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In this paper, we investigated the spin transport properties of binuclear manganese phthalocyanine (M n 2 P c 2) spintronic devices sandwiched between two nickel electrodes using the non-equilibrium Green's function method in combination with density functional theory. Based on the calculation results, the M n 2 P c 2 device exhibited excellent spin-filtering capabilities, demonstrating an exceptionally high spin filter efficiency (SFE). Irrespective of the parallel or antiparallel orientation of magnetization in the electrodes, we observed that when both manganese atoms were in a spin-up state, the SFE of spin-resolved currents under finite bias and the thermoelectric currents induced by temperature gradients at fixed temperatures were both close to 100%. The large spin Seebeck polarization of the M n 2 P c 2 device was also obtained at low reference temperatures. This study explores the potential for developing multifunctional spintronic single-molecule devices using Ni − M n 2 P c 2. [ABSTRACT FROM AUTHOR]

Anthocyanins are widely found in plants and have significant functions. The accurate detection and quantitative assessment of anthocyanin content are essential to assess its functions. The anthocyanin content in plant tissues is typically quantified by wet chemistry and spectroscopic techniques. However, these methods are time-consuming, labor-intensive, tedious, expensive, destructive, or require expensive equipment. Digital photography is a fast, economical, efficient, reliable, and non-invasive method for estimating plant pigment content. This study examined the anthocyanin content of Rosa chinensis petals using digital images, a back-propagation neural network (BPNN), and the random forest (RF) algorithm. The objective was to determine whether using RGB indices and BPNN and RF algorithms to accurately predict the anthocyanin content of R. chinensis petals is feasible. The anthocyanin content ranged from 0.832 to 4.549 µmol g−1 for 168 samples. Most RGB indices were strongly correlated with the anthocyanin content. The coefficient of determination (R2) and the ratio of performance to deviation (RPD) of the BPNN and RF models exceeded 0.75 and 2.00, respectively, indicating the high accuracy of both models in predicting the anthocyanin content of R. chinensis petals using RGB indices. The RF model had higher R2 and RPD values, and lower root mean square error (RMSE) and mean absolute error (MAE) values than the BPNN, indicating that it outperformed the BPNN model. This study provides an alternative method for determining the anthocyanin content of flowers. [ABSTRACT FROM AUTHOR]

Spin transport properties of single rhenium phthalocyanine (RePc) and double-rhenium phthalocyanine (Re2Pc2) molecular devices with gold electrodes have been investigated by combining Density Functional theory and nonequilibrium Green's functions. It was found that the RePc molecular devices exhibited good spin filtration efficiency in the small bias range even in the absence of magnetic electrodes. The Re2Pc2 molecular device exhibited a large magnetoresistance and excellent spin-filtering properties at a finite bias, which can only be achieved by altering the magnetization orientation of the rhenium atom at the center of the phthalocyanine molecule. These conclusions of the rhenium phthalocyanine molecule may have potential application in magnetoresistive devices and spin filters. [ABSTRACT FROM AUTHOR]

