Self-Healable, Self-Adhesive and Degradable MXene-Based Multifunctional Hydrogel for Flexible Epidermal Sensors.

Conductive hydrogels have garnered significant interest in the realm of wearable flexible sensors due to their close resemblance to human tissue, wearability, and precise signal acquisition capabilities. However, the concurrent attainment of an epidermal hydrogel sensor incorporating reliable self-healing capabilities, biodegradability, robust adhesiveness, and the ability to precisely capture subtle electrophysiological signals poses a daunting and intricate challenge. Herein, an innovative MXene-based composite hydrogel (PBM hydrogel) with exceptional self-healing, self-adhesive, and versatile functionality is engineered through the integration of conductive MXene nanosheets into a well-structured poly(vinyl alcohol) (PVA) and bacterial cellulose (BC) hydrogel three-dimensional (3D) network, utilizing multiple dynamic cross-linking synergistic repeated freeze-thaw strategy. The hydrogel harnesses the presence of dynamically reversible borax ester bonds and multiple hydrogen bonds between its constituents, endowing it with rapid self-healing efficiency (97.8%) and formidable self-adhesive capability. The assembled PBM hydrogel epidermal sensor possesses a rapid response time (10 ms) and exhibits versatility in detecting diverse external stimuli and human movements such as vocalization, handwriting, joint motion, Morse code signals, and even monitoring infusion status. Additionally, the PBM hydrogel sensor offers the added advantage of swift degradation in phosphate-buffered saline solution (within a span of 56 days) and H2O2 solution (in just 53 min), maintaining an eco-friendly profile devoid of any environmental pollution. This work lays the groundwork for possible uses in electronic skins, interactions between humans and machines, and the monitoring of individualized healthcare.

C/EBPß-TFAM-Mediated NLRP3 Inflammasome Activation Contributes to Arsenic-Induced Rat Kidney Injury.

Compelling evidence has demonstrated that arsenic (As) exposure is associated with kidney injuries. Given that inflammatory responses and immune imbalances are the root causes of several kidney diseases, this study investigated the potential mechanisms underlying NLRP3 inflammasome activation in As-induced kidney injury. A rat model of sub-chronic As exposure was established via oral administration of NaAsO2. The results revealed that urinary ß-2-microglobulin (ß2-MG), N-acetyl-ß-D-glucosidase (NAG) and albumin (ALB) were increased in the As-exposed group, reflecting kidney impairment. Moreover, significant glomerular vacuole-like changes, tubular dilatation and inflammatory cell infiltration were observed. Meanwhile, the expression levels of neutrophil gelatinase-associated lipocalin (NGAL), IL-1ß and IL-18 were enhanced in the kidney tissues of As-treated rats. Further, increased expression of NLRP3, ASC and caspase-1, which are NLRP3 inflammasome-associated proteins, were observed in the kidney tissues of rats in the As-treated groups. The expression levels of the NLRP3 upstream regulators C/EBPß and TFAM were also elevated. These findings suggest that sub-chronic As exposure triggers inflammatory responses in rat kidney tissue and impairs kidney function. The underlying mechanisms may be related to the C/EBPß-TFAM pathway and activation of the NLRP3 inflammasome pathway.

Effect of Alloying Powders on Microstructure and Mechanical Properties of Aluminum Alloy Arc Additive Manufacturing.

Cold metal transfer arc additive manufacturing technique was used to produce 5356 aluminum alloy by adding refining agents to solve the problems of coarse grains and poor performance. Metallic powders (Ti, TiH, and Ti+B4C) were used to refine the grain size and promote the mechanical properties of the alloy. The effects of refining agents on the microstructure and mechanical properties of straight wall samples (SWSs) were studied. Samples with Ti+B4C addition had a profound impact on morphology. However, the TiH added sample revealed uneven transition between sediment layers, unstable precipitation process, unstable wall height and wall width, poor morphology, and defects. All SWSs with powder addition revealed the formation of the Al3Ti phase. Moreover, the columnar grains between the layers were transformed into equiaxed grains and finer grains at the center of the layers. There was a significant effect of TiH on the grain refinement. The samples with Ti demonstrated superior mechanical properties. The tensile strength and elongation of the SWSs increased by 28 MPa and 4.6% in the parallel additive direction and by 37 MPa and 8.9% in the vertical direction. The addition of Ti also contributed to the even distribution of the mechanical properties in both directions.

Growth behavior of helical cellular automata.

A helical cellular automata (HCA) model constructed on a two-dimensional grid of cells with a helical structure is presented and the pattern formation of this model studied by numerous computer simulations. It is found that the evolutions of the HCA are sensitive to the circumference of the helix p. With various p, the initial growth of the model generates various patterns ranging from Sierpinski triangle gasket, complex textured pattern, to lateral quasiperiodic structure. A sudden transition from regular fractal to compact pattern occurs near the point where p is equal to a positive integer power of 2. With increasing height of the patterns (increasing growth time), the model also exhibits different growth behaviors in the vertical direction for various p, including the formation of regular periodic patterns and the evolution from initial regular patterns to eventual random structures. Fractal dimension analysis is used to characterize these different evolution processes quantitatively.

