bluuebunny/crossref_metadata_2025 huggingface dataset:
Control of an Omnidirectional UAV for Transportation and Manipulation Tasks
Authors: Nigro Michelangelo , Pierri Francesco , Caccavale Fabrizio
Published: November 2021

This paper presents a motion control scheme for a new concept of omnidirectional aerial vehicle for transportation and manipulation tasks. The considered aerial platform is a novel quadrotor with the capability of providing multi-directional thrust by adding an actuated gimbal mechanism in charge of modifying the orientation of the frame on which the four rotors are mounted. The above mechanical design, differently from other omnidirectional unmanned aerial vehicles (UAVs) with tilted propellers, avoids internal forces and energy dissipation due to non-parallel propellers’ axes. The proposed motion controller is based on a hierarchical two-loop scheme. The external loop computes the force to be applied to the vehicle and the reference values for the additional joints, while the inner loop computes the joint torques and the moment to be applied to the multirotor. In order to make the system robust with respect to the external loads, a compensation of contact forces is introduced by exploiting the estimate provided by a momentum based observer. The stability of the motion control scheme is proven via Lyapunov arguments. Finally, two simulation case studies prove the capability of the omnidirectional UAV platform to track a 6-DoFs trajectory both in free motion and during a task involving grasping and transportation of an unknown object.
Scalable Fog Computing Orchestration for Reliable Cloud Task Scheduling
Authors: Lim Jongbeom
Published: November 2021

As Internet of Things (IoT) and Industrial Internet of Things (IIoT) devices are becoming increasingly popular in the era of the Fourth Industrial Revolution, the orchestration and management of numerous fog devices encounter a scalability problem. In fog computing environments, to embrace various types of computation, cloud virtualization technology is widely used. With virtualization technology, IoT and IIoT tasks can be run on virtual machines or containers, which are able to migrate from one machine to another. However, efficient and scalable orchestration of migrations for mobile users and devices in fog computing environments is not an easy task. Naïve or unmanaged migrations may impinge on the reliability of cloud tasks. In this paper, we propose a scalable fog computing orchestration mechanism for reliable cloud task scheduling. The proposed scalable orchestration mechanism considers live migrations of virtual machines and containers for the edge servers to reduce both cloud task failures and suspended time when a device is disconnected due to mobility. The performance evaluation shows that our proposed fog computing orchestration is scalable while preserving the reliability of cloud tasks.
Response of Sex Steroid Hormone Synthesis Substrates in Serum and Testes of Male Tilapia (Oreochromis niloticus) Exposed to Methomyl and Its Recovery Pattern
Authors: Meng Shunlong , Chen Xi , Song Chao , Fan Limin , Qiu Liping , Hu Gengdong , Chen Jiazhang , Xu Pao
Published: November 2021

The response of synthetic substrates of sex steroid hormones—cholesterol (CHO), pregnenolone (PREG), and progesterone (PROG)—in the serum and testes of male tilapia (Oreochromis niloticus) to the environmental estrogen pesticide methomyl (0.2, 2, 20, and 200 μg·L−1) was evaluated using static-water contact toxicity tests. The results showed that low methomyl concentrations (0.2 and 2 μg·L−1) had no significant effects on the contents of CHO, PREG, and PROG in the serum and testes of male tilapia (p > 0.05). Consequently, the concentration of 2 μg·L−1 could be used as a preliminary reference threshold for the non-effective dose of methomyl in male tilapia. Exposure to high methomyl concentrations (20 and 200 μg·L−1) significantly inhibited the levels of CHO, PREG, and PROG in the serum and testes of male tilapia (p < 0.05) and showed a dose–response relationship. Sex steroid hormone synthesis substrate damage to male tilapia caused by less than 20 μg·L−1 methomyl was reversible, while the damage caused by equal to or greater than 200 μg·L−1 methomyl was irreversible when tilapia were transferred to methomyl-free water for 18 days. Thus, a concentration of 200 μg·L−1 could be used as a reference threshold for irreversible damage caused by methomyl in male tilapia.
Pressure Loss in Ducts by Dissipative Splitter Silencers: Comparative Study of Standardized, Numerical and Experimental Results
Authors: Chmielewski Bartosz , Herrero-Durá Iván , Nieradka Paweł
Published: November 2021

Dissipative splitter silencers are widely used in industry for the reduction of propagated sound waves in ducts. Even though these systems are effective from the acoustics point of view when they are properly designed, they also introduce a pressure loss in the system, due to the modification of the properties of the flow circulating inside the duct. This effect is not desired in some industrial applications, so it is necessary to be able to predict the pressure loss as precisely as possible to design silencers according to the needs. Nevertheless, the prediction made by standards are usually limited to given geometries or flow speed. In this work, we present a comparative study on the results obtained for the pressure loss by means of the standards ISO 14163 and VDI 1801-1, numerical simulations with the finite element method, and experimental measurements. Additionally, two different profile shapes and four input face velocities are tested in order to know the influence of these parameters in the variations of the flow and the accuracy of the prediction of the different methods.
Effect of Rotational Speed Variation on the Flow Characteristics in the Rotor-Stator System Cavity
Authors: Zhao Zhizhou , Song Wenwu , Jin Yongxin , Lu Jiaxing
Published: November 2021

