Herein, a novel near-infrared (NIR) self-powered photoelectrochemical platform was constructed based on nonmetallic plasmon Ti3C2 MXene coupled with sulphur vacancy engineered Bi2S3. The continuous ...photoelectron injection from Bi2S3 to Ti3C2 MXene induced a stable SPR effect and high photoelectric conversion efficiency, which is beneficial for developing high-performance NIR self-powered biosensors. As a proof of concept, a sensitive NIR self-powered sensor was constructed by conjunction with an aptamer using Microcystin-RR as a model analyte, which is one of the most common and toxic hepatotoxins released by cyanobacteria.
Wound with drug‐resistant bacterial infections has become a serious challenge for the healthcare system, and designing wound dressing to self‐adapt to the need of different stage of wound healing ...remains challenging. Herein, self‐adaptive wound dressings with multiple stimuli‐responsiveness and antibacterial activity are developed. Specifically, MoS2 carrying a reactive oxygen species (ROS) responsive nitric oxide (NO) release precursor L‐arginine (MSPA) is designed and incorporated into carboxymethyl chitosan/poly(N‐isopropylacrylamide) based cryogels (CMCS/PNIPAM) with multiple responsiveness (pH, near infrared (NIR), and temperature) to form self‐adaptive antibacterial cryogels that adapt to the therapeutic needs of different stages in infected wound healing. In response to the slightly acidic environment of bacterial infection, the cryogels assist the bacterial capture capacity through acid‐triggered protonation behavior, and effectively enhance the photodynamic antibacterial efficiency. Controllable on‐demand delivery of ROS, NO, and remote management of infected biofluid are achieved with NIR light as a trigger switch. The multiple stimuli‐responsive nanozyme‐based cryogels efficiently eliminate MRSA bacterial biofilm through NO assisted photodynamicand photothermal therapy (PDT&PTT). The multiple enzyme‐like activities of the cryogels effectively relieved oxidative damage. Notably, these cryogels effectively reduce wound infection, alleviated oxidative stress, and accelerate collagen deposition and angiogenesis in infected wounds, indicating that multiple stimuli‐responsive self‐adaptive wound dressings provide new ideas for infected wound treatment.
Self‐adaptive wound dressings are proposed and designed based on MoS2 carrying a reactive oxygen species‐responsive NO release precursor L‐arginine and carboxymethyl chitosan/poly(N‐isopropylacrylamide) based cryogels. These self‐adaptive wound dressings with multiple stimuli‐responsiveness and NO assisted photodynamicand photothermal antibacterial activity can meet the need of different stage of wound healing and offer new approach for infected wound treatment.
Long persistent luminescence (LPL) materials have a unique photophysical mechanism to store light radiation energy for subsequent release. However, in comparison to the common UV source, white‐light ...(WL) and near‐infrared (NIR) excited LPL is scarce. Herein we report a metal–organic supramolecular box based on a D–π–A‐type ligand. Owing to the integrated one‐photon absorption (OPA) and two‐photon absorption (TPA) attributes of the ligand, the heavy‐atom effect of the metal center, as well as π‐stacking and J‐aggregation states in the supramolecular assembly, LPL can be triggered by all wavebands from the UV to the NIR region. This novel designed supramolecular kit to afford LPL by both OPA and TPA pathways provides potential applications in anti‐counterfeiting, camouflaging, decorating, and displaying, among others.
All paths lead to Rome: By the careful design of a donor–π–acceptor ligand with both one‐ and two‐photon absorption attributes (OPA and TPA), LPL could be triggered in an assembled metal–organic supramolecular box through either OPA or TPA pathways by several wavebands of light: UV, white (WL), and NIR (see picture). Such systems have potential for a range of applications, including anti‐counterfeiting, camouflaging, decorating, and displays.
