Combination Of Techniques Research Articles

Advancement and Innovations in Drying of Biopharmaceuticals, Nutraceuticals, and Functional Foods

AbstractDrying is a crucial unit operation within the functional foods and biopharmaceutical industries, acting as a fundamental preservation technique and a mechanism to maintain these products' bioactive components and nutritional values. The heat-sensitive bioactive components, which carry critical quality attributes, necessitate a meticulous selection of drying methods and conditions backed by robust research. In this review, we investigate challenges associated with drying these heat-sensitive materials and examine the impact of various drying methods. Our thorough research extensively covers ten notable drying methods: heat pump drying, freeze-drying, spray drying, vacuum drying, fluidized bed drying, superheated steam drying, infrared drying, microwave drying, osmotic drying, vacuum drying, and supercritical fluid drying. Each method is tailored to address the requirements of specific functional foods and biopharmaceuticals and provides a comprehensive account of each technique's inherent advantages and potential limitations. Further, the review ventures into the exploration of combined hybrid drying techniques and smart drying technologies with industry 4.0 tools such as automation, AI, machine learning, IoT, and cyber-physical systems. These innovative methods are designed to enhance product performance and elevate the quality of the final product in the drying of functional foods and biopharmaceuticals. Through a thorough survey of the drying landscape, this review illuminates the intricacies of these operations and underscores their pivotal role in functional foods and biopharmaceutical production.

Introduction of Endovascular Thrombectomy to The Island Nation — The Maldives

Over the years multiple treatment trials were researched up on for acute management of ischemic stroke to reduce mortality risk and morbidity rate among adults who suffered. Here, we report a case of 63 years Muslim diabetic female with multiple co-morbidities of coronary heart disease, pulmonary disease, and internal carotid artery aneurysm presented with thrombotic occlusion of left middle cerebral artery who underwent Maldives first ever endovascular thrombectomy using combined technique.

A Novel Combined Cartilage-Fascia Technique for Anterior Perforation in Type-1 Underlay Tympanoplasty

Background: Biomaterials and surgical techniques for reconstructive tympanic membrane surgery are under development. Objectives: The objective of this study is to analyze the functional and surgical outcomes of a novel fascia with cartilage reinforcement technique for anterior tympanic membrane perforation in tympanoplasty. Methods: Records of 198 patients with anterior tympanic membrane perforation who underwent tympanoplasty between August 2018 and March 2021 were prospectively reviewed. Patients with dry anterior quadrant perforations of the tympanic membrane were included and underwent tympanoplasty using two methods: Type 1 tympanoplasty with temporalis fascia only, and tympanoplasty with fascia and cartilage reinforcement. Postoperative functional and surgical outcomes were analyzed. Results: Comparing the pre-operative and post-operative air conduction levels and air-bone gaps showed significant improvement in both groups (P < 0.001). Additionally, no significant difference was observed between air-bone gap closure (P = 0.316) and increase in air conduction levels (P = 0.222) according to graft type. Conclusions: Both temporalis muscle fascia and temporalis muscle fascia with cartilage reinforcement revealed satisfactory functional and surgical outcomes. Furthermore, the novel combined cartilage-fascia technique had a comparable graft take rate and hearing results in anterior perforations, with no significant change in tympanic membrane vibratory properties.

Physical activity maintenance in colorectal cancer survivors after an exercise intervention applying behaviour change techniques: a systematic review and meta-analysis.

The purpose of this systematic review and meta-analysis is to determine the long-term effect of combined physical activity (PA) and behaviour change techniques (BCT) interventions in PA maintenance of colorectal cancer survivors (CRCS) and identify the most frequent BCT implemented in them. PRISMA recommendations were followed. Databases were searched for randomized controlled trials up to October 2023. Studies in which CRCS completed a PA intervention based on any Theoretical Model of Behaviour Change (TMBC) and a subsequent follow-up period were included. Between-group differences at baseline and after follow-up were pooled for meta-analysis. BCT codification was performed using the BCT taxonomy v1. Methodological quality and evidence certainty were also assessed. Five studies involving 906 CRCS met the inclusion criteria. PA interventions applying BCT showed a significant change with a small positive effect (pooled SMD = 0.22 (0.09, 0.35)) on the PA after a follow-up period between 3 and 12months. Twenty-two different BCTs were identified (mean 17.2, range 15-19) of which 12 were common across all interventions. PA and BCT interventions have been found to be effective in improving the long-term maintenance of PA in CRCS. Further studies with higher methodological quality are needed to confirm these findings. Aerobic exercise, pedometers, PA diaries and educational materials seem to be important aspects to achieve sustainable adherence to an active lifestyle over time. Supervision, access to fitness areas and applying some BCT appear to be differentiating features to obtain more successful PA maintenance.

