bluuebunny/crossref_metadata_2025 huggingface dataset:
Drug-Induced Podocytopathies: Report of Four Cases and Review of the Literature
Authors: Athanasopoulou Diamanto , Lionaki Sophia , Skalioti Chrysanthi , Liapis George , Vlachoyiannopoulos Panayiotis , Boletis Ioannis
Published: May 2023

Kidney injury due to medications is a well-known clinical entity. Although drug-induced tubulointerstitial disease is commonly encountered, there are few reports in the literature associated with glomerular injury due to medications. The recognition of this type of kidney injury is crucial, as rapid discontinuation of the offending agent is critical to maximizing the likelihood of quick and effective renal function recovery. In this article, we present four cases that presented with nephrotic syndrome and were diagnosed with biopsy-proven podocytopathies, associated with exposure to a certain medication. All of them experienced complete resolution of nephrotic syndrome within days or weeks after discontinuation of the offending drug. We also present the data, which were found in a Medline search from the year 1963 until the present, regarding cases with podocytopathies associated with penicillamine, tamoxifen and the combination of pembrolizumab-axitinib, including only adult cases from the English literature. The Medline search revealed nineteen cases of penicillamine-induced minimal-change disease (MCD), one case of tamoxifen-induced MCD, and none associated with pembrolizumab-axitinib therapy. We also searched for the largest studies and meta-analyses regarding drug-induced podocytopathies after a Medline search from 1967 to the present of the English literature.
Novel Drugs for the Management of Diabetes Kidney Transplant Patients: A Literature Review
Authors: Valencia-Morales Nancy Daniela , Rodríguez-Cubillo Beatriz , Loayza-López Rómulo Katsu , Moreno de la Higuera Maria Ángeles , Sánchez-Fructuoso Ana Isabel
Published: May 2023

The management of diabetes and renal failure is changing thanks to the appearance of new drugs such as glucagon-like peptide 1 receptor agonists (GLP1-RA) and sodium-glucose cotransporter type 2 inhibitors (SGLT2i) that have benefits in terms of survival and cardiorenal protection. Based on the potential mechanisms of GLP1-RA, kidney transplant recipients (KTRs) could benefit from their effects. However, high-quality studies are needed to demonstrate these benefits, in the transplant population, especially those related to cardiovascular benefits and renal protection. Studies with SGLT2i performed in KTRs are much less potent than in the general population and therefore no benefits in terms of patient or graft survival have been clearly demonstrated in this population to date. Additionally, the most frequently observed side effects could be potentially harmful to this population profile, including severe or recurrent urinary tract infections and impaired kidney function. However, benefits demonstrated in KTRs are in line with a known potential effects in cardiovascular and renal protection, which may be essential for the outcome of transplant recipients. Better studies are still needed to confirm the benefits of these new oral antidiabetics in the renal transplant population. Understanding the characteristics of these drugs may be critical for KTRs to be able to benefit from their effects without being damaged. This review discusses the results of the most important published studies on KTRs with GLP1-RA and SGLT2i as well as the potential beneficial effects of these drugs. Based on these results, approximate suggestions for the management of diabetes in KTRs were developed.
Mechanism and Experimental Study on Electrostatic Atomization Using Needle-Shaped Electrodes
Authors: Ma Hao , Yang Min
Published: May 2023

The conventional pneumatic Minimum Quantity Lubrication (MQL), when not properly designed, may have poor atomization and insufficient wetting performance, resulting in higher oil mist concentration and poor film formation ability in the cutting zone. The intervention of an external electric field can change the atomization mechanism of microdroplets and enhance the lubrication and cooling capability of MQL. However, the mechanism of the effect of jet parameters on the atomization performance of Electrostatic Minimum Quantity Lubrication (EMQL) under the synergistic effect of multiple fields has not been fully analyzed. In this paper, based on the designed needle electrode charging nozzle, the atomization medium charging and atomization mechanisms are investigated, and a mathematical model of the volume average diameter of droplets (VAD) is established. Based on multi-parameter atomization experiments, the electrode conical jet atomization model is validated and the mechanism of the influence of jet parameters on the atomization characteristics is analyzed. The results show that the VAD is negatively correlated with air pressure and electrical. The atomization performance of the droplets was improved under the applied voltage condition, which was manifested by the obvious refinement of the VAD, with a maximum reduction of 34.67%, a maximum reduction of 20% in the droplet group size distribution span (R.S.), and a different degree of reduction in the percentage concentration of fine particulate matter. In addition, the model fitted well with the experimental values, with an overall error of about 10%.
Application of a Wear Debris Detection System to Investigate Wear Phenomena during Running-In of a Gasoline Engine
Authors: Bastidas Sophia , Allmaier Hannes
Published: May 2023

