Adsorption and dissociation of H<inf>2</inf> on Pd doped graphene-like SiC sheet

© 2016 Hydrogen Energy Publications LLCDoped porous SiC nanostructures with metallic atoms, nanoclusters and nanoparticles have been recognized as promising materials for hydrogen storage. With this regards transition metal elements are interesting impurities for use as doping. In view of this prospect, a theoretical approach based on density functional theory (DFT) was applied to study of the interaction between hydrogen molecule and a graphene-like SiC sheet doped with palladium atom. We have selected a single graphene-like SiC layer, due to its more surface charge polarization in comparison with pure graphene which makes possible remarkable interactions with adsorbed hydrogen molecules. In our study we have included two different configurations of H2 adsorption: 1) at the first state, hydrogen atoms after adsorption stretched and distance between H[sbnd]H atoms has increased but their chemical bond doesn't break. In this situation a physical adsorption occurred and the binding energy restricts applicable interests where it is appropriate for reversible hydrogen storage; 2) at the second situation, atoms of hydrogen molecule discrete from each other and adsorption occurred in a chemical manner. As instance the when a H2 molecule interact simultaneously with Pd atom and SiC nanosheet, it can be dissociated as in this case a hydrogen atom makes bond with Pd atom and the other can be adsorbed chemically on the SiC nanosheet surface. More details about adsorption mechanism are discussed it the context

Eco-physiological, Biochemical and Herbicidal Characteristics of Lavandula stricta, Cassia obovata, Cocculus pendulus and Solanum xanthocarpum

