bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vitro Antisalmonellal and Antioxidant Activities of Leaves Extracts of Tectona grandis L. F. (Verbenaceae)
Authors: Kamsu Gabriel Tchuente , Simo Tagne Richard , P. C. Fodouop Siméon , Ndel Famen Louis-Claire , Kodjio Norbert , Endeguele Ekom Steve , Gatsing Donatien 
Published: November 2019

Aim: Study aimed to evaluate the in vitro antisalmonellal and antioxidant properties of Tectona grandis, a medicinal plant commonly used in traditional Cameroonian medicine for the treatment of typhoid fever.
Study Design: In vitro Antimicrobial and antioxidant analyses of plant extract using established protocols.
Place and Duration of Study: Plant materiel collection at Loum (Moungo Division, Littoral region of Cameroon), identification at the National Herbarium of Cameroon, extraction of plant and all analyses at the Research Unit of Microbiology and Antimicrobial Substances, Department of Biochemistry, University of Dschang-Cameroon, between August 2018 and April 2019.
Methodology: In vitro antisalmonellal activity of Tectona grandis extracts was evaluated by the liquid microdilution method as well as their antioxidant activity using by standard methods of H2O2 trapping, FRAP, DPPH radical trapping and OH radical trapping. Quantification test of total phenols and flavonoids and phytochemical screening of extract were also done.
Results: The results showed that most of the Tectona grandis extracts had minimal inhibitory concentrations (MICs) ranging from 64 to 1024 μg/mL. Ethanolic extract, 70% ethanol extract and aqueous decoction are the most effective compared to aqueous extracts with activities between 64 and 128 μg/mL on the bacteria tested. Antioxidant tests showed that all extracts except macerated and aqueous infused extracts exhibited high DPPH trapping activities. The antioxidant activities of the extracts are proportionally linked in most cases to their flavonoid and total phenol contents at a concentration of 200 µg/mL. Aqueous decoction showed better H2O2 trapping activity at concentrations less than or equal to 25 µg/mL.
Conclusion: These results show that the ethanolic extract and decocted aqueous of Tectona grandis leaves can be used as an alternative to treat salmonellosis.
Antibiotic Resistance Profile of Escherichia coli and Klebsiella spp Isolated from Post-weaned Piglet Faeces under Penicillin-streptomycin Combination Therapy (Penstrep®) in Abidjan, Côte d’Ivoire
Authors: Koné A. N. T. , N’gbesso N. K. , Guédé B. K. , Ouattara M. B. , Konan F. K. , Dadié A. , Guessennd N. K. 
Published: November 2019

Aim: The current study was aimed at evaluating the antibiotic resistance profile of Escherichia coli and Klebsiella spp isolated from post-weaned piglets treated with penicillin-streptomycin combination therapy.
Study Design: Bacteriological study.
Place and Duration of Study: Laboratory of the National Reference Center for antibiotics at Institut Pasteur Côte d’Ivoire, between March 2018 and June 2018.
Methodology: Escherichia coli and Klebsiella species were isolated from post weaned piglets stool on Mac Conkey medium added up separately with penicillin, streptomycin and combined penicillin-streptomycin and identified. Antibiotic susceptibility test was performed using disk diffusion method on Müller-Hinton agar.
Results: Escherichia coli and Klebsiella species resistance to penicillin, streptomycin and combined penicillin-streptomycin evaluated, respectively, reached 80.5% (Day 0) to 92.0% (Day 4); 17.0% (Day 0) to 39.9% (Day 4) and 31.3% (Day 0) to 70.9% (Day 4) for piglets treated with Penstrep®. In addition, antibiotic susceptibility test carried out for Escherichia coli and Klebsiella spp strains isolated from piglets treated with Penstrep® revealed resistance to amoxicillin for each bacterial species at a rate of 86.0% and 89.0%. Furthermore, control piglets showed lesser resistance to streptomycin (E.coli 31.0% and Klebsiella spp 38.0%) than those treated with the combination therapy Penstrep® (E. coli 73.0% and Klebsiella spp 48.0%). As for netilmicin, imipenem and colistin, no resistance was detected for treated piglets as well as untreated ones.
Conclusion: The combination therapy with Penstrep® has increased Escherichia coli and Klebsiella species resistance to antibiotics tested in the current study.
Neuroprotective Potential of Mahanimbine against Lipopolysaccharides (LPS)-Induced Neuronal Deficits on SK-N-SH Cells and Antioxidant Potentials in ICR Mice Brain
Authors: Azahan Nur Syamimi Mohd , Mani Vasudevan , Ramasamy Kalavathy , Lim Siong Meng , Alhowail Ahmad , Sajid Sultan , Majeed Abu Bakar Abdul 
Published: November 2019

