2,175 research outputs found
Silicon nitride metalenses for unpolarized high-NA visible imaging
As one of nanoscale planar structures, metasurface has shown excellent
superiorities on manipulating light intensity, phase and/or polarization with
specially designed nanoposts pattern. It allows to miniature a bulky optical
lens into the chip-size metalens with wavelength-order thickness, playing an
unprecedented role in visible imaging systems (e.g. ultrawide-angle lens and
telephoto). However, a CMOS-compatible metalens has yet to be achieved in the
visible region due to the limitation on material properties such as
transmission and compatibility. Here, we experimentally demonstrate a divergent
metalens based on silicon nitride platform with large numerical aperture
(NA~0.98) and high transmission (~0.8) for unpolarized visible light,
fabricated by a 695-nm-thick hexagonal silicon nitride array with a minimum
space of 42 nm between adjacent nanoposts. Nearly diffraction-limit virtual
focus spots are achieved within the visible region. Such metalens enables to
shrink objects into a micro-scale size field of view as small as a single-mode
fiber core. Furthermore, a macroscopic metalens with 1-cm-diameter is also
realized including over half billion nanoposts, showing a potential application
of wide viewing-angle functionality. Thanks to the high-transmission and
CMOS-compatibility of silicon nitride, our findings may open a new door for the
miniaturization of optical lenses in the fields of optical fibers,
microendoscopes, smart phones, aerial cameras, beam shaping, and other
integrated on-chip devices.Comment: 16 pages, 7 figure
Blockade of Persistent Sodium Currents Contributes to the Riluzole-Induced Inhibition of Spontaneous Activity and Oscillations in Injured DRG Neurons
In addition to a fast activating and immediately inactivating inward sodium current, many types of excitable cells possess a noninactivating or slowly inactivating component: the persistent sodium current (INaP). The INaP is found in normal primary sensory neurons where it is mediated by tetrodotoxin-sensitive sodium channels. The dorsal root ganglion (DRG) is the gateway for ectopic impulses that originate in pathological pain signals from the periphery. However, the role of INaP in DRG neurons remains unclear, particularly in neuropathic pain states. Using in vivo recordings from single medium- and large-diameter fibers isolated from the compressed DRG in Sprague-Dawley rats, we show that local application of riluzole, which blocks the INaP, also inhibits the spontaneous activity of A-type DRG neurons in a dose-dependent manner. Significantly, riluzole also abolished subthreshold membrane potential oscillations (SMPOs), although DRG neurons still responded to intracellular current injection with a single full-sized spike. In addition, the INaP was enhanced in medium- and large-sized neurons of the compressed DRG, while bath-applied riluzole significantly inhibited the INaP without affecting the transient sodium current (INaT). Taken together, these results demonstrate for the first time that the INaP blocker riluzole selectively inhibits INaP and thereby blocks SMPOs and the ectopic spontaneous activity of injured A-type DRG neurons. This suggests that the INaP of DRG neurons is a potential target for treating neuropathic pain at the peripheral level
Biocrust reduces the soil erodibility of coral calcareous sand by regulating microbial community and extracellular polymeric substances on tropical coral island, South China Sea
Tropical coral islands assume a pivotal role in the conservation of oceanic ecosystem biodiversity. However, their distinctive environmental attributes and limited vegetation render them highly susceptible to soil erosion. The biological soil crust (biocrust), owing to its significant ecological role in soil stabilization and erosion prevention, is deemed an effective means of mitigating soil erosion on coral island. However, existing research on the mechanisms through which biocrusts resist soil erosion has predominantly concentrated on arid and semi-arid regions. Consequently, this study will specifically delve into elucidating the erosion-resistant mechanisms of biocrusts in tropical coral island environments, South China Sea. Specifically, we collected 16 samples of biocrusts and bare soil from Meiji Island. High-throughput amplicon sequencing was executed to analyze the microbial community, including bacteria, fungi, and archaea. Additionally, quantitative PCR was utilized to assess the abundance of the bacterial 16S rRNA, fungal ITS, archaeal 16S rRNA, and cyanobacterial 16S rRNA genes within these samples. Physicochemical measurements