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The article studies the performance of a 14 cm bore solenoid wound with 400 meters of multifilament copper stabilized tape. Results suggest that the magnet reaches 175 A at 16 K with a central magnetic flux density of 1 Tesla.

The article discusses the design and testing of Mg[B.sub.2] windings. Findings reveal the feasibility of coils production using magnesium diboride conductor.

Several studies and experiments are conducted for the synthesis and testing of [Mg.sub.2] tapes and bindings in DC, as well as an AC regime. The analysis shows that in spite of some degradation, these windings exhibit very high critical currents.

A high-purity MgB4 phase has been synthesized and used as the precursor powder for the realization of in situ wires. Various final heat treatments, from 550 to 1100 °C for 20 min each, have been carried out to convert the inner mixture to MgB2. Critical current densities up to 1.75 × 106 and 0.98 × 106 A cm-2 at 4.2 and 20 K, with 0.2 T, up to 0.76 × 105 A cm-2 at 4.2 K and 4 T, and up to 0.78 × 105 A cm-2 at 20 K and 2 T were measured. Critical temperatures up to 38.5 K were measured. These results suggest that this could be a good alternative to both ex situ and classical in situ routes. [ABSTRACT FROM AUTHOR]

In the design and feasibility of electric power applications with MgB2 conductors, thermal conductivity plays an important role. In composite wires and tapes it is mainly determined by the amount of stabilizer (usually copper), while for coils the electric insulation and epoxy binder characteristics are added. In this paper we present results on quench development and propagation on isolated superconducting tapes and small single pancake coils cooled by thermal conduction, for three types of MgB2 tape with different stabilizations. The quench parameters at different temperatures, such as minimum quench energy (MQE), minimum propagation zone (MPZ) and quench propagation velocity (vp), are reported. A complete electrical and thermal characterization of the superconducting tapes and of non-superconducting materials used in the coil manufacture has been made. With these data, numerical computational models using finite element simulations have been performed for isolated wires and single pancake coils, and the results of the relevant quench parameters have been compared with the measured values. [ABSTRACT FROM AUTHOR]

Feasibility of industrial production of MgB2 cables and magnets has been established, thus leading to MRI systems realization. Apart from continuing the development in performances of both cable and magnet, a further important step consists in applying superconductive junctions to windings, to obtain a better field stability. In 2006 a technique to obtain some tens of Ampere in persistent mode operation in a joined MgB2 cable was found. Since then, short windings were repetitively built to test the progress of the performances of the junctions. Among them, a single junction, five meter long windings with a diameter of 260 millimeter were put in persistent mode (i.e. with total resistance less than 10-14 Ohm) with 300 Ampere circulating at 20 Kelvin, self-field; also windings with two junctions and about one meter long with the same diameter were put in persistent mode with 200 Ampere circulating at 20 Kelvin, self-field. [ABSTRACT FROM AUTHOR]

In the frame of a research and development project named LIMSAT several MgB2 tapes and windings were fabricated and tested in DC and AC current regime. All technical aspects related to the choice of the MgB2 tape layout as well as the winding technology and insulation will be reported. Different tape layout and insulating technique were used for the different windings, in particular several lengths of MgB2 multifilamentary Cu-stabilized Ni-sheathed tape. Critical current measurements on short samples of the tape used, performed in a cryogenic-free test facility, showed currents over 250 A at 20K, 1 T. Five non inductive MgB2 windings were made using lengths from about 35 to 130 m and tested in liquid He and liquid Ne. The results from electrical DC and AC tests are reported and discussed. [ABSTRACT FROM AUTHOR]

The properties of MgB2 have the potential to make this material a viable solution for applications in which temperature, costs or weight are considered relevant constraints. In order to realize large scale applications, it is important to investigate the material, but also the winding process for MgB2 wires and tapes. In the literature small coils have already demonstrated central magnetic flux density above 2 Tesla, overcoming common winding problems related to MgB2 wires. In this current research, efforts are being made in order to improve the performance of solenoid coils, which are of particular interest for many applications, e.g. for space propulsion systems such as the VASIMR engine. A number of coils with MgB2 tapes are being built. In this paper we present results of the test of a 14 cm bore solenoid wound with 400 meters of multifilament, copper stabilized tape. The magnet was tested in a cryocooled vacuum chamber and it reached 175 A at 16 K with a central B0 of 1 Tesla. [ABSTRACT FROM AUTHOR]

Since the development of the first MgB2 tapes, ASG Superconductors started an R&D activity aimed to produce magnets using the MgB2 conductor. Reacted & wound magnesium diboride double pancake coils were designed, manufactured (using industrial equipment) and tested, in a cryogen free apparatus, by ASG Superconductors. Each double pancake coil was produced by winding a single length of MgB2, 1600 m long, multifilamentary stabilized tape. The successful achievement of the tests allowed us to produce and test the first coil made with 6 single double pancakes, then the second coil and finally the completion of a cryogen free magnet for MRI application. This paper reports the main features of the coil design and construction, the magnet and the test results. [ABSTRACT FROM AUTHOR]

