bluuebunny/crossref_metadata_2025 huggingface dataset:
Confocal Raman Micro-Spectroscopy for Discrimination of Glycerol Diffusivity in Ex Vivo Porcine Dura Mater
Authors: Jaafar Ali , Darvin Maxim E. , Tuchin Valery V. , Veres Miklós
Published: October 2022

Dura mater (DM) is a connective tissue with dense collagen, which is a protective membrane surrounding the human brain. The optical clearing (OC) method was used to make DM more transparent, thereby allowing to increase in-depth investigation by confocal Raman micro-spectroscopy and estimate the diffusivity of 50% glycerol and water migration. Glycerol concentration was obtained, and the diffusion coefficient was calculated, which ranged from 9.6 × 10−6 to 3.0 × 10−5 cm2/s. Collagen-related Raman band intensities were significantly increased for all depths from 50 to 200 µm after treatment. In addition, the changes in water content during OC showed that 50% glycerol induces tissue dehydration. Weakly and strongly bound water types were found to be most concentrated, playing a major role in the glycerol-induced water flux and OC. Results show that OC is an efficient method for controlling the DM optical properties, thereby enhancing the in-depth probing for laser therapy and diagnostics of the brain. DM is a comparable to various collagen-containing tissues and organs, such as sclera of eyes and skin dermis.
Herbal Cannabis Use Is Not Associated with Changes in Levels of Endocannabinoids and Metabolic Profile Alterations among Older Adults
Authors: Abuhasira Ran , Azar Shahar , Nemirovski Alina , Tam Joseph , Novack Victor
Published: October 2022

Activation of the endocannabinoid system has various cardiovascular and metabolic expressions, including increased lipogenesis, decreased blood pressure, increased heart rate, and changes in cholesterol levels. There is a scarcity of data on the metabolic effects of exogenous cannabis in older adults; therefore, we aimed to assess the effect of exogenous cannabis on endocannabinoid levels and the association with changes in 24 h ambulatory blood pressure and lipid levels. We conducted a prospective study of patients aged 60 years or more with hypertension treated with a new prescription of herbal cannabis. We assessed changes in endocannabinoids, blood pressure, and metabolic parameters prior to and following three months of cannabis use. Fifteen patients with a mean age of 69.47 ± 5.83 years (53.3% male) underwent complete evaluations. Changes in 2-arachidonoylglycerol, an endocannabinoid, were significantly positively correlated with changes in triglycerides. Changes in arachidonic acid levels were significantly positively correlated with changes in C-reactive protein and with changes in mean diastolic blood pressure. Exogenous consumption of cannabidiol was negatively correlated with endogenous levels of palmitoylethanolamide and oleoylethanolamide. On average, cannabis treatment for 3 months does not result in a significant change in the levels of endogenous cannabinoids and thus has a safe metabolic risk profile.
Bile Microbiome in Patients with Recurrent Common Bile Duct Stones and Correlation with the Duodenal Microbiome
Authors: Lee Jungnam , Park Jin-Seok , Bae Jaewoong , Lee Sohee , Hwang Yeonju
Published: October 2022

Background: Common bile duct (CBD) stone recurrence is a common late adverse event after CBD stone treatment. In this preliminary study, we compared the bile fluid and duodenum microbial profiles of patients with or without recurrent CBD stones to identify risk factors associated with recurrence. Methods: Bile fluid samples of 47 consecutive patients who underwent ERCP for biliary diseases were subjected to microbiome analysis. Nineteen patients were stone-recurrent (SR), and 28 patients were non-stone-recurrent (NSR). Paired samples (duodenum biopsy tissue and bile fluid samples) from five SR patients were used to compare microbiome compositions in the biliary system and duodenum. In addition, we compared the microbiome compositions of these duodenal tissue samples with those 12 controls (gastric ulcer patients without recurrent CBD stones). Results: Enterococcaceae_unclassified and enterococcus were more abundant in bile fluid in the SR group than in the NSR group (p = 0.002 and p = 0.003, respectively). A comparison of the microbiome compositions of duodenum tissue and bile fluid samples of the five recurrent CBD stone patients revealed proteobacteria compositions were almost identical from the phylum to genus level. In these five patients, alpha and beta diversities were no different in bile fluid and duodenal tissues. Furthermore, a comparison of the microbiome compositions of duodenal mucosa in patients with recurrent CBD stone patients (n = 5) and controls (n = 12) revealed significant differences between microbiome compositions. Conclusions: Enterococcus seems to contribute to CBD stone development. Furthermore, our results indicate that retrograde migration of the duodenal microbiome may contribute to bile microbiome alterations. We recommend that more research be conducted to confirm this hypothesis.
Migration and Transformation of Arsenic in Rice and Soil under Different Nitrogen Sources in Polymetallic Sulfide Mining Areas
Authors: Yao Shuhua , Yang Dan , Zhang Xuexia , Shi Lei , Zhang Xiaoxia
Published: October 2022

