bluuebunny/crossref_metadata_2025 huggingface dataset:
Maternal Diet Quality, Body Mass Index and Resource Use in the Perinatal Period: An Observational Study
Authors: Szewczyk Zoe , Weaver Natasha , Rollo Megan , Deeming Simon , Holliday Elizabeth , Reeves Penny , Collins Clare
Published: November 2020

The impact of pre-pregnancy obesity and maternal diet quality on the use of healthcare resources during the perinatal period is underexplored. We assessed the effects of body mass index (BMI) and diet quality on the use of healthcare resources, to identify whether maternal diet quality may be effectively targeted to reduce antenatal heath care resource use, independent of women’s BMI. Cross-sectional data and inpatient medical records were gathered from pregnant women attending publicly funded antenatal outpatient clinics in Newcastle, Australia. Dietary intake was self-reported, using the Australian Eating Survey (AES) food frequency questionnaire, and diet quality was quantified from the AES subscale, the Australian Recommended Food Score (ARFS). Mean pre-pregnancy BMI was 28.8 kg/m2 (range: 14.7 kg/m2–64 kg/m2). Mean ARFS was 28.8 (SD = 13.1). Higher BMI was associated with increased odds of caesarean delivery; women in obese class II (35.0–39.9 kg/m2) had significantly higher odds of caesarean delivery compared to women of normal weight, (OR = 2.13, 95% CI 1.03 to 4.39; p = 0.04). Using Australian Refined Diagnosis Related Group categories for birth admission, the average cost of the birth admission was $1348 more for women in the obese class II, and $1952 more for women in the obese class III, compared to women in a normal BMI weight class. Higher ARFS was associated with a small statistically significant reduction in maternal length of stay (RR = 1.24, 95% CI 1.00, 1.54; p = 0.05). There was no evidence of an association between ARFS and mode of delivery or “midwifery-in-the-home-visits”.
Development and Validation of a Questionnaire to Measure Knowledge of and Attitude toward COVID-19 among Nursing Students in Greece
Authors: Patelarou Athina E. , Konstantinidis Theocharis , Kartsoni Evangelia , Mechili Enkeleint A. , Galanis Petros , Zografakis-Sfakianakis Michail , Patelarou Evridiki
Published: November 2020

Background: During the COVID-19 pandemic, nursing students have had a key role in supporting the healthcare sector. They can join healthcare professionals in clinical practice or provide information to increase citizens’ levels of knowledge and their compliance with the restriction measures. The study aimed to develop and validate a tool to measure knowledge of and attitudes toward COVID-19 among nursing students in Greece. Methods: A questionnaire was developed through theoretical research and expert consultation. A cross-sectional study was conducted among 348 undergraduate nursing students of the Department of Nursing, Hellenic Mediterranean University, recruited by convenient sampling. Validity and reliability were analyzed. Results: The Kaiser–Meyer–Olkin measure was 0.84, indicating that the sample size was adequate for factor analysis. In addition, the p-value for Bartlett’s test of sphericity was <0.001, denoting that the correlation matrix was suitable for factor analysis. The construct validity of the questionnaire was determined through exploratory factor analysis (EFA), which revealed that 16 items lead to four factors: knowledge, attitude toward restriction measures, compliance with them, and volunteering. One of the key findings of this study was that participants preferred to receive information from valid sources rather than social media during the crucial period of the “infodemic”. Conclusions: The questionnaire was shown to have satisfying psychometric properties and, therefore, can be used as a tool in future research in the area of nursing students’ knowledge, attitudes, compliance, and volunteering during the COVID-19 pandemic.
PXO_RS20535, Encoding a Novel Response Regulator, Is Required for Chemotactic Motility, Biofilm Formation, and Tolerance to Oxidative Stress in Xanthomonas oryzae pv. oryzae
Authors: Antar Abdulwahab , Lee Mi-Ae , Yoo Youngchul , Cho Man-Ho , Lee Sang-Won
Published: November 2020

Xanthomonas oryzae pv. oryzae (Xoo), a causal agent of bacterial leaf blight of rice, possesses two-component regulatory systems (TCSs) as an intracellular signaling pathway. In this study, we observed changes in virulence, biofilm formation, motility, chemotaxis, and tolerance against oxidative stress of a knockout mutant strain for the PXO_RS20535 gene, encoding an orphan response regulator (RR). The mutant strain lost virulence, produced significantly less biofilm, and showed remarkably reduced motility in swimming, swarming, and twitching. Furthermore, the mutant strain lost glucose-guided movement and showed clear diminution of growth and survival in the presence of H2O2. These results indicate that the RR protein encoded in the PXO_RS20535 gene (or a TCS mediated by the protein) is closely involved in regulation of biofilm formation, all types of motility, chemotaxis, and tolerance against reactive oxygen species (ROS) in Xoo. Moreover we found that the expression of most genes required for a type six secretion system (T6SS) was decreased in the mutant, suggesting that lack of the RR gene most likely leads to defect of T6SS in Xoo.
Critical Review: Propensity of Premise Plumbing Pipe Materials to Enhance or Diminish Growth of Legionella and Other Opportunistic Pathogens
Authors: Cullom Abraham C. , Martin Rebekah L. , Song Yang , Williams Krista , Williams Amanda , Pruden Amy , Edwards Marc A.
Published: November 2020

