Search

In-band full-duplex (FD) operation can double the spectral efficiency of massive multiple-input multiple-output (mMIMO) systems by allowing simultaneous transmission and reception over the same time/frequency slot. However, the main challenge encountered in implementing an FD radio wireless transceiver is to greatly suppress the residual self-interference (SI) generated from its own transmitter below the receiver noise floor to avoid performance degradation in the detection of the signal of interest received from remote transmitters. It is pointed out that the single-stage digital beamforming (DBF) scheme would introduce an impractically high complexity unsuitable for implementing FD-mMIMO. This paper considers an FD hybrid beamforming (FD-HBF) scheme for multi-user (MU)-mMIMO systems, in which large SI-suppression is achieved by exploring dynamic transmitter/receiver (Tx/Rx) isolation using RF-beamforming designs, and exploiting the degrees of freedom of a large number of antenna elements in separate Tx and Rx antenna arrays, in conjunction with high-performance baseband (BB) digital fractionally-spaced (FS) SI-cancellation (SIC) techniques. This paper starts with a discussion of the main parameters and impairments (in an mMIMO transceiver) that can impact the SI-suppression performance and the proposed RF-beamforming Tx/Rx isolation and BB SI-cancellation design strategies along with their achieved performance and complexities. Joint-beamforming optimization to maximize both Tx/Rx performance and isolation is discussed with an example of a nature-inspired optimization scheme to achieve an average Tx/Rx RF isolation of 64.4 dB and the best isolation of 76 dB. The paper continues with a description of an FD-mMIMO transceiver prototype using Tx/Rx 8x8-element antenna arrays along with analytical, simulation and measured results. Illustrative results indicate that the proposed combination of RF-beamforming Tx/Rx isolation and BB digital fractionally spaced SI-cancellation can offer an overall SI suppression of more than 131 dB and bring the residual SI below the receiver noise floor.

Objectives: Human milk content varies across mother–child dyads, environments, and populations. Among the hormones in milk is cortisol, a glucocorticoid; its impact on the breastfeeding child is unknown. Milk cortisol may constitute a signal to the child's developing physiology which can shape characteristics (e.g., growth, temperament) to prevailing environmental conditions. This exploratory study evaluated the maternal, breastfeeding, and infant characteristics associated with milk cortisol. Methods: We evaluated archived milk specimens for cortisol using enzyme immunoassay and employed an information‐theoretic approach to assess associations between milk cortisol and participant characteristics with linear regression modeling. Because we employed secondary data, information for some variables likely to impact milk cortisol variation (e.g., time of day, socioeconomic status, maternal or infant body mass index, milk energy density) was unavailable. Results: Participants were 48 lactating mothers from upstate New York, aged 21–40 years. Milk cortisol ranged from 0.098 to 1.007 μg/dL. Child age ranged from 1 to 26 months. In linear regression employing best fit modeling criteria, milk cortisol increased with child age (B: 0.069; p:.000; a 7.1% increase in milk cortisol for each month of child age), while child symptoms of illness (B: −0.398; p:.057; a 33% decrease) and consumption of complementary foods (B: −.525; p:.020; a 41% decrease) were associated with lower milk cortisol. Conclusions: We speculate that increasing milk cortisol with child age plays a role in signaling development (e.g., as increasing independence increases risk for injury and other negative health outcomes), independent of the maternal stressors we could capture. [ABSTRACT FROM AUTHOR]

Chronic back and leg pain are leading causes of disability worldwide. The purpose of this study was to compare the care in a unidisciplinary (USC) versus multidisciplinary (MSC) spine clinic, where patients are evaluated by different specialists during the same office visit. Adult patients presenting with a chief complaint of back and/or leg pain between June 2018 and July 2019 were assessed for eligibility. The main outcome measures included the first treatment recommendations, the time to treatment order, and the time to treatment occurrence. A 1:1 propensity score-matched analysis was performed on 874 patients (437 in each group). For all patients, the most common recommendation was physical therapy (41.4%), followed by injection (14.6%), and surgery (9.7%). Patients seen in the MSC were more likely to be recommended injection (p < 0.001) and less likely to be recommended surgery as first treatment (p = 0.001). They also had significantly shorter times to the injection order (log-rank test, p = 0.004) and the injection occurrence (log-rank test, p < 0.001). In this study, more efficient care for patients with back and/or leg pain was delivered in the MSC setting, which was evidenced by the shorter times to the injection order and occurrence. The impact of the MSC approach on patient satisfaction and health-related quality-of-life outcome measures warrants further investigation.

Diabetes mellitus renders patients susceptible to chronic wounds and various infections. Regarding the latter, fungal infections are of particular concern since, although they are the source of significant morbidity and mortality in immunocompromised patients, they are generally resistant to conventional treatment and a definite treatment strategy has not yet been established. Herein, we report the treatment of skin wounds in a diabetic rat model, infected by Candida albicans, with low temperature helium plasma generated in a hand-held atmospheric jet device. A fungal infection was induced on two dorsal skin wounds of the diabetic rats, and one wound was treated with the plasma jet whereas the other served as a control. Histological analysis revealed accelerated skin wound healing and decreased evidence of fungal infection in the plasma-treated group, as compared to the control group. Regeneration of the epidermis and dermis, collagen deposition, and neovascularization were all observed as a result of plasma treatment, but without wound contraction, scar formation or any evidence of thermal damage to the tissue. These findings demonstrate that the He plasma jet is remarkably effective in diabetic skin wounds infected by Candida albicans, thereby providing a promising medical treatment option for diabetes mellitus patients with skin wound and fungal infections.