Nitrogen (N) fertilizer affects the migration and transformation of arsenic (As) in soil and rice. We conducted pot experiments and studied the effects of 0.1, 0.2, and 0.4 g∙kg−1 N levels of NH4Cl, (NH4)2SO4, and NH4NO3 fertilizers on the As bioavailability in the As-contaminated inter-rhizosphere soil and As accumulation in the rice organs. The results showed that the concentration of bioavailable As in the rice rhizosphere soil was significantly negatively correlated with pH under the 0.4 g∙kg−1 N level of each fertilizer. At the same N level, while the As concentration was maturity stage > tillering stage in rice stems and leaves treated with NH4Cl and (NH4)2SO4, it was the opposite in roots. This suggests that the transfer of As from roots to stems and leaves mainly occurs in the late stage of rice growth under the condition of only NH4+-N fertilizer applying. The As concentration in rice aboveground organ (grains and stems–leaves) decreased with the increasing N application under the same N fertilizer treatment condition during the mature stage. In addition, the As concentration in rice grains treated with (NH4)2SO4 was the lowest. This result indicated that SO42− and NH4+-N had a significant synergistic inhibition on the As accumulation in rice grains. It was concluded that appropriate (NH4)2SO4 levels for As-contaminated paddy soils with high sulfur (S) contents would obtain rice grains with inorganic As concentrations below 0.2 mg·kg−1.
Novel PCR-Based Multiplex Assays for Detecting Major Quality and Biotic Stress in Commercial and Weedy Rice
Authors: Mohd Hanafiah Noraikim , Cheng Acga , Lim Phaik-Eem , Sethuraman Gomathy , Mohd Zain Nurul Amalina , Baisakh Niranjan , Mispan Muhamad Shakirin
Published: October 2022

While previous research has demonstrated that multiplex polymerase chain reaction (PCR) can be a cost-effective approach to detect various genes in crops, the availability of multiplex assays to simultaneously screen both grain quality and biotic stress resistance traits in rice (Oryza sativa) is limited. In this work, we report six novel multiplex assays that use a universal protocol to detect major rice grain quality (amylose content and fragrance) and biotic stress (blast, sheath blight, and bacterial leaf blight) traits with amplified products consisting of up to four primer pairs that can be analyzed using a standard agarose-based gel electrophoresis system. Recent studies have suggested that weedy rice has novel sources of disease resistance. However, an intensive screening of weedy biotypes has not been reported in Malaysia. Accordingly, we employed one of the developed multiplex assays to screen reported genes or quantitative trait loci (QTLs) associated with blast, sheath blight, and bacterial leaf blight diseases in 100 weedy rice biotypes collected from five local fields, with phenotyping performed to validate the genotyping results. In conclusion, our universal multiplex protocol is effective for the large-scale genotyping of rice genetic resources, and it can be employed in routine molecular laboratories with limited resources.
EVs-miRNA: The New Molecular Markers for Chronic Respiratory Diseases
Authors: Soccio Piera , Moriondo Giorgia , Lacedonia Donato , Tondo Pasquale , Quarato Carla Maria Irene , Foschino Barbaro Maria Pia , Scioscia Giulia
Published: October 2022

Idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD), asthma and sleep disorders are chronic respiratory diseases that affect the airways, compromising lung function over time. These diseases affect hundreds of millions of people around the world and their frequency seems to be increasing every year. Extracellular vesicles (EVs) are small-sized vesicles released by every cell in the body. They are present in most body fluids and contain various biomolecules including proteins, lipids, mRNA and non-coding RNA (micro-RNA). The EVs can release their cargo, specifically micro-RNAs (miRNAs), to both neighboring and/or distal cells, playing a fundamental role in cell–cell communication. Recent studies have shown their possible role in the pathogenesis of various chronic respiratory diseases. The expression of miRNAs and, in particular, of miRNAs contained within the extracellular vesicles seems to be a good starting point in order to identify new potential biomarkers of disease, allowing a non-invasive clinical diagnosis. In this review we summarize some studies, present in the literature, about the functions of extracellular vesicles and miRNAs contained in extracellular vesicles in chronic respiratory diseases and we discuss the potential clinical applications of EVs and EVs-miRNAs for their possible use such as future biomarkers.
Seaweed-Derived Phenolic Compounds in Growth Promotion and Stress Alleviation in Plants
Authors: Aina Omolola , Bakare Olalekan Olanrewaju , Daniel Augustine Innalegwu , Gokul Arun , Beukes Denzil R. , Fadaka Adewale Oluwaseun , Keyster Marshall , Klein Ashwil
Published: October 2022

Abiotic and biotic stress factors negatively influence the growth, yield, and nutritional value of economically important food and feed crops. These climate-change-induced stress factors, together with the ever-growing human population, compromise sustainable food security for all consumers across the world. Agrochemicals are widely used to increase crop yield by improving plant growth and enhancing their tolerance to stress factors; however, there has been a shift towards natural compounds in recent years due to the detrimental effect associated with these agrochemicals on crops and the ecosystem. In view of these, the use of phenolic biostimulants as opposed to artificial fertilizers has gained significant momentum in crop production. Seaweeds are marine organisms and excellent sources of natural phenolic compounds that are useful for downstream agricultural applications such as promoting plant growth and improving resilience against various stress conditions. In this review, we highlight the different phenolic compounds present in seaweed, compare their extraction methods, and describe their downstream applications in agriculture.
Wound Infections in Adult Patients after Berlin Heart® EXCOR Biventricular Assist Device Implantation
Authors: Kremer Jamila , El-Dor Abbas , Rivinius Rasmus , Schlegel Philipp , Sommer Wiebke , Warnecke Gregor , Karck Matthias , Ruhparwar Arjang , Meyer Anna L.
Published: October 2022

