Experimental construction of force- and frequency-response curves of nonlinear resonators.

We present an experimental technique to construct the response of nonlinear resonators under harmonic excitation as a control parameter is swept. Our technique can resolve nonlinear features in the resonator response, such as bifurcations and hysteresis. To validate it, we construct the frequency response of a MEMS resonator while the excitation frequency is swept. The response is measured optically and recorded in the time domain. The root-mean-square of the response is calculated over a variable-size time-window. The sweep time, window size, and frequency step size were found to be limited by the quality factor of the resonator under test. We examine and describe those limitations in terms of the slew rate and sampling frequency. Although we used optical measurements to validate the technique, the methods described herein are applicable to any measured response signal.

Detection of Volatile Organic Compounds by Using MEMS Sensors.

We report on the deployment of MEMS static bifurcation (DC) sensors for the detection of volatile organic compounds (VOCs): hydrogen sulfide and formaldehyde. We demonstrate a sensor that can detect as low as a few ppm of hydrogen sulfide. We also demonstrate a sensor array that can selectively detect formaldehyde in the presence of benzene, a closely related interferent. Toward that end, we investigate the sensitivity and selectivity of two detector polymers-polyaniline (PANI) and poly (2,5-dimethyl aniline) (P25DMA)-to both gases. A semiautomatic method is developed to functionalize individual sensors and sensor arrays with the detector polymers. We found that the sensor array can selectively sense 1 ppm of formaldehyde in the presence of benzene.

An Electrostatic MEMS Roll-Pitch Rotation Rate Sensor with In-Plane Drive Mode.

In this paper, we presented a novel electrostatic Roll/Pitch MEMS gyroscope with in-plane drive mode and out-of-plane sense mode. The proposed structure is developed based on a tuning fork gyroscope with decoupled sense mass on each tine that control the sense out-of-plane frequency. A multi-height deep reactive ion etching (DRIE) fabrication process was utilized to achieve and enhance decoupling between the drive and sense modes. We presented our design methodology followed by an analytical and finite element (FEM) model. Our experimental results showed a good match between the analytical model and those obtained experimentally, from the drive and sense oscillation frequencies. Our characterization setup used a custom made application specific integrated circuit (ASIC) for characterization and was able to achieve ARW of 0.2 deg/rt-h, a bias instability 5.5 deg/h, and scale factor non-linearity (SFNL) 156 ppm FS.

Locally Advanced Oral Cavity Cancers: What Is The Optimal Care?

Patients with oral cavity cancers often present late to seek medical care. Surgery is usually the preferred upfront treatment. However, surgical resection cannot be achieved in many cases with advanced disease without major impact on patient's quality of life. On the other hand, radiotherapy (RT) and chemotherapy (CT) have not been employed routinely to replace surgery as curative treatment or to facilitate surgery as neoadjuvant therapy. The optimal care of these patients is challenging when surgical treatment is not feasible. In this review, we aimed to summarize the best available evidence-based treatment approaches for patients with locally advanced oral cavity cancer. Surgery followed by RT with or without CT is the standard of care for locally advanced oral cavity squamous cell carcinoma. In the case of unresectable disease, induction CT prior to surgery or chemoradiotherapy (CRT) can be attempted with curative intent. For inoperable patients or when surgery is expected to result in poor functional outcome, patients may be candidates for possibly curative CRT or palliative RT with a focus on quality of life.

PHENOS: a high-throughput and flexible tool for microorganism growth phenotyping on solid media.

