bluuebunny/crossref_metadata_2025 huggingface dataset:
FMRP Interacts with RARα in Synaptic Retinoic Acid Signaling and Homeostatic Synaptic Plasticity
Authors: Park Esther , Lau Anthony G. , Arendt Kristin L. , Chen Lu
Published: June 2021

The fragile X syndrome (FXS) is an X-chromosome-linked neurodevelopmental disorder with severe intellectual disability caused by inactivation of the fragile X mental retardation 1 (FMR1) gene and subsequent loss of the fragile X mental retardation protein (FMRP). Among the various types of abnormal synaptic function and synaptic plasticity phenotypes reported in FXS animal models, defective synaptic retinoic acid (RA) signaling and subsequent defective homeostatic plasticity have emerged as a major synaptic dysfunction. However, the mechanism underlying the defective synaptic RA signaling in the absence of FMRP is unknown. Here, we show that RARα, the RA receptor critically involved in synaptic RA signaling, directly interacts with FMRP. This interaction is enhanced in the presence of RA. Blocking the interaction between FMRP and RARα with a small peptide corresponding to the critical binding site in RARα abolishes RA-induced increases in excitatory synaptic transmission, recapitulating the phenotype seen in the Fmr1 knockout mouse. Taken together, these data suggest that not only are functional FMRP and RARα necessary for RA-dependent homeostatic synaptic plasticity, but that the interaction between these two proteins is essential for proper transcription-independent RA signaling. Our results may provide further mechanistic understanding into FXS synaptic pathophysiology.
Genome-Wide Identification, Diversification, and Expression Analysis of Lectin Receptor-Like Kinase (LecRLK) Gene Family in Cucumber under Biotic Stress
Authors: Haider Muhammad Salman , De Britto Savitha , Nagaraj Geetha , Gurulingaiah Bhavya , Shekhar Ravikant , Ito Shin-ichi , Jogaiah Sudisha
Published: June 2021

Members of the lectin receptor-like kinase (LecRLKs) family play a vital role in innate plant immunity. Few members of the LecRLKs family have been characterized in rice and Arabidopsis, respectively. However, little literature is available about LecRLKs and their role against fungal infection in cucumber. In this study, 60 putative cucumber LecRLK (CsLecRLK) proteins were identified using genome-wide analysis and further characterized into L-type LecRLKs (24) and G-type LecRLKs (36) based on domain composition and phylogenetic analysis. These proteins were allocated to seven cucumber chromosomes and found to be involved in the expansion of the CsLecRLK gene family. Subcellular localization of CsaLecRLK9 and CsaLecRLK12 showed green fluorescence signals in the plasma membrane of leaves. The transcriptional profiling of CsLecRLK genes showed that L-type LecRLKs exhibited functional redundancy as compared to G-type LecRLKs. The qRT-PCR results indicated that both L- and G-type LecRLKs showed significant response against plant growth-promoting fungi (PGPF-Trichoderma harzianum Rifai), powdery mildew pathogen (PPM—Golovinomyces orontii (Castagne) V.P. Heluta), and combined (PGPF+PPM) treatments. The findings of this study contribute to a better understanding of the role of cucumber CsLecRLK genes in response to PGPF, PPM, and PGPF+PPM treatments and lay the basis for the characterization of this important functional gene family.
Complement Components C3 and C4 Indicate Vasculitis Manifestations to Distinct Renal Compartments in ANCA-Associated Glomerulonephritis
Authors: Hakroush Samy , Tampe Désirée , Korsten Peter , Ströbel Philipp , Tampe Björn
Published: June 2021

Acute kidney injury (AKI) is a common and severe complication of antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) causing progressive chronic kidney disease (CKD), end-stage renal disease (ESRD) or death. Pathogenic ANCAs, in particular proteinase 3 (PR3) and myeloperoxidase (MPO), trigger a deleterious immune response resulting in pauci-immune necrotizing and crescentic glomerulonephritis (GN), a common manifestation of glomerular injury in AAV. However, there is growing evidence that activation of the complement pathway contributes to the pathogenesis and progression of AAV. We here aimed to compare glomerular and tubulointerstitial lesions in ANCA GN and extrarenal manifestation of AAV in association with levels of circulating complement components C3c and C4. Methods: Plasma levels of C3c and C4 in a total number of 53 kidney biopsies with ANCA GN were retrospectively included between 2015 and 2020. Glomerular and tubulointerstitial lesions were evaluated according to established scoring systems for ANCA GN and analogous to the Banff classification. Results: We here show that circulating levels of C3c and C4 in ANCA GN were comparable to the majority of other renal pathologies. Furthermore, hypocomplementemia was only detectable in a minor subset of ANCA GN and not correlated with renal or extrarenal AAV manifestations. However, low levels of circulating C3c correlated with AKI severity in ANCA GN independent of systemic disease activity or extrarenal AAV manifestation. By systematic scoring of glomerular and tubulointerstitial lesions, we provide evidence that low levels of circulating C3c and C4 correlated with vasculitis manifestations to distinct renal compartments in ANCA GN. Conclusions: We here expand our current knowledge about distinct complement components in association with vasculitis manifestations to different renal compartments in ANCA GN. While low levels of C4 correlated with glomerulitis, our observation that low levels of circulating complement component C3c is associated with interstitial vasculitis manifestation reflected by intimal arteritis implicates that C3c contributes to tubulointerstitial injury in ANCA GN.
The Transplantation Resistance of Type II Diabetes Mellitus Adipose-Derived Stem Cells Is Due to G6PC and IGF1 Genes Related to the FoxO Signaling Pathway
Authors: Horiguchi Michiko , Turudome Yuya , Ushijima Kentaro
Published: June 2021

