Summary Intervertebral disc (IVD) degeneration is a complicated process that involves both age-related change and tissue damage caused by multiple stresses. In a degenerative IVD, cellular senescence ...accumulates and is associated with reduced proliferation, compromised self-repair, increased inflammatory response, and enhanced catabolic metabolism. In this review, we decipher the senescence mechanism of IVD degeneration (IVDD) by interpreting how aging coordinates with age-related, microenvironment-derived stresses in promoting disc cell senescence and accelerating IVDD. After chronic and prolonged replication, cell senescence may occur as a natural part of the disc aging process, but can potentially be accelerated by growth factor deficiency, oxidative accumulation, and inflammatory irritation. While acute disc injury, excessive mechanical overloading, diabetes, and chronic tobacco smoking contribute to the amplification of senescence-inducing stresses, the avascular nature of IVD impairs the immune-clearance of the senescent disc cells, which accumulate in cell clusters, demonstrate inflammatory and catabolic phenotypes, deteriorate disc microenvironment, and accelerate IVDD. Anti-senescence strategies, including telomerase transduction, supply of growth factors, and blocking cell cycle inhibitors, have been shown to be feasible in rescuing disc cells from early senescence, but their efficiency for disc regeneration requires more in vivo validations. Guidelines dedicated to avoiding or alleviating senescence-inducing stresses might decelerate cellular senescence and benefit patients with IVD degenerative diseases.
Accumulation of organic wastes, especially in livestock facilities, can be a potential pollution issue. The black soldier fly, Hermetia illucens L. (Diptera: Stratiomyidae), can consume a wide range ...of organic material and has the potential to be used in waste management. In addition, the prepupae stage of this insect can be harvested and used as a valuable nutritious feed for animal livestock. Five waste types with a wide range of organic source matter were specifically chosen to evaluate the consumption and reduction ability of black soldier fly larvae. H. illucens was able to reduce all waste types examined: 1) control poultry feed, 2) pig liver, 3) pig manure, 4) kitchen waste, 5) fruits and vegetables, and 6) rendered fish. Kitchen waste had the greatest mean rate of reduction (consumption by black soldier fly) per day and produced the longest and heaviest black soldier flies. Larvae reared on liver, manure, fruits and vegetables, and fish were approximately the same length and weight as larvae fed the control feed, although some diets produced larvae with a higher nutritional content. The black soldier fly has the ability to consume and reduce organic waste and be utilized as valuable animal feed. Exploration of the potential use of black soldier flies as an agent for waste management on a large-scale system should continue.
This study is the first in a series of papers that aim to develop high-resolution emission databases for different anthropogenic sources in China. Here we focus on on-road transportation. Because of ...the increasing impact of on-road transportation on regional air quality, developing an accurate and high-resolution vehicle emission inventory is important for both the research community and air quality management. This work proposes a new inventory methodology to improve the spatial and temporal accuracy and resolution of vehicle emissions in China. We calculate, for the first time, the monthly vehicle emissions for 2008 in 2364 counties (an administrative unit one level lower than city) by developing a set of approaches to estimate vehicle stock and monthly emission factors at county-level, and technology distribution at provincial level. We then introduce allocation weights for the vehicle kilometers traveled to assign the county-level emissions onto 0.05° × 0.05° grids based on the China Digital Road-network Map (CDRM). The new methodology overcomes the common shortcomings of previous inventory methods, including neglecting the geographical differences between key parameters and using surrogates that are weakly related to vehicle activities to allocate vehicle emissions. The new method has great advantages over previous methods in depicting the spatial distribution characteristics of vehicle activities and emissions. This work provides a better understanding of the spatial representation of vehicle emissions in China and can benefit both air quality modeling and management with improved spatial accuracy.
