bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Heavy Metals on β-galactosidase Activity in Marine Bacteria
Authors: Joy Osigwe Ogechi , Nchedo Ariole Caroline , Anthony Ibiene Abiye
Published: February 2020

Background: Due to metal pollution and its toxicity in the coastal areas, the enzymatic activities of bacteria involved in the breakdown of organic compounds are repressed leading to decline in biodegradation rate.

Aim: The influence of heavy metals (copper, lead, zinc, manganese and iron) on β-galactosidase activity in three bacterial strains (Providencia stuartii, Pantoea dispersa and Aeromonas dhakensis) isolated from coastal marine sediment collected from coastal zone in Bonny Island, Nigeria was investigated.

Methodology: The strains were cultivated in Z- buffered medium having lactose as enzyme inducer. Beta galactosidase assay was done via 2-nitrophenol β-D-galactopyranoside as the substrate. The absorbances of p-nitrophenol solution formed were measured at 420 nm in a spectrophotometer. The β-galactosidase activities were calculated comparative to controls.

Results: Presence of the metals significantly affected β-galactosidase activities. Metal concentration of 0.001 mg/L triggered a decrease in enzyme activity. The sensitivity patterns of Pantoea dispersa and Aeromonas dhakensis were Cu>Pb>Zn>Mn>Fe while that of Providencia stuartii was Pb>Cu>Zn>Mn>Fe. The effect of metal stress to enzyme synthesis is reliant on the organism and the metal. This might be described with logistic dose-response model using elevated coefficient of inhibition (R > 0.81).

Conclusion: The results revealed that concentration of metal as low as 0.001 mg/L when deposited in the environment has detrimental effect on microbial activities and consequently on biogeochemical cycles. The isolated bacterial strains could serve as ideal organisms for heavy metal toxicity evaluation.
Epidemiological Trend, Risk Factors, Prevention and Treatment Strategies of Self-directed Violent Behavior: A Critical Appraisal of Relevant Literature
Authors: Akhtar Qureshi Naseem , Abdullah Alduraihem Rashid , Mohammad Aldosari Sarah , Abdullah Alhabeeb Abdulhameed
Published: February 2020

Background: Suicide is an intentional fatal act of self-destruction and largely preventable phenomenon. Early Identification of suicide risk factors, proactive preventive steps and therapeutic interventions tend to reduce robustly its epidemiological trends including associated high mortality around the world.

Objective: This review study aimed to critically describe the identified potential risk factors underlying suicide together with a specific focus on its relevant preventive and management strategies.

Methods: A selective e-searches of Google Scholar, PubMed/MEDLINE and Science Direct of relevant English literature (2000-2019) was conducted by using keywords and Boolean operators, and following exclusion and inclusion criteria included 115 most influential articles for this critical review.

Results: Suicide is a global preventable phenomenon determined by multiple interconnected risk factors and mechanisms embedded in several levels; population (indigenous people and social media), individual (distal predisposing factors), developmental (mediating factors) and proximal (precipitating factors). Evidently suicide needs multimodal intervention approach in terms of universal, selective and indicated prevention.

Conclusion: Suicide is a global heterogeneous phenomenon and needs continuing concerted efforts of multidisciplinary health team and multi-sector stakeholders because its risk pathways and protective factors dynamically changes overtime across the world.
A Clinical and Preliminary Study for Anti-angiogenesis Therapy: Endostatin, VEGF and Microvessel Density in the OSCC in Different Stages and Differentiations
Authors: He Hong , Wang Jiaqin , Deng Xiaotong , Zhao Danping
Published: February 2020

Aims: This study was to analyze the association among ES, VEGF, Microvessel Density (MVD), clinicopathologic characteristics, angiogenesis and prognosis of OSCC.

Methods: Eight normal samples of oral epithelia and 52 Oral Squamous Cell Carcinoma (OSCC) samples were analyzed by immunohistochemical evaluation to study the expression and significance of Endostatin (ES) and Vascular Endothelial Growth Factor (VEGF) during the development of OSCC.

Results: Statistically significant differences were found as p<0.05 between VEGF expressions and clinicopathologic stages of OSCC and as p<0.01 between VEGF expressions and lymph node metastases of OSCC. And Statistically significant discrepancy was also found as p<0.05 between MVD and differentiation degrees and lymphnode metastases of OSCC, as well as p<0.01 between VEGF expressions and MVD. Additionally MVD increased gradually in accordance with the progression of the Cancer. While there was no obvious correlation between ES and VEGF, ES and MVD, as well as between ES and the development of OSCC.

