Evaluation of the cytotoxic effects of sodium hypochlorite on human dental stem cells

Purpose: To investigate the influence of sodium hypochlorite (NaOCl) on human dental stem cell proliferation and differentiation.Method: Dental pulp stem cells (DPSCs), periodontal ligament stem cell (PDLSCs), and gingival mesenchymal stem cells (GMSCs) were treated with NaOCl. Cell viability was evaluated with cellular counting kit-8 (CCK8), and cellular adenosine triphosphate (ATP) levels were analyzed by bromodeoxyuridine (BrdU) incorporation and subsequent flow cytometry. Quantitative polymerase chain reaction (qPCR) and western blotting were performed to detect the expressions of differentiation markers.Results: The viability and ATP levels of all three stem cells types were impaired by NaOCl in a concentration- and time-dependent manners. However, the decrease ATP in GMSCs was less than the other two stem cell population (p < 0.05). NaOCl treatment significantly suppressed the proliferation of dental stem cells (p < 0.05). With regard to differentiation marker expression levels, the decrease in Stro-1 was greater in treatment groups when compared to control on Day 7, while increase in levels of dentin sialophosphoprotein (DSPP), bone sialoprotein (BSP), and osteocalcin (OC) was smaller (p < 0.05). The expressional changes of Stro-1, DSPP, BSP, and OC were more prominent in DPSMs and PDLSCs than in GMSCs.Conclusion: NaOCl dose-dependently impairs the viability, proliferation and differentiation of dental stem cells. Thus, its toxicity to dental stem cells needs to be considered in clinical application.Keywords: Dental stem cells, Sodium hypochlorite, Viability, Proliferation, Differentiatio

Genomic prediction of drought tolerance during seedling stage in maize using low-cost molecular markers

Drought tolerance in maize is a complex and polygenic trait, especially in the seedling stage. In plant breeding, complex genetic traits can be improved by genomic selection (GS), which has become a practical and effective breeding tool. In the present study, a natural maize population named Northeast China core population (NCCP) consisting of 379 inbred lines were genotyped with diversity arrays technology (DArT) and genotyping-by-sequencing (GBS) platforms. Target traits of seedling emergence rate (ER), seedling plant height (SPH), and grain yield (GY) were evaluated under two natural drought stress environments in northeast China. Adequate genetic variations were observed for all the target traits, but they were divergent across environments. Similarly, the heritability of the target trait also varied across years and environments, the heritabilities in 2019 (0.88, 0.82, 0.85 for ER, SPH, GY) were higher than those in 2020 (0.65, 0.53, 0.33) and cross-2-years (0.32, 0.26, 0.33). In total, three marker datasets, 11,865 SilicoDArT markers obtained from the DArT-seq platform, 7837 SNPs obtained from the DArT-seq platform, and 91,003 SNPs obtained from the GBS platform, were used for GS analysis after quality control. The results of phylogenetic trees showed that broad genetic diversity existed in the NCCP population. Genomic prediction results showed that the average prediction accuracies estimated using the DArT SNP dataset under the two-fold cross-validation scheme were 0.27, 0.19, and 0.33, for ER, SPH, and GY, respectively. The result of SilicoDArT is close to the SNPs from DArT-seq, those were 0.26, 0.22, and 0.33. For the trait with lower heritability, the prediction accuracy can be improved using the dataset filtered by linkage disequilibrium. For the same trait, the prediction accuracies estimated with two DArT marker datasets were consistently higher than that estimated with the GBS SNP dataset under the same genotyping cost. The prediction accuracy was improved by controlling population structure and marker quality, even though the marker density was reduced. The prediction accuracies were improved by more than 30% using the significant-associated SNPs. Due to the complexity of drought tolerance under the natural stress environments, multiple years of data need to be accumulated to improve prediction accuracy by reducing genotype-by-environment interaction. Modeling genotype-by-environment interaction into genomic prediction needs to be further developed for improving drought tolerance in maize. The results obtained from the present study provides valuable pathway for improving drought tolerance in maize using GS

The Challenges of Advanced CMOS Process from 2D to 3D

The architecture, size and density of metal oxide field effect transistors (MOSFETs) as unit bricks in integrated circuits (ICs) have constantly changed during the past five decades. The driving force for such scientific and technological development is to reduce the production price, power consumption and faster carrier transport in the transistor channel. Therefore, many challenges and difficulties have been merged in the processing of transistors which have to be dealed and solved. This article highlights the transition from 2D planar MOSFETs to 3D fin field effective transistors (FinFETs) and then presents how the process flow faces different technological challenges. The discussions contain nano-scaled patterning and process issues related to gate and (source/drain) S/D formation as well as integration of III-V materials for high carrier mobility in channel for future FinFETs

Effects of upregulation of Hsp27 expression on oocyte development and maturation derived from polycystic ovary syndrome.

