We demonstrate a high-sensitivity relative humidity (RH) sensor taking advantage of single-band narrow plasmon resonance of a single Au nanorod coupled to a whispering gallery cavity mode of a ...polyacrylamide microfiber. From the resonance peak shift, the sensor could achieve a sensitivity up to 0.51 nm/% RH with a cavity size of about 2 μm. By coupling multiple Au nanorods along the microfiber axis, we demonstrate a position-dependent microfiber optical humidity sensor with a 1.5-mm spatial resolution, which can be potentially reduced to micrometer level, paving a way toward high-resolution distributed microfiber optical sensors.
Using a sample of
1.31
×
10
9
J
/
ψ
events collected with the BESIII detector, we perform a study of
J
/
ψ
→
γ
K
K
¯
η
′
.
X
(2370) is observed in the
K
K
¯
η
′
invariant-mass distribution with a ...statistical significance of
8.3
σ
. Its resonance parameters are measured to be
M
=
2341.6
±
6.5
(stat.)
±
5.7
(syst.)
MeV
/
c
2
and
Γ
=
117
±
10
(stat.)
±
8
(syst.)
MeV
. The product branching fractions for
J
/
ψ
→
γ
X
(
2370
)
,
X
(
2370
)
→
K
+
K
-
η
′
and
J
/
ψ
→
γ
X
(
2370
)
,
X
(
2370
)
→
K
S
0
K
S
0
η
′
are determined to be
(
1.79
±
0.23
(stat.)
±
0.65
(syst.)
)
×
10
-
5
and
(
1.18
±
0.32
(stat.)
±
0.39
(syst.)
)
×
10
-
5
, respectively. No evident signal for
X
(2120) is observed in the
K
K
¯
η
′
invariant-mass distribution. The upper limits for the product branching fractions of
B
(
J
/
ψ
→
γ
X
(
2120
)
→
γ
K
+
K
-
η
′
)
and
B
(
J
/
ψ
→
γ
X
(
2120
)
→
γ
K
S
0
K
S
0
η
′
)
are determined to be
1.49
×
10
-
5
and
6.38
×
10
-
6
at the 90% confidence level, respectively.
The infusion of coronavirus disease 2019 (COVID-19) patients with mesenchymal stem cells (MSCs) potentially improves clinical symptoms, but the underlying mechanism remains unclear. We conducted a ...randomized, single-blind, placebo-controlled (29 patients/group) phase II clinical trial to validate previous findings and explore the potential mechanisms. Patients treated with umbilical cord-derived MSCs exhibited a shorter hospital stay (P = 0.0198) and less time required for symptoms remission (P = 0.0194) than those who received placebo. Based on chest images, both severe and critical patients treated with MSCs showed improvement by day 7 (P = 0.0099) and day 21 (P = 0.0084). MSC-treated patients had fewer adverse events. MSC infusion reduced the levels of C-reactive protein, proinflammatory cytokines, and neutrophil extracellular traps (NETs) and promoted the maintenance of SARS-CoV-2-specific antibodies. To explore how MSCs modulate the immune system, we employed single-cell RNA sequencing analysis on peripheral blood. Our analysis identified a novel subpopulation of VNN2
hematopoietic stem/progenitor-like (HSPC-like) cells expressing CSF3R and PTPRE that were mobilized following MSC infusion. Genes encoding chemotaxis factors - CX3CR1 and L-selectin - were upregulated in various immune cells. MSC treatment also regulated B cell subsets and increased the expression of costimulatory CD28 in T cells in vivo and in vitro. In addition, an in vivo mouse study confirmed that MSCs suppressed NET release and reduced venous thrombosis by upregulating kindlin-3 signaling. Together, our results underscore the role of MSCs in improving COVID-19 patient outcomes via maintenance of immune homeostasis.
ABSTRACT
Based on Insight-HXMT data, we report on the pulse fraction evolution during the 2017–2018 outburst of the newly discovered first Galactic ultraluminous X-ray (ULX) source Swift ...J0243.6+6124. The pulse fractions of 19 observation pairs selected in the rising and fading phases with similar luminosity are investigated. The results show a general trend of the pulse fraction increasing with luminosity and energy at supercritical luminosity. However, the relative strength of the pulsation between each pair evolves strongly with luminosity. The pulse fraction in the rising phase is larger at luminosity below 7.71 × 1038 erg s−1, but smaller at above. A transition luminosity is found to be energy independent. Such a phenomenon is first confirmed by Insight-HXMT observations and we speculate that it may have relation with the radiation-pressure-dominated accretion disc.