The Berlin Heart® EXCOR is a paracorporeal, pulsatile ventricular assist device used in patients of all age groups. However, adolescent and adult patients on EXCOR support are scarcely explored. Herein, we present a detailed description of infectious complications in this patient cohort. From 2006 to 2020, 58 patients received a biventricular assist device (BiVAD) at our institution and were included in this study. Postoperative infections were assessed after BiVAD implantation and subsequent heart transplantation (HTx). A Berlin Heart® EXCOR BiVAD was implanted as a bridge to transplantation in 58 patients (12–64 years). Most patients were INTERMACS I, and their median age was 49 years. Wound infections (WI) specific to the ventricular assist device (VAD) occurred in 31 (53.4%) patients with a mean time of 113 ± 155 days after BiVAD implantation. HTx was performed in 30 (51.7%) patients and thereof 10 (33.3%) patients developed at least one WI post-HTx. The mean time of WI after HTx was 17 ± 14 days. In four cases, WIs were caused by the same pathogen as before HTx. According to our institutional BiVAD wound classification, the mean wound score was 3. The VAD-specific wound infections were manageable and did not increase mortality nor precluded HTx in Berlin Heart® EXCOR patients. No specific risk factors for VAD-specific wound infections could be identified.
Computed Tomography Angiography (CTA) in Selected Scenarios with Risk of Possible False-Positive or False-Negative Conclusions in Diagnosing Brain Death
Authors: Schwarz Gerhard , Errath Maximilian , Argüelles Delgado Placido , Wießpeiner Ulrike , Voit-Augustin Henrika , Grims Robert , Kaltenböck Friedrich , Kober Eva Maria , Schöpfer Andreas , Fuchs Gottfried
Published: October 2022

It is widely accepted that brain death (BD) is a diagnosis based on clinical examination. However, false-positive and false-negative evaluation results may be serious limitations. Ancillary tests are used when there is uncertainty about the reliability of the neurologic examination. Computed tomography angiography (CTA) is an ancillary test that tends to have the lowest false-positive rates. However, there are various influencing factors that can have an unfavorable effect on the validity of the examination method. There are inconsistent protocols regarding the evaluation criteria such as scoring systems. Among the most widely used different scoring systems the 4-point CTA-scoring system has been accepted as the most reliable method. Appropriate timing and/or Doppler pre-testing could reduce the number of possible premature examinations and increase the sensitivity of CTA in diagnosing cerebral circulatory arrest (CCA). In some cases of inconclusive CTA, the whole brain computed tomography perfusion (CTP) could be a crucial adjunct. Due to the increasing significance of CTA/CTP in determining BD, the methodology (including benefits and limitations) should also be conveyed via innovative electronic training tools, such as the BRAINDEXweb teaching tool based on an expert system.
The Interplay between Anti-Angiogenics and Immunotherapy in Colorectal Cancer
Authors: Maiorano Brigida Anna , Parisi Alessandro , Maiello Evaristo , Ciardiello Davide
Published: October 2022

Angiogenesis, a hallmark of cancer, plays a fundamental role in colorectal cancer (CRC). Anti-angiogenic drugs and chemotherapy represent a standard of care for treating metastatic disease. Immune checkpoint inhibitors (ICIs) have changed the therapeutic algorithm of many solid tumors. However, the efficacy of ICIs is limited to mCRC patients carrying microsatellite instability (MSI-H), which represent approximately 3–5% of mCRC. Emerging evidence suggests that anti-angiogenic drugs could exhibit immunomodulatory properties. Thus, there is a strong rationale for combining anti-angiogenics and ICIs to improve efficacy in the metastatic setting. Our review summarizes the pre-clinical and clinical evidence regarding the combination of anti-angiogenics and ICIs in mCRC to deepen the possible application in daily clinical practice.
Protein Hydrolysates from Brewing By-Products as Natural Alternatives to ACE-Inhibitory Drugs for Hypertension Management
Authors: Ribeiro-Oliveira Rita , Martins Zita E. , Faria Miguel Ângelo , Sousa Joana Beatriz , Ferreira Isabel M. P. L. V. O. , Diniz Carmen
Published: October 2022

The treatment of hypertension is of major importance to reduce the risk of cardiovascular disease, the leading cause of death worldwide. Angiotensin-converting enzyme (ACE) inhibitors are anti-hypertensive drugs associated with several side effects. Natural products, namely bioactive peptides from brewing by-products, brewers’ spent grain (BSG), and yeast (BSY), are promising alternatives since they can inhibit ACE in vitro. However, the oral intake of these peptides may modify their expected inhibitory effect owing to possible changes in active peptides’ bioavailability, which have not been assessed so far. The goal of this study was to simulate oral administration to evaluate BSG/BSY peptides’ effectiveness by submitting protein hydrolysates sequentially to simulated gastrointestinal digestion, intestinal absorption (Caco-2 cells), and liver metabolism (HepG2 cells). MTT assay was used to assess BSG/BSY protein hydrolysates safeness. The ACE-inhibitory potential of initial and final protein hydrolysates (BSY, BSG, and a new product, MIX) were tested using a fluorometric assay and compared with captopril (1 µM, an ACE-inhibitory drug). Simulation of oral administration greatly increased BSY and MIX protein hydrolysates’ ACE-inhibitory capacity, though final MIX and BSG revealed greater ACE-inhibitory potential than captopril. Notwithstanding, all final protein hydrolysates presented ACE-inhibitory capacity, thus being promising compounds to manage hypertension.
Ischemic Heart Disease in the Context of Different Comorbidities
Authors: Costache Irina-Iuliana , Mihai Bogdan-Mircea , Badescu Minerva Codruta
Published: October 2022

