The Microstructure and Mechanical Properties of Si3N4f/BN/SiBCN Microcomposites Fabricated by the PIP Process.

SiBCN ceramics based on SiC, BN and Si3N4 structures have good comprehensive properties such as high-temperature resistance, oxidation resistance, creep resistance and long life, which makes it one of the very promising ceramic material systems in military and aerospace fields, etc. In this study, SiBCN ceramics, as well as Si3N4f/BN/SiBCN microcomposites, were prepared by a polymer infiltration pyrolysis method using PBSZ as the polymer precursor. The PBSZ was completely ceramized by pyrolysis at 900 °C. The weight loss and elemental bonding forms of the products after the pyrolysis of the precursors hardly changed from 600 °C to 900 °C. After pyrolysis at 600 °C for 4 h and using the BN coating obtained from twice deposition as the interfacial phase, a more desirable weak interface of fiber/matrix with a binding strength of 21.96 ± 2.01 MPa can be obtained. Si3N4f/BN/SiBCN ceramic matrix microcomposites prepared under the same pyrolysis conditions have a relatively good tensile strength of 111.10 MPa while retaining a weak interface between the fibers and the matrix. The results of the study provide more theoretical and methodological support for the application of new composite structural ceramic material systems.

MMP19 Variants in Familial and Sporadic Idiopathic Pulmonary Fibrosis.

BACKGROUND: Gene variants have been identified in patients with familial or sporadic idiopathic pulmonary fibrosis (IPF). These variants may partially account for the genetic risk of IPF. The aim of this study was to identify potential genes involved in both familial and sporadic IPF. METHODS: A Han family in northern China with four members diagnosed with IPF was investigated in this observational study. Whole-exome sequencing (WES) was used to identify germline variants underlying disease phenotypes in five members of this family. Candidate rare variants were validated by Sanger sequencing in samples from 16 family members and 119 patients with sporadic IPF. The plasma levels of proteins encoded by the above candidate genes were also examined in 16 family members, 119 other patients with sporadic IPF and 120 age- and sex-matched healthy controls. RESULTS: In a Chinese Han family, MMP19 c.1222 C > T was identified in all familial IPF patients and six offspring from generations III and IV. This variant introduces a premature stop codon, which may damage protein function. Sanger sequencing revealed that 7.6% (9/119) of sporadic IPF patients harbored three MMP19 variants. The genetic risk analysis for pulmonary fibrosis showed that MMP19 c.1499 C > T and c.1316G > A were significantly associated with an increased risk of IPF (OR 3.66, p = 0.028 and OR 8.64, p < 0.001, respectively). The plasma levels of MMP19 were significantly higher in patients with sporadic or familial IPF than in healthy controls (all p < 0.001). CONCLUSIONS: MMP19 variants were identified in familial or sporadic IPF, thus providing a potential new clue into IPF pathogenesis.

COPD Assessment Test as a Screening Tool for Anxiety and Depression in Stable COPD Patients: A Feasibility Study.

Anxiety and depression are common comorbidities in chronic obstructive pulmonary disease (COPD) patients but are often under-diagnosed. We aimed to assess the suitability of the COPD Assessment Test (CAT) in screening anxiety and depression in patients with COPD. Stable COPD patients from a cross-sectional observational study were assessed by CAT. Anxiety and depression were identified using the Generalized Anxiety Disorder questionnaire (GAD-7) and Patient Health Questionnaire (PHQ-9), respectively. Logistic regression analysis and receiver operating characteristic curve analysis were used to identify factors associated with anxiety or depression and to calculate the predictive values. A total of 530 stable COPD patients were enrolled and of those, the proportions of anxiety and depression were 17.0% and 21.5%, respectively. The adjusted odds ratios of the CAT for the presence of anxiety and depression were 1.094 (95%CI: 1.057-1.131) and 1.143 (95%CI: 1.104-1.183), respectively. The CAT score had a significant predictive value for the presence of anxiety (AUC = 0.709) and depression (AUC = 0.791) with an optimum cutoff score of 15. However, the psychometric properties of CAT were undesirable, presenting high negative predictive value (NPV) but low positive predictive value (PPV). Among CAT items, analysis further showed that non-respiratory CAT components were superior to respiratory components in identifying both anxiety and depression. Our results indicated that CAT is more useful to exclude anxiety and depression rather than detect them.

