bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Antibacterial Activity of Methanolic Extract of Avicennia marina Leaf Extract against Staphylococcus aureus
Authors: Ramasubramanian Swetha , Roy Anitha , Sivaperumal Pitchiah , Lakshmi T. 
Published: February 2022

Introduction: Mangrove are widespread in the tropical and subtropical regions of Indo-West-Pacific area. Avicennia marina possesses vast medicinal values. The pharmacological activity of the plant is attributed to the presence of several phytochemicals.
Aim: To evaluate the antibacterial activity of Avicennia marina leaf extract against Staphylococcus aureus.
Methods and Materials: Plant extract prepared by adding 20g of dried powdered mangrove leaf sample to 100 ml of methanol. MDRSA, MRSA & VRSA were cultured in Muller –Hinton Broth for 24 hr at room temperature. From this prepared bacterial suspension, 1ml of was spread over Muller Hinton agar plate and incubated for 24hrs at ambient temperature. Antibacterial activity carried out through the disc diffusion method. Whatman filter paper discs (5mm) were impregnated with various concentrations (50, 100, 150, 200, 250 & 300 µg/ml) of leaf extract. After incubating the plates for 24hr at room temperature the zone of inhibition was measured. Minimum Inhibitory Concentration was determined in 5 concentrations (50 -300 µg/ml) with blank (extract in Muller Hinton broth). The inoculated bacteria in test tubes are incubated for 24hr in ambient temperature. The results are noted as well growth (+) and inhibited (-). Tetracycline (1µg/ml) was used as standard and DMSO as negative control.
Results: The zone of inhibition was greater at 300µg/ml of the extract for MDRSA ( 13±1.2) , MRSA ( ( 13±1.4) )& VRSA ( 9±1.2). MIC for MDRSA, MRSA and VRSA was 250µg/ml, 200µg/ml 150µg/ml respectively.
Conclusion: The present study showed effective antibacterial activity of Avicennia marina against MDRSA, MRSA, VRSA. Hence, this extract may be used for infections against resistant Staphylococcus aureus.
Preparation of Mouthwash Using Red Tea and Its Antimicrobial and Antioxidant Activity
Authors: Ramamoorthy Jagadheeswari , Rajasekar Arvina , Rajeshkumar S. 
Published: February 2022

Background: Poor oral hygiene provides an optimum environment for bacterial biofilms formation leading to the development of periodontal diseases. Currently, researchers focus on developing oral hygiene products such as mouthwash that contain available natural products with superior biocompatibility and a low cost.
Aim: The aim of the study was to prepare mouthwash using red tea and to evaluate its antimicrobial and antioxidant properties.
Materials and Methods: This study was performed as an in vitro study under a laboratory setting. Mouthwash was prepared using red tea in the lab. Subsequently the formulation was tested for its antimicrobial and antioxidant activity. Antimicrobial activity was conducted through agar well diffusion method. Antioxidant activity of the herbal mouthwash was tested using the DPPH assay at various concentrations. The obtained values were compared with that of the standard. The data was tabulated represented by the means of bar graphs.
Results: There was an increase in the zone of inhibition of bacteria with an increase in concentration of mouthwash. DPPH assay for antioxidant activity revealed that at all concentrations the standard had more antioxidant activity compared to the herbal mouthwash. Throughout from 10 μl to 50 μl the antioxidant activity of the standard was greater than the prepared red tea mouthwash.
Conclusion: Within the limitations of this study, Red tea mediated mouthwash was found to possess antioxidant and anti-inflammatory properties at varied concentrations.
Anticariogenic Activity of Copper Nanoparticles Synthesized Using Red Tea: An In vitro Study
Authors: Sagana M. , Rajasekar Arvina , Rajeshkumar S. 
Published: February 2022

