Publications by authors named "Ramadan Sami"

Combining energy harvesting with energy storage systems in a single device could offer great advantages for continuous power supply in both indoor and outdoor electric applications. In this work, we demonstrate a photochargeable sodium-ion battery (PSIB) based on a photoactive cathode of two-dimensional crystals of MoSe. This photocathode enables spontaneous photodriven charging of a sodium-ion battery cathode under illumination and an increase in the reversible capacity to 29% at 600 mA g compared to that under dark conditions during galvanostatic cycling.

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Topological Insulators (TIs) are promising platforms for Quantum Technology due to their topologically protected surface states (TSS). Plasmonic excitations in TIs are especially interesting both as a method of characterisation for TI heterostructures, and as potential routes to couple optical and spin signals in low-loss devices. Since the electrical properties of the TI surface are critical, tuning TI surfaces is a vital step in developing TI structures that can be applied in real world plasmonic devices.

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Conventional surface acoustic wave (SAW) atomizers require a direct water supply on the surface, which can be complex and cumbersome. This paper presents a novel SAW atomizer that uses lateral acoustic wetting to achieve atomization without a direct water supply. The device works by simply pressing a piece of wetted paper strip against the bottom of an excited piezoelectric transducer.

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Accurate and effective detection is essential to against bacterial infection and contamination. Novel biosensors, which detect bacterial bioproducts and convert them into measurable signals, are attracting attention. We developed an artificial intelligence (AI)-assisted smartphone-based colorimetric biosensor for the visualized, rapid, sensitive detection of pathogenic bacteria by measuring the bacteria secreted hyaluronidase (HAase).

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The lumbosacral plexus is the network of nerves responsible for the motor and sensory function of the pelvis and lower limb. Our observation is that the anatomy of this plexus is less familiar to surgeons than that of the brachial plexus. Damage to the lumbosacral plexus and its terminal branches may have a significant impact on locomotion, posture, and stability.

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Shear horizontal surface acoustic wave (SH-SAW) sensors are regarded as a promising alternative for label-free, sensitive, real time and low-cost detection. Nevertheless, achieving high sensitivity with SH-SAW has approached its limit imposed by the mass transport and probe-target affinity. We present here an SH-SAW biosensor accompanied by a unique Rayleigh wave-based actuator.

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Triple-negative breast cancer (TNBC) is highly malignant and prone to recurrence and metastasis. Patients with TNBC have limited therapeutic options, often resulting in poor prognosis. Some new treatments for TNBC have been considered in the past decade, such as immunotherapy, photothermal therapy (PTT), and ferroptosis therapy, that allow the rapid and minimally invasive ablation of cancer.

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Article Synopsis
  • * Researchers conducted a retrospective review of cases from a hospital, analyzing data from 34 patients, with a focus on patient demographics and injury details.
  • * Findings indicate no significant difference in recovery outcomes (measured by the British MRC scale, BrAT, and SPONEA scores) between traumatic and atraumatic conditions, suggesting that nerve transfers may be beneficial for both types of injury.
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Biosensors based on graphene field effect transistors (GFETs) have the potential to enable the development of point-of-care diagnostic tools for early stage disease detection. However, issues with reproducibility and manufacturing yields of graphene sensors, but also with Debye screening and unwanted detection of nonspecific species, have prevented the wider clinical use of graphene technology. Here, we demonstrate that our wafer-scalable GFETs array platform enables meaningful clinical results.

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Owing to its high electrical conductivity, low density, and flexibility, graphene has great potential for use as a building block in a wide range of applications from nanoelectronics to biosensing and high-frequency devices. For many device applications, it is required to deposit dielectric materials on graphene at high temperatures and in ambient oxygen. This has been proven to be highly challenging because these conditions cause significant degradation in graphene.

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Graphene field-effect transistor (GFET) biosensors exhibit high sensitivity due to a large surface-to-volume ratio and the high sensitivity of the Fermi level to the presence of charged biomolecules near the surface. For most reported GFET biosensors, bulky external reference electrodes are used which prevent their full-scale chip integration and contribute to higher costs per test. In this study, GFET arrays with on-chip integrated liquid electrodes were employed for COVID-19 detection and functionalized with either antibody or aptamer to selectively bind the spike proteins of SARS-CoV-2.