In cases of patients with rapidly progressive diabetes mellitus (DM), autologous stem cell transplantation is considered as one of the regenerative treatments. However, whether the effects of autonomous stem cell transplantation on DM patients are equivalent to transplantation of stem cells derived from healthy persons is unclear. This study revealed that adipose-derived mesenchymal stem cells (ADSC) derived from type II DM patients had lower transplantation efficiency, proliferation potency, and stemness than those derived from healthy persons, leading to a tendency to induce apoptotic cell death. To address this issue, we conducted a cyclopedic mRNA analysis using a next-generation sequencer and identified G6PC3 and IGF1, genes related to the FoxO signaling pathway, as the genes responsible for lower performance. Moreover, it was demonstrated that the lower transplantation efficiency of ADSCs derived from type II DM patients might be improved by knocking down both G6PC3 and IGF1 genes. This study clarified the difference in transplantation efficiency between ADSCs derived from type II DM patients and those derived from healthy persons and the genes responsible for the lower performance of the former. These results can provide a new strategy for stabilizing the quality of stem cells and improving the therapeutic effects of regenerative treatments on autonomous stem cell transplantation in patients with DM.
Natural Polyphenols as Modulators of Etoposide Anti-Cancer Activity
Authors: Kluska Magdalena , Woźniak Katarzyna
Published: June 2021

Polyphenols are naturally occurring compounds found in abundance in fruits and vegetables. Their health-promoting properties and their use in the prevention and treatment of many human diseases, including cancer, have been known for years. Many anti-cancer drugs are derived from these natural compounds. Etoposide, which is a semi-synthetic derivative of podophyllotoxin, a non-alkaloid lignan isolated from the dried roots and rhizomes of Podophyllum peltatum or Podophyllum emodi (Berberidaceae), is an example of such a compound. In this review, we present data on the effects of polyphenols on the anti-cancer activity of etoposide in in vitro and in vivo studies.
THE MAIN CYTOTOXIC EFFECTS OF METHYLSELENINIC ACID ON VARIOUS CANCER CELLS
Authors: Varlamova Elena G. , Turovsky Egor A.
Published: June 2021

Studies of recent decades have repeatedly demonstrated the cytotoxic effect of selenium-containing compounds on cancer cells of various origins. Particular attention in these studies is paid to methylseleninic acid, a widespread selenium-containing compound of organic nature, for several reasons: it has a selective cytotoxic effect on cancer cells, it is cytotoxic in small doses, it is able to generate methylselenol, excluding the action of the enzyme β-lyase. All these qualities make methylseleninic acid an attractive substrate for the production of anticancer drugs on its basis with a well-pronounced selective effect. However, the studies available to date indicate that there is no strictly specific molecular mechanism of its cytotoxic effect in relation to different cancer cell lines and cancer models. This review contains generalized information on the dose- and time-dependent regulation of the toxic effect of methylseleninic acid on the proliferative properties of a number of cancer cell lines. In addition, special attention in this review is paid to the influence of this selenium-containing compound on the regulation of endoplasmic reticulum stress and on the expression of seven selenoproteins, which are localized in the endoplasmic reticulum.
D-Amino Acid-Containing Lipopeptides Derived from the Lead Peptide BP100 with Activity against Plant Pathogens
Authors: Oliveras Àngel , Moll Luís , Riesco-Llach Gerard , Tolosa-Canudas Arnau , Gil-Caballero Sergio , Badosa Esther , Bonaterra Anna , Montesinos Emilio , Planas Marta , Feliu Lidia
Published: June 2021

From a previous collection of lipopeptides derived from BP100, we selected 18 sequences in order to improve their biological profile. In particular, analogues containing a D-amino acid at position 4 were designed, prepared, and tested against plant pathogenic bacteria and fungi. The biological activity of these sequences was compared with that of the corresponding parent lipopeptides with all L-amino acids. In addition, the influence of the length of the hydrophobic chain on the biological activity was evaluated. Interestingly, the incorporation of a D-amino acid into lipopeptides bearing a butanoyl or a hexanoyl chain led to less hemolytic sequences and, in general, that were as active or more active than the corresponding all L-lipopeptides. The best lipopeptides were BP475 and BP485, both incorporating a D-Phe at position 4 and a butanoyl group, with MIC values between 0.8 and 6.2 µM, low hemolysis (0 and 24% at 250 µM, respectively), and low phytotoxicity. Characterization by NMR of the secondary structure of BP475 revealed that the D-Phe at position 4 disrupts the α-helix and that residues 6 to 10 are able to fold in an α-helix. This secondary structure would be responsible for the high antimicrobial activity and low hemolysis of this lipopeptide.
Contribution of K2P Potassium Channels to Cardiac Physiology and Pathophysiology
Authors: Herrera-Pérez Salvador , Campos-Ríos Ana , Rueda-Ruzafa Lola , Lamas José Antonio
Published: June 2021

