Comparative evaluation of pit & fissure sealant retention using cotton roll & rubber dam isolation techniques – a systematic review & meta-analysis
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Characterization of cis-polyisoprene produced in Periploca sepium, a novel promising alternative source of natural rubber
Natural rubber is an important industrial raw material and is almost exclusively produced from Hevea brasiliensis latex. Because H. brasiliensis is limited its cultivation to specific tropical regions, the insufficient capacity of natural rubber has become increasingly urgent. To develop a novel alternative plant for natural rubber production, we selected a perennial shrub Periploca sepium, which is widely distributed from tropical to temperate regions. P. sepium can produce latex and contains the rubber component polyisoprene with a high-molecular-weight distribution ranging from 104-106. Its main chain structure was identified as cis-1,4-polyisoprene, similar to that of H. brasiliensis. The polyisoprenes were observed to be present mainly in the secondary phloem adjacent to the cambium and pith, and almost entirely overlapped with the distributions of three rubber particle-associated proteins, cis-prenyltransferase (CPT), small rubber particle protein (SRPP) and rubber elongation factor (REF). The three genes were genome edited via CRISPR-Cas9 in P. sepium, and the total contents and high-molecular-mass regions of the cis-polyisoprenes in the transgenic plants with mutations were reduced to different degrees, indicating that the three genes apparently play important roles in natural rubber biosynthesis. This research will promote the development of P. sepium as an alternative source of natural rubber.
Insights from a century of data reveal global trends in ex situ living plant collections
Ex situ living plant collections play a crucial role in providing nature-based solutions to twenty-first century global challenges. However, the complex dynamics of these artificial ecosystems are poorly quantified and understood, affecting biodiversity storage, conservation and utilization. To evaluate the management of ex situ plant diversity, we analysed a century of data comprising 2.2 million records, from a meta-collection currently holding ~500,000 accessions and 41% of global ex situ species diversity. Our study provides critical insights into the historical evolution, current state and future trajectory of global living collections. We reveal sigmoidal growth of a meta-collection that has reached capacity in both total accessions and total diversity, and identify intrinsic constraints on biodiversity management, including a median survival probability of 15 years. We explore the impact of external constraints and quantify the influence of the Convention on Biological Diversity, which we link to reduced acquisition of wild-origin and internationally sourced material by 44% and 38%, respectively. We further define the impact of these constraints on ex situ conservation but highlight targeted initiatives that successfully mitigate these challenges. Ultimately, our study underscores the urgent need for strategic prioritization and the re-evaluation of ex situ biodiversity management to achieve both scientific and conservation goals.
Microbiota transplantation for cotton leaf curl disease suppression—core microbiome and transcriptome dynamics
Microbiota transplantation is a strong tool for managing plant disease. This study investigates the effects of microbiota transplantation on Cotton Leaf Curl Disease (CLCuD) resistance in Gossypium hirsutum, a species with good fiber length but high susceptibility to biotic stresses. Using metabarcoding for V3-V4 16S rRNA gene amplicon, microbial fractions from both rhizosphere and phyllosphere of CLCuD-resistant species Gossypium arboreum, and susceptible cotton varieties are analyzed. Unique bacterial taxa have been identified associated with disease resistance. Interspecies and intraspecies microbiota transplantation is conducted, followed by CLCuD incidence assays. It is seen that rhizospheric microbiota transplantation from G. arboreum FDH228 significantly suppresses CLCuD in G. hirsutum varieties, outperforming exogenous salicylic acid application. While phyllospheric transplants also reduce disease incidence, they are less effective than rhizospheric transplants. Differential expression analysis DESeq2 is utilized to identify key bacterial genera correlated with CLCuD suppression, including Pseudoxanthomonas and Stenotrophomonas in the rhizosphere of G. arboreum FDH228. Functional pathway analysis reveals upregulation of stress response and metabolism in tolerant species. Transcriptomics reveals upregulation of genes involved in protein phosphorylation and stress response in interspecies rhizospheric microbiota transplants. This study highlights microbiota transplantation as a sustainable method for controlling CLCuD along with specific microbial and genetic mechanisms contributing to CLCuD resistance.
High-performance achromatic flat lens by multiplexing meta-atoms on a stepwise phase dispersion compensation layer
Flat optics have attracted interest for decades due to their flexibility in manipulating optical wave properties, which allows the miniaturization of bulky optical assemblies into integrated planar components. Recent advances in achromatic flat lenses have shown promising applications in various fields. However, it is a significant challenge for achromatic flat lenses with a high numerical aperture to simultaneously achieve broad bandwidth and expand the aperture sizes. Here, we present the zone division multiplex of the meta-atoms on a stepwise phase dispersion compensation (SPDC) layer to address the above challenge. In principle, the aperture size can be freely enlarged by increasing the optical thickness difference between the central and marginal zones of the SPDC layer, without the limit of the achromatic bandwidth. The SPDC layer also serves as the substrate, making the device thinner. Two achromatic flat lenses of 500 nm thickness with a bandwidth of 650–1000 nm are experimentally achieved: one with a numerical aperture of 0.9 and a radius of 20.1 µm, and another with a numerical aperture of 0.7 and a radius of 30.0 µm. To the best of our knowledge, they are the broadband achromatic flat lenses with highest numerical apertures, the largest aperture sizes and thinnest thickness reported so far. Microscopic imaging with a 1.10 µm resolution has also been demonstrated by white light illumination, surpassing any previously reported resolution attained by achromatic metalenses and multi-level diffractive lenses. These unprecedented performances mark a substantial step toward practical applications of flat lenses.
Fasting appetite-related gut hormone responses after weight loss induced by calorie restriction, exercise, or both in people with overweight or obesity: a meta‐analysis
Altered appetite-related gut hormone concentrations may reflect a physiological adaptation facilitating weight regain after weight loss. This review investigates hormonal changes after weight loss achieved through calorie restriction (CR), exercise (EX), or both combined (CREX).
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