Heat shock protein 27 (Hsp27) is a heat shock protein family member which can inhibit apoptosis. Our previous studies reported down-regulated Hsp27 in ovarian tissue derived from women with polycystic ovary syndrome (PCOS) however, the exact effect of Hsp27 on oocyte maturation and developmental competence in PCOS is unclear. The effect of Hsp27 over-expression was studied in vitro using oocytes derived from PCOS patients. An artificial GFP-plasmid was injected into human oocyte to increase Hsp27 protein level. Oocyte maturation was evaluated by morphological observation. Mature oocytes were fertilized by intracytoplasmic sperm injection (ICSI) and embryonic developmental competence was evaluated. Critical apoptotic factors and cytokines were measured at both the mRNA and protein level. Our results revealed that Overexpression of HSP27 lowered the maturation rate of oocytes derived from PCOS patients. Meanwhile, fertilization rate and high quality embryo rate were similar between the Hsp27 overexpressing group and controls; however, the blastocyst formation rate in this group was significantly higher than control. Expression analysis revealed that the oocyte-secreted factors, BMP15 and GDF9, and the apoptotic-related regulators, Caspase 3, 8 and 9, were all significantly decreased in Hsp27 overexpressing oocytes. In conclusion, upregulation of Hsp27 inhibits oocyte maturation from PCOS patients, but improves embryonic developmental potential

Miniaturization of CMOS

When the international technology roadmap of semiconductors (ITRS) started almost five decades ago, the metal oxide effect transistor (MOSFET) as units in integrated circuits (IC) continuously miniaturized. The transistor structure has radically changed from its original planar 2D architecture to today’s 3D Fin field-effect transistors (FinFETs) along with new designs for gate and source/drain regions and applying strain engineering. This article presents how the MOSFET structure and process have been changed (or modified) to follow the More Moore strategy. A focus has been on methodologies, challenges, and difficulties when ITRS approaches the end. The discussions extend to new channel materials beyond the Moore era

Glycine receptors and glycinergic synaptic input at the axon terminals of mammalian retinal rod bipolar cells

We investigated the properties of glycine receptors and glycinergic synaptic inputs at the axon terminals of rod bipolar cells (RBCs) in rats by patch-clamp recording. Glycine currents recorded from isolated axon terminals were larger than those from isolated somata/dendrites; this was confirmed by puffing glycine onto these two regions in retinal slices. The current density at terminal endings was more than one order of magnitude higher than the density at somatic/dendritic regions. Glycine currents from isolated terminals and isolated somata/dendrites showed similar sensitivity to picrotoxinin blockade. Single-channel opening recorded from isolated terminals and somata/dendrites displayed a similar main-state conductance of ≈46 pS. Application of glycine effectively suppressed depolarization-evoked increases in intracellular Ca2+ at the terminals. In the presence of GABAA and GABAC antagonists, strychnine-sensitive chloride currents were evoked in RBCs in retinal slices by puffing kainate onto the inner plexiform layer. No such currents were observed if the recorded RBCs did not retain axon terminals or if Ca2+ was replaced by Co2+ in the extracellular solution. The currents displayed discrete miniature-like events, which were partially blocked by tetrodotoxin. Consistent with early studies in the rabbit and mouse, this study demonstrates that glycine receptors are highly concentrated at the axon terminals of rat RBCs. The pharmacological and physiological properties of glycine receptors located in the axon terminal and somatic/dendritic regions, however, appear to be the same. This study provides evidence for the existence of functional glycinergic synaptic input at the axon terminals of RBCs, suggesting that glycine receptors may play a role in modulating bipolar cell synaptic transmission