Ischemic heart disease (IHD) is a leading cause of morbidity and mortality worldwide [...]
Higher Expressions of SHH and AR Are Associated with a Positive Receptor Status and Have Impact on Survival in a Cohort of Croatian Breast Cancer Patients
Authors: Budimir Ivan , Tomasović-Lončarić Čedna , Kralik Kristina , Čonkaš Josipa , Eljuga Domagoj , Žic Rado , Gorjanc Božo , Tucaković Hrvoje , Caktaš Doroteja , Jaman Josip , Lisek Valentino , Vlajčić Zlatko , Martić Krešimir , Ozretić Petar
Published: October 2022

Breast cancers (BC) are usually classified into four molecular subtypes according to the expression of estrogen (ER), progesterone (PR), and human epidermal growth factor 2 (HER2) receptors and proliferation marker Ki-67. Despite available anti-hormonal therapies and due to the inherent propensity of some subtypes to develop metastasis, there is a permanent need to discover new prognostic and predictive biomarkers, as well as therapeutic targets for BC. In this study, we used immunohistochemical staining to determine the expression of androgen receptor (AR) and sonic hedgehog protein (SHH), the main ligand of the Hedgehog-GLI (HH-GLI) signaling pathway, in 185 archival primary BC tissue samples and correlated it with clinicopathological characteristics, molecular subtypes, receptors statuses, and survival in a cohort of Croatian BC patients. Results showed that higher SHH and AR expressions were associated with positive receptor status, but increased SHH expression had a negative impact on survival in receptor-negative BCs. On the contrary, higher AR expression was mostly protective. However, multivariate analysis showed that only higher AR expression could be considered as an independent prognostic biomarker for poorer overall survival in triple-negative breast cancer patients (TNBC) (HR 10.9, 95% CI 1.43–83.67; p = 0.021), what could be Croatian population-related. SHH could be a potential target for treating TNBCs and HER2-enriched BCs, in cases where HH-GLI signaling is canonical (SHH-dependent).
The Impact of Myocardial Bridging on the Coronary Functional Test in Patients with Ischaemia with Non-Obstructive Coronary Artery Disease
Authors: Teragawa Hiroki , Oshita Chikage , Uchimura Yuko
Published: October 2022

Background: The possibility of myocardial bridging (MB) causing chest pain has been widely reported; however, the effect of MB on coronary microvessels has not been thoroughly investigated. Therefore, this study evaluated the effects of MB on epicardial coronary artery and coronary microvascular function during coronary angiography (CAG) and coronary function test (CFT) in patients with ischaemia with non-obstructive coronary artery disease (INOCA). Methods: This study included 62 patients with INOCA who underwent CAG and CFT for the left anterior descending coronary artery (LAD) to evaluate chest pain. In the CFT, acetylcholine was first administered intracoronarily in a stepwise manner, followed by chest symptoms, electrocardiographic ST-T changes and CAG. Positive coronary spasm was defined as coronary vasoconstriction of >90% on CAG accompanied by chest symptoms or electrocardiographic ST-T changes. After nitroglycerin administration, CAG was performed to assess MB, which was defined as systolic narrowing of the coronary artery diameter by >20% compared with that in diastole. Coronary flow reserve (CFR) and index of microcirculatory resistance (IMR) were subsequently obtained via transvenous adenosine triphosphate infusion using a pressure wire. Coronary microvascular vasodilatory dysfunction (CMD) was defined as a CFR of <2.0 or an IMR of ≥25 units. Results: Of the 62 patients, 15 (24%) had MB. The patients’ characteristics did not differ between the two groups. Regarding the CAG and CFT results, the presence of coronary spasm in the LAD was higher in the MB (+) group (87%) than in the MB (−) group (53%, p = 0.02), whereas the values of CFR (MB (+): 2.7 ± 1.4, MB (−): 2.8 ± 1.1) and IMR (MB (+): 26.9 ± 1.0, MB (−): 30.0 ± 17.3) and the presence of CMD (MB (+): 53%, MB (−): 60%) were similar in the two groups. Conclusions: The findings suggest that MB predisposes patients with INOCA to coronary spasms. Conversely, MBs may have a limited effect on microvessels, particularly in such patients.
Acquisition of Dual Ribozyme-Functions in Nonfunctional Short Hairpin RNAs through Kissing-Loop Interactions
Authors: Mutsuro-Aoki Hiromi , Tamura Koji
Published: October 2022

The acquisition of functions via the elongation of nucleotides is an important factor in the development of the RNA world. In our previous study, we found that the introduction of complementary seven-membered kissing loops into inactive R3C ligase ribozymes revived their ligation activity. In this study, we applied the kissing complex formation-induced rearrangement of RNAs to two nonfunctional RNAs by introducing complementary seven-membered loops into each of them. By combining these two forms of RNAs, the ligase activity (derived from the R3C ligase ribozyme) as well as cleavage activity (derived from the hammerhead ribozyme) was obtained. Thus, effective RNA evolution toward the formation of a life system may require the achievement of “multiple” functions via kissing-loop interactions, as indicated in this study. Our results point toward the versatility of kissing-loop interactions in the evolution of RNA, i.e., two small nonfunctional RNAs can gain dual functions via a kissing-loop interaction.
The Role of Systems Biology in Deciphering Asthma Heterogeneity
Authors: Hachim Mahmood Yaseen , Alqutami Fatma , Hachim Ibrahim Yaseen , Heialy Saba Al , Busch Hauke , Hamoudi Rifat , Hamid Qutayba
Published: October 2022

