Nonlinear Parameter Identification of a Resonant Electrostatic MEMS Actuator.

We experimentally investigate the primary superharmonic of order two and subharmonic of order one-half resonances of an electrostatic MEMS actuator under direct excitation. We identify the parameters of a one degree of freedom (1-DOF) generalized Duffing oscillator model representing it. The experiments were conducted in soft vacuum to reduce squeeze-film damping, and the actuator response was measured optically using a laser vibrometer. The predictions of the identified model were found to be in close agreement with the experimental results. We also identified the noise spectral density of process (actuation voltage) and measurement noise.

Nintedanib and pirfenidone for idiopathic pulmonary fibrosis in King Abdulaziz Medical City, Riyadh: Real-life data.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a chronic progressive age-related lung disease causing relentless fibrosis of the lung parenchyma. Currently, pirfenidone and nintedanib are the two antifibrotic drugs, approved for the treatment of IPF. Both are shown to slow progression by preserving lung functions from rapid decline compared to a placebo. We are reporting a real-life patient experience using these two antifibrotic medications (AFMs) in our tertiary care hospital. METHODS: A retrospective cohort study was conducted for all IPF cases diagnosed in multidisciplinary meetings between 2015 and 2020 at KAMC, Riyadh (Saudi Arabia). We are reporting patients' demographics, lung function, survival, tolerance, side effects, or death in patients taking AFMs. RESULTS: A total of 81 cases were identified. The majority of patients aged 67 years (68%) were men with a median age of 68 years. Late presentation, severe disease, and definite usual interstitial pneumonia patterns were reported in 60% of our patients. The average number of hospital admissions before starting treatment was 1 (range: 0-3) in the nintedanib group and 1.4 (range: 1.2-5) in the pirfenidone group. There was an increase in the number of hospital admissions in the group started on pirfenidone 1.7 (range: 1.9-8) compared to nintedanib 0.5 (range: 0-3), P = 0.001. The observed mortality outcome in this cohort was 4 (11%) and 12 (27%) for nintedanib and pirfenidone, respectively. The predominant side effects were gastrointestinal symptoms for both the groups 18 (22%). CONCLUSIONS: Pirfenidone and nintedanib are the available approved antifibrotic agents used for many years to treat IPF patients. Real-life data showed better tolerability than reported in the West, good compliance, and a manageable side effect profile in this group of elderly and severe IPF patients.

Nano Groove and Prism-Structured Triboelectric Nanogenerators.

Enhancing the output power of triboelectric nanogenerators (TENGs) requires the creation of micro or nano-features on polymeric triboelectric surfaces to increase the TENGs' effective contact area and, therefore, output power. We deploy a novel bench-top fabrication method called dynamic Scanning Probe Lithography (d-SPL) to fabricate massive arrays of uniform 1 cm long and 2.5 µm wide nano-features comprising a 600 nm deep groove (NG) and a 600 nm high triangular prism (NTP). The method creates both features simultaneously in the polymeric surface, thereby doubling the structured surface area. Six thousand pairs of NGs and NTPs were patterned on a 6×5 cm2 PMMA substrate. It was then used as a mold to structure the surface of a 200 µm thick Polydimethylsiloxane (PDMS) layer. We show that the output power of the nano-structured TENG is significantly more than that of a TENG using flat PDMS films, at 12.2 mW compared to 2.2 mW, under the same operating conditions (a base acceleration amplitude of 0.8 g).

Prognostic utility of various multidimensional grading scales among Saudi patients with bronchiectasis.

INTRODUCTION: A number of multidimensional scoring systems, including the Bronchiectasis Severity Index (BSI), the FACED score, and the Exacerbation-FACED (Exa-FACED, a derivative of FACED), have been proposed and validated to assess the severity and prognosis in patients with bronchiectasis. Although these metrics have been validated through large multicenter efforts in Europe and Latin America, there have been no attempts at external validation in other populations. OJECTIVES: The aim of this study was to validate specific multidimensional grading scales (BSI, FACED, and Exa-FACED) in predicting mortality, future exacerbations, and hospitalizations among Saudi patients with bronchiectasis. METHODS: A prospective observational cohort study was conducted at a tertiary care centre. The three multidimensional grading scales (BSI, FACED, and Exa-FACED) were calculated for each patient. Future frequent acute exacerbations (≥2/year) and severe acute exacerbations leading to hospitalization were recorded for 1 year, and all-cause mortality was monitored for up to 5 years. RESULTS: A total of 301 patients with bronchiectasis (mean age of 60±17 years and 66% female) were include. All Grading scales performed well in predicting 5-year survival. Area under the curve (AUC) values for BSI (0.86, 95% CI: 0.82-0.90), FACED (0.81, 95% CI: 0.76-0.85), and Ex-FACED (0.83, 95% CI: 0.78-0.87). The BSI (AUC=0.98, 95% CI: 0.96-0.99) performed better than FACED scoring (AUC=0.77, 95% CI: 0.71-0.81; P<0.0001) in predicting hospitalization. Exa-FACED scoring (AUC=0.84, 95% CI: 0.80-0.88) improved upon FACED scores in predicting hospitalization. The BSI (AUC=0.95, 95% CI: 0.91-0.97) fared significantly better than FACED scoring (AUC=0.76, 95% CI: 0.70-0.80; p<0.0001) in predicting frequent acute exacerbations (≥2/year). Again, Exa-FACED scoring (AUC=0.85, 95% CI: 0.81-0.89) improved upon FACED scores in predicting frequent acute exacerbations (≥2/year). CONCLUSIONS: All scoring systems performed adequately in 5-year mortality projections. Although Exa-FACED scoring improved upon FACED scores in predicting forthcoming frequent acute exacerbations and hospitalization, the BSI outperformed both in this regard.

