[Marked improvement in rheumatoid lung nodules after treatment with tocilizumab combined with glucocorticoids and leflunomide: a case report and literature review].

Rheumatoid arthritis (RA), a chronic autoimmune disorder, is characterized by erosive inflammation of bone and cartilage, leading to progressive joint destruction. Pulmonary involvement occurs in approximately 60% of RA patients, manifests most commonly as interstitial lung disease and, less commonly, as rheumatoid lung nodules. Here, we report a 50-year-old woman, non-smoker, with recurrent cough and sputum of 7 years' duration, accompanied by a chest CT showing multiple cavitary nodules in both lungs. She had been treated empirically at several medical centers and was finally diagnosed with rheumatoid lung nodules. Marked improvement in rheumatoid lung nodules was observed after treatment with tocilizumab in combination with glucocorticoids and leflunomide. The aim of this study was to improve clinicians' understanding of rheumatoid lung nodules by analyzing the clinical features, diagnosis, and treatment of this case, and reviewing the relevant medical literature.

[Prognosis and related risk factors of acute respiratory distress syndrome in elder patients].

Objective: To study the risk factors associated with the hospital survival rate of elder patients with acute respiratory distress syndrome (ARDS) in Medical/Respiratory Intensive Care Units (MICUs/RICUs) by evaluating the prognosis, and therefore to provide insight into patient treatment strategy. Methods: Twenty MICUs/RICUs of 19 general hospitals in mainland China participated in the multicenter prospective cohort study carried out from Mar 1st, 2016 to Feb 28th, 2018. Patients who met the criteria of Berlin ARDS and older than 65 years were recruited. Baseline data, risk factors of ARDS, ventilator setup and prognosis data were collected from all patients. Univariant and multivariant regression analysis were conducted to analyze the factors associated with the prognosis. Results: 170 elder ARDS patients (age≥65 years) met the Berlin ARDS criteria, among whom 8.8% (15/170), 42.9% (73/170) and 48.2% (82/170) patients had mild, moderate and severe ARDS, respectively. The most common predisposing factor for elder ARDS was pneumonia, which was present in 134 patients (78.8%). 37.6% (64/170) patients were treated with noninvasive mechanical ventilation (NIV), but 43.8% (28/64) cases experienced treatment failure. 76.5% (130/170) patients were treated with invasive mechanical ventilation. All patients 80 years or older were given invasive mechanical ventilation. 51.8% (88/170) cases had complications of non-pulmonary organ failure. 61.8% (105/170) patients deceased during hospital stay. Multivariant logistic analysis showed that the independent risk factors for hospital survival rate in elder patients with ARDS were SOFA score (P=0.030, RR=0.725, 95% CI 0.543-0.969), oxygen index after 24 hours of ARDS diagnosis (P=0.030, RR=0.196, 95% CI 0.045-0.853), accumulated fluid balance within 7 days after diagnosis of ARDS (P=0.026, RR=1.000, 95% CI 1.000-1.000) and shock (P=0.034, RR=0.140, 95% CI 0.023-0.863). Conclusion: Among 20 ICUs, the high mortality rate of elder patients with ARDS was correlated with higher 24 hour SOFA score, lower 24 hour oxygen index after ARDS diagnosis, more positive fluid balance within 7 days and concomitant shock. The conservative fluid strategy within 7 days of ARDS diagnosis may benefit the elder ARDS patients.

[Changes and implications of esophageal function in patients with chronic cough induced by gastroesophageal reflux].