In this paper, to study the effect of dynamic and static interference of clearance flow in fluid machinery caused by changes in rotational speed, the model was simplified to a rotor-stator system cavity flow. Investigating the flow characteristics in the cavity by changing the rotor speed of the rotor-stator system is of considerable significance. ANSYS-CFX was applied to numerically simulate the test model and the results were compared with the experimental results of the windage torque of the rotor-stator system. The inlet flow rate and geometric model remained unchanged. With an increase in the rotating Reynolds number, the shear stress on the rotor wall gradually increased, and the maximum gradient was within l* < 0.15. In addition to the shear stress, the tangential Reynolds stress Rrθ contributed partly to the torque on the rotor wall. The swirling vortex formed by entrainment in the cavity of the rotor-stator system tended to separate at ReΦ= 3.53 × 106. As the rotating Reynolds number continued to increase, the secondary vortex finally separated completely. The strength of the vortex in the rotor turbulent boundary layer decreased with an increase in the rotating speed, but the number of vortex cores increased with the increase of speed. Depending on the application of the fluid machine, controlling the rotating speed within a reasonable range can effectively improve the characteristics of the clearance flow.
Recombinant Human Erythropoietin Production in Chinese Hamster Ovary Cells Is Enhanced by Supplementation of α-Helix Domain of 30Kc19 Protein
Authors: Cha Hyeonjin , Park Ju-Hyun
Published: November 2021

The enhancement of recombinant therapeutic protein production in mammalian cell culture has been regarded as an important issue in the biopharmaceutical industry. Previous studies have reported that the addition of the recombinant 30Kc19 protein, a silkworm-derived plasma protein with simultaneous cell-penetrating and mitochondrial enzyme-stabilizing properties, can enhance the recombinant protein expression in Chinese hamster ovary (CHO) cell culture. Here, we produced an α-helix N-terminal domain of 30Kc19, called (30Kc19α), and investigated its effects on the production of human erythropoietin (EPO), a widely used therapeutic protein for the treatment of anemia, in recombinant CHO cell culture. Similar to the full-length 30Kc19, 30Kc19α was able to be mass-produced in a form of recombinant protein through an Escherichia coli expression system and delivered into EPO-producing CHO (EPO–CHO) cells. Supplementing the medium of EPO–CHO cell culture with 30Kc19α increased the intracellular NADPH/NADP+ ratio related to the flux of metabolic reducing power for protein biosynthesis, subsequently enhancing EPO production in serum-free culture. 30Kc19α is considered to have certain advantages in the downstream purification process of therapeutic protein production when it is used as a medium supplement due to its small size and low isoelectric point compared to the full-length 30Kc19. These results suggest that 30Kc19α has potential use for manufacturing biopharmaceutical proteins.
Improvement of the Method for Fixing a Punch in the Punch Holder
Authors: Semaan Melissa , Castex Victor , Ruiz Arramendy Eneko , Paredes Manuel
Published: November 2021

The punching process allows large quantities of parts to be produced at very low cost. This paper studies how the technique used for fixing a punch can be improved in order to increase productivity before punch fracture, which results in large numbers of parts failing to be produced, thus creating a significant shortfall. In this context, the study deals with an industrial case, specifically the manufacturing (metal sheeting and metal forming) of a connector made of stainless steel. A broken tool is first analyzed in order to identify the source of the premature breakage. Then, the tool and the process are modeled using finite element analysis (FEA) to act as a reference. Then, the improvements in the geometry and fixing method, intended to increase the tool lifespan, are assessed and modeled using FEA. Finally, the modified profile with only one central hole proves to be very efficient.
Design and Performance Evaluation of a Cherry Tomato Calyx Remover
Authors: Kim Yeongsu , Kang Seokho , Park Hyunggyu , Woo Seungmin , Uyeh Daniel Dooyum , Ha Yushin
Published: November 2021

A prototype for the remover of cherry tomato calyxes was designed and manufactured. The tap remover was designed and manufactured considering the conveyor transport speed, brush length and clearance, and diameter. These were adjusted in three levels to determine the optimal design factor. Performance tests were conducted using Icon 513, a circular-shaped cherry tomato variety, and Minimaru, a jujube-shaped cherry tomato variety. Conveyor transport speeds were set at 210, 280, and 350 mm/s; brush lengths at 70, 80, and 90 mm; brush clearances at 20, 22, and 24 mm; and brush diameters at 0.8, 1.0, and 1.2 mm. The two varieties showed a similar damage rate during calyx removal. However, Minimaru showed a higher calyx removal rate than Icon 513, indicating that it is most suitable for the calyx removal mechanization process.
Cellular Stress Responses of the Endemic Freshwater Fish Species Alburnus vistonicus Freyhof & Kottelat, 2007 in a Constantly Changing Environment
Authors: Tsakoumis Emmanouil , Tsoulia Thomais , Feidantsis Konstantinos , Mouchlianitis Foivos Alexandros , Berillis Panagiotis , Bobori Dimitra , Antonopoulou Efthimia
Published: November 2021

Herein we investigated the cellular responses of the endemic fish species Alburnus vistonicus Freyhof & Kottelat, 2007, under the variation of several physico-chemical parameters including temperature (°C), salinity (psu), dissolved oxygen (mg/L), pH and conductivity (μS/cm), which were measured in situ. Monthly fish samplings (October 2014–September 2015) were conducted in Vistonis Lake in northern Greece, a peculiar ecosystem with brackish waters in its southern part and high salinity fluctuations in its northern part. Fish gills and liver responses to the changes of the physico-chemical parameters were tested biochemically and histologically. Heat shock protein levels appeared to be correlated with salinity fluctuations, indicating the adaptation of A. vistonicus to the particular environment. The latter is also enhanced by increased Na+-K+ ATPase levels, in response to salinity increase during summer. The highest mitogen activated protein kinases phosphorylation levels were observed along with the maximum mean salinity values. A variety of histological lesions were also detected in the majority of the gill samples, without however securing salinity as the sole stress factor. A. vistonicus cellular stress responses are versatile and shifting according to the examined tissue, biomarker and season, in order for this species to adapt to its shifting habitat.
A Novel Integration Method for D Numbers Based on Horizontal Comparison
Authors: Hou Haiyang , Zhao Chunyu
Published: November 2021