When a tribological system is operated for the first time, the first hours of operation are of the utmost importance as the surfaces of the contacting elements mate to each other, involving significant wear processes until the surfaces reach stable topological characteristics. This initial phase in a combustion engine is known as running-in and is of critical importance in the study of friction and wear phenomena. Despite this, there is little information in the literature dedicated to running-in and, therefore, data improving its understanding is greatly anticipated. In this work, a novel wear debris detection system measuring in real time was employed to investigate the running-in of an inline 4-cylinder gasoline engine; it consists primarily of an optical sensor with the capability of detecting very small particles from 4 μm. For the tests, the engine was mounted on a test bench and operated under stationary working conditions. The results of the wear debris measurements showed interesting insights into the engine running-in process; although in general, the results followed the expected trend, they also showed an unexpected behavior: it was expected to obtain the highest amounts of wear debris at the beginning of the running-in, but instead the number of debris stagnated and only started to increase after about 20 h to then decrease again. The best operating conditions to run-in the engine were identified at the middle of the running-in period, without the presence of large wear debris that could lead to severe wear. Finally, it was found that the engine running-in was not finished until at least 75 h of operation, although commonly, a running-in time of 10 h is used in the industry.
Microstructural Understanding of Flow Accelerated Corrosion of SA106B Carbon Steel in High-Temperature Water with Different Flow Velocities
Authors: Hu Ying , Xin Long , Hong Chang , Han Yongming , Lu Yonghao
Published: May 2023

All light or heavy water reactors fabricated with carbon steels suffer from flow-accelerated corrosion (FAC). The FAC degradation of SA106B with different flow velocities was investigated in terms of microstructure. As flow velocity increased, the major corrosion type changed from general corrosion to localized corrosion. Severe localized corrosion occurred in the pearlite zone, which can be the prior location for generating pits. After normalizing, the improvement in microstructure homogeneity reduced the oxidation kinetics and lowered cracking sensitivity, causing a decrease in FAC rates of 33.28%, 22.47%, 22.15%, and 17.53% at flow velocity of 0 m/s, 1.63 m/s, 2.99 m/s, and 4.34 m/s, respectively. Additionally, localized corrosion tendency was decreased by reducing the micro-galvanic effect and tensile stresses in oxide film. The maximum localized corrosion rate decreased by 21.7%, 13.5%, 13.8%, and 25.4% at flow velocity of 0 m/s, 1.63 m/s, 2.99 m/s, and 4.34 m/s, respectively.
Effect of Annealing Temperature on Mechanical Properties and Work Hardening of Nickel-Saving Stainless Steel
Authors: Pei Wei , Yang Shaoguang , Cao Kuo , Zhao Aimin
Published: May 2023

Compared to Cr-Ni stainless steel, nickel-saving stainless steel is a low-cost austenitic stainless steel. We studied the deformation mechanism of stainless steel at various annealing temperatures (850 °C, 950 °C, and 1050 °C). The grain size of the specimen increases with increasing annealing temperature while the yield strength decreases, which follows the Hall–Petch equation. When plastic deformation occurs, dislocation increases. However, the deformation mechanisms can vary between different specimens. Stainless steel with smaller grains is more likely to transform into martensite when deformed. While twinning occurs when the grains are more prominent, the deformation results in twinning. The phase transformation during plastic deformation relies on the shear, so the orientation of the grains is relevant before and after plastic deformation.
Effect of Surface Modifications on Surface Roughness of Ti6Al4V Alloy Manufactured by 3D Printing, Casting, and Wrought
Authors: Kónya János , Hargitai Hajnalka , Jaber Hassanen , Pinke Péter , Kovács Tünde Anna
Published: May 2023

This work aimed to comprehensively evaluate the influence of different surface modifications on the surface roughness of Ti6Al4V alloys produced by selective laser melting (SLM), casting and wrought. The Ti6Al4V surface was treated using blasting with Al2O3 (70–100 µm) and ZrO2 (50–130 µm) particles, acid etching with 0.017 mol/dm3 hydrofluoric acids (HF) for 120 s, and a combination of blasting and acid etching (SLA). It was found that the optimization of the surface roughness of Ti6Al4V parts produced by SLM differs significantly from those produced by casting or wrought processes. Experimental results showed that Ti6Al4V alloys produced by SLM and blasting with Al2O3 followed by HF etching had a higher surface roughness (Ra = 2.043 µm, Rz = 11.742 µm), whereas cast and wrought Ti6Al4V components had surface roughness values of (Ra = 1.466, Rz = 9.428 m) and (Ra = 0.940, Rz = 7.963 m), respectively. For Ti6Al4V parts blasted with ZrO2 and then etched by HF, the wrought Ti6Al4V parts exhibited higher surface roughness (Ra = 1.631 µm, Rz = 10.953 µm) than the SLM Ti6Al4V parts (Ra = 1.336 µm, Rz = 10.353 µm) and the cast Ti6Al4V parts (Ra = 1.075 µm, Rz = 8.904 µm).
Recent Advances in Processing of Titanium and Titanium Alloys through Metal Injection Molding for Biomedical Applications: 2013–2022
Authors: Basir Al , Muhamad Norhamidi , Sulong Abu Bakar , Jamadon Nashrah Hani , Foudzi Farhana Mohd
Published: May 2023

Metal injection molding (MIM) is one of the most widely used manufacturing processes worldwide as it is a cost-effective way of producing a variety of dental and orthopedic implants, surgical instruments, and other important biomedical products. Titanium (Ti) and Ti alloys are popular modern metallic materials that have revamped the biomedical sector as they have superior biocompatibility, excellent corrosion resistance, and high static and fatigue strength. This paper systematically reviews the MIM process parameters that extant studies have used to produce Ti and Ti alloy components between 2013 and 2022 for the medical industry. Moreover, the effect of sintering temperature on the mechanical properties of the MIM-processed sintered components has been reviewed and discussed. It is concluded that by appropriately selecting and implementing the processing parameters at different stages of the MIM process, defect-free Ti and Ti alloy-based biomedical components can be produced. Therefore, this present study could greatly benefit future studies that examine using MIM to develop products for biomedical applications.
Near-Surface-Defect Detection in Countersunk Head Riveted Joints Based on High-Frequency EMAT
Authors: Zhang Shuchang , Xu Jiang , Yang Xin , Lin Hui
Published: May 2023