Objective: To explore the changes in the esophageal function and their association with the therapeutic outcome in patients with gastroesophageal reflux-induced chronic cough (GERC). Methods: One hundred thirty-five patients with definite GERC consecutively referred to our respiratory clinic were recruited into the study between January 2012 and August 2015.Cough was due to acid reflux in 81 patients and non-acid reflux in 54 patients, with the favorable response to the standard antireflux therapy in 88 patients and to the intensified antireflux treatment in 47 patients. The control groups included 26 patients with gastroesphageal reflux disease without cough and 22 healthy volunteers. All the subjects underwent an esophageal manometry from which the parameters were recorded, including the pressure, length and relaxation rate of lower esophageal sphincter, and the peristaltic contractive amplitude, wave velocity and contractive time of esophagus. The data were combined with the results of multi-channel intraluminal impedance combined with pH monitoring to analyze the changes of esophageal function in the patients with acid or non-acid GERC and their relation to the outcomes of antireflux therapy. Results: Compared with healthy volunteers, patients with GERC presented with a lower pressure [(11±5) mmHg vs (15±5) mmHg (1 mmHg=0.133 kPa), q=3.70, P=0.000], shorter overall length [(2.2±0.5) cm vs (3.0±1.0) cm, q=2.78, P=0.017] and similar relaxation rate of lower esophageal sphincter(q=1.14, P=0.258). Furthermore, they also showed a decrease in esophageal peristaltic contractive amplitude [(33±13) mmHg vs (45±11) mmHg, q=2.19, P=0.030] and wave velocity [(2.6±0.8) cm/s vs (3.4±0.6) cm/s, q=2.91, P=0.010] but an increase in esophageal contractive time of esophagus [(4.9±2.2) s vs (3.1±0.8) s, q=3.25, P=0.001] in addition to a linear negative correlation between esophageal peristaltic wave velocity and bolus clearance (r=-0.603, P=0.000). However, these parameters were not different between patients with GERC and gastroesophageal reflux disease without cough. The patients with GERC due to acid and non-acid reflux presented with a similar esophageal dysmotility but different variables reflecting the acidity of refluxates as indicated by multi-channel intraluminal impedance combined with pH monitoring. The esophageal peristaltic wave velocity was significantly lower in the patients with GERC responsive to the standard antireflux therapy than in those responsive to the intensified antireflux therapy [(2.2±0.6) cm/s vs (3.0±1.0) cm/s, t= 2.066, P= 0.041]. Conclusions: Esophageal dysfunction is present in patients with GERC. Its characteristics and severity are not associated with the types of gastroesophageal reflux inducing cough, but may predict the efficacy of medical antireflux therapy.

SERS detection of R6G based on a novel graphene oxide/silver nanoparticles/silicon pyramid arrays structure.

We present a novel surface-enhanced Raman scattering (SERS) substrate based on graphene oxide/silver nanoparticles/silicon pyramid arrays structure (GO/Ag/PSi). The SERS behaviors are discussed and compared by the detection of R6G. Based on the contrast experiments with PSi, GO/PSi, Ag/PSi and GO/AgA/PSi as SERS substrate, the perfect bio-compatibility, good homogeneity and chemical stability were confirmed. We also calculated the electric field distributions using Finite-difference time-domain (FDTD) analysis to further understand the GO/Ag/PSi structure as a perfect SERS platform. These experimental and theoretical results imply that the GO/Ag/PSi with regular pyramids array is expected to be an effective substrate for label-free sensitive SERS detections in areas of medicine, food safety and biotechnology.

Sapphire-based graphene saturable absorber for long-time working femtosecond lasers.

We report a long-time working femtosecond laser using metal-free sapphire-based graphene as a saturable absorber (SA). The sapphire-based graphene yielded excellent nonlinear saturable absorption properties and was demonstrated to be suitable as an SA for an ultrafast solid-state laser. Stable mode-locked pulses of 325 fs were obtained at a central wavelength of 1032 nm with a repetition rate of 66.3 MHz. At pump power of 8.23 W the average output power was 1.78 W and the highest pulse energy reached 26.8 nJ with a peak power of 72.6 kW. Our work opens up a facile route for making reliable graphene SA in the mode-locking technique and also displays an exciting prospect in making low-cost and ultrafast lasers.

Ag-decorated TiO2 nanograss for 3D SERS-active substrate with visible light self-cleaning and reactivation.

