Abstract Background and Instability of slopes leading to roads in steep mountainous areas is a major problem in the development of roads worldwide, causing excessive human as well as financial losses. Soil nailing is one way of in-situ soil reinforcement. The behavior of a reinforced soil system depends on different parameters including geometry of the structure, mechanical characteristics of the soil, density of the reinforcing material, and length of the soil reinforcing material as well as the angle it makes with the failure plane. Though much research has been conducted on earth slope stability, few studies have examined the effect on slope stability of the soil nailing angle and tensile force distribution along the nail. In spite of the extensive studies conducted on slope stability, no specific insight has been obtained so far on the effect of the failure plane or soil nailing angle on the tensile force distribution along the nails. In view of these facts, this study aims to examine the effect of nail angle as well as nail length on the nail safety factor with due consideration of the effect of shear strain distribution on slope stability. Selecting the slope leading to Ilam-Salehabad Road in western Iran as our case study, we studied the stability of this slope at different nail lengths and angles. The slope leading to Ilam-Saalehabad Road (after the Karbala Road tunnel) was selected as the case study. To determine the mechanical parameters of the soil, we provided soil samples from the slope site and tested them at the laboratory in accordance with ASTM code to obtain the required soil characteristics. The powerful geotechnical software FLAC2 was subsequently used for modeling the slope leading to the road. Upon completion of analysis, we compared the settlement obtained from the software at two points on the earth slope with similar measurements obtained from the instruments, and observed a good agreement between them, with an approximate maximum error of 3%. In the following, the effect of soil nailing angle (with the horizontal line) as well as the length of the nail on the nail safety factor and nail tensile force is discussed. Discussion and Our results showed that increasing the soil nailing angle (i.e., nail driving angle defined as the angle between the soil nail and the horizontal line) from 0 to 30 degrees would increase the nail safety factor by about 23%. Thereafter, increasing the nail driving angle from 30 to 45 would cause a reduction of 2.8% in the safety factor. A further increase of nail angle (with the horizon) caused a corresponding increase in the tensile force induced in the nails, so that the maximum tensile force at 30 degrees increased by about 6%. The maximum nail driving angle efficiency was observed at the points undergoing maximum shear strain: increasing the drive angle to 30 degrees led to a 10-fold increase in the tensile force developed in the nails at points with maximum shear strains. On the other hand, increasing the nail length increased nail safety factor, so that increasing the nail length by 1 meter would increase nail safety factor by 4.3%. However, increasing the nail length beyond 1 meter reduced the rate of increase of the safety factor. Accordingly, the optimum length increase in the nails was taken as 1 meter.

Psoriasis is a common skin disease in which occurrence rates of clinical features of nail psoriasis vary considerably in the literature. The present study was undertaken to evaluate the frequency of nail involvement in psoriatic patients, to assess the types of nail changes in psoriasis, furthermore to find eventual relationships between nail involvement and some clinical parameters, and finally compare our clinical findings with the few reports available in the literature. From January 2003 to October 2005, patients suffering from psoriasis with nail involvement, attending at a private dermatology clinic, and at the outpatient Clinic of Dermatology in Imam Khoumeini Hospital, Ahwaz, southwest of Iran, were included in the study. The diagnosis was made clinically and in some cases based on histopathological studies.In our study, 500 patients were studied and 296 (59.2%) patients, 177 males (59.8%) and 119 women (40.2%), had nail changes. The mean age of patients was 35±16.95 years and the mean duration of the nail involvement was 6.9±6.88 years. Men involvement percent was a little more than women (59.8% vs 40.2%). The most common clinical type of psoriasis was plaque type psoriasis (67.2%). The most common nail abnormality observed on both finger nails and toe nails was onycholysis (82.8%), followed by pitting (72.6%), subungual hyperkeratosis (72%), nail thickening (37.5%), discoloration of the nail (36.5%), onychodystrophy (12.8%), oil spot (3.7%), Beau’s line (7.8%), nail loss (1%), and splinter hemorrhage (0.7%). Of the 296 patients, 227 patients (76.7%) had not involvement of the proximal and lateral nail folds, and 69 (23.7%) had involvement of the proximal and lateral nail folds. The frequency of nail involvement and nail changes in our patients is nearly similar to those in textbooks of dermatology and literatures. About, a third our patients with nail changes, had nail fold involvement, resulting in increased severity of nail changes in these patients.