Background: Nanotechnology is rapidly growing in various fields of science like medicinal, agricultural and physical and material sciences. Copper nanoparticles are particularly attractive because of copper’s high natural abundance and low cost and the practical and straightforward multiple ways of preparing copper based nanomaterials.
Aim: To assess the anticariogenic activity of copper nanoparticles synthesized using red tea.
Materials and Methods: The red tea powder was acquired. An aqueous extract was prepared and mixed with copper sulphate for copper nanoparticles formation and centrifuged for 10 minutes. The extract was then placed in the well cultured agar plates against Candida albicans, Streptococcus mutans, S. aureus and E. faecalis and incubated for 24 hours. The zones of inhibition were then calculated.
Results: Against S. aureus, 50 μl showed 20 mm of zone of inhibition, 100 μl showed 16 mm of zone of inhibition and 150 μl showed 20 mm of zone of inhibition. 19 mm of zone of inhibition were noted against the antibiotic. Against C. albicans, 50 μl showed 12 mm of zone of inhibition, 100 μl showed 13 mm of zone of inhibition and 150 μl showed 12 mm of zone of inhibition. 10 mm of zone of inhibition were noted against the antibiotic. Against S. mutans, 50 μl showed 17 mm of zone of inhibition, 100 μl showed 14 mm of zone of inhibition and 150 μl showed 19 mm of zone of inhibition. 35 mm of zone of inhibition were noted against the antibiotic. Against E. faecalis, 50 μl showed 12 mm of zone of inhibition, 100 μl showed 15 mm of zone of inhibition and 150 μl showed 19 mm of zone of inhibition. 35 mm of zone of inhibition were noted against the antibiotic.
Conclusion: The anticariogenic activity of copper nanoparticles synthesized using red tea were studied and their wider zones of inhibition were suggestive of good anticariogenic activity. We conclude that copper nanoparticles synthesized using red tea can be used against S. aureus, S. mutans, C. albicans and E. faecalis as an anticariogenic agent.
Anti Inflammatory and Antioxidant Activity of Stevia and Peppermint Herbal Formulation
Authors: Ramya G. , Varghese Sheeja. S. , Rajeshkumar S. 
Published: February 2022

Introduction: It is important to counteract the oxidative stress and inflammatory burden occurring in the body. The use of herbal components obtained via green synthesis, such as Stevia and peppermint which are alcohol-free and comprise relatively of less chemical components and have been therapeutically found effective for antidiabetic properties can prove to be more efficient and biocompatible to tackle the same.
Aim: The aim of the study was to evaluate the anti-inflammatory and antioxidant properties of a herbal formulation of stevia rebaudiana and peppermint at varying concentrations.
Materials and Methods: The study was performed as an in vitro study under a laboratory setting. Synthesis of the herbal formulation was performed using stevia and peppermint in the lab. Subsequently the formulation was tested for its anti-inflammatory activity using the protein denaturation assay and antioxidant activity using the DPPH Assay method at various concentrations. The obtained values were compared with that of the known standard. The statistical analysis was done using IBM SPSS software analysis version 23.
Results: Anti inflammatory property of the Steviaa and peppermint herbal formulation was significantly less at 10μL concentration but at higher concentrations it was comparable to the standard. Regaling the antioxidant property, the herbal formulation showed a concentration dependent increase from lower concentration to higher concentration but at all levels it was significantly lesser than the standard.
(p<0.05)
Conclusion: The herbal formulation of Stevia and peppermint is a potent anti-inflammatory agent. It possesses antioxidant properties, however which are not as effective as the standard.
Iterative learning control for repetitive tasks with randomly varying trial lengths using successive projection
Authors: Zhuang Zhihe , Tao Hongfeng , Chen Yiyang , Stojanovic Vladimir , Paszke Wojciech 
Published: February 2022

SummaryThis article proposes an effective iterative learning control (ILC) approach based on successive projection scheme for repetitive systems with randomly varying trial lengths. A modified ILC problem is formulated to extend the classical ILC task description to incorporate a randomly varying trial length, while its design objective considers the mathematical expectation of its tracking error to evaluate the task performance. To solve this problem, this article employs the successive projection framework to give an iterative input signal update law by defining the corresponding convex sets based on the design requirements. This update law further yields an ILC algorithm, whose convergence properties are proved to be held under mild conditions. In addition, the input signal constraint can be embedded into the design without violating the convergence properties to obtain an alternative algorithm. The performance of the proposed algorithms is verified using a numerical model to show the effectiveness at occasions with and without input constraints.
Tunable Magnetic Anisotropy in Patterned SrRuO3 Quantum Structures: Competition between Lattice Anisotropy and Oxygen Octahedral Rotation
Authors: Wang Hongguang , Laskin Gennadii , He Weiwei , Boschker Hans , Yi Min , Mannhart Jochen , van Aken Peter A. 
Published: February 2022