BACKGROUND: Microbial arrays, with a large number of different strains on a single plate printed with robotic precision, underpin an increasing number of genetic and genomic approaches. These include Synthetic Genetic Array analysis, high-throughput Quantitative Trait Loci (QTL) analysis and 2-hybrid techniques. Measuring the growth of individual colonies within these arrays is an essential part of many of these techniques but is useful for any work with arrays. Measurement is typically done using intermittent imagery fed into complex image analysis software, which is not especially accurate and is challenging to use effectively. We have developed a simple and fast alternative technique that uses a pinning robot and a commonplace microplate reader to continuously measure the thickness of colonies growing on solid agar, complemented by a technique for normalizing the amount of cells initially printed to each spot of the array in the first place. We have developed software to automate the process of combining multiple sets of readings, subtracting agar absorbance, and visualizing colony thickness changes in a number of informative ways. RESULTS: The "PHENOS" pipeline (PHENotyping On Solid media), optimized for Saccharomyces yeasts, produces highly reproducible growth curves and is particularly sensitive to low-level growth. We have empirically determined a formula to estimate colony cell count from an absorbance measurement, and shown this to be comparable with estimates from measurements in liquid. We have also validated the technique by reproducing the results of an earlier QTL study done with conventional liquid phenotyping, and found PHENOS to be considerably more sensitive. CONCLUSIONS: "PHENOS" is a cost effective and reliable high-throughput technique for quantifying growth of yeast arrays, and is likely to be equally very useful for a range of other types of microbial arrays. A detailed guide to the pipeline and software is provided with the installation files at https://github.com/gact/phenos .

Hepatitis C virus infection in Jeddah city, Saudi Arabia: Seroprevalence and knowledge.

The infection rate of the hepatitis C virus (HCV) in Saudi Arabia is among the lowest in the world. However, it is likely that poor knowledge and awareness of HCV infection could minimize the effectiveness of prevention and control programs in the kingdom. Thus, the study objective was to estimate the prevalence of HCV infection, and to assess current knowledge about it, in the targeted population. Data on 5482 Saudi people attending primary healthcare centers in Jeddah City in 2014/2015 were analyzed in this cross-sectional study. Questions that covered the natural history, risk behavior, and prevention, and treatment of HCV were collected using a predesigned questionnaire. HCV seroprevalence was assessed using an enzyme-linked immunosorbent assay. HCV prevalence of 0.38% (95% confidence interval: 0.22-0.54) was found. The level of knowledge of the natural history, risk behavior, and prevention and treatment of HCV was poor among the participants. The lowest level of knowledge for all participants pertained to its prevention and treatment. The prevalence of HCV was low in Saudi Arabia (0.38%). However, adequate knowledge of HCV was lacking. Thus, the need to increase knowledge and awareness of HCV in the Saudi population is warranted.

Clinical implementation of AXB from AAA for breast: Plan quality and subvolume analysis.

PURPOSE: Two dose calculation algorithms are available in Varian Eclipse software: Anisotropic Analytical Algorithm (AAA) and Acuros External Beam (AXB). Many Varian Eclipse-based centers have access to AXB; however, a thorough understanding of how it will affect plan characteristics and, subsequently, clinical practice is necessary prior to implementation. We characterized the difference in breast plan quality between AXB and AAA for dissemination to clinicians during implementation. METHODS: Locoregional irradiation plans were created with AAA for 30 breast cancer patients with a prescription dose of 50 Gy to the breast and 45 Gy to the regional node, in 25 fractions. The internal mammary chain (IMCCTV ) nodes were covered by 80% of the breast dose. AXB, both dose-to-water and dose-to-medium reporting, was used to recalculate plans while maintaining constant monitor units. Target coverage and organ-at-risk doses were compared between the two algorithms using dose-volume parameters. An analysis to assess location-specific changes was performed by dividing the breast into nine subvolumes in the superior-inferior and left-right directions. RESULTS: There were minimal differences found between the AXB and AAA calculated plans. The median difference between AXB and AAA for breastCTV V95% , was <2.5%. For IMCCTV , the median differences V95% , and V80% were <5% and 0%, respectively; indicating IMCCTV coverage only decreased when marginally covered. Mean superficial dose increased by a median of 3.2 Gy. In the subvolume analysis, the medial subvolumes were "hotter" when recalculated with AXB and the lateral subvolumes "cooler" with AXB; however, all differences were within 2 Gy. CONCLUSION: We observed minimal difference in magnitude and spatial distribution of dose when comparing the two algorithms. The largest observable differences occurred in superficial dose regions. Therefore, clinical implementation of AXB from AAA for breast radiotherapy is not expected to result in changes in clinical practice for prescribing or planning breast radiotherapy.

Atypical Meningioma: Referral Patterns, Treatment and Adherence to Guidelines.