Growth of Legionella pneumophila and other opportunistic pathogens (OPs) in drinking water premise plumbing poses an increasing public health concern. Premise plumbing is constructed of a variety of materials, creating complex environments that vary chemically, microbiologically, spatially, and temporally in a manner likely to influence survival and growth of OPs. Here we systematically review the literature to critically examine the varied effects of common metallic (copper, iron) and plastic (PVC, cross-linked polyethylene (PEX)) pipe materials on factors influencing OP growth in drinking water, including nutrient availability, disinfectant levels, and the composition of the broader microbiome. Plastic pipes can leach organic carbon, but demonstrate a lower disinfectant demand and fewer water chemistry interactions. Iron pipes may provide OPs with nutrients directly or indirectly, exhibiting a high disinfectant demand and potential to form scales with high surface areas suitable for biofilm colonization. While copper pipes are known for their antimicrobial properties, evidence of their efficacy for OP control is inconsistent. Under some circumstances, copper’s interactions with premise plumbing water chemistry and resident microbes can encourage growth of OPs. Plumbing design, configuration, and operation can be manipulated to control such interactions and health outcomes. Influences of pipe materials on OP physiology should also be considered, including the possibility of influencing virulence and antibiotic resistance. In conclusion, all known pipe materials have a potential to either stimulate or inhibit OP growth, depending on the circumstances. This review delineates some of these circumstances and informs future research and guidance towards effective deployment of pipe materials for control of OPs.
Methicillin Resistant Staphylococcus Aureus Shoulder Pyomyositis with Multifocal Lung Infiltrations
Authors: Troisi Angela , Graziani Giulia , Macaluso Alessandra , Mambelli Lorenzo , Marchetti Federico
Published: November 2020

Pyomyositis is a rare condition in temperate climates. We present a case of Methicillin Resistant Staphylococcus aureus pyomyositis of the shoulder complicated by multifocal lung infiltrations, treated successfully with antibiotic therapy. After excluding shoulder septic arthritis, a low threshold of suspicion for the diagnosis of shoulder pyomyositis should be applied to patients with persistent fever, pain, and decreased range of shoulder motion. A prompt diagnosis and a rapid rise in antibiotic therapy are important to avoid local and systemic complications.
Small-Dose Sunitinib Modulates p53, Bcl-2, STAT3, and ERK1/2 Pathways and Protects against Adenine-Induced Nephrotoxicity
Authors: Saleh Mohamed A. , Awad Ahmed M. , Ibrahim Tarek M. , Abu-Elsaad Nashwa M.
Published: November 2020

The therapeutic use of numerous pharmacological agents may be limited due to their nephrotoxicity and associated kidney injury. The aim of our study is to test the hypothesis that the blockade of tyrosine kinase-linked receptors signaling protects against chemically induced nephrotoxicity. To test our hypothesis, we investigated sunitinib as an inhibitor for tyrosine kinase signaling for both vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptors (PDGFR) against adenine-induced nephrotoxicity. Four groups of adult male Swiss albino mice were investigated: normal group, adenine group, sunitinib group, and the adenine+sunitinib group that received concurrent administration for both adenine and sunitinib. Kidney function and oxidative stress biomarkers were analyzed. Tubular injury and histopathological changes were examined. Renal expression of B-cell lymphoma-2 (Bcl-2), the tumor suppressor p53, transforming growth factor beta-1 (TGF-β1), phospho-extracellular signal-regulated kinase 1/2 (p-ERK1/2), and phospho-signal transducer and activator of transcription (phospho-STAT3) were measured. The results obtained showed significant improvement (p < 0.05) in kidney function and antioxidant biomarkers in the adenine+sunitinib group. Kidney fibrosis and tubular injury scores were significantly (p < 0.05) less in the adenine+sunitinib group and that of p53 expression as well. Furthermore, sunitinib decreased (p < 0.5) renal levels of TGF-β1, p-ERK1/2, and phospho-STAT3 while elevating Bcl-2 expression score. In conclusion, sunitinib diminished adenine-induced nephrotoxicity through interfering with profibrogenic pathways, activating anti-apoptotic mechanisms, and possessing potential antioxidant capabilities.
Sustainability of Biosimilars in Europe: A Delphi Panel Consensus with Systematic Literature Review
Authors: Vulto Arnold G. , Vanderpuye-Orgle Jackie , van der Graaff Martin , Simoens Steven R. A. , Dagna Lorenzo , Macaulay Richard , Majeed Beenish , Lemay Jeffrey , Hippenmeyer Jane , Gonzalez-McQuire Sebastian
Published: November 2020

Introduction: Biosimilars have the potential to enhance the sustainability of evolving health care systems. A sustainable biosimilars market requires all stakeholders to balance competition and supply chain security. However, there is significant variation in the policies for pricing, procurement, and use of biosimilars in the European Union. A modified Delphi process was conducted to achieve expert consensus on biosimilar market sustainability in Europe. Methods: The priorities of 11 stakeholders were explored in three stages: a brainstorming stage supported by a systematic literature review (SLR) and key materials identified by the participants; development and review of statements derived during brainstorming; and a facilitated roundtable discussion. Results: Participants argued that a sustainable biosimilar market must deliver tangible and transparent benefits to the health care system, while meeting the needs of all stakeholders. Key drivers of biosimilar market sustainability included: (i) competition is more effective than regulation; (ii) there should be incentives to ensure industry investment in biosimilar development and innovation; (iii) procurement processes must avoid monopolies and minimize market disruption; and (iv) principles for procurement should be defined by all stakeholders. However, findings from the SLR were limited, with significant gaps on the impact of different tender models on supply risks, savings, and sustainability. Conclusions: A sustainable biosimilar market means that all stakeholders benefit from appropriate and reliable access to biological therapies. Failure to care for biosimilar market sustainability may impoverish biosimilar development and offerings, eventually leading to increased cost for health care systems and patients, with fewer resources for innovation.
Manufacturing Considerations for the Development of Lipid Nanoparticles Using Microfluidics
Authors: Roces Carla B. , Lou Gustavo , Jain Nikita , Abraham Suraj , Thomas Anitha , Halbert Gavin W. , Perrie Yvonne
Published: November 2020

