Magnetic Properties and THz Emission from Co/CoO/Pt and Ni/NiO/Pt Trilayers

THz radiation emitted by ferromagnetic/non-magnetic bilayers is a new emergent field in ultra-fast spin physics phenomena with a lot of potential for technological applications in the terahertz (THz) region of the electromagnetic spectrum. The role of antiferromagnetic layers in the THz emission process is being heavily investigated at the moment. In this work, we fabricate trilayers in the form of Co/CoO/Pt and Ni/NiO/Pt with the aim of studying the magnetic properties and probing the role of very thin antiferromagnetic interlayers like NiO and CoO in transporting ultrafast spin current. First, we reveal the static magnetic properties of the samples by using temperature-dependent Squid magnetometry and then we quantify the dynamic properties with the help of ferromagnetic resonance spectroscopy. We show magnetization reversal that has large exchange bias values and we extract enhanced damping values for the trilayers. THz time-domain spectroscopy examines the influence of the antiferromagnetic interlayer in the THz emission, showing that the NiO interlayer in particular is able to transport spin current.

Therapeutic Plasma Exchange in Catastrophic Antiphospholipid Syndrome (CAPS): A Rare Case Report and Literature Review

BACKGROUND/AIM

Catastrophic antiphospholipid syndrome (CAPS) may be the first manifestation ("de novo") of antiphospholipid syndrome (APS) or a complication in the clinical course of patients known to have this syndrome. Approximately 40% of patients had an associated autoimmune disease, mainly, systemic lupus erythematosus (SLE). The trigger can be one of the following: infections, surgical interventions, neoplasms, pregnancy, discontinuation of anticoagulant treatment, and others. CAPS is a medical emergency in which early identification and prompt initiation of aggressive therapy is extremely important. According to the Guidelines for the use of Therapeutic Apheresis in Clinical Practice developed by the American Society for Apheresis (ASFA), last updated in April 2023, in CAPS, the indication for therapeutic plasma exchange (TPE) is category I, grade 2C.

CASE REPORT

We present a case of probable CAPS secondary to systemic lupus erythematosus (SLE) in an elderly patient in whom clinical and biological improvement was achieved through a multidisciplinary approach and prompt initiation of TPE. Because TPE is considered first-line therapy in CAPS, we initiated the procedure as soon as the attending rheumatologist raised this suspicion. Four plasmapheresis sessions were performed in the Intensive Care Unit. We used TPE by membrane filtration. Following the therapeutic intervention with TPE, corticotherapy (Solumedrol in puls-therapy), cyclophosphamide and anticoagulant treatment, the evolution was favourable, with clinical and biological improvement.

CONCLUSION

The prompt initiation of TPE, because of the suspicion of CAPS, increases the chances of a favourable evolution.

Novel Rare Earth (RE)-Free Nanocomposite Magnets Derived from L10-Phase Systems

In the quest for novel rare earth (RE)-free magnetic materials, which also exhibit other additional properties such as good corrosion resistance and potential to operate at higher temperatures, an alloy deriving from the binary FePt system, with Mo and B addition, has been synthesized for the first time, using the out-of-equilibrium method of rapid solidification form the melt. The alloy with the composition Fe₄₉Pt₂₆Mo₂B₂₃ has been subjected to thermal analysis through differential scanning calorimetry in order to detect the structural disorder - order phase transformation as well as to study the crystallization processes. For the stabilization of the formed hard magnetic phase, the sample has been annealed at 600 °C and further structurally and magnetically characterized by means of X-ray diffraction, transmission electron microscopy, ⁵⁷Fe Mössbauer spectrometry as well as magnetometry experiments. It has been proven that after annealing at 600 °C the tetragonal hard magnetic L1₀ phase emerges via crystallization from a disordered cubic precursor and becomes the predominant phase in terms of relative abundance. Moreover, it has been revealed by quantitative analysis via Mössbauer spectroscopy that the annealed sample exhibits a complex phase structure, where the L1₀ hard magnetic phase is accompanied by few other soft magnetic phases, in minority abundance: the cubic A1, orthorhombic Fe₂B and residual intergranular region. The magnetic parameters have been derived from 300 K hysteresis loops. It was shown that, contrary to the as-cast sample which behaves as a typical soft magnet, the annealed sample presents strong coercivity and high remanent magnetization, accompanied by a large saturation magnetization. These findings offers good insight into the potential developing of novel class of RE-free permanent magnets, based on Fe-Pt-Mo-B, where the magnetic performance emerges from the co-existence of hard and soft magnetic phases in controlled and tunable proportions, capable of finding good applicability in fields requiring good catalytic properties and strong corrosion resistance.

