199 research outputs found
Double-crash on L4 Nerve Root at Different Segments
No full textAlthough lumbar disc herniation is one of the most common pathologies in neurosurgery, each patient has different challenges. With multiple level disc herniation, decision making process gets more complicated. Here we report a unique case with multiple level herniation that both compress the same nerve root. 62 Year-old woman admitted with left leg pain and her neurological examination showed weakness on quadriceps femoris and reduced patellar reflex. Imaging studies show L3-4 paramedian and L4-5 far-lateral disc herniation, both of which compress left L4 root causing a double-crash. She was operated with a median incision conformed for L3-4 standard discectomy and extended slightly caudally. This approach permitted L3-4 hemilaminectomy and L4-5 extra foraminal approaches. Patients are rarely symptomatic from multiple level disc herniation and multiple level discectomy should be exceptionally rare. A thorough neurologic examination is vital for multiple level disc herniation and usually point an individual level that causes symptoms. This patient is a unique example that needs multiple level discectomy although her neurologic examination shows compression on a single nerve root. A midline incision slightly extended caudally is sufficient to expose both levels in a patient with double-crash
Esophageal perforation after anterior cervical surgery: a review of the literature for over half a century with a demonstrative case and a proposed novel algorithm
No full textTo review relevant data for the management of esophageal perforation after anterior cervical surgery. A case of delayed esophageal perforation after anterior cervical surgery has been presented and the relevant literature between 1958 and 2014 was reviewed. A total of 57 papers regarding esophageal perforation following anterior cervical surgery were found and utilized in this review. The treatment options for esophageal perforation after anterior cervical surgery were discussed and a novel management algorithm was proposed. Following anterior cervical surgery, patients should be closely followed up in the postoperative period for risk of esophageal perforation. Development of symptoms like dysphagia, pneumonia, fever, odynophagia, hoarseness, weight loss, and breathing difficulty in patients with a history of previous anterior cervical surgery should alert us for a possible esophageal injury. Review of the literature revealed that conservative treatment is advocated for early and small esophageal perforations. Surgical treatment may be considered for large esophageal defects
Static and dynamic properties of CN/Cu(001) surfaces and oxidation, dissociation and bimolecular debarboxylation of isocyanate species adsorbed on Cu(001)
No full textThis dissertation presents an outlines my investigations of static and dynamic properties of adsorbed cyanide (CN) and isocyanate (-NCO) species as well as some of their chemistries. Surface bound CN-containing species have not previously been studied extensively, partially due to the inapplicability of fundamental e-beam based surface analysis techniques for investigations. I had the opportunity in my studies to employ multiple surface probing techniques, i.e. HAS, XPS, NEXAFS, TPD and RAIRS, to compile and cross-examine information from CN, –NCO, and derived species, adsorbed on the Cu(001) surface. While angle resolved He atom scattering (HAS) was employed to identify and investigate the ordered superstructure of CN/Cu(001) surfaces, TOF-HAS was employed to investigate its dynamic properties. The CN/Cu(001) surface induced unprecedented simultaneous coherent He diffraction with a large “classical” multiphonon backscattered He intensity. A superstructure is implied that contains both rigidly bound CN species, which maintain the long range c(10x6) translational symmetry, together with bound highly-dynamic CN species that exhibit large thermally induced displacements. The NEXAFS measurements suggest multiple spatial binding configurations for the adsorbed CN moieties. In addition, TPD spectra of C2N2 desorption from CN/Cu(001) surface were analyzed, using my newly developed method, to determine the activation energies for desorption as a function of CN coverage. There are two reactions of NCO species examined in my studies. The first is the newly discovered mutual reaction between NCO species. This type of interaction had not been seen before, as it is essentially difficult to prepare pure