A Model to Assess Leanness Capability of Enterprises

AbstractIn today's competitive business environment, enterprises are facing tremendous pressure of customers’ various requests, demand responsiveness, and reducing cost. To meet with such expectations and to enhance the effectiveness of processes of enterprise, lean philosophy is one of the best initiatives. This paper proposes a model that assesses leanness out of four perspectives, three level structures of leanness criterion and twenty eight main criterions

Geçiş metali karbürlerinin elastik özelliklerinin yoğunluk fonksiyon teorisi ile incelenmesi

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Bu tezde, yoğunluk fonksiyon teorisine bağlı olan birinci ilke pseudo potansiyel metodunu kullandık. Atomlar için pseudo potansiyeller Troullier ve Martins' in şemasına göre üretilmiştir. Yoğunluk fonksiyon teorisi Perdew-Burke-Ernzerhof metodu kullanılarak genelleştirilmiş gradyan yaklaşımı (PBE-GGA) içinde kullanılmıştır. Khon-Sham eşitliklerinin kendi kendine tutarlı çözümlerinde özel k noktaları kullanılarak ve Brillouin bölgesinin indirgenemez parçası örnek alınarak elde edilmiştir. 60 Ryd kesme kinetik enerjisi kullanılmıştır.Bu tezin birinci bölümünde, karbidlerin taban durumu özellikleri toplam enerjinin birim hücrenin hacmi V' ye göre minimize edilmesiyle tanımlanır. Daha sonra, teorik denge örgü sabiti a, statik hacim modülü B ve hacim modülünün basınca göre türevi B' Murnaghan eşitlik durumunun hacmin bir fonksiyonu olarak statik toplam enerji hesaplanarak elde edilmiştir. Malzemenin yapısal özelliklerini üreten bu modelde önceki teorik çalışmalar deneysel sonuçlar kadar iyi bulunmuştur.Tezin ikinci bölümünde, bu maddelerin elastik sabitlerini hesaplamak için ab initio modeli kullanıldı. Kaya tuzu yapısı C11, C12 ve C44 birbirinden bağımsız 3 tane elastik sabite sahiptir. Böylece, bu sabitleri elde etmek için 3 denklem grubuna ihtiyaç vardır. C11 - C12 sırasıyla hacim koruyucu tetragonal ve monoclinic gerilmeler tarafından hesaplanır. C11 ve C12' yi ayrı ayrı elde etmek için, bu elastik sabitler ve hacim modülü arasındaki ilişki; kullanıldı. Enerji farkı 1mRy den daha az olduğu için elastik sabitleri çok yüksek hassaslıkta hesaplamaya ihtiyaç vardır. Bu durum iyi bir k örgü noktası kullanılmasını gerektirir. Böylece elastik sabitler 24x24x24 Monkshort-Pack k örgüsüyle hesaplanmıştır.Elastik hesaplamalar için gerekli yapısal bilgi ab initio pseudo potansiyel hesaplamalarımızdan elde edilmiştir. Bulunan sonuçlar mevcut deneysel ve teorik sonuçlarla karşılaştırılmış ve iyi bit uyum gözlenmiştir. Özellikle, kristalin mekanik dengesinde zorlanma enerjisi pozitif olmalıdır. Kübik kristal için, mekanik denge şartları; C11>0, C12>0, C11-C12>0, C11+2C12>0 olarak verilir. Hesapladığımız elastik sabitler bu denge koşullarına uyarlar. Bu sonuçlar gösterir ki, bütün karbid çalışmalarında bu hesaplamalar uygundur.Anahtar Kelimeler: Yoğunluk fonksiyon teorisi, pseudo potansiyeli, brillouin bölgesi, karbid, örgü sabiti, elastik sabiti, hacim modülü.In the this thesis, we have used a first-principles pseudo potential method based on the density functional theory. The pseudo potentials for atoms are generated according to the scheme of Troullier and Martins. The density functional theory has been implemented within a generalised gradient approximation, using the Perdew-Burke-Ernzerhof method. The Kohn-Sham single-particle functions were expanded in a basis of plane waves. Self-consistent solutions of Kohn-Sham equations were obtained by sampling the irreducible part of the Brillouin zone by employing special k points. A kinetic energy cut off of 60 Ryd is used.In the first part of this thesis, the ground state properties of bulk refractory carbides are determined by minimization of the total energy with respect to the unit-cell volume V. Then, the theoretical equilibrium lattice constant a, the static bulk modulus B, and the first-order pressure derivative of the bulk modulus B' have been obtained by fitting the calculated static total energies as a function of volume to the Murnaghan equation of state. It is found that this model produces the structural properties of these materials which are in good agreement with previous theoretical as well as experimental results.In the second part of thesis, ab initio model is used to calculate elastic constants of thesematerials. The rock-salt structure has only three independent elastic constants, namely C11, C12 and C44. Thus, a set of three equations is needed to obtain these constants. C11-C12 are calculated by volume-conserving tetragonal and monoclinic strains, respectively. In order to obtain C11 and C12 separately, the relationship between these elastic constants and bulk modulus; is also used. The elastic constants calculations require a very high degree of precision because the energy difference involved are the order less than l mRy. This circumstance requires the use of a fine k-point mesh. Thus, the elastic constants were calculated with a 24x24x24 Monkhorst-Pack k mesh.The structural information necessary for elastic calculations is taken from our ab ini¬tio pseudo potential calculations. The obtained results compare well with available ex-perimental and theoretical results. In particular, the mechanical stability of crystal im-plies that strain energy must be positive. For cubic crystal, the necessary conditions for mechanical stability are given by C11>0, C12>0, C11-C12>0, C11+2C12>0 our calculated elastic constants obey these stability conditions, including the fact that C11 should be greater than C12. This results shows that all studied refractory carbides are stable in this calculation.Keywords: Density function theory, pseudo potential, Brillouin zone, carbide, lattice constant, elastic constant, bulk modulus