Years before the first two-pore domain potassium channel (K2P) was cloned, certain ion channels had already been demonstrated to be present in the heart with characteristics and properties usually attributed to the TREK channels (a subfamily of K2P channels). K2P channels were later detected in cardiac tissue by RT-PCR, although the distribution of the different K2P subfamilies in the heart seems to depend on the species analyzed. In order to collect relevant information in this regard, we focus here on the TWIK, TASK and TREK cardiac channels, their putative roles in cardiac physiology and their implication in coronary pathologies. Most of the RNA expression data and electrophysiological recordings available to date support the presence of these different K2P subfamilies in distinct cardiac cells. Likewise, we show how these channels may be involved in certain pathologies, such as atrial fibrillation, long QT syndrome and Brugada syndrome.
Natural Phytochemicals Derived from Gymnosperms in the Prevention and Treatment of Cancers
Authors: Ghaffari Tayyebeh , Hong Joo-Hyun , Asnaashari Solmaz , Farajnia Safar , Delazar Abbas , Hamishehkar Hamed , Kim Ki Hyun
Published: June 2021

The incidence of various types of cancer is increasing globally. To reduce the critical side effects of cancer chemotherapy, naturally derived compounds have been considered for cancer treatment. Gymnosperms are a group of plants found worldwide that have traditionally been used for therapeutic applications. Paclitaxel is a commercially available anticancer drug derived from gymnosperms. Other natural compounds with anticancer activities, such as pinostrobin and pinocembrin, are extracted from pine heartwood, and pycnogenol and enzogenol from pine bark. Gymnosperms have great potential for further study for the discovery of new anticancer compounds. This review aims to provide a rational understanding and the latest developments in potential anticancer compounds derived from gymnosperms.
Putative Cooperative ATP–DnaA Binding to Double-Stranded DnaA Box and Single-Stranded DnaA-Trio Motif upon Helicobacter pylori Replication Initiation Complex Assembly
Authors: Jaworski Pawel , Zyla-Uklejewicz Dorota , Nowaczyk-Cieszewska Malgorzata , Donczew Rafal , Mielke Thorsten , Weigel Christoph , Zawilak-Pawlik Anna
Published: June 2021

oriC is a region of the bacterial chromosome at which the initiator protein DnaA interacts with specific sequences, leading to DNA unwinding and the initiation of chromosome replication. The general architecture of oriCs is universal; however, the structure of oriC and the mode of orisome assembly differ in distantly related bacteria. In this work, we characterized oriC of Helicobacter pylori, which consists of two DnaA box clusters and a DNA unwinding element (DUE); the latter can be subdivided into a GC-rich region, a DnaA-trio and an AT-rich region. We show that the DnaA-trio submodule is crucial for DNA unwinding, possibly because it enables proper DnaA oligomerization on ssDNA. However, we also observed the reverse effect: DNA unwinding, enabling subsequent DnaA–ssDNA oligomer formation—stabilized DnaA binding to box ts1. This suggests the interplay between DnaA binding to ssDNA and dsDNA upon DNA unwinding. Further investigation of the ts1 DnaA box revealed that this box, together with the newly identified c-ATP DnaA box in oriC1, constitute a new class of ATP–DnaA boxes. Indeed, in vitro ATP–DnaA unwinds H. pylori oriC more efficiently than ADP–DnaA. Our results expand the understanding of H. pylori orisome formation, indicating another regulatory pathway of H. pylori orisome assembly.
Pancreatic Ductal Adenocarcinoma: Relating Biomechanics and Prognosis
Authors: MacCurtain Benjamin M. , Quirke Ned P. , Thorpe Stephen D. , Gallagher Tom K.
Published: June 2021

Pancreatic ductal adenocarcinoma (PDAC) is the most common form of pancreatic cancer and carries a dismal prognosis. Resectable patients are treated predominantly with surgery while borderline resectable patients may receive neoadjuvant treatment (NAT) to downstage their disease prior to possible resection. PDAC tissue is stiffer than healthy pancreas, and tissue stiffness is associated with cancer progression. Another feature of PDAC is increased tissue heterogeneity. We postulate that tumour stiffness and heterogeneity may be used alongside currently employed diagnostics to better predict prognosis and response to treatment. In this review we summarise the biomechanical changes observed in PDAC, explore the factors behind these changes and describe the clinical consequences. We identify methods available for assessing PDAC biomechanics ex vivo and in vivo, outlining the relative merits of each. Finally, we discuss the potential use of radiological imaging for prognostic use.
Role of Endoscopic Sinus Surgery and Dental Treatment in the Management of Odontogenic Sinusitis Due to Endodontic Disease and Oroantral Fistula
Authors: Gâta Anda , Toader Corneliu , Valean Dan , Trombitaș Veronica Elena , Albu Silviu
Published: June 2021

Background: Odontogenic sinusitis (ODS) is frequently encountered in ENT practice; however, there are no guidelines regarding its management. This study aims to analyse the results of endoscopic sinus surgery versus dental treatment in ODS. Additionally, we aim to demonstrate the benefit of associating endoscopic sinus surgery (ESS) to surgical closure of chronic oroantral fistulas (OAF) by comparing mean time to healing in patients who opted or not for concurrent ESS. Methods: Records of patients with ODS were reviewed. Group one consisted of patients with ODS caused by periapical pathology undergoing either endoscopic sinus surgery (ESS) or dental treatment. Resolution of ODS was considered treatment success and was compared between the two treatment strategies. Group two included patients with ODS and associated chronic oroantral communication. Time to healing was compared between patients undergoing OAF closure alone versus patients receiving associated ESS, using the Log-Rank test to correlate Kaplan–Meier curves. Results: 25 patients from a total of 45 in group one underwent dental treatment alone, and 20 opted for exclusive ESS treatment. The failure rate was 40% for patients treated with ESS compared to 4% (one patient) for dental treatment. ODS resolved in all patients in the second group, but the mean time to healing was half (10 days) when ESS was complementary to OAF closure. Conclusion: The present study represents the first estimator of the role ESS plays in OAF treatment. Nonetheless, it provides proof of the importance of first addressing dental problems in odontogenic sinusitis.
Realistic Advantages of Early Surgical Drain Removal after Pancreatoduodenectomy: A Single-Institution Retrospective Study
Authors: Yoon So-Jeong , Yoon So-Kyung , Jung Ji-Hye , Han In-Woong , Choi Dong-Wook , Heo Jin-Seok , Shin Sang-Hyun
Published: June 2021