Microcrystallization Effects Induced by Laser Annealing in Cr-Al-C Ion-Beam-Sputtered Films

The microcrystallization effects induced by the real-time laser annealing in Cr-Al-C ion-sputtered films with an off-stoichiometric composition are studied. The laser annealing has been performed during Raman experiments with tunable laser power densities. Morphostructural changes induced during laser annealing were investigated by scanning electron microscopy. It has been proven that real-time laser annealing in the high-laser-power-density mode promotes quite clearly the formation of nanograins through surface microcrystallization. Detailed Raman analysis allowed for the observation of the optical modes that unequivocally identifies the low-symmetry 211 MAX phase in both low- and high-power-density modes. Such findings confirming the microcrystallization as well as the stabilization of the grain boundaries by carbon nanoclustering are confirmed by X-ray diffraction results, where the single-phase hexagonal 211 was unequivocally proven to form in the high-laser-power-density mode. The microcrystallization via laser annealing was also found to be beneficial for the elastic behavior, as the hardness values between 16 and 26 GPa were found after laser annealing, accompanied by a significantly high Young's bulk modulus. Such large values, larger than those in bulk compounds, are explicable by the nanometric grain sizes accompanied by the increase of the grain boundary regions.

Temperature-Dependent Phase Evolution in FePt-Based Nanocomposite Multiple-Phased Magnetic Alloys

A quaternary Fe-Pt-Nb-B alloy has been fabricated by the melt spinning method with the purpose of the formation of crystallographically coherent multiple magnetic phases, emerging from the same metastable precursor, as well as to investigate the phase interactions and the influence of their coupling on magnetic performances. For this purpose, extended structural and magnetic investigations were undertaken by making use of X-ray diffraction, transmission electron microscopy, and ⁵⁷Fe Mössbauer spectroscopy, as well as magnetic measurements using SQUID magnetometry. It was documented that intermediate metastable phases formed during primary crystallization, in intermediate stages of annealing, and a growth-dominated mode was encountered for the secondary crystallization stage upon annealing at 700 °C and 800 °C where fcc Fe3Pt and fct Fe2B polycrystalline were formed. The Mössbauer investigations have documented rigorously the hyperfine parameters of each of the observed phases. The fcc A1 FePt phase was shown to exhibit a peculiar ferromagnetic transition, and this transition has been proven to occur gradually between 300 K and 77 K. The magnetic measurements allowed us to identify the annealing at 700 °C as optimal for obtaining good magnetic features. Coercive field dependence shows similarities to the random anisotropy model for samples annealed at 500 °C to 700 °C which are nanocrystalline. These results show good perspectives for use in applications where different magnetic states are required at different operating temperatures.

Morpho-Structural Investigations and Carbon Nanoclustering Effects in Cr-Al-C Intermetallic Alloys

Intermetallic Cr-Al-C thin films from the 211 class of MAX phases were fabricated via ion beam deposition and structural investigations were undertaken to obtain information about morpho-structural effects propelled by carbon excess in the stoichiometry of the films. In order to promote the occurrence of the Cr₂AlC MAX phase, the stoichiometric thin films were subsequently annealed at two temperature values: 650 °C and 700 °C in UHV conditions for 30 min. The morpho-structural effects in both as-deposited and annealed films were monitored using scanning electron microscopy, X-ray diffraction, and Raman spectroscopy. XRD analysis showed that the as-deposited sample was almost completely crystallized in the hexagonal Cr₂AlC structure, with a remaining amorphous fraction of about 17%, most probably rich in carbon. Raman analysis allowed the identification of three spectral regions, two of them encompassing the Raman optical modes belonging to the Cr₂AlC 211 MAX phase, while the third one gave strong evidence of highly intense and large D- and G-bands of carbon. Structural parameters such as the crystal lattice parameters as well as the volume of the crystal unit cell were found to decrease upon annealing; this decrease is attributed to the grain growth. The average crystallite dimension was proven to increase after annealing, while the lattice micro-strain lowered to approximately 63% in the annealed thin film compared to the as-deposited one. Well-formed and intense Raman peaks attributed to D- and G-bands of carbon were also observed and, corroborated with the structural data, seemed to indicate an overall increased level of crystal ordering as well as potential carbon nanoclustering after thermal treatments with thin Cr₂AlC films. This observed phenomenon concords with previously documented reports on ab initio modelling of possible Cr₂AlC structures with carbon excess.