and assessments of extracellular polymeric substances (EPSs) were conducted to characterize the soil properties. The study reported a significantly decreased soil erodibility factor after biocrust formation. Compared to bare soil, soil erodibility factor decreased from 0.280 to 0.190βtβhβMJβ1 mmβ1 in the biocrusts. Mechanistically, we measured the microbial EPS contents and revealed a negative correlation between EPS and soil erodibility factor. Consistent with increased EPS, the abundance of bacteria, fungi, archaea, and cyanobacteria were also detected significantly increased with biocrust formation. Correlation analysis detected Cyanobacteria, Chloroflexi, Deinococcota, and Crenarchaeota as potential microbials promoting EPSs and reducing soil erosion. Together, our study presents the evidence that biocrust from tropical coral island in the South China Sea promotes resistance to soil erosion, pinpointing key EPSs-producing microbials against soil erosion. The findings would provide insights for island soil restoration
Effects of mGluR5 Antagonists on Parkinson's Patients With L-Dopa-Induced Dyskinesia: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Background: Modulation of Metabotropic glutamate receptor 5 (mGluR5) may be a novel therapeutic approach to manage Parkinson's disease (PD) Patients with L-dopa-induced dyskinesia (LID).Objectives: The objective of this meta-analysis was to evaluate the effects of mGluR5 antagonists for the treatment of LID patients.Methods: Several electronic databases were consulted up to July 30, 2017. Randomized clinical trials (RCTs) that compared mGluR5 antagonists vs. placebo in LID patients were included. Pooled weighted mean difference (WMD) with 95% confidence intervals (CIs) were calculated using random-effects models.Results: Nine trials including 776 patients met all inclusion criteria. We pooled the whole data and found apparent difference between mGluR5 antagonists and placebo in terms of mAIMS (p = 0.010). However, there was no significant improvements on antidyskinetic in terms of LFADLDS (p = 0.42) and UPDRS Part IV (p = 0.20). Meanwhile, the effect size of UPDRS part III was similar in mGluR5 antagonist groups with in placebo groups (p = 0.25). Adverse events incidence was higher with mGluR5 antagonists than with placebo, especially at the expense of increased dizziness (16.3 vs. 4.3%), visual hallucination (10.1 vs. 1.1%), or fatigue (10.1 vs. 4.8%).Conclusions: mGluR5 antagonists had a greater treatment effect on the mAIMS in LID patients, however, there was no improvements on antidyskinetic in terms of LFADLDS and UPDRS Part IV compared with placebo. According to these results, we unable to recommend mGluR5 antagonists for the routine treatment of LID patients right now
Molecular Cloning of the Genes Encoding the PR55/BΞ²/Ξ΄ Regulatory Subunits for PP-2A and Analysis of Their Functions in Regulating Development of Goldfish, Carassius auratus
The protein phosphatase-2A (PP-2A), one of the major phosphatases in eukaryotes, is a heterotrimer, consisting of a scaffold A subunit, a catalytic C subunit and a regulatory B subunit. Previous studies have shown that besides regulating specific PP-2A activity, various B subunits encoded by more than 16 different genes, may have other functions. To explore the possible roles of the regulatory subunits of PP-2A in vertebrate development, we have cloned the PR55/B family regulatory subunits: Ξ² and Ξ΄, analyzed their tissue specific and developmental expression patterns in Goldfish ( Carassius auratus). Our results revealed that the full-length cDNA for PR55/BΞ² consists of 1940 bp with an open reading frame of 1332 nucleotides coding for a deduced protein of 443 amino acids. The full length PR55/BΞ΄ cDNA is 2163 bp containing an open reading frame of 1347 nucleotides encoding a deduced protein of 448 amino acids. The two isoforms of PR55/B display high levels of sequence identity with their counterparts in other species. The PR55/BΞ² mRNA and protein are detected in brain and heart. In contrast, the PR55/BΞ΄ is expressed in all 9 tissues examined at both mRNA and protein levels. During development of goldfish, the mRNAs for PR55/BΞ² and PR55/BΞ΄ show distinct patterns. At the protein level, PR55/BΞ΄ is expressed at all developmental stages examined, suggesting its important role in regulating goldfish development. Expression of the PR55/BΞ΄ anti-sense RNA leads to significant downregulation of PR55/BΞ΄ proteins and caused severe abnormality in goldfish trunk and eye development. Together, our results suggested that PR55/BΞ΄ plays an important role in governing normal trunk and eye formation during goldfish development