Probing the Topological Effects on Stability Enhancement and Therapeutic Performance of Protein Bioconjugates: Tadpole, Macrocycle versus Figure-of-Eight.

Chemical topology provides a unique dimension for making therapeutic protein bioconjugates with native structure and intact function, yet the effects of topology remain elusive. Herein, the design, synthesis, and characterization of therapeutic protein bioconjugates in three topologies (i.e., tadpole, macrocycle, and figure-of-eight), are reported. The interferon α2b (IFN) and albumin binding domain (ABD) are selected as the model proteins for bioconjugation and proof-of-concept. The biosynthesis of these topological isoforms is accomplished via direct expression in cells using SpyTag-SpyCatcher chemistry and/or split-intein-mediated ligation for topology diversification. The corresponding topologies are proven with combined techniques of LC-MS, SDS-PAGE, and controlled proteolytic digestion. While the properties of these topological isoforms are similar in most cases, the figure-of-eight-shaped bioconjugate, f8-IFN-ABD, exhibits the best thermal stability and anti-aggregation properties along with prolonged half-life and enhanced tumor retention relative to the tadpole-shaped control, tadp-IFN-ABD, and the macrocyclic control, c-IFN-ABD, showcasing considerable topological effects. The work expands the topological diversity of proteins and demonstrates the potential advantages of leveraging chemical topology for functional benefits beyond multi-function integration in protein therapeutics.

Association of first-line thrombectomy technique and outcome in late-window large vessel occlusion strokes: A post hoc analysis of the MR CLEAN-LATE trial.

This study aimed to compare direct aspiration, stent retriever, and the combined thrombectomy technique on clinical, safety, and technical outcomes in late-window stroke patients included in the MR CLEAN-LATE trial. This post hoc analysis of the MR CLEAN-LATE trial included patients treated with direct aspiration, stent retriever, or combined thrombectomy technique as first-line approach. Primary outcome was the modified Rankin Scale (mRS) score at 90 days follow-up, and compared between the three groups with ordinal logistic regression analysis. Secondary outcomes included mortality at 90 days, total technique switches, procedure time, recanalization rate measured with the expanded thrombolysis in cerebral infarction (eTICI) score, and symptomatic intracranial hemorrhage (sICH). Predefined variables were used for adjustments. In the MR CLEAN-LATE trial, 258 patients underwent endovascular treatment and 232 were included in our analyses. The mRS at 90 days did not differ (stent retriever vs. direct aspiration: adjusted common odds ratio (acOR) = 1.35, 95% confidence interval (CI) = 0.73 to 2.50; stent retriever vs. combined: acOR = 1.13, 95% CI = 0.64 to 2.00; direct aspiration vs. combined: acOR = 1.19, 95% CI = 0.64 to 2.21). Direct aspiration thrombectomy was accompanied with more switches to another technique compared to the stent retriever (adjusted odds ratio (aOR) = 6.50, 95% CI = 2.52 to 16.8) or combined group (aOR = 4.67, 95% CI = 1.80 to 12.1) and with higher sICH rates compared to the combined technique (13% vs. 2.5%; aOR = 8.19, 95% CI = 1.49 to 45.1). Mortality, procedure time, and eTICI did not differ. Stent retriever, direct aspiration, or the combined thrombectomy technique as first-line approach showed no differences in clinical outcome in late-window stroke patients. Direct aspiration was accompanied with higher sICH rates and more switcher to another technique compared to the combined group.