Conclusion: By MVD et al evaluation, VEGF is one of the major angiogenesis factors for angiogenesis and lymphonode metastasis of oral carcinomas, as an important indicator for the development and malignancy of OSCC, while ES is of significance for anti-angiogenesis in tumor therapy.
ABC’s of Publishing a Scientific Paper in a Journal for the Novice Researchers
Authors: Chandrasekhara Reddy Sagili , Ambigga K.
Published: February 2020

Writing a scientific paper, choosing a journal, submitting/uploading the paper in the journal website, the peer review process, revising the paper based on the reviewer's comments, and galley proofreading after the acceptance of the paper are the essential components of publishing a paper. Publishing is the ultimate goal of all researchers. Writing a scientific paper requires an extensive literature search, collection of reference articles, acquisition of data of research work, analysis of data and discussing the results comparing with other findings published in similar papers. The final version of the paper should be read by all authors and approved before the submission of the manuscript. One has to select the journal and edit the paper as per the author's instructions of that journal before submission. The article will be reviewed by two experts in that field and they will send their comments about the contents of the paper. The comments should be answered point by point, and the revised paper should be sent again to the editor. If required one has to be prepared to do more than one revision of the paper. If the paper is rejected, one should not be disappointed. You can further improve the quality of the paper by including the answers for the deficiencies and send the revised paper to another suitable journal. Finally, when it is accepted, the galley proof of the article should be read carefully and send the corrected proof to the editor in-time. The 'pdf' copy of the published paper should be kept for sending a copy to the people who request a reprint of your article.
Wafer Preparation Parameter Optimization for Wafer Defects Elimination
Authors: Bacquian B. C. , Gomez F. R.
Published: February 2020

In every new technology developed and introduced to the manufacturing floor, particularly in the wafer preparation, entails problems that later induce defects affecting the wafer yield. This paper discusses the optimization of wafer preparation parameters, particularly the tensionless backgrinding tape lamination and DAF cut vacuum control, that mitigates wafer yield detractors such as edge cut, kerf shift and dice pop-out. Based on the evaluation results, tensionless backgrinding lamination affects the kerf shifting and edge cutting, and with proper vacuum control to attain zero dice pop-out process.
Socioeconomic Impact of Development Projects on the Livelihood of Farmers: A Case Study of the Bui Dam Hydroelectric Project
Authors: Emmanuel Amankwah , Edward Awafo , Thomas Atta-Darkwa
Published: February 2020

The development of major social projects such as hydroelectric dams, roads and mining often result in the loss of properties and sometimes relocation of the affected people or communities. This paper examined the impact of the Bui Dam Hydroelectric project on the livelihood of the people affected, especially farmers in the Bono Region of Ghana. The paper also reviewed the Environmental and Social Impact Assessment (ESIA) report of the project in line with the Environmental Protection Agency requirement, examined the compensation and the living conditions of the farmers in the affected communities. Interviews and focus group discussions of farmers in four communities were conducted which was later followed by the administration of questionnaires to seventy-five (75) farmers. The data obtained from the questionnaires were analyzed using descriptive statistics such as frequencies, percentages and Excel software for the development of charts. The review of the ESIA report of the Bui dam showed that an extensive ESIA was conducted with only few lapses outlined in the text. The interviews and the questionnaires  revealed  that  the  farmers  who  were  relocated  have  problems  with  land acquisition, soil fertility and irrigation facilities when they were moved to their new location. There were also concerns about inadequate payment of compensations and unfulfilled promises. However, about 97.3% of the respondents were comfortable at their new location because of the proximity to health services, access to good roads, nice buildings and provision of some basic social amenities such as light and water, as well as possible business and employment opportunities. The paper makes suggestions for improving compensations and resettlement schemes in Ghana.
Using Mobile– iPhone as New Visible Colour Detector for Determination of Pharmaceutical (Potassium Permanganate)
Authors: Abdulkadhim Hussein Mustafa , Risan Al-Iessa Lamia Abdultef , Majeed Alrufaie Mohauman Mohammed , Al–Sowdani K. H.
Published: February 2020

In this work the use of a mobile phone as a spectrophotometer using camera resolution by installing the software (application store AAP) on the phone (i Phone 6), which analyzes the colour images (RGB) in results with a colour length where it was possible to calculate the colour value of each image representing a specific concentration of the solution under study. A calibration curve with a range of (1 × 10-3 - 6.25 × 10-4) mmole.L-1 using optical image analysis with the concentration of the preparation of potassium permanganate (KMnO4). A calibration curve for statistical correlation range of 0.993 (R2) was found.
Stomach Cancer and Parabens
Authors: Alloujami Lama , Barguil Sophi
Published: February 2020

Background and Objectives: Parabens are one of the chemicals used widely in preserving foods and pharmaceutical preparations. Although it was safe for many years, recently it has been proven that its action mimics estrogen in the body when it is linked to its receptors, known as estrogen receptors which are present in many systems of the body and that it may have a link with breast cancer, especially after it was found in samples of breast cancer. As known that estrogen receptors are placed in different areas in the body, including the stomach, therefore it may have a role in cancer formation and development in the stomach.

The purpose of this manuscript is to investigate the presence of Methyl, Ethyl and Propylparaben in stomach cancer in men and women.

Methods: Samples of stomach cancer have been collected immediately after surgery in Al Assad University Hospital and after extracting parabens from samples, they have been analyzed by HPLC / MS in the science faculty at Damascus University.

Results: All samples have the three types of parabens with total mean concentration (22.5 ± 0.4 ng/g).

The concentration of Methylparaben was the highest (8.2 ± 0.3 ng/g) then Propylparaben (7.4 ± 0.4 ng/g) and finally Ethylparaben (6.9 ± 0.2 ng/g).

