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In this paper we provide new characterizations of the Gehring–Hayman theorem from the point of view of Gromov boundary and uniformity. We also determine the critical exponents for the uniformized space to be a uniform space in the case of the hyperbolic spaces, the model spaces \(\mathbb{M}^{\kappa}_n\) of the sectional curvature \(\kappa

In this paper, we establish several characterizations for quasihyperbolic mappings in Banach spaces. As an application, we provide a partial solution to a problem left open by Vaisala regarding the local properties of quasihyperbolic mappings.

In the process of synthetic aperture radar image noise suppression by the bi‐dimensional empirical mode decomposition (BEMD) algorithm, the edge effect is a key problem in the BEMD operation. To weaken this effect, an improved BEMD‐kernel principal component analysis (BEMD‐KPCA) method of image denoising is proposed in this study. Experimental results show that the BEMDKPCA algorithm has a good capability of improving edge effects in the BEMD decomposition process and satisfying the requirement of the reliable decomposition results. Compared with the traditional BEMD method, the proposed approach has a good effect on suppressing speckle noise. Additionally, the denoised image from the decomposed components of the IMFs processed by the BEMD‐KPCA method sufficiently preserves the edge and detail information, confirming its high coherency with the original image.

Sepsis-induced acute lung injury (ALI) is associated with poor survival rates. The identification of potential therapeutic targets for preventing sepsis-induced ALI has clinical importance. Here, we show that estrogen-related receptor alpha (ERRα) protects against sepsis-induced ALI through ERRα-mediated apoptosis and autophagy. ERRα was upregulated in inflammation models from lipopolysaccharides (LPS)-treated rat pulmonary microvascular endothelial cells (PMVECs) and cecal ligation and puncture (CLP)-induced septic rats. In vitro , overexpression of ERRα ameliorated LPS-induced degradation of adherens junctional molecules, upregulation of bax, cleaved caspase 3 and cleaved caspase 9 levels and downregulation of anti-apoptotic protein Bcl-2 level, and promoted the formation of autophagic flux, while the knockdown of ERRα exacerbated LPS-induced apoptosis and inhibited the activation of autophagy. Rats injected with ERRα agonist were subjected to CLP to elucidate the role of ERRα in sepsis-induced ALI in vivo . Administration of ERRα agonist alleviated the pathological damage of lung tissue, increased the levels of tight junction proteins and adherens junction proteins, and decreased the expression of apoptosis-related proteins. Promoting the expression of ERRα significantly enhanced the process of autophagy and reduced CLP-induced ALI. Mechanistically, ERRα is essential to regulate the balance between autophagy and apoptosis to maintain the adherens junctional integrity. These findings indicate that activation of ERRα provides a new therapeutic opportunity to prevent sepsis-induced ALI.

The aim of this paper is to investigate the equivalence conditions for uniform perfectness of quasimetric spaces. We also obtain the invariance property of uniform perfectness under quasim?bius mappings in quasimetric spaces. In the end, two applications are given.

By introducing new deformations on symbolic Cantor sets and ultrametric spaces, we prove that doubling ultrametric spaces admit bilipschitz embedding into Cantor sets. If in addition the spaces are uniformly perfect, we show that they are quasisymmetrically equivalent to Cantor sets. As an application, we provide a new proof for a recent work of Heer (Anal. Geom. Metr. Spaces, 2017) regarding quasim\"obius uniformization of Cantor set., Comment: 8 pages, BMMS revised

