Humans are fundamentally interested in monitoring and understanding interactions that occur in and around our bodies. Biological interactions within the body determine our physical condition and can be used to improve medical treatments and develop new drugs. Daily life involves contact with numerous chemicals, ranging from household elements, naturally occurring scents from common plants and animals, and industrial agents. Many chemicals cause adverse health and environmental effects and require regulation to prevent pollution. Chemical detection is critically important for food and environmental quality control efforts, medical diagnostics, and detection of explosives. Thus, sensitive devices are needed for detecting and discriminating chemical and biological samples. Compared to other sensing devices, the Quartz Crystal Microbalance (QCM) is well-established and has been considered and sufficiently sensitive for detecting molecules, chemicals, polymers, and biological assemblies. Due to its simplicity and low cost, the QCM sensor has potential applications in analytical chemistry, surface chemistry, biochemistry, environmental science, and other disciplines. QCM detection measures resonate frequency changes generated by the quartz crystal sensor when covered with a thin film or liquid. The quartz crystal is sandwiched between two metal (typically gold) electrodes. Functionalizing the electrode’s surface further enhances frequency change detection through to interactions between the sensor and the targeted material. These sensors are sensitive to high frequencies and can recognize ultrasmall masses. This review will cover advancements in QCM sensor technologies, highlighting in-sensor and real-time analysis. QCM-based sensor function is dictated by the coating material. We present various high-sensitivity coating techniques that use this novel sensor design. Then, we briefly review available measurement parameters and technological interventions that will inform future QCM research. Lastly, we examine QCM’s theory and application to enhance our understanding of relevant electrical components and concepts.

Fine-tuning of the morphology from two-dimensional (2D) to three-dimensional (3D) nanostructures by structural engineering leads to improved biosensing. Herein, a 3D assembly of MXene and rGO nanosheets was synthesized by a hydrothermal process, and then, a naturally abundant and promising biosensing catalyst of Cu2O was added by a coprecipitation method to prepare a 3D ternary composite (MXene graphene aerogel–Cu2O composite). The prepared ternary nanocomposite was characterized by X-ray diffraction, field emission scanning electron microscopy (FE-SEM), Raman spectroscopy, and Brunauer–Emmett–Teller (BET). It exhibited a low crystallite size, spherical-shaped Cu2O, and a large surface area with a porous structure. Further, a sensing electrode was fabricated by the drop-casting method, and then, a chronoamperometric (CA) study was performed to understand the sensing performance of the 3D ternary composite. The fabricated electrode showed sensitivities of 264.52 and 137.95 μA cm–2 mM–1 compared to 2D composites (126.6 μA cm–2 mM–1) with two wide linear ranges of 0.1–14 and 15–40 mM, respectively. The electrode also gave a low detection limit and good stability, selectivity, and reproducibility, thus making it suitable for the determination of glucose levels in human serum samples. These findings reveal that the 3D network of MXene and rGO nanosheets assists in effective charge transfer and promotes the sensing activity of nonenzymatic glucose sensors.

Acute abdominal pain is a common cause of visits to the emergency department. Acute appendicitis remains the most common indication for abdominal surgical intervention in the pediatric age group. However, several conditions may present with a clinical picture similar to that of acute appendicitis. We report the case of a 7-year-old girl with a history of right lower quadrant abdominal pain of two days in duration. The pain was associated with vomiting and was exacerbated by movement. Abdominal examination revealed a localized tenderness in the right iliac fossa with guarding, giving the impression of acute appendicitis. After a thorough investigation, the patient was diagnosed as having acute omental infarction given the radiological findings seen in the computed tomography scan. The patient was successfully managed conservatively with analgesics and anti-inflammatory drugs. Physicians should keep a high index of suspicion for this condition when encountering a patient presenting with an acute right lower quadrant abdominal pain. Imaging modalities play a pivotal role in making the diagnosis.

Cluster headache (CH) has always been associated with several risk factors, including hereditary, environmental, and lifestyle habits. This study focuses on important risk factors, including family history, smoking, alcohol consumption, male predominance, and head trauma associated with CH. The present study aimed at investigating the available literature on cluster headaches and evaluating their associated risk factors. A systematic data search was designed, and scientific data were collected from renowned databases, including PubMed, Cochrane, Embase, Cumulative Index of Nursing and Allied Health Literature (CINAHL), and Google Scholar. Thirty-two studies were selected to execute a systemic review, and 26 studies, consisting of 6,065 CH patients, qualified for a meta-analysis. Statistical analyses were conducted by using MedCalc, version 16.8.4; (MedCalc Software, Ostend, Belgium; http://www.medcalc.org ) and Rapidminer statistical software, version 9.6.0 ( www.rapidminer.com ). We conclude the evidence of family history, smoking, alcohol consumption, male predominance, and head trauma are associated with cluster headaches. However, sex discrimination in familial cases needs to be revisited because of the female predominance reported by familial history and CH association studies.

We discuss several micromechanical sensor methods for utilizing technologies to detect gamma and beta radiation. The bending and resonance-frequency shifts of microcantilever sensors exhibit high sensitivity to ionizing radiation. Quartz oscillators, as well as microcantilevers coated with different materials, can aid in increasing the sensor sensitivity. Introducing MEMS technology to hydrogen-pressure sensors increased the ability of the sensors to detect low doses of radiation. Quartz tuning forks show excellent sensitivity to radiation and prove to be good candidates for radiation detection. It has been reported as will be discussed in this review that a limit of detection of as low as 0.3 μGy has been possible using micromechanical sensors.