Case report: Invasive fungal rhinosinusitis in the immunocompetent host

Invasive fungal rhinosinusitis is a rare and, because of the possible CNS invasion, potentially life-threatening disease. It usually occurs in immunocompromised patients undergoing chemotherapy, transplantation, patients with hematologic malignancy, diabetes or AIDS. However, there have been noted few cases of invasion occurring in previously healthy individuals

Resonant Frequency and Phase Noise of Nanoelectromechanical Oscillators Based on Two-dimensional Crystal Resonators

This study presents a theoretical analysis of one of the most promising nanoelectromechanical (NEMS) components – a NEMS oscillator. The analyzed oscillator contains a stretched circular plate, fabricated of two-dimensional crystals (graphene, bBN, MoS2 etc.), as a resonator. The calculation of resonant frequency based on the classical continuum theory of plates and membranes is presented, and then the phase noise theory of the oscillators using a circular plate as a frequency determining element. We assume that thermal and 1/f noise are present in the oscillator circuit. A satisfactory agreement is obtained between our calculations and recent experimental literature data for graphene

Intrinsic noise equivalent concentration of dynamic mode microcantilever biosensors

The presented theory enables systematic investigation of the dependence of the minimal detectable concentration of the target analyte, determined by the cantilever intrinsic noise, on various parameters. Inclusion of the influence of effects such as the mass transfer in noise considerations results in a more accurate noise model, which is necessary when methods based on noise measurements are developed.\ud \ud Poster presented at the 38th International Conference on Micro and Nano Engineering MNE, 16-20 September 2012, Toulouse, Franc

Steady-state analysis of stochastic time response of chemical and biological microfluidic sensors

In this paper we first give a short review of two stochastic models describing both the expected value and variance of the random number of adsorbed particles in microfluidic adsorption-based chemical and biological sensors. One model takes into account the influence of coupling of stochastic adsorptiondesorption processes and mass transfer on the change of the number of adsorbed particles, while the other neglects the influence of mass transfer. Subsequently, by using the two models, we perform the analysis of the expected value and variance, as well as the sensor's signal-to-noise ratio, after reaching the steady state of all transient processes. We compare the results obtained by using the different models, and determine conditions for their application. We estimate the influences of the sensing surface area and the concentration of target particles on statistical parameters of sensor response and signal-to-noise ratio, considering the cases where mass transfer is significant, and those where it is not. We particularly analyze the mass transfer influence on the expected value, variance and signal-to-noise ratio. Such analysis does not exist in the available literature. The presented analysis yields new knowledge about the stochastic response of adsorption-based sensors, and it is significant for their optimization in order to achieve reliable analyte detection and improved sensing performance

Analysis of the Fundamental Detection Limit in Microfluidic Chemical and Biological Sensors

Detection limits in microfluidic chemical and biological sensors, which determine the range of analyte concentrations reliably detectable by the sensor, are important sensor parameters. The lower limit of detection, defined as the lowest concentration that can be distinguished from noise, has its minimum determined by the fundamental adsorption-desorption (AD) noise, inevitable in adsorption-based devices. In this work, we analyze this fundamental detection limit, particularly considering the influence of mass transfer processes in microfluidic devices. For that purpose, we derive the expression for the sensor’s signal-to-noise ratio (SNR), which takes into account the AD noise, and then the equation for the minimal analyte concentration at which the SNR has a sufficiently high value for reliable analyte detection. Subsequently, we analyze the mass transfer influence on the sensor’s maximal achievable signal-to-noise ratio and on the fundamental detection limit. The results of the analysis show a significant mass transfer influence on these important sensor performance metrics. They also provide guidelines for achieving the sensor’s best possible detection performance through the optimization of the sensor design and operating conditions

Steady-state analysis of stochastic time response of chemical and biological microfluidic sensors

In this paper we first give a short review of two stochastic models describing both the expected value and variance of the random number of adsorbed particles in microfluidic adsorption-based chemical and biological sensors. One model takes into account the influence of coupling of stochastic adsorptiondesorption processes and mass transfer on the change of the number of adsorbed particles, while the other neglects the influence of mass transfer. Subsequently, by using the two models, we perform the analysis of the expected value and variance, as well as the sensor's signal-to-noise ratio, after reaching the steady state of all transient processes. We compare the results obtained by using the different models, and determine conditions for their application. We estimate the influences of the sensing surface area and the concentration of target particles on statistical parameters of sensor response and signal-to-noise ratio, considering the cases where mass transfer is significant, and those where it is not. We particularly analyze the mass transfer influence on the expected value, variance and signal-to-noise ratio. Such analysis does not exist in the available literature. The presented analysis yields new knowledge about the stochastic response of adsorption-based sensors, and it is significant for their optimization in order to achieve reliable analyte detection and improved sensing performance

