Class-switch recombination (CSR) alters the Ig isotype to diversify antibody effector functions. IgD CSR is a rare event, and its regulation is poorly understood. We report that deficiency of 53BP1, ...a DNA damage-response protein, caused age-dependent overproduction of secreted IgD resulting from increased IgD CSR exclusively within B cells of mucosa-associated lymphoid tissues. IgD overproduction was dependent on activation-induced cytidine deaminase, hematopoietic MyD88 expression, and an intact microbiome, against which circulating IgD, but not IgM, was reactive. IgD CSR occurred via both alternative nonhomologous end-joining and homologous recombination pathways. Microbiota-dependent IgD CSR also was detected in nasal-associated lymphoid tissue of WT mice. These results identify a pathway, present in WT mice and hyperactivated in 53BP1-deficient mice, by which microbiota signal via Toll-like receptors to elicit IgD CSR.
ABSTRACT
Fast transitions between different types of power density spectra (PDS) happening over time-scales of several tens of seconds are rare phenomena in black hole X-ray binaries. In this paper, ...we report a broad-band spectral-timing analysis of the fast transitions observed in the 2021 outburst of GX 339−4 using NICER and Insight-HXMT observations. We observe transitions between band-limited noise-dominated PDS and type-B quasi-periodic oscillations (QPOs), and their rapid appearance or disappearance. We also make a detailed comparison between the fast transitions in GX 339−4 with those seen in MAXI J1820+070 and MAXI J1348−630. By comparing the spectra of the periods with and without type-B QPOs, we find that the spectral ratios above 10 keV are nearly constant or slightly decreasing, and the values are different between sources. Below 10 keV, the flux change of the Comptonization component is inversely proportional to the flux change of the thermal component, suggesting that the appearance of type-B QPOs is associated with a redistribution of the accretion power between the disc and the Comptonizing emission region. The spectral ratios between the periods with type-B QPO and those with broad-band noise are significantly different from that with type-B QPO and without type-B QPO, where the ratios (type-B QPO/broad-band noise) show a maximum at around 4 keV and then decrease gradually towards high energies. Finally, we discuss the possible change of the geometry of the inner accretion flow and/or jet during the transitions.
To investigate the imaging features of hemangiomas in long tabular bones for better diagnosis.
Twenty-four patients with long bone hemangiomas confirmed by pathology were enrolled. Nineteen patients ...had plain radiography, fourteen patients had computed tomography (CT) and eleven had magnetic resonance imaging (MRI). The hemangioma was divided into medullary 13, periosteal 6 and intracortical type 5.
Among 19 patients with plain radiography, eleven patients were medullary, three periosteal, and five intracortical. In the medullary type, the lesion was primarily osteolytic, including five cases with irregular and unclear rims and one lesion having osteosclerotic and unclear rims. In three patients with the periosteal type, the lesion had clear rims with involvement of the cortical bone in the form of bone defect, including two cases with local thickened bone periosteum and one case having expansile periosteum. Five intracortical hemangiomas had intracortical osteolytic lesions with clear margins. Among 14 patients with CT imaging, 8 cases were medullary, three periosteal, and three intracortical. Among 8 medullary hemangiomas, one had ground glass opacity, and seven had osteolytic, expansile lesions like soft tissue density with no calcification. In three periosteal cases, the lesion was osteolytic with thickened periosteum and narrowed medullary cavity. In three intracortical hemangiomas, the lesion was of even soft tissue density with no calcification. Among 11 patients with MRI imaging, seven were medullary, two periosteal, and two intracortical. Among 7 medullary lesions, six were of hypointense signal on T1WI and hyperintensesignal on T2 WI. In two periosteal cases, the periosteum was thickened, with one case being of equal signal, and the other having no signal. Two intracortical hemangiomas were both of slightly low signal on T1WI but hyperintense signal on T2WI.
