Viral exposure—the complete history
In addition to causing illness, viruses leave indelible footprints behind, because infection permanently alters the immune system. Blood tests that detect ...antiviral antibodies can provide information about both past and present viral exposures. Typically, such tests measure only one virus at a time. Using a synthetic representation of all human viral peptides, Xu
et al.
developed a blood test that identifies antibodies against all known human viruses. They studied blood samples from nearly 600 people of differing ages and geographic locations and found that most had been exposed to about 10 viral species over their lifetime. Despite differences in the rates of exposure to specific viruses, the antibody responses in most individuals targeted the same viral epitopes.
Science
, this issue
10.1126/science.aaa0698
A complete history of viral exposure over a lifetime can be deduced from a drop of blood.
Introduction
The collection of viruses found to infect humans can have profound effects on human health. In addition to directly causing acute or chronic illness, viral infection can alter host immunity in more subtle ways, leaving an indelible footprint on the immune system. This interplay between virome and host immunity has been implicated in the pathogenesis of complex diseases such as type 1 diabetes, inflammatory bowel disease, and asthma. Despite the growing appreciation for the importance of interactions between the virome and host, a comprehensive method to systematically characterize these interactions has yet to be developed.
Rationale
Current serological methods to detect viral infections are predominantly limited to testing one pathogen at a time and are therefore used primarily to address specific clinical hypotheses. A method that could simultaneously detect responses to all human viruses would allow hypothesis-free analysis to detect associations between past viral infections and particular diseases or population structures. Humoral responses to infection typically arise within 10 to 14 days of initial exposure and can persist over years or decades, thus providing a rich source of the history of pathogen encounters. In this work, we present VirScan, a high-throughput method that allows comprehensive analysis of antiviral antibodies in human sera. VirScan uses DNA microarray synthesis and bacteriophage display to create a uniform, synthetic representation of peptide epitopes comprising the human virome. Immunoprecipitation and high-throughput DNA sequencing reveal the peptides recognized by antibodies in the sample. The analysis requires less than 1 μl of blood.
Results
We screened sera from 569 human donors across four continents, assaying a total of over 10
8
antibody-peptide interactions for reactivity to 206 human viral species and >1000 strains. We found that VirScan’s performance in detecting known infections and distinguishing between exposures to related viruses is comparable to that of classical serum antibody tests for single viruses. We detected antibodies to an average of 10 viral species per person and 84 species in at least two individuals. Our approach maps antibody targets at 56–amino acid resolution, and our results nearly double the number of previously established viral B cell epitopes. Although rates of specific virus exposure varied depending on age, HIV status, and geographic location of the donor, we observed strong similarities in antibody responses across individuals. In particular, we found multiple instances of single peptides that were recurrently recognized by antibodies in the vast majority of donors. We performed tiling mutagenesis and found that these antibody responses targeted substantially conserved “public epitopes” for each virus, suggesting that antibodies with highly similar specificities, and possibly structures, are elicited across individuals.
Conclusion
VirScan is a method that enables human virome-wide exploration, at the epitope level, of immune responses in large numbers of individuals. We have demonstrated its effectiveness for determining viral exposure and characterizing viral B cell epitopes in high throughput and at high resolution. Our preliminary studies have revealed intriguing general properties of the human immune system, both at the individual and the population scale. VirScan may prove to be an important tool for uncovering the effect of host-virome interactions on human health and disease and could easily be expanded to include new viruses as they are discovered, as well as other human pathogens, such as bacteria, fungi, and protozoa.
Systematic viral epitope scanning (VirScan).
This method allows comprehensive analysis of antiviral antibodies in human sera. VirScan combines DNA microarray synthesis and bacteriophage display to create a uniform, synthetic representation of peptide epitopes comprising the human virome. Immunoprecipitation and high-throughput DNA sequencing reveal the peptides recognized by antibodies in the sample. The color of each cell in the heatmap depicts the relative number of antigenic epitopes detected for a virus (rows) in each sample (columns).