D numbers theory is an extension of Dempster–Shafer evidence theory. It eliminates the constraints of mutual exclusion and completeness under the frame of discernment of Dempster–Shafer evidence theory, so it has been widely used to deal with uncertainty modelling, but if it cannot effectively deal with the problem of missing information, sometimes unreasonable conclusions will be drawn. This paper proposes a new type of integration representation of D numbers, which compares the data of multiple evaluation items horizontally, and can reasonably fill in missing information. We apply this method to the user experience evaluation problem of online live course platform to verify the effectiveness of this method.
Association of Mutations Identified in Xanthinuria with the Function and Inhibition Mechanism of Xanthine Oxidoreductase
Authors: Sekine Mai , Okamoto Ken , Ichida Kimiyoshi
Published: November 2021

Xanthine oxidoreductase (XOR) is an enzyme that catalyzes the two-step reaction from hypoxanthine to xanthine and from xanthine to uric acid in purine metabolism. XOR generally carries dehydrogenase activity (XDH) but is converted into an oxidase (XO) under various pathophysiologic conditions. The complex structure and enzymatic function of XOR have been well investigated by mutagenesis studies of mammalian XOR and structural analysis of XOR–inhibitor interactions. Three XOR inhibitors are currently used as hyperuricemia and gout therapeutics but are also expected to have potential effects other than uric acid reduction, such as suppressing XO–generating reactive oxygen species. Isolated XOR deficiency, xanthinuria type I, is a good model of the metabolic effects of XOR inhibitors. It is characterized by hypouricemia, markedly decreased uric acid excretion, and increased serum and urinary xanthine concentrations, with no clinically significant symptoms. The pathogenesis and relationship between mutations and XOR activity in xanthinuria are useful for elucidating the biological role of XOR and the details of the XOR reaction process. In this review, we aim to contribute to the basic science and clinical aspects of XOR by linking the mutations in xanthinuria to structural studies, in order to understand the function and reaction mechanism of XOR in vivo.
Utility of the Intelligibility in Context Scale for Predicting Speech Intelligibility of Children with Cerebral Palsy
Authors: Soriano Jennifer U. , Olivieri Abby , Hustad Katherine C.
Published: November 2021

The Intelligibility in Context Scale (ICS) is a widely used, efficient tool for describing a child’s speech intelligibility. Few studies have explored the relationship between ICS scores and transcription intelligibility scores, which are the gold standard for clinical measurement. This study examined how well ICS composite scores predicted transcription intelligibility scores among children with cerebral palsy (CP), how well individual questions from the ICS differentially predicted transcription intelligibility scores, and how well the ICS composite scores differentiated between children with and without speech motor impairment. Parents of 48 children with CP, who were approximately 13 years of age, completed the ICS. Ninety-six adult naïve listeners provided orthographic transcriptions of children’s speech. Transcription intelligibility scores were regressed on ICS composite scores and individual item scores. Dysarthria status was regressed on ICS composite scores. Results indicated that ICS composite scores were moderately strong predictors of transcription intelligibility scores. One individual ICS item differentially predicted transcription intelligibility scores, and dysarthria severity influenced how well ICS composite scores differentiated between children with and without speech motor impairment. Findings suggest that the ICS has potential clinical utility for children with CP, especially when used with other objective measures of speech intelligibility.
Anxiety, Perceived Stress, and Resilience during the COVID-19 Pandemic: Population Estimates of Persons Presenting to a General Practitioner in Romania
Authors: Ionescu Tiberiu Constantin , Fetecau Bogdana Ioana , Boscaiu Voicu , Tudose Catalina
Published: November 2021

Facing the COVID-19 pandemic, individuals are experiencing severe mental distress. Thus, during the last year, drastic changes occurred in everyday life of every human being. Following social distancing and economic insecurity, significant increases in mental health concerns (loneliness, anxiety, depression, or insomnia) have developed. The objective of this study was to explore the anxiety, perceived stress, and resilience in a population presenting at the general practitioner, during the COVID-19 pandemic. Data were collected between February and April 2021 and 440 individuals who presented to the general practitioner were evaluated. Concerning anxiety level, almost half of the respondents (49,3%, N = 217) scored above the threshold value on the anxiety scale (mild intensity 38.6%, moderate intensity 9.9%, severe intensity 0.8%). Having a low level of resilience, as well as experiencing a high level of stress, are both predictive of the occurrence of high anxiety (p < 0.001, r = −0.551 and p < 0.001, r = 0.622, respectively). Furthermore, resilience is negatively related to perceived stress (p < 0.001, r = −0.676). It is critical in the current crisis to recognize those at risk of developing mental illnesses, taking into consideration the various socioeconomic classes, as well as to maintain and improve the general public’s mental health using appropriate psychological interventions.
UK Women’s Views of the Concepts of Personalised Breast Cancer Risk Assessment and Risk-Stratified Breast Screening: A Qualitative Interview Study
Authors: Kelley-Jones Charlotte , Scott Suzanne , Waller Jo
Published: November 2021