Craniopharyngioma

Craniopharyngioma (CP) is a rare, benign, slow-growing, but clinically aggressive tumor located mainly in the sellar and suprasellar regions. While it occurs equally in children and adults, there are two peaks in the age distribution: first in 5–14 years of age and second in 45–74 years of age. The clinical presentation varies according to the age of patients, while the predominant symptoms are visual disturbances, headache, and endocrine dysfunctions. CPs are topographically classified in several subgroups based on the relationship of the tumor to the sella, diaphragma sellae, optic chiasm, stalk, and third ventricle; whereas the pathological classification includes two types: adamantinomatous (aCP) and papillary (pCP). Distinctive features of aCP are cysts with content of “motor-oil” fluid, calcification, wet keratin, peripheral palisading of basal cells, stellate reticulum, and mutations in CTNNB1/β-catenin gene; and those of Pcp are regular stratified squamous epithelium, devoid of cilia, papillary projections, no calcification, rare cyst with a clear fluid, and mutations in BRAF V600E. The surgical approaches include transcranial (subfrontal, pterional, transcallosal, and transcortical-transventricular) and transsfenoidal approaches, having different selection criteria, advantages, and disadvantages. Despite complete resection and radiotherapy, CPs are inclined to recur causing high morbidity and mortality

Thioredoxin System and miR-21, miR-23a/b and let-7a as Potential Biomarkers for Brain Tumor Progression: Preliminary Case Data

