The association of benign prostatic hyperplasia with lower urinary tract stones in adult men: A retrospective multicenter study

Objective:To examine the relationship between benign prostatic hyperplasia(BPH)and the presence of lower urinary tract stones.Methods:We retrospectively reviewed the records of men with lower urinary tract stones who presented to three clinical centers in Korea over a 4-year period.We divided the patients into two groups based on the location of urinary stones:Group 1(bladder calculi)and Group 2(urethral calculi).We compared the characteristics of both groups and performed univariate and multivariate analyses with a logistic regression model to investigate the relationship between BPH and lower urinary tract stones.Results:Of 221 patients,194(87.8%)had bladder calculi and 27(12.2%)had urethral calculi.The mean age of Group 1 was higher than that of Group 2(68.96
12.11 years vs.55.74
14.20 years,p<0.001).The mean prostate volume of Group 1 was higher than that of Group 2(44.47
27.14 mL vs.24.70
6.41 mL,respectively,p<0.001).Multivariate logistic regression showed that age(OR Z 1.075,95%CI:1.023e1.129)and prostate volume(OR Z 1.069,95%CI:1.017e1.123)were independently associated with increased risk for bladder calculi.Upper urinary tract stones and/or hydronephrosis conferred a 3-fold risk for urethral calculi(OR Z 3.468,95%CI:1.093e10.999).Conclusion:Age and prostate volume are independent risk factors for bladder calculi.In addition,men with upper urinary tract disease are at greater risk for urethral calculi,which may migrate from the upper urinary tract rather than from the bladder.

Flexible and disposable paper-based gas sensor using reduced graphene oxide/chitosan composite

Nitrogen dioxide(NO_(2))is a representative toxicant in air pollution that mostly arises from the exhaust gas released by automobiles.It is related to various respiratory diseases such as pneumonia and sudden infant death syndrome.Additionally,because the toxicity of nitrogen dioxide is high in overpopulated areas(i.e.,a capital or metropolis),the development of simple,practical,and facile sensors is highly needed.This work presents a flexible and disposable paper-based NO_(2)sensor based on a reduced graphene oxide/chitosan(r GO/CS)composite.The synthesized r GO/CS composite can be easily flexed and deformed into various shapes,which are attributed to chitosan molecules that function as a dispersion and reduction agent and support material.In addition,this composite can be attached to paper owing to its adhesive property;hence it can be utilized in versatile applications in a disposable manner.By analyzing the conductive change of the r GO/CS composite when it reacts with NO_(2),we can detect nitrogen dioxide in a concentration range of 0–100 ppm with a detection limit of 1 ppm.Moreover,we performed NO_(2)detection in the exhaust gas released by automobiles using the r GO/CS composite for practical application.The results indicated that the r GO/CS composite has the potential to be used in feasible gas sensing as a facile and disposable sensor under various conditions.