175 research outputs found

    Recurrence after correction of acquired ankle equinus deformity in children using Ilizarov technique

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    To describe our Ilizarov technique for the treatment of acquired equinus deformity in children and to determine if compliance with continuous use of an ankle foot orthosis (after removal of the fixator and until skeletal maturity) can influence the severity of recurrence. A cohort of 26 children with post-traumatic or post-burn contractures producing an equinus deformity was followed up for a minimum of 2 years after skeletal maturity. Cases with a bony deformity and/or nerve injury were excluded from this study. All patients were managed by a percutaneous tendo-Achilles lengthening followed by application of an Ilizarov external fixator. Post-operative treatment was in the form of gradual correction at a rate of 0.5 mm per day. Correction started from the second postoperative day until an over-correction of 15 degrees dorsiflexion was achieved. Ankle range of movement was encouraged 4 weeks prior to removal of the external fixator. On removal of the fixator, a posterior splint was applied until substituted by an ankle foot orthoses (AFO). The AFO was used continuously during the first 2–3 months and at nighttime thereafter until skeletal maturity. Fifteen children were compliant with the use of the AFO until skeletal maturity and 11 non-compliant. We compared the recurrence and the size of deformity between the two groups. The rate of recurrence, degree of equinus at recurrence and number of episodes of external fixation surgery showed statistical significant differences (P < 0.01) between the groups. The Ilizarov technique for treatment of acquired equinus deformity secondary to soft tissue scarring is a safe and effective technique. The use of an AFO until skeletal maturity can decrease the risk and degree of recurrence

    Experimental and Theoretical Study on Reverse Osmosis Based Water Desalination

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    Freshwater availability has dropped due to population growth, inefficient use, climate change, and industrial pollution. Although the reverse osmosis, RO, system is one of the most effective desalination technologies worldwide, spiral wound membranes still need deeper theoretical and experimental investigations for removing salts under low energy consumption. In this study, the performance of a commercial pilot RO plant that utilizes a spiral wound seawater membrane module is experimentally investigated under a wide range of operating parameters. In addition, a Mathematical model is developed based on the solution-diffusion model theory and then solved using an in-house MATLAB algorithm to analyze its performance. The theoretical and experimental results were then compared. The present results revealed that the mathematical model’s predictions were highly consistent with the actual experimental results, achieving an average accuracy of about 98%. The average deviation was 4.0578% when predicting water productivity and just 0.2755% when estimating the salt rejection coefficient. The findings of this study could assist designers in predicting the membrane’s performance and selecting the most advantageous operational parameters for supplying water to the RO system

    Experimental and Theoretical Study on Reverse Osmosis Based Water Desalination

    Get PDF
    Freshwater availability has dropped due to population growth, inefficient use, climate change, and industrial pollution. Although the reverse osmosis, RO, system is one of the most effective desalination technologies worldwide, spiral wound membranes still need deeper theoretical and experimental investigations for removing salts under low energy consumption. In this study, the performance of a commercial pilot RO plant that utilizes a spiral wound seawater membrane module is experimentally investigated under a wide range of operating parameters. In addition, a Mathematical model is developed based on the solution-diffusion model theory and then solved using an in-house MATLAB algorithm to analyze its performance. The theoretical and experimental results were then compared. The present results revealed that the mathematical model’s predictions were highly consistent with the actual experimental results, achieving an average accuracy of about 98%. The average deviation was 4.0578% when predicting water productivity and just 0.2755% when estimating the salt rejection coefficient. The findings of this study could assist designers in predicting the membrane’s performance and selecting the most advantageous operational parameters for supplying water to the RO system

    BIOPROCESIRANJE PRIRODNE FOSFATNE RUDE BAKTERIJOM STAPHYLOCOCCUS AUREUS

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    Phosphate ores are in high demand around the world because they are the primary raw materials used in the manufacturing of phosphatic fertilizers and other chemicals. Since the grade of the ore is gradually declining, it is becoming economically viable to mine and beneficiate numerous lower-grade deposits, and a significant number of precious minerals are discarded due to the inadequacy of new technological advances. Thus, biological processes are becoming more appealing in mineral processing due to their lower operating costs and potential applications to beneficiate low-grade complex ores through the interaction of bacteria and mineral surfaces, resulting in surface modification and mineral separation via bio-flotation. Staphylococcus aureus was supplied by the mineral bioprocessing lab, CMRDI. Bacterial adhesion measurements revealed a higher affinity for apatite than quartz. A binary mixture containing 12.5% P2O5 and 42.5% SiO2 yielded a concentrate containing 20.15% P2O5 and 33.5% SiO2. Using the bio-flotation process with Staphylococcus aureus and the optimal conditions on natural phosphate ore, a concentrate with 30.25% P2O5 was obtained from a feed containing 21.89% P2O5.Diljem svijeta velika je potražnja za fosfatnom rudom s obzirom na to da je riječ o primarnoj sirovini koja se koristi u proizvodnji fosfatnih gnojiva i drugih kemikalija. Budući da se koncentracija rude postupno smanjuje, ekonomski je sve isplativije eksploatirati i oplemenjivati brojna ležišta niže koncentracije s obzirom na to da se znatne količine korisne mineralne sirovine nedovoljno iskorištavaju zbog neadekvatnosti novih tehnologija. Stoga biološki procesi postaju sve zanimljiviji u oplemenjivanju SiO2 mineralnih sirovina zbog nižih operativnih troškova i potencijalne primjene za obogaćivanje kompleksnih ruda niskoga stupnja koncentracije, i to interakcijom bakterija i površine minerala, što rezultira površinskom modifikacijom i odvajanjem minerala putem bioflotacije. Bakteriju Staphylococcus aureus isporučio je laboratorij za bioprocesiranje minerala, CMRDI. Mjerenja bakterijske adhezije pokazala su veći afinitet za apatit nego za kvarc. Binarna smjesa koja je sadržavala 12,5 % P2O5 i 42,5 % SiO2 dala je koncentrat koji je sadržavao 20,15 % P2O5 i 33,5 % SiO2. Postupkom bioflotacije bakterijom Staphylococcus aureus pri optimalnim uvjetima na prirodnoj fosfatnoj rudi dobiven je koncentrat s 30,25 % P2O5 iz sirovine koja je sadržavala 21,89 % P2O5

