Application of hydrophobic fluorinated silicon oxide nanoparticle coating on electrodynamic screen (EDS) films for enhancing self-cleaning function of solar collectors

Optical surfaces, which are exposed to outdoor environmental conditions, are susceptible to dust deposition. Sunlight incident on the surface of photovoltaic (PV) modules is attenuated by the dust layer accumulation on the front surface of the modules. Energy-yield decrease by dust layer accumulation, called soiling losses, can be 5 to 40 percent annually unless the modules are cleaned frequently. Cleaning the optical surface with water is generally used in solar plants, which causes an unsustainable demand for freshwater in semi arid and desert areas. Adhesion of soil on the front surface of solar collectors plays a major role in the cleaning process. For low water cleaning, the module surface is often coated with an anti-soiling coating. If the surface is made hydrophilic, water can wet the surface most effectively making the cleaning process efficient, but requiring a low amount of water. If the surface is made hydrophobic, the surface energy is decreased reducing the adhesion force; the cleaning can be performed even with a lesser amount of water or with an application of an external removal force, such as wind. Major problems with the application of anti-soiling coatings are their environmental durability, poor adhesion of the coating on the surface and low resistance to abrasion. Since the removal of dust still requires spraying of water to the PV modules, the coatings get removed within a short period. Similarly, another dust removal method that does not require water for cleaning PV modules, is the Electrodynamic Screen (EDS) film, which consists of series of parallel transparent electrodes embedded within two transparent dielectric films and laminated on the surface of the solar collectors. When the electrodes are activated film by applied voltage pulses there will be a traveling electric field on the EDS surface, then the dust particles on the film surface gets charged electrostatically and are removed by Coulomb forces applied by the electric field. The EDS film application is an elective removal of the dust particles from the PV module surface without requiring any water or mechanical forces. However, the applied Coulomb force cannot overcome the dust adhesion force when the particles are smaller than 2 m in diameter or if the capillary adhesion forces are present because of the high humidity environment. The objective of the thesis is to decrease the particle adhesion forces of the EDS film surface by the application of a hydrophobic coating so that the dust removal efficiency is enhanced for moving small particles. To improve EDS film based dust-removal performance it is necessary to have the coating non-conductive and optically transparent and hydrophobic for the effective application electrostatic removal mechanisms. The hydrophobic coating would reduce the surface energy and hence the dust adhesion force, assisting the self-cleaning effect, which would not require any water consumption. Since water-based cleaning is no longer needed for dust removal when the EDS film surface is modified with hydrophobic surface properties, the durability of the coating would improve. We describe here a synthesis of a hydrophobic fluorinated silicon oxide nanoparticle coating on the EDS films for enhancing the self-cleaning function of solar collectors. We used dip-coating method to apply a single-layer hydrophobic silicon oxide nanoparticle film with a large static water contact angle on the EDS film surface. silicon oxide was prepared by the sol-gel method using Tetraethylorthosilicate (TEOS) and ammonium hydroxide as a precursor anda catalyst. The suspension was treated with 3-aminopropyltriethoxysilane (APS) and 1H,1H,2H,2H-perfluorodecyltriethoxysilane (FAS-17) to modify the surface of the coating, which greatly improved the hydrophobicity, and thus gave the coating the desired self-cleaning property. We used polyurethane (PU) as a binder between the substrate and coating to enhance the durability of the lm in outdoors applications. Experimental data on the optical transmittance, adhesion of the hydrophobic film on the glass surface of the EDS lm, and the dust removal efficiency are presented. The average optical transmission efficiency (TE) decreased from 93.43 to 89.78 percent and the output power restoration (OPR) of the solar panels laminated with EDS film with SH coating increased from 98.3 to 99.19 percent. Possible improvements to the hydrophobic coating process and its durability and future research needs are discussed

High Resolution Genome Wide Binding Event Finding and Motif Discovery Reveals Transcription Factor Spatial Binding Constraints