Aims: Murraya koenigii commonly known as curry leaves, is traditionally used in India and other South Asian countries as a spice for its characteristic flavor and aroma. Mahanimbine is a major carbazole alkaloid derived from Murraya koenigii leaves. There are numerous reports that support the neuroprotective role of various alkaloids. The present study investigated the neuroprotective potential of mahanimbine against lipopolysaccharides (LPS)-induced neuronal deficits of SK-N-SH cells and antioxidant potentials in ICR mouse brain.
Study Design: The targeted compound mahanimbine was subjected to both in vitro and in vivo studies.
Place and Duration of Study: The study was conducted in Faculty of Pharmacy, Universiti Teknologi MARA, Malaysia and College of Pharmacy, Qassim University, Kingdom of Saudi Arabia between June 2015 and August 2017.
Methodology: For the in vitro study, SK-N-SH cells were induced with the 100µg/ml of LPS. Then, neuroprotection and reactive oxygen species (ROS) assays were conducted to assess cell viability and the formation of ROS. On the other hand, ICR mice were being fed with mahanimbine (1, 2 and 5 mg/kg, p.o.) for 30 days for in vivo study. Neuroinflammation was thereafter induced by intraperitoneal injection of LPS (250 μg/kg) for 4 days. At the end of the treatment, the animals were sacrificed. The brain was collected for antioxidants assays, measuring oxidative biomarkers such as catalase, reduced glutathione, superoxide dismutase, glutathione reductase, and thiobarbituric acid (TBARs).
Results: SK-N-SH cells exposed to 100 μg/ml LPS showed a significant cell viability loss and increased level of ROS. However, pre-treatment of SK-N-SH cells with mahanimbine significantly prevented cell loss and consequently attenuated LPS-induced ROS formation. In addition, mahanimbine also inhibited β-secretase (BACE50 = 4µg/mL) that is important for production of β-amyloid (Aβ). For in vivo study, the biochemical analysis of the whole brain detected increased catalase (CAT) and glutathione reductase (GRD) levels, and significantly decreased malondialdehyde (MDA) level in mahanimbine treated groups as compared to LPS-induced but untreated group.
Conclusion: The overall findings supported the neuroprotective and antioxidant potential of mahanimbine against LPS-induced neurotoxicity.
Antifungal Activity and Fourier Transform Infrared Spectrometric Characterization of Aqueous Extracts of Acacia senegal and Acacia tortilis on Phytopathogenic Fungi
Authors: Fatimah Al-Otibi 
Published: November 2019