The production of SERS-active substrates which are uniform, sensitive, reproducibile and durable still remains an important issue. Here, we report a strategy for the fabrication of a large-area Ag-decorated TiO2 nanograss SERS-active substrate by a simple solvothermal approach combined with Ag evaporation. The nanograss consists of dense rutile TiO2 nanorods of about 5 nm in diameter and the decorated Ag nanoparticles are an average of 8 nm in diameter. The Ag protrusions and gaps between them contribute to three dimensional SERS "hot spots" which can be modulated by simply controlling the Ag evaporating parameters. The Ag-decorated TiO2 substrate is highly efficient in detecting rhodamine 6G (R6G) and 4-aminothiophenol (4-ATP) molecules and has good homogeneity. An obvious red shift and even high enhancement of b2 vibration mode were observed in detecting 4-ATP due to the effective charge transfer from the Ag atoms to sulfur atoms. The Ag-decorated TiO2 substrate can be easily self-cleaned and reactivated by visible light irradiation without obvious degeneration of SERS signals. Our results demonstrate that the Ag-decorated TiO2 substrate with high and homogeneous SERS activity has potential feasibility as a sensitive SERS probe.

Facile synthesis of graphene on dielectric surfaces using a two-temperature reactor CVD system.

Direct deposition of graphene on a dielectric substrate is demonstrated using a chemical vapor deposition system with a two-temperature reactor. The two-temperature reactor is utilized to offer sufficient, well-proportioned floating Cu atoms and to provide a temperature gradient for facile synthesis of graphene on dielectric surfaces. The evaporated Cu atoms catalyze the reaction in the presented method. C atoms and Cu atoms respectively act as the nuclei for forming graphene film in the low-temperature zone and the zones close to the high-temperature zones. A uniform and high-quality graphene film is formed in an atmosphere of sufficient and well-proportioned floating Cu atoms. Raman spectroscopy, scanning electron microscopy and atomic force microscopy confirm the presence of uniform and high-quality graphene.

Molecular cloning of a new wheat calreticulin gene TaCRT1 and expression analysis in plant defense responses and abiotic stress resistance.

Calreticulin proteins play essential roles in regulating various metabolic processes and in molecular signal transduction in animals and plants. Using homologous PCR, we screened a cDNA library of the wheat resistance gene Yr5 from a near-isogenic line in the susceptible common wheat variety Taichung 29, which was inoculated with an incompatible race CYR32 of Puccinia striiformis. We isolated a novel full-length cDNA encoding calreticulin protein, which we named TaCRT1. Sequence analyses indicated that TaCRT1 contains an open reading frame of 1287 bp in length; it was deduced to encode 428 amino acids. Clustering analysis showed that TaCRT1 belongs to group III of the calreticulin protein family. Semi-quantitative RT-PCR was used to analyze expression profiles of the isolated gene under biotic and abiotic stresses. Expression of TaCRT1 was suppressed by exogenous application of phytohormones, such as abscisic acid and methyl jasmonate, and by dehydration; but it was induced by CYR32 infection and cold treatment. Based on the expression patterns, we propose that TaCRT1 participates in regulatory processes involved in defense responses and stress resistance in wheat.

The relationship between intestinal flora changes and osteoporosis in rats with inflammatory bowel disease and the improvement effect of probiotics.

