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Examines step-edge junction radio frequency-superconducting quantum interference device (SQUID) magnetometers and gradiometers fabricated using yttrium-barium-copper-oxide films. Effects of step structures and film properties on yield, optimal operating temperature and SQUID low-frequency noise; Sensitivity to the step structure of devices fabricated on different substrates.

Presents information on an eddy current system in cojunction with a planar Superconducting Quantum Interference Device (SQUID) gradiometer, for detection of deep-lying flaws in aircraft structures. Importance of a mobile system; Results of the operation of high temperature superconductor (HTS) SQUIDs.

The article "Electro-optic sensor for static fields", written by "J. O. Grasdijk, X. F. Bai, I. Engin, K. Jungmann, H. J. Krause, B. Niederländer, A. Off enhäuser, M. Repetto, L. Willmann, S. Zimmer [ABSTRACT FROM AUTHOR]

The in-phase current noise of the two junctions leads to additional 1/f noise in dc SQUIDs, which is reduced by the well-known bias reversal technique (ac bias reversal). In this paper, a new idea for dc SQUID operation with ac bias reversal non-constant bias current is described. In most conventional readout electronics with constant dc bias, the dc SQUID is connected to the preamplifier by means of a transformer in order to enhance the SQUID voltage signal and thus reduce the preamplifier noise contribution. We analyse this case in ac bias condition and find that the current through the SQUID is not constant after the bias reversal. In order to solve this problem, we derived the differential equation governing the network and solved it for a constant current through the SQUID. The transient of the applied bias current is chosen to satisfy this differential equation. The time constant of the transient does not depend on the dynamic resistance of the SQUID. The bias reversal frequency could be increased without introducing additional noise to the SQUID. [Copyright &y& Elsevier]

Although the sensitivity of the magnetic field sensor is important for many applications in electromagnetic testing, SQUID sensors are usually employed for other reasons. For successful defect detection, properties such as high linearity, large dynamic range, and good spatial resolution are required. We present the implementation of a SQUID magnetometer in an eddy current testing system for the measurement of very thick structures of large aircrafts. A three-layer aluminium sample from EADS Airbus was measured, with a total thickness of 62 mm, resembling the projected outer wing splice of the Airbus A-380. The sample has bolted joints and second-layer cracks adjacent to the titanium bolts. The combination of field sensitivities of a few pT/√Hz and a large dynamic range of about 140 dB/√Hz at low frequencies enables us to detect defects at a depth of up to 40 mm in aluminium. For sufficient current penetration into the layered aluminium sample, remarkably low excitation frequencies in the range of 10–40 Hz are required. The small field variations caused by the defects are superimposed on the current distortions and the corresponding field changes in the vicinity of the titanium bolts. Separation of these two contributions requires additional efforts in signal processing and simulations. The measurements were complemented by 3D-FEM calculations in order to find proper excitation frequencies, thus providing an easier separation of flaw signatures from structural background signals. [Copyright &y& Elsevier]

Epithelial cells of human breast glands are exposed to various mechanical ECM stresses that regulate tissue development and homeostasis. Mechanoadaptation of breast gland tissue to ECM-transmitted shear stress remained poorly investigated due to the lack of valid experimental approaches. Therefore, we created a magnetic shear strain device that enabled, for the first time, to analyze the instant shear strain response of human breast gland cells. MCF10A-derived breast acini with basement membranes (BM) of defined maturation state and basoapical polarization were used to resemble breast gland morphogenesis in vitro . The novel biophysical tool was used to apply cyclic shear strain with defined amplitudes (≤15%, 0.2 Hz) over 22 h on living spheroids embedded in an ultrasoft matrix (<60 Pa). We demonstrated that breast spheroids gain resistance to shear strain, which increased with BM maturation and basoapical polarization. Most intriguingly, poorly developed spheroids were prone to cyclic strain-induced extrusion of apoptotic cells from the spheroid body. In contrast, matured spheroids were insensitive to this mechanoresponse-indicating changing mechanosensing or mechanotransduction mechanisms during breast tissue morphogenesis. Together, we introduced a versatile tool to study cyclic shear stress responses of 3D cell culture models. It can be used to strain, in principle, all kinds of cell clusters, even those that grow only in ultrasoft hydrogels. We believe that this approach opens new doors to gain new insights into dynamic shear strain-induced mechanobiological regulation circuits between cells and their ECM., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Friedland, Babu, Springer, Konrad, Herfs, Gerlach, Gehlen, Krause, De Laporte, Merkel and Noetzel.)

We observe a deuteron beam polarization lifetime near 1000 s in the horizontal plane of a magnetic storage ring (COSY). This long spin coherence time is maintained through a combination of beam bunching, electron cooling, sextupole field corrections, and the suppression of collective effects through beam current limits. This record lifetime is required for a storage ring search for an intrinsic electric dipole moment on the deuteron at a statistical sensitivity level approaching 10^{-29}  e cm.

