Epidemiological and Clinical Features of Pediatric Open Globe Injuries: A Report from Southern Iran

Purpose: To evaluate the epidemiological features of open globe injury (OGI) in a tertiary ophthalmic center in the south of Iran. Methods: The medical files of pediatric patients diagnosed with OGI between March 2014 and March 2019 were reviewed retrospectively. Demographic data, laterality, time of injury, cause of trauma, location and mechanisms, complications, and the involved tissues, visual acuity, type of operation, and antibiotic therapy were all analyzed. Data were processed using the SPSS. Results: In total, 110 eyes of 108 patients were included. Ages <7 years comprised 49.1%, 7–12 years 26.4%, and 13–18 years 24.5% of cases. Of the 108 patients, 76 (70.3%) were males. No significant difference between right versus left eyes was seen. The incidence of OGI was lowest in winter and highest in spring, and it had more prevalence on the weekends. Sharp objects were the most common cause of OGI in ages <7 years, while blunt objects, accidents and falls, and guns and fireworks were more prevalent in older children. Home was the most common place of injury overall. The most common type of injury was penetrating trauma. Upon arrival, most of the children had a visual acuity <0.1 decimal. Primary wound closure was the most prevalent type of surgery done predominantly within 24 hr from admission time. Conclusion: Ages <7 years and male gender were the most common age and sex of pediatric OGI, respectively, and sharp objects were the predominant etiology. Early management and primary repair are essential for prevention of complications such as endophthalmitis and amblyopia

Analysis of lecithin : cholesterol acyltransferase (LCAT) protein structure and its influence on binding to plasma lipoproteins

Lecithin: cholesterol acyltransferase (EC 2.3.1.43) (LCAT) is synthesized by the liver in mammals and it is responsible for esterification of unesterified cholesterol (UC) in plasma. This plasma glycoprotein plays an important role in reverse cholesterol transport (RCT) and High density lipoprotein (HDL) metabolism. In this thesis, functional mutants of LCAT were utilized to study the factors influencing interaction of this protein with the plasma lipoproteins. McArdle 7777 cells were used to produce LCAT from a hepatic derived expression system. The expressed enzyme was uniformly glycosylated with biantennary oligosaccharide residues, which was significantly different from the glycosylation pattern observed in the plasma LCAT and the baby hamster kidney (BHK) expressed LCAT. Despite the differences in the glycosylation architecture, the new recombinant LCAT (rLCAT) displays similar kinetic properties to those of the plasma and BHK LCATs, suggesting that the differences in glycosylation architecture may not influence activity of the enzyme. Subsequently, interaction of rLCAT with lipoprotein substrates was studied to determine the binding characteristics of wild type (WT) and fish-eye disease (FED) plasma LCAT in vivo, and rLCAT in vitro. Endogenous LCAT was shown to remain bound to low-density lipoprotein (LDL) as well as HDL and that beta and alpha LCAT activity co-eluted with LDL and HDL particles, respectively. In vitro binding studies with whole plasma, total lipoproteins, and individual lipoproteins showed no differential association of rLCAT, either WT or FED (T123I), with HDL and LDL particles and that the majority of rLCAT did not bind to the plasma lipoproteins. BIAcore experiments using native plasma lipoproteins and proteoliposmes also showed little or no association of rLCAT with plasma lipoproteins, but a strong association with the synthetic HDL analogue particles. The final aspect of this thesis was concerned with the relationship of LCAT mutations with its structural and functional characteristics involving the study of two very unique mutations, which result in an increase in the LCAT activity. The kinetic data obtained from this study showed that the combination of the two mutations did not have an additive effect, but in fact resulted in reduction of LCAT activity. Although this effect may be due to lack of independence in mechanism of action or inability of the protein to tolerate sequence alterations, it suggests that the fourth oligosaccharide chain may influence LCAT function in more ways than just inhibiting substrate accessibility. In conclusion, although the glycosylation architecture of LCAT does not significantly alter the kinetic properties of the recombinant protein, it may influence binding/association of rLCAT to the plasma lipoproteins. In addition, the fourth oligosaccharide moiety of LCAT may play an important role (other than inhibitory) in LCAT activity.Medicine, Faculty ofPathology and Laboratory Medicine, Department ofGraduat

Investigation on Physical and Mechanical Properties of Medium Density Fiberboard Produced From Eucalyptus camaldulensis Fibers