Any introduction of risk-stratification within the NHS Breast Screening Programme needs to be considered acceptable by women. We conducted interviews to explore women’s attitudes to personalised risk assessment and risk-stratified breast screening. Twenty-five UK women were purposively sampled by screening experience and socioeconomic background. Interview transcripts were qualitatively analysed using Framework Analysis. Women expressed positive intentions for personal risk assessment and willingness to receive risk feedback to provide reassurance and certainty. Women responded to risk-stratified screening scenarios in three ways: ‘Overall acceptors’ considered both high- and low-risk options acceptable as a reasonable allocation of resources to clinical need, yet acceptability was subject to specified conditions including accuracy of risk estimates and availability of support throughout the screening pathway. Others who thought ‘more is better’ only supported high-risk scenarios where increased screening was proposed. ‘Screening sceptics’ found low-risk scenarios more aligned to their screening values than high-risk screening options. Consideration of screening recommendations for other risk groups had more influence on women’s responses than screening-related harms. These findings demonstrate high, but not universal, acceptability. Support and guidance, tailored to screening values and preferences, may be required by women at all levels of risk.
The Risk of Psychological Stress on Cancer Recurrence: A Systematic Review
Authors: Oh Hyeon-Muk , Son Chang-Gue
Published: November 2021

Cancer recurrence is a significant clinical issue in cancer treatment. Psychological stress has been known to contribute to the incidence and progression of cancer; however, its effect on cancer recurrence remains inconclusive. We conducted a systematic review to examine the current evidence from the Medline (PubMed), Embase and Cochrane Library up to May 2021. Among 35 relevant articles, a total of 6 studies (10 data points) were finally selected, which enrolled 26,329 patients (26,219 breast cancer patients except hepatocellular carcinoma patients in 1 study), 4 cohort studies (8 data points) and 2 RCTs (2 data points). Among the 8 data points in cohort studies, four psychological stress-related factors (two ‘anxiety’, one ‘depression’, and one ‘hostility’) were shown to be moderately related with the risk for cancer recurrence, while ‘loss of partner’ resulted in opposite outcomes. The ‘emotional‘ and ‘mental’ health factors showed conflicting results, and an RCT-derived meta-analysis proved the positive efficiency of psychotherapies in reducing the cancer recurrence risk among breast cancer patients (HR = 0.52; 95% CI 0.33–0.84). Despite the limitations, this study produces comprehensive information about the effect of psychological stress on cancer recurrence and provides reference data to clinicians and scientists for further studies.
Immunotherapy for Diffuse Large B-Cell Lymphoma: Current Landscape and Future Directions
Authors: Modi Dipenkumar , Potugari Bindu , Uberti Joseph
Published: November 2021

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease. B-cell receptor (BCR) pathway is essential for malignant B-cell growth, survival, and proliferation. Various immune cells, including T-cells and macrophages in the tumor microenvironment (TME) contribute to tumor cell survival and pathogenesis of chemo-resistance. The presence of many targets on the malignant B-cells and in the TME has led to emergence of novel therapeutic agents. Stem cell transplant is the oldest treatment modality leveraging immune system in DLBCL. Subsequently, CD20 targeting monoclonal antibody and chimeric antigen receptor (CAR) T-cell therapy changed the treatment landscape of DLBCL. Recently, multiple novel immunotherapeutic agents have been added in the armamentarium for the management of DLBCL, and many are under development. In this review article, we will review latest updates of immunotherapeutic agents in the management of DLBCL.
Detecting Progression of Treated Choroidal Melanomas: Is Ultrasonography Necessary?
Authors: Negretti Guy S. , Harley Umiya , Arora Amit K. , Hay Gordon , Sagoo Mandeep S. , Damato Bertil E.
Published: November 2021

Prompt detection and treatment of local treatment failure after radiotherapy for choroidal melanoma optimises any opportunities for conserving vision and the eye, possibly reducing an increased risk of metastatic disease. Long-term surveillance is therefore required but is hampered by the perceived need to perform ultrasonography, which may not be available at a patient’s local hospital. The aim of this study was to determine whether local treatment failure can reliably be detected with colour fundus photography alone, and, if so, in which patients. Patients were included in the study if diagnosed with local treatment failure between April 2016 and February 2021 after eye-conserving therapy for choroidal melanoma. Wide-field colour and fundal autofluorescence (FAF) images, optical coherence tomography (OCT), and ultrasonography (US) were analysed by two of the authors (GN and UH). The cohort included 87 patients with local treatment failure. In 75 patients with clear media, tumour progression was detected by colour photography alone in 74 (98.7%) patients. Sensitivity was not increased by the addition of either OCT or AF. One patient with clear media developed extraocular extension detected with US without visible change in the intraocular part of the tumour. In the other 12 patients, US was required because of opaque media and a consequently poor fundal view. Local treatment failure after radiotherapy for choroidal melanoma is detected in 98.7% of cases with colour photography when the media are clear. Ultrasonography is useful when photography is prevented by opaque media or tumours having locations in the far periphery.
Surgical Therapy of Esophageal Adenocarcinoma—Current Standards and Future Perspectives
Authors: Schröder Wolfgang , Gisbertz Suzanne S. , Voeten Daan M. , Gutschow Christian A. , Fuchs Hans F. , van Berge Henegouwen Mark I.
Published: November 2021