The diagnostic yield and safety of sputum induction in suspected pulmonary tuberculosis: The experience of a single tertiary care center in Saudi Arabia.

Background: Sputum smear microscopy examination and culture for tuberculosis (TB) remain a fundamental tool of diagnosis but may be negative up to 50% case of active pulmonary TB. Bronchoscopy to obtain sputum is invasive and not readily available. Alternative methods of obtaining sputum specimens are crucial in suspected pulmonary TB cases who are unable to expectorate. In this context, it may be beneficial to stimulate sputum production by administering a mist of hypertonic saline produced by ultrasonic nebulization. The aims of the study are to describe the experience of a tertiary center in Saudi Arabia with sputum induction (SI) for the investigation of patients suspected to have sputum scare TB. Methods: A retrospective cohort study was performed. All patients suspected of sputum scare TB and investigated with SI were included. Standard descriptive statistics were used. Categorical data presented as frequency were compared using the Chi square test. Continuous data presented as mean ± standard deviation were compared using Student's t test. Sensitivity, specificity, and predictive values were calculated. Results: Of 252 patients with suspected TB who underwent SI, 78 (31%) were ultimately diagnosed to have TB. Culture of induced sputum confirmed the diagnosis of TB in 44 (56.4%) of these patients. However, the diagnosis of TB would have been missed in 13.5% of the cohort if no further investigations were done. The incidence of complications was low. No patients required hospitalization or specialist intervention. Conclusions: SI is safe well tolerated and inexpensive. It may reduce the need for bronchoscopy in patients with suspected sputum scare TB. However, around 20% of TB can be missed by SI unless further investigations are performed. Hence, patients suspected to have sputum scare TB in whom the risk of bronchoscopy is high, a clinical decision on the appropriateness of empirical therapy is often required.

Do ward rounds offer effective teaching and training? Obstacles to learning and what makes good teaching in a large tertiary care hospital from trainee doctor's perspective.

Background: Ward rounds (WR) have been integral to the process of teaching and learning medicine and also provides a vital opportunity to communicate with the patient, their relatives, and other healthcare professionals. Yet in recent years trainees' perception of the educational value of WRs seems to have declined. Objectives: The aim of this study to assess trainees' perception of the educational value of WRs at King Abdulaziz Medical City(KAMC), Riyadh, a 1500 bed academic hospital in Saudi Arabia. Methods: A self-administered, paper-based survey was distributed to physicians in training at KAMC between October and December 2019. All residents who attended WRs were invited to participate. The questionnaire was adapted from a survey used in a previous study. The demographic section requested details of the respondent's age, gender, specialty, and seniority. The second and third sections asked about the logistics of current ward round practices. It included several questions on the structure as well as the duration and frequency of ward rounds. The fourth and fifth sections asked for participant's perception of the opportunities for, and the obstacles to, learning on ward rounds. The subsequent sections asked several questions onward round structure and the clinical teacher. Responses were requested on a 5-point Likert-type scale (strongly disagree, disagree, neutral, agree, strongly agree). The last section asked the participant for general comments and feedback Result: The study targeted 250 residents in specialties that routinely performed WRs. Only 166 residents returned the questionnaire (response rate of 66.4%). Male 89 (53.6%), medical 108 (65.1%), surgical 58 (34.9%), resident in first year 81 (48.8%). The overall average time spent on WR was 13 (± 11 SD) hours per week. The WR was perceived as a good opportunity to learn about diagnostic investigation 138 (83%) and patient management 133(80.1%), history taking114 (68.7%) physical examination 103 (62.0%), and time management skills 86 (51.8%). The majority of our trainees felt that the WR was educationally very useful to 86 (52%) and attribute to at least a third of the education they receive during their training. They also reported that about the quarter of the time spent on WRs is devoted to teaching. The good teacher described as enthusiastic to teach 137 (82.5%), provide feedback to trainees 135 (81%), do not rush 139(83.7), communicate to trainee 144 (86.7), and consultant level,101 (60.8). Trainees also identify a few factors that hinder their training such as lack of time 130 (79%), and the number of patients 129 (78.3). Conclusion: This study identifies the strengths and weaknesses of WR in our institution. Finding will help training supervisors in addressing and rectifying these shortcoming and factors hinder training.