Asthma is one of the most common and lifelong and chronic inflammatory diseases characterized by inflammation, bronchial hyperresponsiveness, and airway obstruction episodes. It is a heterogeneous disease of varying and overlapping phenotypes with many confounding factors playing a role in disease susceptibility and management. Such multifactorial disorders will benefit from using systems biology as a strategy to elucidate molecular insights from complex, quantitative, massive clinical, and biological data that will help to understand the underlying disease mechanism, early detection, and treatment planning. Systems biology is an approach that uses the comprehensive understanding of living systems through bioinformatics, mathematical, and computational techniques to model diverse high-throughput molecular, cellular, and the physiologic profiling of healthy and diseased populations to define biological processes. The use of systems biology has helped understand and enrich our knowledge of asthma heterogeneity and molecular basis; however, such methods have their limitations. The translational benefits of these studies are few, and it is recommended to reanalyze the different studies and omics in conjugation with one another which may help understand the reasons for this variation and help overcome the limitations of understanding the heterogeneity in asthma pathology. In this review, we aim to show the different factors that play a role in asthma heterogeneity and how systems biology may aid in understanding and deciphering the molecular basis of asthma.
Estimating Equivalent Alkane Carbon Number Using Abraham Solute Parameters
Authors: Acree William E. , Chong Wei-Khiong , Lang Andrew S.I.D. , Mozafari Hamed
Published: October 2022

The use of equivalent alkane carbon numbers (EACN) to characterize oils is important in surfactant-oil-water (SOW) systems. However, the measurement of EACN values is non-trivial and thus it becomes desirable to predict EACN values from structure. In this work, we present a simple linear model that can be used to estimate the EACN value of oils with known Abraham solute parameters. We used linear regression with leave-one-out cross validation on a dataset of N = 80 oils with known Abraham solute parameters to derive a general model that can reliably estimate EACN values based upon the Abraham solute parameters: E (the measured liquid or gas molar refraction at 20 °C minus that of a hypothetical alkane of identical volume), S (dipolarity/polarizability), A (hydrogen bond acidity), B (hydrogen bond basicity), and V (McGowan characteristic volume) with good accuracy within the chemical space studied (N = 80, R2 = 0.92, RMSE = 1.16, MAE = 0.90, p < 2.2 × 10−16). These parameters are consistent with those in other models found in the literature and are available for a wide range of compounds.
Student-Centered Curriculum Design and Evaluation in Logistics Management
Authors: Fayezi Sajad
Published: October 2022

Background: In this essay, we address an important issue in the logistics education discourse relating to student-centered curriculum design and evaluation. Methods: We adopt an integrative approach based on conceptual development and guided by constructive alignment. Results: We apply and elaborate our conceptual framework using a case of a teaching plan in logistics management. We also propose an evaluation strategy for our teaching plan in the form of a template. Conclusions: Our essay contributes to the logistics education discourse by using learning theories and developing curriculum design and evaluation guidelines that can be replicated by other educators.
Thermal Characteristics of a Vertical Hydrostatic Guideway System for Precision Milling Machine Applications
Authors: Huang Hua-Chih , Yang Wen-Hao
Published: October 2022

This paper investigates the thermal characteristics of a vertical guideway system for precision milling machine applications by considering three heat sources, namely motor heat, viscous shearing heat of hydrostatic bearings, and friction heat from a ballscrew nut. A finite element (FE) model using ANSYS/Fluent was used to simulate the thermal characteristics of the system by considering the oil film friction of the hydrostatic bearings in the operational feed speed and heat generation in the ballscrew nut. Eight K-type thermocouples were installed in the vertical hydrostatic guideway system to measure the temperature rise in the key components. Nine thermal experiments of the vertical hydrostatic guideway system under three operational feed rates, namely 1.25, 2.5 and 5 m/min were conducted to measure the temperature of seven thermocouples in practical running conditions. The experimental temperature data then was used to adjust the FE model setting to guarantee the accurate prediction of the thermal deformation in real operational conditions. The FE model of the vertical hydrostatic guideway system built in this study can be used to predict the thermal deformation of worktable at center point at any running conditions. At a sliding feed rate of 1 m/s, the thermal positioning error of worktable at center point was 0.1539 µm in the X direction, 0.0009 µm in the Y direction and 2.0246 µm in Z direction.
Cavitation Morphology Study between Hemispherical Textured Rotating Friction Pairs
Authors: Sun Junyu , Chen Liyu , Zhang Bing , Huang Hua , Qian Pengfei
Published: October 2022

A non-direct contact rotary interface uses a viscous fluid as the lubricant working medium. Because the oil film friction coefficient formed is extremely small, so it has great application potential in sealing, fluid transmission, thermosolutal convection, and bionics. Research on mechanical seals, wet clutches, and dynamic load bearing have proven that micro-textures can effectively improve friction and lubrication performance. However, when the fluid flows through the texture boundary, pressure disturbances can induce hydrodynamic cavitation. A pair of rotating disks are selected as our research objects. From the simulation and experiment research, we found that cavitation volume does not always increase with an increase in the texture rate, and cavitation always occurs preferentially at the outer diameter, so it is necessary to avoid machining the texture structure at the outer diameter of the mechanical seal end. Once the conditions for cavitation are met, a complete cavity is formed in approximately 0.015 s. The study also verifies that the cavitation gas originates from the phase change of the oil.
Spontaneous Enantiomeric Resolution of 1,3-Diols from the Naphtylidene Derivative of 2,4-Pentanedione
Authors: Alvarez-Ricardo Yair , Sánchez-López Dylan , Meza-Morales William , Obregón-Mendoza Marco A. , Arenaza-Corona Antonino , Germán-Acacio Juan M. , Toscano Rubén A. , Zermeño-Ortega Miriam R. , Morales-Morales David , Enríquez Raúl G.
Published: October 2022

