Search

Epilepsy is one of the leading chronic diseases of childhood, and an underlying IEM is an etiology that can easily be overlooked. The aim of this study was to determine the frequency of metabolic disease in patients diagnosed with epilepsy in the first two years of life, as well as to determine the clinical, radiological, and electroencephalographic (EEG) characteristics of the metabolic disease subtypes associated with epilepsy and evaluate treatment response in our study.The records of patients diagnosed with epilepsy before the age of 2 years in our pediatric neurology clinic between 2014 and 2021 were reviewed retrospectively. Those diagnosed with an IEM and followed up in the pediatric neurology and pediatric metabolism departments of our hospital were included in the study.A total of 990 patients under the age of 2 years were diagnosed with epilepsy in the pediatric neurology clinic of our hospital and 74 (7.5%) of them had IEM. Thirty-nine (52.7%) of the 74 patients were female. The median age at admission was 144 days (min-max: 0-284). Of the 74 patients diagnosed with metabolic epilepsy, 38 patients were diagnosed with amino acid metabolism disorder, 17 with lysosomal storage disease, 9 with energy metabolism disorder, 5 with vitamin/cofactor/trace element metabolism disorders, 2 with fatty acid metabolism disorder, 2 with peroxisomal disease, and 1 with carbohydrate metabolism disorder. Epilepsy was refractory despite appropriate treatment in 39 patients (52.7%).Inborn errors of metabolism are a rare cause of epilepsy, in regions like our country with high rates of consanguineous marriage, IEM should be considered in patients presenting with seizures that do not respond to conventional antiepileptic treatments.

Purpose Bearing performance characteristics, such as stiffness and load capacity, are related to the viscosity of the fluid circulating through the gap. Nanoparticle additives in lubricant are one way to enhance of the viscosity. This study aims to investigate the effect of nanoparticle additives on the thermohydrodynamic performance of journal bearing with different bearing parameters. Design/methodology/approach The temperature distribution is modeled using a three-dimensional energy equation. The velocity components are calculated on the pressure distribution governed by Dowson’s equation. Moreover, the heat transfer between the journal and lubricant is modeled with Fourier heat conduction equation. On the other hand, the viscosity equation is derived for Al2O3 nanoparticles as a function of the volume ratio and the temperature. An algorithm based on the finite difference method is developed, and a serial simulation is performed for different parameters and different volume ratio of nanoparticle. Findings With the increase in the nanoparticle volume ratio, the maximum temperature decreases for the lower clearance values, but the addition of the nanoparticle influence on the maximum temperature reverses when the clearance grows up. The nanoparticle additives increase further the maximum temperature for higher values of L/D ratios. Moreover, the effects of the nanoparticle additives on the pressure are stronger at high eccentricity ratios for all bearing parameters. Originality/value This paper provides valuable design parameters for journal bearing with lubricant containing the nanoparticle additives.

In this study, we planned to investigate the clinical course of patients with breast cancer with oligometastatic bone disease (OMBD). The patients were grouped according to the characteristics and the sites of metastases. Group I included 928 patients without metastasis. Group II, the OMBD group, included 68 patients. Group III, the widespread metastasis group, comprised 185 patients with multiple bone metastases and/or solid organ metastases. The mean overall survival of the groups was 16.7 ± 0.3 years in group 1, and 7.8 ± 0.8 and 5.9 ± 0.4 years in groups 2 and 3, respectively (p p p = 0.037 for group 2 vs. group 3). In the subgroup survival analysis of patients in group 2 (OMBD), the mean and median survival was 5.5 ± 0.8 and 4.0 ± 0.8 years vs. 9.2 ± 0.98 and 9.0 ± 1.05 years in patients with more than one bone metastasis and single bone metastasis, respectively (p = 0.019). OMBD seems to be a different disease than breast cancer with isolated bone metastases. The high risk of developing OMBD, especially following locoregional recurrence, increases the importance of locoregional therapy in large T and N stage tumors.