The latest guidelines from the Enhanced Recovery After Surgery (ERAS®) Society stated that early drain removal after pancreatoduodenectomy (PD) is beneficial in decreasing complications including postoperative pancreatic fistulas (POPFs). This study aimed to ascertain the actual benefits of early drain removal after PD. The data of 450 patients who underwent PD between 2018 and 2020 were retrospectively reviewed. The surgical outcomes were compared between patients whose drains were removed within 3 postoperative days (early removal group) and after 5 days (late removal group). Logistic regression analysis was performed to identify the risk factors for clinically relevant POPFs (CR-POPFs). Among the patients with drain fluid amylase < 5000 IU on the first postoperative day, the early removal group had fewer complications and shorter hospital stays than the late removal group (30.9% vs. 54.5%, p < 0.001; 9.8 vs. 12.5 days, p = 0.030, respectively). The incidences of specific complications including CR-POPFs were comparable between the two groups. Risk factor analysis showed that early drain removal did not increase CR-POPFs (p = 0.163). Although early drain removal has not been identified as apparently beneficial, this study showed that it may contribute to an early return to normal life without increasing complications.
Hemoglobin A1c in Patients with Diabetes Predict Long-Term Mortality Following Coronary Artery Surgery
Authors: Abu Tailakh Muhammad , Ishay Shlomo-yaron , Awesat Jenan , Poupko Liat , Sahar Gidon , Novack Victor
Published: June 2021

Objective: to estimate the association between preoperative hemoglobin A1c (HbA1c) levels below and above 7%, and the rate of all-cause mortality (ACM) in diabetes mellitus (DM) patients after coronary artery bypass grafting (CABG) within a ten-year follow-up period. Methods: we collected data on patient HbA1c levels that were measured up to 3 months prior to isolated CABG in consecutive patients with DM, and analyzed the rates of ACM over a median of a 5.9-year post-operative period. Results: preoperative HbA1c levels were collected in 579 DM patients. The mean HbA1c was 8.0 ± 1.7%, where 206 (35.6%) patients had an HbA1c ≤ 7% and 373 (64.4%) had an HbA1c > 7%. During the follow-up period, mortality rates were 20.4% and 28.7% in the HbA1c ≤ 7% and HbA1c > 7% groups, respectively (Kaplan-Meier estimates, log-rank p = 0.01). Multivariable Cox proportional hazards regression, adjusted for age, gender, smoking status, chronic obstructive pulmonary disease, hypertension, chronic renal failure, old myocardial infarction, number of coronary artery bypass surgeries, and post-operative glycemic control, showed a hazard ratio of 2.67 for long-term ACM (p = 0.001) in patients with HbA1c > 7%. Conclusions: DM patients with high HbA1c levels prior to CABG are at higher risk for long-term complications, especially late ACM.
Body Mass Index and Birth Weight Improve Polygenic Risk Score for Type 2 Diabetes
Authors: Moldovan Avigail , Waldman Yedael Y. , Brandes Nadav , Linial Michal
Published: June 2021

One of the major challenges in the post-genomic era is elucidating the genetic basis of human diseases. In recent years, studies have shown that polygenic risk scores (PRS), based on aggregated information from millions of variants across the human genome, can estimate individual risk for common diseases. In practice, the current medical practice still predominantly relies on physiological and clinical indicators to assess personal disease risk. For example, caregivers mark individuals with high body mass index (BMI) as having an increased risk to develop type 2 diabetes (T2D). An important question is whether combining PRS with clinical metrics can increase the power of disease prediction in particular from early life. In this work we examined this question, focusing on T2D. We present here a sex-specific integrated approach that combines PRS with additional measurements and age to define a new risk score. We show that such approach combining adult BMI and PRS achieves considerably better prediction than each of the measures on unrelated Caucasians in the UK Biobank (UKB, n = 290,584). Likewise, integrating PRS with self-reports on birth weight (n = 172,239) and comparative body size at age ten (n = 287,203) also substantially enhance prediction as compared to each of its components. While the integration of PRS with BMI achieved better results as compared to the other measurements, the latter are early-life measurements that can be integrated already at childhood, to allow preemptive intervention for those at high risk to develop T2D. Our integrated approach can be easily generalized to other diseases, with the relevant early-life measurements.
Exploring the Drivers of Sentinel-2-Derived Crop Phenology: The Joint Role of Climate, Soil, and Land Use
Authors: Bajocco Sofia , Vanino Silvia , Bascietto Marco , Napoli Rosario
Published: June 2021