Countersunk head riveted joints (CHRJs) are essential for the aerospace and marine industries. Due to the stress concentration, defects may be generated near the lower boundary of the countersunk head parts of CHRJs and require testing. In this paper, the near-surface defect in a CHRJ was detected based on high-frequency electromagnetic acoustic transducers (EMATs). The propagation of ultrasonic waves in the CHRJ with a defect was analyzed based on the theory of reflection and transmission. A finite element simulation was used to study the effect of the near-surface defect on the ultrasonic energy distribution in the CHRJ. The simulation results revealed that the second defect echo can be utilized for defect detection. The positive correlation between the reflection coefficient and the defect depth was obtained from the simulation results. To validate the relation, CHRJ samples with varying defect depths were tested using a 10-MHz EMAT. The experimental signals were denoised using wavelet-threshold denoising to improve the signal-to-noise ratio. The experimental results demonstrated a linearly positive correlation between the reflection coefficient and the defect depth. The results further showed that high-frequency EMATs can be employed for the detection of near-surface defects in CHRJs.
A Semi-Empirical Damage Model of Helankou Rocks Based on Acoustic Emission
Authors: Yang Youzhen , Lin Qingqing , Ma Hailong , Israr Jahanzaib , Liu Wei , Zhao Yishen , Ma Wenguo , Zhang Gang , Li Hongbo
Published: May 2023

The Helankou rock as the relics carrier in Ningxia, China, have been suffering from serious weathering caused by variable environmental conditions. To study the freeze-thaw damage characteristics of Helankou relics carrier rocks, three dry-wet conditions (i.e., drying, pH = 2 and pH = 7) together with freeze-thaw experiments have been carried out at 0, 10, 20, 30, and 40 cycles. Additionally, a series of triaxial compression tests have been carried out at four different cell pressures of 4 MPa, 8 MPa, 16 MPa, and 32 MPa in tandem with a non-destructive acoustic emission technique. Subsequently, the rock damage variables were identified based on elastic modulus and acoustic emission ringing counts. It has been revealed that the acoustic emission positioning points reflected that the cracks would be concentrated near the surface of main fracture at higher cell pressures. Notably, the rock samples at 0 freeze-thaw cycles failed in pure shear. However, both shear slip and extension along the tensile cracks were observed at 20 freeze-thaw cycles, while tensile-oblique shear failure occurred at 40 freeze-thaw cycles. Not surprisingly, the decreasing order of deterioration inside the rock was observed to be (drying group) > (pH = 7 group) > (pH = 2 group). The peak values of damage variables in these three groups were also found to be consistent with the deterioration trend observed under freeze-thaw cycles. Finally, the semi-empirical damage model could rigorously ascertain stress and deformation behavior of rock samples, thus providing theoretical basis to establish a protection framework for Helankou relics.
The Combined Effects of Hydraulic Calcium Silicate Cement and Enamel Matrix Derivative Regarding Osteogenic and Dentinogenic Differentiation on Human Dental Pulp Stem Cells
Authors: Yune Ji-Young , Lee Donghee , Kim Sin-Young
Published: May 2023

The ideal treatment option for immature necrotic permanent teeth is regeneration of the pulp–dentin complex. Mineral trioxide aggregate (MTA), the conventional cement used for regenerative endodontic procedures, induces hard tissue repair. Various hydraulic calcium silicate cements (HCSCs) and enamel matrix derivative (EMD) also promote osteoblast proliferation. The purpose of the present study was to determine the osteogenic and dentinogenic potential of commercially distributed MTA and HCSCs when applied in combination with Emdogain gel on human dental pulp stem cells (hDPSCs). The presence of Emdogain resulted in greater cell viability, and higher alkaline phosphatase activity was detected in the Emdogain-supplemented groups in the early days of cell culture. On qRT–PCR, the groups treated, respectively, with Biodentine and Endocem MTA Premixed in the presence of Emdogain showed an increased expression of the dentin formation marker DSPP, and the group treated with Endocem MTA Premixed in the presence of Emdogain showed an upregulated expression of the bone formation markers OSX and RUNX2. In an Alizarin Red-S staining assay, all of the experimental groups exhibited a greater formation of calcium nodules when treated in combination with Emdogain. Overall, the cytotoxicity and osteogenic/odontogenic potential of HCSCs were similar to that of ProRoot MTA. The addition of the EMD increased the osteogenic and dentinogenic differentiation markers.
Defect Dipole Behaviors on the Strain Performances of Bismuth Sodium Titanate-Based Lead-Free Piezoceramics
Authors: Wang Yiyi , Wang Pu , Liu Laijun , Wang Yuyin , Zhao Yingying , Tian Wenchao , Liu Xiao , Zhu Fangyuan , Shi Jing
Published: May 2023

