Background: The introduction of assisted reproductive technology (ART) has played a major role in reducing the burden of infertility among couples. Although most pregnancies following assisted conception will progress normally without any increased risk to the mother or baby, studies have shown that some women who conceive in this manner as well as their babies are indeed at increased risk of c...

BACKGROUND Prediction of natural conception in subfertile couples can help to differentiate between couples who should have immediate treatment and couples who can aim for natural conception for some time. Natural conception rates are often estimated using standard techniques such as Kaplan-Meier or Cox proportional hazard models. These estimates can be biased by incorrect handling of data from...

In the process of mathematics learning, most elementary students never think but receive all the methods their teachers have taught. In other word, they don’t catch the basic concept in every unit. Based on the Petri-Net theory, this paper designs a guided learning system to correct the mis conception of elementary students. We expect to achieve the best effect of computer-assisted instruction ...