700 research outputs found

    Delayed surgical debridement in pediatric open fractures: a systematic review and meta-analysis.

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    Purpose: Open fractures are considered orthopedic emergencies that are traditionally treated with surgical debridement within 6 h of injury to prevent infection. However, this proclaimed “6-h rule” is arbitrary and not based on rigorous scientific evidence. The aim of our study was to systematically review the literature that compares late (>6 h from the time of injury) to early (<6 h from the time of injury) surgical debridement of pediatric open fractures. Methods: We searched several databases from 1946 to 2013 for any observational or experimental studies that evaluated late and early surgical debridement of pediatric open fractures. We performed a meta-analysis using a random effects model to pool odds ratios for a comparison of infection rates between children undergoing late versus early surgical debridement. We also investigated the infection rates in upper- and lower-limb pediatric open fractures. Descriptive, quantitative, and qualitative data were extracted. Results: Of the 12 articles identified, three studies (retrospective cohort studies) were eligible for the meta-analysis, encompassing a total of 714 open fractures. The pooled odds ratio (OR = 0.79) for infection between late and early surgical debridement was in favor of late surgical debridement but was not statistically significant (95 % CI 0.32, 1.99; p = 0.38, I 2 = 0 %). No significant difference in infection rate was detected between pediatric open fractures in the upper and lower limbs according to the time threshold in the included studies (OR = 0.72, 95 % CI 0.29, 1.82; p = 0.40, I 2 = 0 %). Conclusions: The cumulative evidence does not, at present, indicate an association between late surgical debridement and higher infection rates in pediatric open fractures. However, initial expedient surgical debridement of open fractures in children should always remain the rule. Thus, multi-center randomized controlled trials or prospective cohort studies will be able to answer this question with more certainty and a higher level of evidence

    Adaptive Resource Management in Asynchronous Real-time Distributed Systems Using Feedback Control Functions

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    Presents feedback control techniques for performing adaptive resource management in asynchronous real-time distributed systems. Such systems are characterized by significant execution time uncertainties in the application environment and system resource state. Thus, such systems require adaptive resource management that dynamically monitor the system for adherence to the desired real-time requirements and perform run-time adaptation of the application to changing workloads when unacceptable timeliness behavior is observed. We propose adaptive resource management techniques that are based on feedback control theory. The controllers solve resource allocation problems that arise during run-time adaptation using the classical proportional-integral-derivative (PID) control functions. We study the performance of the controllers through simulation. The simulation results indicate that the controllers produce low missed deadline ratios and resource utilizations during situations of high workloads

    Intelligent Feedback Control-based Adaptive Resource Management for Asynchronous, Decentralized Real-time Systems

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    Presents intelligent feedback control techniques for adaptive resource management in asynchronous, decentralized real-time systems. We propose adaptive resource management techniques that are based on feedback control theory and are designed using the intelligent control design paradigm. The controllers solve resource allocation problems that arise during run-time adaptation using the classic proportional-integral-derivative (PID) control functions and fuzzy logic. We study the performance of the controllers through simulation. The simulation results indicate that the controllers produce low missed deadline ratios and resource utilizations during high-workload situations

    Swarm Intelligence Applications in Electric Machines

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    RESPONSE OF GROWTH, ESSENTIAL OIL CONTENT AND ITS CONSTITUENT'S OF PLECTRANTHUS AMBOINICUS TO IRON AND/OR UREA FOLIAR APPLICATION UNDER SALINE IRRIGATION

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    Objective: To study the response of Plectranthus amboinicus plants to iron and/or urea foliar application using tap water and Nacl saline water for irrigation, a pot experiment was conducted during two successive seasons (2014 and 2015) under the natural conditions of the greenhouse of the National Research Center, Dokki, Giza, Egypt.Methods: Plectranthus amboinicus cuttings were transplanted in the pots in February of each season. After one month, seedlings were irrigated with (2 levels: Tap water (0.40 dsm-1), and Nacl solution (4 dsm-1)) and FeUrea (4 levels: None, EDTA (200 ppm), urea (1000 ppm), and mixture of urea (1000 ppm) and Fe EDTA (200 ppm)) were applied one month from transplanting. The foliar application treatments were sprayed at 60, 90, 120 and 150 d from transplanting. Plant fresh mass (g/plant) and proline content were determined in the first and second cuts after 120 and 180 d from transplanting, respectively. The essential oil was obtained by hydrodistillation and essential oil % was expressed as ml 100 g/fresh herb. The chemical composition of the essential oil was studied using GC-MS and compounds were identified based on their mass spectra and literature.Results: Repeated measures analysis of the data showed significant effects of irrigation and iron/urea on fresh weight of herb, essential oil (%), oil yield, and proline in both first and second cuts. Plectranthus amboinicus plants sprayed with urea/or iron under tap and Nacl saline conditions were better than the control (unsprayed) plants. While saline irrigation decreased fresh weight, essential oil and oil yield, it increased proline; and 200Fe+1000Urea gave significantly higher proline for both tap and Nacl irrigations. Within each irrigation, the highest fresh mass and oil yield were obtained from 200Fe+1000Urea. Fresh mass for tap irrigation was significantly higher during the second cut than during the first cut, but it was the opposite for oil yield. This research demonstrated that application of iron and/or urea decreases salinity stress, and increases proline content. The GC/MS analysis revealed the major components of Plectranthus amboinicus to be p-cymene, carvacrol, (+)-epibicyclosesquiphellandrene, β-cadinene and α-cadinol.Conclusion: It may be concluded that Plectranthus amboinicus is tolerant to Nacl irrigations, thus we may recommend its cultivation in slain soil of Egypt. Foliar spraying with iron and/or urea under these conditions could be much more efficient than the not application of nutrients. So, we recommended that foliar application of iron and/or urea to raise the salt stress tolerance of Plectranthus amboinicus