Background The modified Boston criteria (mBC) define the probability for the diagnosis of cerebral amyloid angiopathy (CAA). Its initial clinical presentation differs from asymptomatic cerebral microbleedings (cMBs), acute ischemic stroke (AIS), cortical hemosiderosis (cSS), to lobar ICH (lICH). Methods Retrospective analyses and clinical follow-ups of individuals with at least mBC “possible” CAA from 2005 to 2018. Results 149 patients were classified in subgroups due to the index event: lICH (n = 91), AIS (n = 32), > 3 cMBs only (n = 16) and cSS (n = 10). Patients in the lICH subgroup had a significantly higher percentage of single new lICHs compared to other groups, whereas patients in the AIS-group had a significantly higher percentage of multiple new AIS. cMBs as index event predisposed for AIS during follow up (p p Conclusions A new classification system of CAA should add subgroups according to the initial clinical presentation to the mBCs allowing individual prognosis, acute treatment and secondary prophylaxis.

Objectives Acromesomelic dysplasia, type Maroteaux, is an autosomal recessive skeletal dysplasia caused by biallelic loss of function variations of NPR2, which encodes a cartilage regulator C-type natriuretic peptide receptor B. NPR2 variations impair skeletal growth. It is a rare type of dwarfism characterized by shortening of the middle and distal segments of the limbs with spondylar dysplasia. Methods We performed detailed clinical and radiological evaluation and sequence analysis for NPR2. Results Herein, we report nine patients from eight families with two novel NPR2 pathogenic variants. Conclusions This study describes typical clinical phenotypes of Maroteaux type acromesomelic dysplasia, and enriches the variant spectrum of NPR2 by reporting one nonsense and one missense novel variant. We emphasize the importance of detailed clinical evaluation before genetic testing in diagnosing rare skeletal disorders.

Background: Intradiscal ozone therapy, a minimally invasive technique, is used in patients that do not respond to standard conservative therapies for low back pain due to degenerative disc-induced lumbar disc herniation (LDH). Many studies on clinical efficacy lack a standardized injection method and are limited by inadequate study design. Objective: This study aimed to determine the efficacy of periforaminal steroid injection together with intradiscal ozone therapy. Study Design: A prospective, double-blinded, randomized controlled trial. Setting: A tertiary care center. Methods: This study was conducted in 65 patients with low back and leg pain caused by LDH. Group 1 received intradiscal ozone therapy (n = 35) and Group 2 received intradiscal ozone therapy with periforaminal steroid injection (n = 30). Patients were evaluated for pain using the visual analogue scale (VAS), for disability using Oswestry Disability Index (ODI), and for quality of life using the short form 36 health survey administered pre-injection and at one and 6 months postinjection. All procedures were performed under sterile conditions using C-arm fluoroscopy. Results: Significant improvements were observed in pain, disability, and quality of life in both groups post-treatment compared to pre-injection. Mean pre-injection VAS was not significantly different between the groups (VAS: 7.8 ± 1.1 for Group 1, 7.8 ± 1.2 for Group 2). VAS values at 6 months for Group 1 and Group 2 were as follows: 3.6 ± 2.4, 4.1 ± 1.6, respectively) (P < 0.001). Mean pre-injection ODI was not significantly different between the groups (ODI: 20.9 ± 9.6 for Group 1, 25.2 ± 10.3 for Group 2). ODI values at 6 months for Group 1 and Group 2 were as follows: 12.8 ± 9.2, 14.3 ± 7.2, respectively) (P < 0.001). However, there were no significant differences between the groups. Similarly, there was no significant difference between the 2 groups on any of these parameters. Limitations: A limited number of patients and limited follow-up time. Conclusion: This study showed that intradiscal ozone injection alone was sufficient to treat low back and leg pain caused by LDH and that periforaminal steroid injection does not provide additional benefit, which is contrary to the literature. Key words: Low back pain, intradiscal ozone, steroid, lumbar disc herniation, lumbar disc degeneration

Post-traumatic hydrocephalus (PTH) is one of the primary complications during the course of traumatic brain injury (TBI). The aim of this study was to define factors associated with the development of PTH in patients who underwent unilateral decompressive craniectomy (DC) for TBI. A total of 126 patients, who met the inclusion criteria of the study, were divided into two groups: patients with PTH (n = 25) and patients without PTH (n = 101). Their demographic, clinical, radiological, operative, and postoperative factors, which may be associated with the development of PTH, were compared. Multivariate logistic regression analysis revealed that cranioplasty performed later than 2 months following DC was significantly associated with the requirement for ventriculoperitoneal shunting due to PTH (p