OBJECTIVE: The aim of this study was to investigate the relationship between the changes in intestinal flora and the occurrence of osteoporosis in rats with inflammatory bowel disease and the improvement effect of probiotics. MATERIALS AND METHODS: A total of 100 Sprague Dawley (SD) model rats with colitis were selected as research objects. All rats were randomly divided into two groups, including: bowel disease group and osteoporosis group, with 50 rats in each group. Stool samples were collected from all rats, and Lactobacillus, Escherichia coli and Bifidobacteria were cultured and counted. The relationship between the occurrence of related osteoporosis and intestinal flora was analyzed as well. Thereafter, the rats in osteoporosis group were randomly divided into two subgroups, namely, control group (n=25) and observation group (n=25). Observation group was treated with probiotics by gastrogavage, while the control group was treated with the same volume of physiological saline. Next, the changes in serum osteoprotegerin (OPG), osteoprotegerin ligand [receptor activator of nuclear factor-kappa B ligand (RANKL)], procollagen type I carboxy-terminal propeptide (PICP), bone mineral density (BMD), bone alkaline phosphatase (BALP), tartrate-resistant acid phosphatase (TRACP), calcium concentration (Ca), and inflammatory cytokine levels were compared between the two groups after intervention. RESULTS: Osteoporosis group had significantly more Escherichia coli and notably fewer Lactobacillus and Bifidobacteria than bowel disease group (p<0.05). Pearson correlation analysis revealed that the occurrence of osteoporosis in rats with inflammatory bowel disease was negatively correlated with the count of Escherichia coli, whereas was positively related to the counts of Lactobacillus and Bifidobacteria (p<0.05). Moreover, the levels of serum OPG, PICP, TRACP, and Ca in observation group were remarkably higher than those in the control group (p<0.05). However, the levels of serum RANKL, BALP, interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and interferon-gamma (INF-γ) were markedly lower than those in the control group (p<0.05). CONCLUSIONS: Osteoporosis in rats with inflammatory bowel disease has a negative association with the count of Escherichia coli, and a positive correlation with the counts of Lactobacillus and Bifidobacteria. In addition, treatment with probiotics can effectively alleviate osteoporosis symptoms in rats with inflammatory bowel disease by influencing the level of corresponding cytokines.

Race Dynamics, Diversity, and Virulence Evolution in Puccinia striiformis f. sp. tritici, the Causal Agent of Wheat Stripe Rust in China from 2003 to 2007.

Stripe (or yellow) rust caused by Puccinia striiformis f. sp. tritici is the most destructive foliar disease of wheat in China. The pathogen populations were analyzed for virulence evolution, complexity, phenotypic dynamics, and diversity on temporal and spatial bases. A total of 41 races were identified and characterized from 4,714 stripe rust isolates collected during 2003 through 2007 from wheat growing areas in 15 provinces in China. The races were based on avirulence/virulence patterns to 19 differential host genotypes. Chinese stripe rust population exhibited high diversity with a complex virulence structure. Comparisons using the relative Shannon's index indicated that some differences in the richness and evenness of races were present in pathogen populations within years and between regions despite a national tendency to reduced diversity over time. A noticeably increased frequency of race CYR33 (Chinese yellow rust 33) with virulence for YrSu was the major virulence change recorded in this study compared to the results on an annual basis. Isolates of Puccinia striiformis f. sp. tritici from different regions showed differences in the composition of races, distribution frequency, and diversity. The uneven distribution of major races and comparatively greater diversity in the Northwest and Southwest regions than that in the Huang-Huai-Hai region suggest that long-distance migrations of the pathogen occur from one or more over-summering areas eastward into over-wintering areas. This supports the hypothesis that southern Gansu and northwestern Sichuan comprises a "center of origin for virulence". Mutation of virulence or avirulence for host resistance in the stripe rust fungus may be the basic cause of the occurrence of new virulent types. The subsequent dominance of certain races will vary with parasitic fitness and the opportunities to be selected through large-scale cultivation of varieties with matching resistance genes. Implications of the center of origin for virulence variation and diversity in the pathogen population and an alternative strategy for limiting virulence evolution are discussed.

Sustained BMP-2 release and platelet rich fibrin synergistically promote tendon-bone healing after anterior cruciate ligament reconstruction in rat.

OBJECTIVE: Anterior cruciate ligament (ACL) injuries which cause knee disabilities remain a clinical challenge due to the compromised tendon-bone repair. Multiple strategies have been proposed to treat the tendon-bone injuries, and the combination of these therapies hold great potential to achieve synergistic effects. MATERIALS AND METHODS: We built PLGA-BMP-2 (bone morphogenetic protein 2) system and confirmed the sustained release of BMP-2 both in vitro and in vivo. We then applied different therapies to treat rat ACL reconstruction. We collected the tissue sample and analyzed the BMP-2 concentration both in serum and in injured sites. We tested the mRNA expression of genes that were related to inflammation, tissue repair and bone formation in damaged tissues. We also analyzed the protein levels of some genes associated with tendon formation and check the function of newly generated bone through biomechanical test. RESULTS: We found that, compared to monotherapies, simultaneous utilization of sustained BMP-2 release and platelet-rich fibrin (PRF) after anterior cruciate ligament reconstruction showed better therapeutic effects on tendon-bone healing in rat. This combined therapy efficiently enhanced the levels of growth factors that favor the angiogenesis and relieved the inflammatory responses in the injured sites. Of note, the combined therapy efficiently promoted the signals associated with bone formation and tendon regeneration. CONCLUSIONS: We demonstrated that the combined therapy with BMP-2 and PRF achieves synergistic effects on tendon-bone healing and holds great potential for the treatment of ACL reconstruction.