The long bone hemangiomas had characteristic cystic honeycomb-like presentations in plain radiograph. CT and MRI imagings are helpful for diagnosis of hemangiomas in long bone.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Periodical Al nanoparticle (NP) arrays were applied to enhance the ultraviolet (UV) light emission of ZnO by localized surface plasmon resonance (LSPR) effect and electron transfer mechanism. By ...applying corresponding anodic aluminum oxide (AAO) templates, periodical Al NP arrays with different diameters (D) and spaces (S) were manufactured by magnetron sputtering. Theoretical simulation by FDTD-solution indicates that local electric field around Al NPs is significantly enhanced, and the surface plasmon resonance wavelength is determined by D and S. Al NP arrays with D of 70 nm and S of 125 nm enhanced near band-edge emission of ZnO by 2.4 times. By adding Al NP arrays, the photonic lifetime of ZnO decreased by 0.09 ns according to time-resolved photoluminescence spectra, indicating that the enhancement in UV luminescence intensity of ZnO is ascribed to the coupling between surface plasmons of Al NPs and ZnO excitons. Deep-level emission spectra analysis indicates that there lies another mechanism of electron transfer from the Al NPs to surface plasmon resonance (SPR) level and then further to ZnO conduction band.
•A 2.4-fold photoluminescence enhancement of the near band-edge emission from ZnO was obtained by introducing Al NP arrays.•The UV light emission enhancement was attributed to both the surface plasmon-exciton coupling and transferred electron.•The diameter and space of Al NP arrays can be accurately controlled by the anodic aluminum oxide (AAO) templates.
We report on the lattice structures and optical properties of Ce:LYSO crystal waveguides implanted with C, Si and Cu ions at 6 MeV. SRIM software was used to reconstruct the elastic collisions ...between the implanted ions and target nuclei. The maximum structural changes were induced by the Cu-ion implantation, as determined by XRD and Raman spectra. Photoluminescent and absorption spectra were used to study the optical properties of Ce3+ ions in the Ce:LYSO waveguides. Prism-coupling and end-face coupling methods, respectively, were used to measure the guiding modes and the near-field intensity distribution of light at 633 nm. Typical well + barrier waveguides were formed in the Ce:LYSO crystals implanted by C, Si and Cu ions, which will be a interest application in integrated optical devices.
•Typical “well + barrier” waveguide structures in Ce:LYSO crystals by implanting C-, Si- and Cu-ions at 6 MeV.•Prism-coupling and end-face coupling methods used to measure the guiding modes and near-field intensity distribution of light, respectively, indicated that light was confined in these structures at 633 nm.•XRD spectra showed the widening and disappearance of diffraction peaks in the Si- and Cu-ion implanted crystals, respectively, and the photoluminescent (PL) and PL excitation spectra correlated to the Ce3+ ions were retained.
Abstract
Here we report the spectral-timing results of the black hole X-ray binary 4U 1630–47 during its 2021 outburst using observations from the Hard X-ray Modulation Telescope (Insight-HXMT). Type ...C quasi-periodic oscillations (QPOs) in ∼1.6–4.2 Hz and quasi-regular modulation (QRM) near 60 mHz are detected during the outburst. The mHz QRM has a fractional rms of ∼10%–16% in the 8–35 keV energy band with a
Q
factor (frequency/width) of ∼2–4. Benefiting from the broad energy band of Insight-HXMT, we study the energy dependence of the ∼60 mHz QRM in 1–100 keV for the first time. We find that the fractional rms of the mHz QRM increases with photon energy, while the time lags of the mHz QRM are soft and decrease with photon energy. Fast recurrence of the mHz QRM, in a timescale of less than 1 hr, has been observed during the outburst. During this period, the corresponding energy spectra moderately change when the source transitions from the QRM state to the non-QRM state. The QRM phenomenon also shows a dependence with the accretion rate. We suggest that the QRM could be caused by an unknown accretion instability aroused from the corona.
