Protective role of hydrogen sulfide （H2S） on seed germination and seedling growth was studied in wheat （Triticum） seeds subjected to aluminum （Al3＋） stress. We show that germination and seedling ...growth of wheat is inhibited by high concentrations of AICI3. At 30 mmol/L AICI3 germination is reduced by about 50% and seedling growth is more dramatically inhibited by this treatment. Pre-incubation of wheat seeds in the H2S donor NaHS alleviates AICI3-induced stress in a dose-dependant manner at an optimal concentration of 0.3 mmol/L. We verified that the role of NaHS in alleviating Al3＋ stress could be attributed to H2S/HS- by showing that the level of endogenous H2S increased following NaHS treatment. Furthermore, other sodium salts containing sulfur were ineffective in alleviating Al3＋ stress. NaHS pretreatment significantly increased the activities of amylases and esterases and sustained much lower levels of MDA and H2O2 in germinating seeds under Al3＋ stress. Moreover, NaHS pretreatment increased the activities of guaiacol peroxidase, ascorbate peroxidase, superoxide dismutase and catalase and decreased that of lipoxygenase. NaHS pretreatment also decreased the uptake of Al3＋ in AICI3-treated seed. Taken together these results suggest that H2S could increase antioxidant capability in wheat seeds leading to the alleviation of Al3＋ stress.
We propose a novel deep layer cascade (LC) method to improve the accuracy and speed of semantic segmentation. Unlike the conventional model cascade (MC) that is composed of multiple independent ...models, LC treats a single deep model as a cascade of several sub-models. Earlier sub-models are trained to handle easy and confident regions, and they progressively feed-forward harder regions to the next sub-model for processing. Convolutions are only calculated on these regions to reduce computations. The proposed method possesses several advantages. First, LC classifies most of the easy regions in the shallow stage and makes deeper stage focuses on a few hard regions. Such an adaptive and difficulty-aware learning improves segmentation performance. Second, LC accelerates both training and testing of deep network thanks to early decisions in the shallow stage. Third, in comparison to MC, LC is an end-to-end trainable framework, allowing joint learning of all sub-models. We evaluate our method on PASCAL VOC and Cityscapes datasets, achieving state-of-the-art performance and fast speed.
Mesenchymal stem cells (MSCs) are promising cell sources for regenerative medicine. Growing evidence has indicated that mechanical stimuli are crucial for their lineage-specific differentiation. ...However, the effect of mechanical loading on redox balance and the intracellular antioxidant system in MSCs was unknown. In this study, human bone marrow-derived MSCs (BM-MSCs) were subjected to cyclic stretch at the magnitude of 2.5%, 5%, and 10%. Cell proliferation, intracellular reactive oxygen species (ROS), expression of antioxidant enzymes, and osteogenic differentiation were evaluated. RNA was extracted and subjected to DNA microarray analysis. Sirtinol and compound C were used to investigate the underlying mechanisms involved silent information regulator type 1 (SIRT1) and AMP-activated protein kinase (AMPK). Our results showed that mechanical stretch at appropriate magnitudes increased cell proliferation, up-regulated extracellular matrix organization, and down-regulated matrix disassembly. After 3 days of stretch, intracellular ROS in BM-MSCs were decreased but the levels of antioxidant enzymes, especially superoxide dismutase 1 (SOD1), were up-regulated. Osteogenesis was improved by 5% stretch rather than 10% stretch, as evidenced by increased matrix mineralization and osteogenic marker gene expression. The expression of SIRT1 and phosphorylation of AMPK were enhanced by mechanical stretch; however, inhibition of SIRT1 or AMPK abrogated the stretch-induced antioxidant effect on BM-MSCs and inhibited the stretch-mediated osteogenic differentiation. Our findings reveal that mechanical stretch induced antioxidant responses, attenuated intracellular ROS, and improved osteogenesis of BM-MSCs. The stretch-induced antioxidant effect was through activation of the AMPK-SIRT1 signaling pathway. Our findings demonstrated that appropriate mechanical stimulation can improve MSC antioxidant functions and benefit bone regeneration.
Display omitted
•Mechanical stretch induces antioxidant responses in BM-MSCs.•Intracellular ROS formation is attenuated by cyclic stretch.•Stretch-mediated antioxidant effect is via activation of AMPK and SIRT1.•Appropriate stretch promotes osteogenic differentiation of BM-MSCs.•Excessive stretch has an adverse effect on cellular antioxidant system.