An essential component of genome function is the syntax of genomic regulatory elements that determine how diverse transcription factors interact to orchestrate a program of regulatory control. A precise characterization of in vivo spacing constraints between key transcription factors would reveal key aspects of this genomic regulatory language. To discover novel transcription factor spatial binding constraints in vivo, we developed a new integrative computational method, genome wide event finding and motif discovery (GEM). GEM resolves ChIP data into explanatory motifs and binding events at high spatial resolution by linking binding event discovery and motif discovery with positional priors in the context of a generative probabilistic model of ChIP data and genome sequence. GEM analysis of 63 transcription factors in 214 ENCODE human ChIP-Seq experiments recovers more known factor motifs than other contemporary methods, and discovers six new motifs for factors with unknown binding specificity. GEM's adaptive learning of binding-event read distributions allows it to further improve upon previous methods for processing ChIP-Seq and ChIP-exo data to yield unsurpassed spatial resolution and discovery of closely spaced binding events of the same factor. In a systematic analysis of in vivo sequence-specific transcription factor binding using GEM, we have found hundreds of spatial binding constraints between factors. GEM found 37 examples of factor binding constraints in mouse ES cells, including strong distance-specific constraints between Klf4 and other key regulatory factors. In human ENCODE data, GEM found 390 examples of spatially constrained pair-wise binding, including such novel pairs as c-Fos:c-Jun/USF1, CTCF/Egr1, and HNF4A/FOXA1. The discovery of new factor-factor spatial constraints in ChIP data is significant because it proposes testable models for regulatory factor interactions that will help elucidate genome function and the implementation of combinatorial control

Modular combinatorial binding among human trans-acting factors reveals direct and indirect factor binding

Background The combinatorial binding of trans-acting factors (TFs) to the DNA is critical to the spatial and temporal specificity of gene regulation. For certain regulatory regions, more than one regulatory module (set of TFs that bind together) are combined to achieve context-specific gene regulation. However, previous approaches are limited to either pairwise TF co-association analysis or assuming that only one module is used in each regulatory region. Results We present a new computational approach that models the modular organization of TF combinatorial binding. Our method learns compact and coherent regulatory modules from in vivo binding data using a topic model. We found that the binding of 115 TFs in K562 cells can be organized into 49 interpretable modules. Furthermore, we found that tens of thousands of regulatory regions use multiple modules, a structure that cannot be observed with previous hard clustering based methods. The modules discovered recapitulate many published protein-protein physical interactions, have consistent functional annotations of chromatin states, and uncover context specific co-binding such as gene proximal binding of NFY + FOS + SP and distal binding of NFY + FOS + USF. For certain TFs, the co-binding partners of direct binding (motif present) differs from those of indirect binding (motif absent); the distinct set of co-binding partners can predict whether the TF binds directly or indirectly with up to 95% accuracy. Joint analysis across two cell types reveals both cell-type-specific and shared regulatory modules. Conclusions Our results provide comprehensive cell-type-specific combinatorial binding maps and suggest a modular organization of combinatorial binding. Keywords Computational genomics Transcription factor Combinatorial binding Direct and indirect binding Topic modelNational Institutes of Health (U.S.) (grant 1U01HG007037-01

Nifedipine promotes the proliferation and migration of breast cancer cells

Nifedipine is widely used as a calcium channel blocker (CCB) to treat angina and hypertension,but it is controversial with respect the risk of stimulation of cancers. In this study, we demonstrated that nifedipine promoted the proliferation and migration of breast cancer cells both invivo and invitro. However, verapamil, another calcium channel blocker, didn’t exert the similar effects. Nifedipine and high concentration KCl failed to alter the [Ca2+]i in MDA-MB-231 cells, suggesting that such nifedipine effect was not related with calcium channel. Moreover, nifedipine decreased miRNA-524-5p, resulting in the up-regulation of brain protein I3 (BRI3). Erk pathway was consequently activated and led to the proliferation and migration of breast cancer cells. Silencing BRI3 reversed the promoting effect of nifedipine on the breast cancer. In a summary, nifedipine stimulated the proliferation and migration of breast cancer cells via the axis of miRNA-524-5p-BRI3–Erk pathway independently of its calcium channel-blocking activity. Our findings highlight that nifedipine but not verapamil is conducive for breast cancer growth and metastasis, urging that the caution should be taken in clinic to prescribe nifedipine to women who suffering both hypertension and breast cancer, and hypertension with a tendency in breast cancers

Clinical Efficacy and Meta-Analysis of Stem Cell Therapies for Patients with Brain Ischemia