Features of transbronchial lung cryobiopsy-diagnosed fibrotic hypersensitivity pneumonitis.

BACKGROUND: Hypersensitivity pneumonitis (HP) is a common type among all the interstitial lung diseases, and transbronchial lung cryobiopsy is an alternative diagnostic technique for interstitial lung diseases. In this study, we describe the clinical and pathological features of fibrotic hypersensitivity pneumonitis diagnosed with transbronchial lung cryobiopsy (TBLC). METHODS: A total of 46 diffused parenchyma lung disease (DPLD) patients received TBLC were included in this study. Medical records including medical history spirometry examinations, 6-min walk test (6MWT) results, high resolution computed tomographic (HRCT) scans, BAL, and histopathology were collected. Results of HRCT and histopathology were compared and classified, especially. RESULTS: Sixteen patients were diagnosed with fibrotic HP, the mean age of whom was 56.3 ± 12.1 years, and 62.5% of them were male. Three of the 16 patients had been misdiagnosed as tuberculosis and received antituberculosis medications, five patients had been diagnosed as unclassifiable pulmonary fibrosis, and five patients had been diagnosed as idiopathic pulmonary fibrosis (IPF). Thirteen (81.3%) patients had a normal lymphocyte count in BAL. The pathological features of usual interstitial pneumonia (UIP) were detected in 11 (68.8%) of the cases, poor defined granulomatous was detected in nine (56.3%) of the cases, and bronchiolocentric fibrosis was detected in two (12.5%) of the 16 cases. CONCLUSIONS: Fibrotic hypersensitivity pneumonitis should be included in differential diagnosis of pulmonary fibrosis. Pathological characteristics of fibrotic hypersensitivity pneumonitis could be demonstrated from cryobiopsy lung tissue. TBLC is recommended as an alternative diagnostic technique, which may improve the specificity of hypersensitivity pneumonia detection, and UIP is the most frequent pathological finding.

Reactive Flame-Retardant Cotton Fabric Coating: Combustion Behavior, Durability, and Enhanced Retardant Mechanism with Ion Transfer.

In recent years, we have witnessed numerous indoor fires caused by the flammable properties of cotton. Flame-retardant cotton deserves our attention. A novel boric acid and diethylenetriaminepenta (methylene-phosphonic acid) (DTPMPA) ammonium salt-based chelating coordination flame retardant (BDA) was successfully prepared for cotton fabrics, and a related retardant mechanism with ion transfer was investigated. BDA can form a stable chemical and coordination bond on the surface of cotton fibers by a simple three-curing finishing process. The limiting oxygen index (LOI) value of BDA-90 increased to 36.1%, and the LOI value of cotton fabric became 30.3% after 50 laundering cycles (LCs) and exhibited excellent durable flame retardancy. Fourier-transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) methods were used to observe the bonding mode and morphology of BDA on cotton fibers. A synergistic flame-retardant mechanism of condensed and gas phases was concluded from thermogravimetry (TG), cone calorimeter tests, and TG-FTIR. The test results of whiteness and tensile strength showed that the physical properties of BDA-treated cotton fabric were well maintained.

Research and Application Progress of Geopolymers in Adsorption: A Review.

Geopolymer is a porous inorganic material with a three-dimensional mesh structure, good mechanical properties, a simple preparation process (no sintering) and a low economic cost, and it is environmentally friendly. Geopolymer concrete has been widely used in the construction field, and many other studies have revealed that geopolymer will become one of the most promising inorganic materials with unique structure and properties. This paper provides a review of the development and current status of geopolymers and briefly explains the effects of material proportioning, experimental factors and activators on geopolymer performance. Because of the advantages of high specific surface area and high porosity, geopolymers could be used as adsorbent materials. This paper summarizes the research progresses of the adsorption of metal cations, anions, dyes, and gases by geopolymers, which emphasizes the geopolymer membranes in adsorption, and discusses the challenges and opportunities for the development of more efficient, sustainable and practical adsorption protocols.

