bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment of Communication Strategies of Fadama User Groups in Ido Local Government Area of Oyo State, Nigeria
Authors: Amusat A. S. , Fadairo A. O. , Dauda A. W. 
Published: August 2020

The success or otherwise of any development project partly depend on the effectiveness of communication strategies used in such project. The study assessed the communication strategies utilised by Fadama User Groups (FUGs) for fadama programme. Structured questionnaire was used to collect data from 120 members of the Fadama User Groups randomly selected from 10 villages in Ido Local Government which was purposively selected based on the preponderance of Fadama User Groups in the Local Government. The data collected were subjected to descriptive (percentage and frequency ) and inferential (Chi square).Result shows that majority of respondents were male (75.0%), married (95.0%) between the age of 36-40 ( 30.8%) with 66.6% having household size of 1-3 persons and ( 75.0% ) had access to extension services. Majority preferred group discussion (66.7%) and radio (62.5%) as medium of communication. Larger percentage of the respondents (69.2 %) had high access to different communication strategies in the study area. Language barrier ( =2.00) and irregular power supply ( =1.50) were the major constraints against effective utilisation of communication strategies used by members of Fadama User Groups. Significant relationship existed between occupation (x2=14.106, p=0.001) and communication strategies of Fadama User Groups in the study area. It is recommended that members of FUG should be encouraged on the need to sustain the use of different communication strategies to enable them get timely information on modern system of farming.
Awareness of Dental Students on the Application of PRF in Dental Practice - A Survey
Authors: Sriram Kadambari , Ganapathy Dhanraj , Duraisamy Revathi 
Published: August 2020

Platelet-rich fibrin (PRF) is a fibrin matrix in which platelet cytokines, growth factors, and cells are trapped and may be released after a certain time and that can serve as a resorbable membrane.
In other words, it is an increased concentration of platelets suspended in a matrix which can serve as a vehicle to carry cells involved in tissue regeneration. This survey aimed at assessing the knowledge and awareness of Platelet-rich fibrin among dental students. The study was done in an online setting among the dental students of the Chennai population. The sample size of 150 participants of the age group 20-23 years, both males and females were selected by a simple random sampling method. Both descriptive (frequency of the responses) and inferential statistics (Chi-square tests) were done and the results were presented in the forms of graphs. According to this survey-based study, it was noted that the majority of participants were comprised of females (67%). It was observed that 87% of the population participated in the study were aware of the term PRF (ie. platelet-rich fibrin) whereas 13% of the population was not aware of the term. The statistical association between gender and the awareness of PRF, its advantages, and components was found to be significant (p<0.05), with females having more awareness than males. Within the limitations of this study, we can conclude that while dental students are aware of PRF they do not have extensive knowledge of its components and its application in various procedures. It was also observed that there was a disparity in awareness between the genders where females were much aware compared to males. We propose to include this knowledge of PRF in the curriculum to ensure increased awareness of PRF among dental students.
Awareness of Therapeutic Benefits of Green Tea among Dental Fraternity
Authors: Raj Mohamed Naz Fathima , Ganapathy Dhanraj , Sasanka L. Keerthi 
Published: August 2020

Green tea is a popular beverage and in vitro studies have shown that green tea phenols inhibit the growth and cellular adherence of periodontal pathogens and their production of virulence factors. The antioxidants, bacteria battling catechins and other micronutrients in green tea fortify tooth structures, whitens teeth, keep breath fresh, and dissolves plaque. Green tea controls bacteria and lowers the acidity of saliva and dental plaque, it may be a useful tool in preventing cavities. Green tea’s anti-inflammatory powers seem to help control periodontal (gum) disease. The aim of this present survey was to establish awareness of the therapeutic benefits of green tea among the dental fraternity. A descriptive survey was conducted among dental students of Saveetha Dental college using a questionnaire in the google form. The questionnaire consists of 15 questions that were framed based on the knowledge of the therapeutic benefits of green tea in oral health and sent to 75 subjects. The data was collected and systematically analyzed that 62% of participants reported that green tea removes bad breath, 68% of participants reported that green tea has anti-inflammatory effects that heal gum diseases. About 64% of participants reported that frequent intake of green tea would decrease dental caries formation. About 60% of participants reported that green tea has curative properties against dental caries, gingivitis, periodontitis, and oral malignancy. Based on this survey, the knowledge and awareness about the therapeutic benefits of green tea among the dental fraternity have been known by the majority of persons.
Antigen‐Presenting Cells
Authors: Stagg Andrew J , Hornsby Eve , Knight Stella C 
Published: August 2020

