No abstract

Using reaction pathway sampling, we have investigated the shear stress dependences of the activation energies of shuffle-set and glide-set dislocation nucleation from a sharp corner in silicon. The gradient of the glide-set dislocation curve is lower than that of the shuffle-set dislocation, and the athermal stress of glide-set dislocation is largely higher than that of shuffle-set dislocation. As a result, the two curves have a cross point, which means that shuffle-set dislocation is likely nucleated at high stress and low temperature and glide-set dislocation is likely nucleated at low stress and high temperature. Our result clearly explains the mechanism of recent molecular dynamics on these two types of dislocation nucleation at different temperatures and stress regimes. With increased compressive stress on the slip plane, the activation energy of the shuffle-set dislocation nucleation is greatly decreased, while that of glide-set dislocation nucleation is slightly increased. That would explain why shuffle-set dislocations were found under compressive stress fields.

In view of the evidence that vasoactive intestinal peptide (VIP) may modulate acute inflammatory injury in the lung, we investigated the presence and characteristics of VIP receptors on alveolar macrophages (AMs). We examined the binding of monoiodinated [Tyr(125I)10]-labeled VIP (125I-VIP) to rat AMs (> 96% pure), obtained from Sprague-Dawley rats by bronchoalveolar lavage (BAL). At 23 degrees C, the interaction of 125I-VIP with AMs was rapid, reversible, saturable, and linearly proportional to the number of cells. At equilibrium, the binding was competitively inhibited by 10(-11)-10(-6) M of native peptide [half-maximal inhibition (IC50) = 0.53 +/- 0.34 nM, n = 8], with evidence for two classes of binding sites: one with a high affinity (Kd = 0.20 +/- 0.09 nM) and a low capacity (1,190 +/- 640 sites/cell) and another with a low affinity (Kd = 43.2 +/- 13.8 nM) and a high capacity (51,700 +/- 14,000 sites/cell). VIP-related peptides inhibited the binding with the order of potency: VIP > peptide histidine isoleucine > helodermin >> secretin; glucagon was ineffective. In the presence of 3-isobutyl-1-methylxanthine, VIP dose dependently stimulated adenosine 3',5'-cyclic monophosphate accumulation in intact AMs, with maximal stimulation (6.3 times basal level) at 1 nM, and half-maximal accumulation at 0.23 +/- 0.11 nM VIP (Kd for high-affinity sites). For determination of the mass of the VIP receptor, 125I-VIP was covalently bound to AMs with the cross-linking agent dithiobis succinimidyl propionate. Autoradiographic studies after sodium dodecyl sulfate/polyacrylamide gel electrophoresis of solubilized affinity-labeled cells revealed a single major band of M(r) 76,400. We conclude that VIP binds to specific receptors on rat AMs that are coupled to adenylate cyclase, through which VIP may modulate inflammatory responses within the lung.

Hydroxy-substituted aromatic nitrone derivatives were used for the photochemical control of the refractive index of poly(methyl methacrylate) (PMMA) films. Upon irradiation with 366-nm light in solution, these derivatives underwent rearrangement reactions, which eventually produced N,N-diarylformamide derivatives in quantitative yields. Similar photoreactions of the aromatic nitrones in the PMMA films lowered the refractive index of the films by as much as 0.014. The magnitude of the observed refractive-index change was enough for hydroxy-substituted nitrones to be used as additives for the fabrication of gradedindex-type polymer optical fibers. In addition, the refractive index of the PMMA films remained almost constant at any conversion of the starting nitrone derivatives for at least 70 days at room temperature.

Background and Objectives: Measured blood loss frequently underestimates true blood loss; this discrepancy is called hidden blood loss (HBL). The purpose of the present study was to measure HBL in oblique lateral interbody fusion (OLIF). Materials and Methods: Patients who underwent two-stage OLIF at our institute from September 2017 to September 2021 were retrospectively reviewed. Total blood loss (TBL) and HBL were calculated using the gross formula. The age, sex, body mass index (BMI), operation time, measured blood loss, the number of fused segments, hematocrit (HCT), anticoagulant or platelet medication, blood transfusion, days of hospitalization, pre-/postoperative Japanese Orthopedic Association (JOA) score, and JOA recovery rate were compared. Results: A total of thirteen patients were included in the study. The average age, BMI, number of fused segments, operation time, estimated blood loss, and blood transfusion were 69.5 years, 23.3, 2.5, 250 min, 122 mL, and 230 mL, respectively. Five patients received anticoagulant or platelet therapy. Days of hospitalization, pre-/postoperative JOA score, and JOA recovery rate were 14.9 ± 5.1, 19.9 ± 2.7, and 18.0 ± 43.4%, respectively. The TBL and HBL were 688 and 797 mL, respectively. Stepwise multiple regression analysis revealed that younger age (p = 0.01), female sex (p = 0.01), and number of fused segments (p = 0.02) were significantly associated with higher HBL. Conclusions: The HBL in OLIF was 797 mL, which was more than other previously reported procedures. Therefore, OLIF may not be less invasive in terms of HBL. Blood loss after surgery should be considered, especially when patients are younger, are female, and have a greater number of fused segments.