Composition and Structure Progress of the Catalytic Interface Layer for Bipolar Membrane.

Bipolar membranes, a new type of composite ion exchange membrane, contain an anion exchange layer, a cation exchange layer and an interface layer. The interface layer or junction is the connection between the anion and cation exchange layers. Water is dissociated into protons and hydroxide ions at the junction, which provides solutions to many challenges in the chemical, environmental and energy fields. By combining bipolar membranes with electrodialysis technology, acids and bases could be produced with low cost and high efficiency. The interface layer or junction of bipolar membranes (BPMs) is the connection between the anion and cation exchange layers, which the membrane and interface layer modification are vital for improving the performance of BPMs. This paper reviews the effect of modification of a bipolar membrane interface layer on water dissociation efficiency and voltage across the membrane, which divides into three aspects: organic materials, inorganic materials and newly designed materials with multiple components. The structure of the interface layer is also introduced on the performance of bipolar membranes. In addition, the remainder of this review discusses the challenges and opportunities for the development of more efficient, sustainable and practical bipolar membranes.

Stochastic bursting in networks of excitable units with delayed coupling.

We investigate the phenomenon of stochastic bursting in a noisy excitable unit with multiple weak delay feedbacks, by virtue of a directed tree lattice model. We find statistical properties of the appearing sequence of spikes and expressions for the power spectral density. This simple model is extended to a network of three units with delayed coupling of a star type. We find the power spectral density of each unit and the cross-spectral density between any two units. The basic assumptions behind the analytical approach are the separation of timescales, allowing for a description of the spike train as a point process, and weakness of coupling, allowing for a representation of the action of overlapped spikes via the sum of the one-spike excitation probabilities.

Noise-induced swarming of active particles.

We report on the effect of spatially correlated noise on the velocities of self-propelled particles. Correlations in the random forces acting on self-propelled particles can induce directed collective motion, i.e., swarming. Even with repulsive coupling in the velocity directions, which favors a disordered state, strong correlations in the fluctuations can align the velocities locally leading to a macroscopic, turbulent velocity field. On the other hand, while spatially correlated noise is aligning the velocities locally, the swarming transition to globally directed motion is inhibited when the correlation length of the noise is nonzero, but smaller than the system size. We analyze the swarming transition in d-dimensional space in a mean field model of globally coupled velocity vectors.

Transition to synchrony in a three-dimensional swarming model with helical trajectories.

We investigate the transition from incoherence to global collective motion in a three-dimensional swarming model of agents with helical trajectories, subject to noise and global coupling. Without noise this model was recently proposed as a generalization of the Kuramoto model and it was found that alignment of the velocities occurs discontinuously for arbitrarily small attractive coupling. Adding noise to the system resolves this singular limit and leads to a continuous transition, either to a directed collective motion or to center-of-mass rotations.

Covalent Coupling-Stabilized Transition-Metal Sulfide/Carbon Nanotube Composites for Lithium/Sodium-Ion Batteries.

Transition-metal sulfides (TMSs) powered by conversion and/or alloying reactions are considered to be promising anode materials for advanced lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). However, the limited electronic conductivity and large volume expansion severely hinder their practical application. Herein, we report a covalent coupling strategy for TMS-based anode materials using amide linkages to bind TMSs and carbon nanotubes (CNTs). In the synthesis, the thiourea acts as not only the capping agent for morphology control but also the linking agent for the covalent coupling. As a proof of concept, the covalently coupled ZnS/CNT composite (CC-ZnS/CNT) has been prepared, with ZnS nanoparticles (∼10 nm) tightly anchored on CNT bundles. The compact ZnS-CNT heterojunctions are greatly beneficial to facilitating the electron/ion transfer and ensuring structural stability. Due to the strong coupling interaction between ZnS and CNTs, the composite presents prominent pseudocapacitive behavior and highly reversible electrochemical processes, thus leading to superior long-term stability and excellent rate capability, delivering reversible capacities of 333 mAh g-1 at 2 A g-1 over 4000 cycles for LIBs and 314 mAh g-1 at 5 A g-1 after 500 cycles for SIBs. Consequently, CC-ZnS/CNT exhibits great competence for applications in LIBs and SIBs, and the covalent coupling strategy is proposed as a promising approach for designing high-performance anode materials.