Abstract

Professional antigen‐presenting cells (APCs) comprise dendritic cells (DCs), macrophages (MΦs) and B cells. Collectively, they initiate an adaptive immune response to pathogens, shape the nature of this response and contribute to its regulation and termination. They also play key roles in maintenance of tolerance to self‐antigens. Only DCs are able to activate naïve T cells, and from this pivotal position at the initiation of a response, they are able to shape the differentiation of the T cells towards different functional fates and instruct trafficking of these cells to sites of infection. In contrast, MΦs and B cells re‐stimulate T cells, previously activated by DCs in an antigen‐specific manner. They function to amplify the initial DC‐activated response and to elicit the targeted production of T cell‐derived factors required for antibody production by B cells and the enhanced microbicidal activity of MΦs.

Key Concepts

Cells that express MHC class II under resting conditions are often termed ‘professional’ antigen‐presenting cells (APCs).

Professional APCs comprise dendritic cells (DCs), macrophages (MΦs) and B cells.

Many tissue MΦs are derived from embryonic precursors and locally renew; DCs, B cells and some MΦs are derived by distinct pathways, in adult bone marrow.

Only DCs can activate naïve T cells.

DC‐derived signals shape the differentiation of CD4 T cells towards different functional subsets and can influence the trafficking of the cells generated to different tissues.

DCs can also induce tolerance via deletion, anergy and generation of T cells with regulatory properties.

Small numbers of DCs carrying self‐antigens constitutively migrate to secondary lymphoid organs (SLOs), but in the absence of exposure to infection‐associated ‘danger’ signals they express low levels of co‐stimulatory molecules and fail to stimulate adaptive immunity.

In infection, DCs undergo maturation in response to danger signals; mature DCs presenting foreign antigens and expressing high levels of co‐stimulatory molecules induce effector T cell responses.

B cells present antigen to DC‐activated T cells in order to trigger the targeted release of T cell derived factors that are required by B cells for production of high‐quality antibodies (‘T cell help’).

MΦs present antigen to DC‐activated T cells in order to trigger the targeted release of cytokines that activate the MΦ for enhanced microbicidal activity, reducing collateral tissue damage caused by toxic metabolites involved in pathogen killing.
Pituitary
Authors: Seejore Khyatisha , Murray Robert D 
Published: August 2020

Abstract

The pituitary gland is central to the regulation and functional integrity of many peripheral hormone systems. Based at the base of the brain, the pituitary integrates signals from the hypothalamus with feedback from the peripheral endocrine glands, and in turn, releases the requisite amount of hormone or trophic factor for the ambient metabolic and physiological conditions. The past decades have seen key milestones in recombinant production of all known pituitary and hypothalamic hormones, characterisation of their receptors and discovery of additional hypothalamic peptides regulating the pituitary. These have enabled an in‐depth understanding of hypothalamic–pituitary physiology and pathophysiology.

Key Concepts

The pituitary gland is centrally regulated by the hypothalamus.

The anterior pituitary (adenohypophysis) contains five distinct glandular cell types that secrete growth hormone (GH), prolactin, gonadotrophins (luteinizing hormone, LH; follicle‐stimulating hormone, FSH), adrenocorticotropic hormone (ACTH) and thyroid‐stimulating hormone (TSH).

Anterior pituitary hormones are secreted in pulses under control of hypothalamic trophic factors released in the hypophyseal portal circulation.

The ultradian pulsed patterns of GH, prolactin, ACTH and TSH secretion follow endogenous circadian rhythms.

