The presence of co-existing or additional diseases with reference to an initial diagnosis or with reference to the index condition that is the subject of study.

共病是指相对于原始诊断或相对于研究主题所指病情而言，共同存在或附加的疾病。

youdao

The conductivity of a solution is sensitive to the presence of impurities, so its value is meant to be more an index of impurity than a characteristic constant.

溶液的电导率对杂质的存在是很敏感的。这就意味着电导率的数值随存在杂质的不同而异，而不只是一个特征常数。

youdao

Conclusion: Respiratory variation of SVC systolic forward flow was a sensitive index for evaluating presence and severity of PH in patients with COPD.

结论：SVC收缩期正向血流的呼吸变化性是检测COPD患者肺动脉高压的敏感指标。

youdao

He provided stats on crime, educational attainment, presence of four-year colleges and an index on cultural and recreational opportunities.

FORBES: Best Places For Business And Careers

Moreover, the insurer has the biggest presence on the Taipei bourse, fully 5% of the index.

CNN: Another Lease on Life?