system with an intensity modulator and a Mach–Zehnder interferometer structure is demonstrated, not only providing wavelength information, but also distinguishing the direction of the horizontal deflection. The measured vertical deflection sensitivity reaches 0.135 nm mm−1, and its horizontal counterparts along the positive and negative axes achieve 0.602 nm mm−1 and −0.572 nm mm−1, respectively. [ABSTRACT FROM AUTHOR]

Objective: To investigate the sensitivity of tumor organoids derived from samples of colorectal cancer to lobaplatin and oxaliplatin hyperthermic perfusion in vitro and to assist clinical development of hyperthermic intraperitoneal chemotherapy. Method: Tumor samples and relevant clinical data were collected from patients with pathologically confirmed colorectal cancer in the Sixth Affiliated Hospital of Sun Yat-sen University from July 2021 to December 2022. Organoids were cultured and tumor tissue were passaged. In vitro hyperthermic perfusion experiments were performed on organoids with good viability. Firstly, 10 organoids were treated with oxaliplatin and lobaplatin at the following six concentrations: 1 000, 250, 62.5, 15.6, 3.9, and 0.98 μmol/L. The organoids were exposed to oxaliplatin at 42℃ for 30 minutes and to lobaplatin at 42℃ for 60 minutes. Dose-response curves of responses to in vitro hyperthermic perfusion with these two drugs were constructed and evaluated. Clinical doses of oxaliplatin and lobaplatin were further tested on 30 organoids. This testing revealed oxaliplatin was effective at 579 µmol/L at a hyperthermic perfusion temperature of 42℃ for 30 min and lobaplatin was effective at 240 µmol/L at a hyperthermic perfusion temperature of 42℃ for 60 minutes. Result: Thirty-two tumor organoids were cultured from samples of colorectal cancer. The median concentration required for oxaliplatin to eliminate 50% of tumor cells (IC50) was 577.45 µmol/L (IQR: 1846.09 µmol/L). The median IC50 for lobaplatin was 85.04 µmol/L (IQR: 305.01 µmol/L).The difference between the two groups was not statistically significant ( Z =1.784, P =0.084). In seven of 10 organoids, lobaplatin showed a greater IC50 after in vitro hyperthermic perfusion than did oxaliplatin. Testing of 30 organoids with clinical doses of oxaliplatin and lobaplatin revealed that oxaliplatin achieved an average inhibition rate of 39.6% (95%CI: 32.1%‒47.0%), whereas the average rate of inhibition for lobaplatin was 89.7% (95%CI: 87.0%‒92.3%): this difference is statistically significant ( t =‒15.282, P <0.001). Conclusion: The rate of inhibition achieved by hyperthermic perfusion of lobaplatin in vitro is better than that achieved by hyperthermic perfusion with oxaliplatin. Lobaplatin is more effective than oxaliplatin when administered by hyperthermic intraperitoneal perfusion and therefore has the potential to replace oxaliplatin in this setting.

Studying vegetation cover variation and its responding mechanism to climate change and human activities is of great significance for regional ecological protection and vegetation restoration. In this study, on the basis of MODIS NDVI, in situ climate data, and land use type data using Theil-Sen Median analysis, the Mann-Kendall significance test, residual analysis, partial correlation analysis, and multi-correlation analysis, the spatial and temporal variation in vegetation cover and its response to climate change and the land use/land cover change in each geomorphological unit in southwest China were analyzed. The vegetation cover showed a fluctuant increasing trend, and the changing trend exhibited obvious spatial heterogeneity, with the increasing rate being higher in the southeast and lower in the northwest of southwest China from 2000 to 2020. The vegetation variation was dominated by positive effects of the climate change and human activities in southwest China, and the positive effects were stronger in Guangxi Hill than those in other geomorphological units. Furthermore, from 2000 to 2020 the vegetation cover was positively associated with precipitation and temperature and negatively correlated with relative humidity and sunshine duration in southwest China. Temperature was considered to be the dominate climate factor controlling the vegetation variation in the study area. Urban expansion had decreased the region vegetation cover, but the overall vegetation cover had increased in southwest China due to the suitable regional climate conditions and the implementation of ecological reforestation projection. These results can provide scientific references for ecological protection and economic sustainable development in southwest China.

Aging is the greatest challenge to humankind worldwide. Aging is associated with a progressive loss of physiological integrity due to a decline in cellular metabolism and functions. Such metabolic changes lead to age-related diseases, thereby compromising human health for the remaining life. Thus, there is an urgent need to identify geroprotectors that regulate metabolic functions to target the aging biological processes. Nutrients are the major regulator of metabolic activities to coordinate cell growth and development. Iron is an important nutrient involved in several biological functions, including metabolism. In this study using yeast as an aging model organism, we show that iron supplementation delays aging and increases the cellular lifespan. To determine how iron supplementation increases lifespan, we performed a gene expression analysis of mitochondria, the main cellular hub of iron utilization. Quantitative analysis of gene expression data reveals that iron supplementation upregulates the expression of the mitochondrial tricarboxylic acid (TCA) cycle and electron transport chain (ETC) genes. Furthermore, in agreement with the expression profiles of mitochondrial genes, ATP level is elevated by iron supplementation, which is required for increasing the cellular lifespan. To confirm, we tested the role of iron supplementation in the AMPK knockout mutant. AMPK is a highly conserved controller of mitochondrial metabolism and energy homeostasis. Remarkably, iron supplementation rescued the short lifespan of the AMPK knockout mutant and confirmed its anti-aging role through the enhancement of mitochondrial functions. Thus, our results suggest a potential therapeutic use of iron supplementation to delay aging and prolong healthspan.

