Effect of hot isostatic pressing treatment on porosity reduction and mechanical properties enhancement of 316L stainless steel fabricated by binder jetting

In this work, a hot isostatic pressing (HIP) treatment was used to reduce the pores and improve the mechanical properties of binder jetting (BJ) fabricated 316L stainless steel. The relative density of the HIP treated samples sintered under vacuum, nitrogen, and argon atmospheres increased from 89.20∼90.76% to 94.02∼98.35%. The mean diameter of the internal closed pores decreased from 11.83∼14.70 μm to 0.94∼1.53 μm, and the internal porosity reduced from 5.47∼8.67% to 0.14∼0.35%. A remarkable enhancement of mechanical properties was achieved with the tensile strength by ∼15% and the elongation by ∼100% due to the reduction of porosity. The mechanical properties of the BJ 316L sintered under nitrogen and treated with HIP were even better than those of the direct powder HIP components due to the interstitial solution strengthening. These findings will be a valuable reference for optimising the HIP parameters to produce metal BJ components with superior mechanical properties

Fully Biobased Shape Memory Material Based on Novel Cocontinuous Structure in Poly(Lactic Acid)/Natural Rubber TPVs Fabricated via Peroxide-Induced Dynamic Vulcanization and in Situ Interfacial Compatibilization

Shape memory polymers (SMPs) based on fully biobased poly­(lactide) (PLA)/natural rubber (NR) thermoplastic vulcanizates (TPVs) were fabricated via peroxide-induced dynamic vulcanization. Simultaneously, in situ reactive compatibilization was achieved by PLA molecule grafting onto NR chains. Differing from the general concept of spherical rubber particles being formed after dynamic vulcanization, the cross-linked NR was found to be a “netlike” continuous phase in the PLA matrix. This novel structure explained the surprising shape memory property of PLA/NR TPVs well (shape fixities ∼ 100%, shape recoveries > 95%, and fast recovery speed < 15 s at the switching temperature, ∼60 °C): the cross-linked NR continuous phase offers strong resilience and the PLA phase serves as the heat-control switch. We envision that the “green” raw materials and excellent shape memory properties of the dynamically vulcanized PLA/NR SMPs will open up a wide range of potential applications in intelligent medical devices

Bio-Based PLA/NR-PMMA/NR Ternary Thermoplastic Vulcanizates with Balanced Stiffness and Toughness: “Soft–Hard” Core–Shell Continuous Rubber Phase, In Situ Compatibilization, and Properties

Stiffness and toughness are two mutually exclusive attributes of polymer materials that contribute to significant improvements in impact strength, usually accompanied by a reduction in tensile strength. In this study, ternary thermoplastic vulcanizates (TPVs) consisting of poly­(lactic acid) (PLA), poly­(methyl methacrylate)-grafted natural rubber (NR-PMMA), and natural rubber (NR) with balanced stiffness and toughness were successfully prepared via peroxide-induced dynamic vulcanization. With 10 wt% of NR and NR-PMMA, the PLA/NR-PMMA/NR ternary TPV displayed an enhanced yield stress of 41.7 MPa (only 38% loss compared to neat PLA) and a significantly higher impact strength of 91.30 kJ/m² (nearly 32 times that of neat PLA). The in situ compatibilization between PLA and rubber phases was confirmed by Fourier transform infrared spectroscopy. Interfacial, rheological, and calorimetric measurements confirmed that the NR was encapsulated by NR-PMMA in the PLA phase. It was found that the flexibility of the “soft” NR core and outer “hard” NR-PMMA shell with excellent PLA/rubber interfacial adhesion are responsible for the super toughness and considerable tensile strength of the PLA/NR-PMMA/NR ternary TPVs

The role of Cdx2 as a lineage specific transcriptional repressor for pluripotent network during the first developmental cell lineage segregation