NCO/metallic surfaces. Copper was chosen as a substrate as HNCO exposures of Cu(001) at RT, followed by spontaneous H2 desorption, do produce NCO only surfaces. A thermal treatment of the surface, at 573K, leads to a bimolecular decarboxylation of NCO, leaving a carbodimide species (NCN) on the surface. The sp-hybridized linear NCN moieties, which are bound nearly parallel to the substrate, show high thermal stability. The second reaction of NCO, which I have studied, is its oxidation. In particular, the effect of CN coadsorbates on the oxidation of NCO was studied. It was found that the presence of CN catalyzes a dissociation reaction of NCO species on Cu(001).Ph. D.Includes bibliographical referencesby Erkan Ziya Ciftlikl
A developmental study of glutamatergic neuron populations in the ventrobasal and the lateral geniculate nucleus of the thalamus: Comparing Genetic Absence Rats from Strasbourg (GAERS) and normal control wistar rats
No full textAn imbalance of GABAergic inhibition and glutamatergic excitation is suspected to be the cause of absence epileptic seizures. Absence seizures are known to be generated in thalamocortical circuitry. In the present study we used light microscopy immunohistochemistry to quantify the density of glutamate+ve neurons at two developmental stages (P10 and P60) in two thalamic nuclei, the ventrobasal (VB) and lateral geniculate nucleus (LGN) in Wistar rats and compared the results with similar data obtained from genetic absence epilepsy rats from Strasbourg (GAERS). Rats were perfused transcardially with glutaraldehyde and paraformaldehyde fixative, then samples from VB and LGN were removed from each animal and sectioned. The glutamatergic neurons were labelled using light-microscopic glutamate immunohistochemistry. The disector method was used to quantify the glutamate+ve neurons in VB and LGN of GAERS and Wistar rats. The data were statistically analyzed. The distribution of the glutamate+ve neurons in the VB thalamic nucleus showed a significant reduction in the neuronal profiles per unit thalamic area from P10 to P60 in both Wistar and GAERS. The decrease was greater in the GAERS compared to the Wistar animals. However, in the LGN no reduction was observed either in the Wistar or in the GAERS. Comparing the density of glutamate+ve neurons in the VB thalamic nucleus of P10 of Wistar animals with of P10 GAERS showed statistically significant greater densities of these neurons in GAERS than in the Wistar rats. However no significant difference was present at P60 between the Wistar and GAERS animals. The disproportional decrease in GAERS may be related to the onset of absence seizures or may be related to neurogenesis of absence epilepsy. (C) 2016 ISDN. Published by Elsevier Ltd. All rights reserved
Effect of size and slenderness on the axial-compressive behavior of basalt FRP-confined predamaged concrete
No full textTo investigate the size and slenderness effect on the axial-compressive behavior of basalt fiber-reinforced polymer (BFRP)-confined predamaged concrete, five groups of concrete cylinders with different sizes and slenderness ratios were designed and tested. The cylinders were axially preloaded to three predamage levels, then repaired using BFRP, and reloaded. The results showed that the concrete predamage had an adverse effect on the ultimate strength and initial elastic modulus of BFRP-confined concrete. Except for the smallest specimens affected by the wall effect, the initial analysis found that the ultimate strength of BFRP-confined concrete decreased with an increase in size and slenderness ratio, and the size and slenderness effect decreased with an increase in BFRP confining pressure, while these increased with the severity of concrete predamage. However, there was no obvious size or slenderness effect on the ultimate strain of BFRP-confined concrete. Through multifactorial analysis, it was confirmed that the ultimate strength of BFRP-confined undamaged and predamaged concrete was influenced by the slenderness. Considering the effect of size, slenderness, and predamage, monotonic and cyclic models were developed for BFRP-confined concrete. Finally, a uniaxial material object was added into OpenSees to provide an effective numerical material model for theoretical analyses and engineering applications. © 2021 American Society of Civil Engineers.The present research was supported by the National Natural Science Foundation of China (Grant No. 51878268) and the Natural Science Foundation of Hunan Province, China (Grant No. 2020JJ4195).
