Influence of temperature, ripening time and calcination on the morphology and crystallinity of hydroxyapatite nanoparticles

Nano-sized hydroxyapatite (HA) particles were prepared by chemical precipitation through aqueous solutions of calcium chloride and ammonium hydrogenphosphate. The influence of temperature, ripening time and calcination on the crystallinity and morphology of the HA nanoparticles were investigated. It was found that the crystallinity and crystallite size increased with the increase of synthetic temperature and ripening time. XRD and TEM results showed that the morphology change of HA nanoparticles was related to their crystallinity. High crystallinity of HA led to regular shape and smooth surface of the nanoparticles. The crystallinity of HA powders increased greatly after calcination at 650 C for 6 h but the change of the crystallite size after calcination was dependent on the crystallinity and crystallite size of ‘‘as prepared’’ HA nanoparticles

Historical Development of the Undergraduate Educational Model at BIT from the Perspective of Suzhi Education

From the perspective of suzhi education, this study analyses the historical development of the undergraduate educational model at Beijing Institute of Technology (BIT). It could be argued that BIT’s talent-cultivating system’s transformations from 1940 to 2020 echo Chinese higher education’s reform and development. This study concludes that BIT has experienced four phases: (1) from advocacy for general-specialized education’s integration to general education’s disappearance, (2) from the rectification of specialized education to the germination of suzhi and general education, (3) the flourishing of suzhi education and general education, and (4) the establishment of the Shuyuan System. The case of BIT reflects Chinese higher education’s development and the process of transforming from meritocracy to popularization. Chinese universities have changed their paradigm from emphasizing specialized education to highlighting suzhi education, as well as from focusing on training students into specialists to stressing students’ holistic development

Chemokine receptor CXCR3 is important for lung tissue damage and airway remodeling induced by short-term exposure to cigarette smoking in mice

Aim: To investigate the role of chemokine receptor CXCR3 in cigarette smoking (CS)-induced pulmonary damage. Methods: CXCR3 knockout (CXCR3-/-) mice were used. Differences in airspace enlargement, mRNA expression of matrix metalloproteinases (MMPs), transforming growth factor (TGF) β1, CXCL10 in lung homogenates, and CXCL10 content in bronchoalveolar lavage (BAL) fluids and homogenates were compared between CXCR3-/- mice and wild-type (WT) mice three days after three-day CS exposures. Results: The linear intercept was significantly less in CXCR3-/- mice than in WT mice (30.1±0.9 μm vs 40.3±2.4 μm, P<0.01). Morphologically, collagen was deposited less around airways and vessels in CXCR3-/- mice. The lung hydroxyproline content was significantly lower in CXCR3-/- mice than in WT mice (6.0±1.0 μg/mL vs 12.0±1.6 μg/mL, P<0.05). Profoundly lower mRNA expression of MMP2, MMP12, TGFβ1, and CXCL10 was seen in lung homogenates from CXCR3-/- mice. CXCL10 concentrations in BAL fluid and lung homogenates were significantly lower in CXCR3-/- mice than in WT mice (BAL fluid: 19.3±1.4 pg/mL vs 24.8±1.6 pg/mL, P<0.05; lung homogenates: 76.6±7.0 pg/mL vs 119.5±15.9 pg/mL, P<0.05). Conclusion: CXCR3 is important in mediating lung tissue damage and airway remodeling following a short-term CS insult, possibly through up-regulation of CXCL10 and inducement of mRNA expression of MMPs. Targeting CXCR3 may be helpful for prevention of CS-induced pulmonary pathology

Tetra­kis(1-phenyl-1H-imidazole-κN 3)bis­(thio­cyanato-κN)nickel(II)

The title compound, [Ni(NCS)2(C9H8N2)4], crystallizes with two independent half-mol­ecules in the asymmetric unit and the NiII ions situated on centres of symmetry. In both independent mol­ecules, the NiII ion displays a compressed octa­hedral environment formed by four N atoms from the 1-phenyl-1H-imidazole ligands, which define the equatorial plane, with a mean Ni—N distance of 2.119 (11) Å, and two axial N atoms from two NCS− anions, with a mean Ni—N distance of 2.079 (7) Å. The crystal packing exhibits weak inter­molecular S⋯S contacts of 3.411 (2) Å

Feline mammary carcinoma stem cells are tumorigenic, radioresistant, chemoresistant and defective in activation of the ATM/p53 DNA damage pathway

AbstractCancer stem cells were identified in a feline mammary carcinoma cell line by demonstrating expression of CD133 and utilising the tumour sphere assay. A population of cells was identified that had an invasive, mesenchymal phenotype, expressed markers of pluripotency and enhanced tumour formation in the NOD-SCID mouse and chick embryo models. This population of feline mammary carcinoma stem cells was resistant to chemotherapy and radiation, possibly due to aberrant activation of the ATM/p53 DNA damage pathway. Epithelial–mesenchymal transition was a feature of the invasive phenotype. These data demonstrate that cancer stem cells are a feature of mammary cancer in cats

Novel biomass-based polymeric dyes: preparation and performance assessment in the dyeing of biomass-derived aldehyde-tanned leather

High-performance chrome-free leather production is currently one of the most concerning needs to warrant the sustainable development of the leather industry due to the serious chrome pollution. Driven by these research challenges, this work explores using biobased polymeric dyes (BPDs) based on dialdehyde starch and reactive small-molecule dye (reactive red 180, RD-180) as novel dyeing agents for leather tanned using a chrome-free, biomass-derived aldehyde tanning agent (BAT). FTIR, 1H NMR, XPS, and UV-visible spectrometry analyses indicated that a Schiff base structure was generated between the aldehyde group of dialdehyde starch (DST) and the amino group of RD-180, resulting in the successful load of RD-180 on DST to produce BPD. The BPD could first penetrate the BAT-tanned leather efficiently and then be deposited on the leather matrix, thus exhibiting a high uptake ratio. Compared with the crust leathers prepared using a conventional anionic dye (CAD), dyeing, and RD-180 dyeing, the BPD-dyed crust leather not only had better coloring uniformity and fastness but it also showed a higher tensile strength, elongation at break, and fullness. These data suggest that BPD has the potential to be used as a novel sustainable polymeric dye for the high-performance dyeing of organically tanned chrome-free leather, which is paramount to ensuring and promoting the sustainable development of the leather industry