OBJECTIVE: To determine the referral rate to radiation oncologist (RO), use of postoperative radiotherapy (PORT) and the impact of a clinical practice guideline (CPG) on patients with atypical meningioma (AM). METHODS: A retrospective review of meningioma patients (n=526) treated between 2003 and 2013 was undertaken. Patients' characteristics, extent of surgical resection (EOR), RO referral, PORT, date and treatment of first recurrence were collected for all patients >18 years with a new diagnosis of AM after surgical resection (n=83). Progression free survival (PFS) and overall survival (OS) according to EOR were assessed by the Log-Rank test of Kaplan-Meier survival. RESULTS: Median age was 57 years. EOR was gross total (GTR) in 44 patients, subtotal (STR) in 36 patients and 3 patients had unknown EOR. RO referral rate was 26.5% (n=22); 5 patients initially had GTR and 17 had STR. Only 7 patients received PORT. At a median follow up time of 29 months, recurrences occurred in 28 patients, 4 had GTR, 21 had STR and 3 had an unknown EOR. With PORT, 2 patients developed recurrence. 5-year PFS was 62% after GTR and 33% after STR (P=0.002). 5-year OS was 92% after GTR and 83% after STR (P=0.45). CONCLUSION: In this cohort with AM, RO referral rate was low and was not influenced by the CPG. Use of PORT was also low. Given the lack of conclusive evidence supporting PORT in such patients, a multidisciplinary approach, including RO consultation, is needed to provide patients with optimal and individualised care.

Derivation and validation of clinical phenotypes for COPD: a systematic review.

BACKGROUND: The traditional classification of COPD, which relies solely on spirometry, fails to account for the complexity and heterogeneity of the disease. Phenotyping is a method that attempts to derive a single or combination of disease attributes that are associated with clinically meaningful outcomes. Deriving phenotypes entails the use of cluster analyses, and helps individualize patient management by identifying groups of individuals with similar characteristics. We aimed to systematically review the literature for studies that had derived such phenotypes using unsupervised methods. METHODS: Two independent reviewers systematically searched multiple databases for studies that performed validated statistical analyses, free of definitive pre-determined hypotheses, to derive phenotypes among patients with COPD. Data were extracted independently. RESULTS: 9156 citations were retrieved, of which, 8 studies were included. The number of subjects ranged from 213 to 1543. Most studies appeared to be biased: patients were more likely males, with severe disease, and recruited in tertiary care settings. Statistical methods used to derive phenotypes varied by study. The number of phenotypes identified ranged from 2 to 5. Two phenotypes, with poor longitudinal health outcomes, were common across multiple studies: young patients with severe respiratory disease, few cardiovascular co-morbidities, poor nutritional status and poor health status, and a phenotype of older patients with moderate respiratory disease, obesity, cardiovascular and metabolic co-morbidities. CONCLUSIONS: The recognition that two phenotypes of COPD were often reported may have clinical implications for altering the course of the disease. This review also provided important information on limitations of phenotype studies in COPD and the need for improvement in future studies.

A Cross-Sectional Study of Mental Illnesses Among Infertile Women in Saudi Arabia.

BACKGROUND: Infertility is a global issue and carries significant mental health implications. Data on mental health among infertile women in Saudi Arabia are limited. OBJECTIVE: This study aimed to assess the prevalence and severity of depression, anxiety, and stress among infertile women in Saudi Arabia. METHODS: This analytical cross-sectional study included women of reproductive age visiting governmental hospitals in Jeddah, Saudi Arabia. The participants were asked to fill out a pre-structured questionnaire, which included the Depression, Anxiety, and Stress Scale (DASS-21) to assess their mental health status. Data analysis was conducted using IBM SPSS Statistics, Version 29.0 (released 2023, IBM Corp., Armonk, NY). The three outcome variables derived from the DASS-21 were categorized into five distinct groups for descriptive purposes. RESULTS: In this study, infertile women had significantly higher median scores for depression (18), anxiety (15), and stress (20) compared to fertile women who had median scores of 8, 8, and 10 for depression, anxiety, and stress, respectively. The differences between these two groups were statistically significant (p-value < 0.001). Furthermore, employed infertile women reported higher median scores for depression (87), anxiety (84.5), and stress (84.5) compared to unemployed women. In addition, infertile women with a monthly income of 10,001-20,000 SAR had notably higher median scores for depression (89.56), anxiety (90.22), and stress (89.94) compared to other income groups. These differences were statistically significant (p-values < 0.05). CONCLUSION: Infertility significantly contributes to mental health issues among women in Saudi Arabia. The findings highlight the need for targeted psychological interventions alongside infertility treatment to enhance the quality of life of these women.