Enantiomers (2S, 4S)- and (2R, 4R)-3-(naphthalene-1-ylmethyl) pentane-2,4-diols were synthesized by the reduction of (Z)-4-hydroxy-3-(naphthalene-1-ylmethyl) pent-3-en-2-one with NaBH4 in methanol (MeOH). Crystallization in dichloromethane of this racemic mixture led to simple crystals with a crystalline habit with similar morphologies; however, in a group of them, it was possible to find a barely observable difference that allowed determining a crystal structure for each of the enantiomers, the 2S,4S, and the 2R,4R.
Synthesis and Pharmacological Evaluation of (+)-Usnic Acid Derivatives as Hypoglycemic Agents
Authors: Borisov Sergey A. , Luzina Olga A. , Khvostov Mikhail V. , Tolstikova Tatiana G. , Salakhutdinov Nariman F.
Published: October 2022

Usnic acid is produced by lichens and exhibits different biological properties, including hypoglycemic ones. However, this effect becomes noticeable only at relatively high doses, something that may lead to some adverse effects. The chemical modification of the molecule is able to enhance its safety profile and its hypoglycemic properties. We synthesized six enamine derivatives of (+)-usnic acid, and two of them are novel. All compounds were evaluated for the hypoglycemic effect after oral introduction in mice with alloxan-induced diabetes mellitus at a dose of 50 mg/kg. The derivative containing a 4-trifluoromethylphenyl fragment showed the most pronounced hypoglycemic effect, which was detected starting from sixth day of the experiment. Also, OGTT was performed in mice without alteration of glucose metabolism (C57BL/6), which showed no hypoglycemic effect after oral introduction of all studied compounds.
3-Methyl 5-{3-[(4-Methylbenzenesulfonyl)oxy]propyl} 4-(2,3-Dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate
Authors: Borgarelli Carlotta , Lenaers Stijn , De Borggraeve Wim M. , Ismalaj Ermal
Published: October 2022

The 1,4-dihydropyridine is a ubiquitous scaffold employed not only in medicinal chemistry but also in organic synthesis, given its ability to act as a hydrogen transfer reagent, thus emulating NAD(P)H reducing agents. In this work, we describe the synthesis of 3-methyl 5-{3-[(4-methylbenzenesulfonyl)oxy]propyl} 4-(2,3-dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate as scaffold, which enables downstream derivatization towards new 1,4-dihydropyridine molecules. Inspired by the literature, a new two-step synthesis was planned that involved: (i) synthesis of a silylated 1,4-dihydropyridine derivative and (ii) deprotection and tosylation in one step using tosyl fluoride.
Microstructural Origin of the High-Energy Storage Performance in Epitaxial Lead-Free Ba(Zr0.2Ti0.8)O3 Thick Films
Authors: Ouyang Jun , Wang Xianke , Shao Changtao , Cheng Hongbo , Zhu Hanfei , Ren Yuhang
Published: October 2022

In our previous work, epitaxial Ba(Zr0.2Ti0.8)O3 thick films (~1–2 μm) showed an excellent energy storage performance with a large recyclable energy density (~58 J/cc) and a high energy efficiency (~92%), which was attributed to a nanoscale entangled heterophase polydomain structure. Here, we propose a detailed analysis of the structure–property relationship in these film materials, using an annealing process to illustrate the effect of nanodomain entanglement on the energy storage performance. It is revealed that an annealing-induced stress relaxation led to the segregation of the nanodomains (via detailed XRD analyses), and a degraded energy storage performance (via polarization-electric field analysis). These results confirm that a nanophase entanglement is an origin of the high-energy storage performance in the Ba(Zr0.2Ti0.8)O3 thick films.
Reaction Mechanism of CA6, Al2O3 and CA6-Al2O3 Refractories with Refining Slag
Authors: Liu Jie , Liu Zheng , Feng Jisheng , Li Bin , Chen Junhong , Ren Bo , Jia Yuanping , Yin Shu
Published: October 2022

In this study, to clarify the corrosion mechanism of CA6 based refractory by refining slag, the static crucible tests for CA6, CA6-Al2O3, and Al2O3 refractory, were carried out and the detail reaction processes were analyzed from the perspective of thermodynamic simulation and structural evolution. From the results, CaAl4O7 plays a vital role in the slag corrosion resistance of the three refractories. Regarding CA6 refractory, the double pyramid module in CA6 crystal structure was destroyed very quickly, leading to the rapid collapse of its structure to form the denser CaAl4O7 in high amounts. As a result, a reaction layer mainly composed of CaAl4O7 formed, which effectively inhibited the slag corrosion, so CA6 refractory exhibits the most excellent slag corrosion. Meanwhile, the formation of CaAl4O7 can also avoid CA6 particles entering the molten steel to introduce exogenous inclusions. For Al2O3 refractory, the generation of CaAl4O7 is much slower than that of CA6 and CA6-Al2O3 refractory, and the amount generated is also quite small, resulting in its worst slag corrosion among the three crucibles. Therefore, CA6 based refractory has excellent application potential in ladle refining and clean steel smelting.
Technological Optimization of the Stirrup Casting Process with the Use of Computer Simulations
Authors: Małysza Marcin , Żuczek Robert , Wilk-Kołodziejczyk Dorota , Jaśkowiec Krzysztof , Głowacki Mirosław , Długosz Piotr , Dudek Piotr
Published: October 2022