Intermedin (IMD), a paracrine/autocrine peptide, protects against cardiac fibrosis. However, the underlying mechanism remains poorly understood. Previous study reports that activation of nucleotide-binding oligomerization domain (NOD)–like receptor family pyrin domain containing 3 (NLRP3) inflammasome contributes to cardiac fibrosis. In this study, we aimed to investigate whether IMD mitigated cardiac fibrosis by inhibiting NLRP3. Cardiac fibrosis was induced by angiotensin II (Ang II) infusion for 2 weeks in rats. Western blot, real-time PCR, histological staining, immunofluorescence assay, RNA sequencing, echocardiography, and hemodynamics were used to detect the role and the mechanism of IMD in cardiac fibrosis. Ang II infusion resulted in rat cardiac fibrosis, shown as over-deposition of myocardial interstitial collagen and cardiac dysfunction. Importantly, NLRP3 activation and endoplasmic reticulum stress (ERS) were found in Ang II–treated rat myocardium. Ang II infusion decreased the expression of IMD and increased the expression of the receptor system of IMD in the fibrotic rat myocardium. IMD treatment attenuated the cardiac fibrosis and improved cardiac function. In addition, IMD inhibited the upregulation of NLRP3 markers and ERS markers induced by Ang II. In vitro, IMD knockdown by small interfering RNA significantly promoted the Ang II–induced cardiac fibroblast and NLRP3 activation. Moreover, silencing of inositol requiring enzyme 1 α (IRE1α) blocked the effects of IMD inhibiting fibroblast and NLRP3 activation. Pre-incubation with PKA pathway inhibitor H89 blocked the effects of IMD on the anti-ERS, anti-NLRP3, and anti-fibrotic response. In conclusion, IMD alleviated cardiac fibrosis by inhibiting NLRP3 inflammasome activation through suppressing IRE1α via the cAMP/PKA pathway. [ABSTRACT FROM AUTHOR]

Objective: To summarize data from a serological survey of high‐risk populations in Guangdong Province, China, and to perform a meta‐analysis to investigate the prevalence and seroprevalence of celiac disease (CD) in the Chinese general and high‐risk populations. Methods: We collected data from the serological survey of high‐risk population of CD in Guangdong Province, China (N = 1390) by testing their serum tissue transglutaminase immunoglobulin A (tTG‐IgA), deamidated gliadin peptides immunoglobulin A (DGP‐IgA) and deamidated gliadin peptides immunoglobulin G (DGP‐IgG). Additionally, a literature search was performed on PubMed, EMBASE, Cochrane Library and three Chinese databases for articles published up to 20 December 2020 to estimate the pooled prevalence and seroprevalence of CD in China. Results: In the serological survey, 0.94% (13/1390) of individuals were positive for CD antibodies. In a meta‐analysis of 18 studies, the seroprevalence of CD in the general Chinese population was 0.27% (95% confidence interval [CI] 0.02%‐0.71%). While that in the high‐risk population was 8.34% (95% CI 4.90%‐12.54%) (odds ratio 7.27, 95% CI 4.06‐13.04). The prevalence of biopsy‐confirmed CD in high‐risk Chinese populations was 4.44% (95% CI 1.53%‐8.58%). The seroprevalence of CD varied with patients' geographical origin, being higher in northern China than in southern China. Conclusions: Early diagnosis of CD by serological screening in high‐risk population and generous serological testing in those with vague symptoms, especially in northern China, are recommended. [ABSTRACT FROM AUTHOR]

aim of this work was to evaluate the association between SO and hypertension, diabetes, and abnormal lipid metabolism in Chinese adults, and explore the prediction of SO using relevant anthropometric indicators. Materials and Methods: All participants underwent a questionnaire interview for the collection of demographic data. Thereafter, they underwent physical examination for the measurement of anthropometric variables, which was performed using bioelectrical impedance analysis. Biochemical measurements were determined according to standard laboratory procedures used for the evaluation of blood parameters. Results: We included 14,926 patients aged 35– 74 years old. The mean age of the participants was 56.75 ± 9.76 years old, and 39.80% of them were male. The mean body mass index (BMI) was 24.94 ± 3.40 kg/m2, and the overall prevalence of SO was 65.1%. The results showed that shorter people; people with faster heart rate; heavier weight; lower waist circumference (WC), BMI, triglyceride level, total cholesterol, and low-density lipoprotein cholesterol levels; and higher high-density lipoprotein cholesterol level are at risk for SO. Conclusion: The prevalence of SO is high (65.1%) in Chinese adults aged 35– 74 years old. The occurrence of SO is related to hypertension, diabetes, and abnormal lipid metabolism. BMI, WC, and waist-hip ratio may be predictive indicators of SO. The incidence of SO may be reduced by timely intervention and health education for persons at risk of the condition. [ABSTRACT FROM AUTHOR]

