bluuebunny/crossref_metadata_2025 huggingface dataset:
Pollution Status of Heavy Metals in Spent Oil-Contaminated Soil in Gwagwalada
Authors: Nna Orji Chinenye , Abdulrahman Funke Wosilat , Rosemary Isu Nnennaya
Published: July 2019

The pollution status of some selected heavy metals namely: Pb, Fe, Zn, Cu, Cr, Ni and Cd, in spent oil-contaminated soil were investigated. The soil samples were obtained from different spots of the automobile mechanic workshop, wet digested and the concentrations of the heavy metals in the soil digest determined using Atomic Absorption Spectrophotometer (AAS). The concentration of Pb was significantly higher (p<0.05) than the concentrations of each of the other six heavy metals while cadmium had the least concentration. In most of the sampling spots analyzed, the concentrations Cd were below the detection limit of the instrument used. The order of the concentrations of the heavy metals were Pb> Fe> Zn> Cu> Cr> Ni> Cd and Fe > Cr > Zn> Pb> Cu> Ni> Cd for the spent oil-contaminated and control soils respectively. The concentration of iron, cadmium, copper, nickel and zinc in the control soil were significantly lower (p<0.05) than the concentration of iron, zinc and lead in the oil-contaminated soil. The concentration of Pb exceeded the limits of both the background and intervention lead value set by DPR (Department of Petroleum Resources) of Nigeria. The contamination and potential ecological factors of Zn, Cu, Fe, Cr and Cd were categorized low except Pb which was categorized as having very high contamination factor and moderate potential ecological risk factor. The entire studied spots showed moderate degree of contamination. The potential risk index of the heavy metals ranged from 44.23 to 51.91, which had a low grade category; implying that the heavy metals have caused low harm to the soil of the workshop. This paper gives information on the present status of heavy metals in the soil and the need for continuous monitoring so as to avert further contamination of this workshop.
Inhibition of Mild Steel Corrosion in Acidic Medium by Telfairia occidentalis Rind Extract
Authors: A. Akpan Inemesit , U. Abakedi Okon , A. James Mfon
Published: July 2019

Telfairia occidentalis rind extract has been studied as a potential green inhibitor for mild steel corrosion in 1 M H2SO4 using weight loss and hydrogen evolution methods. The results of the investigation reveal that Telfairia occidentalis rind extract is a good inhibitor of mild steel corrosion in sulphuric acid solution. The inhibition efficiency increases with increase in rind extract concentration but decreases with increase in temperature. The calculated thermodynamic parameters reveal that the corrosion inhibition process was endothermic and spontaneous. Physical adsorption has been proposed for the adsorption of Telfairia occidentalis rind extract onto mild steel surface. The adsorption of the extract on mild steel surface obeys the Langmuir adsorption isotherm.
Physicochemical Properties of Alchornea cordiforlia, Cyperus esculentum and Irvingia gabonensis Seed Oils and Their Applications
Authors: Michael Akomaye Akpe , Faith Patrick Inezi
Published: July 2019

The physicochemical properties of oils extracted from three locally available plant seeds in Nigeria namely: Alchomea cordiforlia, Cyperus esculentum and Irvingia gabonensis using n-Hexane were determined. The results of the analysis revealed that their % yield were 37.00, 27.50 and 33.00 for A. cordiforlia, C. esculentum and I. gabonensis respectively. Their odour was non-offensive and their colours were reddish, light yellow and milky white for A. cordifolia, C. esculentum and I. gabonensis respectively, making them bright and attractive. The specific gravity of the oils at 25oc was 0.91, 0.94 and 0.92 for A. cordiforlia, C. esculentum and I. gabonensis  respectively. Their flash points in °c were also 155, 159 and 229 respectively, indicating that I. gabonensis is the most thermally stable oil and suitable for frying. The chemical properties for A. cordiforlia, C.esculentum, and I. gabonensis respectively were as follows: Acid values in mgKOH/g were 24.67, 5.33 and 3.73. Peroxide values in mEqKg-1 were 7.26, 9.86 and 2.96. Saponification values in mgKOH/g were 162.13, 179.52 and 238.43. Iodine values in g/100g were 24.62, 11.68 and 3.38. These results indicate that the three seeds are viable sources of oil based on their % yield. They are good for both domestic and industrial use based on their acid, saponification and iodine values. Their properties in most cases compete favorably with palm kernel oil (PKO) which is currently being used for many domestic and industrial purposes in Nigeria especially for the making of paints, soap, cosmetics, lubricant, and varnishes.
Development of a Simple and Accurate Spectrophotometric Method for the Determination of Trace Levels of Cu, Zn and Pb in Adult Egyptian Blood Samples Using (1,5-Diphenylthiocarbazone)
Authors: S. E. El-Dars Farida M. , Abd El-Razek Rasha , Ali Samah
Published: July 2019

Aims: Development of a simple and accurate spectrophotometric method for the determination of Cu, Zn and Pb in adult Egyptians’ blood, plasma and serum using dithizone.

Place of Study:  Hematology Laboratory, Armed Forces Laboratories for Medical Research and Blood Bank, Kobry El-Kobba, Cairo, Egypt.

Methodology:  100 blood samples from adults frequenting the Hematology Lab services were randomly obtained.  The tested group comprised 57 males aging from 22 to 55 years and 43 females aging from 27 to 57 years.  Three methods: Ready-to-use Kit (Reference method), ICP-MS (validation method) and Dithizone spectrophotometric method were used to determine Cu, Zn and Pb levels in these samples.

