Electrical simulation in addition to passive stretch has a small effect on spasticity and contracture in children with cerebral palsy: a randomised within-participant controlled trial

QuestionDoes electrical stimulation in addition to passive stretching reduce spasticity and contracture more than passive stretching alone in children with cerebral palsy?DesignRandomised within-participant controlled trial with concealed allocation, assessor blinding, and intention-to-treat analysis.ParticipantsEleven (one dropout) children with cerebral palsy and bilateral knee flexor spasticity aged 13 years (SD 1).InterventionOne leg in each participant received the experimental intervention for four weeks which consisted of 30 min of electrical stimulation of the quadriceps 3 times per week and passive stretching of the hamstrings 5 times per week. The other leg received the control intervention for four weeks which consisted of passive stretching of the hamstrings 5 times per week.Outcome measuresSpasticity of the hamstrings was measured using the modified Ashworth scale. Contracture was measured as maximum passive knee extension using goniometry.Results: The mean difference in decrease in the modified Ashworth score due to the addition of electrical stimulation to the stretching regimen was 0.8 points (95% CI 0.1 to 1.5). The mean difference in increase in passive knee extension due to the addition of electrical stimulation to the stretching regimen was 4 degrees (95% CI 0 to 7).ConclusionElectrical stimulation combined with passive stretching is marginally more effective than passive stretching alone for spastic limbs of children with cerebral palsy

On Optimal Multi-user Beam Alignment in Millimeter Wave Wireless Systems

Directional transmission patterns (a.k.a. narrow beams) are the key to wireless communications in millimeter wave (mmWave) frequency bands which suffer from high path loss and severe shadowing. In addition, the propagation channel in mmWave frequencies incorporates only a few number of spatial clusters requiring a procedure to align the corresponding narrow beams with the angle of departure (AoD) of the channel clusters. The objective of this procedure, called beam alignment (BA) is to increase the beamforming gain for subsequent data communication. Several prior studies consider optimizing BA procedure to achieve various objectives such as reducing the BA overhead, increasing throughput, and reducing power consumption. While these studies mostly provide optimized BA schemes for scenarios with a single active user, there are often multiple active users in practical networks. Consequently, it is more efficient in terms of BA overhead and delay to design multi-user BA schemes which can perform beam management for multiple users collectively. This paper considers a class of multi-user BA schemes where the base station performs a one shot scan of the angular domain to simultaneously localize multiple users. The objective is to minimize the average of expected width of remaining uncertainty regions (UR) on the AoDs after receiving users' feedbacks. Fundamental bounds on the optimal performance are analyzed using information theoretic tools. Furthermore, a beam design optimization problem is formulated and a practical BA scheme, which provides significant gains compared to the beam sweeping used in 5G standard is proposed

Impact of antimicrobial stewardship programme on hospitalized patients at the intensive care unit: a prospective audit and feedback study

AIMS: Inappropriate use of antibiotics is one of the most important factors contributing to the emergence of drug resistant pathogens. The purpose of this study was to measure the clinical impact of antimicrobial stewardship programme (ASP) interventions on hospitalized patients at the Intensive care unit at Palestinian Medical Complex. METHODS: A prospective audit with intervention and feedback by ASP team within 48-72 h of antibiotic administration began in September 2015. Four months of pre-ASP data were compared with 4 months of post-ASP data. Data collected included clinical and demographic data; use of antimicrobials measured by defined daily doses, duration of therapy, length of stay, readmission and all-cause mortality. RESULTS: Overall, 176 interventions were made the ASP team with an average acceptance rate of 78.4%. The most accepted interventions were dose optimization (87.0%) followed by de-escalation based on culture results with an acceptance rate of 84.4%. ASP interventions significantly reduces antimicrobial use by 24.3% (87.3 defined daily doses/100 beds vs. 66.1 defined daily doses/100 beds P < 0.001). The median (interquartile range) of length of stay was significantly reduced post ASP [11 (3-21) vs. 7 (4-19) days; P < 0.01]. Also, the median (interquartile range) of duration of therapy was significantly reduced post-ASP [8 (5-12) days vs. 5 (3-9); P = 0.01]. There was no significant difference in overall 30-day mortality or readmission between the pre-ASP and post-ASP groups (26.9% vs. 23.9%; P = 0.1) and (26.1% vs. 24.6%; P = 0.54) respectively. CONCLUSIONS: Our prospective audit and feedback programme was associated with positive impact on antimicrobial use, duration of therapy and length of stay

Additive manufacturing and physicomechanical characteristics of PEGDA hydrogels: recent advances and perspective for tissue engineering