The human virome plays important roles in health and immunity. However, current methods for detecting viral infections and antiviral responses have limited throughput and coverage. Here, we present VirScan, a high-throughput method to comprehensively analyze antiviral antibodies using immunoprecipitation and massively parallel DNA sequencing of a bacteriophage library displaying proteome-wide peptides from all human viruses. We assayed over 10
8
antibody-peptide interactions in 569 humans across four continents, nearly doubling the number of previously established viral epitopes. We detected antibodies to an average of 10 viral species per person and 84 species in at least two individuals. Although rates of specific virus exposure were heterogeneous across populations, antibody responses targeted strongly conserved “public epitopes” for each virus, suggesting that they may elicit highly similar antibodies. VirScan is a powerful approach for studying interactions between the virome and the immune system.
Although two‐dimensional (2D) carbon materials are widely investigated, a well‐defined 2D carbon nanosheet with an ordered mesostructure has rarely been realized. Monolayer‐ordered mesoporous carbon ...nanosheets (OMCNS) were prepared through confinement assembly of resol and F127 in the interlayer of montmorillonite (MONT). The nanoscale distance of the interlayer space of MONT only allow the assembly of resol and F127 in the same plane, leading to ordered mesopores perpendicular to carbon nanosheets, and favor the formation of sp2 carbon, resulting in a high degree of graphitization. The mesopores on the carbon nanosheets provide efficient ion diffusion, and the high degree of graphitization provides a fast electron‐transport route, enabling OMCNS as excellent electrode materials for electric double layer capacitors.
Ordered mesoporous carbon nanosheets (OMCNS) were prepared through confinement assembly of resol (see picture: blue) and F127 (yellow) in the interlayer of montmorillonite (MONT). The nanoscale interlayer space of MONT only allows the assembly of resol and F127 in the same plane, leading to ordered mesopores perpendicular to carbon nanosheets after carbonization.
Abstract
We describe a
Herschel Space Observatory
194–671
μ
m spectroscopic survey of a sample of 121 local luminous infrared galaxies and report the fluxes of the CO
J
to
J
–1 rotational transitions ...for
, the N
ii
205
μ
m line, the C
i
lines at 609 and 370
μ
m, as well as additional and usually fainter lines. The CO spectral line energy distributions (SLEDs) presented here are consistent with our earlier work, which was based on a smaller sample, that calls for two distinct molecular gas components in general: (i) a cold component, which emits CO lines primarily at
J
≲ 4 and likely represents the same gas phase traced by CO (1−0), and (ii) a warm component, which dominates over the mid-
J
regime (4 <
J
≲ 10) and is intimately related to current star formation. We present evidence that the CO line emission associated with an active galactic nucleus is significant only at
J
> 10. The flux ratios of the two C
i
lines imply modest excitation temperatures of 15–30 K; the C
i
370
μ
m line scales more linearly in flux with CO (4−3) than with CO (7−6). These findings suggest that the C
i
emission is predominantly associated with the gas component defined in (i) above. Our analysis of the stacked spectra in different far-infrared (FIR) color bins reveals an evolution of the SLED of the rotational transitions of
vapor as a function of the FIR color in a direction consistent with infrared photon pumping.
Traditional imaging systems exhibit a well-known trade-off between the resolution and the field of view of their captured images. Typical cameras and microscopes can either "zoom in" and image at ...high-resolution, or they can "zoom out" to see a larger area at lower resolution, but can rarely achieve both effects simultaneously. In this review, we present details about a relatively new procedure termed Fourier ptychography (FP), which addresses the above trade-off to produce gigapixel-scale images without requiring any moving parts. To accomplish this, FP captures multiple low-resolution, large field-of-view images and computationally combines them in the Fourier domain into a high-resolution, large field-of-view result. Here, we present details about the various implementations of FP and highlight its demonstrated advantages to date, such as aberration recovery, phase imaging, and 3D tomographic reconstruction, to name a few. After providing some basics about FP, we list important details for successful experimental implementation, discuss its relationship with other computational imaging techniques, and point to the latest advances in the field while highlighting persisting challenges.
The exploration of a new family of materials with superior performance for capacitive deionization (CDI) compared to commercial activated carbons is of significant interest. In this work, a ...three-dimensional (3D) nanoarchitecture composed of metal–organic frameworks (MOFs) interwoven by carbon nanotubes (CNTs) has been synthesized by utilizing CNTs to bridge the neighboring MOF nanocrystals. The resulting MOF/CNT hybrid not only shows improved electrical conductivity and 3D hierarchical structure but also retains the high porosity of MOFs. Consequently, the MOF/CNT hybrid exhibits a high desalination capacity of 16.90 mg g–1, highlighting the potential of noncarbonized MOF-based materials as CDI electrodes.
