Photocatalytic water splitting is a promising technology to solve serious energy and environmental problems. The PtS2 monolayer has been previously predicted to be a water splitting photocatalyst. ...But the high efficiency of carrier recombination in the monolayer results in poor photocatalytic performance. It is well known that the construction of van der Waals (vdW) heterojunctions can improve the photocatalytic performance of a monolayer. In this investigation, we constructed a PtS2/SnS2 vdW heterojunction and systematically investigated the influence of the doping position and doping ratio on its performance using density functional theory calculations. Interestingly, the band alignment transforms from Type-II to Type-I and from Type-I to Type-II when the S in SnS2 is replaced with Se in the PtS2/SnS2 vdW heterojunction and the S in PtS2 is replaced with Se in the PtS2/SnSe2 vdW heterojunction, respectively. More importantly, from the PtS2/SnS2 to PtSe2/SnSe2 vdW heterojunction, the decomposition of water also changes from semi-decomposed water to fully decomposed water. Furthermore, the results show that the direct Z-scheme photocatalytic mechanism exists in the PtSSe/SnSe2 vdW heterojunction by analysis of the migration paths of photoinduced electrons and holes. And compared with the PtS2/SnS2, the PtSSe/SnSe2 heterostructure exhibits better photocatalytic water splitting activities. These results can provide a direction that doping can improve the photocatalytic water splitting performance of heterojunction photocatalysts.
•Ar-Crk expression in diapause embryos was significantly lower than non-diapause embryos.•Knockdown of Ar-Crk by RNAi induced the formation of diapause embryos.•Downregulation of Ar-Crk led to cell ...cycle arrest and metabolic suppression.
To survive under harsh environments, embryonic development of Artemia was arrested at the gastrula stage and released as the diapause embryo. Cell cycle and metabolism were highly suppressed in this state of quiescence. However, cellular mechanisms underlying diapause remain largely unclear. In this study, we found that the expression level of a CT10 regulator of kinase-encoding gene (Ar-Crk) in diapause embryos was significantly lower than non-diapause embryos at the early embryogenetic stage of Artemia. Knockdown of Ar-Crk by RNA interference induced formation of diapause embryos, while the control group produced nauplii. Western blot analysis and metabolic assays revealed that the diapause embryos produced by Ar-Crk-knocked-down Artemia had similar characteristics of diapause markers, arrested cell cycle, and suppressed metabolism with those diapause embryos produced by natural oviparous Artemia. Transcriptomic analysis of Artemia embryos revealed knockdown of Ar-Crk induced downregulation of the aurora kinase A (AURKA) signaling pathway, as well as energetic and biomolecular metabolisms. Taken together, we proposed that Ar-Crk is a crucial factor in determining the process of diapause in Artemia. Our results provide insight into the functions of Crk in fundamental regulations such as cellular quiescence.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract
Blood vessels in the adult mammal exist in a highly organized and stable state. In the ischemic heart, limited expansion capacity of the myocardial vascular bed cannot satisfy demands for ...oxygen supply and the myocardium eventually undergoes irreversible damage. The predominant contribution of endogenous c-Kit
+
cells is understood to be in the development and homeostasis of cardiac endothelial cells, which suggests potential for their targeting in treatments for cardiac ischemic injury. Quiescent cells in other tissues are known to contribute to the long-term maintenance of a cell pool, preserve proliferation capacity and, upon activation, facilitate tissue homeostasis and regeneration in response to tissue injury. Here, we present evidence of a Setd4-expressing quiescent c-Kit
+
cell population in the adult mouse heart originating from embryonic stages. Conditional knock-out of
Setd4
in
c-Kit-CreER
T2
;
Setd4
f/f
;
Rosa26
TdTomato
mice induced an increase in vascular endothelial cells of capillaries in both neonatal and adult mice. We show that Setd4 regulates quiescence of c-Kit
+
cells by the PI3K-Akt-mTOR signaling pathway via H4K20me3 catalysis. In myocardial infarction injured mice,
Setd4
knock-out resulted in attenuated cardiomyocyte apoptosis, decreased infarction size and improved cardiac function. Lineage tracing in
Setd4-Cre
;
Rosa26
mT/mG
mice showed that Setd4
+
cells contribute to each cardiac lineage. Overall, Setd4 epigenetically controls c-Kit
+
cell quiescence in the adult heart by facilitating heterochromatin formation via H4K20me3. Beyond activation, endogenous quiescent c-Kit
+
