Context. Photochemical escape of hot atoms is crucial to the long-term evolution of the Martian climate. For atomic C and N, photochemical escape is primarily driven by photodissociation (PD) of CO ...and N2. Aims. Combining the Mars Atmosphere and Volatile Evolution (MAVEN) measurements of atmospheric neutral densities and solar EUV/X-ray irradiance, we perform a state-of-the-art analysis of atomic C and N escape on Mars. Methods. For each MAVEN orbit, we calculated the hot C and N production rates in the dayside Martian upper atmosphere via PD, from which the escape rates are estimated using a simplified technique to parameterize the respective escape probabilities taking into account multiple collisions with ambient neutrals. Results. The mean C and N escape rates are 1 × 1024 s−1 and 9 × 1024 s−1, appropriate for low to moderate solar activity conditions, and thermospheric PD makes a larger contribution to the total N escape than to the total C escape. The above differences highlight the importance of nascent energy, with more energetic nascent escaping atoms able to survive collisions with ambient neutrals more easily, thus extending down to deeper regions of the atmosphere. Solar cycle variation in C and N escape is revealed by our analysis, whereas solar zenith angle variation is absent for both species. These results could be explained by the fact that the production of nascent escaping atoms responds to varying solar illumination angle at low altitudes where the escape probability is negligible, but responds to varying level of solar EUV/X-ray irradiance at high altitudes where the atmosphere is essentially collisionless.
Background
The epidemiology, diagnosis, and treatment of motor neuron disease (MND) in Chinese patients are ill known.
Methods
A registered study of 461 MND patients was conducted across 10 ...facilities in 7 Chinese cities from February 2009 to March 2010.
Results
Patients were classified as amyotrophic lateral sclerosis (ALS) (84.4%), progressive bulbar palsy (PBP) (4.1%), progressive muscular atrophy (PMA) (10.4%), or primary lateral sclerosis (PLS) (0.9%). MND was predominant in men (men/women; 1.6:1.0). Mean onset age was 52.6 years, with the highest incidence being observed between 51 and 60 years. Notably, 26.0% of MND patients were employed in forestry, fishery, or animal husbandry industries. Ten cases (2.7%) reported family history of MND, and 54.2% exhibited cervical onset. MND was also associated with head/neck trauma. Non‐invasive positive pressure ventilation was the most common supportive therapy.
Conclusion
As a novel comprehensive report of a Chinese population, this study reveals that epidemiological characteristics of MND patients were similar to those observed in international populations. MND is age‐related, male gender predominant, and may be associated with both environmental and genetic risk factors.
The Crab pulsar and the surrounding nebula powered by the pulsar's rotational energy through the formation and termination of a relativistic electron-positron wind is a bright source of gamma-rays ...carrying crucial information about this complex conglomerate. We report the detection of \(\gamma\)-rays with a spectrum showing gradual steepening over three energy decades, from \(5\times 10^{-4}\) to \(1.1\) petaelectronvolt (PeV). The ultra-high-energy photons exhibit the presence of a PeV electron accelerator (a pevatron) with an acceleration rate exceeding 15% of the absolute theoretical limit. Assuming that unpulsed \(\gamma\)-rays are produced at the termination of the pulsar's wind, we constrain the pevatron's size, between \(0.025\) and \(0.1\) pc, and the magnetic field \(\approx 110 \mu\)G. The production rate of PeV electrons, \(2.5 \times 10^{36}\) erg \(\rm s^{-1}\), constitutes 0.5% of the pulsar's spin-down luminosity, although we do not exclude a non-negligible contribution of PeV protons to the production of the highest energy \(\gamma\)-rays.
The pseudokinase mixed lineage kinase domain-like protein (MLKL) is a key component of tumor necrosis factor (TNF)-induced necroptosis and plays a crucial role in necroptosis execution. However, the ...mechanisms that control MLKL activity are not completely understood. Here, we identify the molecular chaperone Hsp90 as a novel MLKL-interacting protein. We show that Hsp90 associates with MLKL and is required for MLKL stability. Moreover, we find that Hsp90 also regulates the stability of the upstream RIP3 kinase. Interference with Hsp90 function with the 17AAG inhibitor destabilizes MLKL and RIP3, resulting in their degradation by the proteasome pathway. Furthermore, we find that Hsp90 is required for TNF-stimulated necrosome assembly. Disruption of Hsp90 function prevents necrosome formation and strongly reduces MLKL phosphorylation and inhibits TNF-induced necroptosis. Consistent with a positive role of Hsp90 in necroptosis, coexpression of Hsp90 increases MLKL oligomerization and plasma membrane translocation and enhances MLKL-mediated necroptosis. Our findings demonstrate that an efficient necrotic response requires a functional Hsp90.
Graphene oxide-particle composite films with filtration function have been successfully synthesized by a two-step method. First, graphene oxide–TiO2 composite sheets are prepared, which can form ...stable dispersion in water. Then, by assembling these composite sheets, graphene oxide–TiO2 films are obtained. In these as-prepared films, dilated space and channels are desirably formed by introducing nanoparticles between these carbon sheets, making them promising separation membranes. We used these films as filtration membranes to remove dye molecules (methyl orange and rhodamine B) from water. The results show that apart from the adsorption capacities of these dyes, these graphene oxide–TiO2 films can also capture additional amount of dye molecules, indicating their potential applications in water purification areas.