Mathematical Modeling and Optimization of Lactobacillus Species Single and Co-Culture Fermentation Processes in Wheat and Soy Dough Mixtures

To improve food production via fermentation with co-cultures of microorganisms (e.g., multiple lactic acid bacteria-LAB strains), one must fully understand their metabolism and interaction patterns in various conditions. For example, LAB can bring added quality to bread by releasing several bioactive compounds when adding soy flour to wheat flour, thus revealing the great potential for functional food development. In the present work, the fermentation of three soy and wheat flour mixtures is studied using single cultures and co-cultures of Lactobacillus plantarum and Lactobacillus casei. Bio-chemical processes often require a significant amount of time to obtain the optimal amount of final product; creating a mathematical model can gain important information and aids in the optimization of the process. Consequently, mathematical modeling is used to optimize the fermentation process by following these LAB’s growth kinetics and viability. The present work uses both multiple regression and artificial neural networks (ANN) to obtain the necessary mathematical model, useful in both prediction and process optimization. The main objective is to find a model with optimal performances, evaluated using an ANOVA test. To validate each obtained model, the simulation results are compared with the experimental data.

The Effect of Convalescent Plasma in Patients With Covid-19 in Intensive Care Unit

BACKGROUND/AIM

Convalescent plasma collected from COVID-19 survivors contains antibodies against receptor binding domains with potent antiviral activity. The use of this therapy for COVID-19 is still under investigation, as the pathophysiological and immunological mechanisms responsible for the evolution of the disease have not been fully identified.

PATIENTS AND METHODS

In this retrospective observational study, we included all patients with a confirmed SARS-Cov-2 infection based on positive RT-PCR testing, who received convalescent plasma treatment in addition to standard therapy, between 17.05.2020 and 27.11.2020, following hospitalization in the Anaesthesia and Intensive Care Unit of the Sibiu County Emergency Clinical Hospital, Romania.

RESULTS

Convalescent plasma therapy of patients with SARS-Cov-2 infection and severe forms of the disease (requiring only high-flow oxygen therapy or non-invasive ventilation) significantly improved inflammatory markers (CRP, fibrinogen) and ventilatory parameters (SaO2, paO2, paO2/FiO2) reducing the need of supplemental oxygen delivery (p<0.05). Other factors that had a significant influence on the outcome were age and comorbidity.

CONCLUSION

Inflammatory markers and ventilatory parameters were significantly improved and the need of supplemental oxygen delivery was reduced in COVID-19 patients treated with convalescent plasma.

Silica Coating of Ferromagnetic Iron Oxide Magnetic Nanoparticles Significantly Enhances Their Hyperthermia Performances for Efficiently Inducing Cancer Cells Death In Vitro

Increasing the biocompatibility, cellular uptake, and magnetic heating performance of ferromagnetic iron-oxide magnetic nanoparticles (F-MNPs) is clearly required to efficiently induce apoptosis of cancer cells by magnetic hyperthermia (MH). Thus, F-MNPs were coated with silica layers of different thicknesses via a reverse microemulsion method, and their morphological, structural, and magnetic properties were evaluated by multiple techniques. The presence of a SiO2 layer significantly increased the colloidal stability of F-MNPs, which also enhanced their heating performance in water with almost 1000 W/gFe as compared to bare F-MNPs. The silica-coated F-MNPs exhibited biocompatibility of up to 250 μg/cm2 as assessed by Alamar Blues and Neutral Red assays on two cancer cell lines and one normal cell line. The cancer cells were found to internalize a higher quantity of silica-coated F-MNPs, in large endosomes, dispersed in the cytoplasm or inside lysosomes, and hence were more sensitive to in vitro MH treatment compared to the normal ones. Cellular death of more than 50% of the malignant cells was reached starting at a dose of 31.25 μg/cm2 and an amplitude of alternating magnetic field of 30 kA/m at 355 kHz.