Impact of some inorganic anions on the corrosion of nickel in a solution containing Na2SO4 and NaClO4.

Potentiodynamic study was carried out on nickel in Na2SO4 solution in the presence of ClO4-, WO42-, MoO42-, NO2- and NO3- ions. The anodic excursion spans of the metal nickel in a solution of Na2SO4 are marked by the appearance of clearly defined anodic peak, passive region, and transpassive shoulder. According to the data, the anodic peak current density (IPAI) rise from 1.82 to 8.12 mA cm-2 as the concentration of the Na2SO4 solution rises from 0.2 to 1.0 M. It is clear that as scan rate increases, the IPAI rises reaching to 11.8 mA cm-2. The apparent activation energy of nickel corrosion in Na2SO4 is 33.25 kJ mol-1. ClO4- anion addition speeds up nickel's active dissolution, as well tends to break down the passive layer, and causes pitting penetration. It was found that, the pitting potential (Epit) of nickel in solutions containing the two anions ClO4- and SO42- shifts to the positive direction by addition of WO42-, MoO42-, NO2- anions and shifts to the negative direction by addition NO3- anion. Epit increased by 0.67, 0.37 and 0.15 V in the presence of WO42-, MoO42- and NO2-, respectively. WO42- > MoO42- > NO2- was the order in which the inhibitors were most effective.

Advantages of CoS2 nano-particles on the corrosion resistance and adhesiveness of epoxy coatings.

Researchers face significant challenges because of the inadequate corrosion resistance and weak adherence of epoxy (EP) coatings. We deal with these issues here by means of a novel nano-composite coating (EP/nano-CoS2). In order to create a composite coating (EP/nano-CoS2), CoS2 nanoparticles (nano-CoS2) were prepared and incorporated to an epoxy (EP) resin. The synthesized CoS2 was characterized using XRD and FT-IR spectroscopic techniques. The mean particle size was determined using Scherer equation and found to be 19.38 nm. The zeta potential was also determined (- 9.78 mV). Electrochemical impedance spectroscopies (EIS) as well as pull-off assessments were used to quantify the EP/nano-CoS2 coating's anti-corrosion capabilities and adhesive power. The findings demonstrate that the EIS variables of the EP/nano-CoS2 composite coating are markedly improved when compared to raw EP coating. The corrosion resistance or even adhesion of EP protective layer can be markedly increased by using the synthesized nanoparticles as nano-fillers.

An unexpected opportunist: Magnusiomyces capitatus infection in an immunocompetent patient.

Magnusiomyces capitatus is an uncommon opportunistic fungal pathogen primarily affecting immunocompromised individuals. While rare, cases have been reported in immunocompetent patients. We present a documented case of Magnusiomyces capitatus invasive infection in an immunocompetent patient with no previous medical history. This case shows that invasive fungal infections by Magnusiomyces capitatus might affect even the immunocompetent patients.

Impact of Co3O4 nanoparticles on epoxy's mechanical and corrosion-resistance properties for carbon steel in seawater.

Co3O4 nanoparticles (Co3O4-NPs) are synthesized using the facile solvothermal method. FT-IR and XRD spectroscopic analyses verify the creation of cobalt oxide nanoparticles with an average size of 13.20 nm. Furthermore, Zeta potential assessments were carried out to identify the electrical charge of the surface of the produced Co3O4-NPs, which was found to be -20.5 mV.  In addition, the average pore size of Co3O4-NPs is 19.8 nm, and their BET surface area is 92.4 m/g. The study also concerned the effect of Co3O4-NPs on epoxy's improvement of mechanical and corrosion protection for carbon steel in salt solution. By including Co3O4-NPs in an epoxy (EP) coating, corrosion is effectively prevented by non-permeable protective coatings that effectively reduce the transfer of corrosion ions and oxygen.

