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The effects of transcranial direct current stimulation (tDCS) on post-stroke executive impairment (PSEI) remain controversial. Resting stateelectroencephalogram (EEG) can assist in the diagnosis and assessment of executive dysfunction.We aimed to use EEG to explore the effect of tDCS on executive function among stroke patients.Twenty-four patients with PSEI were randomly divided into experimental and control groups, which received real and sham stimulation, respectively. Anodal electrical stimulation was applied to the left dorsolateral prefrontal lobe (F3). The stimulation intensity was 2 mA for 20 min once daily for 7 days. Executive function was monitored using neuropsychological scales.The experimental group outperformed the control group in clinical scale results, with significant differences in the following scores: symbol digital modalities test, TMT-A, TMT-B, and digital span test. In the left central zone, theta band power was significantly higher after anodal electrical stimulation than before. Analysis of the correlation between EEG power and psychometric scores revealed that the power change was positively correlated with the scores on the symbol digital modality test (r = 0.435, p 0.05).Anodal tDCS can enhance executive function in patients with PSEI, and tDCS-related improvements are related to the enhancement of theta power in the affected region.

Objective. Hypertensive disorders of pregnancy (HDP) can cause serious prenatal and postnatal complications and is a threat to maternal and fetal health. To offer guidance for clinical decisions, we systematically reviewed the effects of misoprostol on induction of labour in HDP patients. Methods. PubMed, Web of Science, Embase, CNKI, and Wanfang databases were searched for relevant literature from 2010 to 2020. Subsequently, a meta-analysis was performed to compare the effective rate of induction of labour and reducing postpartum hemorrhage (PPH) between the intervention group (n = 544, misoprostol) and the control group (n = 543, oxytocin). Results. A total of 10 studies with 1087 patients were included. The 10 studies compared the effective rate of induction of labour between the two groups and confirmed that the effective rate in the intervention group was significantly higher than that in the control group (OR = 4.37; 95% CI: 2.73, 7.00). Seven studies compared PPH between the groups and showed that it was significantly reduced in the intervention group compared to the control group (SMD = −1.32; 95% CI: −2.05, −0.59; P < 0.0001 ). Conclusion. Misoprostol has a high effective rate of induction of labour in HDP patients and is an effective uterotonic agent in reducing PPH. This meta-analysis provides clinicians with meaningful information to help them make evidence-based decisions.

Owing to the frequent accidents in primary and secondary schools (PSS) in China in the past decades, a systematic analysis of indicators influencing safety risks in PSS is critical to identifying preventive measures. A two-hierarchy structure of indicators was identified by analyzing various cases, intensive interviews, and related previous literature. A combination of the analytic hierarchy process and the entropy weight method was developed to synthetically assess the primary and secondary risk indicators through a case study of Ma Shan School in China. The results are as follows: (1) the primary risk indicators, namely, natural disasters, public health, facility safety, accidental injury, public security, school bullying, and individual health constitute the evaluation framework of the safety risks in PSS. (2) Public health risks and accidental injury risks are the most critical factors that should be prioritized. In addition to providing academic implications, several managerial implications are proposed for these stakeholders to reduce the safety risks in PSS.

The patent value of military equipment assets is an important index to measure military equipment assets, which reflects the technical level and economic value of military equipment assets. To evaluate the patent value of military equipment, based on the comprehensive theoretical analysis and practical investigation, this study analyzes the influencing factors of the patent value of military equipment, constructs the evaluation index system of the patent value of military equipment, and uses fuzzy analytic network process (FANP) method to evaluate the patent value of military equipment. The evaluation results show that factors such as Irreplaceability (A3), Technological added value (A2), Service military capability (A1), Scope of patent rights (L3), Advances of patent right (T2), and Innovation (T1) have considerable influence. This study discusses the value evaluation of military equipment patents to provide a reference for the creation, operation, and transformation of military equipment patents and provide a theoretical basis for the management of military equipment intangible assets.