Partnering bevacizumab with irinotecan as first line-therapy of metastatic colorectal cancer improves progression free survival-A retrospective analysis

Colorectal cancer remains one of the most frequent malignancies (third place at both genders) worldwide in the last decade, owing to significant changes in modern dietary habits. Approximately half of the patients develop metastases during the course of their disease. The available therapeutic armamentarium is constantly evolving, raising questions regarding the best approach for improving survival. Bevacizumab remains one of the most widely used therapies for treating metastatic colorectal cancer and can be used after progression. This study aimed to identify the best chemotherapy partner for bevacizumab after progression. We performed a retrospective analysis of patients with metastatic colorectal cancer who were treated with bevacizumab as first- and second-line chemotherapy. Data were collected for 151 patients, 40 of whom were treated with double-dose bevacizumab after the first progression. The two standard chemotherapy regimens combined with bevacizumab were FOLFIRI/CAPIRI and FOLFOX4/CAPEOX. The initiation of first-line treatment with irinotecan-based chemotherapy improved progression-free survival and time to treatment failure but not overall survival. After the first progression, retreatment with the same regimen as that used in the induction phase was the best approach for improving overall survival (median overall survival: 46.5 vs. 27.0 months for the same vs. switched strategy, respectively). No correlations were observed between the dose intensity of irinotecan, oxaliplatin, 5-fluorouracil, or bevacizumab and the overall survival, progression-free survival in the first-/second-line treatment, and time to treatment failure. Interaction between an irinotecan-based regimen as a second-line treatment and double-dose bevacizumab after progression was associated with an improved overall survival (p = 0.06). Initiating systemic treatment with an irinotecan-based regimen in combination with bevacizumab improved the progression-free survival in the first-line treatment and time to treatment failure. In terms of overall survival, bevacizumab treatment after the first progression is better partnered with the same regimen as that used in the induction phase.

Magnetic Phase Coexistence and Hard-Soft Exchange Coupling in FePt Nanocomposite Magnets

With the aim of demonstrating phase coexistence of two magnetic phases in an intermediate annealing regime and obtaining highly coercive FePt nanocomposite magnets, two alloys of slightly off-equiatomic composition of a binary Fe-Pt system were prepared by dynamic rotation switching and ball milling. The alloys, with a composition Fe53Pt47 and Fe55Pt45, were subsequently annealed at 400 °C and 550 °C and structurally and magnetically characterized by means of X-ray diffraction, 57Fe Mössbauer spectrometry and Superconducting Quantum Interference Device (SQUID) magnetometry measurements. Gradual disorder-order phase transformation and temperature-dependent evolution of the phase structure were monitored using X-ray diffraction of synchrotron radiation. It was shown that for annealing temperatures as low as 400 °C, a predominant, highly ordered L10 phase is formed in both alloys, coexisting with a cubic L12 soft magnetic FePt phase. The coexistence of the two phases is evidenced through all the investigating techniques that we employed. SQUID magnetometry hysteresis loops of samples annealed at 400 °C exhibit inflection points that witness the coexistence of the soft and hard magnetic phases and high values of coercivity and remanence are obtained. For the samples annealed at 500 °C, the hysteresis loops are continuous, without inflection points, witnessing complete exchange coupling of the hard and soft magnetic phases and further enhancement of the coercive field. Maximum energy products comparable with values of current permanent magnets are found for both samples for annealing temperatures as low as 500 °C. These findings demonstrate an interesting method to obtain rare earth-free permanent nanocomposite magnets with hard-soft exchange-coupled magnetic phases.