Performance of Multidimensional Severity Scoring Systems in Patients with Post-Tuberculosis Bronchiectasis.

Objective: The aim of this study was to assess the clinical characteristics and outcomes of patients with post-tuberculosis (post-TB) bronchiectasis. We also evaluated the performance of various multidimensional severity score systems to predict mortality, future exacerbation, and hospitalization. Methods: We conducted a prospective observational cohort study to evaluate the etiology of bronchiectasis in 301 patients. Patients fell into three groups: post-TB (129 [43%]), idiopathic (76 [25%]), and other (96 [32%]) etiologies of bronchiectasis. Four multidimensional grading scales, including the Bronchiectasis Severity Index (BSI), the FACED score, and two derivative versions of the FACED score, Exacerbation (Exa-FACED and E-FACED), were calculated and compared for each patient. Results: Patients with post-TB bronchiectasis were predominantly female (61%) with a mean age of 68±11 years. Moreover, 26% of post-TB bronchiectasis patients were colonized with Pseudomonas aeruginosa. At baseline, patients with post-TB bronchiectasis were older, had higher severity scores, and were more likely to have experienced severe exacerbations that required hospitalization compared to patients with idiopathic bronchiectasis or bronchiectasis arising from other causes. During follow-up, 52% of patients required hospitalization, 58% had frequent (≥2 per year) acute exacerbations, and the overall 5-year mortality rate was 30%. Five-year survival was efficiently predicted by each of the grading scales. Although the modified variations of the FACED outperformed the original FACED scale in predicting forthcoming frequent acute exacerbations and hospitalization, the BSI outperformed all three systems in this regard. Conclusion: Patients with post-TB bronchiectasis had higher severity scores than patients with idiopathic bronchiectasis or bronchiectasis arising from other causes. In addition, all scoring systems performed adequately in 5-year mortality projections. BSI and the modified versions of the FACED outperformed the FACED in predicting forthcoming exacerbations and hospitalizations.

Attitudes and behaviours of physicians towards the relationship with the pharmaceutical industry in Saudi Arabia.

BACKGROUND: The relationship and interactions between physicians and the pharmaceutical industry can affect patient care. A physician's practice can be influenced by this relationship. It is believed that these interactions are common among doctors in Saudi Arabia. AIMS: This study was undertaken to assess the frequency of such relationships and physicians' attitudes and behaviours toward them. METHODS: This was a cross-sectional questionnaire survey completed by practicing physicians at four Saudi government and private tertiary care centres in Riyadh, Saudi Arabia. The questionnaire addressed the frequency of meetings with representatives of pharmaceutical companies (PRs) and of receiving gifts and considered the physicians' attitudes and behaviours towards PRs. RESULTS: A total of 300 completed questionnaires were obtained. Among the physicians surveyed, 223 (74.3%) met PRs one to three times per month. Up to 191 (64%) of physicians admitted receiving gifts. More than two thirds of physicians-192 (63%) have been invited to activities sponsored by pharmaceutical companies. Among the physicians, 239 (80%) agreed that PRs use promotional techniques in their approach and 251 (84%) of them stressed the need for expert physicians to attend presentations by PRs to correct the facts. CONCLUSION: The frequent meetings between physicians and PRs and the use of promotional techniques by PRs are concerning. Future studies should assess the impact of this involvement on medical practice and drugs prescription in Saudi Arabia.

Saudi lung cancer management guidelines 2017.

BACKGROUND: Lung cancer management is getting more complex due to the rapid advances in all aspects of diagnostic and therapeutic options. Developing guidelines is critical to help practitioners provide standard of care. METHODS: The Saudi Lung Cancer Guidelines Committee (SLCGC) multidisciplinary members from different specialties and from various regions and healthcare sectors of the country reviewed and updated all lung cancer guidelines with appropriate labeling of level of evidence. Supporting documents to help healthcare professionals were developed. RESULTS: Detailed lung cancer management guidelines were finalized with appropriate resources for systemic therapy and short reviews highlighting important issues. Stage based disease management recommendation were included. A summary explanation for complex topics were included in addition to tables of approved systemic therapy. CONCLUSION: A multidisciplinary lung cancer guidelines was developed and will be disseminated across the country.