Constraining Sub-Parsec Binary Supermassive Black Holes in Quasars with Multi-Epoch Spectroscopy. II. The Population with Kinematically Offset Broad Balmer Emission Lines

A small fraction of quasars have long been known to show bulk velocity offsets in the broad Balmer lines with respect to the systemic redshift of the host galaxy. Models to explain these offsets usually invoke broad-line region gas kinematics/asymmetry around single black holes (BHs), orbital motion of massive (~sub-pc) binary black holes (BBHs), or recoil BHs, but single-epoch spectra are unable to distinguish between these scenarios. The line-of-sight (LOS) radial velocity (RV) shifts from long-term spectroscopic monitoring can be used to test the BBH hypothesis. We have selected a sample of 399 quasars with offset broad H-beta lines from the SDSS DR7 quasar catalog, and have conducted second-epoch optical spectroscopy for 50 of them. Combined with the existing SDSS spectra, the new observations enable us to constrain the LOS RV shifts of broad H-beta lines with a rest-frame baseline of a few years to nearly a decade. Using cross-correlation analysis, we detect significant (99% confidence) radial accelerations in the broad H-beta lines in 24 of the 50 objects. We suggest that 9 of the 24 detections are sub-pc BBH candidates, which show consistent velocity shifts independently measured from a second broad line (either H-alpha or Mg II) without significant changes in the broad-line profiles. Combining the results on the general quasar population studied in Paper I, we find a tentative anti-correlation between the velocity offset in the first-epoch spectrum and the average acceleration between two epochs, which could be explained by orbital phase modulation when the time separation between two epochs is a non-negligible fraction of the orbital period of the motion causing the line displacement. We discuss the implications of our results for the identification of sub-pc BBH candidates in offset-line quasars and for the constraints on their frequency and orbital parameters. [Abridged]Comment: 23 pages, 18 figures, ApJ in pres

Thermoplasmatales and Methanogens: Potential Association with the Crenarchaeol Production in Chinese Soils

Crenarchaeol is a unique isoprenoid glycerol dibiphytanyl glycerol tetraether (iGDGT) lipid, which is only identified in cultures of ammonia-oxidizing Thaumarchaeota. However, the taxonomic origins of crenarchaeol have been debated recently. The archaeal populations, other than Thaumarchaeota, may have associations with the production of crenarchaeol in ecosystems characterized by non-thaumarchaeotal microorganisms. To this end, we investigated 47 surface soils from upland and wetland soils and rice fields and another three surface sediments from river banks. The goal was to examine the archaeal community compositions in comparison with patterns of iGDGTs in four fractional forms (intact polar-, core-, monoglycosidic- and diglycosidic-lipid fractions) along gradients of environments. The DistLM analysis identified that Group I.1b Thaumarchaeota were mainly responsible for changes in crenarchaeol in the overall soil samples; however, Thermoplasmatales may also contribute to it. This is further supported by the comparison of crenarchaeol between samples characterized by methanogens, Thermoplasmatales or Group I.1b Thaumarchaeota, which suggests that the former two may contribute to the crenarchaeol pool. Last, when samples containing enhanced abundance of Thermoplasmatales and methanogens were considered, crenarchaeol was observed to correlate positively with Thermoplasmatales and archaeol, respectively. Collectively, our data suggest that the crenarchaeol production is mainly derived from Thaumarchaeota and partly associated with uncultured representatives of Thermoplasmatales and archaeol-producing methanogens in soil environments that may be in favor of their growth. Our finding supports the notion that Thaumarchaeota may not be the sole source of crenarchaeol in the natural environment, which may have implication for the evolution of lipid synthesis among different types of archaea

Structural and crystal-chemical characteristics of the apatite deposits from human aortic walls