ABSTRACT We performed a comprehensive stacking analysis on ∼14,200 quiescent galaxy (QG) candidates at z = 0-3 across mid-, far-infrared (MIR and FIR), and radio wavelengths. Identified via their ...rest-frame NUV − r and r − J colors, the QG candidates ( ) have drastically different IR and radio properties depending on their 24 m emission strength. The fraction of QG candidates with strong 24 m emission (equivalent to inferred star formation rates SFR , hereafter "IR-bright") increases with redshift and peaks at 15%, and their stacked MIPS 24 m, Herschel (PACS and SPIRE) and VLA emissions are consistent with being star-forming galaxies (SFGs). In contrast, the majority of QG candidates are faint or undetected at 24 m individually (i.e., SFR24 < 100 M yr−1, hereafter "IR-faint"). Their low dust-obscured SFRs derived from Herschel stacking (SFRH 3, 15, 50 M yr−1 out to z ∼ 1, 2, 3) are >2.5-12.5× lower than compared to SFGs. This is consistent with the quiescence, as expected from their low unobscured SFRs, as inferred from modeling their ultraviolet-to-NIR photometry. The discrepancy between the LIR derived from stacking Herschel and 24 m indicates that IR-faint QGs have dust SEDs that are different from those of SFGs. For the most massive ( ) IR-faint QGs at z < 1.5, the stacked 1.4 GHz emission is in excess of that expected from other SFR indicators, suggesting a widespread presence of low-luminosity active galactic nuclei. Our results reaffirm the existence of a significant population of QGs out to z = 3, thus corroborating the need to quench star formation in galaxies at early epochs.
Light scattering by biological tissues sets a limit to the penetration depth of high-resolution optical microscopy imaging of live mammals in vivo. An effective approach to reduce light scattering ...and increase imaging depth is to extend the excitation and emission wavelengths to the second near-infrared window (NIR-II) at >1,000 nm, also called the short-wavelength infrared window. Here we show biocompatible core-shell lead sulfide/cadmium sulfide quantum dots emitting at ~1,880 nm and superconducting nanowire single-photon detectors for single-photon detection up to 2,000 nm, enabling a one-photon excitation fluorescence imaging window in the 1,700-2,000 nm (NIR-IIc) range with 1,650 nm excitation-the longest one-photon excitation and emission for in vivo mouse imaging so far. Confocal fluorescence imaging in NIR-IIc reached an imaging depth of ~1,100 μm through an intact mouse head, and enabled non-invasive cellular-resolution imaging in the inguinal lymph nodes of mice without any surgery. We achieve in vivo molecular imaging of high endothelial venules with diameters as small as ~6.6 μm, as well as CD169 + macrophages and CD3 + T cells in the lymph nodes, opening the possibility of non-invasive intravital imaging of immune trafficking in lymph nodes at the single-cell/vessel-level longitudinally.
In a multiwavelength survey of 13 quasars at 5.8 z 6.5, which were preselected to be potentially young, we find five objects with extremely small proximity zone sizes that may imply UV-luminous ...quasar lifetimes of 100,000 yr. Proximity zones are regions of enhanced transmitted flux in the vicinity of quasars that are sensitive to the quasars' lifetimes because the intergalactic gas has a finite response time to their radiation. We combine submillimeter observations from the Atacama Large Millimetre Array and the NOrthern Extended Millimeter Array, as well as deep optical and near-infrared spectra from the medium-resolution spectrograph on the Very Large Telescope and on the Keck telescopes, in order to identify and characterize these new young quasars, which provide valuable clues about the accretion behavior of supermassive black holes in the early universe and pose challenges on current black hole formation models to explain the rapid formation of billion-solar-mass black holes. We measure the quasars' systemic redshifts, black hole masses, Eddington ratios, emission-line luminosities, and star formation rates of their host galaxies. Combined with previous results, we estimate the fraction of young objects within the high-redshift quasar population at large to be 5% fyoung 10%. One of the young objects, PSO J158-14, shows a very bright dust continuum flux (Fcont = 3.46 0.02 mJy), indicating a highly starbursting host galaxy with a star formation rate of approximately 1420 M yr−1.
A new kind of ultrafast near-infrared light responsive shape memory assisted self-healing polymer composite was prepared by introducing polydopamine particles (PDAPs) into polyurethane containing ...Diels–Alder bonds. The mechanical properties of the polyurethane composites are significantly enhanced with the addition of PDAPs due to the strong interface interaction between PDAPs and polyurethane segments. Owing to the outstanding photothermal effect of PDAPs and excellent dynamic properties of Diels–Alder bonds, the composites possess rapid light responsive shape memory and self-healing properties. The shape memory ability of the materials also plays an important role in improving the self-healing efficiency. Due to the excellent dispersion and easy preparation method, PDAPs have great potential to be used as high-efficiency and environmentally friendly fillers to obtain novel photoactive functional polymer composites.