Background
Flap viability after transfer depends on blood flow from the arterial blood supply below the fascia. This study evaluated survival of a pedicle flap with a perforator lateral branch and ...flow‐through blood supply, compared with that of a flap with a flow‐end blood supply and perforator terminal branch.
Methods
Forty Sprague–Dawley rats, 20 in each group, were assigned to transfer of a superficial epigastric artery pedicle island flap with a flow‐through or flow‐end configuration of blood supply. Laser Doppler imaging was used to evaluate flap perfusion 2 h, 3 days and 5 days after surgery. The rats were killed on day 5, and lead oxide–gelatine‐enhanced flap angiography and histology with haematoxylin and eosin staining was performed. Dorsal midline tissue was excised for quantification of vascular endothelial growth factor by western blot assay.
Results
On day 5 after surgery, the flow‐through group exhibited a significantly greater mean(s.d.) flap survival area (97·8(3·5) versus 80·8(10·2) per cent; P = 0·003), microvascular density (303(19) versus 207(41) per mm2; P < 0·001) and perfusion (8·64(0·14) versus 5·95(0·14) perfusion units; P < 0·001) than the flow‐end group. The flow‐through group exhibited more angiosomes connected by dilated vascular anastomoses between the skin and subcutaneous fasciae.
Conclusion
The flow‐through blood supply improved pedicle perforator flap survival.
Surgical relevance
Perforator flap failure is mainly the result of impaired blood supply, as a flow‐end blood configuration is nourished only by the perforator terminal branch of the artery.
This work showed that the flow‐through blood supply nourished by the perforator lateral branch improved flap survival, with dilatation of collateral vascular anastomoses and increased neoangiogenesis.
The use of a flow‐through configuration improves perforator flap survival and could therefore minimize morbidity resulting from flap necrosis.
Flow‐through blood supply improved flap survival
Ethylene/α-olefin copolymers are produced in huge scale and widely used, but their after-use disposal has caused plastic pollution problems. Their chemical inertness made chemical re/upcycling ...difficult. Ideally, PE materials should be made de novo to have a circular closed-loop lifecycle. However, synthesis of circular ethylene/α-olefin copolymers, including high-volume, linear low-density PE as well as high-value olefin elastomers and block copolymers, presents a particular challenge due to difficulties in introducing branches while simultaneously installing chemical recyclability and directly using industrial ethylene and α-olefin feedstocks. Here we show that coupling of industrial coordination copolymerization of ethylene and α-olefins with a designed functionalized chain-transfer agent, followed by modular assembly of the resulting AB telechelic polyolefin building blocks by polycondensation, affords a series of ester-linked PE-based copolymers. These new materials not only retain thermomechanical properties of PE-based materials but also exhibit full chemical circularity via simple transesterification and markedly enhanced adhesion to polar surfaces.
Background Magnifying endoscopy with narrow-band imaging (ME-NBI) can more clearly assess the surface pattern and microvascular architecture of gastric lesions. Objective To evaluate the diagnostic ...efficacy of ME-NBI in patients with early gastric cancer. Design Prospective study. Setting Single academic center. Patients This study involved 164 suspected gastric lesions in 146 consecutive patients who underwent ME-NBI for additional differential diagnosis before treatment. Intervention ME-NBI findings were classified into 3 groups based on irregularities, absence of surface pattern, and microvascular architecture. All lesions were treated endoscopically or surgically, and ME-NBI diagnosis was compared with histopathological findings. Main Outcome Measurements Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of real-time ME-NBI diagnosis were determined. Results The sensitivity, specificity, and accuracy of ME-NBI were 97.3%, 84.4%, and 90.2%, respectively, in distinguishing between cancerous and noncancerous lesions and were 92.3%, 89.7%, and 90.4%, respectively, in distinguishing undifferentiated from differentiated adenocarcinoma. ME-NBI accurately predicted depth of invasion in 37 of 39 differentiated adenocarcinomas (95%). Limitations The sample size was relatively small. Conclusions ME-NBI can successfully distinguish between cancerous and noncancerous lesions and between undifferentiated and differentiated adenocarcinomas. Of the 3 patterns on ME-NBI, type A is mainly characteristic of noncancerous lesions, type B is a good indicator of differentiated adenocarcinoma and intramucosal/superficially invasive cancers, and type C is indicative of undifferentiated adenocarcinoma or differentiated cancer with deep submucosal invasion.