Extended Abstract (Paper pages 201-224) Introduction Soil nails are traditionally designed with uniform length and equal spacing to stabilize slopes which do not meet safety requirements. However, nails with uniform layout in a slope may not be the optimal design if the construction cost is taken into account. The optimal layouts lead to a minimum usage of nails and satisfies the allowable factor of safety and wall deformation. In this study a decreasing trend of nails length along the wall height was considered to investigate the stability and the performance of the wall in different nail patterns. Then nail density was introduced as an important factor on the overall stability and deformation of the wall. It can be beneficial in the preliminary estimation of the required nail length at the beginning of a project. Findings of this study are helpful for effective design of soil–nailed slopes. Materials and Methods The finite element analyses were conducted to investigate the effects of nails pattern on the overall stability and deformation of soil–nailed walls. Slope/W software was used to obtain the Factor of safety and Plaxis 2D was used to calculate the deformation of the soil nail walls. Soil hardening model was used to simulate the behavior of soil. In this study, various walls with different specifications were modeled and analyzed. As an example, a 10 m deep soil nail wall with C=10 kN/m2, ?=25 deg, Eoed=20000 kN/m2 is discussed here to monitor the trends (C represents cohesion, ? is the angle of friction and Eoed is the modulus of elasticity of the soil). As it is shown in Figure 1, by considering the decreasing trend of nail length along the wall height, an ordered arrangement (pattern) is introduced by presenting “L” as the base nail length and “” as the inclination of stabilized zone border then, the effect of nail arrangement on the safety factor and deformation of nailed wall is investigated. The nails were installed with an angle of 15 degrees relative to the horizon. According to FHWA a minimum value of 1.35 is considered for the factor of safety. Circular failure surfaces are assumed and the tensile and pullout resistance of the nails crossing the failure surfaces are considered as the governing stabilizing forces. Results and discussion In this study, soil nails pattern effects on the performance and the stability of the soil nail wall are investigated. In Figure 2 variation of safety factors caused by different soil nails arrangements is illustrated. Generally three separated trends are observed in each curve. It demonstrates that at lower values of  with small bond length, the factor of safety is constant. As  increases the bond length behind the slip surface becomes longer and the safety factor is increases gradually. Eventually it reaches a point that the nails are long enough that increasing the nails length is not influential in the stability of the wall. Hence, nails at different elevations of a slope have different contribution to the overall stability of soil–nailed slopes. Wall deformations need to be controlled by the allowable deformation level in designing the soil nailed wall especially when buildings or other underground facilities exist near the excavation. One of the most important parameters on soil nailed wall deformations is the arrangement of nail lengths. Figure 3 shows the effect of nail arrangements on the wall horizontal deflection. In general, as and L increase, horizontal deflection of the wall decreases. The rate of this reduction is higher in lower base length. As it is illustrated in Figure 3, by increasing the length of the nails, the deflection is decreased till no significant reduction is observed. As it is shown the arrangement and the layout of the nails are influential on the stability and deformation of the soil nailed walls. However, it is important to identify an optimal layout in a way that with optimum nail length, allowable stability is reached and the wall deformation stay in an allowable range. Nail density is defined as the ratio of the required nail length per the unit area of the wall surface and defined as below: D_n=(∑_(i=1)^n▒L_i )/A (1) where Li is nail length of each row and A is the stabilization area. Hence, estimating the nail density can be beneficial for the engineers to have a preliminary estimation of the costs of the project at beginning of the project. Figure 4 indicates that the nail density governs the wall deformation. As it is seen, for different layouts with the same nail density, the resulted deflections are so close. Hence, it can be concluded that nail density is a key factor in determination of the wall deflection. It is also illustrated that, as the nail density increases, the reduction rate of the deflection is decreased. Effective nail density is defined as a threshold point that increasing the nail density is no longer effective on deformations. As it is demonstrated in Figure 5, different layouts with a similar nail density have close values of safety factors. In walls with higher nail density increasing the nail length is fruitless and at lower nail density nails are not effective. So Optimum designation should be somewhere at the middle part with an allowable factor of safety. In the middle part the variation of factors of safety is more tangible. Horizontal deflection profile During the construction process the wall tends to move outward. Figure 6 illustrates the effect of soil nails arrangements on the deformation of a 10 m deep wall for a constant base length. As it is shown, by increasing  the horizontal deflection at the top of the wall decreases in a way that at higher  values, the wall deformation mode changes from overturning mode to bulging mode. Conclusion In this paper the effects of soil nail arrangement on the stability and performance of the wall was investigated. An ordered arrangement of the nails was introduced and the effect of various nail lengths at different elevations of the wall was discussed. Major findings concluded from this research are summarized as follows: Nail density was defined as a key parameter and the findings demonstrate that nail density plays an important role in controlling the stability and the performance of the soil nail walls, in a way that patterns with the same nail densities but different arrangements, result in the almost similar factors of safety and deformations. Therefore based on the allowable factor of safety and deformation, nail density can be concluded and the nail arrangement which meets the standards, is selected. Threshold nail density is defined as a value of nail density which no significant reduction of deflection happens afterward. Uniform distribution of the nails and lower values of  generates the maximum deflection at the top of the wall. As  increases, the bond length in the upper parts of the wall controls the deformation. In that case, the deflection value is bounded and the maximum deflection occurs at the middle depth of the wall. Therefore the mode of deformation changes from overturning mode to bulging mode. As a result, in the projects which their adjacent structures are of high importance, it is recommended to use more nail.