The exploration of crop seasonality across a region offers a way to help understand the phenological spatial patterns of complex landscapes, like agricultural ones. Knowing the role of environmental factors in influencing crop phenology patterns and processes is a key aspect for understanding the impact of climate and land use changes on agricultural landscape dynamics. We identified pixels with similar phenological behavior (i.e., pheno-clusters) and compared them to the land cover map of the study area to assess the role of the land management component in controlling the phenological patterns identified. Results demonstrated that soil texture is the most important factor for permanent crops, while large amount of rainfall and high values of available water content are the main drivers in spring cultivations (i.e., irrigated crops). Scarce water availability (in terms of soil texture, low annual precipitation and high minimum temperature) represented the main driving factor for non-irrigated crops, whose phenology is characterized by summer drought and fall-winter productivity. Compared to vegetation maps that use only land cover from a single season or period, using seasonality of the NDVI time series to classify the agricultural landscape provides different and more ecologically relevant information about croplands.
Exploring the Distribution of Gardens in Suzhou City in the Qianlong Period through a Space Syntax Approach
Authors: Yun Jiayan , Yu Wenbo , Wang Hao
Published: June 2021

This study explored the spatial distribution of Suzhou gardens in the Qianlong period (AD 1736–1796) through an innovative method combining spatial syntax and historical textual analysis. Through a spatial syntax approach, a street axis model analysis suggested that the greater the degree of integration and prosperity of a street, the denser the distribution of gardens surrounding it. A canal axis model analysis indicated that more gardens were built around canals that were less integrated and had less traffic. The accuracy and reliability of the axis model analysis results were validated using historical documents and images. The following was observed: (1) Gardens were densely distributed in the prosperous commercial areas at the northern and southern ends of Suzhou City. The more prosperous the location of a garden, the greater the influence on its popularity. (2) Gardens were concentrated in residential areas with booming businesses. (3) Large numbers of gardens were built along canals with poor traffic functions. Building gardens by diverting water into them reflected the complementary relationship between urban geographical characteristics and garden-building techniques. (4) Gardens promoted commercial development, and commerce drove the preservation and continuation of gardens. The findings revealed the complementary relationship between garden preservation and commercial development.
Comparison of Physiological Responses and Training Load between Different CrossFit® Workouts with Equalized Volume in Men and Women
Authors: Toledo Ronam , Dias Marcelo R. , Toledo Ramon , Erotides Renato , Pinto Daniel S. , Reis Victor M. , Novaes Jefferson S. , Vianna Jeferson M. , Heinrich Katie M.
Published: June 2021

The purpose of the present study was to compare the heart rate (HR), blood lactate and training load between different CrossFit® workouts, with equalized total work volumes in men and women. The study included 23 individuals (13 men and 10 women) experienced in CrossFit® training, who performed two workouts with different training types (as many reps as possible (AMRAP) and ‘for time’) but an equalized volume. Measurements of lactate, HR and rating of perceived exertion (RPE) were performed. The results show that there was no HR interaction between workout time and sex (p = 0.822; η2 = 0.006) and between workout type and sex (p = 0.064, η2 = 0.803). The HR significantly differed during each workout type (p < 0.001, η2 = 0.621), but not between the two workout types (p = 0.552, η2 = 0.017). Lactate showed no difference between the workout types (p = 0.474, η2 = 0.768), although the training load was higher (p = 0.033, η2 = 0.199) in women when they performed AMRAP. Altogether, the HR was not significantly different between training types or sex, while RPE, lactate and training load showed statistically significant differences depending on the group (women or men) or workout type (AMRAP or ‘for time’).
Numerical Investigation of Deposition Characteristics of PLA on an ABS Plate Using a Material Extrusion Process
Authors: Chua Bih-Lii , Baek Sun-Ho , Park Keun , Ahn Dong-Gyu
Published: June 2021

Three-dimensional prototypes and final products are commonly fabricated using the material extrusion (ME) process in additive manufacturing applications. However, these prototypes and products are limited to a single material using the ME process due to technical challenges. Deposition of plastic on another dissimilar plastic substrate requires proper control of printing temperature during an ME process due to differences in melting temperatures of dissimilar plastics. In this paper, deposition of PLA filament on an ABS substrate during an ME process is investigated using finite element analysis. A heat transfer finite element (FE) model for the extrusion process is proposed to estimate the parameters of the ME machine for the formulation of a heat flux model. The effects of printing temperature and the stand-off distance on temperature distributions are investigated using the proposed FE model for the extrusion process. The heat flux model is implemented in a proposed heat transfer FE model of single bead deposition of PLA on an ABS plate. From this FE model of deposition, temperature histories during the ME deposition process are estimated. The results of temperature histories are compared with experiments. Using the calibrated FE model, a proper heating temperature of ABS for deposition of PLA is evaluated.
Characterization of Burning Behaviors and Particulate Matter Emissions of Crop Straws Based on a Cone Calorimeter
Authors: Song Wei , He Yanrong , Wu Yuzhang , Qu Wei
Published: June 2021

