Separation Procedure Research Articles

Cartilage Biopsy for Autologous Cell–Based Repair of the Knee in the Wide-Awake Setting Using Needle Arthroscopy

Chondral and osteochondral lesions of the knee are a commonly occurring pathology that can pose challenges to the treating surgeon. For the appropriate cartilage injury, autologous cell–based articular cartilage repair techniques have shown promising results. However, these treatments traditionally require 2 separate surgical procedures. Recent advances in needle arthroscopy technology have made it possible to conduct the first stage of autologous chondrocyte implantation surgery in the wide-awake office setting, mitigating cost and resource utilization. The purpose of this technical note is to serve as a proof of concept and describe the process of obtaining a cartilage sample in the wide-awake patient using a needle arthroscope.

Chemical Profiling on Bioactive Stilbenoids in the Seeds of Paeonia Species Growing Wild in Greece

The seeds of Paeonia clusii Stern subsp. clusii and Paeonia mascula (L.) Mill. subsp. mascula growing wild in Greece, though not previously investigated, has been studied as a source of bioactive stilbenoids and other phenolics. Their methanol extracts were analyzed using ultra high-performance liquid chromatography—high-resolution mass spectrometry (UHPLC-HRMS), and among the identified metabolites (62), 19 paeoniflorin’s derivatives, 17 flavonoids and 12 stilbenes were detected. Moreover, through classic phytochemical separation procedures, twelve among them were isolated and fully spectrally determined as trans-resveratrol, trans-resveratrol-4′-O-β-D-glucopyranoside, cis-resveratrol-4′-O-β-D-glucopyranoside, trans-gnetin-H, trans-ε-viniferin, luteolin, luteolin-3′-O-β-D-glucopyranoside, luteolin-3′,4′-di-O-β-D-glucopyranoside, apigenin, hispidulin, paeoniflorin and benzoyl-paeoniflorin. All seed extracts were measured for their total phenolic content (TPC), appearing as a rich source (116.04 and 103.63 mg GAE/g extract, respectively), followed by free radical (DPPH) scavenging capacity (75.24% and 91.54% inhibition at the concentration of 200 μg/mL). The evaluation of tyrosinase inhibition for both extracts (61% and 70%, respectively) confirmed the potential for their future application in skin health care, comparable with other paeonies of Chinese origin, which are well-known as skin whitening and anti-aging promoters.

Using dielectrophoretic spectra to identify and separate viable yeast cells.

Immotile yeast cells were transiently moved in nonuniform sinusoidal electric fields using multiple pairs of micro-parallel cylindrical electrodes equipped with a sequential signal generator (SSG) to analyze cell viability at a clinical scale for the brewery/fermentation industry. Living yeast cells of Saccharomyces cerevisiae during the exponential-stationary phase, with a cell density of 1.15 × 105 cells mL-1 were suspended in sucrose medium. The conductivity (σs) was adjusted to 0.01 S m-1 with added KCl. Cells exposed in electric field strengths ranging from 32.89 to 40.98 kV m-1, exhibited positive dielectrophoresis (pDEP) with the lower critical frequencies (LCF) at 85.72 ± 3.59 kHz. The optimized value of LCF was shifted upwards to 780.00 ± 83.67 kHz when σswas increased to 0.10 S m-1. Dielectrophoretic and LCF spectra (translational speed of cells vs. electric field frequencies) of yeast suspensions during positive dielectrophoresis were analyzed in terms of the dielectric properties of the cell membrane and cytoplasm which reflect yeast cell viability and metabolic health status. The dielectrophoretic collection yield of cells using positive dielectrophoresis was reported on the monitor of sequential signal generator software to evaluate the number of living and dead cells through a real-time image processing analyzer. The spectra of both positive dielectrophoresis of the living and dead cells had distinguishable dielectric properties. The conductivity of the yeast cytoplasm (σc) of the dead cells was significantly less (≈ ≤ 0.05 S m-1) than that of the living yeast cells which typically had a cytoplasmic conductivity of ≈ 0.2 S m-1. This difference between viable and non-viable cells is sufficient for cell separation procedures. KEY POINTS: • Dielectrophoresis can be used to separate viable and non-viable yeast cells, • Cellular dielectric properties can be derived from the analysis of their dielectric spectra, • Cytoplasmic conductivity of viable cells is ≈ 0.2 S m-1 while that of non-viable cells ≈ ≤ 0.05 S m-1.