Objective: To evaluate the in vitro antifungal activity of aqueous extracts of Acacia senegal (A. senegal) and Acacia tortilis (A. tortilis) against three phytopathogenic fungi (viz., Alternaria alternata [A. alternata], Helminthosporium rostratum [H. rostratum] and Fusarium solani [F. solani]).
Methods: Crude aqueous extracts of A. senegal and A. tortilis at 1%, 2.5% and 5% concentrations were used for screening. Antifungal activities of the extracts were evaluated against three phytopathogenic fungal strains (A. alternata, H. rostratum and F. solani) by poisoned food technique. Scanning electron microscopy (SEM) of the treated and untreated mycelia was employed to analyze the ultrastructural changes and Fourier-transform infrared (FTIR) spectrometry analysis was performed to identify important functional groups.
Results: Aqueous extract of A. tortilis at high concentrations exhibited moderate inhibitory activity against the selected fungal strains. The aqueous extract of A. senegal showed no effect on A. alternata, while exhibited very mild activity against H. rostratum and F. solani at high concentrations (2.5% and 5%). Scanning electron microphotographs of the untreated fungal cells showed no structural changes (well‒defined mycelium and conidia without any distortion), whereas the treated cells showed structural distortions, twisted and wrecked mycelia and showed the presence of vesicles on the surface. FTIR analysis showed the presence of important functional groups such as alcohols, carboxylic acids and aromatic compounds.
Conclusion: Results from this study indicate that the aqueous extracts of both A. senegal and A. tortilis have the potential to be used as natural fungicidal agents in the management of diseases caused by plant pathogenic fungi.
Characterization and Correlation of Aliphatic Hydrocarbons in Oil Polluted Waters of Bonny Local Government Area, Rivers State
Authors: Chinonye Iheonye , Leo Osuji , Mark Onyema 
Published: November 2019

Forensic chemical analyses was used to characterize, determine the source and correlate aliphatic hydrocarbons (AHCs) in water samples collected from Bonny L.G.A, Rivers State. AHCs were extracted from the water samples with n-hexane in a separatory funnel, clean-up achieved by column chromatography using n-hexane and analysis by Gas Chromatography Flame Ionization Detector (GC-FID). The GC chromatogram showed well resolved AHC peaks which distributed from nC9 –nC40. The GC chromatograms of AHCs, with a wide range of low molecular weight hydrocarbons, indicate minimal biodegradation of the oil hydrocarbons in the samples. CPI values from 0.68 to 0.78 for BY-A1, BY-A3, BY-A4 and 0.97 for BY-A2 suggest two sources of oil hydrocarbons. Calculated Pr/Ph ratios showed BY-A1 (2.08), BY-A3 (2.00) and BY-A4 (2.20) were derived from mixed marine and terrestrial source deposited in suboxic environment, while BY-A2 (3.70) was mainly terrigenous source in an oxic environment. A cross-plot of Pr/n-C17 and Ph/n-C18 ratios also showed a tight cluster for samples BY-A1, BY-A3 and BY-A4 which were degraded with sample BY-A2 separate and slightly degraded. Results from this study revealed that the spilled oil was derived from mixed organic sources deposited in an oxic environment with different oil input from external sources showing more terrestrial contribution.
Dosimetric comparison of three‐dimensional conformal radiotherapy and intensity‐modulated radiotherapy for left‐sided chest wall and lymphatic irradiation
Authors: Kivanc Huseyin , Gultekin Melis , Gurkaynak Murat , Ozyigit Gokhan , Yildiz Ferah 
Published: November 2019

