Direct Detection Constraints on Dark Photons with the CDEX-10 Experiment at the China Jinping Underground Laboratory

We report constraints on the dark photon effective kinetic mixing parameter (κ) with data taken from two p-type point-contact germanium detectors of the CDEX-10 experiment at the China Jinping Underground Laboratory. The 90% confidence level upper limits on κ of solar dark photon from 205.4 kg-day exposure are derived, probing new parameter space with masses (m_{V}) from 10 to 300  eV/c^{2} in direct detection experiments. Considering dark photon as the cosmological dark matter, limits at 90% confidence level with m_{V} from 0.1 to 4.0  keV/c^{2} are set from 449.6 kg-day data, with a minimum of κ=1.3×10^{-15} at m_{V}=200  eV/c^{2}.

Immediate early response protein 2 promotes the migration and invasion of hepatocellular carcinoma cells via regulating the activity of Rho GTPases

Human immediate early response 2 (IER2) has been implicated in tumor cell motility and metastasis; however, the underlying mechanisms in hepatocellular carcinoma (HCC) metastasis remain to be clarified. In this study, we demonstrate that dysregulation of IER2 was shown in HCC clinical samples, and IER2 expression resulted in the promotion of cell migration and invasion in vitro, and HCC tumor growth and pulmonary metastasis in vivo. Moreover, we showed that IER2 expression altered assembly of the actin cytoskeleton rearrangement. Furthermore, MAPK and PI3K/Akt signaling pathways induced by IER2 were confirmed to be probably involved in regulating the activity of Rho GTPases, such as RhoA, Rac1 and Cdc42. Collectively, our results indicated a significant role of IER2 in the HCC cell motility and metastasis through MAPK and PI3K/Akt signaling pathways to regulate the activity of Rho GTPases, thereby modulating actin cytoskeleton rearrangement, unveiling a novel mechanism of cell motility regulation induced by IER2.

Search for Light Weakly-Interacting-Massive-Particle Dark Matter by Annual Modulation Analysis with a Point-Contact Germanium Detector at the China Jinping Underground Laboratory

We present results on light weakly interacting massive particle (WIMP) searches with annual modulation (AM) analysis on data from a 1-kg mass p-type point-contact germanium detector of the CDEX-1B experiment at the China Jinping Underground Laboratory. Datasets with a total live time of 3.2 yr within a 4.2-yr span are analyzed with analysis threshold of 250 eVee. Limits on WIMP-nucleus (χ-N) spin-independent cross sections as function of WIMP mass (m_{χ}) at 90% confidence level (C.L.) are derived using the dark matter halo model. Within the context of the standard halo model, the 90% C.L. allowed regions implied by the DAMA/LIBRA and CoGeNT AM-based analysis are excluded at >99.99% and 98% C.L., respectively. These results correspond to the best sensitivity at m_{χ}<6  GeV/c^{2} among WIMP AM measurements to date.

A simple method for in situ measurement of vacuum window birefringence

We present a simple method to measure the degrees of circular polarization (DoCP) of laser light inside a vacuum chamber and the birefringence of a vacuum window by detecting the fluorescence emitted by Doppler cooled ions in an ion trap. Imperfect laser polarization will cause ions to be pumped to the dark state which will decrease the fluorescence rates of the ions. With a simulation based on the rate equations of the relevant energy levels of ²⁵Mg⁺ ions, we find that the fluorescence rate is sensitive to the DoCP of the laser. Based on the simulation result, we present a new method to optimize the DoCP of the laser inside the vacuum chamber by adjusting fast axis azimuthal angles of a half-wave plate and a quarter-wave plate outside the vacuum chamber. The laser light is optimized to be circularly polarized with an uncertainty of the DoCP of 7.8 × 10^-5. With the obtained polarization information on both sides of the vacuum window and treating the vacuum window as an unknown wave plate, the phase delay and the fast axis azimuthal angle of the vacuum window can be determined in the form of Mueller matrix. The phase delay is determined to be 197.60(39)°, and the fast axis azimuthal angle is determined to be 104.00(5)°.

