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In this study, a new analytical model is provided in order to calculate the radial suspension force in bearingless surface-mounted permanent magnet synchronous motor with static rotor eccentricity. The proposed model is based on the harmonic analysis of magnetic flux density, and considers the influence of both radial and tangential air-gap field components on the computation of radial suspension force. This model can reveal the generation mechanism of the radial suspension force and identify the generation sources of the force ripples. Furthermore, the magnitudes and frequencies of radial suspension force harmonics, and the relationship between the radial suspension force and rotor eccentric displacements can be accurately predicted by the proposed model. However, this model cannot be used for saturated machines. The analytical model is verified by finite-element analyses and the result of static experimental study.

Organic agriculture has conspicuous advantages from the perspective of sustainable development, though its lower productivity compared to conventional agriculture is still a major issue. To increase the productivity and economic benefits of organic farming, it is essential to evaluate land suitability for the production of various organic crops. Agricultural land suitability evaluation utilizes multi-criteria analysis, spatial data analytics, and other analytical methodologies to find suitable locations for agricultural practices. In this study, first, the widely used agricultural land suitability evaluation methods including limitation, parametric, and Multi-Criteria Decision-Making (MCDM) methods are critically reviewed and then, as a case study, an Analytic Hierarchy Process (AHP) coupled with Geographic Information System (GIS) is developed to examine land suitability for the organic cultivation of rain-fed wheat in Duplin County, North Carolina. Several climatic, soil, and topographic criteria are organized in a hierarchy structure, weighted by AHP, and spatially analyzed by GIS to explore the most suitable agricultural lands. The results show that 16.11 and 82.47% of Duplin County’s agricultural lands are, respectively, highly and moderately suitable for the organic production of rain-fed wheat. The land suitability evaluation method developed in this study can be effectively applied for the production of other crops in different regions.

Despite the growing interest in organic farming, its practice remains limited because of its lower productivity relative to conventional farming. Land suitability evaluation for organic crops can p...

The purpose of this article is to investigate the relationship between job satisfaction (JS) and customer satisfaction (CS) in the Social Security Insurance Organization (SSIO) in Iran. The statistical population of this research is composed of employees and customers of Tehran SSIO. Two questionnaires were used to measure the variables of the research. A job descriptive index (JDI) & service quality (SERVQUAL) questionnaire are used to measure JS and CS. Data are analyzed using Pearson Correlation Coefficient and regression analysis. The results indicated that there is no significant relationship JS and CS of Tehran Social SSIO (P > 0.05). Among all the research variables, only satisfaction from colleagues, employee satisfaction and satisfaction with management performance were able to predict CS from the services of the SSIO. Service satisfaction and satisfaction from colleagues also have the ability to predict satisfaction with management performance. In the end, only satisfaction with management performance and service satisfaction has been a significant predictor of CS.

The purpose of this study was to quantify phosphorus bioavailability and various forms of this element in surface sediments of the southern Caspian Sea. To do, sediment samples were collected from different depths in autumn 2015 using a Van Veen Grab. Phosphorus forms were recognized by a sequential extraction procedure (SEDEX). Results revealed that the range of total phosphorus (TP) was between 431 ppm and 594 ppm with a mean value of 535.25 ± 45.05 ppm. Organic phosphorus (OP) ranged from 62 to 99 ppm and contributed 14.85 ± 2.21% of total phosphorus in average. The contents of loosely phosphorus, iron-bound phosphorus, authigenic phosphorus and detrital phosphorus varied 35–55 ppm, 50–94 ppm, 125–189 ppm and 152–217 ppm, respectively. Generally, inorganic phosphorus (IP) was between 365 and 522 ppm which comprised 81.9–88.53% of total phosphorus. Findings showed levels of different phosphorus forms in a descending order: detrital P > Authigenic P > Organic P > Fe-P > Loosely P. Bioavailable phosphorus concentration was between 153 ppm and 240 ppm and consisted 37.21 ± 3% of total phosphorus. Based on molar ratio of TOC/OP, organic matter obtained from the studied stations suggested a terrestrial origin.