A complex of a metal in its zero oxidation state can be considered a stabilized, but highly reactive, form of a single metal atom. Such complexes are common for the more noble transition metals. ...Although rare examples are known for electronegative late-main-group p-block metals or semimetals
, it is a challenge to isolate early-main-group s-block metals in their zero oxidation state
. This is directly related to their very low electronegativity and strong tendency to oxidize. Here we present examples of zero-oxidation-state magnesium (that is, magnesium(0)) complexes that are stabilized by superbulky, monoanionic, β-diketiminate ligands. Whereas the reactivity of an organomagnesium compound is typically defined by the nucleophilicity of its organic groups and the electrophilicity of Mg
cations, the Mg
complexes reported here feature electron-rich Mg centres that are nucleophilic and strongly reducing. The latter property is exemplified by the ability to reduce Na
to Na
. We also present a complex with a linear Mg
core that formally could be described as a Mg
-Mg
-Mg
unit. Such multinuclear mixed-valence Mg
clusters are discussed as fleeting intermediates during the early stages of Grignard reagent formation. Their remarkably strong reducing power implies a rich reactivity and application as specialized reducing agents.
Summary
Porcine reproductive and respiratory syndrome virus (PRRSV) is a major economically significant pathogen that has adversely affected China's swine industry. Currently, a novel type 2 PRRSV, ...called the NADC30‐like strain, is epidemic in numerous provinces of China, and commercial vaccines provide limited protection for infected animals. The extensive recombination phenomenon among NADC30‐like PRRSVs is identified as a unique molecular characteristic of the virus. However, our understanding of how recombination influences NADC30‐like PRRSVs is largely inadequate. In this study, we analysed the genetic characteristics of a recombinant NADC30‐like PRRSV (SC‐d) and examined its pathogenicity compared with a non‐recombinant NADC30‐like PRRSV (SD‐A19) and a highly pathogenic PRRSV (HuN4). SC‐d has three discontinuous deletions in nsp2, consistent with NADC30 isolated from the United States in 2008. Furthermore, we identified four recombination breakpoints in the SC‐d genome, which separated the SC‐d genome into four regions (regions A, B, C and D). Regions A and C are closely related to the JXA1‐like strain, one of the earliest Chinese HP‐PRRSV strains, and regions B and D are closely related to the NADC30 strain. Moreover, SC‐d inoculated piglets exhibited a persistent fever, moderate weight loss, mild thymus atrophy and obvious microscopic lung lesions. In summary, the recombinant NADC30‐like PRRSV SC‐d strain displayed a higher pathogenicity than the non‐recombinant NADC30‐like PRRSV SD‐A19 strain; however, the pathogenicity of the NADC30‐like PRRSV SC‐d was lower compared with the HP‐PRRSV HuN4 strain in piglets. Our findings demonstrate that recombination is responsible for the enormous genetic diversity and pathogenicity variance of the NADC30‐like PRRSV in China. This study provides a theoretical basis for developing a more reasonable PRRSV control and prevention strategy.
We report the experimental generation of highly energetic carbon ions up to 48 MeV per nucleon by shooting double-layer targets composed of well-controlled slightly underdense plasma and ultrathin ...foils with ultraintense femtosecond laser pulses. Particle-in-cell simulations reveal that carbon ions are ejected from the ultrathin foils due to radiation pressure and then accelerated in an enhanced sheath field established by the superponderomotive electron flow. Such a cascaded acceleration is especially suited for heavy ion acceleration with femtosecond laser pulses. The breakthrough of heavy ion energy up to many tens of MeV/u at a high repetition rate would be able to trigger significant advances in nuclear physics, high energy density physics, and medical physics.
Aim
Magnetic resonance imaging (MRI), endorectal ultrasound (EUS) and computed tomography (CT) are commonly used to evaluate lymph node (LN) metastasis for rectal cancer, but there is no agreement on ...which form of imaging is most accurate. The study aimed to review systematically the diagnostic performance of the three imaging modalities.
Method
The PubMed, Cochrane Library and EMBASE databases were systematically searched for English and Chinese language studies evaluating the diagnostic accuracy of MRI, EUS and/or CT for evaluating LN metastasis. Papers published before 31 December 2013 were included in the search. Subject‐level data were included. Diagnostic odds ratios were calculated for each modality and summary receiver operating characteristic curves were constructed using hierarchical regression models. The performance of the three modalities was compared.