AbstractArtificial perovskite oxide nanostructures possess intriguing magnetic properties due to their tailorable electron–electron interactions, which are extremely sensitive to the oxygen coordination environment. To date, perovskite oxide nanodots with sizes below 50 nm have rarely been reported. Furthermore, the oxygen octahedral distortion and its relation to magnetic properties in perovskite oxide nanodots remain unexplored thus far. Here, the magnetic anisotropy in patterned SrRuO3 (SRO) nanodots as small as 30 nm are studied. The constituent elements, in particular oxygen ions, are directly visualized via performing atomic resolution electron microscopy and spectroscopy. It is observed that the magnetic anisotropy and RuO6 octahedra distortion in SRO nanodots are both nanodot size‐dependent but remain unchanged in the first 3‐unit‐cell interfacial SRO monolayers regardless of the dots’ size. Combined with first principle calculations, a unique structural mechanism behind the nanodots’ size‐dependent magnetic anisotropy in SRO nanodots is unraveled, suggesting that the competition between lattice anisotropy and oxygen octahedral rotation mediates anisotropic exchange interactions in SRO nanodots. These findings demonstrate a new avenue toward tuning magnetic properties of correlated perovskite oxides and imply that patterned nanodots could be a promising playground for engineering emergent functional behaviors.
Micro Eddy Current Facilitated by Screwed MoS2 Structure for Enhanced Hydrogen Evolution Reaction
Authors: Su Meixia , Zhou Wenda , Liu Lin , Chen Mingyue , Jiang Zhenzhen , Luo Xingfang , Yang Yong , Yu Ting , Lei Wen , Yuan Cailei 
Published: February 2022

AbstractEddy current is a magnetic field effect generated in alternating magnetic field (AMF), which could trigger continuous local heating, reducing the energy consumption without impairing the life of the catalyst or reactor. Unfortunately, the investigation of eddy current effect on transition metal disulfides (TMDs) electrocatalysis is still in its infancy, and its actual electrocatalytic applications has been impeded by the multilayered structure of traditional layered TMDs. Typically, the step pyramid MoS2, with a layer‐by‐layer stacking structure just like the silicon steel plate in the transformer, showing an inevitable interlayer potential barrier will suppress the generation of eddy current and cause low efficiency of magnetic heating. In this work, the designed screw pyramid MoS2 can facilitate the formation of micro eddy current and maximize utilization of magnetic heating to boost electrocatalytic activity, benefiting from its eliminated interlayer potential barrier. This work provides a new thinking for the design of field‐assisted electrocatalytic reactions and development of the advanced catalyst technology.
Passivation Failure of Al Current Collector in LiPF6‐Based Electrolytes for Lithium‐Ion Batteries
Authors: Yoon Eunjung , Lee Jihye , Byun Seongmin , Kim Dohyun , Yoon Taeho 
Published: February 2022

AbstractNext‐generation Li‐ion batteries are being developed with high‐voltage cathodes to maximize their energy and power densities. However, the commercialization of high‐voltage cathodes has been delayed due to the degradations of active materials and electrolytes in long‐term cycling. Recent advances have made significant improvements in these issues; however, the corrosion of Al current collector and its effects on battery performances have not been studied in detail despite its importance. In this study, the compositional and morphological evolutions of the passivation layer formed on Al are examined. The ion fluxes of Al3+ and F− through the native oxide layer of Al play a critical role in the formation of the passivation film and the inhibition of further corrosion. However, the continuous diffusion of the ions during long‐term cycling at elevated temperature deteriorates the passivation ability of the film. An artificial diffusion barrier on the surface of Al effectively suppresses the ion fluxes to enhance the cyclability of LiNi0.5Mn1.5O4. This work contributes to improving the stability of the current collector at high voltages and serves as a benchmark for corrosion studies concerning advanced energy storage devices.
Operation of Wearable Thermoelectric Generators Using Dual Sources of Heat and Light
Authors: Jeong Myeong Hoon , Kim Kwang‐Chon , Kim Jin‐Sang , Choi Kyoung Jin 
Published: February 2022

AbstractA wearable thermoelectric generator (WTEG) that utilizes human body heat can be a promising candidate for the wearable power generators. The temperature difference (ΔT) between the body and the environment is a stable source driving the WTEG, but this driving force is limited by the ambient temperature itself at the same time. Here, a novel WTEG that can be operated using the dual source of body heat and light with exceptionally high driving force is fabricated. The printable solar absorbing layer attached to the bottom of the WTEG absorbs ≈95% of the light from ultraviolet to far infrared and converts it into heat. To optimize the power density of WTEGs, the fill factor of the thermoelectric (TE) leg/electrode is considered through finite‐difference time‐domain (FDTD) simulation. When operated by the dual sources, the WTEG exhibits a power density of 15.33 µW cm−2, which is the highest under “actual operating conditions” among all kinds of WTEGs. In addition, unlike conventional WTEGs, the WTEG retains 83.1% of its output power at an ambient temperature of 35 °C compared to its output power at room temperature. This study will accelerate the commercialization of WTEGs by introducing a novel method to overcome their limitations.
Highly Thermally/Electrochemically Stable I−/I3−Bonded Organic Salts with High I Content for Long‐Life Li–I2Batteries
Authors: Li Pei , Li Xinliang , Guo Ying , Li Chuan , Hou Yue , Cui Huilin , Zhang Rong , Huang Zhaodong , Zhao Yuwei , Li Qing , Dong Binbin , Zhi Chunyi 
Published: February 2022