Background: The thioredoxin system and microRNAs (miRNAs) are potential targets for both cancer progression and treatment. However, the role of miRNAs and their relation with the expression profile of thioredoxin system in brain tumor progression remains unclear. Methods: In this study, we aimed to determine the expression profiles of redox components Trx-1, TrxR-1 and PRDX-1, and oncogenic miR-21, miR-23a/b and let-7a and oncosuppressor miR-125 in different brain tumor tissues and their association with increasing tumor grade. We studied Trx-1, TrxR-1, and PRDX-1 messenger RNA expression levels by quantitative real-time polymerase chain reaction and protein levels by Western blot and miR-23a, miR-23b, miR-125a, miR-21, and let-7a miRNA expression levels by quantitative real-time polymerase chain reaction in 16 glioma, 15 meningioma, 5 metastatic, and 2 benign tumor samples. We also examined Trx-1, TrxR-1, and PRDX-1 protein levels in serum samples of 36 patients with brain tumor and 37 healthy volunteers by enzyme-linked immunosorbent assay. Results: We found that Trx-1, TrxR-1, and PRDX-1 presented high messenger RNA expression but low protein expression in low-grade brain tumor tissues, whereas they showed higher protein expression in sera of patients with low-grade brain tumors. miR-23b, miR-21, miR-23a, and let-7a were highly expressed in low-grade brain tumor tissues and positively correlated with the increase in thioredoxin system activity. Conclusions: Our findings showed that Trx-1, TrxR-1, miR-21, miR-23a/b, and let-7a might be used for brain tumor diagnosis in the clinic. Further prospective studies including molecular pathway analyses are required to validate the miRNA/Trx system regulatory axis in brain tumor progression. © 2022 Elsevier Inc

Surgical Results in Temporal Lobe Epilepsies Due to Structural Lesions

Objective:Temporal lobe epilepsy (TLE) is the most common localization-related epilepsy syndrome in adults. The aim of this study was to determine the long-term efficacy of epilepsy surgery in patients with TLE with focal lesions and to evaluate the predictive factors for seizure-free status after surgery.Methods:Among 109 patients aged more than 17 years, 26 cases with a postoperative follow-up period of at least 2 years and who underwent anterior temporal lobectomy and lesionectomy were included in the study. Each patient was evaluated with a detailed history, video-electroencephalography (EEG), neuroimaging, and postsurgical outcomes according to Engel classification to predict postsurgical seizure freedom.Results:Patients with chronic TLE (n=26) associated with structural lesions were included in the study. According to Engel’s classification, the seizure freedom rate was found to be 92.3% in the first year and 80.8% in the second year after surgery. At the postoperative 2nd year, demographic parameters, disease duration before surgery, mean age of patients, presence of focus to bilateral tonic-clonic seizure, EEG, video EEG monitoring, clinical lateralization, scanning results, surgical technique, and histopathological diagnosis did not demonstrate a significant difference between the seizure-free (Engel’s class I) and non-seizure-free groups (Engel’s class II, III, IV) (p>0.05).Conclusion:Refractory epilepsy surgery for temporal lobe tumors often offers complete seizure freedom. Complete surgical excision of the epileptogenic region is of great importance for achieving seizure-freeness

The protective effect of infliximab against carbon tetrachloride-induced acute lung injury

cure, erkan/0000-0001-7807-135X; Cure, Medine Cumhur/0000-0001-9253-6459WOS: 000380177400015PubMed: 27482351Objective(s): Carbon tetrachloride (CCl4) causes pulmonary toxicity. Infliximab (Ib) is a potent inhibitor of tumor necrosis factor-alpha (TNF-alpha). We aimed to investigate whether Ib has a protective effect on CCl4 induced lung injury. Materials and Methods: Rats were divided into control, CCl4, and CCl4+Ib groups. A single dose of 2 ml/kg CCI4 was administered to CCI4 group and a single dose of 7 mg/kg Ib was given to CCl4+Ib group 24 hr before applying CCI4. Results: TNF-alpha, malondialdehyde (MDA), nitric oxide (NO) and caspase-3 levels of the CCl4 group were markedly higher than both the control and CCl4+Ib groups. the CCI4+Ib group had lower histopathological injury than the CCl4 group. Conclusion: Ib as a strong TNF-alpha blocker decreases the production of proinflammatory cytokines, MDA, and oxidative stress leading to a protective effect against CCl4 induced lung tissue injury

