Direct Detection of Thrombin Binding to 8-Bromodeoxyguanosine-Modified Aptamer: Effects of Modification on Affinity and Kinetics

The affinity of an 8-bromodeoxyguanosine- (8-BrdG-) substituted thrombin-binding aptamer (TBA-Br), which has the 1st and 10th guanosine residues replaced with 8-BrdG, was estimated using reflectometric interference spectroscopy (RIfS). When comparing TBA-Br with unmodified TBA (TBA-H), it was demonstrated that the modification effectively improved the affinity of TBA; dissociation constants (KD) of TBA-H and TBA-Br were 45.4 nM and 1.99 nM, respectively. These values, which were obtained by direct observation of thrombin binding using RIfS, have the same order of magnitude as those obtained in our previous study utilizing conformational changes in TBA to detect thrombin binding, thus confirming the validity of the obtained KD values. RIfS measurements also revealed that the 8-BrdG modification resulted in a lower dissociation rate constant (kd), which suggests that the enhancement of affinity can be attributed to the stabilization of the G-quadruplex structure on introduction of 8-BrdG

Prediction of fetal acidemia in placental abruption

BACKGROUND: To determine the major predictive factors for fetal acidemia in placental abruption. METHODS: A retrospective review of pregnancies with placental abruption was performed using a logistic regression model. Fetal acidemia was defined as a pH of less than 7.0 in umbilical artery. The severe abruption score, which was derived from a linear discriminant function, was calculated to determine the probability of fetal acidemia. RESULTS: Fetal acidemia was seen in 43 survivors (43/222, 19%). A logistic regression model showed bradycardia (OR (odds ratio) 50.34, 95% CI 11.07 – 228.93), and late decelerations (OR 15.13, 3.05 – 74.97), but not abnormal ultrasonographic findings were to be associated with the occurrence of fetal acidemia. The severe abruption score was calculated for the occurrence of fetal acidemia, using 6 items including vaginal bleeding, gestational age, abdominal pain, abnormal ultrasonographic finding, late decelerations, and bradycardia. CONCLUSIONS: An abnormal FHR pattern, especially bradycardia is the most significant risk factor in placental abruption predicting fetal acidemia, regardless of the presence of abnormal ultrasonographic findings or gestational age

Reaction cross section of proton scattering consistent with PREX-II

Background: The neutron skin thickness $R_{\rm skin}^{\rm PV}$ of PREX-II is presented in Phys. Rev. Lett. {\bf 126}, 172502 (2021). The reaction cross section $\sigma_R$ is useful to determine the matter radius $R_m$ and $R_{\rm skin}$. For proton scattering, the reaction cross section $\sigma_R$ are available for $E_{\rm in} > 400$ MeV. Method and results: We determine $R_n^{\rm exp}=5.727 \pm 0.071$ fm and $R_m^{\rm exp}=5.617 \pm 0.044$ fm from $R_p^{\rm exp}$ = 5.444 fm and $R_{\rm skin}^{\rm PV}$. The $R_p^{\rm GHFB}$ calculated with D1S-GHFB with the angular momentum projection (AMP). agrees with $R_p^{\rm exp}$. The neutron density calculated with GHFB+AMP is scaled so as to $R_n^{\rm scaling}=5.727$ fm. The Love-Franey $t$-matrix model with the scaled densities reproduces the data on $\sigma_R$. Aim: Our aim is to find the $\sigma_R$ of proton scattering consistent with $R_{\rm skin}^{\rm PV}$. Conclusion: The $\sigma_R$ of proton scattering consistent with $R_{\rm skin}^{\rm PV}$ are $\sigma_R^{\rm exp}$ at $E_{\rm in} = 534.1, 549, 806$ MeV.Comment: arXiv admin note: text overlap with arXiv:2010.0245

Folding-model approach to reaction cross section of 4,6,8^{4,6,8}He+12^{12}C scattering at 790 MeV

Tanihata {\it et al.} determined matter radii $r_{m}(\sigma_{\rm I})$ for $^{4,6,8}$He from interaction cross sections $\sigma_{\rm I}$ of $^{4,6,8}$He+$^{12}$C scattering at 790 MeV per nucleon, using the optical limit of the Glauber model. Lu {\it et al.} determined proton radii $r_{p}({\rm AIS})$ for $^{4,6,8}$He with the atomic isotope shifts (AIS). We investigate whether the Love-Franey $t$-matrix folding model is good for $^{4,6,8}$He+$^{12}$C scattering at 790 MeV per nucleon