AbstractRechargeable lithium–iodine batteries are highly attractive energy storage systems featuring high energy density, superior power density, sustainability, and affordability owing to the promising redox chemistries of iodine. However, severe thermodynamic instability and shuttling issues of the cathode have plagued the active iodine loading, capacity retention and cyclability. Here the development of highly thermally and electrochemically stable I−/I3−‐bonded organic salts as cathode materials for Li–I2batteries is reported. The chemical bonding of iodine/polyiodide ions with organic groups allows up to 80 wt% iodine to be effectively stabilized without sacrificing fast and reversible redox reaction activity. Thus, the shuttle effect is significantly inhibited, which improves cathode capacity and restrains side‐reactions on the Li anode. As a result, such cathodes afford Li–I2batteries a specific capacity of 173.6 mAh g−1methylamine hydroiodide (MAI)(217 mAh g−1I) at 0.5 C, superior rate capability of 133.1 mAh g−1MAIat 50 C, and ultrahigh capacity retention rate of 98.3% over 10000 cycles (5 months). In‐situ, ex‐situ spectral characterizations and density functional theory calculations clarify the robust chemical interaction between iodides and organic groups. The cathode chemistries elucidated here propel the development of Li–I2batteries and are expected to be extended to other metal‐iodine battery technology.
Cobalt‐Free Cathode Materials: Families and their Prospects
Authors: Zhao Hong , Lam Wai‐Yu Ashley , Sheng Li , Wang Li , Bai Peng , Yang Yang , Ren Dongsheng , Xu Hong , He Xiangming 
Published: February 2022

AbstractWith the rapid growth of global electro‐mobility, the demand for cobalt is rapidly increasing because it is currently an indispensable component of the cathode materials in lithium‐ion batteries (LIBs). However, the use of Co raises moral issues caused by its exploitation and the geographic limitations of Co resources may result in risking the supply of LIBs. Thus, the development of cobalt‐free (Co‐free) cathodes has become a focus in the LIBs industry. Currently, Co‐free cathodes of lithium‐rich oxides, nickel‐rich layered oxides and spinel lithium nickel manganese oxide (LNMO) are promising candidates but face severe problems. This review article is the first to synthesize and present the progress of Co‐free cathodes made with Li‐rich oxides, Ni‐rich layered oxides and spinel LNMO, identifying their performance, problems and potential development trends. In particular, the roles of cobalt are further clarified, and the full‐cell performance and related commercialization prospects of the three above‐mentioned Co‐free cathodes are also objectively assessed. The focus of this work is to distill detailed and timely insights from the corresponding research progress on these materials and to demonstrate the associated urgency, challenges and opportunities in this field, thus facilitating a faster industrialization of Co‐free cathodes.
Weit verbreitete bifunktionelle, bakterielle Cytochrom P450 Enzyme katalysieren sowohl eine intramolekulare C−C‐Bindung incyclo‐l‐Tyr‐l‐Tyr als auch dessen Verknüpfung mit Nukleinbasen
Authors: Liu Jing , Harken Lauritz , Yang Yiling , Xie Xiulan , Li Shu‐Ming 
Published: February 2022

AbstractModifizierende Enzyme spielen eine wichtige Rolle in der Biosynthese von Naturstoffen. Wir berichten hier über sechs orthologe Gencluster mit jeweils zwei Genen für die Biosynthese von Mycocyclosin und Guatyromycinen. Die Expression der CyclodipeptidsynthasegenegymA1–gymA6inEscherichia coliführte zur Produktion voncyclo‐l‐Tyr‐l‐Tyr als Hauptprodukt. Durch Rekonstruktion des Biosynthesewegs inStreptomyces albusin Kombination mit biochemischen Untersuchungen konnte bewiesen werden, dass die Cytochrom P450 Enzyme sowohl als intramolekulare Oxidasen, wie auch als Nukleinbasen‐Transferasen agieren. Sie katalysieren nicht nur die oxidative C−C Verknüpfung innerhalb voncyclo‐l‐Tyr‐l‐Tyr, woraus Mycocyclosin resultiert, sondern auch dessen Verbindung mit Guanin und Hypoxanthin. Somit sind sie verantwortlich für die Entstehung der tyrosinhaltigen Guatyromycine, anstatt der bisher bekannten tryptophanhaltigen Nukleinbasen‐Addukte. Phylogenetische Daten lassen vermuten, dass es mindestens 47 solcher orthologen GymBs gibt. Dies spricht für eine weitverbreitete Enzymklasse.
Widely Distributed Bifunctional Bacterial Cytochrome P450 Enzymes Catalyze both Intramolecular C−C Bond Formation incyclo‐l‐Tyr‐l‐Tyr and Its Coupling with Nucleobases
Authors: Liu Jing , Harken Lauritz , Yang Yiling , Xie Xiulan , Li Shu‐Ming 
Published: February 2022