Crop residue burning is one of the major sources of particulate matter (PM) in the air. The burning behaviors and PM emissions of the three typical crop residues (rice straw, wheat straw, corn straw) in China were characterized by a cone calorimeter (CONE) coupled with a laser dust meter. The water-soluble compounds, carbonaceous content, and morphology of PM were measured by ion chromatography, elemental analyzer, transmission electron microscopy (TEM) and energy-dispersive X-ray spectrometer (EDS). The results showed that thermal stability of corn straw was the worst among the three crop straws. The heat release rate (HRR) curves of the three crop straws were the typical curves of thermally thick charring (residue forming) samples. Wheat straw had the highest smoke yield, which was 2.9 times that of rice straw. The PM emission factor of wheat straw was 180.91 µg/g, which was about three times that of rice straw. The contents of K+, Na+, and Cl− in PM were significantly higher than those of the other six water-soluble inorganic ions. The ratio of organic carbon and elemental carbon (OC/EC) ranged from 14.82 to 30.82, which was similar to the results of open burning. There were mainly three kinds of aggregates in the PM of crop straws: network, chain-like, and soot. Individual particles were mixtures of KCl and organic matters. Core-shell structures were found in PM of rice straw and corn straw. The results in this study were provided based on CONE, an ISO-standard apparatus, which could avoid data conflicts caused by the difference of combustion devices. The relationship between the burning behavior and PM emission characteristics of crop straws was established, which is helpful to understand emissions of crop straws and to find a novel way to solve the problems from the burning of crop residues.
The Combined Use of Gentamicin and Silver Nitrate in Bone Cement for a Synergistic and Extended Antibiotic Action against Gram-Positive and Gram-Negative Bacteria
Authors: Jackson John , Lo Joey , Hsu Eric , Burt Helen M. , Shademani Ali , Lange Dirk
Published: June 2021

Using bone cement as a carrier, gentamicin was for years the default drug to locally treat orthopedic infections but has lost favor due to increasing bacterial resistance to this drug. The objective of this study was to investigate the effect of combining gentamicin with silver nitrate in bone cement against S. aureus and P. aeruginosa. Antibacterial effects (CFU counts) of gentamicin and silver were initially studied followed by studies using subtherapeutic concentrations of each in combination. The release rates from cement were measured over 10 days and day 7 release samples were saved and analyzed for antibiotic activity. A strong synergistic effect of combining silver with gentamicin was found using both dissolved drugs and using day 7 bone cement release media for both Gram-positive and Gram-negative bacteria. The cement studies were extended to vancomycin and tobramycin, which are also used in bone cement, and similar synergistic effects were found for day 7 release media with P. aeruginosa but not S. aureus. These studies conclude that the combined use of low loadings of gentamicin and silver nitrate in bone cement may offer an economical and much improved synergistic method of providing anti-infective orthopedic treatments in the clinic.
The Influence of Titanium Dioxide on Silicate-Based Glasses: An Evaluation of the Mechanical and Radiation Shielding Properties
Authors: Albarzan Badriah , Hanfi Mohamed Y. , Almuqrin Aljawhara H. , Sayyed M. I. , Alsafi Haneen M. , Mahmoud K. A.
Published: June 2021

The mechanical and radiation shielding features were reported for a quaternary Na2O-CaO-SiO2-TiO2 glass system used in radiation protection. The fundamentals of the Makishima–Mazinize model were applied to evaluate the elastic moduli of the glass samples. The elastic moduli, dissociation energy, and packing density increased as TiO2 increased. The glasses’ dissociation energy increased from 62.82 to 65.33 kJ/cm3, while the packing factor slightly increased between 12.97 and 13.00 as the TiO2 content increased. The MCNP-5 code was used to evaluate the gamma-ray shielding properties. The best linear attenuation coefficient was achieved for glass samples with a TiO2 content of 9 mol%: the coefficient decreased from 5.20 to 0.14 cm−1 as the photon energy increased from 0.015 to 15 MeV.
Capture of Fullerenes in Cages and Rings by Forming Metal-π Bond Arene Interactions
Authors: Rios Citlalli , Molina Bertha , Salcedo Roberto
Published: June 2021

Nowadays, the task of the selectively capture of fullerene molecules from soot is the subject of several studies. The low solubility of fullerenes represents a drawback when the goal is to purify them and to carry out chemical procedures where they participate. There are different molecules that can act as a kind of cocoon, giving shelter to the fullerene cages in such a way that they can be included in a solution or can be extracted from a mix. In this work, a theoretical study of some known and new proposed organic molecules of this kind is presented. In all cases, the interaction occurs with the help of a metallic atom or ion which plays the role of a bridge, providing a place for a metallocene like interaction to occur. The thermodynamic arguments favoring the formation of this adduct species are addressed as well as the nature of the bond by means QTAIM parameters and frontier molecular orbitals analysis.
A Study on Heat Storage and Dissipation Efficiency at Permeable Road Pavements
Authors: Yang Ching-Che , Siao Jun-Han , Yeh Wen-Cheng , Wang Yu-Min
Published: June 2021

The main contributing factor of the urban heat island (UHI) effect is caused by daytime heating. Traditional pavements in cities aggravate the UHI effect due to their heat storage and volumetric heat capacity. In order to alleviate UHI, this study aims to understand the heating and dissipating process of different types of permeable road pavements. The Ke Da Road in Pingtung County of Taiwan has a permeable pavement materials experiment zone with two different section configurations which were named as section I and section II for semi-permeable pavement and fully permeable pavement, respectively. The temperature sensors were installed during construction at the depths of the surface course (0 cm and 5 cm), base course (30 cm and 55 cm) and subgrade (70 cm) to monitor the temperature variations in the permeable road pavements. Hourly temperature and weather station data in January and June 2017 were collected for analysis. Based on these collected data, heat storage and dissipation efficiencies with respect to depth have been modelled by using multi regression for the two studied pavement types. It is found that the fully permeable pavement has higher heat storage and heat dissipation efficiencies than semi-permeable pavement in winter and summer monitoring period. By observing the regressed model, it is found that the slope of the model lines are almost flat after the depth of 30 cm. Thus, from the view point of UHI, one can conclude that the reasonable design depth of permeable road pavement could be 30 cm.
NBT-Pluronic F-127 Hydrogels Printed on Flat Textiles as UV Radiation Sensors
Authors: Sąsiadek Elżbieta , Jaszczak Malwina , Skwarek Joanna , Kozicki Marek
Published: June 2021