Directing Intrinsic Chirality in Gold Nanoclusters: Preferential Formation of Stable Enantiopure Clusters in High Yield and Experimentally Unveiling the "Super" Chirality of Au144.

Chiral gold nanoclusters offer significant potential for exploring chirality at a fundamental level and for exploiting their applications in sensing and catalysis. However, their widespread use is impeded by low yields in synthesis, tedious separation procedures of their enantiomeric forms, and limited thermal stability. In this study, we investigated the direct synthesis of enantiopure chiral nanoclusters using the chiral ligand 2-MeBuSH in the fabrication of Au25, Au38, and Au144 nanoclusters. Notably, this approach leads to the unexpected formation of intrinsically chiral clusters with high yields for chiral Au38 and Au144 nanoclusters. Experimental evaluation of chiral activity by circular dichroism (CD) spectroscopy corroborates previous theoretical calculations, highlighting the stronger CD signal exhibited by Au144 compared to Au38 or Au25. Furthermore, the formation of a single enantiomeric form is experimentally confirmed by comparing it with intrinsically chiral Au38(2-PET)24 (2-PET: 2-phenylethanethiol) and is supported theoretically for both Au38 and Au144. Moreover, the prepared chiral clusters show stability against diastereoisomerization, up to temperatures of 80 °C. Thus, our findings not only demonstrate the selective preparation of enantiopure, intrinsically chiral, and highly stable thiolate-protected Au nanoclusters through careful ligand design but also support the predicted "super" chirality in the Au144 cluster, encompassing hierarchical chirality in ligands, staple configuration, and core structure.

Creation of a Highly Active Small Cu-Based Catalyst Derived from Copper Aluminium Layered Double Hydroxide Supported on α-Al2 O3 for Acceptorless Alcohol Dehydrogenation.

A highly dispersed carbonate-intercalated Cu2+ -Al3+ layered double hydroxide (CuAl LDH) was created on an unreactive α-Al2 O3 surface (CuAl LDH@α-Al2 O3 ) via a simple coprecipitation method of Cu2+ and Al3+ under alkaline conditions in the presence of α-Al2 O3 . A highly reducible CuO nanoparticles was generated, accompanied by the formation of CuAl2 O4 on the surface of α-Al2 O3 (CuAlO@α-Al2 O3 ) after calcination at 1073 K in air, as confirmed by powder X-ray diffraction (XRD) and Cu K-edge X-ray absorption near edge structure (XANES). The structural changes during the progressive heating process were monitored by using in-situ temperature-programmed synchrotron XRD (tp-SXRD). The layered structure of CuAl LDH@α-Al2 O3 completely disappeared at 473 K, and CuO or CuAl2 O4 phases began to appear at 823 K or 1023 K, respectively. Our synthesised CuAlO@α-Al2 O3 catalyst was highly active for the acceptorless dehydrogenation of benzylic, aliphatic, or cyclic aliphatic alcohols; the TON based on the amount of Cu increased to 163 from 3.3 of unsupported CuAlO catalyst in 1-phenylethanol dehydrogenation. The results suggested that Cu0 was obtained from the reduction of CuO in the catalyst matrix during the reaction without separate reduction procedure and acted as a catalytically active species.