A nonmagnetic sheath, namely a Ni/Cr alloy (Ni80/Cr20), was used to fabricate MgB2 tapes through the powder-in-tube (PIT) ex-situ technique. A series of samples sintered at different temperatures between 200°C and 950° C were prepared in order to correlate all the superconducting properties between them and with the sintering temperature. The possibility of using a nonmagnetic but at the same time hard sheath chemically compatible with the MgB2 phase made possible a simpler interpretation of transport and magnetic measurements in magnetic field. With the chosen cold working parameters, we found that the amount of MgB2 lattice strain was not sufficient to produce any enhancement of the upper critical field. The effect of the heat treatment temperature was on one hand to increase the grain connectivity but also to reduce the pinning properties of the superconductor. [ABSTRACT FROM AUTHOR]

Purpose: Among the treatment options for Obstructive Sleep Apnea (OSA), intrapharyngeal surgery has undergone significant changes and received solid scientific support. However, it is crucial to identify the best candidate. This study aims to present the results of the modified Alianza technique in our clinic to show the differences in the impact of surgery on supine and non-supine apnea levels in moderate-severe OSA patients., Methods: Adult patients affected by moderate-severe OSA (Apnea-Hypopnea Index (AHI) > 15), having circular palatal collapse, and candidates for modified Alianza Tecnique were retrospectively enrolled. Each subject performed polysomnography pre- and post-operatively, and the follow-up check was performed after at least six months., Results: This study enrolled 24 patients who underwent the Modified Alianza technique for sleep apnea. We found significant reductions in both supine and non-supine AH) after surgery. Non-supine AHI showed a greater reduction (from 20.89 to 11.64 episodes/hour, p = 0.0001) than supine AHI (from 42.51 to 25.93, p = 0.0003). We subsequently divided the patients into two groups based on whether they were affected by positional OSA before surgery. There was a lower percentage decrease in non-supine AHI compared to supine AHI after surgery in patients who were positional before surgery, but this difference was not statistically significant. Conversely, in the non-positional patient group, there was a higher decrease in non-supine AHI compared to supine AHI, although this was not statistically significant., Conclusion: The Modified Alianza Tecnique leads to notable enhancement in AHI among patients with OSA. Non-supine apneas exhibit a more favorable response to the surgery than supine apneas., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Approximately 45% of adults snore occasionally, and 25% snore regularly, with a higher prevalence in men and an increase among postmenopausal women due to hormonal changes. Snoring is a health concern linked to vascular disease and decreased quality of life for both snorers and their bed partners. Effective snoring treatment, which aims to reduce or eliminate the sound, is challenging and depends on factors like age, comorbidities, disease severity, and anatomical features. This review aims to provide a systematic overview of the current literature on the effects of positional therapy (PT) on snoring. Various devices facilitate PT, including anti-snoring pillows and vibration alarms. PT devices maintain head and neck alignment to keep airways open, while head of bed elevation (HOBE) solutions reduce upper airway collapses by elevating the head and trunk. Studies show that PT and HOBE reduce snoring by increasing airway cross-sectional area and decreasing closing pressure. Despite their benefits, these non-surgical treatments have limitations, such as discomfort in certain sleeping positions and intolerance to prolonged head elevation. While reducing snoring intensity is critical for health reasons, further comparative studies between the different devices are needed to enhance snoring management.

Parkinson's disease is a progressive neurodegenerative disorder characterized by the deposition of misfolded alpha-synuclein in different regions of the central and peripheral nervous system. Motor impairment represents the signature clinical expression of Parkinson's disease. Nevertheless, non-motor symptoms are invariably present at different stages of the disease and constitute an important therapeutic challenge with a high impact for the patients' quality of life. Among non-motor symptoms, pain is frequently experienced by patients, being present in a range of 24-85% of Parkinson's disease population. Moreover, in more than 5% of patients, pain represents the first clinical manifestation, preceding by decades the exordium of motor symptoms. Pain implies a complex biopsychosocial experience with a downstream complex anatomical network involved in pain perception, modulation, and processing. Interestingly, all the anatomical areas involved in pain network can be affected by a-synuclein pathology, suggesting that pathophysiology of pain in Parkinson's disease encompasses a 'pain spectrum', involving different anatomical and neurochemical substrates. Here the various anatomical sites recruited in pain perception, modulation and processing are discussed, highlighting the consequences of their possible degeneration in course of Parkinson's disease. Starting from peripheral small fibres neuropathy and pathological alterations at the level of the posterior laminae of the spinal cord, we then describe the multifaceted role of noradrenaline and dopamine loss in driving dysregulated pain perception. Finally, we focus on the possible role of the intertwined circuits between amygdala, nucleus accumbens and habenula in determining the psycho-emotional, autonomic and cognitive experience of pain in Parkinson's disease. This narrative review provides the first anatomically driven comprehension of pain in Parkinson's disease, aiming at fostering new insights for personalized clinical diagnosis and therapeutic interventions., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Guarantors of Brain.)