Peripheral hormones released from target endocrine organs regulate secretion of anterior pituitary hormones in negative feedback loops, with the exception of prolactin.

Prolactin is produced by pituitary lactotrophs and is tonically inhibited by the hypothalamic neurotransmitter, dopamine.

The neurohypophysis (posterior pituitary) is constituted of axonal projections extending from the hypothalamic supraoptic and paraventricular nuclei that secrete arginine vasopressin (AVP) and oxytocin.

Posterior pituitary hormones are secreted and regulated via neural pathways to coordinate water balance and reproductive function.
Viroids
Authors: Flores Ricardo , Daròs José‐Antonio , Hernández Carmen , Navarro Beatriz , Serio Francesco Di 
Published: August 2020

Abstract

Viroids are infectious, nonprotein‐coding, highly structured small circular ribonucleic acids (RNAs) able to replicate autonomously and induce diseases in higher plants. Viroids and viruses differ in structure, function and evolutionary origin (with the former regarded as relics of a primitive RNA world). Viroids are classified into the families
Pospiviroidae
and
Avsunviroidae
, the members of which replicate in the nucleus and chloroplast, respectively, through an RNA‐based rolling circle mechanism with three steps catalysed by (1) host deoxyribonucleic acid (DNA)‐dependent RNA polymerases redirected to accept RNA templates, (2) ribonucleases or, in the
Avsunviroidae
, hammerhead ribozymes and (3) RNA ligases, either DNA ligase 1 redirected to accept RNA substrates in the
Pospiviroidae
or a tRNA ligase in the
Avsunviroidae
. When infecting a cell, the viroid RNA must travel to its replication organelle, with the resulting progeny moving cell‐to‐cell through plasmodesmata and reaching distal parts through the phloem. Pathogenesis could be triggered by the replicating viroid itself, or via RNA silencing. Viroids are detected by nucleic acid‐based approaches, some can be eliminated from infected plants by meristem tip culturing, and biotechnological approaches are being developed for their control.

Key Concepts

Viroids are small nonprotein‐coding RNAs that replicate, infect and may induce disease in higher plants.

Viroids differ from viruses in fundamental aspects that include structure, function and evolutionary origin.

Viroids are classified into the families
Pospiviroidae
(nuclear viroids) and
Avsunviroidae
(chloroplastic viroids).

Viroid RNAs adopt compact secondary structures additionally stabilised by elements of tertiary structure.

Viroids replicate through a rolling circle mechanism with only RNA intermediates and enzyme or ribozyme processing.

Different viroids have distinct host ranges and closely related viroids display cross‐protection effects when co‐infecting a common host.

Viroids move intracellularly, cell‐to‐cell through plasmodesmata, and long distance through the phloem.

Viroids may infect their host plants latently or induce different pathogenic alterations including death.

Viroids propagate in their hosts as a population of closely related variants (quasispecies).

Viroids may be molecular fossils of the RNA world postulated to have preceded our present world dominated by DNA and proteins.
Oestrogens: Structure, Mechanisms of Action and Role in Mood and Cognition
Authors: Almeida Osborne FX , Patchev Vladimir K 
Published: August 2020