The objective of this study was to investigate of possibility of MDF production from successful Eucalyptus Species. Eucalyptus  camaldulensis  fibers were produced using different levels of steaming time ( 7.5 and 15 minutes), press temprature (170, 180 and 190 ºC ) and press time (3 and 4 minutes) and used for panel making. Physical and mechanical properties of panels were measured and analyzed. The results indicated that increasing of steaming time, lowered MOR of boards. The press temprature had significant effect on MOR, and with increasing press temprature, MOR increased. Furthermore increasing of steaming time, decreased the IB of boards and increasing steaming time from 7.5 to 15 minutes, decreased IB from 0.787 to 0.533 MPa. Increasing of steaming time, also decreased thickness swelling of boards. However, the results of this study showed that, the MOR and MOE of boards produced from Eucalyptus  camaldulensis  fibers are around standard level. But in other hand, the internal bonding and thickness swelling of boards are higher than level standard

Investigation of physical and mechanical properties of paulownia wood in particleboard Industry

In this investigation feasibility of Paulownia tomentosa wood in particleboards production were prepared at four different Combination of 100%,75%,50%,and 25%(base of  paulownia) , three different press time of 4,5,and 6 minutes.  Based on the EN standards physical and mechanical properties including MOR, MOE, IB, and thickness swelling (after 2 and 24 immersion in water) were tested. Based on the factorial experimental design at completely random tests were analyses. The results showed that utilization of paulownia wood in particleboard production in 5 minutes and up to 50% paulownia wood particles were optimized

Effect of cemical modification of lignocellulosics fiber on physical and mechanical properties in MDF

The goal of this study was to investigate the use of bagasse fibers as raw material for making laboratory  medium density fiberboard (MDF). Effect of treatment (with maleic anhydride and without maleic anhydride) of fibers and the press temperatures (180 ºC , 190 ºC , and 200 ºC) on the mechanical and dimensional  stability properties of MDF panels were determined. Physical (thickness swelling, water absorption, and swilling in water at ambient temperatures and in steam for 12-216 h.) and mechanical properties (modulus of rupture, modulus of elasticity, and internal bond strength) of the panels were determined according to the procedure of EN standards.This study showed all MDF panels made from bagasse fibers treated with maleic anhydride (MA) at 190 ºC press temperature had the highest values among the other types of specimens for general purpose boards. The thickness swelling and water absorption value with treated bagasse fibers and 190 ºC press temperature were very lower than all MDF panels. Treated bagasse fibers at 190 ºC show a minimum steam absorption. The absorption of steam increase with increase in time from 2 to 120 h in all the six treatments. Beyond 120 h. no additional absorption of steam is found in any of the six MDF boards

Utilization of Recycled Polyethylene For Physical & Mechanical Properties Modification of Particleboard

The aim of this study has been utilization of recycled polyethylene in modification of physical and mechanical properties of particleboard. Therefore, three levels of resin consumption content ( 10, 7 and 4% ) and three levels of recycled polyethylene consumption content 5, 10 and 15% in surface layer of mat, particleboards produced. Also in order to influence of these variables on physical and mechanical properties of produced boards, 3 particleboards with 10% resin content in surface layer and without polyethylene as control samples produced. The physical and mechanical properties of boards measured and analyzed. The results of this study indicated that with increasing of the recycled polyethylene consumption content, the MOR, MOE and thickness swelling of boards improved significantly and the produced boards with 15% recycled polyethylene in compare with control boards increased 59 and 53% respectively. Also the results revealed that the water absorption of boards decreased with increasing of increasing of recycled polyethylene consumption content, and the minimum of water absorption of boards observed in the produced boards with 15% recycled polyethylene. Based on the results of this research and with increasing of polymeric residues in the envirement , we conclude that the utilization of recycled polyethylene in particleboard production has different advantages

The potential of utilization of alder wood fibers In medium density fiberboard production

In this investigation, 36 laboratory medium density fiberboard (MDF) panels were produced using Alder wood fibers. Variables factors were steaming time ( 5, 10 and 15 minutes), press time (4 and 6 minutes) and resin consumption (9 and 11%). The physical and mechanical properties of panels were measured and analyzed. The results indicated that the maximum MOR was observed panels produced applying 6 minutes press time and resin consumption of 11%. The maximum Internal Bonding (IB) was related to panels made employing steaming time of 15 minutes and resin consumption of 11%. However, test panels produced at 6 minutes press time showed minimum of thickness swelling. The results indicated that the MDF boards produced from alder wood fibers exhibit desirable physical & mechanical properties were above than EN standard requirement. Consequently application of alder wood fibers to improve physical & mechanical properties of MDF panels which are produced from nonwood materials and agricaltural residues is recommended

