Due to the advantages of small size, high sensitivity, and strong anti-interference ability, optical fiber sensors are widely used in gas detection. Meanwhile, concentration and humidity detection ...based on optical fiber sensing are paramount technologies in the field of gas sensing. However, how to solve the issue of cross sensitivity of concentration and humidity of optical fiber gas sensors and realize synchronous detection of two parameters are current common challenges. In this study, taking carbon dioxide as an example, a detection method based on double fiber Bragg grating (FBG) string is proposed to measure carbon dioxide (CO 2 ) concentration and air humidity simultaneously. Here, a pair of FBGs are welded in series on an optical fiber after being filled with special materials. Using the control variable method, the performance parameters of the sensor can be determined through calculation. The experimental results demonstrate that the gas concentration sensitivity is 0.5952 pm/ppm in the range of 0-2250 ppm. In the range of 25%-65%, the air humidity sensitivity is 28.62 pm/RH. Moreover, it is less affected by temperature and has satisfactory repeatability and reproducibility. The sensor realizes high sensitivity and low crosstalk measurement of concentration and humidity and can be applied to the simultaneous detection of CO 2 concentration and air humidity in specific confined space.
The past decade has witnessed numerous discoveries of two-dimensional (2D) semimetals and insulators, whereas 2D metals were rarely identified. Borophene, a monolayer boron sheet, has recently ...emerged as a perfect 2D metal with unique electronic properties. Here we study collective excitations in borophene, which exhibit two major plasmon modes with low damping rates extending from the infrared to ultraviolet regime. The anisotropic 1D plasmon originates from electronic transitions of tilted Dirac cones in borophene, analogous to that in extreme doped graphene. These features enable borophene as an integrated platform of 1D, 2D, and Dirac plasmons, promising for directional polariton transport and broadband optical communication in next-generation optoelectronic devices.
The main challenge associated with sodium-ion battery (SIB) anodes is a search for novel candidate materials with high capacity and excellent rate capability. The most commonly used and effective ...route for graphene-based anode design is the introduction of in-plane "hole" defects via nitrogen-doping; this creates a spacious reservoir for storing more energy. Inspired by mountains in nature, herein, we propose another way - the introduction of blistering in graphene instead of making "holes"; this facilitates adsorbing/inserting more Na+ ions. In order to properly answer the key question: ""protrusions" or "holes" in graphene, which is better for sodium ion storage?", two types of anode materials with a similar doping level were designed: a phosphorus-doped graphene (GP, with protrusions) and a nitrogen-doped graphene (GN, with holes). As compared with GN, the GP anode perfectly satisfies all the desired criteria: it reveals an ultrahigh capacity (374 mA h g-1 after 120 cycles at 25 mA g-1) comparable to the best graphite anodes in a standard Li-ion battery ( similar to 372 mA h g-1), and exhibits an excellent rate capability (210 mA h g-1 at 500 mA g-1). In situ transmission electron microscopy (TEM) experiments and density functional theory (DFT) calculations were utilized to uncover the origin of the enhanced electrochemical activity of "protrusions" compared to "holes" in SIBs, down to the atomic scale. The introduction of protrusions through P-doping into graphene is envisaged to be a novel effective way to enhance the capacity and rate performance of SIBs.
Abstract
Trigonal tellurium (Te) is a chiral semiconductor that lacks both mirror and inversion symmetries, resulting in complex band structures with Weyl crossings and unique spin textures. Detailed ...time-resolved polarized reflectance spectroscopy is used to investigate its band structure and carrier dynamics. The polarized transient spectra reveal optical transitions between the uppermost spin-split
H
4
and
H
5
and the degenerate
H
6
valence bands (VB) and the lowest degenerate
H
6
conduction band (CB) as well as a higher energy transition at the L-point. Surprisingly, the degeneracy of the
H
6
CB (a proposed Weyl node) is lifted and the spin-split VB gap is reduced upon photoexcitation before relaxing to equilibrium as the carriers decay. Using ab initio density functional theory (DFT) calculations, we conclude that the dynamic band structure is caused by a photoinduced shear strain in the Te film that breaks the screw symmetry of the crystal. The band-edge anisotropy is also reflected in the hot carrier decay rate, which is a factor of two slower along the
c
-axis than perpendicular to it. The majority of photoexcited carriers near the band-edge are seen to recombine within 30 ps while higher lying transitions observed near 1.2 eV appear to have substantially longer lifetimes, potentially due to contributions of intervalley processes in the recombination rate. These new findings shed light on the strong correlation between photoinduced carriers and electronic structure in anisotropic crystals, which opens a potential pathway for designing novel Te-based devices that take advantage of the topological structures as well as strong spin-related properties.