Geochemical speciation of As, Cd, Co, Cr, Cu, Ni, Pb, V and Zn were determined in the surface sediments of the southern Caspian Sea. A five-step sequential extraction technique was used to determine the chemical forms of metals. Mean concentrations (ppm) of heavy metals were (mean ± S.D.) As: 9.94 ± 1.71, Cd: 0.87 ± 0.23, Co: 14.85 ± 2.80, Cr: 72.29 ± 19.48, Cu: 18.91 ± 4.48, Ni: 32.87 ± 5.25, Pb: 12.48 ± 3.22, V: 86.07 ± 20.71 and Zn: 66.85 ± 10.11. Among the metals, Cu, As, Pb and Zn exhibited relatively higher mobility, while Cd, Co, Cr, Ni and V were found mainly in the residual fractions. Cu and As showed the highest percentages in the exchangeable phase while Co and Cr had the lowest percentages in the phase. The Risk Assessment Code (RAC) values indicated that As, Cu and V had medium risk at some sampling sites. According to pollution load index (PLI), sediments from some sampling sites were polluted.

We investigated the bioavailability, mobility, and origin of heavy metals present in sediments from the Anzali Wetland. Chemical speciation of the metals was performed according to the Tessier method. Results indicated that Cd and As showed the highest level of bioavailability, whereas Cr showed the lowest level. Cr, Co, and V were shown to have a terrestrial origin. The metal As was mostly found in the reducible fraction (F3), whereas other metals were highest in the residual phase. The levels of Co present in the oxidizable fraction (F4); Pb and Cd present in the carbonate fraction (F2); and the other metals present in the exchangeable fraction (F1) were found to be the lowest. On the basis of the Risk Assessment Code of metals, Cd at most stations, As and Ni at some stations, and Zn at one station revealed to have a moderate risk. Co and Pb were found to have a low risk at all stations. Considering Pollution Load Index, stations 2 and 3 were classified as moderately polluted and the remaining stations were unpolluted. As suggested by enrichment factor analysis, As was moderately enriched and other metals had a deficiency to minimal enrichment at all the stations.

Hemangiopericytoma (HPC) is a rare tumor of the central nervous system. Primary spinal occurrence of this tumor is extremely uncommon and cases involving the intramedullary spinal cord are even more rare. The purpose of this study was to explore the clinical features, surgical strategies, outcome and pathology in a consecutive series of patients treated at a single institution.The authors performed a retrospective review of the clinicopathological characteristics of four patients with a pathological diagnosis of spinal HPC.Four cases with intradural as well as intra/extra-medullary components were identified. Gross total resection with no recurrence at the operative site was achieved in the majority of patients with a spinal HPC. One patient had significant recurrence and eventually, succumbed to the disease.Increased awareness of these tumors' capability to occur intradurally and intramedullarly can help surgeons accurately diagnose and choose an effective plan of care. Gross total resection of hemangiopericytomas is the mainstay of treatment and should be pursued if feasible. Histopathology is essential to the diagnosis.

Esthesioneuroblastoma (ENB) is an uncommon aggressive malignant intranasal neoplasm that originates from neural crest cells of the olfactory epithelium. Although local invasion to the sinuses is common, spinal metastasis of ENB is rare with only 28 documented cases involving the spine spinal cord, or leptomeninges. We report a case of ENB with multiple drop metastases to the cervical and thoracic spine, and review the patient’s disease, medical history, and multiple interventions during a span of 15 years following the initial cranial resection. Despite aggressive multiple surgical resections, radiation, and chemotherapy, the tumor had significant progression and recurrence. The literature is reviewed, followed by a discussion of the natural progression of the disease and various reported interventions. Although a combination of surgery with chemotherapy and radiation therapy has been recommended, no definitive management has been established for ENB. Further research is needed to determine decisive treatment for metastatic ENB to the spine.

Uterine leiomyosarcomas do not frequently metastasize to the bone, and spinal column metastases are even less common. Surgery is the treatment of choice. Adjuvant radiation with or without chemotherapy depending on the extent of disease can be beneficial. We present the case of leiomyosarcoma metastasis to the spine with a previous history of known primary disease complicated by thrombocytopenia. Thrombocytopenia can present surgical challenges, but can also be present concurrently unrelated to the primary disease. A thorough evaluation is needed to rule out any underlying lymphoproliferative disorder or microangiopathic phenomenon.