Improved virus concentration methods for wash waters from decontamination of permeable and non-permeable surfaces

Surface decontamination is a method of using wash water to decontaminated surfaces preventing transmission of biological contaminants that can pose potential health risks to responders and the public. However, the risks associated with handling used wash water are largely unknown due to the lack of effective methodology to screen for pathogenic microorganisms present in these samples, especially viral pathogens. This study adapted the dead-end hollow-fiber ultrafiltration (D-HFUF) system to wash waters, including a separate procedure for recovering particle attached viruses. Simulated wash water was created using dechlorinated tap water containing a mild surfactant (0.05 % Tween 80). To determine virus recovery efficiencies, measured amounts of somatic and F+ coliphage were spiked into 2-liter volumes of wash water under the following scenarios: (1) wash water was amended with a measured amount of sterile river sediment with no sediment separation prior to filter concentration; or (2) sediment added to wash water was allowed to settle prior to filter concentrating clarified liquid portions, while precipitated sediment was subjected to viral extraction techniques to recover particle attached virus; and (3) the optimized method was deployed on non-porous and porous surfaces to simulate a decontamination clean-up event. Separation of sediment prior to D-HFUF significantly increased recovery of coliphages, (P = <0.0001) versus filtration of sediment and liquids simultaneously. A tryptic soy broth (TSB) elution solution was significantly more effective (P = ≤0.010) for recovery of both somatic and F+ coliphage, (108 ± 9 % and 92 ± 9 %, respectively), compared to elution buffers containing various surfactants (sodium hexametaphosphate, Tween 80) for recovering particle attached virus. Simulating a biocontaminate clean-up event (using the optimized sediment separation and elution protocol) resulted in coliphage recoveries of 75–96 % (permeable surface) and 71–92 % (non-permeable surface). This procedure can be used to effectively detect viruses in used wash waters aiding in reducing risks to human health during site decontamination.

Contemporary Applications and Outcomes of Pulmonary Artery Banding: An Analysis of The Society of Thoracic Surgeons Congenital Heart Surgery Database

BackgroundPulmonary artery banding (PAB) in isolation or combined with a congenital cardiac surgical procedure is common and has important mortality. We aimed to determine patient characteristics, clinical outcomes, variation in clinical outcomes by diagnoses, and center variation in PAB use. MethodsUsing The Society of Thoracic Surgeons Congenital Heart Surgery Database (STS CHSD), this study evaluated outcomes of patients undergoing PAB across diagnoses, participating centers, and additional procedures. Patients were identified by procedure and diagnosis codes from 2016 to 2019. We separated patients into groups of main and bilateral PAB and described their outcomes, focusing on patients with main PAB. ResultsThis study identified 3367 PAB procedures from 2016 to 2019 (3% of all STS CHSD cardiovascular cases during this period): 2677 main PAB, 690 bilateral PAB. Operative mortality was 8% after main PAB and 26% after bilateral PAB. There was significant variation in use of main PAB by center, with 115 centers performing at least 1 main PAB procedure (range, 1-134; Q1-Q3, 8-33). For patients with main PAB, there were substantial differences in mortality, depending on timing of main PAB relative to other procedures. The highest operative mortality (25%; P < .0001) was in patients who underwent main PAB after another separate procedure during their admission, with extracorporeal membrane oxygenation being the most frequent preceding procedure. ConclusionsPAB is a frequently used congenital cardiac procedure with high mortality and variation in use across centers. Outcomes vary widely by banding type and patient diagnosis. Main PAB after cardiac surgical procedures, especially extracorporeal membrane oxygenation, is associated with very high operative mortality.

B-212 Application of Annexin A5Coated Beads for Collection of Extracellular Vesicles and Their Content RNA as Liquid Biopsy for Lung Cancer

Abstract Background Extracellular vesicles (EVs) carry molecules derived from cells, such as RNA. Measurement of tumor-derived extracellular RNA (exRNA) in EVs from plasma can be a promising approach for the development of blood-based cancer detection. However, the lack of an easy method for EVs separation limits its application. The aim of this study is to establish a procedure for EV collection and exRNA detection for non-small-cell lung cancer (NSCLC) diagnosis and monitoring. Methods Annexin A5-coated magnetic beads (ANX beads) were developed for EVs isolation. Next, we established a procedure for EV separation and exRNA detection from fluidic specimens using the ANX beads. Then blood samples from 22 NSCLC patients and 20 healthy controls were collected to evaluate the procedure and we detected different RNAs in the samples. Results We evaluated the ability of ANX beads in EVs separation and found that the beads could capture large and small EVs and could increase RNA concentration. Then we detected different RNAs in the samples and found that CK19 mRNA, MALAT1 lncRNA, and miR155 microRNA had good performance to differentiate NSCLC from healthy controls. Conclusion In conclusion, this assay protocol could separate EVs to enrich RNA concentration. The EVs separation employed was captured by magnetic beads which could be adopted into an automatic nucleic acid extract system to conveniently concentrate and extract nucleic acid from EVs.