Image post-processing for SILMAS: structured illumination light sheet microscopy with axial sweeping.

In this article, we propose a post-processing scheme for the novel volumetric microscopy technique SILMAS. We demonstrate this scheme on data from an alpha-synuclein transgenic mouse brain. By combining structured illumination and axial sweeping, a SILMAS measurement provides a prerequisite for quantitative data extraction through improved contrast and optical sectioning. However, due to the technique's efficient removal ofb multiple scattered light, image artifacts such as illumination inhomogeneity, shadowing stripes, and signal attenuation, are highlighted in the recorded volumes. To suppress these artifacts, we rely on the strengths of the imaging method. The SILMAS data, together with the Beer-Lambert law, allow for an approximation of real light extinction, which can be used to compensate for light attenuation in a near-quantitative way. Shadowing stripes can be suppressed efficiently using a computational strategy thanks to the large numerical aperture of an axially swept light sheet. Here, we build upon prior research that employed wavelet-Fourier filtering by incorporating an extra bandpass step. This allows us to filter high-contrast light sheet microscopy data without introducing new artifacts and with minimal distortion of the data. The combined technique is suitable for imaging cleared tissue samples of up to a centimeter scale with an isotropic resolution of a few microns. The combination of a thin and uniform light sheet, scattered light suppression, light attenuation compensation, and shadowing suppression produces volumetric data that is seamless and highly uniform.

Treatment Modalities and Rehabilitation Procedures of Dentigerous Cyst Among the Paediatric Population - A Systematic Review of Case Reports

BACKGROUND: The dentigerous cyst which wraps around the impacted teeth is the most prevalent developmental odontogenic cyst among the Paediatric population in India. Various treatment modalities were proposed previously, such as enucleation, marsupialization, fenestration, or a combination technique with or without preservation of the affected dentition. OBJECTIVES: The aim of the Paediatric dentist should rely on the preservation of permanent teeth. Hence, this systematic review aimed to evaluate the prevalence and describe the different treatment methods and rehabilitation techniques conducted following the surgical excision of dentigerous cysts among the Paediatric population in India, which is significant to Paediatric dentists. METHODS: Systematic review registered under PROSPERO following PRISMA guidelines. Thorough search was done in PubMed, EMBASE, ProQuest and Cochrane Library. RESULTS: The results showed that the dentigerous cyst occurred commonly in the age group of children aged 6 – 10 years (72.22%), with a male predilection (80.56%). The complete cyst enucleation with the removal of milk teeth and permanent dentition (52.78%) was preferred more than the preservation of the affected dentition. After complete enucleation of the cyst in only 57.89% of cases, rehabilitation procedures were planned. The results showed that proper rehabilitation was not planned in many cases, which may lead to poor oral hygiene maintenance and early space loss. CONCLUSIONS: It is important for the Paediatric Dentist to know the importance of preserving the permanent teeth or plan a wise rehabilitation procedure to replace missing teeth to maintain the proper oral health of the children. Keywords: Dentigerous Cyst, Paediatric Dentistry, Enucleation, Marsupialization, Oral Rehabilitation.

Predicting grout’s uniaxial compressive strength (UCS) for fully grouted rock bolting system by applying ensemble machine learning techniques

This study proposes a novel system for accurately predicting grout’s uniaxial compressive strength (UCS) in fully grouted rock bolting systems. To achieve this, a database comprising 73 UCS values with varying water-to-grout (W/G) ratios ranging from 22 to 42%, curing times from 1 to 28 days, the admixture of fly ash contents ranging from 0 to 30%, and two Australian commercial grouts, Stratabinder HS, and BU-100, was built after conducting comprehensive series of experimental tests. After building the dataset, a metaheuristic technique, the jellyfish search (JS) algorithm was employed to determine the weight of base models in the ensemble system. This system combined various data and modelling techniques to enhance the accuracy of the UCS predictions. What sets this technique apart is the comprehensive database and the innovative use of the JS algorithm to create a weighted averaging ensemble model, going beyond traditional methods for predicting grout strength. The proposed ensemble model was called the weighted averaging ensemble model (WAE-JS), in which the obtained results of several soft computing models such as multi-layer perceptron (MLP), Bayesian regularized (BR) neural networks, generalized feed-forward (GFF) neural networks, classification and regression tree (CART), and random forest (RF) were weighted based on JS and the new results were then generated. Eventually, the result of WAE-JS was compared to other models, including MLP, BR, GFF, CART, and RF, based on some statistical parameters, such as R-squared coefficients, RMSE, and VAF as indices for evaluating the performance and capability of the proposed model. The results suggested the superiority of the ensemble WAE-JS system over the base models. In addition, the proposed WAE-JS model effectively improved the predicting accuracy achieved from the MLP, BR, GFF, CART, and RF. Furthermore, the sensitivity analysis revealed that the W/G had the most significant impact on the grout’s UCS values.