In the recent of years, the use of lipid nanoparticles (LNPs) for RNA delivery has gained considerable attention, with a large number in the clinical pipeline as vaccine candidates or to treat a wide range of diseases. Microfluidics offers considerable advantages for their manufacture due to its scalability, reproducibility and fast preparation. Thus, in this study, we have evaluated operating and formulation parameters to be considered when developing LNPs. Among them, the flow rate ratio (FRR) and the total flow rate (TFR) have been shown to significantly influence the physicochemical characteristics of the produced particles. In particular, increasing the TFR or increasing the FRR decreased the particle size. The amino lipid choice (cationic—DOTAP and DDAB; ionisable—MC3), buffer choice (citrate buffer pH 6 or TRIS pH 7.4) and type of nucleic acid payload (PolyA, ssDNA or mRNA) have also been shown to have an impact on the characteristics of these LNPs. LNPs were shown to have a high (>90%) loading in all cases and were below 100 nm with a low polydispersity index (≤0.25). The results within this paper could be used as a guide for the development and scalable manufacture of LNP systems using microfluidics.
Echinacea angustifolia DC. Lipophilic Extract Patch for Skin Application: Preparation, In Vitro and In Vivo Studies
Authors: Hasa Dritan , Žakelj Simon , Grabnar Iztok , Cilurzo Francesco , Dall’Acqua Stefano , Riva Antonella , Perissutti Beatrice , Voinovich Dario
Published: November 2020

Dodeca-2E,4E,8Z,10E/Z-tetraenoic isobutylamide (tetraene) is the main component of Echinacea angustifolia DC. lipophilic extract, the bioavailability and immunomodulatory effect after oral administration in soft gel capsules in healthy volunteers of which we have already demonstrated. In the present work, we assessed the transdermal administration as an alternative route of administration of such an alkamide. The first step, therefore, encompassed the preparation of a drug-in-adhesive patch with an area of 868 mm2 and containing a dose of 0.64 mg of tetraene. In vitro skin permeation studies in Franz-type diffusion chambers resulted in a tetraene flux of (103 ± 10) ng × cm−2 × h−1 with a very good linearity (r = 0.99). The relatively low lag time of just 13 min indicates low binding and the accumulation of tetraene in the skin. Finally, the patch was administered to six healthy volunteers, and the pharmacokinetic analysis was performed by nonlinear mixed effects modelling with soft gel oral capsules serving as the reference formulation. The in vivo results correlated well with the in vitro permeation and indicated an initial burst tetraene absorption from the patch that was in parallel with the zero-order kinetics of absorption. The rate of the latter process was in good agreement with the one estimated in vitro. The tetraene absorption rate was therefore slow and prolonged with time, resulting in a bioavailability of 39% relative to the soft gel capsules and a very flat plasma concentration profile.
Hyperthermia-Induced Controlled Local Anesthesia Administration Using Gelatin-Coated Iron–Gold Alloy Nanoparticles
Authors: Ting Chien-Kun , Dhawan Udesh , Tseng Ching-Li , Alex Gong Cihun-Siyong , Liu Wai-Ching , Tsai Huai-De , Chung Ren-Jei
Published: November 2020

The lack of optimal methods employing nanoparticles to administer local anesthesia often results in posing severe risks such as non-biocompatibility, in vivo cytotoxicity, and drug overdose to patients. Here, we employed magnetic field-induced hyperthermia to achieve localized anesthesia. We synthesized iron–gold alloy nanoparticles (FeAu Nps), conjugated an anesthetic drug, Lidocaine, and coated the product with gelatin to increase the biocompatibility, resulting in a FeAu@Gelatin–Lidocaine nano-complex formation. The biocompatibility of this drug–nanoparticle conjugate was evaluated in vitro, and its ability to trigger local anesthesia was also evaluated in vivo. Upon exposure to high-frequency induction waves (HFIW), 7.2 ± 2.8 nm sized superparamagnetic nanoparticles generated heat, which dissociated the gelatin coating, thereby triggering Lidocaine release. MTT assay revealed that 82% of cells were viable at 5 mg/mL concentration of Lidocaine, indicating that no significant cytotoxicity was induced. In vivo experiments revealed that unless stimulated with HFIW, Lidocaine was not released from the FeAu@Gelatin–Lidocaine complex. In a proof-of-concept experiment, an intramuscular injection of FeAu@Gelatin–Lidocaine complex was administered to the rat posterior leg, which upon HFIW stimulation triggered an anesthetic effect to the injected muscle. Based on our findings, the FeAu@Gelatin–Lidocaine complex can deliver hyperthermia-induced controlled anesthetic drug release and serve as an ideal candidate for site-specific anesthesia administration.
Binary Mixtures of Some Active Pharmaceutical Ingredients with Fatty Alcohols—The Criteria of Successful Eutectic Formation and Dissolution Improvement
Authors: Jin Songhee , Jang Jisun , Lee Soyeon , Kim Il Won
Published: November 2020