Supplemental Digital Content is available in the text., Objectives: To investigate whether XueBiJing injection improves clinical outcomes in critically ill patients with severe community-acquired pneumonia. Design: Prospective, randomized, controlled study. Setting: Thirty-three hospitals in China. Patients: A total of 710 adults 18–75 years old with severe community-acquired pneumonia. Interventions: Participants in the XueBiJing group received XueBiJing, 100 mL, q12 hours, and the control group received a visually indistinguishable placebo. Measurements and Main Results: The primary outcome was 8-day improvement in the pneumonia severity index risk rating. Secondary outcomes were 28-day mortality rate, duration of mechanical ventilation and total duration of ICU stay. Improvement in the pneumonia severity index risk rating, from a previously defined endpoint, occurred in 203 (60.78%) participants receiving XueBiJing and in 158 (46.33%) participants receiving placebo (between-group difference [95% CI], 14.4% [6.9–21.8%]; p < 0.001). Fifty-three (15.87%) XueBiJing recipients and 84 (24.63%) placebo recipients (8.8% [2.4–15.2%]; p = 0.006) died within 28 days. XueBiJing administration also decreased the mechanical ventilation time and the total ICU stay duration. The median mechanical ventilation time was 11.0 versus 16.5 days for the XueBiJing and placebo groups, respectively (p = 0.012). The total duration of ICU stay was 12 days for XueBiJing recipients versus 16 days for placebo recipients (p = 0.004). A total of 256 patients experienced adverse events (119 [35.63%] vs 137 [40.18%] in the XueBiJing and placebo groups, respectively [p = 0.235]). Conclusions: In critically ill patients with severe community-acquired pneumonia, XueBiJing injection led to a statistically significant improvement in the primary endpoint of the pneumonia severity index as well a significant improvement in the secondary clinical outcomes of mortality, duration of mechanical ventilation and duration of ICU stay.

The main purpose of this paper is to investigate the properties of a mapping which is required to be roughly bilipschitz with respect to the Apollonian metric (roughly Apollonian bilipschit...

This study is based on the belief of that enquiry-based learning should be made an integral part of any student’s learning, especially at university level. To find out the students’ perceptions towards library user education, 426 questionnaire surveys have been collected from the Peking University (PKU), China and the University of Tsukuba (UT), Japan. The results of this study indicate that compared with UT, PKU students on the whole expressed higher ratings in many areas towards the user education programs provided by their respective library, and they also had a more positive view about the professional competence of the user education (reference services) librarians. The researchers believed that the different perceptions found between the PKU and UT groups were a direct result of the distinctive learning practices and curricular requirements exercised between the two universities. There are not many articles that explore the relation between enquiry-based learning and the library user education in Asia. The findings of this study are useful for identifying the different learning modes amongst these two groups of students, as well as other barriers that were preventing the library user education programs to be integrated into Inquiring-based learning, and the university’s core curriculum as a whole.

Inflammation and oxidative stress are critical pathologies that contribute to sepsis-induced acute lung injury (ALI). This study investigated the regulatory role of estrogen-related receptor alpha (ERRα) in an experimental model of sepsis-induced ALI. In vivo, a cecal ligation and puncture- (CLP-) induced ALI model was established in anesthetized rats. Animals were then randomly assigned to receive an intraperitoneal injection of vehicle or ERRα inverse agonist (XCT-790, 2.5 mg/kg). Administration of XCT-790 significantly aggravated a sepsis-induced increase in pathological damage of lung tissues, lung endothelial permeability, myeloperoxidase (MPO) activity in lung tissues, production of serum inflammatory factors, and inflammatory cell accumulation in bronchoalveolar lavage fluid. In addition, XCT-790 treatment exacerbated a CLP-induced decrease in lung superoxide dismutase and an increase in lung malondialdehyde levels. In vitro, the exposure of rat pulmonary microvascular endothelial cells (PMVECs) to lipopolysaccharide (LPS) resulted in increased endothelial permeability and reduced expression of tight junction protein ZO-1, Occludin, JAM-A, and adherens junction protein VE-cadherin, which were further deteriorated by knockdown of ERRα. In addition, LPS-triggered inflammatory factor production and increase in the expression of phosphorylated IκBα and NF-κB p65 were also exacerbated by silencing ERRα gene. Meanwhile, knockdown of ERRα dramatically promoted LPS-activated mitochondrial reactive oxygen species production and LPS-induced downregulation of Sirt3 protein levels in rat PMVECs. Taken together, our present study provides evidences that ERRα functions as a novel negative modulator of sepsis-induced ALI in rats. The underlying mechanisms responsible for ERRα-elicited effects are largely dependent on the regulation of inflammatory response and oxidative stress.

