62 research outputs found
Computer-Assisted Design of Environmentally Friendly and Light-Stable Fluorescent Dyes for Textile Applications.
Five potentially environmentally friendly and light-stable hemicyanine dyes were designed based on integrated consideration of photo, environmental, and computational chemistry as well as textile applications. Two of them were synthesized and applied in dyeing polyacrylonitrile (PAN), cotton, and nylon fabrics, and demonstrated the desired properties speculated by the programs. The computer-assisted analytical processes includes estimation of the maximum absorption and emission wavelengths, aquatic environmental toxicity, affinity to fibers, and photo-stability. This procedure could effectively narrow down discovery of new potential dye structures, greatly reduce and prevent complex and expensive preparation processes, and significantly improve the development efficiency of novel environmentally friendly dyes
Chlorine and Bromine Isotope Fractionation of Halogenated Organic Pollutants on Gas Chromatography Columns
Compound-specific chlorine/bromine isotope analysis (CSIA-Cl/Br) has become a
useful approach for degradation pathway investigation and source appointment of
halogenated organic pollutants (HOPs). CSIA-Cl/Br is usually conducted by gas
chromatography-mass spectrometry (GC-MS), which could be negatively impacted by
chlorine and bromine isotope fractionation of HOPs on GC columns. In this
study, 31 organochlorines and 4 organobromines were systematically investigated
in terms of Cl/Br isotope fractionation on GC columns using GC-double focus
magnetic-sector high resolution MS (GC-DFS-HRMS). On-column chlorine/bromine
isotope fractionation behaviors of the HOPs were explored, presenting various
isotope fractionation modes and extents. Twenty-nine HOPs exhibited inverse
isotope fractionation, and only polychlorinated biphenyl-138 (PCB-138) and
PCB-153 presented normal isotope fractionation. And no observable isotope
fractionation was found for the rest four HOPs, i.e., PCB-101,
1,2,3,7,8-pentachlorodibenzofuran, PCB-180 and 2,3,7,8-tetrachlorodibenzofuran.
The isotope fractionation extents of different HOPs varied from below the
observable threshold (0.50%) to 7.31% (PCB-18). The mechanisms of the on-column
chlorine/bromine isotope fractionation were tentatively interpreted with the
Craig-Gordon model and a modified two-film model. Inverse isotope effects and
normal isotope effects might contribute to the total isotope effects together
and thus determine the isotope fractionation directions and extents. Proposals
derived from the main results of this study for CSIA-Cl/Br research were
provided for improving the precision and accuracy of CSIA-Cl/Br results. The
findings of this study will shed light on the development of CSIA-Cl/Br methods
using GC-MS techniques, and help to implement the research using CSIA-Cl/Br to
investigate the environmental behaviors and pollution sources of HOPs.Comment: 30 pages, 5 figure
Efficient Matching Boundary Conditions of Two-dimensional Honeycomb Lattice for Atomic Simulations
In this paper, we design a series of matching boundary conditions for a
two-dimensional compound honeycomb lattice, which has an explicit and simple
form, high computing efficiency and good effectiveness of suppressing boundary
reflections. First, we formulate the dynamic equations and calculate the
dispersion relation for the harmonic honeycomb lattice, then symmetrically
choose specific atoms near the boundary to design different forms of matching
boundary conditions. The boundary coefficients are determined by matching a
residual function at some selected wavenumbers. Several atomic simulations are
performed to test the effectiveness of matching boundary conditions in the
example of a harmonic honeycomb lattice and a nonlinear honeycomb lattice with
the FPU- potential. Numerical results illustrate that low-order matching
boundary conditions mainly treat long waves, while the high-order matching
boundary conditions can efficiently suppress short waves and long waves
simultaneously. Decaying kinetic energy curves indicate the stability of
matching boundary conditions in numerical simulations
DF-GAN: Deep Fusion Generative Adversarial Networks for Text-to-Image Synthesis
Synthesizing high-quality realistic images from text descriptions is a
challenging task. Almost all existing text-to-image Generative Adversarial
Networks employ stacked architecture as the backbone. They utilize cross-modal
attention mechanisms to fuse text and image features, and introduce extra
networks to ensure text-image semantic consistency. In this work, we propose a
much simpler, but more effective text-to-image model than previous works.
Corresponding to the above three limitations, we propose: 1) a novel one-stage
text-to-image backbone which is able to synthesize high-quality images directly
by one pair of generator and discriminator, 2) a novel fusion module called
deep text-image fusion block which deepens the text-image fusion process in
generator, 3) a novel target-aware discriminator composed of matching-aware
gradient penalty and one-way output which promotes the generator to synthesize
more realistic and text-image semantic consistent images without introducing
extra networks. Compared with existing text-to-image models, our proposed
method (i.e., DF-GAN) is simpler but more efficient to synthesize realistic and
text-matching images and achieves better performance. Extensive experiments on
both Caltech-UCSD Birds 200 and COCO datasets demonstrate the superiority of
the proposed model in comparison to state-of-the-art models
Computer-Assisted Design of Environmentally Friendly and Light-Stable Fluorescent Dyes for Textile Applications
Five potentially environmentally friendly and light-stable hemicyanine dyes were designed based on integrated consideration of photo, environmental, and computational chemistry as well as textile applications. Two of them were synthesized and applied in dyeing polyacrylonitrile (PAN), cotton, and nylon fabrics, and demonstrated the desired properties speculated by the programs. The computer-assisted analytical processes includes estimation of the maximum absorption and emission wavelengths, aquatic environmental toxicity, affinity to fibers, and photo-stability. This procedure could effectively narrow down discovery of new potential dye structures, greatly reduce and prevent complex and expensive preparation processes, and significantly improve the development efficiency of novel environmentally friendly dyes
Autonomous Nanorobots as Miniaturized Surgeons for Intracellular Applications
Artificial nanorobots have emerged as promising tools for a wide range of biomedical applications, including biosensing, detoxification, and drug delivery. Their unique ability to navigate confined spaces with precise control extends their operational scope to the cellular or subcellular level. By combining tailored surface functionality and propulsion mechanisms, nanorobots demonstrate rapid penetration of cell membranes and efficient internalization, enhancing intracellular delivery capabilities. Moreover, their robust motion within cells enables targeted interactions with intracellular components, such as proteins, molecules, and organelles, leading to superior performance in intracellular biosensing and organelle-targeted cargo delivery. Consequently, nanorobots hold significant potential as miniaturized surgeons capable of directly modulating cellular dynamics and combating metastasis, thereby maximizing therapeutic outcomes for precision therapy. In this review, we provide an overview of the propulsion modes of nanorobots and discuss essential factors to harness propulsive energy from the local environment or external power sources, including structure, material, and engine selection. We then discuss key advancements in nanorobot technology for various intracellular applications. Finally, we address important considerations for future nanorobot design to facilitate their translation into clinical practice and unlock their full potential in biomedical research and healthcare
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