Polychlorinated biphenyls (PCBs) were not widely manufactured or used in China before they became the subject of international bans on production. Recent work has shown that they have reached China ...associated with imported wastes and that there are considerable unintentional sources of PCBs that have only recently been identified. As such, it was hypothesized that the source inventory and profile of PCBs may be different or unique in China, compared to countries where they were widely used and which have been widely studied. For the first time in this study, we undertook a complete analysis of 209 PCB congeners and assessed the contribution of unintentionally produced PCBs (UP-PCBs) in the atmosphere of China, using polyurethane foam passive air samplers (PUF-PAS) deployed across a wide range of Chinese locations. ∑209 PCBs ranged from 9 to 6856 pg/m3 (median: 95 pg/m3) during three deployments in 2016–2017. PCB 11 was one of the most detected congeners, contributing 33 ± 19% to ∑209 PCBs. The main sources to airborne PCBs in China were estimated and ranked as pigment/painting (34%), metallurgical industry/combustion (31%), e-waste (23%), and petrochemical/plastic industry (6%). For typical Aroclor-PCBs, e-waste sources were dominated (>50%). Results from our study indicate that UP-PCBs have become the controlling source in the atmosphere of China, and an effective control strategy is urgently needed to mitigate emissions from multiple industrial sources.
Abstract Nerve guide scaffolds from block polyurethanes without any additional growth factors or protein were prepared using a particle leaching method. The scaffolds of block polyurethanes ...(abbreviated as PUCL- ran -EG) based on poly(ɛ-caprolactone) (PCL-diol) and poly(ethylene glycol) (PEG) possess highly surface-area porous for cell attachment, and can provide biochemical and topographic cues to enhance tissue regeneration. The nerve guide scaffolds have pore size 1–5 μm and porosity 88%. Mechanical tests showed that the polyurethane nerve guide scaffolds have maximum loads of 4.98 ± 0.35 N and maximum stresses of 6.372 ± 0.5 MPa. The histocompatibility efficacy of these nerve guide scaffolds was tested in a rat model for peripheral nerve injury treatment. Four types of guides including PUCL- ran -EG scaffolds, autograft, PCL scaffolds and silicone tubes were compared in the rat model. After 14 weeks, bridging of a 10 mm defect gap by the regenerated nerve was observed in all rats. The nerve regeneration was systematically characterized by sciatic function index (SFI), histological assessment including HE staining, immunohistochemistry, ammonia silver staining, Masson's trichrome staining and TEM observation. Results revealed that polyurethane nerve guide scaffolds exhibit much better regeneration behavior than PCL, silicone tube groups and comparable to autograft. Electrophysiological recovery was also seen in 36%, 76%, and 87% of rats in the PCL, PUCL- ran -EG, and autograft groups respectively, whilst 29.8% was observed in the silicone tube groups. Biodegradation in vitro and in vivo show proper degradation of the PUCL- ran -EG nerve guide scaffolds. This study has demonstrated that without further modification, plain PUCL- ran -EG nerve guide scaffolds can help peripheral nerve regeneration excellently.
On the H i Content of MaNGA Major Merger Pairs Yu, Qingzheng; Fang, Taotao; Feng, Shuai ...