Introduction  Lavandula stricta, Cassia obovata, Cocculus pendulus, and Solanum xanthocarpum are among the species that can be grown in Bushehr province, and so far, there is no report describing the ecophysiological, herbicidal and biochemical characteristics of these species in Iran. In recent decades, many chemical herbicides have been used to control weeds in agricultural ecosystems. Despite the many benefits of these herbicides, their improper use has caused devastating effects on the environment and agricultural production and ultimately has harmed human health. At present, the approach of developed countries is to use non-chemical methods and natural materials (biocides) to control weeds. Bushehr province with an area of about 252,653 Km2 in southern Iran and the Persian Gulf and at an altitude of 0 to195 meters above sea level. The average rainfall in Bushehr province is 250 mm. Bushehr province has a great variety in terms of having medicinal plants that allopathic substances and secondary metabolites of these plants have received less attention. Therefore, the identification of secondary metabolites and plants with allopathic properties is very important for the production of biological herbicides.   Materials and Methods  This study was conducted to evaluate the eco-physiological, biochemical and herbicidal characteristics of Lavandula stricta, Cassia obovata, Cocculus pendulus and Solanum xanthocarpum. The plants were collected in April and May 2019. The location was situated in Kangan and Dashti, Bushehr Province, Iran. The ecological characteristics of the four areas such as latitude and longitude (UTM) and altitude were also recorded. Also, in order to determine the physicochemical properties of the soil in the collection areas of the studied plants, samples were taken from 15 different points of plant growth, from a depth of 0-30 cm and their properties were reported. In order to investigate the phytotoxic activity of the studied plants on germination and growth characteristics of Malva sylvestris and Chenopodium album in laboratory conditions, the seeds were first disinfected in 5% sodium hypochlorite for 5 minutes. Then the seeds were washed for 15 minutes and then dried at room temperature. In this study, Solanum xanthocarpum juice and alcoholic extracts of Lavandula stricta, Cassia obovata and Cocculus pendulus were used to investigate the phytotoxic properties and biochemical traits. From the extracts, concentrations of 0 (distilled water), 200, 400, 600, 800 and 1000 µl.L-1 were prepared and added to Petri dishes containing 25 seeds. In order to germinate the seeds, Petri dishes containing the extracts related to the extract were placed in suitable light conditions at a temperature of 25°C. Two weeks after treatment, germination percentage (%), germination rate index (number of day), radicle and plumule length (cm) and allopathic index were measured. Determination of free radical scavenging was performed by using the DPPH test. The samples’ absorptions were read at a wavelength of 517 nm with Epoch Microplate Spectrophotometer, BioTek Instruments, Inc., USA. Measuring the total phenols was performed according to Folin’s reagent method and the use of gallic acid as standard by using a spectrophotometer at the wavelength of 765 nm. Total flavonoid content was measured using a spectrophotometer at a wavelength of 510 nm through a standard curve of quercetin from Sigma-Aldrich. Flavones and flavonols were measured using 2% aluminum chloride and methanol at 425 nm. To isolate and measure the amount of polyphenols, an HPLC Agilent HPLC 1200 series model was used. Data were analyzed by using Duncan’s multiple range test (P< 0.05) by SAS, version 9.4 for Windows.   Results and Discussion  Among the studied plants, the highest  and lowest amount of total phenol was found in Cocculus pendulus and Cassia obovata, respectively. The results showed, the highest amount of the total flavonoid in the extract, was achieved in Lavandula stricta plants collected in Kangan. The lowest (0.37 mg QUE. 100 g-1 DW) and highest (2.79 mg QUE. 100 g-1 DW) amount of flavon and flavonol was found in Cassia obovata and Cocculus pendulus, respectively. Also, antioxidant activity (I%) for Cocculus pendulus, Lavandula stricta and Solanum xanthocarpum were 77, 57 and 35%, respectively. Although, the lowest amount of antioxidant activity was found in Cassia obovata plants collected in Dashti. The results showed, the Lavandula stricta plants collected in Kangan had p-coumaric acid (PC) and ellagic acid (EA) by 0.565 and 1.28 mg g-1 DW. Among the phenolic acids evaluated, only catechin (0.262 mg g-1 DW) and p-coumaric acid (0.163 mg g-1 DW) were observed in the Cocculus pendulus plants collected in Kangan. The Cassia obovata plants collected in Dashti, had ellagic acid by 0.915 mg g-1 DW. The results of this study showed that the phenolic compounds identified in Solanum xanthocarpum juice were caffeic acid, chlorogenic acid, pi-coumaric acid, vanillin and hesperidin. Chlorogenic acid was the predominant phenolic compound by 457 mg g-1 DW. Laboratory results showed Cocculus pendulus and Solanum xanthocarpum extracts had the most inhibition effect on the germination and growth of Malva sylvestris at the concentration of 1000 µl L-1.   Conclusion  In this study, as the concentration of the extracts increased, the germination percentage, germination rate index (GRI), radicle and plumule lengths of Chenopodium album decreased significantly. Moreover, Solanum xanthocarpum juice showed the highest inhibition effect on Chenopodium album growth and germination at 1000 µl L-1. Due to the high potential allelopathy of the Cocculus pendulus and Solanum xanthocarpum, they can be used for Malva sylvestris and Chenopodium album control. Also, Cocculus pendulus extract can be used as a natural antioxidant source in related industries

ANALISA AGREGAT KASAR SEBAGAI VARIABEL BAHAN CAMPURAN BETON MENGGUNAKAN METODE SNI DAN ACI (Studi Kasus Beton Mutu K-275)