Bismuth sodium titanate (BNT)-based, lead-free piezoelectric materials have been extensively studied due to their excellent strain characteristics and environmental friendliness. In BNTs, the large strain (S) usually requires a relatively large electric field (E) excitation, resulting in a low inverse piezoelectric coefficient d33* (S/E). Moreover, the hysteresis and fatigue of strain in these materials have also been bottlenecks impeding the applications. The current common regulation method is chemical modification, which mainly focuses on forming a solid solution near the morphotropic phase boundary (MPB) by adjusting the phase transition temperature of the materials, such as BNT-BaTiO3, BNT-Bi0.5K0.5TiO3, etc., to obtain a large strain. Additionally, the strain regulation based on the defects introduced by the acceptor, donor, or equivalent dopant or the nonstoichiometry has proven effective, but its underlying mechanism is still ambiguous. In this paper, we review the generation of strain and then discuss it from the domain, volume, and boundary effect perspectives to understand the defect dipole behavior. The asymmetric effect caused by the coupling between defect dipole polarization and ferroelectric spontaneous polarization is expounded. Moreover, the defect effect on the conductive and fatigue properties of BNT-based solid solutions is described, which will affect the strain characteristics. The optimization approach is appropriately evaluated while there are still challenges in the full understanding of the defect dipoles and their strain output, in which further efforts are needed to achieve new breakthroughs in atomic-level insight.
Properties of Accelerating Edge Dislocations in Arbitrary Slip Systems with Reflection Symmetry
Authors: Blaschke Daniel N. , Dang Khanh , Fensin Saryu J. , Luscher Darby J.
Published: May 2023

We discuss the theoretical solution to the differential equations governing accelerating edge dislocations in anisotropic crystals. This is an important prerequisite to understanding high-speed dislocation motion, including an open question about the existence of transonic dislocation speeds, and subsequently high-rate plastic deformation in metals and other crystals.
Ureido Hyperbranched Polymer Modified Urea-Formaldehyde Resin as High-Performance Particleboard Adhesive
Authors: Yang Hongxing , Wang Hao , Du Guanben , Ni Kelu , Wu Yingchen , Su Hang , Gao Wei , Tan Xiaoping , Yang Zhaojin , Yang Long , Ran Xin
Published: May 2023

The performance of urea-formaldehyde (UF) resin and its formaldehyde emission is a natural contradiction. High molar ratio UF resin performance is very good, but its formaldehyde release is high; low molar ratio UF resin formaldehyde release is reduced, but the resin itself performance becomes very bad. In order to solve this traditional problem, an excellent strategy of UF resin modified by hyperbranched polyurea is proposed. In this work, hyperbranched polyurea (UPA6N) is first synthesized by a simple method without any solvent. UPA6N is then added into industrial UF resin in different proportions as additives to manufacture particleboard and test its related properties. UF resin with a low molar ratio has a crystalline lamellar structure, and UF-UPA6N resin has an amorphous structure and rough surface. The results show that internal bonding strength increased by 58.5%, modulus of rupture increased by 24.4%, 24 h thickness swelling rate (%) decreased by 54.4%, and formaldehyde emission decreased by 34.6% compared with the unmodified UF particleboard. This may be ascribed to the polycondensation between UF and UPA6N, while UF-UPA6N resin forms more dense three-dimensional network structures. Finally, the application of UF-UPA6N resin adhesives to bond particleboard significantly improves the adhesive strength and water resistance and reduces formaldehyde emission, suggesting that the adhesive can be used as a green and eco-friendly adhesive resource for the wood industry.
Hydromagnetic Waves in Cold Nuclear Matter
Authors: Mişicu Şerban
Published: May 2023

I consider a proton–neutron fluid mixture placed in an ultra-strong external static magnetic field and derive the spin-independent, small-amplitude disturbances in infinitely extended systems. As a theoretical framework I adopt a hydrodynamical model for the proton and neutron fluids moving in a Skyrme mean-field derived from the time-dependent Hartree Fock formulation of the many-body nuclear problem. From the mass, momentum balance, and Maxwell equations, I set up a system of equations governing the electromagnetic field and the continuum-mechanical fields of the mixture. Next, the hydromagnetic equations are linearized, and the occurrence of small-amplitude distortions of the velocity field is analyzed for various orientations of the constant external magnetic induction with respect to the wave propagation vector. The derivation of the above equations is carried out for the inviscid case.
Study of Dynamic Viscoelasticity of a Mineral Oil-Based Magnetic Fluid
Authors: Li Zhanxian , Guo Yifei , Wang Hujun , Deng Chengyao , Dong Jiahao , Song Zhongru , Li Zhenkun
Published: May 2023

Magnetic fluid is a field-responsive intelligent fluid, which has the flow characteristics of liquid and the elastic properties of solid. Because of its unique properties, it has a strong application prospect in the fields of magnetic soft robot, intelligent sensor, and so on. Dynamic viscoelasticity is a significant index to investigate the performance of magnetic fluid in the application process. In this paper, the dynamic viscoelasticity of a homemade mineral oil-based magnetic fluid was investigated under oscillatory shear experimental conditions using an MCR302 rheometer, and the effects of different temperatures and magnetic fields on the dynamic viscoelasticity were examined. Amplitude sweeps tests showed that the value of the storage modulus remained constant within the linear viscoelastic region (LVE) and the stable structure was not destroyed. As the magnetic field strength increased or the temperature increased, the range of the linear viscoelastic zone decreased. At large amplitude, the loss modulus will first appear as a peak and then decrease. The frequency sweep experiment showed that the storage modulus and loss modulus increased with the increase in angular frequency, and the greater the magnetic field intensity, the longer the internal structure relaxation time. When the magnetic field was constant, the higher the temperature, the smaller the storage modulus and loss modulus of the magnetic fluid. At high temperature, the loss coefficient of mesmeric fluid was large, and the magnetic fluid was more viscous. The lower the temperature is, the smaller the loss coefficient of the magnetic fluid is, and the magnetic fluid is more pliant. The study of dynamic viscoelasticity of magnetic fluids lays the foundation for establishing the complete structure intrinsic relationship of magnetic fluids and provides guidance for the application of magnetic fluids in magnetic 3D printing, droplet robot, and smart wear.
Magnetism and Exchange Bias Properties in Ba2ScRuO6
Authors: Mohanty Prachi , Marik Sourav , Singh Ravi Prakash
Published: May 2023