Recent developments, advances and strategies in heterogeneous photocatalysts for water splitting.

Photocatalytic water splitting (PWS) is an up-and-coming technology for generating sustainable fuel using light energy. Significant progress has been made in the developing of PWS innovations over recent years. In addition to various water-splitting (WS) systems, the focus has primarily been on one- and two-steps-excitation WS systems. These systems utilize singular or composite photocatalysts for WS, which is a simple, feasible, and cost-effective method for efficiently converting prevalent green energy into sustainable H2 energy on a large commercial scale. The proposed principle of charge confinement and transformation should be implemented dynamically by conjugating and stimulating the photocatalytic process while ensuring no unintentional connection at the interface. This study focuses on overall water splitting (OWS) using one/two-steps excitation and various techniques. It also discusses the current advancements in the development of new light-absorbing materials and provides perspectives and approaches for isolating photoinduced charges. This article explores multiple aspects of advancement, encompassing both chemical and physical changes, environmental factors, different photocatalyst types, and distinct parameters affecting PWS. Significant factors for achieving an efficient photocatalytic process under detrimental conditions, (e.g., strong light absorption, and synthesis of structures with a nanometer scale. Future research will focus on developing novel materials, investigating potential synthesis techniques, and improving existing high-energy raw materials. The endeavors aim is to enhance the efficiency of energy conversion, the absorption of radiation, and the coherence of physiochemical processes.

Cancer Research Challenges and Potential Solutions in Saudi Arabia: A Qualitative Discussion Group Study.

PURPOSE: Cancer incidence in Saudi Arabia has recently shown an upward trend. Research efforts within the different cancer continuum are pivotal to strengthening control measures. Since cancer research is evolving in the country, it is crucial to understand the current challenges and implement defined interventions to overcome them. The present qualitative study aimed to assess cancer research barriers among researchers and identify potential solutions from their perspectives. METHODS: We conducted a focus group discussion among 17 Saudi-based cancer researchers from diverse research backgrounds, provinces, and institutions. We used descriptive-interpretive thematic analysis following an open-ended approach to investigate the challenges in conducting cancer research. We also captured the solutions suggested based on the researchers' experiences. RESULTS: Six major themes emerged from the analysis: requirements of the data landscape, organizational support, national research roadmap, sustainable funding, clearer policies and regulations, and capacity building. To address challenges in these areas, researchers stressed the need for improved interinstitutional collaborations, immediate availability of research materials, and unlimited and easy access to research data. CONCLUSION: Improving health research is one of the primary goals of Saudi Vision 2030. It is, therefore, essential to overcome the current challenges in cancer research, enabling research findings to inform policies related to cancer control and care provision.

Synthesis, surface activity, and corrosion inhibition capabilities of new non-ionic gemini surfactants.

Several environmentally acceptable non-ionic gemini surfactants are synthesized in this work using natural sources, including polyethenoxy di-dodecanoate (GSC12), polyethenoxy di-hexadecanoate (GSC16), and polyethenoxy di-octadecenoate (GSC18). The produced surfactants are confirmed by spectrum studies using FT-IR, 1HNMR, and 13CNMR. It explored and examined how the length of the hydrocarbon chain affected essential properties like foaming and emulsifying abilities. Surface tension examinations are used to assess the surface activity of the examined gemini surfactants. The lower value of critical micelle concentrations (0.381 × 10-4M) is detected for GSC18. Their spontaneous character is shown by the negative values of the free energy of adsorption (ΔGads) and micellization (ΔGmic) which arranged in the order GSC18 > GSC16 > GSC12. Based on theoretical, weight loss, and electrochemical investigations, these novel surfactants were investigated for their possible use in inhibiting carbon steel from corroding in 1 M HCl. Measuring results show that GSC18 inhibits corrosion in carbon steel by 95.4%. The isotherm of adsorption evaluated for the investigated inhibitors and their behavior obeys Langmuir isotherm.

Retraction: A Giant Porencephaly: A Rare Etiology of Pediatric Seizures.

[This retracts the article DOI: 10.7759/cureus.19623.].