The main purpose of this paper is to study the characterizations of John spaces. We obtain five equivalent characterizations for length John spaces. As an application, we establish a dimension-free quasisymmetric invariance of length John spaces. This result is new also in the case of the Euclidean space.

Background There is a lack of large-scale epidemiological data on the clinical practice of enteral nutrition (EN) feeding in China. This study aimed to provide such data on Chinese hospitals and to investigate factors associated with EN delivery. Methods This cross-sectional study was launched in 118 intensive care units (ICUs) of 116 mainland hospitals and conducted on April 26, 2017. At 00:00 on April 26, all patients in these ICUs were included. Demographic and clinical variables of patients on April 25 were obtained. The dates of hospitalization, ICU admission and nutrition initiation were reviewed. The outcome status 28 days after the day of investigation was obtained. Results A total of 1953 patients were included for analysis, including 1483 survivors and 312 nonsurvivors. The median study day was day 7 (IQR 2–19 days) after ICU entry. The proportions of subjects starting EN within 24, 48 and 72 h after ICU entry was 24.8% (84/352), 32.7% (150/459) and 40.0% (200/541), respectively. The proportion of subjects receiving > 80% estimated energy target within 24, 48, 72 h and 7 days after ICU entry was 10.5% (37/352), 10.9% (50/459), 11.8% (64/541) and 17.8% (162/910), respectively. Using acute gastrointestinal injury (AGI) 1 as the reference in a Cox model, patients with AGI 2–3 were associated with reduced likelihood of EN initiation (HR 0.46, 95% CI 0.353–0.599; p

We show that every quasihyperbolic geodesic in a John space admitting a roughly starlike Gromov hyperbolic quasihyperbolization is a cone arc. This result provides a new approach to the elementary metric geometry question, formulated in \cite[Question 2]{Hei89}, which has been studied by Gehring, Hag, Martio and Heinonen. As an application, we obtain a simple geometric condition connecting uniformity of the space with the existence of Gromov hyperbolic quasihyperbolization.

Suppose that $X$ and $Y$ are quasiconvex and complete metric spaces, that $G\subset X$ and $G'\subset Y$ are domains, and that $f: G\to G'$ is a homeomorphism. In this paper, we first give some basic properties of short arcs, and then we show that: if $f$ is a weakly quasisymmetric mapping and $G'$ is a quasiconvex domain, then the image $f(D)$ of every uniform subdomain $D$ in $G$ is uniform. As an application, we get that if $f$ is a weakly quasisymmetric mapping and $G'$ is an uniform domain, then the images of the short arcs in $G$ under $f$ are uniform arcs in the sense of diameter., Comment: Comput. Methods Funct. Theory;2018. arXiv admin note: substantial text overlap with arXiv:1501.07375

Aiming at the problems existing in the current radio energy transmission system, we propose a wireless power transmission (WPT) system with the parallel–parallel (PP)-compensated structure. The transmitter of the transmission system adopts a separate topological structure to suppress the current shock and noise. In order to improve the efficiency of the WPT, reduce the static loss, and reduce the current oscillation loss on the power side, the input current ripple can be improved by two parallel phase-shifting methods. In this paper, two topological theories are analyzed, and the simulation and experiment results verify the correctness of these theories under both static and on-load conditions. After the final two-way phase-shift, 61.99% of the ripple is reduced. It provides a new approach for the design of WPT systems with PP structure.

Most studies on Chinese academic resource selection have used a qualitative approach, focusing on issues such as resource distribution and accessibility. To fill the research gap, the current article analyses the responses of 190 undergraduate students of the Peking University to a questionnaire survey, revealing various academic resources' access methods, usage frequency, and access obstacles, while exploring underlying factors affecting resource usage with a focus on the language impacts. Further, the application of the innovation diffusion model to study the utilization of library electronic resources is novel. The current findings showed that open-shelf books, electronic journals, and open-access resources were highly utilized because of their high quality. Electronic resources were displacing printed resources. Based on Bass's innovation diffusion model, diffusion of different electronic resources among undergraduate students fit well with the S-curve, though with significantly different slopes, for ...