cells were able to improve cardiac function in myocardial infarction injured mice via the neovascularization of capillaries.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Doublesex (DSX) proteins are members of the Doublesex/mab-3-related (DMRT) protein family and play crucial roles in sex determination and differentiation among the animal kingdom. In the present ...study, we identified two Doublesex (Dsx)-like mRNA isoforms in the brine shrimp Artemia franciscana (Kellogg 1906), which are generated by the combination of alternative promoters, alternative splicing and alternative polyadenylation. The two transcripts exhibited sex-biased enrichment, which we termed AfrDsxM and AfrDsxF. They share a common region which encodes an identical N-terminal DNA-binding (DM) domain. RT-qPCR analyses showed that AfrDsxM is dominantly expressed in male Artemia while AfrDsxF is specifically expressed in females. Expression levels of both isoforms increased along with the developmental stages of their respective sexes. RNA interference with dsRNA showed that the knockdown of AfrDsxM in male larvae led to the appearance of female traits including an ovary-like structure in the original male reproductive system and an elevated expression of vitellogenin. However, silencing of AfrDsxF induced no clear phenotypic change in female Artemia. These results indicated that the male AfrDSXM may act as inhibiting regulator upon the default female developmental mode in Artemia. Furthermore, electrophoretic mobility shift assay analyses revealed that the unique DM domain of AfrDSXs can specifically bind to promoter segments of potential downstream target genes like AfrVtg. These data show that AfrDSXs play crucial roles in regulating sexual development in Artemia, and further provide insight into the evolution of sex determination/differentiation in sexual organisms.
Abstract
In the adult pancreas, the presence of progenitor or stem cells and their potential involvement in homeostasis and regeneration remains unclear. Here, we identify that SET domain-containing ...protein 4 (SETD4), a histone lysine methyltransferase, is expressed in a small cell population in the adult mouse pancreas. Genetic lineage tracing shows that during pancreatic development, descendants of SETD4
+
cells make up over 70% of pancreatic cells and then contribute to each pancreatic lineage during pancreatic homeostasis. SETD4
+
cells generate newborn acinar cells in response to cerulein-induced pancreatitis in acinar compartments. Ablation of SETD4
+
cells compromises regeneration of acinar cells, in contrast to controls. Our findings provide a new cellular narrative for pancreatic development, homeostasis and response to injury via a small SETD4
+
cell population. Potential applications may act to preserve pancreatic function in case of pancreatic disease and/or damage.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Tumor therapeutics often target the primary tumor bulk but fail to eradicate therapy-resistant cancer stem cells (CSCs) in quiescent state. These can then become activated to initiate recurrence ...and/or metastasis beyond therapy. Here, we identified and isolated chemoradiotherapy-resistant CSCs in quiescent state with high capacity of tumor-initiation and tumorsphere formation from three types of breast tumors in mice. Experiments of knockdown and rescue revealed DEK, a nuclear protein, as essential for CSC activation. Exogenous DEK was then used to trigger quiescence exit of CSCs. ChIP-seq and ATAC-seq showed that DEK directly binds to chromatin, facilitating its genome-wide accessibility. The resulting epigenetic events upregulate the expression of cellular activation-related genes including MYC targets, whereas cellular quiescence-related genes including the p53 signaling pathway are silenced. However, twinned with DEK-induced activation, formerly resistant CSCs were then destroyed by chemotherapy in vitro. In mice, traditional chemoradiotherapy concurrent with the injection of DEK-containing exosomes resulted in eradication of primary tumors together with formerly resistant CSCs without recurrence or metastasis. Our findings advance knowledge of the mechanism of quiescent CSC activation and may provide novel clinical opportunities for removal of quiescence-linked therapy resistance.