Conclusion: Because of the presence of parabens in all stomach cancer samples, so more studies must be done to research if parabens may have any effect in the formation of abnormal cells and the formation of cancer in the body systems which have estrogen receptors.
Design and Construction of Densification Machine for Vegetables in Rural Settlements
Authors: Agunsoye J. K. , Abubakar I. , Ogijo S. I. , Zakariyah A. , A. Okaiyeto S.
Published: February 2020

This research work was carried out to improve the storage space and effective handling of dried vegetables specifically tomatoes, onion and okra, for consumers and marketers. The machine basically consists of an upper compression plate, machine mould, piston, lower compression plate and a 3-tons hydraulic jack. The machine performance was evaluated based on Output Capacity and Machine Compression Efficiency. The results showed that the machine output capacity and efficiency were 0.291 kg/h and 96.3%, respectively. The machine production cost stood at N35,000.00 only. The machine is therefore recommended to farmers.
Conduit Mentality and the Economy: The Nigerian Experience
Authors: Ogunbiyi S. Samuel, , Monogbe G. Tunde,
Published: February 2020

The study is about conduit mentality and the Nigerian economy. Conduit mentality was proxied by annual values of aggregate illicit funds, then the economy was proxied by Educational level (EDU), Standard of living and Health in Nigeria over the period of 1996 to 2018. The research design is expost facto, for our analysis, we used the Autoregressive Distributed Lag Method of regression Analysis. Our result showed that, as expected, the relationship that exists between the dependent and independent variables are negative. We discovered that corruption as proxied by illicit funds is a serious issue in Nigeria and must be tackled if we intend to develop our economy as desired.
Characterization and Application of Molten Slag as Catalyst in Pyrolysis of Waste Cooking Oil
Authors: Kamil Faten Hameed , Ali Salmiaton , Hafriz Raja Shahruzzaman Raja Mohamad , Hussien Intesar Razaq , Omer Rozita
Published: February 2020

Chemical and physical analysis was performed to identify the molten slag composition and its ability to be used as alternative catalyst in pyrolysis of waste cooking oil. The implementation such type of catalytic material could be useful in reducing the process cost. To increase the efficiency (increase the active site) of molten slag, it was modified by acid washing that resulted in an increase in the acidity from 159 to 1224 µmol/g. The results showed that the yield of bio-fuel was increased and the product selective to n-C15 upon the modification of molten slag by acid treatment. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
A Review Paper on Heterogeneous Fenton Catalyst: Types of Preparation, Modification Techniques, Factors Affecting the Synthesis, Characterization, and Application in the Wastewater Treatment
Authors: Kumar Vijyendra , Mohapatra Titikshya , Dharmadhikari Sandeep , Ghosh Prabir
Published: February 2020

This comprehensive review focuses on the different factors, modification in the synthesis method, characterization and application of heterogeneous catalyst in the wastewater treatment based on the Fenton process. The present review highlights the different catalyst preparation methods like wet impregnation method, hydrothermal method, sol-gel method, precipitation method and their application to treat different recalcitrant organic chemicals. Major heterogeneous catalyst synthesis methods were discussed with their excellent workability. The importance of modification through physical and chemical method  was  also reported. Different catalyst, pollutants and optimum parametric conditions available in the literature along with some relevant studies are summarized. The effect of factors like pH, calcination and some other modifiers on the synthesis and their efficiency in the wastewater treatment has been described. The important characterization of synthesized catalysts explaining their working efficiency has also been discussed. In the final section, the application of heterogeneous catalyst synthesized by different methods in the wastewater/effluent treatment has been investigated. The main aim of this review is to find out the influence of process parameters and catalytic method on degradation/decolorization of organic compounds present in industrial or synthetic wastewater. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Degradation of Phenol in Pharmaceutical Wastewater using TiO2/Pumice and O3/Active Carbon
Authors: Ratnawati R. , Enjarlis E. , Husnil Yuli Amalia , Christwardana Marcelinus , Slamet S.
Published: February 2020

Phenol is a toxic organic compound that detectable in the pharmaceutical wastewater, and therefore it should be eliminated. This study aims to degrade phenol in the pharmaceutical wastewater treatment using Advanced Oxidation Processes (AOPs) include the photocatalytic process applying Titanium Oxide (TiO2) that immobilized on pumice stone (PS), as well as ozone process with O3 and O3/granulated activated carbon (GAC). Degradation system used two configuration reactors that worked alternately at pH 3 and 9. Photocatalysis was conducted for 4 hours in the photoreactor that equipped with mercury lamp as a photon source, while ozonation was performed for 1 hour in the cylinder glass reactor contained an ozone generator. Phenol degradations were done by photocatalysis, ozonation, photocatalysis followed by ozonation and vice versa. The FESEM-EDS and XRD results depicted that TiO2 has impregnated on pumice stone and FESEM characterization also indicated that the photocatalyst spread across the surface of the pumice stone. BET analysis results in an increased surface area of the PS-TiO2 by 3.7 times, whereas bandgap energy down to 3 eV. It can be concluded that ozone process (with O3/GAC) that followed by photocatalysis at pH 9 could treat the liquid waste with phenol concentration 11.2 down to 1.2 ppm that nearly according to the discharge standards quality (1 ppm). Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Zn-M-CO3 Layered Double Hydroxides (M=Fe, Cr, or Al): Synthesis, Characterization, and Removal of Aqueous Indigo Carmine
Authors: Bouteraa Salima , Saiah Fatiha Boukraa Djelllal , Hamouda Sarah , Bettahar Nourredine
Published: February 2020