This work reports on the surface-modified woven fabrics for use as UV radiation sensors. The cotton and polyamide fabrics were printed with radiochromic hydrogels using a screen-printing method. The hydrogels used as a printing paste were composed of water, poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (Pluronic F-127) as a gel matrix and nitro blue tetrazolium chloride as a radiation-sensitive compound. The development of the hydrogels’ colour occurs after exposure to UV radiation and its intensity increases with increasing absorbed dose. The features of the NBT-Pluronic F-127 radiochromic hydrogels and the fabrics printed with the hydrogels were examined using UV-Vis and reflectance spectrophotometry as well as scanning electron microscopy (SEM). The effects of NBT concentration and UV radiation type (UVA, UVB, UVC) on dose responses of the hydrogels and printed fabrics were also examined. The results obtained reveal that the fabrics printed with NBT-Pluronic F-127 hydrogels can be potentially useful as UV radiation sensors.
Microbial Oligosaccharides with Biomedical Applications
Authors: Xu Jian-Lin , Liu Zhi-Feng , Zhang Xiao-Wei , Liu Hai-Li , Wang Yong
Published: June 2021

Microbial oligosaccharides have been regarded as one of the most appealing natural products attributable to their potent and selective bioactivities, such as antimicrobial activity, inhibition of α-glucosidases and lipase, interference of cellular recognition and signal transduction, and disruption of cell wall biosynthesis. Accordingly, a handful of bioactive oligosaccharides have been developed for the treatment of bacterial infections and type II diabetes mellitus. Given that naturally occurring oligosaccharides have increasingly gained recognition in recent years, a comprehensive review is needed. The current review highlights the chemical structures, biological activities and divergent biosynthetic origins of three subgroups of oligomers including the acarviosine-containing oligosaccharides, saccharomicins, and orthosomycins.
Comparison of Corrosion Resistance of the AA2524-T3 and the AA2024-T3
Authors: Queiroz Fernanda Martins , Terada Maysa , Bugarin Aline F. Santos , de Melo Hercílio Gomes , Costa Isolda
Published: June 2021

The 2XXX Al alloys are characterized by their superior mechanical properties resulting from alloying elements and precipitation hardening treatments. The AA2524-T3 alloy was developed to replace the AA2024-T3 alloy in the aerospace industry. However, both alloys present many intermetallic particles (IMCs) in their microstructure, and this is the main reason for their high susceptibility to localized corrosion (such as pitting and stress corrosion cracking). Despite the similarities between these alloys (e.g., chemical composition and type of intermetallics) the literature comparing their properties is scarce and focuses mainly on their mechanical properties, not their corrosion resistances. In this investigation, the corrosion resistance of the AA2524-T3 alloy was compared to the AA2024-T3 alloy. The microstructure of both alloys was analyzed by Scanning Electron Microscopy before and after immersion in the test electrolyte, and the number and area fraction of intermetallics of each alloy was determined. The corrosion resistance of both alloys was monitored as a function of exposure time by electrochemical impedance spectroscopy and the results were fitted using electrical equivalent circuits. The AA2524-T3 alloy presented not only higher impedance values but also less corroded areas than the AA2024-T3 alloy.
Determination of Critical Hydrogen Concentration and Its Effect on Mechanical Performance of 2200 MPa and 600 HBW Martensitic Ultra-High-Strength Steel
Authors: Fangnon Eric , Yagodzinskyy Yuriy , Malictki Evgenii , Mehtonen Saara , Virolainen Esa , Vilaça Pedro
Published: June 2021

The influence of hydrogen on the mechanical performance of a hot-rolled martensitic steel was studied by means of constant extension rate test (CERT) and constant load test (CLT) followed with thermal desorption spectroscopy measurements. The steel shows a reduction in tensile strength up to 25% of ultimate tensile strength (UTS) at critical hydrogen concentrations determined to be about 1.1 wt.ppm and 50% of UTS at hydrogen concentrations of 2 wt.ppm. No further strength degradation was observed up to hydrogen concentrations of 4.8 wt.ppm. It was observed that the interplay between local hydrogen concentrations and local stress states, accompanied with the presence of total average hydrogen reducing the general plasticity of the specimen are responsible for the observed strength degradation of the steel at the critical concentrations of hydrogen. Under CLT, the steel does not show sensitivity to hydrogen at applied loads below 50% of UTS under continuous electrochemical hydrogen charging up to 85 h. Hydrogen enhanced creep rates during constant load increased linearly with increasing hydrogen concentration in the steel.
Establishment of Babesia bovis In Vitro Culture Using Medium Free of Animal Products
Authors: Álvarez Martínez Jesús A. , Figueroa Millán Julio V. , Ueti Massaro W. , Rojas-Martínez Carmen
Published: June 2021

