5,211 research outputs found
Bacteria photosensitized by intracellular gold nanoclusters for solar fuel production.
The demand for renewable and sustainable fuel has prompted the rapid development of advanced nanotechnologies to effectively harness solar power. The construction of photosynthetic biohybrid systems (PBSs) aims to link preassembled biosynthetic pathways with inorganic light absorbers. This strategy inherits both the high light-harvesting efficiency of solid-state semiconductors and the superior catalytic performance of whole-cell microorganisms. Here, we introduce an intracellular, biocompatible light absorber, in the form of gold nanoclusters (AuNCs), to circumvent the sluggish kinetics of electron transfer for existing PBSs. Translocation of these AuNCs into non-photosynthetic bacteria enables photosynthesis of acetic acid from CO2. The AuNCs also serve as inhibitors of reactive oxygen species (ROS) to maintain high bacterium viability. With the dual advantages of light absorption and biocompatibility, this new generation of PBS can efficiently harvest sunlight and transfer photogenerated electrons to cellular metabolism, realizing CO2 fixation continuously over several days
Effect of propionate on the production of natamycin with Streptomyces gilvosporeus XM-172
This study described the influence of feeding short-chain fatty acids and alcohols on natamycin production in the glucose basal medium, produced by Streptomyces gilvosporeus XM-172. The highest natamycin production was obtained with feeding propionate as compared to other precursors. The optimal propionate concentration and feeding time were 6 g L-1 and early log phase, respectively. This optimal propionate feeding strategy led to a natamycin production of 6.72 g L-1, which was nearly 85% higher than that of the control. It was firstly revealed that propionate could greatly promote natamycin biosynthesis by S. gilvosporeus.Key words: Precursor, propionate, natamycin production, Streptomyces gilvosporeus XM-172
Uni-ControlNet: All-in-One Control to Text-to-Image Diffusion Models
Text-to-Image diffusion models have made tremendous progress over the past
two years, enabling the generation of highly realistic images based on
open-domain text descriptions. However, despite their success, text
descriptions often struggle to adequately convey detailed controls, even when
composed of long and complex texts. Moreover, recent studies have also shown
that these models face challenges in understanding such complex texts and
generating the corresponding images. Therefore, there is a growing need to
enable more control modes beyond text description. In this paper, we introduce
Uni-ControlNet, a unified framework that allows for the simultaneous
utilization of different local controls (e.g., edge maps, depth map,
segmentation masks) and global controls (e.g., CLIP image embeddings) in a
flexible and composable manner within one single model. Unlike existing
methods, Uni-ControlNet only requires the fine-tuning of two additional
adapters upon frozen pre-trained text-to-image diffusion models, eliminating
the huge cost of training from scratch. Moreover, thanks to some dedicated
adapter designs, Uni-ControlNet only necessitates a constant number (i.e., 2)
of adapters, regardless of the number of local or global controls used. This
not only reduces the fine-tuning costs and model size, making it more suitable
for real-world deployment, but also facilitate composability of different
conditions. Through both quantitative and qualitative comparisons,
Uni-ControlNet demonstrates its superiority over existing methods in terms of
controllability, generation quality and composability. Code is available at
\url{https://github.com/ShihaoZhaoZSH/Uni-ControlNet}.Comment: Camera Ready, Code is available at
https://github.com/ShihaoZhaoZSH/Uni-ControlNe
SDSS J143030.22-001115.1: A misclassified narrow-line Seyfert 1 galaxy with flat X-ray spectrum
We used multi-component profiles to model H and [O III]4959,5007 lines for SDSS J143030.22-001115.1, a narrow-line Seyfert 1
galaxy (NLS1) in a sample of 150 NLS1s candidates selected from the Sloan
Digital Sky Survey (SDSS) Early Data Release (EDR). After subtracting the
H contribution from narrow line regions (NLRs), we found that its full
width half maximum (FWHM) of broad H line is nearly 2900 \kms,
significantly larger than the customarily adopted criterion of 2000 \kms. With
its weak Fe II multiples, we think that SDSS J143030.22-001115.1 can't be
classified as a genuine NLS1. When we calculate the virial black hole masses of
NLS1s, we should use the H linewidth after subtracting the H
contribution from NLRs.Comment: 7 pages, 1 table, accepted by ChJA
Exact Analysis of Scaling and Dominant Attractors Beyond the Exponential Potential
By considering the potential parameter as a function of another
potential parameter [47], We successfully extend the analysis of
