Aldehyde group pendant-grafted pectin-based injectable hydrogel.

Periodate oxidation has been the widely accepted route for obtaining aldehyde group-functionalized polysaccharides but significantly influenced the various physicochemical properties due to the ring opening of the backbone of polysaccharides. The present study, for the first time, presents a novel method for the preparation of aldehyde group-functionalized polysaccharides that could retain the ring structure and the consequent rigidity of the backbone. Pectin was collected as the representative of polysaccharides and modified with cyclopropyl formaldehyde to obtain pectin aldehyde (AP), which was further crosslinked by DL-lysine (LYS) via the Schiff base reaction to prepare injectable hydrogel. The feasibility of the functionalization was proved by FT-IR and 1H NMR techniques. The obtained hydrogel showed acceptable mechanical properties, self-healing ability, syringeability, and sustained-release performance. Also, as-prepared injectable hydrogel presented great biocompatibility with a cell proliferation rate of 96 %, and the drug-loaded hydrogel exhibited clear inhibition of cancer cell proliferation. Overall, the present study showed a new method for the preparation of aldehyde group-functionalized polysaccharides, and the drug-loaded hydrogel has potential in drug release applications.

Super-twisting sliding mode control for neutral point voltage of three-phase four-wire inverter based on SiC/Si hybrid switch.

The three-phase four-wire voltage source inverter (3P4W VSI) is widely used in applications like uninterrupted power supply (UPS) and bidirectional onboard charger. The increasing power density demand requires higher switching frequency and lower switching loss. To fulfill the conflicting objectives, two-fold methodology is proposed in this paper: 1) SiC/Si hybrid switches (HyS) together with recently reported gate trigger are reported for the first time in the 3P4W VSI; 2) the natural point voltage is controlled to track a sinusoidal voltage with the frequency equal to 3 times of fundamental frequency in order to achieve higher DC-bus voltage utilization rate, and further reduce the switching loss. The traditional PI controller is very hard to achieve desired performance due to both the nonlinearity and the variant reference of the natural point voltage control system. Thereby, the super-twisting sliding mode control (ST-SMC) is proposed in this paper to achieve desired tracking performance and fast dynamic response. The effectiveness and superiority of the system are verified by both simulation and experiment comparison with the existing methods using a 5 kW prototype.

Metal/Semiconductor Nanocomposites for Photocatalysis: Fundamentals, Structures, Applications and Properties.

Due to the capability of utilizing light energy to drive chemical reactions, photocatalysis has been widely accepted as a green technology to help us address the increasingly severe environment and energy issues facing human society. To date, a large amount of research has been devoted to enhancing the properties of photocatalysts. As reported, coupling semiconductors with metals is one of the most effective methods to achieve high-performance photocatalysts. The excellent properties of metal/semiconductor (M/S) nanocomposite photocatalysts originate in two aspects: (i) improved charge separation at the metal-semiconductor interface; and (ii) increased absorption of visible light due to the surface plasmon resonance of metals. So far, many M/S nanocomposite photocatalysts with different structures have been developed for the application in environmental remediation, selective organic transformation, hydrogen evolution, and disinfection. Herein, we will give a review on the M/S nanocomposite photocatalysts, regarding their fundamentals, structures (as well as their typical synthetic approaches), applications and properties. Finally, we will also present our perspective on the future development of M/S nanocomposite photocatalysts.

The high concentration of progesterone is harmful for endometrial receptivity and decidualization.

Progesterone is required for the establishment and maintenance of mammalian pregnancy and widely used for conservative treatment of luteal phase deficiency in clinics. However, there are limited solid evidences available for the optimal timing and dose of progesterone therapy, especially for the possible adverse effects on implantation and decidualization when progesterone is administrated empirically. In our study, mouse models were used to examine effects of excess progesterone on embryo implantation and decidualization. Our data indicate that excess progesterone is not only harmful for mouse implantation, but also impairs mouse decidualization. In excess progesterone-treated mice, the impaired LIF/STAT3 pathway and dysregulated endoplasmic reticulum stress may lead to the inhibition of embryo implantation and decidualization. It is possible that the decrease in birth weight of excess progesterone-treated mice is due to a compromised embryo implantation and decidualization. Furthermore, excess progesterone compromises in vitro decidualization of human endometrial stromal cells.

Alcohol Dehydrogenases and Acetaldehyde Dehydrogenases are Beneficial for Decidual Stromal Cells to Resist the Damage from Alcohol.