Constraints on Spin-Independent Nucleus Scattering with sub-GeV Weakly Interacting Massive Particle Dark Matter from the CDEX-1B Experiment at the China Jinping Underground Laboratory

We report results on the searches of weakly interacting massive particles (WIMPs) with sub-GeV masses (m_{χ}) via WIMP-nucleus spin-independent scattering with Migdal effect incorporated. Analysis on time-integrated (TI) and annual modulation (AM) effects on CDEX-1B data are performed, with 737.1 kg day exposure and 160 eVee threshold for TI analysis, and 1107.5 kg day exposure and 250 eVee threshold for AM analysis. The sensitive windows in m_{χ} are expanded by an order of magnitude to lower DM masses with Migdal effect incorporated. New limits on σ_{χN}^{SI} at 90% confidence level are derived as 2×10^{-32}∼7×10^{-35}  cm^{2} for TI analysis at m_{χ}∼50-180  MeV/c^{2}, and 3×10^{-32}∼9×10^{-38}  cm^{2} for AM analysis at m_{χ}∼75  MeV/c^{2}-3.0  GeV/c^{2}.

[Study on treatment of chronic tinnitus by tetanus stimulation and evaluation methods of tinnitus]

Objective:The purpose of this study was to explore the efficacy of tetanus stimulation in tinnitus treatment and the correlation between the mainstream questionnaires of tinnitus and tinnitus-matching in order to find a more convenient and accurate method for tinnitus evaluation. Method:Ten patients with chronic tinnitus and normal or mild hearing impairment were enrolled in this study, totaling 13 ears. Their age ranged from 23 to 53 years old. The stimulus sound（white noise, frequency modulation 14.1 Hz, repetitive amplitude modulation, duty cycle 0.5） was selected and the sound intensity was 50 dB SL. Experimental procedure: （4 minutes sound stimulation+4 minutes rest） ×4 times, totaling 32 minutes. The patients were treated three times a week for 5 weeks. The loudness of tinnitus was matched before and after each treatment, and tinnitus handicap inventory（THI）, tinnitus handicap questionnaire（THQ） and visual analog scales（VAS） were also used for assessment before the first treatment each week. The loudness matching and the above scales were performed once more at follow-up for one week after end-of-treatment. Result:①Single treatment: the matched loudness value decreased by 1.000（0.000, 3.000） dB（Z=7.553, P<0.01） after each single treatment. ②After five weeks' treatment: the matched loudness value decreased（9.692±8.038） dB（t=4.348, P<0.01）; VAS value decreased by 2.000（1.000, 3.000）（Z=2.890, P<0.01）; total score of THQ decreased（7.389%±8.847%）（t=2.641, P<0.05）. ③Correlation analysis: there was positive correlation between total scores of THI and THQ（r=0.747, P<0.01）; the matched loudness values have positive correlation with VAS value（r=0.593, P<0.01）, THI-F（r=0.346, P<0.01） and THQ-factor 3 score（r=0.294, P<0.05）; there was positive correlation between the VAS value and THI-F（r=0.326, P<0.05）, the total score of THI（r=0.466, P<0.01）, THQ-factor 3 score（r=0.291, P<0.05）, the total score of THQ（r=0.497, P<0.01）. Conclusion:The loudness of tinnitus declined with significant fluctuation during tetanus sound therapy. THQ scale is recommended as a sensitive indicator for evaluating the efficacy of tinnitus treatment; VAS is recommended for rapid assessment of tinnitus. Tetanus stimulation is expected to become an important direction in tinnitus sound therapy.

Wash-induced multicolor tuning of carbon nano-dot/micro-belt hybrids with full recyclability and stable color convertibility

Multicolor carbon phosphors as emerging light conversion materials, with full recyclability and stable color convertibility, are poised to accelerate the sustainable development of environment-friendly optoelectronics. Herein, we firstly report a facile strategy, combining single-step hydrothermal and differential washing methods, for the preparation of multicolor carbon emitters with nano-dot/micro-belt structures. The as-prepared hybrids exhibit excellent film-forming ability and demonstrate controllable multicolor solid-state luminescence ranging from white and green to blue light emission, by utilizing the synergistic effect between nano-dot and micro-belt structures. Particularly, the hybrid white emitters possess a robust ability of being fully recyclable without any performance degradation and formation of harmful byproducts. Moreover, light-emitting devices (LEDs) coated with the hybrid emitters show stable voltage-independent luminescence behavior in lighting applications. This work provides a simple route to modulate the optical properties of multicolor carbon-based emitters and shows great potential in the sustainable development of lighting-related products.