[SR-XRF analysis of characteristics of heavy element concentration in qingdao algae and application to monitoring oceanic pollution].

Quantitative and qualitative analysis of the heavy element concentration characteristics of 14 specimens of 9 kinds of Qingdao algae by synchrotron radiation X-ray fluorescence (SR-XRF) are presented. Results show that various algae are quite different in element concentration. Some algae reveal super concentration ability, such as Sargassum pallidum for As and Sr, Symphyocladia latiuscula for Br and Laminaria japonica for I. Changes in the ratio of peak intensities of Mn and Fe in XRF spectrum reflect on the antagonism between elements in algae, relatively to the environment pollution. The minimum detection limit (MDL) of standard specimen, Antarctic mosses, was measured. Quantitative analysis and comparison of 10 specimens of 5 kind algae gathered from the same zone of Qingdao near-sea in 1985 and in 1999 were done. The contents of Mn, Fe, Zn, As, Br and Pb increased in 1999, in which, As in Sargassum pallidum increased 155% and Pb in Codium fragil increased 120%. The results indicated that the pollution in the near-sea of Qingdao is currently tending toward severity.

[Expression pattern of hsa-miR-9 and its association with BCL6 in EBV-positive and EBV-negative Burkitt lymphoma cell lines].

OBJECTIVE: To investigate the differential expression pattern of hsa-miR-9 between EBV-positive and -negative Burkitt lymphoma cell lines and its association with BCL-6. METHODS: The expression of hsa-miR9 and BCL-6 mRNAs in EBV(+) Raji and EBV-Ramous cells in mRNA levels were detected using fluorescence quantitative PCR (QRT-PCR). The two cells lines were transiently transfected with hsa-mir9-inhibitor and hsa-mir9-minicsvia Oligofectamine 2000, and the changes in BCL6 expressions was detected using QRT-PCR and Western blotting. Annexin V/PI staining was used to analyze the apoptosis and morphological changes of the transfected cells. RESULTS: The expression of Hsa-miR9 and BCL-6 was significantly higher in EBV(+) Raji cells than EBV(-) Ramous cells (P<0.01). BCL-6 mRNA and protein expression was reduced in EBV(+) Raji cells after transfection with hsa-miR9-inhibitor but up-regulated in EBV(-) Ramous cells transfected with hsa-miR9-minics. Flow cytometry revealed a significantly decreased apoptosis rate in EBV(+) Raji cells transfected with hsa-miR9-inhibitor but an increased rate in EBV(-) Ramous cells transfected with hsa-miR9-minics, and the results were confirmed by microscopic observations. CONCLUSION: Hsa-miR9 positively regulate the expression of BCL-6 and apoptosis of EBV(+) Raji cells and EBV(-) Ramous cells.

[Expression of miR-9 in B lymphocytes and B cell lymphomas cell lines and its significance].

OBJECTIVE: To investigate the expression of miR-9 in B lymphocytes, B cell lymphoma and classical Hodgkin's lymphoma (cHL) cell lines and its significance. METHODS: CD19(+) B lymphocytes were sorted from normal lymph node by magnetic beads. Total cellular micro-RNA was extracted from cHL cell line L428, B cell lymphoma cell lines Ly1 and Ly10 (diffuse large B cell lymphoma), Raji cells (Burkitt's lymphoma) and CD19(+) B lymphocytes, respectively. These micro-RNAs were separately transformed into cDNA by reverse transcription. The expression levels of miR-9 were measured by fluorescence quantitative PCR. In situ hybridization was used to detect the expression of miR-9 in cell lines. RESULTS: The expression of miR-9 was high in L428 cells (104.44 ± 1.61), and low in cell lines of B cell lymphoma (Ly1: 2.17 ± 0.38; Ly10: 1 ± 0.015; Raji: 2.65 ± 0.89), and extremely low in CD19(+) B lymphocytes (0.0026 ± 0.00040). Compared with that in the other cell lines, the expression of miR-9 in L428 cells was statistically significant (P < 0.05). miR-9 localized in the cytoplasm diffusely and strongly in L428, but scattered and slightly with some prominent distribution around the nuclear membranes in Ly1 and Ly10, and only weakly in Raji. CONCLUSIONS: miR-9 highly expressed in cHL cell line and might be a molecular marker for diagnosis and treatment of cHL.

[Preparation of RNA probe for cd99l2 gene of zebrafish labeled with digoxingenin-UTP].

OBJECTIVE: To study the expression pattern of cd99l2 gene during zebrafish development, the RNA probes for whole-mount in situ hybridization were prepared in this study. METHODS: The cd99l2 fragment obtained by RT-PCR was cloned into pGM-T Easy, then the plasmids were linearized with the restriction enzymes SacII or SalI. Using Sp6 or T(7) RNA polymerase, the digoxingenin-labeled antisense and sense probes were synthesized and confirmed by whole-mount in situ hybridization. RESULTS: The plasmid cd99l2/pGM-T was constructed. cd99l2 gene expression pattern during embryogenesis of zebrafish was examined using the antisense probe, and intense expression was detected in the central nervous system during zebrafish development. CONCLUSION: The antisense probe can be used for study of the spatial and temporal distribution of cd99l2 during zebrafish development using the sense probe as control.