Pharmaceutical eutectics are solid mixtures, where the crystals of active pharmaceutical ingredients (APIs) are finely divided in the phase-separated microstructures. The size reduction makes the eutectic formation a viable option to improve the dissolution rate of the poorly soluble APIs. In the present study, ibuprofen, naproxen, and sorafenib were investigated in terms of their phase behaviors with fatty alcohols, such as tetradecanol, octadecanol, and docosanol. Among the studied APIs, only ibuprofen was able to form eutectics with the fatty alcohols, and this was in agreement with the feasibility prediction based on the van ’t Hoff equation and solubility parameters. In vitro release behavior was significantly improved for the ibuprofen/octadecanol eutectic mixture, although the practical insolubility of octadecanol in water was the opposite of the outstanding hydrophilicity of usual eutectic formers. The feasibility prediction and the choice of eutectic formers in the present study will be useful in advancing the utility of the pharmaceutical eutectics.
Microneedles Drug Delivery Systems for Treatment of Cancer: A Recent Update
Authors: Seetharam Aravindram Attiguppe , Choudhry Hani , Bakhrebah Muhammed A. , Abdulaal Wesam H. , Gupta Maram Suresh , Rizvi Syed Mohd Danish , Alam Qamre , Siddaramaiah  , Gowda Devegowda Vishakante , Moin Afrasim
Published: November 2020

Microneedles (MNs) are tiny needle like structures used in drug delivery through layers of the skin. They are non-invasive and are associated with significantly less or no pain at the site of administration to the skin. MNs are excellent in delivering both small and large molecules to the subjects in need thereof. There exist several strategies for drug delivery using MNs, wherein each strategy has its pros and cons. Research in this domain lead to product development and commercialization for clinical use. Additionally, several MN-based products are undergoing clinical trials to evaluate its safety, efficacy, and tolerability. The present review begins by providing bird’s-eye view about the general characteristics of MNs followed by providing recent updates in the treatment of cancer using MNs. Particularly, we provide an overview of various aspects namely: anti-cancerous MNs that work based on sensor technology, MNs for treatment of breast cancer, skin carcinoma, prostate cancer, and MNs fabricated by additive manufacturing or 3 dimensional printing for treatment of cancer. Further, the review also provides limitations, safety concerns, and latest updates about the clinical trials on MNs for the treatment of cancer. Furthermore, we also provide a regulatory overview from the “United States Food and Drug Administration” about MNs.
Biogeography of Stigmaphyllon (Malpighiaceae) and a Meta-Analysis of Vascular Plant Lineages Diversified in the Brazilian Atlantic Rainforests Point to the Late Eocene Origins of This Megadiverse Biome
Authors: de Almeida Rafael Felipe , van den Berg Cássio
Published: November 2020

We investigated the biogeography of Stigmaphyllon, the second-largest lianescent genus of Malpighiaceae, as a model genus to reconstruct the age and biogeographic history of the Brazilian Atlantic Rainforest (BAF). Few studies to date have focused on the tertiary diversification of plant lineages in the BAFs, especially on Stigmaphyllon. Phylogenetic relationships for 24 species of Stigmaphyllon (18 ssp. From the Atlantic forest (out of 31 spp.), three spp. from the Amazon Rainforest, two spp. from the Caatinga biome, and a single species from the Cerrado biome) were inferred based on one nuclear DNA (PHYC) and two ribosomal DNA (ETS, ITS) regions using parsimony and Bayesian methods. A time-calibrated phylogenetic tree for ancestral area reconstructions was additionally generated, coupled with a meta-analysis of vascular plant lineages diversified in the BAFs. Our results show that: (1) Stigmaphyllon is monophyletic, but its subgenera are paraphyletic; (2) the most recent common ancestor of Stigmaphyllon originated in the Brazilian Atlantic Rainforest/Caatinga region in Northeastern Brazil ca. 26.0 Mya; (3) the genus colonized the Amazon Rainforest at two different times (ca. 22.0 and 6.0 Mya), the Caatinga biome at least four other times (ca. 14.0, 9.0, 7.0, and 1.0 Mya), the Cerrado biome a single time (ca. 15.0 Mya), and the Southern Atlantic Rainforests five times (from 26.0 to 9.0 Mya); (4) a history of at least seven expansion events connecting the Brazilian Atlantic Rainforest to other biomes from 26.0 to 9.0 Mya, and (5) a single dispersion event from South America to Southeastern Asia and Oceania at 22.0 Mya via Antarctica was proposed. Compared to a meta-analysis of time-calibrated phylogenies for 64 lineages of vascular plants diversified in the Brazilian Atlantic Rainforests, our results point to a late Eocene origin for this megadiverse biome.
Evaluating the Contribution of Growth, Physiological, and Ionic Components Towards Salinity and Drought Stress Tolerance in Jatropha curcas
Authors: Abrar Muhammad Mohsin , Saqib Muhammad , Abbas Ghulam , Atiq-ur-Rahman Muhammad , Mustafa Adnan , Shah Syed Atizaz Ali , Mehmood Khalid , Maitlo Ali Akbar , ul-Hassan Mahmood , Sun Nan , Xu Minggang
Published: November 2020