AbstractOestrogens are steroid hormones that act through specific receptors in the brain to influence a variety of functions, including mood and cognition. The best‐known and most potent endogenous oestrogen is 17β‐oestradiol (17β‐E2). Oestrogen actions in the brain include alterations of neuronal excitability, neurotransmitter synthesis and metabolism, neuronal development, morphology and survival as well as connectivity between different brain areas so as to generate behaviours that are appropriate to internal (physiological) and external (environmental) demands. In the so‐called classical mode of action, oestrogens bind to specific receptors located in the cell nucleus that regulate gene transcription and ultimately protein synthesis. Such receptors are widely distributed in the brain and peripheral tissues such as breast, uterus, bone, liver and heart. Oestrogen actions mediated by nuclear receptors only become detectable after several hours. In contrast, more recently described membrane‐bound receptors allow oestrogens to rapidly alter the excitability of neuronal and nonneuronal membranes. Thus, oestrogens have the potential to influence brain function through slow‐ and/or fast‐acting modes. Knowledge about how and what brain structures and functions are responsive to oestrogens over the entire lifespan is key to informing future improvements in women's health, from adolescence through to old age.Oestrogens are steroid hormones that modulate neuronal structure, activity and function; the term ‘oestrogen’ refers to both naturally produced hormones and synthetic analogues.Modern industrial products contain a variety of chemicals with oestrogen‐like properties. These so‐called endocrine disruptor compounds are considered to be environmental health hazards.Oestrogen secretion starts during early development, varies cyclically from puberty onwards and gradually diminishes with age (menopause in women).Oestrogens and oestrogen‐like compounds bind to oestrogen receptors located in either the plasma membrane or cell nucleus that lead to rapid changes in neuronal excitability and slow‐onset changes in protein synthesis, respectively.Both the rapid and slow modes of oestrogen action contribute to the regulation of complex behaviours such as mood and cognition.Oestrogens have wide therapeutic applications, for example in contraception and management of postmenopausal symptoms, but their prescription requires careful tailoring to individual needs and potential risk factors.Phytoestrogens are natural (plant) compounds. Although they are widely promoted in alternative medicine, their efficacy is questionable.
Drosophila
Embryo: Maternal Interactions in Specification of the Anterior–Posterior Axis
Authors: Kugler Jan‐Michael , Lasko Paul 
Published: August 2020

Abstract

Studies of the maternal processes that specify the
Drosophila
anteroposterior embryonic axis have yielded rich insight into various biological processes required for animal development. As the oocyte is a single cell with a single, largely quiescent nucleus, polarising and symmetry‐breaking events must be executed through molecular mechanisms other than transcriptional control. These include intercellular interactions such as signal transduction and differential cell adhesion. mRNA‐based mechanisms are also prominent in establishing the anteroposterior embryonic axis. Specific mRNAs become enriched at the anterior or posterior poles through motor‐protein driven microtubule‐dependent transport, or through bulk cytoplasmic movement followed by anchoring. Proteins encoded by these mRNAs establish gradients through spatiotemporal control of translation and by diffusion coupled with degradation.

Ovary structure determines the activities of polarising pathways that establish the anteroposterior embryonic axis.

Initial asymmetries correlate with unequal cell divisions, a polarised cytoskeleton and differential cell adhesion.

Germ cell – follicle cell interactions establish and maintain polarity in developing follicles.

Microtubule‐dependent mRNA localisation is critical to axis establishment.

Localised determinants initiate regulatory cascades that establish the anteroposterior body axis of the embryo and specify primordial germ cells.

Various ribonucleoprotein complexes (RNPs) are essential for germ line development and for axis formation.

Phase transition of proteins with intrinsically disordered domains are involved in the formation of several classes of these RNPs.
Mastering the Tools: Natural versus Artificial Vesicles in Nanomedicine
Authors: Leggio Loredana , Arrabito Giuseppe , Ferrara Vittorio , Vivarelli Silvia , Paternò Greta , Marchetti Bianca , Pignataro Bruno , Iraci Nunzio 
Published: August 2020

AbstractNaturally occurring extracellular vesicles and artificially made vesicles represent important tools in nanomedicine for the efficient delivery of biomolecules and drugs. Since its first appearance in the literature 50 years ago, the research on vesicles is progressing at a fast pace, with the main goal of developing carriers able to protect cargoes from degradation, as well as to deliver them in a time‐ and space‐controlled fashion. While natural occurring vesicles have the advantage of being fully compatible with their host, artificial vesicles can be easily synthetized and functionalized according to the target to reach. Research is striving to merge the advantages of natural and artificial vesicles, in order to provide a new generation of highly performing vesicles, which would improve the therapeutic index of transported molecules. This progress report summarizes current manufacturing techniques used to produce both natural and artificial vesicles, exploring the promises and pitfalls of the different production processes. Finally, pros and cons of natural versus artificial vesicles are discussed and compared, with special regard toward the current applications of both kinds of vesicles in the healthcare field.
Time‐Resolved Structural Kinetics of an Organic Mixed Ionic–Electronic Conductor
Authors: Paulsen Bryan D. , Wu Ruiheng , Takacs Christopher J. , Steinrück Hans‐Georg , Strzalka Joseph , Zhang Qingteng , Toney Michael F. , Rivnay Jonathan 
Published: August 2020