Separation of a two binary-azeotrope acetonitrile-cyclohexane-toluene ternary mixture via continuous triple column extractive distillation with heat integration: design, simulation, and multi-objective genetic-algorithm (MOGA) optimization

ABSTRACT Using a sustainable method for separating azeotropic mixtures, such as extractive distillation, is crucial for environmental and resource sustainability. Cyclohexane, acetonitrile, and toluene are essential solvents in different chemical processes. This ternary mixture has two binary azeotropes between cyclohexane-acetonitrile and acetonitrile-toluene at atmospheric pressures. Using residue curve maps and a uni-volatility line, n-butylbenzene was selected as a viable entrainer for extractive distillation, among other possibilities. Unlike conventional designs, the recycled entrainer was only sent to the first column in this simulation. The wasted energy from the recycled entrainer was used to supply reboilers duty through integration. A 3-D material balance was performed to understand the separation procedures better. High-purity acetonitrile, cyclohexane, and toluene will also be obtained from the first, second, and third columns. Finally, a multi-objective genetic algorithm with 14 key decision variables was utilized to reduce total annual cost (TAC) and CO2 emissions and improve thermodynamic efficiency as objective functions from economic, environmental, and energy efficiency perspectives. Optimized results reveal that a heat-integrated design reduces almost 25% TAC and 46% CO2 emissions compared to conventional extractive distillation and does not significantly affect thermodynamic efficiency. This research could be valuable for separating azeotrope systems from other ternary mixtures.

Separation and purification of light rare earth elements from chloride media using P204 and Cyanex272 in sulfonated kerosene under non-saponification conditions

The extraction of light rare earths (Pr and Nd) from chloride medium was investigated using a mixture of di(2-ethylhexyl) phosphoric acid (P204) and bis(2,4,4-trimethylpentyl) phosphinic acid (Cyanex272) in sulfonated kerosene. The P204+Cyanex272 system exerted a synergistic effect on the separation of light rare earths, and the separation coefficient was higher than when P204 and Cyanex272 were used as extractants alone. The separation coefficient of Pr and Nd in the extraction system reached 1.75 when the pH of the aqueous phase material solution was approximately 2.5, and 1.5 mol/L hydrochloric acid as a stripping agent effectively eluted the rare earth ions in the loaded organic phase. Combining the slope method, infrared spectroscopy, and nuclear magnetic resonance spectroscopy, we explored the mechanism of the extracted Nd and Pr into the organic phase complex, and finally entered the organic phase with Re(HA&lt;sub&gt;2&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;B. The P-O-H bond and P=O bond in the extractant P204 and Cyanex272 formed a coordination bond with Re&lt;sup&gt;3+&lt;/sup&gt;. Therefore, this extraction method also provides a reference for a more environmentally friendly and efficient procedure for separation and purification of light rare earth elements Pr and Nd.

DIRECTIONS OF REALIZATION OF THE ORGANIZATIONAL AND ECONOMIC MECHANISM OF FORMATION OF THE ENERGY SECURITY SYSTEM OF UKRAINE: THE ELECTRIC POWER ASPECT