Thermal behavior of biological apatite is the object of several studies. Crystal size, carbonate content, phase composition, and other parameters change during annealing up to 900 °C in biological minerals with apatite structure. The way these parameters change reflects the specific properties of the initial bioapatite. This work presents data on thermal transformations of pathological bioapatite from the human cardiovascular system, namely aortic wall deposits. Some minor elements, foreign to calcium hydroxyapatite (e.g., Na and Mg), can be both incorporated in the apatite structure and localized in the surface layers of crystals, modifying functions of the mineral. A new approach was proposed to determine the predominant location of minor elements, such as Mg, Na, and K, in the mineral of pathological deposits. Mg and Na in pathological apatite can be in both structurally bound (substituting calcium in lattice) and labile (localized on the crystal surface) states, while K is not able to join the apatite structure in significant amount or be chemically bound to it. This approach, based on atomic spectrometry, can be used effectively in combination with a set of traditional techniques, such as like EDS, IRS, and XRD

Genome-Wide Identification, Evolution, and Co-expression Network Analysis of Mitogen-Activated Protein Kinase Kinase Kinases in Brachypodium distachyon

Mitogen-activated protein kinase (MAPK) cascades are the conserved and universal signal transduction modules in all eukaryotes, which play the vital roles in plant growth, development and in response to multiple stresses. In this study, we used bioinformatics methods to identify 86 MAPKKK protein encoded by 73 MAPKKK genes in Brachypodium. Phylogenetic analysis of MAPKKK family from Arabidopsis, rice and Brachypodium has classified them into three subfamilies, of which 28 belonged to MEKK, 52 to Raf and 6 to ZIK subfamily respectively. Conserved protein motif, exon-intron organization and splicing intron phase in kinase domains supported the evolutionary relationships inferred from the phylogenetic analysis. And gene duplication analysis suggested the chromosomal segment duplication happened before the divergence of the rice and Brachypodium, while all of three tandem duplicated gene pairs happened after their divergence. We further demonstrated that the MAPKKKs have evolved under strong purifying selection, implying the conservation of them. The splicing transcripts expression analysis showed that the splicesome translating longest protein tended to be adopted. Furthermore, the expression analysis of BdMAPKKKs in different organs and development stages as well as heat, virus and drought stresses revealed that the MAPKKK genes were involved in various signaling pathways. And the circadian analysis suggested there were 41 MAPKKK genes in Brachypodium showing cycled expression in at least one condition, of which seven MAPKKK genes expressed in all conditions and the promoter analysis indicated these genes possessed many cis-acting regulatory elements involved in circadian and light response. Finally, the co-expression network of MAPK, MAPKK and MAPKKK in Brachypodium was constructed using 144 microarray and RNA-seq datasets, and ten potential MAPK cascades pathway were predicted. To conclude, our study provided the important information for evolutionary and functional characterization of MAPKKK family in Brachypodium, which will facilitate the functional analysis of BdMAPKKK genes, and also will facilitate better understanding the MAPK signal pathway in Brachypodium and beyond

Thermoplasmatales and Methanogens: Potential Association with the Crenarchaeol Production in Chinese Soils

Crenarchaeol is a unique isoprenoid glycerol dibiphytanyl glycerol tetraether (iGDGT) lipid, which is only identified in cultures of ammonia-oxidizing Thaumarchaeota. However, the taxonomic origins of crenarchaeol have been debated recently. The archaeal populations, other than Thaumarchaeota, may have associations with the production of crenarchaeol in ecosystems characterized by non-thaumarchaeotal microorganisms. To this end, we investigated 47 surface soils from upland and wetland soils and rice fields and another three surface sediments from river banks. The goal was to examine the archaeal community compositions in comparison with patterns of iGDGTs in four fractional forms (intact polar-, core-, monoglycosidic- and diglycosidic-lipid fractions) along gradients of environments. The DistLM analysis identified that Group I.1b Thaumarchaeota were mainly responsible for changes in crenarchaeol in the overall soil samples; however, Thermoplasmatales may also contribute to it. This is further supported by the comparison of crenarchaeol between samples characterized by methanogens, Thermoplasmatales or Group I.1b Thaumarchaeota, which suggests that the former two may contribute to the crenarchaeol pool. Last, when samples containing enhanced abundance of Thermoplasmatales and methanogens were considered, crenarchaeol was observed to correlate positively with Thermoplasmatales and archaeol, respectively. Collectively, our data suggest that the crenarchaeol production is mainly derived from Thaumarchaeota and partly associated with uncultured representatives of Thermoplasmatales and archaeol-producing methanogens in soil environments that may be in favor of their growth. Our finding supports the notion that Thaumarchaeota may not be the sole source of crenarchaeol in the natural environment, which may have implication for the evolution of lipid synthesis among different types of archaea