AbstractIntroductionThe aim of this study was to compare five different techniques for chest wall (CW) and lymphatic irradiation in patients with left‐sided breast carcinoma.MethodsThree‐dimensional conformal radiotherapy (3DCRT), forward‐planned intensity‐modulated radiotherapy (FP‐IMRT), inverse‐planned IMRT (IP‐IMRT; 7‐ or 9‐field), and hybrid IP‐/FP‐IMRT were compared in 10 patients. Clinical target volume (CTV) included CW and internal mammary (IM), supraclavicular (SC), and axillary nodes. Planning target volumes (PTVs), CTVs, and organs at risks (OARs) doses were analyzed with dose–volume histograms (DVHs).ResultsNo differences could be observed among the techniques for doses received by 95% of the volume (D95%) of lymphatics. However, the FP‐IMRT resulted in a significantly lower D95% dose to the CW‐PTV compared to other techniques (P = 0.002). The 9‐field IP‐IMRT achieved the lowest volumes receiving higher doses (hotspots). Both IP‐IMRT techniques provided similar mean doses (Dmean) for the left lung which were smaller than the other techniques. There was no difference between the techniques for maximum dose (Dmax) of right breast. However, FP‐IMRT resulted in lower Dmean and volume of right breast receiving at least 5 Gy doses compared to other techniques.ConclusionThe dose homogeneity in CW‐CTV was better using IMRT techniques compared to 3DCRT. Especially 9‐field IP‐IMRT provided a more homogeneous dose distribution in IM and axillary CTVs. Moreover, the OARs volumes receiving low radiation doses were larger with IP‐IMRT technique, while volumes receiving high radiation doses were larger with FP‐IMRT technique. Hybrid IMRT plans were found to have the advantages of both FP‐ and IP‐IMRT techniques.
Skeletal Muscle Constructs Engineered from Human Embryonic Stem Cell Derived Myogenic Progenitors Exhibit Enhanced Contractile Forces When Differentiated in a Medium Containing EGM‐2 Supplements
Authors: Xu Bin , Zhang Mengen , Perlingeiro Rita C. R. , Shen Wei 
Published: November 2019

AbstractThree‐dimensional (3D) skeletal muscle constructs engineered from myogenic progenitors derived from human pluripotent stem cells (hPSCs) have a wide range of applications, but to date, such constructs generate lower specific tetanic force than adult human muscles. Methods enhancing functional muscle differentiation and force generation of these constructs are highly desirable. The finding of this study is that addition of the supplements in the endothelial cell growth medium‐2 (EGM‐2) to the myogenic differentiation medium can substantially enhance contractile force generation. For constructs differentiated for 4 weeks, addition of the EGM‐2 supplements in the first 2 weeks leads to tenfold and sevenfold increases in twitch and tetanic forces, respectively. The specific tetanic force generated by these constructs is 33 mN mm−2, which is significantly higher than previously reported. These constructs show wider myotubes and higher gene expression levels for all skeletal muscle‐specific myosin heavy chain isoforms, suggesting that a more mature differentiation stage of the cells underlies the greater contractile force generation. The constructs exposed to these supplements for 4 weeks do not generate as high contractile forces, suggesting that prolonged treatment is not beneficial. These results suggest that temporal conditioning with the EGM‐2 supplements assists functional development of hPSC‐derived skeletal muscle constructs.
Organic Light‐Emitting Transistors: Advances and Perspectives
Authors: Chaudhry Mujeeb Ullah , Muhieddine Khalid , Wawrzinek Robert , Sobus Jan , Tandy Kristen , Lo Shih‐Chun , Namdas Ebinazar B. 
Published: November 2019

AbstractThe rapid development of charge transporting and light‐emitting organic materials in the last decades has advanced device performance, highlighting the high potential of light‐emitting transistors (LETs). Demonstrated for the first time over 15 years ago, LETs have transformed from an optoelectronic curiosity to a serious competitor in the race for cheaper and more efficient displays, also showing promise for injection lasers. Thus, what is an LET, how does it work, and what are the current challenges for its integration into mainstream technologies? Herein, some light is shed on these questions. This work also provides the fundamental working principle of LETs, materials that have been used, and device physics and architectures involved in the progression of LET technology. The state‐of‐the‐art development of LETs is also explored as prospect avenues for the future of research and applications in this area.
A Visible‐ and NIR‐Light Responsive Photothermal Therapy Agent by Chirality‐Dependent MoO3−x Nanoparticles
Authors: Li Yiwen , Miao Ziwei , Shang Zhengwen , Cai Ying , Cheng Jiaji , Xu Xiaoqian 
Published: November 2019