Objectives Congenital disorders of glycosylation (CDGs) are a group of genetic disorders due to hypoglycosylation of proteins and lipids. A type I pattern is associated with defects in glycan assembly and transfer (CDG-I; cytosol; and endoplasmic reticulum defects), a type II pattern is seen in processing defects of the Golgi apparatus. MAN1B1-CDG is an autosomal recessive CDG-II due to mutations in the α 1,2-mannosidase gene (MAN1B1), mainly characterized by psychomotor disability, facial dysmorphism, truncal obesity, and hypotonia. Case presentation Three patients (two males and one female), with MAN1B1-CDG who had elevated transaminase levels are presented. All patients had presented due to dysmorphic and neurological findings and hypertransaminasemia was remarkable. A type 2 pattern was found on serum transferrin isoelectrofocusing analysis of the presented cases. MAN1B1-CDG was confirmed by genetic analysis. Conclusions Although the cause of the increased serum transaminase levels in the present patients is not clear, no evidence for an infection or underlying liver pathology could be identified. In order to know if this is a consistent feature, we suggest measuring serum transaminase levels regularly in MAN1B1-CDG patients.

This report presents, in detail, the development and implementation of a wireless solar powered DAQ system for continuous real-time monitoring of the Sagamore Parkway Bridge using the data collected from strain gauges installed in the bridge pier and its foundation piles. The data analysis showed that there is no significant change in the load-settlement response of the bridge pier 3 years after its construction. The pile cap contribution in carrying the total load carried by the bridge pier is significant (about 20%). The hourly ambient temperature trends match with the incremental bending moments measured on the bridge pier and the piles. The daily temperature cycles also affected the load transferred between the piles within the pile group. The water level fluctuations of the Wabash River impacted the total load carried by the pier, such that a rise in water level resulted in slight drop in the total load carried by the bridge pier due to buoyant forces. The overall results of the bridge monitoring showed that the bridge has performed well since its construction.

Objectives: The aim of the present study was to investigate the effect of previous spinal surgery on intradiscal ozone–oxygen (O2–O3) treatment in low back pain associated with lumbar disc herniation (LDH). Methods: Patients who underwent intradiscal O2–O3 therapy for LDH-induced low back pain were screened retrospectively from hospital records. To ensure homogenization of participants, patients who had received O2–O3 therapy to L4–L5 and L5–S1 intervertebral discs, those with pre-injection and post-injection month 1 data, and those who completed the first year of treatment were included in the study. Patients who completed the first year of treatment but with missing data were contacted and followed up by phone. Patients who underwent surgery at the same level as the injection level were classified as Group 1 (n=30), and those without surgery were classified as Group 2 (n=43). Pain and disability were measured by Visual Analog Scale (VAS) and Oswestry Disability Index (ODI), respectively. Results: There was no statistically significant difference between the pre-injection VAS and ODI scores of the groups (p=0.719 and p=0.108). Group 1 had significantly higher VAS and ODI scores on month 1 and year 1 than Group 2, and statistically significant decreases were seen in VAS and ODI scores in both groups at follow-up (p

Background: The relationship between superior cervical ganglia (SCG) ischemia due to bilateral common carotid artery ligation (BCCAL) and basilar artery (BA) reconfiguration was investigated. Methods: Twenty-three rabbits were randomly divided into 3 groups: group III rabbits underwent BCCAL (n = 13), group II rabbits were sham-operated controls (n = 5), and group I rabbits did not undergo surgery (n = 5). Degenerated neuron densities (DND) within the SCG were correlated with the BA vasodilatation index (VDI). Results: Mean live and DND in SCG of group I rabbits were 11.235 ± 982/μm3 and 11 ± 3/μm3, respectively, with a mean heart rate of 294 ± 21 beats/min. Mean SCG DND and heart rates were 213 ± 42/μm3 and 242 ± 17 beats/min for the sham group (group II) rabbits and 1743 ± 285/μm3 and 199 ± 19 beats/min for the study group (group III) rabbits, respectively. The BA VDI values in the sham group (group II) (1.32 ± 0.10) and the study group (group III) (0.976 ± 0.112) significantly differed from those in the control group (group I) (1.65 ± 0.12; P < 0.005) versus the sham group (group II) (P < 0.0001) versus the BCCAL applied group (group III) and between group II and group III (P < 0.005). Conclusions: A meaningful and paradoxic correlation was detected between the BA VDI values and degenerated neuron density of SCG after BCCAL. Although a low degenerated neuron density within SCG may provoke excessive sympathetic activity and prevent excessive BA dilatation with steno-occlusive carotid artery diseases, a high degenerated neuron density may cause dangerous vasodilatation of BA.