Objective·To investigate the correlation between early quantitative electroencephalogram (QEEG) features and brain CT perfusion imaging parameters in the patients with acute ischemic stroke (AIS), and analyze the correlation between QEEG features and National Institutes of Health Stroke Scale (NIHSS) score. Methods·Ninety-two patients with AIS admitted to the First People's Hospital of Qinzhou from March 2014 to June 2016 were enrolled. All the patients were given emergency CT perfusion imaging to determine the ischemic lesion areas. And then they were monitored by electroencephalogram for at least 2 h. The assessment by using NIHSS was performed after admission. Cerebral blood flow (CBF), mean transit time (MTT) and time to peak (TTP) were obtained from CT perfusion imaging. α wave index, θ wave index, δ wave index, slow wave index, α/δ power ratio (ADR), (δ + θ)/(α + β) power ratio and brain symmetry index (BSI) were obtained from QEEG analysis. With Pearson linear correlation analysis, the correlation between CT perfusion imaging parameters and QEEG features in the ischemic lesions, the correlation between CT perfusion imaging parameters and NIHSS score, and the correlation between QEEG features and NIHSS score were analyzed. Results·The AIS patients had decreased CBF, prolonged MTT and TTP, increased δ wave index, slow wave index and BSI, and decreased ADR and DTABR in the ischemic lesion areas than those in the contralateral regions. The differences were statistically significant (all P<0.05). MTT was positively correlated with δ wave index, slow wave index and BSI (all P<0.05), and negatively correlated with ADR and DTABR (all P<0.05); TTP was positively correlated with δ wave index, slow wave index and BSI (all P<0.05), and negatively correlated with ADR and DTABR (all P<0.05); the NIHSS score was positively correlated with MTT, TTP, δ wave index, slow wave index and BSI (all P<0.05), and negatively correlated with CBF, ADR and DTABR (all P<0.05). Conclusion·There exists correlation between QEEG features and CT perfusion imaging parameters in the patients with AIS. Early recording of the patients' QEEG features can help assess the changes of ischemic lesions and neurological deficits and realize dynamic monitoring. [ABSTRACT FROM AUTHOR]

Wuqi County of Shaanxi Province, where the vegetation recovering measures have been carried out for years, was taken as the study area. A total of 100 loess samples from 24 different profiles were collected. Total nitrogen (TN) and alkali hydrolysable nitrogen (AHN) contents of the soil samples were analyzed, and the soil samples were scanned in the visible/near infrared (VNIR) region of 350-2500 nm in the laboratory. The calibration models were developed between TN and AHN contents and VNIR values based on correlation analysis (CA) and partial least squares regression (PLS). Independent samples validated the calibration models. The results indicated that the optimum model for predicting TN of loess was established by using first derivative of reflectance. The best model for predicting AHN of loess was established by using normal derivative spectra. The optimum TN model could effectively predict TN in loess from 0 to 40 cm, but the optimum AHN model could only roughly predict AHN at the same depth. This study provided a good method for rapidly predicting TN of loess where vegetation recovering measures have been adopted, but prediction of AHN needs to be further studied. [ABSTRACT FROM AUTHOR]

The quantum transport in S3 clusters sandwiched between electrodes was investigated using density functional theory and nonequilibrium Green's function method. Five different configurations were considered, and the equilibrium conductance and the projected density of states were obtained at optimal positions. Results revealed local minima for two strain chains connected to the pyramidal electrodes at the top site and a triangular S3 open chain linked to the pyramidal electrodes at the top hollow site. The relationship between conductance and external bias voltage was also calculated. Transmission of straight chains was determined by resonance and strongly affected by the bias voltage. Transport of top-hollow configuration was dominated by several closely spaced and broad molecular orbitals; hence, the transmission coefficient was almost flat around the gold Fermi level. The calculations proved that the coupling morphologies of S3 clusters connected with the electrodes significantly affected the electrical transport properties of nanoscale junctions. [ABSTRACT FROM AUTHOR]