Background The most common materials of artificial blood vessels are polyethylene terephthalate and polytetrafluoroethylene. But polycarbonate polyurethane (PCU) is an ideal material for vascular prostheses because of their excellent characteristics. As far as we know, our artificial blood vessel is the first type of hybrid PCU/polyester three-layered large-diameter artificial blood vessel in the world. Objective The purpose of this preclinical animal experiment is to evaluate the hemocompatibility, histocompatibility, effectiveness, and safety of the three-layered large-diameter artificial blood vessel in sheep. Methods The artificial blood vessels took place of the initial segments of the sheep’s thoracic aorta by end-to-end anastomosis. Results All of the 14 sheep are male, their average body weight (BW) was 30.57 ± 3.95 kg. All 14 artificial blood vessels successfully replaced the thoracic aortas. 5 sheep did not survive to the end of the experiment, while the remaining 9 sheep did. After the surgery, the blood biochemical and blood routine indicators fluctuate slightly within the normal range. The angiography showed that the implanted artificial blood vessels were unobstructed without obvious stenosis or expansion. 24 weeks after surgery, the lumen surfaces of the artificial blood vessels were covered by endothelia in different degrees, and the average endothelialization rate was 69.44% (range: 20% to 100%). Conclusions This artificial blood vessel is the first to use PCU in large-diameter artificial vascular grafts. It has excellent blood compatibility, wonderful biocompatibility, high endothelialization rate, and 100% patency.

Purpose The purpose of this paper is to analyze the crowd stampede risk mechanism from the perspective of systems thinking. Design/methodology/approach Causal loop diagram is drawn to outline the non-linear interactions among complex factors across the whole system and dissect the contributory factors of crowd stampede accident. To systematically construct the theoretical framework and find fundamental solutions, co-word analysis with Citespace is used to get the critical data. An agent-based simulation using Pathfinder is conducted to develop a spatial model for the Shanghai Stampede Accident that happened in 2014. Findings The causal loop diagram is formed to not only illustrate the symptomatic solutions with a quick fix but also dissect the fundamental solutions through an underlying systemic analysis. The simulation shows that crowd stampede experiences an interactive process of accumulation, trigger, delay, break and diffusion of risk factors within the crowd system. A linkage effect among the multidimensional characters of individuals and the system accelerates the stampede risk deterioration. There exists delay of the result of effect from the deep-level measure. Practical implications A top-down approach is offered to policymakers for crowd stampede risk protocol design and synergic emergency control that may reduce the risk of the stampede. Originality/value In this study, SDFT paradigm is proposed as the critical solution for the crowd stampede accident. In addition, a chain effect of energy and a linkage effect within the crowd system is illustrated for in-depth understanding of crowd stampede risk.

Background Single intrauterine death in twin pregnancy has become a relatively frequent complication of twin pregnancy. Preterm delivery is one of the complications with high incidence, and is closely related to the prognosis of the surviving fetus. However, studies about preterm delivery related to single intrauterine death are limited. The purpose of this paper is to analyze the factors associated with preterm birth in twins after single intrauterine death.Methods This was a case-control study of single intrauterine death in twins delivered at Shengjing Hospital over a 12-year period, from January 1, 2008, to November 30, 2020. We classified these cases into the preterm birth group and full-term birth group according to gestational age at birth. We selected age, gestational age at Single intrauterine death, and parity, etc, as related factors of the preterm birth group. Logistic regression analyses were performed to determine the relevance and importance of related factors and their association with preterm birth. We divided the preterm birth group into four smaller groups according to gestational age at single intrauterine death (14-19 weeks, 20-24 weeks, 25-30 weeks, and 31-36 weeks) and compared them. To exclude human intervention, we analyzed the spontaneous delivery cases as well.Results The analysis included 175 twins (mean [SD] gestational age at single intrauterine death, 27.0 [5.8] weeks; mean [SD] gestational age at birth, 33.8 [3.2] weeks ) with single intrauterine death. A total of 139 (79.4%) were cases of preterm birth. A significant risk factor associated with preterm birth was gestational age at single intrauterine death (odds ratio [OR], 2.89; 95% CI, 1.90-4.39). We found that the 14- to 19-week age group had the oldest gestational age at birth (37.25 [1.29]weeks ). The length of gestation in 14-19 weeks group, 20-24 weeks group, 25-30 weeks group and 31-36 weeks group were 20.5 weeks, 11.0 weeks, 4.77 weeks and 1.12 weeks respectivelyConclusion The fetus’ gestational age at single intrauterine death was a risk factor for preterm birth in their twin. The length of gestation was inversely proportional to increasing gestational age at single intrauterine death.