Adilay, Hüseyin Utku (Balikesir Author), Study Design. The effect of cetuximab on the development of epidural fibrosis (EF) was assessed using immunohistochemical methods as well as antibodies for CD105 and osteopontin (OPN). Objective. The goal of this study was to assess of EGFR inhibition for the postoperative treatment of fibrosis. Summary of Background Data. EF is one of most common causes of failed back surgery syndrome, which occurs after laminectomy. Numerous causes and mechanisms have been proposed to explain its development after laminectomy. Many agents have been tested to prevent the development of EF. EGFR, a multi-functional transmembrane glycoprotein, causes cell growth, proliferation, and EF by interacting with epidermal growth factor and TGF-b1. The inhibition of postoperative fibrosis using cetuximab, an epidermal growth factor receptor blocker, is theoretically possible. However, this has not been tested to date. Methods. Sixteen Wistar-Albino rats were divided into two groups, namely, control and cetuximab groups. L1-2 laminectomy alone was performed in both groups, and topical cetuximab was applied to the treatment group. After 6 weeks, rats were sacrificed and examined histopathologically and immunohisto-chemically; EF tissue was also graded. Statistical significance was accepted at P< 0.05. Results. Fibroblast counts and fibrosis density, determined by histopathologic examination, and EF, according to immunohistochemical assessment based on CD105, were found to be higher in the treatment group than in the control group, and this was statistically significant (P< 0.001). Based on OPN staining, the results were consistent with classical methods, and no significant difference was detected among the groups (P 1/4 0.358). Conclusion. Our study revealed that cetuximab inhibits the development of EF and that CD105, and not OPN, is a reliable marker for grading EF. In addition, cetuximab did not result in toxic, systemic side effects in surrounding tissues.

In this study, we planned to investigate the clinical course of breast cancer patients with oligometastatic bone disease (OMBD).The patients were grouped according to the characteristics and the sites of metastases. Group I included 928 patients without metastasis. Group II, OMBD group, icluded 68 patients. Group III, widespread metastasis group, consisted of 185 patients with multiple bone metastases and/or solid organ metastases.The mean overall survival of the groups were 16.7 ± 0.3 years in Group 1, and 7.8 ± 0.8 and 5.9 ± 0.4 years in Group 2 and 3, respectively (p

The objective of the study was to analyze the complications of neurosurgical operations during the COVID-19 pandemic by comparing them with the complications observed in the pre-pandemic period.Two groups were formed: (1) Patients who were operated in the 5-month period of the pandemic (March-July 2020) and (2) those who were operated the same operations in the same period 1 year before (March-July 2019). Demographics, characteristics, medical follow-up data, complications, and outcome compared between the groups.Similar demographics were observed between the groups. The number of all neurosurgical cases and neurotrauma cases decreased by 79% and 68% in pandemic period, respectively. The rate of emergency surgeries was significantly higher in pandemic group (p0.001). The operation time was significantly longer in pandemic group (p=0.014). Total complication rate was significantly higher in pandemic group (p=0.002). Specifically, the rate of pulmonary complications was significantly higher during pandemic period (p0.001). The infection rate (p0.001), antibiotic use (p0.001), and intensive care unit stay (p=0.023) were significantly higher in pandemic group.During pandemic period complication rates increased and a higher risk than expected was encountered. Treatment should be performed by taking the precautions and informing the patients about additional risks.