    Validity of the Shahin Mixed Depression Scale: A Self-Rated Instrument Designed to Measure the Non-DSM Mixed Features in Depression

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    Background: The DSM5-defined mixed features in depression do not include psychomotor agitation, irritability or distractibility because they are considered overlapping symptoms. A growing number of modern psychiatrists have expressed dissatisfaction with this and proposed alternative sets of mixed symptoms that are much more common and clinically relevant. Among such alternative criteria were those proposed by Koukopoulos. He utilized the research diagnostic criteria of agitated depression (RDC-A) as a mixed depression subtype, and validated another form of mixed depression, the Koukopoulos criteria for mixed depression (K-DMX). Purpose: This study provides psychometric validation for the first self-rated scale designed to measure the most common mixed symptoms in depression as proposed by Koukopoulos. Patients and methods: We conducted a multicenter cross-sectional study of 170 patients with unipolar depression. They completed the Shahin Mixed Depression Scale (SMDS) and underwent expert interviews as a gold standard reference. SMDS' psychometric properties were assessed, including Cronbach's alpha, factor analysis, sensitivity, specificity, predictive value and accuracy. Results: We found significant association and agreement between mixity according to SMDS and the gold standard (K-DMX and RDC-A according to expert interview) with good internal consistency (Cronbach's alpha=0.87), high sensitivity (=91.4%), specificity (=98.0%), positive predictive value (=96.9%), negative predictive value (= 94.2%) and accuracy (=95.2%). Factor analysis identified one factor for psychomotor agitation and another for mixity without psychomotor agitation. Conclusion: SMDS was a reliable and valid instrument for assessing the frequently encountered and clinically relevant mixed features in depression

    Simulation of scattering from layered spheres with known surface electric field distributions using Mie theory and modified angular spectrum method: Applications to corneal sensing

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    Mie theory is a powerful method to evaluate the scattered fields from the multilayered sphere, where the incident field is expanded to the vector spherical harmonic (VSH) presentation. Then scattered fields are obtained by the T-matrix method. However, obtaining the VSH coefficients for arbitrarily shaped incident fields is difficult and time-consuming. This paper proposes a novel 3D angular spectrum method (3D ASM) for evaluating the VSH coefficients for the incident field, which is defined from the required electric field distribution positioned on the spherical surface. This allows the VSH expansion and evaluation of the scattered fields from a multilayered sphere illuminated with an arbitrary incident wavefront in the Mie Scattering range. This has been computationally challenging with previous methods. First, the advantage of the beam created with the proposed method compared to the nominal Gaussian beam illumination is addressed with the spherical bandstop filter simulation. Then the incident field computed by the proposed method is compared to the physical-optics simulations showing precise agreement. As an example of the proposed methodology, the cornea is modeled as a multilayered spherical structure, and the scattered fields are computed from the cornea illuminated by the incident field with spherical top-hat and tapered top-hat wavefronts. Also, the coupling coefficients of the incident and scattered fields from the cornea model are computed in the 200 - 400 GHz frequency range. The results are compared with coupling coefficients obtained with Gaussian beam illumination and referenced to the reflectivity obtained from plane wave illumination on an analog planar structure. The top-hat beams show increased agreement with the planar stratified medium theory compared to the plane wave and Gaussian beam illumination

    Symbiotic ambient backscatter IoT transmission over NOMA-enabled network

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    Non-orthogonal multiple access (NOMA) and ambient backscatter communication (AmBC) play major roles to enhance spectrum efficiency in wireless communication systems. Besides, the AmBC provides good reinforcement for the current trend towards dispensing batteries for battery-free Internet-of-Things (IoT) devices. In this paper, we propose a symbiotic battery-free IoT system, that exploits the downlink transmission of a NOMA multiplexing enabled cellular network, to permit an IoT spectrum-efficient uplink communication. The IoT backscatter device (BD) performs a symbiotic radio (SR) relation with the cellular source to power its communication by intelligently reflecting the received power. We derive a closed-form expression of the ergodic capacity (EC) of the BD transmission and tight approximations of the ECs of the cellular source transmission, where all channels undergo Nakagami-m fading. Additionally, we validate the analytical results obtained using Monte-Carlo simulations. The influences of several system parameters such as power allocation factor, reflection coefficient, and channels' severity factors have been investigated. Finally, the performance of the proposed system is compared with a benchmark OMA-based system to highlight the achievable performance improvement