Pullout resistance of cement-grouted soil nails is a key factor affecting the safety conditions of retaining walls, slopes and excavations. Hence, survey of resistence of pullout nail is the one of the most important parameters in designing of nailing functions. This parameter depend on critical factors including: instalation method, overburden press, grouting pressure, degree of saturation of the soil, the roughness of nail surface, changes of lengh & diameter of nail, the shear strengh of the soil and etc. Sometimes, used soil nail layers affected by cyclic loads due of traffic passing, train and so on. Hence the research aimed to study influence of this kind loadings on resistence of nail post-cyclic pullout and affective factors on it. The study pointed to apply slopes and nailed retaining walls next to traffic loads and rail-roads. Several studies conducted; according to, vary factors influence on nail pullout behavior that buried into soil. Key studies carried out in form of impression of static loading on nail pullout resistance including: overburden stress, grouting stress, impression of an addition to grouting, nail geometry, nail spaces, using spiral nails, comparison laboratory results of pullout set with direct shear test in interface grouted-nail to earn identical ratio and etc. yet, it not examineted cyclic loading impression on post-cyclic pullout resistance in nails. The study just focus on geogrid. For the first time, this research provide impression of cyclic loading on post-cyclic pullout resistance in nails. This research used nail pullout set; able to apply static and cyclic loads in conditions of force or displacement controling with differ frequencies and sinus shape of cyclic wave. This search used the notes of specifications of pullout set; also, sampling due to test and tables of done tests. In this research examined affection of variation of static, cyclic load rate. Resistance of post-cyclic pullout nail generally is more to static pullout resistance; even though , more affections of cyclic loading lead to decrease of resistance; also, obserued in the cyclic part developing in displacement.

In recent decades, the use of an efficient and cost-effective method to provide soil stability has been a major challenge for civil engineers. With increasing urban population, the need for underground spaces increases and deep excavation is an inevitable affair in civil projects. Deep tunnels and large buildings require deep excavations, which must use some techniques for stabilize it. Soil-nailing (reinforcing soil at the site) due to the fast build, is a good way to provide stability. It can also be described as a top-down construction technique for the improvement of behavioural properties of in-situ soil mass. Soil-nailed system is formed by inserting relatively slender reinforcing bars into the slope. Depending upon the project cost, site accessibility, availability of working space, and the soil and groundwater conditions, soil-nails can be inserted into the ground. Soil-nail is generally known as conventional and injectable nails but nails with screw plates or "helical soil-nails" are also important due to the faster build and no need for groutings. Helical soil-nails are new alternative to the conventional soil nails or tie-backs for stabilization of slopes, excavations and embankments due to ease of installation, minimal site disturbance and immediate loading capability. Helical soil-nails are installed by application of torque without a drill hole and derive its capacity from one or more helical plates attached to the nail. The shear strength-displacement behavior at the interface is an important parameter in design of various geotechnical engineering projects, for example, soil-nails, retaining walls, shallow foundations, pile foundations, etc. In soil-nailing, behavioure of interface between the soil and nail estimated by pull-out test. The behaviour of interface is governed by numerous factors, such as stress conditions, soil properties, method of installation and soil-nail interface boundary conditions. The pull-out resistance is measured as the most important factor in the design of the nailing system, by pull-out test. This study, because of limited learning of helical soil nail, aimed to investigate the pull-out resistance by a 3D finite element modeling with abaqus software and compare its results with laboratory data. A review of the literature for the screw soil-nails as well as a comparison of its performance with conventional soil nails is discussed and numerical results of a series of pull-out tests on a screw soil-nail are presented. And review of  the overburden pressure and plate number and plate distance effect is followed. The results show that in helical soil-nail pull-out a high overburden pressure effect can be seen. A semi-linear relationship between peak pull-out force and overburden pressure is observed for different methods of calculating the helical soil-nail capacity that it is indicating that it satisfies the Mohr-Coulomb failure criteria. Rupture surfaces occur at distances farther than the nail surface, and three times the diameter can be considered the optimal distance of the plates. Using fewer plate distance does not increase resistance, also using more plate with fewer distance does not increase resistance. Comparison of modeling and laboratory results indicates that modeling of pull-out test can model the behavior of helical soil-nail and verify its performance in a field soil slope.