Telomerase gene variants and telomere shortening in patients with silicosis or asbestosis.

OBJECTIVES: Telomerase gene variants that lead to accelerated telomere shortening are linked to progressive-fibrosing interstitial lung diseases. However, little is known about their relationships with pneumoconiosis. This study aimed to identify TERT/TERC variants and leucocyte telomere lengths (LTL) in patients with silicosis or asbestosis. METHODS: In the present study, Sanger sequencing of TERT/TERC variants was performed in 193 Chinese Han patients with pneumoconiosis, including 109 with silicosis and 84 with asbestosis. Quantitative PCR was used to measure LTL in peripheral blood of the patients and 200 age and sex-matched healthy controls. RESULTS: In total, 7.3% patients with pneumoconiosis had 17 TERT/TERC variants. Among which 8.3% of patients with silicosis and 3.6% of patients with asbestosis had TERT variants, respectively. No TERC variants were detected in silicosis, whereas 3.6% of patients with asbestosis had TERC variants. Telomeres were significantly shorter in the patients with pneumoconiosis compared with healthy controls (p<0.001). No significant differences in LTL were found between TERT/TERC variant carriers and non-carriers. Exposure to silica dust was associated with the severity of pneumoconiosis after adjusting for covariates (OR 4.92, p=0.002). However, TERT/TERC variants and short telomeres were not associated with the severity of pneumoconiosis. CONCLUSION: Telomerase gene variants and short telomeres may be identified in the patients with silicosis and asbestosis in response to the exposure to silica or asbestos dust but are not related to disease severity.

Fractional Exhaled Nitric Oxide is Associated with the Severity of Stable COPD.

The value of fractional exhaled nitric oxide (FeNO) in patients with chronic obstructive pulmonary disease (COPD) remains unclear. We aimed to assess whether FeNO is a more valuable biomarker than blood eosinophil count for identifying clinical characteristics of COPD. Stable COPD patients (n = 390) were included and stratified by FeNO and blood eosinophil counts at recruitment. The demographic characteristics, lung functions, St George Respiratory Questionnaire (SGRQ), serum inhaled allergen-specific IgE and the exacerbations in the preceding 12 months were compared. Risk factors for moderate or severe exacerbation in the preceding 12 months were examined by binary regression analysis. The cross-sectional study showed that 167 patients had high level of FeNO (≥25 ppb) and 223 in low level (<25 ppb), while 138 patients had high blood eosinophil count (≥200 cells/µL) and 252 had low (<200 cells/µL). Compared with the high FeNO group, there were higher proportion of patients with GOLD III-IV, higher SGRQ scores, more exacerbations in the preceding 12 months, and with lower positive proportion of sIgE in the low FeNO group (p < 0.05 for all). However, these phenomena above were not associated with blood eosinophil count. Finally, high FeNO level was associated with a lower moderate or severe exacerbation in preceding 12 months (RR: 0.541 [95%CI 0.319-0.917], p = 0.023). In stable COPD patients, FeNO, but not blood eosinophil count was associated with the COPD severity and allergic airway inflammation. However, the role of FeNO in guiding personalized treatment of COPD patients need to be further investigated.

Prognosis of combined pulmonary fibrosis and emphysema: comparison with idiopathic pulmonary fibrosis alone.