Transthoracic esophagectomy is currently the predominant curative treatment option for resectable esophageal adenocarcinoma. The majority of carcinomas present as locally advanced tumors requiring multimodal strategies with either neoadjuvant chemoradiotherapy or perioperative chemotherapy alone. Minimally invasive, including robotic, techniques are increasingly applied with a broad spectrum of technical variations existing for the oncological resection as well as gastric reconstruction. At the present, intrathoracic esophagogastrostomy is the preferred technique of reconstruction (Ivor Lewis esophagectomy). With standardized surgical procedures, a complete resection of the primary tumor can be achieved in almost 95% of patients. Even in expert centers, postoperative morbidity remains high, with an overall complication rate of 50–60%, whereas 30- and 90-day mortality are reported to be <2% and <6%, respectively. Due to the complexity of transthoracic esophagetomy and its associated morbidity, esophageal surgery is recommended to be performed in specialized centers with an appropriate caseload yet to be defined. In order to reduce postoperative morbidity, the selection of patients, preoperative rehabilitation and postoperative fast-track concepts are feasible strategies of perioperative management. Future directives aim to further centralize esophageal services, to individualize surgical treatment for high-risk patients and to implement intraoperative imaging modalities modifying the oncological extent of resection and facilitating surgical reconstruction.
Metastatic Lymph Node Ratio for Predicting Recurrence in Medullary Thyroid Cancer
Authors: Kim Jinyoung , Park Jun , Park Hyunju , Choi Min Sun , Jang Hye Won , Kim Tae Hyuk , Kim Sun Wook , Chung Jae Hoon
Published: November 2021

The lymph node ratio (LNR) has been investigated as a prognostic factor in many different types of cancers, including differentiated thyroid cancer; however, reports regarding medullary thyroid cancer (MTC) are limited. Therefore, this study aims to evaluate LNR as a risk factor for structural recurrence in patients with MTC. Medical records of patients treated for MTC in a single tertiary center between 1995 and 2017 were retrospectively reviewed. LNR is defined as the number of metastatic lymph nodes or lymph node metastases (LNM) divided by the number of retrieved lymph nodes or lymph node yield (LNY). In the survival analysis, recurrence-free survival was defined as the time from the date of total thyroidectomy to recurrence or last follow-up. To identify risk factors influencing structural recurrence, univariable and multivariable Cox proportional hazard models were used. A total of 132 patients were enrolled. The mean age of study participants was 49.7 years, and 86 patients (65%) were women. Structural recurrence was identified in 39 patients at the end of the study period, and the median follow-up period was 8.7 years. In univariable analyses, gross extra thyroidal extension, N stage, postoperative serum calcitonin and carcinoembryonic antigen (CEA) levels, and LNR were significant (p < 0.05) predictors of structural recurrence. In multivariable analysis, postoperative serum calcitonin, postoperative serum CEA, and LNR were identified as a predictor of disease-free survival (p < 0.05). LNR can potentially predict structural recurrence as a quantitative evaluation tool for lymph node metastasis in patients with MTC.
Use of NaNO3/SiAl as Heterogeneous Catalyst for Fatty Acid Methyl Ester Production from Rapeseed Oil
Authors: Encinar José María , González Juan Félix , Martínez Gloria , Nogales-Delgado Sergio
Published: November 2021

The use of heterogeneous catalysts to produce fatty acid methyl esters (FAME) through transesterification with methanol might contribute to both green chemistry and a circular economy, as the process can be simplified, not requiring additional stages to recover the catalyst once the reaction takes place. For this purpose, different catalysts are used, including a wide range of possibilities. In this research the use of NaNO3/SiAl as a heterogeneous catalyst for FAME production through transesterification of rapeseed oil with methanol is considered. A thorough characterization of the catalyst (including XDR and XPS analysis, SEM microscopy, lixiviation and reusability tests, among others), specific optimization of transesterification by using the final catalyst (considering catalyst amount, stirring rate, methanol/oil ratio, and temperature), and quality determination of the final biodiesel (following the UNE-EN 14214 standard) were carried out. In conclusion, 20 mmolNa·gsupport−1 (that is, NaNO3/SiAl 20/1) offered the best results, with a high activity (exceeding 99% w/w of FAMEs) without requiring higher impregnation amounts. The best chemical conditions for this heterogeneous catalyst were 5% w/w catalyst, 700 rpm, 9:1 methanol/oil ratio, and 65 °C, obtaining Ea = 73.3 kJ·mol−1 and a high-quality biodiesel, similar to those obtained through homogeneous catalysis. Consequently, this catalyst could be a suitable precursor for FAME production.
Au-Ag/TiO2 Thin Films Preparation by Laser Ablation and Sputtering Plasmas for Its Potential Use as Photoanodes in Electrochemical Advanced Oxidation Processes (EAOP)
Authors: Martínez-Chávez Luis Alejandro , Rivera-Muñoz Eric Mauricio , Velázquez-Castillo Rodrigo Rafael , Escobar-Alarcón Luis , Esquivel Karen
Published: November 2021