In this approach, Zn-M+3 layered double hydroxides (LDHs) with M+3 = Fe, Cr, or Al were synthesized by the co-precipitation method from the aqueous solution at a constant solution pH. The as-synthesized samples were characterized by XRD analysis, FTIR spectra, BET techniques and simultaneous thermogravimetric-differential scanning calorimetry (TGA/DSC). XRD analysis showed that Zn-Fe-CO3 had the greatest lattices parameters. BET surface area of Zn-Fe-CO3 was calculated as 52.24 m2.g-1 and was higher than Zn-Cr-CO3 and Zn-Al-CO3 with 46.70 and 49.99 m2.g-1, respectively. The FTIR spectra clearly confirmed the presence of carbonate anions in the structure of the LDHs. Adsorption experiments for Indigo Carmine (IC), as the main model organic pollutant in this study from aqueous solution onto synthetized samples were carried out in terms of solution pH, contact time and initial dye concentration. Experimental results indicate that the capacity of dye uptake augmented rapidly within the first 15, 40, and 55 minuts for Zn-Fe-CO3, Zn-Cr-CO3 and Zn-Al-CO3 respectively and then stayed practically the same regardless of the concentration. Adsorption kinetics studies revealed that the adsorption process followed pseudo-second order kinetics model instead of a pseudo-first-order model. The adsorption isotherm data follow the Langmuir equation in which parameters are calculated. The maximum Langmuir monolayer adsorption capacities were 94.87, 21.79, and 66.71 mg.g-1, respectively, for Zn-Fe-CO3, Zn-Cr-CO3, and Zn-Al-CO3. The adsorption capacities were slightly influenced by the pH variations from 5 to 10, showing the advantage of using these materials in water treatments in a wide pH range. Finally, the IC removal is proven by the presence of IC functional groups in IR spectra and thermograms. TGA/DSC of Zn-Fe-CO3 obtained after removal of IC indicate that the LDHs stabilizes IC and delays the combustion of adsorbed molecules. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Facile Investigation of Ti3+ State in Ti-based Ziegler-Natta Catalyst with A Combination of Cocatalysts Using Electron Spin Resonance (ESR)
Authors: Pongchan Thanyaporn , Praserthdam Piyasan , Jongsomjit Bunjerd
Published: February 2020

This study aims to investigate the influences of a combination of cocatalysts including triethylaluminum (TEA) and tri-n-octylaluminum (TnOA) for activation of a commercial Ti-based Ziegler-Natta catalyst during ethylene polymerization and ethylene/1-hexene copolymerization on the change in Ti3+ during polymerization. Thus, electron spin resonance (ESR) technique was performed to monitor the change in Ti3+ depending on the catalyst activation by a single and combination of cocatalyst. It revealed that the amount of Ti3+ played a crucial role on both ethylene polymerization and ethylene/1-hexene copolymerization. For ethylene polymerization, the activation with TEA apparently resulted in the highest catalytic activity. The activation with TEA+TnOA combination exhibited a moderate activity, whereas TnOA activation gave the lowest activity. In case of ethylene/1-hexene copolymerization, it revealed that the presence of 1-hexene decreased activity. The effect of different cocatalysts tended to be similar to the one in the absence of 1-hexene. The decrease of temperature from 80 to 70 °C in ethylene/1-hexene copolymerization tended to lower catalytic activity for TnOA and TEA+TnOA, whereas only slight effect was observed for TEA system. The effect of different cocatalyst activation on the change of Ti3+ state of catalyst was elucidated by ESR measurement. It appeared that the activation of catalyst with TEA+TnOA combination essentially inhibited the reduction of Ti3+ to Ti2+ leading to lower activity.  Furthermore, the polymer properties such as morphology and crystallinity can be altered by different cocatalysts. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Enhancing Enzymatic Digestibility of Coconut Husk using Nitrogen-assisted Subcritical Water for Sugar Production
Authors: Muharja Maktum , Fadhilah Nur , Nurtono Tantular , Widjaja Arief
Published: February 2020

Coconut husk (CCH) as an abundant agricultural waste in Indonesia has the potential to be utilized for sugar production, which is the intermediate product of biofuel. In this study, subcritical water (SCW) assisted by nitrogen (N2) was developed to enhance the enzymatic hydrolysis of CCH. SCW process was optimized by varying the operation condition: the pressure of 60-100 bar, the temperature of 150-190 °C, and the time of 20-60 min. The SCW-treated solid was subsequently hydrolyzed by utilizing a mixture of commercial cellulase and xylanase enzymes. The result shows that the optimum total sugar yield was obtained under the mild condition of SCW treatment, resulting in the sugar of 15.67 % and 10.31 % gained after SCW and enzymatic hydrolysis process, respectively. SEM and FTIR analysis of SCW-treated solid exhibited the deformation of lignin and solubilization of cellulose and hemicellulose, while XRD and TGA revealed an increase of the amount of crystalline part in the solid residue. The use of N2 in SCW treatment combined with enzymatic hydrolysis in this study suggested that the method can be considered economically for biofuel production from CCH waste in commercial scale. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Soluble Colloidal Manganese Dioxide: Formation, Characterization and Application in Oxidative Kinetic Study of Ciprofloxacin
Authors: Tazwar Gajala , Devra Vijay
Published: February 2020