Results
The analysis included data from 123 studies evaluating LN metastasis. The sensitivity and specificity in patients having no chemoradiotherapy were 0.77 and 0.76 for MRI, 0.57 and 0.80 for EUS and 0.79 and 0.76 for CT. The three modalities showed similar accuracy (P = 0.39). MRI showed higher accuracy than EUS for patients who received neoadjuvant therapy (P = 0.04). MRI at a field strength > 1.5 T yielded better performance than EUS (P = 0.03) and similar performance to CT (P = 0.17). High resolution MRI showed similar diagnostic accuracy to EUS (P = 0.18) and CT (P = 0.16).
Conclusion
MRI, EUS and CT show similar accuracy but none could provide reliable evaluation for LN metastasis. MRI rather than EUS is recommended for LN evaluation after neoadjuvant therapy. MRI at a field strength of 3.0 T is the recommended method for MRI examination. But high resolution MRI does not improve the diagnostic performance in evaluating LN metastasis.
Following our first detection reported in Izotov et al., we present the detection of Lyman continuum (LyC) radiation of four other compact star-forming galaxies observed with the Cosmic Origins ...Spectrograph (COS) onboard the Hubble Space Telescope. These galaxies, at redshifts of z ∼ 0.3, are characterized by high emission-line flux ratios O iii λ5007/O ii λ3727 ≳ 5. The escape fractions of the LyC radiation f
esc(LyC) in these galaxies are in the range of ∼6–13 per cent, the highest values found so far in low-redshift star-forming galaxies. Narrow double-peaked Ly α emission lines are detected in the spectra of all four galaxies, compatible with predictions for LyC leakers. We find escape fractions of Ly α, f
esc(Ly α) ∼ 20–40 per cent, among the highest known for Ly α emitting galaxies. Surface brightness profiles produced from the COS acquisition images reveal bright star-forming regions in the centre and exponential discs in the outskirts with disc scalelengths α in the range ∼0.6–1.4 kpc. Our galaxies are characterized by low metallicity, ∼1/8–1/5 solar, low stellar mass ∼(0.2–4) × 109 M⊙, high star formation rates, SFR ∼ 14–36 M⊙ yr−1, and high SFR densities, Σ ∼ 2–35 M⊙ yr−1 kpc−2. These properties are comparable to those of high-redshift star-forming galaxies. Finally, our observations, combined with our first detection reported in Izotov et al., reveal that a selection for compact star-forming galaxies showing high O iii λ5007/O ii λ3727 ratios appears to pick up very efficiently sources with escaping LyC radiation: all five of our selected galaxies are LyC leakers.
Here we report that attempted preparation of low-valent Ca
complexes in the form of LCa-CaL (where L is a bulky β-diketiminate ligand) under dinitrogen (N
) atmosphere led to isolation of LCa(N
)CaL, ...which was characterized crystallographically. The N
- anion in this complex reacted in most cases as a very potent two-electron donor. Therefore, LCa(N
)CaL acts as a synthon for the low-valent Ca
complex LCa-CaL, which was the target of our studies. The N
- anion could also be protonated to diazene (N
H
) that disproportionated to hydrazine and N
The role of Ca d orbitals for N
activation is discussed.
Background
IL‐25 has been proposed to play a key role in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP). This study aimed to evaluate the association of IL‐25 with the ...Th2‐biased inflammatory profiles in CRSwNP.
Methods
Nasal polyp (NP) tissues and control uncinate process tissues were collected from 92 patients with CRSwNP, 20 patients with chronic rhinosinusitis without nasal polyps (CRSsNP), and 16 normal control subjects. IL‐25 expression was examined using immunohistochemistry and immunofluorescence staining, flow cytometry, RT‐qPCR, and ELISA. The inflammatory profiles and clinical characteristics of 2 NP subtypes (IL‐25high and IL‐25low) were evaluated, and the effects of IL‐25 on Th2 cytokine production in cultured dispersed polyp cells were examined in vitro.
Results
The mRNA and protein levels of IL‐25 were significantly increased in the polyp tissues compared with the control uncinate process tissues. The IL‐25high subtype showed greater computed tomography scores, endoscopic scores, and Th2 response. Exposure to IL‐25 activated type 2 innate lymphoid cells and Th2 cells in NP simultaneously which further increased Th2 cytokine production in vitro.
Conclusions
Local IL‐25 plays a crucial role in promoting Th2‐biased inflammatory profiles in NP and may serve as a promising therapeutic target in CRSwNP patients.
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