101 research outputs found
Study on Fatigue Characteristics of Concrete Sleepers with Porous Basalt as the Aggregate
Due to the shortage of local materials, porous basalt was used as the coarse aggregate in the prefabrication of sleepers for the Mombasa-Nairobi Railway in Kenya. To study their fatigue characteristics, the sleepers were measured under fatigue loading for their local strain, overall deformation and crack initiation. The methods used include the traditional strain measurement, the sleeper deflection measurement and the 3D optical strain measurement. To be more specific, the traditional strain measurement method was employed to compare the strain-load relation of the sleepers under different cyclic loading times. Deflection variations of the sleepers were taken into consideration to analyze sleeper local defects and the variation law of the constitutive relation for concrete. And the 3D optical non-contact strain measurement method was adopted to monitor the sleeper crack initiation and growth process under fatigue loading and analyze the crack growth law
Simulation and Test of Lateral Ballast Resistance to 1435 mm/1000 mm Dual-Gauge Sleepers
The stability of a 1000 mm/1435 mm dual-gauge track is lower than that of a single-gauge track. One of the important factors that affects the stability of the track is the lateral resistance of the track bed. We have established a discrete element simulation model of the dual-gauge sleeper-track bed in PFC to analyse the characteristics of the lateral resistance of the 1000 mm/1435 mm dual-gauge sleeper. With China Type IIIc sleepers as the control group, we carried out the lateral resistance test for the full-scale sleeper model under the same conditions. The research results indicate that the most effective way to increase the lateral resistance of the dual-gauge track bed is to increase the end surface area and bottom area of the sleeper. The application of adjacent sleepers is an effective way to increase the lateral resistance of the track bed further. The research results gained from this study can be used to guide the design of dual-gauge sleepers
Successful Management of Chromoblastomycosis Utilizing Conventional Antifungal Agents and Imiquimod Therapy
Chromoblastomycosis (CBM), a chronic fungal infection affecting the skin and subcutaneous tissues, is predominantly caused by dematiaceous fungi in tropical and subtropical areas. Characteristically, CBM presents as plaques and nodules, often leading to scarring post-healing. Besides traditional diagnostic methods such as fungal microscopy, culture, and histopathology, dermatoscopy and reflectance confocal microscopy can aid in diagnosis. The treatment of CBM is an extended and protracted process. Imiquimod, acting as an immune response modifier, boosts the host\u27s immune response against CBM, and controls scar hyperplasia, thereby reducing the treatment duration. We present a case of CBM in Guangdong with characteristic reflectance confocal microscopy manifestations, effectively managed through a combination of itraconazole, terbinafine, and imiquimod, shedding light on novel strategies for managing this challenging condition
Spectrally resolved two-photon interference in a modified Hong-Ou-Mandel interferometer
A modified Hong-Ou-Mandel(HOM) interference reveals that the two-photon
interference phenomenon can be explained only by the concept of a two-photon
wave packet rather than the single-photon one. Previously, the measurements for
such interference were usually performed in the time domain where the spectral
information of the involved photons was integrated and lost during the
measurement. Here, we theoretically explore the spectrally resolved two-photon
interference for the modified HOM interferometer both in the cases of CW pump
and pulse pump. It is found that, in the CW-pumped case, a one-dimensional (1D)
temporal interferogram can be directly recovered by projecting a 2D spectrally
resolved interferogram at different phases, without a standard delay-scanning.
In the pulse-pumped case, the joint spectral intensity is phase-dependent and
can be modulated by the time delay along the directions of both frequency sum
and frequency difference between signal and idler photons, which may provide a
versatile way to generate high-dimensional frequency entanglement and engineer
high-dimensional quantum states. These results not only show more rich spectral
information that cannot be extracted from the time domain, but also shed new
light on a comprehensive understanding of the two-photon interference
phenomenon in the frequency domain.Comment: 13 pages, 6 figure
Polarization-multiplexed dual-comb fiber laser based on an all-polarization-maintaining cavity configuration
In this study, we present a polarization-multiplexed, erbium-doped dual-comb fiber laser based on an all-polarization-maintaining cavity configuration. We observed that the dual-comb fiber laser easily realized the self-starting mode-locking operation due to the non-linear amplifying loop mirror (NALM) with a non-reciprocal phase shifter. Furthermore, owing to the sharing of the NALM part, the two outputs from this laser configuration had similar center wavelengths, with small different repetition rates (∆frep). In the free-running operation, the standard deviation of relative stability for Δfrep of 2.09 kHz was measured to be 1.59 Hz, and the full width at half-maximum of the relative beat note between the two frequency combs in the optical frequency domain was approximately 1 kHz. These results show that the two frequency combs from this laser configuration have high relative stability and mutual coherence
Phase gradient protection of stored spatially multimode perfect optical vortex beams in a diffused rubidium vapor
We experimentally investigate the optical storage of perfect optical vortex (POV) and spatially multimode perfect optical vortex (MPOV) beams via electromagnetically induced transparency (EIT) in a hot vapor cell. In particular, we study the role that phase gradients and phase singularities play in reducing the blurring of the retrieved images due to atomic diffusion. Three kinds of manifestations are enumerated to demonstrate such effect. Firstly, the suppression of the ring width broadening is more prominent for POVs with larger orbital angular momentum (OAM). Secondly, the retrieved double-ring MPOV beams’ profiles present regular dark singularity distributions that are related to their vortex charge difference. Thirdly, the storage fidelities of the triple-ring MPOVs are substantially improved by designing line phase singularities between multi-ring MPOVs with the same OAM number but π offset phases between adjacent rings. Our experimental demonstration of MPOV storage opens new opportunities for increasing data capacity in quantum memories by spatial multiplexing, as well as the generation and manipulation of complex optical vortex arrays
