In our study, we introduced a rapid, low-cost and nondestructive ‘surface spray’ method to achieve the quantitative detection of the pesticide residues on fruits skins. Taking advantage of the high ...enhancement ability of the surface-enhanced Raman spectroscopy (SERS) of the optimized Ag nanoparticles colloid, the limit of detection (LOD) of paraquat (PQ) on the peels of pears and apples could reach the order of magnitude of 10−9M, much lower than the maximum residue limit of 0.05mg/kg (∼10−4M) in a large number of countries including the USA and China. The quantitative detection of PQ was achieved as well. This opens a new avenue for advancing the applications of SERS technique in the fields of food safety, drug security, and environment monitoring.
A golden opportunity: A highly robust catalyst system consisting of gold nanoparticles supported on acid‐tolerant ZrO2 promoted the conversion of biomass‐derived levulinic acid (1) and formic acid ...(2) into γ‐valerolactone without the use of an external H2 supply (see scheme, red). The Au/ZrO2 catalyst was also used for the direct one‐pot synthesis of highly valuable pyrrolidone derivatives from 1, 2, and primary amines (see scheme, blue).
Self-healing injectable hydrogels can be formulated as three-dimensional carriers for the treatment of neurological diseases with desirable advantages, such as avoiding the potential risks of cell ...loss during injection, protecting cells from the shearing force of injection. However, the demands for biocompatible self-healing injectable hydrogels to meet above requirements and to promote the differentiation of neural stem cells (NSCs) into neurons remain a challenge. Herein, we developed a biocompatible self-healing polysaccharide-based hydrogel system as a novel injectable carrier for the delivery of NSCs. N-carboxyethyl chitosan (CEC) and oxidized sodium alginate (OSA) are the main backbones of the hydrogel networks, denoted as CEC-l-OSA hydrogel ("l" means "linked-by"). Owing to the dynamic imine cross-links formed by a Schiff reaction between amino groups on CEC and aldehyde groups on OSA, the hydrogel possesses the ability to self-heal into a integrity after being injected from needles under physiological conditions. The CEC-l-OSA hydrogel in which the stiffness mimicking nature brain tissues (100~1000 Pa) can be finely tuned to support the proliferation and neuronal differentiation of NSCs. The multi-functional, injectable, and self-healing CEC-l-OSA hydrogels hold great promises for NSC transplantation and further treatment of neurological diseases.
Abnormal epigenetic regulation has been implicated in oncogenesis. We report here the identification of somatic mutations by exome sequencing in acute monocytic leukemia, the M5 subtype of acute ...myeloid leukemia (AML-M5). We discovered mutations in DNMT3A (encoding DNA methyltransferase 3A) in 23 of 112 (20.5%) cases. The DNMT3A mutants showed reduced enzymatic activity or aberrant affinity to histone H3 in vitro. Notably, there were alterations of DNA methylation patterns and/or gene expression profiles (such as HOXB genes) in samples with DNMT3A mutations as compared with those without such changes. Leukemias with DNMT3A mutations constituted a group of poor prognosis with elderly disease onset and of promonocytic as well as monocytic predominance among AML-M5 individuals. Screening other leukemia subtypes showed Arg882 alterations in 13.6% of acute myelomonocytic leukemia (AML-M4) cases. Our work suggests a contribution of aberrant DNA methyltransferase activity to the pathogenesis of acute monocytic leukemia and provides a useful new biomarker for relevant cases.
Aim
The relationships between biome shifts and global environmental changes in temperate zone habitats have been extensively explored; yet, the historical dynamics of taxa found in the tropical rain ...forest (TRF) remain poorly known. This study aims to reconstruct the relationships between tropical rain forest shifts and global environmental changes through the patterns of historical biogeography of a pantropical family of monocots, the Zingiberaceae.
Location
Global.
Taxon
Zingiberaceae.
Methods
We sampled DNA sequences (nrITS, trnK, trnL‐trnF and psbA‐trnH) from GenBank for 77% of the genera, including 30% of species, in the Zingiberaceae. Global fossil records of the Zingiberaceae were collected from literatures. Rates of speciation, extinction and diversification were estimated based on phylogenetic data and fossil records through methods implemented in BAMM. Ancestral ranges were estimated using single‐tree BioGeoBEARS and multiple‐trees BioGeoBEARS in RASP. Dispersal rate through time and dispersal rate among regions were calculated in R based on the result of ancestral estimation.
Results
The common ancestor of the Zingiberaceae likely originated in northern Africa during the mid‐Cretaceous, with later dispersal to the Asian tropics. Indo‐Burma, rather than Malesia, was likely a provenance of the common ancestor of Alpinioideae–Zingiberoideae. Several abrupt shifts of evolutionary rates from the Palaeocene were synchronized with sudden global environmental changes.