Results: The results for the proposed dithizone revealed that the Cu levels were higher than those obtained for Zn content.  As for the per gender levels, the Cu concentration range was (60 -148.11 µg/dL) for males and for females, it was (60.71-159.19 µg/dL).  The measured Zn levels for males ranged between 72.2-132.83 µg/dL but for females, it was between 55.95 – 123.62 µg/dL.  Pb levels obtained ranged from 0 - 25.8 µg/dL and the results showed no gender distinction.  The proposed method was validated and showed a linear regression coefficient (R2) above 0.99 for all elements.  The limit of detection (LOD) for the developed method was 4.47, 4.37 and 3.97 µg/dL for Cu, Zn and Pb, respectively.  As well, the limit of quantification (LOQ) was 13.55, 13.25 and 12.03 µg/dL for Cu, Zn and Pb respectively. The modality of the data obtained was tested statistically.

Conclusion: The developed method provided wider calibration and working ranges for Cu, Zn and Pb in the tested blood samples than that reported for the reference and validation methods.  The higher levels of Cu and Zn may be linked to dietary/nutrition intake while Pb content may be more linked to anthropogenic exposure.
Synthesis of New Thiosemicarbazone Derivatives Substituted with Heterocycles with Potential Antitumor Activity
Authors: S. Barbosa Patrícia , S. De Souza Dayane S. , D. Rodrigues Maria , M. Marques Karla , G. Da Silva Teresinha , G. De Lima José
Published: July 2019

Aims: To find new thiosemicarbazone derivatives with antitumor activity and good physico-chemical parameters.

Study Design:  A preliminary SAR study with pyrrolidinyl, piperidinyl, and morpholinyl heterocycles as well as hydrogen, alkyl and phenyl groups in the thiosemicarbazone scaffold.

Place and Duration of Study: Department of Pharmaceutical Sciences and Department of Antibiotics, from Federal University of Pernambuco (Brazil), between January 2016 and February 2017.

Methodology: The thiosemicarbazones were synthesized through a condensation reaction between benzaldehyde substituted with heterocycles and several thiosemicarbazides, using a catalytic amount of hydrochloric acid. The new compounds were characterised using classical spectroscopic and spectrometric techniques. The cytotoxicity were evaluated using MTT assay against five cancer cell lines and doxorubicin as reference compound. The LogP was also predicted using the software MarvinSketch 17.4.3 and promising results were found.

Results: We found five new thiosemicarbazone derivatives with excellent cytotoxicity.

Conclusion: Thiosemicarbazone derivatives are promising compounds in medicinal chemistry field and certainly should be considered as scaffold for drug candidates.
Synthesis and Characterization of a Butenafine Analogue
Authors: Muhammad M. A. , M. Jimoh A. , Awwal A.
Published: July 2019

Aims: The study aims: (I) To synthesise N-(4-(tert-butyl) benzyl)-1-(4-tert-butyl) phenyl)-N-methyl methanaminium chloride, an  analogue  of butenafine from tertiary-butyl benzyl derivatives, (II) to compare the solvent actions of Tetrahydrofuran (THF), acetonitrile, methanol and 1,2-dichloroethane (DCE), and the reducing efficiencies of NaBH4 and sodium triacetoxyborohydride (STAB) during the synthesis.

Study Design:  The study involved laboratory experiments leading to the synthesis of the target compound by varying the non-aqueous solvents used, the reducing agent and the temperature of the operations. Silica chloride catalyst was used to speed up the reaction in one of the syntheses and in each synthesis, Thin Layer Chromatography was used to monitor the progress of the reaction. The time taken by each reaction and the yield were used as the basis for determining the solvent action and the reducing efficiency. 

Place and Duration of Study: M.Sc. Access controlled Teaching Laboratory, School of Chemistry, Newcastle University, New castle upon Tyne, United Kingdom from June to August 2012.

Methodology: Reductive amination was carried out by reacting 4-tert-butylbenzaldehyde and 4-tert-butylbenzylamine, using the direct and then the indirect approaches. This was followed by methylation using the Eschweiler-Clarke reaction in each of the two approaches. The time taken by each reaction was monitored and the product of each approach was characterised by EIS-MS, 1H NMR, 13C NMR and FTIR.

Results: 1,2-dichloroethane gave the best solvent action at 40°C (Yield: 75%) and NaBH4  gave the best-reducing action with silica chloride catalyst at 25°C (Yield: 50%). At the end of each synthesis,  in all obtained  products, 1H NMR spectrum gave a single peak of 18 hydrogen atoms at 1.3 -1.5 ppm for the existence of 6 methyl groups in the two tertiary-butyl substituents, the 13C NMR spectrum also showed a peak at  31-32 ppm for the six methyl carbon atoms in the two tertiary-butyl substituents, the FTIR spectrum showed  a strong band at  2460 cm-1 for the presence of a tertiary ammonium ion and finally the EIS-MS gave  a mass to charge ratio of 324.2693 as a confirmation of the relative molecular mass of the compound.