Evidence is mounting that emotional conflict is mainly resolved by the rostral anterior cingulate inhibiting the processing of emotional distractors. However, this theory has not been verified from the perspective of memory retrieval. This experiment aimed to explore the offline effect of emotional conflict processing on memory retrieval. We adopted a modified encoding-retrieval paradigm to explore this issue. Participants’ electroencephalography (EEG) signal were also collected. A face-word Stroop task was used to create the congruency factor. In addition, an old/new judgment task was used to evaluate the recognition performance. During the retrieval phase, the response time of the incongruent condition was longer and the recognition accuracy was lower compared with congruent and neutral conditions in the behavioral data. For event-related potentials (ERP), we detected two well-established old/new effects related to memory retrieval under both neutral and emotional conditions: the frontal negativity (FN400) related to familiarity-driven recognition and the late posterior negativity (LPN) related to reconstructive processing or evaluation of retrieval outcomes. More importantly, the old/new effects were missing for incongruent condition during the early stage of FN400 (300–400 ms). Besides, for LPN (700–900 ms), the old/new effects of the incongruent condition are greater than the congruent condition. The results prove that the encoding phase's emotional congruency factor has a regulatory effect on the retrieval phase's early familiarity processing and evaluation of retrieval outcomes. Our data confirm the inhibitory effect of emotional conflict control on memory retrieval and support the emotional conflict control mechanism found in previous studies.

Pollution of Sb(III) in water has caused great concern in recent years. Nanoscale zero-valent iron (nZVI) can detoxify Sb(III) polluted water, but the rapid passivation and low adsorption capacity limit its practical application. Hence, this study provides a new and efficient nanotechnology to remove Sb(III) using the sulfidated nanoscale zero-valent iron (S-nZVI). The S-nZVI exhibits higher Sb(III)-removal efficiency than pristine nZVI under both aerobic and anoxic conditions. The adsorption capacity of Sb(III) by optimized S-nZVI (465.1 mg/g) is 6 times as high as that of the pristine nZVI (83.3 mg/g) under aerobic conditions. The results indicate that Sb(III) and Sb(V) can be immobilized on the surface of S-nZVI by forming Fe-S-Sb precipitates. Moreover, characterization results demonstrate that the existence of S2− can not only activate H2O2 to produce hydroxyl radical, but also accelerate the cycle of Fe3+/Fe2+ to improve the efficiency of Fenton reaction. Therefore, S-nZVI can produce more hydroxyl radicals to oxidize Sb (III) to Sb (V) and results in 2.3-fold higher oxidation rate of Sb(III) compared to pristine nZVI. The formed FeS layer on the S-nZVI surface can also improve the release ability of Fe2+ and accelerate the formation of nZVI corrosion products. S-nZVI thus holds great potential to be applied in antimony removal.

In recent years, as a novel financing mechanism, crowdfunding has gained popularity worldwide. In China, Crowdfunding started in 2011 and has experienced extremely fast growth since then. Several studies have identified success factors for crowdfunding. While these studies help infer the dynamics of crowdfunding, such dynamics have not been sufficiently examined, particularly by large-scale empirical studies. In addition, the relationship between crowdfunding market characteristics and project funding success remains fuzzy. In this research, we first empirically assessed the effect of crowdfunding success factors using a large sample (N = 5128) collected from Taobao.com , a leading crowdfunding platform in China. Built upon these factors, we conducted a multi-period, multi-party simulation study that evaluate crowdfund raisers’ project positioning decisions and investors’ project funding decision in a massive market. In the simulation study, we varied market characteristics such as the number of projects, number of investors per project, entrepreneurs’ moral risk, and ratio of community over financial benefits, to observe their effect on participants’ decisions and consequently, project funding success rate. Results reveal that dynamics of a crowdfunding market are rather complex. These insights contribute to a more in-depth theoretical understanding of crowdfunding, as well as provide useful guidance for crowdfund raisers, investors, and administrators.