A telescope based high definition (HD) video system (VITOM®, Karl Storz GmBH & Co., Tuttlingen, Germany) has recently been proposed as an alternative to the operating microscope for microneurosurgery. It remains unclear which clinical situations will benefit from its advantages. In light of the uncomfortable surgeon position and fatigue often associated with pineal region surgery, we used the VITOM® HD exoscope system to perform an infratentorial supracerebellar resection of a pineal tumor. The VITOM® dramatically improved surgeon comfort and ease of operating by permitting the surgeon to stand upright and in a comfortable position and avoid the need to extend the arm or assume an awkward. position commonly encountered when using the microscope for these approaches. The marked improvement in surgeon comfort afforded by the VITOM® exoscope indicates that this system may have significant advantages over traditional microscope based surgery for tumors of the pineal region approached using an infratentorial supracerebellar approach.

BACKGROUND Spinal dural arteriovenous fistulas (DAVF) in the cervical spine are known to cause subarachnoid hemorrhage. Vasospasm after rupture of a DAVF, however, has not previously been reported. CASE PRESENTATION A 48-year-old woman who presented with the sudden onset of altered mental status. Imaging demonstrated extensive subarachnoid hemorrhage and spinal DAVF at C1 to C2. The patient underwent a suboccipital craniotomy for DAVF ligation. On post-operative day three, she began having acute weakness in all her extremities with proprioception and vibration preserved, whereas pain and temperature sensation was lost. An angiogram demonstrated bilateral vertebral artery vasospasm with no filling of the anterior spinal artery. Bilateral angioplasty of the vertebral arteries was performed successfully and post-angioplasty, the right vertebral artery was filling the anterior spinal artery. The patient clinically improved. She subsequently required treatment with n-butyl cyanoacrylic acid (nBCA) embolization and gamma knife radiosurgery to achieve obliteration of the lesion. CONCLUSIONS For patients with subarachnoid hemorrhage of unknown origin, differential diagnosis should include DAVF. This patient also presented with vasospasm in the context of ruptured DAVF, a complication previously unreported in the literature. This finding suggests that close monitoring for vasospasm after rupture of DAVF is warranted.

Intracerebral hemorrhage (ICH) is associated with perihematoma inflammation and edema. We have recently shown cell death and a robust activation of the proinflammatory transcription factor, nuclear factor-κB (NF-κB) in brain areas adjacent to the hematoma. Proteasome represents a key component necessary for the activation of NF-κB. The aim of our present study was to examine if selective proteasome inhibition with a clinically relevant agent, PS-519, might influence the ICH pathogenesis, and improve functional outcome. ICH was induced in Sprague–Dawley rats by the double blood injection method. PS-519 was administered intravenously 4 h and 15 min after induction of ICH. Behavioral testing was performed 3, 5, and 7 days later. The animals were sacrificed on day 7, and their brains were evaluated for hemorrhage size and inflammation using immunohistochemistry with antibody to various inflammatory markers. Treatment with PS-519 significantly (p

This paper proposes a new Integer-Coded Genetic Algorithm (ICGA) for the solution of the thermal unit commitment problem. The thermal generating units scheduling consists of the sequence of operation/reservation times of the generating units, which is coded into a sequence of alternating sign integer numbers in the proposed ICGA. The minimum up and down time constraints of the generating units are directly coded in the chromosome structure of the ICGA. The proposed ICGA has a new hybrid crossover composed of modified average bound and swapping operators. In addition, a combination of uniform and non-uniform mutations is used as the mutation operator. As a result, the algorithm robustness is improved. Test results with systems of up to 300 units and 24 hours scheduling horizon are presented. The comparison of the obtained results with those of other Unit Commitment (UC) methods justifies the effectiveness of the proposed method in light of minimizing the total operation cost. Copyright © 2008 John Wiley & Sons, Ltd.