Conclusion:  The target compound can be synthesised by both direct and the indirect approaches of reductive amination in any of the solvents tested with/without a catalyst at room or elevated temperature using NaBH4 or STAB as a reducing agent but the best solvent action can be achieved with DCE at 40°C and the best-reducing action can be achieved with NaBH4 in the presence of silica chloride.
Groundwater Quality Evaluation for Irrigation and Drinking Utilities Collected from Sadar Upazila of Jamalpur District, Bangladesh
Authors: Zakir H. M. , Akter Arifa , Rahman A. , Sharmin Shaila , Y. Arafat M.
Published: July 2019

The study was undertaken to evaluate groundwater quality both for drinking and irrigation usage collected from the Sadar upazila of Jamalpur district, Bangladesh. Total 20 groundwater samples were collected from the whole area and analysed for various physicochemical parameters following standard protocols at the Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh during March to December 2017. Concentrations of different heavy metal (Fe, Mn, Cu, Pb, Cr, Cd and Zn) in groundwater samples were measured by an atomic absorption spectrophotometer (AAS). Major cation chemistry showed their dominance in order of Ca > Mg > Na > K. Among the anions, HCO3 was the most dominating ion, which makes all groundwater unsuitable for irrigation. But considering major cations and anions, all groundwater samples were rated as suitable for drinking. In context of heavy metals, the amounts of Mn, Cd and Pb in groundwater were comparatively higher than the standard limits, which makes 14, 8 and 19 samples problematic for irrigation, and 13, 18 and 1 samples unsuitable for drinking, respectively. Electrical conductivity (EC) and sodium adsorption ratio (SAR) reflected that all groundwater samples were low to medium salinity (C1-C2) and low alkalinity (S1) hazards classes. As regards to hardness, out of 20 groundwater samples, 9 samples were classified as moderately hard, 10 were hard and only 1 sample was very hard in quality. According to residual sodium carbonate (RSC), 18 groundwater samples were found in suitable class, 1 sample was rated as marginal and the rest 1 was categorised as unsuitable class. The study concluded that HCO3, Mn, Cd and Pb were the major contaminants in groundwater of Sadar upazila of Jamalpur district, Bangladesh. Finally, the study suggested that the groundwater in this area needs to treat to minimise the amount of contaminants before using both for irrigation and drinking.
Study on Variation of Non-polar Metabolites in Gossypium hirsutum L. under Water Stress Condition Using Gas Chromatography-mass Spectroscopy Technique
Authors: Bisht Hema , K. Bhatnagar M. , Bhatnagar Prakhar
Published: July 2019

Present work was aimed at studying the variation of non polar metabolites content in Gossypium hirsutum L. under water stress condition using a gas chromatography-mass spectrometry (GC-MS) technique. A total of 17 non-polar metabolites were detected in control and water stressed G. hirsutum leaf. The major metabolites were quinoline derivative (26.37±0.29%), 2- methylhexadecan-1-ol (7.47±0.07%), phytol (7.71±0.02%), myristic acid (5.94±0.04%), hexadecanol (14.30±0.94%), nonadecane (1.67±0.05%) and palmitic acid (3.20±1.39%). Fourteen metabolites were detected in control and water stressed G. hirsutum stem. The major metabolites were dodecene (1.67±0.11%), L-lysine (0.65±0.06%), dibutylphthalate (5.06±1.88%), linoleic acid (10.26±0.07%), campesterol (0.87±0.04%) and stigmasterol (1.13±0.55%). Statistical analysis of GC-MS data was carried out by Mann-Whitney U test without normal distribution using statistical software SYSTAT version 12.0. Significant variation in the content of the most of the metabolites were observed between control and water stressed leaf or stem (Mann-Whitney U test, P =0.05). It concludes that the major metabolites played an important role during water stress and can be consider as metabolites responsible for water stress tolerance in G. hirsutum.
A Comparative Study of Two Albanian Post-Byzantine Icons Attributed to Simoni i Ardenices
Authors: Franceschi Enrico , Nole Dion , Vassallo Stefano
Published: July 2019

Aims: The present study is part of a project concerning the characterisation of a limited number of selected Albanian Byzantine and post-Byzantine icons, through the identification of pigments, of painting technique and the state of conservation of the artworks. The Albanian iconographers produced an extraordinary amount of icons from the 14th till the 19th century, and over six thousand of them are kept in the Museum of Medieval Art of Korça (Albania). This paper refers to the results obtained in the study of two artworks, the first one by Simoni i Ardenices an important Albanian painter of XVII century, and the second one attributed to him.

Study Design:  The present work is part of a more general study concerning Albanian Byzantine and post-Byzantine icons.

Place and Duration of Study: Museum of Medieval Art of Korça, Albania, between June 2008 and July 2009.

Methodology: The work was conducted by non-destructive methods, X-ray fluorescence, visible light reflectance spectrophotometry and UV fluorescence analysis, according to a systematic procedure developed in the same Chemical Physical Laboratory for Cultural Heritage. A number of areas, for each painting, were chosen in order to carry out the measurements. With this procedure, we could identify the inorganic pigments from their characteristic features. Moreover, the study of the chemical physical properties of paintings is of fundamental importance for any accurate restoration intervention. 

Results and Conclusion: The present work, concerning the study of two icons of the second half of 17th century by Simoni i Ardenices, has allowed us to identify the painting technique and the palette used in these works of art. Moreover, the areas of the paintings in which old restorations have been made have also been identified.
Quality Assessment of Surface and Ground Water of Hong Local Government Area of Adamawa State, Nigeria
Authors: Alexander Priscilla , Dahiru Janyo Noseh , Garba W. Hassan
Published: July 2019