Background: Surfactant protein-A (SP-A) contributes to the regulation of sepsis-induced acute kidney injury. In a previous study, we demonstrated that the expression of SP-A in the human renal tubular epithelial (HK-2) cells can be stimulated by lipopolysaccharide (LPS). The present study evaluated the possible signal-transducing mechanisms of LPS-induced SP-A biosynthesis in the HK-2 cells. Methods: Tetrazolium salt colorimetry (MTT) assay was used to detect cell viability of HK-2 cells after LPS stimulation on different time points. HK-2 cells were stimulated with 100 ng/ml of LPS for different durations to determine the effects of LPS on SP-A and toll-like receptor 4 (TLR4) messenger RNA (mRNA) expression, as well as phosphorylation of mitogen-activated/extracellular signal-regulated kinase (MEK) 1, extracellular signal-regulated kinase 1/2 (ERK1/2), p38 mitogen-activated protein kinase (p38MAPK), and nuclear factor-kappa B (NF-κB) inhibitor-alpha (IkB-α). Then, HK-2 cells were pretreated with CLI-095, a TLR4 inhibitor, to analyze mRNA and protein levels of SP-A and TLR4 and expression of NF-κB in the cytoplasm and nucleus of HK-2 before LPS exposure. Results: HK-2 cells exposed to 100 ng/ml of LPS for 1, 6, and 24 h did not affect cell viability which showed no toxic effect of 100 ng/ml LPS on cells (P = 0.16); however, the biosynthesis of SP-A mRNA and protein in HK-2 cells was significantly increased (P = 0.02). As to the mechanism, LPS enhanced transmembrane receptor TLR4 protein expression. Sequentially, LPS time dependently augmented phosphorylation of MEK1, ERK1/2, and p38MAPK. In addition, levels of phosphorylated IκB-α and nuclear NF-κB were augmented with LPS exposure for 2 h. LPS-induced SP-A and TLR4 mRNA as well as NF-κB expression were significantly inhibited by pretreatment with CLI-095. Conclusions: The present study exhibited that LPS can increase SP-A synthesis in human renal epithelial cells through sequentially activating the TLR4-related MEK1-ERK1/2-NF-κB-dependent pathway. Key words: Acute Kidney Injury; HK-2 Cells; Lipopolysaccharide; Signal Pathway; Surfactant Protein-A

The aim of this note is to construct a ψ-uniform domain G in the complex plane C such that the identity mapping id: ( G , j G ) → ( G , k G ) is not an η-quasi-symmetric mapping for any homeomorphism η: [ 0 , ∞ ) → [ 0 , ∞ ) . This result shows that the answer to the related open problem, posed by Hasto, Klen, Sahoo and Vuorinen, is negative.

Tetraspanin 12 (TSPAN12), as an earliest member of tetraspanin family, has been recently shown to be highly expressed in several malignant tumors, such as lung cancer and breast cancer, which plays an important role in regulating cell proliferation, migration and invasion. However, the functional roles of TSPAN12 in colorectal cancer (CRC) remain largely unclear. In this study, the expression of TSPAN12 was up-regulated compared to that in paracarcinoma tissues. Higher TSPAN12 expression was significantly correlated with TNM stage, tumor size and lymph node metastasis. The vitro functional analysis, including MTT, colony formation, flow cytometry and transwell assays indicated that lentivirus-mediated TSPAN12 knockdown significantly suppressed cell proliferation, migration and invasion, induced cell apoptosis of CRC cells. In addition, knockdown of TSPAN12 remarkably decreased the growth of subcutaneously inoculated tumors in nude mice. Our findings for the first time supported that TSPAN12 might play a positive role in the regulation of CRC cell proliferation, migration and invasion. The inhibition of TSPAN12 may serve as a novel promising therapeutic strategy against human CRC.

