5,370 research outputs found
Two-photon excited hemoglobin fluorescence
We discovered that hemoglobin emits high energy Soret fluorescence when two-photon excited by the visible femtosecond light sources. The unique spectral and temporal characteristics of hemoglobin fluorescence were measured by using a time-resolved spectroscopic detection system. The high energy Soret fluorescence of hemoglobin shows the spectral peak at 438 nm with extremely short lifetime. This discovery enables two-photon excitation fluorescence microscopy to become a potentially powerful tool for in vivo label-free imaging of blood cells and vessels
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Modulating Linker Composition of Haptens Resulted in Improved Immunoassay for Histamine.
Histamine (HA) is an important food contaminant generated during food fermentation or spoilage. However, an immunoassay for direct (derivatization free) determination of HA has rarely been reported due to its small size to induce the desired antibodies by its current hapten-protein conjugates. In this work, despite violating the classical hapten design criteria which recommend introducing a linear aliphatic (phenyl free) linker into the immunizing hapten, a novel haptens, HA-245 designed and synthesized with a phenyl-contained linker, exhibited significantly enhanced immunological properties. Thus, a quality-improved monoclonal antibody (Mab) against HA was elicited by its hapten-carrier conjugates. Then, as the linear aliphatic linker contained haptens, Hapten B was used as linker-heterologous coating haptens to eliminate the recognition of linker antibodies. Indirect competitive ELISA (ic-ELISA) was developed with a 50% inhibition concentration (IC50) of 0.21 mg/L and a limit of detection (LOD) of 0.06 mg/L in buffer solution. The average recoveries of HA from spiked food samples for this ic-ELISA ranged from 84.1% and 108.5%, and the analysis results agreed well with those of referenced LC-MS/MS. This investigation not only realized derivatization-free immunoassay for HA, but also provided a valuable guidance for hapten design and development of immunoassay for small molecules
N 2,N 2,N 5,N 5-Tetrakis(2-chloroethyl)-3,4-dimethylthiophene-2,5-dicarboxamide
In the title compound, C16H22Cl4N2O2S, the two imide groups adopt a trans arrangement relative to the central thienyl ring, so the four terminal 2-chloroethyl arms adopt different orientations. In the crystal, molecules are linked by weak C—H⋯Cl and C—H⋯O hydrogen bonds into a three-dimensional network
Fast generation of mock galaxy catalogues with COLA
We investigate the feasibility of using COmoving Lagrangian Acceleration
(COLA) technique to efficiently generate galaxy mock catalogues that can
accurately reproduce the statistical properties of observed galaxies. Our
proposed scheme combines the subhalo abundance matching (SHAM) procedure with
COLA simulations, utilizing only three free parameters: the scatter magnitude
() in SHAM, the initial redshift () of the
COLA simulation, and the time stride () used by COLA. In this
proof-of-concept study, we focus on a subset of BOSS CMASS NGC galaxies within
the redshift range . We perform simulation
and low-resolution COLA simulations with various combinations of , each using particles in an box.
By minimizing the difference between COLA mock and CMASS NGC galaxies for the
monopole of the two-point correlation function (2PCF), we obtain the optimal
. We have found that by setting and
, we achieve a good agreement between COLA mock and CMASS NGC galaxies
within the range of 4 to , with a computational cost two
orders of magnitude lower than that of the N-body code. Moreover, a detailed
verification is performed by comparing various statistical properties, such as
anisotropic 2PCF, three-point clustering, and power spectrum multipoles, which
shows similar performance between GADGET mock and COLA mock catalogues with the
CMASS NGC galaxies. Furthermore, we assess the robustness of the COLA mock
catalogues across different cosmological models, demonstrating consistent
results in the resulting 2PCFs. Our findings suggest that COLA simulations are
a promising tool for efficiently generating mock catalogues for emulators and
machine learning analyses in exploring the large-scale structure of the
Universe.Comment: 24 pages, 14 figures, 4 table
Universal Instance Perception as Object Discovery and Retrieval
All instance perception tasks aim at finding certain objects specified by
some queries such as category names, language expressions, and target
annotations, but this complete field has been split into multiple independent
subtasks. In this work, we present a universal instance perception model of the
next generation, termed UNINEXT. UNINEXT reformulates diverse instance
perception tasks into a unified object discovery and retrieval paradigm and can
flexibly perceive different types of objects by simply changing the input
prompts. This unified formulation brings the following benefits: (1) enormous
data from different tasks and label vocabularies can be exploited for jointly
training general instance-level representations, which is especially beneficial
for tasks lacking in training data. (2) the unified model is
parameter-efficient and can save redundant computation when handling multiple