Penelitian ini dilakukan dengan maksud dan tujuan adalah untuk menganalisa dan membandingkan kuat tekan beton yang dapat dicapai menggunakan agregat kasar sumber Padang Ratu, Tegineneng dan Tanjungan. Selain itu juga untuk mengetahui kualitas agregat kasar yang bersumber dari daerah Padang Ratu, Tegineneng dan Tanjungan sebagai bahan campuran beton dengan metode SNI dan ACI. Untuk membandingkan nilai kuat tekan beton yang dihasilkan menggunakan agregat kasar yang bersumber dari daerah Padang Ratu, Tegineneng dan Tanjungan korelasinya terhadap pencapaian mutu beton K-275 atau setara dengan 22,825 Mpa. Penelitian ini menggunakan sampel Uji Silinder diameter 15 cm dan tinggi 30 cm. Pengujian dilakukan saat umur 7, 14, 21 dan 28 dan setiap umur terdiri dari 3 benda uji. Sehingga dibutuhkan 72 benda uji. Dengan 3 variasi penggunaan agregat kasar dari 3 quarry yaitu Tanjungan, Padang Ratu dan Tegineneng menggunakan metode SNI dan ACI. Hasil penelitian menunjukkan bahwa kualitas agregat mempengaruhi mutu beton yang dihasilkan. Hubungan kuat tekan beton dengan umur beton menunjukkan bahwa semakin bertambahnya umur beton, kuat tekan beton meningkat juga. Dari hasil penelitian, beton yang mencapai kuat tekan rencana adalah pada campuran beton  menggunakan agregat kasar Tanjungan dengan umur 28 hari yaitu : 23,10 Mpa (Metode ACI) dan 277,42 Kg/cm2 (Metode SNI)

On-Site Detection of Carcinoembryonic Antigen in Human Serum

Real-time connectivity and employment of sustainable materials empowers point-of-care diagnostics with the capability to send clinically relevant data to health care providers even in low-resource settings. In this study, we developed an advantageous kit for the on-site detection of carcinoembryonic antigen (CEA) in human serum. CEA sensing was performed using cellulose-based lateral flow strips, and colorimetric signals were read, processed, and measured using a smartphone-based system. The corresponding immunoreaction was reported by polydopamine-modified gold nanoparticles in order to boost the signal intensity and improve the surface blocking and signal-to-noise relationship, thereby enhancing detection sensitivity when compared with bare gold nanoparticles (up to 20-fold in terms of visual limit of detection). Such lateral flow strips showed a linear range from 0.05 to 50 ng/mL, with a visual limit of detection of 0.05 ng/mL and an assay time of 15 min. Twenty-six clinical samples were also tested using the proposed kit and compared with the gold standard of immunoassays (enzyme linked immunosorbent assay), demonstrating an excellent correlation (R = 0.99). This approach can potentially be utilized for the monitoring of cancer treatment, particularly at locations far from centralized laboratory facilities.</jats:p

The Murine Caecal MicroRNA Signature Depends on the Presence of the Endogenous Microbiota

The intestinal messenger RNA expression signature is affected by the presence and compo-sition of the endogenous microbiota, with effects on host physiology. The intestine is also characterized by a distinctive micronome. However, it is not known if microbes also impact intestinal gene expression epigenetically. We investigated if the murine caecal microRNA expression signature depends on the presence of the microbiota, and the potential implica-tions of this interaction on intestinal barrier function. Three hundred and thirty four mi-croRNAs were detectable in the caecum of germ-free and conventional male mice and 16 were differentially expressed, with samples from the two groups clustering separately based on their expression patterns. Through a combination of computational and gene expression analyses, including the use of our curated list of 527 genes involved in intestinal barrier reg-ulation, 2,755 putative targets of modulated microRNAs were identified, including 34 intes-tinal barrier-related genes encoding for junctional and mucus layer proteins and involved in immune regulation. This study shows that the endogenous microbiota influences the caecal microRNA expression signature, suggesting that microRNA modulation is another mecha-nism through which commensal bacteria impact the regulation of the barrier function and intestinal homeostasis. Through microRNAs, the gut microbiota may impinge a much larger number of genes than expected, particularly in diseases where its composition is altered. In this perspective, abnormally expressed microRNAs could be considered as novel therapeutic targets

NAViGaTing the Micronome – Using Multiple MicroRNA Prediction Databases to Identify Signalling Pathway-Associated MicroRNAs

