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1.
Sci Rep ; 14(1): 1658, 2024 Jan 18.
Article in English | MEDLINE | ID: mdl-38238363

ABSTRACT

The properties of layered materials are significantly dependent on their lattice orientations. Thus, the growth of graphene nanowalls (GNWs) on Cu through PECVD has been increasingly studied, yet the underlying mechanisms remain unclear. In this study, we examined the GNWs/Cu interface and investigated the evolution of their microstructure using advanced Scanning transmission electron microscopy and Electron Energy Loss Spectroscopy (STEM-EELS). GNWs interface and initial root layers of comprise graphitic carbon with horizontal basal graphene (BG) planes that conform well to the catalyst surface. In the vertical section, the walls show a mix of graphitic and turbostratic carbon, while the latter becomes more noticeable close to the top edges of the GMWs film. Importantly, we identified growth process began with catalysis at Cu interface forming BG, followed by defect induction and bending at 'coalescence points' of neighboring BG, which act as nucleation sites for vertical growth. We reported that although classical thermal CVD mechanism initially dominates, growth of graphene later deviates a few nanometers from the interface to form GNWs. Nascent walls are no longer subjected to the catalytic action of Cu, and their development is dominated by the stitching of charged carbon species originating in the plasma with basal plane edges.

2.
Adv Mater ; 36(3): e2305326, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37907810

ABSTRACT

Superconductivty has recently been induced in MXenes through surface modification. However, the previous reports have mostly been based on powders or cold-pressed pellets, with no known reports on the intrinsic superconsucting properties of MXenes at the nanoale. Here, it is developed a high-temperature atomic exchange process in NH3 atmosphere which induces superconductivity in either singleflakes or thin films of Nb2 CTx MXene. The exchange process between nitrogen atoms and fluorine, carbon, and oxygen atoms in the MXene lattice and related structural adjustments are studied using both experiments and density functional theory. Using either single-flake or thin-film devices, an anisotropic magnetic response of the 2D superconducting transformation has been successfully revealed. The anisotropic superconductivity is further demonstrated using superconducting thin films uniformly deposited over a 4 in. wafers, which opens up the possibility of scalable MXene-based superconducting devices.

3.
Nanotechnology ; 35(8)2023 Dec 04.
Article in English | MEDLINE | ID: mdl-37931315

ABSTRACT

Graphene nanowalls (GNWs) can be described as extended nanosheets of graphitic carbon where the basal planes are perpendicular to a substrate. Generally, existing techniques to grow films of GNWsare based on plasma-enhanced chemical vapor deposition (PECVD) and the use of diverse substrate materials (Cu, Ni, C, etc) shaped as foils or filaments. Usually, patterned films rely on substrates priorly modified by costly cleanroom procedures. Hence, we report here the characterization, transfer and application of wafer-scale patterned GNWsfilms that were grown on Cu meshes using low-power direct-current PECVD. Reaching wall heights of ∼300 nm, mats of vertically-aligned carbon nanosheets covered square centimeter wire meshes substrates, replicating well the thread dimensions and the tens of micrometer-wide openings of the meshes. Contrastingly, the same growth conditions applied to Cu foils resulted in limited carbon deposition, mostly confined to the substrate edges. Based on the wet transfer procedure turbostratic and graphitic carbon domains co-exist in the GNWsmicrostructure. Interestingly, these nanoscaled patterned films were quite hydrophobic, being able to reverse the wetting behavior of SiO2surfaces. Finally, we show that the GNWscan also be used as the active material for C-on-Cu anodes of Li-ion battery systems.

4.
Cureus ; 15(6): e41016, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37519556

ABSTRACT

Hydroxychloroquine (HCQ), a drug used to treat many diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), has limited reports documenting drug-induced myopathies as a side effect. This entity is underdiagnosed with unclear treatment interventions apart from discontinuing the offending drug. We report a case of a biopsy-proven hydroxychloroquine-induced myopathy in a 35-year-old female patient with SLE. The offending drug was stopped, but the patient did not improve. However, she showed marked improvement after the use of intravenous immunoglobulin (IVIG).

5.
Cureus ; 14(6): e25791, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35812574

ABSTRACT

Background Adverse childhood experiences (ACEs) are traumatic events that occur before 18 years of age. ACEs have been associated with many negative health problems, including the development of chronic diseases, such as irritable bowel syndrome (IBS), a functional gastrointestinal disorder characterized by abdominal pain. We investigated the prevalence of ACEs among patients with IBS, identified the types of ACEs commonly related to patients with IBS, and further assessed the impact of ACEs on IBS severity. Methodology A cross-sectional study was performed. The study targeted patients with IBS aged ≥ 18 years who were recruited from gastroenterology outpatient clinics at King Abdulaziz University Hospital. Adults were contacted and invited to take part in the study by completing a survey. Data were collected using two validated questionnaires, the ACE questionnaire for adults and the IBS symptom severity scoring system. Results The study included 109 patients with IBS (59.6% females). The prevalence of ACEs (patients with IBS exposed to at least one ACE) was 63.3%. The most prevalent type was emotional abuse (34.9%), followed by both physical abuse and emotional neglect (28.4%). Females reported significantly more ACEs (p = 0.035) than males. The overall IBS symptoms (r = 0.195, p = 0.043) and abdominal pain (r = 0.240, p = 0.012) severity were significantly correlated with total ACEs score. Conclusions Our findings point to a probable association between ACEs exposure and IBS, demonstrating their long-term impacts on symptoms severity. Further studies are needed to acquire a better understanding of the potential impact of ACEs on IBS.

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