To review the advances in the computational fluid dynamics (CFD) in tissue engineering.
The latest research of CFD applied to tissue engineering were extensively retrieved and analyzed, the ...optimization of bioreactor design and the simulation of fluid dynamics and cell growth kinetics during tissue regeneration
were mainly reviewed.
The simulation and predictive capabilities of CFD can provide important guidance for the optimization of bioreactor design, and the cultivation of engineering tissue. The accuracy of model prediction results can be further improved by combining with experimental research.
As a new and effective research tool, CFD has its unique advantages in the application of tissue engineering. However, a more comprehensive and accurate simulation of the whole process of tissue regeneration still needs further studies.
Graphene-wrapped ZnO nanocomposites were fabricated by a simple solvothermal technology with a one-pot route. The structure and morphology of these as-fabricated samples were systematically ...characterized. The adding of graphene enhanced the content of the oxygen vacancy defect of the sample. All gas-sensing performances of sensors based on as-prepared samples were thoroughly studied. Sensors displayed an ultrahigh response and exceptional selectivity at room temperature under blue light irradiation. This excellent and enhanced toluene gas-sensing property was principally attributed to the synergistic impacts of the oxygen vacancy defect and the wrapped graphene in the composite sensor. The photo-activated graphene-wrapped ZnO sensor illustrated potential application in the practical detection of low concentrations of toluene under explosive environments.
Breathing in mammals relies on permanent rhythmic and bilaterally synchronized contractions of inspiratory pump muscles. These motor drives emerge from interactions between critical sets of brainstem ...neurons whose origins and synaptic ordered organization remain obscure. Here, we show, using a virus-based transsynaptic tracing strategy from the diaphragm muscle in the mouse, that the principal inspiratory premotor neurons share V0 identity with, and are connected by, neurons of the preBötzinger complex that paces inspiration. Deleting the commissural projections of V0s results in left-right desynchronized inspiratory motor commands in reduced brain preparations and breathing at birth. This work reveals the existence of a core inspiratory circuit in which V0 to V0 synapses enabling function of the rhythm generator also direct its output to secure bilaterally coordinated contractions of inspiratory effector muscles required for efficient breathing.The developmental origin and functional organization of the brainstem breathing circuits are poorly understood. Here using virus-based circuit-mapping approaches in mice, the authors reveal the lineage, neurotransmitter phenotype, and connectivity patterns of phrenic premotor neurons, which are a crucial component of the inspiratory circuit.
Despite years of research investigating osteoblast differentiation, the mechanisms by which transcription factors regulate osteoblast maturation, bone formation, and bone homeostasis is still ...unclear. It has been reported that runt-related transcription factor 1 (Runx1) is expressed in osteoblast progenitors, pre-osteoblasts, and mature osteoblasts; yet, surprisingly, the exact function of RUNX1 in osteoblast maturation and bone formation remains unknown. Here, we generated and characterized a pre-osteoblast and differentiating chondrocyte-specific Runx1 conditional knockout mouse model to study RUNX1's function in bone formation. Runx1 ablation in osteoblast precursors and differentiating chondrocytes via osterix-Cre (Osx-Cre) resulted in an osteoporotic phenotype and decreased bone density in the long bones and skulls of Runx1f/fOsx-Cre mice compared with Runx1f/f and Osx-Cre mice. RUNX1 deficiency reduced the expression of SRY-box transcription factor 9 (SOX9), Indian hedgehog signaling molecule (IHH), Patched (PTC), and cyclin D1 in the growth plate, and also reduced the expression of osteocalcin (OCN), OSX, activating transcription factor 4 (ATF4), and RUNX2 in osteoblasts. ChIP assays and promoter activity mapping revealed that RUNX1 directly associates with the Runx2 gene promoter and up-regulates Runx2 expression. Furthermore, the ChIP data also showed that RUNX1 associates with the Ocn promoter. In conclusion, RUNX1 up-regulates the expression of Runx2 and multiple bone-specific genes, and plays an indispensable role in bone formation and homeostasis in both trabecular and cortical bone. We propose that stimulating Runx1 activity may be useful in therapeutic approaches for managing some bone diseases such as osteoporosis.
In the present work, a two-layer hydroxyapatite (HA)/Cu-doped TiO2 composite coating was prepared via one-step micro-arc oxidation in an aqueous electrolyte containing calcium acetate, sodium ...di-hydrogen phosphate and ethylene diamine tetraacetic acid cupric disodium (CuNa2-EDTA) at a constant current density of 100 mA/cm2. After micro-arc oxidation for 20 min, Cu species incorporate into the TiO2 as CuO and Cu2O, resulting in the formation of Cu-doped TiO2-based coating. In addition, spherical-shaped HA phase of nanometre scale is also present on the Cu-doped TiO2-based coating. With HA phase boosting osseointegration and Cu species killing pathogenic microbes, a bi-functional coating fabricated by one-step micro-arc oxidation is of promising potential application in the bio-medical field.