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Changes in nitrogen (N) deposition and litter mixtures have been shown to influence ecosystem processes such as litter decomposition. However, the interactive effects of litter mixing and ...N‐deposition on decomposition process in desert regions remain poorly identified. We assessed the simultaneous effects of both N addition and litter mixture on mass loss in a litterbag decomposition experiment using six native plants in single‐species samples with diverse quality and 14‐species combinations in the Gurbantunggut Desert under two N addition treatments (control and N addition). The N addition had no significant effect on decomposition rate of single‐species litter (expect Haloxylon ammodendron), whereas litter mass loss and decomposition rate differed significantly among species, with variations positively correlated with initial phosphorus concentration and negatively correlated with initial lignin concentration. After 18 months, the average mass loss across litter mixtures did not overall differ from those predicted from single species either in control or N addition treatments, that is, mixing of different species had no non‐additive effects on decomposition. The N addition, however, did modify the direction of mixture effects and interacted with incubation time. Added N transformed synergistic effects of litter mixtures to antagonistic effects on mass loss after 1 month of decomposition, while transforming neutral effects of litter mixture to synergistic effects after 6 months of decomposition. Our results demonstrated that initial chemical properties played an important role in litter decomposition, while no effects of litter mixture on decomposition process in this desert region. The N addition altered the litter mixture effects on mass loss with incubation time, implying that increased N deposition in the future may have profound effects on carbon turnover to a greater extent than previously thought in desert ecosystems.
This paper demonstrated that the initial chemical properties played an important role in litter decomposition, while no effects of litter mixture on decomposition process in this desert region. The N addition altered the litter mixture effects on mass loss with incubation time, implying that increased N deposition in the future may have profound effects on carbon turnover to a greater extent than previously thought in desert ecosystems.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Membrane potential (V
) is a key bioelectric property of non-excitable cells that plays important roles in regulating cell proliferation. However, the regulation of V
itself remains largely ...unexplored. We found that, under nutrient starvation, during which cell division is inhibited, MKN45 gastric cancer cells were in a hyperpolarized state associated with a high intracellular chloride concentration. AMP-activated protein kinase (AMPK) activity increased, and expression of cystic fibrosis transmembrane conductance regulator (CFTR) decreased, in nutrient-starved cells. Furthermore, the increase in intracellular chloride concentration level and V
hyperpolarization in nutrient-starved cells was suppressed by inhibition of AMPK activity. Intracellular chloride concentrations and hyperpolarization increased after over-activation of AMPK using the specific activator AICAR or suppression of CFTR activity using specific inhibitor GlyH-101. Under these conditions, proliferation of MKN45 cells was inhibited. These results reveal that AMPK controls the dynamic change in V
by regulating CFTR and influencing the intracellular chloride concentration, which in turn influences cell-cycle progression. These findings offer new insights into the mechanisms underlying cell-cycle arrest regulated by AMPK and CFTR.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
A 3PRR parallel precision positioning system, driven by three ultrasonic linear motors, was designed for use as the object stage of a scanning electron microscope (SEM). To improve the tracking ...accuracy of the parallel platform, the positioning control algorithms for the drive joints needed to be studied. The dead-zone phenomenon caused by static friction reduces the trajectory tracking accuracy significantly. Linear control algorithms such as PID (Proportion Integration Differentiation) are unable to compensate effectively for the dead-zone nonlinearity. To address this problem, two types of feedforward compensation control algorithms have been investigated. One is constant feedforward with the integral separation PID; the other is adaptive feedback and feedforward based on the model reference adaptive control (MRAC). Simulations and experiments were conducted using these two control algorithms. The results demonstrated that the constant feedforward with integral separation PID algorithm can compensate for the time-invariant system after identifying the dead-zone depth, while the adaptive feedback and feedforward algorithm is more suitable for the time-varying system. The experimental results show good agreement with the simulation results for these two control algorithms. For the dead-zone nonlinearity caused by the static friction, the adaptive feedback and feedforward algorithm can effectively improve the trajectory tracking accuracy.
•A positioning system has been built for the driven joints of the 3-PRR in SEM.•The dead-zone of the system has been identified and applied to compensation.•The proposed control algorithm improves the tracking precision significantly.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
PDF