This chapter mainly describes the fabrication and application of iron-based nanohybrids for aquatic recalcitrant pollutant treatment. First, ZVI-based nanohybrid materials and magnetic nanohybrids are classified. The fabrication methods of iron-based nanohybrids with different chemical and physical properties are detailed. Second, the performances of iron-based nanohybrids toward aquatic recalcitrant organic pollutants and heavy metals are discussed as well as relevant reaction mechanisms including adsorption, reduction, oxidation, and synergetic effects. Third, the environmental risks and the application of iron-based nanohybrids for aquatic recalcitrant pollutant treatment are summarized. Finally, the challenges and future perspective in the application of iron-based nanohybrid nanomaterials for environmental pollution control are provided.

The morphology of a multicomponent transition metal sulfide electrode plays a vital role in the electrochemical properties of advanced supercapacitors. However, the control of hybrid metal sulfide morphology during preparation remains a challenge. This study demonstrated the controlled synthesis of NixCo1-xMoSy (NCMS) nanorods, nanoplate-on-nanoparticles and nanoparticles by adjusting the NaOH concentration of the ethanol-water solution used in the hydrothermal step of a simple coprecipitation-hydrothermal method. The NCMS electrode materials with the nanoplate-on-nanoparticle and nanoparticle morphologies had a higher available surface area for electrolyte penetration and a larger number of pseudocapacitive redox reaction sites during the charge/discharge process in alkaline solution. The NCMS electrode exhibited a high specific capacity of 227 mAh g−1 at 1 A g−1, a good rate capability with 76.7% retention at increasing current densities from 1 to 20 A g−1, and a high cyclability with 70.48% retention at 5 A g−1 after 1000 cycles. An asymmetrical supercapacitor assembled using NCMS as the positive electrode and active carbon as the negative electrode had an energy density of 55 Wh kg−1 at a power density of 850 W kg−1 (1 A g−1). These results demonstrated the excellent applicability of this NCMS electrode material in high-performance supercapacitors.

The aim of the current study was to investigate the role of phospholipase C (PLC)γ/protein kinase C (PKC)/C-kinase-activated protein phosphatase-1 (CPI-17) signaling pathways in uterine smooth muscle during parturition. Samples of uterine tissue were collected from pregnant patients who underwent a caesarean section for preterm delivery, full-term delivery with labor onset, full-term delivery without labor onset, and from a non-pregnant control group undergoing surgery for cervical intraepithelial neoplasia III. Immunohistochemistry, and western blotting were used to assess the association between TRPC3 levels and parturition and the influence of calcium ion channels. In addition, pregnant mice were used to explore the effect of uterine canonical transient receptor potential 3 (TRPC3) expression on the parturition-triggering mechanism and PLCγ/PKC/CPI-17 signaling pathways. Pregnant mouse uterine smooth muscle cells were cultivated, with and without TRPC3 silencing, and the expression levels of PLCγ, PKC and CPI-17, the upstream and downstream factors of the TRPC3 pathway, were measured in pregnant mouse uterine smooth muscle cells, in order to provide a theoretical basis for the prevention and treatment of premature labor. In the preterm and full-term without labor onset patient groups, the TRPC3 gene expression in the mSMCs was significantly overexpressed when compared with the non-pregnant group (P0.05). During pregnancy, compared with the non-pregnant controls, Cav1.2, Cav3.1 and Cav3.2 gene expression levels were markedly increased (P

To determine the methylation status of progesterone receptor B (PR-B) promoter and how PR-B regulates progesterone action in placenta during human pregnancy. Placentas were obtained from the pregnancy women at term who underwent cesarean delivery and vaginal delivery. The methylation status of the PR-B promoter was analyzed using the methylation-specific polymerase chain reaction (PCR) and bisulfite sequencing PCR. And the messenger RNA (mRNA) and protein expression of the PR-B and DNA methyltransferases (DNMTs) were determined by quantitative real-time PCR and Western blot. Compared with the cesarean group, the placentas of vaginal delivery group had greater levels of PR-B DNA methylation, and the PR-B, DNMT1, DNMT3a, and DNMT3b mRNA and protein expression were significantly decreased. Progesterone receptor B methylation occurs with high frequency after labor onset and may play an important epigenetic mechanism of labor-related PR-B negative expression, thereby mediating the biological process of functional progesterone withdrawal at term for parturition.