    Assessing Drought Tolerance of Newly Developed Tissue-Cultured Canola Genotypes under Varying Irrigation Regimes

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    This article belongs to the Special Issue Crop Tolerance under Biotic and Abiotic Stresses[Abstract] Drought is a major abiotic stress that greatly affects canola growth, production, and quality. Moreover, water scarcity is projected to be more severe and frequent as a result of climate change, in particular in arid environments. Thereupon, developing drought-tolerant and high-yielding canola genotypes has become more critical to sustaining its production and ensuring global food security with the continuing population growth. In the present study, ten canola genotypes comprising six developed tissue-cultured canola genotypes, two exotic genotypes, and two commercial cultivars were evaluated under four irrigation regimes. The applied irrigation regimes were well-watered (100% crop evapotranspiration, ETc), mild drought (80% ETc), moderate drought (60% ETc), and severe drought (40% ETc) conditions. Drought-stress treatments (80, 60, and 40% ETc) gradually reduced the chlorophyll content, relative water content, flowering time, days to maturity, plant height, number of pods, number of branches, seed yield, and oil percentage, and increased proline, phenolic, anthocyanin, and glycine betaine contents. The evaluated genotypes exhibited varied responses to drought-stress conditions. The developed tissue-cultured genotypes T2, T3, and T1, as well as exotic genotype Torpe, possessed the highest performance in all evaluated parameters and surpassed the other tested genotypes under water-deficit conditions. Overall, our findings elicited the superiority of certain newly developed tissue-cultured genotypes and exotic ones compared with commercial cultivars, which could be exploited in canola breeding under water-deficit conditions.This research was funded by the Researchers Supporting Project number (RSPD-2023R730), King Saud University, Riyadh, Saudi ArabiaKing Saud University (Riad, Arabia Saudí); RSPD-2023R73

    Far-Lateral Cervical Approach as a Minimally Invasive Technique for Excision of Upper Cervical Anterolateral and Anterior Meningiomas and Dumbbell Schwannomas: Technical Report and Case Series

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    Objective To demonstrate the details of the far-lateral approach (FLA) as a minimally invasive technique for the excision of the upper cervical anterolateral and anterior meningiomas and dumbbell schwannomas, and to assess the clinical and radiological outcomes. Methods In this technical report and case series we report the FLA technique and patients who underwent the FLA for C1-C4 anterolateral and anterior meningiomas and dumbbell schwannomas between June 2007 and June 2020. All patients’ relative preoperative demographic, clinical, radiographic, operative, histopathological, and perioperative complications and follow-up clinical and radiographic data were reported. Results A total of 19 patients including 12 females and 7 males with a mean age 56.7±17.6 years and mean duration of symptoms 12.8±12.3 months were reported. 9 patients with anterolateral meningiomas, 5 with anterior meningiomas, and 5 with dumbbell schwannomas underwent uneventful FLA procedures. Gross total resection of tumors was reported in 17 patients (89.5%). Preoperative JOA score was normal in ten, grade-I in five, and grade-II in 4 patients, while at the last follow-up it improved to normal in seventeen and grade-I in two patients. Reported postoperative JOA scores at 6 months and at the last follow-up showed that all patients improved at least one grade on JOA scores. There was CSF leak in three patients and superficial wound infection in one. Conclusion Our results advocate the far-lateral cervical approach as a minimally invasive technique in the resection of the upper cervical anterolateral and anterior meningiomas and dumbbell schwannomas as a safe and effective technique

    Applications of Artificial Intelligence in Philadelphia-Negative Myeloproliferative Neoplasms.

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    Philadelphia-negative (Ph-) myeloproliferative neoplasms (MPNs) are a group of hematopoietic malignancies identified by clonal proliferation of blood cell lineages and encompasses polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). The clinical and laboratory features of Philadelphia-negative MPNs are similar, making them difficult to diagnose, especially in the preliminary stages. Because treatment goals and progression risk differ amongst MPNs, accurate classification and prognostication are critical for optimal management. Artificial intelligence (AI) and machine learning (ML) algorithms provide a plethora of possible tools to clinicians in general, and particularly in the field of malignant hematology, to better improve diagnosis, prognosis, therapy planning, and fundamental knowledge. In this review, we summarize the literature discussing the application of AI and ML algorithms in patients with diagnosed or suspected Philadelphia-negative MPNs. A literature search was conducted on PubMed/MEDLINE, Embase, Scopus, and Web of Science databases and yielded 125 studies, out of which 17 studies were included after screening. The included studies demonstrated the potential for the practical use of ML and AI in the diagnosis, prognosis, and genomic landscaping of patients with Philadelphia-negative MPNs
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