Factors associated with postoperative pain following functional sinus surgery

Introduction: Functional endoscopic sinus surgery is a minimally invasive technique used to restore sinus ventilation and normal function. Nowadays, it is a common procedure with minimal complication rate. As with any other surgical procedure, post-operative pain is something to expect. Methods: We conducted a retrospective study of postoperative pain using a VAS score scale. Statistical analysis was performed using the Mann Whitney U test and Pearson test for correlation between postoperative pain and the extension of intraoperative nasal packing and administered anestetics, perioperative antibiotis administration, age and duration of operation. Results: 124 patients were enrolled in this study, the median age was 48 (21-75) years, the average duration of surgery was 103 (±46.43) minutes, in 73.4% of patients surgery was bilateral, in 33% the procedure was revisional. 43.5% of patients received antibiotic therapy perioperatively. The mean VAS score was higher in the second postoperative day in patients with more extended nasal packing (p=0.02). We did not find any significant association between the age, duration of surgery, antibiotic therapy, remifentanil intraoperatively and VAS scale. In the first postoperative day, in patients older than 50, the mean VAS score was 1.52 vs 0.97 in those younger than 50 (p=0.19). Conclusion: Post-operative pain affects recovery, risk of post-operative complications and equally important – the quality of life. Preoperative evaluation with careful perioperative planning and individualized treatment can reduce post-operative pain and improve the quality of life of our patients. Our findings show us the need for better monitoring of post-operative pain

CSF Leaks after Endoscopic Skull Base Surgery: A Single Institution Experience

Objective: To review our experience with endoscopic endonasal skull base reconstruction. Materials and Methods: A retrospective review of a single-institution endoscopic endonasal patient database from 2014-2019. The CSF leaks were graded based on defect size from 0 (no leak) to 2. The reconstruction method was documented for all patients. Results: There were in total 341 endoscopic endonasal operations for performed parasellar pathology. The pathology was: pituitary adenomas (85%), craniopharyngioma (1.1%), meningioma (2.9%), malignant tumors (0.5%) and other (9.9%). The total postoperative CSF leaks rates were 8.7%, and meningitis rates were 4.4%. The vast majority of CSF leaks were in the first 2 years of endoscopic endonasal skull base surgery. The flaps that were used: nasoseptal flap, middle turbinate flap (vascularized), free mucosal graft, fat graft and fat plug and the combination of these matherials. Conclusion: Reconstruction of skull base defects is of uttermost importance in the prevention of meningitis. There is a slow learning curve in achieving the surgical skills for endoscopic endonasal skull base surgery. The nasoseptal flap is the “work-horse” for anterior skull base reconstruction

CSF Leaks after Endoscopic Skull Base Surgery: A Single Institution Experience

Objective: To review our experience with endoscopic endonasal skull base reconstruction. Materials and Methods: A retrospective review of a single-institution endoscopic endonasal patient database from 2014-2019. The CSF leaks were graded based on defect size from 0 (no leak) to 2. The reconstruction method was documented for all patients. Results: There were in total 341 endoscopic endonasal operations for performed parasellar pathology. The pathology was: pituitary adenomas (85%), craniopharyngioma (1.1%), meningioma (2.9%), malignant tumors (0.5%) and other (9.9%). The total postoperative CSF leaks rates were 8.7%, and meningitis rates were 4.4%. The vast majority of CSF leaks were in the first 2 years of endoscopic endonasal skull base surgery. The flaps that were used: nasoseptal flap, middle turbinate flap (vascularized), free mucosal graft, fat graft and fat plug and the combination of these matherials. Conclusion: Reconstruction of skull base defects is of uttermost importance in the prevention of meningitis. There is a slow learning curve in achieving the surgical skills for endoscopic endonasal skull base surgery. The nasoseptal flap is the “work-horse” for anterior skull base reconstruction

Poslijeoperacijska bol nakon funkcionalne endoskopske operacije sinusa

We conducted a retrospective review of medical records using our institution electronic database with the purpose to identify factors that could influence postoperative pain after functional endoscopic sinus surgery. The studied factors were gender, age, American Society of Anesthesiologists (ASA) status, duration of surgery, extent of surgery, primary versus revision surgery, and extent of nasal packing. One hundred and twenty-four patients were enrolled in this study, 60.5% of them male, mean age 48 years. The mean postoperative pain reported on the visual analog scale was 1.20 on the day of surgery and 1.05 on postoperative day 1. On the day of surgery, patients who had unilateral type of surgery experienced less pain than patients with bilateral surgery (p<0.01). We did not find any statistically significant association of the reported postoperative pain with age, gender, ASA status, duration of surgery, antibiotic therapy, and type and extensiveness of nasal packing.Proveli smo retrospektivni pregled medicinske dokumentacije koristeći informatički sustav naše ustanove s ciljem identificiranja čimbenika koji bi mogli utjecati na poslijeoperacijsku bol nakon funkcionalne endoskopske operacije sinusa. Proučavani čimbenici su bili: spol, dob, ASA status, trajanje operacije, opsežnost operacije, razlika primarne i revizijske operacije te opsežnost nosne tamponade. U studiju je uključeno 124 bolesnika, 60,5% od njih su bili muškarci, a srednja dob iznosila je 48 godina. Srednja vrijednost poslijeoperacijske boli na ljestvici VAS bila je 1,20 na dan operacije te 1,05 prvog poslijeoperacijskog dana. Na dan operacije bolesnici kod kojih je proveden jednostrani zahvat imali su manju bol naspram bolesnika kod kojih je učinjen obostrani zahvat. Nije pronađena statistički značajna povezanost poslijeoperacijske boli i dobi, spola, ASA statusa, trajanja operacije, antibiotske terapije i opsežnosti nosne tamponade