•Microbial fermentation is the key factor controlling the quality of dark tea.•Serial reactions modify the chemical constituents of tea leaves during fermentation.•Multi-omics approaches are used to ...reveal microbial impact on dark tea quality.
Dark tea is a unique fermented tea produced by solid-state fermentation of tea leaves (Camellia sinensis). It includes ripe Pu-erh tea, Fu brick tea, Liupao tea, and other teas. Microbial fermentation is considered to be the key factor controlling the quality of dark tea. It involves a series of reactions that modify the chemical constituents of tea leaves. These chemical conversions during microbial fermentation of dark tea are associated with a variety of functional core microorganisms. Further, Multi-omics approaches have been used to reveal the microbial impact on the conversion of the chemical components in dark tea. In the present review, we provide an overview of the most recent advances in the knowledge of the microbial bioconversion of the chemical components in dark tea, including the chemical composition of dark tea, microbial community composition and dynamics during the fermentation process, and the role of microorganisms in biotransformation of chemical constituents.
We report a 2-family cluster of persons infected with severe acute respiratory syndrome coronavirus 2 in the city of Zhoushan, Zhejiang Province, China, during January 2020. The infections resulted ...from contact with an infected but potentially presymptomatic traveler from the city of Wuhan in Hubei Province.
Vascular disease remains the leading cause of death and disability, the etiology of which often involves atherosclerosis. The current treatment of atherosclerosis by pharmacotherapy has limited ...therapeutic efficacy. Here we report a biomimetic drug delivery system derived from macrophage membrane coated ROS-responsive nanoparticles (NPs). The macrophage membrane not only avoids the clearance of NPs from the reticuloendothelial system, but also leads NPs to the inflammatory tissues, where the ROS-responsiveness of NPs enables specific payload release. Moreover, the macrophage membrane sequesters proinflammatory cytokines to suppress local inflammation. The synergistic effects of pharmacotherapy and inflammatory cytokines sequestration from such a biomimetic drug delivery system lead to improved therapeutic efficacy in atherosclerosis. Comparison to macrophage internalized with ROS-responsive NPs, as a live-cell based drug delivery system for treatment of atherosclerosis, suggests that cell membrane coated drug delivery approach is likely more suitable for dealing with an inflammatory disease than the live-cell approach.
Optical imaging in the second near infrared region (NIR‐II, 1000–1700 nm) provides higher resolution and deeper penetration depth for accurate and real‐time vascular anatomy, blood dynamics, and ...function information, effectively contributing to the early diagnosis and curative effect assessment of vascular anomalies. Currently, NIR‐II optical imaging demonstrates encouraging results including long‐term monitoring of vascular injury and regeneration, real‐time feedback of blood perfusion, tracking of lymphatic metastases, and imaging‐guided surgery. This review summarizes the latest progresses of NIR‐II optical imaging for angiography including fluorescence imaging, photoacoustic (PA) imaging, and optical coherence tomography (OCT). The development of current NIR‐II fluorescence, PA, and OCT probes (i.e., single‐walled carbon nanotubes, quantum dots, rare earth doped nanoparticles, noble metal‐based nanostructures, organic dye‐based probes, and semiconductor polymer nanoparticles), highlighting probe optimization regarding high brightness, longwave emission, and biocompatibility through chemical modification or nanotechnology, is first introduced. The application of NIR‐II probes in angiography based on the classification of peripheral vascular, cerebrovascular, tumor vessel, and cardiovascular, is then reviewed. Major challenges and opportunities in the NIR‐II optical imaging for vascular imaging are finally discussed.
Optical imaging in the second near infrared window (NIR‐II) provides a prospective strategy to early diagnosis and curative effect assessment of vascular anomalies. This review summarizes optimizations of the NIR‐II probes regarding fluorescence imaging, photoacoustic imaging, and optical coherence tomography to enable mapping of complicated vascular networks in deep tissues and molecular variations associated with vascular diseases.
We herein report a new coordination network that deforms in a smooth and reversible manner under either thermal or pressure stimulation. Concomitantly, the organic fluorophores coordinatively bound ...to the channel in a face‐to‐face arrangement respond to this structural deformation by finely adapting their conformation and arrangement. As a result, the material exhibits a remarkable dual‐stimuli‐responsive luminescence shift across almost the entire visible region: The emission color of the crystal gradually changes from cyan to green upon heating and then to red upon pressure compression. Furthermore, each stage exhibits a linear dependence of both the emission maximum and intensity on the stimulus and is fully reversible.