Therapeutic effect of ethylenediaminetetraacetic acid irrigation solution against wound infection with drug-resistant bacteria in a rat model: an animal study

Objectives

Irrigation is the cornerstone of treating skeletal infection by eliminating pathogens in wounds. A previous study shows that irrigation with normal saline (0.9%) and ethylenediaminetetraacetic acid (EDTA) could improve the removal of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) compared with normal saline (NS) alone. However, it is still unclear whether EDTA solution is effective against infection with drug-resistant bacteria.

Methods

We established three wound infection models (skin defect, bone-exposed, implant-exposed) by inoculating the wounds with a variety of representative drug-resistant bacteria including methicillin-resistant S. aureus (MRSA), extended spectrum beta-lactamase-producing E. coli (ESBL-EC), multidrug-resistant Pseudomonas aeruginosa (MRPA), vancomycin-resistant Enterococcus (VRE), multidrug-resistant Acinetobacter baumannii (MRAB), multidrug-resistant Enterobacter (MRE), and multidrug-resistant Proteus mirabilis (MRPM). Irrigation and debridement were repeated until the wound culture became negative. The operating times required to eliminate pathogens in wounds were compared through survival analysis.

Results

Compared with other groups (NS, castile soap, benzalkonium chloride, and bacitracin), the EDTA group required fewer debridement and irrigation operations to achieve pathogen eradication in all three models of wound infection.

Conclusion

Irrigation with EDTA solution was more effective than the other irrigation fluids used in the treatment of wound infections caused by drug-resistant pathogens.

Cite this article: Z. Deng, F. Liu, C. Li. Therapeutic effect of ethylenediaminetetraacetic acid irrigation solution against wound infection with drug-resistant bacteria in a rat model: an animal study. Bone Joint Res 2019;8:189–198. DOI: 10.1302/2046-3758.85.BJR-2018-0280.R3.

Li(Cd,Mn)P: a new cadmium based diluted ferromagnetic semiconductor with independent spin & charge doping

We report a new diluted ferromagnetic semiconductor Li_1+y(Cd,Mn)P, wherein carrier is doped via excess Li while spin is doped by isovalence substitution of Mn²⁺ into Cd²⁺. The extended Cd 4d-orbitals lead to more itinerant characters of Li_1+y(Cd,Mn)P than that of analogous Li_1+y(Zn,Mn)P. A higher Curie temperature of 45 K than that for Li_1+y(Zn,Mn)P is obtained in Li_1+y(Cd,Mn)P polycrystalline samples by Arrott plot technique. The p-type carriers are determined by Hall effect measurements. The first principle calculations and X-ray diffraction measurements indicate that occupation of excess Li is at Cd sites rather than the interstitial site. Consequently holes are doped by excess Li substitution. More interestingly Li_1+y(Cd,Mn)P shows a very low coercive field (<100 Oe) and giant negative magnetoresistance (~80%) in ferromagnetic state that will benefit potential spintronics applications.

Aqueous acid-based synthesis of lead-free tin halide perovskites with near-unity photoluminescence quantum efficiency

Recently, lead halide perovskites with outstanding emission performance have become new candidate materials for light-emitting devices and displays; however, the toxicity of lead and instability of halide perovskites remain significant challenges. Herein, we report the aqueous acid-based synthesis of highly emissive two-dimensional (2D) tin halide perovskites, (octylammonium)₂SnX₄ (X = Br, I, or mixtures thereof), which displayed a high absolute photoluminescence (PL) quantum yield of near-unity in the solid-state, PL emission centered at 600 nm with a broad bandwidth (136 nm), a large Stokes shift (250 nm), long-lived luminescence (τ = 3.3 μs), and zero overlap between their absorption and emission spectra. Significantly, the stability study of 2D tin halide perovskites monitored by the PL quantum yield showed no changes after 240 days of storage at room temperature under ambient air and humidity conditions. The PL emission of the 2D tin halide perovskites was tuned from yellow to deep red by controlling halide composition. Furthermore, new yellow phosphors with superior optical properties are used to fabricate UV pumped white light emitting diodes (WLEDs). We expect these results to facilitate the development of new environmentally friendly and high-performance phosphors for future lighting and display technologies.