In this brief review, we discuss the recent advancements in using poly(ethylene glycol) diacrylate (PEGDA) hydrogels for tissue engineering applications. PEGDA hydrogels are highly attractive in biomedical and biotechnology fields due to their soft and hydrated properties that can replicate living tissues. These hydrogels can be manipulated using light, heat, and cross-linkers to achieve desirable functionalities. Unlike previous reviews that focused solely on material design and fabrication of bioactive hydrogels and their cell viability and interactions with the extracellular matrix (ECM), we compare the traditional bulk photo-crosslinking method with the latest three-dimensional (3D) printing of PEGDA hydrogels. We present detailed evidence combining the physical, chemical, bulk, and localized mechanical characteristics, including their composition, fabrication methods, experimental conditions, and reported mechanical properties of bulk and 3D printed PEGDA hydrogels. Furthermore, we highlight the current state of biomedical applications of 3D PEGDA hydrogels in tissue engineering and organ-on-chip devices over the last 20 years. Finally, we delve into the current obstacles and future possibilities in the field of engineering 3D layer-by-layer (LbL) PEGDA hydrogels for tissue engineering and organ-on-chip devices

Effects of in-vitro application of pentoxifylline on the morphology of human spermatozoa after vitrification in asthenozoospermic patients

Cryopreservation of human spermatozoa is widely used in many assisted reproduction units to preserve male fertility [1]. Vitrification is based on the ultrarapid freezing and is routinely assayed for cryopreservation in assisted reproductive technology. Mohamed [2] showed that cryopreservation significantly affects progressive motility, viability and mitochondrial membrane potential of spermatozoa. Pentoxifylline (PX) is a phosphodiesterase considered to be a sperm movement enhancer, hyperactivation agent, inhibitor of reactive oxygen species and acrosome reaction-improving agent. The aim of our study was to evaluate the effect of in-vitro application of PX on sperm parameters and ultrastructure after vitrification. A total of 30 asthenozoospermic semen samples were selected and divided into two groups after vitrification: control (without PX) and experimental (with PX). A significant decrease in sperm motility, morphology and viability was observed post vitrification, but sperm motility was increased significantly following application of PX. On the other hand, PX did not exert any significant effect on the ultrastructure of the acrosome, plasma membrane and tail of vitrified spermatozoa

Mechanical behavior of 3d printed poly(ethylene glycol) diacrylate hydrogels in hydrated conditions investigated using atomic force microscopy

Three-dimensional (3D) printed hydrogels fabricated using light processing techniques are poised to replace conventional processing methods used in tissue engineering and organ-on-chip devices. An intrinsic potential problem remains related to structural heterogeneity translated in the degree of cross-linking of the printed layers. Poly(ethylene glycol) diacrylate (PEGDA) hydrogels were used to fabricate both 3D printed multilayer and control monolithic samples, which were then analyzed using atomic force microscopy (AFM) to assess their nanomechanical properties. The fabrication of the hydrogel samples involved layer-by-layer (LbL) projection lithography and bulk cross-linking processes. We evaluated the nanomechanical properties of both hydrogel types in a hydrated environment using the elastic modulus (E) as a measure to gain insight into their mechanical properties. We observed that E increases by 4-fold from 2.8 to 11.9 kPa transitioning from bottom to the top of a single printed layer in a multilayer sample. Such variations could not be seen in control monolithic sample. The variation within the printed layers is ascribed to heterogeneities caused by the photo-cross-linking process. This behavior was rationalized by spatial variation of the polymer cross-link density related to variations of light absorption within the layers attributed to spatial decay of light intensity during the photo-cross-linking process. More importantly, we observed a significant 44% increase in E, from 9.1 to 13.1 kPa, as the indentation advanced from the bottom to the top of the multilayer sample. This finding implies that mechanical heterogeneity is present throughout the entire structure, rather than being limited to each layer individually. These findings are critical for design, fabrication, and application engineers intending to use 3D printed multilayer PEGDA hydrogels for in vitro tissue engineering and organ-on-chip devices

Nanoindentation response of 3D printed PEGDA hydrogels in hydrated environment

Hydrogels are commonly used materials in tissue engineering and organ-on-chip devices. This study investigated the nanomechanical properties of monolithic and multilayered poly(ethylene glycol) diacrylate (PEGDA) hydrogels manufactured using bulk polymerization and layer-by-layer projection lithography processes, respectively. An increase in the number of layers (or reduction in layer thickness) from 1 to 8 and further to 60 results in a reduction in the elastic modulus from 5.53 to 1.69 and further to 0.67 MPa, respectively. It was found that a decrease in the number of layers induces a lower creep index (CIT) in three-dimensional (3D) printed PEGDA hydrogels. This reduction is attributed to mesoscale imperfections that appear as pockets of voids at the interfaces of the multilayered hydrogels attributed to localized regions of unreacted prepolymers, resulting in variations in defect density in the samples examined. An increase in the degree of cross-linking introduced by a higher dosage of ultraviolet (UV) exposure leads to a higher elastic modulus. This implies that the elastic modulus and creep behavior of hydrogels are governed and influenced by the degree of cross-linking and defect density of the layers and interfaces. These findings can guide an optimal manufacturing pathway to obtain the desirable nanomechanical properties in 3D printed PEGDA hydrogels, critical for the performance of living cells and tissues, which can be engineered through control of the fabrication parameters