Background High mortality rate of critically-ill patients could be induced by sepsis and septic shock, which is the extremely life threatening. The purpose of this work is to identify and evaluate the potential regulatory mechanism of LPS-induced inflammation associated with miR-6835 and lipid rafts in HUVECs. Methods The 3’ UTR luciferase activity of AdipoR1 was detected, which was predicted the potential target gene of miR-6835. Moreover, the treated HUVECs with or without inhibitors or mimics of miR-6835 were used. Furthermore, the bio-functions of HUVECs were explored. The protein expression levels of SIRT-1, AMPK, and AdipoR1 were assessed, which were involved in the AdipoR1 signaling pathway. Then, the interaction between TLR-4 and AdipoR1 in lipid rafts and its mediation role on LPS-induced inflammation was investigated in HUVECs. Results MiR-6835 targeted directly on AdipoR1, and suppressed its expression in mRNA (mimics of miR-6835: 0.731±0.016 vs control: 1.527±0.015, P

Sepsis is a major cause of acute kidney injury (AKI) with high rates of morbidity and mortality. Surfactant proteins A and D (SP-A, SP-D) play a critical role in host defense and regulate inflammation during infection. Recent studies indicate SP-A and SP-D are expressed in the kidney. The current study examines the role of SP-A and SP-D in the pathogenesis of sepsis-induced AKI. Wild-type (WT) and SP-A/SP-D double-knockout (KO) C57BL/6 mice were treated by cecal ligation and puncture (CLP) or sham surgery. Histological, cellular, and molecular indices of kidney injury were investigated in septic mice 6 and 24 h after CLP. Twenty-four hours after CLP, kidney injury was more severe, renal function was decreased, and blood creatinine and blood urea nitrogen were higher in septic SP-A/SP-D KO mice (P < 0.05, versus septic WT mice). Kidney edema and vascular permeability were increased in septic SP-A/SP-D KO mice (P < 0.01, versus septic WT mice). Apoptotic cells increased significantly (P < 0.01) in the kidney of septic SP-A/SP-D KO mice compared with septic WT mice. Molecular analysis revealed levels of Bcl-2 (an inhibitor of apoptosis) were lower and levels of caspase 3 (a biomarker of apoptosis) were higher in the kidney of septic SP-A/SP-D KO mice (P < 0.01, versus septic WT mice). Furthermore, levels of nuclear factor κB and phosphorylated IκB-α increased significantly in the kidney of septic SP-A/SP-D KO mice compared with septic WT mice, suggesting SP-A/SP-D KO mice have a more pronounced inflammatory response to sepsis. We conclude SP-A and SP-D attenuate kidney injury by modulating inflammation and apoptosis in sepsis-induced AKI.

In this paper, we investigate the relationship between semisolidity and locally weak quasisymmetry of homeomorphisms in quasiconvex and complete metric spaces. Our main objectives are to (1) generalize the main result in [X. Huang and J. Liu, Quasihyperbolic metric and quasisymmetric mappings in metric spaces, Trans. Amer. Math. Soc. 367 (2015), 6225-6246] together with other related results, and (2) give a complete answer to the open problem given in [X. Huang and J. Liu, Quasihyperbolic metric and quasisymmetric mappings in metric spaces, Trans. Amer. Math. Soc. 367 (2015), 6225-6246]. As an application, we prove that the composition of two locally weakly quasisymmetric mappings is a locally weakly quasisymmetric mapping and that it is quasiconformal., 34 pages, 1 figures