Apoptosis plays a dual role in cancer development and malignancy. The role of apoptosis-related caspases in cancer remains controversial, particularly in oral tongue squamous cell carcinoma (OTSCC). ...In this study, we examined the protein levels of cleaved caspase-3, caspase-3, caspase-8, and caspase-9 on tissue microarrays consisting of samples from 246 OTSCC patients by immunohistochemistry. Wilcoxon signed-rank test indicated that the protein levels of cleaved caspase-3, caspase-3, caspase-8, and caspase-9 in tumor tissues were significantly higher compared to those in adjacent normal tissues (all p<0.001). The expression level of caspase-8 in tumors was elevated in patients with lymph node invasion. Moreover, positive expression of cleaved caspase-3 was associated with shorter disease-free survival (DFS) in OTSCC patients with moderate differentiation and lymph node invasion. Combination of either positive cleaved caspase-3 or higher caspase-3 expression or both was associated with poor DFS. Interestingly, stratification analysis showed that co-expression levels of positive cleaved caspase-3 or/and higher caspase-3 were associated with better disease-specific survival in patients with advanced stages of the disease, such as large tumor size and lymph node invasion, whereas it was associated with poor DFS in OTSCC patients with moderate cell differentiation and small tumor size. Taken together, cleaved caspase-3 and caspase-3/8/9 could be biomarkers for tumorigenesis in OTSCC patients. The co-expression level of cleaved caspase-3 and caspase-3 might be a prognostic biomarker for OTSCC patients, particular in those patients with certain tumor stages and cell differentiation status.
•A discrete unified gas kinetic scheme for non-gray phonon transport is developed.•The dispersion and polarization of phonons is considered.•Cross-plane, in-plane, transient thermal grating problems ...are numerically solved by DUGKS.•Results for different thickness of thin films are consistent with analytical or other results.•The present approach can accurately capture ballistic-diffusive transport phenomenon.
Different from the gray model for phonon transport, the non-gray model takes account of the dispersion and polarization of phonons. Under the consideration of the real dispersion curve, the phonon transport in micro and nanoscale devices is intractable multiscale problem. On the basis of previous work about gray model for phonon transport by a discrete unified gas kinetic scheme (DUGKS), we extend the DUGKS to solving non-gray transport determined by the frequency-dependent phonon Boltzmann equation. The extension is straightforward due to the intrinsic multiscale property of the DUGKS. Four classic test cases, cross-plane heat conduction, in-plane heat conduction, one-dimensional transient thermal grating problem and two-dimensional steady phonon conduction are used to validate our scheme. Numerical results show that the present scheme can accurately capture ballistic-diffusive transport phenomenon in a wide range. This method may provide a powerful numerical tool for a deep research into nanoscale and microscale heat transport.
Graphene oxide (GO), tungsten trioxide (WO3) and graphene–WO3 nanobelt composites (GW) were synthesized and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ...high-resolution transmission electron microscopy (HRTEM), UV–vis diffuse reflection spectra (DRS) and X-ray photoelectron spectroscopy (XPS) valence band spectra. We demonstrated that the graphene can elevate the conduction band of WO3 toward photocatalytic reduction of CO2 into hydrocarbon fuels under visible-light irradiation. And the photocatalytic activity of GW is higher than that of GO, WO3 and P25 TiO2.
We demonstrated that the graphene can elevate the conduction band of WO3 toward photocatalytic reduction of CO2 into hydrocarbon fuels under visible-light irradiation. Display omitted
•One-pot synthesis of grahene-WO3 nanobelt composites (GW)•Graphene can elevate the conduction band of WO3.•GW showed high photocatalytic activity for CO2 photocatalytic reduction.
Of noble descent: A fully noble‐metal‐free system for the photocatalytic reduction of water at room temperature has been developed. This system consists of CuI complexes as photosensitizers and ...Fe3(CO)12 as the water‐reduction catalyst. The novel Cu‐based photosensitizers are relatively inexpensive, readily available from commercial sources, and stable to ambient conditions, thus making them an attractive alternative to the widely used noble‐metal based systems.
•The impacts of climate change on ecological factors are both uncertain and diverse.•There is no viable solution to these problems and a model to assess the impacts.•A set pair analysis model (SPAM) ...for ecological resistance and corridors is designed.•The resistance's SPAM results in 5 scenarios, ranging from 0.085 to 0.501.•The ecological connectivity in Central and Southern Jiangxi region will deteriorate.