Part of this research was completed by the first author in collaboration with the third and fourth authors during his one-year visit to Ohio State University. The first author acknowledges the State Scholarship Fund of China Scholarship Council (Grant No. 201606135057) for supporting this work and his research visit to the United States
A Comparison of the Ballistic Performances of Various Microstructures in Mil-A Armor Steel
No full textKonca, Erkan/0000-0001-8943-091XDue to their advantageous properties, there is a growing interest in developing armor steels containing fully or partially bainitic microstructures. In this study, bainitic and martensitic microstructures were obtained in rolled homogeneous armor (RHA) steel samples and their ballistic protection performances were investigated. RHA (MIL-A-12560) steel samples were subjected to isothermal heat treatments at three different temperatures, where one temperature (360 degrees C) was above the martensite formation start (Ms) temperature of 336 degrees C while the other two (320 degrees C and 270 degrees C) were below. For the assessment of the ballistic protection performance, the kinetic energy losses of the 12.7 mm bullets fired at the test samples were determined. The promising nature of the bainite microstructure was confirmed as the sample isothermally treated at 360 degrees C provided approximately 10% higher ballistic protection as compared to the regular RHA sample of tempered martensite microstructure. However, the ballistic performances of the isothermally treated samples decreased as the treatment temperature went below the Ms temperature. Following the ballistic tests, hardness measurements, impact tests at -40 degrees C, and macro- and microstructural examinations of the samples were performed. No correlation was found between the hardness and impact energies of the samples and their ballistic performances.ROKETSAN Missile Industries Inc. (Ankara, Turkey)This research was funded by ROKETSAN Missile Industries Inc. (Ankara, Turkey). The APC was paid for by the author
Growth rate of a giant Tarlov (perineural) cyst with intrapelvic extension
No full textMalcok, Umit Ali/0000-0002-1272-9654Background and importanceGiant Tarlov cysts (GTCs) are perineural cysts and their presacral intrapelvic extension are extremely rare entities. We present a case of GTC with intrapelvic extension who has preoperative Magnetic Resonance Imaging (MRI) follow-ups of 12 years, and we demonstrate the annual growth rate and the time-size correlation of a GTC.MethodsCase report.Clinical presentationA 37-year-old woman was admitted with left gluteal pain radiating to left foot, left leg numbness, progressed over 12 years. On MRI, starting from the L5-S1 level, a giant Tarlov cyst with an atypical configuration, is observed. The patient had a known sacral Tarlov cyst, first discovered on MRI obtained 12 years before the surgery. She had 6 consecutive MRI follow-ups in 12 years preoperatively. The cysts diameters have been measured and the growth rate was estimated. We showed for the first time that presented GTC grows in in both Sagittal Diagonal (SD) and Sagittal Craniocaudal (SC) diameters over time with overall annual growth rates, 7.671% for RGR_SD and 6.237% for RGR_SC.ConclusionWhen the time-size correlation is observed, it becomes evident that the GTSs' growing speed increases over the years because of minimal resistance in the intrapelvic cavity. Early surgery may be considered to prevent rapid growth in the intrapelvic cavity and to reduce possible complications of the giant cyst.Scientific and Techno-logical Research Council of Turkiye (TUBIdot;TAK)Open access funding provided by the Scientific and Techno-logical Research Council of Turkiye (TUB & Idot;TAK).Science Citation Index Expande
The Effect of Atlantoaxial Stabilization on Juvenile Idiopathic Scoliosis Involving Chiari Malformation and Syrinx
No full textIdiopathic scoliosis (IS) is frequently asSociated with Chiari malformation (CM) and syringomyelia, conditions thought to share a common underlying cause: Atlantoaxial instability. Atlantoaxial stabilization has recently emerged as a novel treatment option. A 4-year-old girl presented with progressive scoliosis (Cobb angle of 28.6 degrees), neck pain, CM, and syringomyelia. The patient was diagnosed with central or axial atlantoaxial instability and underwent C1-C2 fixation. Postoperatively, she experienced significant relief from neck pain. Follow-ups demonstrated progressive syrinx reduction, while X-rays revealed a Cobb angle decrease to 21 degrees in 18 months. This case highlights the potential of atlantoaxial stabilization to halt scoliosis progression in IS patients with CM and syringomyelia. Unlike traditional multisegmental stabilization, C1-C2 fixation offers a minimally invasive approach and preserves spinal mobility in growth-age patients. Atlantoaxial instability should be considered in IS cases with CM and syringomyelia. Atlantoaxial stabilization alone may provide effective treatment with favorable clinical and radiological outcomes.Emerging Sources Citation Inde
