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1. chinaXiv:201908.00095 [pdf]

First report of immature feathers in juvenile?enantiornithines from the Early Cretaceous Jehol avifauna

Jingmai K. O’CONNOR; Amanda FALK; WANG Min; ZHENG Xiao-Ting
Subjects: Biology >> Zoology

Molting—the process replacing one plumage with another—is a critically important?biological function in Aves. This process annually replaces the feather coat, damaged by normal?wear and tear, produces ontogenetic changes in feathering, and produces alternate breeding?plumages associated with reproductive activity in adults. Immature, growing feathers are?encased in a keratinous sheath, giving them a narrow, tubular, and featureless appearance. The?complete loss of the sheath indicates the feather is mature. Despite the wealth of integumentary?data published from the Jehol Biota, immature feathers have never been definitively reported,?although they may potentially be preserved in a juvenile specimen of the non-avian oviraptorosaur?theropod dinosaur Similicaudipteryx from the 120 Ma Jiufotang Formation. A developing?feather has been reported in a 99 Ma enantiornithine neonate preserved in Burmese amber, in?which three-dimensional preservation makes interpretations of integumentary structures more?straightforward. Here we report on probable immature feathers in four juvenile enantiornithines?(Aves: Ornithothoraces) from the Jehol Group. As observed in developing feathers in extant?birds, the purported immature fossil feathers appear proximally narrow and featureless with?barbs protruding only distally. Based on our observations, we suggest that similar-appearing?feather structures preserved on the manus and tibiotarsus in the holotype of the enantiornithine?Cruralispennia multidonta may alternatively be interpreted as immature feathers. The presence?of immature feathers in combination with sexually dimorphic ornamental feathers in juvenile?enantiornithines suggests the complex molting patterns of Neornithes, in which such ornaments?only appear after several years (following several molts) when reproductive activity is achieved,?are limited to a subset of crownward avians.

submitted time 2019-08-27 From cooperative journals:《古脊椎动物学报》 Hits6156Downloads500 Comment 0

2. chinaXiv:201711.02431 [pdf]

Conditional knock-out of lipoic acid protein ligase 1 reveals redundancy pathway for lipoic acid metabolism in Plasmodium berghei malaria parasite

Wang, M?(Wang, Min); Wang, Q?(Wang, Qiong); Gao, X?(Gao, Xiang); Su, Z?(Su, Zhong)
Subjects: Biology >> Ecology

Background:?Lipoic?acid?is a cofactor?for?a-keto?acid?dehydrogenase system that is involved?in?the central energy?metabolism.?In?the apicomplexan?parasite,?Plasmodium,?lipoic?acid?protein?ligase?1?(LplA1) and LplA2 catalyse the ligation?of?acquired?lipoic?acid?to the dehydrogenase complexes?in?the mitochondrion. The enzymes LipB and LipA mediate?lipoic?acid?synthesis and ligation to the enzymes?in?the apicoplast. These enzymes?in?the?lipoic?acid?metabolism?machinery have been shown to play important roles?in?the biology?of?Plasmodium?parasites, but the relationship between the enzymes is not fully elucidated.?Methods: We used an anhydrotetracycline (ATc)-inducible transcription system to generate transgenic P. berghei parasites in which the lplA1 gene was conditionally knocked out (LplA1-cKO). Phenotypic changes and the lplA1 and lplA2 gene expression profiles of cloned LplA1-cKO parasites were analysed.Results: LplA1-cKO parasites showed severely impaired growth in vivo in the first 8 days of infection, and retarded blood-stage development in vitro, in the absence of ATc. However, these parasites resumed viability in the late stage of infection and mounted high levels of parasitemia leading to the death of the hosts. Although lplA1 mRNA expression was regulated tightly by ATc during the whole course of infection, lplA2 mRNA expression was significantly increased in the late stage of infection only in the LplA1-cKO parasites that were not exposed to ATc. Conclusions: The lplA2 gene can be activated as an alternative pathway to compensate for the loss of LplA1 activity and to maintain lipoic acid metabolism.

submitted time 2017-11-17 Hits372Downloads202 Comment 0

3. chinaXiv:201605.00712 [pdf]

A fully human monoclonal antibody targeting PD-L1 with potent anti-tumor activity

Luan, Yan; Chai, Dafei; Peng, Jianjian; Ma, Shuli; Wang, Min; Ma, Hui; Li, Xiang; Fu, Shilong; Pan, Xiaolong; Xu, Ting; Luan, Yan; Qin, Songbing; Wang, Xiaoxiao; Xu, Ting;
Subjects: Biology >> Biophysics >> Immunology

Background: Programmed cell death ligand-1 (PD-L1) with its receptor PD-1 pathway is overactivated in many tumors. Inhibiting the interaction of PD-L1 and PD-1 is an attractive strategy to restore tumor-specific T cell immunity for tumor therapy. Methods: A fully human anti-PD-L1 monoclonal antibody (mAb) B60-55 was identified by yeast surface display. The affinity, specificity, activity, and efficacy of mAb B60-55 were investigated in vitro or in vivo. Results: mAb B60-55 (purity >99%) could bind to PD-L1 that is expressed on HEK293 cells with a dissociation constant of 02 nM, and specifically bind to human or cynomolgus macaque PD-L1 without a cross-reaction with murine PD-L1. Moreover, mAb B60-55 is an antagonistic antibody, which can block PD-L1 binding to its receptors, including PD-1 (PDCD1) and B7.1 (CD80). In vitro assays demonstrated the ability of mAb B60-55 to enhance T cell responses and cytokine production in the mixed lymphocyte reaction. In vivo studies showed that administration of mAb B60-55 exhibited a potent antitumor activity toward tumor cell carcinoma xenograft, with a mean half-life of 177.9 h in cynomolgus monkeys. Conclusion: mAb B60-55 is a potential candidate for clinical development in cancer treatment. (C) 2016 Elsevier B.V. All rights reserved.

submitted time 2016-05-05 Hits1203Downloads687 Comment 0

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