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Article Synopsis
  • GFAP is an important blood biomarker for neurological diseases, especially traumatic brain injury, but accurate detection in patient samples is currently lacking.
  • A new graphene field-effect transistor (GFET) biosensing method has been developed to quickly and sensitively detect GFAP in patient plasma, achieving very low limits of detection.
  • This GFET biosensor outperforms traditional methods like ELISA and other advanced technologies, offering faster results, cost-effectiveness, and ease of use, making it a promising option for point-of-care diagnostics.
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The performance of graphene devices is often limited by defects and impurities induced during device fabrication. Polymer residue left on the surface of graphene after photoresist processing can increase electron scattering and hinder electron transport. Furthermore, exposing graphene to plasma-based processing such as sputtering of metallization layers can increase the defect density in graphene and alter the device performance.

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Graphene field-effect transistors (GFETs) are suitable building blocks for high-performance electrical biosensors, because graphene inherently exhibits a strong response to charged biomolecules on its surface. However, achieving ultralow limit-of-detection (LoD) is limited by sensor response time and screening effect. Herein, we demonstrate that the detection limit of GFET biosensors can be improved significantly by decorating the uncovered graphene sensor area with carbon dots (CDs).

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Heterostructures involving two-dimensional (2D) transition metal dichalcogenides and other materials such as graphene have a strong potential to be the fundamental building block of many electronic and optoelectronic applications. The integration and scalable fabrication of such heterostructures are of the essence in unleashing the potential of these materials in new technologies. For the first time, we demonstrate the growth of few-layer MoS films on graphene via nonaqueous electrodeposition.

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Currently the world is being challenged by a public health emergency caused by the coronavirus pandemic (COVID-19). Extensive efforts in testing for coronavirus infection, combined with isolating infected cases and quarantining those in contact, have proven successful in bringing the epidemic under control. Rapid and facile screening of this disease is in high demand.

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A graphene field-effect transistor (gFET) was non-covalently functionalised with 1-pyrenebutyric acid N-hydroxysuccinimide ester and conjugated with anti-CD63 antibodies for the label-free detection of exosomes. Using a microfluidic channel, part of a graphene film was exposed to solution. The change in electrical properties of the exposed graphene created an additional minimum alongside the original Dirac point in the drain-source current (I) - back-gate voltage (V) curve.

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Acute traumatic patellar dislocation is a common injury, and spontaneous reduction may occur at the time of injury or may be reduced at the field of the accident by someone. It may be associated with osteochondral fractures and rupture of medial patellar stabilizers leading to recurrent patellar instability. The aim of this prospective study was to evaluate the outcomes of medial patellofemoral (PF) ligament (MPFL) reconstruction in recurrent traumatic patellar dislocation.

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Background: In lower limb reconstruction the cosmetic outcome is influenced by the contouring of the flap at the recipient site as well as by the donor site closure. It is also important to minimise compression of the flap pedicle. We discuss the outcomes of a versatile ALT flap design that allows freedom in skin paddle tailoring without elongating the scar, reduction of the tension over the pedicle and improved cosmetic results of both donor and recipient sites.

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Background: Rotational instability of the knee remains an issue after anterior cruciate ligament (ACL) reconstruction. Hypothesis/Purpose: The purpose was to evaluate the subjective and objective outcomes of combined reconstruction of the ACL and anterolateral ligament (ALL) of the knee. The hypothesis was that favorable outcomes can be achieved with this surgical procedure compared with isolated anatomic reconstruction of the ACL.

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A multilayer structure of TeO/interdigital transducers (IDTs)/ZnO(112¯0)/Si(100) was proposed and investigated to achieve both high sensitivity and temperature-stability for bio-sensing applications. Dispersions of phase velocities, electromechanical coupling coefficients K, temperature coefficient of delay (TCD) and sensitivity in the multilayer structures were simulated as functions of normalized thicknesses of ZnO (h/λ) and TeO (h/λ) films. The fundamental mode of Love mode (LM) - surface acoustic wave (SAW) shows a larger value of K and higher sensitivity compared with those of the first mode.

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We report the first investigation into the potential of electroless nickel deposition to form ohmic contacts on single layer graphene. To minimize the contact resistance on graphene, a statistical model was used to improve metal purity, surface roughness, and coverage of the deposited film by controlling the nickel bath parameters (pH and temperature). The metalized graphene layers were patterned using photolithography and contacts deposited at temperatures as low as 60 °C.

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The reliable and controllable fabrication of silicon nanowires is achieved, using mature CMOS technology processes. This will enable a low-cost route to integrating novel nanostructures with CMOS logic. The challenge of process repeatability has been overcome by careful study of material properties for processes such as etching and oxidation.

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Critically ill surgical patients are always at increased risk of actual or potentially life-threatening health complications. Central/peripheral venous lines form a key part of their care. We review the current evidence on incidence of central and peripheral venous catheter-related bloodstream infections in critically ill surgical patients, and outline pathways for prevention and intervention.

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