Energy saving is an important problem area in heating and cooling systems. Reducing heat loss from cooling panels is crucial for reducing operating cost, increasing system efficiency and energy saving. For his reason in this paper, the thermal performance of new type of insulation materials for an industry cold storage is numerically investigated for different configurations. Two different solution methods are used. For the first method, insulation materials are used in layers in three different configurations. For the second method, thermal performance of PU based homogeneous composite insulation materials is numerically investigated. Ansys Fluent 19.3 CFD program is used for numerical analysis. As a result; using Magpan-PU composite insulation material (configuration-2) causes a reduction of 9.3% on heat loss according to the reference PU foam (configuration -1). For comparing PU based homogeneous composite insulation materials, using 5% doped silica aerogel PU causes an increase of 19.9% on the thermal performance of insulation material and using 1% doped nano-clay PU causes a decrease of 9.8% on the thermal performance of insulation material. It is determined that model results can represent the physical process and can be used for modeling different type of insulation materials for different parameters., Enerji tasarrufu, ısıtma ve soğutma sisteminde karşılaşılan en önemli problem sahalarından birisidir. Soğutma panellerinde ısı kaybının azaltılması; işletme maliyetinin azaltılması, sistem veriminin arttırılması ve enerji tasarrufu açısından büyük öneme sahiptir. Bu sebeple bu çalışmada; bir endüstriyel soğuk hava deposunun soğutma panelinde kullanılabilecek yeni tip yalıtım malzemelerinin farklı konfigürasyonlar için ısıl performansı sayısal olarak incelenmiştir. Çalışmada iki farklı çözüm yaklaşımı incelenmiştir. Birinci yaklaşımda; yalıtım malzemeleri tabakalar halinde kullanılmış ve üç farklı konfigürasyon oluşturulmuştur. İkinci yaklaşımda; poliüretan (PU) esaslı homojen yapılı kompozit yalıtım malzemelerinin ısıl performansı incelenmiştir. Sayısal çalışmada; Ansys Fluent 19.3 Hesaplamalı Akışkanlar Dinamiği programı kullanılmıştır. Sonuç olarak; Magpan-PU tabakalı yapısının (Konfigürasyon-2), yalnızca PU köpük kullanılma durumuna (Konfigürasyon-1) göre ısı kaybında %9,3’lük bir azalmaya sebep olduğu belirlenmiştir. Poliüretan esaslı homojen yapılı kompozit yalıtım malzemeleri karşılaştırıldığında ise; %5 Silika aerojel katkılı PU köpük malzemenin, yalnızca PU köpük malzeme kullanılması durumuna göre ısıl performansında %19,9 artış gösterdiği, %1 nanokil içeren PU köpük malzeme kullanılma durumunda ise, ısıl performansında %9,8 azalma tespit edilmiştir. Model sonuçlarının, fiziksel durumu iyi bir şekilde temsil edebildiği, homojen yapıyı farklı tip yalıtım malzemelerinin modellenmesinde farklı parametreler için kullanılabileceği değerlendirilmiştir.

Background During the COVID-19 pandemic emergency departments have noted a significant decrease in stroke patients. We performed a timely analysis of the Bavarian telestroke TEMPiS “working diagnosis” database. Methods Twelve hospitals from the TEMPiS network were selected. Data collected for January through April in years 2017 through 2020 were extracted and analyzed for presumed and definite ischemic stroke (IS), amongst other disorders. In addition, recommendations for intravenous thrombolysis (rtPA) and endovascular thrombectomy (EVT) were noted and mobility data of the region analyzed. If statistically valid, group-comparison was tested with Fisher’s exact test considering unpaired observations and ap-value < 0.05 was considered significant. Results Upon lockdown in mid-March 2020, we observed a significant reduction in recommendations for rtPA compared to the preceding three years (14.7% [2017–2019] vs. 9.2% [2020], p = 0.0232). Recommendations for EVT were significantly higher in January to mid-March 2020 compared to 2017–2019 (5.4% [2017–2019] vs. 9.3% [2020], p = 0.0013) reflecting its increasing importance. Following the COVID-19 lockdown mid-March 2020 the number of EVT decreased back to levels in 2017–2019 (7.4% [2017–2019] vs. 7.6% [2020], p = 0.1719). Absolute numbers of IS decreased in parallel to mobility data. Conclusions The reduced stroke incidence during the COVID-19 pandemic may in part be explained by patient avoidance to seek emergency stroke care and may have an association to population mobility. Increasing mobility may induce a rebound effect and may conflict with a potential second COVID-19 wave. Telemedical networks may be ideal databases to study such effects in near-real time.