Prevalence of Internet Gaming Disorder Among Intermediate and High School Students in Albaha, Saudi Arabia: A Cross-Sectional Study.

Background and Objectives Excessive video game use, particularly among young people, is a growing problem that poses potential serious mental health risks in many parts of the world. However, there is a lack of research on the prevalence of internet gaming disorder (IGD) in Saudi Arabia, particularly in Albaha region. The objective of this study was to determine the prevalence of IGD among a sample of intermediate and high school students in Albaha and to identify potential factors associated with the development of the disorder. Methods In this cross-sectional study, we collected data between August and November 2022 using a self-administered online Arabic questionnaire, which included a validated translation of the IGD-20 test, which is a tool based on the DSM-5 criteria for diagnosing IGD. We used a multistage sampling technique, with two administrative areas as clusters, to randomly select eight intermediate and high schools with an equal distribution of male and female students. We analyzed the data using descriptive statistics and chi-square analysis. Results A total of 391 participants were included in the study, with an age range of 12 to 18 years. Males accounted for 51.4% (n=201) of the sample, and females accounted for 48.6% (n=190). The prevalence of IGD was found to be 3.5% (n=14), with males accounting for 64% (n=9) of affected participants. The study found that prolonged gaming duration (three or more hours per day), using mobile phones for gaming, and engaging in online gaming were significant factors associated with the diagnosis of IGD (p<0.001, p<0.001, and p=0.004, respectively). Conclusion This study provides preliminary evidence on the prevalence of IGD among intermediate and high school students in Albaha, Saudi Arabia. The results suggest a lower incidence of IGD compared to studies conducted in other regions of the country. A larger study with in-person interviews is needed to confirm the findings and extend the generalizability of the results. Furthermore, the study highlights the need for further research to explore the risk factors associated with IGD and to develop interventions to address this emerging mental health issue among Saudi Arabian youth.

Perception and Acceptance of COVID-19 Vaccine Among Healthcare Workers in Jeddah, Saudi Arabia.

Introduction The COVID-19 pandemic has resulted in significant hospitalizations and deaths, particularly among healthcare workers (HCWs). Various therapeutic and preventive measures have been introduced, with vaccination considered the primary preventive measure. This study aims to assess the perceptions and acceptance of COVID-19 vaccination among HCWs. Methods We conducted an analytical cross-sectional study on HCWs in hospitals located in Jeddah, Saudi Arabia. The study included physicians, nurses, pharmacists, lab technicians, and radiologists who work in the Ministry of Health's general hospitals. A total of 394 participants were included in the study. Data were analyzed using SPSS v26, and a p-value less than 0.05 was considered significant. Results A majority of the participants (72.6%) were female, aged between 31-40 years (55.3%), and married (59.6%). More than half of the participants (55.6%) had received training on dealing with COVID-19. The mean scores for COVID-19 vaccine refusal, perceived susceptibility, perceived severity, perceived benefits, perceived barriers, and perceived effectiveness of COVID-19 vaccination were 18.36 ± 7.02, 14.48 ± 3.62, 11.51 ± 2.99, 12.39 ± 3.5, 8.25 ± 2.35, and 8.40 ± 2.46, respectively. Age was found to be correlated with the perceived severity of COVID-19 in non-vaccination (p=0.048), while gender was associated with the perceived severity of COVID-19 (p=0.015). Marital status (p=0.001), years of experience (p=0.009), profession (p=0.019), and education (p=0.028) were found to be correlated with perceived susceptibility. Education levels were found to be correlated with the perceived benefits of vaccination (p=0.007), perceived barriers to vaccines (p=0.002), and vaccine views (p=0.002). Years of experience (p=0.017) were found to be correlated with perceived severity of COVID-19, while profession type was significantly associated with perceived severity of COVID-19 (p=0.016) and vaccine view (p=0.008) Conclusion The study found that participants had a positive perception and high acceptance of COVID-19 vaccination. The results also indicated that various sociodemographic factors were associated with the perception and acceptance of COVID-19 vaccines among HCWs. These findings could help in formulating effective strategies to improve vaccination uptake rates among HCWs, thereby reducing transmission and mortality among Health Care Workers due to COVID-19.