A controllable gelatin-based microcarriers fabrication system for the whole procedures of MSCs amplification and tissue engineering.

Biopolymer microbeads present substantial benefits for cell expansion, tissue engineering, and drug release applications. However, a fabrication system capable of producing homogeneous microspheres with high precision and controllability for cell proliferation, passaging, harvesting and downstream application is limited. Therefore, we developed a co-flow microfluidics-based system for the generation of uniform and size-controllable gelatin-based microcarriers (GMs) for mesenchymal stromal cells (MSCs) expansion and tissue engineering. Our evaluation of GMs revealed superior homogeneity and efficiency of cellular attachment, expansion and harvest, and MSCs expanded on GMs exhibited high viability while retaining differentiation multipotency. Optimization of passaging and harvesting protocols was achieved through the addition of blank GMs and treatment with collagenase, respectively. Furthermore, we demonstrated that MSC-loaded GMs were printable and could serve as building blocks for tissue regeneration scaffolds. These results suggested that our platform held promise for the fabrication of uniform GMs with downstream application of MSC culture, expansion and tissue engineering.

Contrast-enhanced CT longitudinal tail sign as a marker of positive resection margins in adenoid cystic carcinoma of the central airway.

BACKGROUND: Due to submucosal infiltration's biological nature along the airway, adenoid cystic carcinoma (ACC) frequently leaves positive surgical margins. This study evaluated the clinicopathologic, and computed tomography (CT) features for predicting surgical margin status in central airway ACC. METHODS: We retrospectively analyzed the files of 71 patients with ACC of the central airway proven by histopathology and surgery who had presented between January 2010 and December 2018. All patients were classified into positive and negative surgical margin groups according to margin status. Univariate analysis and multivariable logistic regression models were then performed to compare demography, histopathology, and CT characteristics between ACC patients with positive and negative margins. RESULTS: After surgical resection, 59 (83.1%) patients had positive margins, and 12 (16.9%) had negative margins. The contrast-enhanced CT (CECT) longitudinal tail sign (LTS) was identified in 55 of 59 (93.2%) patients with positive margins and was the only feature that had a significant association with positive margins (odds ratio 41.250, 95% CI: 7.886-215.767; P<0.001). Moreover, positive margins in upper or/and lower directions were associated with the LTS in corresponding directions (P<0.001). CONCLUSIONS: Most central airway ACC patients exhibited positive margins following surgery. The appearance of the LTS on CECT was significantly associated with positive margins and could help preoperatively predict the submucosal invasion of ACC.

TruthTrust: Truth Inference-Based Trust Management Mechanism on a Crowdsourcing Platform.

On a crowdsourcing platform, in order to cheat for rewards or sabotage the crowdsourcing processes, spam workers may submit numerous erroneous answers to the tasks published by requesters. This type of behavior extremely reduces the completion rate of tasks and the enthusiasm of honest users, which may lead a crowdsourcing platform to a failure. Defending against malicious attacks is an important issue in crowdsourcing, which has been extensively addressed by existing methods, e.g., verification-based defense mechanisms, data analysis solutions, trust-based defense models, and workers' properties matching mechanisms. However, verification-based defense mechanisms will consume a lot of resources, and data analysis solutions cannot motivate workers to provide high-quality services. Trust-based defense models and workers' properties matching mechanisms cannot guarantee the authenticity of information when collusion requesters publish shadow tasks to help malicious workers get more participation opportunities. To defend such collusion attacks in crowdsourcing platforms, we propose a new defense model named TruthTrust. Firstly, we define a complete life cycle system that from users' interaction to workers' recommendation, and separately define the trust value of each worker and the credence of each requester. Secondly, in order to ensure the authenticity of the information, we establish a trust model based on the CRH framework. The calculated truth value and weight are used to define the global properties of workers and requesters. Moreover, we propose a reverse mechanism to improve the resistance under attacks. Finally, extensive experiments demonstrate that TruthTrust significantly outperforms the state-of-the-art approaches in terms of effective task completion rate.

Bacillus salipaludis sp. nov., isolated from saline-alkaline soil.

A Gram-staining-positive, endospore-forming, aerobic strain, designed WN066T, was isolated from saline-alkali wetland soil of Tianjin, China. Phylogenetic analysis based on 16S rRNA gene sequence indicated WN066T was a member of the genus of Bacillus, and most closely related to Bacillus drentensis DSM 15600T (98.9%), Bacillus cucumis CCM 8651T (98.8%), Bacillus bataviensis DSM 15601T (98.7%) and Bacillus niacini DSM 2923T (98.7%). However, the average nucleotide identity (ANI) and digital DNA-DNA hybridization (DDH) values between strain WN066T and the most closely related species were less than the previously proposed cutoff values for differentiating species within the genus, suggesting that this strain represented a novel Bacillus species. The strain grew at 19-42 °C (optimally 33-37 °C) in the presence of 3-20% (w/v) NaCl (optimally 8-12%(w/v)), and at pH 6.5-11.0 (optimally 7.5-8.5). The major cellular fatty acids were iso-C15:0 (24.8%) and anteiso-C15:0 (38.9%). The predominant polar lipids consisted of diphosphatidylglycerol (DPG), phosphatidylglycerol (PG) and phosphatidylethanolamine (PE). The size of the draft genome was 6,213,503 bp in size and had a G + C content of 38.6 mol %. The peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. On basis of phenotypic, phylogenetic, chemotaxonomic and genomic features, strain WN066T represented a novel species within the genus Bacillus, for which the name B. salipaludis sp. nov. is proposed. The type strain is WN066T (= KCTC 33953T = ACCC 60085T).

PD-L1 is increased in the spinal cord and infiltrating lymphocytes in experimental allergic encephalomyelitis.

Experimental allergic encephalomyelitis is a mouse model of human multiple sclerosis with similar pathology and pathogenesis. Th1 cells play an important role in the pathogenesis of experimental allergic encephalomyelitis. This study determined the potential effect of programmed cell death 1 ligand 1 in the pathogenesis of experimental allergic encephalomyelitis induced by injecting myelin oligodendrocyte glycoprotein, complete Freund's adjuvant and Bordetella pertussis toxin into C57BL/6J mice. Experimental allergic encephalomyelitis mice developed disease and showed inflammatory changes in the central nervous system by hematoxylin-eosin staining of spinal cord pathological sections, demyelination by Luxol fast-blue staining and clinical manifestations. The expression of programmed cell death 1 ligand 1 in mice was detected by immunohistochemistry, flow cytometry and western blot analysis. The expression of programmed cell death 1 ligand 1 in the spinal cord and splenocytes of mice was significantly increased compared with normal mice. Our findings suggest the involvement of programmed cell death 1 ligand 1 in the pathogenesis of experimental allergic encephalomyelitis and suggest this should be studied in multiple sclerosis.