A new method to determine the spin tune is described and tested. In an ideal planar magnetic ring, the spin tune-defined as the number of spin precessions per turn-is given by ν(s)=γG (γ is the Lorentz factor, G the gyromagnetic anomaly). At 970  MeV/c, the deuteron spins coherently precess at a frequency of ≈120  kHz in the Cooler Synchrotron COSY. The spin tune is deduced from the up-down asymmetry of deuteron-carbon scattering. In a time interval of 2.6 s, the spin tune was determined with a precision of the order 10^{-8}, and to 1×10^{-10} for a continuous 100 s accelerator cycle. This renders the presented method a new precision tool for accelerator physics; controlling the spin motion of particles to high precision is mandatory, in particular, for the measurement of electric dipole moments of charged particles in a storage ring.

We investigated several factors which may affect the accuracy of fetal cardiac time intervals (CTI) determined in magnetocardiographic (MCG) recordings: observer differences, the number of available recording sites and the type of sensor used in acquisition. In 253 fetal MCG recordings, acquired using different biomagnetometer devices between the 15th and 42nd weeks of gestation, P-wave, QRS complex and T-wave onsets and ends were identified in signal averaged data sets independently by different observers. Using a defined procedure for setting signal events, interobserver reliability was high. Increasing the number of registration sites led to more accurate identification of the events. The differences in wave morphology between magnetometer and gradiometer configurations led to deviations in timing whereas the differences between low and high temperature devices seemed to be primarily due to noise. Signal-to-noise ratio played an important overall role in the accurate determination of CTI and changes in signal amplitude associated with fetal maturation may largely explain the effects of gestational age on reproducibility. As fetal CTI may be of value in the identification of pathologies such as intrauterine growth retardation or fetal cardiac hypertrophy, their reliable estimation will be enhanced by strategies which take these factors into account.

A production process is described that yields nanocapsules instead of nanoparticles. The process allows the encapsulation of lipophilic drugs such as triamcinolone acetonide with an O/W emulsion system. The capsular structure of the products was confirmed by transmission and scanning electron microscopy. The nanocapsules displayed a mean size of 141 ± 47 nm to 523 ± 340 nm (mean ± S.D.) and a drug content of 7 % to 15.4 % w/w. Drug release experiments showed that the encapsulated triamcinolone acetonide was released more slowly than micronized drug crystals. A more pronounced retarded release could be achieved by raising the pH during the hardening reaction or by encapsulating cholesterol into the nanocapsules.

Use of liposomal drug delivery systems can enhance the therapeutic potential of membrane active anti-cancer and anti-infectious drugs. Thus, the therapeutic index of the important antifungal agent amphotericin B is markedly improved via incorporation of the drug into liposomes. The mechanistic basis of this effect seems to be an increase in the selectivity of the drug at the cellular level. Thus, free amphotericin B can readily partition into both fungal and mammalian membranes and can cause toxicity to both types of cells, giving rise to the notorious in vivo toxicity of this drug. By contrast, when amphotericin B is formulated in certain types of liposomes, the drug still readily partitions into fungal membranes but can no longer partition into animal cell membranes, thus markedly reducing its toxicity. Liposomes can also be used to reduce the toxicity of membrane-active antitumor drugs. Thus, the peptide ionophore valinomycin is far less toxic to animals when presented in liposomal form. Nonetheless, the drug retains useful antitumor activity in this form. The underlying basis of the enhanced therapeutic index of liposomal valinomycin is unknown at this time but is being explored. The development of membrane-active anti-tumor drugs, in conjunction with liposomal delivery systems, could be an important new approach in cancer chemotherapy. While no anticancer drug is likely to be free of toxic side effects, the toxicities engendered by membrane-active antitumor drugs are likely to affect a different spectrum of tissues and organs than those caused by "conventional" antitumor drugs. Thus membrane-active drugs could complement existing drugs and provide a valuable adjunct to therapy.

We have investigated the blood clearance kinetics and tissue distribution of large multilamellar liposomes (MLVs) and small unilamellar liposomes (SUVs) composed of the photopolymerizable lipid bis[12-(methacryloyloxy)dodecanoyl]-L-alpha-phosphatidylcholine. Polymerized MLVs or SUVs are cleared from the bloodstream more rapidly than nonpolymerized vesicles with similar size profiles. Both polymerized and nonpolymerized vesicles primarily accumulate in liver and spleen. However, the polymerized vesicles display an enhanced biostability as revealed by an elevated level of radioactive lipid marker remaining in the tissues.

We have prepared lipid vesicles (liposomes) composed of polymerized bis[12-(methacryloyloxy)dodecanoyl]-L-alpha-phosphatidylcholine (DPL) which contain the antifungal polyene antibiotic amphotericin B (AMB). It was necessary to devise a novel method for incorporating AMB into the liposomes subsequent to polymerization. The polymer liposome AMB was as effective as AMB in "conventional" liposomes in terms of inhibiting fungal growth in vitro. However, in contrast to "conventional" liposomes, the polymerized DPL vesicles did not protect mammalian cells against AMB induced toxicity.