The quality of water from surface and ground water sources in Hong Local Government Area of Adamawa State was studied to determine their suitability or otherwise for drinking and domestic purposes. Nine (9) samples, three (3) each from streams, dug wells and boreholes were randomly collected, during the dry season, in the months of October and November, 2016. The samples were analysed, and the values compared with WHO and NAFDAC standards to ascertain their compliance. The results of the analysis revealed that the physico-chemical parameters studied and concentrations of heavy metals determined, falls within the maximum permissible limits of WHO and NAFDAC standards for drinking water. However, the water samples were predominantly alkaline (pH 6.30 ± 0.10 to 7.00 ± 0.10), (6.70 ± 0.20 to 7.30 ± 0.20), and (7.60 ±0.20 to 8.20 ± 0.10), for boreholes, dug wells and streams respectively. The heavy metals concentrations were determined using Atomic Absorption Spectrophotometric method. The suitability of water for domestic and drinking purposes indicates that water samples were within the standards prescribed for potable waters.
Determination of the Quality of Coconut Oils (Unrefined Grade) and (Refined Grade) Produced from Three Survey Regions of East Godavari District, India
Authors: Kumar G. V. Pavan , Lakshmi N. V. V. S. S. , Deena Ch. , Sekhar V. Chandra , Nikhitha N. Mehar , Begum Md. Mb. Husnara , Bhavani V. B. , Kumar P. Rajendra
Published: July 2019

Aim: The study sought to assess the quality of coconut oil extracted from fresh copra milk by Traditional fermentation(FWCE) and from dry copra balls by continuous processing using expellers(TDCE,DMCE) method with respect to moisture content (MC), free fatty acid (FFA) content, Acid value (AV) and Saponification value in comparison with Food safety and standards authority of India.

Methodology: Three samples of coconut oil were taken from major processing centers in east Godavari district (AMP, SML, KRG) for quality determination. Similarly three samples of coconut oil were prepared from fresh grated coconut milk in the Medicinal chemistry laboratory at Korangi College of pharmacy and three samples were prepared from dry coconut cups. Replicate titer values of each of the nine (09) oil samples obtained were compared with brand double refined oil and the averages were taken into consideration. The AOAC and AOCS methods were used in the analyses and the results compared with Standards provided by Food safety and standards authority of India, Coconut Development Board, Kochi.

Results: The results showed that 50% of the total fermented oil sample had high moisture content than standard and expected to undergo oxidative rancidity. According to the standards, 100% of the oil samples had free fatty acids and acid value within acceptable range indicating no signs of rancidity.

Conclusion: There was a significant difference in saponification value, free fatty acid profile and moisture content of Traditional fermented (FWCE) and dry copra balls by continuous processing expellers (TDCE, DMCE) method. The ANOVA (P<0.05) showed that there were significant differences in the MC, FFA, AV of oils produced among the processing centers and that produced in laboratory. The processes involved in all the extraction centers vary and might have accounted for that. The results indicate that the coconut oils produced in both the cases meet the standards however new technologies in processing should be adopted to improve the quality to meet the standards.
Application of Selected Ion Monitoring-Gas Chromatography Mass Spectrometry (SIM-GCMS) for Quantification of Poly Aromatic Hydro Carbons in Surface Water from Sarawak, Mambong River (Malaysia)
Authors: Umaru Isaac John , Samling Benedict , Umaru Hauwa A.
Published: July 2019

Background: Increasing activities have led to serious environmental problems due to Pullution caused by toxic materials such as poly aromatic carbons whose levels are rising in the environment.

Objective: The study presented here carried out the ultra-trace Quantification of Poly Aromatic Hydro carbons in surface water using Selected Ion Monitoring with optimization Gas Chromatography Mass Spectrometry parameter.

Methods: A Shimadzu QP 2010 Plus GCMS equipped with an auto-injector AOC-20i, 30 m x 0.25 mm x 0.25 um of BP-X5 capillary column (SGE, USA) was used to obtain the result of poly aromatic hydrocarbons to separate and quantify the PAH compounds as well as to identify the Polyromantic Hydrocarbon using USEPA.

Results: The amount of polycyclic aromatic hydrocarbons (PAHs) at ultra-trace level in the surface water samples was estimated. Sixteen Poly Aromatic Hydro carbons were identified among which Naphthalene Pyrene (45.7 ng/L), Chrysene (59.38 ng/L), Benzo (g, h, i) perylene (40.35 ng/L) as the major pollutants in the water surface of Mambong River water. Total Poly Aromatic Hydro carbons (PAHs) concentrations ranged from 2.0 to 40 ng L-1 was detected in the river water.

Conclusion: The Selected Ion Monitoring -Gas Chromatography Mass Spectrometry (SIM-GCMS) can be considered as sensitive and robust method to analyse PAHs contamination in environmental samples. Thus, help the researchers to uncover the critical areas of environmental pollution at ultra-trace level that many researchers were not able to explore.
Single-step Syznthesis of Coenzyme Q0
Authors: Yan Yi-Yu , Qiu Yong-Fu , Zhang Tian-Li , He Yu-Bei , Qi Shi , Tian Jian-Hua , Luo Wan-Yue , Zhao Yan , Wang Jin
Published: July 2019

A new method for the preparation of 2-methyl-5,6-dimethoxy-1,4-benzoquinone (Coenzyme Q0) was developed. This improved process in one step by the oxidation of 3,4,5-trimethoxytoluene to coenzyme Q0 by simple oxidation using potassium or ammonium persulfate under transition -metal free conditions.
Adsorption Performance of Packed Bed Column for the Removal of Lead (II) Using Velvet Tamarind (Dialium indum) Shells
Authors: Akoji Jibrin Noah
Published: July 2019

