Final Pattern Research Articles

Preparing for Puberty in Girls With Special Needs: A Cohort Study of Caregiver Concerns and Patient Outcomes.

To characterize the patient population with cognitive or physical impairments that presents for anticipatory guidance of puberty, evaluate caregiver concerns with respect to puberty, and describe chosen management strategies and outcomes following menarche. Retrospective cohort study SETTING: Academic tertiary care women and children's hospital PARTICIPANTS: Eligible female patients with special needs up to age 26 years presenting for anticipatory guidance from 2009 to 2018 MAIN OUTCOME MEASURES: Primary outcomes included characterization of patients presenting for anticipatory guidance and their reasons for menstrual management. Secondary outcomes were satisfaction with menstrual management and bleeding patterns. A total of 61 patients presented for anticipatory guidance of puberty, on average 13.5 months prior to menarche. Compared to the overall adolescent population with special needs who presented for gynecologic care, patients who had autism spectrum disorder (ASD), were nonverbal, or had attention-deficit/hyperactivity disorder (ADD/ADHD) were more likely to present for a pre-menarchal visit to discuss anticipated pubertal development (P < .001, P = .009, and P = .04, respectively). More than half of families described potential behavioral changes as their main concern. The majority of post-menarchal patients (80%) desired hormonal management of menses, including 30% of patients who had placement of a levonorgestrel intrauterine device. In all, 96% of patients were satisfied with their final menstrual bleeding pattern; 50% achieved amenorrhea or light spotting. This study describes the important role of pre-menarchal reproductive counseling for girls with disabilities. Anticipation of puberty causes great anxiety in families and patients, especially those with ASD, ADD/ADHD, and non-verbal status. Providers should consider initiating these conversations early in pubertal development.

Towards a model for structured mass movements: the OpenLISEM hazard model 2.0a

Abstract. Mass movements such as debris flows and landslides differ in behaviour due to their material properties and internal forces. Models employ generalized multi-phase flow equations to adaptively describe these complex flow types. Such models commonly assume unstructured and fragmented flow, where internal cohesive strength is insignificant. In this work, existing work on two-phase mass movement equations are extended to include a full stress–strain relationship that allows for runout of (semi-)structured fluid–solid masses. The work provides both the three-dimensional equations and depth-averaged simplifications. The equations are implemented in a hybrid material point method (MPM), which allows for efficient simulation of stress–strain relationships on discrete smooth particles. Using this framework, the developed model is compared to several flume experiments of clay blocks impacting fixed obstacles. Here, both final deposit patterns and fractures compare well to simulations. Additionally, numerical tests are performed to showcase the range of dynamical behaviour produced by the model. Important processes such as fracturing, fragmentation and fluid release are captured by the model. While this provides an important step towards complete mass movement models, several new opportunities arise, such as application to fragmenting mass movements and block slides.

Recent Advances in Nanomaterials for Dermal and Transdermal Applications

The stratum corneum, the most superficial layer of the skin, protects the body against environmental hazards and presents a highly selective barrier for the passage of drugs and cosmetic products deeper into the skin and across the skin. Nanomaterials can effectively increase the permeation of active molecules across the stratum corneum and enable their penetration into deeper skin layers, often by interacting with the skin and creating the distinct sites with elevated local concentration, acting as reservoirs. The flux of the molecules from these reservoirs can be either limited to the underlying skin layers (for topical drug and cosmeceutical delivery) or extended across all the sublayers of the epidermis to the blood vessels of the dermis (for transdermal delivery). The type of the nanocarrier and the physicochemical nature of the active substance are among the factors that determine the final skin permeation pattern and the stability of the penetrant in the cutaneous environment. The most widely employed types of nanomaterials for dermal and transdermal applications include solid lipid nanoparticles, nanovesicular carriers, microemulsions, nanoemulsions, and polymeric nanoparticles. The recent advances in the area of nanomaterial-assisted dermal and transdermal delivery are highlighted in this review.