Intracranial metastases are rare from gastrointestinal stromal tumor (GIST). We report a 60-year-old male with a history of stomach GIST who presented with ataxia 2.5 years after a partial gastrectomy. MRI revealed enhancing masses in the cerebellum and frontal lobe. A suboccipital craniotomy revealed metastatic GIST. With subsequent radiosurgical boost to the resection cavity and frontal lobe lesion, the patient is doing well 15 months postoperatively. To our knowledge, this is one of only a few reports on cerebral GIST metastases from the stomach.

Introduction Spontaneous vertebral artery dissection (VAD) is a rare condition and can potentially cause a stroke, particularly in young to middle-aged people. Bilateral extracranial VAD is extremely rare. Case report A 37-year-old woman complained of severe headache 1 hour postpartum. Her pain was relieved with medication and she was subsequently discharged. Three days later, the patient returned with worsening headache that she described as the worst headache of her life. Computed tomography and lumbar puncture was negative for subarachnoid hemorrhage. Magnetic resonance angiography showed bilateral extracranial vertebral artery occlusion. The patient remained stable with conservative therapy without further worsening of headache or any new neurological deficits. Conclusions This is the first reported case of bilateral extracranial VAD in an immediate postpartum woman in the literature. The postpartum state is a risk factor for clinically relevant dissection, and this diagnosis should be considered. Outcomes for vertebral arterial dissection are usually favorable, but early diagnosis is critical for initiation of appropriate treatment of possible complications. Physicians must have a high index of suspicion for arterial dissection when patients note severe, atypical headache or neck pain.

Atlas of emergency neurosurgery , Atlas of emergency neurosurgery , کتابخانه الکترونیک و دیجیتال - آذرسا

This paper, explained the simulation of electrical motor drive using three softwares: simulink, Simplorer and Maxwell. Simulink software provides a suitable environment for designing controllers, simplorer is good for inspecting behavior of power electronic components and Maxwell is a powerful in designing electrical motors. By linking these, an appropriate tool is provided for more realistic analyzing a driver with an electrical motor. Simulation results of a BLDC1 motor with sensorless drive is mentioned to demonstrate the efficiency of this environment. The advantages of this environment in compare to simulink software are more realistic voltages, currents and torque, loss and temperature calculation, accurate motor model and so on.

Antiphospholipid syndrome (APS) is an autoimmune condition involving arterial and venous thrombosis. An unusual APS variant, catastrophic antiphospholipid syndrome (CAPS), includes rapid multi-organ failure from widespread small vessel thrombosis. Central nervous system complications arise in one-third of CAPS patients. In rare cases, CAPS co-manifests with cerebellar hemorrhage presenting a neurosurgical emergency. We present a 65-year-old woman with CAPS-related cerebellar hematoma, co-morbid idiopathic thrombocytopenic purpura, deep vein thrombosis and altered mental status, with treatment complicated by thrombocytopenia. The patient suddenly deteriorated, secondary to a cerebellar subdural hematoma, and underwent decompression and excision of the hematoma. After recovery in the intensive care unit, she developed a new spontaneous epidural hematoma requiring additional surgery. Management of these patients is hematologically complex and often requires a multi-disciplinary team of physicians. This patient provides an important learning point for clinicians – consider CAPS when hemorrhage and thrombosis are present.

Endolymphatic sac tumors (ELSTs) are rare, low-grade, histologically benign tumors arising from the epithelial lining of the endolymphatic duct or sac. They are slow growing but locally invasive and can be associated with von Hippel-Lindau disease. While there are cases in the medical literature documenting this type of tumor in adults, reports of ELSTs in the pediatric population are limited. The authors report the fifth reported case of a pediatric ELST in the English literature. A 14-year-old Jehovah’s Witness presented with a progressive two-year history of right-sided hearing loss, balance problems, gait difficulty, and bleeding behind the right tympanic membrane. Computed topography (CT) and magnetic resonance imaging (MRI) of the brain and temporal bone revealed a large lesion eroding into the petrous and mastoid bones with extension abutting the brain stem and invading the right transverse sinus. Due to the size and hypervascularity of the tumor, as well as the refusal of the patient and family to receive possible intra-operative blood transfusion, pre-operative tumor embolization and staged surgical resection were used for excision. Histopathological staining and electron microscopy confirmed the diagnosis of ELST. Immediate post-operative imaging did not reveal any residual tumor. Post-operative examination revealed persistence of the right-sided hearing loss that was present pre-operatively. A new facial nerve paralysis was noted post-operatively and remained unchanged at 21 months post-resection follow-up. MRI imaging at 21 months follow-up revealed recurrent tumor. The imaging workup for von Hippel-Lindau disease has been negative. We conclude that it is possible to have reasonable functional outcomes for children with ELSTs using staged resection techniques, though such approaches do not preclude delayed recurrence.