A Comparison of Ramipril and Bevacizumab to Mitigate Radiation-Induced Brain Necrosis: An Experimental Study

Background: Bevacizumab, an anti-vascular endothelial growth factor (VEGF) antibody, is a new treatment approach for radionecrosis. In our study, we compared the prophylactic and therapeutic usage of a promising agent, ramipril (an angiotensin-converting enzyme inhibitor), with that of bevacizumab for reducing radiation-induced brain injury after high-dose stereotactic radiosurgery (SRS). Methods: A total of 60 Wistar rats were used. The rats were irradiated with a single dose of 50 Gy using a Leksell Gamma Knife device. Bevacizumab and ramipril were administered in the prophylactic protocol (starting the first day of SRS) and in the therapeutic protocol (starting the fourth week of SRS). Their usage was continued until 12 weeks, and the right frontal lobes of the rats were examined histologically (hematoxylin and eosin stain) and immunohistochemically (hypoxia-inducible factor [HIF]-1α, VEGF, and CD31 antibody expression). Results: The expression of VEGF, HIF-1α, and CD31 had significantly increased at 12 weeks after SRS compared with the control group. The addition of bevacizumab or ramipril to SRS significantly mitigated the histological severity of radiation injury and the expression of VEGF, HIF-1α, and CD31. However, the prophylactic use of bevacizumab and ramipril seemed to be more effective than therapeutic administration. Our results also revealed that the greatest benefit was achieved with the use of prophylactic administration of bevacizumab compared with other treatment protocols. Conclusions: Ramipril might be a promising agent for patients with radionecrosis. Clinical studies are required to investigate the effective and safe doses of ramipril, which is an inexpensive, well-tolerated drug that can cross the blood–brain barrier. © 2020 Elsevier Inc

Stereotactic biopsy of the brain mass lesions: a tertiary hospital experience

Objectives: Stereotactic biopsy (SB) is a guided technic performed for the lesions on eloquent brain areas. The aim of this study is revealing the diagnostic reliability and the risk ratio of SB. Methods: Data of patients performed SB due to various intracranial lesions was collected retrospectively. The study took place in Department of Neurosurgery, Gazi University Faculty of Medicine between February 2004 and April 2014. Data analysis performed in terms of age, gender, lesion location, histopathology, and outcomes of surgery. Results: Sixty percent of patients were male (146 patients) and forty percent of them was female (96 patients), between the ages of 11 and 84 years (mean age of 49 years) with a total number of 242. Mortality and morbidity rates were respectively 0.4% and 3.3%. The overall diagnostic yield was 81% (196 patients), while 19% (46 patients) had nonspecific results, which did cannot lead any further therapy. Among 36 patients of whom pathologies were confirmed with an excisional biopsy, the diagnostic accuracy was shown in 24 patients (67%). Conclusions: Beside low risk of mortality and morbidity, the high rate of non-diagnostic results and low rate of diagnostic accuracy are the limitations of SB, which should be improved by careful skills to obtain more specimen, sophisticated software for planning, and intraoperative pathological examination for guaranteeing

Investigation and Expression Analysis of R2R3-MYBs and Anthocyanin Biosynthesis-Related Genes during Seed Color Development of Common Bean (Phaseolus vulgaris)