MicroRNAs are a class of small RNAs known to regulate gene expression at the transcript level, the protein level, or both. Since microRNA binding is sequence-based but possibly structure-specific, work in this area has resulted in multiple databases storing predicted microRNA:target relationships computed using diverse algorithms. We integrate prediction databases, compare predictions to in vitro data, and use cross-database predictions to model the microRNA:transcript interactome--referred to as the micronome--to study microRNA involvement in well-known signalling pathways as well as associations with disease. We make this data freely available with a flexible user interface as our microRNA Data Integration Portal--mirDIP (http://ophid.utoronto.ca/mirDIP).mirDIP integrates prediction databases to elucidate accurate microRNA:target relationships. Using NAViGaTOR to produce interaction networks implicating microRNAs in literature-based, KEGG-based and Reactome-based pathways, we find these signalling pathway networks have significantly more microRNA involvement compared to chance (p<0.05), suggesting microRNAs co-target many genes in a given pathway. Further examination of the micronome shows two distinct classes of microRNAs; universe microRNAs, which are involved in many signalling pathways; and intra-pathway microRNAs, which target multiple genes within one signalling pathway. We find universe microRNAs to have more targets (p<0.0001), to be more studied (p<0.0002), and to have higher degree in the KEGG cancer pathway (p<0.0001), compared to intra-pathway microRNAs.Our pathway-based analysis of mirDIP data suggests microRNAs are involved in intra-pathway signalling. We identify two distinct classes of microRNAs, suggesting a hierarchical organization of microRNAs co-targeting genes both within and between pathways, and implying differential involvement of universe and intra-pathway microRNAs at the disease level

Identification and Pathway Analysis of microRNAs with No Previous Involvement in Breast Cancer

microRNA expression signatures can differentiate normal and breast cancer tissues and can define specific clinico-pathological phenotypes in breast tumors. In order to further evaluate the microRNA expression profile in breast cancer, we analyzed the expression of 667 microRNAs in 29 tumors and 21 adjacent normal tissues using TaqMan Low-density arrays. 130 miRNAs showed significant differential expression (adjusted P value = 0.05, Fold Change = 2) in breast tumors compared to the normal adjacent tissue. Importantly, the role of 43 of these microRNAs has not been previously reported in breast cancer, including several evolutionary conserved microRNA*, showing similar expression rates to that of their corresponding leading strand. The expression of 14 microRNAs was replicated in an independent set of 55 tumors. Bioinformatic analysis of mRNA targets of the altered miRNAs, identified oncogenes like ERBB2, YY1, several MAP kinases, and known tumor-suppressors like FOXA1 and SMAD4. Pathway analysis identified that some biological process which are important in breast carcinogenesis are affected by the altered microRNA expression, including signaling through MAP kinases and TP53 pathways, as well as biological processes like cell death and communication, focal adhesion and ERBB2-ERBB3 signaling. Our data identified the altered expression of several microRNAs whose aberrant expression might have an important impact on cancer-related cellular pathways and whose role in breast cancer has not been previously described

On the design of output feedback sliding mode control for a class of uncertain system

In this study, output feedback sliding mode control (OFSMC) is proposed for a class of system with the uncertainties present in its output matrix. The uncertain output exist in practical system is mainly due to measurement error contributed by sensor noise or low measurement resolution. Sliding Mode Control (SMC) approach is able to provide a promisable solution due to its robustness toward system uncertainties and disturbances, However, OFSMC has imposed a greater challenge due to inaccessibility to all of the system states. In this work, an OFSMC is designed in which the actual system output will follow the desired trajectory in spite of the presence of uncertainties. The control law is designed based on Lyapunov function which the proposed controller guarantees the asymptotic convergence of the output. The sliding surface is formulated such that stability of the reduced-order system is maintained and the convex formulation of the problem is solved by using Linear Matrix Inequality (LMI). Simulation result based on a numerical example is obtained to demonstrate the efficacy of proposed method