We study the composition of the faint radio population selected from the Karl G. Jansky Very Large Array Cosmic Evolution Survey (VLA-COSMOS) 3 GHz Large Project, which is a radio continuum survey ...performed at 10 cm wavelength. The survey covers a 2.6 square degree area with a mean rms of ~ 2.3 μJy/beam, cataloging 10 830 sources above 5σ, and enclosing the full 2 square degree COSMOS field. By combining these radio data with optical, near-infrared (UltraVISTA), and mid-infrared (Spitzer/IRAC) data, as well as X-ray data (Chandra), we find counterparts to radio sources for ~93% of the total radio sample reaching out to z ≲ 6; these sources are found in the unmasked areas of the COSMOS field, i.e., those not affected by saturated or bright sources in the optical to near-infrared (NIR) bands. We further classify the sources as star-forming galaxies or AGN based on various criteria, such as X-ray luminosity; observed mid-infrared color; UV–far-infrared spectral energy distribution; rest-frame, near-UV optical color that is corrected for dust extinction; and radio excess relative to that expected from the star formation rate of the hosts. We separate the AGN into subsamples dominated by low-to-moderate and moderate-to-high radiative luminosity AGN, i.e., candidates for high-redshift analogs to local low- and high-excitation emission line AGN, respectively. We study the fractional contributions of these subpopulations down to radio flux levels of ~11 μJy at 3 GHz (or ~20 μJy at 1.4 GHz assuming a spectral index of –0.7). We find that the dominant fraction at 1.4 GHz flux densities above ~200 μJy is constituted of low-to-moderate radiative luminosity AGN. Below densities of ~100 μJy the fraction of star-forming galaxies increases to ~ 60%, followed by the moderate-to-high radiative luminosity AGN (~ 20%) and low-to-moderate radiative luminosity AGN (~ 20%). Based on this observational evidence, we extrapolate the fractions down to sensitivities of the Square Kilometer Array (SKA). Our estimates suggest that at the faint flux limits to be reached by the (Wide, Deep, and UltraDeep) SKA1 surveys, a selection based only on radio flux limits can provide a simple tool to efficiently identify samples highly (>75%) dominated by star-forming galaxies.
imaging is a powerful approach to study biological processes. Beyond cellular methods,
studies allow for biological stimuli (small molecules or proteins) to be studied in their native environment. ...This has the potential to aid in the discovery of new biology and guide the development of diagnostics and therapies for diseases. To ensure selectivity and an observable readout, the probe development field is shifting towards activity-based sensing (ABS) approaches and near-infrared (NIR) imaging modalities. This perspective will highlight recent
ABS applications that utilize NIR imaging platforms.
Abstract
The Nancy Grace Roman Space Telescope will conduct a High Latitude Spectroscopic Survey (HLSS) over a large volume at high redshift, using the near-IR grism (1.0–1.93
μ
m,
R
= 435–865) and ...the 0.28 deg
2
wide-field camera. We present a reference HLSS that maps 2000 deg
2
and achieves an emission-line flux limit of 10
−16
erg s
−1
cm
−2
at 6.5
σ
, requiring ∼0.6 yr of observing time. We summarize the flowdown of the Roman science objectives to the science and technical requirements of the HLSS. We construct a mock redshift survey over the full HLSS volume by applying a semianalytic galaxy formation model to a cosmological
N
-body simulation and use this mock survey to create pixel-level simulations of 4 deg
2
of HLSS grism spectroscopy. We find that the reference HLSS would measure ∼10 million H
α
galaxy redshifts that densely map large-scale structure at
z
= 1–2 and 2 million O
iii
galaxy redshifts that sparsely map structures at
z
= 2–3. We forecast the performance of this survey for measurements of the cosmic expansion history with baryon acoustic oscillations and the growth of large-scale structure with redshift-space distortions. We also study possible deviations from the reference design and find that a deep HLSS at
f
line
> 7 × 10
−17
erg s
−1
cm
−2
over 4000 deg
2
(requiring ∼1.5 yr of observing time) provides the most compelling stand-alone constraints on dark energy from Roman alone. This provides a useful reference for future optimizations. The reference survey, simulated data sets, and forecasts presented here will inform community decisions on the final scope and design of the Roman HLSS.
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