118 research outputs found
Co-influence of nanofiller content and 3D printing parameters on mechanical properties of thermoplastic Polyurethane (TPU)/halloysite nanotube (HNT) nanocomposites
Thermoplastic polyurethane (TPU) belongs to a polyurethane family that possesses an
elongation much higher than 300%, despite having low mechanical strength, which can be overcome
by incorporating clay-based halloysite nanotubes (HNTs) as additives to manufacture TPU/HNT
nanocomposites. This paper focuses on the co-influence of HNT content and 3D printing parameters
on the mechanical properties of 3D printed TPU/HNT nanocomposites in terms of tensile properties,
hardness, and abrasion resistance via fused deposition modelling (FDM). The optimum factor-level
combination for different responses was determined with the aid of robust statistical Taguchi design of
experiments (DoEs). Material characterisation was also carried out to evaluate the surface morphology,
nanofiller dispersion, chemical structure, thermal stability, and phase behaviour corresponding to the
DoE results obtained. It is evidently shown that HNT level and infill density play a significant role in
impacting mechanical properties of 3D-printed TPU/HNT nanocomposites
Preparation and toughening mechanism of Al2O3 composite ceramic toughened by B4C@TiB2 coreāshell units
In this paper, the concept of incorporating coreāshell structured units as secondary phases to toughen Al2O3 ceramics is proposed. Al2O3 composite ceramics toughened by B4C@TiB2 coreāshell units are successfully synthesized using a combination of molten salt methodology and spark plasma sintering. The synthesis of B4C@TiB2 coreāshell toughening units stems from the prior production of coreāshell structural B4C@TiB2 powders, and this coreāshell structure is effectively preserved within the Al2O3 matrix after sintering. The B4C@TiB2 coreāshell toughening unit consists of a micron-sized B4C core enclosed by a shell approximately 500 nm in thickness, composed of numerous nanosized TiB2 grains. The regions surrounding these coreāshell units exhibit distinct geometric structures and encompass multidimensional variations in phase composition, grain dimensions, and thermal expansion coefficients. Consequently, intricate stress distributions emerge, fostering the propagation of cracks in multiple dimensions. This behavior consumes a considerable amount of crack propagation energy, thereby enhancing the fracture toughness of the Al2O3 matrix. The resulting Al2O3 composite ceramics display relative density of 99.7%Ā±0.2%, Vickers hardness of 21.5Ā±0.8 GPa, and fracture toughness 6.92Ā±0.22 MPaĀ·m1/2
Comparative genomics reveals Cyclospora cayetanensis possesses coccidia-like metabolism and invasion components but unique surface antigens
Assessment of the completeness of sequenced Toxoplasma gondii, Eimeria tenella and Cyclospora cayetanensis genomes based on core eukaryotic protein-encoding genes search using BUSCO. (DOCX 14 kb
Coexistence of Histologically Confirmed Hashimoto's Thyroiditis with Different Stages of Papillary Thyroid Carcinoma in a Consecutive Chinese Cohort
Purpose. To determine the relationship between Hashimoto's thyroiditis (HT) and all stages of papillary thyroid carcinoma (PTC) with or without local lymph node metastasis (LNM). Methods:. We conducted a retrospective study of thyroidectomies from 2008ā2013 in First Affiliated Hospital of Nanjing Medical University. We categorized patients according to the presence of histopathologically proven HT. The prevalence of mPTC (maximum diameter ā¤ 10 mm) and crPTC (clinical relevant PTC) and local LNM rates were compared. Results:. We evaluated 6,432 consecutive thyroidectomies. In total, 1,328 specimens were confirmed as HT. The prevalence of PTC in this HT cohort was 43.8%, significantly higher than non-HT group. After adjustment of gender and age, the prevalence of PTC was still higher in HT group. HT was a risk factor for PTC in multivariate analysis with odds ratio 2.725 (95% CI, 2.390ā3.109) (P < 0.001). However, no correlation was found between HT and LNM of PTC. Conclusion:. HT was associated with an increased prevalence of all stages of PTC, independent of tumor size, gender, and age. In contrast, locally advanced disease defined by LNM was unrelated to HT. These data suggest an association of HT with low risk PTC and a potential protective immunologic effect from further disease progression
Superior cervical ganglionectomy alters gut microbiota in rats
The diversity and complexity of sympathetic function highlight the importance of fundamental research. Little is known about the interaction of superior cervical sympathetic ganglion (SCG) and gut microbiota. In this study, the engagement of the sympathetic ganglia with gut microbiota was investigated. Bilateral superior cervical ganglionectomy (SCGx) significantly altered the microbiota composition in rats 14 days post-surgery, and these microbiotas may participate in several biological pathways in the host, suggesting the vital role of the cervical sympathetic ganglion in regulating the microbiome-brain axis, and further confirming that the sympathetic nervous system (SNS) regulates the microbiome-brain axis