Enhancement of tendon-bone healing after rotator cuff injuries using combined therapy with mesenchymal stem cells and platelet rich plasma.

OBJECTIVE: The injuries of rotator cuff will cause the shoulder dysfunctions. Due to limited self-regeneration abilities of the tendon-bone part, rotator cuff injuries remain a clinical challenge. Previous studies have proposed many strategies for treating this disease. In this work, we aimed to combine different strategies to achieve better beneficial effects on tendon-bone repair. MATERIALS AND METHODS: We isolated mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP) and tested the effects of PRP on the gene expression, cell death resistance, and osteogenic differentiation of MSCs. Then, we utilized multiple strategies to treat rotator cuff injuries. We evaluated the expression of genes that related to tissue repair, bone formation, and tendon regeneration. We also tested the biomechanical property of repair tissues. RESULTS: We found that the in-vitro co-culture with PRP endowed MSCs with enhanced production of growth factors, better osteogenic differentiation ability, and stronger ability to resist cell death. Next, we applied MSCs, PRP, and MSCs-PRP combined therapies in rat rotator cuff injury model to compare their therapeutic effects in vivo. Through biomechanical testing, we found that the combined therapy was most efficient to promote tissue regeneration and enhance the biomechanical property of the newly generated bone. CONCLUSIONS: The combined treatment induced strongest signals related to angiogenesis, bone formation, and tendon generation in-situ. We demonstrated that the combination of MSCs and PRP synergistically promotes tendon-bone healing and holds great promise for the treatment of rotator cuff injuries.

[Multi-center empirical study of virtual gastroscopy simulator in the examination of clinical practice skills of specialist physicians].

Objective: To study the role of virtual gastroscopy simulator in the examination of clinical practice skills of gastrointestinal specialists. Methods: A multi-center empirical study was carried out. In June 2018, ninety participants from three tertiary care teaching hospitals in China, including Zhongshan Hospital of Fudan University, Shanghai Tongji Hospital and Xiangya Hospital of Central South University, took part in the examination. Participants were selected as follows: 30 specialists without any experience of gastroscopy exams, 30 with basic knowledge (gastroscopy exams <500 cases) and 30 with good skill (gastroscopy exams ≥500 cases). These 90 students participated in this empirical study after theoretical study and simulator training. Among them, 50 (55.6%) were undergraduates, 25 (27.8%) masters, and 15 (16.7%) doctors; 42 (46.7%) were residents, 39 (43.3%) attending physicians, and 9 (10.0%) deputy chief physicians. The assessment was divided into two parts. The first part was to use the simulator (GI mentor II) for ballooning within 10 minutes, with a total score of 40 points. The second part was a complete gastroscopy exam on the simulator, including preparation before gastroscopy exam, gastroscopy exam, post - exam management and related knowledge quiz. The difficulty and discrimination of the assessment plan were evaluated by the extreme grouping method parameters (difficulty P definition: <0.3 was difficult, 0.3 to 0.7 was medium, ≥0.7 was easy; discrimination degree D definition: <0 was poor, 0 to 0.2 was medium, ≥0.2 was good), and by comparing the virtual gastroscopy assessment scores of different experience, academic, and professional title groups. The score analysis of the student group was expressed using the mastering rate (the average score divided by the total score). The data of the normal distribution was represented by (mean±SD) (range), and the data of the nonnormal distribution was represented by M (P25, P75). Kruskal-Wallis non-parametric test was used for comparison between groups. Results: The total score of 90 students was (82.9±10.9) (55.8 to 99.0), and the mastering rate was 82.9%. The overall difficulty of the first and the second parts were 0.78 and 0.76, respectively, and the difficulty level was easy. The overall discrimination of the first and the second parts were 0.70 and 0.67, respectively, and the discrimination was good. The stratified analysis was performed according to the professional title. The median score was 83.2 (75.5, 89.0) in the residents, 82.5 (71.7, 93.6) in the attending physicians, and 93.5 (88.5, 99.0) in the deputy chief physicians, and the difference was statistically significant (H=6.213, P=0.045). According to the stratification analysis of academic qualifications, the median score was 81.7 (73.0, 87.5) in participants with undergraduate degree, 91.0 (79.0, 95.0) in those with master degree and 88.0 (81.7, 93.5) in those with doctor degree, whose difference was statistically significant (H=9.233, P=0.010). The stratified analysis of the second part showed that the median scores of the "operational process" part of the low, medium and high basis group were 33.0 (30.5, 36.5), 34.0 (32.0, 36.0) and 37.0 (35.0, 37.5), respectively, whose difference was statistically significant (H=7.603, P=0.022). The median scores of the "operational process" section of the resident, attending physician, and deputy chief physician were 33.0 (30.5, 35.0) points, 36.0 (34.0, 37.5) points and 37.0 (37.0, 37.5) points, respectively, whose difference was statistically significant (H=18.563, P=0.001). Conclusions: The virtual gastroscopy simulator can reflect the true level of gastroscopy exam skills of the students. The examination questions are moderately difficult, and there is a good discrimination of the exam.