Aim:To identify novel small compound inhibitor of p53 protein.Methods:Mouse embryonic fibroblasts (MEF) and mouse embryonic stem (ES) cells were tested. Cell proliferation rate was determined using a Cell Proliferation Kit. The mRNA and protein levels of p53-related genes were measured using real-time PCR and Western blotting, respectively. Global response in the p53 signaling network was analyzed using Illumina whole-genome expression BeadChips.Results:Treatment of MEF cells with a small molecule 1,4-bis-[4-(3-phenoxy-propoxy)-but-2-ynyl]-piperazine (G5) at 10 μmol/L for 24 h markedly reduced the mRNA and protein levels of the p53 downstream genes MDM2 and p21. In G5-treated ES cells, a total of 372 differentially expressed genes were identified, and 18 among them were direct downstream genes of p53; 6 out of 9 p53-repressed genes were upregulated, and 5 out of 9 p53-activated genes were downregulated. In both MEF cells and ES cells, treatment of with G5 (10 μmol/L) up to 48 h neither affected the proliferation rate nor caused morphological alterations.Conclusion:G5 inhibits p53 activity and simultaneously preserves the normal growth and proliferation of cells, therefore is a new compound for studies of p53-mediated cell manipulation. [ABSTRACT FROM AUTHOR]

An intumescent flame retardant (IFR), pentaerytheritol phosphate ester melamine salt (PPEM) was synthesized and chemically modified by magnesium oxide (MgO) or/and calcium oxide (CaO), respectively. The fire retardant efficiency of MgO and CaO as synergistic agents in polypropylene (PP) was evaluated by normal fire testing methods. The results showed that MgO and CaO exhibited a synergistic effect on fire retardancy of PP. The addition of 0.2% of MgO or CaO into PP/PPEM composite could decrease the self-extinguishing time and improve the limited oxygen index (LOI) obviously. The cone calorimeter (CONE) tests and the thermal analysis revealed that the introduction of MgO and CaO neutralized the acidity of PPEM, which leads to a thermal stabilization and a delay of the intumescent process of the system, and promote the formation of a high quality charred layer which can prevent PP from decomposing. Thus, a suitable amount of MgO and CaO acts as a synergistic agent in the flame-retarded PP/PPEM system. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]

In the framework of factorization, based on the first-order of isospin violation, we study direct CP violation in the decay of $\bar{B}^0\rightarrow \rho^0(\omega)\rho^0(\omega) \rightarrow\pi^+\pi^-\pi^+\pi^-$ including the effect of ρ-ω mixing. The CP violation depends strongly on Cabibbo-Kobayashi-Maskawa (CKM) matrix elements and the effective parameter, Nc. Recently, the experimental data for the branching ratios of $\bar{B}^0 \rightarrow\rho^0\rho^0$ are accurate and we can give the strong constraint on the range of Nc. We find that the CP violating asymmetry is large and ranges from -82% to -98% via ρ-ω mixing mechanism when the invariant mass of the π+π- pair is in the vicinity of the ω resonance. We also discuss the possibility to observe the predicted CP violating asymmetries at the LHC. [ABSTRACT FROM AUTHOR]

Background: Metabolic syndrome (MS) is combination of medical disorders that increase people's risk for cardiovascular disease and diabetes mellitus. Little data exists on the prevalence of MS of rural original adults in Ningxia of China. Methods: A cross-sectional survey method was used and the participants were interviewed by trained health workers under a structured questionnaire in rural of Ningxia in 2008. The number of research subjects was 1612. MS was defined by International Diabetes Federation IDF (2005). Results: The age-adjusted prevalence of the metabolic syndrome was 11.8%, whereas ethnic-specific prevalence was 10.3% in Han ethnic group and 13.7% in Hui ethnic group. Components of MS and MS were more common in Hui ethnic group than Han ethnic group. The mean levels and prevalence of abnormal value increased with increasing age in both ethnic groups (Cochran-Artimage test for trend, Hui ethnic group P < 0.05, Han ethnic group P < 0.01). Conclusions: The prevalence of MS was high in rural residents' adults in Ningxia. Clustering of MS components and MS was increased with age. The components of MS have big differences among different ethnic groups. [ABSTRACT FROM AUTHOR]