ROS-scavenging hydrogel as protective carrier to regulate stem cells activity and promote osteointegration of 3D printed porous titanium prosthesis in osteoporosis
Stem cell-based therapy has drawn attention as an alternative option for promoting prosthetic osteointegration in osteoporosis by virtue of its unique characteristics. However, estrogen deficiency is the main mechanism of postmenopausal osteoporosis. Estrogen, as an effective antioxidant, deficienncy also results in the accumulation of reactive oxygen species (ROS) in the body, affecting the osteogenic differentiation of stem cells and the bone formation i osteoporosis. In this study, we prepared a ROS-scavenging hydrogel by crosslinking of epigallocatechin-3-gallate (EGCG), 3-acrylamido phenylboronic acid (APBA) and acrylamide. The engineered hydrogel can scavenge ROS efficiently, enabling it to be a cell carrier of bone marrow-derived mesenchymal stem cells (BMSCs) to protect delivered cells from ROS-mediated death and osteogenesis inhibition, favorably enhancing the tissue repair potential of stem cells. Further in vivo investigations seriously demonstrated that this ROS-scavenging hydrogel encapsulated with BMSCs can prominently promote osteointegration of 3D printed microporous titanium alloy prosthesis in osteoporosis, including scavenging accumulated ROS, inducing macrophages to polarize toward M2 phenotype, suppressing inflammatory cytokines expression, and improving osteogenesis related markers (e.g., ALP, Runx-2, COL-1, BSP, OCN, and OPN). This work provides a novel strategy for conquering the challenge of transplanted stem cells cannot fully function in the impaired microenvironment, and enhancing prosthetic osteointegration in osteoporosis
Efficacy of early biologic therapy versus late/conventional therapy in children and adolescents with Crohn's disease: A systematic review and meta-analysis
Background: The objective of this study was to estimate the effectiveness of early biologics compared to conventional treatment in the management of Crohn's disease among pediatric and adolescent patients.
Methods: A comprehensive literature search was conducted in four electronic databases to identify relevant studies published from inception to 2023. The inclusion criteria comprised randomized controlled trials (RCTs) and cohort studies that reported on the efficacy and clinical outcomes of early biologic therapy compared to late/conventional therapy in children with Crohn's disease. The quality of the studies was assessed using the Cochrane Risk of Bias tool and the Newcastle Ottawa scale.
Results: A total of 13 studies (2 RCTs and 11 cohort studies), involving 861 patients, were included in the meta-analysis. The results demonstrated that early biologic therapy was associated with a significantly higher rate of clinical remission (risk ratio [RR] 1.30, 95% confidence interval [CI] 1.10ā1.54), lower relapse rates (RR 0.33, 95% CI 0.21ā0.53), and improved mucosal healing (RR 1.47, 95% CI 1.10ā1.97) compared to late/conventional therapy. However, it should be noted that there was evidence of publication bias among studies reporting clinical remission.
Conclusion: In conclusion, early biologic therapy is significantly more effective in achieving clinical remission (within two years of diagnosis), promoting mucosal healing, and reducing relapse rates in pediatric and adolescent patients with Crohn's disease, compared to late/conventional therapy. These findings emphasize the importance of initiating biological therapy early in the treatment of Crohn's disease in this patient population
Upcycling of spent LiCoO2 cathodes via nickelā and manganeseādoping
Abstract Direct recycling has been regarded as one of the most promising approaches to dealingĀ with the increasing amount of spent lithiumāion batteries (LIBs). However, the current direct recycling method remains insufficient to regenerate outdated cathodes to meet current industry needs as it only aims at recovering the structure and composition of degraded cathodes. Herein, a nickel (Ni) and manganese (Mn) coādoping strategy has been adopted to enhance LiCoO2 (LCO) cathode for nextāgeneration highāperformance LIBs through a conventional hydrothermal treatment combined with short annealing approach. Unlike direct recycling methods that make no changes to the chemical composition of cathodes, the unique upcycling process fabricates a series of cathodes doped with different contents of Ni and Mn. The regenerated LCO cathode with 5% doping delivers excellent electrochemical performance with a discharge capacity of 160.23āmAhāgā1 at 1.0āC and capacity retention of 91.2% after 100 cycles, considerably surpassing those of the pristine one (124.05āmAhāgā1 and 89.05%). All results indicate the feasibility of such NiāMn coādopingāenabled upcycling on regenerating LCO cathodes
- ā¦