Climate change significantly impacts ecological resistance and ecological corridors. However, the difficulty in evaluating this impact lies in two crucial issues: (i) the uncertainty arising from spatial heterogeneity, and (ii) the diversity of impacts arising from this uncertainty. A set pair analysis (SPA) model is designed to assess the impact of climate change on ecological resistance and ecological corridors for addressing the aforementioned problems. First, the ecological resistance and corridors under different climate change scenarios are simulated. Then, the five-element connection number is used to reflect changes in ecological resistance and corridors influenced by climate change and uncertainty. Finally, the influence indices are constructed to quantify the three distinct impacts of climate change on them. The evaluation results for Jiangxi Province are as follows. (i) The province’s UR index values are 0.085, 0.127, 0.351, 0.501, and 0.468 under five climate change scenarios, respectively. The impact of climate change on ecological resistance is rapidly deteriorating, and the central region is the high-value center for future ecological resistance. (ii) The values of UC in the central and southern regions range from − 0.568 to − 0.320 and from − 0.816 to − 0.446, respectively. In the two regions, the assessments of the impact of climate change on ecological corridors are negative, which results in a reduction in connectivity. (iii) The crucial meteorological risks with the greatest impact on ecological resistance and corridors are floods and high-temperature disasters. (iv) The proposals for Jiangxi Province to address climate change are as follows: enhancing flood prevention, improving high-temperature monitoring, and establishing an ecological management system. (v) The SPA model can effectively assess the different impacts of climate change with spatial uncertainty on ecological resistance and corridors.
The reduction of water has been achieved through a non‐noble‐metal‐based homogeneous catalyst system that is formed in situ. Optimisation of the ligand quantities increased catalyst turnover numbers ...compared to preformed complexes. Mechanistic studies confirm a heteroleptic Cu complex as the active photosensitiser (PS) and an in situ formed Fe–phosphido dimer complex as the water reduction catalyst. The in situ method has been used to screen a range of ligands for the active PS, which has led to the identification a number of structural features important to longevity and performance.
Cheap ′n′ easy H2: The reduction of water was achieved through a non‐noble‐metal‐based homogeneous catalyst system that is formed in situ. Mechanistic studies confirm a heteroleptic Cu complex as the active photosensitiser (PS) and an in situ formed Fe–phosphido dimer complex as the water reduction catalyst (see scheme). The in situ method was used to screen a range of ligands for the active PS, which led to the identification of a number of structural features important to longevity and performance.
Triple negative breast cancer (TNBC) lacks both early detection biomarkers and viable targeted therapeutics. Moreover, chemotherapy only produces 20-30% pathologic complete response. Because miRNAs ...are frequently dysregulated in breast cancer and have broad tissue effects, individual or combinations of circulating miRNAs may serve as ideal diagnostic, predictive or prognostic biomarkers, as well as therapeutic targets. Understanding the role and mechanism of dysregulated miRNAs in TNBC may help to develop novel diagnostic and prognostic strategy for TNBC patients.
The miRNA array profiles of 1299 breast cancer patients were collected from the Metabric database and subjected to analysis of the altered miRNAs between TNBC and non-TNBC. In Student's t-test and Kaplan-Meier analysis, four upregulated miRNAs correlated with poor survival in TNBC but not in non-TNBC. Four miRNAs were manipulated in multiple cell lines to investigate their functional role in carcinogenesis. From these results, we studied miR-105 and miR-93-3p in greater detail. The level of miR-105 and miR-93-3p were evaluated in 25 breast cancer tumor tissues. In addition, the diagnostic utility of circulating miR-105 and miR-93-3p were examined in 12 normal and 118 breast cancer plasma samples by ROC curve construction.
miR-105 and miR-93-3p were upregulated and correlated with poor survival in TNBC patients. Both miR-105 and miR-93-3p were found to activate Wnt/β-catenin signaling by downregulation of SFPR1. By this action, stemness, chemoresistance, and metastasis were promoted. Importantly, the combination of circulating miR-105/93-3p may serve as a powerful biomarker for TNBC, even in early-stage disease.
miR-105/93-3p activates Wnt/β-catenin signaling by downregulating SFRP1 and thereby promotes stemness, chemoresistance, and metastasis in TNBC cells. Most importantly, combined circulating miR-105/93-3p levels represent a prime candidate for development into a diagnostic biomarker for both early- and late-stage TNBC.
PDF