Objectives: Intradiscal ozone treatment is a minimally-invasive method that can be applied to patients who have low back pain and do not respond to conservative treatment. This retrospectively designed study aimed to evaluate its clinical efficacy, adverse effects, or complication rates. Methods: Patients with lumbar degenerative disc disease (LDDD) who underwent intradiscal O2-O3 treatment between January 2016 and April 2018 were included in the study. Pain and disability levels were assessed at pre-injection, 1-month and 1-year post-injection periods using visual analog scale (VAS) and Oswestry Disability Index (ODI), respectively. Results: A total of 520 patients (270 males and 250 females) with the mean age of 38.9±5.7 years included in the study. First-month and 1st-year post-injection VAS and ODI scores were significantly lower than pre-injection scores (p

The present study is focused on the numerical investigation of heat transfer from a heated surface by using swirling jets and nanofluids. Consequences of discrete Reynolds number, inlet configuration and types of nanofluids (pure water, Al2O3- -H2O, Cu-H2O, and TiO2-H2O) were studied numerically on heat transfer and fluid-flow. As a base coolant Al2O3-H2O nanofluid was chosen for all parameters. So, a numerical analysis was done by using a k-? turbulent model of PHOENICS CFD code. It is determined that increasing Reynolds number from Re = 12000-21000 causes an increment of 51.3% on average Nusselt Number. Using 1-jet causes an increase of 91.6% and 29.8% on average Nusselt number according to the channel flow and 2-jet. Using Cu-H2O nanofluid causes an increase of 3.6%, 7.6%, and 8.5% on the average Nusselt number with respect to TiO2-H2O, Al2O3-H2O and pure water.

Objective Craniopharyngiomas are one of the most challenging problems for neurosurgeons because of the high recurrence rates due to their localization and associated endocrinological disorders. This study reports the outcomes of surgeries and recurrence rates of 45 craniopharyngioma cases. Method Patients who were diagnosed with craniopharyngioma in the authors' clinic between 1998 and 2016 evaluated retrospectively. Results A total of 45 patients (25 males and 20 females; age, 3-56 years) who had previously undergone surgery for craniopharyngioma were enrolled and followed up for 12 to 222 months (mean follow-up duration, 73.5 ± 55.2 months). Among these, 25 were children (55.5%) with a mean age of 9.5 ± 4.6 years and 20 were adults (45.5%) with a mean age of 37.2 ± 12.7 years. A total of 39 (86.6%) patients underwent total tumor resection, while 6 (13.4%) underwent subtotal tumor removal. During 12 to 30 months of follow-up, the progression of residual tumor was recorded in 4 patients, 3 of whom underwent surgery and postoperative radiotherapy. Despite the total resection of tumor in their first surgery, 3 patients showed tumor recurrence during 15 to 34 months of the follow-up. Conclusion Our findings suggest that the total resection of craniopharyngiomas, when possible, results in a favorable quality of life, with acceptable mortality and morbidity rates.

The present study is focused on numerical investigation of heat enhancement and fluid-flow from a heated surface by using nanofluids with three impinging jets. Effects of different volume ratio, different heat flux and different types of nanofluids (CuO-water, Al2O3-water, Cu-water, TiO-water, and pure water) on heat transfer and fluid-flow were studied numerically. The CuO-water nanofluid was used as a coolant in the other parameter. Three impinging jets were used to cool the surface. Low Reynolds number k-? turbulent model of PHONEICS CFD code was used for numerical analysis. It is obtained that increasing volume ratio from ?=2% to 8% causes an increase of 10.4% on average Nusselt number. Increasing heat flux six times has not a significant effect on average Nusselt number. Using Cu-water nanofluid causes an increase of 2.2%, 5.1%, 4.6%, and 9.6% on average Nusselt number with respect to CuO-water, TiO-water, Al2O3-water, and pure water.

Present study is focused on improving heat transfer from a porous plate by cooling of air with transpiration cooling. Effects of Reynolds number of the air channel flow and particle diameter on cooling effectiveness of porous plate and efficiency of system were investigated experimentally. It was observed that increasing Reynolds number of 15.2% causes a decrease of 6.9% on cooling efficiency of the system and a decrease of 8.6% on cooling effectiveness of porous plate. Decreasing particle diameter causes a significant decrease on surface temperature and an increase on cooling effectiveness of porous plate. Difference of cooling effectiveness of porous plate from dp = 40-200 ?m is 12%. Verification of this study was also shown by comparing experimental results of this study with literature.