Astrophysical journal/The Astrophysical journal,
08/2022, Letnik:
934, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Abstract
The role of H
i
content in galaxy interactions is still under debate. To study the H
i
content of galaxy pairs at different merging stages, we compile a sample of 66 major-merger galaxy ...pairs and 433 control galaxies from the Sloan Digital Sky Survey IV (SDSS-IV) MaNGA IFU survey. In this study, we adopt kinematic asymmetry as a new effective indicator to describe the merging stage of galaxy pairs. With archival data from the HI-MaNGA survey and new observations from the Five-hundred-meter Aperture Spherical radio Telescope (FAST), we investigate the differences in H
i
gas fraction (
f
H I
), star formation rate (SFR), and H
i
star formation efficiency (SFE
H I
) between the pair and control samples. Our results suggest that the H
i
gas fraction of major-merger pairs on average is marginally decreased by ∼15% relative to isolated galaxies, implying mild H
i
depletion during galaxy interactions. Compared to isolated galaxies, pre-passage paired galaxies have similar
f
H I
, SFR, and SFE
H I
, while pairs during the pericentric passage have weakly decreased
f
H I
(−0.10 ± 0.05 dex), significantly enhanced SFR (0.42 ± 0.11 dex), and SFE
H I
(0.48 ± 0.12 dex). When approaching the apocenter, paired galaxies show marginally decreased
f
H I
(−0.05 ± 0.04 dex), comparable SFR (0.04 ± 0.06 dex), and SFE
H I
(0.08 ± 0.08 dex). We propose that the marginally detected H
i
depletion may originate from the gas consumption in fueling the enhanced H
2
reservoir of galaxy pairs. In addition, new FAST observations also reveal a H
i
absorber (
N
H I
∼ 4.7 × 10
21
cm
−2
), which may suggest gas infalling and the triggering of active galactic nuclei activity.
ABSTRACT
The gas needed to sustain star formation in galaxies is supplied by the circumgalactic medium (CGM), which in turn is affected by accretion from large scales. In a series of two papers, we ...examine the interplay between a galaxy’s ambient CGM and central star formation within the context of the large-scale environment. We use the IllustrisTNG-100 simulation to show that the influence exerted by the large-scale galaxy environment on the CGM gas angular momentum results in either enhanced (Paper I) or suppressed (Paper II, this paper) star formation inside a galaxy. We find that for present-day quenched galaxies, both the large-scale environments and the ambient CGM have always had higher angular momenta throughout their evolutionary history since at least $z$ = 2, in comparison to those around present-day star-forming disc galaxies, resulting in less efficient gas inflow into the central star-forming gas reservoirs. A sufficiently high CGM angular momentum, as inherited from the larger-scale environment, is thus an important factor in keeping a galaxy quenched, once it is quenched. The process above naturally renders two key observational signatures: (1) a coherent rotation pattern existing across multiple distances from the large-scale galaxy environment, to the circumgalactic gas, to the central stellar disc; and (2) an anticorrelation between galaxy star-formation rates and orbital angular momenta of interacting galaxy pairs or groups.
We present results of a statistical study of the cosmic evolution of the mass-dependent major-merger rate since z = 1. A stellar mass limited sample of close major-merger pairs (the CPAIR sample) was ...selected from the archive of the COSMOS survey. Pair fractions at different redshifts derived using the CPAIR sample and a local K-band-selected pair sample show no significant variations with stellar mass. The pair fraction exhibits moderately strong cosmic evolution, with the best-fitting function of functionof sub(pair) = 10 super(-1.88(+ or - 0.03))(1 + z) super(2.2(+ or - 0.2)). The best-fitting function for the merger rate is R sub(mg) (Gyr super(-1)) = 0.053 x (M sub(star)/10 super(10.7) M sub(middot in circle)) super(0.3)(1 + z) super(2.2)/(1 + z/8). This rate implies that galaxies of M sub(star) ~ 10 super(10)-10 super(11.5) M sub(middot in circle) have undergone ~0.5-1.5 major mergers since z = 1. Our results show that, for massive galaxies (M sub(star) > or =, slanted 10 super(10.5) M sub(middot in circle)) at z < or =, slant 1, major mergers involving star-forming galaxies (i.e., wet and mixed mergers) can account for the formation of both ellipticals and red quiescent galaxies (RQGs). On the other hand, major mergers cannot be responsible for the formation of most low mass ellipticals and RQGs of M sub(star) <, ~ 10 super(10.3) M sub(middot in circle). Our quantitative estimates indicate that major mergers have significant impact on the stellar mass assembly of the most massive galaxies (M sub(star) > or =, slanted 10 super(11.3) M sub(middot in circle)), but for less massive galaxies the stellar mass assembly is dominated by the star formation. Comparison with the mass-dependent (ultra)luminous infrared galaxies ((U)LIRG) rates suggests that the frequency of major-merger events is comparable to or higher than that of (U)LIRGs.
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