With the development of the technology and economic, the video supervising equipment are widely used in commercial, private areas and public management. It is innovative of the paper to make full use of the video images to estimation the crowd density and defend risks of stampedes. According to connect data in different crowds, this paper proposes a method that is based on the Gaussian Background Modeling and binary image to estimate crowd density. Results of this study provide a theoretical basis for the stampedes risk early warning.

The aim of the current study was to investigate the role of phospholipase C (PLC)γ/protein kinase C (PKC)/C‑kinase‑activated protein phosphatase‑1 (CPI‑17) signaling pathways in uterine smooth muscle during parturition. Samples of uterine tissue were collected from pregnant patients who underwent a caesarean section for preterm delivery, full‑term delivery with labor onset, full‑term delivery without labor onset, and from a non‑pregnant control group undergoing surgery for cervical intraepithelial neoplasia III. Immunohistochemistry, and western blotting were used to assess the association between TRPC3 levels and parturition and the influence of calcium ion channels. In addition, pregnant mice were used to explore the effect of uterine canonical transient receptor potential 3 (TRPC3) expression on the parturition‑triggering mechanism and PLCγ/PKC/CPI‑17 signaling pathways. Pregnant mouse uterine smooth muscle cells were cultivated, with and without TRPC3 silencing, and the expression levels of PLCγ, PKC and CPI‑17, the upstream and downstream factors of the TRPC3 pathway, were measured in pregnant mouse uterine smooth muscle cells, in order to provide a theoretical basis for the prevention and treatment of premature labor. In the preterm and full‑term without labor onset patient groups, the TRPC3 gene expression in the mSMCs was significantly overexpressed when compared with the non‑pregnant group (P0.05); however, TRPC3 expression was not elevated in the full‑term with labor onset group, exhibiting no significant difference compared with the non‑pregnant group (P0.05). During pregnancy, compared with the non‑pregnant controls, Cav1.2, Cav3.1 and Cav3.2 gene expression levels were markedly increased (P0.05) in mSMCs from the preterm delivery group and the full‑term with labor onset group, however were non‑significantly increased in the full‑term without labor onset group. The level of TRPC3 was highest in the preterm group, while the levels of Cav1.2, Cav3.1 and Cav3.2 were highest in the full‑term with labor onset group. In the preterm, LPS‑treated preterm and full‑term groups, TRPC3, MAPK, ERK1/2, P‑ERK, Cav3.2, Cav3.1 and Cav1.2 were all expressed at higher levels than in the unfertilized group. In the LPS‑treated preterm group, the levels of TRPC3, MAPK, ERK1/2, P‑ERK, Cav3.2, Cav3.1 and Cav1.2 were increased compared with the preterm group. Furthermore, following transfection of small interfering TRPC3 (siTRPC3) into cells, it was demonstrated that the levels of TRPC3, PLCγ, PKC, CPI‑17, P‑CPI‑17, Cav1.2, Cav3.1 and Cav3.2 expression were lower in the LPS siTRPC3 group when compared with that of the LPS‑treated untransfected control group.