This paper presents structural, detailed magnetic, and exchange bias studies in polycrystalline Ba2ScRuO6 synthesized at ambient pressure. In contrast to its strontium analogue, this material crystallizes in a 6L hexagonal structure with space group P3¯m1. The Rietveld refinement using the room-temperature powder XRD pattern suggests a Ru-Sc disorder in the structure. The temperature variation of the DC electrical resistivity highlights a semiconducting behavior with the electron conduction corresponding to Mott’s 3D variable range hopping (VRH) model. The detailed magnetization measurements show that Ba2ScRuO6 develops antiferromagnetic ordering at TN≈ 9 K. Interestingly, below 9 K (TN), the field-cooled magnetic field variation (FC) of the magnetization curves highlights an exchange bias effect in the sample. The exchange bias field reaches a maximum value of 1.24 kOe at 2 K. The exchange bias effect below the magnetic ordering temperature can be attributed to the inhomogeneous magnetic correlations due to the disorder in the structure. Remarkably, the appearance of a large exchange bias field in Ba2ScRuO6 indicates that inhomogeneous hexagonal double perovskites are a promising class to explore new materials having potential applications in spintronics.
Transitive Deficiency One Parallelisms of PG(3, 7)
Authors: Topalova Svetlana , Zhelezova Stela
Published: May 2023

Consider the n-dimensional projective space PG(n,q) over a finite field with q elements. A spread in PG(n,q) is a set of lines which partition the point set. A parallelism is a partition of the set of lines by spreads. A deficiency one parallelism is a partial parallelism with one spread less than the parallelism. A transitive deficiency one parallelism corresponds to a parallelism possessing an automorphism group which fixes one spread and is transitive on the remaining spreads. Such parallelisms have been considered in many papers. As a result, an infinite family of transitive deficiency one parallelisms of PG(n,q) has been constructed for odd q, and it has been proved that the deficiency spread of a transitive deficiency one parallelism must be regular, and its automorphism group should contain an elation subgroup of order q2. In the present paper we construct parallelisms of PG(3,7) invariant under an elation group of order 49 with some additional properties, and thus we succeed to obtain all (46) transitive deficiency one parallelisms of PG(3,7). The three parallelisms from the known infinite family are among them. As a by-product, we also construct a much bigger number (55,022) of parallelisms which have the same spread structure, but are not transitive deficiency one.
Optical Solitons and Modulation Instability Analysis with Lakshmanan–Porsezian–Daniel Model Having Parabolic Law of Self-Phase Modulation
Authors: Al-Kalbani Kaltham K. , Al-Ghafri Khalil S. , Krishnan Edamana V. , Biswas Anjan
Published: May 2023

This paper seeks to find optical soliton solutions for Lakshmanan–Porsezian–Daniel (LPD) model with the parabolic law of nonlinearity. The spatiotemporal dispersion is included to the model, as it can contribute to handling the problem of internet bottleneck. This study was performed analytically using the traveling wave hypothesis to reduce the model to an integrable form. Then, the resulting equation was handled with two approaches, namely, the auxiliary equation method and the Bernoulli subordinary differential equation (sub-ODE) method. With an intentional focus on hyperbolic function solutions, abundant optical soliton waves including W-shaped, bright, dark, kink-dark, singular, kink, and antikink solitons were derived with the existing conditions. Furthermore, the behaviors of some optical solitons are illustrated. The spatiotemporal dispersion was found to significantly affect the pulse propagation dynamics. Finally, the modulation instability (MI) of the LPD model is explained in detail along with the extraction of the expression of MI gain.
On the Regulation of Wind Energy Conversion Systems Working as Conventional Generation Plants
Authors: Lopez-Garcia Irvin , Lopez-Monsalvo Cesar S. , Gomez-Gonzalez Oscar , Sanabria-Villamizar Mauricio , Beltran-Carbajal Francisco , Escarela-Perez Rafael
Published: May 2023

In this work, we obtain bounds for the wind speed interval in which a wind energy conversion system can be regulated in a similar manner to a conventional power generation plant. In particular, we conducted a steady-state analysis of a wind turbine coupled to a doubly fed induction generator (DFIG) that delivers power according to the electric grid requirements, and in a safe manner. In this sense, our main contribution is twofold. On the one hand, it involves expanding the secure operation window by adjusting the gearbox ratio, thus improving the reliability of the utility of grid integration. On the other hand, the WECS is controlled within new, safe wind speed intervals through a passivity-based controller and a proportional–integral controller, showing adequate performances in both cases.
Applications of Some Subclasses of Meromorphic Functions Associated with the q-Derivatives of the q-Binomials
Authors: Ali Ekram E. , Srivastava Hari M. , Lashin Abdel Moneim Y. , Albalahi Abeer M.
Published: May 2023