    Metastatic rhabdomyosarcoma of the thyroid gland, a case report

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    The thyroid gland is a known but an unusual site for metastatic tumors from various primary sites. Despite the fact that it is one of the largest vascular organs in the body, clinical and surgical cases have given an incidence of 3 % of secondary malignances of the organ. Nevertheless, thyroid metastases are not an exceptional finding at autopsy, they are encountered in 2 % to 24 % of the patients with malignant neoplasm. Soft tissue sarcomas metastatic to the thyroid are extremely rare as the majority of thyroid metastasis are caused by tumors of the kidneys, lungs, mammary glands, ovaries , and colon or by melanomas. We report a case of 22-years-old woman with right leg rhabdomyosarcoma metastatic to the thyroid gland

    Fuzzy modeling and parameters optimization for the enhancement of biodiesel production from waste frying oil over montmorillonite clay K-30

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    Transesterification is a promising technology for the biodiesel production to provide an alternative fuel that considers the environmental concerns. From the economic and environmental protection points of view, utilization of waste frying oil for the production of biodiesel addresses very beneficial impacts. Production of higher yield of biodiesel is a challenging process in order to commercialize it with a lower cost. The current study focuses on the influence of different parameters such as reaction temperature (°C), reaction period (min), oil to methanol ratio and amount of catalyst (wt%) on the production of biodiesel. The main objective of this work is to develop a model via fuzzy logic approach in order to maximize the biodiesel produced from waste frying oil using montmorillonite Clay K-30 as a catalyst. The optimization for the operating parameters has been performed via particle swarm optimization (PSO) approach. During the optimization process, the decision variables were represented by four different operating parameters: temperature (40–140 °C), reaction period (60–300 min), oil/methanol ratio (1:6–1:18) and amount of catalyst (1–5 wt%). The model has been validated with the experimental data and compared with the optimal results reported based on other optimization techniques. Results showed the increment of biodiesel production by 15% using the proposed strategy compared to the earlier study. The obtained biodiesel production yield reached 93.70% with the optimal parameters for a temperature at 69.66 °C, a reaction period of 300 min, oil/methanol ratio of 1:9 and an amount of catalyst of 5 wt%

    Identification of NeVIII lines in H-deficient (pre-) white dwarfs: a new tool to constrain the temperature of the hottest stars

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    For the first time, we have identified NeVIII absorption lines in far-UV spectra of the hottest known (Teff>150,000 K) hydrogen-deficient (pre-) white dwarfs of spectral type PG1159. They are of photospheric origin and can be matched by synthetic non-LTE line profiles. We also show that a number of UV and optical emission lines in these stars can be explained as being photospheric NeVIII features and not, as hitherto suspected, as ultrahigh ionised OVIII lines created along shock-zones in the stellar wind. Consequently, we argue that the long-standing identification of the same emission lines in hot [WR]-type central stars as being due to ultrahigh-ionised species (OVII-VIII, CV-VI) must be revised. These lines can be entirely attributed to thermally excited species (NeVII-VIII, NV, OVI). Photospheric NeVIII lines are also identified in the hottest known He-rich white dwarf KPD0005+5106 some of which were also attributed to OVIII previously. This is a surprise because it must be concluded that KPD0005+5106 is much hotter (Teff=200,000 K) than hitherto assumed (Teff=120,000 K). This is confirmed by a re-assessment of the HeII line spectrum. We speculate that the temperature is high enough to explain the mysterious, hard X-ray emission (1 keV) as being of photospheric origin.Comment: Accepted for publication in A&

    Hip decompression of unstable slipped capital femoral epiphysis: a systematic review and meta-analysis

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    Purpose Slipped capital femoral epiphysis (SCFE) is one of the most common adolescent hip conditions. Unstable SCFE is characterized by sudden and severe hip pain with the inability to weight bear, even with crutches. Osteonecrosis of the femoral head is increased in patients with unstable SCFE. The aim of our study was to systematically review the literature that compares hip decompression to no hip decompression of unstable SCFE. Methods We searched several databases from 1946 to 2014 for any observational or experimental studies that evaluated hip decompression and osteonecrosis of unstable SCFE. We performed a meta-analysis using a random effects model to pool odds ratios (ORs) for the comparison of osteonecrosis between patients undergoing hip decompression and no hip decompression. We also investigated the type of hip decompression performed. Descriptive, quantitative, and qualitative data were extracted. Results Of the 17 articles identified, nine studies (eight case series and one retrospective cohort study) were eligible for the meta-analysis, with a total of 302 unstable SCFE. The pooled OR = 0.91 of osteonecrosis between hip decompression and no hip decompression was in favor of hip decompression, but was not statistically significant [95 % confidence interval (CI): 0.47, 1.75; p = 0.54, I2 = 0 %]. No significant differences in the rates of osteonecrosis were detected in unstable SCFE with open and percutaneous hip decompression alone (OR = 0.97, 95 % CI: 0.36, 2.62; p = 0.69, I2 = 19.1 %) or hip decompression with bony procedures (OR = 0.99, 95 % CI: 0.35, 2.79; p = 0.69, I2 = 0 %). Conclusions The cumulative evidence at present does not indicate an association between hip decompression and a lower rate of osteonecrosis of unstable SCFE. However, hip decompression of unstable SCFE remains an option that can potentially decompress the intracapsular hip pressure and optimize the blood flow to the femoral head. Thus, multicenter prospective cohort studies are required and will be able to answer this question with more certainty and a higher level of evidence
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