Purpose This study investigated the role and mechanism of Cdc42 in Endothelin-1 (ET-1)-induced trophoblast cell migration. Methods We examined ET-1-mediated stimulation of trophoblast migration with HTR-8/SVneo cells. Cdc42 activation was measured after ET-1 treatment of HTR-8/SVneo cells. To determine the ET receptor subtype involved in ET-1-mediated Cdc42 activation, experiments were performed in the presence of ET A and ET B receptor antagonists. Finally, using siRNA we knocked down the expression of Cdc42 to examine the involvement of Cdc42 in the regulation of ET-1-stimulated trophoblast cell migration. Results ET-1 was shown to have a dose-dependent effect on trophoblast migration. At low concentrations of ET-1 (0.1 nmol/L) ET-1 had a stimulatory effect on cell migration. ET-1 (10 nmol/L) increased HTR-8/svneo cell migration index by 2.5 fold. ET-1 (10 nmol/L) elevated protein level and activity of Cdc42. ET-1 induced activation of Cdc42 GTPase was mediated by both ET A and ET B . ET-1-induced cell migration was shown to be inhibited by Cdc42 siRNA.The inhibition was not mitigated by the addition of ET-1, suggesting that Cdc42 plays an important role in trophoblast migration and is obligatory for ET-1 action. Conclusions ET-1 stimulates EVT migration through Cdc42 activation.

Disseminated intravascular coagulation (DIC) and abdominal compartment syndrome (ACS) are rare complications of pregnancy, and even more rare are cases with both complications occurring concomitantly. Obstetricians are relatively unfamiliar with these types of cases, the majority of which are fatal. We describe here a primigravida with acute fatty liver of pregnancy and a multipara with placental abruption who each developed uterine inertia complicated by postpartum DIC that required total hysterectomy. They developed ACS postoperatively and required decompressive laparotomy to alleviate increased intra-abdominal pressure and end-organ dysfunction. After timely decompressive laparotomy, both patients recovered without any additional complications and were discharged within 4 weeks of their initial admission. These 2 cases serve to remind obstetricians to consider the possibility of ACS whenever there is a fresh wound in the abdominal cavity of a patient with postpartum DIC. However, even when there is severe deterioration in the condition of a patient with ACS, immediate decompressive laparotomy may not be appropriate; the timing of the procedure is very important.

The risks of crowd gathering which are often neglected may incur severe catastrophe. With the development of economics and technology, there has been more and more opportunity for people to get together. At the same time, significant progress has been made in the field of risk prevention, such as cell senor and face recognition. The paper presents an idea to count the number of pedestrians by making use of the cell sensor and adjust the number by using face recognition. Based on the result of cell sensor and face recognition, the paper proposes a framework about the measurement of the crowd density and avoidance of the risks of crowd gathering.

Infection is a significant cause of preterm birth. Abnormal changes in intracellular calcium signals are the ultimate triggers of early uterine contractions that result in preterm birth. T‑type calcium channels play an important role in the pathogenesis of cancer, as well as endocrine and cardiovascular diseases. However, there are limited studies on their role in uterine contractions and parturition. In the present study, mouse uterine smooth muscle cells were isolated and treated with lipopolysaccharides (LPS) to mimic the microenvironment of uterine infection in vitro to investigate the role of T‑type calcium channels in the process of infection‑induced preterm birth. The results from quantitative polymerase chain reaction and western blot analysis showed that LPS significantly induced the expression of the Cav3.1 and Cav3.2 subtypes of T‑type calcium channels. Measurements of intracellular calcium concentration showed a significant increase in response to LPS. However, these effects can be reversed by T‑type calcium channel blockers. Western blot analysis further indicated that LPS induced the activation of the nuclear factor (NF)‑κB signaling pathway, and endothelin‑1 (ET‑1) was significantly upregulated, whereas NF‑κB inhibitors significantly inhibited the LPS‑induced upregulation of Cav3.1, Cav3.2 and ET‑1 expression. In addition, ET‑1 directly induced Cav3.1 and Cav3.2 expression, whereas ET‑1 antagonists inhibited the LPS‑induced upregulation of Cav3.1 and Cav3.2 expression. In conclusion, the present study demonstrates that infection triggers the upregulation of T‑type calcium channels and promotes calcium influx. This process relies on the activation of the NF‑κB/ET‑1 signaling pathway. The T‑type calcium channel is expected to become an effective target for the prevention of infection‑induced preterm birth.