Optimization of a Single-Particle Micropatterning System With Robotic nDEP-Tweezers

In this study, a system of automatic microparticle patterning that could enable the separation, trapping, and translation of single microbeads in liquid suspension using negative dielectrophoresis (DEP) tweezers was presented to form a single-bead pattern. A microchip with integrated electrodes was flipped and placed above the substrate through a micromanipulator. Microparticles laying on the substrate could be displaced to different positions relative to the electrodes on the microchip, and only the selected particles would be trapped by the electric fields generated from electrodes. Vision-based approaches were used to evaluate the necessary information, such as the gap distance and the positions of electrodes and microparticles in the image. A strategy for separating nearby particles was proposed to achieve single-bead patterning with high accuracy. A controller was used to guide the microparticles toward the position for trapping while avoiding flow disturbance. Different strategies were simulated to decrease the patterning time and find the minimum traveling distance and the best route of movement. The optimization problem is NP-hard. Hence, global optimization algorithms, such as genetic algorithm, particle swarm optimization, and ant colony optimization (ACO), were simulated, and the results were compared with those of the local optimization method. The comparison results showed that ACO obtained the best performance among the methods. The strategy for constructing high-quality microparticle patterns was also examined through experiments. Orange fluorescent polystyrene beads suspended in 6-aminohexanoic acid solution were considered and successfully patterned on a glass substrate by using the proposed system. <i>Note to Practitioners</i>&#x2014;Micropatterning is an effective tool for pharmaceutical research and drug discovery. However, the reliability of results depends on the quality of patterns. Existing approaches, such as microfluidic devices, are limited to create a pattern from one chip for single use, and the entire process is sealed and isolated from the environment. In this study, a multielectrode microchip combined with a vision-based micromanipulator is introduced to create a novel noncontact approach for microparticle patterning, which offers high flexibility and guarantees the quality of the constructed patterns. The electrodes on the chip can be selectively energized to determine the shape of the final pattern. A real-time screening is performed so that the micromanipulator will only guide the particles in good condition for selection. An optimization algorithm is implemented to aid the particle selection with the electrodes, allowing high-quality microparticle patterns to be constructed in a short time for various applications.

Satisfaction With Hormonal Treatment for Menstrual Suppression in Adolescents and Young Women With Disabilities

PurposeTo characterize the population of adolescents and young women with special needs presenting for gynecologic care, describe usage patterns of hormonal suppression methods, and evaluate outcomes of menstrual management. MethodsThis retrospective cohort study included females with special needs up to age 26 years presenting for menstrual management from 2009 to 2018. Demographic, social, and medical histories were collected to investigate effects on bleeding pattern and satisfaction with menstrual management. ResultsOf 262 patients who presented for menstrual complaints, final methods of treatment included combined hormonal contraceptives (30.9%), oral progestins (19.8%), depot medroxyprogesterone acetate (8.0%), etonogestrel implant (1.9%), and levonorgestrel intrauterine device (16.8%). Eighty-five percent of patients were satisfied with their final bleeding pattern. Patients with amenorrhea or light regular periods were more likely to be satisfied than patients with heavy or irregular bleeding (p < .001). Satisfied patients tried an average of 1.4 methods, compared to 1.8 methods tried by the unsatisfied group (p = .042). By the end of the study, 26.0% were amenorrheic and 12.8% had only light spotting. Satisfaction rates were similar with each method, including 88.4% with use of combined hormonal contraceptives, 82.5% with oral progestins, 93.3% with depot medroxyprogesterone acetate, 100% with etonogestrel implant, and 83.9% with levonorgestrel intrauterine device. ConclusionsAmenorrhea or light regular bleeding led to satisfaction in most patients. No hormonal method was superior. When counseling families and patients who present for menstrual suppression, emphasis should be placed on goals of treatment and expectations for outcomes, as light regular periods may be as acceptable as amenorrhea.

Study on the failure mechanism of geopolymeric recycled concrete using digital image correlation method

In this study, an experimental investigation was conducted to understand the failure mechanism of geopolymeric recycled aggregate concrete (GRAC) under compression. GRAC specimens with different recycled aggregate (RA) replacement ratios were prepared and tested. A digital image correlation (DIC) system was used to monitor the displacement field and strain distribution over the surface of the specimen. The results revealed that RA replacement adversely affected the mechanical properties of geopolymeric concrete, including compressive strength, elastic modulus, and splitting tensile strength. For all the specimens, cracks mainly initiated near the interfacial transition zones, and usually nucleated around natural aggregate (NA) rather than RA. As observed from the final crack patterns, it was more frequent for the RA that cracks passed through the aggregate particles, in comparison with the NA. The location of strain concentration region detected by the DIC method was closely consistent with that of the formed macro cracks.

Interconnected drying phenomena in nanoparticle laden water-ethanol binary droplets.