Exploring the viability of combined laser-induced breakdown spectroscopy and Raman spectroscopy for stratigraphic analysis of murals containing isomeric pigments: a case study on realgar and orpiment

A novel combined measurements techniques has been designed in this work, enabling the acquisition of laser-induced breakdown spectroscopy (LIBS) and Raman spectral signals at the same point on a sample. The application of this combined technique to the analysis of multi-layered mock-up blocks painted with orpiment and realgar pigments has yielded significant insights. By correlating variations in the emission line intensity of characteristic elements within the LIBS spectra with depth-specific Raman spectra, the number of laser pulses that penetrated the pigment layers has been accurately determined, thereby establishing a method to measure layer thickness. Finally, the technique wasto analysis the actual mural fragment from Mogao Cave 196, determining the types of pigment and the thickness of the pigment layers.Graphical

Renal Access in Pediatric Supine Miniaturized Percutaneous Nephrolithotomy: Comparative Evaluation of Ultrasound-Fluoroscopy Combined and Biplanar (0°-90°) Fluoroscopic Techniques.

Introduction: Ultrasound (US)-guided puncture has the benefits of avoiding radiation and limiting the risk of visceral injury. We aimed to evaluate the results of two different renal access techniques during pediatric supine mini percutaneous nephrolithotomy (smPCNL) in a comparative manner. Patients and Methods: Data obtained from pediatric patients undergoing smPCNL by single surgeon between September 2021 and 2023 were reviewed retrospectively. Children were divided into two groups namely; biplanar 0°-90° fluoroscopy (Group-F) and US-fluoroscopy combined (Group-C). In all cases, preoperative, operative, and postoperative findings were recorded. Success was defined as the determination of either no (complete stone-free status) or < 4 mm residual fragments (CIRF) on US and X-ray (postoperative 3rd month) images. Complications were evaluated according to modified Clavien-Dindo classification. Results: Data of 54 patients with a mean age of 8.6 years (Group-F = 30, Group-C = 24) are reviewed. In addition to the similar success rates in both groups (Group-F = 86.7% Group-C = 87.5% p = 0.928), similar minor complications were noted in the majority of the cases. No child required transfusion and/or angioembolization. Although the fluoroscopy and operation time were lower in Group-C, the difference was not statistically significant. Conclusion: US-fluoroscopy combined access technique can be applied with similar success and complication rates in pediatric smPCNL. Ultimately, as experience is gained, this technique may lower radiation exposure, although this was not observed in the current study.

A two-tier feature selection method for predicting mortality risk in ICU patients with acute kidney injury

Acute kidney injury (AKI) is one of the most important lethal factors for patients admitted to intensive care units (ICUs), and timely high-risk prognostic assessment and intervention are essential to improving patient prognosis. In this study, a stacking model using the MIMIC-III dataset with a two-tier feature selection approach was developed to predict the risk of in-hospital mortality in ICU patients admitted for AKI. External validation was performed using separate MIMIC-IV and eICU-CRD. The area under the curve (AUC) was calculated using the stacking model, and features were selected using the Boruta and XGBoost feature selection methods. This study compares the performance of a stacking model using two-tier feature selection with a model using single-tier feature selection (XGBoost: 85; Boruta: 83; two-tier: 0.91). The predictive effectiveness of the stacking model was further validated by using different datasets (Validation 1: 0.83; Validation 2: 0.85) and comparing it with a simpler model and traditional clinical scores (SOFA: 0.65; APACH IV: 0.61). In addition, this study combined interpretable techniques and causal inference to analyze the causal relationship between features and predicted outcomes.