AbstractThe structure and packing of organic mixed ionic–electronic conductors have an especially significant effect on transport properties. In operating devices, this structure is not fixed but is responsive to changes in electrochemical potential, ion intercalation, and solvent swelling. Toward this end, the steady‐state and transient structure of the model organic mixed conductor, poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), is characterized using multimodal time‐resolved operando techniques. Steady‐state operando X‐ray scattering reveals a doping‐induced lamellar expansion of 1.6 Å followed by 0.4 Å relaxation at high doping levels. Time‐resolved operando X‐ray scattering reveals asymmetric rates of lamellar structural change during doping and dedoping that do not directly depend on potential or charging transients. Time‐resolved spectroscopy establishes a link between structural transients and the complex kinetics of electronic charge carrier subpopulations, in particular the polaron–bipolaron equilibrium. These findings provide insight into the factors limiting the response time of organic mixed‐conductor‐based devices, and present the first real‐time observation of the structural changes during doping and dedoping of a conjugated polymer system via X‐ray scattering.
Tunable Dual‐Split‐Disk Resonator with Electromagnetically Induced Transparency Characteristic
Authors: Zheng Daoye , Lin Yu‐Sheng 
Published: August 2020

AbstractA tunable dual‐split‐disk resonator (TDSDR) composed of top and bottom Au split‐disk resonators (SDRs) in the terahertz (THz) wave is presented. TDSDR exhibits electromagnetically induced transparency (EIT) characteristic by changing the rotation angle of top SDR (θ) and distance between top and bottom SDRs (h). The bright and dark modes are defined by the resonances with θ = 90° and 0°, respectively. The resonances could also be controlled by changing h values. It can generate a tunable sharp resonance by moving the top SDR to change h value. Furthermore, the amplitude of EIT resonance could be tuned and switched on/off state, i.e., bright and dark modes by rotating top SDR with specific h value. When h value is 1 µm, the free spectra range (FSR) could be tuned 0.24 THz and EIT characteristic is not clear. By continuously changing h value to 3 µm, EIT characteristic could be tuned with a modulation depth of 75.58%. The average quality factor (Q‐factor) of resonances is 11.54 and average figure of merit (FOM) is 7.06. When h value is enlarged to 5 µm, EIT characteristic could be tuned with a modulation depth of 62.73%, while the average Q‐factor is 14.50 and average FOM is 9.35.
Photoinvertible Chiral Liquid Crystal that Affords Helicity‐Controlled Aromatic Conjugated Polymers
Authors: Yoshida Satoru , Morikawa Santa , Ueda Kenta , Hidaka Masatomo , Kaneko Kosuke , Kaneko Kimiyoshi , Hanasaki Tomonori , Akagi Kazuo 
Published: August 2020

AbstractPhotoinvertible chiral compounds are synthesized by linking a photoresponsive bisbenzothienylethene moiety with an axially chiral binaphthyl moiety and used as chiral dopants to prepare a photoinvertible chiral nematic liquid crystal (N*‐LC) field. Subsequently, electrochemical polymerizations of ethylenedioxythiophene (EDOT) in the N*‐LC field to synthesize helical poly(ethylenedioxythiophene)s (H‐PEDOTs) are achieved. The H‐PEDOTs show not only spiral morphologies resembling the fingerprinted texture of N*‐LC in polarizing optical microscope but also bisignate Cotton effects in circular dichroism spectra, indicating the formation of a helically π‐stacked structure in terms of the main chains of H‐PEDOT. In addition, the signs of the bisignate Cotton effect are strictly determined by the helicity of the N*‐LC. The present N*‐LC is the first reaction field exhibiting photoinvertible chirality with extremely high fatigue resistance and serves as an asymmetric medium for electrochemical polymerization, leading to dynamic helicity control of conjugated polymers.