Titanium dioxide (TiO2) is widely used, studied, and synthesized using different methodologies. By a modification of the material, it can be applied to wastewater treatment. A combined sputtering-laser ablation setup was used to deposit TiO2 thin films modified, individually and simultaneously, with gold (Au) and silver (Ag). To investigate the effect of the metal incorporation in titanium and its impact on the photocatalytic activity, with dye discoloration as a pollutant compound model, the deposited films were characterized by UV–Vis, photoluminescence, and Raman spectroscopies, as well as by parallel beam X-ray diffraction. The results showed that films with different Au and Ag loads, and an 18 nm average crystallite size, were obtained. These metals have an essential effect on the deposited film’s compositional, structural, and optical properties, directly reflected in its photocatalytic activity. The photocatalytic test results using UV-Vis showed that, after 1 h of applying a 4.8 V electric voltage, a discoloration of up to 80% of malachite green (MG) was achieved, using ultraviolet (UV) light.
Synthesis and Catalytic Properties of Novel Ruthenacarboranes Based on nido-[5-Me-7,8-C2B9H10]2− and nido-[5,6-Me2-7,8-C2B9H9]2− Dicarbollide Ligands
Authors: Grishin Ivan D. , Zimina Anastasiya M. , Anufriev Sergey A. , Knyazeva Nadezhda A. , Piskunov Alexander V. , Dolgushin Fedor M. , Sivaev Igor B.
Published: November 2021

The effect of methyl substituents in the lower belt of dicarbollide ligands on the redox potential of ruthenacarboranes based thereof, as well as the ability of the metallacarboranes obtained to catalyze radical polymerization with atom transfer were studied. For this purpose, a new approach to the synthesis of closo-ruthenacarboranes based on substituted dicarbollide ligands was developed and six new complexes 3,3-(Ph2P(CH2)4PPh2)-3-H-3-Cl-9-Me-12-X-closo-3,1,2-RuC2B9H9, 3,3,8-(Ph2P(CH2)4PPh-μ-(C6H4-o))-3-Cl-9-Me-12-X-closo-3,1,2-RuC2B9H8 and 3,3,4,8-(Ph2P(CH2)4P-μ-(C6H4-o)2)-3-Cl-9-Me-9-X-closo-3,1,2-RuC2B9H7 (X = H, Me) were synthetized and characterized by single crystal X-ray diffraction, NMR and ESR spectroscopy and MALDI TOF mass-spectrometry. Comparison of the values of the redox potentials of the synthesized ruthenium complexes in 1,2-dichloroethane with the values previously found for the corresponding ruthenacarboranes based on the parent dicarbollide anion showed that the introduction of methyl substituents into the carborane cage led to a decrease in the redox potentials of the complexes, which made them more preferable catalysts for ATRP. Test experiments on the polymerization of MMA showed that the synthesized ruthenacarboranes were effective catalysts for ATRP, the most active being the complex with two methyl groups and two ortho-phenylenecycloboronated fragments.
Ethanol Dehydrogenation to Acetaldehyde over Co@N-Doped Carbon
Authors: Chernov Aleksey N. , Astrakova Tatiana V. , Koltunov Konstantin Yu. , Sobolev Vladimir I.
Published: November 2021

Cobalt and nitrogen co-doped carbon materials (Co@CN) have recently attracted significant attention as highly efficient noble-metal-free catalysts exhibiting a large application range. In a similar research interest, and taking into account the ever-increasing importance of bioethanol as a renewable raw material, here, we report the results on ethanol dehydrogenation to acetaldehyde over Co@NC catalysts. The catalyst samples were synthesized by a variety of affordable techniques, ensuring generation of various types of Co species incorporated in carbon, such as subnanosized cobalt sites and nano-sized particles of metallic cobalt and cobalt oxides. The catalytic activity was tested under both oxidative and non-oxidative gas-phase conditions at 200–450 °C using a fixed-bed flow reactor. The non-oxidative conditions proved to be much more preferable for the target reaction, competing, however, with ethanol dehydration to ethylene. Under specified reaction conditions, ethanol conversion achieved a level of 66% with 84% selectivity to acetaldehyde at 400 °C. The presence of molecular oxygen in the feed led mainly to deep oxidation of ethanol to COx, giving acetaldehyde in a comparatively low yield. The potential contribution of carbon itself and supported cobalt forms to the observed reaction pathways is discussed.
Enduring Effects of Conditional Brain Serotonin Knockdown, Followed by Recovery, on Adult Rat Neurogenesis and Behavior
Authors: Sidorova Maria , Kronenberg Golo , Matthes Susann , Petermann Markus , Hellweg Rainer , Tuchina Oksana , Bader Michael , Alenina Natalia , Klempin Friederike
Published: November 2021

Serotonin (5-hydroxytryptamine, 5-HT) is a crucial signal in the neurogenic niche of the hippocampus, where it is involved in antidepressant action. Here, we utilized a new transgenic rat model (TetO-shTPH2), where brain 5-HT levels can be acutely altered based on doxycycline (Dox)-inducible shRNA-expression. On/off stimulations of 5-HT concentrations might uniquely mirror the clinical course of major depression (e.g., relapse after discontinuation of antidepressants) in humans. Specifically, we measured 5-HT levels, and 5-HT metabolite 5-HIAA, in various brain areas following acute tryptophan hydroxylase 2 (Tph2) knockdown, and replenishment, and examined behavior and proliferation and survival of newly generated cells in the dentate gyrus. We found that decreased 5-HT levels in the prefrontal cortex and raphe nuclei, but not in the hippocampus of TetO-shTPH2 rats, lead to an enduring anxious phenotype. Surprisingly, the reduction in 5-HT synthesis is associated with increased numbers of BrdU-labeled cells in the dentate gyrus. At 3 weeks of Tph2 replenishment, 5-HT levels return to baseline and survival of newly generated cells is unaffected. We speculate that the acutely induced decrease in 5-HT concentrations and increased neurogenesis might represent a compensatory mechanism.
The Secrets of Alternative Autophagy
Authors: Urbańska Kaja , Orzechowski Arkadiusz
Published: November 2021