Soluble colloidal manganese dioxide was formed by reduction of potassium permanganate with sodium thiosulphate in neutral aqueous medium at 25 ºC. The obtained nano-sized colloidal manganese dioxide was found to be dark reddish-brown in color and stable for several months. The formation of manganese dioxide was confirmed by UV-visible spectrophotometer and determination of oxidation state of Mn species in manganese dioxide. The effect of different concentration of sodium thiosulphate on the formation of manganese dioxide was also studied. The nano-sized colloid manganese dioxide was characterized by transmission electron microscopy and Fourier transform infrared spectrophotometer. The formed soluble colloidal manganese dioxide was used as an oxidant in oxidation of ciprofloxacin in perchloric acid medium at 35 ºC. The reaction was first-order concerning to concentration of manganese dioxide and hydrogen ion but fractional order with ciprofloxacin. The results suggest formation of complex between ciprofloxacin and manganese dioxide. The oxidation products were also identified based on stoichiometric and characterization results. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Structural, Thermal, Morphological, Adsorption and Catalytic Properties of Poly(BPDAH-co-ODA/PPDA)-Ag/V2O5 Nanocomposites
Authors: Sribala Govindharajan , Meenarathi Balakrishnan , Anbarasan Ramasamy
Published: February 2020

Thermally stable polyimides (PIs) were prepared by condensation technique at 160 ºC for 5 hours in N-methylpyrrolidone (NMP) medium under N2 atmosphere both in the presence and absence of metal (Ag) and metaloxide (MO) (V2O5) nanoparticles (NPs). The synthesized polymers are characterized by Fourier Transform Infra Red (FT-IR) spectroscopy, 1H Nuclear Magnetic Resonance (1H NMR) spectroscopy, Differential Scanning Calorimetry (DSC), Thermal Gravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Field Emission Scanning Electron Microscopy with Energy Dispersive X-Ray (FE-SEM and EDX). The FT-IR spectrum showed a peak at 1786 cm-1 corresponding to the C=O stretching of dianhydride. The aromatic proton signals appeared between 6.7 and 7.5 ppm in the 1H-NMR spectrum of the resultant PIs. The oxydianiline (ODA) based PI with Ag NP loaded system exhibited the highest Tg value. The apparent rate constant values for the adsorption and catalytic reduction of p-nitrophenol (PNP), Cr6+ and rhodamine 6G (R6G) dye were determined with the help of UV-visible spectrophotometer. Among the catalysts, the system loaded with V2O5 NP has higher kapp values. The experimental results are critically analyzed and compared with the previously available literature values. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Catalytic Dehydration of Ethanol over W/TiO2 Catalysts Having Different Phases of Titania Support
Authors: Kerdnoi Pongsatorn , Autthanit Chaowat , Chitpong Nithinart , Jongsomjit Bunjerd
Published: February 2020

This study aims to investigate the catalytic behaviors on W/TiO2 catalysts having different phases of TiO2 towards catalytic dehydration of ethanol to higher value products including ethylene, diethyl ether, and acetaldehyde. In fact, TiO2 support with different crystalline phases can result in differences of physico-chemical properties of the catalyst. Therefore, the present work reports on the catalytic behaviors that were altered with different phases of TiO2 in catalytic ethanol dehydration to diethyl ether or ethylene as a major product. To prepare the catalysts, three different phases [anatase (A), rutile (R), and mixed phases (P25)] of TiO2 supports were impregnated with 10 wt% of tungsten (W). It was found that the W/TiO2-P25 catalyst revealed higher activity among other catalysts. At 300 °C, all catalysts can produce the diethyl ether yield of 24.1%, 22.8%, and 10.6% for W/TiO2-P25, W/TiO2-A, and W/TiO2-R catalysts, respectively. However, when the reaction temperature was increased to 400°C, ethylene is the major product. The W/TiO2-P25 and W/TiO2-A catalysts render the ethylene yield of 60.3% and 46.2%, respectively, whereas only 15.9% is obtained from W/TiO2-R catalyst. The most important parameter influencing their catalytic properties appears to be the proper pore structure, acidity, and distribution of W species. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Polymerization of Ethylene Glycol Dimethacrylate (EGDM), Using An Algerian Clay as Eco-catalyst (Maghnite-H+ and Maghnite-Na+)
Authors: Haoue Sara , Derdar Hodhaifa , Belbachir Mohammed , Harrane Amine
Published: February 2020

In this paper we have explored a novel and green method to synthesis and polymerize ethylene glycol dimethacrylate (EGDM). This technique consists on using Maghnite (Algerian clay) as a green catalyst to replace toxic catalysts. The Algerian clay has been modified using two ion exchange process to obtain Maghnite-H+ (proton exchanged process) and Maghnite-Na+ (sodium exchanged process). Synthesis experiments of EGDM and Poly (EGDM) are performed in bulk respecting the principles of green chemistry. The structure of the obtained monomer and the obtained polymer was confirmed by FT-IR, 1H-NMR and 13C-NMR, where the methacrylate end groups are clearly visible. The presence of unsaturated end group in the structure of monomer was confirmed by UV-Visible analysis. Thermogravimetric analysis (TGA) was used to study the thermal stability of these obtained products. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Dynamic Model-Free and Model-Fitting Kinetic Analysis during Torrefaction of Oil Palm Frond Pellets
Authors: Matali Sharmeela , Abd Rahman Norazah , Idris Siti Shawalliah , Yaacob Nurhafizah
Published: February 2020

