25 research outputs found
Systematic review of the stage of innovation of biological mesh for complex or contaminated abdominal wall closure
Background
Achieving stable closure of complex or contaminated abdominal wall incisions remains challenging. This study aimed to characterize the stage of innovation for biological mesh devices used during complex abdominal wall reconstruction and to evaluate the quality of current evidence.
Methods
A systematic review was performed of published and ongoing studies between January 2000 and September 2017. Eligible studies were those where a biological mesh was used to support fascial closure, either prophylactically after midline laparotomy, or for reinforcement after repair of incisional hernia with midline incision. The primary outcome measure was the IDEAL framework stage of innovation. The key secondary outcome measure was the GRADE criteria for study quality.
Results
Thirtyâfive studies including 2681 patients were included. Four studies considered mesh prophylaxis, 23 considered hernia repair, and eight reported on both. There was one published randomized trial (IDEAL stage 3), none of which was of high quality; the others were nonârandomized studies (IDEAL stage 2a). A detailed description of surgical technique was provided in most studies (27 of 35); however, no study reported outcomes according to the European Hernia Society consensus statement and only two described quality control of surgical technique during the study. From 21 ongoing randomized trials and observational studies, 11 considered repair of incisional hernia and 10 considered prophylaxis (seven in elective settings).
Conclusion
The evidence base for biological mesh is limited, and better reporting and quality control of surgical techniques are needed. Although results of ongoing trials over the next decade will improve the evidence base, further study is required in the emergency and contaminated settings
Association between audiometric profile and intraoperative findings in patients with chronic suppurative otitis media
Introduction: Although the incidence and prevalence of chronic suppurative otitis media (CSOM) has been decreased in recent decades, but it is still a major health problem in both developing and developed countries. CSOM can cause major and life-threatening complications such as hearing loss, meningitis and cerebral abscess. Since hearing loss is the most common complication of CSOM, we aimed to evaluate audiometric profile in patients with CSOM and its relation with intra-operative pathologic findings Materials and Methods: Between 2008-2010, 80 patients with CSOM subjected to tympanomastoidectomy or tympanoplasty entered this study. The detailed patients' history, physical examination, audiometric evaluations and findings during surgeries were collected. Finally, the associations between data were analyzed. Results: CSOM had higher prevalence among female (67.5), but difference was not statically significant. Speech recognition test and air-bone gap were significantly associated with CSOM (P<0.001). While cholesteatoma and granulation significantly associated with air-bone gap (P=0.044) and speech recognition test (P=0.032), respectively, ossicular defects significantly associative with both of them (P=0.001 and P=0.032, respectively). There was not any association between sclerosis and audiometric parameters. Also presence of the cholesteatoma and ossicular defects associated with size of the tympanic perforation (P=0.001). Conclusion: The preoperative and surgical findings can predict the patients' conductive hearing loss in chronic otitis media, but this relationship is not significant in all variables
Variations in photoperiods and their impact on yield, photosynthesis and secondary metabolite production in basil microgreens
Abstract Background The effects of different photoperiods on plant phytochemical synthesis can be improved by adjusting the daily light integral. Photoperiod is one of the most important environmental factors that control growth, plantâs internal rhythm and the synthesis of secondary metabolites. Information about the appropriate standard in terms of photoperiod for growing basil microgreens as one of the most important medicinal plants is limited. In this study, the effects of five different photoperiods, 6 (6Â h Ă 3 cycles), 8 (8Â h Ă 2 cycles), 16, 18, and 24Â h dayââ1 on the yield, photosynthesis and synthesis of secondary metabolites of three cultivars and one genotype of basil microgreens in floating system were evaluated. The purpose of this research was to determine the feasibility of using permanent light in growing basil microgreens and to create the best balance between beneficial secondary metabolites and performance. Results The results showed that the effects of photoperiod and cultivar on all investigated traits and their interaction on photosynthetic pigments, antioxidant capacity, total phenolic compounds, proline content and net photosynthesis rate were significantly different at the 1% level. The highest levels of vitamin C, flavonoids, anthocyanins, yield and antioxidant potential composite index (APCI) were obtained under the 24-h photoperiod. The highest antioxidant capacity was obtained for the Kapoor cultivar, and the highest total phenolic compound and proline contents were measured for the Ablagh genotype under a 24-h photoperiod. The highest yield (4.36Â kg mââ2) and APCI (70.44) were obtained for the Ablagh genotype. The highest nitrate content was obtained with a photoperiod of 18Â h for the Kapoor cultivar. The highest net photosynthesis rate was related to the Violeto cultivar under a 24-hour photoperiod (7.89 ÎŒmol CO2 mââ2 sââ1). Antioxidant capacity and flavonoids had a positive correlation with phenolic compounds and vitamin C. Yield had a positive correlation with antioxidant capacity, flavonoids, vitamin C, APCI, and proline. Conclusions Under continuous light conditions, basil microgreens resistance to light stress by increasing the synthesis of secondary metabolites and the increase of these biochemical compounds made basil microgreens increase their performance along with the increase of these health-promoting compounds. The best balance between antioxidant compounds and performance was achieved in continuous redâ+âblue light. Based on these results, the use of continuous artificial LED lighting, due to the increase in plant biochemical with antioxidant properties and yield, can be a suitable strategy for growing basil microgreens in floating systems