For many years, it was thought that ATG5 and ATG7 played a pivotal role in autophagy, and that the knockdown of one of these genes would result in its inhibition. However, cells with ATG5 or ATG7 depletion still generate autophagic vacuoles with mainly trans-Golgi-originated isolation membranes and do not die. This indicates that autophagy can occur via ATG5/ATG7-independent alternative autophagy. Its molecular mechanism differs from that of the canonical pathway, including inter alia the phosphorylation of ULK1, and lack of LC3 modifications. As the alternative autophagy pathway has only recently been described, little is known of its precise role; however, a considerable body of evidence suggests that alternative autophagy participates in mitochondrion removal. This review summarizes the latest progress made in research on alternative autophagy and describes its possible molecular mechanism, roles and methods of detection, and possible modulators. There is a need for further research focused on types of autophagy, as this can elucidate the functioning of various cell types and the pathogenesis of human and animal diseases.
Microbiome Analysis of Mucosal Ileoanal Pouch in Ulcerative Colitis Patients Revealed Impairment of the Pouches Immunometabolites
Authors: Palmieri Orazio , Castellana Stefano , Biscaglia Giuseppe , Panza Anna , Latiano Anna , Fontana Rosanna , Guerra Maria , Corritore Giuseppe , Latiano Tiziana , Martino Giuseppina , Mazza Tommaso , Andriulli Angelo , Perri Francesco , Bossa Fabrizio
Published: November 2021

The pathogenesis of ulcerative colitis (UC) is unknown, although genetic loci and altered gut microbiota have been implicated. Up to a third of patients with moderate to severe UC require proctocolectomy with ileal pouch ano-anastomosis (IPAA). We aimed to explore the mucosal microbiota of UC patients who underwent IPAA. Methods: For microbiome analysis, mucosal specimens were collected from 34 IPAA individuals. Endoscopic and histological examinations of IPAA were normal in 21 cases, while pouchitis was in 13 patients. 19 specimens from the healthy control (10 from colonic and 9 from ileum) were also analyzed. Data were analyzed using an ensemble of software packages: QIIME2, coda-lasso, clr-lasso, PICRUSt2, and ALDEx2. Results: IPAA specimens had significantly lower bacterial diversity as compared to normal. The microbial composition of the normal pouch was also decreased also when compared to pouchitis. Faecalibacterium prausnitzii, Gemmiger formicilis, Blautia obeum, Ruminococcus torques, Dorea formicigenerans, and an unknown species from Roseburia were the most uncommon in pouch/pouchitis, while an unknown species from Enterobacteriaceae was over-represented. Propionibacterium acnes and Enterobacteriaceae were the species most abundant in the pouchitis and in the normal pouch, respectively. Predicted metabolic pathways among the IPAA bacterial communities revealed an important role of immunometabolites such as SCFA, butyrate, and amino acids. Conclusions: Our findings showed specific bacterial signature hallmarks of dysbiosis and could represent bacterial biomarkers in IPAA patients useful to develop novel treatments in the future by modulating the gut microbiota through the administration of probiotic immunometabolites-producing bacterial strains and the addition of specific prebiotics and the faecal microbiota transplantation.
Quantification of EGFR-HER2 Heterodimers in HER2-Overexpressing Breast Cancer Cells Using Liquid-Phase Electron Microscopy
Authors: Peckys Diana B. , Gaa Daniel , de Jonge Niels
Published: November 2021

Currently, breast cancer patients are classified uniquely according to the expression level of hormone receptors, and human epidermal growth factor receptor 2 (HER2). This coarse classification is insufficient to capture the phenotypic complexity and heterogeneity of the disease. A methodology was developed for absolute quantification of receptor surface density ρR, and molecular interaction (dimerization), as well as the associated heterogeneities, of HER2 and its family member, the epidermal growth factor receptor (EGFR) in the plasma membrane of HER2 overexpressing breast cancer cells. Quantitative, correlative light microscopy (LM) and liquid-phase electron microscopy (LPEM) were combined with quantum dot (QD) labeling. Single-molecule position data of receptors were obtained from scanning transmission electron microscopy (STEM) images of intact cancer cells. Over 280,000 receptor positions were detected and statistically analyzed. An important finding was the subcellular heterogeneity in heterodimer shares with respect to plasma membrane regions with different dynamic properties. Deriving quantitative information about EGFR and HER2 ρR, as well as their dimer percentages, and the heterogeneities thereof, in single cancer cells, is potentially relevant for early identification of patients with HER2 overexpressing tumors comprising an enhanced share of EGFR dimers, likely increasing the risk for drug resistance, and thus requiring additional targeted therapeutic strategies.
Butyrate and Class I Histone Deacetylase Inhibitors Promote Differentiation of Neonatal Porcine Islet Cells into Beta Cells
Authors: Zhang Yichen , Lei Yutian , Honarpisheh Mohsen , Kemter Elisabeth , Wolf Eckhard , Seissler Jochen
Published: November 2021