The removal of Pb ions by activated carbons prepared from velvet tamarind (Dialium indum) shells was studied to investigate its uptake potentials using column sorption at different operating conditions (flow rates, initial concentrations and bed height). The prepared adsorbent was characterized by determining the physicochemical properties, proximate analysis, carbon, Hydrogen, Nitrogen and Sulpur analysis, Fourier Transform-Infra Red, Potentiometric titration. Different dynamic models were used to describe the sorption processes. The FTIR analysis results suggested the presence of functional groups such as hydroxyl, carbonyl, carboxyl and amine which could bind the metals and remove them from the solution. The values of moisture content, volatile matter, fixed carbon and ash content as obtained from % proximate analysis are 3.43, 27.07, 65.05, 4.45 for activated carbons prepared from velvet tamarind shells. Ultimate analysis revealed that activated carbons prepared from velvet tamarind shells contained 75% carbon. The surface area and Iodine number of activated carbon from velvet tamarind shell are 570 m2g-1 and 614.7 mgg-1 respectively. The column experimental data revealed that an increase in bed height and initial metal concentration or a decrease of flow rate enhances the longevity of column performance by increasing both breakthrough time and exhaustion time thereby delaying bed saturation. Low ash content and high surface areas are indication of good mechanical strength and microporosity of the activated carbons prepared from this precursor.  The activated carbons are inexpensive and appeared to be effective and can be explore for future commercial application for environmental sustainability.
A Comparative Study of the Phytochemical Activities of Some Nigerian Indigenous Kola Nuts Kola acuminate (Igbo Kola Nut), Kola vera (Hausa Kola Nut), and Garcinia kola (Bitter Kola)
Authors: Egbujor M. C. , Ike S. E. , Anieze E. O. , Kanayochukwu U. L. , Nwankwo N. E. , Chidebelu I. C. , Okenwa-Ani C. G.
Published: July 2019

Aims: Nigerian indigenous kola nuts (Garcinia kola, Kola acuminate, Kola vera) were evaluated for potential phytochemical properties.

Study Design: Phytochemical analysis.

Place and duration of Study: Renaissance University, Ugbawka, Enugu State, Nigeria, July 2016.

Methodology: The nuts were dried, ground and extracted by cold maceration with 99.5% methanol for 72 hours after which the methanol was allowed to evaporate.

Results: The phytochemical evaluation revealed the presence of saponin glycosides, glycoside, volatile oil, steroid and alkaloid in Kola vera; saponin, saponin glycoside, glycoside, tannins, pseudo tannins, volatile oil, steroid and alkaloid in Kola acuminate while flavonoid, alkaloid and steroid were found in Garcinia kola.

Conclusion: The phytochemical activities results showed that kola acuminate and Garcinia kola extracts exhibited more phytochemical than kola vera.
Investigation of Extent of Interaction of Thiobarbituric Acid and Two Selected Amino Acids with Three Divalent Metal Ions in Aqueous-organic Medium at Different Temperatures
Authors: Oladipo M. A. , Ishola K. T. , Ajayeoba T. A.
Published: July 2019

The formation constants of binary and ternary complexes of Thiobarbituric acid as primary ligand and L-tyrosine and L-histidine as secondary ligands have been examined in 40% (v/v) ethanol-water mixture at 27oC and 35oC and at ionic strength of 0.02 NaNO3 by potentiometric method. The ligands formed 1:1 binary complexes with the metal ions. The primary and secondary ligands simultaneously coordinated to the metal ions to form 1:1:1 ternary complexes. The difference in stability constants of binary and ternary complexes were determined by DlogK and RS%. Ternary complexes exhibited enhanced stability than the binary complexes. The stability of the complexes decrease with increase in temperature. The thermodynamic parameters such as Gibb’s free energy change (ΔG), entropy change (ΔS) and enthalpy change (ΔH) accompany the interactions were evaluated. The interactions were found to be spontaneous, exothermic, and entropically favoured.
Algorithmic Meta-analysis of the Effects of Social Services on the Vulnerable Population
Authors: Carreón-Guillén J. , Quiroz-Campas C. Y. , Bolivar-Mojica E. , Coronado-Rincón O. , Hernández-Valdés J. , Morales-Ortega N. A. , García-Lirios C.
Published: July 2019

Meta-analytic studies are distinguished by comparing literature that reports positive effects with respect to literature that warns of spurious or negative effects. The aim of the present work was to establish the proportion of probabilities between categories and subcategories extracted from the consulted, updated and specialized literature. A documentary study was carried out with a selection of sources indexed to international repositories such as Copernicus, Dialnet, Ebsco, Latindex, Redalyc, Scielo. An indistinct scenario was found, even though the literature that reports positive effects on the quality of life and the subjective well-being of public health services prevails; suggesting the extension of the work to repositories like WoS and Scopus.
Clinical trial of a humanized anti‐IL‐2/IL‐15 receptor β chain in HAM/TSP
Authors: Enose‐Akahata Yoshimi , Oh Unsong , Ohayon Joan , Billioux Bridgette Jeanne , Massoud Raya , Bryant Bonita R. , Vellucci Ashley , Ngouth Nyater , Cortese Irene , Waldmann Thomas A. , Jacobson Steven
Published: July 2019

Objective

Human T cell lymphotropic virus 1 (HTLV‐1)‐associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a chronic, progressive, neurological disease. Chronic activation of CD8+ T cells, as evidenced by increased spontaneous lymphoproliferation and HTLV‐1‐specific cytotoxic T cells, has been demonstrated in HAM/TSP patients. Since IL‐2 and IL‐15 stimulate memory CD8+ T cell activity, these cytokines have been implicated in the immunopathogenesis of HAM/TSP. In this phase I trial, we evaluated the safety, pharmacokinetics, and ability of Hu‐Mikβ1, a humanized monoclonal antibody directed toward the IL‐2/IL‐15 receptor β‐chain (IL‐2/IL‐15Rβ: CD122), to saturate CD122 and regulate abnormal immune responses in patients with HAM/TSP by inhibition of IL‐15 action.