A new desensitization protocol, overcoming hypersensitivity reactions to chemotherapy

e15523

Background: Despite the progress for cancer treatment, some drugs remain a cornerstone for an optimal approach. Hypersensitivity reactions to chemotherapy may render these essential chemotherapeutic agents useless and for some types of cancer continuing the therapeutic scheme could be crucial. Various regimens for desensitization to allow chemotherapy administration through the time were conceived, with different dilutions, time and settings of administration. Methods: A prospective study of patients with systemic treatment for histopathologically confirmed cancer in our Oncological Institute „Prof. Ion Chiricuta” Cluj-Napoca, with an allergic reaction during treatment being the keys inclusion criteria in the analysis. Patients were administered a three days desensitization regimen from the following cycle of treatment with blood samples that were taken to observe the predictive value of biological markers. Results: Eighty-two patients were the initial pool, with a median age of 56 years. Platin derivates containing regiments were responsible for an allergic reaction for 75 out of 82 patients. Four of them were known with a previous allergic reaction for chemotherapy in their personal medical history, and 56 of them had more than one chemotherapy line in their treatment. More than 688 desensitization cycles were administrated during our study with a rate of failure of 1.3 %. The main reason for discontinuation was disease progression or adjuvant character (limited duration) of the chemotherapy administration. Conclusions: Allergic reaction does not impede the administration of the responsible drug. A 3-day inpatient regimen could be a valuable option with a successful rate of administration without the need for ICU monitoring.

Gastric cancer: adjuvant chemotherapy versus chemoradiation. A clinical point of view

Gastric cancer represents one of the most severe cancers with poor overall survival. Despite the availability of published data on the efficacy of adjuvant treatment, the actual percentage of treated patients remains low. The toxicity of radiotherapy or chemotherapy regimens differ and clinicians need accessible tools in order to better select candidates for adjuvant treatment. In this review, we present published data from clinical trials and cancer registries that might be useful for properly balancing the efficacy and toxicity of adjuvant treatment in gastric cancer patients who underwent surgery with curative intent.

3D Superparamagnetic Scaffolds for Bone Mineralization under Static Magnetic Field Stimulation

We reported on three-dimensional (3D) superparamagnetic scaffolds that enhanced the mineralization of magnetic nanoparticle-free osteoblast cells. The scaffolds were fabricated with submicronic resolution by laser direct writing via two photons polymerization of Ormocore/magnetic nanoparticles (MNPs) composites and possessed complex and reproducible architectures. MNPs with a diameter of 4.9 ± 1.5 nm and saturation magnetization of 30 emu/g were added to Ormocore, in concentrations of 0, 2 and 4 mg/mL. The homogenous distribution and the concentration of the MNPs from the unpolymerized Ormocore/MNPs composite were preserved after the photopolymerization process. The MNPs in the scaffolds retained their superparamagnetic behavior. The specific magnetizations of the scaffolds with 2 and 4 mg/mL MNPs concentrations were of 14 emu/g and 17 emu/g, respectively. The MNPs reduced the shrinkage of the structures from 80.2 ± 5.3% for scaffolds without MNPs to 20.7 ± 4.7% for scaffolds with 4 mg/mL MNPs. Osteoblast cells seeded on scaffolds exposed to static magnetic field of 1.3 T deformed the regular architecture of the scaffolds and evoked faster mineralization in comparison to unstimulated samples. Scaffolds deformation and extracellular matrix mineralization under static magnetic field (SMF) exposure increased with increasing MNPs concentration. The results are discussed in the frame of gradient magnetic fields of ~3 × 10⁻⁴ T/m generated by MNPs over the cells bodies.

New 5-Thiazolyl-carbohydrazon-n-allyl-thiazolines Synthesis, characterization and antioxidant activity

In an effort to obtain new NSAIDs, that act as COX-2 selective inhibitors with simultaneous iNOS inhibition properties and direct antioxidant activity, we designed a series of 8 new compounds bearing the 5-thiazolyl-carbohydrazon-N-allyl-thiazoline scaffold. The synthesized compounds were physicochemically characterized by: 1H-NMR, MS and elemental analysis. An initial, in vitro, free radical scavenging assay (DPPH bleaching) test showed that most compounds are superior to standard antioxidants Trolox and BHT.

