A Material Perspective on Consequence of Deformation Heating During Stamping of DP Steels

Recent studies showed that, during stamping of high strength steels at industrially relevant production rates, local temperature in the blank may rise up to 200°C – 300°C due to deformation heating. Moreover, die temperature may also rise up to 100°C – 150°C for progressive stamping dies. Based on the common assumption that the blank softens as the temperature increases, thermal softening creates a margin in Forming Limit Diagram (FLD) and therefore the FLD determined at room temperature can safely be used for those cases. In this article, the validity of this assumption on DP590 steel is questioned by high temperature tensile tests (RT - 300°C) at various strain rates (10-3 s-1 – 1 s-1). The results indicated a decrease both in uniform and total elongation in 200°C – 300°C range together with several other symptoms of Dynamic Strain Aging (DSA) at all strain rates. Concurrent with the DSA, the simulated FLD confirms the lower formability at high temperature and strain rates. Thus, it is concluded FLD determined at RT may not be valid for the investigated steels

The Effects of Austempering and Induction Hardening on the Wear Properties of Camshaft Made of Ductile Cast Iron

The aim of this study is to investigate the effects of heat austempering and induction hardening on the wear properties of GGG60 ductile cast iron for camshaft production. For this purpose, camshafts have been produced by sand mould casting method. Fe-Si-Mg alloy has been used for inoculation process to achieve iron nodulization. The casting has been done between 1410-1420°C. The casted camshafts have been austenitized at two different temperatures (800 and 900°C) and time intervals (60 and 90 min) under controlled furnace atmosphere. The austenitized camshafts have been quenched into the molten salt bath at 360°C, held there for 90 min and then cooled in air. This way, austempering heat treatment has been applied. After that, surface hardening process was conducted using induction hardening machine with medium frequency. Microstructure of camshafts has been examined by optical methods and mechanical tests have been performed. Results show that austempering heat treatment increases the wear resistance of camshaft, compared to as-cast condition. Wear resistance of the camshaft increases with increasing austenitizing temperature, time and with induction hardening. The lowest weight loss of 0.62 mg has been obtained for the induction hardened camshaft austenitized at 900°C for 90 min

Immunohistochemical markers in renal tumors and findings in non-tumoral renal parenchyma

Objective: Renal epithelial cells comprise distinct pathological and physiological differences. Renal epithelial neoplasms derived from these cells may show overlapping morphological features, and differential diagnosis requiring the use of ancillary methods. The purpose of this study was to determine the diagnostic utility of the immunohistochemical expression patterns of a wide range of markers in renal epithelial cells. Material and Method: Normal renal cortical parenchyma and renal pelvis were immunostained for cytokeratin (CK) subtypes (CK7, CK19, CK34ße12), vimentin, RCCMa, CD10, CD117, AMACR, WT-1, eMA and p63. The immunohistochemical expression patterns were examined in 10 cases. Results: Although there is some overlap, subtypes of epithelial cells showed distinctive CK and CD expression profiles. Proximal tubular cells showed CD10, RCCMa, AMACR expression. Distal tubular cells and collecting ducts showed CK7, CK19 and eMA expression. Urothelial cells showed CK7, CK19, CK34ße12, and p63 expression. CD117 and vimentin selectively stained intermittently in some cells lining the tubules. endothelial cells and visceral epithelial cells stained with WT-1. Glomerular epithelial cells stained with CD10, but focal and intermittent staining with AMACR, CK7, CK 19, and RCCMa was found in parietal cells. Conclusion: In conclusion, a panel of cytokeratins, CDs and other markers are helpful in distinguishing epithelial cells and urothelial cells. The expression patterns of these markers may be helpful in the differential diagnosis of epithelial neoplasms

Renal stone therapy in a patient with urinary diversion: A case report [Üriner diversiyon uygulanan soliter böbrekli hastada böbrek taşinin tedavisi: Bir olgu sunumu ve yayinlarin gözden geçirilmesi]

Introduction: Radical cystectomy and urinary diversion remains the gold standard treatment for pT2 bladder cancers. There are many, early and long-term complications after urinary diversion. Urolithiasis is the main long-term complication after urinary diversion which serious influenced the quality of life and the survival of patients. In this report we describe the treatment of kidney stone after urinary diversion in solitary kidney patient. A 70-year old woman presented with right kidney stone, which was determined in routine follow up after 7 year of operation. She had nonfonctional contralateral kidney. We performed percutaneous nephrolithotomy for this patient. The imaging of the upper urinary tract at the access of the kidney was performed by means of administering of dilute opaque from ileal pouch. Stone was fragmantated by pneumatic lithotriptor and removed by forceps. There was no residual fragment in postoperative KUB

