Precise protein photolithography (P3) for fabricating high performance bioarchitectures using silk fibroin light chain as the photoresist

High-resolution fabrication platforms using materials from biological precursors have been proposed as feasible routes not only for sustainable bionanomanufacturing, but also for creating organic devices to interface and interact with biological systems. In this study, silk fibroin, as a biomaterial, has been used as a photoresist via chemical conjugation with photocrosslinkers. The Achilles heel of natural silk fibroin based resists is the inevitable wide molecular weight distribution (ranging from a few tens to a few hundreds of kDa). Such essential issue hinders their practical uses in the semiconductor industry where reliability and repeatability are paramount. To solve such an issue, we report on wafer-scale high resolution patterning of bio-microstructures using silk fibroin light chain (L-fibroin or LC) as the resist material. The L-fibroin fragments with the well-defined molecular weight were successfully isolated from the integral silk fibroins consisting of both heavy and light chains. Under facile biochemical modification, the L-fibroin photoresist is synthesized via conjugating commercial photocrosslinkers as crosslinking sites in the presence of ultraviolet light. To explore the characteristics and to explain the mechanism of resolution, roughness and etch resistance of the as-prepared patterns, we use the scattering-type scanning near-field microscope (s-SNOM) which provides direct imaging and chemical identification of the thin protein layers at the nanoscale. The enhanced patterning resolution, the improved etch resistance and the inherent biocompatibility of such protein-based photoresist provide new opportunities in fabricating large scale biocompatible functional microstructuresMechanical Engineerin

Neutron lifetime anomaly and mirror matter theory

This paper reviews the puzzles in modern neutron lifetime measurements and related unitarity issues in the CKM matrix. It is not a comprehensive and unbiased compilation of all historic data and studies, but rather a focus on compelling evidence leading to new physics. In particular, the largely overlooked nuances of different techniques applied in material and magnetic trap experiments are clarified. Further detailed analysis shows that the ``beam'' approach of neutron lifetime measurements is likely to give the ``true'' $\beta$-decay lifetime, while discrepancies in ``bottle'' measurements indicate new physics at play. The most feasible solution to these puzzles is a newly proposed ordinary-mirror neutron ($n-n'$) oscillation model under the framework of mirror matter theory. This phenomenological model is reviewed and introduced, and its explanations of the neutron lifetime anomaly and possible non-unitarity of the CKM matrix are presented. Most importantly, various new experimental proposals, especially lifetime measurements with small/narrow magnetic traps or under super-strong magnetic fields, are discussed in order to test the surprisingly large anomalous signals that are uniquely predicted by this new $n-n'$ oscillation model.Comment: 31 pages, 6 figures, review paper for Univers

Effects of TNF-a on lysyl oxidase in Wnt induced cells at post-transcriptional level by miRNA

Thesis (MSD) --Boston University, Henry M. Goldman School of Dental Medicine, 2013 (Department of Periodontology and Oral Biology).Includes bibliographic references: leaves 50-67.Objective: Lysyl oxidase (LOX) dependent cross-linking is deficient in diabetic bone, contributing to osteopenia. Here we Investigate regulation of lysyl oxidase by Wnt3a and TNF-a in a mesenchymal stem cell line as a model for a novel mechanism of diabetic osteopenia. Methods: Wnt3a-treated C3Hl 0Tl/2 cells were treated with or without of TNF-a. Lysyl oxidase expression ( qPCR) and mRNA stability were measured. A comprehensive PCR-based microarray screen (Qiagen/SA Biosciences) was next performed to_ identify miRNAs which regulate LOX mRNA stability in response to TNF-a. The functionality of identified miRNA was independently determined by the use of miRNA mimics. Results: Wnt3a up-regulated LOX up to 3.2-fold by treating C3H10Tl/2 cells with Wnt3a compared to controls. TNF-a (20 ng/ml) blocked Wnt3a up-regulation of LOX. TNF-a decreased the stability of LOX mRNA determined in the presence of a transcription inhibitor in control- and Wnt3a plus TNF-a-treated cells. A micro (miR) array screen performed on RNA isolated from Wnt3a plus TNF-a treated and control cells identified miR203 as being up-regulated 13-fold by TNF-a. Independent analyses ... [TRUNCATED

Effects of Home Education Guidance Services and Improvement Measures: An Analysis Based on Survey Data of 1,850 Families in Hubei Province

Home education guidance services play an important role in enhancing the quality of home education and supporting child healthy and holistic development. Based on survey data of 1,850 families from eight cities and 18 counties in Hubei Province, this study examined the effects of home education guidance services on parental education literacy, parental education involvement, and child development. Ordinary least squares regression (OLS) and propensity score matching (PSM) were used in the analysis. The purpose of this article was to provide implications for improving the effectiveness of home education guidance

Mirror symmetry for new physics beyond the Standard Model in 4D4D spacetime

The two discrete generators of the full Lorentz group $O(1,3)$ in $4D$ spacetime are typically chosen to be parity inversion symmetry $P$ and time reversal symmetry $T$, which are responsible for the four topologically separate components of $O(1,3)$. Under general considerations of quantum field theory (QFT) with internal degrees of freedom, mirror symmetry is a natural extension of $P$, while $CP$ symmetry resembles $T$ in spacetime. In particular, mirror symmetry is critical as it doubles the full Dirac fermion representation in QFT and essentially introduces a new sector of mirror particles. Its close connection to T-duality and Calabi-Yau mirror symmetry in string theory is clarified. Extension beyond the Standard model can then be constructed using both left- and right-handed heterotic strings guided by mirror symmetry. Many important implications such as supersymmetry, chiral anomalies, topological transitions, Higgs, neutrinos, and dark energy, are discussed.Comment: 25 pages, published in Symmetry, more related papers on https://www.wanpengtan.com/smm