Background: With promising outcomes, platelet-rich plasma (PRP) has recently been suggested as a treatment for olfactory dysfunction (OD)., Methods: Clinical studies utilizing PRP in OD caused by COVID-19, trauma, anesthetic exposure, viral infection, and chronic rhinosinusitis were included in a systematic review., Results: Ten clinical studies were qualitatively analyzed. Six of these studies used the PRP for OD caused by COVID-19, one on OD after functional endoscopic sinus surgery, and three on post-infectious or post-trauma OD. The population included 531 patients, ranging in age from 15 to 63., Conclusion: The use of PRP may be a risk-free and efficient therapeutic option with very encouraging outcomes. Indeed, it enhances olfactory perception in patients who not only exhibit COVID-19 infection aftereffects, but also in those who have lost their sense of smell due to trauma, rhinosinusitis, rhinitis, or even surgery. To evaluate the PRP's therapeutic benefits in OD patients and to compare the efficacy of different therapeutic protocols with regard to treatment schedules, there is an urgent need for focused controlled trials.

Recent shifts in the ecological condition of Walden Pond, MA, are of potentially wide interest due to the lake's importance as a cultural, historical, and recreational resource in addition to its scientific value as an indicator of local and global environmental change. Algal microfossils in six sediment cores document changes in hydroclimate and trophic status of the lake during the last 1800 years and extend two previous sediment core records of shorter length. Low percentages of planktonic diatoms in the longest cores (WAL-3, WAL-15) indicate shallowing and/or greater water clarity associated with a relatively arid interval during the Medieval Climate Anomaly, ca. A.D. 1150-1300, Cultural eutrophication of the lake since the A.D. 1920s caused diatoms in the genera Asterionella and Synedra to increase in relative abundance at the expense of Cyclotella, Discostella, and the chrysophyte alga Mallomonas allorgei. Percentages of Asterionella and Synedra have remained fairly stable since A.D. 2000 when a previous sediment core study was conducted, but scaled chrysophytes have become more numerous. These findings suggest that, although mitigation efforts have curtailed anthropogenic nutrient inputs to Walden Pond, the lake has not returned to the pre-impact condition described by Henry David Thoreau and may become increasingly vulnerable to further changes in water quality in a warmer and possibly wetter future.

The complete amino acid sequence of mature C8 beta has been derived from the DNA sequence of a cDNA clone identified by expression screening of a human liver cDNA library. Comparison with the amino acid sequence of C9 shows an overall homology with few deletions and insertions. In particular, the cysteine-rich domains and membrane-inserting regions of C9 are well conserved. These findings are discussed in relation to a possible mechanism of membrane attack complex formation.

One of the most obvious characteristics of the egg cells of oviparous animals is their large size resulting to a major extent from the deposition of nutritional reserves, mainly constituted of yolk proteins. In general, these are derived from a precursor called vitellogenin, which undergoes posttranslational modifications during secretion and during transport into and storage within the oocytes. Comparative analysis of the structural organization of the vitellogenin gene and of its product in different species shows that the vitellogenin gene is very ancient and that in vertebrates the gene may have more resemblance to the earliest gene than in invertebrates.

Sequence data from regions of five vertebrate vitellogenin genes were used to examine the frequency, distribution, and mutability of the dinucleotide CpG, the preferred modification site for eukaryotic DNA methyltransferases. The observed level of the CpG dinucleotide in all five genes was markedly lower than that expected from the known mononucleotide frequencies. CpG suppression was greater in introns than in exons. CpG-containing codons were found to be avoided in the vitellogenin genes, but not completely despite the redundancy of the genetic code. Frequency and distribution patterns of this dinucleotide varied dramatically among these otherwise closely related genes. Dense clusters of CpG dinucleotides tended to appear in regions of either functional or structural interest (e.g., in the transposon-like Vi-element of Xenopus) and these clusters contained 5-methylcytosine (5 mC). 5 mC is known to undergo deamination to form thymidine, but the extent to which this transition occurs in the heavily methylated genomes of vertebrates and its contribution to CpG suppression are still unclear. Sequence comparison of the methylated vitellogenin gene regions identified C----T and G----A substitutions that were found to occur at relatively high frequencies. The predicted products of CpG deamination, TpG and CpA, were elevated. These findings are consistent with the view that CpG distribution and methylation are interdependent and that deamination of 5 mC plays an important role in promoting evolutionary change at the nucleotide sequence level.

In Xenopus laevis four estrogen-responsive genes are expressed simultaneously to produce vitellogenin, the precursor of the yolk proteins. One of these four genes, the gene A2, was sequenced completely, as well as cDNAs representing 75% of the coding region of the gene. From this data the exon-intron structure of the gene was established, revealing 35 exons that give a transcript of 5,619 bp without the poly A-tail. This A2 transcript encodes a vitellogenin of 1,807 amino acids, whose structure is discussed with respect to its function. At the nucleic acid as well as at the protein level no extensive homologies with any sequences other than vitellogenin were observed. Comparison of the amino acid sequence of the vitellogenin A2 molecule with biochemical data obtained from the different yolk proteins allowed us to localize the cleavage products on the vitellogenin precursor as follows: NH2 - lipovitellin I - phosvitin (or phosvette II - phosvette I) - lipovitellin II - COOH.