Coping with pressure and heat: In response to changes in temperature and pressure, the flexible scaffold of a luminescent coordination network underwent smooth and reversible structural deformation that regulated the conformation and arrangement of the emissive organic molecules coordinatively bound to the channel in the structure. As a result, a reversible fluorescence shift across almost the entire visible region was observed (see picture).
We report a phosphine‐catalyzed ring opening of electron‐deficient alkylidenecyclopropanes (ACPs) to generate allylic phosphonium zwitterions that resemble the well‐studied phosphine‐allene adducts ...but exhibit distinct properties. The potent reactivity of these intermediates has been demonstrated in three types of substrate‐controlled phosphine‐catalyzed rearrangements of alkylidenecyclopropylketones, which chemoselectively afford tri‐ and tetrasubstituted furans, and trisubstituted dienones in good yields.
One to three: Phosphine‐catalyzed activation of alkylidenecyclopropanes (ACPs) generates allylic phosphonium intermediates that resemble the well‐studied phosphine‐allene adducts but exhibit distinct properties. These intermediates facilitate three types of rearrangements to form polysubstituted furans and dienones.
Ramie, Boehmeria nivea (L.) Gaudich, family Urticaceae, is a plant native to eastern Asia, and one of the world's oldest fibre crops. It is also used as animal feed and for the phytoremediation of ...heavy metal‐contaminated farmlands. Thus, the genome sequence of ramie was determined to explore the molecular basis of its fibre quality, protein content and phytoremediation. For further understanding ramie genome, different paired‐end and mate‐pair libraries were combined to generate 134.31 Gb of raw DNA sequences using the Illumina whole‐genome shotgun sequencing approach. The highly heterozygous B. nivea genome was assembled using the Platanus Genome Assembler, which is an effective tool for the assembly of highly heterozygous genome sequences. The final length of the draft genome of this species was approximately 341.9 Mb (contig N50 = 22.62 kb, scaffold N50 = 1,126.36 kb). Based on ramie genome annotations, 30,237 protein‐coding genes were predicted, and the repetitive element content was 46.3%. The completeness of the final assembly was evaluated by benchmarking universal single‐copy orthologous genes (BUSCO); 90.5% of the 1,440 expected embryophytic genes were identified as complete, and 4.9% were identified as fragmented. Phylogenetic analysis based on single‐copy gene families and one‐to‐one orthologous genes placed ramie with mulberry and cannabis, within the clade of urticalean rosids. Genome information of ramie will be a valuable resource for the conservation of endangered Boehmeria species and for future studies on the biogeography and characteristic evolution of members of Urticaceae.
What a turnover! An efficient chiral iridium catalyst that bears a tridentate spiro aminophosphine ligand catalyzes the asymmetric hydrogenation of ketones with excellent enantioselectivities (up to ...99.9 % ee) and extremely high turnover numbers (TONs; as high as 4 550 000).
Chinese mahogany (Toona sinensis) is a woody plant that is widely cultivated in China and Malaysia. Toona sinensis is important economically, including as a nutritious food source, as material for ...traditional Chinese medicine and as a high‐quality hardwood. However, the absence of a reference genome has hindered in‐depth molecular and evolutionary studies of this plant. In this study, we report a high‐quality T. sinensis genome assembly, with scaffolds anchored to 28 chromosomes and a total assembled length of 596 Mb (contig N50 = 1.5 Mb and scaffold N50 = 21.5 Mb). A total of 34,345 genes were predicted in the genome after homology‐based and de novo annotation analyses. Evolutionary analysis showed that the genomes of T. sinensis and Populus trichocarpa diverged ~99.1–103.1 million years ago, and the T. sinensis genome underwent a recent genome‐wide duplication event at ~7.8 million years and one more ancient whole genome duplication event at ~71.5 million years. These results provide a high‐quality chromosome‐level reference genome for T. sinensis and confirm its evolutionary position at the genomic level. Such information will offer genomic resources to study the molecular mechanism of terpenoid biosynthesis and the formation of flavour compounds, which will further facilitate its molecular breeding. As the first chromosome‐level genome assembled in the family Meliaceae, it will provide unique insights into the evolution of members of the Meliaceae.
We report an asymptomatic child who was positive for a coronavirus by reverse transcription PCR in a stool specimen 17 days after the last virus exposure. The child was virus positive in stool ...specimens for at least an additional 9 days. Respiratory tract specimens were negative by reverse transcription PCR.
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