A novel homeobox-like gene associated with reaction to stripe rust and powdery mildew in common wheat.

Stripe rust and powdery mildew, caused by Puccinia striiformis f. sp. tritici and Blumeria graminis f. sp. tritici, respectively, are severe diseases in wheat (Triticum aestivum) worldwide. In our study, differential amplification of a 201-bp cDNA fragment was obtained in a cDNA-amplified fragment length polymorphism (AFLP) analysis between near-isogenic lines Yr10NIL and Avocet S, inoculated with P. striiformis f. sp. tritici race CYR29. A full-length cDNA (1,357 bp) of a homeobox-like gene, TaHLRG (GenBank accession no. EU385606), was obtained in common wheat based on the sequence of GenBank accession AW448633 with high similarity to the above fragment. The genomic DNA sequence (2,396 bp) of TaHLRG contains three exons and two introns. TaHLRG appeared to be a novel homeobox-like gene, encoding a protein with a predicted 66-amino-acid homeobox domain. It was involved in race-specific responses to stripe rust in real-time quantitative polymerase chain reaction (PCR) analyses with Yr9NIL, Yr10NIL, and Avocet S. It was also associated with adult-plant resistance to stripe rust and powdery mildew based on the field trials of doubled haploid lines derived from the cross Bainong 64/Jingshuang 16 and two F(2:3) populations from the crosses Lumai 21/Jingshuang 16 and Strampelli/Huixianhong. A functional marker, THR1 was developed based on the sequence of TaHLRG and located on chromosome 6A using a set of Chinese Spring nulli-tetrasomic lines.

[Application of MDCT and post-processing in children with tracheal foreign body].