Investigation on the utilization of papolar clones grown on Short - rotation age (three years) for particleboard production

ه منظور ساخت تخته خرده چوب از گونه های مختلف صنوبر تولید شده در دوره سه ساله 17 کلن از گونه های مختلف در ایستگاه البرز کرج انتخاب شده و یک نمونه شاهد از گونه راش (جمعا 18 ترکیب) و از هر تیمار 4 تخته و در کل 72 نمونه آزمونی ساخته شده است. تاثیر گونه های مختلف صنوبر بر خواص فیزیکی و مکانیکی مورد بررسی قرار گرفته است. نتایج نشان می دهد که کلن Populus e. 561.41 در دوره سه ساله از حداکثر مقاومت خمشی بهره مند بوده است. کلن صنوبر Populus a.44.9 از مدول الاستیسیته بالائی برخوردار بوده است و مقاومت به چسبندگی داخلی در کلن صنوبر Populus a. nivea حداکثر بوده است.حداقل درصد جذب آب در تخته های آزمونی 2 و 44 ساعتی به ترتیب برای کلن Populus a.44.9 و Populus e. costanzo به دست آمده است. با در نظر گرفتن میزان خواص فیزیکی و مکانیکی گونه شاهد (راش) مشخص شده است که اکثر کلن های مختلف صنوبر دوره سه ساله از خواص کاربردی بالاتری نسبت به شاهد برخوردار می باشند. در دوره های کوتاه مدت سه ساله برای ساخت تخته خرده چوب کلنهای صنوبر Populusn.42.78 Populus a. nivea, Populus a .44.9, Populus e. 561. 41, Populus a. Populus trichocarpa, Populus e. costanzo Populus d. 69.55  که تخته ها آنها دارای حداکثر خواص کاربردی بوده اند، پیشنهاد می گردد

INVESTIGATION ON UTILIZATION OF COTTON STALK IN PARTICLEBOARD PRODUCTION

The purpose of this study was to investigation the utilization of cotton stalk and Eucalyptus wood (E. Camaldulensis) in particleboard production. Experimental boards were produced with using of 0, 25, 50 and 75% cotton stalk particles with Eucalyptus wood particles, press time at 3, 4 and 5 minutes. 36 boards were produced and physical & mechanical properties of their tested and analyzed. The results indicated that the modulus of rupture (MOR) and modulus of elasticity (MOE) of boards with increasing of cotton stalk particles were modified significantly, and MOR and MOE of boards produced with 75% cotton stalk and 25% of Eucalyptus wood particles were maximum. The results indicated that the internal bonds (IB) of boards with increasing press time were improved and the IB of boards produced at 5 minutes of press time was maximum, in order to the lowest of thickness swelling (T.S) of boards observed in same conditions. However thickness swelling of boards produced with 50 and 75% cotton stalk were higher than other treatments, significantly. The results of this study showed that in conditions that apply of species with high density such as Eucalyptus is unavoidable in particleboard production. Between 50 to 75 percent of wood materials that utilized in particleboard production, can be obtained from cotton stalk and with apply of their in particleboards can be produced particleboards in standard levels

Investigation on the properties of medium density fiberboard produced from rose flower residues

The objective of the present study was the utilization of rose flower residues for the production of medium density fiberboard. MDF was produced applying two  moisture gradients of 0 and 4%  between surface and core layer, two press temperatures of 175 and 185 °C and three pressing times of 3,4 and 5 minutes. The mechanical and physical properties of the boards were measured and statistically analyzed using factorial experiment and complete randomized design. In case statistical difference was observed between the averages, then Duncn multiple range test was used for grouping of the averages. The results revealed that the moisture gradient statistically influenced the flexural strength and internal bonding of the boards. In both moisture gradients, the internal bond of the boards increased and the maximum was reached when 5 minutes pressing time was applied. The pressing time also statistically influenced the thickness swelling and the lowest values were measured on boards pressed for five minutes. Generally, the strength properties of the boards were in accordance with the required specification of EN standard, which indicates that rose flower residue can be considered as a suitable raw material for medium density fiberboard production