In this study, we examined differences in serum laminin expression in patients with intractable epilepsy. Our results suggest that elevated laminin may contribute to the pathogenesis of intractable epilepsy. ELISA and western blots were used to measure laminin in the serum of 30 intractable epilepsy patients, 46 nonintractable epilepsy patients, and 20 normal subjects. By ELISA, serum laminin levels were greater in intractable epilepsy patients (177.396 ± 30.602) and nonintractable epilepsy patients (121.915 ± 35.215) than in normal control subjects (67.474 ± 7.197); laminin was significantly greater in the intractable epilepsy group than in the nonintractable epilepsy group. In western blots, the optical density ratio of laminin to ss-actin was 0.871 ± 0.032 for the intractable epilepsy group, 0.686 ± 0.017 for the nonintractable epilepsy group, and 0.385 ± 0.024 for the normal control group. The optical density ratios of the intractable and nonintractable epilepsy groups were higher than those for the normal control group, and the intractable epilepsy group was even greater than the nonintractable epilepsy group. Thus, laminin is significantly increased in epilepsy patients, and this increase is more profound in intractable epilepsy patients. [ABSTRACT FROM AUTHOR]

An algebraic method (AM) used to study the full vibrational spectra of diatomic systems, and an analytical formula used to calculate accurate molecular dissociation energies are applied to study the full vibrational spectra and molecular dissociation energies of some electronic states of homonuclear and heteronuclear diatomic molecules and diatomic ions. Studies show that the AM method and the analytical expression are reliable and economical physical methods for studying full vibrational spectra and molecular dissociation energies of diatomic electronic systems theoretically. They are particularly useful for those diatomic systems whose high-lying vibrational energies may not be available. [ABSTRACT FROM AUTHOR]

Three carboxylate silver(I) complexes, [Ag(fbc)]n, (1), [Ag2(cpd)]n (2) and [Ag2(idc)]n (3), were prepared and characterized by X-ray single crystal analysis, where fbcH is 4-fluorobenzoic acid, cpdH2 is cyclopentane-1,1-dicarboxylic acid and idcH2 is iminodiacetic acid. The three coordination polymers show clear Ag–Ag bonds in their structures. The Ag–Ag bond length 2.850?Å both in 1 and 2 is much shorter than that (2.89?Å) in metal silver, which is the shortest silver–silver interaction reported. The result of cytotoxicity of the three complexes indicates that they have very high crytotoxicity properties to normal cells and carcinoma cells. [ABSTRACT FROM AUTHOR]

Two cobalt(II) complexes, [Co 3 L 4 (APYH) 2 ](SO 4 ) 2 (1) and [Co 3 L 4 (APY) 2 ](ClO 4 ) 2 (2), where APY is 2-aminopyridine and L is N-salicylaldehyde-2-iminopyridine anion, were prepared and characterized by single crystal structure determination. The crystallographic study shows that each of the two complexes consists of a discrete trinuclear cobalt(II) dication, two sulfate anions in (1) or two perchlorate anions in (2). The similar cations in the two complexes are composed of three cobalt(II) atoms, four tridentate Schiff base ligands (L), and two protonated 2-aminopyridines for (1) or two 2-aminopyridine molecules for (2). [ABSTRACT FROM AUTHOR]

Focuses on the synthesis and characterization of silver salts with diethylenetriamine. Solubility of silver compounds in common solvents and a sensitivity toward photodecomposition; Factors that appear to modulate the stereochemistry of silver complexes; Location of the remaining non-hydrogen atoms by use of successive difference Fourier maps and full-matrix least-squares refinement.