Measurement of the elliptic anisotropy of charged particles produced in PbPb collisions at βsNN=2.76 TeV
The anisotropy of the azimuthal distributions of charged particles produced in [β over s[subscript NN]]=2.76 TeV PbPb collisions is studied with the CMS experiment at the LHC. The elliptic anisotropy parameter, v[subscript 2], defined as the second coefficient in a Fourier expansion of the particle invariant yields, is extracted using the event-plane method, two- and four-particle cumulants, and Lee-Yang zeros. The anisotropy is presented as a function of transverse momentum (p[subscript T]), pseudorapidity (Ξ·) over a broad kinematic range, 0.3<p[subscript T]<20 GeV/c, |Ξ·|<2.4, and in 12 classes of collision centrality from 0 to 80%. The results are compared to those obtained at lower center-of-mass energies, and various scaling behaviors are examined. When scaled by the geometric eccentricity of the collision zone, the elliptic anisotropy is found to obey a universal scaling with the transverse particle density for different collision systems and center-of-mass energies
Measurement of the charge asymmetry in top-quark pair production in protonβproton collisions at βs = 7 TeV
The difference in angular distributions between top quarks and antiquarks, commonly referred to as the charge asymmetry, is measured in pp collisions at the LHC with the CMS experiment. The data sample corresponds to an integrated luminosity of 1.09 fb[superscript β1] at a centre-of-mass energy of 7 TeV. Top-quark pairs are selected in the final state with an electron or muon and four or more jets. At least one jet is identified as originating from b-quark hadronization. The charge asymmetry is measured in two variables, one based on the pseudorapidities (Ξ·) of the top quarks and the other on their rapidities (y). The results A[Ξ· over C] = β0.017 Β± 0.032 (stat.)[+0.025 over β0.036] (syst.) and A[y over C] = β0.013 Β± 0.028 (stat.)[+0.029 over β0.031] (syst.) are consistent within uncertainties with the standard-model predictions.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio
Search for the standard model Higgs boson decaying into two photons in pp collisions at βs = 7 TeV
A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a center-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 fb[superscript β1]. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1Ο . The global significance of observing an excess with a local significance β©Ύ3.1Ο anywhere in the search range 110β150 GeV is estimated to be 1.8Ο. More data are required to ascertain the origin of this excess.United States. Dept. of EnergyNational Science Foundation (U.S.
KIR and HLA Loci Are Associated with Hepatocellular Carcinoma Development in Patients with Hepatitis B Virus Infection: A Case-Control Study
BACKGROUND: Natural killer (NK) cells activation has been reported to contribute to inflammation and liver injury during hepatitis B virus (HBV) infection both in transgenic mice and in patients. However, the role of NK cells in the process of HBV-associated hepatocellular carcinoma (HCC) development has not been addressed. Killer cell immunoglobulin-like receptors (KIRs) are involved in regulating NK cell activation through recognition of specific human leukocyte antigen (HLA) class I allotypes. METHODOLOGY/PRINCIPAL FINDINGS: To investigate whether KIR and HLA genes could influence the risk of HBV-associated HCC development, 144 HBV-infected patients with HCC and 189 well-matched HBV infectors with chronic hepatitis or cirrhosis as non-HCC controls were enrolled in this study. The presence of 12 loci of KIR was detected individually. HLA-A, -B, -C loci were genotyped with high-resolution. HLA-C group 1 homozygote (OR = 2.02; p = 0.005), HLA-Bw4-80I (OR = 2.67; p = 2.0E-04) and combination of full-length form and 22 bp-deleted form of KIR2DS4 (KIR2DS4/1D) (OR = 1.89; p = 0.017) were found associated with HCC incidence. When the combined effects of these three genetic factors were evaluated, more risk factors were observed correlating with higher odds ratios for HCC incidence (P trend = 7.4E-05). Because all the risk factors we found have been reported to result in high NK cell functional potential by previous studies, our observations suggest that NK cell activation may contribute to HBV-associated HCC development. CONCLUSIONS/SIGNIFICANCE: In conclusion, this study has identified significant associations that suggest an important role for NK cells in HCC incidence in HBV-infected patients. Our study is useful for HCC surveillance and has implications for novel personalized therapy strategy development aiming at HCC prevention in HBV-infected patients
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