The article presents the optimization of high-pressure die casting process technology for equestrian stirrups with the application of computer simulation. In the initial stage, the output technology was analyzed, and on the basis of a series of virtual experiments the cause of defects in the casting was highlighted. The optimization process includes different designs of a gating system. Additionally, the casting application properties were evaluated in an exploitation simulation, taking into account predicted defects resulting from the casting and solidification process. Based on the conducted analyses, technological changes were made to the casting technology design allowing the defects occurring in the original technological concept to be removed.
Simulation and Mechanical Properties of Fine-Grained Heat-Affected Zone Microstructure in 18CrNiMo7-6 Steel
Authors: Vuherer Tomaž , Smaili Fidan , Bjelajac Edvard , Manjgo Mirza , Lojen Gorazd
Published: October 2022

Heat-affected zones (HAZs) in real welds are usually quite narrow, and consequently most standard mechanical tests are difficult or even impossible. Therefore, simulated microstructures are often used for mechanical tests. However, the most often used weld thermal cycle simulator produces only a few millimeters wide area of simulated microstructure in the middle of specimens. Consequently, these kind of simulated specimen are not suitable for standard tensile tests, and even for Charpy impact tests, the simulated area can be too narrow. Therefore, to investigate the mechanical properties of a fine-grain heat-affected zone in 18CrNiMo7-6 steel, two methods were used for simulation of as-welded microstructures: (a) a weld thermal cycle simulator, and (b) as an alternative, though not yet verified option, austenitizing in a laboratory furnace + water quenching. The microstructures were compared and mechanical properties investigated. The grain sizes of the simulated specimens were 10.9 μm (water-quenched) and 12.6 μm (simulator), whereby the deviations from the real weld were less than 10%. Both types of simulated specimen were used for hardness measurement, Charpy impact tests, and fatigue tests. Water-quenched specimens were large enough to enable standard tensile testing. A hardness of 425 HV, yield strength Rp02 = 1121 MPa, tensile strength Rm = 1475 MPa, impact energy KV = 73.11 J, and crack propagation threshold ΔKthR = 4.33 MPa m0.5 were obtained with the water quenched specimens, and 419 HV, KV = 101.49 J, and ΔKthR = 3.4 MPa m0.5 with the specimens prepared with the simulator. Comparison of the results confirmed that the annealed and quenched specimens were suitable for mechanical tests of FG HAZs, even for standard tensile tests. Due to the use of simulated test specimens, the mechanical properties determined can be linked to the FG HAZ microstructure in 18CrNiMo7-6 steel.
Eddy Current Testing of Artificial Defects in 316L Stainless Steel Samples Made by Additive Manufacturing Technology
Authors: Geľatko Matúš , Hatala Michal , Botko František , Vandžura Radoslav , Hajnyš Jiří
Published: October 2022

Additive manufacturing has many positives, but its incorporation into functional parts production is restricted by the presence of defects. Eddy current testing provides solutions for their identification; however, some methodology and measurement standards for AM (additive manufacturing) products are still missing. The main purpose of the experiment described within this article was to check the ability of eddy current testing to identify AM stainless steel parts and to examine the data obtained by eddy currents variation under the influence of various types of designed artificial defects. Experimental samples were designed and prepared with SLM (selective laser melting) technology. Artificial defects, included in the samples, were detected using the eddy current testing device, taking the important circumstances of this non-destructive method into account. The presented research shows significant potential for eddy current testing to identify defects in AM products, with a resolution of various types and sizes of defects. The obtained data output shows the importance of choosing the right measurement regime, excitation frequency and secondary parameters setup. Besides the eddy current testing conditions, defect properties also play a significant role, such as their shape, size, if they are filled with unmolten powder or if they reach the surface.
Reaching Visible Light Photocatalysts with Pt Nanoparticles Supported in TiO2-CeO2
Authors: Mejia-Estrella Ixchel Alejandra , Pérez Larios Alejandro , Sulbarán-Rangel Belkis , Guzmán González Carlos Alberto
Published: October 2022

Nanostructured catalysts of platinum (Pt) supported on commercial TiO2, as well as TiO2-CeO2 (1, 5 and 10 wt% CeO2), were synthesized through the Sol-Gel and impregnation method doped to 1 wt% of Platinum, in order to obtain a viable photocatalytic material able to oxidate organic pollutants under the visible light spectrum. The materials were characterized by different spectroscopy and surface techniques such as Specific surface area (BET), X-ray photoelectron spectroscopy (XPS), XRD, and TEM. The results showed an increase in the diameter of the pore as well as the superficial area of the supports as a function of the CeO2 content. TEM images showed Pt nanoparticles ranking from 2–7 nm, a decrease in the particle size due to the increase of CeO2. The XPS showed oxidized Pt2+ and reduced Pt0 species; also, the relative abundance of the elements Ce3+/Ce4− and Ti4+ on the catalysts. Additionally, a shift in the Eg band gap energy (3.02–2.82 eV) was observed by UV–vis, proving the facticity of applying these materials in a photocatalytic reaction using visible light. Finally, all the synthesized materials were tested on their photocatalytic oxidation activity on a herbicide used worldwide; 2,4-Dichlorophenoxyacetic acid, frequently use in the agriculture in the state of Jalisco. The kinetics activity of each material was measured during 6 h of reaction at UV–Vis 190–400 nm, reaching a removal efficiency of 98% of the initial concentration of the pollutant in 6 h, compared to 32% using unmodified TiO2 in 6 h.
Tuning the Porosity of Piezoelectric Zinc Oxide Thin Films Obtained from Molecular Layer-Deposited “Zincones”
Authors: Kräuter Marianne , Abu Ali Taher , Stadlober Barbara , Resel Roland , Unger Katrin , Coclite Anna Maria
Published: October 2022