The process of reforming the electricity market has been underway for a long time. The European market liberalization guidelines encourage changes in Ukraine. However, internal contradictions of the domestic market slow down these changes. The basis for these changes is the Law of Ukraine, "On the Electricity Market," adopted in 2017, which lays the foundation for deep reform. This is manifested in the following: all enterprises (producers and suppliers) in the electricity market must operate on separate, self-organized principles; openness and transparency, and free access to the use of networks of all business entities based on public contracts; the law provides for and creates several electricity markets: the intraday market, the balancing market, and the ancillary services market. Each has a separate operating procedure, electricity purchase and sale system, pricing, and the establishment of sales volume standards and quotas. The purpose of the article is to determine the priority areas for implementing the organizational and economic mechanism for the formation of Ukraine's energy security system in the context of the electricity sector. The situation in the electricity market requires significant investments (about USD 25 billion over ten years) to ensure the reliability and continuity of electricity supply. Reform of the electricity market should be based on the following principles: efficiency and transparency of the National Commission for State Regulation of Energy and Public Utilities; separation of electricity generation from distribution; certification of the transmission system operator; updating system, technical, software and information software; optimization of measures and reform of the retail market to meet the needs of consumers; economic justification of pricing to meet the needs and capabilities of consumers, including changes in the cross-subsidization mechanism. Implementing the planned goals and priority areas will help reduce risks in reforming the electricity market, intensify the competitive basis between market participants (entities), create conditions for improving service quality, and limit negative factors' impact on the environment with an incentive pricing policy. The structured structure of the organizational and economic mechanism will allow us to systematize the understanding of the stages of the electricity market functioning. Thus, a unified system of interrelations between the goals of reform, the search for reform methods, sources of financial support, subject and object positions, principles, and methods of their regulation, which directly or indirectly affect the efficiency of the electricity market, will be formed.

ОПТИМАЛЬНІ ОЦІНКИ ВЕКТОРА СТАНУ ДЛЯ ДИСКРЕТНИХ СТОХАСТИЧНИХ СИСТЕМ З НЕВИЗНАЧЕНИМИ ЗБУРЕННЯМИ ТА ШУМОМ

Assessment of the dynamic systems state is widely used in various areas of technical activity. In practice, the most well-known and common methods of estimation are the methods of the Kalman filter and Luenberger observers. Most of the results known in the scientific literature for constructing estimates of the dynamic systems state in the presence of acting uncontrolled disturbances and noise are associated with stationary systems. The insensitivity of such estimates to the influence of accompanying uncontrolled perturbations is ensured by the introduction of certain restrictions that are imposed on a number of system matrices, and their optimality is achieved by minimizing the estimation errors covariance matrix trace due to those degrees of freedom that remained after the separation procedure was performed. The aim of the work is to develop a filter capable of generating state vector optimal estimates of a stochastic linear system with changeable parameters that are insensitive to the influence of uncontrolled inputs. In this case, the conditions that guarantee the convergence of the estimates obtained must be easily verifiable. The goal is achieved by using a one-to-one transformation of the equations of systems, followed by the application of the Kalman filter. The O'Reilly functional observer is used as the specified transformation. An example is given that illustrates the effectiveness of the proposed filter.

The concept and nature of the occurrence of doctrinal legal errors

The concept and nature of the occurrence of doctrinal legal errors

Risk Factors and Characteristics of Recalcitrant Osteomyelitis Following Initial Surgical and Antibiotic Treatment.

To evaluate the injury, patient, and microbiological characteristics that place patients at risk for recalcitrant fracture related infection and osteomyelitis despite appropriate initial treatment. Retrospective Chart Review. Three level I trauma centers. Two hundred and fifty-seven patients undergoing surgical debridement and antibiotic therapy for osteomyelitis from 2003 to 2019. Patients were categorized as having undergone serial bone debridement if they had two separate procedures a minimum of six weeks apart with a full course of appropriate antibiotics in between. Patient records were reviewed for age, injury location, body mass index (BMI), smoking status, comorbidities, and culture results including the presence of multidrug resistant organisms (MDRO) and culture-negative osteomyelitis. A total of 257 patients were identified; 49% (n=125) had a successful single course of treatment, and 51% (n=132) required repeat debridement for recalcitrant osteomyelitis. At the index treatment for osteomyelitis, the most common organisms in both groups were Methicillin-resistant (MRSA) and Methicillin-sensitive Staphylococcus aureus (MSSA). There was no significant difference in incidence of polymicrobial infection between the two groups (25% vs 20%, p=0.49). The most common organisms cultured at the time of repeat saucerization remained MRSA and MSSA, however, the same organism was cultured from both the index and repeat procedure in only 28% (n=37) of cases. Diabetic patients, IVDU, delay to diagnosis, and open fractures of the lower leg are independent risk factors for failure of initial treatment of post-traumatic osteomyelitis. Successful eradication of fracture related infection and post-traumatic osteomyelitis is difficult and fails 51% of the time despite standard surgical and antimicrobial therapy. While MRSA and MSSA remain the most common organisms cultured, patients who fail initial treatment for osteomyelitis often do not culture the same organisms as those obtained at the index procedure.