Torrefaction is a thermal conversion method extensively used for improving the properties of biomass. Usually this process is conducted within a temperature range of 200-300 °C under an inert atmosphere with residence time up to 60 minutes. This work aimed to study the kinetic of thermal degradation of oil palm frond pellet (OPFP) as solid biofuel for bioenergy production. The kinetics of OPFP during torrefaction was studied using frequently used iso-conversional model fitting (Coats-Redfern (CR)) and integral model-free (Kissinger-Akahira-Sunose (KAS)) methods in order to provide effective apparent activation energy as a function of conversion. The thermal degradation experiments were conducted at four heating rates of 5, 10, 15, and 20 °C/min in a thermogravimetric analyzer (TGA) under non-oxidative atmosphere. The results revealed that thermal decomposition kinetics of OPFP during torrefaction is significantly influenced by the severity of torrefaction temperature. Via Coats-Redfern method, torrefaction degradation reaction mechanism follows that of reaction order with n = 1. The activation energy values were 239.03 kJ/mol and 109.28 kJ/mol based on KAS and CR models, respectively. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
DES2 is a fatty acid Δ11 desaturase capable of synthesizing palmitvaccenic acid in the arbuscular mycorrhizal fungus Rhizophagus irregularis
Authors: Cheeld Henry , Bhutada Govindprasad , Beaudoin Frederic , Eastmond Peter J.
Published: February 2020

Arbuscular mycorrhizal (AM) fungi are oleaginous organisms, and the most abundant fatty acyl moiety usually found in their lipids is palmitvaccenic acid (16:1Δ11cis). However, it is not known how this uncommon fatty acid species is made. Here, we have cloned two homologues of lepidopteran fatty acyl‐coenzyme A Δ11 desaturases from the AM fungus Rhizophagus irregularis. Both enzymes, DES1 and DES2, are expressed in intraradical mycelium and can complement the unsaturated fatty acid‐requiring auxotrophic growth phenotype of the Saccharomyces cerevisiae ole1Δ mutant. DES1 expression leads almost exclusively to oleic acid (18:1Δ9cis) production, whereas DES2 expression results in the production of 16:1Δ11cis and vaccenic acid (18:1Δ11cis). DES2 therefore encodes a Δ11 desaturase that is likely to be responsible for the synthesis of 16:1Δ11cis in R. irregularis.
Opiate Receptors
Authors: Zheng Hui , Law Ping‐Yee , Loh Horace H
Published: February 2020

Morphine and its congeners are considered to be the best painkilling agents available. The molecular basis for the observed analgesics effects and other pharmacological functions of opioid analgesic drugs are defined by multiple opioid receptors. The opioid receptors are typical G protein‐coupled receptors and activate a variety of downstream signalling pathways via G protein‐ or β‐arrestin‐dependent pathway. Because of the existence of multiple endogenous peptide ligands and the crosstalk with other nonreceptor signalling pathways or neurological circuitries, the pharmacological functions mediated by the multiple opioid receptors are quite complex and are involved in multiple physiological processes, such as the effects on the functions of immune cells and neural stem cells.

Key Concepts

The molecular basis for the observed pharmacological functions of opioid analgesic drugs is defined by multiple opioid receptors.

Signalling transduction from opioid receptors is essential for the functions of opioids.

As classical GPCR, agonist‐selective signalling can be observed with opioid receptors.

Opioid analgesic drugs and opioid receptors contribute to other CNS functions in addition to pain relief.

The observed pharmacological functions of opioid analgesic drugs involve nonreceptor elements.
Bacterial Endospores
Authors: Flores Matthew J , Popham David L
Published: February 2020

Species of the genera
Bacillus
and
Clostridium
form dormant, resistant cells are known as endospores in response to stressful conditions. Endospores form inside of a mother cell, or sporangia, via a modified, asymmetrical cell division pathway followed by a variety of spore‐specific modifications to cell structure and content. Once the spore is formed, it is metabolically dormant and highly resistant to various insults such as heat, noxious chemicals, desiccation and UV irradiation. Several significant pathogens are spore formers, which makes disease prevention via food and environment sterilisation challenging. The resistance properties of spores are derived from chemical and physical alterations such as dehydration and mineralisation of the cytoplasm, protective alteration of DNA structure by specialised proteins and formation of impermeable proteinaceous spore coats. Dormancy is ended when the spore enters an environment where spore germination is favourable.

Key Concepts

Bacterial endospores can survive for decades and are highly resistant to numerous environmental insults.

The resistance properties of bacterial endospores contribute to their roles in food spoilage and in human and animal pathogenesis.

Bacterial endospores are cells with specialised modifications to their structure and contents.

Bacterial endospores are produced via a simple developmental process involving cooperative and regulated gene expression of two cells.

Heat resistance of bacterial endospores is determined by several factors, the most important being the relative dehydration of the spore core.