Multi-Criteria Model for Identifying and Ranking Risky Types of Maritime Accidents Using Integrated Ordinal Priority Approach and Grey Relational Analysis Approach

Accidents in marine operations are occurring consistently despite government safety initiatives and efforts to lower the number of accidents and the ensuing human casualties. Since each accident type has a different frequency and casualty rate, identifying risky accident types is important to determine the priority for taking necessary risk reduction actions. Usually, a risk is calculated using two criteria, i.e., the frequency and fatality of an accident. However, the accident statistics show that for the last 5 years from 2018 to 2022, the injury rate is more than three times the death rate in maritime accidents in Korean waters. Considering the importance of injury, unlike other previous studies, we perform a risk analysis with three criteria, i.e., frequency, death, and injury to complement the conventional risk calculation methods, which can help decision-makers allocate the limited resources to the riskiest types of accidents in order of priority. In doing so, we employed an integrated ordinal priority approach (OPA) and grey relational analysis (GRA) method to assign proper weight to each criterion and rank eight accident types. We categorized the accidents types into three different groups where safety accidents and collisions were ranked as the most dangerous types. The combined OPA and GRA technique has been effectively applied to other risky industries, as well as the maritime industry. Additionally, the proposed method is suitable for multi-criteria models when each criterion has a different importance. Finally, the method can be integrated into the framework of the risk ranking process to enhance the analysis results.

A three-step modification of the DRASTIC model using spatial multi criteria decision making methods to assess groundwater vulnerability

Groundwater vulnerability assessment, as a key tool, is essential for assisting decision-makers and experts in identifying highly vulnerable areas and devising efficient pollution reduction strategies. The widely utilized DRASTIC model for assessing groundwater vulnerability incorporates seven key geological and hydrological parameters. To address the limitations of the DRASTIC model, this study proposes a novel three-step modification by introducing an extra parameter, adjusting default weights, and utilizing alternative aggregation methods. These modifications aim to capture the unique characteristics of a specific region more accurately. The first step involves incorporating the Land Use (LU) parameter as the eighth parameter in the DRASTIC model, resulting in an updated 8-parameter model. The second step involves integrating the Analytic Hierarchy Process (AHP) to adjust parameter weights based on input from local experts. Lastly, while the Weighted Linear Combination (WLC) technique has conventionally been used for aggregating layers in the GIS environment, this study suggests employing the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). Furthermore, to consider decision makers' risk attitudes, the Ordered Weighted Averaging (OWA) method is utilized.To assess its effectiveness, the modified model was applied to Khoy County in Iran. Then, the results were compared to the DRASTIC model using correlation analysis based on nitrate concentrations. The results indicated a correlation coefficient of 0.67 for the modified model compared to 0.47 for the DRASTIC model. This suggests that the proposed modified model is an enhanced and highly effective approach for evaluating groundwater vulnerability.

Investigation of continuous wave/coaxial waterjet-assisted laser combined machining of micro holes in GH3536

A two-step combined processing technique, combining a continuous-wave laser with a waterjet-assisted nanosecond laser, has been introduced to enhance the quality and efficiency of laser micro-hole processing for nickel-based superalloys. Initially, a through-hole was created using a continuous-wave laser, followed by hole refinement with a coaxial waterjet-assisted nanosecond laser. In the first step, orthogonal testing methods were employed to investigate the impact of various parameters, including power, duty ratio, frequency, defocusing amount, and processing time, on the entrance and exit apertures, as well as the hole taper. Through the analysis of variance (ANOVA) method, the optimal parameter combination A2B1C4D3E1 was identified, achieving the minimal hole taper. This combination comprised a power level of 80 %, a duty ratio of 15 %, a frequency of 400 Hz, a defocusing amount of 2 mm, and a processing time of 10 ms. In the second step, a comparison was made between scanning and trepan drilling machining methods. The results unequivocally demonstrated that scanning drilling achieves superior entrance and exit morphologies. Furthermore, the effect of water jet velocity on the morphology of micropores was thoroughly analyzed. The voltage range of the water pump was adjusted from 10 V to 24 V, revealing that a voltage of 20 V produced the smallest hole taper. The scanning filling diameter was accurately preset according to the preformed hole aperture as well as the thickness of the recast layer. Finally, after coaxial waterjet-assisted laser precision machining, the inner wall of the hole is free of cracks, and the recast layer and oxide layer are effectively minimized. The initial hole prefabrication with the continuous-wave laser took merely 0.01 s, and the subsequent fine-tuning with the coaxial waterjet-assisted laser took 2 min and 25 s.