Porous zinc oxide (ZnO) thin films were synthesized via the calcination of molecular layer-deposited (MLD) “zincone” layers. The effect of the MLD process temperature (110 °C, 125 °C) and of the calcination temperature (340 °C, 400 °C, 500 °C) on the chemical, morphological, and crystallographic properties of the resulting ZnO was thoroughly investigated. Spectroscopic ellipsometry reveals that the thickness of the calcinated layers depends on the MLD temperature, resulting in 38–43% and 52–56% of remaining thickness for the 110 °C and 125 °C samples, respectively. Ellipsometric porosimetry shows that the open porosity of the ZnO thin films depends on the calcination temperature as well as on the MLD process temperature. The maximum open porosity of ZnO derived from zincone deposited at 110 °C ranges from 14.5% to 24%, rising with increasing calcination temperature. Compared with the 110 °C samples, the ZnO obtained from 125 °C zincone yields a higher porosity for low calcination temperatures, namely 18% for calcination at 340 °C; and up to 24% for calcination at 500 °C. Additionally, the porous ZnO thin films were subjected to piezoelectric measurements. The piezoelectric coefficient, d33, was determined to be 2.8 pC/N, demonstrating the potential of the porous ZnO as an, e.g., piezoelectric sensor or energy harvester.
Analysis of the Influence of Waste Seashell as Modified Materials on Asphalt Pavement Performance
Authors: Fan Guopeng , Liu Honglin , Liu Chaochao , Xue Yanhua , Ju Zihao , Ding Sha , Zhang Yuling , Li Yuanbo
Published: October 2022

An increasing amount of waste seashells in China has caused serious environmental pollution and resource waste. This paper aims to solve these problems by using waste seashells as modified materials to prepare high-performance modified asphalt. In this study, seashell powder (SP) and stratum corneum-exfoliated seashell powder (SCESP) were adopted to prepare 10%, 20% and 30% of seashell powder-modified asphalt (SPMA) and stratum corneum-exfoliated seashell powder-modified asphalt (SCESPMA) by the high-speed shear apparatus, respectively. The appearance and composition of two kinds of SPs were observed and determined by the scanning electron microscope (SEM). The types of functional groups, temperature frequency characteristics, low temperature performance and adhesion of SPMA were tested by the Fourier-transform infrared (FTIR) spectrometer, dynamic shear rheometer (DSR), bending beam rheometer (BBR) and contact angle meter. The results show that the SP and SCESP are rough and porous, and their main component is CaCO3, which is physically miscible to asphalt. When the loading frequency ranges from 0.1 Hz to 10 Hz, the complex shear modulus (G*) and phase angle (δ) of SPMA and SCESPMA increase and decrease, respectively. At the same load frequency, SCESPMA has a larger G* and a smaller δ than SPMA. At the same temperature, SCESPMA has a larger rutting factor (G*/sin δ) and better high-temperature deformation resistance than SPMA. SP and SCESP reduce the low-temperature cracking resistance of asphalt, of which SCESP has a more adverse effect on the low-temperature performance of asphalt than SP. When SP and SCESP are mixed with asphalt, the cohesion work (Waa), adhesion work (Was) and comprehensive evaluation parameters of water stability (ER1, ER2 and ER3) of asphalt are improved. It is shown that both SP and SCESP have good water damage resistance, of which SCESP has better water damage resistance than SP. These research results have important reference value for the application of waste biological materials in asphalt pavement.
Effect of Ta Interlayers on Texture and Magnetic Properties of FeSi Films with Micrometer Thickness
Authors: He Jialian , Zhang Zhong , Bao Zhihao , Sun Guangai , Li Xinxi , Qiu Xuepeng , Wang Shiqiang , Wang Zhanshan , Huang Qiushi , Yi Shengzhen
Published: October 2022

Magnetized soft ferromagnetic films with micrometer thickness were studied. A FeSi film, with a total thickness of 2000 nm, separated by 10 nm-thick Ta interlayers, was fabricated using the direct-current magnetron sputtering technique. The thickness of each FeSi layer between adjacent Ta layers was 100 nm. Hysteresis loop measurement was used to characterize the magnetic properties of the layer. X-ray diffraction patterns and high-resolution transmission electron microscopy were used to characterize its texture. The experimental results showed that the FeSi film separated by Ta interlayers exhibited a lower saturation magnetization and a higher coercivity than those of the 1140 nm-thick FeSi film. The insertion of Ta interlayers resulted in the disappearance of the crystal plane of FeSi (221), and better texture of the crystal plane of FeSi (210). The FeSi film exhibited a crystal plane of FeSi (210) with a bcc crystalline structure. The Ta interlayers were partially amorphous, exhibiting crystal plane of Ta (002) and TaSi2 (310). The matching of magnetic properties between interlayers and soft magnetic layers played an important role in maintaining its soft magnetic properties.