Bacterial endospores possess a unique mode of resistance to UV irradiation involving specialised DNA‐binding proteins.
Bacterial Flagella
Authors: Kühne Caroline , Guse Alina , Hüsing Svenja , Erhardt Marc
Published: February 2020

Bacteria propel themselves through liquid or over semisolid media using rotation of a propeller‐like organelle, the flagellum. The membrane‐embedded basal body is connected via a flexible coupling structure, the hook, to the rigid, external filament. The flagellum is a sophisticated, molecular nanomachine, and to build a flagellum, several thousand copies of more than two dozen proteins assemble in an ordered process. Flagellar gene expression is temporally coupled to its assembly state, and complex self‐assembly mechanisms control the accurate size and subunit composition of flagellar substructures. A specialised protein export machine, termed type‐III secretion system, transports flagellar substrates across the inner membrane. Secreted substrates diffuse through a narrow channel within the flagellum and self‐assemble at the distal end. Intermittent secretion of a molecular ruler protein controls the hook length, while diffusion of flagellin proteins intrinsically limits the length of the flagellar filament.

Key Concepts

Bacteria swim through their environment by rotating an extracellular appendage, the flagellum.

Rotation of the flagellum is energised by influx of ions through stator proteins that are attached to the cell body, which is called the ion motive force.

The bacterial flagellum consists of three major parts: (1) the basal body as the engine, (2) a flexible joint structure, the hook, that connects the engine to (3) the long external filament.

Assembly of the flagellum involves dozens of proteins and the coordination of gene expression to the assembly state of the flagellum.

A specialised protein export system, a type‐III secretion apparatus, is responsible for the export of flagellar secretion substrates, including the majority of the external structures of the flagellum.

Protein export via the flagellar‐specific type‐III secretion system is dependent on the proton motive force.

The length of the hook structure is regulated to an optimal length of 55 nm in
Salmonella
. A molecular ruler controls the final length and catalyses a switch in secretion specificity from early to late substrate secretion mode.

After proton motive force‐dependent injection, flagellin molecules, the building blocks of the filament, diffuse through a narrow channel and self‐assemble at the distal tip of the structure.
Methane Paradox
Authors: Bižić Mina , Grossart Hans‐Peter , Ionescu Danny
Published: February 2020

In contrast to common textbook knowledge, substantial amounts of the potent greenhouse gas methane are produced and emitted from oxygenated freshwater and marine systems. Since this phenomenon contradicts the belief that biological methane production occurs only under strictly anoxic conditions, it was termed the ‘Methane Paradox’. Several biotic and abiotic mechanisms have been suggested to explain the ‘Methane Paradox’. These include the transport of methane from anoxic environments, the formation of microenvironments able to support the classical anaerobic methanogenesis and novel pathways. Among the latter demethylation of methylphosphonates has been proposed as an important pathway in both marine and freshwater systems. Nevertheless, recent studies point to the ability of a broad spectrum of organisms to produce methane independent of the currently known biochemical pathways.

Key Concepts

Methane has roughly 30 times the global warming potential of carbon dioxide by mass over a century.

Methane is emitted from oxygen‐rich environments and not only from anoxic ones as is often stated.

The ‘Methane Paradox’ describes the occurrence of elevated methane concentrations in the upper oxic water column as compared to deeper waters, suggesting local production despite the strict anaerobic nature of all known
Archaea
‐based methanogenic pathways.

Abiotic factors can contribute to the presence of methane in oxic waters and include transport of methane produced in anoxic environments and nonbiological degradation of methylated compounds.

Biotic factors contributing to the presence of methane in oxic waters include local production by microorganisms in anoxic microniches, degradation of methylated compounds and direct, photosynthesis‐related production by phytoplankton like
Cyanobacteria
, diatoms, green algae and
Coccolithofores
.
The Chemistry of Porous Organic Molecular Materials
Authors: Little Marc A. , Cooper Andrew I.
Published: February 2020

Porous organic molecular materials are a subclass of porous solids that are defined by their modular, molecular structures, and the absence of extended covalent or coordination bonding in the solid‐state. As a result, porous molecular materials are soluble and they can be processed into different forms, such as mixed matrix membranes. The structure of the porous modules can be fine‐tuned for specific applications, such as gas isotope separations, and in some cases the solid‐state properties of these materials can be defined by the structure of the porous molecule as viewed in isolation. In this review, the authors focus on the design of porous organic molecular materials and how their properties can be tuned for specific applications by using crystal engineering techniques. The authors distinguish between strategies where porosity is defined largely by the molecule itself, for example, in porous organic cages, and cases where porosity is generated by the solid‐state crystalline assembly. They emphasize the importance of computational techniques in the de novo design of functional, porous organic molecular materials, and how molecular modeling is applied to understand the properties of these materials.
Tailoring 2D Heteroatom‐Doped Carbon Nanosheets with Dominated Pseudocapacitive Behaviors Enabling Fast and High‐Performance Sodium Storage
Authors: Jin Qianzheng , Li Wei , Wang Kangli , Li Haomiao , Feng Pingyuan , Zhang Zhuchan , Wang Wei , Jiang Kai
Published: February 2020