The Death of an Insolvent Entrepreneur in the Light of Bankruptcy Law Regulations

Abstract This study aims to identify and analyse the specific regulations of the Bankruptcy Law to the extent that they relate to the death of an insolvent debtor. The authors attempt to determine the correct interpretation de lege lata, and where it is justified, draw conclusions de lege ferenda. Due to the fact that regulations must be interpreted together with the provisions of inheritance law and other regulations, their correct interpretation may be difficult. This study contains an analysis of three possible cases: when death occurred after the filing of a bankruptcy petition, during the course of bankruptcy proceedings, but also on the brink of bankruptcy before the petition was filed by an authorized person. In the event of death after filing for bankruptcy or after its declaration, the problem is essentially of a procedural nature and is generally resolved by identifying the persons participating in the proceedings (usually a trustee). On the other hand, in the event of the death of an insolvent entrepreneur before they file for bankruptcy, the Bankruptcy Law provides for a separate procedure. At the same time, it seems that due to the distinctness of this situation, the introduction of a different, specific definition of insolvency is justified, which the authors present in this study.

Janus membranes with opposite wettability prompting the synchronous synthesis and separation of hydrophobic ionic liquids

Traditional production of ionic liquids (ILs) includes isolated processes of synthesis followed by extraction purification with organic solvents. A remained challenge is to produce these green solvents by a simultaneous synthesis and separation procedure disusing volatile organic solvents. Herein, we describe a framework for the synchronous synthesis and separation of hydrophobic ILs based on an environmentally benign membrane reactor system. A Janus hollow fiber membrane reactor (JHFMR) with a thin and charged inner surface (IL-phobic) and an IL-philic outer surface is prepared by mussel-inspired co-deposition technique. The hydrophilic lumen surface supplies a reaction zone for anion metathesis. The inner surface charge destabilizes the emulsified target ILs dispersed in water. The deemulsified ILs actively pass through the JHFMR from IL-phobic side to IL-philic side driven by the gradient of surface energy. Multiple JHFMRs are ultimately assembled to prepare a JHFMR module for achieving a continuous and large-scale production of hydrophobic ILs in a cross-flow mode. The final ILs yield under a low reactant concentration (l.0 mol/L) is enhanced to reach 96% after 30 h by doubling the packing density of module. The residual water content in IL products is below 1.0 wt%. Other ion impurity is negligible (Li+ < 10 ppm, and Br- is below the detectable limit). Such enormously low impurity level is attributable to the synchronous separation of ILs once they are synthesized within the JHFMR module. Moreover, the module maintains a stable performance after repeated cycles. The proposed all-in-one strategy has a potential for continuous preparation of hydrophobic ILs at a large scale, with high yield and low impurity under “greener” operating conditions, e.g., at room temperature and avoidance of using volatile organic solvents.

Multi‐tiered dispute resolution clauses in engineering contracts: A Jordanian legal perspective