Event‐triggered output quantization control for asynchronously switched interval type‐2 fuzzy systems

AbstractThis article considers exponential stabilization (ES) of switched interval type‐2 (SIT2) fuzzy systems with asynchronous switching control. The SIT2 fuzzy system switches from one mode to another according to transition probabilities (TPs). A general SIT2 fuzzy quantized event‐triggered output controller (QETOC) is designed to save the communication resources. The QETOC employs distinctive membership functions from those of the IT2 fuzzy model and switches with mode‐pendent switching delay, which is more practical than asynchronously switched control techniques with a common switching delay and control schemes without TP. By designing discretized multiple Lyapunov function (DMLF) and using convex combination technique, sufficient conditions formulated by linear matrix inequalities (LMIs) are obtained to ensure that the DMLF does not ‘jump high’ at the moment of switching, and hence the conservatism of obtained results is significantly reduced since no additional dwell time is needed for the stabilization. It is discovered that the SIT2 fuzzy system is not necessary to be unstable on mismatched intervals, and it can be unstable on matched intervals. The advantages of theoretical analysis are verified by numerical simulations, and the classical assumption that each subsystem is unstable on mismatched intervals is conservative for control design.

Urinary continence following extraperitoneal radical prostatectomy: impact of surgical technique and pelvic fascial spaces reconstruction

Introduction. Urinary incontinence is a common complication of radical prostatectomy. The development of surgical techniques when performing radical prostatectomy that improve the function of urinary continence after surgery is actual.Objective. To compare urinary continence functions in long-term follow-up after open and laparoscopic radical prostatectomy when only posterior or combined (anterior + posterior) reconstruction of the pelvic fascial spaces is performed.Materials &amp; methods. The study included 130 patients aged 63.0 [59.0; 68.0] years with local prostate cancer (сT1a-2сN0-xM0; 1 – 4 ISUP groups), subjected to non-nerve-sparing retropubic radical prostatectomy with posterior reconstruction and non-nerve-sparing extraperitoneal laparoscopic radical prostatectomy with isolated posterior or combined (anterior + posterior) fascial reconstruction of the pelvic fascial spaces. Postoperative continence function was studied at 1, 3, 6, and 12 months following surgery using a standard pad test.Results. The incidence of urinary continence was higher at all follow-up periods during laparoscopic surgery. From the 6-months follow-up, these patients did not have severe urinary incontinence. At the same time, the rate of growth of some patients who began to retain urine did not depend on the method of reconstruction of the pelvic fascial spaces. The use of combined reconstruction of the pelvic fascial spaces at 12-months follow-up showed an advantage in urinary continence over performing only posterior reconstruction. Such patients achieved urinary continence in 90% of cases compared to 80.0% of cases. At the same time, the restoration of urinary continence at all periods of observation had a relatively uniform linear rate of increase in the indicator.Conclusion. Reconstruction of the pelvic fascial spaces during open and laparoscopic radical prostatectomy allows one to achieve satisfactory continuation in the postoperative period. However, higher efficiency is achieved when using a combined reconstruction technique.