Main conclusions
Integrating phylogenetic patterns with fossil records suggests that the Zingiberaceae dispersed to Asia through drift of the Indian Plate from Africa in the late Palaeocene. Formation of island chains, land corridors and warming temperatures facilitated the emigration of the Zingiberaceae to a broad distribution across the tropics. Moreover, dramatic fluctuations of the speciation rate of Zingiberoideae appear to have been synchronized with global climate fluctuations. In general, the evolutionary history of the Zingiberaceae broadens our understanding of the association between TRF shifts in distribution and past global environmental changes, especially the origin of TRF in Southeast Asia.
A novel biocompatible polysaccharide‐based self‐healing hydrogel, CEC‐l‐OSA‐l‐ADH hydrogel (“l” means “linked‐by”), is developed by exploiting the dynamic reaction of N‐carboxyethyl chitosan (CEC) ...and adipic acid dihydrazide (ADH) with oxidized sodium alginate (OSA). The self‐healing ability, as demonstrated by rheological recovery, macroscopic observation, and beam‐shaped strain compression measurement, is attributed to the coexistence of dynamic imine and acylhydrazone bonds in the hydrogel networks. The CEC‐l‐OSA‐l‐ADH hydrogel shows excellent self‐healing ability under physiological conditions with a high healing efficiency (up to 95%) without need for any external stimuli. In addition, the CEC‐l‐OSA‐l‐ADH hydrogel exhibits good cytocompatibility and cell release as demonstrated by three‐dimensional cell encapsulation. With these superior properties, the developed hydrogel holds great potential for applications in various biomedical fields, e.g., as cell or drug delivery carriers.
A novel biocompatible polysaccharide‐based self‐healing hydrogel containing dynamic imine and acylhydrazone bonds can be prepared by the dynamic reaction of N‐carboxyethyl chitosan, adipic acid dihydrazide with oxidized sodium alginate. The self‐healing efficiency can autonomously achieve 95% under physiological conditions, holding great potential for applications in biomedical field.
Growing evidence has shown that gut microbiome is a key factor involved in liver health. Therefore, gut microbiota modulation with probiotic bacteria, such as Saccharomyces boulardii, constitutes a ...promising therapy for hepatosis. In this study, we aimed to investigate the protective effects of S. boulardii on D-Galactosamine-induced liver injury in mice. Liver function test and histopathological analysis both suggested that the liver injury can be effectively attenuated by S. boulardii administration. In the meantime, S. boulardii induced dramatic changes in the gut microbial composition. At the phylum level, we found that S. boulardii significantly increased in the relative abundance of Bacteroidetes, and decreased the relative abundance of Firmicutes and Proteobacteria, which may explain the hepatic protective effects of S. boulardii. Taken together, our results demonstrated that S. boulardii administration could change the gut microbiota in mice and alleviate acute liver failure, indicating a potential protective and therapeutic role of S. boulardii.
Recent studies have shown that oxidative phosphorylation (OXPHOS) is a target for the effective attenuation of cancer drug resistance. OXPHOS inhibitors can improve treatment responses to anticancer ...therapy in certain cancers, such as melanomas, lymphomas, colon cancers, leukemias and pancreatic ductal adenocarcinoma (PDAC). However, the effect of OXPHOS on cancer drug resistance is complex and associated with cell types in the tumor microenvironment (TME). Cancer cells universally promote OXPHOS activity through the activation of various signaling pathways, and this activity is required for resistance to cancer therapy. Resistant cancer cells are prevalent among cancer stem cells (CSCs), for which the main metabolic phenotype is increased OXPHOS. CSCs depend on OXPHOS to survive targeting by anticancer drugs and can be selectively eradicated by OXPHOS inhibitors. In contrast to that in cancer cells, mitochondrial OXPHOS is significantly downregulated in tumor-infiltrating T cells, impairing antitumor immunity. In this review, we summarize novel research showing the effect of OXPHOS on cancer drug resistance, thereby explaining how this metabolic process plays a dual role in cancer progression. We highlight the underlying mechanisms of metabolic reprogramming in cancer cells, as it is vital for discovering new drug targets.
• Water-mediated fertilization is ubiquitous in early land plants. This ancestral mode of fertilization has, however, generally been considered to have been lost during the evolutionary history of ...terrestrial flowering plants.
• We investigated reproductive mechanisms in the subtropical ginger Cautleya gracilis (Zingiberaceae), which has two pollen conditions – granular and filiform masses – depending on external conditions. We tested whether rain transformed granular pollen into filiform masses and whether this then promoted pollen-tube growth and fertilization of ovules. Using experimental manipulations in the field we investigated the contribution of water-mediated fertilization to seed production.
• Rain caused granular pollen to form filiform masses of germinating pollen tubes, which transported sperm to ovules, resulting in fertilization and seed set. Flowers exposed to rain produced significantly more seeds than those protected from the rain, which retained granular pollen. Insect pollination made only a limited contribution to seed set because rainy conditions limited pollinator service.
• Our results reveal a previously undescribed fertilization mechanism in flowering plants involving water-mediated fertilization stimulated by rain. Water-mediated fertilization is likely to be adaptive in the subtropical monsoon environments in which C. gracilis occurs by ensuring reproductive assurance when persistent rain prevents insect-mediated pollination.
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