Mucinous tubular and spindle cell carcinoma of kidney and problems in diagnosis [Böbregin müsinöz tübüler i·gsi hücreli karsinomu ve tani{dotless} sorunlari{dotless}]

PubMed ID: 21630197Objective: Mucinous tubular and spindle cell carcinomas (MTSCC's) are recently described rare type of renal cell carcinoma (RCC). MTSCC's are characterized by small, elongated tubules lined by cuboidal cells and/or cords of spindled cells separated by pale mucinous stroma. They have morphological similarities to papillary RCC (papRCC). We evaluated the importance of the immunohistochemical features in the differential diagnosis of MTSCC and papRCC. Material and Method: We re-evaluated 9 cases of MTSCC diagnosed between 2004 and 2010 and compared 10 cases of papRCC. All tumors were stained with alpha-methylacyl-CoA racemase (AMACR), cytokeratin 7 (CK7), CK19, renal cell carcinoma marker (RCC Ma), CD10 and kidney specific cadherin (KspCad). Results: A total of 6/9 cases were considered classical. Two of 9 MTSCC's were classified as "mucin-poor". Foamy macrophages were identified in 4 cases. The immunoreactivity in MTSCC was AMACR 100%, CK7 100%, CK19 100%, RCC Ma 50%, CD10 11%, and KspCad 38% while the values for papRCC were AMACR 100%, CK7 90%, CK19 100%, RCC Ma 100%, CD10 80%, and KspCad 0%. Conclusion: MTSCCs may include little mucin and show a marked predominance of either of its principal morphological components. They may mimic other forms of RCC. Pathologists should be aware of the histological spectrum of MTSCCs to ensure an accurate diagnosis. Careful attention to the presence of a spindle cell population may be helpful in the differential diagnosis in tumors with predominant compact tubular growth. Immunohistochemical stains for papRCC are also expressed in MTSCC, but strong CD10 expression may not favor MTSCC

Ho:YAG laser versus pneumatic lithotripsy for management of pediatric ureteral stones: a prospective–comparative analysis with adults

PubMed: 318379442-s2.0-85076500001Background: There are limited number of studies comparing the results of Holmium:YAG laser lithotripsy (LL) and pneumatic lithotripsy (PL) for pediatric ureteral stones. Objectives: To perform a comparative analysis of LL and PL in the management of ureteral stones in children and adults. Study design: Ninety-eight children (56 boys and 42 girls) and 623 adults (360 men and 263 women), who were treated for ureteral stones at our clinic between 2017 and 2019, were the subjects of this study. Patients were grouped according to their age as group 1 (n:98, pediatric [<18 age]) and group 2 (n:623, adult [?18 age]). The patients were then grouped according to lithotripter type as laser (n:580) and pneumatic (n:141). The effects of lithotripter type, stone size and location, and operative times on success and complication rates were investigated. Results: In both groups, mean operation time was in favor of PL (14.6 vs 22.8 min, p = 0.042 and 26.4 vs 36.3 min, p = 0.013, respectively). In both groups, overall stone-free rates (SFR) were in favor of LL (86.8% vs 66.7%, p < 0.001, and 83% vs 73.9%, p = 0.005, respectively), but there was no significant difference in overall SFRs between adults and children (78.4% vs 76.7, p = 0.390). Retreatment rates were higher in the pneumatic group in both children and adults (p = 0.026 and p = 0.041, respectively). While there was no significant difference in the overall complication rates between adults and children (53.5% vs 40.6%, p = 0.816), the rate of complications with LL was lower in adults (37.7% vs 69.4%, p < 0.001) (TABLE). Discussion: This paper is the first to report a comparative analysis of factors affecting URS success in adults and children. SFRs were higher in all ureteral locations for LL. LL, lower ureteral location, and <6 mm ureteral stone were determined as the predictors of success for both pediatric and adult patients. The presence of multiple surgeons with different levels of experience is the main limitation of this study. Conclusion: Both LL and PL are safe in children and adults with similar clinically insignificant complication rates. However, in the short term, LL provides better SFRs in both children and adults, especially in the upper ureteral stones. Surgeons should decide the energy technique to be used in URS according to the characteristics of the stone rather than the patient's age group. © 2019 Journal of Pediatric Urology Compan