AbstractChirality‐based semiconducting nanocrystals, as an emerging area, are envisioned to have great potential in chiral sensing, biomedicine, and chiroptical devices. Herein, chiral substoichiometric molybdenum oxide (l/d‐Cys‐MoO3−x) nanoparticles are synthesized via step‐by‐step reduction treatment with chiral cysteine molecules. The obtained nanoparticles are used as visible‐ and near‐infrared‐light dual responsive photothermal therapy agent for tumor cell ablation. Notably, the chiral nanoparticles show chiral selectivity for incident light, i.e., when irradiated by left‐circularly polarized light, l‐Cys‐MoO3−x is the most sensitive agent giving the highest mortality for HeLa cell ablation in vitro, and vice versa for right‐circularly polarized light with d‐Cys‐MoO3−x. In comparison to traditional photothermal therapy with near‐field light source, the investigations with chiral visible light at 532 nm indicate the possibility of chiral Cys‐MoO3−x nanoparticles for visible light‐based phototherapy via metal–ligand charge transfer chirality, which provides insights for new methods in nanotechnology supported photothermal treatments.
Layered‐Herringbone Polymorphs and Alkyl‐Chain Ordering in Molecular Bilayer Organic Semiconductors
Authors: Arai Shunto , Morita Kaede , Tsutsumi Jun'ya , Inoue Satoru , Tanaka Mutsuo , Hasegawa Tatsuo 
Published: November 2019

AbstractProduction and control of 2D self‐organized layers of π‐conjugated molecules is a fundamental issue in organic electronics devices. This study reports that an intralayer polymorphic transformation is apparently observed in abilayer‐type layered‐herringbonepacking of a series of 2‐mono‐alkylated‐benzothieno[3,2‐b][1]benzothiophenes (mono‐Cn‐BTBTs) with the change in the substituted alkyl‐chain length,n. Slight variation in the intermolecular arrangement in the single‐crystal films is investigated with reasonable sensitivity via polarized optical absorption spectroscopy through the excitonic interactions between neighboring π‐electron cores. A clear polymorphic transition is observed based on the features of the in‐plane optical anisotropy with the change in the chain length betweenn= 7 (or less) and 8 (or more). A unique phase separation of the polymorphs is also observed in the films produced using a mixed solution with molecules having differentn: the respective polymorphic phases appear separately, either as single molecular bilayers or multibilayer‐stacked films owing to geometrical frustration. The results indicate that the intralayer packing motif is predetermined by the competition and balance between the intermolecular core–core and chain–chain interactions. These findings pave the way for rational designing of organic molecules with considerably high layered crystallinity, and thus, of efficient carrier transport in organic thin‐film transistors.
Coreless Fiber‐Based Whispering‐Gallery‐Mode Assisted Lasing from Colloidal Quantum Well Solids
Authors: Sak Mustafa , Taghipour Nima , Delikanli Savas , Shendre Sushant , Tanriover Ibrahim , Foroutan Sina , Gao Yuan , Yu Junhong , Yanyan Zhou , Yoo Seongwoo , Dang Cuong , Demir Hilmi Volkan 
Published: November 2019

AbstractWhispering gallery mode (WGM) resonators are shown to hold great promise to achieve high‐performance lasing using colloidal semiconductor nanocrystals (NCs) in solution phase. However, the low packing density of such colloidal gain media in the solution phase results in increased lasing thresholds and poor lasing stability in these WGM lasers. To address these issues, here optical gain in colloidal quantum wells (CQWs) is proposed and shown in the form of high‐density close‐packed solid films constructed around a coreless fiber incorporating the resulting whispering gallery modes to induce gain and waveguiding modes of the fiber to funnel and collect light. In this work, a practical method is presented to produce the first CQW‐WGM laser using an optical fiber as the WGM cavity platform operating at low thresholds of ≈188 µJ cm−2 and ≈1.39 mJ cm−2 under one‐ and two‐photon absorption pumped, respectively, accompanied with a record low waveguide loss coefficient of ≈7 cm−1 and a high net modal gain coefficient of ≈485 cm−1. The spectral characteristics of the proposed CQW‐WGM resonator are supported with a numerical model of full electromagnetic solution. This unique CQW‐WGM cavity architecture offers new opportunities to achieve simple high‐performance optical resonators for colloidal lasers.
Photoinduced Directional Proton Transport through Printed Asymmetric Graphene Oxide Superstructures: A New Driving Mechanism under Full‐Area Light Illumination
Authors: Zhang Yanbing , Li Fengyu , Kong Xian , Xue Tangyue , Liu Dan , Jia Pan , Wang Lili , Ding Liping , Dong Huanli , Lu Diannan , Jiang Lei , Guo Wei 
Published: November 2019