Abstract: Polyurethane was blended with silk fibroin and heparin to prepare a heparin-releasing system. The release rate and the percentage of the cumulative amount of the released heparin can be controlled by the loading amount of heparin in the film, the composition ratio of silk fibroin to polyurethane, and the thickness of the film. The slower and more sustained release of heparin can be obtained by increasing the film thickness, the loading amount of heparin and the content of silk fibroin in the film. Thus the high bioactivity and long lasting antithrombogenicity of the raw heparin can be maintained for the blended film. The coagulation time tests showed that the composite film had good blood compatibility. [Copyright &y& Elsevier]

Aging is an independent risk factor for vascular diseases. Perivascular adipose tissue (PVAT), an active component of the vasculature, contributes to vascular dysfunction during aging. Identification of underlying cell types and their changes during aging may provide meaningful insights regarding the clinical relevance of aging‐related vascular diseases. Here, we take advantage of single‐cell RNA sequence to characterize the resident stromal cells in the PVAT (PVASCs) and identified different clusters between young and aged PVASCs. Bioinformatics analysis revealed decreased endothelial and brown adipogenic differentiation capacities of PVASCs during aging, which contributed to neointimal hyperplasia after perivascular delivery to ligated carotid arteries. Mechanistically, in vitro and in vivo studies both suggested that aging‐induced loss of peroxisome proliferator‐activated receptor‐γ coactivator‐1 α (PGC1α) was a key regulator of decreased brown adipogenic differentiation in senescent PVASCs. We further demonstrated the existence of human PVASCs (hPVASCs) and overexpression of PGC1α improved hPVASC delivery‐induced vascular remodeling. Our finding emphasizes that differentiation capacities of PVASCs alter during aging and loss of PGC1α in aged PVASCs contributes to vascular remodeling via decreased brown adipogenic differentiation. [ABSTRACT FROM AUTHOR]

A novel 36-metallacrown-6 complex [CuL(N(CN)2)(PF6)]6∙0.5H2O 1 was achieved using a tridendate ligand, 1,4,7-triisopropyl-1,4,7-triazacyclononane (L), and a flexible ligand, dicyanamide in MeOH. The μ1,5 bridging models of the dicyanamide ligand linked the macrocycle to form in a specific size with the chair conformation. The anion was important to form this 36-metallacrown-6 complex, as change was obtained with the larger anion BPh4−, binuclear copper compound 2. The magnetic property indicates that slightly ferromagnetic interactions resulted from a superexchange mechanism. DNA binding properties were also studied. UV and fluorescence spectra showed that complex 1 could bind with DNA. [ABSTRACT FROM AUTHOR]

The conductance stabilities of carbon atomic chains (CACs) with different lengths are investigated by performing theoretical calculations using the nonequilibrium Green’s function method combined with density functional theory. Regular even–odd conductance oscillation is observed as a function of the wire length. This oscillation is influenced delicately by changes in the end carbon or sulfur atoms as well as variations in coupling strength between the chain and leads. The lowest unoccupied molecular orbital in odd-numbered chains is the main transmission channel, whereas the conductance remains relatively small for even-numbered chains and a significant drift in the highest occupied molecular orbital resonance toward higher energies is observed as the number of carbon atoms increases. The amplitude of the conductance oscillation is predicted to be relatively stable based on a thiol joint between the chain and leads. Results show that the current–voltage evolution of CACs can be affected by the chain length. The differential and second derivatives of the conductance are also provided. [ABSTRACT FROM AUTHOR]

