Background: Becker’ s naevus (BN) may represent a distressing cosmetic handicap and a challenging issue regarding treatment. Objectives: To compare clinical and histopathological findings of patients with BN treated ...Background: Becker’ s naevus (BN) may represent a distressing cosmetic handicap and a challenging issue regarding treatment. Objectives: To compare clinical and histopathological findings of patients with BN treated with two different lasers: an erbium: yttrium-aluminium-garnet (Er: YAG) system vs. a neodymium: YAG (Nd: YAG) laser. Patients and methods: In this prospective and comparative study we present the clinical and histopathological evolution during a 2-year follow-up of 22 patients with BN treated with only one pass of the Er: YAG laser (n=11) or three treatment sessions with the Q-switched Nd: YAG system (n=11). Results: Clinical evaluation 2 years after treatment with the Er: YAG laser showed complete clearance (100% ) in 54% of the patients (n=6) and clearance of>50% in 100% of the subjects. In relation to Nd: YAG laser treatments our results echo those of other authors. Numerous sessions are necessary to get an acceptable clinical clearance rate. Only one patient showed marked clearance(51-99% )after three treatment sessions. Moderate (26- 50% ) and mild (1-25% ) clearance was observed in 45- 5% (n=5) and 27-3% (n=3) of the patients. Conclusions: Both Er: YAG and Nd: YAG are safe tools to treat BN. However, in terms of pigment removal, one pass with Er: YAG is a superior technique to three treatment sessions with the Nd: YAG.展开更多
This note establishes a pair of exponential generating functions for generalized Eulerian polynomials and Eulerian fractions, respectively. A kind of recurrence relation is obtained for the Eulerian fractions. Finally...This note establishes a pair of exponential generating functions for generalized Eulerian polynomials and Eulerian fractions, respectively. A kind of recurrence relation is obtained for the Eulerian fractions. Finally, a short proof of a certain summarion formula is given展开更多
It is shown that Howard＇s degenerate weighted Stirling numbers can be used to construct a fruitful summation formula for a class of formal power series involving generalized factorials.This is achieved with the aid o...It is shown that Howard＇s degenerate weighted Stirling numbers can be used to construct a fruitful summation formula for a class of formal power series involving generalized factorials.This is achieved with the aid of a series-transformation formula due to He,Hsu and Shiue,and several identities involving generalized Stirling numbers and Bell numbers are given to illustrate the application of the formula obtained.展开更多
文摘Background: Becker’ s naevus (BN) may represent a distressing cosmetic handicap and a challenging issue regarding treatment. Objectives: To compare clinical and histopathological findings of patients with BN treated with two different lasers: an erbium: yttrium-aluminium-garnet (Er: YAG) system vs. a neodymium: YAG (Nd: YAG) laser. Patients and methods: In this prospective and comparative study we present the clinical and histopathological evolution during a 2-year follow-up of 22 patients with BN treated with only one pass of the Er: YAG laser (n=11) or three treatment sessions with the Q-switched Nd: YAG system (n=11). Results: Clinical evaluation 2 years after treatment with the Er: YAG laser showed complete clearance (100% ) in 54% of the patients (n=6) and clearance of>50% in 100% of the subjects. In relation to Nd: YAG laser treatments our results echo those of other authors. Numerous sessions are necessary to get an acceptable clinical clearance rate. Only one patient showed marked clearance(51-99% )after three treatment sessions. Moderate (26- 50% ) and mild (1-25% ) clearance was observed in 45- 5% (n=5) and 27-3% (n=3) of the patients. Conclusions: Both Er: YAG and Nd: YAG are safe tools to treat BN. However, in terms of pigment removal, one pass with Er: YAG is a superior technique to three treatment sessions with the Nd: YAG.
文摘This note establishes a pair of exponential generating functions for generalized Eulerian polynomials and Eulerian fractions, respectively. A kind of recurrence relation is obtained for the Eulerian fractions. Finally, a short proof of a certain summarion formula is given
文摘It is shown that Howard＇s degenerate weighted Stirling numbers can be used to construct a fruitful summation formula for a class of formal power series involving generalized factorials.This is achieved with the aid of a series-transformation formula due to He,Hsu and Shiue,and several identities involving generalized Stirling numbers and Bell numbers are given to illustrate the application of the formula obtained.
