Silicon is the most widely used material in numerous fields. Traditional mechanical machining methods have been unable to meet the higher requirements of processing quality. Laser machining is ...especially suitable for processing hard and brittle materials due to the non-contact processing characteristics. This article summarizes the nanosecond, picosecond, femtosecond laser drilling and cutting technologies of silicon according to the classification of laser pulse widths. For the most typical field assisted machining technology, liquid-assisted laser drilling and cutting are also discussed. In consideration of the heat generated during laser processing is likely to cause stress in the material, resulting in micro-cracks and other processing defects. Laser induced thermal crack propagation cutting technology (LITP) successfully uses the cracks produced in laser machining to achieve the high cutting quality of silicon. As a new way of material internal processing, laser stealth dicing is the most promising method in the field of wafer cutting. The mechanism and processing characteristics of laser stealth dicing are described. At the end of paper, a summary and outlook are provided.
Background and Aims
DNA damage‐induced NF‐κB activation is a major obstacle to effective antitumour chemotherapy. Long noncoding RNAs (lncRNAs) that regulate chemoresistance of cancer cells remain ...largely unknown. This study aimed to characterize the lncRNAs that may affect chemotherapy sensitivity.
Approach and Results
We found that lncRNA PDIA3P1 (protein disulfide isomerase family A member 3 pseudogene 1) was up‐regulated in multiple cancer types and following treatment with DNA‐damaging chemotherapeutic agents, like doxorubicin (Dox). Higher PDIA3P1 level was associated with poorer recurrence‐free survival of human hepatocellular carcinoma (HCC). Both gain‐of‐function and loss‐of‐function studies revealed that PDIA3P1 protected cancer cells from Dox‐induced apoptosis and allowed tumor xenografts to grow faster and to be more resistant to Dox treatment. Mechanistically, miR‐125a/b and miR‐124 suppressed the expression of tumor necrosis factor receptor‐associated factor 6 (TRAF6), but PDIA3P1 bound to miR‐125a/b/miR‐124 and relieved their repression on TRAF6, leading to activation of the nuclear factor kappa B (NF‐κB) pathway. Consistently, the effect of PDIA3P1 inhibition in promoting Dox‐triggered apoptosis was antagonized by silencing the inhibitor of κBα (IκBα) or overexpressing TRAF6. Administration of BAY 11‐7085, an NF‐κB inhibitor attenuated PDIA3P1‐induced resistance to Dox treatment in mouse xenografts. Moreover, up‐regulation of PDIA3P1 was significantly correlated with elevation of TRAF6, phosphorylated p65, or NF‐κB downstream anti‐apoptosis genes in human HCC tissues. These data indicate that enhanced PDIA3P1 expression may confer chemoresistance by acting as a microRNA sponge to increase TRAF6 expression and augment NF‐κB signaling. Subsequent investigations into the mechanisms of PDIA3P1 up‐regulation revealed that human homologue of mRNA transport mutant 4 (hMTR4), which promotes RNA degradation, could bind to PDIA3P1, and this interaction was disrupted by Dox treatment. Overexpression of hMTR4 attenuated Dox‐induced elevation of PDIA3P1, whereas silencing hMTR4 increased PDIA3P1 level, suggesting that Dox may up‐regulate PDIA3P1 by abrogating the hMTR4‐mediated PDIA3P1 degradation.
Conclusion
There exists a hMTR4‐PDIA3P1‐miR‐125/124‐TRAF6 regulatory axis that regulates NF‐κB signaling and chemoresistance, which may be exploited for anticancer therapy.
We report the synthesis and spectroscopic identification of the trisbenzene complexes of strontium and barium M(Bz)3 (M=Sr, Ba) in low‐temperature Ne matrix. Both complexes are characterized by a D3 ...symmetric structure involving three equivalent η6‐bound benzene ligands and a closed‐shell singlet electronic ground state. The analysis of the electronic structure shows that the complexes exhibit metal–ligand bonds that are typical for transition metal compounds. The chemical bonds can be explained in terms of weak donation from the π MOs of benzene ligands into the vacant (n−1)d AOs of M and strong backdonation from the occupied (n−1)d AO of M into vacant π* MOs of benzene ligands. The metals in these 20‐electron complexes have 18 effective valence electrons, and, thus, fulfill the 18‐electron rule if only the metal–ligand bonding electrons are counted. The results suggest that the heavier alkaline earth atoms exhibit the full bonding scenario of transition metals.
Bonding scenarios: The synthesis and spectroscopic identification of the trisbenzene complexes of strontium and barium M(Bz)3 (M=Sr, Ba) in a low‐temperature Ne matrix is reported. The complexes exhibit metal–ligand bonds that are typical for transition‐metal compounds. The results suggest that the heavier alkaline‐earth atoms exhibit the full bonding scenario of transition metals.
Fluorescent probe technology has been widely used in biochemistry, medicine, environmental science and industry. Resorufin has been widely used in the design of small molecule fluorescent chemical ...sensors due to its excellent optical properties. It has found a wide range of applications in molecular recognition and molecular imaging in analytical chemistry, biology and medicine. In this review, we systematically summarize the development of resorufin-based fluorescent probes to detect biologically active substances such as enzymes, reactive oxygen species (ROS), reactive nitrogen species (RNS), reactive sulfur species (RSS), ions, etc. The design strategies and biological applications of various resorufin-based fluorescent probes are discussed in detail, so as to promote the development of more powerful fluorescent probes for extensive and exciting applications in the future. In addition, we also outlook on the development trend and the prospects of probes based on the resorufin platform.
