Improving multi-block sigma-coordinate for 3D simulation of sediment transport and steep slope bed evolution

This paper aims at developing a multi-block sigma-coordinate to simulate morphological evolutions. The developed multi-block sigma-coordinate can represent a steep slope topography smoothly with different numbers of horizontal layers, without producing any truncation error and artificial flux (PGFE). The multi-block sigma–coordinate can easily increase the depth-direction resolution of the sediment transport module in the sub-regions, without the aggregation of computational points in the shallow areas which may be caused by using high resolution over the entire domain. The model is beneficial for long-term simulation of morphological evaluations in lakes where the bed slope near delta region (the sedimentary area which forms where a river enters a lake/ocean) is mostly steep, and delta keeps advancing down the lake. The multi-block sigma approach at the block interface, where the number of horizontal layers varies, allocates the flux to the neighboring cells according to two essential factors, namely “the common border length” and “satisfying continuity” which lead to defining the virtual cells. A series of numerical tests have been performed. Comparison between the numerical results, the analytical solutions, and the experimental data demonstrated an appreciable accuracy, a satisfactory performance and the efficiency of this scheme.

Synthesis of a magnetic-based yolk-shell nano-reactor: A new class of monofunctional catalyst by Cu0-nanoparticles and its application as a highly effective and green catalyst for A3 coupling reaction

Neutron stars with spin polarized self-interacting dark matter

Dark matter, one of the important portion of the universe, could affect thevisible matter in neutron stars. An important physical feature of dark matteris due to the spin of dark matter particles. Here, applying the piecewisepolytropic equation of state for the neutron star matter and the equation ofstate of spin polarized self-interacting dark matter, we investigate thestructure of neutron stars which are influenced by the spin polarizedself-interacting dark matter. The behavior of the neutron star matter and darkmatter portions for the stars with different values of the interaction betweendark matter particles and spin polarization of dark matter is considered. Inaddition, we present the value of the gravitational redshift of these stars indifferent cases of spin polarized and self-interacting dark matter.

Efficient and cost-effective generation of hepatocyte-like cells through microparticle-mediated delivery of growth factors in a 3D culture of human pluripotent stem cells

Biomedical application of human pluripotent stem cell-derived hepatocyte-like cells (hPSC-HLCs) relies on efficient large-scale differentiation, which is commonly performed by a suspension culture of three-dimensional (3D) multicellular spheroids in bioreactors. However, this approach requires large amounts of growth factors (GFs) and the need to overcome limited diffusional transport posed by the inherent 3D structure of hPSC spheroids. Here, we have hypothesized that localized delivery of GFs by incorporation of GF-laden degradable polymeric microparticles (MPs) within the hPSC spheroids would circumvent such limitations. In this study, GFs for hepatocytic differentiation were encapsulated in gelatin-coated poly (l-lactic acid)/poly (DL-lactic-co-glycolic acid) (PLLA/PLGA) MPs which were subsequently incorporated into the hPSC spheroids. Gene expression analyses demonstrated that MP delivery of the GFs resulted in similar expression levels of hepatocytic markers despite the use of 10-fold less total GFs. The differentiated HLCs in the MP group exhibited ultrastructure and functional characteristics comparable with the conventional soluble GF group. The generated HLCs in the MP group were successfully engrafted in an acute liver injury mouse model and maintained hepatocytic function after implantation. These results suggested that sustained and localized delivery of GFs using MPs might offer a novel approach towards scalable technologies for hepatocytic differentiation and engineer a better 3D microenvironment for cells.

Cardioprotective and anti-inflammatory effects of G-protein coupled receptor 30 (GPR30) on postmenopausal type 2 diabetic rats

Diabetic cardiomyopathy is the most common chronic disease in postmenopausal women, but the mechanism(s) is unclear. G-protein coupled receptor 30 (GPR30) is one of the receptors that binds to 17-β Estradiol (E2). To date, there is little information on GPR30 and its expression in postmenopausal type 2 diabetes (T2D) in the heart. The current study hypothesized that GPR30 mediated cardioprotective effects of E2 in ovariectomized diabetic rats. Female ovariectomized diabetic rats were divided in nine groups: Control, Vehicle, Diabetes, Proestrous, Non-proestrous, E 2 , E2+Vehicle, E2+G15, and G1. G15 is a GPR30 antagonist, while G1 is an agonist of GPR30. T2D was induced by high fat diet and streptozotocin. E2, G1 and G15 were administrated for four weeks after establishment of T2D. Results showed that mean arterial pressure, fasting blood glucose and HOMA-IR in diabetic and vehicle groups were alleviated by E2 and G1, while salutary effects of E2 were inhibited by G15. Furthermore, E2 and G1 improved cardiac weight, atherogenic and cardiovascular risk indices; meanwhile G15 exacerbated cardiac weight and atherogenic indices. Also, diabetes increased cardiac levels of tumor necrosis factor-alpha and interleukin 6 and E2 only decreased interleukin 6. Significant decrement in the level of interleukin 10, and GPR30 protein were observed in diabetic group, whereas E2 and G1 increased the cardiac levels of interleukin 10, and GPR30 protein. Our study suggested that beneficial and anti-inflammatory effects of E2 on diabetic cardiomyopathy are probably mediated via non-genomic E2 pathways.