High-resolution neuroimaging modalities are used often in studies involving healthy volunteers. Subsequently, a significant increase in the incidental discovery of asymptomatic intracranial abnormalities raised the important ethical issues of when follow-up and treatment may be necessary. We examined the literature to establish a practical set of criteria for approaching incidental findings. Our objective is to develop an algorithm for when follow-up may be important and to provide recommendations that would increase the likelihood of follow-up. A systematic literature search was performed using the PubMed and MEDLINE databases to identify articles describing brain tumors and intracranial aneurysms. The treatment algorithm we present suggests that incidental intracranial masses suspicious for glioma should be biopsied or resected, while other masses are to be followed with serial imaging based on the expected growth pattern. Lack of follow-up can result in adverse outcomes that can be mitigated by using technology to facilitate communication and improve follow-up care. The importance of training physicians to be good communicators is also stressed. New technology including automated telephone systems, texting and email will improve access to patients and hopefully encourage compliance and follow-up.

Spinal dural arteriovenous fistulas (DAVF) in the cervical spine are known to cause subarachnoid hemorrhage. Vasospasm after rupture of a DAVF, however, has not previously been reported.A 48-year-old woman who presented with the sudden onset of altered mental status. Imaging demonstrated extensive subarachnoid hemorrhage and spinal DAVF at C1 to C2. The patient underwent a suboccipital craniotomy for DAVF ligation. On post-operative day three, she began having acute weakness in all her extremities with proprioception and vibration preserved, whereas pain and temperature sensation was lost. An angiogram demonstrated bilateral vertebral artery vasospasm with no filling of the anterior spinal artery. Bilateral angioplasty of the vertebral arteries was performed successfully and post-angioplasty, the right vertebral artery was filling the anterior spinal artery. The patient clinically improved. She subsequently required treatment with n-butyl cyanoacrylic acid (nBCA) embolization and gamma knife radiosurgery to achieve obliteration of the lesion.For patients with subarachnoid hemorrhage of unknown origin, differential diagnosis should include DAVF. This patient also presented with vasospasm in the context of ruptured DAVF, a complication previously unreported in the literature. This finding suggests that close monitoring for vasospasm after rupture of DAVF is warranted.

Object Athletes present with back pain as a common symptom. Various sports involve repetitive hyperextension of the spine along with axial loading and appear to predispose athletes to the spinal pathology spondylolysis. Many athletes with acute back pain require nonsurgical treatment methods; however, persistent recurrent back pain may indicate degenerative disc disease or spondylolysis. Young athletes have a greater incidence of spondylolysis. Surgical solutions are many, and yet there are relatively few data in the literature on both the techniques and outcomes of spondylolytic repair in athletes. In this study, the authors undertook a review of the surgical techniques and outcomes in the treatment of symptomatic spondylolysis in athletes. Methods A systematic review of the MEDLINE and PubMed databases was performed using the following key words to identify articles published between 1950 and 2011: “spondylolysis,” “pars fracture,” “repair,” “athlete,” and/or “sport.” Papers on both athletes and nonathletes were included in the review. Articles were read for data on methodology (retrospective vs prospective), type of treatment, number of patients, mean patient age, and mean follow-up. Results Eighteen articles were included in the review. Eighty-four athletes and 279 nonathletes with a mean age of 20 and 21 years, respectively, composed the population under review. Most of the fractures occurred at L-5 in both patient groups, specifically 96% and 92%, respectively. The average follow-up period was 26 months for athletes and 86 months for nonathletes. According to the modified Henderson criteria, 84% (71 of 84) of the athletes returned to their sports activities. The time intervals until their return ranged from 5 to 12 months. Conclusions For a young athlete with a symptomatic pars defect, any of the described techniques of repair would probably produce acceptable results. An appropriate preoperative workup is important. The ideal candidate is younger than 20 years with minimal or no listhesis and no degenerative changes of the disc. Limited participation in sports can be expected from 5 to 12 months postoperatively.