Sonochemical synthesis and characterization of SnF2 as a potential fluoride-ion conducting solid electrolyte

Fluoride ion batteries (FIBs) are emerging as a promising alternative to conventional lithium-ion batteries, primarily because of their high theoretical energy density and environmentally sustainable characteristics. For the development of a high-performance solid-state fluoride ion battery, an engineered electrolyte is crucial. As the synthesis technique impacts the phase, microstructure, and morphology of the materials, a unique and facile sonochemical route is employed for the first time herein for synthesizing Tin (II) fluoride as a solid electrolyte. The XRD investigations have indicated the formation of the α-SnF2 phase with a monoclinic structure, and space group C2/c. The particle size of SnF2 synthesized using 225 W and 325 W power of probe sonicator is found to be 2 μm and 0.8 μm respectively, as revealed by Scanning Electron Micrographs. SnF2 prepared with 325 W ultrasonic power has exhibited the maximum ionic conductivity of value 3.4 × 10−4 S/cm at room temperature, with a significant enhancement regarding the values reported so far. The anionic transport number of the electrolyte estimated at room temperature using the combined AC-DC technique is found to be 0.96, indicating fluoride ion conduction.

Aerodynamic and Structural Design Procedures Supported by Fabrication and Flight Testing of a Small Unmanned Helicopter

In this work, typical design, production, and testing procedures for a small unmanned helicopter are explained and performed. In doing so, preliminary sizing of the helicopter and three main disciplines are conducted: aerodynamic analytical and numerical simulations, power calculations, and structure analysis assessment. First, a thorough survey is implemented to obtain the trends for the maximum take-off weight versus some design constraints such as rotor diameter, motor power, payload, and empty weight. Performance calculation results are obtained to figure out all aspects that correspond to the specified mission. The designed rotor geometry along with the aerodynamic characteristics and flight performance variables is then validated using the blade element theory and numerical simulations. Second, based on the power curves obtained for different flight regimes, an electric brushless motor is selected. The numerical simulations (Computational Fluid Dynamics) analysis is used to enhance the selection which implies that the motor power should be greater than 5.4 kW to overcome the drag forces. The motor power selection corresponds to a maximum rotor pitch angle of 15∘ and a maximum rotor speed of 1450 RPM. Then, the aerodynamic loads are used as an input for the structural analysis using one-way coupling of fluid–structure interaction (FSI) and consequently designing the internal structure of the blade. Eventually, the internal structure manufactured using carbon fiber-reinforced polymer (CFRP) by applying a combined technique between wet layup and compression molding. The blade is statically tested compared with numerical finite element model results. The fuselage structure along with hub and tail units is manufactured and assembled with the existing on-shelf components to examine the helicopter lift capability with different payloads up to 9 kg. The results show that the detailed design process is significant for manufacturing such blades and the helicopter is capable of lifting off the ground with various payloads depending on the rotor pitch angles (8∘, 12∘, and 15∘) at a constant rotor speed of 1450 RPM.

Preservation of the native urethral plate and corpus spongiosum combined with buccal mucosa graft plus Orandi's penile skin flap as an alternative to staged urethroplasty for narrow penile strictures.

In narrow anterior urethral strictures, the combined buccal mucosa graft (BMG) with pedicled penile skin flap (PSF) represents a well-known effective alternative to staged urethroplasty. We hypothesized that if the native urethral plate and adjacent corpus spongiosum were preserved, a narrower flap would be needed, and reinforced ventral stability could be achieved without compromising the surgical outcome. Twelve patients with narrow penile urethral strictures underwent single-stage augmentation urethroplasty using a combined technique. A BMG was quilted to the corpora cavernosa in a dorsal onlay approach, and a longitudinal ventral PSF was transposed ventrally and sutured to the scarred native urethral mucosa on one side and to the BMG on the other side to form a neourethra of triangular form. The preserved corpus spongiosum was wrapped and fixed around the flap ventrally. The median age was 47 years (IQR 35-59), and the median stricture length was 5 cm (IQR 3, 8-7). The median surgical time was 205 min (IQR 172-236). The overall success rate (SR) was 91.7% without sacculation or diverticula formation after a median follow-up period of 38 months (IQR 33-40). Three transient fistulas healed through prolonged urinary diversion. Five patients (41.7%) reported postvoid dribbling following urethroplasty. Preservation of the native urethral plate is a valuable adjunct to the combination of graft and flap for single-stage augmentation urethroplasty for narrow urethral strictures, with satisfactory mid-term success and an acceptable complication rate.