Surfactant protein A (SP-A) contributes to the regulation of sepsis-induced acute lung injury. In a previous study, we demonstrated the expression and localization of SP-A in the kidneys. The present study evaluated the effect of SP-A on lipopolysaccharide (LPS)-induced tumor necrosis factor-a (TNF-α) expression and its underlying mechanisms in the human renal tubular epithelial (HK-2) cells.Indirect immunofluorescence assay was used to detect SP-A distribution and expression in HK-2 cells. HK-2 cells were treated with various concentrations of LPS (0, 0.1, 1, 2, 5, and 10 mg/L) for 8 hours and with 5 mg/L LPS for different times (0, 2, 4, 8, 16, and 24 hours) to determine the effects of LPS on SP-A and TNF-α expression. Then, HK-2 cells were transfected with SP-A siRNA to analyze nuclear factor κB (NF-κB) P65 and TNF-α expression of HK-2 cells after LPS-treatment.Indirect immunofluorescence assay revealed that SP-A is localized to the membrane and cytoplasm of HK-2 cells. Interestingly, SP-A1/SP-A2 and TNF-a expression were found to be significantly increased in HK-2 cells upon LPS treatment. Transfection of LPS-treated HK-2 cells with SP-A siRNA resulted in significant increases in the levels of NF-κB P65 protein and TNF-α mRNA and protein compared to those in non-transfected LPS-treated HK-2 cells.SP-A plays an important role in protecting cells against sepsis-induced acute kidney injury by inhibiting NF-κB activity to modulate LPS-induced increase in TNF-α expression.

A model of cerebral ischemia and reperfusion was established in mice. Mice were treated with ketamine via intraperitoneal injection immediately following ischemia or ischemia/reperfusion. Ketamine did not remarkably change infarct volume in mice immediately following ischemia, but injection immediately following ischemia/reperfusion significantly decreased infarct volume. Ketamine injection immediately after ischemia or ischemia/reperfusion inhibited c-Jun protein expression in mouse hippocampus, but nuclear factor kappa B expression was unaltered. In addition, the Longa scale score for neural impairment was not reduced in mice following cerebral ischemia/reperfusion. These results indicate that ketamine can protect mice against cerebral ischemia and reperfusion injury by modulating c-Jun protein expression in mouse hippocampus.

Purpose To investigate and compare the effects of propofol and midazolam on inflammation and oxidase stress in children with congenital heart disease undergoing cardiac surgery. Materials and Methods Thirty-two ASA class I-II children with congenital heart disease undergoing cardiac surgery were randomly divided into two groups: propofol combined with low dose fentanyl (PF group, n = 16) and midazolam combined with low dose fentanyl (MF group, n = 16). Tracheal extubation time and length of Intensive Care Unit (ICU) stay were recorded. Blood samples were taken before operation (T0), at 2 h after release of the aorta cross-clamp (T3) and at 24 h after operation (T4) to measure interleukin 6 (IL-6), IL-8, superoxide dismutase (SOD) and malondialdehyde (MDA) levels. Myocardium samples were collected at 10-20 min after aorta cross-clamp (T1) and at 10-20 min after the release of the aorta cross-clamp (T2) to detect heme oxygenase-1 (HO-1) expression. Results Tracheal extubation time and length of ICU stay in PF group were significantly shorter than those of the MF group (p < 0.05, respectively). After cardiopulmonary bypass, IL-6, IL-8 and MDA levels were significantly increased, and the SOD level was significantly reduced in both two groups, but PF group exhibited lower IL-6, IL-8 and MDA levels and higher SOD levels than the MF group (p < 0.05, respectively). The HO-1 expression in the PF group was significantly higher than that in MF group at the corresponding time points (p < 0.05, respectively). Conclusion Propofol is superior to midazolam in reducing inflammation and oxidase stress and in improving post-operation recovery in children with congenital heart disease undergoing cardiac surgery.

Diels-Alder reactions of 1,1-dimethyl-2,3,4,5-tetraphenyl-1-silacyclopentadiene, 1,1-dimethyl-2,5-diphenyl-1-silacyclopentadiene and 1,1-dimethyl-3,4-diphenyl-2-silacyclopentadiene with maleic anhydride have been carried out. The rates of these second order reactions have been measured by 1 H FT NMR over a range of temperatures. Arrhenius plot of these data yield the activation parameters for these reactions. The synthesis of 1,1-dimethyl-3,4-diphenyl-1-silacyclopentadiene is reported.