Objective:To explore the clinical value of MDCT and post-processing in children with suspected foreign body in trachea.Method:Two hundred patients with suspected tracheal foreign body were treated with 64-slice spiral CT (MDCT) and simulated endoscopic imaging,then compared with seen in bronchoscopy; Compare the results of MDCT and post-processing with the coincidence of intraoperative findings.Result:One hundred and eighty-four cases of positive children were examined by MDCT postprocessing technique and bronchoscopy,179 cases were obstructed by exogenous foreign body,5 cases were phlegm thrombosis (endogenous foreign body) obstruction; 16 cases of children with no foreign body diagnosed by MDCT post-processing technique were also examined by bronchoscopy. The results showed that there was a foreign body in 1 case,and the foreign body was located in the pharyngeal cleft (watermelon spermoderm),and the remaining 15 cases had no foreign body. MDCT and post-treatment techniques for children with tracheal foreign body diagnosis of 99.4% sensitivity,specificity of 75%.There was no significant difference in the detection rate of foreign body between the two techniques of MDCT and post-processing technique and bronchoscopy (P>0.05). Examed by MDCT and postprocessing,we can understand the specific location and size of foreign body,nature,shape preoperatively.Conclusion:Although MDCT and post-processing techniques can not be used to treat tracheal foreign bodies,but the diagnostic rate of bronchial foreign bodies is comparable to that of bronchoscopy. We could apply MDCT examination and post processing before the bronchoscopy,for foreign body inhalation history is not clear,or suspected airway foreign body. We can improve the level of diagnosis and treatment through guiding the operation of bronchoscopy focus.

Quantum chemical prediction of reaction pathways and rate constants for dissociative adsorption of CO(x) and NO(x) on the graphite (0001) surface.

We present predictions of reaction rate constants for dissociative adsorption reactions of CO(x) (x = 1, 2) and NO(x) (x = 1, 2) molecules on the basal graphite (0001) surface based on potential energy surfaces (PES) obtained by the integrated ONIOM(B3LYP:DFTB-D) quantum chemical hybrid approach with dispersion-augmented density functional tight binding (DFTB-D) as low level method. Following an a priori methodology developed in a previous investigation of water dissociative adsorption reactions on graphite, we used a C(94)H(24) dicircumcoronene graphene slab as model system for the graphite surface in finite-size molecular structure investigations, and single adsorbate molecules reacting with the pristine graphene sheet. By employing the ONIOM PES information in RRKM theory we predict reaction rate constants in the temperature range between 1,000 and 5,000 K. We find that among CO(x) and NO(x) adsorbate species, the dissociative adsorption reactions of CO(2) and both radical species NO and NO(2) are likely candidates as a cause for high temperature oxidation and erosion of graphite (0001) surfaces, whereas reaction with CO is not likely to lead to long-lived surface defects. High temperature quantum chemical molecular dynamics simulations (QM/MD) at T = 5,000 K using on-the-fly DFTB-D energies and gradients confirm the results of our PES study.

Efficient removal of Cr(VI) from wastewater under sunlight by Fe(II)-doped TiO2 spherical shell.

Fe(II)-doped TiO2 spherical shell catalyst was synthesized by one-pot hydrothermal method. The photocatalytic removal of Cr(VI) from plating wastewater under sunlight of the catalyst was demonstrated. It was found that the removal effectiveness of about 99.99% for initial Cr(VI) concentration of 102.3 ppm and 99.01% for 153.4 ppm under 3h sunlight irradiation is realized. The Fe(II) ions serve not only as reducing agents for reducing the Cr(VI) to Cr(III) but also as an intermedium of a two-step reduction, in which the TiO2 photoreduces the Fe(II) ions to Fe atoms firstly, and then the Fe atoms reduce the Cr(VI) to Cr(III). The improved photocatalytic activity of the catalyst is considered due to the synergistic effect of a multi reducing process by Fe(II) doping. The extended optical response and effectively utilization of sunlight of the special spherical-shell-like morphology also contribute to the enhanced photocatalytic activity.

Bone morphogenetic protein-2 (BMP-2) signaling to the Col2alpha1 gene in chondroblasts requires the homeobox gene Dlx-2.