2D carbon nanosheets are considered to be promising candidates for use as sodium ion battery (SIB) anodes due to their large specific surface area and excellent electronic conductivity. However, their applications are hampered by inferior cycling performance, insufficient storage capacity, and high cost. N, B co‐doping carbon nanosheets (NBTs) are synthesized using biomass‐based gelatin as carbon precursor and boric acid as template, and demonstrate their great potential as high‐performance SIB anodes in practical applications. The synergistic effect of heteroatom doping and ultrathin 2D structure provides the NBTs with abundant defects, active sites, and short ion/electron transfer distance, which favors and improves the storage capabilities and rate performances. The optimized NBTs present a remarkable cyclability and superb rate capability (309 mAh g−1 at 0.2 A g−1 for 200 cycles; 225 mAh g−1 at 1 A g−1 for 2000 cycles). Meanwhile, the Na storage mechanism is proved to be a pseudocapacitive‐controlled process, which accounts for the fast charge/discharge behaviors. This work demonstrates an effective template method to produce 2D heteroatoms co‐doping carbon nanosheets to achieve excellent Na storage performances.
Silica Nanodepletors: Targeting and Clearing Alzheimer's β‐Amyloid Plaques
Authors: Jung Huijin , Chung You Jung , Wilton Rosemarie , Lee Chang Heon , Lee Byung Il , Lim Jinyeong , Lee Hyojin , Choi Jong‐Ho , Kang Hyuno , Lee Byeongdu , Rozhkova Elena A. , Park Chan Beum , Lee Joonseok
Published: February 2020

Abnormal accumulation of β‐amyloid (Aβ) peptide aggregates in the brain is a major hallmark of Alzheimer's disease (AD). Aβ aggregates interfere with neuronal communications, ultimately causing neuronal damage and brain atrophy. Much effort has been made to develop AD treatments that suppress Aβ aggregate formation, thereby attenuating Aβ‐induced neurotoxicity. Here, the design of Aβ nanodepletors consisting of ultralarge mesoporous silica nanostructures and anti‐Aβ single‐chain variable fragments, with the goal of targeting and eliminating aggregative Aβ monomers, is reported. The Aβ nanodepletors impart a notable decline in Aβ aggregate formation, resulting in significant mitigation of Aβ‐induced neurotoxicity in vitro. Furthermore, stereotaxic injections of Aβ nanodepletors into the brain of an AD mouse model system successfully suppress Aβ plaque formation in vivo up to ≈30%, suggesting that Aβ nanodepletors can serve as a promising antiamylodoisis material.
Narrowband‐Absorption‐Type Organic Photodetectors for the Far‐Red Range Based on Fullerene‐Free Bulk Heterojunctions
Authors: Xia Kai , Li Yachen , Wang Yan , Portilla Luis , Pecunia Vincenzo
Published: February 2020

Spectrally‐selective photodetection via organic semiconductors manifesting narrowband absorption (NBA photodetection) is highly attractive for emerging applications that require ultrathin, lightweight, and low‐cost solutions. While successful over mainstream color bands, NBA photodetectors have struggled so far to meet the functional and/or performance demands at longer wavelengths, importantly in the far‐red (700–750 nm), a range relevant to diverse applications in analytical biology, medical diagnostics, remote sensing, etc. In consideration of the potential of a nonfullerene‐acceptor route to address this challenge, the narrowband photodetection capabilities of SBDTIC, a recently‐developed benzodithiophene‐based acceptor with narrowband absorption in the far‐red, are explored. Two bulk‐heterojunction NBA configurations are considered, in which SBDTIC is combined with a donor either absorbing also in the far‐red, or transparent through the visible. It is found that the latter configuration provides superior narrowband functionality, with peak detectivity of 1.42 × 1013 Jones and spectral width of 141 nm—the highest detectivity to date for NBA far‐red‐selective photodetectors, and the smallest spectral width of all solution‐processed implementations. In self‐powered operation, such photodetectors additionally present a quasilinear response over a photocurrent range of least four orders of magnitude, and respond in the microsecond range, further evidencing the suitability of this approach to address the wealth of target applications.
Synthesis and Application of Heterocyclic Germatranes via Rhodium‐Catalyzed Directed C−H Activation/Annulation with Alkynyl Germatranes and Palladium‐Catalyzed Cross‐Coupling
Authors: Xu Meng‐Yu , Wang Chao , Jiang Wei‐Tao , Xiao Bin
Published: February 2020

Rhodium‐catalyzed C−H activation and annulation with alkynyl germatranes for the synthesis of heterocyclic germatranes is described. Various heterocyclic germatranes were constructed by this protocol and applied in multiple derivatizations such as palladium‐catalyzed cross‐coupling reactions.

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The Opportunity Cost of the Conservation Reserve Program: A Kansas Land Example
Authors: Taylor Mykel R. , Hendricks Nathan P. , Sampson Gabriel S. , Garr Dillon
Published: February 2020

The effects of the Conservation Reserve Program (CRP) on farmland values is investigated using a set of parcel‐level data for land sales in Kansas over the period 1998 to 2014. The sales data are used to estimate a hedonic model of land values that allows for the opportunity cost of CRP enrollment to vary across space and time. Factors impacting the opportunity costs include the relative productivity of land, returns to farming, and the time remaining under the CRP contracts. We find that the discount associated with having land under CRP contract averages 7%.