RAD17, a replication factor C (RFC)-like DNA damage sensor protein, is involved in DNA checkpoint control and required for both meiosis and mitosis in yeast and mammals. In plant, the meiotic function of RAD17 was only reported in rice so far. Here, we identified and characterized the RAD17 homolog in maize. The Zmrad17 mutants exhibited normal vegetative growth but male was partially sterile. In Zmrad17 pollen mother cells, non-homologous chromosome entanglement and chromosome fragmentation were frequently observed. Immunofluorescence analysis manifested that DSB formation occurred as normal and the loading pattern of RAD51 signals was similar to wild-type at the early stage of prophase I in the mutants. The localization of the axial element ASY1 was normal, while the assembly of the central element ZYP1 was severely disrupted in Zmrad17 meiocytes. Surprisingly, no obvious defect in female sterility was observed in Zmrad17 mutants. Taken together, our results suggest that ZmRAD17 is involved in DSB repair likely by promoting synaptonemal complex assembly in maize male meiosis. These phenomena highlight a high extent of divergence from its counterpart in rice, indicating that the RAD17 dysfunction can result in a drastic dissimilarity in meiotic outcome in different plant species., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Zhang, Jing, Liu and He.)

The meiotic TopoVI B subunit (MTopVIB) plays an essential role in double-strand break formation in mouse ( Mus musculus ), Arabidopsis ( Arabidopsis thaliana ), and rice ( Oryza sativa ), and recent work reveals that rice MTopVIB also plays an unexpected role in meiotic bipolar spindle assembly, highlighting multiple functions of MTopVIB during rice meiosis. In this work, we characterized the meiotic TopVIB in maize ( Zea mays ; ZmMTOPVIB ). The ZmmtopVIB mutant plants exhibited normal vegetative growth but male and female sterility. Meiotic double-strand break formation was abolished in mutant meiocytes. Despite normal assembly of axial elements, mutants showed severely affected synapsis and disrupted homologous pairing. Importantly, we showed that bipolar spindle assembly was also affected in ZmmtopVIB , resulting in triad and polyad formation. Overall, our results demonstrate that ZmMTOPVIB plays critical roles in double-strand break formation and homologous recombination. In addition, our results suggest that the function of MTOPVIB in bipolar spindle assembly is likely conserved across different monocots., (© 2020 American Society of Plant Biologists. All Rights Reserved.)

Meiosis is an essential cell-division process for ensuring genetic diversity across generations. Meiotic recombination ensures the accuracy of genetic interchange between homolous chromosomes and segregation of parental alleles. Programmed DNA double-strand breaks (DSBs), catalyzed by the evolutionarily conserved topoisomerase VIA (a subunit of the archaeal type II DNA topoisomerase)-like enzyme Spo11 and several other factors, is a distinctive feature of meiotic recombination initiation. The meiotic DSB formation and its regulatory mechanisms are similar among species, but certain aspects are distinct. In this review, we introduced the cumulative knowledge of the plant proteins crucial for meiotic DSB formation and technical advances in DSB detection. We also summarized the genome-wide DSB hotspot profiles for different model organisms. Moreover, we highlighted the classical views and recent advances in our knowledge of the regulatory mechanisms that ensure the fidelity of DSB formation, such as multifaceted kinase-mediated phosphorylation and the consequent high-dimensional changes in chromosome structure. We provided an overview of recent findings concerning DSB formation, distribution and regulation, all of which will help us to determine whether meiotic DSB formation is evolutionarily conserved or varies between plants and other organisms.

DNA methylation plays a crucial role in suppressing mobilization of transposable elements and regulation of gene expression. A number of studies have indicated that DNA methylation pathways and patterns exhibit distinct properties in different species, including Arabidopsis, rice, and maize. Here, we characterized the function of DDM1 in regulating genome-wide DNA methylation in maize. Two homologs of ZmDDM1 are abundantly expressed in the embryo and their simultaneous disruption caused embryo lethality with abnormalities in cell proliferation from the early stage of kernel development. We establish that ZmDDM1 is critical for DNA methylation, at CHG sites, and to a lesser extent at CG sites, in heterochromatic regions, and unexpectedly, it is required for the formation of m CHH islands. In addition, ZmDDM1 is indispensable for the presence of 24-nt siRNA, suggesting its involvement in the RdDM pathway. Our results provide novel insight into the role of ZmDDM1 in regulating the formation of m CHH islands, via the RdDM pathway maize, suggesting that, in comparison to Arabidopsis, maize may have adopted distinct mechanisms for regulating m CHH., (© 2019 Institute of Botany, Chinese Academy of Sciences.)

Purpose: To summarize the clinical application of special designed Upcera ST zirconia all-ceramic restorations in cases with limited occlusal space., Methods: Twenty-one patients with 23-unit restorations were enrolled in this study. First, the shape of abutment teeth and diagnostic wax-up were captured and digitized by Sirona inEos system. Then, each individually shaped framework to grant a defined ST zirconia base core was created by the reduced program of inLab software. Finally, all restorations were veneered with VITA VM9 and evaluated at placement using modified U.S.Public Health Service Criteria 6 to 12 months after restoration. Patients were inquired with satisfaction questionnaire at the same time., Results: During 6 to 12 months of follow-up visit, except for one of 23 restorations was rated as failure by fractured root, none was replaced due to framework fracture or unrestorable delamination of the ceramic veneer. The shape and colour of all restorations were satisfactory., Conclusions: To ensure optimum long-term clinical results of all-ceramic crown restorations, one important key is to overcome the fragmentation of dental prosthesis through modifying the shape of restoration. Based on the results of this study, the specially designed processing technology shows sufficient stability for ST zirconia all-ceramic restorations within a short term, which is deserved to be used in selected cases.