Research Progress in Molecular Biology of Fish Immunoglobulin M (IgM)

Immunoglobulin (Ig) is a type of globulin produced by B lymphocytes during pathogenic infection of vertebrates. It has immune functions and can realize specific recognition and neutralization of corresponding antigens. As IgM is reported first in fish, IgM is the first antibody produced during immune responses and plays a vital role in systemic and mucosal immune tissues. IgM molecules have two forms: membrane-bound IgM (mIgM) and secreted IgM (sIgM). The latter is produced by plasmacytes and secreted into body fluid, existing as immunological effect molecules. The former embeds into B cytomembrane and exists as an antigen receptor. It binds with assistant molecules to form cell receptor compounds. This study reviews research progress on the structures and production processes of IgM genes in different fish species and the distribution characteristics of IgM on B cells, mediated signal pathways, and functions. It aims to enrich basic theoretical knowledge of fish immunology and provide some scientific references for disease control in fishes

Effect of oxygen coordination environment of Ca-Mn oxides on catalytic performance of Pd supported catalysts for aerobic oxidation of 5-hydroxymethyl-2-furfural

This work was supported by Natural Science Foundation of Tianjin (Grant No. 17JCYBJC22600) and the Fundamental Research Funds for the Central Universities. Computational support was provided by the Beijing Computing Center (BCC).Four types of Ca-Mn oxides, including CaMnO3, CaMn2O4, CaMn3O6 and Ca2Mn3O8, have been prepared and used as supports for Pd nanoparticles. The oxygen activation capacity of these oxides and the catalytic activity of the oxide supported Pd nanocatalysts have been investigated using the aerobic oxidation of 5-hydroxymethyl-2-furfural as a model reaction. It is found that the local coordination environment of lattice oxygen sites plays a crucial role on their redox property and charge transfer ability from Pd nanoparticles to the support. In particular, the Ca-Mn oxide with lower oxygen coordination number, weaker metal-oxygen bonds and tunnel crystal structure, e.g. CaMn2O4, exhibits promoted oxygen activation capacity, and stronger electron transfer ability. Consequently, Pd/CaMn2O4 exhibits the highest catalytic activity among these catalysts, providing a promising yield of 2,5-furandicarboxylic acid. This work may shed light on the future investigation on the design of local structure of active oxygen sites in oxides or oxide supported catalysts for redox reactions.PostprintPeer reviewe

Research Progress on the Fish Complement C3 Gene

Complement (C) is a serum protein with immunity-related functions and enzymatic activities. It can induce inflammatory responses and antibody formation following activation by substances such as pathogens. Moreover, it is a crucial molecule in the congenital immune defense system. Complement manifests earlier than immunoglobulin in the evolutionary process of fish's immune system. Therefore, the complement system of fish is vital for congenital and acquired immunities. A complement system is a polymolecule system comprising more than 30 soluble proteins, membrane-bound proteins, and complement receptors. It can be activated through three pathways for immunoregulation, the clearance of the immune complex, etc. The liver primarily produces the fish complement C3, which is a significant component of the complement system of fishes. C3 is the hub of three activation pathways. Research works concerning the structure, generation process, expression, and functions of C3 in fishes are reviewed in this study

Acupuncture versus rehabilitation for post-stroke shoulder-hand syndrome: a systematic review and meta-analysis of randomized controlled trials