BACKGROUND: Combined pulmonary fibrosis and emphysema (CPFE) is a syndrome characterized by the coexistence of upper lobe emphysema and lower lobe fibrosis. However, whether CPFE has a higher or lower mortality than idiopathic pulmonary fibrosis (IPF) alone is still not clear. In this study we conducted a meta-analysis to assess the survival rate (SR) of CPFE versus IPF alone in clinical trials. METHODS: We performed a systematic search of PubMed, Embase, and the Cochrane Central Register of Controlled Trials for trials published prior to 31 March 2018. Extracts from the literature were analyzed with Review Manager version 5.3. RESULTS: Thirteen eligible trials were included in this analysis (involving 1710 participants). Overall, the pooled results revealed that no statistically significant difference was detected in the 1-year [relative risk (RR) = 0.98, 95% confidence interval (CI): 0.94-1.03, p = 0.47], 3-year (RR = 0.83, 95% CI: 0.68-1.01, p = 0.06), and 5-year (RR = 0.80, 95% CI: 0.59-1.07, p = 0.14) SRs of CPFE versus IPF alone. CONCLUSIONS: CPFE exhibits a very poor prognosis, similar to IPF alone. Additional studies are needed to provide more convincing data to investigate the natural history and outcome of patients with CPFE in comparison to IPF. The reviews of this paper are available via the supplemental material section.

Recurrent primary spontaneous pneumothorax in a large Chinese family: a clinical and genetic investigation.

BACKGROUND: Primary spontaneous pneumothorax (PSP) is a common manifestation of Birt-Hogg-Dubé (BHD) syndrome, which is an autosomal dominant disorder caused by mutation of the folliculin (FLCN) gene. This study was established to investigate the mutation of the FLCN gene and the phenotype in a family with PSP. METHODS: We investigated the clinical and genetic characteristics of a large Chinese family with recurrent spontaneous pneumothorax. Genetic testing was performed by Sanger sequencing of the coding exons (4-14 exons) of the FLCN gene. RESULTS: Among ten affected members in a multi-generational PSP kindred, with a total of 18 episodes of spontaneous pneumothorax, the median age for the initial onset of pneumothorax was 42.5 years (interquartile range: 28.8-57.2 years). Chest computed tomography scan of the proband showed pulmonary cysts and pneumothorax. A novel nonsense mutation (c.1273C>T) in exon 11 of FLCN gene that leads to a pre-mature stop codon (p.Gln425*) was identified in the family. The genetic analysis confirmed the diagnosis of BHD syndrome in this family in the absence of skin lesions or renal tumors. CONCLUSIONS: A novel nonsense mutation of FLCN gene was found in a large family with PSP in China. Our results expand the mutational spectrum of FLCN gene in patients with BHD syndrome.

Stochastic bursting in unidirectionally delay-coupled noisy excitable systems.

We show that "stochastic bursting" is observed in a ring of unidirectional delay-coupled noisy excitable systems, thanks to the combinational action of time-delayed coupling and noise. Under the approximation of timescale separation, i.e., when the time delays in each connection are much larger than the characteristic duration of the spikes, the observed rather coherent spike pattern can be described by an idealized coupled point process with a leader-follower relationship. We derive analytically the statistics of the spikes in each unit, the pairwise correlations between any two units, and the spectrum of the total output from the network. Theory is in good agreement with the simulations with a network of theta-neurons.

Repulsively coupled Kuramoto-Sakaguchi phase oscillators ensemble subject to common noise.

We consider the Kuramoto-Sakaguchi model of identical coupled phase oscillators with a common noisy forcing. While common noise always tends to synchronize the oscillators, a strong repulsive coupling prevents the fully synchronous state and leads to a nontrivial distribution of oscillator phases. In previous numerical simulations, the formation of stable multicluster states has been observed in this regime. However, we argue here that because identical phase oscillators in the Kuramoto-Sakaguchi model form a partially integrable system according to the Watanabe-Strogatz theory, the formation of clusters is impossible. Integrating with various time steps reveals that clustering is a numerical artifact, explained by the existence of higher order Fourier terms in the errors of the employed numerical integration schemes. By monitoring the induced change in certain integrals of motion, we quantify these errors. We support these observations by showing, on the basis of the analysis of the corresponding Fokker-Planck equation, that two-cluster states are non-attractive. On the other hand, in ensembles of general limit cycle oscillators, such as Van der Pol oscillators, due to an anharmonic phase response function as well as additional amplitude dynamics, multiclusters can occur naturally.

Acinetobacter baumannii outer membrane protein A induces HeLa cell autophagy via MAPK/JNK signaling pathway.