Alternative Solutions for Data Storage Using Magnetic Films Exchange-Coupled Through Non-Magnetic Layer

Abstract—We describe an alternative solution to encode information in magnetic films that goes beyond the conventional way of digital magnetic recording. In our approach the information is stored via a continuous variable, namely the remanent coupling angle between two magnetic films that are separated by a nonmagnetic spacer layer. Using the technique of nuclear resonant scattering (NRS) [1, 2] we show with good precision, how this coupling angle can be conveniently adjusted with high degree of remanence by shortly applied external magnetic fields. Moreover this effect is explained using a micromagnetic model [3, 4]. Extremely important for future applications of this concept, we demonstrate, that the remanent coupling angles can be read out via magneto-optical or magneto-resistance effects. In principle, this approach allows to design novel memory cells for advance data storage devices, where multiple states per unit cell can be generated and recorded. Index Terms—Magnetic films, data storage, FePt

The synthesis and antiproliferative activities of new arylidene-hydrazinyl-thiazole derivatives

New and known arylidene-hydrazinyl-thiazole derivatives have been synthesized by a convenient Hantzsch condensation. All compounds were evaluated for their in vitro cytotoxicity on two carcinoma cell lines, MDA-MB231 and HeLa. Significant antiproliferative activity for 2-(2-benzyliden-hydrazinyl)-4-methylthiazole on both MDA-MB-231 (IC50: 3.92 µg/mL) and HeLa (IC50: 11.4 µg/mL) cell lines, and for 2-[2-(4-methoxybenzylidene) hydrazinyl]-4-phenylthiazole on HeLa (IC50: 11.1 µg/mL) cell line is reported. Electrophoresis experiments showed no plasmid DNA (pTZ57R) cleavage in the presence of the investigated thiazoles.

Novel gas-stabilized iron clusters: synthesis, structure and magnetic behaviour

A novel method for the synthesis of nanostructured films produced by depositing gas-phase magnetic nanoparticles is presented and the properties of the films are reported. The technique mixes metal vapour and small argon clusters produced in a supersonic expansion. The condensed clusters are subsequently deposited in situ onto copper grids. The cluster size is controlled by the vapour pressure of the metal inside the pick-up chamber. Detailed analysis of the transmission electron micrographs of the Fe clusters shows that there is a simple linear relationship between the average metal cluster diameter and the metal vapour pressure during deposition. Furthermore, the nanoparticles show a relatively narrow size distribution for a given set of experimental conditions. Structural and magnetic investigations have been performed on Fe cluster samples, and the influence of the metal vapour pressure has been studied. Detailed analysis of the magnetic and structural data has been performed and valuable information such as cluster size distributions, strength of the interparticle dipolar interactions and average magnetic moment per cluster are derived. It is shown that, at room temperature, the magnetic behaviour of the films is consistent with nanoparticle supermoments interacting via dipolar interactions.

[Management of hypertension and obesity: the observatory of management of uncontrolled hypertensives with respect to the presence or absence of overweight (PHYSIObs)]

The object of this study was to compare the management of uncontrolled hypertensives (BP > 140/90 mmHg) by general practitioners with respect to the presence or absence of overweight (BMI > or =25 Kg/m2). A 2/1 stratification allowed comparison of 4080 patients who were overweight and 1951 patients with a normal body weight (normal BMI < 25 Kg/m2). The BP of patients who were overweight (> or =25 Kg/m2) was slightly higher than those with a normal BMI (161 +/- 12 mmHg vs. 159 +/- 12 mmHg, p < 0.001). The presence of a metabolic syndrome (43% vs. 7%, ATPIII criteria) was, logically, commoner in the patients overweight. However, the practitioners only recognised the presence of a metabolic syndrome in 65% of the overweight patients (28% true positives and 37% true negatives). The practitioners fixed their target value of systolic BP at 136.5 +/- 5.6 mmHg, in accordance with the recent recommendations of the Health Authorities. The targets were judged to be difficult to obtain in 18% of the overweight group and in 5% of patients with normal body weights. This optimism contrasted with the prescriptions, especially in the overweight patients, 46% of whom were treated by monotherapy and who remained for 44% on monotherapy at the end of the consultation. This descriptive study confirms the lack of awareness of the metabolic syndrome in overweight patients and identifies barriers to effective management of the hypertension of these high risk patients.