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Purpose: Fatigue was a common symptom of non-alcoholic fatty liver disease (NAFLD), which seriously affected patients' quality of life. The aim of this study was to detect fatigue rate and to evaluate factors associated with fatigue in NAFLD patients. Patients and Methods: A cross-sectional study was carried out from the Huadong Sanatorium between April 2022 and May 2023, and 133 NAFLD patients were included in this study. They completed Fatigue Severity Scale to assess fatigue, the Hospital Anxiety and Depression Scale to estimate psychological status, and the Pittsburgh Sleep Quality Index for sleep quality. Data were analyzed by independent samples t-tests, χ 2 tests and logistic regression models. Results: We found that 51.1% of NAFLD patients had fatigue. Exercise, anxiety, depression, subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disorders, daytime dysfunction and overall sleep quality were related to fatigue among NAFLD patients. Moreover, logistic regression models indicated anxiety, habitual sleep efficiency and sleep disorders as important predictors of fatigue. Conclusion: This was the first time to explore demographic, clinical, psychological and sleeping correlated factors for fatigue in Chinese NAFLD patients. Our study showed that more than half of NAFLD patients had fatigue, and anxiety, habitual sleep efficiency and sleep disorders were significantly associated with fatigue in NAFLD. The findings indicated that it was very necessary to pay more attention to fatigue of NAFLD patients, especially those with negative emotions and poor sleep quality by favorable intervention to relieve fatigue symptoms, so as to improve quality of life. [ABSTRACT FROM AUTHOR]

As track density increases, it has become even more critical to understand the track edge. In this study, the impact of media design on the track edges in perpendicular magnetic recording has been investigated. This study shows that soft under layer thickness and intergranular exchange coupling have significant impact on both track edge erasure and write width. In the range we studied, head-to-keeper spacing and media coercivity have a strong impact on write width, but not on track edge erasure. On the other hand, media design does not impact transition curvature significantly. Experimental observations were supported by media micromagnetic modeling results and write field simulation using a finite element model. Analyzing the write bubble helps to understand the dependence of adjacent track encroachment on media design. Cross track profiles of various signal-to-noise ratio (SNR) components can provide valuable insights into different track edge mechanisms. Index Terms--Encroachment, erase, exchange, side-reading, track edge, underlayer.

[Al.sub.2][O.sub.3] films made with atomic layer deposition (ALD) have been developed for use as isolation layers in CPP tunneling magnetoresistive readers. A low-temperature deposition process was developed to permit integration with a self-aligned patterning scheme. The resulting films show excellent thickness uniformity (< 2% within-wafer), leakage current density ([J.sub.leak] < 1 x [10.sup.-8] A][cm.sup.2]) and breakdown properties ([F.sub.bd] > 9 MV/cm). TEMs of sub-100 nm TMR readers fabricated using these processes show > 95% conformality on junction sidewalls, indicating nonselective growth of ALD [Al.sub.2][O.sub.3] on the various stack and bottom shield surfaces. Permanent magnets with well-controlled junction grain structure and coercivities in excess of 2500 Oe have been deposited with existing processes. FEM modeling shows the effective stabilizing field from the magnets at the junction edge scales inversely with ALD layer thickness, in agreement with device-level free layer stability metrics showing improvements at lower ALD thicknesses. As the conformal ALD layer thickness is easily tuned, this technology provides flexibility in trading off reader amplitude and stability that should support scaling of the abutted TMR design out to 1 Tb/[in.sub.2] and beyond. Index Terms--Atomic layer deposition, isolation, permanent magnet, reader, tunneling magnetoresistance.

Grain boundaries play a crucial role in determining the macroscopic properties of magnetic recording media. The authors employ electronic structure theory, based on the local spin density approximation, to calculate the exchange energy, anisotropy energy, and magnetization at two types of grain boundaries. They incorporate these values into a micromagnetic simulation, thus correlating hysteresis loops and switching properties to atomic features. The authors show that small intergranular spacings (less than 0.2 nm) effectively break exchange, while a larger Cr thickness is required to achieve the same effect. Index Terms--Electronic structure, grain boundaries, intergranular exchange, micromagnetic simulation.

A strategy for high-density perpendicular magnetic recording with a soft underlayer is introduced. The approach is based on three concepts: 1) the nonzero magnetic susceptibility of the recording layer; 2) the use of intergranular exchange to partially cancel magnetostatic effects; and 3) a novel head architecture. Micromagnetic simulations involving recording head, soft underlayer, and recording layer are employed to specify a particularly advantageous design. It is shown that the expected density approaches 1 Tbit/[in.sup.2]. Index Terms--High-density perpendicular recording, intergranular exchange, micromagnetics, permeability.

Perpendicular recording applications use a soft magnetic underlayer (SUL) in the media to enhance the writer field and control its angle. In this paper, a micromagnetic/FEM model (MagPar) was used to investigate the physics of the write process while a nonlinear magnetoelectrical model (Klaassen) helped identify the value of the damping constant under a particular MagPar mesh. The field strength and direction produces a domain under the writer pole in areas where the field opposes the SUL magnetization direction. These areas are located over the next tracks (right or left). This temporary domain changes the response of the SUL by affecting the flux path and increasing the return pole field near the domain. Since the return poles are very large and behave quite linearly, fields in some areas near the return pole edge are bigger due to large writer currents with overshoot and little or no damping from saturated regions. The return pole fields could be large enough to degrade transitions in adjacent tracks particularly when they are applied multiple times to those tracks. The erasure location changes with current polarity and SUL magnetization direction. Index Terms--Erasure, perpendicular recording, write head, write process, writer flux.

Adjacent track erasure in longitudinal recording was studied using a micromagnetic model. The gap and fringe fields of two heads designed to work for 100 kTPI were used to write and erase a 31-bit pseudorandom sequence (PRS) in the main track. Comparisons on recording performance were made based on the calculated magnetization profile and the equalized PRS read back signal. It was shown that, for the case of a 3800-Oe fringe field, the quality of the transitions degraded drastically when the transitions were exposed to the fringe field more than 1000 times. On the other hand, a 2000-Oe fringe field left unaffected transitions even when the transitions were exposed to the field more than 100 000 times. Index Terms--High-density recording, longitudinal recording, read and write theory and modeling, test and characterization.

The life time of stored data depends on the storage density as well as the physical properties and microstructure of the media. Perpendicular media for ultra-high density recording needs to have high anisotropy to withstand thermal instabilities over long time. In this study, we used a micromagnetic model based on a scaling method to numerically calculate the percentage of magnetic decay caused by thermal fluctuations after ten years. Realistic grain configurations for 1 Tbit/[in.sup.2] and 125 Ghit/[in.sup.12] recording were used to seek the critical grain magnetization and anisotropy field of magnetic media that are thermally stable, for ten years. For less than 10% decay, an [H.sub.K] of 20 kOe and [M.sup.grain.sub.S] of 600 emu/[cm.sup.3] is required. Alternatively, [H.sub.K] can be reduced to 16 kOe if [M.sup.grain.sub.S] is 800 emu/[cm.sup.3]. Index Terms--Micromagnetics, perpendicular recording, perpendicular recording media, thermal decay.

A new scaling technique has been used to forecast bit decay over long time scales. A comparison of a longitudinal film with a perpendicular film with an identical grain configuration indicates that the perpendicular film is more thermally stable at high recording densities.