Methods

Hu‐Mikβ1 was administered intravenously at doses of 0.5 mg/kg, 1.0 mg/kg, or 1.5 mg/kg in a total of nine HAM/TSP patients. Five doses of Hu‐Mikβ1 were administered at 3‐week intervals. The clinical response was evaluated using standardized scales. Viral and immunologic outcome measures were examined including HTLV‐1 proviral load, T cell phenotypic analysis and spontaneous lymphoproliferation in HAM/TSP patients.

Results

There was no significant toxicity associated with Hu‐Mikβ1 administration in HAM/TSP patients. Saturation of CD122 by Hu‐Mikβ1 was achieved in five out of nine HAM/TSP patients. Administration of Hu‐Mikβ1 was associated with inhibition of aberrant CD8+ T cell function including spontaneous lymphoproliferation and degranulation and IFN‐γ expression, especially in HAM/TSP patients that achieved CD122 saturation.

Interpretation

The treatment with Hu‐Mikβ1 had a number of immunological effects on HAM/TSP patients although no clinical efficacy was observed. We also did not see any dose‐related toxicity.
Evolution of Twin Boundaries and Contribution to Dynamic Recrystallization and Grain Growth of Inconel 625
Authors: Jia Zhi , Gao Zexi , Ji Jinjin , Liu Dexue , Guo Tingbiao , Ding Yutian
Published: July 2019

Dynamic recrystallization (DRX) and grain growth behaviors of Inconel 625 alloy are investigated via hot compression test in the temperature range of 900–1200 °C and strain rate range of 0.01–10 s−1. The electron backscatter distribution technique is an effective method for identifying twin boundary evolution on the basis of temperature and strain rate; this approach is applied in this study to investigate the effects of twins on the DRX process and grain growth. The fraction of DRX increases with temperature under all strain rates, but the strain rate exerts a complex effect on DRX. Grain size variation with temperature follows a similar trend of declining and then increasing, whereas no apparent trend is observed at various strain rates. The DRX mechanism of the Inconel 625 alloy shifts from discontinuous DRX to continuous DRX with a reduction in deformation temperature and increase in strain rate. The fraction of Σ3n (n = 1, 2, 3) boundaries (twin boundaries) increases with increasing temperature at low temperatures (<1100 °C), but declines with increasing temperature at high temperatures (≥1100 °C). At low temperatures (<1100 °C), the fraction of Σ3n (n = 1, 2, 3) boundaries declines with an increasing strain rate up to 1 s−1 and then increases.
Microstructure and Failure Characteristics of Nanostructured Molybdenum–Copper Composites
Authors: Schwarz Katharina T. , Rosalie Julian M. , Wurster Stefan , Pippan Reinhard , Hohenwarter Anton
Published: July 2019

Liquid‐metal infiltrated Cu30Mo70 (wt%) is subjected to severe plastic deformation using high‐pressure torsion. The initially equiaxed dual‐phase structure is gradually transformed into a lamellar structure composed of individual Cu and Mo layers. The thickness of the lamellae varies between the micro‐ and nanometer ranges depending on the amount of applied strain. Consistent with the refinement of the microstructural features, strength and hardness substantially increase. In addition, an acceptable ductility is found in the intermediate deformation range. An assessment of the damage tolerance of the produced composites is performed by measuring the fracture toughness in different crack propagation directions. The results indicate the development of a pronounced anisotropy with increasing degree of deformation which is an effect of the concurrent alignment of the nanostructured lamellar composite into the shear plane.
Annealing Treatment Methods and Mechanisms for Refining Mixed and Coarse Grains in a Solution Treatment Nickel‐Based Superalloy
Authors: Chen Ming-Song , Wang Guan-Qiang , Li Hong-Bin , Lin Yong-Cheng , Zou Zong-Huai , Ma Yan-Yong
Published: July 2019

The annealing treatment methods and mechanisms for refining deformed mixed and coarse grains in a solution treatment nickel‐based superalloy are investigated. The single‐stage annealing tests are done first, and it is found that the mixed and coarse grains are hardly refined to about 10 μm by a direct annealing at 980 °C due to lack of δ phase. Then, two‐stage annealing tests, in which the deformed sample is first heated to 900 °C for 12 h for precipitating some δ phases and then reheated to 980 °C for a recrystallization annealing treatment (RT), are designed. It is found that the recrystallization is still not complete although a long‐time RT is done. The main reason is that the distances between adjacent δ phases precipitating during direct aging are so small that the recrystallization nuclei are hard to form. So, three‐stage annealing tests, including a pre‐recrystallization annealing treatment (PRT) at 980 °C, an aging annealing treatment (AT) at 900 °C, and an RT at 980 °C, are designed. It is found that the PRT has a favorable influence on the refinement of mixed and coarse grains during the subsequent AT and RT. The mixed and coarse grains can be refined after the three‐stage annealing treatment of 980 °C × 3 min/WQ + 900 °C × 12 h/WQ + 980 °C × 120 min/WQ.
Recent Progress in Lithium Niobate: Optical Damage, Defect Simulation, and On‐Chip Devices
Authors: Kong Yongfa , Bo Fang , Wang Weiwei , Zheng Dahuai , Liu Hongde , Zhang Guoquan , Rupp Romano , Xu Jingjun
Published: July 2019