BackgroundShoulder-hand syndrome (SHS) is one of the common sequelae after stroke, which not only hinders the recovery of patients, but also increases the economic burden of the family. In the absence of effective treatment measures, acupuncture treatment has been widely used in China to treat post-stroke shoulder-hand syndrome, but the details are unclear. Therefore, this review aims to evaluate the true efficacy of acupuncture in patients with SHS.MethodsWe searched eight databases [PubMed, Embase, Web of Science, Cochrane library, China Biomedical Literature Database (CBM), China Science and Technology Journal (VIP) database, the China National Knowledge Infrastructure (CNKI) database, and Wan fang database] from its inception to March 2025, randomized controlled trials (RCTs) of SHS acupuncture treatment combined with rehabilitation (Rehab). Two investigators independently used pre-designed forms to extract valid data from eligible randomized controlled trials. Meta-analysis was implemented through the Rev. Man software (version 5.4). The strength of the evidence obtained was implemented using the GRADE profiler software. Adverse events (AEs) were collected by reading the full text and used to evaluate the safety of acupuncture treatment.ResultsForty-seven studies, involving 4,129 participants, met the eligibility criteria, and were included in the review. Overall meta-analysis showed that combined acupuncture rehabilitation significantly improved motor function (upper-limb Fugl-Meyer Assessment (FMA): 41 studies, mean difference (MD) 9.50, 95% confidence interval (CI) [8.47, 10.53]) and pain reduction (visual analog score (VAS): 37 studies, MD: −1.49, 95% CI [−1.66, −1.33]). It also improved activities of daily living (ADL) compared to rehabilitation alone (ADL: 17 studies, MD: 11.94, 95% CI [8.26, 13.63]). There was no significant difference in the occurrence of adverse events (AEs) between acupuncture treatment combined with Rehab and Rehab alone (p > 0.05). The certainty of the evidence was rated low level because of flaws in the study design and considerable heterogeneity among the included studies.ConclusionThis review found that acupuncture treatment combined with Rehab treatment may have a positive promoting effect on improving motor function, reducing pain, and improving daily living ability in SHS patients. However, due to the existing methodological quality issues, our findings should be treated with caution. Future high-quality studies are urgently needed to validate our findings.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/view/CRD42024536169

Association between Metabolic Score for Visceral Fat and the risk of hypertension in different ethnic groups: a prospective cohort study in Southwest China

ObjectiveVisceral adipose tissue assessment holds significant importance in hypertension prevention. This study aimed to explore the association between the Metabolic Score for Visceral Fat (METS-VF), a new indicator based on laboratory and anthropometry measures, and hypertension risk and to further investigate the association between the METS-VF and the risk of hypertension in different ethnic groups.MethodsIn this study, a total of 9,280 people from 48 townships in 12 districts (counties) of Guizhou Province were selected for the survey using a multistage cluster random sampling method, and 5,127 cases were finally included in the analysis after excluding those with missing relevant data, losing visits, dying at follow-up, those who suffered from hypertension at baseline, and those whose information on the outcome of hypertension was not clear. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) between METS-VF and incident hypertension, and an accelerated failure time (AFT) model was applied to analyze the association between METS-VF and the onset time of hypertension.ResultsThe total person-years (PYs) of the 5,127 subjects were 36,188.52 years, and the median follow-up time was 6.64 years. During follow-up, 1,127 patients were newly diagnosed with hypertension, and the incidence density was 31.14/1,000 PYs. After adjusting for multivariables, compared with the METS-VF first (Q1), the third (Q3) and fourth (Q4) groups of the METS-VF increased by 29.9% and 61.5%, respectively (HR = 1.299 [1.061, 1.590] and 1.615 [1.280, 2.036]). The risk of hypertension increased with higher METS-VF values (HR = 1.323 [1.167, 1.500], ptrend < 0.001). In the Han Chinese population, Q2 and Q3 increased the risk of hypertension (HR = 1.459 [1.111, 1.917], 1.999 [1.417, 2.718]), and the onset of hypertension was advanced by 0.653 (β = −0.653 (−0.930, −0.375]) years for per 1 unit increase in METS-VF. However, these associations were not found in ethnic minorities.ConclusionMETS-VF was significantly positively associated with the risk of hypertension, and the association was different among ethnic groups