Background Adamkiewicz arteries vasospasm in spinal cord subarachnoid hemorrhage (SAH) can affect the spinal cord. Although muscle dysfunction of extremities is a common problem after spinal cord ischemia induced by SAH, to our knowledge there are no studies on degenerative changes in peripheral nerves. We studied the histopathologic changes in sciatic nerves after spinal SAH. Methods This study was carried out on 19 rabbits. Five of them were used as control animals, 5 were in the sham group, and 9 were in the study group. For the procedure, 0.5 cm3 of serum saline for the sham group and autologous arterial blood for the study group was injected into the lumbar subarachnoid space at the L5 level. After 2 weeks of follow-up, the sciatic nerve roots at the L5-S3 levels with spinal cords and sciatic nerves were bilaterally extracted to the levels of the collum femoris. The specimens were evaluated by stereologic methods, and degenerated sciatic nerve axons were estimated by Cavalieri methods. Kruskal-Wallis and Mann-Whitney U tests were used for data analysis. Differences of P Results The mean number of degenerated axon density per square millimeter of sciatic nerve at the collum femoris level was 7 ± 2/mm2 in the control group, 23 ± 7/mm2 in the sham group (P Conclusions We concluded that SAHs frequently affect the spinal cord and result in axonal injury to peripheral nerves, of which there is no mention in the literature.

Bu çalışmada; gelişen teknolojilere bağlı olarak artan elektronik elemanların ısıl yük problemini çözmek maksadıyla, yüksek ısı akılı bir yüzeyden olan ısı transferinin, nanoakışkanların çarpan akışkan jet tekniği ile kullanılarak iyileştirilmesi sayısal olarak incelenmiştir. Farklı hacim oranları, farklı ısı akıları ve farklı tipte hazırlanan nanoakışkanların ısı transferine etkisi çalışmada kullanılan parametrelerdir. Çalışmada PHONEICS HAD programının düşük Reynolds sayılı k-ε türbülans modeli kullanılmıştır. Sonuç olarak, hacimsel oran %2’den %8’e artırıldığında ortalama Nusselt sayısında %15,2 oranında bir iyileşme tespit edilmiştir. Yüzeydeki ısı akısı iki kat artırıldığında, yüzey sıcaklıklarının arttığı ancak yerel Nusselt sayısında belirgin bir değişiklik olmadığı tespit edilmiştir. Cu-H2O nanoakışkanı kullanılması durumunda, ortalama Nusselt sayısında sırasıyla CuO-H2O, TiO2-H2O, Al2O3-H2O ve saf suya göre %2,6, %5,5, %6,1, %9,6 iyileşme olduğu gözlemlenmiştir. Sayısal modelde kullanılan düşük Reynolds sayılı k-ε türbülans modelinin sıcaklık dağılımını ve akış özelliklerini iyi bir şekilde temsil edebildiği görülmüştür.

The present study is focused on investigation of heat transfer from a porous plate by cooling of air with transpiration cooling. Effects of Reynolds number of hot gas stream, inlet temperature of air and mass flow rate of water on local wall temperature and cooling effectiveness of porous flat plate and efficiency of the system inside a rectangular channel with air as a hot gas stream and water as a coolant were investigated numerically. Increasing Reynolds number causes an increase on surface temperature and a decrease on cooling effectiveness of porous plate and efficiency of the system. Increasing of air inlet temperature does not cause a significant increase on cooling efficiency of the system. An increase of water flow rate causes a decrease on surface temperature and an increase on effectiveness of porous plate and cooling efficiency of the system. Numerical results prepared by RNG k-epsilon turbulence model have a good approximation and show a similar flow characteristic with experimental results.