Lithium niobate (LN) is one of the most important synthetic crystals. In the past two decades, many breakthroughs have been made in material technology, theoretical understanding, and application of LN crystals. Recent progress in optical damage, defect simulation, and on‐chip devices of LN are explored. Optical damage is one of the main obstacles for the practical usage of LN crystals. Recent results reveal that doping with ZrO2 not only leads to better optical damage resistance in the visible but also improves resistance in the ultraviolet region. It is still awkward to extract defect characteristics and their relationship with the physical properties of LN crystals directly from experimental investigations. Recent simulations provide detailed descriptions of intrinsic defect models, the site occupation of dopants and the variation of energy levels due to extrinsic defects. LN is considered to be one of the most promising platforms for integrated photonics. Benefiting from advances in smart‐cut, direct wafer bonding and layer transfer techniques, great progress has been made in the past decade for LNs on insulators. Recent progress on on‐chip LN micro‐photonic devices and nonlinear optical effects, in particular photorefractive effects, are briefly reviewed.
Smart Textile‐Integrated Microelectronic Systems for Wearable Applications
Authors: Shi Jidong , Liu Su , Zhang Lisha , Yang Bao , Shu Lin , Yang Ying , Ren Ming , Wang Yang , Chen Jiewei , Chen Wei , Chai Yang , Tao Xiaoming
Published: July 2019

The programmable nature of smart textiles makes them an indispensable part of an emerging new technology field. Smart textile‐integrated microelectronic systems (STIMES), which combine microelectronics and technology such as artificial intelligence and augmented or virtual reality, have been intensively explored. A vast range of research activities have been reported. Many promising applications in healthcare, the internet of things (IoT), smart city management, robotics, etc., have been demonstrated around the world. A timely overview and comprehensive review of progress of this field in the last five years are provided. Several main aspects are covered: functional materials, major fabrication processes of smart textile components, functional devices, system architectures and heterogeneous integration, wearable applications in human and nonhuman‐related areas, and the safety and security of STIMES. The major types of textile‐integrated nonconventional functional devices are discussed in detail: sensors, actuators, displays, antennas, energy harvesters and their hybrids, batteries and supercapacitors, circuit boards, and memory devices.
Porous Membrane‐Enabled Fast Liquid Metal Patterning in Thin Blind‐Ended Microchannels
Authors: Wang Ronghang , Gui Lin , Zhang Lunjia , He Zhizhu , Gao Meng , Chen Sen , Zhou Xuyan , Cui Yuntao , Deng Zhongshan
Published: July 2019

A porous membrane‐enabled fast liquid metal patterning method in thin blind‐ended microchannels is reported. The principle is to introduce a thin porous membrane in polydimethylsiloxane (PDMS) chips, effectively releasing the air pressure of the inner microchannel during the injection process. Traditional direct injection method requires microchannels with both an inlet and an outlet, making blind‐ended microchannel filling impossible. The vacuum filling requires adequate chip thickness and stiffness for the channel to recover after filling. Additionally, high injection pressure may cause leakages and damage to the microchannels. Experiment results indicate that this novel method promotes the injection in thin blind‐ended microchannels without voids and damages. The finest channel that can be filled successfully using this mechanism is with around 12 µm width and 20 µm height. Series of tensile texts for comb capacitor demonstrate that the electrodes have marvelous flexibility. Overall, the capability of filling the mazy blind‐ended channels entirely quickly makes it promising in the fast fabrication of ultrathin stretchable electronics.
Indirect 3D and 4D Printing of Soft Robotic Microstructures
Authors: de Marco Carmela , Alcântara Carlos C. J. , Kim Sangwon , Briatico Francesco , Kadioglu Ahmet , de Bernardis Gaston , Chen Xiangzhong , Marano Claudia , Nelson Bradley J. , Pané Salvador
Published: July 2019

The development of 3D soft‐robotic components is currently hindered by material limitations associated with conventional 3D printing techniques. To overcome this challenge, an indirect 3D printing approach based on the fabrication of 3D printed sacrificial templates is proposed. High‐resolution micromolds produced by direct laser writing are infused with polymers and then dissolved, leading to the final 3D printed soft microstructures. This method is used to indirectly print 3D and 4D soft microrobots. The versatility of this technique is shown through the fabrication and actuation of gelatin helices filled with magnetic nanoparticles. In addition, it is shown that stent‐like microstructures with shape memory properties can be manufactured with minimum features of 5 µm, which is 40 times smaller than those reported to date. In summary, the utilization of this technique can overcome obstacles associated with the fabrication of soft microrobots and surgical tools for minimally invasive surgery.
Anisotropic Nonlinear Optical Properties of a SnSe Flake and a Novel Perspective for the Application of All‐Optical Switching
Authors: Zhang Chenxi , Ouyang Hao , Miao Runlin , Sui Yizhen , Hao Hao , Tang Yuxiang , You Jie , Zheng Xin , Xu Zhongjie , Cheng Xiang'ai , Jiang Tian
Published: July 2019

The deceptively simple tin selenide (SnSe) film has emerged as an appealing 2D material with a narrow bandgap, high charge carrier mobility, and significant thermoelectric figure of merit. In particular, compared with most commonly investigated 2D materials, SnSe with a puckered honeycomb structure possesses a lower lattice symmetry, resulting in prominent in‐plane anisotropy. Herein, with polarization‐dependent Raman spectroscopy and polarization‐dependent nonlinear absorption measurements, pronounced polarization‐dependent nonlinear optical properties of a SnSe flake are demonstrated originating from the anisotropic optical transition probability of SnSe, which is confirmed by ultrafast polarization‐dependent pump–probe experiments. Furthermore, a novel SnSe‐based all‐optical switch is proposed and experimentally explored. Specifically, due to the polarization‐dependent nonlinear optical response of SnSe, this all‐optical switch can access the “ON” and “OFF” modes of continuous‐wave signal light (633 nm, 13 µW) by altering the polarization of the switching light (800 nm, 65 fs, 1 kHz, 34 GW cm−2), rather than modifying its intensity, achieving an unexpectedly high ON/OFF ratio (the difference of the normalized transmittance of signal light between “ON” and “OFF” modes) of 44%. This work opens up real perspectives for versatile optoelectronic devices based on SnSe materials.
Terahertz Reflectarray with Enhanced Bandwidth
Authors: You Xiaolong , Ako Rajour T. , Lee Wendy S. L. , Low Mei Xian , Bhaskaran Madhu , Sriram Sharath , Fumeaux Christophe , Withayachumnankul Withawat
Published: July 2019