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•A review systematically summarizes the development of resorufin-based fluorescent probes.•The protection of 7-hydroxy group and substitution of N atom of resorufin are two general strategies to develop probes.•Resorufin-based probes could detect enzymes, ROS, RNS, RSS, ions, and target organelle.•NIR-I or NIR-II and ratiometric fluorescent probes could be the optimal pursuit.
Severe challenges are still remained for development of highly sensitive, selective and stable photoelectrochemical (PEC) sensing technology, albeit with its broad application for chloramphenicol ...(CAP) detection. Herein, a novel “signal-on” PEC aptasensor was fabricated based on a 3D self-supporting Z-scheme AgI/Ag/BiOI heterojunction arrays subtly integrated with in-situ formed biocatalytic precipitation (BCP) for highly sensitive and selective determination of CAP. Impressively, the HRP modified CAP aptamer (HRP-CAP aptamer) was released from the electrode by its strong affinity to the introduced CAP, and gradually terminated the BCP reaction, in turn recovering the photocurrent. By virtues of the 3D self-supporting AgI/Ag/BiOI Z-scheme heterojunction arrays and BCP signal amplification strategy, the resultant PEC sensor exhibited a wide linear range of 2–250 nM with a limit of detection (LOD) as low as 0.226 nM (S/N = 3). This work opens a new avenue for design of PEC aptasensing strategy and exhibits the marvelous potential in bioanalysis of environmental samples.
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•AgI/Ag/BiOI Z-scheme heterojunction arrays were prepared by ion-exchange and photoreduction.•A novel “signal-on” cathodic PEC aptasensor was constructed.•The BCP-based signal amplification strategy was designed for ultrasensitive analysis of CAP.•The PEC sensor exhibited highly improved analytical performance for CAP.
Zearalenone (ZEA) can perturb the differentiation of cells, reduce the generation of reproductive cells and induce a death of germ cells, but the molecular mechanism remains unclear. In order to ...investigate the potential mechanism of ZEA-induced cell cycle arrest and apoptosis, we studied the effects of ZEA on cell proliferation, cell-cycle distribution, cell-cycle-related proteins, cell death, cell apoptosis, ROS generation and the ATP/AMPK pathway in Sertoli cells. The role of ROS, ER stress and the ATP/AMPK pathway in ZEA-induced cell-cycle arrest and cell apoptosis was explored by using the antioxidant NAC, ER stress inhibitor 4-PBA and the AMPK inhibitor dorsomorphin, respectively. The results revealed that ZEA inhibited the cell proliferation, influenced the distribution of the cell cycle and induced cell apoptosis through the ATP/AMPK pathway. The ATP/AMPK pathway was regulated by ER stress that was induced by ROS generation after exposure to ZEA. Taking these together, this study provided evidence that ROS regulated the process of ZEA-induced cell cycle arrest and cell apoptosis through ER stress and the ATP/AMPK signal ways.
Trace elements have been recognized to play an important role in the development of Parkinson's disease (PD). However, it is difficult to precisely identify the relationship between these elements ...and the progression of PD because of an insufficient number of patients. In this study, quantifications of selenium (Se), copper (Cu), iron (Fe) and zinc (Zn) by atomic absorption spectrophotometry were performed in plasma from 238 PD patients and 302 controls recruited from eastern China, which is so far the largest cohort of PD patients and controls for measuring plasma levels of these elements. We found that plasma Se and Fe concentrations were significantly increased whereas Cu and Zn concentrations decreased in PD patients as compared with controls. Meanwhile, these four elements displayed differential changes with regard to age. Linear and logistic regression analyses revealed that both Fe and Zn were negatively correlated with age in PD patients. Association analysis suggests that lower plasma Se and Fe levels may reduce the risk for PD, whereas lower plasma Zn is probably a PD risk factor. Finally, a model was generated to predict PD patients based on the plasma concentrations of these four trace elements as well as other features such as sex and age, which achieved an accuracy of 80.97±1.34% using 10-fold cross-validation. In summary, our data provide new insights into the roles of Se, Cu, Fe and Zn in PD progression.
The physiological role of microRNAs (miRNAs) in osteoblast differentiation remains elusive. Exosomal miRNAs isolated from human bone marrow-derived mesenchymal stem cells (BMSCs) culture were ...profiled using miRNA arrays containing probes for 894 human matured miRNAs. Seventy-nine miRNAs (∼8.84%) could be detected in exosomes isolated from BMSC culture supernatants when normalized to endogenous control genes RNU44. Among them, nine exosomal miRNAs were up regulated and 4 miRNAs were under regulated significantly (Relative fold>2, p<0.05) when compared with the values at 0 day with maximum changes at 1 to 7 days. Five miRNAs (miR-199b, miR-218, miR-148a, miR-135b, and miR-221) were further validated and differentially expressed in the individual exosomal samples from hBMSCs cultured at different time points. Bioinformatic analysis by DIANA-mirPath demonstrated that RNA degradation, mRNA surveillance pathway, Wnt signaling pathway, RNA transport were the most prominent pathways enriched in quantiles with differential exosomal miRNA patterns related to osteogenic differentiation. These data demonstrated exosomal miRNA is a regulator of osteoblast differentiation.
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