This study aimed to investigate the genetic pathogeny of multiple morphological anomalies of the flagella (MMAF), which is a genetically heterogeneous disorder leading to male infertility. Nine ...patients with severe asthenozoospermia caused by MMAF were recruited. Whole genome sequencing and Sanger sequencing were performed, and we found that four of the nine patients were affected by the same homozygous frameshift mutation c.11726_11727delCT (p.Pro3909ArgfsTer33) in exon 73 of dynein axonemal heavy chain 1 (
DNAH1
) gene. The parents and the sibling of proband 1 were all identified as heterozygous carriers. This mutation was distinct from previously reported
DNAH1
mutations associated with MMAF and only affected the East Asian group. Furthermore, the variant DNAH1 protein could not be detected in spermatozoa by Western blot or immunofluorescence staining although
DNAH1
mRNA was expressed in the spermatozoa. Scanning electron microscopy and transmission electron microscopy analysis showed the anomalies in sperm flagella morphology and ultrastructure in patients carrying this genetic variant. In conclusion, our results add to knowledge of the genetic pathogeny of MMAF and further confirmed the effectiveness of genetic screening in the diagnosis of MMAF.
The aim of this study was to determine whether Lactobacillus rhamnosus GG (LGG) components (surface layer protein, SLP; genomic DNA, gDNA; unmethylated cytosine‐phosphate‐guanine‐containing ...oligodeoxynucleotide, CpG‐ODN), alone or in combination, could affect immunomodulation, and evaluate the signalling mechanism in mouse macrophage RAW264.7 cells challenged with lipopolysaccharide (LPS). LGG components were used to treat cells before LPS stimulation. Cytokine and Toll‐like receptor (TLR) expression were assessed using real‐time quantitative PCR (RT‐qPCR). Mitogen‐activated protein kinase (MAPK), extracellular regulated protein kinase (ERK) and nuclear factor‐kappa B (NF‐κB) signalling pathways were evaluated using immunoblots and immunofluorescence. SLP or SLP + gDNA pre‐treatment significantly reduced the LPS‐induced mRNA expression of tumour necrosis factor alpha (TNF‐α). Pre‐treatment with LGG single components (SLP, gDNA or CpG) or their combinations (SLP + gDNA or SLP + CpG) significantly decreased the LPS‐induced interleukin‐6 (IL‐6) mRNA level (P < 0·05). Pre‐treatment with SLP or gDNA, alone or in combination, significantly suppressed LPS‐induced TLR2 and TLR4 mRNA levels (P < 0·05). SLP pre‐treatment also significantly decreased the LPS‐induced expression of TLR9 (P < 0·05). Pre‐treatment with LGG single components or combinations significantly suppressed the LPS‐induced phosphorylation levels of ERK (P > 0·05). In conclusion, pre‐incubation with LGG components, singly or in combination, generally inhibited the activation of TLR, MAPK and NF‐κB signalling pathways in LPS‐stimulated cells, leading to attenuated inflammatory cytokine TNF‐α and IL‐6 production. These results indicate that nonviable probiotic LGG components exert an anti‐inflammation effect on epithelial cells.
Significance and Impact of the Study
Lactobacillus rhamnosus GG (LGG) is widely used as probiotics. However, its main components are not well known for affecting immunomodulation. This study investigated the effects of pre‐treatments with different components such as surface layer protein, genomic DNA and unmethylated cytosine‐phosphate‐guanine‐containing oligodeoxynucleotides, alone or in combination on immunomodulation, and evaluated the signalling mechanism in mouse macrophage RAW264.7 cells challenged with lipopolysaccharide. Pre‐incubation with components alone or in combination generally inhibited the activation of Toll‐like receptor, mitogen‐activated protein kinases, extracellular regulated protein kinases and nuclear factor‐kappa B signalling pathways in lipopolysaccharide‐stimulated cells, which generally leads to attenuated inflammatory cytokine interleukin‐6 and tumour necrosis factor alpha production. These results indicate that nonviable probiotic LGG components exert an anti‐inflammation effect on epithelial cells.
Significance and Impact of the Study: Lactobacillus rhamnosus GG (LGG) is widely used as probiotics. However, its main components are not well known for affecting immunomodulation. This study investigated the effects of pre‐treatments with different components such as surface layer protein, genomic DNA and unmethylated cytosine‐phosphate‐guanine‐containing oligodeoxynucleotides, alone or in combination on immunomodulation, and evaluated the signalling mechanism in mouse macrophage RAW264.7 cells challenged with lipopolysaccharide. Pre‐incubation with components alone or in combination generally inhibited the activation of Toll‐like receptor, mitogen‐activated protein kinases, extracellular regulated protein kinases and nuclear factor‐kappa B signalling pathways in lipopolysaccharide‐stimulated cells, which generally leads to attenuated inflammatory cytokine interleukin‐6 and tumour necrosis factor alpha production. These results indicate that nonviable probiotic LGG components exert an anti‐inflammation effect on epithelial cells.
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