Salinity and drought stress, singly or in combination, are major environmental menaces. Jatropha curcas L. is a biodiesel plant that can tolerate long periods of drought. However, the growth performance and stress tolerance based on physical, chemical, and physiological attributes of this plant have not yet been studied. To address this question, J. curcas seedlings were grown in a completely randomized design in plastic pots filled with soil to evaluate the effects of salinity and drought stresses on growth, ionic composition, and physiological attributes. The experiment consisted of six treatments: control (without salinity and drought stress), salinity alone (7.5 dS m−1, 15 dS m−1), drought, and a combination of salinity and drought (7.5 dS m−1+ Drought, 15 dS m−1+Drought). Our results revealed that, compared with the control, both plant height (PH) and stem diameter (SD) were reduced by (83%, 80%, and 77%) and (69%, 56%, and 55%) under salinity and drought combination (15 dS m−1+Drought) after three, six, and nine months, respectively. There was 93% more leaf Na+ found in plants treated with 15 dS m−1+Drought compared with the control. The highest significant average membrane stability index (MSI) and relative water content (RWC) values (81% and 85%, respectively) were found in the control. The MSI and RWC were not influenced by 7.5 dS m−1 and drought treatments and mostly contributed towards stress tolerance. Our findings imply that J. curcas is moderately tolerant to salinity and drought. The Na+ toxicity and disturbance in K+: Na+ ratio were the main contributing factors for limited growth and physiological attributes in this plant.
Effect of Cadmium Toxicity on Growth, Oxidative Damage, Antioxidant Defense System and Cadmium Accumulation in Two Sorghum Cultivars
Authors: Jawad Hassan Muhammad , Ali Raza Muhammad , Ur Rehman Sana , Ansar Muhammad , Gitari Harun , Khan Imran , Wajid Muhammad , Ahmed Mukhtar , Abbas Shah Ghulam , Peng Yan , Li Zhou
Published: November 2020

Heavy metal stress is a leading environmental issue reducing crop growth and productivity, particularly in arid and semi-arid agro-ecological zones. Cadmium (Cd), a non-redox heavy metal, can indirectly increase the production of reactive oxygen species (ROS), inducing cell death. A pot experiment was conducted to investigate the effects of different concentrations of Cd (0, 5, 25, 50, 100 µM) on physiological and biochemical parameters in two sorghum (Sorghum bicolor L.) cultivars: JS-2002 and Chakwal Sorghum. The results showed that various concentrations of Cd significantly increased the Cd uptake in both cultivars; however, the uptake was higher in JS-2002 compared to Chakwal Sorghum in leaf, stem and root. Regardless of the cultivars, there was a higher accumulation of the Cd in roots than in shoots. The Cd stress significantly reduced the growth and increased the electrolyte leakage (EL), hydrogen peroxide (H2O2) concentration and malondialdehyde (MDA) content in both cultivars, but the Chakwal Sorghum showed more pronounced oxidative damage than the JS-2002, as reflected by higher H2O2, MDA and EL. Moreover, Cd stress, particularly 50 µM and 100 µM, decreased the activity of different antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). However, the JS-2002 exhibited higher SOD, POD and CAT activities than the Chakwal Sorghum under different Cd-levels. These findings revealed that JS-2002 had a stronger Cd enrichment capacity and also exhibited a better tolerance to Cd stress due to its efficient antioxidant defense system than Chakwal Sorghum. The present study provides the available information about Cd enrichment and tolerance in S. bicolor, which is used as an important agricultural crop for livestock feed in arid and semi-arid regions.
Efficacy of Antimicrobial and Larvicidal Activities of Green Synthesized Silver Nanoparticles Using Leaf Extract of Plumbago auriculata Lam
Authors: Govindan Lakshmanan , Anbazhagan Sathiyaseelan , Altemimi Ammar B. , Lakshminarayanan Karthik , Kuppan Sivaranjan , Pratap-Singh Anubhav , Kandasamy Murugesan
Published: November 2020

This work reports the synthesis of silver nanoparticles (AgNPs) using aqueous extract of Plumbago auriculata, and evaluates their antibacterial and larvicidal activities. The synthesized silver nanoparticles were characterized by various spectroscopy techniques, such as FTIR, XRD, TEM, EDX, Zeta potential, and DLS. The synthesized AgNPs exhibited significant antibacterial activity against Gram-positive and Gram-negative bacteria, such as Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae. Furthermore, synthesized nanoparticles inhibited the fourth instars larvae of Aedes aegypti and Culex quinquefasciatus at the concentration of 45.1 and 41.1 µg/mL respectively. Results of dose-dependent studies showed that synthesized nanoparticles were also effective at low concentrations. Molecular docking studies performed with the salivary protein and odorant-binding protein of Aedes aegypti and Culex quinquefasciatus demonstrated that the naphthoquinone compound plumbagin exhibited reliable binding affinity towards the two enzymes. The findings thus reveal that the plant extract and its nanoparticles can be a better alternative to available chemicals to control mosquitos.
Growth and Bioactive Compound Content of Glehnia littoralis Fr. Schmidt ex Miquel Grown under Different CO2 Concentrations and Light Intensities
Authors: Lee Hye Ri , Kim Hyeon Min , Jeong Hyeon Woo , Oh Myung Min , Hwang Seung Jae
Published: November 2020

This study aims to determine the effect of different CO2 concentrations and light intensities on the growth, photosynthetic rate, and bioactive compound content of Glehnia littoralis Fr. Schmidt ex Miquel in a closed-type plant production system (CPPS). The plants were transplanted into a deep floating technique system with recycling nutrient solution (EC 1.0 dS·m-1 and pH 6.5) and cultured for 96 days under a temperature of 20 ± 1 °C, a photoperiod of 12/12 h (light/dark), and RGB LEDs (red:green:blue = 7:1:2) in a CPPS. The experimental treatments were set to 500 or 1500 µmol∙mol−1 CO2 concentrations in combination with one of the three light intensities: 100, 200, or 300 µmol∙m−2∙s−1 photosynthetic photon flux density (PPFD). The petiole length of G. littoralis was the longest in the 500 µmol∙mol−1 CO2 concentration with the 100 µmol∙m−2∙s−1 PPFD. The fresh weight (FW) and dry weight (DW) of shoots and roots were the heaviest in the 300 µmol∙m−2∙s−1 PPFD regardless of the CO2 concentration. Higher CO2 concentrations and light intensities produced the greatest photosynthetic rates. However, the SPAD value was not significantly different between the treatments. Higher light intensities produced greater content per biomass of chlorogenic acid and total saponin, although the concentration per DW or FW was not significantly different between treatments. The first and second harvest yields were the greatest in the 300 µmol∙m−2∙s−1 PPFD, regardless of the CO2 concentration. These results show that the 300 µmol∙m−2∙s−1 PPFD enhanced the growth, photosynthetic rate, and bioactive compound accumulation of G. littoralis, regardless of the CO2 concentration in a CPPS.
Progress in the Chemistry of Macrocyclic Meroterpenoids
Authors: Shurpik Dmitriy N. , Akhmedov Alan A. , Cragg Peter J. , Plemenkov Vitaliy V. , Stoikov Ivan I.
Published: November 2020