Aims: The aim of this study was to examine the effect of alcohol on the decidualization of human endometrial stromal cells during early pregnancy. Methods: During in vitro decidualization, human endometrial stromal cells were treated with alcohol, 4-methylpyrazole hydrochloride (FPZ), the inhibitor of alcohol dehydrogenases (ADHs), and tetraethylthiuram disulfide (DSF), the inhibitor of acetaldehyde dehydrogenases (ALDHs), respectively. Cell viability and decidualization were examined. Apoptosis and proliferation were also evaluated. Results: The findings showed that ADHs and ALDHs were up-regulated during decidualization. After alcohol treatment, the cell viability of decidual stromal cells was significantly higher than control, which was abrogated by FPZ or DSF. When cells were treated with alcohol, proliferation-related signal pathways were up-regulated in decidualized cells. Additionally, FOXO1 transcriptionally up-regulates ADH1B. Conclusion: Our study provided an evidence that highly expressed ADHs and ALDHs endow decidual stromal cells an ability to alleviate the harm from alcohol.

Identification of gene expression changes in rabbit uterus during embryo implantation.

Embryo implantation in the rabbit is unique in that a typical fusion type of implantation is employed, in which trophoblast cells adhere and fuse to the apical surface of uterine epithelial cells. In the present study, we analyzed global gene expression changes in the rabbit uterus during embryo implantation by using RNA-seq. We identified a total of 536 differentially expressed genes (fold change >2 and adjusted p-value <0.01), of which 266 genes were down-regulated and 270 genes were up-regulated at the implantation site compared to the inter-implantation site. Functional clustering revealed that cell adhesion is among top ranked enriched terms from both gene ontology and pathway analysis, highlighting the importance of cell adhesion during embryo implantation in rabbits. Through gene network analysis, we prioritized 9 genes using the hub gene method. Our study provides a valuable resource for in-depth understanding of the mechanism underlying embryo implantation in rabbits.

The Impact of Multiparity on Uterine Gene Expression and Decidualization in Mice.

It has been well established that a previous pregnancy exhibits a beneficial effect on the subsequent pregnancy. However, the underlying mechanisms have not been defined. We hypothesized that multiparity may affect decidualization process during early pregnancy. To test this hypothesis, we analyzed global gene changes associated with multiparity in the mouse uterus using RNA-sequencing (RNA-seq). We identified a total of 131 differentially expressed genes (fold change > 2 and false discovery rate < 0.05), of which 58 were downregulated and 73 genes were upregulated in the second pregnancy (SP) compared to the first pregnancy. Functional clustering analysis showed that genes involved in stress response were significantly enriched. Most importantly, a significant portion of differentially expressed genes, 14 genes or 10.7%, overlapped with the gene list associated with decidualization. Quantitative reverse transcription (RT) polymerase chain reaction (qRT-PCR) analysis confirmed a decreased expression of 4 genes (Klk1, kallikrein 1; H2-Eb1, histocompatibility 2 class II antigen E beta; Mmp7, matrix metallopeptidase 7; Pdpn, podoplanin) and an increase in expression of 2 genes (Thy1, thymus cell antigen 1; Ptgs2, prostaglandin-endoperoxide synthase 2) in SP. Beyond protein-coding genes, we also identified a differentially expressed long noncoding RNA AI506816. Our data provide new insights into the molecular mechanisms underlying the beneficial effect of multiparity.

A Transcriptomic Study of Maternal Thyroid Adaptation to Pregnancy in Rats.

Thyroid disorders are relatively frequently observed in pregnant women. However, the impact of pregnancy on maternal thyroid has not been systematically evaluated. In the present study, using the rat as an animal model, we observed that the weight of maternal thyroid increased by about 18% in late pregnancy. To gain an insight into the molecular mechanisms, we took advantage of RNA-seq approaches to investigate global gene expression changes in the maternal thyroid. We identified a total of 615 differentially expressed genes, most of which (558 genes or 90.7%) were up-regulated in late pregnancy compared to the non-pregnant control. Gene ontology analysis showed that genes involved in cell cycle and metabolism were significantly enriched among up-regulated genes. Unexpectedly, pathway analysis revealed that expression levels for key components of the thyroid hormone synthesis pathway were not significantly altered. In addition, by examining of the promoter regions of up-regulated genes, we identified MAZ (MYC-associated zinc finger protein) and TFCP2 (transcription factor CP2) as two causal transcription factors. Our study contributes to an increase in the knowledge on the maternal thyroid adaptation to pregnancy.

Efficient prediction of progesterone receptor interactome using a support vector machine model.

Protein-protein interaction (PPI) is essential for almost all cellular processes and identification of PPI is a crucial task for biomedical researchers. So far, most computational studies of PPI are intended for pair-wise prediction. Theoretically, predicting protein partners for a single protein is likely a simpler problem. Given enough data for a particular protein, the results can be more accurate than general PPI predictors. In the present study, we assessed the potential of using the support vector machine (SVM) model with selected features centered on a particular protein for PPI prediction. As a proof-of-concept study, we applied this method to identify the interactome of progesterone receptor (PR), a protein which is essential for coordinating female reproduction in mammals by mediating the actions of ovarian progesterone. We achieved an accuracy of 91.9%, sensitivity of 92.8% and specificity of 91.2%. Our method is generally applicable to any other proteins and therefore may be of help in guiding biomedical experiments.