A dendritic amphiphilic block copolymer H40‐poly( d,l ‐lactide)‐block‐d‐α‐tocopheryl polyethylene glycol 1000 succinate (H40‐PLA‐ b ‐TPGS) is synthesized, which is then employed to develop a system of nanoparticles (NPs) loaded with docetaxel (DTX) as a model drug for cancer treatment due to its higher drug‐loading content and drug encapsulation efficiency, smaller particle size, faster drug release, and higher cellular uptake in comparison to the linear PLA polymer NPs and PLA‐ b ‐TPGS copolymer NPs. The drug‐loaded NPs are prepared by a modified nanoprecipitation method and characterized in terms of size and size distribution, surface morphology, drug release profile, and physical state of DTX. Cellular uptake of coumarin 6‐loaded NPs by MCF‐7 cancer cells is determined by flow cytometry and confocal laser scanning microscopy. The antitumor efficacy of the drug‐loaded NPs is investigated in vitro by MTT assay and in vivo by xenograft tumor model. The 72 h IC50 of the drug formulated in the PLA, PLA‐ b ‐TPGS, and H40‐PLA‐ b ‐TPGS NPs is found to be, 1.5 ± 0.3, 0.9 ± 0.1, and 0.15 ± 0.06 μg mL −1 , which are 7.3, 12.2, and 73.3‐fold effective than 11.0 ± 1.2 μg mL −1 for Taxotere, respectively. Such advantages are further confirmed by the measurement of the tumor size and weight.
Abstract A new pollination mechanism is reported of an orchid species, Bulbophyllum penicillium, based on a field observation in Southeast Yunnan of China. This species has a sensitive lip, and there is a distance of 2–3 mm between it and column apex. Once the lip is touched by a landing insect, it will move up and down or swing left and right continuously, just like a moving caterpillar. By suck a lip movement, the pollinator, a very small fruit fly (Drosophila sp.) ca. 1 mm in height, will be pressed toward the column apex where anther and stigma are located, and then cross-pollination takes place. This unique mode of pollination, depending on the movement of lip rather than insect itself, has never been found before in either Orchidaceae or other families of angiosperms.
Background The monocot family Hypoxidaceae consists of nine genera with nearly 200 species. They occur mostly in the Southern Hemisphere with only a few species in the Northern Hemisphere, of which three genera, Hypoxis, Molineria, and Curculigo, with eight species are distributed in China. Recently, we have found a hypoxid-like plant in China that is quite different in floral structure from any of the three genera and even of the known taxa in Hypoxidaceae. Methodology/Principal Findings In addition to morphological analysis, we performed maximum parsimony, maximum likelihood, and Bayesian inference analyses based on fragments of the chloroplast matK and rbcL genes of 60 taxa in 12 families representing all major clades of the Hypoxidaceae alliance. Results showed that Hypoxidaceae is monophyletic and and that the new plant belongs to it, forming a distinct clade within the family Hypoxidaceae as a sister of Molineria. Phylogeny of the Hypoxidaceae family was constructed based on a combined matrix of the chloroplast rbcL, trnS-G, and trnL-F regions of 59 taxa in Hypoxidaceae and its alliance. Findings of the molecular investigation is consistent with those of the morphological analysis. Conclusions/Significance Based on the results of our molecular and morphological analyses in the present study, we propose a new genus, Sinocurculigo.
Containing the largest number of species, the orchid family provides not only materials for studying plant evolution and environmental adaptation, but economically and culturally important ornamental plants for human society. Previously, we collected genome and transcriptome information of Dendrobium catenatum, Phalaenopsis equestris, and Apostasia shenzhenica which belong to two different subfamilies of Orchidaceae, and developed user-friendly tools to explore the orchid genetic sequences in the OrchidBase 4.0. The OrchidBase 4.0 offers the opportunity for plant science community to compare orchid genomes and transcriptomes and retrieve orchid sequences for further study.In the year 2022, two whole-genome sequences of Orchidoideae species, Platanthera zijinensis and Platanthera guangdongensis, were de novo sequenced, assembled and analyzed. In addition, systemic transcriptomes from these two species were also established. Therefore, we included these datasets to develop the new version of OrchidBase 5.0. In addition, three new functions including synteny, gene order, and miRNA information were also developed for orchid genome comparisons and miRNA characterization.OrchidBase 5.0 extended the genetic information to three orchid subfamilies (including five orchid species) and provided new tools for orchid researchers to analyze orchid genomes and transcriptomes. The online resources can be accessed at https://cosbi.ee.ncku.edu.tw/orchidbase5/.
Multimode Q-switching and spatiotemporal mode-locking are achieved in multimode fiber lasers. The transition between multimode Q-switching and spatiotemporal mode-locking is experimentally revealed.
We report experimental observation of multimode Q -switching and spatiotemporal mode locking in a multimode fiber laser. A typical steady Q -switching state is achieved with a 1.88 μs pulse duration, a 70.14 kHz repetition rate, and a 215.8 mW output power, corresponding to the single pulse energy of 3.08 μJ. We find weak spatial filtering is essential to obtain stable Q -switched pulses, in contrast to the relatively stronger spatial filtering for spatiotemporal mode locking. Furthermore, a reversible transition process, as well as a critical bistable state, between multimode Q -switching and spatiotemporal mode locking, is achieved with specific spatial coupling and waveplates sets. We believe the results will not only contribute to understanding the complicated nonlinear dynamics in multimode, fiber-based platforms, but also benefit the development of promising high-pulse energy lasers.
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