In this article, we make use of the q-binomial theorem to introduce and study two new subclasses ℵ(αq,q) and ℵ(α,q) of meromorphic functions in the open unit disk U, that is, analytic functions in the punctured unit disk U∗=U\{0}={z:z∈Cand0<z<1}. We derive inclusion relations and investigate an integral operator that preserves functions which belong to these function classes. In addition, we establish a strict inequality involving a certain linear convolution operator which we introduce in this article. Several special cases and corollaries of our main results are also considered.
Simulation and Economic Analysis of the Biotechnological Potential of Biomass Production from a Microalgal Consortium
Authors: Cabrera-Capetillo Christian Ariel , Castillo-Baltazar Omar Surisadai , Petriz-Prieto Moisés Abraham , Guzmán-López Adriana , Valdovinos-García Esveidi Montserrat , Bravo-Sánchez Micael Gerardo
Published: May 2023

The biomass of microalgae and the compounds that can be obtained from their processing are of great interest for various economic sectors. Chlorophyll from green microalgae has biotechnological applications of great potential in different industrial areas such as food, animal feed, pharmaceuticals, cosmetics, and agriculture. In this paper, the experimental, technical and economic performance of biomass production from a microalgal consortium (Scenedesmus sp., Chlorella sp., Schroderia sp., Spirulina sp., Pediastrum sp., and Chlamydomonas sp.) was investigated in three cultivation systems (phototrophic, heterotrophic and mixotrophic) in combination with the extraction of chlorophyll (a and b) on a large scale using simulation; 1 ha was established as the area for cultivation. In the laboratory-scale experimental stage, biomass and chlorophyll concentrations were determined for 12 days. In the simulation stage, two retention times in the photobioreactor were considered, which generated six case studies for the culture stage. Subsequently, a simulation proposal for the chlorophyll extraction process was evaluated. The highest microalgae biomass concentration was 2.06 g/L in heterotrophic culture, followed by mixotrophic (1.98 g/L). Phototrophic and mixotrophic cultures showed the highest chlorophyll concentrations of 20.5 µg/mL and 13.5 µg/mL, respectively. The simulation shows that higher biomass and chlorophyll production is attained when using the mixotrophic culture with 72 h of retention that we considered to evaluate chlorophyll production (a and b). The operating cost of the entire process is very high; the cultivation stage has the highest operating cost (78%), mainly due to the high energy consumption of the photobioreactors.
Marine Puupehenone and Puupehedione: Synthesis and Future Perspectives
Authors: Rosales Martínez Antonio , Rodríguez-García Ignacio
Published: May 2023

Puupehenone and puupehedione are natural products isolated from marine organisms. These compounds display a broad spectrum of biological activities, the in vitro antitubercular activity of puupehenone being a stand out, and are equipped with an interesting structural complexity. These products have served to stimulate the continual interest of the synthetic community. The first part of this article is a review of their total synthesis, using natural compounds which have the potential to be transformed into these marine compounds as starting materials; the synthetic routes employed to generate the basic skeleton; and the advances made to synthesize the pyran C ring with the required diastereoselectivity to obtain the natural products. Finally, this perspective shows a personal reflection of the authors on a possible unified and efficient retrosynthetic route that could allow easy access to these natural products, as well as their epimers at the C8 carbon and which could be used to address future biological issues in the production of pharmacologically active compounds.
Influence of Intestinal Barrier on Alleviating an Increase in Blood Pressure by Sodium Alginate Intake in 2-Kidney, 1-Clip Renovascular Hypertensive Rats
Authors: Maruyama Saki , Segawa Yukiko , Harui Ayaka , Yamamoto Kanae , Hashimoto Hiroko , Osera Tomoko , Kurihara Nobutaka
Published: May 2023

Sodium alginate (SALG) is a substance derived from brown seaweed that has been shown to reduce blood pressure (BP). However, its effects on renovascular hypertension caused by 2-kidney, 1-clip (2K1C) are not yet clear. Previous research suggests that hypertensive rats have increased intestinal permeability, and that SALG improves the gut barrier in inflammatory bowel disease mouse models. Therefore, the goal of this study was to determine whether the antihypertensive effects of SALG involve the intestinal barrier in 2K1C rats. Rats were fed either a 1.0% SALG diet or a control diet for six weeks after being subjected to 2K1C surgery or a sham operation. The systolic BP was measured weekly, and the mean arterial BP was measured at the end of the study. Intestinal samples were taken for analysis, and plasma lipopolysaccharide (LPS) levels were measured. The results showed that BP in 2K1C rats was significantly higher than in SHAM rats when fed CTL, but not when fed SALG. The gut barrier in 2K1C rats was improved by SALG intake. Plasma LPS levels also differed depending on the animal model and diet. In conclusion, dietary SALG may alleviate 2K1C renovascular hypertension by altering the gut barrier.
Design, Synthesis, and Anticancer Activity of Novel 3,6-Diunsaturated 2,5-Diketopiperazines
Authors: Li Xiaolin , Xun Tianrong , Xu Huayan , Pang Xiaoyan , Yang Bin , Wang Junfeng , Zhou Xuefeng , Lin Xiuping , Tan Suiyi , Liu Yonghong , Liao Shengrong
Published: May 2023