The first cellular differentiation event in mouse development leads to the formation of the blastocyst consisting of the inner cell mass (ICM) and trophectoderm (TE). The transcription factor CDX2 is required for proper TE specification, where it promotes expression of TE genes, and represses expression of Pou5f1 (OCT4). However its downstream network in the developing embryo is not fully characterized. Here, we performed high-throughput single embryo qPCR analysis in Cdx2 null embryos to identify CDX2-regulated targets in vivo. To identify genes likely to be regulated by CDX2 directly, we performed CDX2 ChIP-Seq on trophoblast stem (TS) cells. In addition, we examined the dynamics of gene expression changes using inducible CDX2 embryonic stem (ES) cells, so that we could predict which CDX2-bound genes are activated or repressed by CDX2 binding. By integrating these data with observations of chromatin modifications, we identify putative novel regulatory elements that repress gene expression in a lineage-specific manner. Interestingly, we found CDX2 binding sites within regulatory elements of key pluripotent genes such as Pou5f1 and Nanog, pointing to the existence of a novel mechanism by which CDX2 maintains repression of OCT4 in trophoblast. Our study proposes a general mechanism in regulating lineage segregation during mammalian development

Bile acid profiling as an effective biomarker for staging in pediatric inflammatory bowel disease

ABSTRACTRapid and accurate clinical staging of pediatric patients with inflammatory bowel disease (IBD) is crucial to determine the appropriate therapeutic approach. This study aimed to identify effective, convenient biomarkers for staging IBD in pediatric patients. We recruited cohorts of pediatric patients with varying severities of IBD to compare the features of the intestinal microbiota and metabolites between the active and remitting disease stages. Metabolites with potential for staging were targeted for further assessment in both patients and colitis model mice. The performance of these markers was determined using machine learning and was validated in a separate patient cohort. Pediatric patients with IBD exhibited distinct gut microbiota structures at different stages of disease activity. The enterotypes of patients with remitting and active disease were Bacteroides-dominant and Escherichia-Shigella-dominant, respectively. The bile secretion pathway showed the most significant differences between the two stages. Fecal and serum bile acid (BA) levels were strongly related to disease activity in both children and mice. The ratio of primary BAs to secondary BAs in serum was developed as a novel comprehensive index, showing excellent diagnostic performance in stratifying IBD activity (0.84 area under the receiver operating characteristic curve in the primary cohort; 77% accuracy in the validation cohort). In conclusion, we report profound insights into the interactions between the gut microbiota and metabolites in pediatric IBD. Serum BAs have potential as biomarkers for classifying disease activity, and may facilitate the personalization of treatment for IBD

Additional file 15: of Mapping human pluripotent stem cell differentiation pathways using high throughput single-cell RNA-sequencing

Table S14. List of GO terms used in Additional file 1: Figure S9. (XLSX 22 kb

Additional file 4: of Mapping human pluripotent stem cell differentiation pathways using high throughput single-cell RNA-sequencing

Table S3. List of genes used in Fig. 2b for heatmap. (XLSX 468 kb

Additional file 2: of Mapping human pluripotent stem cell differentiation pathways using high throughput single-cell RNA-sequencing

Table S1. Immunofluorescence antibody. (XLSX 33 kb

Additional file 1: of Mapping human pluripotent stem cell differentiation pathways using high throughput single-cell RNA-sequencing

Figure S1. Quality control of the dataset. Figure S2. Surface marker analysis and GO enrichment analysis of lineage progenitors. Figure S3. FeaturePlot of specific genes from neural and muscle sub-clusters. Figure S4. Differentiation trajectories and GO analysis of neural and muscle sub-clusters. Figure S5. GO analysis and expression dynamics of gene clusters I–VI. Figure S6. Network of potential cell–cell interactions in EBs. Figure S7. Signaling pathways involved in differentiation of various progenitor cells. Figure S8. The identification of Naïve-like H9. Figure S9. Surface marker analysis and GO analysis of Primed and Naïve-like H9. Figure S10. The identification and GO analysis of Primed and Naïve-like H1 (Additional file 11: Table S10, Additional file 12: Table S11, Additional file 13: Table S12, Additional file 14: Table S13, Additional file 15: Table S14). (DOCX 19207 kb

Additional file 9: of Mapping human pluripotent stem cell differentiation pathways using high throughput single-cell RNA-sequencing

Table S8. List of genes used in Fig. 6c for heatmap. (XLSX 12 kb