AbstractThis study delves into the intricacies of the multi‐tier dispute resolution clause in engineering contracts, particularly within the Jordanian legal system. The multi‐tier dispute resolution clause has evolved from a traditional arbitration clause into a more comprehensive approach, reflecting the complexities of modern contractual relationships. The study employs a doctrinal or library‐based methodology involving a comprehensive review of relevant legal texts, statutes, regulations, and case law. The multi‐tier dispute resolution clause is defined as a contractual clause that stipulates the existence of different stages, each involving separate procedures, to address disputes and seek to resolve them. The study also examines the mandatory nature of the multi‐tier dispute resolution clause and the procedural defense based on an arbitration clause. The study concludes that following the sequence outlined, the multi‐tier dispute resolution clause should be binding. This necessitates the Jordanian legislator's intervention to establish a legislative framework that empowers decisions made by the Dispute Adjudication Board (DAB) or Dispute Avoidance/Adjudication Board (DAAB) to achieve the goals of multi‐tiered dispute resolution clause. It also calls for an amendment to Article (109) of the Civil Procedure Law, allowing procedural defense based on the Multi‐Tiered Dispute Resolution Clause, not limiting it to the arbitration clause, even if arbitration is not one of its tiers. This power should also extend to amicable settlements to ensure the proper implementation of the steps under the multi‐tiered dispute resolution clause.

Phonology Analysis Theory of Phonetics

Phonetic features such as phonemes, minimal pairs, suspicious pairs, and procedures are applied in this study. Identifies the analyzed phoneme, interview methods, native speaker involment and methods. Literature studies are for data collection, data analysis, and especially during analysis. Phonemes are completed through multiple processes including preprocessing (pre-process), separation process, merger process (separation procedure).

Enhancing the Performance of a Renewable Energy System Using a Novel Predictive Control Method

The current study concerns improving the performance of a renewable energy system using systematically designed control algorithms. The performance of the system under study is evaluated under two operating scenarios: the first in which the system consists of only a wind-driven synchronous generator connected to the utility grid; in the second scenario, the generator is combined with a photo-voltaic solar system and a battery for supplying a load. Each system component is modeled and thoroughly described. To maximize the benefits of solar and wind energies, two separate maximum power point tracking procedures are adopted. Furthermore, to enhance the generator’s dynamics, a novel predictive control scheme is designed and validated by comparing its performance with traditional predictive control. The novel predictive controller utilized a simple and unique cost function to avoid the shortages of traditional predictive controllers. For standalone operation, an effective procedure is adopted to ensure the power balance between the generation, storage, and isolated load units. To evaluate the effectiveness of the designed controllers under different operating regimes, Matlab/Simulink is utilized for this task. The obtained results confirm the superiority of the novel predictive scheme used with the synchronous generator over the classic control approach for the two operating scenarios. This has been shown in the form of reduced ripples and reduced current harmonics. The obtained results are also confirming the validity of the adopted maximum power tracking strategies with solar panels and wind turbines as well. Furthermore, balanced power delivery is achieved thanks to the adopted management strategy for standalone operation, which enhances the overall system performance.

Opioid Use, Disposition, and Parent Satisfaction Following Common Pediatric Surgical Procedures.

There is wide variability in prescribing practices among providers, even for patients undergoing the same operations. Our study aims to analyze the variation in opioid prescription practices using a patient-centered approach to establish more appropriate prescribing guidelines for health care providers. We conducted phone surveys 30days after surgery to assess patient-reported opioid use. Over a two-year collection period, we identified patients that had undergone common outpatient pediatric surgery procedures in our 4-surgeon group. Included in the survey tool was the narcotic prescribed (if any), the amount used, and patient/family rating of pain control. We collected data for 189 separate procedures (88 umbilical hernias, 30 laparoscopic inguinal hernias, 2 open inguinal hernias, 41 appendectomies, 15 laparoscopic cholecystectomies, and 13 pectus bar removals). Patient age ranged from less than 1month to 246months. 83.5% of patients had a narcotic prescribed. The average number of doses used was 4, ranging from 0 (11.3%) to 30 (1.5%). 72.6% of families surveyed felt pain control was appropriate. However, 19.6% did feel they received too much pain medication. 10.6% reported completing their entire prescription; however, only 13.6% of families with excess narcotics reported proper disposal. Despite heightened awareness of the opioid epidemic, there is still a poor understanding of appropriate pain control regimens in the pediatric surgical population. We demonstrate that most patients are discharged home with excess opioids and that many families save the leftover pills/liquid. Further research and education are encouraged to limit the use of opioids in standard pediatric surgical procedures.