To understand the role of Dlx genes in the process of chondrogenesis, we studied the expression of Dlx-2 and Dlx-5 mRNAs in a mouse clonal chondroblast cell line, TMC23. We also examined the involvement of Dlx2 in the bone morphogenetic protein-2 (BMP-2) signaling to the type II collagen gene, Col2alpha1, in this cell line. In this report, we show that the TMC23 cells express Dlx-2 and Dlx-5 mRNAs, and the levels can be upregulated by recombinant BMP-2 at an early stage of chondroblast differentiation. Addition of rBMP-2 dramatically increased type II collagen expression at both the mRNA and the protein level. Also, rBMP-2 increased transcription of Col2alpha1, as shown by stimulation of a chondrocyte-specific Col2alpha1 enhancer. The mechanism involves Dlx-2, as the stimulatory effect of rBMP-2 on the Col2alpha enhancer was blocked by an antisense oligonucleotide against Dlx-2 mRNA. The rBMP-2 signaling to the Col2alpha1 enhancer was also blocked by a dominant-negative Smad1 expression vector. These data demonstrate that Dlx-2 is a downstream target of the BMP-2 signaling pathway in chondroblasts. Therefore, we propose a model in which rBMP-2 stimulates Dlx-2 expression, which then serves as a necessary transcription factor for Col2alpha1 gene expression through a chondrocyte-specific enhancer fragment.

Captopril cardioplegia on myocardial protection in the hypertrophied rat hearts.

Hearts with pressure-overload hypertrophy show an increased intracardiac activation of the renin-angiotensin system (RAS) which may contribute to myocardial ischemia and reperfusion injury. This study investigates whether the hypertrophied myocardium is more vulnerable to ischemia and reperfusion injury and whether the specific inhibition of the cardiac RAS by captopril would modify ischemia and reperfusion injury in the hypertrophied myocardium. By using the isolated working rat heart model, hypertrophied hearts, induced by abdominal aortic banding for 6 weeks, were subjected to 120 min of hypothermic ischemic arrest followed by 30 min of reperfusion. The postischemic cardiac function recovery was measured in both the untreated (n = 10) and the captopril-treated (n = 11) groups and was compared with that of the sham-operated non-hypertrophied control hearts (n = 10). Captopril (23.0 microM) was given to one group with the hypertrophied hearts from the beginning of ischemia to the end of reperfusion. In comparison with the normal control hearts, the cardiac function recovery after 30 min reperfusion was poorer in the hypertrophied hearts, which was associated with a lower recovery of coronary flow (CF), a higher myocardial lactate content and a retarded peak myocardial creatinkinase (CK) release. Captopril significantly improved the cardiac function recovery, which was associated with an increased CF recovery and a lower myocardial lactate content, and a rapid peak CK release. In conclusion, this study shows that the hypertrophied myocardium leads to an increased susceptibility to ischemia and reperfusion injury. Captopril, most likely by its inhibition of the cardiac RAS, is effective in preventing the ischemia and reperfusion injury in the hypertrophied heart.

Effect of captopril cardioplegia on renin-angiotensin system, prostaglandins, free radicals and electrolytes in the isolated hypothermic ischemic and reperfusion rabbit hearts.

The effect of captopril cardioplegia on ischemic and reperfusion myocardium after 3 hours of hypothermic (13 +/- 1 C) arrest and 35 minutes of reperfusion was studied in the isolated working rabbit heart. In comparison with the control group, captopril cardioplegia reduced the content of angiotensin II (381 +/- 56 vs 507 +/- 84 pg/g wt of the control group, P < 0.01) and MDA (50.0 +/- 9.2 vs 85.1 +/- 16.1 pmol/mg pr, P < 0.01) in the reperfusion myocardium; augmented the renin activity of ischemic (1050 +/- 353 vs 669 +/- 301 pg/g wt/h, P < 0.05) and reperfusion myocardium (1261 +/- 421 vs 498 +/- 353 pg/g wt/h, P < 0.01) increased the 6-K-PGF1 alpha/TXB2 ratio in the reperfusion myocardium (by 48.1% of the control group). Meanwhile, captopril cardioplegia could also decrease the content of calcium (0.027 +/- 0.015 vs 0.045 +/- 0.014 microM/mg pr, P < 0.05) and sodium (0.54 +/- 0.26 vs 0.82 +/- 0.15 microM/mg pr, P < 0.05) in the reperfusion myocardium, but had no effect on the potassium content. The results show that the protective effect of captopril on hypothermic myocardium may be related to the free radical scavenging action, inhibition of angiotensin II production, improvement of PGI2/TXA2 ratio and decrease of calcium and sodium overload in the myocardium.