Abstract2D‐material‐based membranes with densely packed sub‐nanometer‐height fluidic channels show exceptional transport properties, and have attracted broad research interest for energy‐, environment‐, and healthcare‐related applications. Recently, light‐controlled active transport of ionic species in abiotic materials have received renewed attention. However, its dependence on inhomogeneous or site‐specific illumination is a challenge for scalable application. Here, directional proton transport through printed asymmetric graphene oxide superstructures (GOSs) is demonstrated under full‐area illumination. The GOSs are composed of partially stacked graphene oxide multilayers formed by a two‐step direct ink writing process. The direction of the photoinduced proton current is determined by the position of top graphene oxide multilayers, which functions as a photogate to modulate the horizontal ion transport through the beneath lamellar nanochannels. This transport phenomenon unveils a new driving mechanism that, in asymmetric nanofluidic structures, the decay of local light intensity in depth direction breaks the balance of electric potential distribution in horizontal direction, and thus generates a photoelectric driving force for ion transport. Following this mechanism, the GOSs are developed into photonic ion transistors with three different gating modes. The asymmetrically printed photonic‐ionic devices provide fundamental elements for light‐harvesting nanofluidic circuits, and may find applications for artificial photosynthesis and artificial electric organs.
Atomically Defined Undercoordinated Active Sites for Highly Efficient CO2 Electroreduction
Authors: Zheng Wanzhen , Yang Jian , Chen Hengquan , Hou Yang , Wang Qi , Gu Meng , He Feng , Xia Ying , Xia Zheng , Li Zhongjian , Yang Bin , Lei Lecheng , Yuan Chris , He Qinggang , Qiu Ming , Feng Xinliang 
Published: November 2019

AbstractElectrocatalytic reduction of carbon dioxide (CO2ER) in rechargeable Zn–CO2 battery still remains a great challenge. Herein, a highly efficient CO2ER electrocatalyst composed of coordinatively unsaturated single‐atom copper coordinated with nitrogen sites anchored into graphene matrix (Cu–N2/GN) is reported. Benefitting from the unsaturated coordination environment and atomic dispersion, the ultrathin Cu–N2/GN nanosheets exhibit a high CO2ER activity and selectivity for CO production with an onset potential of −0.33 V and the maximum Faradaic efficiency of 81% at a low potential of −0.50 V, superior to the previously reported atomically dispersed Cu–N anchored on carbon materials. Experimental results manifest the highly exposed and atomically dispersed Cu–N2 active sites in graphene framework where the Cu species are coordinated by two N atoms. Theoretical calculations demonstrate that the optimized reaction free energy for Cu–N2 sites to capture CO2 promote the adsorption of CO2 molecules on Cu–N2 sites; meanwhile, the short bond lengths of Cu–N2 sites accelerate the electron transfer from Cu–N2 sites to *CO2, thus efficiently boosting the *COOH generation and CO2ER performance. A designed rechargeable Zn–CO2 battery with Cu–N2/GN nanosheets deliver a peak power density of 0.6 mW cm−2, and the charge process of battery can be driven by natural solar energy.