Reflectarrays offer unique potential for beamforming at terahertz frequencies as they combine the advantages of low‐profile of phased arrays and high‐efficiency of parabolic antennas. However, one challenge associated with reflectarrays is their bandwidth limitation resulting from the nonlinear phase response. To enhance bandwidth, a single‐layer stub‐loaded resonator is proposed for constructing reflectarrays. This resonator design shows a smooth and near‐linear phase response with a complete 360° phase coverage at and around the design frequency. To demonstrate its capability in realizing beamforming, a focusing reflectarray is then constructed using the proposed resonator as a building block. The measured results reveal that the 3 dB relative bandwidths of the reflectarray for the transverse electric (TE)‐ and transverse magnetic (TM)‐polarized excitations are 23.3% and 23.9%, respectively, while retaining an efficiency of 71.9% for the TE polarization and 71.0% for the TM polarization at the center frequency of 1.00 THz. The simulation bandwidth of this proposed focusing reflectarray is over twice that of an existing dielectric resonator reflectarray. The proposed resonator has a potential to enhance the bandwidth of terahertz reflectarrays for various beamforming functions.
Imaging and Mapping Characterization Tools for Perovskite Solar Cells
Authors: Hidalgo Juanita , Castro‐Méndez Andrés‐Felipe , Correa‐Baena Juan‐Pablo
Published: July 2019

Perovskite solar cells (PSCs) have attracted much attention as efficiencies have gone beyond 24%. To achieve these impressive numbers, the PSC scientific community is working to improve the perovskite optoelectronic properties. Imaging and mapping characterization techniques have been widely used to understand the fundamental properties that allow lead halide perovskites to achieve high performance. In this review, these techniques are evaluated, from simple tools, such as electron microscopy, to more complex systems that include atomic force microscopy, synchrotron‐based X‐ray mapping, and ultrafast and photoluminescence mapping. These tools have helped understand lead halide perovskites and their impressive optoelectronic properties, which make them outstanding materials for solar cell applications.
Gathering Diverse Perspectives to Tackle “Wicked Problems”: Racial/Ethnic Disproportionality in Educational Placement
Authors: NeMoyer Amanda , Nakash Ora , Fukuda Marie , Rosenthal Jill , Mention Najeia , Chambers Valeria A. , Delman Deborah , Perez Gilberto , Green Jennifer G. , Trickett Edison , Alegría Margarita
Published: July 2019

Among students receiving behavioral health and special education services, racial/ethnic minority students are consistently overrepresented in settings separate from general classrooms. Once separated, many young people struggle to improve academically and face significant difficulty upon trying to return to a general education setting. Given the complex, ongoing, and multifaceted nature of this challenge, racial/ethnic disproportionality can be identified as a “wicked problem,” for which solutions are not easily identified. Here, we describe our community‐engaged research efforts, eliciting perspectives from relevant partners in an ongoing dialogue, to better integrate diverse stakeholders’ perspectives when attempting to address such disparities. We conducted focus groups and qualitative interviews with members of three stakeholder groups: community‐serving organizations, individuals with lived experience of behavioral health conditions, and state‐level policymakers, with a shared interest in addressing racial and ethnic disparities. Participant responses illustrated the “wickedness” of this problem and highlighted the need for additional supports for students, families, and school personnel, increased collaboration across relevant systems and agencies, and reduced barriers related to funding. Overall, this methodology bridged differing perspectives to develop, in concert with our partners, a shared language of the problem and a core set of issues to consider when seeking to effect change.
Testosterone is positively and estradiol negatively associated with mucosal immunity in Amazonian adolescents
Authors: Hodges‐Simeon Carolyn R. , Asif Soubhana , Gurven Michael , Blackwell Aaron D. , Gaulin Steven J. C.
Published: July 2019

Objectives

A core assumption of life history theory and the immunocompetence handicap hypothesis (ICHH) is that testosterone (T) upregulates energetic investment in mating effort at the expense of immunity. This tenet, along with observed positive relationships between estrogens and immunity, may contribute to the higher observed morbidity and mortality of males. In the present study, we examine the association between sex steroid hormones and mucosal immunity as well as sex differences in immunity in a rural Amazonian population of immune‐challenged Bolivian adolescents.

Methods

Salivary steroid hormones (T [males only] and estradiol [E2, females only]), Tsimane‐specific age‐standardized BMI z‐scores, and salivary mucosal immunity (sIgA, secretory IgA) were measured in 89 adolescent males and females.

Results

Males had significantly higher sIgA levels than females, which may be due to the observed immune‐endocrine associations found in the present study. Controlling for age and phenotypic condition, higher T significantly predicted higher sIgA; whereas higher E2 was associated with lower sIgA in females.

Conclusions

Results stood in contrast to common interpretations of the ICHH, that is, that T should be inversely associated with immunity. Findings from the present study support the notion that the endocrine system likely affects immunity in a regulatory fashion, upregulating certain aspects of immunity while downregulating others. An important remaining question is the adaptive reason(s) for sex differences in endocrine‐mediated immuno‐redistribution.