Pd4Fe alloy nanoflowers with hierarchical nanosheet petals that mainly exposed the (111) crystal plane were prepared. The Pd4Fe nanoflowers possessed the advantage of hierarchical architectures and ...2D alloy nanosheets simultaneously, with excellent catalytic performances for the oxygen reduction reaction.
Few‐layer black phosphorus (BP) is a promising semiconductor with excellent optoelectronic properties. However, the poor stabilization and strong asymmetry between electron and hole transports hinder ...the application of BP. Doping of heteroatoms is an effective strategy to regulate the electronic structure and stability of BP without sacrificing its unique 2D structure, which is a promising way to tune the physicochemical properties of BP for various applications. In this review, the recent advances in doping engineering of BP are summarized, involving the theoretical prediction of new characteristic for doped BP and the corresponding experimental synthesis methods. The effects of dopant atoms on the structure and performance of BP and its related applications, such as the field‐effect transistors, optoelectronic devices, inverter devices, and catalysis, are also summarized.
In this review, we summarize the preparation and application progress of heteroatom doped BP and look forward to the future challenges and opportunities.
We aimed to identify an unique host transcriptional signature in peripheral blood mononuclear cells (PBMCs) in response to
antigens to distinguish between patients with leprosy and non-leprosy ...controls for early diagnosis of the disease. Sixteen individuals were enrolled in the discovery cohort eight patients with leprosy, comprising four multibacillary (MB) and four paucibacillary (PB); and eight non-leprosy controls, comprising four healthy house contacts (HHCs) and four endemic controls (ECs). The differences in the transcriptome response of PBMCs to
sonicate antigen were evaluated between leprosy patients and non-leprosy controls, and 12 differentially expressed genes (
,
,
,
,
,
,
,
,
,
, and
) were identified. The accuracy of the 12 differentially expressed genes was further validated for the diagnosis of leprosy using real-time quantitative PCR in 82 individuals (13 MB, 10 PB, 37 HHCs, and 22 ECs) in the validation cohort. We found that a 5 gene signature set
,
,
,
and
had a suitable performance in discriminating leprosy from ECs. In addition, elevated expression of
,
,
and
was associated with MB diagnosis compared with ECs, whereas increased expression of
,
,
and
was found to be useful biomarkers for PB diagnosis from ECs. Moreover, we found decreased expression of
among leprosy patients could distinguish leprosy from HHCs, whereas higher expression of
among MB than PB could distinguish different leprosy patients. In conclusion, among the 12 candidate host genes identified, a three gene signature
, and
showed the best performance in distinguishing leprosy patients from healthy controls. These findings may have implications for developing a rapid blood-based test for early diagnosis of leprosy.
A highly active γ-Al 2 O 3 -supported Ru catalyst (Ru/γ-Al 2 O 3 -PHR) for Fischer–Tropsch synthesis (FTS) under mild conditions, with a catalytic activity of 13.0 mol CO mol Ru −1 h −1 at 423 K, was ...prepared by reducing γ-Al 2 O 3 -supported ruthenium oxide, RuO 2 · x H 2 O/γ-Al 2 O 3 , with hydrogen in water. It was found that the infrared absorption spectrum of CO adsorbed on Ru/γ-Al 2 O 3 -PHR is quite different from that of usual Ru catalysts, and CO adsorbed on Ru/γ-Al 2 O 3 -PHR tends to dissociate, revealing the reason for the high catalytic activity. The reduction conditions of RuO 2 · x H 2 O/γ-Al 2 O 3 have significant influences on the catalytic properties due to the formation of different surface structures of the alumina-supported Ru catalyst. The present work provides not only a way to improve the catalytic activity of supported ruthenium catalysts for FTS but also new information for understanding the high catalytic activity over Ru catalysts for FTS at relatively low temperatures.
To evaluate antigen-specific immune responses for leprosy diagnosis in a hyperendemic area in China.