AbstractTailoring enzymes are important modification biocatalysts in natural product biosynthesis. We report herein six orthologous two‐gene clusters for mycocyclosin and guatyromycine biosynthesis. Expression of the cyclodipeptide synthase genesgymA1–gymA6inEscherichia coliresulted in the formation ofcyclo‐l‐Tyr‐l‐Tyr as the major product. Reconstruction of the biosynthetic pathways inStreptomyces albusand biochemical investigation proved that the cytochrome P450 enzymes GymB1–GymB6act as both intramolecular oxidases and intermolecular nucleobase transferases. They catalyze not only the oxidative C−C coupling withincyclo‐l‐Tyr‐l‐Tyr, leading to mycocyclosin, but also its connection with guanine and hypoxanthine, and are thus responsible for the formation of tyrosine‐containing guatyromycines, instead of the reported tryptophan‐nucleobase adducts. Phylogenetic data suggest the presence of at least 47 GymB orthologues, indicating the occurrence of a widely distributed enzyme class.
Textbook typologies: Challenging the myth of the perfect obstetric pelvis
Authors: VanSickle Caroline , Liese Kylea L. , Rutherford Julienne N. 
Published: February 2022

AbstractMedical education's treatment of obstetric‐related anatomy exemplifies historical sex bias in medical curricula. Foundational obstetric and midwifery textbooks teach that clinical pelvimetry and the Caldwell–Moloy classification system are used to assess the pelvic capacity of a pregnant patient. We describe the history of these techniques—ostensibly developed to manage arrested labors—and offer the following criticisms. The sample on which these techniques were developed betrays the bias of the authors and does not represent the sample needed to address their interest in obstetric outcomes. Caldwell and Moloy wrote as though the size and shape of the bony pelvis are the primary causes of “difficult birth”; today we know differently, yet books still present their work as relevant. The human obstetric pelvis varies in complex ways that are healthy and normal such that neither individual clinical pelvimetric dimensions nor the artificial typologies developed from these measurements can be clearly correlated with obstetric outcomes. We critique the continued inclusion of clinical pelvimetry and the Caldwell–Moloy classification system in biomedical curricula for the racism that was inherent in the development of these techniques and that has clinical consequences today. We call for textbooks, curricula, and clinical practices to abandon these outdated, racist techniques. In their place, we call for a truly evidence‐based practice of obstetrics and midwifery, one based on an understanding of the complexity and variability of the physiology of pregnancy and birth. Instead of using false typologies that lack evidence, this change would empower both pregnant people and practitioners.
Fermentation optimization of surfactin production of Bacillus amyloliquefaciens HM618
Authors: Liu Song , Tang Min‐Hui , Cheng Jing‐Sheng 
Published: February 2022

AbstractThis work isolated a strain named Bacillus amyloliquefaciens HM618 from the soil, which can inhibit the growths of Botrytis cinerea, Rhizoctonia solani, and Escherichia coli DH5α. Based on the results of response surface methodology, the surfactin levels of strain HM618 were elevated from 0.724 to 1.876 g/L and 0.995 to 1.888 g/L under the pure culture with the optimized medium (containing 62.39 g/L sucrose, 15.06 g/L yeast extracts, and 3.27 g/L aspartate) and under the coculture of strains HM618 and Bacillus subtilis 168 with the optimized medium (containing 50.52 g/L sucrose, 19.76 g/L yeast extracts, and 1.02 g/L glutamate), respectively. Additionally, influences of nonconstitutive amino acids involved in the biosynthesis of surfactin were also explored. The highest surfactin level reached 2.04 g/L after adding 3.0 g/L exogenous ornithine. However, the surfactin production of strain HM618 was significantly inhibited after adding the mixtures of nonconstitutive amino acids.