Based on the marine natural products piperafizine B, XR334, and our previously reported compound 4m, fourteen novel 3,6-diunsaturated 2,5-diketopiperazine (2,5-DKP) derivatives (1, 2, 4–6, 8–16), together with two known ones (3 and 7), were designed and synthesized as anticancer agents against the A549 and Hela cell lines. The MTT assay results showed that the derivatives 6, 8–12, and 14 had moderate to good anticancer capacities, with IC50 values ranging from 0.7 to 8.9 μM. Among them, compound 11, with naphthalen-1-ylmethylene and 2-methoxybenzylidene functions at the 3 and 6 positions of 2,5-DKP ring, respectively, displayed good inhibitory activities toward both A549 (IC50 = 1.2 μM) and Hela (IC50 = 0.7 μM) cancer cells. It could also induce apoptosis and obviously block cell cycle progression in the G2/M phases in both cells at 1.0 μM. The electron-withdrawing functions might not be favorable for the derivatives with high anticancer activities. Additionally, compared to piperafizine B and XR334, these semi-N-alkylated derivatives have high liposolubilities (>1.0 mg mL−1). Compound 11 can be further developed, aiming at the discovery of a novel anticancer candidate.
Remdesivir Treatment Lacks the Effect on Mortality Reduction in Hospitalized Adult COVID-19 Patients Who Required High-Flow Supplemental Oxygen or Invasive Mechanical Ventilation
Authors: Huang Chienhsiu , Lu Tsung-Lung , Lin Lichen
Published: May 2023

Background and Objectives: The therapeutic impact of remdesivir on hospitalized adult COVID-19 patients is unknown. The purpose of this meta-analysis was to compare the mortality outcomes of hospitalized adult COVID-19 patients receiving remdesivir therapy to those of patients receiving a placebo based on their oxygen requirements. Materials and Methods: The clinical status of the patients was assessed at the start of treatment using an ordinal scale. Studies comparing the mortality rate of hospitalized adults with COVID-19 treated with remdesivir vs. those treated with a placebo were included. Results: Nine studies were included and showed that the risk of mortality was reduced by 17% in patients treated with remdesivir. Hospitalized adult COVID-19 patients who did not require supplemental oxygen or who required low-flow oxygen and were treated with remdesivir had a lower mortality risk. In contrast, hospitalized adult patients who required high-flow supplemental oxygen or invasive mechanical ventilation did not have a therapeutic benefit in terms of mortality. Conclusions: The clinical benefit of mortality reduction in hospitalized adult COVID-19 patients treated with remdesivir was associated with no need for supplemental oxygen or requiring supplemental low-flow oxygen at the start of treatment, especially in those requiring supplemental low-flow oxygen.
Accuracy of ZedView, the Software for Three-Dimensional Measurement and Preoperative Planning: A Basic Study
Authors: Nozaki Asami , Imai Norio , Funayama Kazuhisa , Horigome Yoji , Suzuki Hayato , Minato Izumi , Kobayashi Koichi , Kawashima Hiroyuki
Published: May 2023

Background and Objectives: In the field of orthopedic surgery, novel techniques of three-dimensional shape modeling using two-dimensional tomographic images are used for bone-shape measurements, preoperative planning in joint-replacement surgery, and postoperative evaluation. ZedView® (three-dimensional measurement instrument and preoperative-planning software) had previously been developed. Our group is also using ZedView® for preoperative planning and postoperative evaluation for more accurate implant placement and osteotomy. This study aimed to evaluate the measurement error in this software in comparison to a three-dimensional measuring instrument (3DMI) using human bones. Materials and Methods: The study was conducted using three bones from cadavers: the pelvic bone, femur, and tibia. Three markers were attached to each bone. Study 1: The bones with markers were fixed on the 3DMI. For each bone, the coordinates of the center point of the markers were measured, and the distances and angles between these three points were calculated and defined as “true values.” Study 2: The posterior surface of the femur was placed face down on the 3DMI, and the distances from the table to the center of each marker were measured and defined as “true values.” In each study, the same bone was imaged using computed tomography, measured with this software, and the measurement error from the corresponding “true values” was calculated. Results: Study 1: The mean diameter of the same marker using the 3DMI was 23.951 ± 0.055 mm. Comparisons between measurements using the 3DMI and this software revealed that the mean error in length was <0.3 mm, and the error in angle was <0.25°. Study 2: In the bones adjusted to the retrocondylar plane with the 3DMI and this software, the average error in the distance from the planes to each marker was 0.43 (0.32–0.58) mm. Conclusion: This surgical planning software could measure the distance and angle between the centers of the markers with high accuracy; therefore, this is very useful for pre- and postoperative evaluation.
Risk Factors for Bleeding Varicose Veins in Patients with Chronic Venous Disease
Authors: Costa Davide , Ielapi Nicola , Minici Roberto , Peluso Antonio , Bracale Umberto Marcello , Andreucci Michele , Serra Raffaele
Published: May 2023