Understanding the evaporation of a multi-component droplet has found immense importance in various technological applications. This study investigates the evaporation behaviour of a colloidal binary droplet system comprising of the ethanol-water mixture and polystyrene nanoparticles. The wetting and evaporation dynamics were studied with an emphasis on the collective influence of ethanol and nanoparticle concentrations. The temporal behaviour of the contact angles, shapes and volumes of the droplets was monitored in order to analyse the evaporative behaviour. With increase of ethanol concentrations, the binary droplet volumes were found to decrease nonlinearly with time. Ethanol being more volatile evaporated in the initial stage. Towards the end of the evaporation process, the evaporation characteristics mimics the behaviour of pure water. Our study shows that the initial contact angle decreases monotonically with increased concentration of ethanol in the mixture. The contact angle is maximum for a particular nanoparticle concentration. Droplets with higher ethanol concentration show higher wettability which in its turn is maximum for low nanoparticle concentrations. This trend shows the interconnected effect of ethanol and nanoparticle concentrations on evaporation. Rim width of the final deposition pattern increases with nanoparticle concentration although it is almost independent of ethanol concentration. Finally, it is noticed that fast evaporation of a relatively more volatile component in a binary mixture droplet leads to nanoparticle segregation for low nanoparticle concentrations. Thus for binary mixtures, the evaporation of the more volatile component, ethanol for our case, offers characteristic differences in the resulting evaporation dynamics from that of pure water which finds applicability for multi-component evaporation processes.

Nonlocal pattern formation effects in evolutionary population dynamics

In this work, we derive a deterministic equation for a generalized nonlocal population dynamics that depends fundamentally on two lengths parameters (α,β). We associate these parameters to the reproduction, competition, and pattern formation in bacterial dynamics. We propose that each set of parameters defines a state, and based on that, we formulate a stochastic cellular automaton for describing the evolutionary dynamics of a bacterial colony. It results in a selection of the bacteria more able to share space. In this way, we show that the evolution of the colony towards a maximum population allowed, in a given niche, defines the final pattern.

Connectivity and edge effects increase bee colonization in an experimentally fragmented landscape

Though landscape corridors increase dispersal of many animals and plants, it remains unknown whether these positive effects extend to the process of colonization and establishment of new populations in fragments. Working in experimentally fragmented landscapes, we tested how two aspects of habitat fragments altered by corridors – connectivity and edge‐to‐area ratio – determine patterns of colonization by a solitary, cavity‐nesting bee Megachile rotundata. We found that though connectivity initially affected rates of nest‐site occupation, edge‐to‐area ratio ultimately determined the final patterns of patch occupation and nest building, likely due to habitat selection by our focal species. Bee colonization was also higher in patches with higher abundances of their preferred food resources, flowers from the Fabaceae family. Our results show the importance of considering the effects of both connectivity and edge on population dynamics in habitat‐based conservation.

Design and evaluation of a freeform lens-array for a structured light illumination

In illumination applications, freeform lens design starts by modeling the light source intensity, then determining the lens surface. Therefore, any change in the source intensity distribution directly impacts the created illuminance. Freeform lens-array could reduce the dependency between the illuminance pattern and the source intensity distribution. It divides the light source energy into separate beams; each creates the same illuminance pattern. All separated beams are superimposed at a distant target to generate the final illuminance pattern. This paper explains the design procedures of a freeform lens-array in detail, simulates the optical performance, and experimentally evaluates the working principle. Experiments evaluate using different light sources and using a variable illuminated aperture. Moreover, simulations compare the freeform lens-array to a traditional freeform lens.

Steganography algorithm based on modified EMD-coded PU partition modes for HEVC videos

As High Efficiency Video Coding (HEVC) is a worldwide popular video coding standard, the steganography of HEVC videos has gained more and more attention. Prediction unit (PU) is one of the most important innovative modules of HEVC; thus, PU partition mode-based steganography is becoming a novel branch of HEVC steganography. However, the embedding capacity of this kind of steganography is limited by the types of PU partition modes. To solve the problem, modified exploiting modification direction (EMD)-coded PU partition mode-based steganography is proposed in this paper, which can hide a secret digit in a (2n + x − 1)-ary notational system in a pair of PU partition modes and thus enlarging the capacity. Furthermore, two mapping patterns for PU partition modes are analyzed, and the one that performs the better is selected as the final mapping pattern. Firstly, 8 × 8- and 16 × 16-sized PU partition modes are recorded according to the optimal mapping pattern in the video encoding process. Then, PU partition modes are modified by using the proposed method to satisfy the requirement of secret information. Finally, the stego video can be obtained by re-encoding the video with the modified PU partition modes. Experimental results show that the embedding capacity can be significantly enlarged, and compared with the state-of-the-art work, the proposed method has much larger capacity while keeping high visual quality.