Eighty-three leprosy patients and 161 non-leprosy controls were enrolled from Hani-yi Autonomous ...Prefecture of Honghe, Yunnan Province, China. Leprosy patients were divided into multibacillary (MB, n = 38), paucibacillary (PB, n = 23), and post-multi-drug therapy (MDT, n = 22) groups. Controls were divided into the following groups: healthy household contacts (HHC, n = 119), tuberculosis (TB, n = 11), and endemic controls (EC, n = 31). The NDO-LID Rapid Test, M. leprae antigen-specific ELISA and antigen-specific IFN-γ secretion in a whole blood assay (WBA) were used to evaluate these subjects.
The NDO-LID Rapid Test achieved higher positive response rates in MB than in PB patients94.7%(36/38) vs 65.2%(15/23), and these rates were higher than those observed by ELISA using anti-LID-192.1%(35/38) vs 52.2%(12/23), anti-NDO-LID92.1%(35/38) vs 47.8% (11/23), and anti-ND-O-BSA89.5%(34/38) vs 60.9%(14/23). However, the NDO-LID Rapid Test also showed a higher positive response rate in the EC group (33.3%,10/31), which was higher than the rates observed for anti-NDO-LID (12.9%,4/31) and anti-ND-O-BSA (16.1%,5/31). M. leprae antigen-specific ELISA demonstrated relatively high specificity (86.84-97.37%) but low sensitivity (15.97-72.73%) in discriminating between leprosy patients and non-leprosy controls by ROC curve analysis. In contrast, M. leprae antigen-specific IFN-γ secretion detection achieved higher positive response rates in PB than in MB patients (positive ratio of MB vs PB: 40% vs 56% for LID-1, 28.6% vs 47.8% for ML89, 31.4% vs 60.7% for ML2044, and 31.4 vs 47.8% for ML2028) and could distinguish MB from EC when stimulated with ML89(AUC = 0.6664) and PB fromTB when stimulated with ML2044 and ML2028(AUC = 0.7549 and 0.7372, respectively).
The NDO-LID Rapid Test and M. leprae antigen-specific ELISA are useful tools to assist in the diagnosis of leprosy patients, especially MB patients, although the former had higher sensitivity but lower specificity than the latter. M. leprae antigen-specific IFN-γ release assessed by WBA has diagnostic value for distinguishing PB from TB but not for distinguishing PB from HHC or EC. Screening novel M. leprae-specific antigens, combining different M. leprae antigens and a multi-cytokine analyte model may be needed for more effective diagnosis of leprosy.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This meta-analysis compared the long-term (12 months or 24 months) efficacy and safety of intravitreal aflibercept injection (IAI) for diabetic macular edema (DME) and proliferative diabetic ...retinopathy (PDR).
We selected 16 randomized controlled trials (RCTs) performed after 2015 that had a minimum of 12 months and up to 24 months of treatment and conducted a meta-analysis with Review Manager version 5.3. Visual acuity (VA), central subfield thickness (CST) and adverse events were the outcomes selected for evaluation from the eligible studies.
Based on 16 RCTs, we evaluated a total of 7125 patients. For PDR and severe DME with poor baseline vision, after a minimum of 12 months and up to 24 months of treatment, the aflibercept treatment group obtained better VA improvement than the focal/grid laser photocoagulation treatment group (MD=13.30; 95%CI: 13.01~13.58;
<0.001) or other treatments (ranibizumab, focal/grid laser photocoagulation, PRP, et al.) group (MD=1.10; 95%CI: 1.05~1.16;
<0.001). In addition, the aflibercept treatment group got higher CST reduction than the focal/grid laser photocoagulation treatment (MD=-33.76; 95%CI: -45.53 ~ -21.99;
<0.001) or other treatments (ranibizumab, focal/grid laser photocoagulation, et al.) group (MD=-33.76; 95%CI: -45.53 ~ -21.99;
<0.001). There was no significant difference in the overall incidence of ocular and non-ocular adverse events in each treatment group.
This meta-analysis showed that the advantages of IAI are obvious in the management of DME and PDR with poor baseline vision for long-term observation (a minimum of 12 months and up to 24 months) with both VA improvement and CST reduction. Applied IAI separately trended to be more effective than panretinal photocoagulation separately in VA improvement for PDR. More parameters should be required to assess functional and anatomic outcomes.
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