In this work, we report on the gas-sensing behavior of Al-doped SnO2 nanotubes (NTs) in order to evaluate the effect of Al on improved sensing performance and propose an oxygen-vacancy-dominating ...sensing mechanism of SnO2. The hierarchical mesoporous Al-doped SnO2 NTs are fabricated by simple electrospinning method and annealing treatment. Al-doping shows profound influence on the oxygen vacancy of SnO2 which changes as a function of Al/(Al+Sn) ratio and the oxygen vacancy exhibits a maximum value when the ratio is 8%. As a result, the gas-sensing response to formaldehyde varies following the oxygen vacancies. Oxygen vacancies at the surface of SnO2 facilitate oxygen adsorption and the formation of surface catalytic active O−O−, thus the gas response is remarkably enhanced. Furthermore, a new fundamental understanding toward the gas-sensing performance of oxygen-vacancy-dominating SnO2 is proposed.
Inactivation of the RB1 tumor suppressor gene is common in several types of therapy-resistant cancers, including metastatic castration-resistant prostate cancer, and predicts poor clinical outcomes. ...Effective therapeutic strategies against RB1-deficient cancers remain elusive. Here, we showed that RB1 loss/E2F activation sensitized cancer cells to ferroptosis, a form of regulated cell death driven by iron-dependent lipid peroxidation, by upregulating expression of ACSL4 and enriching ACSL4-dependent arachidonic acid-containing phospholipids, which are key components of ferroptosis execution. ACSL4 appeared to be a direct E2F target gene and was critical to RB1 loss-induced sensitization to ferroptosis. Importantly, using cell line-derived xenografts and genetically engineered tumor models, we demonstrated that induction of ferroptosis in vivo by JKE-1674, a highly selective and stable GPX4 inhibitor, blocked RB1-deficient prostate tumor growth and metastasis and led to improved survival of the mice. Thus, our findings uncover an RB/E2F/ACSL4 molecular axis that governs ferroptosis and also suggest a promising approach for the treatment of RB1-deficient malignancies.
Vegetation cover plays a key role in terrestrial ecosystem; therefore, it is important for researchers to investigate the variation and influencing factors of vegetation cover. China has experienced ...a large-scale vegetation cover change in recent years. We summarized the literature of vegetation cover change and revealed how large-scale anthropogenic activities influence vegetation cover change in China. Afforestation and intensification of cropland played a key role in large-scale greening. Urbanization showed a “U” shape to influence vegetation cover change. Mining and reclamation, land abandonment and land consolidation, and regional natural protection all had a unique influence on the change of vegetation cover. Indeed, the large-scale vegetation cover change was caused by interaction of anthropogenic factors and part human-driven climate change. Anthropogenic factors influenced climate change to indirectly alter the condition of plant growth. Interaction between climate change and human activities influence on vegetation cover still needs to be further investigated in the future.
Atrial arrhythmia is an important cause of late death in patients after the Fontan-Style operation. However, the detailed electrophysiological characteristics of the post-Fontan atrium and its ...underlying mechanisms are largely unknown. In this study, we investigated electrophysiological characteristics and the ionic remodeling in the right atrium (RA) of a canine model after the Fontan operation. We performed the operation of RA to pulmonary artery connection to mimic the Fontan operation. We undertook hemodynamic measurements, cardiac electrophysiological studies, and ion current measurements. The expression of ionic channels was analyzed by PCR and western-blotting. Our Fontan model induced RA hypertension, enlarged the size of RA, and increased atrial fibrosis, representing the classic characteristic of Fontan patients. In the Fontan group, the atrial effective refractory period and the active potential duration were reduced, and the atrial tachycardia has been more often to be induced. The electrical conduction mapping showed that the Fontan group reduced the conduction velocity. The Fontan operation significantly down-regulated the expression of
KCND
3/Kv4.3,
CACNA1C
/Cav1.2 and
SCN5A
, but up-regulated the expression of
KCNJ2
/Kir2.1. Correspondingly, The Fontan operation reduced transient-outward (
I
to
) and L-type Ca2 (
I
Ca,L
) and
I
Na
currents, while increasing the inward-rectifier current (
I
K1
). Thus, the net shortening of the action potential in the post-Fontan atrium is associated with the altered expression of ionic channels which disturbed the balance between inward and outward currents. Taken together, the Fontan operation induces the ionic remodeling, and thus altered electrophysiological characteristics of the right atrium, improving our understanding on the pathophysiology of atrial arrhythmias in Fontan patients.
Articulated wheel loaders used in the construction industry are heavy vehicles and have poor stability and a high rate of accidents because of the unpredictable changes of their body posture, mass ...and centroid position in complex operation environments. This paper presents a novel distributed multi-sensor system for real-time attitude estimation and stability measurement of articulated wheel loaders to improve their safety and stability. Four attitude and heading reference systems (AHRS) are constructed using micro-electro-mechanical system (MEMS) sensors, and installed on the front body, rear body, rear axis and boom of an articulated wheel loader to detect its attitude. A complementary filtering algorithm is deployed for sensor data fusion in the system so that steady state margin angle (SSMA) can be measured in real time and used as the judge index of rollover stability. Experiments are conducted on a prototype wheel loader, and results show that the proposed multi-sensor system is able to detect potential unstable states of an articulated wheel loader in real-time and with high accuracy.
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