In this paper, we enumerate the parameter matrices of all perfect 2-colorings of the generalized prism graph Cn × C3, where n ≥ 3,. We also present some generalized results for Cn × Cm, where m, n ≥ 3.

Introduction: Today, temporary or permanent venous catheters are being increasingly used in patients with renal failure. It seems a necessity to be familiar with their clinical applications and complications as well as their efficacy. The aim of this study was to compare the efficacy of two catheters of 16 cm and 20 cm lengths.Methods: This research project was a descriptive, analytic study conducted on 40 hemodialysis patients in Zahedan. The patients were randomly allocated into two groups (n=20 per group). Analyses were made using Kolgromorov-Smironov test (P>0.05) to examine normal distribution, and chi-square test for qualitative data at the significant level of a=0.05.The data were analyzed by SPSS 15.Results: Infection frequency rates in 16 cm and 20 cm catheter groups were 10% and 15% respectively. The difference was not significant (P=0.633). The 20 cm catheter was of longer efficacy duration (744.1±10.13) than the 16 cm catheter (625.2±45.12). Again, the difference was not significant (P=0.259).Conclusions: Femoral catheters of 16 cm or 20 cm sizes do not differ in terms of infection or efficacy, and one cannot be preferable to the other in this regard.

Introduction: Laparoscopic adrenalectomy remains a controversial procedure for large tumors. The incidence of adrenocortical carcinoma increases and technical difficulty of adrenalectomy increases as the size increases. We examined the outcome and complications of laparoscopic adrenalectomy for such lesions.Materials and Methods: Twenty-nine patients underwent laparoscopic adrenalectomy, of which 19 had tumors larger than 5 cm in diameter, having a median tumor size of 7.0 cm. They were compared with patients whose adrenal tumors were smaller than 5 cm.Results: Patients with small tumors (< 5 cm) had a significantly shorter median operative time of 90 minutes as compared to 145 minutes in those with large tumors (> 5 cm). There was no significant difference in the median hemoglobin drop (1.05 g/dL versus 1.30 g/dL), time for starting oral intake (24 hours in both groups) or hospital stay (3.5 days versus 4.0 days) between patients with small and large tumors, respectively. There were no intra-operative complications except for 1 incidence of supraventricular tachycardia in a patient with a large pheochromocytoma. There were no major complications seen in any of the patients and no open conversions. Histopathology of large tumors revealed 16 benign tumors (8 pheochromocytomas, 4 adenomas, 2 ganglioneuromas, 1 pseudocyst, and 1 myelolipoma) and 3 malignancies, of which 1 was primary adrenocortical carcinoma and 2 were metastatic renal cell carcinoma. Conclusion: In experienced hands, laparoscopic adrenalectomy is safe and feasible for large functioning adrenal tumors. Large adrenal tumors suspicious of harboring malignancy with no peri-adrenal involvement can be tackled laparoscopically.