In this paper, the notion of M-fuzzifying convex remotehood systems is introduced and characterizations of M-fuzzifying convex spaces are obtained. Further, notions of remote mappings and ...M-fuzzifying convex quasi-uniformities are introduced. It is proved that M-fuzzifying convex quasi-uniform space and M-fuzzifying convex space are mutually induced. In order to discuss categorical relationships among M-fuzzifying convex quasi-uniform spaces, M-fuzzifying convex remotehood spaces and M-fuzzifying convex spaces, notions of M-fuzzifying quasi-uniformizable convex structures and M-fuzzifying quasi-uniformizable convex remotehood spaces are presented. It is proved that the category of M-fuzzifying quasi-uniformizable convex spaces and the category of M-fuzzifying quasi-uniformizable convex remotehood spaces can be embedded into the category of M-fuzzifying convex quasi-uniform spaces as subcategories.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
A metal-free brand-new one-pot multinitrogenation of amides for the chemo- and regioselective synthesis of 1,5-disubstituted tetrazoles has been developed. By means of electrophilic amide activation, ...and further C-C bond cleavage and rearrangement, a diverse set of functionalized 1,5-DST derivatives were selectively constructed under mild conditions. As showcased in the mechanisms, the chemoselectivity is easily switched by the selection of the starting materials in the reaction.
Total organic acid secretion of vitis rootstocks all increased under alkali stress, and the increment of organic acid secretion was A17>A15>1103P, and whether under normal growth conditions or NaHCO3 ...treatment, oxalic acid was the main organic acid in root. The H + −ATPase inhibitor Na3VO4 significantly reduced oxalic acid secretion suggesting oxalic acid secretion might be relevant to the proton pump H + −ATPase activity.
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•Under NaHCO3 stress, the organic acids secreted by root system of the rootstocks were mainly oxalic acid.•The vitis rootstocks which had strong alkaline resistance secreted more oxalic acid.•H + −ATPase plays an important role in grape root secretion of oxalic acid.
To elucidate the mechanism of organic acid metabolism in rootstocks under alkali stress, rootstocks A15 and A17 (V. amurensis cv. Zuoshan1×SO4), both with strong alkaline resistance, and a control rootstock 1103P (V. berlandieri×V. rupestris) were used as materials. Tissue culture plants were treated with NaHCO3 or Na3VO4 (H + − ATPase inhibitors). The pH value of the three rootstock rhizospheres decreased following NaHCO3 stress. Oxalic acid was the main organic acid, and its secretion significantly increased after NaHCO3 treatment. Oxalic acid secretion of A15 and A17 was significantly higher than that of 1103P before and after NaHCO3 treatment. Oxalic acid content and secretion decreased in rootstock A15 under Na3VO4+NaHCO3 treatment. The changes in PEPC (phosphoenolpyruvate carboxylase) activity in A15 and the ICL (isocitrate lyase) activity in A17 were significantly increased. The relative expression of VvICL (isocitrate lyase gene) in A15 and VvPEP (phosphoenolpyruvate carboxylase gene) in A17 was significantly upregulated compared with the control. The relative expression of VvPMA3 (H + −ATPase family gene) was higher in rootstock A15 and peaked after 24h treatment. This suggests that the proton pump (VvPMA3) may play an important role in NaHCO3 stress, through promotion of organic acid secretion in the roots to reduce NaHCO3 stress.
The heterofunctional lactone furo3,4‐bpyridin‐5(7H)‐one (L1) undergoes a coordination‐induced ring‐opening reaction with Zn(NO3)2 ⋅ 6H2O to yield the zwitterionic Zn(L1′)2(H2O)2 (1, ...L1′=2‐(hydroxymethyl)nicotinate) with an uncoordinated carboxylate. The same reaction with Cd(NO3)2 ⋅ 4H2O provides a two‐dimensional (2D) network of Cd(L1′)2n (3) with the carboxylates coordinated to cadmium(II) propagating the assembly. The corresponding reactions of Zn(NO3)2 ⋅ 6H2O and Cd(NO3)2 ⋅ 4H2O with 2‐(hydroxymethyl)isonicotinic acid (HL2) generated zwitterionic Zn(L2)2(H2O)2 (2) and a 2D network Cd(L2)2n⋅nDMF (4, DMF=N,N′‐dimethylformamide), respectively. Complexes 1–4 are weakly emissive, giving ligand‐centered emissions at 409 nm (1), 412/436 nm (2), 404 nm (3), and 412/436 nm (4) in CHCl3 solutions upon excitation at 330 nm. This work points to the potential of using ‘hidden’ functionalities widely found in small organic molecules and natural products for the construction of coordination complexes with new functionality and potential applications.
Zwitterions for MOFs: Zn‐based zwitterions of Zn(L1′)2(H2O)2 (1, L1′=2‐(hydroxymethyl)nicotinate) and Zn(L2)2(H2O)2 (2, HL2=2‐(hydroxymethyl)isonicotinic acid), and Cd‐based MOFs of Cd(L1’)2n (3) and Cd(L2)2n⋅nDMF (4) have been synthesized and characterized. Complexes 1–4 exhibit ligand‐centered emissions at 409 nm (1), 412/436 nm (2), 404 nm (3), and 412/436 nm (4) in CHCl3 solutions upon excitation at 330 nm.
Hepatocellular carcinoma (HCC) is one of the most common and fatal tumors in the world, ranking third in cancer-related mortality. Chronic HBV infection is one of the major risk factors for ...hepatocellular carcinoma in China, Korea, and Sub-Saharan Africa. The HBx protein encoded by the X gene of HBV is a broadly regulated protein involved in transcriptional activation, epigenetics, apoptosis, DNA repair, and other regulatory processes. This study aimed to investigate the mechanism of HBx regulation of miR-155 and PTEN (Phosphatase and tensin homolog deleted on chromosome ten) in HBV-HCC.