In the last decade, the chemistry of meroterpenoids—conjugated molecules formed from isoprenyl fragments through biosynthetic pathways—has developed rapidly. The class includes some natural metabolites and fully synthetic fragments formed through nonbiological synthesis. In the field of synthetic receptors, a range of structures can be achieved by combining fragments of different classes of organic compounds into one hybrid macrocyclic platform which retains the properties of these fragments. This review discusses the successes in the synthesis and practical application of both natural and synthetic macrocycles. Among the natural macrocyclic meroterpenoids, special attention is paid to isoprenylated flavonoids and phenols, isoprenoid lipids, prenylated amino acids and alkaloids, and isoprenylpolyketides. Among the synthetic macrocyclic meroterpenoids obtained by combining the “classical” macrocyclic platforms, those based on cyclodextrins, together with meta- and paracyclophanes incorporating terpenoid fragments, and meroterpenoids obtained by macrocyclization of several terpene derivatives are considered. In addition, issues related to biomedical activity, processes of self-association and aggregation, and the formation of host–guest complexes of various classes of macrocyclic merotenoids are discussed in detail.
Managing an Invasive Weed Species, Parthenium hysterophorus, with Suppressive Plant Species in Australian Grasslands
Authors: Belgeri Amalia , Bajwa Ali Ahsan , Shabbir Asad , Navie Sheldon , Vivian-Smith Gabrielle , Adkins Steve
Published: November 2020

Parthenium weed has been invading native and managed Australian grasslands for almost 40 years. This study quantified the potential of selected plant mixtures to suppress the growth of parthenium weed and followed their response to grazing and their impact upon plant community diversity. The first mixture consisted of predominantly introduced species including Rhodes grass, Bisset bluegrass, butterfly pea and green panic. This mixture produced biomass rapidly and showed tolerance to weed species other than parthenium weed. However, the mixture was unable to suppress the growth of parthenium weed. The second mixture of predominantly native pasture species (including forest bluegrass, Queensland bluegrass, Buffel grass and siratro) produced biomass relatively slowly, but eventually reached the same biomass production as the first mixture 12 weeks after planting. This mixture suppressed parthenium weed re-establishment by 78% compared to the control treatment. Its tolerance to the invasion of other weed species and the maintenance of forage species evenness was also superior. The total diversity was five times higher for the mixture communities as compared to the plant community in the control treatment. Therefore, using the suppressive pasture mixtures may provide an improved sustainable management approach for parthenium weed in grasslands.
Competitive Exclusion of Flavescence dorée Phytoplasma Strains in Catharanthus roseus Plants
Authors: Rossi Marika , Vallino Marta , Galetto Luciana , Marzachì Cristina
Published: November 2020

Flavescence dorée phytoplasmas (FDp, 16SrV-C and -D) are plant pathogenic non-cultivable bacteria associated with a severe grapevine disease. The incidence of the two reference strains on cultivated grapevines is unbalanced, and mixed infections are rare. To investigate the interaction between the two strains, Catharanthus roseus plants were graft-infected with both strains, either simultaneously or sequentially. Different combinations of lateral and apical grafting were applied to avoid possible benefits due to graft position. The infection was monitored for four months through a new diagnostic protocol developed for differentiation and relative quantification of the two strains. Regardless of the temporal or spatial advantage at grafting, FD-C generally outcompeted FD-D. The prevalence of FD-C increased over time and, at the end of the experiment, FD-C was the unique strain detected in the aerial part and the roots of 74% and 90% of grafted plants, respectively. These data indicate that the interaction between the two strains results in competitive exclusion. Understanding the bases of the competition between FD-C and FD-D may contribute to explain the biology of the coexistence of different FDp strains under field conditions, aiming at identifying potential suppressor strains, which can provide alternative and environmentally sustainable solutions for FD control.
Effect of Iron-Oxide Nanoparticles Impregnated Bacterial Cellulose on Overall Properties of Alginate/Casein Hydrogels: Potential Injectable Biomaterial for Wound Healing Applications
Authors: Patwa Rahul , Zandraa Oyunchimeg , Capáková Zdenka , Saha Nabanita , Sáha Petr
Published: November 2020