Background and Objectives: Chronic venous disease (CVD) is a widespread clinical condition that is very common in western countries in the adult general population with a wide range of clinical manifestations, such as varicose veins (VVs) that in certain circumstances may complicate with rupture and subsequent bleeding that may even be fatal. The aim of this study is to evaluate risk factors for bleeding VVs. Materials and Methods: This is a retrospective study conducted in patients with CVD complicating with bleeding of VVs over a 4-year period (2019–2022). A random sample, for the same 4-year period and with a 3:1 ratio, was selected from other CVD patients without VVs bleeding that served as the control group. Results: From a global population of 1048 patients with CVD over a 4-year period, a total of 33 patients (3.15%) with VVs bleeding were selected. A group of 99 patients without VVs bleeding were randomly selected from the total population of 1048 patients with CVD. Findings of this study showed that advanced clinical stage of CVD (i.e., C4b stage), advanced age, living alone, suffering from cardiovascular co-morbidity (i.e., hypertension and CHF), assuming certain drugs that act on blood coagulation (i.e., aspirin, anticoagulants), assuming psychotropic medication, having particular venous reflux patterns (i.e., below-knee GSV reflux, non-saphenous veins reflux, Cockett’s perforators reflux), and not having been assessed and treated previously for CVD (i.e., with VADs, CT, or surgery) may predispose a high risk for bleeding VVs. Conclusions: Bleeding VVs may be a life-threatening complications of CVD patients, and monitoring risk factors found in this study and others that, hopefully, may be discovered in the future through further focused research will help to reduce the impact of this problem in this patient population.
Enhanced Recovery of Zn from Carbonate-Type Mixed Oxidized Ore (CMO) by Combining Organic Acid Leaching with Mechanical Activation
Authors: Deng Hao , Pan Xuelin , Chen Fanyun , Gao Qingshan , Tian Chen , Lin Zhang
Published: May 2023

With excessive consumption of sulfide ores, using low-grade Pb-Zn mixed ores to obtain Zn has attracted more attention. Acid leaching is an effective method for Zn recovery; however, a high concentration of inorganic acid brings severe environmental issues, including acidic wastewater, contaminated soil, etc. Compared with inorganic acid, organic acid showed lower acidity and toxicity. Herein, we applied an effective method for Zn recovery from carbonate-type Pb-Zn mixed ore (CMO), by combining organic acid leaching with mechanical activation. Among the organic acids applied (lactic, malonic, citric, amber, acetic, and tartaric one), lactic acid was selected for its high leaching efficiency. The optimum condition was identified via response surface methodology, with a lactic acid concentration of 1.15 mol/L, L/S ratio of 20, leaching time of 75 min, and temperature of 75 °C. The effect of mechanical activation on Zn leaching was further investigated. The leaching efficiency increased to 90.1% after mechanical activation, which was the highest leaching efficiency for organic acid leaching. Mineralogical characterization showed that the bulk minerals were milled into small particles while the proportion of amorphization increased. Such activation effects improved the acid-solubility of Zn speciation. This work provided a potential green method for metal recovery from low-grade sources.
Investigation on Interface of CuW/Al Composite Using Ni Interlayer by Vacuum Hot-Pressing Diffusion Bonding
Authors: Wang Chan , Chen Jian , Shao Wenting , Liang Shuhua
Published: May 2023

In this study, the bonding of a CuW/Al composite with a Ni interlayer was designed and established by vacuum hot-pressing diffusion bonding. The interfacial microstructure was systematically discussed based on experimental characterization and first-principles calculations. The result indicated that the interface consisted of intermetallic compounds (IMCs) of Al3Ni2 and a few of Al3Ni. The interfacial microstructure significantly differed from the interface without the Ni interlayer. The growth kinetics of the Al3Ni2 layer followed a parabolic behavior, which was mainly affected by the volume diffusion mechanism. The interfacial thickness decreased significantly, and the average thickness was ~35 μm. The microstructural evolution revealed that Al3Ni2 was the phase that was formed first. By introducing a Ni interlayer, the interfacial strength was significantly enhanced due to the IMCs that were changed from Al–Cu and Al–W IMCs to Al–Ni IMCs. The maximum shear strength reached 90.9 MPa, which was increased by 76% compared to that of the sample without the Ni interlayer. An analysis of the fracture morphology analysis showed that the crack was prone to exist at the Al3Ni2/Ni interface and presented a cleavage fracture characteristic.
Dietary Intake of Micronutrients and Disease Severity in Patients with Amyotrophic Lateral Sclerosis
Authors: Barros Acsa Nara de Araújo Brito , Felipe Maria Luisa do Nascimento , Barbosa Isabelle Ribeiro , Leite-Lais Lucia , Pedrosa Lucia Fátima Campos
Published: May 2023

Vitamins and essential metals have been studied as potential risk and prognostic factors in amyotrophic lateral sclerosis (ALS). This study aimed to evaluate the prevalence of inadequate micronutrient intake in ALS patients, comparing subgroups according to the disease severity. Data were obtained from the medical records of 69 individuals. Assessment of disease severity was determined by the revised ALS Functional Scale (ALSFRS-R), using the median as the cutoff. The prevalence of inadequate micronutrient intake was estimated using the Estimated Average Requirements (EAR) cut-point method. The prevalence of inadequate vitamin D, E, riboflavin, pyridoxine, folate, cobalamin, calcium, zinc, and magnesium intake was considered severe. Patients with lower ALSFRS-R scores had lower intakes of vitamin E (p < 0.001), niacin (p = 0.033), pantothenic acid (p = 0.037), pyridoxin (p = 0.008), folate (p = 0.009) and selenium (p = 0.001). Therefore, ALS patients should be monitored regarding dietary intake of micronutrients essential in neurological processes.