Balancing Yield and Antioxidant Capacity in Basil Microgreens: An Exploration of Nutrient Solution Concentrations in a Floating System
The appropriate concentration of the nutrient solution (NS) plays an important role in the yield, antioxidant capacity, and biochemical compounds of basil microgreens in the floating system. This study examined the impact of five different concentrations of Hoaglandâs NS (25%, 50%, 75%, 100%, and 125%) on the antioxidant capacity, biochemical compounds, and yield of four basil cultivars and genotypes (Persian Ablagh, Violeto, Kapoor and Red Rubin) in a floating system, utilizing a split plots designs. Results revealed that the highest yield was achieved with a 50% NS concentration. The Persian Ablagh genotype, under a 125% NS concentration, exhibited the highest content of carotenoids, flavonoids, phenolic compounds, and antioxidant potential index (APCI). The Violeto cultivar at a 100% NS concentration produced the highest amounts of vitamin C and anthocyanin. The Kapoor cultivar, when grown with a 100% NS concentration, demonstrated the greatest antioxidant capacity. The nutrient solution with 125% concentration compared to 50% concentration reduced the yield by 23.29%. Also, the performance of the Violeto cultivar increased by 36.24% compared to the red variety of Robin. According to the APCI index, the genotype of Iranian Ablaq basil increased by 152.79% in the treatment of nutrient solution with a concentration of 125% compared to 50%. In this study, yield and total chlorophyll showed a significant negative correlation. A significant positive correlation was observed between vitamin C content and flavonoids, anthocyanin, phenolic compounds, and antioxidant capacity. Anthocyanin content exhibited a positive and significant correlation with the APCI. Based on these findings, we recommend a 50% NS concentration of Hoaglandâs NS for optimal yield, a 125% NS concentration for the production of secondary metabolites with enhanced antioxidant capacity, and a 100% NS concentration as a balance between antioxidant properties and yield for basil microgreens production in a floating system
Management of Secondary Metabolite Synthesis and Biomass in Basil (<i>Ocimum basilicum</i> L.) Microgreens Using Different Continuous-Spectrum LED Lights
Different LED light spectra (LS) are absorbed by different plant photoreceptors and can control biomass and plant secondary metabolite synthesis. In this study, the effects of continuous-spectrum LED lights (red, blue, white, red + blue, and 12 h blue + 12 h red) on the production value, antioxidant compounds, and biomass of basil (Ocimum basilicum L.) microgreens (Red Rubin, Violeto, and Kapoor cultivars and the Ablagh genotype) were investigated. The results showed significant effects of LS on cultivar (Cv) and the interaction of LS and Cv on the studied traits. The highest quantitys of chlorophyll a, total chlorophyll, and nitrate were obtained in Violeto under blue lighting. Red lighting enhanced starch synthesis in Red Rubin and flavonoids in the Violeto Cv. The highest biomass (4.54 kg mâ2) was observed in the Ablagh genotype and the highest carbohydrate synthesis in Violeto Cv in the red + blue treatment. The highest anthocyanin content (26.33 mg 100 gâ1 FW) was observed for Red Rubin Cv under 12 h blue + 12 h red light. The greatest antioxidant capacity (83.57% inhibition), the highest levels of phenolic compounds (2027.25 mg GA 100 gâ1 FW), vitamin C (405.76 mg 100 gâ1 FW), proline, antioxidant potential composite index (APCI), and the greatest production values were obtained for the Ablagh genotype under blue lighting. Taken together, the experiment findings indicate that growing the Ablagh genotype under continuous blue lighting can increase the antioxidant capacity, phenolic compounds, and vitamin C and that this LED light spectrum can be used as a practical method to produce basil microgreens with high nutritional health value
Turbulent flow predictions using algebraic stress models
SIGLEAvailable from British Library Document Supply Centre- DSC:9091.9F(AERE-R--12694) / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Analysis of ferroresonance effects in distribution networks with distributed source units
The connection of Distributed Generation (DG) units
to existing networks may give rise to harmful effects on the
network and the DG units itself. Therefore, due to increasing
penetration of DG units, it is important to consider these effects
in order to avoid some of harmful events. Ferroresonance is one
of these destructive phenomena. Over voltages due to this
phenomena can damage devices which are connected to the
network. In DG systems, due to the use of capacitor banks which
are used for VAR compensation, grid connection filters, etc.
ferroresonance may appear. Also, special operations like
islanding, may lead these systems to ferroresonance. In
traditional systems ferroresonance normally appear after there is
an unbalance in the system. Nevertheless, for networks with
significant penetration of DG units, the situation that gives rise to
ferroresonance may be different from traditional systems and
they can happen without any unbalancing occurrence. In this
paper a distribution system integrating wind (WT) and
photovoltaic (PV) power systems has been evaluated in order to
analyze the performance of ferroresonance in such systems.
Finally, the most appropriate techniques to prevent its
appearance, and the associated over voltages, have been studied
and implemented using PSCAD/EMTDC.Peer Reviewe