Vocabulary in poet-author Nuri Pakdil in the works of the essasy type
No full textSosyal Bilimler Enstitüsü, Türk Dili ve Edebiyatı Ana Bilim Dalı, Yeni Türk Dili Bilim DalıDilimizdeki sözcüklere cümle içinde kullanım şekline göre çok çeşitli anlamlar yüklenebilmektedir. Bu nedenle bir dildeki sözcüklerin sayısının tespiti kadar kelimelerin çok anlamlılığının tespiti de o dilin zenginliğini ortaya koymada gereklidir. Kelimeleri işleyen, onlara yeni anlatım olanakları sağlayanlar ise şair ve yazarlardır. Nuri Pakdil, kendine has üslubu ve sözcük tercihleriyle oldukça dikkate değer bir yazardır. Hakkında yazılı ve görsel alanda pek çok çalışma yapılmakla birlikte eserleri üzerine söz varlığı açısından bir çalışma yapılmamıştır. Çalışmada Nuri Pakdil'in deneme türündeki eserlerinde yer alan söz varlığının ortaya koyulması amaçlanmıştır. Eserlerin bir bölümü deneme/günlük tarzında olduğundan yazarın yaşamına ait bilgiler de içermektedir. Benzer şekilde eserlerin düşünce yazısı olması sebebiyle yazarın dünya görüşü ile edebî ve fikri eleştirileri de bu eserlerde görülmektedir. Yazarın hayatı, edebi şahsiyeti ve eserleri hakkında bilgi verildikten sonra sözcük ve söz varlığı kavramlarına değinilerek, incelenen eserlerde kullanılan dil, temel söz varlığı bağlamında değerlendirilmeye çalışılmıştır. Çalışmada, eserlerdeki kelimelerin kullanım sıklıklarının tasnifi yapılmıştır. Ayrıca incelenen eserlerin dizinleri de toplu olarak çalışmada yer almaktadır.ABSTRACT The words in our language can be loaded with a variety of meanings according to the usage in the sentence. For this reason, the determination of the number of words in a language as well as the determination of the meaning of words is necessary to reveal the richness of the language. Poet sand writers are the ones who process the word sand provide them with new narrative opportunities. Nuri Pakdil is a remarkable writer with her uniquestyle and vocabulary choices. Although there are many written and visual studies about it, there has not been any study in his vocabulary. Nuri Pakdil, who is a very important man of ideas besides the writer-poet-translatoridentity, is very interesting. In our study, it was a imed to reveal the vocabulary of Nuri Pakdil in his essay types. Since some of the worksare in a trial / daystyle, they also contain information about the life of the author. Similarly, the author's world view and his literary and intellectual criticism can be seen due to the fact that the worksare thought texts. After informing the author about the word and vocabulary in the general framework, the language used in the works examined has been tried to be evaluated in the context of the basic vocabulary. The frequency of use of the words in the Works were classified. In addition, the directories of the studied works are also included in our study
Stem cell/cellular interventions in human spinal cord injury: Is it time to move from guidelines to regulations and legislations? Literature review and Spinal Cord Society position statement
No full textPurpose In preclinical studies, many stem cell/cellular interventions demonstrated robust regeneration and/or repair in case of SCI and were considered a promising therapeutic candidate. However, data from clinical studies are not robust. Despite lack of substantial evidence for the efficacy of these interventions in spinal cord injury (SCI), many clinics around the world offer them as therapy. These clinics claim efficacy through patient testimonials and self-advertisement without any scientific evidence to validate their claims. Thus, SCS established a panel of experts to review published preclinical studies, clinical studies and current global guidelines/regulations on usage of cellular transplants and make recommendations for their clinical use. Methods The literature review and draft position statement was compiled and circulated among the panel and relevant suggestions incorporated to reach consensus. This was discussed and finalized in an open forum during the SCS Annual Meeting, ISSICON. Results Preclinical evidence suggests safety and clinical potency of cellular interventions after SCI. However, evidence from clinical studies consisted of mostly case reports or uncontrolled case series/studies. Data from animal studies cannot be generalized to human SCI with regard to toxicity prediction after auto/allograft transplantation. Conclusions Currently, cellular/stem cell transplantation for human SCI is experimental and needs to be tested through a valid clinical trial program. It is not ethical to provide unproven transplantation as therapy with commercial implications. To stop the malpractice of marketing such unproven therapies to a vulnerable population, it is crucial that all countries unite to form common, well-defined regulations/legislation on their use in SCI. Graphical abstract These slides can be retrieved from Electronic Supplementary Material. [GRAPHICS]
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