Anthocyanins are responsible for the coloration of common bean seeds, and their accumulation is positively correlated with the expression level of anthocyanin biosynthetic genes. The MBW (MYB-bHLH-WD40) complex is thought to regulate the expression of these genes, and MYB proteins, which are a key factor in activating anthocyanin pathway genes, have been identified in several plants. This study demonstrated gene structures, chromosomal placements, gene duplications of R2R3-MYBs, miRNAs associated with R2R3-MYBs, and the interaction of these genes with other flavonoid regulatory genes. qRT-PCR was used to investigate the role of specific R2R3-MYBs and flavonoid genes in common bean seed color development. As a result of a comprehensive analysis with the help of in silico tools, we identified 160 R2R3-MYB genes in the common bean genome. We divided these genes into 16 classes on the basis of their intron-exon and motif structures. Except for three, the rest of the common bean R2R3-MYB members were distributed to all chromosomes with different densities, primarily located on chromosomes 3 and 8. We identified a total of 44 duplicated gene pairs dispersed across 11 chromosomes and evolved under purifying selection (Ka/Ks  <  1), 19 of which were derived from a whole-genome duplication. Our research uncovered 25 putative repressor PvMYB proteins that contain the EAR motif. Additionally, fifty different cis-regulatory elements regulated by light, stress, and hormone were identified. Within the genome of the common bean, we discovered a total of 36 microRNAs that target a total of 72 R2R3-MYB transcripts. The effect of 16 R2R3-MYB genes and 16 phenylpropanoid pathway genes, selected on the basis of their interaction in the protein-protein interaction map, playing role in the regulation of seed coat color development was evaluated using qRT-PCR in 5 different tissues at different developmental stages. The results revealed that these specific genes have different expression levels during different developmental periods, with higher levels in the pod filling and early pod stages than in the rest of the developmental periods. Furthermore, it was shown that PvTT8 (bHLH), PvTT2 (PvMYB42), PvMYB113, PvTTG1, and PvWD68 genes have effects on the regulation of seed coat color. The findings of this study, which is the first to use whole-genome analysis to identify and characterize the R2R3-MYB genes in common bean, may serve as a reference for future functional research in the legume

Investigation and Expression Analysis of R2R3-MYBs and Anthocyanin Biosynthesis-Related Genes during Seed Color Development of Common Bean (Phaseolus vulgaris)

Anthocyanins are responsible for the coloration of common bean seeds, and their accumulation is positively correlated with the expression level of anthocyanin biosynthetic genes. The MBW (MYB-bHLH-WD40) complex is thought to regulate the expression of these genes, and MYB proteins, which are a key factor in activating anthocyanin pathway genes, have been identified in several plants. This study demonstrated gene structures, chromosomal placements, gene duplications of R2R3-MYBs, miRNAs associated with R2R3-MYBs, and the interaction of these genes with other flavonoid regulatory genes. qRT-PCR was used to investigate the role of specific R2R3-MYBs and flavonoid genes in common bean seed color development. As a result of a comprehensive analysis with the help of in silico tools, we identified 160 R2R3-MYB genes in the common bean genome. We divided these genes into 16 classes on the basis of their intron-exon and motif structures. Except for three, the rest of the common bean R2R3-MYB members were distributed to all chromosomes with different densities, primarily located on chromosomes 3 and 8. We identified a total of 44 duplicated gene pairs dispersed across 11 chromosomes and evolved under purifying selection (Ka/Ks  <  1), 19 of which were derived from a whole-genome duplication. Our research uncovered 25 putative repressor PvMYB proteins that contain the EAR motif. Additionally, fifty different cis-regulatory elements regulated by light, stress, and hormone were identified. Within the genome of the common bean, we discovered a total of 36 microRNAs that target a total of 72 R2R3-MYB transcripts. The effect of 16 R2R3-MYB genes and 16 phenylpropanoid pathway genes, selected on the basis of their interaction in the protein-protein interaction map, playing role in the regulation of seed coat color development was evaluated using qRT-PCR in 5 different tissues at different developmental stages. The results revealed that these specific genes have different expression levels during different developmental periods, with higher levels in the pod filling and early pod stages than in the rest of the developmental periods. Furthermore, it was shown that PvTT8 (bHLH), PvTT2 (PvMYB42), PvMYB113, PvTTG1, and PvWD68 genes have effects on the regulation of seed coat color. The findings of this study, which is the first to use whole-genome analysis to identify and characterize the R2R3-MYB genes in common bean, may serve as a reference for future functional research in the legume