Disposal of long-lived fission products (LLFPs) produced in reactors has been paid a lot attention for sustainable and clean nuclear energy. Although a few transmutation means have been proposed to ...address this issue, there are still scientific and/or engineering challenges to achieve efficient transmutation of LLFPs. In this study, we propose a novel concept of advanced nuclear energy system (ANES) for transmuting LLFPs efficiently without isotopic separation. The ANES comprises intense photoneutron source (PNS) and subcritical reactor, which consist of lead-bismuth (Pb-Bi) layer, beryllium (Be) layer, and fuel, LLFPs and shield assemblies. The PNS is produced by bombarding radioactive cesium and iodine target with a laser-Compton scattering (LCS) γ-ray beam. We investigate the effect of the ANES system layout on transmutation efficiency by Monte Carlo simulations. It is found that a proper combination of the Pb-Bi layer and the Be layer can increase the utilization efficiency of the PNS by a factor of ~ 10, which helps to decrease by almost the same factor the LCS γ-beam intensity required for driving the ANES. Supposing that the ANES operates over 20 years at a normal thermal power of 500 MWt, five LLFPs including
Tc,
I,
Pd,
Cs and
Se could be transmuted by more than 30%. Their effective half-lives thus decrease drastically from ~ 10
to less than 10
years. It is suggested that this successful implementation of the ANES paves the avenue towards practical transmutation of LLFPs without isotopic separation.
Van Allen radiation belts are typically two zones of energetic particles encircling the Earth separated by the slot region. How the outer radiation belt electrons are accelerated to relativistic ...energies remains an unanswered question. Recent studies have presented compelling evidence for the local acceleration by very-low-frequency (VLF) chorus waves. However, there has been a competing theory to the local acceleration, radial diffusion by ultra-low-frequency (ULF) waves, whose importance has not yet been determined definitively. Here we report a unique radiation belt event with intense ULF waves but no detectable VLF chorus waves. Our results demonstrate that the ULF waves moved the inner edge of the outer radiation belt earthward 0.3 Earth radii and enhanced the relativistic electron fluxes by up to one order of magnitude near the slot region within about 10 h, providing strong evidence for the radial diffusion of radiation belt relativistic electrons.
Resistance to cytotoxic chemotherapy drugs remains as the major cause of treatment failure in acute myeloid leukemia. Histone deacetylases (HDAC) are important regulators to maintain chromatin ...structure and control DNA damage; nevertheless, how each HDAC regulates genome stability remains unclear, especially under genome stress conditions. Here, we identified a mechanism by which HDAC3 regulates DNA damage repair and mediates resistance to chemotherapy drugs. In addition to inducing DNA damage, chemotherapy drugs trigger upregulation of HDAC3 expression in leukemia cells. Using genetic and pharmacological approaches, we show that HDAC3 contributes to chemotherapy resistance by regulating the activation of AKT, a well-documented factor in drug resistance development. HDAC3 binds to AKT and deacetylates it at the site Lys20, thereby promoting the phosphorylation of AKT. Chemotherapy drug exposure enhances the interaction between HDAC3 and AKT, resulting in decrease in AKT acetylation and increase in AKT phosphorylation. Whereas HDAC3 depletion or inhibition abrogates these responses and meanwhile sensitizes leukemia cells to chemotoxicity-induced apoptosis. Importantly, in vivo HDAC3 suppression reduces leukemia progression and sensitizes MLL-AF9
leukemia to chemotherapy. Our findings suggest that combination therapy with HDAC3 inhibitor and genotoxic agents may constitute a successful strategy for overcoming chemotherapy resistance.
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