Direct Hot-Injection Synthesis of Lead Halide Perovskite Nanocubes in Acrylic Monomers for Ultrastable and Bright Nanocrystal-Polymer Composite Films

In recent years, lead halide perovskite nanocrystals (NCs) have attracted significant attention in both fundamental research and commercial applications because of their excellent optical and optoelectrical properties. However, the protective ligands on the surface of the perovskite NCs could be easily removed after the tedious process of centrifugation, separation, and dispersion, which greatly hampers their stability against light, heat, moisture, and oxygen and limits their practical applications. Here, we report a new post-processing free strategy (i.e., without centrifugation, separation, and dispersion process) of using an ultraviolet (UV)-polymerizable acrylic monomer of lauryl methacrylate as the solvent to synthesize CsPbBr₃ NCs, and then adding polyester polyurethane acrylate oligomer, monomer (IBOA), and initiator for direct UV polymerization to fabricate NC-polymer composite films. These films exhibited an improved photoluminescence quantum yield (85-90%) than classic NC films (40-50%), which were processed using octadecene (ODE) as the solvent for NC synthesis and postprocessed for UV polymerization. Significantly, the as-fabricated films by post-processing free strategy exhibited excellent photostability against strong Xe lamp illumination; while the other films using classic methods were quickly photodegraded. Meanwhile, these NC-polymer composite films showed good stability against moisture and heating when aging in water at 50 °C for over 200 h. These films, along with K₂SiF₆:Mn⁴⁺ (KSF) phosphor emitters, were used as downconverters for blue light-emitting diodes in liquid-crystal displays with a wide color gamut of 115% in the International Commission on Illumination (CIE) 1931 color space. This work provides a facile and effective strategy for the preparation of ultrastable and bright color-conversion NC films for the development of the next-generation wide color gamut displays.

Quench-resistant and stable nanocarbon dot/sheet emitters with tunable solid-state fluorescence via aggregation-induced color switching

Nanocarbon fluorescence materials are promising color converters for multicolor emission via phosphor-coated light emitting devices (LEDs). Herein, a facile time-controlled solvothermal route was developed to prepare solid-state multicolor nanocarbon emitters comprising dot/sheet nanohybrids. The nanocarbons demonstrate an aggregation-induced color switching behavior, leading to tunable light emission from blue to yellow by modulating the solvothermal reaction time. Particularly, these emitters show outstanding film-forming ability directly and a high production yield (∼40%). Moreover, the nanocarbon-coated ultraviolet LEDs exhibit high quality multicolor light emission and excellent color stability at high voltages, impelling the development of emerging carbon phosphors in fundamental research studies and practical applications.

The cellular and molecular mechanism of glutaraldehyde-didecyldimethylammonium bromide as a disinfectant against Candida albicans

OBJECTIVES

In our previous research, we have developed a new combination disinfectant, glutaraldehyde-didecyldimethylammonium bromide (GD). It was verified that GD had a strong effect on both Escherichia coli and Staphylococcus aureus. In this work, Candida albicans was selected as an object, and it could be killed by GD. We aimed to investigate the cellular and molecular mechanism of GD effecting on C. albicans.

METHODS AND RESULTS

The results of sterilization experiment indicated that GD was effective on C. albicans. Flow cytometry and atomic absorption spectrometry were applied to detect cell membrane damage of C. albicans. Luciferase reaction and Bradford method were carried out to detect ATP content and protein quantitation. Transmission electron microscopy was used for intracellular organelles morphological observation. In order to study changes in mitochondrial membrane potential, Rh 123 was used as an indicator. DNA conformation analysis was performed by molecular modelling and circular dichroism. The results indicated that membrane permeability was increased rapidly owing to GD effect, and the leaked K⁺ and Mg²⁺ were about 12·1 and 12·4 times those of the control, respectively, at 10 min after GD treatment. Simultaneously, ATP and protein also leaked rapidly out of the cell. Mitochondrial membrane potential was destroyed, succinic dehydrogenase activity was significantly decreased and DNA conformation was changed because of GD action.