Correlation of High Cycle Fatigue Behavior of Circular and Square Reinforced Concrete Columns Subjected to Shear Controlled Cyclic Loading

In current design practice, mostly architectural needs govern the shape of reinforced concrete columns. There is a need to study and compare the load-deflection behavior and failure pattern of high strength reinforced concrete columns of different shapes. This paper presents a correlation between the performance of equivalent area circular and square columns subjected to shear controlled cyclic loading. Square and circular columns with equal cross-sectional area were experimentally tested in this research. Experimental results show that the maximum load, number of loading cycles and maximum deflection in case of square and circular columns were found to be close however, the final failure pattern was different. In case of columns without shear stirrups, the square column resisted 6.7% more loading cycles as compared to the circular column. However, the square column showed 19% lesser deflection at ultimate stage. In case of columns with shear stirrups, square column resisted only 9% more loading cycles as compared to circular column and exhibited similar ultimate deflection. The fatigue performance of equivalent area circular and square columns was found to be comparable in shear controlled conditions. However, the final failure pattern of circular columns shifted from shear to flexure near final failure.

MTOR Pathway Activation Assessed by Immunohistochemistry in Cervical Biopsies of HPV-associated Endocervical Adenocarcinomas (HPVA): Correlation With Silva Invasion Patterns.

The Silva pattern of invasion, recently introduced to stratify patients at risk for lymph node metastases in human papillomavirus-associated endocervical adenocarcinomas (HPVAs), can only be assessed in cone and loop electrosurgical excision procedure excisions with negative margins or in a hysterectomy specimen. Previous studies found associations between destructive stromal invasion patterns (Silva patterns B and C) and mutations in genes involved in the MEK/PI3K pathways that activate the mammalian target of rapamycin (mTOR) pathway. The primary aim of this study was to use cervical biopsies to determine whether markers of mTOR pathway activation associate with aggressive invasion patterns in matched excision specimens. The status of the markers in small biopsy specimens should allow us to predict the final and biologically relevant pattern of invasion in a resection specimen. Being able to predict the final pattern of invasion is important, since prediction as Silva A, for example, might encourage conservative clinical management. If the pattern in the resection specimen is B with lymphovascular invasion or C, further surgery can be performed 34 HPVA biopsies were evaluated for expression of pS6, pERK, and HIF1α. Immunohistochemical stains were scored semiquantitatively, ranging from 0 to 4+ with scores 2 to 4+ considered positive, and Silva pattern was determined in follow-up excisional specimens. Silva patterns recognized in excisional specimens were distributed as follows: pattern A (n=8), pattern B (n=4), and pattern C (n=22). Statistically significant associations were found comparing pS6 and pERK immunohistochemistry with Silva pattern (P=0.034 and 0.05, respectively). Of the 3 markers tested, pERK was the most powerful for distinguishing between pattern A and patterns B and C (P=0.026; odds ratio: 6.75, 95% confidence interval: 1.111-41.001). Although the negative predictive values were disappointing, the positive predictive values were encouraging: 90% for pERK, 88% for pS6 and 100% for HIF1α. mTOR pathway activation assessed by immunohistochemistry in cervical biopsies of HPVA correlate with Silva invasion patterns.

Ultra-high performance fibre-reinforced concrete under impact of an AP projectile: Parameter identification and numerical modelling using the DFHcoh-KST coupled model

This paper proposes an experimental identification of the parameters of a coupled plasticity-damage model to be used for numerically simulate the mechanical behaviour of an Ultra-High Performance Fibre-Reinforced Concrete (UHPFRC) under impact. In the DFHcoh-KST model, a parabolic relation describes the pressure dependency of yield stresses (in the sense of Von Mises plasticity), and an anisotropic damage model (accounting for strain rate effect and crack bridging of fibre) is used to describe the tensile failure of concrete. This model is implemented in the Finite Element (FE) code Abaqus to simulate the ballistic impact of an AP (Armour-Piercing) projectile. The model parameters are identified under different loading conditions based on quasi-oedometric compression tests, bending tests and spalling tests. Tunnelling and erosion criterion are used in the numerical simulation to overcome the strong element distortions in the FE simulation in the tunnel region. The influence of friction at the projectile-target interface is also discussed. This study shows that yield strength and tensile damage are fundamental to predict the penetration depth of an almost rigid projectile into a UHPFRC target and that the crack bridging of fibre needs to be taken into account to correctly predict the final damage pattern. In contrast, the modelling of the UHPFRC material compaction is found to be negligible due to its low porosity. Finally, numerical results are compared to classical post-mortem observation and a 3D X-ray Computed Tomography (X-ray CT) reconstruction.