Babesia bovis, an etiological agent of bovine babesiosis, causes a significant burden to the cattle industry worldwide. The most efficient method to mitigate bovine babesiosis is a live vaccine produced by serial passage in splenectomized cattle. However, there are several concerns regarding live vaccine production, including variation between batches and the use of many animals. In this study, we report a B. bovis-SF strain continuously cultured in a medium free of components of animal origin enriched with a chemically defined lipid mixture (CD lipid mixture) and the use of a perfusion bioreactor to harvest a large amount of B. bovis. Six culture media were compared, including VP-SFM, CD-CHO, CD-Hydrolyzed, CD-CHO, SFM, and ADMEM/F12. We found that the VP-SFM medium performed the best for B. bovis growth, with a maximum percentage of parasitized erythrocytes (PPE) of 8.6%. The effect of six dilutions of a commercial mixture of CD lipids added to VP-SFM showed that the CD lipid mixture at a dilution of 1:100 had the best B. bovis growth curve, with a maximum PPE of 13.9%. Propagation of the in vitro B. bovis culture was scaled up in a perfusion bioreactor using VP-SFM with a CD lipid mixture, and the PPE reached over 32%. The continuous in vitro B. bovis culture in a medium free of animal origin components could potentially reduce and replace the use of animals to produce a reagent for diagnostics and live vaccines to control bovine babesiosis.
Genetic Characterization of Cryptosporidium cuniculus from Rabbits in Egypt
Authors: Naguib Doaa , Roellig Dawn M. , Arafat Nagah , Xiao Lihua
Published: June 2021

Rabbits are increasingly farmed in Egypt for meat. They are, however, known reservoirs of infectious pathogens. Currently, no information is available on the genetic characteristics of Cryptosporidium spp. in rabbits in Egypt. To understand the prevalence and genetic identity of Cryptosporidium spp. in these animals, 235 fecal samples were collected from rabbits of different ages on nine farms in El-Dakahlia, El-Gharbia, and Damietta Provinces, Egypt during the period from July 2015 to April 2016. PCR-RFLP analysis of the small subunit rRNA gene was used to detect and genotype Cryptosporidium spp. The overall detection rate was 11.9% (28/235). All 28 samples were identified as Cryptosporidium cuniculus. The 16 samples successfully subtyped by the sequence analysis of the partial 60 kDa glycoprotein gene belonged to two subtypes, VbA19 (n = 1) and VbA33 (n = 15). As C. cuniculus is increasingly recognized as a cause of human cryptosporidiosis, Cryptosporidium spp. in rabbits from Egypt have zoonotic potential.
Prevalence of Hepatitis E Virus Infection among Laboratory Rabbits in China
Authors: Wang Lin , Liang Chunnan , Li Xiaobo , Wang Ji , Fu Rui , Xing Jin , Shu Jingyi , Zhao Chenyan , Huang Weijin
Published: June 2021

Hepatitis E virus (HEV) is zoonotic and the leading cause of acute viral hepatitis worldwide. Rabbit HEV can infect humans and is prevalent globally. It is reported that laboratory rabbits are also naturally infected with HEV. Therefore, it is important to investigate in a large scale the prevalence of HEV in laboratory rabbits. Serum samples were collected from 649 laboratory rabbits of 13 different commercial vendors in Beijing, China, from 2017 to 2019, and anti-HEV and HEV antigen (Ag) were tested. Fecal samples were collected from 50 laboratory rabbits from one of the vendors for HEV RNA detection. Six laboratory rabbits with natural HEV infection were euthanized and their liver, kidney, bile and urine samples were collected for HEV RNA quantification. Liver tissues were subjected to histopathology analysis. The overall positive rates of anti-HEV antibodies and HEV-Ag are 2.6% (15/588) and 7.9% (51/649), respectively. HEV RNA was detected in 12.0% (6/50) of the rabbits. High viral load of HEV RNA was detected in liver and bile samples. Liver inflammation was observed. HEV is circulating in laboratory rabbit population in China. Strict screening is crucial to ensure experimental accuracy and prevent zoonotic transmission to research personnel.
Genetic Variability of Mineral Content in Different Grain Structures of Bean Cultivars from Mesoamerican and Andean Gene Pools
Authors: Zeffa Douglas Mariani , Nogueira Alison Fernando , Buratto Juliana Sawada , Oliveira Raquel Barboza Reis de , Neto José dos Santos , Moda-Cirino Vânia
Published: June 2021

Beans (Phaseolus vulgaris L.) are an important source of proteins, carbohydrates, and micronutrients in the diets of millions of people in Latin America and Africa. Studies related to genetic variability in the accumulation and distribution of nutrients are valuable for biofortification programs, as there is evidence that the seed coat and embryo differ in the bioavailability of essential nutrients. In this study, we sought to evaluate the genetic variability of total mineral content in the grain and its constituent parts (seed coat, cotyledon, and embryonic axis) of bean genotypes from Mesoamerican and Andean centers of origin. Grain samples of 10 bean cultivars were analyzed for the content of proteins and minerals (Mg, Ca, K, P, Mn, S, Cu, B, Fe, and Zn) in the whole grains and seed coat, cotyledons, and embryonic axis tissues. Genetic variability was observed among the cultivars for protein content and all evaluated minerals. Moreover, differential accumulation of minerals was observed in the seed coat, cotyledons, and embryonic axis. Except for Ca, which accumulated predominantly in the seed coat, higher percentages of minerals were detected in the cotyledons. Furthermore, 100-grain mass values showed negative correlations with the contents of Ca, Mg, P, Zn, Fe, and Mn in whole grains or in the different grain tissues. In general, the Mesoamerican cultivars showed a higher concentration of minerals in the grains, whereas Andean cultivars showed higher concentrations of protein.