The direct lateral interbody fusion (DLIF), a minimally invasive lateral approach for placement of an interbody fusion device, does not require nerve root retraction or any contact with the great vessels and can lead to short operative times with little blood loss. Due to anatomical restrictions, this procedure has not been used at the lumbosacral (L5-S1) junction. Lumbosacral transitional vertebrae (LSTV), a structural anomaly of the lumbosacral spine associated with low back pain, can result in a level being wrongly identified pre-operatively due to misnumbering of the vertebral levels. To our knowledge, use of the DLIF graft in this patient is the first report of an interbody fusion graft being placed at the disc space between the LSTV and S1 via the transpsoas route. We present a review of the literature regarding the LSTV variation as well as the lateral placement of interbody fusion grafts at the lumbosacral junction.

Giant cell tumors (GCTs) are rare lesions of the cervical spine, with only 14 previously reported pediatric cases in the literature, all occurring in females. The authors present the case of a 15-year-old boy with neck pain who was found to have a lytic GCT of the odontoid process. Following resection, recurrent disease was treated with radiotherapy and chemotherapy and then a final resection. He has remained tumor free for more than 10 years. The rarity of GCTs can make their diagnosis difficult in the cervical spine. Because of their aggressive behavior and relative resistance to adjuvant therapy, GCTs must be monitored diligently and treated aggressively.

Endometriosis consists of ectopic endometrial tissue outside of the uterine cavity. It is typically benign; however, in some cases, it may cause neurological symptoms if involving the central or peripheral nervous system. We present in this report a 46-year-old Caucasian female with lumbar pain progressively worsening for the last 3 years in her left hip and buttock with radicular symptoms radiating to her left anterior thigh with MR imaging showed an enhancing mass in the L4 neural foramen, interpreted as a nerve sheath tumor. At operation the nerve showed extrinsic and intrinsic abnormality, proven to be endometriosis. Postoperatively, the patient reported relief from her radiculopathy. We review the previous cases, discuss the pathogenesis and additional characteristics that highlight that intraspinal endometriosis, although rare, and must be considered as a potential cause of lumbar pain in women. Surgical resection is recommended in cases having severe or worsening neurologic symptoms or signs of cauda equina syndrome but care must be taken to avoid injuring the nerve. Adjunctive treatment may be used in cases of residual or recurrent lesions. doi:10.4021/wjon413w

Object The elderly population (age > 60 years) is the fastest-growing age group in the US. Spinal deformity is a major problem affecting the elderly and, therefore, the demand for surgery for spinal deformity is becoming increasingly prevalent in elderly patients. Much of the literature on surgery for adult deformity focuses on patients who are younger than 60 years, and therefore there is limited information about the complications and outcomes of surgery in the elderly population. In this study, the authors undertook a review of the literature on spinal deformity surgery in patients older than 60 years. The authors discuss their analysis with a focus on outcomes, complications, discrepancies between individual studies, and strategies for complication avoidance. Methods A systematic review of the MEDLINE and PubMed databases was performed to identify articles published from 1950 to the present using the following key words: “adult scoliosis surgery” and “adult spine deformity surgery.” Exclusion criteria included patient age younger than 60 years. Data on major Oswestry Disability Index (ODI) scores, visual analog scale (VAS) scores, patient-reported outcomes, and complications were recorded. Results Twenty-two articles were obtained and are included in this review. The mean age was 74.2 years, and the mean follow-up period was 3 years. The mean preoperative ODI was 48.6, and the mean postoperative reduction in ODI was 24.1. The mean preoperative VAS score was 7.7 with a mean postoperative decrease of 5.2. There were 311 reported complications for 815 patients (38%) and 5 deaths for 659 patients (< 1%). Conclusions Elderly patient outcomes were inconsistent in the published studies. Overall, most elderly patients obtained favorable outcomes with low operative mortality following surgery for adult spinal deformity.