In this study we report the preparation of novel multicomponent hydrogels as potential biomaterials for injectable hydrogels comprised of alginate, casein and bacterial cellulose impregnated with iron nanoparticles (BCF). These hydrogels demonstrated amide cross-linking of alginate–casein, ionic cross-linking of alginate and supramolecular interaction due to incorporation of BCF. Incorporation of BCF into the hydrogels based on natural biopolymers was done to reinforce the hydrogels and impart magnetic properties critical for targeted drug delivery. This study aimed to improve overall properties of alginate/casein hydrogels by varying the BCF loading. The physico-chemical properties of gels were characterized via FTIR, XRD, DSC, TGA, VSM and mechanical compression. In addition, swelling, drug release, antibacterial activity and cytotoxicity studies were also conducted on these hydrogels. The results indicated that incorporation of BCF in alginate/casein hydrogels led to mechanically stronger gels with magnetic properties, increased porosity and hence increased swelling. A porous structure, which is essential for migration of cells and biomolecule transportation, was confirmed from microscopic analysis. The porous internal structure promoted cell viability, which was confirmed through MTT assay of fibroblasts. Moreover, a hydrogel can be useful for the delivery of essential drugs or biomolecules in a sustained manner for longer durations. These hydrogels are porous, cell viable and possess mechanical properties that match closely to the native tissue. Collectively, these hybrid alginate–casein hydrogels laden with BCF can be fabricated by a facile approach for potential wound healing applications.
Thin Film Deposition by Atmospheric Pressure Dielectric Barrier Discharges Containing Eugenol: Discharge and Coating Characterizations
Authors: Getnet Tsegaye Gashaw , Kayama Milton E. , Rangel Elidiane C. , Cruz Nilson C.
Published: November 2020

Eugenol (4-Allyl-2-methoxyphenol) is the main constituent of clove oil. In addition to being widely used as a condiment, it has been recognized as a powerful bactericide. Owing to that, Eugenol has been used in several applications including odontology and as a conservative for food products. Aiming at the development of natural bactericide coatings, in this work, using an atmospheric pressure plasma in a dielectric barrier discharge (DBD) reactor Eugenol was deposited on stainless steel substrate, with argon as a carrier gas. The discharge power supply was a transformer at 14.4 kV peak-to-peak voltage and 60 Hz frequency. Operating with a gas flow rate at 4 L/min, the active power was around 1.2 W. The maximum plasma electron temperature of the plasma with monomers was about 1.5 eV, estimated by visible emission spectroscopy using a local thermodynamic equilibrium approach. The study also comprehended the analysis of the film structure, aging, and thermal stability using infrared reflectance spectroscopy, and its thicknesses and roughness by profilometry. The thickness of the films was in the range of 1000 to 2400 nm with a roughness of up to 800 nm with good adhesion on the substrate. The FTIR result shows a stable coating with a chemical structure similar to that of the monomer. Aging analysis showed that the film does not degrade, even after exposing the film for 120 days in ambient air and for 1.0 h under a high thermal UV-lamp.
Pyrolysis for Nylon 6 Monomer Recovery from Teabag Waste
Authors: Kim Soosan , Lee Nahyeon , Lee Jechan
Published: November 2020

In this work, we used pyrolysis to treat teabag waste (TBW). Changes in the pyrolysis temperature affected the composition and yield of the products. For example, more non-condensable gases and less char were produced with an increase in the pyrolysis temperature. Pyrolysis conducted under a nitrogen environment yielded caprolactam at temperatures between 400 and 700 °C. An increase in the pyrolysis temperature from 400 to 500 °C increased the caprolactam yield from 3.1 to 6.2 wt.%. At 700 °C, the yield decreased to 4.6 wt.%. The highest caprolactam yield (i.e., 6.2 wt.% at 500 °C) was equivalent to 59.2 wt.% on the basis of the weight of the non-biomass part of the TBW. The pyrolytic products other than caprolactam (e.g., combustible gases, pyrolytic liquid, and char) can function as fuels to supply energy during pyrolysis in order to increase and maintain the temperature. The higher heating values (HHVs) of the combustible gases and pyrolytic liquid produced at 500 °C were 7.7 and 8.3 MJ kg−1, respectively. The HHV of the char produced at 500 °C was 23 MJ kg−1, which is comparable to the HHV of coal. This work will help to develop effective pyrolysis processes to valorize everyday waste by recovering value-added chemicals such as polymer monomers and by producing alternative fuels.
Structure and Functions of Cocoons Constructed by Eri Silkworm
Authors: Zhou Bin , Wang Huiling
Published: November 2020

Eri silkworm cocoons (E cocoons) are natural composite biopolymers formed by continuous twin silk filaments (fibroin) bonded by sericin. As a kind of wild species, E cocoons have characteristics different from those of Bombyx mori cocoons (B cocoons). E cocoons have an obvious multilayer (5–9 layers) structure with an eclosion hole at one end and several air gaps between the layers, which can be classified into three categories—cocoon coat, cocoon layer, and cocoon lining—with varying performance indexes. There is a significant secondary fracture phenomenon during the tensile process, which is attributed to the high modulus of the cocoon lining and its dense structure. Air gaps provide cocoons with distinct multistage moisture transmission processes, which form a good moisture buffer effect. Temperature change inside cocoons is evidently slower than that outside, which indicates that cocoons also have an obvious temperature damping capability. The eclosion hole does not have much effect on heat preservation of E cocoons. The high sericin content of the cocoon coat, as well as the excellent ultraviolet absorption and antimicrobial abilities of sericin, allows E cocoons to effectively prevent ultraviolet rays and microorganisms from invading pupae. The ultraviolet protection factor (UPF) of the E cocoon before and after degumming were found to be 17.8% and 9.7%, respectively, which were higher than those of the B cocoon (15.3% and 4.4%, respectively), indicating that sericin has a great impact on anti-UV performance. In the cocoon structure, the outer layer of the cocoon has 50% higher content than the inner layer, and the E cocoon shows stronger protection ability than the B cocoon. Understanding the relationship between the structure, property, and function of E cocoons will provide bioinspiration and methods for designing new composites.
A Review of Wood Biomass-Based Fatty Acids and Rosin Acids Use in Polymeric Materials
Authors: Vevere Laima , Fridrihsone Anda , Kirpluks Mikelis , Cabulis Ugis
Published: November 2020