tasks simultaneously. UNINEXT shows superior performance on 20 challenging
benchmarks from 10 instance-level tasks including classical image-level tasks
(object detection and instance segmentation), vision-and-language tasks
(referring expression comprehension and segmentation), and six video-level
object tracking tasks. Code is available at
https://github.com/MasterBin-IIAU/UNINEXT.Comment: CVPR202
Simulation of Microstructure during Laser Rapid Forming Solidification Based on Cellular Automaton
The grain microstructure of molten pool during the solidification of TC4 titanium alloy in the single point laser cladding was investigated based on the CAFE model which is the cellular automaton (CA) coupled with the finite element (FE) method. The correct temperature field is the prerequisite for simulating the grain microstructure during the solidification of the molten pool. The model solves the energy equation by the FE method to simulate the temperature distribution in the molten pool of the single point laser cladding. Based on the temperature field, the solidification microstructure of the molten pool is also simulated with the CAFE method. The results show that the maximum temperature in the molten pool increases with the laser power and the scanning rate. The laser power has a larger influence on the temperature distribution of the molten pool than the scanning rate. During the solidification of the molten pool, the heat at the bottom of the molten pool transfers faster than that at the top of the molten pool. The grains rapidly grow into the molten pool, and then the columnar crystals are formed. This study has a very important significance for improving the quality of the structure parts manufactured through the laser cladding forming
Clinical and immunological features of an APLAID patient caused by a novel mutation in PLCG2
BackgroundThe APLAID syndrome is a rare primary immunodeficiency caused by gain-of-function mutations in the PLCG2 gene. We present a 7-year-old APLAID patient who has recurrent blistering skin lesions, skin infections in the perineum, a rectal perineal fistula, and inflammatory bowel disease.MethodsTo determine the genetic cause of our patient, WES and bioinformatics analysis were performed. Flow cytometry was used for phenotyping immune cell populations in peripheral blood. Cytokines released into plasma were analyzed using protein chip technology. The PBMCs of patient and a healthy child were subjected to single-cell RNA-sequencing analysis.ResultsThe patient carried a novel de novo missense mutation c.2534T>C in exon 24 of the PLCG2 gene that causes a leucine to serine amino acid substitution (p.Leu845Ser). Bioinformatics analysis revealed that this mutation had a negative impact on the structure of the PLCγ2 protein, which is highly conserved in many other species. Immunophenotyping by flow cytometry revealed that in addition to the typical decrease in circulating memory B cells, the levels of myeloid dendritic cells (mDCs) in the children’s peripheral blood were significantly lower, as were the CD4+ effector T cells induced by their activation. Single-cell sequencing revealed that the proportion of different types of cells in the peripheral blood of the APLAID patient changed.ConclusionsWe present the first case of APLAID with severely reduced myeloid dendritic cells carrying a novel PLCG2 mutation, and conducted a comprehensive analysis of immunological features in the ALPAID patient, which has not been mentioned in previous reports. This study expands the spectrum of APLAID-associated immunophenotype and genotype. The detailed immune analyses in this patient may provide a basis for the development of targeted therapies for this severe autoinflammatory disease
Charge states, triple points and quadruple points in an InAs nanowire triple quantum dot revealed by an integrated charge sensor
A serial triple quantum dot (TQD) integrated with a quantum dot (QD) charge
sensor is realized from an InAs nanowire via a fine finger-gate technique. The
complex charge states and intriguing properties of the device are studied in
the few-electron regime by direct transport measurements and by charge-sensor
detection measurements. The measurements of the charge stability diagram for a
capacitively coupled, parallel double-QD formed from a QD in the TQD and the
sensor QD show a visible capacitance coupling between the TQD and the sensor
QD, indicating a good sensitivity of the charge sensor. The charge stability
diagrams of the TQD are measured by the charge sensor and the global features
seen in the measured charge stability diagrams are well reproduced by the
simultaneous measurements of the direct transport current through the TQD and
by the simulation made based on an effective capacitance network model. The
complex charge stability diagrams of the TQD are measured in detail with the
integrated charge sensor in an energetically degenerate region, where all the
three QDs are on or nearly on resonance, and the formations of quadruple points
and of all possible eight charge states are observed. In addition, the
operation of the TQD as a quantum cellular automata is demonstrated and
discussed.Comment: 18 pages, 4 figures, Supplementary Information include
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