Autophagy is an evolutionary conserved self-balancing process that plays an important role in maintaining cellular homeostasis via the clearance of damaged organelles and misfolded proteins. Infection-triggered autophagy specifically inhibits the invasion of intracellular bacterial replication and hence protects the cells from microbial infections. It has been reported that Acinetobacter baumannii trigger cell autophagy. However, the role of its virulence protein OmpA remains unclear. Therefore, this study aimed to explore the effects of Acinetobacter baumannii OmpA on cell autophagy and its underlying molecular mechanisms. The results showed that OmpA induced autophagy in HeLa and RAW264.7 cells, increased LC3BII expression, and hindered p62 degradation. Moreover, OmpA triggered incomplete autophagy by interfering the fusion of autophagosomes with lysosomes. Besides, OmpA activated MAPK/JNK signaling pathway and enhanced the phosphorylation levels of JNK, p38, and ERK, c-Jun. Inhibition of JNK signaling pathway suppressed OmpA-induced autophagy in HeLa cells. Ab wild-type strains carrying OmpA triggered incomplete autophagy and resulted in a large number of IL-1ß production. Ab-△OmpA strain (OmpA gene mutation) restored autophagic flux and reduced the accumulation of p62 and the release of IL-1ß in HeLa cells. Rapamycin activated autophagy to inhibit OmpA-induced IL-1ß secretion and protect HeLa cells from inflammatory damage. Collectively, these results suggest that OmpA can induce autophagy in HeLa cells through MAPK/JNK signaling pathway. Pre-treatment with Rapamycin activates autophagy and protects against cell death.

A Rare Missense Variant in Telomerase Reverse Transcriptase is Associated with Idiopathic Pulmonary Fibrosis in a Chinese Han Family.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is an age-related and progressive interstitial lung disease. Up to 20% of cases of IPF cluster in families, genetic factors contribute significantly to the pathogenesis of the disease. This study aimed to explore the association between rare genetic variants and IPF in Chinese Han families. METHODS: A Han family, comprising three IPF patients and five unaffected their first-degree relatives, and 100 ethnically matched control individuals from North China were enrolled in this study. Peripheral blood was collected, and genomic DNA was extracted. To elucidate if rare genetic variants are associated with the familial IPF, we performed whole-exome sequencing of affected members from a Chinese Han IPF family. Candidate rare variants were then confirmed by Sanger sequencing. RESULTS: We identified a potentially damaging rare variant-a heterozygous mutation c.2146G>A in exon 6 of the gene encoding for telomerase reverse transcriptase (TERT), which results in an amino acid substitution (p.Ala716Thr). We confirmed the missense mutation by Sanger sequencing in all the affected family members but did not detect this mutation in 100 ethnically matched healthy controls. Patients carried this mutation were characterized by the frequently acute exacerbation of IPF phenotype, with poor prognosis. The mean time to death was 2.8 years after diagnosis. CONCLUSION: Using next-generation sequencing technology in familial IPF patients, we identified the heterozygous rare variant in TERT gene, and strengthened the importance of genetic variants in telomere-related pathogenesis in Chinese IPF patients.

Mesoporous Graphitic Carbon-Encapsulated Fe2 O3 Nanocomposite as High-Rate Anode Material for Sodium-Ion Batteries.

A mesoporous graphitic carbon-encapsulated Fe2 O3 nanocomposite is synthesized as a superior anode material for sodium-ion batteries. A threefold strategy is adopted to achieve a high rate performance. First, the mesoporous structure with high specific surface area and large pore volume facilitates the transfer of electrolyte and accommodates the large volume change. Secondly, graphitic carbon encapsulation further improves the electronic conductivity of the nanocomposite. Finally, ultrafine Fe2 O3 nanocrystals effectively shorten the Na+ diffusion length. Consequently, this nanocomposite exhibits stable and fast Na+ storage, thus leading to excellent rate capability and cyclability. Pseudocapacitive behavior is found to dominate in the redox reactions, accounting for the outstanding rate and cycling performance. In addition, full cells, assembled with O3-Na0.9 [Cu0.22 Fe0.30 Mn0.48 ]O2 as cathodes, present good electrochemical performance.