Objective. Systematic review and meta-analysis to observe the efficacy and safety of stem cell transplantation therapy in patients with brain ischemia. Methods. We searched Cochrane Library, PubMed, Ovid, CBM, CNKI, WanFang, and VIP Data from its inception to December 2015, to collect randomized controlled trials (RCT) of stem cell transplantation for the ischemic stroke. Two authors independently screened the literature according to the inclusion and exclusion criteria, extracted data, and assessed the risk of bias. Thereafter, meta-analysis was performed. Results. Sixteen studies and eighteen independent treatments were included in the current meta-analysis. The results based upon the pooled mean difference from baseline to follow-up points showed that the stem cell transplantation group was superior to the control group with statistical significance in the neurologic deficits score (NIHSS, MD = 1.57; 95% CI, 0.64-2.51; I2 = 57 %; p = 0.001), motor function (FMA, MD = 4.23; 95% CI, 3.08-5.38; I2 = 0 %; p <0.00001), daily life ability (Barthel, MD = 8.37; 95% CI, 4.83-11.91; I2 = 63 %; p <0.00001), and functional independence (FIM, MD = 8.89; 95% CI, 4.70-13.08; I2 = 79 %; p <0.0001). Conclusions. It is suggested that the stem cell transplantation therapy for patients with brain ischemic stroke can significantly improve the neurological deficits and daily life quality, with no serious adverse events. However, higher quality and larger data studies are required for further investigation to support clinical application of stem cell transplantation

Towards a Holistic, Yet Gene-Centered Analysis of Gene Expression Profiles: A Case Study of Human Lung Cancers

Genome-wide gene expression profile studies encompass increasingly large number of samples, posing a challenge to their presentation and interpretation without losing the notion that each transcriptome constitutes a complex biological entity. Much like pathologists who visually analyze information-rich histological sections as a whole, we propose here an integrative approach. We use a self-organizing maps -based software, the gene expression dynamics inspector (GEDI) to analyze gene expression profiles of various lung tumors. GEDI allows the comparison of tumor profiles based on direct visual detection of transcriptome patterns. Such intuitive “gestalt” perception promotes the discovery of interesting relationships in the absence of an existing hypothesis. We uncovered qualitative relationships between squamous cell tumors, small-cell tumors, and carcinoid tumor that would have escaped existing algorithmic classifications. These results suggest that GEDI may be a valuable explorative tool that combines global and gene-centered analyses of molecular profiles from large-scale microarray experiments

Inhibition of pyruvate kinase M2 by reactive oxygen species contributes to the development of pulmonary arterial hypertension

Aims Pulmonary arterial hypertension [1] is a proliferative disorder associated with enhanced proliferation and suppressed apoptosis of pulmonary artery smooth muscle cells (PASMCs). Reactive oxygen species (ROS) is implicated in the development of PAH and regulates the vascular tone and functions. However, which cellular signaling mechanisms are triggered by ROS in PAH is still unknown. Hence, here we wished to characterize the signaling mechanisms triggered by ROS. Methods and Results By Western blots, we showed that increased intracellular ROS caused inhibition of the glycolytic pyruvate kinase M2 (PKM2) activity through promoting the phosphorylation of PKM2. Monocrotaline (MCT)-induced rats developed severe PAH and right ventricular hypertrophy, with a significant increase in the P-PKM2 and decrease in pyruvate kinase activity which could be attenuated with the treatments of PKM2 activators, FBP and l-serine. The antioxidant NAC, apocynin and MnTBAP had the similar protective effects in the development of PAH. In vitro assays confirmed that inhibition of PKM2 activity could modulate the flux of glycolytic intermediates in support of cell proliferation through the increased pentose phosphate pathway (PPP). Increased ROS and decreased PKM2 activity also promoted the Cav1.2 expression and intracellular calcium. Conclusion Our data provide new evidence that PKM2 makes a critical regulatory contribution to the PAHs for the first time. Decreased pyruvate kinase M2 activity confers additional advantages to rat PASMCs by allowing them to sustain anti-oxidant responses and thereby support cell survival in PAH. It may become a novel treatment strategy in PAH by using of PKM2 activators

Lattice-based scheduling for multi-FPGA systems

Accelerators are becoming increasingly prevalent in distributed computation. FPGAs have been shown to be fast and power efficient for particular tasks, yet scheduling on FPGA-based multi-accelerator systems is challenging when workloads vary significantly in granularity in terms of task size and/or number of computational units required. We present a novel approach for dynamically scheduling tasks on networked multi-FPGA systems which maintains high performance, even in the presence of irregular tasks. Our topological ranking-based scheduling allows realistic irregular workloads to be processed while maintaining a significantly higher level of performance than existing schedulers.Postprin