The invasion of placental trophoblast cells into the maternal decidua is an essential aspect of placental embedment. The process of placentation bears several striking similarities to tumor cell metastasis. However, trophoblastic migration during implantation and placentation is stringently controlled both in space and time. RhoGDI2 belongs to a family of Rho guanosine diphosphate dissociation inhibitors (RhoGDIs), and RhoGDI2 is a metastasis suppressor gene and a marker of aggressive human cancer. We evaluated whether RhoGDI2 has a physiological role in embryo implantation, particularly trophoblast migration. The mRNA and protein expression levels of RhoGDI2 were higher in term placentas compared with first-trimester placentas as detected by real-time PCR and Western blot. Immunohistochemical studies indicated that RhoGDI2 localized to the cytotrophoblast layer and extravillous trophoblast in first-trimester placentas and was distributed in the syncytiotrophoblast layers of term placentas. Overexpression of RhoGDI2 in HTR-8/SVneo cells was associated with reduced RAC1-guanosine triphosphate (GTP) levels and inhibited cell migration. Conversely, small interfering RNA-mediated downregulation of RhoGDI2 resulted in significantly increased RAC1-GTP levels. Altered RhoGDI2 expression had no significant effects on cell proliferation. In conclusion, RhoGDI2 inhibits trophoblast cell migration, and this function may involve suppression of RAC1 activation.

The invasion of placental trophoblast cells into the maternal decidua is an essential aspect of placental embedment. The process of placentation bears several striking similarities to tumor cell metastasis. However, trophoblastic migration during implantation and placentation is stringently controlled both in space and time. RhoGDI2 belongs to a family of Rho guanosine diphosphate dissociation inhibitors (RhoGDIs), and RhoGDI2 is a metastasis suppressor gene and a marker of aggressive human cancer. We evaluated whether RhoGDI2 has a physiological role in embryo implantation, particularly trophoblast migration. The mRNA and protein expression levels of RhoGDI2 were higher in term placentas compared with first-trimester placentas as detected by real-time PCR and Western blot. Immunohistochemical studies indicated that RhoGDI2 localized to the cytotrophoblast layer and extravillous trophoblast in first-trimester placentas and was distributed in the syncytiotrophoblast layers of term placentas. Overexpression of RhoGDI2 in HTR-8/SVneo cells was associated with reduced RAC1-guanosine triphosphate (GTP) levels and inhibited cell migration. Conversely, small interfering RNA-mediated downregulation of RhoGDI2 resulted in significantly increased RAC1-GTP levels. Altered RhoGDI2 expression had no significant effects on cell proliferation. In conclusion, RhoGDI2 inhibits trophoblast cell migration, and this function may involve suppression of RAC1 activation.

High levels of aldehyde dehydrogenase (ALDH) activity have been detected in various progenitor and stem cells. Thus, Aldefluor fluorescence, which represents precisely the ALDH activity, has been widely used for the identification, evaluation, and isolation of stem and progenitor cells. Recently, ALDH activity was detected in embryonic and adult mouse pancreas, specifically in adult centroacinar and terminal duct cells supposed to harbor endocrine and exocrine progenitor cells in the adult pancreas. Nevertheless, ALDH activity and aldeflour fluorescence have not been examined in beta cells. Here, we report a dynamic increase in the number of aldeflour+ beta cells during pregnancy. Interestingly, nearly all these aldeflour+ beta cells are positive for Ki-67, suggesting that they are in an active cell cycle (G1, S and M phases). To determine precisely at which phase beta cells activate ALDH activity and thus become aldeflour+, we co-stained insulin with additional proliferation markers, phosphohistone3 (PHH3, a marker for M-phase proliferating cells) and Bromodeoxyuridine (BrdU, a marker for S-phase proliferating cells). Our data show little aldeflour+ beta cells that were positive for either PHH3, or BrdU, suggesting that beta cells activate ALDH and become Aldefluor+ when they enter G1-phase of active cell cycle, but may downregulate ALDH when they leave G1-phase and enter S phase. Our data thus reveal a potential change in ALDH activity of proliferating beta cells during pregnancy, which provides a novel method for isolation and analysis of proliferating beta cells. Moreover, our data also suggest that caution needs to be taken on interpretation of Aldefluor lineage-tracing data in pancreas.