SIRT3-mediated cardiac remodeling/repair following myocardial infarction

The recent investigations have extensively focused on the importance of sirtuins, as a highly conserved family of gene products, particularly SIRT3 in various biological and pathological processes. SIRT3, the mitochondrial NAD+-dependent deacetylase has been demonstrated to target a broad range of proteins involved in the oxidative stress, ischemia-reperfusion injury, mitochondrial metabolism homeostasis and cellular death. The critical function of SIRT3 in myocardial infarction (MI), which is one of the complex phenotype of coronary artery disease and a result of interaction between various genetic and environmental factors, as well as in cardiac repair and remodeling post-MI have attracted more attention in the recent years. Therefore, in this review, we will summarize important literature about the involvement of SIRT3 in cardiac remodeling/repair following MI and its potential underlying mechanisms.

Is SUN2 Autoinhibited?

Molecular Insights into the Mechanisms of SUN1 Oligomerization in the Nuclear Envelope

The LINC complex is found in a wide variety of organisms and is formed by the transluminal interaction between outer- and inner-nuclear-membrane KASH and SUN proteins, respectively. Most extensively studied are SUN1 and SUN2 proteins, which are widely expressed in mammals. Although SUN1 and SUN2 play functionally redundant roles in several cellular processes, more recent studies have revealed diverse and distinct functions for SUN1. While several recent in vitro structural studies have revealed the molecular details of various fragments of SUN2, no such structural information is available for SUN1. Herein, we conduct a systematic analysis of the molecular relationships between SUN1 and SUN2, highlighting key similarities and differences that could lead to clues into their distinct functions. We use a wide range of computational tools, including multiple sequence alignments, homology modeling, molecular docking, and molecular dynamic simulations, to predict structural differences between SUN1 and SUN2, with the goal of understanding the molecular mechanisms underlying SUN1 oligomerization in the nuclear envelope. Our simulations suggest that the structural model of SUN1 is stable in a trimeric state and that SUN1 trimers can associate through their SUN domains to form lateral complexes. We also ask whether SUN1 could adopt an inactive monomeric conformation as seen in SUN2. Our results imply that the KASH binding domain of SUN1 is also inhibited in monomeric SUN1 but through weaker interactions than in monomeric SUN2.

NAP enzyme recruitment in simultaneous bioremediation and nanoparticles synthesis

The periplasmic nitrate reductase enzyme (NAP) has become attractive catalyst, whose exploitation has emerged as one of the indispensable strategies toward environmentally benign applications. To achieve them efficiently and overcome the sensitivity of NAP in harsh environmental circumstances, the immobilization for denitrifying bacteria and NAP enzyme for simultaneous bioremediation and bionanoparticles synthesis was studied. NAP catalyzed NO reduction at V of 0.811 μM/min and K of 14.02 mM. Concurrently, the immobilized MMT cells completely removed NO- upon 192 h with AgNPs synthesis ranging from 23.26 to 58.14 nm as indicated by SEM. Wherase, immobilized NAP exhibited lower efficiency with 28.6% of NO elimination within 288 h and large aggregated AgNPs ranging from 94.44 nm to 172.22 nm. To the best of author knowledge, the immobilization for denitrifying bacteria and NAP enzyme for simultaneous bioremediation and bionanoparticles synthesis was not studied before.

Energy Metabolism Rewiring Precedes UVB-Induced Primary Skin Tumor Formation

Although growing evidence indicates that bioenergetic metabolism plays an important role in the progression of tumorigenesis, little information is available on the contribution of reprogramming of energy metabolism in cancer initiation. By applying a quantitative proteomic approach and targeted metabolomics, we find that specific metabolic modifications precede primary skin tumor formation. Using a multistage model of ultraviolet B (UVB) radiation-induced skin cancer, we show that glycolysis, tricarboxylic acid (TCA) cycle, and fatty acid β-oxidation are decreased at a very early stage of photocarcinogenesis, while the distal part of the electron transport chain (ETC) is upregulated. Reductive glutamine metabolism and the activity of dihydroorotate dehydrogenase (DHODH) are both necessary for maintaining high ETC. Mice with decreased DHODH activity or impaired ETC failed to develop pre-malignant and malignant lesions. DHODH activity represents a major link between DNA repair efficiency and bioenergetic patterning during skin carcinogenesis.