The Influence of Microtubule Persistence Length on Their Collective Motion

Collective motion is a self-organized phenomenon widely recognized in nature, from the macroscopic level of fish schools and bird flocks to the microscopic level of bacterial colonies, self-propelled microparticles, and rods. The collective motion has also been found to be existing within the reconstructed cytoskeleton filament-motor system in vitro, such as the microtubule (MT)-kinesin system, and actin filament-myosin system. Although previous studies proved that the collective pattern of filaments is formed through a dynamic process, including filament's collision and alignment, the formation mechanism of the collective pattern is still not clear. Notably, the persistence length of filaments, an apparent factor influencing their gliding trajectories and alignment behavior, should affect the collective motion directly. However, how the filaments’ stiffness influences their collective motion still needs to be clarified, and related experimental verifications also lack. Here, we investigated the influence of MT persistence length on the formation of their collective motion using an MT-kinesin system in the presence of the depletant agent. Based on our previous study that MT stiffness is dependent on its polymerization rate, MTs with various stiffness were prepared by modifying their growth rate via changing the tubulin concentration with the presence of GTP or GMPCPP, respectively. The whole transition process of the MT-kinesin system, from initial homogeneous state to final nematic state, was tracked and quantitatively evaluated by the nematic order parameters and skewness parameters. Moreover, the final collective patterns formed by MTs with various persistence lengths were characterized and further verified with machine learning. All the results indicate that softer MTs finally tend to form a local stream, whereas stiffer MTs prefer to form stable bundles. This work proves that the persistence length influences not only the phase transition process but also their final collective pattern.

Clinical Features and Outcomes of Very-Early-Onset Inflammatory Bowel Disease in Brazilian Children

We report on 20 Brazilian children under 6 years of age with very-early-onset inflammatory bowel disease naive to treatment. The clinical, laboratory, and histopathologic findings at diagnosis and outcomes were reviewed: 13 had ulcerative colitis (UC) and 7 had Crohn disease (CD). The final diagnostic pattern was as follows: 4 children had neonatal-onset (1 UC and 3 CD), 8 had infantile subtype (4 UC and 4 CD), and 8 had UC beyond the neonatal and infantile period. Both forms of inflammatory bowel disease were severe and extensive at diagnosis, with a high prevalence of bloody diarrhea, reflecting the colonic location of the disease. UC was predominantly pancolonic, CD was isolated in the colon and associated with perianal disease. Children with CD were younger than those with UC, were significantly more nutritionally impaired, and had more complications. This study shows that very-early-onset inflammatory bowel disease has an aggressive clinical course with 2 distinct phenotypes, UC and CD, with differences in severity, clinical behavior, and inflammatory pattern but with a preponderance of colonic involvement in both types.

In Reflection Metal-Coated Diaphragm Microphone Using PCF Modal Interferometer

Starting from non-destructive testing to underwater surveillance, acoustic sensors are finding a variety of modern-day applications. In this article, we propose a double/hybrid interferometry optical microphone. We have combined the intermodal interference of SMF-SCPCF section with extrinsic Fabry-Perot interferometer to construct a highly sensitive, compact and robust optical microphone. The sensor head consists of an SMF-SCPCF spliced section placed in front of an aluminium coated nitrile diaphragm. The acoustic sensitivity and noise-limited minimum detectable pressure (MDP) of the proposed microphone is 34.8 nm/kPa and 0.26 P/√Hz at 1400 Hz. We also recorded the angular response of the proposed optical microphone and the final directionality pattern is of `cardioid' type which makes it a preferable option for a wide variety of applications.

Glucose Metabolism Characteristics of Extra-Hypothalamic Cortex in Patients With Hypothalamic Hamartomas (HH) Undergoing Epilepsy Evaluation: A Retrospective Study of 16 Cases.