In this study, enhancement of heat transfer from highheat flux surface was investigated numerically by using nanofluids andimpinging jet technique to solve the problem of increasing heat loads which iscaused by developing technologies of military sistems. Effect of differentReynolds number (Re=2000, 4000, 6000, 8000) and different type of nanofluids(Cu-H2O, CuO-H2O, TiO2-H2O, Al2O3-H2O) on heat transfer are the parameters ofthis study. Low Re k-ε model was used. It was obtained that increasing Renumber causes an increase on local Nusselt number. Increasing Reynolds numberfrom 4000 to 8000 causes an increase of 47.2% on average Nusselt number forCu-H2O nanofluids (particle diameter of 20 nm and volume ratio of 4%). It wasdetermined that using Cu-H2O nanofluid causes an increase of 2.6%, 5.5%, 6.1%and 9.6% on average Nusselt number with respect to CuO-H2O, TiO2-H2O, Al2O3-H2Oand pure water. It was seen that the low Reynolds number k-ε turbulence modelwell represents the temperature distribution and flow properties at this study., ÖzBu çalışmada; askerî sistemlerin gelişen teknolojiyebağlı olarak artan ısıl yük problemini çözmek maksadıyla, nanoakışkanlarınçarpan akışkan jet tekniği ile kullanılarak, yüksek ısı akılı bir yüzeyden olanısı transferinin iyileştirilmesi sayısal olarak incelenmiştir. Farklı Reynoldssayıları (Re=2000, 4000, 6000, 8000) ve farklı tipte hazırlanannanoakışkanların (Cu-H2O, CuO-H2O, TiO2-H2O,Al2O3-H2O) ısı transferine etkisi bu çalışmadakullanılan parametrelerdir. Çalışmada düşük Reynolds sayılı k-ε türbülansmodeli kullanılmıştır. Sonuç olarak; Re sayısı arttıkça yerel Nu sayısınınarttığı görülmüştür. Cu-H2O nanoakışkanı için (20 nm parçacıkçapında, % 4 hacimsel oranda) Re sayısı 4000-8000 aralığında artırıldığında Nuortsayısında %47,2’lik bir artış elde edilebildiği tespit edilmiştir. Cu-H2Onanoakışkanı kullanılması durumunda, ortalama Nusselt sayısında sırasıyla CuO-H2O,TiO2-H2O, Al2O3-H2O vesaf suya göre %2,6, %5,5, %6,1, %9,6 iyileşme olduğu görülmüştür. Sayısalmodelde kullanılan düşük Reynolds sayılı k-ε türbülans modelinin sıcaklıkdağılımını ve akış özelliklerini oldukça iyi bir şekilde temsil edebildiğigörülmüştür.

The heat losses that occur from the surface of the rotary kilns during calcination process are a major source of waste heat in cement production industry. In order to recover this heat, a multi-shell heat exchanger that forms an annular duct over the high temperature zone of the kiln is used. The phase change material (PCM) paraffin wax with a melting point of 68?C is filled in between the gap of the two concentric annular steel shells which are thermally insulated from the outside. In order to draw a comparison and to establish that phase change material improves the waste heat recovery, the heat exchanger model made up of mild steel, which extracts waste heat from a kiln, is experimentally investigated with and without the tertiary shell that contains the phase change material. The outer surface of the heat exchanger is insulated by glass wool, and to facilitate the passage of air between the shells for heat transfer, a variable speed centrifugal fan (for variable flow rate) is installed. The results show that the waste heat recovery rate is increased by 3% to 8% (depending on different air-flow rate) with the use of phase change material. This implies that phase change materials such as paraffin wax can be used in heat exchangers to obtain an improved waste heat recovery rate.

The present study is focused on investigation of heat transfer from a porous plate by cooling of air and surface with transpiration cooling. Effects of Reynolds number of hot air (Re= 3035, 3200, 3300, 3580), effects of flow rate of water as a coolant ((m)over dot(water) 0.000083, 0.000116, 0.000166, 0.000249 kg/s) on local wall temperature and cooling efficiency of porous flat and the system inside a rectangular channel with air as a hot gas stream and water as a coolant were investigated numerically. In this study; different from the literature, transpiration cooling was used as a cooling mechanism of air. It was observed from the results that increasing Reynolds number causes an increase on surface temperature and a decrease on cooling efficiency of porous plate and system. Increase of Reynolds number from Re=3035 to 9430 causes a decrease of efficiency of the system of 13.7%. Increasing water flow rate nine times causes not only a decrease on average surface temperature of 1.1% but also an increase of 6.5% on efficiency of porous plate and an increase of 19.1% on cooling efficiency of the system. Numerical results prepared by RNG k-E turbulence model generally have a good approximation with experimental results.