Congenital micronychia may involve big toes or may involve other nails. The etiology of micronychia is not clear but amniotic bands, teratogens (drugs, alcohol), Nail Patella Syndrome etc. A 44-year-oldwoman with multiple isolated congenital micronychia over her hands and feet was selected. The major affected nails were thumbs and Index fingers. Surgical method were done step by step: Anesthesia of the area, extraction of short nail, elevation of nail bed, longitudinal nail bed incisions, suturing the lateral nail bed to the nail wall, covering the nail bed by a splint of plastic suction tube, bandage with gauze Vaseline. Finally, we hypnotized that in congenital micronychia, the main pathology is in nail bed; through this theory by nail bed expansion better outcomes are coming.

An ectopic nail is an extremely infrequent disorder, also known as onychoheterotopia. Onychoheterotopia can present congenitally as well as in acquired form, although the acquired form is a rare occurrence. Ohya et al. first described the congenital ectopic nail in 1931. The growth of tissue resembling nails at sites different from the nail bed is characteristic of this condition. Acquired type or post-traumatic ectopic nail has been postulated to be due to acute or repeated trauma to the nail unit followed by transfer and inoculation of the nail matrix at another site. A posttraumatic ectopic nail is rare and unusual, making its diagnosis and management important. Histopathological correlation is necessary to confirm the diagnosis and differentiate it from other nail conditions. Here, a classic case of a post-traumatic ectopic nail in the left little finger in a male laborer following a cut injury is reported. The ectopic nail had horizontal growth and was approximately 5 × 3 mm in size and 1 cm away from the normal nail. After surgical resection and biopsy of the resected part, it was successfully diagnosed as a nail of ectopic origin. This is a rare case of a post-traumatic ectopic nail on the little finger with horizontal growth away from the normal nail.

Nail disorders comprise approximately 10% of all dermatological conditions. Abnormalities in the color of nails are called ungal dyschromia or chromonychia. Ungual dyschromia may be endogenous or exogenous. Yellow discoloration of the nails has been reported during the last years as separate observation related to drug administration, during hemodialysis and associated with pulmonary diseases as yellow nail syndrome.Case reports: A 23-year-old female patient was diagnosed with yellow nails induced by application of a specific nail polish. A 67-year-old man presented with transient nail discoloration as a result of the exacerbation of his chronic pulmonary disease. Our cases illustrate transient yellow discoloration of finger nails associated with the use of nail polish, and with an acute episode of chronic bronchitis, with full recovery in the absence of any treatment.

In spite of being rare, intracranial nail gun injury represents one of the fatal penetrating head injuries.
Case Report: Here we report a case of intracranial nail gun injury in a 28 years old well-trained construction worker who left the electric nail gun on the edge of the window to pick up one of his tools from the ground. Unfortunately, his leg got entangled in the nail gun cable and thus the nail gun dropped on the ground firing a nail that killed the worker.
To the best of our knowledge, this first time death from nail gun injury is reported in the Arab world; although, there are previous reports of survivable nail gun cardiac injuries and cranial injuries from Saudi Arabia. Thus, it is important to raise public awareness about such cases in order to reduce the occurrence of nail gun injuries. Moreover, health and safety inspections mandated and supported by law, might be much more effective in reducing such injuries.

In this paper, the performance of soil nailed walls with various nail patterns has been studied to find an optimum layout based on the deformation criterion. To this end, parametric analysis on soil nailed walls with various nailing patterns is performed. Nine patterns including one uniform and eight variable nails length are considered. For each pattern, parametric analysis on different parameters including wall height, surcharge, nails spacing is implemented to find an optimum pattern based on the deformation criterion. The simulation results indicate that using the variable layout with long nails at the top of the wall not only reduces the lateral deformation of soil nailed wall but also decreases the density of nails.