Exosomal miR-155 quantity was analyzed by sampling serum exosomes of patients with hepatocellular carcinoma and normal subjects. The analysis was divided into different subgroups according to HBV positivity or negativity. At the cellular level, the biological roles of HBX, microRNA-155 and PTEN on hepatocellular carcinoma cells and their regulatory relationships with each other were verified.
MicroRNA-155 and PTEN expression in HBV-positive HCC liver cancer tissues were negatively correlated, and HBX and miR-155 expression were positively correlated; microRNA-155 could target and inhibit PTEN expression, thereby promoting hepatocellular carcinoma cell activity, inhibiting apoptosis, and promoting invasion and migration; HBX could upregulate microRNA-155 thereby inhibit PTEN to promote malignant transformation of hepatocellular carcinoma.
HBX could promote malignant transformation of hepatocellular carcinoma cells by upregulating microRNA-155 expression and thereby inhibiting the PTEN/PI3K-AKT pathway. Blocking miR-155 expression could attenuate the proliferation-promoting and invasive effects of HBX.
Correct cognition of the environment is the premise of mobile robots to realize autonomous navigation control tasks. The inconsistency caused by time-varying environmental information is a bottleneck ...for the development and application of cognitive environment technologies. In this article, we propose an environmental cognition method that uses a hand-drawn map. Firstly, we use the single skeleton refinement and fuzzy c-means algorithms to segment the image. Then, we select candidate regions combining the saliency map. At the same time, we use the superpixels straddling method to filter the windows. The final candidate object regions are obtained based on a fusion of saliency segmentation and superpixels clustering. Based on the above objectness estimation results, we use a human–computer interaction method to construct an inaccurate hand-drawn environment map for navigation. The experimental results from PASCAL VOC2007 validate the efficacy of the proposed objectness measure method, where our result of 41.2% on mean average precision is the best of the tested methods. Furthermore, the experimental results of robot navigation in the actual scene also verified the effectiveness of the proposed approach.
It is normally assumed that the sheet resistances under and outside the metal contact are identical when deriving specific contact resistivity of graphene from transmission line model. We considered ...the contact end resistance and obtained the sheet resistance under contact of 670Ω/□, which is much different from that outside the contact of 1840Ω/□. Considering the difference, the value of specific contact resistivity is determined to be 3.3×10−6Ωcm2, which is three times as large as the unmodified value. This indicates that the difference between the sheet resistances under and outside the contact affects the derived specific contact resistivity of graphene significantly.
Abnormal wound healing by pulmonary artery smooth muscle cells (PASMCs) promotes vascular remodeling in hypoxia-induced pulmonary hypertension (HPH). Increasing evidence shows that both the mammalian ...target of rapamycin complex 1 (mTORC1) and nuclear factor-kappa B (NF-κB) are involved in the development of HPH. In this study, we explored the crosstalk between mTORC1 and NF-κB in PASMCs cultured under hypoxic condition and in a rat model of hypoxia-induced pulmonary hypertension (HPH). We showed that hypoxia promoted wound healing of PASMCs, which was dose-dependently blocked by the mTORC1 inhibitor rapamycin (5-20 nM). In PASMCs, hypoxia activated mTORC1, which in turn promoted the phosphorylation of NF-κB. Molecular docking revealed that mTOR interacted with IκB kinases (IKKs) and that was validated by immunoprecipitation. In vitro kinase assays and mass spectrometry demonstrated that mTOR phosphorylated IKKα and IKKβ separately. Inhibition of mTORC1 decreased the level of phosphorylated IKKα/β, thus reducing the phosphorylation and transcriptional activity of NF-κB. Bioinformatics study revealed that dipeptidyl peptidase-4 (DPP4) was a target gene of NF-κB; DPP4 inhibitor, sitagliptin (10-500 μM) effectively inhibited the abnormal wound healing of PASMCs under hypoxic condition. In the rat model of HPH, we showed that NF-κB activation (at 3 weeks) was preceded by mTOR signaling activation (after 1 or 2 weeks) in lungs, and administration of sitagliptin (1-5 mg/kg every day, ig) produced preventive effects against the development of HPH. In conclusion, hypoxia activates the crosstalk between mTORC1 and NF-κB, and increased DPP4 expression in PASMCs that leads to vascular remodeling. Sitagliptin, a DPP4 inhibitor, exerts preventive effect against HPH.
Robot-aided rehabilitation has become an important technology to restore and reinforce motor functions of patients with extremity impairment, whereas it can be extremely challenging to achieve ...satisfactory tracking performance due to uncertainties and disturbances during rehabilitation training. In this paper, a wire-driven rehabilitation robot that can work over a three-dimensional space is designed for upper-limb rehabilitation, and sliding mode control with nonlinear disturbance observer is designed for the robot to deal with the problem of unpredictable disturbances during robot-assisted training. Then, simulation and experiments of trajectory tracking are carried out to evaluate the performance of the system, the position errors, and the output forces of the designed control scheme are compared with those of the traditional sliding mode control (SMC) scheme. The results show that the designed control scheme can effectively reduce the tracking errors and chattering of the output forces as compared with the traditional SMC scheme, which indicates that the nonlinear disturbance observer can reduce the effect of unpredictable disturbances. The designed control scheme for the wire-driven rehabilitation robot has potential to assist patients with stroke in performing repetitive rehabilitation training.
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