In recent decades, vegetable oils as a potential replacement for petrochemical materials have been extensively studied. Tall oil (crude tall oil, distilled tall oil, tall oil fatty acids, and rosin acids) is a good source to be turned into polymeric materials. Unlike vegetable oils, tall oil is considered as lignocellulosic plant biomass waste and is considered to be the second-generation raw material, thus it is not competing with the food and feed chain. The main purpose of this review article is to identify in what kind of polymeric materials wood biomass-based fatty acids and rosin acids have been applied and their impact on the properties.
Investigations of the Optical and Thermal Properties of the Pyrazoloquinoline Derivatives and Their Application for OLED Design
Authors: Lewińska Gabriela , Khachatryan Karen , Danel Krzysztof S. , Danel Zoriana , Sanetra Jerzy , Marszałek Konstanty W.
Published: November 2020

In this study, the photo-optical properties of the series of new 1H-pyrazolo[3,4-b]quinoline derivatives were investigated. Pyrazoloquinoline studies were conducted to explain the electroluminescent effect in organic LEDs. Absorption and photoluminescence spectra for the materials under consideration were examined, and quantum chemical calculations were made. Differential scanning calorimetric and thermogravimetric measurements were carried out for the manufactured materials. The phase situation of the materials was determined, and glassy transitions were detected for three of the investigated materials. Degradation temperatures were obtained. Single-layer luminescent diodes based on the ITO/PEDOT:PSS/active layer/Al scheme were fabricated. Current–voltage and brightness–voltage characteristics of the diodes were determined, ignition voltage was calculated, and electroluminescence types were determined.
Preparation of a Cellulose Column for Enhancing the Sensing Efficiency of the Biocide 2-n-Octyl-4-Isothiazolin-3-One
Authors: Hong Seong Ho , Kang Sang Wook
Published: November 2020

In this study, a cellulose acetate (CA) membrane with pores generated by a water pressure treatment was investigated for its ability to serve as a pretreatment filter device for the detection of 2-n-octyl-4-isothiazolin-3-one (OIT). Pores were generated by applying a water pressure of 8 bar to a membrane manufactured using a CA-based polymer solution. The CA used for the manufacturing was an environment-friendly, low-cost and highly energy-efficient material. Furthermore, since the fabricated porous CA polymeric film possessed many hydrophilic functional groups, it could strongly bind hydrophilic substances while avoiding interaction with hydrophobic substances. OIT, which comprises a hydrophobic bond that forms weak bonds over time, can break down more easily than hydrophilic impurities. The different extents of interaction occurring between either the toxic fungicide OIT or the hydrophilic impurities and the CA film were determined by Fourier-transform infrared (FT-IR) spectroscopy. The physicochemical changes in the resulting membrane, which occurred when the pores were generated, were investigated through scanning electron microscopy (SEM) and thermogravimetric analysis (TGA).
Effect of pH on the Supramolecular Structure of Helicobacter pylori Urease by Molecular Dynamics Simulations
Authors: Barazorda-Ccahuana Haruna L. , Gómez Badhin , Mas Francesc , Madurga Sergio
Published: November 2020

The effect of pH on the supramolecular structure of Helicobacter pylori urease was studied by means of molecular dynamics simulations at seven different pHs. Appropriate urease charge distributions were calculated using a semi-grand canonical Monte Carlo (SGCMC) procedure that assigns each residue’s charge state depending on the assigned individual pKa obtained by PROPKA. The effect of pH on protein stability has been analyzed through root-mean-square deviation (RMSD), radius of gyration (RG), solvent-accessible surface area (SASA), hydrogen bonds (HB) and salt bridges (SB). Urease catalyses the hydrolysis of urea in 12 active sites that are covered by mobile regions that act like flaps. The mobility of these flaps is increased at acidic pHs. However, extreme acidic conditions cause urease to have the least number of stabilizing interactions. This initiates the process of denaturalization, wherein the four (αβ)3 subunits of the global structure ((αβ)3)4 of urease start to separate.
Quaternized Chitosan-Based Anion Exchange Membrane Composited with Quaternized Poly(vinylbenzyl chloride)/Polysulfone Blend
Authors: Nhung Le Thi Tuyet , Kim In Yea , Yoon Young Soo
Published: November 2020

An efficient and effective process for the production of high-performance anion exchange membranes (AEMs) is necessary for the commercial application of fuel cells. Therefore, in this study, quaternized poly vinylbenzyl chloride (QVBC) and polysulfone were composited with glycidyltrimethylammonium-chloride-quaternized chitosan (QCS) at different ratios (viz., 1 wt %, 5 wt %, and 10 wt %). The structure and morphology of the membranes were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy, respectively. Further, the water uptake, swelling ratio, and ionic conductivities of the composite membrane at different wt % of QCS were evaluated. The membrane with 5% QCS exhibited an ionic conductivity of 49.6 mS/cm and 130 mS/cm at 25 °C and 70 °C, respectively.
An Overview of Additive Manufacturing of Polymers and Associated Composites
Authors: Nath Shukantu Dev , Nilufar Sabrina
Published: November 2020

Additive manufacturing is rapidly evolving and opening new possibilities for many industries. This article gives an overview of the current status of additive manufacturing with polymers and polymer composites. Various types of reinforcements in polymers and architectured cellular material printing including the auxetic metamaterials and the triply periodic minimal surface structures are discussed. Finally, applications, current challenges, and future directions are highlighted here.