Suramin Alleviates Glomerular Injury and Inflammation in the Remnant Kidney
Background: Recently, we demonstrated that suramin, a compound that inhibits the interaction of multiple cytokines/ growth factors with their receptors, inhibits activation and proliferation of renal interstitial fibroblasts, and attenuates the development of renal interstitial fibrosis in the murine model of unilateral ureteral obstruction (UUO). However, it remains unclear whether suramin can alleviate glomerular and vascular lesions, which are not typical pathological changes in the UUO model. So we tested the efficacy of suramin in the remnant kidney after 5/6 nephrectomy, a model characterized by the slow development of glomerulosclerosis, vascular sclerosis, tubulointerstitial fibrosis and renal inflammation, mimicking human disease. Methods/Findings: 5/6 of normal renal mass was surgically ablated in male rats. On the second week after surgery, rats were randomly divided into suramin treatment and non-treatment groups. Suramin was given at 10 mg/kg once per week for two weeks. In the remnant kidney of mice receiving suramin, glomerulosclerosis and vascular sclerosis as well as inflammation were ameliorated. Suramin also attenuated tubular expression of two chemokines, monocyte chemoattractant protein-1 and regulated upon expression normal T cell expressed and secreted (RANTES). After renal mass ablation, several intracellular molecules associated with renal fibrosis, including NF-kappaB p65, Smad-3, signal transducer and activator of transcription-3 and extracellular regulated kinase 1/2, are phosphorylated; suramin treatment inhibited thei
Stepwise evolution of Paleozoic tracheophytes from South China: contrasting leaf disparity and taxic diversity
During the late Paleozoic, vascular land plants (tracheophytes) diversified into a remarkable variety of morpho-
logical types, ranging from tiny, aphyllous, herbaceous forms to giant leafy trees. Leaf shape is a key determinant
of both function and structural diversity of plants, but relatively little is known about the tempo and mode of leaf
morphological diversification and its correlation with tracheophyte diversity and abiotic changes during this re-
markable macroevolutionary event, the greening of the continents. We use the extensive record of Paleozoic tra-
cheophytes from South China to explore models of morphological evolution in early land plants. Our findings
suggest that tracheophyte leaf disparity and diversity were decoupled, and that they were under different selec-
tive regimes. Two key phases in the evolution of South Chinese tracheophyte leaves can be recognized. In the first
phase, from Devonian to Mississippian, taxic diversity increased substantially, as did leaf disparity, at the same
time as they acquired novel features in their vascular systems, reproductive organs, and overall architecture.
The second phase, through the Carboniferous–Permian transition, saw recovery of wetland communities in
South China, associated with a further expansion of morphologies of simple leaves and an offset shift in
morphospace occupation by compound leaves. Comparison with Euramerica suggests that the floras from
South China were unique in several ways. The Late Devonian radiation of sphenophyllaleans contributed signif-
icantly to the expansion of leaf morphospace, such that the evolution of large laminate leaves in this group oc-
curred much earlier than those in Euramerica. The Pennsylvanian decrease in taxic richness had little effect on
the disparity of compound leaves. Finally, the distribution in morphospace of the Permian pecopterids,
gigantopterids, and equisetaleans occurred at the periphery of Carboniferous leaf morphospace
Sparse Fusion Imaging for a Moving Target in T/R-R Configuration
For high resolution imaging of a non-cooperative moving target, this paper proposes a sparse fusion imaging method. The imaging system contains two radar stations, which are separated by a certain bistatic angle and configured in a transmitter/receiver-receiver (T/R-R) manner. Consequently, two synthetic apertures are obtained at the same time from different aspect angles. By coherently fusing the echoes of the two radars, a virtual aperture spanned by these two sub-apertures can be constructed, which is larger than either of the sub-apertures; thus, the cross-range resolution of the image is enhanced. Moreover, the fusion of the echoes is realized by exploiting the sparse scattering property of the target. Then, based on the maximum a posteriori (MAP) criterion, the T/R-R fusion imaging problem is converted into a sparse signal recovery problem with unknown parameters. Finally, it is solved in an iterative manner, which contains two steps, i.e., sparse imaging and parameter estimation. Simulation results show that the proposed sparse fusion imaging method can improve the cross-range resolution significantly compared to inverse synthetic aperture radar (ISAR) within the same coherent processing interval (CPI)
PTPN2 can be a potential target for the treatment of psoriasis
Objective To investigate the expression and regulatory mechanism of PTPN2 in psoriasis, and to analyze the effects of PTPN2 on psoriasis related immunity in order to determine whether PTPN2 can be used as a potential therapeutic target for psoriasis. Methods R language (3.6.3 version) was used to determine the difference in expression levels of PTPN2 between psoriatic patients and controls, and the receiver operating characteristic (ROC) curve of PTPN2. The Gene Enrichment Analysis software (GSEA) and the Protein Interaction Analysis Database (STRING) were used to determine enrichment pathway of PTPN2 in the psoriasis dataset, and the interaction network of PTPN2 co-expressed genes. The distribution and expression of immune cells in psoriasis datasets were analyzed with CIBERSORT software. The differential expression of immune response pathways and immune response gene sets in psoriasis and their correlation with PTPN2 were analyzed using R language (version 3.6.3). Results PTPN2 mRNA was highly expressed in psoriatic lesions. Immune infiltrating cells, immune response pathways, and immune response gene sets were abnormal in psoriatic lesions. PTPN2 was associated with some immune infiltrating cells, immune response pathways, and immune response gene sets in psoriasis. Conclusions PTPN2 mRNA is highly expressed in psoriatic lesions, and may participate in the occurrence and development of psoriasis by regulating the immune microenvironment
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