Purpose: There are few studies on the glucose metabolic characteristics of the extra-hypothalamic cortex in the hypothalamic hamartomas (HH). A comprehensive understanding of pathogenic progression of the disease is required from the perspective of cortical metabolism; therefore, we aimed to characterize metabolic characteristics of extra-hypothalamic in HH patients.Methods: We investigated the metabolic characteristics of 16 HH patients, all of whom underwent epilepsy evaluation at Xuan Wu Hospital between 2017 and 2019. The lateralization and cortical distribution pattern of hypometabolism was assessed and related to HH mass neuroanatomy on magnetic resonance imaging (MRI) as well as scalp-electroencephalogram (scalp-EEG) abnormalities. Furthermore, asymmetry measurements of region of interest (ROI) in the temporal cortex (hippocampal formation, amygdala, and lateral temporal neocortex) were quantitatively assessed based on the normalized average positron emission tomography (PET) voxel values. The surgery prognosis was assessed using the International League Against Epilepsy (ILAE) classification system.Results: The lateralization of hypometabolism in global visual ratings was consistent with the HH mass lateralization seen on MRI. Cortical hypometabolism showed three patterns depending whether the HH mass involved mammillary bodies, middle hypothalamus nucleus, or both. The three patterns were hypometabolism of the mesial temporal cortex with symptom of mesial temporal epilepsy (3/16, pattern I), lateral temporal, and extratemporal (frontal or parietal) cortex with symptom of neocortex temporal or frontal epilepsy (5/16, pattern II), and mesial and lateral temporal cortex and extratemporal (frontal or parietal) cortex with varied symptoms (8/16, pattern III), respectively. A significant difference in PET voxel values was found between bilateral hippocampal formation (P = 0.001) and lateral temporal neocortex in the third group (P = 0.005). We suggest that the hypometabolic characteristics of the extra-hypothalamic cortex in HH patients have three patterns. The final cortical hypometabolic pattern depends on the neuroanatomic location of the HH mass and was consistent with the main involved cortex of the interictal and ictal discharges. The third hypometabolic pattern with the most extensive cortical hypometabolism has a poorer prognosis.

High dynamic range real-time 3D measurement based on Fourier transform profilometry

The high dynamic range (HDR) fringe projection technique is widely used to measure the three-dimensional (3D) shapes of objects with shiny surfaces; however, it tends to compromise when measuring the dynamic objects. To reduce the number of images and improve the real-time performance, a Fourier transform profilometry (FTP)-based method that can increase the dynamic range for real-time 3D measurement is proposed. Firstly, single-color patterns are projected onto the measured object, and one captured color image can be separated into three monochrome images with different intensities by taking advantage of the different responses of R, G, and B channels. Second, the HDR fringe pattern is generated by compositing three monochrome images, and then processed by the background-normalized algorithm to obtain the final fringe pattern. Subsequently, FTP is employed to retrieve the phase map and obtain the 3D shape. The experimental results demonstrated that the proposed method can measure the dynamic objects with shiny surfaces in real-time 3D measurement system.

Synoptic aspects associated with pervasive dust storms in the southwestern regions of Iran

Dust storm is a natural hazardous phenomenon that affects arid and semi-arid regions of the world the same as Iran. The present research aims to investigate the formation of synoptic patterns of pervasive dust storms (PDSs) in the southwestern regions of Iran. For this purpose, daily data of visibility less than 1000m in 16 synoptic stations (Ilam and Khuzestan provinces) were reviewed during 2004–2017, and 59 PDSs with more than 2 days of duration (overlapped: 70% of the region) were extracted. In practice, mid-level atmospheric data (500, 700, 850 hPa, and sea level pressure (SLP)) with 2.5*2.5 degree resolution (domain: 0-80°E and 10-70°N) were obtained from NCEP/NCAR reanalysis dataset, and the matrix 825*59 of 500 hPa data was performed. Principal component analysis (PCA) with S-mod, were used for extracting synoptic patterns that make PDSs. PCA showed that the first four components ensured more than 86.45% of the data variance. PDSs classification based on output components showed that the patterns had seasonal structures. Synoptically, the north wind blowing in the first pattern is the most dominant structure in the formation of PDSs in the Middle East. The second and third patterns showed postfrontal structures. The fourth pattern with prefrontal structure was the reason for PDSs in the cold seasons of the year. From the four final patterns, the first three patterns showed the dominance of the Persian trough in the SLP maps. Mean values map analysis of the aerosol optical depth suggests that each of the most consistent synoptic patterns stimulates special dust centers.