two-dimensional autonomous dynamical system of quintessence scalar field model
to the analysis of three-dimension, which makes us be able to research the
critical points of a large number of potentials beyond the exponential
potential exactly. We find that there are ten critical points in all, three
points } are general points which are possessed by all
quintessence models regardless of the form of potentials and the rest points
are closely connected to the concrete potentials. It is quite surprising that,
apart from the exponential potential, there are a large number of potentials
which can give the scaling solution when the function
equals zero for one or some values of
and if the parameter also satisfies the condition
Eq.(16) or Eq.(17) at the same time. We give the differential equations to
derive these potentials from . We also find that, if some
conditions are satisfied, the de-Sitter-like dominant point and the
scaling solution point (or ) can be stable simultaneously but
and can not be stable simultaneity. Although we survey scaling
solutions beyond the exponential potential for ordinary quintessence models in
standard general relativity, this method can be applied to other extensively
scaling solution models studied in literature[46] including coupled
quintessence, (coupled-)phantom scalar field, k-essence and even beyond the
general relativity case . we also discuss the disadvantage
of our approach.Comment: 16 pages,no figure, this new revision has taken the suggestions from
CQG referees and has been accepted for publication in Classical and Quantum
Gravit
A nine months follow-up study of hemodynamic effect on bioabsorbable coronary stent implantation
Coronary artery disease has emerged as one of the major diseases causing death worldwide. Coronary stent has great effect to improve blood flow to the myocardium subtended by that artery, in which bioresorbable vascular scaffolds are new-generation stents used by people. However, Coronary stents implantation has a risk of restenosis, which is relative to hemodynamic parameters. Most of existing literatures studied in this issue have not taken into account such important factors as the strut thickness and lumen profile, and has yet to analyze the time effects among hemodynamic parameters over a certain period of time based on individual models. In this research, we proposed a framework to assess the chronic impact of hemodynamic on coronary stent implantation. In the framework, the optical coherence tomography (OCT) is combined with angiography to reconstruct patient-specific models of bioresorbable vascular scaffolds. Then, the hemodynamics parameters are extracted through the simulated 3D models, obtaining the distribution of wall shear stress (WSS), relative residence time (RRT) and oscillatory shear index (OSI). Finally, the changes of these parameters representing the effectiveness of hemodynamics exerted on the implanted stent can be assessed to estimate the chronic impacts. By a 9-month follow-up case study, it is observed that the difference of hemodynamic parameters are not significance. Both at baseline and 9-month follow-up experiments show that the hemodynamic parameters remain normal and similar, proving that the coronary stent implantation nowadays appears to have a robust and everlasting curative effect
Electrostatic Force Microscopy on Oriented Graphite Surfaces: Where Insulating and Conducting Behaviors Coexist
We present measurements of the electric potential fluctuations on the surface
of highly oriented pyrolytic graphite using electrostatic force and atomic
force microscopy. Micrometric domain-like potential distributions are observed
even when the sample is grounded. Such potential distributions are unexpected
given the good metallic conductivity of graphite because the surface should be
an equipotential. Our results indicate the coexistence of regions with metallic
and insulating behaviors showing large potential fluctuations of the order of
0.25V. We discuss the implications of these measurements in the disorder
structure of graphite.Comment: 14 pages, 5 figure
Sudden drop of fractal dimension of electromagnetic emissions recorded prior to significant earthquake
The variation of fractal dimension and entropy during a damage evolution
process, especially approaching critical failure, has been recently
investigated. A sudden drop of fractal dimension has been proposed as a
quantitative indicator of damage localization or a likely precursor of an
impending catastrophic failure. In this contribution, electromagnetic emissions
recorded prior to significant earthquake are analysed to investigate whether
they also present such sudden fractal dimension and entropy drops as the main
catastrophic event is approaching. The pre-earthquake electromagnetic time
series analysis results reveal a good agreement to the theoretically expected
ones indicating that the critical fracture is approaching
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