CONCLUSIONS

Glutaraldehyde-didecyldimethylammonium bromide disinfected C. albicans through distorting cell membrane integrity and permeability, disturbing the intracellular homeostasis by intracellular substances leakage, especially K⁺ , Mg²⁺ , ATP and protein, causing electrolyte imbalance of mitochondria, changing DNA structure, which finally led to cell death.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study focused on the cellular and molecular mechanism of GD as a disinfectant against C. albicans. It is important to provide theoretical support to GD against Candida albicans in practical application.

Identification of circular RNAs hsa_circ_0044235 in peripheral blood as novel biomarkers for rheumatoid arthritis

Circular RNAs (circRNAs) are a new class of RNAs that can be used as biomarkers in clinical blood samples. However, little is known about circRNAs' diagnostic values for rheumatoid arthritis (RA). In this study, the hsa_circ_0054189, hsa_circ_0008675, hsa_circ_0082689, hsa_circ_0082688, hsa_circ_0010932, hsa_circ_0002473 and hsa_circ_0044235 in peripheral blood were determined by quantitative reverse transcription–polymerase chain reaction (qRT–PCR). For hsa_circ_0044235, only one abnormal expression circRNAs in peripheral blood was selected as a targeted circRNA to explore the diagnostic value for RA. Our work demonstrated that the hsa_circ_0044235 in peripheral blood was decreased significantly in RA patients. The hsa_circ_0044235 in peripheral blood from RA patients did not correlate with C‐reactive protein (CRP), erythrocyte sedimentation rate (ESR), rheumatoid factor (RF), anti‐citrullinated protein antibodies (ACPA) or disease activity score 28 (DAS28). Receiver operating characteristic (ROC) curve analysis suggested that the hsa_circ_0044235 in peripheral blood has significant value in the diagnosis of RA. The risk score based on hsa_circ_0044235 in peripheral blood also distinguished significantly the patients with RA from systemic lupus erythematosus (SLE). This study suggests that the hsa_circ_0044235 in peripheral blood may be a potential biomarker of patients with RA.

The neuroprotection effect of oxygen therapy: A systematic review and meta-analysis

This study reviews the oxygen therapy (normobaric oxygen [NBO] and hyperbaric oxygen [HBO]) in both stroke and traumatic brain injury (TBI) patients and meta-analyzes the efficacy of two oxygen therapies in different kinds of injuries. In stroke patients, NBO showed significant improvement in reperfusion rate while there is no favorable outcome effect of HBO treatment. In patients with TBI, HBO showed significant improvement of Glasgow outcome scale score and reduction of overall mortality while NBO may play a favorable role in improving brain metabolism.

Highly Emissive and Color-Tunable Perovskite Cross-linkers for Luminescent Polymer Networks

Emissive cross-linkers are of special interest for polymer science because of their ability to endow polymer networks with luminescent properties. Methylammonium lead halide perovskite nanoparticles (MAPbCl _xBr_{3- x} NPs) are extensively explored for optical and optoelectronic applications. In this work, MAPbCl _xBr_{3- x} NPs with cross-linkable and polymerizable ligands are successfully prepared as new emissive cross-linkers for polymer networks. Commercially available reagent 2-aminoethyl methacrylate hydrochloride (AMHCl) can act as a ligand to stabilize MAPbBr₃ NPs in solution. Compared with traditional ligands (oleic acid and oleylamine), AMHCl retains the architecture of perovskite effectively and affords polymerizable groups (vinyl) on the surface of perovskites. The as-prepared MAPbCl _xBr_{3- x} NPs can serve as cross-linkers in the radical polymerization of (meth)acrylates by UV-light to form polymer networks. Meanwhile, such cross-linkable emitters exhibit bright luminescence and color-tunability at room temperature, attributed by a unique halide exchange of perovskites between CH₃NH₃Br and AMHCl, which provides the polymer networks with varied emissive bands. These perovskite-crosslinked networks showed high air stability, water stability, and prominent photoluminescence quantum yields. On the basis of these excellent properties, white-light-emitting diodes were successfully fabricated from these perovskite-crosslinked composites with color-coordinate values at (0.316, 0.315), very close to the standard coordinates of white light. This work elucidates a new and convenient technique to convert nanocrystals into luminescent cross-linkers to build functional polymeric networks for technological applications.