In the framework of factorization, based on the first-order of isospin violation, we study direct CP violation in the decay of $\bar{B}^0\rightarrow \rho^0(\omega)\rho^0(\omega) \rightarrow\pi^+\pi^-\pi^+\pi^-$ including the effect of ρ-ω mixing. The CP violation depends strongly on Cabibbo-Kobayashi-Maskawa (CKM) matrix elements and the effective parameter, Nc. Recently, the experimental data for the branching ratios of $\bar{B}^0 \rightarrow\rho^0\rho^0$ are accurate and we can give the strong constraint on the range of Nc. We find that the CP violating asymmetry is large and ranges from -82% to -98% via ρ-ω mixing mechanism when the invariant mass of the π+π- pair is in the vicinity of the ω resonance. We also discuss the possibility to observe the predicted CP violating asymmetries at the LHC. [ABSTRACT FROM AUTHOR]

The reaction of Ag2O and carboxylate ligands in ammonium solution results in three coordination polymers, [Ag(fbc)]n 1, [Ag2(cpd)]n 2 and [Ag2(idc)]n 3, where fbcH is 4-fluorobenzoic acid, cpdH2 is cyclopentane-1,1-dicarboxylic acid and idcH2 is iminodiacetic acid. The X-ray crystal structural analysis indicates that compounds 1 and 2 are two-dimensional frameworks and 3 is a three-dimensional framework. All the three complexes show clear Ag–Ag bonds and high cytotoxicity properties to normal cells and carcinoma cells. [Copyright &y& Elsevier]

Cell-targeted therapies (smart drugs), which selectively control cancer cell progression with limited toxicity to normal cells, have been developed to effectively treat some cancers. However, many cancers such as metastatic prostate cancer (PC) have yet to be treated with current smart drug technology. Here, we describe the thorough preclinical characterization of an RNA aptamer (A9g) that functions as a smart drug for PC by inhibiting the enzymatic activity of prostate-specific membrane antigen (PSMA). Treatment of PC cells with A9g results in reduced cell migration/invasion in culture and metastatic disease in vivo. Importantly, A9g is safe in vivo and is not immunogenic in human cells. Pharmacokinetic and biodistribution studies in mice confirm target specificity and absence of non-specific on/off-target effects. In conclusion, these studies provide new and important insights into the role of PSMA in driving carcinogenesis and demonstrate critical endpoints for the translation of a novel RNA smart drug for advanced stage PC. [ABSTRACT FROM AUTHOR]

Abstract: The morphology of the adult hyobranchial apparatus has played an important role in understanding the systematics and evolution of urodeles, but the hyobranchial apparatus of hynobiid salamanders has received little attention so far. In this study, the hyobranchial apparatus of eight hynobiid salamanders (Hynobius leechii, Onychodactylus zhangyapingi, Ranodon sibiricus, Batrachuperus pinchonii, Salamandrella keyserlingii, Liua shihi, Pachyhynobius shangchengensis and Pseudohynobius flavomaculatus) is described and compared based on the clearing and double-staining method. The basic elements of the hyobranchial apparatus of the eight species are similar, including one basibranchial, cornua, one pair of radial loops, one pair of ceratohyals, one pair of hypobranchials II, one pair of ceratobranchials II, one urohyal (absent in O. zhangyapingi), one pair of the complex of hypobranchial I and ceratobranchial I (separated in certain species). Although the hyobranchial apparatus is similar among hynobiid salamanders and shows a unique morphological pattern, there are also certain species-specific distinctions that may be used for specific or generic diagnosis. The results of an ancestral state reconstruction of five traits showed that the ossified basibranchial, the presence of a separated hypobranchial I and ceratobranchial I, the absence of a urohyal, the ossified hypobranchial I and the partially ossified ceratohyal are derived traits. The state shown by the traits of each species is consistent with the phylogenetic position of each species. Compared with other Urodela, the hyobranchial apparatus of this group shows certain distinctive features that may represent the diagnostic characters of the family Hynobiidae. The partially ossified ceratohyal is correlated with the habitat and represents an ecological adaptation. [Copyright &y& Elsevier]