The V-shaped electrothermal actuator has gained significant popularity as it was demonstrated to be a compact, stable and high rectilinear displacement device. However, existing electrothermal ...actuators usually require the driven voltage as high as several tens of volts to realize large displacements, imposing restrictions on the actuator's integration in miniature mobile mechatronic systems. The paper presents a V-shaped metal-silicon actuator with low voltage, low power consumption and large displacement. The electro-thermal conversion and heat conduction mechanism of the actuator are improved by optimizing the architecture design of the actuator. An innovative method utilizing the double-sided inductively coupled plasma etching technique is developed for the fabrication. The motion of the actuator is characterized with a microscope-based dynamic test system. Finite element analysis is conducted to verify the device design and experimental results. The transient dynamic behaviour of the actuator is modelled for future control strategy. A rectilinear displacement as high as <inline-formula> <tex-math notation="LaTeX">80.7~\mu \text{m} </tex-math></inline-formula> is achieved at a voltage of 4.0 V and power of 1.12 W. The displacement per unit length to voltage ratio of the metal-silicon actuator is the largest among existing silicon actuators. The displacement per unit length to power of the actuator is also comparative to the highest value of existing actuators, demonstrating that the metal-silicon actuator can achieve large displacement with low voltage and power consumption. The proposed actuator has great potential for the applications in the miniature mechatronic systems such as cell phone, camera, safety and arming device. 2021-0048
As China’s first X-ray astronomical satellite, the Hard X-ray Modulation Telescope (HXMT), which was dubbed as
Insight
-HXMT after the launch on June 15, 2017, is a wide-band (1-250 keV) ...slat-collimator-based X-ray astronomy satellite with the capability of all-sky monitoring in 0.2-3 MeV. It was designed to perform pointing, scanning and gamma-ray burst (GRB) observations and, based on the Direct Demodulation Method (DDM), the image of the scanned sky region can be reconstructed. Here we give an overview of the mission and its progresses, including payload, core sciences, ground calibration/facility, ground segment, data archive, software, in-orbit performance, calibration, background model, observations and some preliminary results.
Adhesion G protein-coupled receptors are elusive in terms of their structural information and ligands. Here, we solved the cryogenic-electron microscopy (cryo-EM) structure of apo-ADGRG2, an ...essential membrane receptor for maintaining male fertility, in complex with a Gs trimer. Whereas the formations of two kinks were determinants of the active state, identification of a potential ligand-binding pocket in ADGRG2 facilitated the screening and identification of dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate and deoxycorticosterone as potential ligands of ADGRG2. The cryo-EM structures of DHEA–ADGRG2–Gs provided interaction details for DHEA within the seven transmembrane domains of ADGRG2. Collectively, our data provide a structural basis for the activation and signaling of ADGRG2, as well as characterization of steroid hormones as ADGRG2 ligands, which might be used as useful tools for further functional studies of the orphan ADGRG2.The description of the cryo-EM structure of an orphan adhesion GPCR–Gs protein complex in apo state facilitates the screening and identification of potential ligands of ADGRG2.
Background
Long non-coding RNA (lncRNA) ASB16 antisense RNA 1 (ASB16-AS1) is recognized as an oncogene in several cancer types, but its relation to GC is unknown. Tripartite motif containing 37 ...(TRIM37) has been proven to accelerate the development of gastric cancer (GC), whereas the molecular mechanism assisted ASB16-AS1 and TRIM37 in regulating GC progression remains unclear.
Methods
Differentially expressed lncRNAs in GC samples were analyzed based on Gene Expression Omnibus (GEO) data. CCK-8 and colony formation assays were applied to determine the proliferative ability of GC cells. Stem cell-like phenotype of GC cells was assessed by sphere formation assay and flow cytometry analysis. Luciferase reporter assay, RNA immunoprecipitation (RIP), pulldown, and co-immunoprecipitation (Co-IP) were performed to verify the interplay of RNA molecules.
Results
ASB16-AS1 was upregulated in GC samples according to GEO data and qRT-PCR analysis. ASB16-AS1 strengthened the proliferative ability and stem cell-like characteristics in GC cells. More importantly, ASB16-AS1 encouraged GC cell growth in vivo. Mechanistically, ASB16-AS1 strengthened TRIM37 expression by sequestering miR-3918 and miR-4676-3p. ASB16-AS1 activated NF-kappa B (NF-κB) pathway by cooperating with ATM serine/threonine kinase (ATM) to induce TRIM37 phosphorylation.
Conclusion
In summary, ASB16-AS1 exerted oncogenic functions in GC through modulating TRIM37 expression at both mRNA and protein levels.
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