Neonatal porcine islets-like clusters (NPICCs) are a promising source for cell therapy of type 1 diabetes. Freshly isolated NPICCs are composed of progenitor cells and endocrine cells, which undergo a maturation process lasting several weeks until the normal beta cell function has developed. Here, we investigated the effects of short-chain fatty acids on the maturation of islet cells isolated from two to three day-old piglets. NPICCs were cultivated with acetate, butyrate and propionate (0–2000 µM) for one to eight days. Incubation with butyrate resulted in a significant upregulation of insulin gene expression and an increased beta cell number, whereas acetate or propionate had only marginal effects. Treatment with specific inhibitors of G-protein-coupled receptor GPR41 (β-hydroxybutyrate) and/or GPR43 (GPLG0974) did not abolish butyrate induced insulin expression. However, incubation of NPICCs with class I histone deacetylase inhibitors (HDACi) mocetinostat and MS275, but not selective class II HDACi (TMP269, MC1568) mimicked the butyrate effect on beta cell differentiation. Our study revealed that butyrate treatment has the capacity to increase the number of beta cells, which may be predominantly mediated through its HDAC inhibitory activity. Butyrate and specific class I HDAC inhibitors may represent beneficial supplements to promote differentiation of neonatal porcine islet cells towards beta cells for cell replacement therapies.
Dose and Dose Rate-Dependent Effects of Low-Dose Irradiation on Inflammatory Parameters in ApoE-Deficient and Wild Type Mice
Authors: Glasow Annegret , Patties Ina , Priest Nicholas D. , Mitchel Ronald E. J. , Hildebrandt Guido , Manda Katrin
Published: November 2021

Anti-inflammatory low-dose therapy is well established, whereas the immunomodulatory impact of doses below 0.1 Gy is much less clear. In this study, we investigated dose, dose rate and time-dependent effects in a dose range of 0.005 to 2 Gy on immune parameters after whole body irradiation (IR) using a pro-inflammatory (ApoE−/−) and a wild type mouse model. Long-term effects on spleen function (proliferation, monocyte expression) were analyzed 3 months, and short-term effects on immune plasma parameters (IL6, IL10, IL12p70, KC, MCP1, INFγ, TGFβ, fibrinogen, sICAM, sVCAM, sE-selectin/CD62) were analyzed 1, 7 and 28 days after Co60 γ-irradiation (IR) at low dose rate (LDR, 0.001 Gy/day) and at high dose rate (HDR). In vitro measurements of murine monocyte (WEHI-274.1) adhesion and cytokine release (KC, MCP1, IL6, TGFβ) after low-dose IR (150 kV X-ray unit) of murine endothelial cell (EC) lines (H5V, mlEND1, bEND3) supplement the data. RT-PCR revealed significant reduction of Ki67 and CD68 expression in the spleen of ApoE−/− mice after 0.025 to 2 Gy exposure at HDR, but only after 2 Gy at LDR. Plasma levels in wild type mice, showed non-linear time-dependent induction of proinflammatory cytokines and reduction of TGFβ at doses as low as 0.005 Gy at both dose rates, whereas sICAM and fibrinogen levels changed in a dose rate-specific manner. In ApoE−/− mice, levels of sICAM increased and fibrinogen decreased at both dose rates, whereas TGFβ increased mainly at HDR. Non-irradiated plasma samples revealed significant age-related enhancement of cytokines and adhesion molecules except for sICAM. In vitro data indicate that endothelial cells may contribute to systemic IR effects and confirm changes of adhesion properties suggested by altered sICAM plasma levels. The differential immunomodulatory effects shown here provide insights in inflammatory changes occurring at doses far below standard anti-inflammatory therapy and are of particular importance after diagnostic and chronic environmental exposures.
LSD1: Expanding Functions in Stem Cells and Differentiation
Authors: Martinez-Gamero Carlos , Malla Sandhya , Aguilo Francesca
Published: November 2021

Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSC) provide a powerful model system to uncover fundamental mechanisms that control cellular identity during mammalian development. Histone methylation governs gene expression programs that play a key role in the regulation of the balance between self-renewal and differentiation of ESCs. Lysine-specific demethylase 1 (LSD1, also known as KDM1A), the first identified histone lysine demethylase, demethylates H3K4me1/2 and H3K9me1/2 at target loci in a context-dependent manner. Moreover, it has also been shown to demethylate non-histone substrates playing a central role in the regulation of numerous cellular processes. In this review, we summarize current knowledge about LSD1 and the molecular mechanism by which LSD1 influences the stem cells state, including the regulatory circuitry underlying self-renewal and pluripotency.
Effects of 5′,8′-Cyclo-2′-Deoxypurines on the Base Excision Repair of Clustered DNA Lesions in Nuclear Extracts of the XPC Cell Line
Authors: Kaźmierczak-Barańska Julia , Boguszewska Karolina , Szewczuk Michał , Karwowski Bolesław T.
Published: November 2021

Clustered DNA lesions (CDL) containing 5′,8-cyclo-2′-deoxypurines (cdPus) are an example of extensive abnormalities occurring in the DNA helix and may impede cellular repair processes. The changes in the efficiency of nuclear base excision repair (BER) were investigated using (a) two cell lines, one of the normal skin fibroblasts as a reference (BJ) and the second from Xeroderma pigmentosum patients’ skin (XPC), and (b) synthetic oligonucleotides with single- and double-stranded CDL (containing 5′,8-cyclo-2′-deoxyadenosine (cdA) and the abasic (AP) site at various distances between lesions). The nuclear BER has been observed and the effect of both cdA isomers (5′R and 5′S) presence in the DNA was tested. CdPus affected the repair of the second lesion within the CDL. The BER system more efficiently processed damage in the vicinity of the ScdA isomer and changes located in the 3′-end direction for dsCDL and in the 5′-end direction for ssCDL. The presented study is the very first investigation of the repair processes of the CDL containing cdPu considering cells derived from a Xeroderma pigmentosum patient.